Byte Magazine Volume 06 Number 04 - Future Computers

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YOUR CHOICE-smart either way

• Over 140 software driven functions

• 82 x 24 or 82 x 20 screen format — software selectable

• High resolution 7x12 matrix characters - P-31 green phosphor

• Upper/lower case character set — plus graphics character set

• 56-key alphanumeric keyboard — plus 12-key cursor, numeric pad

• Internal editing functions - insert, delete, scroll, roll, slide, etc.

• Parallel printer I/O port

• 50 to 38,400 baud operation — programmable

• Cursor type, cursor position, print control characters, protected fields, shift inversion, dual intensity and many other features

8212 — twelve-inch diagnonal screen or 8209 — nine-inch diagnonal screen

SOUTHWEST TECHNICAL PRODUCTS CORPORATION

219 W. RHAPSODY

SAN ANTONIO, TEXAS 78216 (512) 344-0241

Circle 360 on inquiry card.

INTELLIGENT 110

I/O INTERFACES

COLOR GRAPHICS

MULTI-PROCESSING

IT-MBYTE

EXTENSIVE

COLOR

FLOPPV DISK

HARD DISK

JOYSTICK

SOFTWARE

PRINTERS

MONITORS

DRIVES

DRIVE

CONSOLE

SUPPORT

What Cromemco computer card capability can do for you

The above diagram shows in a functional way one of the most complete lines of computer cards in the industry.

Look it over carefully. It could be well worth your while.

These are all cards that plug into our S-100 bus microcomputers.

You can also assemble them into a custom system in convenient Cromemco card cages.

MULTI-PROCESSING AND INTELLIGENT I/O

The range of capabilities and versatility you can draw upon is enormous.

In processors, for example, you have a choice of CPU's including our extremely useful new I/O Processor. This can be used as a satellite processor to do off-line processing, multi-processing, and to form intelligent I/O. It opens the door to a whole new group of applications and tasks. Ask us about it.

HIGH RESOLUTION COLOR GRAPHICS

Again, you can have beautiful highresolution color graphics with our color graphics interface. You can select from over 4000 colors and have a picture with a resolution at least equal to quality broadcast-TV pictures.

Q

You have an unprecedented selection of memory including our unusual 48K and 16K two-port RAMs which allow high-speed color graphics.

LOTS OF STORAGE

These days you often want lots of disk storage. So you can select from our disk controller card which will operate our 5" and 8" floppy disk drives (up to 1.2 megabytes). Or select our WDI interface to operate our 11-megabyte hard disk drives.

POWERFUL SOFTWARE AND PERIPHERAL SUPPORT

There's much more yet you can do with our cards. And, of course, there's an easy way to put them to work in our 8-, 12-, and 21-slot card cages. Our PS8 power supply makes it simple to get the system into operation.

Finally, Cromemco offers you the strongest software support in the industry

Cromemco ™

incorporated

280 BERNARDO AVE., MOUNTAIN VIEW, CA 94040 • (415)964-7400

Tomorrow's computers today

Circle 1 on Inquiry card.

with languages like FORTRAN, C, COBOL, ASSEMBLER, LISP, BASIC and others. There is also a wide choice from independent vendors.

To top it all off, you can draw from a substantial array of peripherals: terminals, printers, color monitors and disk drives.

CONTACT YOUR CROMEMCO REP

There is even more capability than we're able to describe here.

Contact your Cromemco rep now and get this capability working for you.

CROMEMCO COMPUTER CARDS PROCESSORS — 4 MHz Z-80 A CPU, single card computer, I/O processor • MEMORY — up to 64K including special 48K and 16K twoport RAMS and our very well known BYTESAVERS® with PROM programming capability • HIGH RESOLUTION COLOR GRAPHICS - our SDI offers up to 754 x 482 pixel resolution. • GENERAL PURPOSE INTERFACES—QUADARTfour-channel serial communications, TU-ART two-channel parallel and two-channel serial, 8PIO 8-port parallel, 4PIO 4-port isolated parallel, D+ 7A 7-channel D/A and A/D converter, printer interface, floppy disk controller with RS-232 interface and system, diagnostics, wire-wrap and extender cards for your development work.

Management Information Display

Ultrasonic heart sector scan

High-resolution display with alphanumerics

Get the professional color

display that has BASIC/FORTRAN simplicity

LOW-PRICED, TOO

Here's a color display that has everything: professional-level resolution, enormous color range, easy software, NTSC conformance, and low price.

Basically, this new Cromemco Model SDI* is a two-board interface that plugs into any Cromemco computer.

The SDI then maps computer display memory content onto a convenient color monitor to give high-quality, highresolution displays (756 H x 482 V pixels).

When we say the SDI results in a highquality professional display, we mean you can't get higher resolution than this system offers in an NTSC-conforming display.

The resolution surpasses that of a color TV picture.

BASIC/FORTRAN programming

Besides its high resolution and low price, the new SDI lets you control with optional Cromemco software packages that use simple BASIC- and FORTRANlike commands.

Pick any of 16 colors (from a 4096-color palette) with instructions like DEFCLR (c, R, G, B). Or obtain a circle of specified size, location, and color with XCIRC (x, y, r, c).

taW\

•U.S. Pat. No. 4121283

Model SDI High-Resolution Color Graphics Interface

HIGH RESOLUTION

The SDI's high resolution gives a professional-quality display that strictly meets NTSC requirements. You get 756 pixels on every visible line of the NTSC standard display of 482 image lines. Vertical line spacing is 1 pixel.

To achieve the high-quality display, a separate output signal is produced for each of the three component colors (red, green, blue). This yields a sharper image than is possible using an NTSC-composite video signal and color TV set. Full image quality is readily realized with our highquality RGB Monitor or any conventional red/green/blue monitor common in TV work.

Model SDI plugs into Z-2H 11-mega byte

hard disk computer or any Cromemco

computer

DISPLAY MEMORY

Along with the SDI we also offer an optional fast and novel two-port memory that gives independent high-speed access to the computer memory. The two-port memory stores one full display, permitting fast computer operation even during display.

CONTACT YOUR REP NOW

The Model SDI has been used in scientific work, engineering, business, TV, color graphics, and other areas. It's a good example of how Cromemco keeps computers in the field up to date, since it turns any Cromemco computer into an up-to-date color display computer.

The SDI has still more features that you should be informed about. So contact your Cromemco representative now and see all that the SDI will do for you.

a Cromemco incorporated 280 BERNARDO AVE., MOUNTAIN VIEW, CA 94043 • (415) 964-7400 Tomorrow's computers today

Circle 1 on inquiry card.

In The Queue

Volume 6, Number 4

April 1981

Features

ZO Recurrence in Numerical Analysis by

James J Davidson / Recurrence can be used to simplify the calculation of Bessel functions.

36 Build a Low-Cost Logic Analyzer by

Steve Ciarcia I Turn your computer into a powerful diagnostic tool.

64 A-L BYTE Guide to The National Computer Conference and Chicago / Up-to-date information on the conference, the city, and much more.

66 Digital Minicassette Controller by

James Kahn / Use an intelligent peripheral controller to lighten the load on your computer system.

102 Programming the Game of Go by

Jonathan K Millen / Even though Go is much harder than chess, a microcomputer Go program can produce surprisingly good play.

122 Build Your Own Turing Machine by

James Willis / Three different practical versions of this theoretical tool produce the same output.

1 50 A Closer Look at the Tl Speak &

Spell by Peter Vernon / The author expands on Michael Rigsby's September 1980 BYTE article.

21 8 An Introduction to Data Compression by Harold Corbin / Information can be transmitted and stored using fewer data bits by appropriate techniques.

Build an Intercomputer Data Link

by Mike Wingfield / Using this software, systems based on the 6800 microprocessor can communicate with other systems.

290 Three-Dimenslonal Computer

Graphics, Part 2 by Franklin C Crow / Software to display solid objects without hidden lines and surfaces.

348 PADDLES: Interfacing with Modular

Breadboards by Roger J Combs and Paul Field / Designing and implementing breadboard circuits is greatly eased with the use of these standardized modules.

Reviews

46 The MicroAce Computer by Delmar Searls 94 A Reformatter for CP/M and IBM Floppy

Disks by John Lehman

188 Three Versions of APL by Gregg Williams

Nucleus

6

10,

12

32,

98,

148

158 186 212 328 332 338 344 345 359 414 415 416

Editorial: Future Trends in Personal Computing

302 BYTE's Bugs

Letters

34 Programming Quickies: Apple Name-Address; A

Graphic Execution Display

304, 310, 314 Technical Forum: MicroShakespeare

Revisited or Kilobard; An ADM-3 Emulator for the

Hazeltine 1500; Challenger Writes on Comprint; On

the Use of Fourier Transforms to Explore Biological

Rhythms

System Notes: A Relocatable Bootstrap for t+ie Tarbell

Disk Controller

Clubs and Newsletters

Cartoon

BYTELINES

Ask BYTE

Event Queue

Books Received

Software Received

BYTE's Bits

What's New?

Unclassified Ads

BOMB, BOMB Results

Reader Service

EITE

Page 36

Page 46

Page 186

Page 302

April 1981 © BYTE Publications Inc 3

m

Editor in Chief Christopher Morgan

Managing Editor

Mark Haas

Technical Editors

Gregg Williams. Senior Editor; Richard S Shuford; Curtis P Feigel; Harold Nelson; Stan Miastkowski; Kevin Cohan; Bruce Roberts; Charles Freiberg. New Products Editor; Steve Garcia. Mark Dahmke, Consulting Editors; Jon Swanson, Draftsman

Copy Editors

Richard Friedman, Chief; Faith Hanson; Warren Williamson; Anthony J Lockwood; Ann Graves

Assistants

Faith Ferry; Debe Wheeler; Karen A Cilley

Production

Nancy Estle, Director; Christine Dixon, Asst Director; Wai Chiu Li; Jonathan M Graves; Deborah Porter; Sherry McCarthy. Chief Typographer; Debi Fredericks; Donna Sweeney; Valerie Horn

Advertising

Thomas Harvey, Director; Marion Gagnon; Barbara J Greene; Rob Hannings

Circulation

Gregory Spitzfaden, Manager; Andrew Jackson, Asst Manager; Agnes E Perry; Barbara Varnum; Louise Menegus; Bill Watson; Dealer Sales: Melanie Bertoni

Marketing

Jill E Callihan, Special Projects; Laura Hanson

Controller's Office

Daniel Rodrigues, Controller; Mary E Fluhr, Asst Controller; Karen Burgess; Jeanne Cilley

Traffic

N Scott Gagnon; Robert A Fiske

Receptionist

Jacqueline Earnshaw

Publishers

Virginia Londoner; Gordon R Williamson; John E Hayes, Associate Publisher; Cheryl A Hurd, Publisher's Assistant

Officers of McGraw-Hill Publications Company: Paul F McPherson, President; Executive Vice Presidents: James E Boddorf, Gene W Simpson; Group Vice President: Daniel A McMillan; Senior Vice President-Editorial: Ralph R Schulz; Vice Presidents: Kemp Anderson, Business Systems Development; Robert B Doll, Circulation; James E Hackett, Controller; Eric B Herr, Planning and Development; H John Sweger, Marketing.

Officers of the Corporation: Harold W McGraw Jr. President, Chief Executive Officer and Chairman of the Board; Robert F Landes, Senior Vice President and Secretary; Ralph J Webb, Treasurer.

In This Issue

"Future Computers" is our cover theme this month and the subject of the editorial. Before you write to comment on our cover's "unusual" design approach (created by artist Robert Tinney), keep in mind the proximity of April 1.

Elsewhere in this issue we describe Steve Ciarcia's latest project, a low-cost logic analyzer, and tell how to build your own Turing machine. Other articles include: a follow-up to our earlier review of the Sinclair computer, this time a description of the MicroAce kit version; a reformatter for CP/M and IBMformat floppy disks; a closer look at the Tl Speak & Spell; a fascinating review of three different APL packages for the patient (but eager) APL fans in our audience; details about data compression; all about intercomputer data links and the game of Go; and the conclusion of an article from last month about 3-D computer graphics.

BYTE is published monthly by BYTE Publications Inc. 70 Main St, Peterborough NH 03458, phone |603) 924-9281, a wholly-owned subsidiary of McGraw-Hill. Inc. Address subscriptions, change of address. USPS Form 3579, and fulfillment questions to BYTE Subscriptions. POB 590, Martinsville NJ 08836. Controlled circulation postage paid at Waseca, Minnesota 56093 - USPS Publication No. 528890 (ISSN 0360-5280). Canadian second class registration number 9321. Subscriptions are S19 for one year, S34 for two years, and S49 for three years in the USA and its possessions. In Canada and Mexico, S21 for one year, S38 for two years. S55 for three years. S43 for one year air delivery to Europe.- S35 surface delivery elsewhere. Air delivery to selected areas at additional rates upon request. Single copy price is S2.50 in the USA and its possessions, S2.95 in Canada and Mexico, S4.00 in Europe, and S4.50 elsewhere. Foreign subscriptions and sales should be remitted in United States funds drawn on a US bank. Printed in United States of America.

Address all editorial correspondence to the editor at BYTE, POB 372, Hancock NH 03449. Unacceptable manuscripts will be returned if accompanied by sufficient first class postage. Not responsible for lost manuscripts or photos. Opinions expressed by the authors are not necessarily those of BYTE. Entire contents copyright © 1981 by BYTE Publications Inc. All rights reserved. Where necessary, permission is granted by the copyright owner for libraries and others registered with the Copyright Clearance Center (CCC) to photocopy any article herein for the base fee of S1.00 per copy of the article or item plus 25 cents per page. Payment should be sent directly to the CCC, 21 Congress St. Salem MA 01970. Copying done for other than personal or internal reference use without the permission of McGraw-Hill is prohibited. Requests for special permission or bulk orders should be addressed to the publisher.

BYTE® is available in microform from University Microfilms International, 300 N Zeeb Rd, DeptPR, Ann Arbor Ml 48106 USA or 18 Bedford Row, Dept PR, London WC1R 4EJ England.

Subscription WATS Line: (800) 258-5485

Office hours: Mon-Thur 8:30 AM - 4:30 PM, Friday 8:30 AM - Noon, Eastern Time

NATIONAL ADVERTISING SALES REPRESENTATIVES:

NORTHEAST (617) 444-3946

Hajar Associates 280 Hillside Ave Needham Heights MA 02194

NORTHWEST (415J 964-0706

Hajar Associates lOOOEIwellCt, Suite 227 Palo Alto CA 94303

MIDWEST (312) 966-0160

Hajar Associates 5225 Old Orchard Dr Skokie IL 60076

SOUTHWEST (714) 540-3554

Hajar Associates 3303 Harbor Blvd Suite K-4 Costa Mesa CA 92626

MID ATLANTIC (212) 682-5844

Hajar Associates 521 Fifth Ave New York NY 10017

SOUTHEAST (305) 886-7210

Hajar Associates 1220 Prairie Lane Apopka FL 32703

April 1981 © BYTE Publications Inc

"... stands well above other S-100 graphics displays in its price and performance range."

BYTE, Product Review

. better monochromatic . display.

ELECTRONIC DESIGN, 1981 Technology Forcast

MICROANGELO

HIGH RESOLUTION GRAPHICS SINGLE BOARD COMPUTER

512 x 480 resolution black and white and vivid color displays

RS-170 composite or direct drive output

Local or external sync generation

4MhzZ80 microprocessor

60 hertz realtime clock

8 level interrupt tie-in

IEEE S100 bus compatible

Screenware™ Pak I

A 4K byte operating system resident in PROM on MicroAngelo™. Pak I emulates an 85 character by 40 line graphics terminal and provides over 40 graphics commands. Provisions exist for user defined character sets and directly callable user extensions to Screenware™ Pak I.

Screenware™ Pak II

An optional software superset of Pak I which adds circle generation, polygon flood, programmable split screen for separate graphics and terminal I/O, relative coordinates, faster vector and character plotting, a macro facility, full UCSD Pascal compatibility, and more.

Light pen interface

Time multiplexed refresh

4K resident

Screenware™

Pak I operating

system

32KRAM

isolated from

host address

space

High speed

communications

over parallel

bus ports

And now.. .COLOR"

The new MicroAngelo™ Palette board treats from 2 to 8 MicroAngelos as "bit planes" at a full 512 x 480 resolution. Up to 256 colors may be chosen from 16.8 million through the programmable color lookup table. Overlays, bit plane precedence, fade-in, fade-out, gray levels, blinking bit plane, and a highly visual color editor are standard.

Circle 2 on inquiry card.

SOON

8455-D Tyco Road • Vienna, Virginia 22180 • TWX: 710-831-9087 • (703) 827-0888

Circle 3 on inquiry card.

UCSD

PASCAL FORTRAN

Portable

Develop on a Z-flOt, runonLSI-1lt, T.I. 990, 6800 or vice versa

Efficient

Structured, readable Speeds development X5 Easy maintenance

Powerful

Full standard Pascal

plus extensions

ANSI '77 Fortran Subset

Cost Effective

Complete system Including Interpreter, screen editor, utilities, filer, assembler, and compiler, with Pascal $400 with Fortran $450 with Both $600

APPLICATIONS

PFAS

(Pascal File Access System) Keyed-ISAM in 6K user memory $200

INTELLECT UL VI.2

A full range LISP interpreter for UCSD p-systems $200

MEDOFFICE

Professional medical office software for 1 to 5 doctors. Call for pricing.

DATEBOOK

Appointment scheduling on your micro $295

READY TO RUN ON DEC PDP-11 for TRS-80 MODEL 11 §

PCD

SYSTEMS

P. 0. Box 143 Penn Yan, NY 14527 315-536-3734

*TM Univ. of Calif.

JTMofZllog

JTM of Digital Equipment

STM of Tandy Corp.

Editorial

Future Trends in Personal Computing

Chris Morgan, Editor in Chief

Future Computers—what will they be like?

Some exciting developments have been occurring in the industry lately that should give us some clues. I attended the Consumer Electronics Show in Las Vegas this past January, where Toshiba introduced what could be the most significant product of the year for the personal-computing market: a pocket-size flat-screen television set. While no specific mention was made of its possible use with a personal computer, it takes only a moment's thought to see the potential of this engineering marvel.

First introduced in japan some months ago, the Toshiba television has a 4.1 by 3.1 cm (l3/5 by 1% inch) LCD (liquid-crystal display) screen housed in a case measuring 17.3 by 8.2 by 1.8 cm (6% by 3% by 7/io inches)! It has only half the resolution of a standard CRT (cathode-ray tube) display, but its small size masks that fact effectively. Toshiba has also solved the problem of liquid-crystal "overhang," the slow-fade effect that plagues LCDs in electronic games. The response time of this particular design is fast enough to handle the 1/30 of a second television-frame refresh rate. Although the screen is dimmer than a CRT display (the im

Photo 1: Toshiba's new pocket-size television prototype. A built-in zoom feature is available that enlarges any one of the four screen quadrants for close-up viewing. Photo by Stan Miastkowski.

age is formed from reflected rather than transmitted light), it has acceptable contrast and sharpness. The screen is fed by a bank of shift registers; it would be an easy task to display computer graphics and characters on it.

The Toshiba flatscreen unit is still in the prototype phase and will probably not be available for a year or so, retailing for approximately $600. I predict that within two years the market will be flooded with portable computers having built-in screens of every size and shape.

Sony has introduced a new electronic "typewriter" that fits in a briefcase and lets you enter, store, and edit up to 200 pages of text using a built-in microcassette recorder. Text is displayed on a one-line liquidcrystal display. Combine such a device with a flat-screen multiline video display and you have a very attractive concept, indeed.

Another Sony breakthrough is a new miniature floppy-disk system (see photo 3, page 10). Each disk measures 8.9 cm (3Vi inches) in diameter and holds over 800,000 bytes 1 The disk resides in a rigid housing for protection. Sony plans to introduce the disk as part of a new, miniature word-processing system.

Percom Mini-Disk Drive Systems for TRS-80* Computers...

Now! Add-On and Add-In Mini-Disk

Storage for your Model III.

New for the TRS-80* Model III

Patterned after our fast-selling TFD Model I drives. And subjected to the same reliability controls. These new TFD mini-disk systems for the Model III provide more features than Tandy drives, yet cost far less.

• Flippy Capability: Both internal (add-in) and external (add-on) drives permit recording on either side of a diskette.

• Greater Storage Capacity: Available with either 40or 80-track drive mechanisms, Percom TFD mini-disk systems store more. A 40-track drive stores up to 180 Kbytes — formatted — on one side of a 5-inch diskette. An 80-track drive stores a whopping 364 Kbytes.

• 1.5 Mbyte On-line: The Percom drive controller (included with the initial drive) handles up to four drives. With four 80-track mini-disk drives you can access over 1.5 million bytes of on-line file data.

Moreover, the initial drive may be either an internal add-in drive or an external add-on drive. And whichever configuration you get, the initial drive kit comes complete with our advanced 4-drive controller, interconnecting cables, power supplies, installation hardware, a DOS and of course the drive mechanism itself.

• First Drive Includes DOS: OS-80™, Percom's fast extendable BASIC-language disk operating system, is included on diskette when you purchase an initial drive kit. Originally called MicroDOS, OS-80 was favorably reviewed in the June 1980 issue of Creative Computing magazine.

• Works with Model III TRSDOS: Besides being fully hardware compatible, Percom's Model III 40-track drive systems may be operated with Tandy's Model III TRSDOS — without any modifications whatsoever. And, TRSDOS may be easily upgraded with simple software patches for operating 80-track drives.

Percom TFD add-on drives start at only $399. Model III Drive kits start at only $749.95.

Quality Percom products are available at authorized dealers. Call toll free 1-800-527-1592 for the address of your nearest dealer or to order direct from Percom.

The industry leader in microcomputer peripherals, Percom not only gives you better design, better quality and first-rate service, but you pay less to boot.

Still #1 for Model I

As if greater storage capacities, exceptional quality control measures and lower prices aren't reasons enough to make Percom your first choice for Model I add-on drives, all Percom Model I drives are also rated for double-density operation.

Add our innovative DOUBLER™ adapter to your Model I Expansion Interface, and with Percom drive systems you can enjoy the same double-density storage capability as Model III owners.

The DOUBLER includes a TRSDOS*-like double-density disk operating system called DBLDOS™

We also offer a double-density Model I version of OS-80 as well as DOUBLEZAP programs for modifying NEWDOS/80 and VTOS 4.0t for DOUBLER compatibility.

Of course you don't have to upgrade your computer for double-density operation to use Percom mini-disk drive systems. In single-density operation, our TRS-80* Model I compatible 40-track drives store 102 Kbytes of formatted data on one side of a diskette, and our 80-track drives store 205 Kbytes. By comparison, Tandy's standard drive for the Model I stores just 86 Kbytes.

And like our Model III drives, Model I add-on drives are optionally available with "flippy" storage capability.

System Requirements:

Model III: 16-Kbyte system (min) and Model III BASIC. The second internal drive may be installed after the first internal drive kit is installed, and external drives #2, #3 and #4 may be added if either an internal or external first-drive kit has been installed. External drives #3 and #4 require an optional interconnecting cable. Model I: 16-Kbyte system (min), Level II BASIC, Expansion Interface, disk operating system and an interconnecting cable. For double-density storage, a Percom DOUBLER must be installed in the Expansion Interface and DBLDOS (comes with the DOUBLER) or other double-density DOS must be used. For single-density operation, a Percom SEPARATOR™ adapter, installed in the Expansion Interface, will virtually eliminate "CRC ERROR — TRACK LOCKED

OUT' read eiTOrS. Prices and specifications subject to change without notice.

PEfiGOM

PERCOM DATA COMPANY, INC.

211 N. KIRBY GARLAND. TEXAS 75042

C214) 272-3421

•Trademark of Tandy Radio Shack Corporation which has no relationship to Percom Data Company. ™DOUBLER, DBLDOS. OS-80 and SEPARATOR are trademarks of Percom Data Company. Inc. tTrademark of Virtual Technology Corporation.

Circle 4 on inquiry card.

BYTE April 1981

Editorial

Photo 2: The Osborne I personal computer. This new 64 K, Z80A machine has two floppy-disk drives and fits under an airline seat. Price: $1795. Photo by Elliot Varner Smith.

Although no official word has come from the company, we have learned that it is developing a complete personalcomputer system. Fujitsu and Seiko are also developing personal computers for the U.S. market.

New Trends in Portability: The Osborne I

This month Adam Osborne introduced a new personal computer, called the Osborne I, at the West Coast Computer Faire in San Francisco. Its features include: a Z80A processor; 64 K bytes of dynamic programmable memory (60 K bytes are available to the programmer; the remaining 4 K bytes are used by the display screen); IEEE and RS-232C interfaces; modem electronics; a 5-inch video monitor with 24 rows of 50 characters, upper- and lowercase, two display intensities, and underlining for all characters; two 5-inch single-density, single-sided floppydisk drives; standard typewriter keyboard; 10-key numeric pad; two pockets for storing floppy disks; and the following software: the CP/M operating system, CBASIC, WordStar, Mailmerge, and a CP/M-compatible spread sheet program that resembles VisiCalc.

There are two particularly interesting points about this computer: (1) it will cost $1795, and (2) it's portable! An optional battery pack will be sold with the unit. Also optional are a 9-inch monitor, an acoustic coupler, and double-density, double-sided floppy-disk drives. The $1795 price tag (which includes all the software) is remarkably low. It remains to be seen if the company can turn a profit at this price. I recently had an opportunity to see the Osborne I in action. I was impressed with its compactness: it will fit under an airplane seat. (Adam

PASCAL/Z ™- Q.E.D.

Ithaca Intersystems PASCAL/Z is the most powerful CP/M™ compatible Z-80™ Pascal compiler ever . . . and here's why:

PASCAL/Z generates true Z-80 native code - ROMable and re-entrant — 5-1 OX faster than P-code interpreters; permits separate compilation; supports Direct File Access and variable length STRINGs; utilizes fast one-pass recursive descent organization; the macro-assembler generates relocatable object modules; and much, much more.

Complete package includes compiler, macro-assembler, linker/loader and source for the full library on one disk; with free copy of Jensen/Wirth book and complete documentation. Only $395.00.

IT'S DEMONSTRABLE! Don't just take our word for it. Ask for a demonstration of these features and more today at Computerland® and other full-service computer stores.

Ithaca Intersystems Inc., 16S0 Hanshaw Road

P.O. Box 91, Ithaca, N.Y. 14850. Phone (607) 257-0190

Computerland is a registered trademark of Computerland Corporation.

CP/M and Z-80 are trademarks of Digital Research Corp. and Zilog, Inc. respectively.

PASCAL/Z and InterSystems are trademarks of Ithaca Intersystems Inc.

8 April 1981 © BYTE Publications Inc

Circle 5 on inquiry card.

Intersysten

Micros for bigger ideas.

The Intersystems price-performance-reliability

story now has three versions.

While everyone's been busy trying to convince you that large buses housed in strong metal boxes will guarantee versatility and ward off obsolescence, we've been busy with something better. Solving the real problem with the first line of computer products built from the ground up to conform to the new IEEE S-100 Bus Standard. Offering you extra versatility in 8-bit applications today. And a full 16 bits tomorrow.

We call our new line Series II. And even if you don't need the full 24-bit address for up to 16 megabytes (!) of memory right now, they're something to think about. Because of all the performance, flexibility and economy

they offer. Whether you're looking at one of our three mainframes, at a new mainframe, expanding your present one or upgrading your system with an eye to the future. (Series II boards are compatible with most existing S-100 systems and all IEEE S-100 Standard cards as other manufacturers get around to building them.)

Consider some of the features: Reliable operation to 4MHz and beyond. Full compatibility with 8- and 16-bit CPUs, peripherals and other devices. Eight levels of prioritized interrupts. Up to 16 individually-addressable DMA devices, with IEEE Standard overlapped operation. User-selectable functions addressed by DIPswitch or jumpers, eliminating soldering. And that's just for openers.

The best part is that all this heady stuff is available nowl In our advanced processor —a full IEEE Bus Master featuring Memory Map addressing to a full megabyte. Our fast, flexible 16K Static RAM and 64K Dynamic RAM boards. An incredibly versatile and

Circle 6 on inquiry card.

economical 2-serial, 4-parallel Multiple I/O board. Our 6-serial I/O board. Our Double-Density High-Speed Disk Controller. And what is undoubtedly the most flexible front panel in the business. Everything you need for a complete IEEE S-100 system. Available separately, or all together in your choice of DPS-1 mainframe styles.

Whatever your needs, why dump your money into obsolete products labelled "IEEE timing compatible" or other words people use to make up for a lack of product. See the future now, at your Intersystems dealer or call/ write for our new catalog. We'll tell you all about Series II and the new IEEE S-100 Bus we helped pioneer. Because it doesn't make sense to buy yesterday's products when tomorrow's are already here.

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607-257-0190/TWX: 510 255 4346

\s^ Ithaca Intersystems Inc.

Micros for bigger ideas.

/

Editorial

Photo 3: Sony's new 3V2-inch floppy disk and drive. Each double-sided floppy disk can hold up to 875 K bytes of information, unformatted. The recording density is 1.47 times that of the 5-inch disk.

Atiast-theDYNATYPER

TYPEWRITER INTERFACE!™

Turn your electric typewriter into a low cost, high quality hard copy printer. 1 year warranty

DYNATYPER - Rochester Data's patented* Computer/Typewj Interface is the industry standard for typewriter output.

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Compatible with all power carriage return JApewriters having standard U.S. keyboard. The Dynatyper j^Stks with Selectrics (model 1) and most non-Selectrics (maps! 2). Please specify. Typewriter conversion between modejapakes 2 minutes and the kit (17 plungers) is available for a nornjoal fee. The Dynatyper is compatible with ^(♦major word processing software. (Scripsit, Pencil, Applewriter»£asywriter, Magic Window, Visi-calc CCADBM, Supertext, WriWStTn)

Interfaces available for "WS-80, APPLE, PET/CBM, OSI, Northstar, HP-85, H-89. WeigljjMnly 3 lbs. Extremely portable. Delivery: StfHk towvo weeks. Price $499 for complete system. F.O.B. Rj^hellfer, Domestic. VISA and Master Card accepted. Ncky at 716-244-7804

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incorporated

Osborne is currently seeking approval from the FAA to operate the unit on board a plane.) One quibble: the screen may be too small for some people's taste. Consulting Editor Mark Dahmke is preparing a full test report on this computer for an upcoming issue of BYTE.

Update

We have received numerous requests for more information on the Microterminal described in the January editorial. We cannot divulge any more information at this time, but watch for a complete report coming soon.

Also in the works: full reports on the Commodore VIC-20 color computer; the TRS-80 color computer hires (high-resolution) graphics; a special issue on local networks; reviews of three LISP packages; the new spellingcorrection programs; Logo for the Apple II and TI 99/4; and our annual August language issue, this year on Smalltalk, one of the most exciting languages in the computer field today. Watch our upcoming editorials for further information about future computers. ■

The Carl Helmers Newsletter

Readers of recent issues of BYTE are probably aware that Carl Helmers, former Editorial Director of BYTE, is now working on projects outside of McGraw-Hill. One of Carl's new undertakings is the Carl Helmers Personal Computer Newsletter, which will cover the present state of personal computing, future developments in hardware and software, artificial intelligence, mass storage, and many other topics. The newsletter will contain no advertising, cost $200 per year, and will appear monthly. Carl is also considering a free "personal computer industry conference call," which would be made available via a toll-free 800 number if interest among subscribers is high enough. The setup would enable up to twenty people to participate in a regularly scheduled monthly "roundtable" discussion.

For more information about subscribing to the newsletter, write to North American Technology Inc, Strand Building, Suite 23, 174 Concord St, Peterborough, NH 03458, or call 603-924-6048. We wish Carl luck in his new venture...CM

BYTE's Bugs

Invisible Software Review

Because of a last-minute scheduling change, the product review by BYTE editor Gregg Williams, "The muSIMP/muMATH-79 Symbolic Math System" (November 1980 BYTE, page 324), did not appear on the "In the Queue" page for that issue. We regret the omission.

10 April 1981 © BYTE Publications Inc

Circle 7 on inquiry card.

Getting the Number Straight

In the February 1981 BYTE, on page 345 of the "What's New?" section, the telephone number given for General Digital Corporation was incorrect. The correct number is (203) 289-7391. We apologize for any difficulties that may have arisen due to the error. ■

Circle 8 on inquiry card. >

Make the Apple II* a powerful IEEE-488 Controller in a snap.

Just plug the SSM A488 board into any Apple II* expansion slot for a low-cost,

full-featured instrumentation interface. SSM gives the Apple II the power and versatility of a $9,000 IEEE-488 controller. At a fraction of the price. Our board converts the Apple II into a truly sophisticated controller that programs and controls up to 15 different instruments connected together on the 488 bus.

We make programming easy. The 68488 chip, designed by Motorola, forms the heart of our A488. We back this chip with powerful on-board firmware to give you system control via simple string commands. The only software you need is easy-to-program Applesoft* Basic. To develop special purpose firmware, simply replace our PROM with a RAM. With the A488, bus communications operate at top speed—without depending on software loops for timing. And like the more expensive IEEE-488 controllers, this system interfaces with more than 1200 instruments and peripherals.

Suitable for OEMs as well as end users. Whether you make test/measurement systems for resale, or simply for yourself, the SSM/Apple combo gives you top performance. As it cuts your costs. Call your local dealer or SSM today for complete details.

IEEE-488 bus cable

(6 ft. with stackable connectors)

Industrial grade circuit board

PROM firmware for powerful user interface 68488 IEEE-488 controller chip.

SSM's A488 board expands the Apple II to a high-performance IEEE-488 controller.

* Registered trademarks of Apple Computer Inc.

SSM Microcomputer Products, Inc.

2190 Paragon Drive San Jose, CA 95131 (408)946-7400 Telex: 171171 TWX: 910-338-2077

Letters

Computers and Trees: The HHC Forest

I read Gregg Williams and Rick Meyer's article about the Panasonic/ Quasar hand-held computers (January 1981 BYTE, page 34), and I could hardly contain my excitement over the potential use for these devices in my field: forest measurements and statistics.

Forest inventory and survey work typically involves many man-hours in the forest collecting information on tree size, species, sawtimber quality and value, growth, etc. This information is normally hand-written on tally sheets in the field, and either hand-tabulated in an office or key-encoded for statistical summary and analysis by computer. Forest scientists and practicing foresters are continually looking for more economical methods of obtaining resource information at the level of precision required for complex management planning and decisionmaking.

The HHCs (hand-held computers) appear to have the capability of being used in the field as data-entry devices, thereby eliminating the need for subsequent key

encoding of hand-written information. With their alphanumeric capability, they should be able to store and manipulate descriptive text as well as numeric information. With suitable applications programs, I would think they are also capable of handling a fairly large repertoire of forestry problems (eg: compiling tables describing timber volumes by species, log grade, and size class; estimating stumpage values for timber sales, etc). For larger data-processing requirements, they could transmit their data, through the modem attachment, to a host computer. In short, I see in these devices a potential for greatly reducing the man-hours required for routine data-entry and processing applications in forestery.

George L Martin Jr

Assistant Professor of Forest Biometry

Department of Forestry

College of Agricultural and Life Sciences

University of Wisconsin

1630 Linden Dr

Madison WI 53706

The advent of HHCs will be a boon to many who must perform data entry and sophisticated calculations in the field. Un

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fortunately, neither the price nor the availability date of the Panasonic/Quasar unit was announced at the CES (Consumer Electronics Show), as I had originally hoped. As an educated guess, I would place the price in the $400 to $650 range, with the units possibly being available as early as mid-1981....GW

Oddest Programming Language of Them All

In the December 1980 BYTE, Mr Daniel Weise presented a version of a self-reproducing program. (See "Thief-Reproduthing Programth," page 16.) The following version of the same fundamental algorithm is written in my favorite programming language—English:

Replace every occurrence of "x" in " x 'x'." by "Replace every occurrence of 'x' in 'x "x".' by ".

Which executes as follows:

Unquote " x 'x'." to obtain the form x "x".

Replace "x" by the quoted substitute to obtain x "Replace every occurrence of 'x' in 'x "x".' by ".

Replacing x by the unquoted substitute we obtain Replace every occurrence of "x" in " x 'x ." by "Replace every occurrence of 'x in 'x "x".' by ".

The operations quote and unquote work as follows:

Quote text = "text*". Unquote "text*" = text.

where text* is a faithful copy of text, except for the replacement of each quote mark, single or double, by its complement. This transformation is idempotent. This is a time-honored syntactic device of English.

I leave it to you, dear reader, to judge the relative perspicuity of this English version and the LISP version provided by Mr Weise.

James P Corbett 24 Sheffield Lane Florence MA 01060

Readers should note that they may not be able to get this program to run on every model of the human brain—which is probably just as well, since once running, it would use up all available processing time and memory space.... CPF

12 April 1981 © BYTE Publications Ire

Circle 9 on inquiry card.

Circle 10 on inquiry card.

Edison had over 1,800 patents in his name, but you can be just as inventive

with an Apple.

Apple is the company with the brightest ideas in hardware and software and the best support — so you can be as creative with a personal computer system as Edison was with the incandescent bulb.

How Apple grows with you.

With Apple's reliable product family, the possibilities of creating your own system are endless. Have expansion capabilities of 4 or 8 accessory slots with your choice of system.

Expand memory to 64K bytes or 128K bytes. Add an A to D conversion board. Plug into time sharing, news and electronic mail services. Use an IEEE 488 bus to monitor lab instruments. Add 4 or 6 disk drives — the 5'A" 143K bytes, high-speed, low-cost drive that's the most popular on the market.

Apple speaks many languages.

Since more than 100 companies create software for Apple, you'll have the most extensive library in the personal

computer world. Want to write your own programs? Apple is fluent in BASIC, Pascal, FORTRAN, PILOT and 6502 assembly language.

There's even a series of utility programs called the DOS Tool Kit that not only lets you design high-resolution graphic displays, but lets you work wonders with creative animation.

More illuminating experiences in store.

You won't want to miss all the Apple products being introduced at your computer store all the time. Don't let history pass you by. Visit your nearest Apple dealer or call 800-538-9696. In California, 800-662-9238. Or write: Apple Computer, 10260 Bandley Drive, Cupertino, CA 95014.

cippkz computer inc.

Letters

Vive la Guerre

I have a few comments on Bruce Carbrey's article "A Pocket Computer? Sizing up the HP-41C." (See the December 1980 BYTE, page 244.) The article was very interesting, since I use both an HP-41C and a TI-59 frequently. Mr Carbrey did a comparison that I had planned but had never done.

On page 246, he states that storing a number in a register on a TI-59 requires three lines. This applied to the earlier SR-52, but only two lines are needed with a TI-59. Two is better than three, but the

one-line approach of the HP-41C is better. It makes editing a program without a printer much easier, especially since you don't have to remember key codes.

Mr Carbrey's benchmark test program does not, however, use the TI-59's strengths well. A major difference between the calculators is that both label and absolute addressing exist on the TI-59, while the HP-41C uses only labels. Since the HP-41C program is compiled, it is not penalized. Using absolute addressing in the TI-59 program cuts run time by 3 seconds and saves a step.

Listing 1 is a benchmark program that

YOU THINK YOU'VE SEEN WORD PROCESSING SOFTWARE?

The

magic wand;

Word Processing

System offers you the best features of any system in the micro market

FEATURES INCLUDE:

Full-screen text editor

Simple, control key operation Edit programs as well as text

Assemble, compile or run programs

without modification Files larger than memory

Files up to 256K Library files

Merge part or all of one file with

another Spool printing

Print a file while editing another Easy page formatting

Simple commands set margins, page

length, etc. Override commands at run-time

Give any command from the keyboard as well as in file Variable pitch control

Change pitch in mid-line, even

mid-word Up to 128 user-defined variables

String, numeric or dollar format Form letter generation from external data files

Compatible with both sequential and

fixed-record files Conditional commands

Any command may be conditional Print to disk and/or printer

Save all or part of output on disk Switch from specialty printer to CP/M list device

Print the same file on either specialty

or standard printer

Version 1.1 is now available

EASE OF OPERATION

With all its power, the MAGIC WAND is remarkably easy to use. This is no accident. The command structure is designed to be flexible and logical so that you can perform basic functions with a minimum of commands.

We have included in the manual a stepby-step instructional program, for the person who has never used a word-processor before. The trainee uses sample files from the system disk and compares his work to simulated screens and printouts.

In addition to the lessons, the manual has a complete documentation of the command structure, special notes for programmers, an introduction to CP/M for non-programmers and a glossary. The manual is typeset, rather than typewritten, for greater legibility.

We have written the manual in nontechnical English, because we want you to read it. We don't overload you with a bunch of jargon that could confuse even a PhD in Computer Sciences.

We send out newsletters so that users of the MAGIC WAND can learn special applications of the print commands. For example, we might show you how to create a mailing list or set up an index for a file.

In short, we've done everything we can to make things easy for you. Because the best software in the world is just a bunch of code if you can't use it.

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uses the TI-59's parenthesis feature. This seemed especially apt considering Hewlett-Packard's and Texas Instruments' battle over Reverse Polish Notation vs Algebraic Operating System. My program is 10 steps shorter, uses 4 data registers, and runs in 33 seconds. This improved performance is achieved by reducing the number of relatively slow memory arithmetic operations and utilizing the TI-59's stack. (Also note that the correct answer in Mr Carbrey's table 1, on page 254, is $17553.30, not $17533.30.)

Listing 1

000

76

LBL

001

11

A

002

58

FIX

003

02

02

004

42

STO

005

01

01

006

91

R/S

007

42

STO

008

02

02

009

91

R/S

010

42

STO

011

03

03

012

91

R/S

013

55

■j.

014

01

1

015

00

0

016

00

0

017

85

+

018

01

1

019

95

=

020

42

STO

021

04

04

022

45

Y*

023

43

RCL

024

02

02

025

94

+ /

026

65

X

027

43

RCL

028

01

01

029

85

+

030

53

(

031

00

0

032

85

+

033

43

RCL

034

04

04

035

45

Y"

036

43

RCL

037

02

02

038

94

+ /

039

97

DSZ

040

02

02

041

00

00

042

32

32

043

54

)

044

65

X

045

43

RCL

046

03

03

047

95

=

048

91

R/S

Much has been made of the HP-4lC's plug-in accessories, but I wonder if they are really a major design change. They obviously follow TI's development of the printer attachment and Solid State Software. The HP printer has excellent print quality and features, but it is very slow. The Bar-Code reading "Warvd" is the only significant advance in my opinion.

The capacities of the two calculators are about equal in my experience. Most users want both a printer and a card

14 April 1981 © BYTE Publications Inc

Circle 11 on inquiry card.

Circle 12 on inquiry card.

Easy on your Eyes

and your Budget

80 character display makes it ideal for word processing

and scientific applications.

America, Inc.

130 Martin Lane,Elk Grove Village, IL 60007

This high quality professional computer monitor provides sharp, clear display of up to 80 characters by 25 lines of text, making it ideal for word processing as well as standard business applications.

Lightweight industrial grade construction gives maximum portability with reliable operation.

Letters

reader, so only two memory modules can be added. Thus, a maximum of 830 program lines is available without data registers in practical applications, and this limit is quickly reduced. Even allowing for the HP-4lC's greater storage efficiency (I find a 50% improvement over the TI-59), the HP-41C is only marginally better.

The lack of a TI response to the HP-41C threat mystifies me. Although users were surveyed last spring, no new product has appeared. The discounts being offered on TI's "59" calculators clearly suggest that something is coming soon, but it has been a year since the HP-4lC's introduction.

Perhaps the pocket computers from Radio Shack and Sharp threw a wrench into the works. TI has always played a game of increased capacity at lower cost in the programmable-calculator marketing wars. I await TI's next entry with great anticipation. Users have profited immensely from the battles between Hewlett-Packard and Texas Instruments in this market. (Take out your old calculator and try using it now.) Vive la guerre!!!

G John Garner 319 Blue Haven Rd Dollard des Ormeaux,

PQ, Canada

INTELLIGENT

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BIZCOMP's Intelligent Modem is new. Brand new. It teams a Bell 103-type "dumb" modem with a custom BIZ-080 microcomputer in an attractive desk-top enclosure. RESULT: Incredibly simple data comm for professional users. No more mad dash to get a handset into coupler muffs before being disconnected by the remote. No more exclusion-key telephone needed to do the dialing. No more outboard coupler boxes. And for computer sites, communications software written in high level language like BASIC or COBOL. How's that for simplicity!

The 1030 gives you automatic dial, automatic answer and, unique to the industry, automatic REPEAT dial. The top-of-the-line 1031 adds command-selectable tone or dial pulse dialing for TWX net applications and self-test for ensuring full functionality. Both models are FCC registered for direct connection and feature comm rates from 110, 134.5, 150, 200 to 300 baud. BIZCOMP's innovative Code-Multiplexed Design enables complete control using a simple 3-wire RS-232 interface. Don't burden your customers with data comm hassles. Install a BIZCOMP Intelligent Modem today.

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Patent Pending

Steve Ciarcia's article "Electromagnetic Interference" (January 1981 BYTE, page 48) is a very good and long-overdue summary of the electronic noise-pollution problem. Many radio engineers have been fighting the battle against the plastic computer box and the poorly designed digital boards that dominate the industry. We are ready for some stiff regulations regarding fundamentals, such as simple metallic shielding and grounding practices, so that the rest of the world can continue to use RF (radio-frequency) communications.

One omission in Mr Ciarcia's article is the reference to a state-of-the-art handbook or text for more comprehensive information on the subject. One of the best comes from Bell Laboratories, in Henry W Ott's book Noise Reduction Techniques in Electronic Systems (New York: John Wiley & Sons Inc, 1976).

R W Burhans Ohio University Avionics Engineering Center Athens OH 45701

This omission was caught and rectified. See "BYTE's Bits" March 1981 BYTE, page 314, for additional reading material. Also, see J N Demas's review in the September 1980 BYTE, page 311....GW

Well-Rounded Machine

We at Hewlett-Packard were very pleased to see Brain Hayes's excellent article on the HP-41C calculator. (See "The HP-41C: A Literate Calculator?", January 1981 BYTE, page 118.) He did make some statements that deserve clarification, however. In particular:

There is something absurd about the world's fanciest calculator not being able to give results accurate to more than seven or eight decimal places.

The example he used was the (-JT) computation, which is a good illustration of a common misunderstanding about computer arithmetic. When calculating \fT, the 41C works internally with 13 digits and then rounds correctly to 10 digits. This helps to insure the accuracy of the displayed result. But this result is still not really -Jl, merely the best representation possible on this, or any other, 10-digit machine: 1.414213562.

At this point, the calculator does not know where this number came from: it could be a previous result, or it could have been entered exactly as such through

16 April 1981 © BYTE Publications Inc

Circle 13 on inquiry card.

THE NEW RELIABLES

Take a look at the new industry standard in reliability.

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Circle 15 on inquiry card.

BYTE April 1981 17

NEW CATALOGUE LISTINGS FROM

JOHN D. OWENS

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Complete S-100 color imaging system with high performance video FRAME GRABBER. 3 fundamental functions are + digitization of video input in real time + + image storage in dual-port, onboard memory + + + video input of buffered image in gray levels, NTSC color or RGB color.

Discount price $1,875.

Write or call for option descriptions and pricing, too numerous to list here.

HOUSTON INSTRUMENTS HIPAD DIGITIZER

Create your own graphics using either stylus or optional cursor. Excellent for architectural drawing, business graphs, schematics, free form drawing, etc. More accurate and easier to use than keyboard input or joysticks. "Stream mode" allows continuous placement of coordinate pairs on 11" X 11" pad using either stylus or optional cursor. For S-100 systems and also Apple, TRS-80, PET. Our discounted price $ 755.

LDOS for TRS-80 USERS

New operating system can support up to 8 drives (either 5V»", 8" or new Winchester fixed disk) in any combination. Features include ISAM Accessing Techniques. Keyboard type ahead, graphics string packer, dated files and many, many more.

Our discounted price $ 126.

Manual only $ 25.

DMA-DOS North Star 8" FLOPPY SUBSYSTEM

A new operating system, completely CP/M® compatible that allows use of both 8" (Shugart single sided, double density via Tarbell controller) and 5'A" drives.

Complete hardware, software package $1,910.

TARBELL CPU Z-80

Features memory management hard ware that allows dynamic mapping of ; logical to 1 MB of physical memory in ~ 4K blocks. Supports an easy to use implementation of MP/M®. Either 2 or 4 MHZ, jumper selectable. TWO on p board RS232 ports will full handshaking s? capability; crystal controlled program mable timer.

SEE OUR ADS ON PAGES 178 AND 179

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212 448-6283 212 448-2913 212 448-6298 Overseas Callers: Phone 212 448-6298

WE HAVE NO READER INQUIRY NUMBER. PLEASE WRITE OR CALL.

Letters

the keyboard. Squaring this number correctly and rounding again yields 1.999999999. Any 10-digit calculator that does otherwise is either doing "funny arithmetic," or else is not telling you everything it knows. But the 41C has lived up to its claim: each calculation was performed correctly to 10 digits. Also, and at least as important, the behavior of the calculator is utterly predictable and repeatable.

A calculator is a tool, and, like any tool, it has its limitations. These limitations must be understood if the tool is to be used properly. The point is this: there exist sequences of calculations that will generate errors of any magnitude on any finite-precision arithmetic machine. Keeping this in mind, the "world's fanciest calculator," the HP-41C, is a tremendously powerful tool indeed.

Steve Abell

Research and Development Engineer

Hewlett Packard Company

Corvallis Division

1000 NE Circle Blvd

Corvallis OR 97330

MIcroAce: More Power to Sinclair

I disagree with John McCallum's statement in 'The Sinclair Research ZX80" (see the January 1981 BYTE, page 94) that by building the kit version "you will not save any money." My MicroAce cost a mere $150—a savings of 25 % over the price of a ZX80. It was easy to build, although the instructions were not nearly as elaborate as Heathkit's.

The MicroAce has room for two more programmable-memory integrated circuits than the ZX80. The increase to 2 K bytes almost triples the possible program length (portions of the first 1 K bytes are used for "housekeeping"). This expanded capacity gives you a much more usable computer. Its unique design means that you can store as much information as other systems that use 3 K to 4 K bytes.

I couldn't afford $500 or more for a computer, but, for about $175 (kit plus memory chips), I have learned quite a bit and gained much enjoyment while doing so.

John R Mullen 8518 Terrang Ct Rockford IL 61111

The MicroAce kit is reviewed by Delmar Searls on page 46 of this issue.

Calling Z8000

The "BYTELINES" section of the January 1981 BYTE (page 200) contained

an item saying that Microsoft proposed a standard set of calling conventions specifying parameter-passing and register usage for the Z8000 microprocessor. It was actually Zilog Inc, inventor of the Z8000, that established the conventions. Zilog announced the Z8000 standards at last year's WESCON show in Anaheim, California. The announcement contained the statement that the conventions "have thus far been adopted by Microsoft and are under consideration by several other companies."

Thank you, BYTE, for letting me set the record straight by pointing out that Zilog originated the Z8000 calling conventions that were subsequently adopted by Microsoft.

Bruce Weiner

Product Marketing Manager

Zilog Inc

10460 Bubb Rd

Cupertino CA 95014

Why Didn't We Think....

-*\i ^

1 mtgml METUflN

I always look forward to the latest issue of BYTE, as I am sure many others do. I would like to pass along this suggestion to my fellow readers who use an Apple II computer. It is my solution to the wellknown "accidental RESET" problem that plagues users of that machine.

Manauba Sakuta, MD 6324 Wilryan Ave Edina MN 55435

December Adventure

BYTE's "Product Reviews" of games in the December 1980 issue were absolutely perfect. There are too many bad programs on the market; being able to see a picture of the display (along with a description of how the game is played) is a big help.

I noticed that BYTE didn't continue this policy in the January 1981 issue—I realize that you can't have seven game reviews in every issue, but it would be nice....

Thanks.

PAD from Livermore CAB

18 April 1981 © BYTE Publications Inc

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Recurrence in Numerical

Analysis

James J Davidson

c/o BYTE Publications

POB 372

Hancock NH 03449

Although Taylor's series are the most universally useful method of computing higher mathematical functions, they do have their drawbacks. In particular, many functions have representations only in the form of alternating series. This can cause great difficulty in maintaining accuracy if large arguments are required. Often, so many significant digits are lost in the process of computation that the results are, at best, useless. At worst, if you do not suspect that gross inaccuracies are occurring, you may make severe engineering mistakes.

If the various remedies such as argument scaling are ineffectual in improving accuracy, the only recourse is to seek alternate methods of computation. Of those alternatives, recurrence relations have the widest applicability.

What's a Recurrence Relation?

Various functions have the mathematical property that if you know two consecutive values, you can use those to find a third. This process can be repeated to find a fourth from the second and third, and so on. Of course, you need to pick the right pair to start from, but if you do, you can get to any value you want.

The simplest illustration of a recurrence relation is the Fibonacci series. This is a series of special numbers known in medieval times to Leonardo of Pisa, surnamed Fibonacci (1175-1230). Fibonacci numbers are found in botany and other natural sciences, as well as in certain mathematical theories of aesthetics. They are interesting in their own right, and there is at least one society devoted to study of their mathematical properties.

The Fibonacci series proceeds in the following fashion:

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, . . .

Each term is obtained by adding the two previous terms. As a formula, the series can be expressed as:

an*2 ~ H„+l + An

where the initial terms must be specified as 0 and 1. Once you get started, it is obvious that you can keep going indefinitely using the same formula. It is not even necessary to begin at the beginning. If you know the thirteenth and fourteenth terms, for instance, you can find the fifteenth by adding them together.

Programming this recurrence relation is not going to be much of a chore. The important thing to keep in mind is that three values must exist within the computer simultaneously: the n and (n + 1) terms, and the sum of these two, which is the value being calculated. Then, after the value is found, it must be slid into the (n + 1) position, with that one being slid into the n position. This sliding process is the only tricky part because it must be done in the proper order, and it is the heart of all recurrence programming.

Listing 1 shows how simple the job is. After initialization, the FOR...NEXT loop handles the calculation in 6 lines. The new term is calculated in line 160 and printed in line 170. The sliding process is done in lines 180 and 190. Note that Al must be slid into A0 before A2 is slid into Al; otherwise, Al will be lost. That, in principle, is all there is to programming recurrence relations.

Forward and Backward Recurrence

Recurrence relations have a property that on first acquaintance seems absolutely incredible: if you go in the "right" direction, you increase the number of significant digits in your answer with every new term. This means that in certain cases you can start out with a completely arbitrary guess and, if you go long enough, end up with eight or nine significant digits in your final result! On the other hand, if you go in the "wrong" direction, you lose digits with each iteration and end up with garbage.

There is nothing at all mysterious about this property. If you think about the Fibonacci series, you will realize

20 April 1981 © BYTE Publications Inc

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that that is exactly what happens there. Starting with two numbers one digit long (0 and 1), you can build up after thirty or forty terms to as many digits as your machine will hold. For this case, we are going in the right direction because the answers get progressively larger as we calculate each new term.

In this case also, we are moving in the direction of increasing index, n. This is called forward recurrence. If we were to start out with a high-order pair of terms and calculate down towards zero, that would be called

Listing 1: The Fibonacci numbers through recurrence. The Fibonacci numbers are used here to demonstrate how easy it is to program a recurrence relationship. All that is necessary is to keep proper order in the calculation and the shifting of variables.

0010 REM

0020 REM *** FIBONACCI NUMBERS

0030 REM *** BY RECURRENCE RELATION.

0040 REM

0100 INPUT "HOW MANY FIBONACCI NUMBERS",N

0110

A0 = 0

0120

PRINT A0

0130

Al = l

0140

PRINT Al

0150

FOR 1=1 TON

0160

A2 = A1 + A0

0170

PRINT A2

0180

A0 = A1

0190

A1=A2

0200

NEXT I

0210

END

Listing 2: A Taylor's series program for the Bessel functions. Lines 160 thru 190 calculate the first term. (Line 160 should not be necessary, but many BASlCs insist on executing a FOR...NEXT loop at least once, regardless of index and target.) This program is not recommended if the argument will ever exceed about five or ten, depending on your BASIC.

0010 REM

0020 REM *** BESSEL FUNCTIONS, FIRST KIND, INTEGER

ORDER

0030 REM **' BY TAYLOR'S SERIES.

0040 REM

0100 INPUT "ARGUMENT", X0

0110 INPUT "ORDER", N

0120 X = X0/2

0130 X2 = X*X

0140 S = 0

0150 T=l

0160 IF N = 0 THEN 200

0170 FOR 1 = 1 TON

0180 T = X/I*T

0190 NEXT I

0200 FOR I = 1 TO 999

0210 S = S + T

0220 T=-X2/I/(N + I)*T

0230 IFSoS + TTHENNEXTI

0240 PRINTS

0250 END

Of the various mathematical functions that can be calculated by recurrence, the ones with the

greatest engineering utility are the Bessel functions.

backward recurrence. For the Fibonacci series, backward recurrence is "wrong" (because you lose significant digits) and forward recurrence is "right" (because you gain them), but for some other functions the reverse is true.

Putting it another way, if you lose digits going one way, it is because (and only because) you are subtracting nearly equal large numbers. Avoidance of that situation is one of the cardinal principles of numerical calculation. In this case, avoidance consists simply of going in the opposite direction, in which case you are adding the numbers instead of subtracting them.

But how do you know which direction to go in? Very simply, look in a mathematics handbook. If that fails, and you have no knowledge of function behavior to guide you, trial and error is a solution. Set the program up for forward recurrence (which usually is easier) and see whether the terms get larger or smaller. If they get smaller, you guessed wrong. (Be sure that the decrease is not just local. Unfortunately, global function behavior must be known before you can be fully certain that you are going the right way.)

Bessel Functions

Of the various mathematical functions that can be calculated by recurrence, the ones with the greatest engineering utility are the Bessel and the Bessel-related functions. This is fortunate because many of these are strictly alternating series with no hope of argument scaling, and large arguments always seem to be the ones of greatest interest.

The family of Bessel functions includes many variations. There are the first, second, and third kinds; integer, fractional, and noninteger orders; and regular and modified types. The related functions include Kelvin, Airy, and Ricatti-Bessel. For now, though, we will be concerned exclusively with regular Bessel functions of the first kind, and of integer order. These arise as solutions of Bessel's differential equation:

x*-pf- + x-&- + (x» - n2)y = 0 dxl dx

This equation appears in a wide variety of engineering and scientific problems, such as heat transfer and membrane vibrations. It also shows up indirectly in the analysis of frequency-modulated signals. Any time cylindrical coordinates are used in analysis, Bessel's equation is almost certain to be involved somewhere. As a consequence of that fact, Bessel functions are also called (particularly in German) cylinder functions.

Let us see where the problem lies in computing these functions by Taylor's series. The Taylor's expansion is:

lm = (t) VJ-r)*(

i!(n + i)!

)

This is clearly a strictly alternating series, and the critical

22 April 1981 © BYTE Publications Ire

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Figure 1: The Bessel function of argument 10 and variable order v. When progamming a recurrence relation, information such as this is needed to determine whether to use backward or forward recurrence. Since the function goes to zero for large orders (values of v), we conclude that we need to use backward recurrence to achieve good accuracy. The Bessel function behaves similarly for other arguments: as soon as the order (v) exceeds the argument (x), the function rapidly declines to zero.

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argument occurs at x = 2. But it is rare that one is satisfied with values that small.

Listing 2 is the program for this series. Keep in mind that the magnitude of the Bessel function can never exceed unity, and see where your machine starts to bomb. If you have double precision, you may want to see how much difference it makes. Recognize, too, that a range of 1038 can be a real limitation. For x = 100, the largest term nearly reaches 1041. Depending on your BASIC, a maximum argument of five to ten is recommended.

Bessel Recurrence Relation

Now to recurrence. The relation we will use is:

/„+1to = (2n/x)]Jx) - J„.i(x)

and the first thing we need to know is which direction to go. This is a recurrence in order, not argument, so the question is whether the function increases or decreases as the order gets larger and the argument stays constant. Figure 1 (from the National Bureau of Standards handbook) answers this clearly. At large positive arguments, the function heads toward zero. This means that, when we want to calculate J„(x) for a given n, we must calculate higher-order values of J(x) and use the recurrence formula to calculate down to order n.

The next problem is where to start. This is quite an involved question, and, unfortunately, there are no established answers.

Let us suppose we want to calculate /8(22). We have to start someplace above eight, but where, and with what? If we knew, for example, 7,8{22) by calculation, we would probably just as easily know /8(22) by calculation and

24 April 1981 © BYTE Publications Inc

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would not need to use recurrence. We will make an arbitrary guess (using it and zero as the two numbers needed to start recurrence) and let the virtues of "right" recurrence provide our significant digits.

However, while it is true that recurrence can provide increased accuracy, this is true only relative to the initial guess, which was arbitrary. This means the result we get may be highly precise but completely inaccurate. What we look for, then, is some way of normalizing, or adjusting, the result. Perhaps somewhere in the process, or in the final answer, there is a clue to what the right output should be. If so, that clue can be used to give us the correct value.

Normalizing Sum

The solution lies in one nice formula:

1 = ]0(x) + 2h(x) + 2h(x) + 2h(x) + ....

If we simply double each even term as we calculate it and add them all together, then subtract one zeroth term (because it is not doubled in the formula), we should get unity. If we do not (and we will not), divide the recurrence result by this sum and out comes a closer approximation to the correct answer.

This does mean, however, that every calculation will always have to proceed all the way to zero order. The formula also tells us how far up we must start: at an order high enough that its contribution to the sum will be negligible.

The full process goes like this: you begin by choosing an argument at random, then finding the highest order that makes a difference in the total sum. If the total sum is greater than 1.00, divide the beginning argument by this

number and repeat the process. The final result should be a beginning argument and an order high enough so that two conditions are true: first, that the next higher-ordeT term does not contribute significantly to the sum; and second, that the sum is approximately equal to 1.00.

You will find that the starting point depends both on the argument and the order of the answer you desire. Larger arguments always require higher starting points, as do higher orders. But the relationship is not simple, and no single equation will fit all points exactly. If the equation must err (and it must), it is best that it do so on the high side, although it should not be too far on the high side.

If the starting point is too low, the normalizing sum is inaccurate, degrading the answer. If it is too high, execution time becomes excessive and you run the risk of exceeding your machine's range. (The sum can grow very quickly.) Note, however, that it is the normalizing sum, not the recurrence calculation, that is the main source of trouble. Recurrence starts with an arbitrary guess anyway and goes in the "right" direction (backward), so accuracy is not an issue here (with one important exception that will be explained later).

Programming all of this—except for the equation derivation—really is not too difficult, but it is messy and time-consuming. Fortunately, it has been gone through by various mathematicians, and formulas do exist for finding the starting order. The results listed will vary, though, depending on the number of significant digits in the particular machine they were developed for.

Table 1 gives the raw data rounded to the next higher even integer of the starting order necessary for ten-place accuracy. This information was compiled by Samuel G Allen of New York on an SR-56 pocket calculator. From

i

1

5

10

15

20

25 30

35 40 45 50 55 60 65 70

75

30

35

30 95 100

0

36

38

5

D 56

64 70 76 86 88 94 98 1C

)4

1

0

116

122 128 134 138

15

22

24

30

36

I

17

24

28

32

36

;

20

26

30

36

38

38

25

30

36

38

42

44

5

D

30

36

40

42

44

46

5

2 56

35

40

44

46

48

48

5

4 58

6

4

40

46

48

50

54

56

5

3 60

6

4 7

0

n

45 50 55

54 58 62

54 58 64

56 60 64

58 62 66

60 64 68

6 6 7

2 64

3 68 D 72

6

7 7

8 7 0 7 4 7

0 7 4 7 8 8

6

8 8 0 8

6 6 8

3

60

66

68

70

72

74

7

3 78

8

0 8

0 8

2 8

6 9

: 9

4

65

70

72

72

76

78

8

D 82

8

4 8

4 8

6 8

8 9

2 9

4 9

8

70

74

76

78

80

82

8

\ 86

8

8 8

3 9

0 9

2 9

4 9

6 10

2 104

75

80

82

84

84

86

8

3 88

9

0 9

2 9

4 9

6 9

3 10

0 10

4 106

1'

0

80

86

86

88

90

90

9

I 94

9

6 9

3 9

8 10

0 10

2 10

4 10

6 108

112

116

85

92

92

92

94

96

9

3 98

10

0 10

2 10

4 10

S 10

3 10

6 10

8 112

116

118

122

90

96

96

98

100

100

10

Z 104

10

4 10

3 10

8 11

D 11

: 11

0 11

2 116

118

120

122 128

95

100

100

102

104

106

10

3 106

10

8 11

D 11

2 11

4 11

3 11

5 11

6 118

122

124

126 130 1C

14

100

104

104

106

108

110

11

D 11

2

11

2 11

4 11

6 11

3 12

D 12

0 12

0 12

2

1J

»6

11

>6

11

?8 1:

32 1C

!4 1:

S8

i

0.1

0.5

1

2

3

4

5

6

7

8

9

10

11

12

0

6

8

10

14

16

18

20

22

24

26

26

28

30

32

1

6

10

10

14

16

18

20

22

24

26

26

28

30

32

2

8

10

12

14

16

18

20

22

24

26

26

28

30

32

4

10

12

12

14

16

18

20

22

24

26

26

28

30

32

n

6

12

12

14

14

18

18

20

22

24

26

26

28

30

32

8

12

14

16

16

18

20

22

22

24

26

26

28

30

32

10

14

16

18

18

20

22

22

24

26

26

26

28

30

32

Table 1: Raw data used by 5 G Allen to derive his equation for the starting order of the recurrence relation.

26 April 1981 © BYTE Publicaeions Inc

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BYTE April 1981 27

Listing 3: Generating Bessel functions by recurrence. This one is slower than Taylor's series for small arguments, but is vastly more accurate for large ones. Within the accuracy range of a machine, no limit has been found on maximum order or argument.

0010 REM 0020 REM ** ORDER 0030 REM *" 0040 REM

0100 0110

0120 0130

BESSEL FUNCTIONS, FIRST KIND, INTEGER BY RECURRENCE RELATION.

INPUT "ARGUMENT", X0 INPUT "ORDER", N

X = X0

IF ABS(X)<1.E

10THENX = 1.E-10

0140 Y = X

0150 IFN>XTHENY = N

0160 N9 = INT(Y + 3*SQR(X) + 9)

0170 J9 = 0

0180 J8=l.E-30

0190 S = 0

0200 FOR I = N9 TO 0 STEP - 1

0210 J7 = 2*I/X*J8-J9

0220 79=78

0230 J8 = I7

0240 IF INT(I/2) = 1/2 THEN S = S + 2*J9

0250 IFI = NTHEN J = J9

0260 NEXT I

0270 S = S-J9

0280 J = I/S

0290 PRINT 7

0300 END

the data, he derived a fairly simple equation which errs conservatively by about ten percent in the region N=4X. The equation is as follows:

N9 = int(max(N,X) + 3-JJC + 9) which is implemented in lines 140 thru 160 of listing 3.

Program Comments

If you have followed the discussion to this point, the program in listing 3 should be straightforward. Lines 140 thru 160 calculate the starting order, and lines 170 thru 190 do the initialization. Note that the arbitrary guess for J8 (]„(x)) is 1.0 X 10"30. It is chosen small (and can be much smaller if your range goes to 10""), so that large arguments can be accommodated without overflowing the normalizing sum. J9 (J„+i(x)) is initialized to zero, which reflects the assumption that the next higher term is too small to be significant.

The recurrence loop (lines 200 thru 260) includes the normalizing sum at line 240. Line 250 picks out the particular order you specified and stores it as variable J.

After exiting from the loop, line 270 subtracts a zeroorder term from the sum, and line 280 divides the chosen value by S to normalize it properly.

One fact has not yet been mentioned: the recurrence relation involves a division by x, so that x = 0 causes an error message. But this is a perfectly legitimate argument at any order, so line 130 assigns a small value instead. It cannot be too small, though, or overflow will occur rapidly because of that division by x.

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Card Cages, Power Supplies, Mainframes, CPU's, Memory, I/O, OEM Variations

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(201) 686-8080

28 April 1981 © BYTE Publications Inc

Circle 22 on inquiry card.

THE DAWN OF A NEW AGE

The 2nd Generation is here!

MEASUREMENT systems & controls proudly introduces its new and exciting "2nd Generation' family of S-100* compatible products. Each has been specifically designed for use with multi-user and network operating systems such as MP/M, CP/NET, and OASIS. Every product is fully tested and burnedin, comes with a 1 year guarantee, and offers you features not currently available from any other source.

Z80 PROCESSOR BOARD — The most powerful CPU board available today. Outstanding features include 4MHz operation, high-speed serial and parallel I/O utilizing DMA or programmed control, eight vectored priority interrupts, and a real time clock.

MULTI-USER SERIAL I/O BOARD — For use in

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'All products meet the new IEEE standards.

Systems

vectored priority interrupts, RS-232C interfaces

with full handshake, asynchronous or synchronous

operation with asynchronous baud rates to 19,200.

Available in four or eight channel versions.

DOUBLE DENSITY

FLOPPY DISK

CONTROLLER BOARD

controls up to four 5Viinch or 8-inch disk drives using IBM soft sectored formats. It features 1K of on-board buffering, DMA controlled data transfers and the performance characteristics of the superior NEC 765 chip.

64K BANK SELECTABLE MEMORY BOARD

Features include I/O port addressing for bank

select with 256 switch selectable I/O ports for the

memory bank addressing. The memory is

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See us at the sixth Computer Faire, booth 1526, San Francisco April 3-5

Altering this program to give a complete array of Bessel functions of various orders for a given argument is easy. Simply define an array of dimension N +1 and start storing values when the variable I becomes equal to N. At the end, each value must be divided by S.

You will find that execution time for this program is quite long. For small x, the Taylor's series is much faster and therefore may be preferred for arguments that are guaranteed restricted. When in doubt, use the recurrence method (listing 3).

Negative Orders

Note from figure 1 that the behavior at negative orders is very different than that of positive orders. So, instead of trying to adapt listing 3 to handle negative N, use the absolute value of N for N and transform the output by the relationship:

Ux) = (-1)" x L(x)

How Accurate Is It?

There is only one practical way to check accuracy on a routine like this: compare the results against known values in a published table. But that creates a problem because available tables give out before the program does. The massive compilation by the staff of the Harvard Computation Laboratory (Harvard: 1947) goes up tox = 100andn = 135.

The most sensitive test, though, is to check in the region of the zeros at various orders. The Bessel functions look like damped sine or cosine waves, crossing zero at

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MTSS provides all of the standard RDOS features for up to 16 users simultaneously and each user is totally independent. Users may edit, compile and execute programs written in FORTRAN IV, FORTRAN V, ALGOL. BASIC, MACS, etc.

This means no software rewriting is necessary. No new operating system need be instdlled. More importantly, MTSS supports all NOVA-'s as well as ECLIPSE"'s so no expensive hardware upgrade is k required.

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The most sensitive test is to check

In the region of the zeros of the

function.

intervals that look as though they might be periodic. (However, they aren't and the exact locations of the zeros is of considerable interest to mathematicians.) Obviously, if you put in an argument that is supposed to be at a zero of the function, you expect to get a result of zero. This is unlikely for two reasons:

• The locations of the zeros are transcendental numbers and cannot be specified exactly. The theoretical result, then, should not be exactly zero.

• Backward recurrence is "right" only when the function increases as you proceed in that direction. But at a zero, the function suddenly nosedives down (see figure 1). Here, (2n/x) X Jn(x) is supposed to equal J„*i(x), so their difference is zero. This is subtraction of nearly equal large numbers, which usually results in a small truncation error.

For the above reasons, all errors and inaccuracies accumulate at the zeros. In particular, truncation errors show up flagrantly here. Not only does truncation cause the output to be nonzero, it actually translates the apparent location of the zero to a lower value. The truncation is not really bad (it usually affects only the last digit), but those interested in the mathematical properties of Bessel functions should be aware that this bias does exist.

With that background, we can state that the accuracy of the program of listing 3 on a nine-digit truncating BASIC is seven to eight decimal digits. Note that I said decimal digits, not significant digits. As far as I can determine, the seventh digit after the decimal point is good to within one count anyplace, including zeros. Away from the zeros, the eighth digit appears good to within one count. This includes any xornup to one hundred, based on spot and systematic checks against the Harvard tables.

Using the Royal Society tables of zeros, further checks can be made under worst-case conditions. For example, the forty-eighth zero of order 19 occurs at

• = 178.846699. The actual output there is 7.6 X 1CT8, which will cause the seventh digit to be off by one count. Worse errors may be possible, but this one is the largest I found.

Other BASICs with fewer digits should have similar properties: about a two-digit loss as long as the range is not exceeded by the normalizing sum. For engineering use, this should be entirely adequate. ■

References

1. Abramowitz, M and I A Stegun. Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables. Washington: National Bureau of Standards, 1964.

2. Harvard Computational Laboratory Staff. Tables of the Bessel Functions of the First Kind. Cambridge: Harvard University Press, 12 volumes, 1947 and following years.

3. Olver, F W J (editor). Royal Society Mathematical Tables, Volume 7: Bessel Functions Part III, Zeros and Associated Values. New York: Cambridge University Press, 1960.

30 April 1981 © BYTE Publications Inc

Circle 23 on inquiry card.

^■>S

^§yj|

■ I

--- i

ml

Ml

Mb

I iia !

■"- "

Atari &Appl< ilc" software.

A financial VP in Massachusetts is cutting the time it takes to prepare month-end reports from three days to three hours.

A California company is replacing most of its time-share computer service with a personal computer and VisiCalc, saving at least $30,000 the first year.

Thousands of other personal computer users are also sold on how VisiCalc is increasing their productivity. Besides saving time and money, they're simplifying their work and getting more information that helps them make better decisions. A typical user reaction comes from a New York dentist:

"VisiCalc has become an integral part of my business'.'

VisiCalc displays an "electronic worksheet" that auto matically calculates nearly any number problem in finance, business management, marketing, sales, engineering and other areas. The huge worksheet is like a blank ledger sheet or matrix. You input problems by typing in titles, headings and your numbers. Where you need calculations, type in simple formulas (+,—, X,-j-) or insert built-in functions such as net present value and averaging. As quickly as you type it in, VisiCalc m\ calculates and displays the results.

"I am extremely impressed with VisiCalc's capability, flexibility and orderly presentation of instructions'.'

So writes the director of a New York corporation. He appreciates VisiCalc's powerful recalculation feature. Change any number in your model and instantly all numbers affected by that change are recalculated and new results are displayed. You can ask "What if.. 7/ analyzing

Commodore is a registered trademark of Commodore Business Machines Inc., Atari is a registered trademark of Atari Inc., Apple is a registered trademark of Apple Computer Inc.

Circle 24 on inquiry card.

more alternatives and forecasting more outcomes. It really increases your decision-making batting average!

When you finish, you can print a copy of the worksheet just as it appears on the screen and/or save it on diskette.

"I like VisiCalc's ease of use'.'

That response comes from a Utah businessman using VisiCalc for production forecasts, financial report ratio analysis and job cost estimating. Ease of use is VisiCalc's best-liked feature. It's designed for a non-programmer, and has an extensive, easyto-understand instruction manual.

Users also like solving a wide variety of problems with VisiCalc . . . and solving them their way. VisiCalc can even justify the cost of a personal computer, according to a New Hampshire financial analyst:

"VisiCalc is paying for itself over and overf'

VisiCalc is available for 32k Commodore PET/CBM, Atari 800 and Apple disk systems. VisiCalc is written by Software Arts, Inc.

See VisiCalc at your Personal Software dealer. For your dealer's name, call Personal Software Inc. at 408-745-7841, or write 1330 Bordeaux Drive, Sunnyvale, CA 94086:

While there, see our other Productivity Series software: Desktop Plan and CCA Data Management System. They're like time on your hands and money in the bank.

See us In Chicago at NCC, booth 881

Programming Quickies

Apple Name-Address

Gary Stotts, 10390 Owens Cr, Broomfield CO 80020

Name-Address is a program that will store up to 100 names, addresses, and telephone numbers. It is written for the Apple personal computer and requires one disk drive. The program is organized as a binary tree so that names can be entered in any order and stored in alphabetical order. A larger number of names and addresses can be stored by changing the DIM statements in lines 30 thru 90.

The program first asks if there is an address file. Next the menu appears as follows:

1 - Add a Name

2 - List a Name

3 - List All Names

4 - Change a Name

5 -End

DISCOUNT PRICES

APPLE II COMPUTERS

16K APPLE II

1089.00

32K APPLE II

1134.00

48K APPLE II

1179.00

DISK W CONTROLLER

545.00

DISK ONLY

475.00

APPLESOFT CARD

159.00

INTEGER CARD

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PASCAL SYSTEM

425.00

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525.00

RAM MEMORY

FOR TRS-80, APPLE I

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BOX OF 10 8" 39.50

FREDERICK COMPUTER PRODUCTS

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(301) 694-8884

The required entries to add or change a name-address record are the name, the street address, the city-state-zip, and the telephone number. To list any one address, enter the name. The name must be entered as last name first with no commas. Option 5, "END", will always create a new name-address file. ■

Listing 1: Name-Address—a program for the Apple II that will store up to 100 entries, as shown here. More entries can be stored by changing the DIM statements in lines 30 thru 90.

DIM NtClOO) DIM A*<100)

DIM B*t100> DIM LUC 100) DIM RY. ( 1 00 > DIM P*(100) DIM 8%C50):

REM REM REM REM

100 1 10 120 130

CHR*

LEFT LINK ARRAY RIGHT LINK ARRAY PHOME * ARRAY STACK ARRAY

PRINT DtT"DPEN NAMAOR.

CALL - 93G: INPUT "IS

IF Y* ■ "N" THEN 200

PRINT D*T"READ NOMADR"

INPUT E

FOR | * 1 TO E

INPUT N*U>! INPUT A*< I )

INPUT B*(I): INPUT P*(1)

INPUT rw. r J )

next

PRINT

CALL

PRINT

PRINT

PRINT

PRINT

PRINT

PRINT

IF Ml

- 93G: print tab

"1 - ADD A NAME"

"2 - LIST A NAME"

"3 - LIST ALL NAMES"

"4 - CHANGE A NAME"

"5 - END"

I INPUT " ENTER YOUR SELECTION

' I DR Ml > 5 THEN 2G0

0.930.1120.1340

NAME/ADDRESS PROGRAM"

n*:ni

PRINT

410 420

430 440 450 460 470

500 510 520 530 540 550 5GO 570 5Bn 590 600 BIO 620 630

ON Ml GOSUB 320.72

GOTO 200

REM

REM (\DD A NAME SUBROUTINE

CALL - 936: PRINT TAB! 7)T"ADD NAME RECORD"

- E + IT REM FIRST EMPTY POSITION IN LIST

- I : REM START SEARCH AT ROOT INPUT "ENTER NAME "TNI*

IF LEN (Nl*) < 1 THEN 350

INPUT "ENTER STREET ADDRESS "Tnt«

IF LEN (Alt) '. 1 THEN 370

INPUT "ENTER CITY-STATE-2IP "IB1*

IF LEN (81*) < 1 THEN 330

INPUT "ENTER PHONE NUMBER "IPl*

REM IF NAME IS LARGER THAN ITH. SEARCH RIGHT BRANCH

IF Nl* > N«(I) THEN S00

IF Nl* < > N«(I) THEN 4BO

PRINT "DUPLICATE NAME"

INPUT "ENTER C TO CONTINUE "IC*

RETURN

REM IF LEFT LINK NOT NULL. SEARCH LEFT BRANCH

IF LX(I) < > 0 THEN I = LY.(I): GOTO 430

REM HANG NEW LEFT LINK ON PRIOR

Y. ( I ) - E

l*(E) - Nl*: REM FILL NEW RECORD

LX(E) ■ 0 RXIE) ■ 0 P*(E) = PI*

RETURN

REM IF RIGHT LINK NOT NULL. SEARCH RIGHT BRANCH

IF RY.(I) < > 0 THEN I » RX(I>: GOTO 430

REM HANG NEW RIGHT LINK ON PRIOR

RX C I ) N*(E)

660 LXIEt G70 RX(E)

Nl*

■ 0

REM FILL

RECORD

6B0 690 700 710 720 730 740 750 7B0 770 760 790

Pli

P*(E)

RETURN

REM

REM LIST A NAME SUBROUTINE

CALL - 936: PRINT TAB( 7K"LIST A NAME/ADDRESS"

PRINT : INPUT "ENTER NAME TO LIST ";N1*

IF LEN (Nl*) < 1 THEN 720 I = 1

IF Nl* > N*(I) THEN 870

IF Nl* < > H*fl) THEN B50

PRINT N* <I>: REM FOUND

PRINT A*(I>

PRINT BS1I)

PRINT P*(I)

PRINT : INPUT "KEY

RETURN

REM SEARCH LEFT

IF LY. II) < > 0 THEN I

REM SEARCH RIGHT

IF RY. ( I) < > 0 THEN I

REM

PRINT "NAME NOT FOUND"

RETURN

REM

TO CONTINUE

L7.( I > : GOTO 7B0

RY.( I I : GOTO 760

Listing 1 continued on page 34

32 April 1981 © BYTE Publications Inc

Circle 25 on inquiry card.

Circle 26 on inquiry card.

d

1

%

Hi*

How to tell if it's a White Computer.

(Users 2 through 16 — multiuser expansion with high performance through distributed processing.)

Look for a single user CP/M® system that expands to multiuser configurations economically.

Look for independent 6 MHz Z80B-based User Modules with 64Kof RAM memory, each module with a port to the user terminal capable of handling baud rates of up to 38K under program selection. Look for high-speed block data transfers from user modules to the Global Processor for disk storage. That way, CP/M programs run independently for each user. Fast. And each users's station acts just like the fastest standalone system — no delays, no waiting for other users.

Look for a Z80-based Global Processor for disk and tape I/O that transfers data from disk to user modules at the data transfer rate of the peripheral device. And a controller that handles as many as 8

SMD disk drives for up to 528 megabytes of hard disk storage, plus up to four 8" floppies, plus optional streaming tape backup.

And look for a Z80-based General I/O Processor that supports up to eight printers — with 64K bytes of independent buffer memory.

That's part of how you tell if it's a White Computer. There's a lot more. Here's a number and address for more information.

CP/N is a registered trademark of Digital Reseach.

Z80, Z80A, Z80B are registered trademarks of Zilog Corporation.

White Computer Company A 1876 Industrial Way Redwood City, California 94063 A 415 364 7570

High Technology

We make our

competition

obsolete

with Information Master.™

Information Master™ is the sophisticate of software packages, but it also speaks your language. Its uncomplicated Englishspeaking design makes it easy to learn. No programming knowledge is necessary. Put it in your Apple II*, and you're ready to go.

High Technology's Information Master organizes and prints everything from mailing lists to stock market data. Specify what records to store, type in the information, and Information Master organizes, calculates, stores and reports. Design your own reports and labels. Information Master is revolutionary in its adaptability and comes with a simple step-by-step instruction manual. Its screen layouts are designed to show you maximum information for easy operation. Information Master is so smart it stops mistakes that our competition lets you make.

If your computer dealer doesn't have Information Master, see one who does.

High Technology's perfect complement to Information Master, Data Master,,Mallows you to change your mind months later

without redoing all the work you've already done. Ask about it!

Technology, Inc.

Software Products Division P.O. Box B-14665 8001 N. Classen Blvd. Oklahoma City, Okla. 73113 405 840-9900

'Apple II is a trade name of Apple Computer, Inc

Programming Quickies.

Listing 1 continued:

920 930 940 T * 950 SX( 3G0 IF 970 T =

EM LIST ALL NAMES SUBROUTINE

■ ULl ■ o:t ■ o: call - 93B

p: rem push stack

0 THEN P - L*/.<P>: GOTO 940

1

990

990

1000

1010

1020

1030

1040

1050

10GO

1070

1090

1090

IF T ' =0 THEN INPUT "ENTER C TD CONTINUE ":C»: RETURN : REM ALL NAME FOUND ' - SX<T>: REM POP 9TACK

PRINT N«<P>: REM PRINT NAME PRINT A*(P> PRINT B*(P> PRINT P*(P) PRINT LI • LI + S IF LI = 20 THEN LI = 0! INPUT "ENTER C TO CONTINUE "!C* I

1 I 30 1140

1 150

' - RV.<P>: REM CHECK FOR RIGHT LINK

GOTO 940

REM

REM CHANGE AN ADDRESS

CALL - 93G: PRINT TAB< 7):"CHANGE A NAME/ADDRESS"

INPUT "ENTER NAME TO CHANGE "INI*

IF LEN (Nl*) : 1 THEN 1120 I * 1

IF NI* '• N*l I ) THEN 1310

IF Nl* ■ > N«tl) THEN tZSO

PRINT "OLD ":A*<I>

input "new ":oi<n

IF LEN (0*<I>) < 1 THEN 1190

PRINT "OLD ";B*(I>

INPUT "NEW ":B*(I>

IF LEN (B*(IH < I THEN 1220

PRINT "OLD "fF*tI>

INPUT "NEW ";p*m

PRINT

RETURN

REM SEARCH LEFT

IF L7. (I 1 < > 0 THEN I ■ I

REM SEARCH RIGHT

IF R'/.(I) ' •• 0 THEN I *

GOTO 11 GO

REM

REM EOJ

PRINT D*T

1350 1360 1370 1380 1390 1400 1410 112

PRI

it D»:

PRINT D«:

PRINT E

FOR I = 1

PRINT NT.( NEXT

PRINT [>*: END

DELETE NAMADR" OPEN NAMADR" 'WRITE NAMADR"

PRINT n*(I 1

PRINT B*tl): PRINT P*( I > : PRINT LRd)! PRINT R«(I]

A Graphic Execution Display

R B Minton, 8617 E Stearn Lake Dr, Tucson AZ 85730

I wrote a program for my Ohio Scientific Superboard to compute artificial satellite orbits and noted it ran slower and slower as time and the number of orbits progressed.

It occurred to me that I could graphically display how fast the program was executing and find out where it was slowing down by adding some extra code. Every 20 lines or so, I inserted K9 = K9 + l:GOSUB 2000, and then at the end:

2000 S9 = 54244

2010 POKE S9 + K9,48 + K9

2020 FORZ = lTO30:NEXTZ

2030 POKES9 + K9,32

2040 IFK9 = 9THENK9=0

2050 RETURN

This flashes the numbers 1 thru 9 from left to right on the bottom row of the video screen every time the main portion of the program loops. You can easily note the delay between certain numbers; this helps to pinpoint where the program is spending most of its time. The troublesome area or line can be further narrowed down by adding more GOSUBs, or by moving those from the faster part to the slower part. (Be sure that there are nine GOSUBs and that each is executed only once within the loop.)

This method alerted me to a poorly written line of code I would have otherwise never suspected. ■

34 April 1981 © BYTE Publications Inc

Circle 27 on inquiry card.

Circle 28 on inquiry card.

TRS-80* Model I Computer Owners . . .

Double-density storage, It's really here!

Here at Percom. And your authorized Percom dealers.

And double-density storage is here in a big way. Because now you can choose from three different levels of mini-disk systems — all double-density rated.

And get the stojrage that precisely meets your application needs.

Not to mention tlje service and quality that's made Percom the industry leader.

Although rated for double-density operation, all levels of Percom drives work equally well in singledensity applications.

You can operate these drives in ordinary singledensity format using TRSDOS* Percom OS-80™ or any other single-density operating system.

Or, you can add a Percom DOUBLER™ to your Tandy Expansion Interface and store data and programs in either single- or double-density format.

Under double-density operation, you can store as much as 350 Kbytes of formatted data — depending on the drive model — on one side of a five-inch minidiskette. That's four times the capacity of standard 35-track Model I minidisks, almost 100 Kbytes more than the capacity of the eight-inch IBM 3740 format!

Available in 1-, 2- and 3-drive configurations in all three model lines, Percom burned-in, fullytested drives start at only $399.

TFD-40™ Drives

TFD-40 Drives store 180 Kbytes (double-density) or 102 Kbytes (single-density) of formatted data on one side of a 40-track minidiskette. Although economically priced, TFD-40 drives receive the same full Percom quality control measures as TFD-100 and TFD-200 drives.

TFD-100™ Drives

TFD-100 drives are "flippy" drives. You store twice the data per minidiskette by using both sides of the disk. TFD-100 drives store 180 Kbytes (doubledensity) or 102 Kbytes (single-density) per side. Under double-density operation, you can store a 70page document on one minidiskette.

TFD-200™ Drives

TFD-200 drives store 350 Kbytes (double-density) or 197 Kbytes (single-density) on one side of a minidiskette. By comparison, 3740-formatted eight-inch disks store only 256 Kbytes. Enormous on-line storage capacity in a 5" drive, plus proven Percom reliability. That's what you get in a TFD-200.

-■/siiiiwj'i.t.i"i''". .•••';. ■ ti.vh.

The DOUBLER™ — This proprietary adapter for the TRS-80* Model I computer packs approximately twice the data on a disk track.

Depending on the type of drive, you can store up to four times as much data — 350 Kbytes — on one side of a minidiskette as you can store using a Tandy standard Model I computer drive.

Easy to install, the DOUBLER merely plugs into the disk controller chip socket of your Expansion Interface. No rewiring. No trace cutting.

And because the DOUBLER reads, writes and formats either single- or double-density disks, you can continue to run all of your single-density software, then switch to double-density operation at any convenient time.

Included with the PC card adapter is a TRSDOS*compatible double-density disk operating system, called DBLDOS™, plus a CONVERT utility that converts files and programs from single- to double-density or double- to single-density format.

Each DOUBLER also includes an on-card highperformance data separator circuit which ensures reliable disk read operation.

The DOUBLER works with standard 35-, 40-, 77- and 80-track drives rated for double-density operation.

Note. Opening the Expansion Interface to install the DOUBLER may void Tandy's limited 90-day warranty.

Free software patch with drive purchase. This software patch, called PATCH PAK,'" upgrades TRSDOS* for singledensity operation with improved 40- and 77-track drives.

Quality Percom products are available at authorized dealers. Call toll free 1-800-527-1592 for the address of your nearest dealer or to order directly from Percom. In Canada call 519-824-7041.

TM , , _ _ _ , Prices and specifications subject to change without notice.

IM trademark of Percom Data Company, Inc.

.nark of Tandy Radio Shack Corporation which has no relationship to Percom Data Company.

PEFQCM

PERCOM DATA COMPANY. INC.

211 N. KIRBY • GARLAND TX • 75042

(214)272-3421

Ciarcia's Circuit Cellar

Build a Low-Cost Logic Analyzer

Steve Ciarcia

POB 582

Glastonbury CT 06033

The Digital Age has spawned a variety of electronic troubleshooting aids, including logic probes, integrated-circuit test clips, multi-trace oscilloscopes, and logic analyzers. All are useful, up to a point, but it is important to know when to use a particular test instrument and how much you can depend on it.

If the logic states of signal lines were the only information needed, a simple voltage measurement would suffice in digital troubleshooting. But timing, rather than absolute voltage level, is the more important consideration in digital systems. Most digital systems operate by setting discrete logic conditions on bus lines and then strobing that data through the system at the occurrence of edges of specific clock pulses. A system operates correctly only if all the parallel states are set correctly at a specific instant in time. The system fails if any single logic state is in error at any clock time during program execution.

Photo 1: One frequently used test instrument is a direct-reading state indicator. The sixteen indicators are transistor-driven incandescent lamps or LEDs (light-emitting diodes). The indicator panel is attached to a "chip-clip" connector so that the logic states on any TTL (transistor-transistor logic) or L5 (low-power Schottky-diode-clamped) TTL dual in-line package can be read while the circuit is energized. The display is most valid for static conditions.

The first special digital instrument was the logic probe. A schematic diagram of a typical logic probe is shown in figure 1. This device accurately indicates the logic state on

LED (light-emitting diode) indicators at any selected point in a circuit. However, it is a static device and will not follow rapidly clocked digital logic other than to indicate general activity. Even when the concept is expanded to include fourteen or sixteen separate indicators on the probe (as shown in photo 1), effective use still depends on stopping the system clock (or slowing it substantially) to examine static logic states. Unfortunately, stopping the clock changes the dynamics of circuit operation and may, in many instances, mask the true cause of problems.

More frequently, digital-logic errors are dynamic and occur during clock-state transitions. The errors are often due to timing problems associated with the propagation of signals through the circuit or with miscuing of multiplexed components. Because the logic state at clock transitions often

Copyright © 1981 by Steven A Garcia. All rights reserved.

36 April 1981 © BYTE Publications Inc

determines either proper operation or failure, a more suitable test instrument would be one that provides the operator with a view of all logic activity coincident with the transition of the clock.

To most people this sounds like a job for a multi-trace oscilloscope with its sweep triggered from the system clock. An oscilloscope can in many instances be of value, but unless it is an expensive storage-tube scope, fast system-clock rates can make viewing difficult. Also, viewing two signals with respect to each other in real time is of little help when the error occurs intermittently and involves more signals than can be viewed simultaneously.

What Is a Logic Analyzer?

One solution to the digitaltroubleshooting dilemma is called a logic analyzer. This is an instrument that displays a "truth table" of the activity of the digital circuit being tested under actual operating conditions. After you have selected a key combination of input signals, called a trigger or sync word, and activated the analyzer, it stores all signal-input logic states for a specific number of

system-clock transitions. Depending upon the sophistication of the particular unit, many commercial logic analyzers can accommodate 32 or more inputs and store up to 256 clock cycles before and after the trigger event.

A logic analyzer acts

like an electronic time

machine.

In effect, a logic analyzer acts like an electronic time machine. When sequentially displayed in the order it was acquired, the stored data can be used to form state tables or timing diagrams of the circuit's operation.

For example, a logic analyzer might be used to troubleshoot a malfunctioning microcomputer I/O (input/output) port that keeps receiving consistent but wrong data. You don't know whether the error is caused by the wrong data being sent to the output register or by an incorrect address signal strobing the register at the

wrong time (try troubleshooting this kind of problem with just an oscilloscope). You can find out by connecting the logic analyzer to the address and data buses of the microcomputer.

Set the trigger-word switches to produce a trigger pulse when the address bus contains the I/O port address. When the trigger pulse occurs, you can examine the logic states on the data bus with the analyzer to see what value was being loaded into the port register at the occurrence of the trigger pulse, as well as those states following the pulse. It is like having an 8- to 32-channel oscilloscope with the display frozen in time on a specific clock cycle.

Commercial logic analyzers are generally stand-alone instruments with integral video-monitor or oscilloscope displays. They can present stored data in a variety of ways. A data-domain analyzer ordinarily displays logic states as lists of Is and Os. The listings are sequential and in either binary, octal, or hexadecimal format. This display method is particularly helpful when you are debugging address-bus problems. In such cases, data is most easily read as

INPUT

+ 5V

Number Type

IC1 74LS14

IC2 74121

+5V GND

14 7

14 7

Figure 1: A simple logic probe that uses two integrated circuits. When a logic-0 signal voltage is applied to the input, the "logic 0" LED will light. When a logic-1 signal voltage is applied to the input, the "logic 1" LED indicator will light. If the input oscillates between the 0 and 1 states, the "Pulse" LED indicator will also light.

April 1981 © BYTE Publications Inc 37

4-digit hexadecimal values.

For hardware troubleshooting, a time-domain analyzer is preferred. This unit presents the stored data in timing-diagram format. The result appears like the display of an 8- or 16-channel oscilloscope. The vertical scale has a high-voltage value that represents a logic 1 and a low-voltage value that represents a logic 0. The

data signals are plotted with respect to each other and can be displayed as a function of actual time.

A third data format is the mapped mode. Essentially, the display screen is divided into an x, y coordinate system, and data points are plotted as dots on the screen. In some units, vectors between dots connect successive data points so that it is easier for an

^^L

\

\

Si

■•

i

%

^^^^^^^^

Photo 2: The prototype logic analyzer described in this article. The switches on the left are for setting the trigger (sync) word.

Photo 3: Inside the box of photo 2 is the circuit of the analyzer as shown schematically in figure 4. Seventeen integrated circuits are used.

operator to trace sequential activity in the device under test. The process of interpreting this kind of display is essentially one of recognizing a "good" pattern and identifying wild vectors. Presumably, a properly operating program will have a repeatable pattern. Any discrepancies will show up as an extra dot or "wild vector."

The various types of logic-analyzer display formats are shown in figure 2 on page 40.

Regardless of the display format, all logic analyzers share a common internal structure. Generally, they incorporate the subsystems outlined in the block diagram of figure 3. All logic analyzers have some form of input conditioning, trigger-word selection and comparison, memory, and display (LEDs, oscilloscope, or rasterdisplay tube, etc). The combination of capabilities is usually a function of price, which can range from $2500 to $10,000.

A Low-Cost Logic Analyzer

Obviously, we cannot hope to construct a logic analyzer that is equivalent to an $8500 HewlettPackard unit. However, we can design a special logic analyzer as a peripheral device of a personal computer. By utilizing the display and processing power of the computer, we can greatly enhance the capabilities of a relatively simple hardware interface. Also, for those readers interested in the concept but not quite ready to grab their soldering irons, I will outline a method that demonstrates how to use your present computer to perform logic-analyzer functions totally in software. First, the hardware approach.

Figure 4 is the schematic diagram of a low-cost eight-input logic-analyzer interface that requires only one and a half parallel I/O ports (9 output and 6 input bits) for complete operation. It is easily expandable to 16 or even 32 inputs.

All probe inputs and clock signals are conditioned through Schmitt triggers to reduce noise and false triggering. When the sync word, set on external switches (SWl through SW8), appears on the input lines, the analyzer automatically collects and stores 16 sequential words repre

38 April 1981 © BYTE Publications Inc

senting input status at the instant of either an internal or external clock signal (usually the system clock). It can operate on either edge of the clock pulse and store data at frequencies as fast as 5 MHz. The prototype interface is shown in photo 2.

Unlike commercial logic analyzers, this unit has no integral CRT (cathode-ray tube) display: it has eight externally controlled LEDs. It depends instead upon the computer to display the list of stored data. After the interface has taken sixteen samples, it sends a Scan Complete signal to the computer. A computer program sets the Read/Write line to the Read mode and sets a 4-bit address to access the contents of the 16-word scratch-pad memory. As the 4-bit address is incremented, the appropriate 8-bit output is placed on the analyzer's data-output lines from the scratch-pad memory and is stored by the computer. In addition, as the computer reads the scratch-pad memory, the contents of each location are displayed on eight LEDs. If the addresses are changed slowly, or are otherwise physically set, the 16 stored words can be viewed directly without a special display program.

Once the data has been acquired by the computer, a format-and-display program lists the values on the computer's display in binary, octal, or hexadecimal format, simulating a commercial analyzer display. To gather an additional 16 words, the computer program merely sets the Read/Write line to the Write mode and toggles the Sample Enable line. The BASIC program in listing 1 on page 43 exercises the interface and displays the output shown in listing 2.

Inside the Interface

The analyzer hardware (shown in photo 3) has an interface consisting of seventeen integrated circuits. Input signals are fed through IC1 and IC2, which are hex Schmitt-trigger inverters. Photo 4 shows typical test connections. These conditioned outputs are in turn buffered and gated through to the memory section by IC3, a type-74LS240 8-input bus driver. The output of this driver is compared to eight preset switches through two 74L85 4-bit comparators (IC7 and IC8). (Trigger-word initiation is disabled by setting all switches to the logic-1 state. Storage will com

mence on the first clock pulse after Sample Enable.) If the switch settings and data input are equal, a pulse is generated which stores the current input data. The first word stored is usually the sync word (assuming that the trigger word and external clockpulse edge are synchronous).

On the trailing edge of the WE (memory-write-enable) pulse, the 4-bit memory-address counter IC9 is incremented. Data will be stored again at the occurrence of the next edge (positive or negative as selected) of the clock pulse.

Text continued on page 42

Photo 4: The analyzer is intended for use while a circuit is in dynamic operation. Connection to the circuit can be done with the "chip-clip" method shown in photo 1, or by using separate test probes. The latter is more versatile. The circuit shown under test is the Disk-80 expansion interface from last month's Circuit Cellar.

Photo 5: When the circuit of figure 5 (on page 42) is attached to the logic analyzer, a data-domain display can be converted to a time-domain display. Essentially nothing more than an eight-channel scope multiplexer, this circuit greatly expands the display potential of the average oscilloscope, as the photo demonstrates.

April 1981 © BYTE Publications Inc 39

(2a)

(2b)

(2c)

(2d)

Figure 2: The data acquired by a logic analyzer can be displayed in various formats. The different types are:

(2a) The ones and zeros logic-state display. In this format, binary words are plotted against clock pulses in a matrix m bits wide by n clock pulses deep. This format is used most often where word flow or data sequence is of prime concern.

(2b) Same as 2a except that the data is listed in hexadecimal notation. Hexadecimal listings are most frequently used in logic analyzers specifically designed for microprocessor troubleshooting, where thirty-two to forty inputs are not uncommon.

(2c) The timing-diagram display. In the timing format, data words are plotted against time. This format is used most often for hardware troubleshooting to detect incorrect timing between signals.

(2d) Vector-display analyzer. In the vector-display format, data words define points on an x, y coordinate system. Usually, the data word is divided in half with a separate D/A converter attached to each segment. One output goes to the display's x input and the other goes to the y input.

INTERNAL CLOCK

EXTERNAL CLOCK

o

o

EIGHT

TTL

LEVEL

INPUTS

ooo

oo

INPUT CONDITIONERS

TRIGGER WORD

SELECTION SWITCHES

DISPLAY I

MEMORY

COMPUTER

WORD

COMPARATOR

AND

TRIGGER

CIRCUITRY

c

SAMPLE AND READ CONTROL

Figure 3: Basic block diagram of the simple logic analyzer. In this case, the block labeled "computer" refers to an externally attached personal computer. In commercial units, the computer and display are integral components of the logic analyzer.

40 April 1981 © BYTE Publications Inc

Figure 4: Schematic diagram of an eight-input logic analyzer. One and a half parallel I/O ports are required for operation. Note that the 74L85 integrated circuits used here have a different pinout specification from the 74LS85. User connections are on the left; computer connections are on the right.

April 1981 © BYTE Publications Inc 41

Number

Type

+ 5V

GND

IC1

74LS14

14

7

IC2

74LS14

14

7

IC3

74LS240

20

10

IC4

7489

16

8

IC5

7489

16

8

IC6

74LS157

16

8

IC7

74L85

16

8

IC8

74L85

16

8

IC9

74LS93

5

10

IC10

74121

14

7

IC11

NE555

8

1

IC12

74121

14

7

IC13

74LS74

14

7

IC14

74LS02

14

7

IC15

74LS20

14

7

IC16

7416

14

7

IC17

7416

14

7

Table 1: Power connections

for in

tegrated circuits of figure 4,

on page

41.

Text continued from page 39:

When sixteen samples have been taken, the 4-bit memory address is binary 1111. IC13 and IC14 detect this condition and set the Scan Complete line to a logic 0. This also disables further storage until the interface is reset with a Sample Enable pulse to IC2.

Reading the contents is simply a matter of setting the Read/Write line to a logic 0 and placing an appropriate 4-bit address on the Read Address input lines. When an address is set on these lines, the data-output lines of the analyzer will contain the contents of that memory location. The eight LEDs will also display that value.

Creating a Time-Domain Display

As previously mentioned, the display format available from this interface is generally a listing of Is and 0s. This is quite useful under most circumstances but not as appealing to hardware buffs as a timing-diagramtype output. Even if your computer has graphics capability, writing a program to simulate a multi-trace oscilloscope display requires considerable software expertise.

The logic-analyzer interface can be converted to a time-domain display with relatively little extra hardware and only a single-line BASIC program. Figure 5 is the schematic diagram of the additional circuitry. Essentially, it consists of a dual 4-input digital multiplexer and 2-bit D/A (digital-to-analog) converter, which offsets each of the four channels when displayed. In effect, it

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03 u-> ""*■ "" "O 7- i

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Figure 5: Eight-channel display multiplexer, which facilitates display of eight TTL inputs on a standard dual-trace oscilloscope. Its intended use is to convert the datadomain output from the circuit of figure 4 into a time-domain display on an oscilloscope.

42 April 1981 © BYTE Publications lnc

allows a dual-trace oscilloscope to display eight channels simultaneously. Such a display appears in photo 5.

Conversion from data-domain to time-domain operation is not as difficult as it might seem. Consider the operation of the analyzer for a moment. Once the 16-word buffer is full, the data can be read out at any rate. If we cycle the read addresses very quickly, the outputs will form a repetitive pattern which can be easily viewed on an oscilloscope. The fast cycling can be accomplished using a 4-bit counter and oscillator source attached to the address-input lines or by using a simple program statement like:

100 FOR X = 0 TO 255:OUT 16,X: NEXT X: GOTO 100

Using a dual-trace oscilloscope, you can view two signals, or, with the circuit of figure 5, you can view all eight data channels simultaneously. Since there is no system clock to contend with and the pattern repeats every sixteen steps, triggering problems are reduced and the display is stationary. All other interface operations remain the same.

Adding a Vector-Display Capability

If you are determined to hunt "wild vectors," the same technique employed to provide a timing plot lends itself to vector display. Using the same methods to cycle the buffer data on the output lines of the analyzer, substitute D/A converters for the multiplexer in figure 5. Typically, two 4-bit D/A converters are needed. One would be attached to the 4 highorder bits and the other to the 4 loworder bits. One D/A converter is attached to the x-axis scope input and the other to the y-axis input. When the buffer is cycled, a unique vector pattern will appear on the screen, describing the 16 data words stored in the analyzer's buffer. (A more informative discussion on this approach to troubleshooting was one of my previous articles, "A Penny Pinching Address State Analyzer," February 1978 BYTE, page 6. It has been reprinted in Ciarcia's Circuit Cellar, Volume I, available from BYTE Books.)

Listing 1: A BASIC program that exercises the computer/logic analyzer interface, displaying output through the computer's normal output devices.

100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450 460 470 480 490

REM Logic Analyzer Program

REM

REM data in on port 16, scan complete on bit 0 of port 17

REM read enable and sample enable are bits 6 and 7

REM of port 16

REM read address is bits 0 thru 3 of port 16

REM memory locations 25000 to 25015 is set aside as the data

REM buffer

PRINT"LOGIC ANALYZER"

PRINT:PRINT"Enable New Sample or List Analyzer Buffer";

PRINT" (E or L)

INPUT A$

IF A$ ="E" THEN 250

IF A$ ="L" THEN 380

GOTO 190

REM Enable Logic Analyzer and take 16 readings

REM pulse sample enable line and set read/write line=0

OUT 16,255:OUT 16,0: OUT 16,255

REM

REM test scan complete line

IF INP(17) =255 THEN GOTO 300

REM when scan is completed store readings in table

FOR S=25000 TO 25015

N=S-25000

REM set read address and store analyzer output

OUT 16,N :A=INP(16):POKE S,A

NEXT S

GOSUB 3 80

REM Ones and Zeros data-domain display routine

PRINT:PRINT

D3 D2 Dl DO" :X=PEEK(S)

PRINT"D7 D6 D5 D4

FOR S=25000 TO 25015

FOR N=7 TO 0 STEP -1

W=X AND 2"N

IF W>0 THEN PRINT"1

IF N=4 THEN PRINT"

NEXT N

PRINT" SAMPLE #";S-24999

NEXT S

GOTO 190

ELSE PRINT"0

READY

Listing 2: Sample output produced by the program of listing 1.

RUN

LOGIC ANALYZER

Enable New Sample or List Analyzer Buffer (E or L) ? E

D7

D6

D5

D4

D3

D2

Dl

DO

0

0

0

0

1

1

1

0

SAMPLE

#

1

1

1

0

1

0

1

0

1

SAMPLE

#

2

0

0

1

1

1

0

1

0

SAMPLE

#

3

1

0

0

0

1

0

0

0

SAMPLE

#

4

0

0

0

0

0

0

0

1

SAMPLE

#

5

1

1

1

1

0

1

0

1

SAMPLE

#

6

1

1

0

0

1

1

0

1

SAMPLE

#

7

0

0

0

1

0

0

0

0

SAMPLE

#

8

0

0

0

1

0

1

1

0

SAMPLE

#

9

1

1

1

1

0

0

0

1

SAMPLE

#

10

1

1

1

0

0

0

1

1

SAMPLE

#

11

0

0

1

0

0

0

1

0

SAMPLE

#

12

1

0

1

0

0

1

1

0

SAMPLE

#

13

0

0

0

0

0

0

0

1

SAMPLE

#

14

0

0

0

1

1

1

1

1

SAMPLE

#

15

1

1

0

0

1

1

0

1

SAMPLE

#

16

Enable New Sample or List Analyzer Buffer (E or L)?

April 1981 © BYTE Publications Inc 43

c

BEGIN

J

SET STORAGE BUFFER POINTERS AND TRIGGER WORD

SET SAMPLE-RATE TIMER VALUE

INITIALIZE PIA AND CLEAR STORAGE BUFFER

READ PIA PARALLEL INPUT PORT

STORE INPUT WORD

INCREMENT

BUFFER

POINTER

Q

EXIT TO DISPLAY PROGRAM

D

READ PIA PARALLEL INPUT PORT

Figure 6a: Flowchart of a software logic analyzer. Using a Motorola 6820 PIA (Peripheral Interface Adapter), this sequence of operations is all that is required to demonstrate logic-analyzer functions in software. This method is limited in speed of operation by the execution time of the program.

v ANALYZER / INPUTS

<CH CLOCK <^]GND

Figure 6b: Pinout chart of the Motorola 6820 PIA used by the algorithm of figure 6a.

Logic-Analyzer Functions Created Through Software

While I generally prefer to demonstrate hardware interfaces in my articles, the functions of a logic analyzer can easily be simulated in software if data-acquisition speed (under 20 kHz) is not critical. While it may not be appropriate for testing microcomputer bus signals, it should work for slower applications.

Figure 6 is a flow diagram outlining the specific steps involved in accomplishing this function. While any existing parallel input port will suffice, the Motorola 6820 PIA (Peripheral Interface Adapter) shown has a separate clock input, which greatly facilitates proper timing.

In Conclusion

As digital hardware becomes more complex, the instruments used in troubleshooting and debugging these circuits must themselves become more sophisticated. This sophistication, however, need not always be provided in the form of a commercially produced test instrument. Often the solution can be intelligent application of existing equipment with limited modifications.

The logic analyzer I have described can be used for all types of troubleshooting and testing of digital circuits. However, its true flexibility is revealed when the instrument captures the extremely fast data flowing in a microcomputer and generates a stationary timing diagram with the results. Built from scratch, combined with an oscilloscope, and exercised by a computer, this interface costs only a fraction of the price of commercial analyzers, yet approximates many of their features.

Next Month:

Build a remote-controlled motorized moving platform. ■

Editor's Note: Steve often refers to previous Circuit Cellar articles as reference material for the articles he presents each month. These articles are available in reprint books from BYTE Books, 70 Main St, Peterborough NH 03458. Ciarcia's Circuit Cellar covers articles appeating in BYTE from September 1977 thru November 1978. Ciarcia's Circuit Cellar, Volume II presents articles from December 1978 thru June 1980.

44 April 1981 © BYTE Publications Inc

Development Software

For Texas Instruments TM990 Micro Modules

v«

<0»

ei*

*<■*

Eyring Research Institute, Inc., authors of Tl's POWER BASIC® and UNIVERSITY BASIC®, is pleased to release development software for use on the TM 990 microcomputer modules. PDOS/ EXPRES® is a powerful multi-user, multi-tasking operating system designed for development, scientific and industrial applications.

The PDOS/EXPRES® system includes:

• 8k byte PDOS multi-tasking operating system

• Advanced EXPRESS BASIC language interpreter

• Stand alone run module support

PDOS supports up to 16 concurrent user tasks with prioritized round robin clock swapping. Up to 32 contiguous or noncontiguous files can be simultaneously open in sequential, random, shared and read only access modes. Large or small floppy disks, bubble memory, hard disks

"After having worked with PDOS and EXPRES for the past three months I have found them to be a powerful and versatile combination. The true multi-user, multi-tasking capability has made it a pleasure to use in our labora tory environment where programs are being used simultaneously for controlling laboratory apparatus taking and reducing data. . .We are enthused by the product. . ."

Tom Ochs

Assistant Research Professor

Desert Research Institute

and extended memory capabilities of up to 256k bytes are handled by the operating system. Named files on 256 directory levels are easily accessible from EXPRES BASIC and assembly language programs. Disk files are time stamped with date of creation and last update. I/O drivers are a simple extension to the PDOS file structure.

The EXPRES BASIC interpreter uses advanced interpreting techniques which approach execution speeds of common threaded code compilers while maintaining the highly advantage

ous interactive approach to program development. Other features include:

• Multi-line recursive functions with local variables

• Variable names of unlimited length

• Reverse Polish pseudo-source token storage

PDOS/EXPRES® is available for either an EPROM based system or a RAM based system. A handsome 250 page Operator Reference Manual walks you through the features and use. All for an attractive price of $1500.00*.

Order your PDOS/EXPRES1158 software from your nearest authorized Texas Instruments distributor or contact Eyring Research Institute, Inc. for further information and a free color brochure. Write or call Eyring Research Institute, Inc., Software Marketing Dept., 1455 West 820 North, Provo, Utah 84601, phone (801) 375-2434.

Eyring Research Institute, Inc.

*U.S. price, subject to change without notice

Circle 29 on inquiry card.

BYTE April 1981 45

System Review

The Micro Ace Computer

Delmar Searls, 1825 S Johnstone, BartlesvUle OK 74003

About the Author

Delmar Searls is a professor of mathematics at BartlesvUle Wesleyan College, BartlesvUle, Oklahoma. His interest in microcomputers is a result of both professional and personal experience: he learned BASIC programming by using a PET microcomputer on the job; at home, he taught himself electronics, beginning with the basics, and continuing through digital electronics and microprocessors. His interest in the MicroAce was sparked by the remarkably low price.

The MicroAce is a small, Z80-based microcomputer in kit form. When completed it measures 23.2 cm by 18.8 cm by 4.1 cm (9% inches deep, 7% inches wide, and 1% inches high). It features an integer BASIC in ROM (readonly memory), touch-sensitive keyboard input, cassette I/O (input/output), and video output through an onboard UHF modulator. The video display consists of 24 lines of 32 alphanumeric and graphics characters.

The kit comes in two forms, depending on the amount of user-programmable memory purchased. For $149 (in

Name

Memory

MicroAce (kit)

4096 bytes of ROM

1024 bytes of pro

Manufacturer

grammable memory

MicroAce

1348 E Edinger

Mass Storage

Santa Ana CA 92705

Cassette tape recorder

(714) 547-2526

supplied by user

Price

Other Features

$149 (with 1 K bytes

Touch-sensitive

of programmable

keyboard, RF

memory)

modulated output

(UHF channel 35),

Dimensions

display of 24 lines by

23.2 cm by 18.8 cm by

32 characters

4.1 cm (9y8 inches by

7% inches by 1% in

Documentation

ches)

Teach-yourself BASIC

manual (67 pages)

Processor

Z80, 8-bit

Audience

Anyone who wants an

System Clock

inexpensive microcom

Frequency

puter

3.25 MHz

eluding shipping) you get a unit with 1 K bytes of programmable memory, expandable to a maximum of 2 K bytes with the purchase of an upgrade kit for $29. You can save $9 by buying the second version of the kit for $169.

Depending on the sources available, you can save even more by buying the 1 K-byte kit and purchasing the extra components from local or mail retailers. You would need to buy three integrated-circuit sockets, two memory circuits, a 74LS32 integrated circuit, and one capacitor.

If my experience is typical, you can expect to wait about a month for your MicroAce to arrive if you mail your order; less if you order by phone.

Construction

The advertisement for the MicroAce (as it appeared in BYTE and in other magazines) states that you will receive a "teach-yourself BASIC manual" and that "a hardware manual is also included with every kit." This is not correct. There is no hardware manual supplied with the kit, only the BASIC manual which includes a section entitled "Construction," preceding the first chapter.

The assembly instructions are very general and, in my opinion, not quite sufficient for those who have no ex

Photo 1: The MicroAce kit as shipped. Starting at the bottom and moving clockwise around the main circuit board are: the discrete components, the integrated circuit sockets, the integrated circuits themselves, voltage regulator, power supply, UHF modulator, antenna switch box, cable materials, and black plastic case. The 8- by HVi-inch instruction manual gives an indication of the size of this computer.

46 April 1981 © BYTE Publications Inc

perience in circuit-board kit construction. There are no guidelines for proper soldering techniques and no stepby-step instructions that are commonly found with kits from the larger kit manufacturers.

Component values are written in a rather unusual notation. For example, a resistance of 470 ohms is written 470R, 1000 ohms is written 1K0, 2200 ohms is written 2K2, 47,000 ohms is written 47K, and 1,000,000 ohms is written 1M0.

There is a logical pattern to the notation, but it is different from that which is normally used. I suspect that the notation is British, since the MicroAce is essentially the kit version of the Sinclair ZX80, which is made in England.

Another unusual practice is the frequent listing of capacitance in nanofarads rather than picofarads. While this notation may be unusual, it should not cause any real problem as color codes and identifying marks are also listed for the various components.

The smaller components are packaged in plastic bags, while the larger items are packed loose (see photo 1). There were no missing parts, and, in fact, I received three extra resistors and one extra capacitor. There was a moment of concern when I discovered that the parts list called for eleven diodes and only nine had been supplied. A close inspection of the circuit board, however, revealed that only nine were required.

The circuit board is double sided with holes soldered through. Component locations are indicated by white outlines and white identification labels on the component side of the board (see photo 2). Component type and value is determined by cross-referencing the identification label (R2, C12, U8, etc) with the parts list.

The actual assembly is straightforward and very easy, especially for those familiar with circuit-board projects. The construction notes suggest that components be soldered to the board in the following order: sockets for the integrated circuits, discrete components, cable sockets, voltage regulator, and the video modulator.

Next, the integrated circuits can be installed. Be sure to follow the appropriate precautions when handling the MOS (metal-oxide semiconductor) devices, which include the Z80, two programmable-memory chips, and the ROM circuit. At this point the unit can be tested for proper operation. The last stage in construction, following successful testing, is the installation of the unit in its case (see photo 3).

The 1 K-byte version of the kit does not provide the sockets for three circuit locations. (These are supplied with the upgrade kit.) I suggest that anyone building this version use masking tape to identify these locations prior to construction. Otherwise, it would be easy to install a socket in one of these locations, only to come up short later on. Once a socket is soldered in, it is practically impossible to remove.

There are no instructions given for the preparation of the cables that will attach your television and cassette recorder. You are provided with about 10Vi feet of shielded cable, two phono plugs, and four mini-jacks. As simple as this task may appear, more instructions should

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<t» .<•; SAVE BUN CONI HEM If INPU' W»Nt

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UTAH i.;li> ■./.'SUB Hi I NEXI

Photo 2: Component side of the main circuit board. Note that component locations are clearly marked, and that the keyboard is an integral part of the printed-circuit board.

■

IS

OEM

cts

GOfeUB

«£«

«*r

a* ak

Photo 3: Completed MicroAce with cables.

April 1981 © BYTE Publications Inc 47

ao PRINT

gOPR CO DISPLAY I

©O PRINT "« MICROftCE COMPUTttft'

©O PfiMENT notice: THAT ft ncu

©O PRINT "PPOGPOM LINE IS

soil

HO PRINT "BOTFITfflBBL

140U ISO

iVO PRINT

NOT AND THEN TO

4.0 <>> c> HOME HUBOUT

■ ■■■■

NEW 10*0 SAVE RUN CONT HEM IF INK)' PRINT

LIST STOP DIM TOW SOTO POKE RAND LET

GLEAM l-LS aOSUB MET NEXT

OUOTP.TION MftRKa..fflB

Photo 5: Layout of the MicroAce keyboard. Note that each BASIC keyword is associated with a specific key.

Photo 4: Sample program displayed on a standard color television set. The current program line is 180, as indicated by the reverse-video cursor.

have been given to aid the inexperienced builder.

The fastenings provided for attaching the circuit board to the lower half of the case, and for fastening the upper half of the case to the lower, are plastic devices referred to as "rivets." In my opinion, these fasteners are inadequate. In fact, the rivet at one circuit-board location was useless and kept popping out. To remedy the problem, I used a fine round file to enlarge the holes in the plastic case, and substituted small nuts and screws for the rivets. Plastic washers were used to prevent the circuit board from becoming marred.

The keyboard appears to be built up with two layers. The bottom layer consists of the front one-third of the circuit board, while the second layer is laid on top and seems to be secured with some sort of adhesive. This is done by the manufacturer, not the kit-builder.

On my unit, this overlay was positioned slightly too far to the left, so that I had to press the right edge of the key, rather than the middle, to get a response to the keyboard entry. In addition, some keys require considerably more pressure than others. These factors, plus the fact that no audio or tactile feedback is given to indicate a successful keyboard entry, make the keyboard a little frustrating to use.

Program Entry

The output of the modulator is received on or near channel 35 on a regular television set. I used an RCA 13-inch color set and had no trouble obtaining a good display. With the controls set for normal reception of commercial broadcasts, the display appears as white characters on a gray background. If desired, white letters on an almost black background can be obtained by adjusting the contrast and brightness controls (see photo 4).

On power-up, the display is blank with the exception of a reverse-video "K" at the lower-left corner of the screen. Whenever this reverse K appears, a nonshifted

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48 April 1981 © BYTE Publications Inc

Circle 30 on inquiry card.

Circle 31 on inquiry card.

dt

H89

Here's the easy way to write your own programs.

Heathkit Self-Study Courses give you a complete command of computer language, so you can write the programs that do your specific tasks. Choose from four programming languages.

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Tests at the end of each unit assure your understanding before proceeding to the next unit. In most courses your reading is reinforced by cassette tapes, so you see and hear, for more thorough learning.

Hands-on programming exercises

You learn by doing, not just reading. Special exercises guide you through the steps of designing and writing your own programs for your computer. Upon completion of the courses you'll be able to tailor existing programs to your specific needs, or write your own original programs from scratch.

Recommended for college credit

Many Heathkit Courses are now recommended for college credit by the American Council on Education. If you can't go back to college, now you can bring college home to you.

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Details and prices on the complete line of Heathkit Self-Study Courses on computer and electronics subjects are in the new, free Heathkit Catalog. Send for yours today or pick one Up I at your nearby Heathkit Electronic Center.

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BASIC": easiest-to-learn, hobbyist's language PASCAL'': sophisticated, easy-to-use language COBOL": the businessman's language ASSEMBLY: very efficient, very precise language Coming soon: FORTRAN" and Microsoft'" BASIC"

Write to Heath Co.,

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Visit your Heathkit Store

Heathkit products ■» " are displayed,

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keyboard entry from the bottom three rows of keys (see photo 5) will result in a BASIC keyword being printed on the screen.

Keywords (and thus the use of a reverse K) are BASIC commands which are stored in a single byte of memory but are spelled out on the screen. For a list of these keywords, as well as other BASIC commands and functions, see table 1.

Nonshifted keyboard entries from the top row are printed as numeric characters for the line numbers (which must be between 1 and 9999, inclusive). As a line number is entered, the reverse K will shift to the right, one space at a time. As long as the reverse K is on the screen, any shifted-key input (other than an editing command) will result in a syntax error. Commands entered without a preceding line number are executed immediately in the "command mode."

After entering a line number, press the key corresponding to the BASIC keyword with which your program line is to begin. Every program line must start with one of these keywords. For example, in some forms of BASIC, the LET keyword is optional, and "10 LET A = 5" can be written "10 A = 5". This is not possible with the Micro Ace.

Following the entry of a keyword, the reverse K cursor changes to a reverse L, signifying that you are in the letter mode and that keyboard entries will be interpreted as regular alphanumeric or graphics characters. As you type in a program line, the system monitor checks for syntax errors after each character is entered. A line contains a syntax error if, in its present form, the line is incorrect or incomplete. Suppose you wish to enter the following line:

SINGLE

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4MHzZ80ACPU CP/M 2 operating system 64K 200ns main memory 6K 300ns video memory 8-inch dual floppy drives

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Quantity discounts are available. OEM inquiries are invited. Please contact:

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20 PRINT 'THE FINAL SUM IS "; A

The PRINT command is entered by pressing one key (the letter O) because the machine is in its keyword mode at the start of each new line. Immediately following the entry of the first set of quotation marks, a reverse-video S (for syntax) appears to the right of the reverse-L program cursor. This does not indicate that an error has been made, but rather that the line is incomplete. As the literal

Keyword Commands

Keyboard

Comments

Abbreviation

CLEAR

Set all variables to zero

CLS

Clear the screen

CONT

Continue

DIM

Dimension (one-dimensional arrays)

FOR

GOSUB

GOTO

IF

INPUT

LET

LIST

LOAD

Cassette input

NEW

NEXT

POKE

PRINT

RAND

Randomize

REM

Remark

RET

Return

RUN

SAVE

Cassette output

STOP

String Functions

Function

Comments

CHR$(/V)

Return character or keyword string corre

sponding to decimal code N.

CODE(S)

Return decimal code number of first

character in string S

STR$(/)

Convert the integer / into its corresponding

string representation.

TL$(S)

Delete the first character from string S.

Other Functions

Function

Comments

ABS(N)

Return absolute value of N.

PEEK(/V)

Return decimal value stored in memory at

address N.

USR(/V)

Start machine-language routine at address

N.

Return a random number between 1 and N

RND(W)

if N is positive.

Logical Functions

Function

Comments

AND

Check to see if two or more conditions are

met simultaneously.

OR

Check to see whether any one of two or

more conditions is met.

NOT

The opposite of a stated condition is tested.

(These logical functions have additional uses which cannot be

detailed here.)

Arithmetic Operations

+

Addition

—

Subtraction

*

Multiplication

/

Division

* *

Exponentiation (2**3 = 2*2*2 = 8)

Table 1: Commands and functions available in MicroAce in

teger BASIC,

with comments at selected points. The manual

supplied with the kit provides a more detailed explanation.

50

Circle 33 on inquiry card.

Solution \s6Jlii-shun\n[ME,fr.MF,£r.L solution-] la: An answer to a problem.

At last there's a microcomputer designed to solve your business' problems, not create new ones. In delivery for close to three years, the MicroDaSys Millie™ is a proven hardware clesign that now comes with the fantastic SoftwareHows™ DBI Accounting Solutionware™you've seen advertised -- a $2500 dollar value alone! This is one computer that's complete when you buy it, right down to the best applications software available. There are no "required options". And we've got all the best features: Z-80, 64K, CP/M1, dual double density 8" floppies for 1MB on line storage, 82x24 CRT with special features, IBM format keyboard with numeric pad, NEC 55cps letter quality printer, S-100 bus. Also, Millie is supported by a nationwide rep network and one of the best service contracts in the business. And Millie is price competitive with much smaller computers. Why settle for less than the best? Call or write today for flyers and manuals. You'll be glad you did.

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■■■H

SYSTEM VARIABLES (40) (eg: POINTERS)

PROGRAM

VARIABLES

END OF VARIABLES (2)

WORKING SPACE

DISPLAY FILE

SPARE

STACK

16384

AVAILABLE ON KEYBOARD AVAILABLE USING

AND USING CHRS CHR$ ONLY

Figure 1: Map of the programmable memory in the MicroAce computer. Fixed boundary addresses are given in decimal; the other boundaries are variable. Numbers in parentheses give the size of a fixed block in decimal bytes.

string is entered, the reverse LS moves to the right as a double cursor. When the second set of quotation marks is entered, the reverse S disappears because the line now has the correct syntax.

Consider a second example. You wish to enter the line:

125 LET 1 = 1 + 1

but inadvertently type:

125 LET 1 + 1 = 1

This line would not be accepted because it contains a syntax error. The reverse S cursor would be located directly after the + symbol.

Notice that in this case the reverse S does not follow the reverse L cursor, but remains at the point where the error occurred. In the case of multiple errors, the reverse S will always be located at the first error contained in the line. When this error is corrected, the reverse S moves to the second error, and so on.

As indicated above, no line containing a syntax error will be accepted into a program. This guarantees that every line in your final program is complete and free of syntax errors. It does not, of course, prevent errors of logic. When a line is complete and correct, it can be entered into a program by pressing the NEWLINE key—the MicroAce equivalent of a RETURN key.

As a line is entered into a program it is placed into memory in two places. First, it is placed into the program storage area, which begins at decimal address 16424. (See figure 1 for a simplified map of the programmable memory.) It is also relocated in the display-file section of memory so that it appears on the upper portion of the screen.

E

H E

a

H

H

Figure 2: Graphics symbols available with the MicroAce. Note that the first ten symbols are addressable from the keyboard, while the second ten are their reverse-video images, available only through the use of the CHR$ function in BASIC.

Recall that on power-up the reverse K was at the lower left and that line entry was done at the bottom of the screen. As new lines are entered they appear in numerical order. The most recently entered line is identified by a line cursor (a reverse video >).

A line entered with a number between those of two previously entered lines is placed in the appropriate position on the display, and the line cursor is moved to its location. When the screen is full, the addition of new lines causes the program listing to scroll up, always leaving the most recently entered portion on the display.

This method of using programmable memory for both program storage and display storage leads to problems. In some systems, the video-display memory is dedicated, meaning that an advertised 1 K bytes of programmable

52 April 1981 © BYTE Publications Inc

Circle 34 on inquiry card.

Most small system users think all microcomputers are created equal. And they're ight. If you want performance, convenience, styling, high technology and reliability (and vho doesn't?) your micro usually has a price ag that looks more like a mini. It seems big lerformance always means big bucks. But rat so with the SuperBrain!

Standard SuperBrain features include: twin double-density 51/4" drives which boast nearly 350,000 bytes of disk storage - expandable :o 10 megabytes. A full 64K of dynamic RAM. A CP/M* Disk Operating System to nsure compatibility to literally hundreds of application packages presently available. And, a 12" non-glare, 24 line by 80 column screen.

You'll also get a full ASCII keyboard with an 18 key numeric pad and individual cursor control keys. Twin RS232C serial ports for fast and easy connection to a modem or printer. Dual Z80 processors which operate at 4 MHZ to insure lightning-fast program execution. And the list goes on! Feature after feature after feature.

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memory are used for program storage only, and that additional memory is supplied for storing video data.

With the MicroAce, the programmable memory available to the user must perform both tasks. Thus, as program length increases, the area for displaying the program listing begins to shrink as less and less memory is available for display storage. As a result, the program line-entry "window" moves up from its bottom position on the screen. The advantage of this system is that when your line-entry window is near the top of the screen, you know you are close to filling the available program memory. The disadvantage is that shorter and shorter segments of a program can be listed at any one time. As you will see later, this dual use of memory causes similar difficulties when running a program.

Another feature of the MicroAce is that there is no limit (other than available memory) to the length of a program line. Thus, a large section of text can be printed using a single PRINT command. This can save time and memory if properly used.

A disadvantage of the system is that multiple statements on a single line are not allowed. For example:

230 LET A = 5: LET B = 9

would have to be written as:

230 LET A=5 235 LET B=9

In another example:

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Early reports from users of Leverage, the microcomputer-based information management system recently introduced by Urban Software Corporation, reveal a level of satisfaction rarely found among users of microcomputer applications programs. Several factors have been cited to explain this highly favorable response, including:

• State of the art human engineering. Features like an extensive on-line manual directly accessible by the program, graphic menu selection and automatically programmed menus allow unparallelled ease of use.

• Several easy to follow tutorials demonstrate the capabilities of the system and provide an ideal vehicle for mastering its operation.

• Clear, complete documentation includes a glossary, an index and numerous tables and figures.

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200 INPUT A,B,C

would have to be written as:

200 INPUT A 205 INPUT B 210 INPUT C

Program Editing

As indicated earlier, new lines can be inserted anywhere in a program by entering them in the normal fashion. Entire lines can be deleted by entering the line number and pressing NEWLINE. If the line that is currently displayed needs editing, the following procedure is used: the up and down arrows (shifted 7 and shifted 6, respectively) are used to locate the line cursor at the proper line; then EDIT (shifted NEWLINE) is pressed to copy the desired line in the program-entry window at the bottom of the screen.

The left and right arrows (shifted 5 and shifted 8, respectively) are used to position the program cursor within the line. Deletions are made by placing the program cursor to the right of the desired character or keyword and pressing RUBOUT (shifted numeral 0).

Insertions are made by merely typing in the correct character or keyword. The portion of the line to the right of the insertion shifts to the right to accommodate the inserted text. You cannot over-type incorrect text; it must be deleted using the RUBOUT command.

A line that is not presently on display can be edited in one of two ways. The up or down arrows can be used to scroll the program listing down or up on the display until the desired line appears, or the LIST command can be used instead.

Normally, a LIST command will list the program starting with the line preceding the requested line. If, for example, the lines are numbered by tens, then a LIST 120 will result in a listing that begins with line 110 and continues as far as space and display memory permit. In either case, once the desired line is displayed on the screen, it can be edited as described above.

MicroAce has one disconcerting feature that affects the entering and editing of programs. The microprocessor performs only one function or task at a time. Thus, it either handles keyboard input or controls the video display, and as a result, every key closure during program entry and editing causes the display to roll. This makes it difficult to use the editing arrows, as it is hard to follow a moving cursor on a rolling display.

Running a Program

A program is executed by entering the RUN keyword command followed by NEWLINE. During program execution, the display remains blank until a STOP or INPUT command is executed, a BREAK or an error occurs, or the program completes its run. At that point, the microprocessor is free to devote its attention to the video display. This means that a PRINT command in a program merely loads the data into the display memory for future use. It will not appear on the display until active execution of the program ceases. For this reason, animated graphics are not possible.

As mentioned earlier, there are some problems related to running programs, because the available program

54 April 1981 © BYTE Publications toe

Circle 35 on inquiry card.

Circle 36 on inquiry card.

Sweeten Your Apple II* with the ES/F Mass Storage System

THESE FACTS SPEAK FOR THEMSELVES!

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100 (C-IO)

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Your users' group is here at last! We are Super*Star International, an independent, world-wide users' group for Intertec Data Systems' SUPERBRAIN™ and COMPUSTAR™ computers.

Our monthly magazine SUPER *STAR will fulfill all your computing desires. When you join our group, you will enjoy the latest: technical information, tips for beginners, special business uses, equipment reviews, the Intertec story — the people, ideas, and machines behind your computer. In every issue you'll get a free program, industry news, and software reviews.

Plus, we want your programs for our Software Supermarket, where all members can buy programs at affordable prices.

We will investigate all the accessories you have always wanted, test them, and offer them for sale at reduced prices.

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Not affiliated with Intertec Data Systems. 'Superbrain and Compustar are the trademarks of Intertec Data Systems.

mable memory is used for both program and display storage. Program memory is given priority, so if, for example, a PRINT command giving some instructions contains more characters than the available display memory can accommodate, the displayed message terminates at the point where display memory was filled, program execution stops, and an error message appears at the lowerleft portion of the screen.

This clearly limits the amount of displayable text that can be included in a program. In the worst possible situation, where the entire screen is filled, 768 bytes of memory (32 X 24 =768) would be required for the display alone. Only 256 bytes remain in which to store system pointers, program lines, variables, and so on.

Furthermore, the display will not scroll during program execution. If a PRINT command results in a line of text beyond line 24, program execution ceases and a different error message is displayed. The PRINT and CLS (clear screen) commands must be used judiciously in order to avoid printing too many lines, on the one hand, and clearing text before it can be read, on the other.

MicroAce Integer BASIC

Integer BASIC is limited in its computational capabilities. All numbers used in computation must be integers in the range —32768 to 32767, inclusive. Results of arithmetic operations are truncated (ie: all fractions are dropped). Thus, 99 divided by 100 would come out 0, because the division normally yields a quotient of 0.99. But integer BASIC drops all fractions, leaving 0.

Only the fundamental operations of addition, subtraction, multiplication, division, and exponentiation (using positive integral exponents) are implemented. This is true not only for MicroAce integer BASIC, but for any form of integer BASIC. The purpose of integer BASIC is to provide the user with a high-level programming language in as little memory as possible. This should be kept in mind when evaluating the capabilities of an integer BASIC.

While the features of MicroAce BASIC are given in table 1, a few points should be emphasized. Note that string manipulation, a feature not always included in integer BASIC, is possible. Also, a USR function is provided which allows the user to run machine-language programs. I have not yet experimented with this feature, but should point out that the manual does not teach you any machine-language programming. It merely suggests that you write a monitor in BASIC to enter machinelanguage programs, and use the USR function to run them.

The use of keywords was discussed earlier. This greatly simplifies program entry because entire commands are entered with a single keystroke. Memory is conserved because each keyword occupies only a single byte of memory. Any keyword command can appear in an executable program line including LIST, LOAD, SAVE, RUN, and NEW.

You have to be very careful with some of these commands. Program execution terminates following a LIST. The NEW command executed in a program, or in command mode (executed directly from the keyboard), would wipe out everything in memory, including the program itself. The LOAD and SAVE commands would be of little value in a program since the cassette recorder

56 April 1981 © BYTE Publications Inc

Circle 37 on inquiry card.

Circle 38 on inquiry card.

THE SOLUTION STORE

Makes The Difference!

MicroAge Computer Stores sell solutions to your professional, business and household-management problems, not just hardware. That's what makes the MicroAge difference! From systems integration to easy-tounderstand application software, research and development to warranty service and repair, systems consulting to training and installation. In all these, we offer the latest, most innovative approaches. That's why we are the forerunners... the pioneers in the microcomputer industry.

But don't just take our word for it. Visit the MicroAge Computer Store nearest you and see the difference solutions make. We have differences you'll experience with every time and money-saving idea. The difference that will keep you satisfied now and for years to come!

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would have to be turned on at just the right moment in order to complete the command execution.

The MicroAce BASIC provides an error message whenever program execution ceases. The number of different messages is limited, but remember that all program lines must have correct syntax before they are accepted into a program. The error messages are given in the format c:nnn where c is an error code, and, in most cases, nnn is the last program line executed. Here are some examples:

0:400This could mean one of two things. Either the program has come to a successful end at line 400, or a BREAK was executed and line 400 would have been the next line executed in the program.

5:40 This indicates that a PRINT command in line 40 attempted to print beyond the twenty-fourth line on the display, which, as noted above, is not possible.

4:40 This might indicate that a LET command was used when there was no more memory available for variables storage. (The error code indicates there is not enough memory to perform the given line.)

The system of error messages, together with the syntax checking feature, make program debugging quite easy. This is definitely one of the strong points of MicroAce BASIC.

One negative aspect of the MicroAce BASIC is the inability to halt program execution at an INPUT command. When executing an INPUT command, the BREAK key is, in effect, ignored. This is not that unusual as other computers exhibit the same property. However, any key entry, including NEWLINE (and that is a bit unusual), that is not a valid response to the INPUT command results in the appearance of the reverse-video S syntax error cursor, which means that the response will not be accepted. It must be deleted using the RUBOUT command, and a correct response must be entered before program execution resumes.

I entered a relatively simple game program which involved locating a submarine within a three-dimensional region. The player is allowed seven trials, and must input three coordinates during each trial. Thus, a maximum of twenty-one INPUT commands will be executed. Unless a STOP command or an escape routine is included in the program (or you disconnect the power), there is no obvious way to terminate execution of the program until all twenty-one INPUTs are responded to properly. This could make debugging of highly interactive programs a time-consuming process. By the way, even though this program was quite short, the instructions for playing the game could not be displayed without overflowing the available display memory. Consequently, they had to be omitted from the program.

Graphics

There are twenty graphics symbols available, as shown in figure 2. Note that only ten are available from the keyboard. The remaining ten are reverse-video graphics available by using the CHR$ function.

In fact, any alphanumeric character, graphics symbol, or keyword string can be printed using the CHR$ func

58 April 1981 © BYTE Publications Inc

Circle 39 on inquiry card.

Circle 40 on inquiry card.

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tion. Most characters can be printed in reverse-video as well. The BASIC manual provides a complete list of all available characters and strings, along with their decimal codes. The code is unique to MicroAce and thus not compatible with standard computer codes.

Since each character position on the 24 by 32 display is divided into four parts by the graphics symbols, a resolution of 48 by 64 dots is possible. Remember though, that an extensive graphics display greatly limits the amount of memory available for program storage.

Cassette Input and Output

I had to try two tape recorders before I could successfully load a program from tape. The first recorder I tried lacked a tone control and could not load a program, regardless of the volume setting. The second recorder had a tone control and loaded properly with the control set at maximum treble.

The proper volume level seems to vary from tape to tape, even when they are made by the same company. Before saving a program, the program name is recorded on the tape by voice.

A cable is attached between the microphone output of the computer and the microphone input of the recorder. The recorder is placed in its record mode and the SAVE command is entered followed by NEWLINE. The television screen goes blank for about five seconds, followed by a jumpy display of horizontal white lines. This indicates that the data is being output to the recorder. When the display returns to normal, the save is complete.

Loading a program involves a similar series of steps. In

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this case, however, you cannot be certain that the program is being input until the screen resumes its normal display, giving a listing of the tail end of the successfully loaded program.

If, after a reasonable interval of time, the display does not return to normal, the BREAK key may be used to reset the computer. Occasionally, you may have to disconnect the power momentarily to recover from an unsuccessful load. Once the proper volume setting is found, however, loading can be done quite reliably.

The Teach-Yourself Manual

The manual supplied with the MicroAce, entitled The Teach-Yourself BASIC Manual, is shown in photo 1. The title may be slightly misleading. It brings to mind a tutorial text complete with exercises for the reader, but it is not that kind of text. It merely introduces the BASIC commands, one at a time, illustrating their proper use and perhaps some typical applications.

At the same time, the processes of program entry, program editing, and program execution are taught. Token coverage is given to the art of programming, but in all fairness it might be unreasonable to expect a more detailed explanation. As an introduction to the use and syntax of fundamental BASIC commands, the manual is quite adequate.

While typing errors (or misprints) are inevitable, I do think that special care should be given to printing sample programs. One program in the manual has two lines which read "GO TO 7000" when the program contains no line numbered 7000. Those two lines should have read "GO TO 1000". As written, the sample program would not run successfully.

Other Considerations

I believe that any product's value is partially determined by the manufacturer's willingness to respond to the consumer's request for aid or assistance. Nine weeks prior to the writing of this review, I sent a letter to MicroAce requesting answers to specific questions related to the MicroAce and to future plans for upgrading and expansion. That letter was never answered. This, to me, indicates a lack of interest in serving the customer.

At the same time that the letter was sent to MicroAce, a similar letter was sent to Sinclair Research Limited, the company that markets the Sinclair ZX80. (The MicroAce is essentially a kit version of Sinclair's machine and is manufactured under a license from Sinclair Research Limited.)

Sinclair's response to my letter left many questions unanswered (especially in regard to future plans), but they did say that the MicroAce operates in the same manner as the ZX80. Consequently, the comments made in this review concerning the operation of the MicroAce would apply to the Sinclair ZX80 as well.

I was also told by Sinclair that while the unit operates like the ZX80, it is not identical to it, and that peripherals marketed for the ZX80 might not work with the MicroAce. They did not elaborate, and, as noted above, MicroAce had no comment at all.

Conclusions

The MicroAce kit is a very inexpensive introduction to the world of microcomputers. Kit construction is easy

60 April 1981 © BYTE Publications Ire

Circle 41 on inquiry card.

Suddenly Radio Shack's New TRS-80 Color Computer is

Even Better!

New Extended Color BASIC. Here's an advanced TRS-80 Color Computer that includes a 16K ROM Extended BASIC with advanced graphics, eight brilliant colors, and sound, for an unprecedented low price! You can draw fine lines, circles, rectangles, boxes and more with easy-to-use one-line commands. Four graphic modes with two color sets allow up to 49,152 programmable screen points (pixels). There are 255 separate tones for music or sound effects. All this on a 16K RAM machine (including video memory) loaded with the dynamic features a serious programmer demands. You get a 32x16 screen, multi-character variable names (two significant), editing, tracing, user-definable keys, 255-character string arrays, floating point 9-digit accuracy, and even machine language routines.

Priced at Only $599, the TRS-80 Extended Color BASIC Computer is useful, entertaining and educational. Yet using it can be as simple as plugging in one of Radio Shack's instant-loading Program Paks. Come in and see what's already available. The computer attaches to your TV, or our own $399 TRS-80 Color Video Receiver. For just $24.95, you can add a pair of joysticks which add flexibility to games and video displays. A built-in serial interface lets you attach a printer or a modem. A tutorial Color BASIC instruction manual is included, of course.

More Good News. Extended Color BASIC is also available as an upgrade kit ($99) for the 4K Color Computer (16K RAM required— $119). There's a modest installation charge for each kit.

New TRS-80 VIDEOTEX Software (with the modem shown below) offers Color Computer owners quick, affordable access to many kinds of information and data services. For example, our exclusive agreement with CompuServei? Information Service gets you local, national and international news, weather and sports from 11 area newspapers and the Associated Press News Service; information on over 32,000 stocks and bonds; an educational reference service; entertainment news and reviews; nationwide Electronic Mail with other users; and much more! You'll also access Dow Jones Information Services for Wall Street news, stock quotes and more.

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enough that beginners can tackle the project with confidence, assuming that they learn correct soldering techniques.

Proper soldering is so crucial to success that I would advise those with no experience to purchase Heathkit's soldering course. This course is part of Heathkit's continuing education program, and costs $15.95 plus shipping. While I have not seen this particular course, I am sure, based on my experience with their other products, that it would be worthwhile. For further information, write to Heath Company, Benton Harbor MI 49022.

MicroAce BASIC contains several nice features. The use of keyword commands simplifies program entry and reduces the amount of memory required for program storage. Because line syntax is checked before the line is entered into a program, fewer programming errors can occur. This feature is especially useful for those just learning how to use BASIC.

The machine's compact size and light weight make storage and transportation very easy. The unit is simple

to attach to a home television set, and the cassette input and output operations are reliable, once the proper settings are found.

The largest drawback is the severely limited amount of programmable memory. This disadvantage is most apparent when you try to write any but the shortest programs utilizing a significant amount of video display. I would strongly encourage any prospective buyer to purchase the 2 K-byte version of the MicroAce. Another drawback is that the screen is blank during active program execution. This limits the types of possible graphic displays, and can be somewhat annoying.

If you recognize the limitations of the machine and don't expect too much, then I think you can buy the MicroAce kit with confidence. It is most appropriate for someone who wants an inexpensive unit as a teaching tool in order to learn the fundamentals of BASIC programming. It might also appeal to hobbyists who want to "tinker around" with microcomputers but don't want to risk their more expensive equipment. ■

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needs and make it your own. It has the flexibility and brains to provide all the performance you need but is priced to make sense whether you need lO or 1,000.

The TeleVideo model 950 detachable keyboard CRT Terminal has 11 special function keys—22 functions with the shift key—that can readily be programmed to your requirements using 256 bytes of on-board RAM.

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Digital Minicassette Controller

James Kahn

2284 Ellena Dr

Santa Clara CA 95050

The microcomputer-system designer has had a difficult time finding low-cost storage devices. Frequently, the choices have been limited to either standard Phillips audio cassettes or floppy disks. Although these are relatively inexpensive storage media, the transport mechanisms, or drives, are not. In addition to the transport, a controller and data formatter is required to interface the transport to the microcomputer system. The controller may either be a dedicated LSI (large-scale integration) device or be

Commonly used massstorage mechanisms and associated controllers are often quite expensive.

built up discretely from SSI (smallscale integration) logic consisting of TTL (transistor-transistor logic) gates and flip-flops.

Photo 1: The author's minicassette system includes an Intel iSBC 80/30 single-board computer and a Braemar CM-600 Mini-Dek transport.

There is now another choice besides the floppy disk and the Phillips cassette: the digital minicassette. Not only is the storage medium inexpensive, so is the transport (about $140, versus $400 for a floppy-disk drive). As a bonus, the transport is extremely compact (only 23 cubic inches) and requires little power (1 watt). This makes it suitable for a wide range of low-end applications ranging from experimental systems to data logging for test instrumentation.

There is one problem with designs using a minicassette: controlling it. There are several choices for the transport controller. One choice is to design a controller of discrete SSI logic. Although this choice will provide good performance, it requires a handful of discrete components. The SSI controller will use much circuitboard space, compromising the advantage of a compact transport. A better design would use a minimal number of components and take advantage of current LSI technology.

One such controller-design solution is to use the Intel 8255A Programmable Peripheral Interface IC (integrated circuit) to interface the transport to a microcomputer system. Although this design provides a simple solution to the problem, the processor would be burdened with providing the low-level control needed by the transport, in addition to supporting its normal real-time I/O (input/output) tasks. Examples of these low-level tasks are transport start-up, data formatting, and transport shutdown.

There is, however, a better LSI solution available: distribute the system intelligence from the micro

66 April 1981 © BYTE Publications Inc

The best news since CP/M... customizable full screen editing

As a serious computer user you spend much of your time editing, whether it be for program development or word processing. Make the best use of your time with the help of VEDIT, an exceptionally fast and easy to use full screen editor. VEDIT is a highly refined and proven editor which is easy enough for novices to leam and use. Yet its unequalled set of features also makes it the choice of computer professionals. And because VEDIT is user customizable, it adapts to your keyboard, hardware, applications and preferences.

In VEDIT, the screen continuously displays the region of the file being edited, a status line and cursor. Changes are made by first moving the cursor to the text you wish to change. You can then overtype, insert any amount of new text or hit a function key. These changes are immediately reflected on the screen and become the changes to the file.

VEDIT has the features you need, including searching, file handling, text move and macros, plus it has many special features. Like an 'UNDO' key which undoes the changes you mistakenly made to a screen line. And a mode which allows a programmer to enter all text in lower case and let VEDIT convert the labels, opcodes and operands, but not the comments, to upper case. The screen writing is almost instantaneous on a memory mapped display or can use your CRT terminal's editing capabilities. Disk access is very fast too, and VEDIT uses less than 12K of memory. The extensive 70 page, clearly written manual has sections for both the beginning and experienced user.

Totally User Customizable

Included is a setup program which allows you to easily customize many parameters in VEDIT, including

the keyboard layout for all cursor and function keys, screen size (up to 70 lines, 200 columns), default tab positions, scrolling methods and much more. This setup program requires no programming knowledge or 'patches', but simply prompts you to press a key or enter a parameter.

The CRT version supports all terminals by allowing you to select during setup which terminal VEDIT will run on. Features such as line insert and delete, reverse scroll and reverse video are used on 'smart' terminals. Special function keys on terminals such as the HI9, Televideo 920C and IBM 3101, and keyboards producing 8 bit codes or escape sequences are also supported.

New Features and Support

The new release includes disk write error recovery, indent and undent keys for structured programming, and the ability to insert a specified line range of another file at the cursor position. Versions for MP/M and the Apple IIR SoftCardRare now also available.

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BYTE April 1981 67

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processor to its peripheral devices by using an intelligent peripheral controller to carry the burden of lowlevel peripheral interface requirements. The processor now interfaces at a higher level, issuing the appropriate command to the controller and transferring the data to and from the controller in response to its I/O requests.

The controller provides a buffer between the processor and the transport. For example, the cassette transport expects data in a serial format, while the microprocessor is designed for handling data in either 8-bit words or 16-bit words. The controller performs data conversion from serial to parallel and buffers the data. This buffering is necessary to compensate for the I/O-service latency caused by other time-critical tasks handled by the microprocessor (ie: the data is held until the computer can devote itself to the controller). As a direct result, the system's work load is reduced, allowing it to utilize this savings in time to support other tasks, yielding a higher-performance microprocessor system.

Applying this to the minicassette design, we look through the available literature for dedicated single-device cassette controllers. Unfortunately, there are no devices of this caliber for minicassettes. There is, however, another solution: use the Intel UPI-41 Universal Peripheral Interface (UPI) integrated circuit. Two versions are available; we can use one of them, the 8741A, and design software, customizing it to control the minicassette transport.

The 8741A, shown in figure 1, is a complete, single-chip microcomputer containing 1024 bytes of EPROM (erasable programmable read-only memory), 64 bytes of programmable memory, 18 programmable I/O lines (providing a direct interface to the peripheral device), and a timer/event counter with an 8-bit prescaler for real-time I/O. In addition, it contains a complete slave-microprocessor bus interface, including both interrupt and direct-memory-access capabilities. A pin- and function-compatible factory-mask ROM (ie: programmed only at the factory) version of the UPI-41, the 8041A, is also available.

The 8243 I/O-port expander completes the system and interfaces directly to the I/O port of either of

68 April 1981 © BYTE Publications Inc

Circle 46 on inquiry card.

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Figure 1: Internal block diagram of the 8741A/8041A Universal Peripheral Interface. I/O lines can be programmed as inputs or outputs; 8041A control-program memory must be factory programmed; 8741A memory is user-programmed.

the two slave microcomputers. Each 8243 provides 16 programmable, bidirectional I/O lines.

Using the 8741A allows the designer to develop a custom peripheral interface for particular I/O problems. These devices have found applications in such diverse areas as character-printer control, data encryption, keyboard control, and intelligent displays. Developing an 8741A design is straightforward. The

designer develops a control algorithm using the UPI-41A cross assembler and programs the on-board EPROM of the 8741 A. Testing may be accomplished using either an ICE-41A in-circuit emulator or the single-step mode of the 8741 A.

The Hardware

The complete microcomputer system is shown in photo 1, including the CM-600 minicassette transport.

The microcomputer system for this design consists of an Intel iSBC 80/30 single-board computer. It supports an 8085A microprocessor, 8 K bytes of EPROM, and 16 K bytes of programmable memory. In addition to an 8255A parallel interface and an 8251A serial interface, it contains a Multibus system bus connector allowing expansion beyond the board's local resources. Incidentally, there is an 8741A socket built into the board as well.

Let us examine the microcomputerto-8741A hardware interface. The computer sees the 8741A as three registers in its I/O address space: the data register, the command register, and the status register. The decoding of these registers is shown in figure 2. Within the 8741A, both the data and commands are written into the same physical register, the Data Bus Buffer Input register (DBBIN). The state of the register-select input, Ao, determines whether a command or data has been written (Ao = 0 for data). All output to the microprocessor is read from the Data Bus Buffer Output register (DBBOUT).

The status register is composed of 4 software-programmable bits and 4 reserved bits reflecting the state of the 8741A slave microcomputer (see figure 3 on page 78). The Input Buffer Full (IBF) bit and Output Buffer Full (OBF) bit reflect the state of the DBBIN and DBBOUT registers, respectively. Flag 0 (F0) and Flag 1 (Fi) can be set and complemented via the

LET YOUR APPLE SEE THE WORLD!

The DS-65 Digisector® is a random access video digitizer which converts a TV camera's output into digital information the Apple can process. It features 256 X 256 resolution with up to 64 levels of grey scale. Scanning sequences are user programmable. On-board software in EPROM is provided for displaying digitized images on the Hi-Res screen.

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70 April 1981 © BYTE Publications Inc

Circle 47 on inquiry card.

The Perfect Fit

The Micromodem II data communications system and the Apple II* computer. What better combination to maximize the capabilities of your personal computer!

This popular direct connect modem can transmit data between an Apple II and another Apple II, a terminal, another microcomputer, minicomputer or even a large time-sharing computer anywhere in North America. The Micromodem II has unique automatic dialing and answer capabilities which further increases the communications possibilities between the Apple II and another computer or terminal.

You can send and/or receive messages or data when you are out of your office, home or out of town. Your branch business locations can communicate with each other regarding inventory and other matters over the phone. Or you can communicate with friends across the country. And you can access information utilities like the SOURCE for various business and personal applications.

The Micromodem II consists of two parts. One part includes the printed circuit board which holds the Micromodem II, ROM firmware and the serial interface. The board plugs directly into the Apple II providing all the functions of a serial interface card plus programmable auto dialing and auto answer capabilities. The on-board ROM firmware enables the Micromodem II to operate in any of three modes to perform different tasks-terminal mode, remote console and program control mode.

The other part of the Micromodem lldatacomm system is a Microcoupler which connects the Micromodem board and Apple II to a telephone line. The Microcoupler gets a dial tone, dials numbers, answers the phone and hangs up when a transmission is over. There are none of the losses or distortions associated with acoustic couplers. The Microcoupler is compatible with any North American standard telephone lines and is FCC-approved for direct connection in the U.S. It works with standard dial phone service or Touch-tone service.

The Micromodem II is completely compatible with Bell 103-type modems. Full and half-duplex operating modes are available as well as speed selectable transmission rates of 110 and 300 bps.

Why not increase your Apple ll's capabilities by outfitting it with the sophisticated Micromodem II data communications system? The Micromodem II is available at retail computer stores nationwide. For the store nearest you, call or write:

fflHayes

Circle 48 on inquiry card.

Hayes Microcomputer Products Inc.

5835 Peachtree Corners East, Norcross, Georgia 30092 (404) 449-8791

™ Micromodem II is a trademark of Hayes Microcomputer Products, Inc.

* Apple II is a registered trademark of Apple Computer Inc.

The Micromodem II can also be used with the Bell & Howell computer.

internal software. The remaining 4 bits are used to indicate the status of the transport.

The TTL-compatible I/O lines of the 8741A provide an uncomplicated interface to the CM-600 Mini-Dek minicassette transport (Mini-Dek is a registered trademark of Braemar Computer Devices Inc). The I/O lines can be divided into three groups: motor control, data control, and cassette status. These I/O port lines are shown in the 8741A interface schematic in figure 4 on page 78. The motor-group controls are go/stop, fast/slow, and forward/reverse. The data controls are read/write, data-in, and data-out. The remaining group of outputs reflects the CM-600's status: clear leader, cassette present, file protected, and cassette side.

The Braemar CM-600 Mini-Dek transport is representative of digital minicassette transports. The transport is compact, requiring only 3 by 3 by 2Vi inches for mounting. It has a single read/write head and uses only one drive motor. Operating from a 5 V supply, it has modest power-supply requirements, needing only 200 mA during a read or write.

Tape speeds are 3 ips (inches per second) during read/write, 5 ips for fast forward, and 15 ips during rewind. Calculating the data-transfer rate based on the read/write speed and the maximum recording density of 800 bpi (bits per inch) yields a maximum data-transfer rate of 2400 bps (bits per second). A more useful representation illustrating the significance of this number is obtained by inverting it. This yields the bit-cell period: 416 /as. This control requirement is easily met by the 8741A, its timer having a minimum resolution of 80 fis. If finer resolution were required, softwaretiming loops would have to be used. The maximum resolution is limited to the instruction-cycle time of the 8741 A, 2.5 /is, necessary for transfer rates of 8000 bps.

Recording Format

Since the CM-600 does not provide any data formatting, the 8741A must perform this additional low-level task. A multitude of encoding techniques are available from which the user may choose [ie: NRZ1 (Nonreturn to Zero, change if 1), Phase, GCR (Group Code Recording)]. For

Introducing...

MINI-FLEX

Designed Specifically

W^tt

Ah

The Newest Member of The Advance Access

Diskette Protection Family

For Further Information

CALLTOLL FREE

800-323-3412

ADVANCE ACCESS GROUP

2200 S. Main St., Lombard, IL 60148 312-629-5800 "Manufacturers of Information Processing Supplies"

this application, a "self-clocking" phase-encoding scheme similar to that used in floppy disks was selected. Phase encoding provides easy encoding and decoding of the serial data, embedding the timing information and data bits together in the recorded bit cells on the tape. This is an effective means of compensating for speed variations of the drive. Reading the data is accomplished by using the clocking information of the bit cell to synchronize the sampling of the data bit coming from the transport.

Figure 5 on page 78 illustrates this encoding technique as applied to the hexadecimal character 3A (all characters referenced in this article are hexadecimal). Notice that each bit cell begins with a transition to a logic level opposite the level of the preceding bit-cell level. Decoding the data is simply a matter of starting a timer on this "clocking" transition of the cell, waiting 3/4 of a bit-cell period, and determining whether a mid-cell transition occurred. Cells with no midcell transitions are 0s; cells with transitions are Is. Besides the encoding Text continued on page 80

8741A

WR RD CS A0

DATA BUS

c

STATUS REGISTER

\ DATA BUS J INPUT REGISTE

DATA BUS OUTPUT REGISTER

CS

RD

WR

A0

REGISTER

0

0

1

0

DBBOUT

0

0

1

1

STATUS

0

1

0

0

DBBIN (DATA)

0

1

0

1

DBBIN (COMMAND)

1

X

X

X

NONE

72 April 1981 © BYTE Publications Inc

Circle 49 on inquiry card.

Figure 2: 8741A system-bus interface and register decoding as seen by the host processor.

Circle 50 on inquiry card. >

First compare quality. Then compare cost.

Morrow Designs910 megabyte hard disk system: $3,695.

MORE MEMORY. LESS MONEY.

Compare Morrow Designs' DISCUS M26™ hard disk systems to any system available for S-100 or Cromemco machines. First, compare features. Then, compare cost per megabyte. The M26 works out to under $200 a megabyte. And the M10 is about half the cost of com peting systems.

COMPLETE SUBSYSTEMS.

Both the M10 (8"), and the M26 (14"), are delivered complete with disk controller, cables, fan, power supply, cabinet and CP/M® operating system. It's your choice: 10 Mb 8" at $3,695 or 26 Mb 14" at $4,995. That's single unit. Quantity prices are available.

BUILD TO FOUR DRIVES.

104 Megabytes with the M26. 40+ megabytes with the M10. Formatted. Additional drives: M26: $4,495. M10: $3,195. Quantity discounts available.

S-100, CROMEMCO AND NORTH STAR?

The M26 and M10 are sealed-media hard disk drives. Both S-100 controllers incorporate intelligence to supervise all data transfers through four I/O ports (command, 2 status and data). Transfers between drives and controllers are transparent to the CPU. The controller can also generate interrupts at the completion of each command ... materially increasing system throughput. Sectors are individually write-protectable for multi use environments. North Star or Cromemco? Call Micro Mike's, Amarillo, TX, (806) 372-3633 for the software package that allows theM26and MIOtorun on North Star DOS. MICAH of

Morrow Designs' 26 megabyte hard disk system: $4,995.

Sausalito, CA, (415) 332-4443, offers a CP/M expanded to full Cromemco CDOS compatibility.

AND NOW, MULT-I/O.™

Mult-I/O is an I/O controller that allows multi-terminal and multi-purpose use of S-100 and Cromemco computers. Three serial and two parallel output ports. Real time clock. Fully programmable interrupt controller. Designed with daisy-wheel printers in mind. Price: $299 (kit), $349 assembled and tested.

MAKE HARD COMPARISONS.

You'll find that Morrow Designs' hard disk systems offer the best price/ performance ratios available for S-100, Cromemco and North Star computers. See the M26 and M10 hard disk subsystems at your computer dealer. Or, write Morrow Designs. Need information fast? Call us at (415) 524-2101.

Look to Morrow for answers.

MORROW DESIGNS

•CP/M is a trademark of Digital Research Corp. 'Cromemco is a trademark of Cromemco, Inc. North Star is a trademark of North Star Computers, Inc.

5221 Central Avenue Richmond. CA 94804

PRINTERS

ANADEX DP-9500 W/2K DUFFER, 1375

ANADEX DP-9501 W/2K DUFFER 1450

DASE 2 800-D 599

C. ITOH STARWRITER 25 CP5 1750

C. ITOH STARWRITER 45 CP5 2450

A. CENTRONICS 707 625

EPSON MX-70 W/GRAPHICS 449

D. EPSON MX-80 132 col .620

PAPER TIGER IDS-445 W/DOT PLOT 749

C. PAPER TIGER IDS-460 W/DOT PLOT '.. 1195

PAPER TIGER IDS-560 W/DOT PLOT 1495

D. QUME SPRINT 5/45 2550

SILENTYPE W/INTERFACE 549

b.

Tpriilii

j£i

SYSTEMS

A. APPLE II PLUS 1 6K 1 049

APPLE II PLUS 46K (APPLE Memory) 11 69

APPLE II STANDARD MODELS CALL

These are the newest models with FCC type approval to prevent RF interference.

D. DISK II DRIVE & CONTROLLER 529

This model includes DOS 3.3 i6 sector

DISK II DRIVE ONLY (ADD-ON) 445

C. CHALLENGER 4P by OHIO SCIENTIFIC 699

C4PMF (MINI FLOPPY SYSTEM) 1 599

OP MODEL II 449

SARGON II (DISK OR CASSETTE) 35

FIG FORTH (DISK ONLY) 69

D. PMC-60 THE TRS-80 WORKALIKE' 629

16K LEVEL II W/PROGRAM RECORDER, CALL OR WRITE FOR MORE INFORMATION

E. EXIDY SORCERER II CALL

AVAILABLE IN 16K, 32K & 48K MODELS

5-100 EXPANSION UNIT 375

WORD PROCESSING PAC 1 79

DEVELOPMENT PAC 89

F. ATARI 800 1 6K 799

ATARI 400 16K 499

810 DISK DRIVE 499

410 PROGRAM RECORDER 69

850 INTERFACE MODULE 175

VIDEO MONITORS

k. AMDEX/LEEDEX VIDEO-100 12" DGW 139

HITACHI 13" COLOR 389

i. NEC 12" P31 GREEN PHOSPHER CALL

PANACOLOR 1 0" COLOR 375

SANYO 9" D&W 179

:. SANYO 12" D&W 255

SANYO 1 2" P31 GREEN PHOSPHER 295

SANYO 13" COLOR 445

SHOPPING MAIL ORDER? CALL US TODAY!

We probably have what your're looking for in stock ot an incredible price. Our company is an authorized dealer for sales and service for Apple Computer. Atari and Ohio Scientific, if you receive a defective product from us we will repair or replace (at our option) any product in warranty, Our Service Center will repair all Apple Computer products, in or out of warranty, whether it was purchased from us or another dealer, (call for more details)

PHONE ORDERS IN CALIFORNIA, ALASKA, HAWAII & FOREIGN (714)698-8086 SHIPPING INFORMATION OR DACKORDERS PLEASE CALL (714)696-0260

SERVICE CENTER AND FOR TECHNICAL INFORMATION (714)460-6502

74 BYTE April 1981

Circle 51 on Inquiry card.

Order Dept.

Open Every Day

9a.m. - 6 p.m.

P.5.T.

TOLL FREE ORDER LINE

600-854-6654

We honor these cords

AMERICAN] .

<•>

APPLE HARDWARE Y APPLE SOFTWARE

TOP FIVE SELLERS

LANGUAGE SYSTEM W/PASCAL.... 425 SILENTYPE PRINTER W/INTERFACE. 549

HAYES MICROMODEM II 319

VIDEX VIDEOTERM 80 w/graphics. 335 Z-80 MICROSOFT CARD 299

APPLE COMPUTER INC.

DISK II DRIVE ONLY 445

INTEGER OR APPLESOFT II FIRMWARE CARD 155

GRAPHICS TABLET 649

PARALLEL PRINTER INTERFACE CARD 155

HI-SPEED SERIAL INTERFACE CARD 155

COMMUNICATIONS INTERFACE CARD 185

SMARTERM 80 COLUMN VIDEO CARD 335

MOUNTAIN COMPUTER INC.

MUSIC SYSTEM (16 Voices) 479

A/D + D/A INTERFACE 319

EXPANSION CHASSIS 555

INTROL/X-10 SYSTEM 249

CLOCK/CALENDAR CARD 239

SUPERTALKER SD-200 249

ROMPLU5 + CARD 135

ROMWRITER CARD 155

CALIFORNIA COMPUTER SYSTEMS

CLOCK/CALENDAR MODULE 1 09

GPID IEEE-488 CARD 259

ASYNCHRONOUS SERIAL INTERFACE CARD 129

CENTRONICS PARALLEL INTERFACE CARD 99

We carry all CCS hardware. Please call

MISC. APPLE HARDWARE

16K RAM UPGRADE (Apple, TRS-80. Exidy) 189

1 6K RAM CARD MICROSOFT 1 89

ACT NUMERIC KEYPAD (old or new kybrd) 115

ADT BAR CODE READER WAND 179

ALF 3 VOICE MUSIC CARD 229

ALF 9 VOICE MUSIC CARD 169

ALPHA SYNTAURI KEYBOARD SYSTEM 1 399

BIT 3 FULL VIEW 80 CARD 349

CAT NOVATION ACOUSTIC MODEM 1 69

CORVUS 10MB HARD DISK CALL

LAZER LOWER CASt PLUS 50

MICRO-SCI DISK DRIVES CALL

PAYMAR LOWER CASE (old or new Kybrd) 55

RADCOM AMATEUR RADIO INTERFACE CARD 189

SPEECHLINK 2000 HEURISTICS 229

SSM AIO SERIAL/PARALLEL CARD A&T 1 89

SUP-R-TERMINAL 80 COL. CARD 339

SVA 6 INCH FLOPPY DISK CONTROLLER 345

VERSAWRITER DIGITIZER PAD 229

VIDEX KEYBOARD ENHANCER 115

We stock much more than listed. Please call.

APPLE COMPUTER INC.

DOS TOOLKIT 65

APPLEPLOT 60

TAX PLANNER 99

APPLE WRITER 65

APPLE POST 45

DOW JONES PORTFOLIO EVALUATOR 45

DOW JONES NEWS G QUOTES REPORTER 85

APPLE FORTRAN 165

APPLE PILOT 129

DOS 3.3 UPGRADE 49

MUSIC THEORY 45

THE CASHIER Retail Mngmnt & Inv 1 99

THE CONTROLLER Gen. Bus. Sys 519

MISC APPLICATIONS PACKAGES

VISICALC 125

DESKTOP PLAN II 169

CCA DATA MANAGMENT DMS 85

EA5YWRITER WORD PROCESSOR 225

EA5YMOVER MAIL SYSTEM 225

EASYMAILER LETTER WRITER 225

ASCII EXPRESS 65

MICROSOFT FORTRAN 185

MICROSOFT COBOL 695

MICROSOFT BASIC COMPILER 375

SUPER TEXT II 139

PROGRAMMA APPLE PIE 119

THE LANDLORD Apt Mngmnt package 649

PEACHTREE BUSINESS SOFTWARE CALL

TAX PREPARER by HowardSoft 89

APPLEBUG ASSEM/DISASSM/EDITOR 75

3-D GRAPHICS By Bill Budge 53

SUPER FORTH 49

TOP TEN GAMES

APPLE GALAXIAN 23

FLIGHT SIMULATOR 34

THE WIZARD AND THE PRINCESS 32

COSMOS MISSION (SPACE INVADERS) 24

SARGON II CHESS 32

HI-RES FOOTBALL 39

COMPUTER QUARTERBACK 39

ADVENTURE BY MICROSOFT 27

PHANTOMS FIVE 39

REVERSAL (OTHELLO) 34

CALL OR WRITE

FOR A COMPLETE

SOFTWARE LIST

ORDERING INFORMATION, Phone Orders invited using VISA MASTERCARD AMERICAN EXPRESS DINERS CLUB CARTE BLANCHE or bonk wire transfer Credit cords subject to service chorge 2% for VISA (j MC 5% for AE DC 6 CB Moil Orders may send credit card account number (include expiration date) cashiers or certified check money order or personal check (ollow 10 days to dear) Pease include o telephone number with oil orders Foreign orders (excluding Military PO s) odd 10% for shipping all funds must be m US dollars Shipping handling and insurance m U S odd 3% (minimum $4 00). California residents add 6% sales tax We accept COD s under S500 OEMs Institutions 0 Corporations please send for written quotation AH equipment is subject to price change ond availability without notice All equipment is new and complete with manufacturer warranty (usually 90 days) We cannot guarantee merchannbility of any produces We ship most orders withm 2 days

WE ARE A MEMDER OF THE DETTER BUSINESS BUREAU AND THE CHAMDER OF COMMERCE SHOWROOM PRICES MAY DIFFER FROM MAIL ORDER PRICES. PLEASE SEND ORDERS TO: CONSUMER COMPUTERS MAIL ORDER 8014 PARKWAY DRIVE, GROS5MONT SHOPPING CENTER NORTH LA MESA CALIF. 92041

Circle 51 on inquiry card.

10 DAY FREE RETURN

NEC THE FIKST NAME IN LETTER QUALITY PRINTERS.

CompuMart ofleis beautiful print quality with NEC Spinwriter terminals. Both KSR and RO versions give unsurpassed hard copy output CALL

CENTRONICS PRINTERS

The incredible Model 737. The closest thing to letter quality print tor under SLOOO. 737-1 (Parallel Interlace)—$899.

NEW FROM INTEGRAL DATATHE IDS 560 PRINTER. 132

column graphics printer. $1,695

IDS 445. Priced lower than the 440 and equipped with a better print head. IDS 445 w/graphics $894. IDS 445 w/o graphics $795.

IDS 460 $1,295

The 460s features include Correspondence quality printing, high resolution graphics capability, programmable print justification

Dysan Diskettes—Single side.

Single density, Hard or Soft Sector

$5. ea

Memoiex 3401's—5 Vt discs

$3.25 with hub ring lor Apple

$3.50.

Memory Integrated Circuits— Call tor qty. discounts when ordering over 50 units. Motorola 4116 (2CO Nanosecond Plastic) $4.50 ea Faircliild 2114 (Standard Power, Plastic) $450 ea

Super Selling Terminals

We have the following Lear Siegler Terminals in stock at prices too low to print—Call for quotes

ADM—3A Industries favorite dumb terminal for some very smart reasons. ADM—3A + NEW from Lear Siegler. CALL! IT IS HEREI-It is the new Intermediate Terminal from Lear Siegler. Call lor details.

Omni Printers from Texas Instruments

The 810-List $1895. SALE! $1795. The 820 (Ro) PackageIncludes machine-mounted paper tray and cable. A compressed print option and device forms control are standard features $2,155.

The 820 (KSR) PackageIncludes full ASCII Keyboard plus all of the features of the RO $2395.

COMPUMART stocks the complete line of MATROX PRODUCTS. Call for specs

COMPUMART now offers the ENTIRE DEC LSI-11 PRODUCT LINE. Call tor prices 8t delivery.

NOVATION CAT1™ ACOUSTIC MODEM

Answer Originate. 3CO Baud, Bell

108, Low Profile Design $179.00

NEW! D-CAT

Direct Coupler from Novation

$199.

We bare the following bestselling Hazeltine terminals in stock at prices much too low to print

(1410.1420,1500,1520,1552) Call COMPUMART Now for our lowest prices ever.

HP-41C Calculator $239.00

Memory Modules. For storing programs or up to 2.000 lines ol program memory $29.95

"Extra Smart" Card Reader. Records programs and data back onto blank magcards. t $199.00

The Printer. Upper and Lower case. High resolution plotting. Portable Thermal

operation $355.00

Application Modules

$29.95

NEW SUPER 41-C Systems with Quad RAMS built-in (Maximum memory onboard leaves slots open for Application Pacs and peripherals. The HP 41C C$325.00 HP 41C-C Plus Card Reader

$495.00 HP 41C-C Plus Card Reader 8c Printer $845.00/ Quad RAMS for the 41-C < (Equivalent to lour Memory Modules^ all packed into one) $95.00

COMPUMARTs Microflex 65 System lor your AIM Includes Adapter Buffer Module w/4-slot module stack. 8K RAM module, 16K PROM/ROM module. Asynchronous communications Interface, and Power Supply $1,299 Call or write lor our complete Microflex 65 brochure

NEW IN STOCK: The PMC-80. The

new computer that's software compatible with the TRS-80. Level II16K at $645.

ACCESSORIES FOR PMC-80 EXP-lOO S-lOO Bus Expander Disk Printer, RS232 I/O $410.

S-32K S-lOO Bus 32K RAM Board

tor EXP-lOO $295

CAB-40 Cable 12" long ribbon cable

lor EXP-lOO $25.

Visit our giant

ANN ARBOR STORE

1250 North Main Street Ann Arbor, Michigan

ROCKWELL AIM 65

Our AIM system includes 4K AM with BASIC interpreter assembler, Power Supply, Cassette recorder 8c Enclosure $799.

4K AIM-65 $499.

PL65 High Level Language $125. Paper lor the AIM (roll) $2.50 Rockwell's 4-slot

Motherboard (sale) $175.

Fourth lor Rockwell AIM 65 $175.

SEND FOR OUR FREE CATALOG

EXCLUSIVE from COMPUMART! Special Oiler. Zenith Color Video Monitor for $379!

NEW FROM SANYO-Four Great

Monitors at Low COMPUMART Prices Sanyo's new line ol CRT data display monitors are designed tor the display ol alphanumeric or graphic data.

9" Sanyo Monitor $169.

12" Sanyo Monitor $289.

12" Sanyo Monitor with green

screen $299.

13" Sanyo Color Display Monitor

$495.

HP-35—Hewlett-Packard's Personal Computer for Industry. This extremely portable computer features extended BASIC to solve your problems quickly and efficiently along with an advanced graphics system to enhance communication

HP-85 ACCESSORIES—We carry HP. Peripherals (Disk Drives to Graphics Plotters) Enhancements (BASIC Training. General Statistics. Financial Decision Math. Linear Programming $95 ea). HP-85 Accessories; (Enhancement ROMs ROM drawer. Overhead Transparency Kit).- Supplies (Plotter Pens, Tape Cartridges), Interface Modules (HP-IB Interface, HP-IB Interconnect Cables, Serial (RS-232C) Interlace Module). We can get your every HP peripheral made tor the HP-85.

VBICALC PLUS FOR HP-85 Every thing you ever wanted from Visicalc plus plotting. $200.

HP83 VIRGO Has the same computing power as the HP85 without the added cost of tape drive and printer, for use with disc drives and optional printer/ plotter accessories. CALL FOR COMPLETE DETAILS 8c SPECS.

COMPUMART exclusive ATARI

SPECIALS—ATARI 8CO Personal

Computer System—Comes with

8CO operators Manual 16K Rany

Memory module, lOk ROM

Operating System Power,

Supply, TV

Switch

Box

$950.

PERIPHERALS

Atari 410 Program Recorder

$89.95

Atari 810 Disk Drive

(SlOO off with purchase) $699.95

NEW Dual Disk double density

$1499.95 825 Printer (Centronics 737)

S995.00 RS232 Interface w/Cable $249.95 NEW! Light Pens $74.95

NEW! Visicalc for Atari $199.00 Educators Take Note. Atari has extended its 3 for 2 deal until 630-8L Any educational institution that buys two Atari 800s will receive an Atari 400 computer absolutely FREE. Call our sales dept tor complete details.

TMPOKTANT ORDEBDJG INFORMATION All Orders must include 4% shipping and handling. Mass. residents add 5% sales tax. Michigan residents 4% tor sales tax Phones open trom 830 a.m. to 700 p.m.. Mon-Fri. 11:00 am. to 400 p.m. Sat P.O.'s accepted from Dun & Biadstreet rated companies—shipment contingent upon receipt ol

signed purchase order. Sale prices valid tor month ol magazine date only—all prices subject to change without notice. Our Ann Arbor retail store is open 1LOO a.m. to 7,00 p.m. Tues-Fri, lOOO a.m. lo 5,00 p.m. Saturdays.

applen

We cany the most complete inventory ol Apple computers, peripherals, and software. CALL! Our Best Selling Apple System. Save over S250 on our most popular Apple System. System includes a 48K Apple n. Apple Disk. DOS3.3. & Controller, and a Sup R. Mod RF Modulator. List $2209.

COMPUMART Sale Price: $1895.

SOFTWARE FROM APPLE

Apple Plot The perfect graphic

complement for Visicalc. S70

Dow Jones News & Quotes $95

Adventure (Uses 48K) $35

DOS Tool Kit $75

Apple Fortran $200

Tax Planner $120

FROM PERSONAL software

Visicalc $149

Desk Top Plan $99 NEW FROM MUSE

The Voice $39.95

Super Text $150

Address Book $49.95

Miscellaneous Apple n Accessories:

Easy Writer (80 col need a Videx) $249

Easy Mover $49

Easy Mailer $69

NEW from Apple lor the Apple

DOS 3.3 Convert disks to 16 sector format for 23% more storage and faster access $60.

NEW lor the Apple n

From Microsoft

16K RAM Board

$195.00

FORTRAN

$175.00

COBOL

$750.00

Card Reader from Mountain

Hardware

$1,195.00

H-Res Dump for 460 Printer from

the Computer Station

$49.95

HARDWARE ACCESSORIES FOR APPLE

Silentype Printer w/x face $635 Super Sound Generator (mono) $159 (stereo) $259 Light Pen $249 X-IO Controller (plugs into paddle port) $49 Mountain Computer—Expansion accessories for your Apple Introl-lO System $289 Super Talker $299 The Music System $545 ROM plus board w/Keyboard filter $199 Clock Calendar $280 16 Channel A to D Converter $35Q

Apple Expansion Chassis $650 ROM Writer $175

From VIDEX!— Video Term.

80 Cot x 24 line. 7x9 Matrix plug in compatible board for the Apple n. Price $325 without graphics EPROM. With graphics EPROM $350.

S.S.M Serial & Parallel Apple Interface $225

ABTs Numeric Key Plan $UO California Microcomputer Keyboard $195

Apple m is in stock—CALL!

Commodore Strikes Back!

CompuMart carries the entire Commodore line ol computers, peripherals, and accessories— call our sales force today for complete prices and specs

The CompuMart/Commodore Word Processing System

Get crisp, letter quality output and ease of operation that's unsurpassed. This system includes a Commodore 8032 32K CPU. a 4040 Dual Disk, a C-Itoh printer and X/face. and Word Pro 4 Plus (all cables included). Call (or details and low prices. List S5685. COMPUMART $4995.

A complete system including a Dual Disk Drive. Tractor Printer, and an 80 column 32K CPU lor under 34,000. No interfaces needed. Cables included. List S3.985. CompuMart $3635

New accessories irom Commodore lor Commodore Visicalc $199 Word Pro 4 $299

Ozz the Information Wizard $395 Wordcralt 80 $395 Tax Preparation Planner $495 Dow Jones Portfolio Management System $149 Personal Tax Calculator $69 PASCAL Development Packaae $295

Assembler Development Fackage $99

Educators Take Note!! Commodore has extended its 3 for 2 deal until 6-30-81.

Complete Word Processing System for Under $5,000!

COMPUMART has been serving the computer needs of industry since 1971.

We stock, for immediate shipment, only those products from the finest micro-computer manufacturers.

And any product, except software, can be returned within lO days for a full refund even if you just change your mind.

We also honor all manufacturers' warranties. Our expert technicians will service any product we sell that cannot be better, or faster, serviced by the manufacturer's local service center.

Call us for more information on products, product configuration and service. Our phones are open Monday thru Friday, &30 a.m. to 700 p.m. and Saturday 1LOO a.m. to 400 p.m.

We have a staff of highly knowledgeable sales people waiting to hear from you, and to help.

Because service is what we're all about.

800-343-5504

— iA*

SYSTEMS,

n

In Mass. Call 617-491-2700

COMPUMART

' 65 BENT STREET, DEPT. 115, P.O. BOX 568 'CAMBRIDGE, MA 02139

Circle 52 on inquiry card.

The joy of music —

without years of practice!

ALF offers the very finest in music hardware and software for the Apple® II. You can enter your own songs from sheet music and play them back very easily — our detailed manual shows you how, step by step. And there's a growing library of preprogrammed songs available too — now over 115 songs on 7 "albums", priced under $15 each. ALF's highly acclaimed music software has many features found on no other Apple music product — and no customer has ever reported a "bug" or error.

Whether you pick our exciting 9-voice MCI music card at just $195, or our gourmet 3-voice MC16 card at $245, you'll get ALF's topquality hardware that's famous for reliability and clean sound (we've been designing computer-controlled musical instruments since 1975).

So see your Apple dealer today, and be sure to specify ALF music cards for the best performance. When you've seen ALF's total music package, you'll know why some music cards are more equal than others!

Please mention this magazine when requesting information from:

<3|\ A L F Products Inc.

^1/ 1448 Estes Denver, CO 80215 (303) 234-0871 Apple is a trademark of Apple Computer Inc.

EAR TRAINING

Four programs (pitch discrimination, interval recognition, chord recognition, and scale recognition) for the ALF MC16 music card (described above) are available on disk (or cassette). Under $50 for the set, see your local Apple dealer.

For more information write:

ALF Products Inc.

1448 Estes Denver, CO 80215 (303) 234-0871

STATUS REGISTER

0BF - OUTPUT BUFFER FULL ■IBF - INPUT BUFFER FULL •F0 - FLAG 0 (USER DEFINED) • Fj - FLAG 1 (USER DEFINED)

- DRIVE ACTIVE -FILE PROTECT -CASSETTE PRESENT

- BUSY

Figure 3: Definitions of the status-register bits; Flag 0 and Flag 1 may be controlled by the user via the internal software.

+ 5V A

C=_)

0BF

IBF

vcc

VDD

cs

RD WR

A0

SS 3 •

TEST 1 p20

'14

»-C RESET

Pl5

P16

EA

VSS

7

MOTOR POWER LOGIC POWER

DATA-OUT DATA - IN

FORWARD/REVERSE

FAST/SLOW READ/WRITE CLEAR LEADER FILE PROTECT CASSETTE PRESENCE POWER GND SIGNAL GND CHASSIS GND

Figure 4: The interface between the CM-600 Mini-Dek, the 8741A, and the host system.

r:\

-MID-CELL

-CLOCKING TRANSITION

LOGIC LEVEL 1 LOGIC LEVEL 0

Figure 5: The hexadecimal character 3A phase-encoded. This is the algorithm used with the minicassette controller. It is not the logic level of a bit cell that determines its value, but the presence or absence of a mid-cell transition.

78 April 1981 © BYTE Publications Ire

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Available with stylus or optional cursor.

The HIP AD™ digitizer

Inexpensive input to your computer

The HIPAD™ digitizer can be used for both converting graphic information into digital values and as a menu. Utilizing either the stylus or the optional cursor, the operator can input graphic data into the computer by locating individual points on the digtizers 11" x 11" (28cm x 28cm) active area. In the "stream mode" a continuance of placements of coordinate pairs may be input.

Not a kit, the HIPAD™ comes complete with both RS-232C and parallel interfaces and has its own built-in power source. The origin is completely relocatable so coordinates may be positive or negative for a true reference value and oversized material may be input by simply resetting the origin.

Accurate positional information, free form sketches, even keyboard simulation

All can be entered using the multi-faceted HIPAD™ digitizer. Its capabilities and low price make the UL listed HIPAD™ a natural selection over keyboard entry, inaccurate joysticks, or expensive approximating light pens. It's perfect for inputting isometric drawings, schematics, X-rays, architectural drawings, business graphs, and many other forms of graphic information, as well as creating your own graphics.

Use it with Apple II™ , TRS-80 Level II ™, PET ™ or other popular computers

The HIPAD's™ built-in RS-232C and parallel 8 bit interfaces make it all possible. (For Apple II order DT-11A, for TRS-80 or PET order DT-11). Furthermore, you get English or metric scaling, data format (Binary/BCD/ASCII), selectable baud rates, and resolution of either .005" or .01".

For complete information contact Houston Instrument, One Houston Square, Austin, Texas 78753. (512)837-2820. For rush literature requests, outside Texas call toll free 1-800-531-5205. For technical information ask for operator #5. In Europe contact Houston Instrument, Rochesterlaan 6, 8240 Gistel, Belgium. Telephone 059/27-74-45.

Available with optional display. 'U.S. Suggested retail price

TM HIPAD is a trademark of Houston Instrument TRS-80 is a trademark ot Tandy Corporation APPLE is a trademark ol Apple Computer Inc. PET is a trademark of Commodore Business Machines, Inc.

Circle 53 for literature

Circle 54 to have representative call

houston instrument

GRAPHICS DIVISION OF

BAUSCHSLOMB ▼

Text continued from page 12: scheme, the data format is also up to the user. The 8741A reads and writes blocks of variable length with an 8-bit checksum for error detection automatically appended. An option is to use the 8741A to check for errors by generating a CRC (cyclic redundancy check) code instead of a checksum, as in the CRC-16 error code used for floppy disks.

A block starts with a Sync character (hexadecimal AA), followed by the data (up to 64 K bytes), which is in turn followed by the checksum byte and trailing Sync

character. Blocks of data are separated by an IRG (inter-record gap). The IRG is such a length that the transport can stop and start within an IRG. The CM-600 drive specification calls for a worst-case start or stop time of 150 ms. A 450 ms IRG was selected for the 8741A to allow plenty of margin for both controlling the transport (ie: starting and stopping) and detecting an IRG during the SKIP operation.

The 8741A Controller Software

The goal of the software design for this application was to make the UPI

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41A microcomputer into an intelligent cassette-control processor. The host microprocessor (8085A, 8080A, 8088, etc) issues a high-level command such as READ or WRITE to the 8741A, which accepts the command and performs the requested operation. Upon completion, it returns a result code notifying the microprocessor of the outcome (eg: Good-Completion, Sync Error, etc). Table 1 on page 92 lists the high-level command and result codes for the functions performed by the minicassette controller.

The internal 8741A software can be roughly divided into the various command functions. At the top of the hierarchy is the command recognizer. Its job is to get a command from the

f WRITE J

GET CNTLSB/ CNTMSB

YES

Terror exit j

INITIALIZE VARIABLES AND START TIMER

START TRANSPORT

(error EXIT J

WRITE IRG AND STOP TRANSPORT

C EX'T )

Figure 6: Flowchart of the WRITE command sequence.

SEE THE COMPLETE SAMS LINE AT NCC. BOOTH #5209. Circle 55 on inquiry card.

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Konan, known throughout the industry for its leading, innovative, guaranteed controllers for S-lOO systems, does it again. Now, it offers you more of the expanded capabilities you want.

Take your pick to suit your needs. There's the SMC-lOO™ storage module (SMD or CDC 9760 interface) hard disk controller. There's the HARDTAPE™ subsystem which offers Winchester hard disk control with tape back up. Or maybe you could use Konan's new KNX-500, software compatible with the AM-500*, for lO megabyte fixed/ removable media hard disks. The "DAVID" is Konan's new error-correcting intelligent disk controller for 51/4" and 8" Winchester hard disk drives. And the "ENHANCER" is an intelligent reel-to-reel tape controller with high speed printer port for spooling, offline sorts, copies, etc. Watch for new controllers coming soon!

Also, Konan introduces OCTOPORT™ and OMNIPORT™-two new serial I/O boards. OCTOPORT™, the 8-port board, offers a real time clock and full interrupt control. And the 16 port OMNIPORT™ offers you an efficient, economical board where more than 8 ports are needed.

With these and other quality products, Konan shows again that when it comes to S-lOO systems, it is definitely in control. (And all at attractive OEM. and dealer prices.)

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'Alpha Micro AM-500 is a irademark of Alpha Micro Systems.

IN CONTROL. SMC-lOO, HARD TAPE, KNX-500. OCTOPORT, and OMNIPORT are trademarks ot Konan Corporation.

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NO

COMPLEMENT TAPE INPUT

YES

GET NEXT BIT OF CHARACTER

Fn=0

CEm )

<^bit

0 \,_

NO

3 jr

YES

COMPLEMENT BIT

'

/CHARACTERS.

YES

\WRITTENyS

NO

GET NEXT CHARACTER

'

GENERATE CHECKSUM

( EX'T )

Figure 7: Flowchart of the WRITE interrupt routine.

microprocessor and branch to the appropriate command routine, executing until either the operation specified by the command is complete or aborted by the microcomputer or CM-600. The command routine then returns to the command recognizer to await the next command. Since only one command routine can be in execution at any one time, the working registers can change function based upon which command is active. These register names were assigned according to their function to aid program clarity. To understand the operation of the controller, let us examine the flow of the various commands in greater detail.

WRITE Command

When the WRITE command is issued by the microprocessor, the 8741A expects a 16-bit unsigned number specifying the number of bytes to be written onto the tape to

follow immediately. The controller requests only the desired number of data bytes by keeping track of the transfer count internally. All data transfers to and from the computer are double buffered. Before starting the transport, the 8741A checks the transport's status, verifying that the cassette is present and writing to the tape is not inhibited. If the drive is not ready for the data transfer, an appropriate error code will be returned; otherwise, the transfer will commence. The flowchart of this function is diagrammed in figures 6 and 7.

The controller begins the block transfer by writing a 450 ms IRG, followed by the leading Sync character, the data, the checksum character, and the final Sync character. The data is encoded with the phase-encoding algorithm described earlier before being written onto the tape. The internal timer is Text continued on page 86

82 April 1981 © BYTE Publications Inc

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START TRANSPORT

(error EXIT J

WAIT FOR CHANGE IN TAPE OUTPUT DATA

START TIMER

STORE DATA IN BUFFER

SKIP TO IRG

(ERROR EXIT )

YES

EMPTY BUFFER

(ERROR EXIT J

YES

( EXIT )

(error exit J

TRANSFER DATA FROM BUFFER TO DBBOUT

Figure 8: Flowchart of the READ command sequence.

Text continued from page 82:

used to signal both the initial cell transition and the mid-cell transition, generating an internal interrupt every 208 /is. Thus, a byte is written every sixteen timer interrupts, or 3.3 ms. If nothing unusual happens during the operation, it returns a GoodCompletion result code (hexadecimal 00) to the host.

If an error occurs, the 8741A minicassette controller provides error

wrap-up facilities, protecting the information on the tape from being corrupted. For example, if the clear leader of the tape is found during a write operation, the transport is halted immediately. Another error results from the processor being late in supplying data to the controller, causing a data-underrun error and aborting the data transfer. A 450 ms IRG is then written onto the tape before the transport is halted.

READ Command

The READ command provides error checking similar to the WRITE command. Once the READ command is issued by the microprocessor, the controller checks for cassette presence and starts the transport. The data output from the transport is then examined and decoded continuously. This function is shown in the flowcharts of figures 8 and 9. The first character must be a Sync, or the

86 April 1981 © BYTE Publications lnc

Introducing

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Paper Tiger 460 Print Sample

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f RD INT J

STORE DATA OUTPUT BIT IN REGISTER

RELOAD AND START TIMER

( EXIT )

Figure 9: Flowchart of the READ interrupt routine.

controller will abort the read operation, return a Bad-First-Sync result code (hexadecimal 42), and advance to the next IRG of the tape. If the Sync character is correct, succeeding characters are read into an internal 30-character FIFO (first-in, first-out) buffer, allowing the processor over 99 ms of service latency before a dataoverrun condition occurs. Whenever the DBBOUT register is empty, data is transferred to it from the FIFO buffer. This continues until an IRG is encountered, at which point the transport is stopped. The controller then tests the last character. If it is a Sync, the controller compares the ac

f SKIP J

GET BLKCNT

YES

SELECT FORWARD

AND

START TRANSPORT

NO

SELECT REWIND

AND

START TRANSPORT

YES

SELECT 3 IPS SPEED

NO /BLKCNT\ YES

>8 P

SELECT 5 IPS SPEED

SKIP A BLOCK

DECREMENT BLKCNT

NO

STOP TRANSPORT

Terror exit J

SKIP A BLOCK

DECREMENT BLKCNT

STOP TRANSPORT

( EX'T )

STOP TRANSPORT

C EXIT )

Figure 10: Flowchart of the SKIP command sequence.

88 April 1981 © BYTE Publications Inc

Meet the Tiger with, a biaaer bite.

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Paper Tiger 560 Print Sample

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For data processing, word processing and small business applications, this is your Tiger. The business-sized Paper Tiger™ 560.

It's a Tiger you can count on.

Call TOLL FREE 800-258-1386 (In New Hampshire, Alaska and Hawaii, call 603-673-9100.) Or write: Integral Data Systems, Inc., Milford, NH 03055.

Tiger 560

■Lw) jlntegral Data Systems, Inc.

Circle 59 on inquiry card.

*Suggested U.S. retail price.

SELECT REWIND AND START TRANSPORT

WAIT 50ms

STOP TRANSPORT

C exit )

( EXIT )

Figure 11: Flowchart of the REWIND command sequence.

cumulated internal checksum to the block's checksum, the last character of the block. If they match, a GoodCompletion result code (hexadecimal 00) is returned to the host. Otherwise, the appropriate error-result code is returned (ie: Bad Sync2 or Checksum error). The READ command also checks continuously for the End-ofTape (EOT) clear leader and returns the appropriate error code if it is found before the read operation is complete.

SKIP Command

The SKIP command (see figure 10) allows the host to skip up to 127 blocks forward or backward. Immediately following the command byte, the controller expects an 8-bit signed-magnitude byte specifying the number of blocks to skip. The most significant bit of this byte selects the direction of the skip (0 = forward, l = reverse). SKIP provides two search speeds in the forward direction. If the number of blocks to skip is greater than 8, the controller uses fast forward (5 ips) until it is within 8 blocks of the desired location, then

switches to the normal read speed of 3 ips to allow accurate placement of the tape.

The reverse SKIP uses only the rewind speed (15 ips). Like the READ and WRITE commands, SKIP also checks for EOT and Beginning-ofTape (BOT) depending upon the tape's direction, returning an error code if either is encountered before the specified number of blocks have been skipped.

REWIND Command

The REWIND command routine, figure 11, sets the transport to fast rewind of 15 ips and waits until the clear-leader status input of the transport is active for more than 50 ms. (There is a hole at each end of the tape. It is guaranteed not to cause the clear-leader input to be active for more than 50 ms.) Once the clear leader is found, the CM-600 is stopped and a Good-Completion result code is loaded into DBBOUT.

ABORT Command

The final command, ABORT, is not a stand-alone command like the

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0 Controls 256 BSR remote switches—not just 16 0 Hardware driven—requires minimum software 0 No ultrasonic link—prevents erratic operation 0 No BSR command module necessary

Real Time Clock gives Remote Controller an added dimension!

Real Time Clocks are now available to make your remote controller even more powerful. The RTC feature allows for energy consumption scheduling, event scheduling and much more. Your imagination is your only limitation when it comes to the ways which this RC/RTC combination can be used.

Real Time Clocks feature:

0 Lithium battery back-up

0 Crystal controlled accuracy (.002%)

0 Clock generates interrupts (seconds, minutes, hours) for foreground/background operation

0 Complete software in BASIC to Set and Read clock

etc)

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S-100 CONTROLLER BOARD S-100 REAL TIME CLOCK BOARD ENCASED CONTROLLER

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90 April 1981 © BYTE Publications Inc

Circle 60 on inquiry card.

Big Savings for SS-50 Bus Computerists

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After five years of solid accomplishments, it's time to celebrate. So we've slashed prices for a gigantic 5th anniversary sale. Now, for a limited time, you can get Percom design and Percom quality at enormous savings. But don't wait. Sale ends April 30th and quantities are limited to stock on hand.

Save $100.00 on fully assembled, tested and burned-in RAM cards! Hurry, regular prices in effect after April 30th.

These RAM cards feature 1-Mbyte extended addressing; buffered data, address and control lines; and, on-card voltage regulation. Cards are fully tested and burned-in. User manuals include 6800 & 6809 diagnostic memory test programs.

M24SS 24-Kbyte STATIC RAM CARD

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Memory is organized as three independent Kbyte blocks. Each block may be located at any 8-Kbyte boundary of a 64-Kbyie address space • Also

available in 8- and 16-Kbyte versions at regular prices. 8-Kbyte RAM expansion kit includes extra RAM chip, plus sockets and other parts. Kit price is $139.95. • Uses 2114L RAM chip, circle 367

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Expandable to 48 Kbytes • Memory is organized as three $100! independent 16-Kbyte blocks. Each block may be located in any of the four 16-Kbyte zones of a 64-Kbyte address space • Special "map-out" strapping can be used to depose any 8-Kbyte block from upper 32-Kbyte memory • Uses type 4116 RAM chips • 16-Kbyte RAM expansion kit includes extra RAM chip, plus sockets and other parts. Kit price is $99.95. circle sea

Watch for the COLOi?AMA-50M

This soon-to-be-announced color VDG card for the SS-50 bus features eleven colorful display formats in 2 to 8 colors, plus 2-color alphanumerics; full graphic resolutions from 64X64 pixels to 256X192 pixels; memory-mapped instant display control; low-cost modulator option for TV interface; 1-Mbyte extended addressing; cassette I/O option; and, operating software. Introductory price is only $219.95.

PERCOM DATA COMPANY, INC

211 M KIRBY GARLAND. TEXAS 75042 1214)272-3421

PRICES AND SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE.

PRICES DO NOT INCLUDE SHIPPING AND HANDLING.

COLORAMA-50. ELECTRIC WINDOW. LFD-400. PSYMON and SBC/9 are trademarks of Percom Data Company. Inc.

Nobody supports the SS-50 bus like Percom

Our field-proven software for 680X computers includes monitors, operating systems, drivers, editors, assemblers, debuggers and highlevel languages like Super BASIC — our popular extended disk BASIC interpreter.

Some of the other hardware products available include versatile prototyping cards in both 30- and 50-pin versions, extendable 50-pin motherboards and 30-pin I/O card motherboards. Function cards, prototyping cards and motherboards are optionally available with goldplated bus connectors. Also, most function cards are available in 86pin, EXORciser bus compatible versions.

Quality Percom products are available at Percom dealers nationwide. Call toll-free, 1-800-527-1592, for the address of your nearest dealer, or to order direct from Percom.

EXORciser is a trademark of Motorola Corporation

others. Instead, the ABORT function is part of each of the other commands, allowing the microcomputer to abort the current operation. If a command is found in DBBIN register during the operation of one of the

other commands, the command is compared to the ABORT command code. If it matches, the routine in execution is terminated. The AbortComplete result code is then placed in DBBOUT to acknowledge the abort.

Hexadecimal

Hexadecimal

Command

Representation

Result-Codes Returned

Representation

READ

01

Good-Completion Buffer Overrun Error Bad Synd Error Bad Sync2 Error Checksum Error Command Error End-of-Tape Error

00 41 42 43 44 45 46

REWIND

04

Good-Completion

00

SKIP

03

Good-Completion End-of-Tape Error Beginning-of-Tape Error

00

47 48

WRITE

02

Good-Completion Buffer Underrun Error Command Error End-of-Tape Error

00 81 82 83

Table 1:

Commands

issued by

the host processor and possible

resultant codes

returned

lo it

when the EPROM

'n the 8741A is programmed with the software de

scribed ir

this

article.

The aborted routine will, however, exit gracefully. An aborted READ or SKIP advances to the next IRG before terminating. An aborted WRITE command will record an IRG before terminating execution. This protection helps insure the integrity of data stored on the minicassette tape.

Conclusion

This application illustrates how the 8741A device can provide intelligent peripheral interfaces between a computer and a peripheral device such as the CM-600 Mini-Dek transport. This benefits the microprocessor system by divorcing it from the close management required by the peripheral. It interfaces to the 8741A controller producing a high-level I/O interface. The 8741A provides all the low-level peripheral-control functions. Another benefit of this task modularity is that it allows the software to be modified and upgraded without affecting the computer system software. In fact, the 8741A software could be adapted to control other cassette transports without affecting the microprocessor. ■

Omikron's Mapper + NEWDOS/80 8 Drives for the TRS-80

NEWDOS/80 is Apparat's latest upgrade to NEWDOS. Features include variable length records, chaining, and drivers specifically configured for Omikron's MAPPER II. $150.

MAPPER II adapts the TRS-80 to run both 5" and 8" drives. With NEWDOS/80, storage is increasedto300Kper8"drive.$99plus$50 per cable connector.

MAPPER I adapts the TRS-80 to run the vast library of CP/M software as well as the TRS-80 software. All Lifeboat Software may be ordered for the MAPPER I. All MAPPER I CP/M software is compatible with the CP/M for the Model II. With MAPPER II and 8" drives, the Model I becomes disk compatible with the Model II.

Standard features include lower case support, serial and parallel printer drivers, and an addressable cursor. MAPPER I is supplied with complete utilities including a memory test, a disk test, a copy program, and a proprietary program for converting TRS-DOS files to CP/M files. $199.

WORD PROCESSING-MAPPER I supports professional word processors like the Magic Wand and Word Star (see reviews in June 80 Kilobaud). Omikron's implementation includes a blinking cursor, auto repeat, shift lock, debouncing, and an input buffer that eliminates missed characters. Magic Wand super discount price $299.

FIEID PROVEN DESIGNS-After one year of MAPPER production, Omikron has established an impeccable reputation for reliability, integrity, and user support. Omikron's customers include the US Government, major corporations, universities, medical doctors, and professionals in all fields.

SYSTEMS—Omikron sells complete systems featuring Model II compatible Shugart disk drives. Call for prices and delivery.

FOREIGN ORDERS must include full payment in US funds plus $25 for air shipping and handling.

See review in July 80 BYTE By Jerry Pournelle.

*CP/M is a TM of Digital Research. TRS-80 is a TM of Tandy Corporation.

Circle 62 on inquiry card.

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810 Basic $1516

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Aitos Call

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HRZ II-32K D (Assm) $2300

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Experienced Equipment

Centronics 779.. $450 Comprint 912 Teletype Model 40 (New) $2750

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Prices reflect 3% cash discount. Product shipped in factory cartons with manufactures warranty. Add 2%, a minimum of $5, for shipping and handling.

BYTE April 1981 93

Software Review

A Reformatter for CP/M and IBM Floppy Disks

John A Lehman, 716 Hutchins #2, Ann Arbor MI 48013

In the "old" days of personal computing (ie: five years ago), the transfer of programs or data between large and small computers was not a major problem. You simply turned on the paper-tape punch in your Teletype ASR33 terminal and listed the program on the source computer. You then took the paper tape to the second computer, inserted it in the paper-tape reader, and read it in. This was slow, noisy, and did not encourage transfer of long programs, which microprocessor-based computers didn't have enough memory to run anyway.

The situation has changed quite a bit. Small computers are no longer mere experimenter's toys, but serious tools for science and business. Instead of being programmed only in machine language or BASIC, they are now programmed in FORTRAN, Pascal, PL/I, COBOL, and many other popular high-level languages. The fact that small machines can now run the same programs as the

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TMATARI is trademark of Atari Corp.

larger ones has increased the demand for program transfer between machines. For example, it is not uncommon for me to take a 1000-line FORTRAN program from a large timesharing system and run it (virtually unchanged) on my CP/M system. However, a program of that size is too large to dump to paper tape, even if any of the systems I use still had a Teletype terminal with a papertape reader.

This is where Microtech Exports' Reformatter for floppy disks comes in. IBM originally intended the floppy disk to be a replacement for punched-card data entry. The IBM 3740 Data-Entry System Basic Exchange Format (BEF) is a fixed-field, uncomplicated standard for data transfer between IBM equipment. Many machines that use floppy disks do not use BEF for normal use, because it is inefficient. However, almost all IBM equipment can use it to transfer files. Reformatter allows the transfer of data both ways between CP/M and BEF files.

Reformatter is a useful product for anyone who wants to take programs developed on one system and run them on another. For example, I have put a number of published FORTRAN packages onto my CP/M system. Going the other way, to avoid being charged for development time, I use my system to develop FORTRAN and PL/I programs to run on larger systems.

Another group who will find Reformatter useful are people with access to large computers that have peripherals they would like to use on a smaller system. For example, my CP/M system has neither 9-track magnetic tape nor a high-speed line printer, but I have access to an IBM Series/l system that does.

So much for the motivation for using the Reformatter package. How does it work? Surprisingly well. It allows

Name

Reformatter

Format

8-inch floppy disk

Type

Translates between CP/M and IBM BasicExchange-Format floppy disks.

Computer

Any CP/M system and any IBM system. Requires two 8-inch disk drives.

Manufacturer

Microtech Exports 912 Cowper St Palo Alto CA 94301 (415) 324-9114

Audience

Anyone with access to both CP/M and IBM systems.

Price

$195

94 April 1981 © BYTE Publications Inc

Circle 63 on inquiry card.

Circle 64 on inquiry card.

BUD

■u

dotasouth announces. • •

THE TOTAL PRINTER PACKAGE!

////

WW

T

9hoa

[

• •

With so many matrix printers on the market today, it may seem tough to find exactly the right one for your application. Some models may offer the speed you need, others the communications flexibility and still others the forms handling capability. But no printer offers all the features you need...until now.

The DS180 matrix printer provides the total package of performance features and reliability required for applications such as CRT slave copy, remote terminal networks and small to mid-range systems. Not a "hobby-grade" printer, the DS180 is a real workhorse designed to handle your most demanding printer requirements. And pricing on the DS180 is hundreds of dollars below competitive units.

High Speed Printing-Bidirectional, logic-seeking printing at 180 cps offers throughput of over 200 Ipm on average text. A 9-wire printhead life-tested at 650 million characters generates a 9x7 matrix with true lower case descenders and underlining.

Non-volatile Format Retention-a unique programming keypad featuring a non-volatile memory allows the user to configure the DS180 for virtually any application. Top of form, horizontal and vertical tabs, perforation skipover, communications parameters

and many other features may be programmed and stored from the keypad.When your system is powered down, the format is retained in memory. The DS180 even remembers the line where you stopped printing. There is no need to reset the top of form, margins, baud rate, etc....it's all stored in the memory. If you need to reconfigure for another application, simply load a new format into the memory.

Communications Versatility-The DS180 offers three interfaces including RS232, current loop and 8-bit parallel. Baud rates from 110-9600 may be selected. A 1K buffer and X-on, X-off handshaking ensure optimum throughput.

Forms Handling Flexibility-Adjustable tractors accommodate forms from 3"-15". The adjustable head can print 6-part forms crisply and clearly making the DS180 ideal for printing multipart invoices and shipping documents. Forms can be fed from the front or the bottom.

If you would like more information on how the DS180's low-cost total printer package can fill your application, give us a call at Datasouth. The DS180 is available for 30-day delivery from our sales/service distributors throughout the U.S.

data@©A

computer corporation

A-IAI\ nminht Cwono Dngil . PhorlnHs MnrlhOarnling 9891(1 • 7(\A/ dOt-H^Ctn

you to initialize Basic-Exchange-Format floppy disks, list their directories, change the file definitions, dump, display, edit, or delete the files, and to transfer data to and from CP/M files. Automatic character-set conversion and proper handling of conversion between fixed- and variable-record formats can be used or disabled. All of these functions work well and rapidly. Reformatter can transfer a file between CP/M and BEF twice as fast as an IBM Series/1 can transfer that same file to hard disk. Its file-manipulation facilities are also considerably more flexible than are the IBM-supplied versions.

Reformatter is also easy to use. It is menu driven, and entering a carriage return at any point backs you up one level in the menu. In terms of ease of use, it ranks in the top quarter of the CP/M software that I have used, and in the top 1% of IBM software.

In fact, any problems I had using this package stemmed from IBM's tendency to do things the hard way from the user's standpoint. With any IBM software that I have used, you are required to specify the size of a file at the

time you create it. On the other hand, CP/M can dynamically expand a file; moreover, it uses variable-length records, as opposed to IBM's fixed-length. The result is that you must specify the size of the IBM file without knowing the size of the CP/M file. There are a number of ways around this. You can set up your IBM disks with only one file per disk, which is not as wasteful as it sounds, since a BEF disk holds about 50 K bytes of text or programs (each line takes a full 128 bytes). The second solution is to purposely create overlapping files, copy them, check the directory for the resulting sizes, and repeat the process again. Finally, you can write a program that counts the lines in a CP/M file and tells you how many tracks and sectors the IBM disk will require.

In summary, if you have access to an IBM or an IBMcompatible computer system and you want your file- and data-transfer problems solved, Reformatter is probably what you've been looking for.

If you have a TRS-80 or access to DEC machines, Microtech Exports has another version for you.H

When will the Personal Computer Explosion touch YOU?

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Start your subscription today. Call Toll Free 800-258-5485

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96 April 1981 © BYTE Publications Inc

1.1

1 m ■

' v 4 1

ill 1

W^^^^KM

L'''1h 1

m *fl^|F kfifl^V

"And in conclusion,

111 only use

my exceptional powers

for the good of mankind."

"That's a vow all we Vector 3005s make. And it's not one we make lightly.

"After all, being the only product on the market with a Vector 3 terminal, a 5%" floppy, and a 5K" Winchester rigid disk drive that provides 5 megabytes of storage is quite a responsibility. It used to take 20 floppies to give you that kind of capacity.

"Our powers don't stop there, however. Each 3005 also comes with a 32-bit error-correcting code —the first time sophisticated IBM-style technology has been available on a small business system.This lets us detect and correct errors, and almost completely eliminates data loss on disks due to dirt, wear, or damage.

"All this makes us pretty awesome, all right. But there's more. When coupled with Vector's MEM0RITE III and EXECUPLAN software packages, we give you a 30,000 word dictionary, the ability to create your own phrase library, a teaching manual right on the screen, pass word security, plus a host of other word processing capabilities as well as financial planning, forecasting and basic accounting.

"And we're reliable. Our powers won't diminish, our abilities won't fade, and dedication to mankind won't weaken.

"For more information and your nearest dealer, call Vector at 800-423-5857. In California, call 800-382-3367. Or write to them at 31364 Via Colinas, Westlake Village, CA 91362.

"Thank you all for coming today. And I hope we'll have the chance to do business together in the future!'

VECTOR GRAPHIC INC. COMPUTERS FOR THE ADVANCEMENT OF SOCIETY.

Circle 66 on inquiry card.

Technical Forum

MicroShakespeare Revisited

or Kilobard

Andrew Kalnik, 3201 Wamath Dr, Charlotte NC 28210

William Shakespeare would have made a first-rate computer analyst. He had all the qualifications: superb powers of observation, capacity to deal with complex problems, imagination, and a fair ability to express himself.

Looking at his writings, you can easily recognize the vocabulary of a systems consultant making his pitch to land an installation contract. Presented in a conference room against a backdrop of easel charts, with goldstamped proposal binders on the broad walnut table, some of his phrases would be right in place:

"...I'll teach you how to flow..." (The Tempest, Act II, scene i)

"What is written shall be executed..." (Titus Andronicus, Act V, scene ii)

"I will execute, and it shall go hard,

but I will better the instruction..."

(Merchant of Venice, Act III, scene i)

"...Our interpreter does it well..." (All's Well That Ends Well, Act IV, scene iii)

From other lines, you can feel the sympathy the Programmer of Avon would give wretches like you and me sentenced to a debugging session:

"O hateful error, melancholy's child

Why dost thou show to the apt thoughts of man The things that are not? O, error, soon conceived

Thou never comest into a happy birth..."

(Julius Caesar, Act V, scene iii)

Here's another short quiz to test how well you can match Master Will's golden words against the shiny silicon jargon of our art. (Try your hand at the other quiz in the April 1980 BYTE, page 104.) What we've done is to make free translations from Shakespearean phrases into terms familiar in computing.

Simply match the letter of the most pertinent modern phrase against the quotations. No prizes, just the satisfaction of puzzling out the answers. The answers and ratings are on page 184. [Editor's note: Each of the items 1 thru 20 will match to one of the answers "a" thru "t, " so read through all the answers before you try to make a match. ...GW]

1. (

2. (

3. ( )

4. (

5. ( )

( )

7. (

We'll evaluate

a. "And that

your purpose,

crashed the

and put on a

whole

form...

program!"

Troilus and

Cressida,

Act III, scene

iii

...an adder did

o. "We'll have

it...

the function

A Midsum

graphed on

mer Night's

screen in a

Dream,

few seconds."

Ill/ii

That one error

:. "I wish I could

fills him with

check the reg

faults.

ister flags."

Two

Gentlemen

of Verona,

V/iv

...shall run in a

d. "There isn't

new channel

much time to

fair and

convert the

evenly...

analog readings

I Henry IV,

between inter

I/i

rupts."

...unpleasantest

2. "Put a scope on

words that ever

it to check

blotted paper...

those big

The Merchant

input spikes."

of Venice,

Ill/ii

...inferreth

:. "With the new

arguments of

I/O board, it

mighty

should just

strength...

perk right

Ill Henry VI,

along."

V/ii

...the minute of

g. "That frosts me

their plot is

—we're not get

almost come...

ting any output

The Tempest,

from those

IV/i

ANDs."

98 April 1981 © BYTE Publications toe

C ^Pascal

Efficiency^rortability Flexibility^otrong Typing

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BYTE April 1981 99

Technical Forum.

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See answers on page 184. ■

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100 April 1981 © BYTE Publications Inc

Circle 68 on inquiry card.

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Programming the Game of Go

Jonathan K Millen

661 Main St Concord MA 01742

Go is a board game. Like chess, it is a game of pure skill; moreover, a considerable body of literature has been devoted to it. Go was invented in China around 2000 BC. Since its introduction into Japan around 700 AD, it has flourished there to the extent that the most accomplished masters of the game are now Japanese. However, the game has spread world-wide. In the United States, one can find Go clubs in the vicinity of large cities and universities, and most large bookstores have at least one substantial book on the game.

Go is played on a 19 by 19 square grid having black spots on nine intersections, as illustrated in figure 1. The traditional board, called a Go Ban, is a wooden block about 17 inches square and several inches thick, with four short feet. It stands alone as a table at just the correct height for players sitting on floor cushions.

One player has a supply of black stones; the other, white stones. The stones are disks about the same size as the grid spacing; they are approximately three-eighths of an inch thick in the middle and almost sharp around the edge. The black stones traditionally are made of slate, and the white stones of clam shell.

Players move alternately, each

placing a stone on the point of intersection of a pair of grid lines. The object of the game is to enclose the most area, measured by the number of unoccupied points enclosed by stones of a given color. A point is enclosed by, say, black, if no path along the grid from the point runs into a white stone. Figure 2 shows some enclosed areas. Note that the edge of the board can form one boundary of an area.

A player can increase his area by capturing the opponent's stones. Stones are captured a connected group at a time. A set of stones forms a connected group if there are paths along the grid from any stone to any other stone in the set, such that all points on the path are occupied by stones in the set. This criterion is easy to visualize because the stones, being as large as the grid spacing, actually touch along paths of connection. The phrase "connected group" also implies that the stones in the group are all of the same color, and that the group is not merely a part of some larger connected group.

A group of stones is captured when it has no liberties. A liberty of a connected group is an unoccupied point adjacent (vertically or horizontally) to a stone in the group. If a group has just one liberty, the opponent may capture it by placing one of his stones

on the liberty. The opponent then picks up the captured stones and keeps them as prisoners. At the end of the game, a player's point count of area is augmented by the number of prisoners he has captured. Figure 3 shows a group having one liberty.

The game ends when both players pass consecutively, because they both see no further advantage in playing more stones. Usually, when this happens, there are white stones within areas enclosed by black, and vice versa. These stones have been given up because the owner can predict that they will be captured. They are removed as prisoners at the end of the game before counting the score.

The remaining rules are technicalities. Two that have a significant effect on the game, concerning "ko" and "suicide," will be mentioned later on. The rest involve details of ending the game and scoring, and are rarely invoked.

A Go-Playing Program

A Go opponent, called Wally, was programmed on a KIM-1 within its approximately 1 K bytes of memory. Wally's algorithm is based on essentially two capabilities: finding the liberties of a connected group, and matching a few common patterns. Moves take less than a second.

A 15 by 15 board was used because

102 April 1981 © BYTE Publications Inc

Circle 69 on inquiry card.

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Figure 1: The Go board. Players move alternately, placing stones on the points of intersection of the lines, rather than in the spaces. The nine dots are handicap-stone locations. The line spacing is about 2.2 cm (seven-eighths of an inch).

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Figure 2: Enclosed areas. Points marked x are in areas enclosed by one player or the other. The figure shows five black points and eight white points.

Figure 3: A black group with exactly one liberty, marked x. If it is white's turn, he can capture the black group by placing a stone at x and removing the black group as his prisoners.

it was convenient for addressing reasons to represent it internally within a single 256-byte page, using one byte per point. Although there would be room for a 16 by 16 board, a Go board ought to have a center point. Rows and columns were numbered from 1 to F (in hexadecimal) so that the coordinates of a move could be entered on the KIM keyboard.

When a move is entered, Wally responds with the coordinates of his move on the KIM display, and the complete board is also output on a video terminal. The display of a game in progress is shown in photo 1.

Once the board representation and the input and output routines were set up, the first major component of the

104 April 1981 © BYTE Publications Inc

Circle 70 on Inquiry card.

Circle 71 on inquiry card.

Multi-User

UniFLEX is the first full capability multi-user operating system available for microprocessors. Designed for the 6809 and 68000, it offers its users a very friendly computing environment. After a user 'logs-in' with his user name and password, any of the system programs may be run at will. One user may run the text editor while another runs BASIC and still another runs the C compiler. Each user operates in his own system environment, unaware of other user activity. The total number of users is only restricted by the resources and efficiency of the hardware in use.

The design of UniFLEX, with its hierarchical file system and device independent I/O, allows the creation of a variety of complex support programs. There is currently a wide variety of software available and under development. Included in this list is a Text Processing System for word processing functions, BASIC interpreter and precompiler for general programming and educational use, native C and Pascal compilers for more advanced programming, sort/merge for business applications, and a variety of debug packages. The standard system includes a text editor, assembler, and about forty utility programs. UniFLEX for 6809 is sold with a single CPU license and one years maintenance for $450.00. Additional yearly maintenance is available for $100.00. OEM licenses are also available.

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program to be written was the routine that walks through a connected group of stones, marking the members of the group, and both marking and counting its liberties. Called COUNT, this routine is a variety of the maze-search algorithm. It was programmed recursively in machine language.

What COUNT does for each board location it looks at is based on the "invariant assertion" that any point it looks at is one of the following:

• a stone in the connected group

• a liberty of the connected group

• a stone of the other color adjacent to the connected group

If it is looking at a stone in the group, it checks to see whether that stone has previously been marked. If not, it marks the stone and calls itself to repeat the same process, starting with each of the four locations north, east, south, and west of the present stone.

Marking a stone or point, of course, means to set a particular bit in the byte corresponding to that point in the board representation. Other bits encode whether the point is

■J

2

1 234!«;i)IICDEf 0 0 0 • - ♦ 0 - IIQ . . .

3 4 S 6 7 8

'. • • • . • t • t •

. ......

I.M.

9

A 1 C D

E F

•••• . e

o •••#0.

Photo 1: A game in progress. Wally (the computer) is playing black, represented by the solid-looking crosshatches (§). The author is playing white, represented by Os. The computer uses a 15 by 15 board; the points of play are indicated by periods. In this game, black was given a nine-stone handicap.

occupied and, if so, by what color stone.

If COUNT is looking at an unoccupied point, it marks the point as a liberty and increments the count of liberties, unless the point has already been marked and counted.

If COUNT is looking at a stone of the other color, it does nothing, and

just returns.

If a stone is on the edge, or first line, of the board, then one (or, in a corner, two) of its neighbors will be off the board. If COUNT is called for an off-board location, it returns immediately.

Note that, if COUNT starts on a stone and operates as described above, the recursive calls to COUNT will carry the center of attention all over the group and onto all neighboring points. The invariant assertion is satisfied because COUNT progresses one step each time only from stones in the group, as sketched in figure 4.

The algorithm for COUNT is specified concisely in listing 1 using a kind of "structured English." The rest of the Go-playing program will be specified similarly, as a collection of modules like COUNT.

Recursion is not difficult to implement; COUNT just calls itself with the usual jump-to-subroutine instruction for each of the neighboring points. The current board location is in a register; it is saved on the KIM stack before it is replaced by the location of each neighboring point, and then restored upon return from each call. The size of the connected group

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106 April 1981 © BYTE Publications Inc

Circle 72 on inquiry card.

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BYTE April 1981 107

is limited by the size of the stack; one byte of board location plus two bytes of return address are pushed for each call, and the calls are nested as the algorithm "walks" around the group. A 100-byte stack can handle a 33-stone group. A group of that size would occur, if at all, only near the end of the game, when Wally's play deteriorates for other reasons anyway.

Main Loop

After COUNT was coded, a reasonable overall structure for a program to use it followed quickly. The main loop is specified in listing 2. The "consequences" of counting a group of stones include removing it from the board (zero out the board locations) if it has no liberties; other consequences have to do with suggesting tentative moves for Wally. Wally always plays black, in accordance with the Go tradition of giving the black stones to the weaker player.

The pattern-matching facility was not implemented immediately. In fact, the first version of the program chose black moves randomly, trying again if it hit upon an occupied point.

At least the capturing of black groups could be tested, and, for the most part, it was playing legal Go.

Tactics and Priorities

The next step in the design of the program was the decision that Wally would make contact moves, adjacent to white stones. In this way, the program would appear to be attempting to capture white groups, and would eventually fill up the liberties of each white group and capture it, if no defensive action were taken.

At the same time, it was clear that Wally also should take some defensive moves to avoid capture. This brought up the question of priorities: when is a black group threatened enough so that Wally should stop attacking white and make a defensive move instead? The answer had to be based on the number of liberties remaining in the black and white groups. It was decided that threats would be ignored until a black group had been reduced down to one or two liberties. Otherwise, Wally attacks whichever white group has the least number of liberties, because that group promises the best chance of be

ing captured.

This strategy was implemented by associating a number of liberties with each suggested black move—namely, the number of liberties remaining for the group contacted by the stone. When a move is suggested, such as some liberty of a white group being

Figure 4: How the procedure COUNT works. When tracing a black group, COUNT begins on a stone in the group and calls itself recursively to look at the four neighboring locations. If a neighbor is a black stone, the process is repeated until all stones in the connected group have been found. All unoccupied points adjacent to stones in the groups (ie: liberties) are also found and counted.

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108 April 1981 © BYTE Publications Inc

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BYTE April 1981 109

Listing 1: Structured English specification of COUNT module to find and count the liberties of a connected group containing a stone at point "x" of color "color." COUNT calls itself recursively, saving x on the push-down stack during each call.

COUNT(x, color):

IF x is not off the edge THEN

IF there is a stone at x AND it is the given color AND it is not marked THEN

mark it

CALL COUNT(NORTH(x), color) CALL COUNT(EAST(x), color) CALL COUNT(SOUTH(x), color) CALL COUNT(WEST(x), color) ELSE IF there is no stone at x THEN

mark the point as a liberty increment the liberty count END END

counted, a best (move, liberties) pair is updated if the new move is adjacent to a group of a smaller or equal number of liberties. Since black groups are counted after the phase in which white groups are counted, a move by black in contact with a black group with one or two liberties is automatically preferred to a move adjacent to a white group with the same number of liberties. An exception was put in later: when Wally finds a chance to capture a white group on the next move, he always takes it, even if some black group also has only one liberty. There is some doubt whether this exception was wise, however.

Ko and Illegal Moves

There are two situations in which a

move on an unoccupied point is illegal. A move that leaves one's own group with no liberties is illegal. Figure 5a shows a move by black that would be illegal because the resulting black group would have no liberties. A move resulting in the capture of an opponent's group, as in figure 5b, is permissible because removing the captured group creates at least one liberty.

The second type of illegal move arises from a ko, illustrated in figure 6a. If white captures the central black stone on his next move, the position will look as in figure 6b. Now black can capture the white stone and reproduce the original position in figure 6a. This could go on forever. To prevent such infinite repetition, the Rule of Ko was introduced: no

Listing 2: Module specification for the main loop of the Goplaying program and two of its called modules.

MAIN:

place black handicap stones

LOOP display the board get white's move from keyboard CALL WEFFECT for the effect of white's move CALL BEFFECT to obtain a tentative black move CALL PATS to check for a pattern match place black stone

END

WEFFECT:

FOR each point x with a black stone DO CALL COUNT(x,black) IF the group has no liberties THEN remove its stones ELSE IF the group has at least one liberty

THEN

choose a liberty not on edge line

IF the group has 1 or 2 liberties

THEN CALL EVAL for the chosen liberty

END END

BEFFECT:

FOR each point x with a white stone DO CALL COUNT(x,white) IF the group has exactly 1 liberty THEN

designate it as the black move remove the white stones EXIT ELSE IF the group has 2 or more liberties THEN

choose a liberty

CALL EVAL for the chosen liberty END END

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110 April 1981 © BYTE Publications lnc

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112 April 1981 © BYTE Publications Inc

(a)

Figure 5: Illegal moves. The point marked x in 5a is illegal for black because it would result in a black group with no liberties. The point marked x in 5b is permissible, however, because it captures the two white stones, leaving the inner black group with two liberties.

player may move so as to reproduce the board position existing just prior to his opponent's last move. A move must be made elsewhere to change the board position before the ko capture is allowed.

Lookahead

Kos are common and often critical in master games, but at Wally's level it was simpler to leave out the Rule of Ko. However, it is essential to avoid suicidal or totally wasted moves which fill in the last liberty of a group, or leave it only one liberty, so that the group will be captured anyway. Hence a limited lookahead capability was adopted. The last step in evaluating a suggested black move is to put the stone down tentatively and count the liberties of the resulting black group. This is done by calling COUNT. The move is rejected if the resulting group does not have at least two liberties.

The complete move evaluation module, EVAL, is shown in listing 3. The module LOOKAHEAD saves the current (move, liberties) pair before COUNT is called with the tentative black stone in place.

Pattern Matching

Wally's most intelligent-looking moves are pattern matches. There are common configurations of stones which suggest an obvious next move to a good player. Wally has a table of

Figure 6: Ko. In 6a, white can capture the black stone, resulting in 6b. It is illegal for black to restore 6a immediately by recapturing the white stone; he must wait a turn.

patterns of this sort; these patterns are illustrated in figure 7. Each pattern includes one white stone and two black stones, with a third black move indicated. Patterns 7a thru 7e represent responses to threatened connections. Patterns 7f and 7g create good "shape."

In Go, as in other spheres, there is truth to the motto, "In unity there is strength." The first step in capturing a group of stones is to cut it off from any other large groups nearby. Two weak groups, when connected into a single large group, often have a much better chance of survival. That is why defensive moves like figures 7a thru 7e are important.

Good shape in Go is a local positional strength. It is characterized by diamond-shaped configurations, or box-like shapes with at least two solid walls. These patterns enclose an area in an easily defended way, and serve as a basis for expansion. Moves like those in figures 7f and 7g are aggressive moves that take area while expanding against the opponent's outposts.

The program looks at each white stone, trying to find two black stones near it in the same relative positions as in one of the patterns. The table entry for a pattern contains the vertical and horizontal displacements of the two black stones relative to the white stone, and that of the suggested black move. If the two black stones

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are found and the point for the black move is unoccupied, the black move is returned for evaluation.

Each pattern must be considered in all possible orientations around the

Listing 3: Module specifications for move evaluation, lookahead, and pattern matching.

E VAL(move, liberties):

GLOBAL (best-move, best-liberties) IF liberties < best-liberties AND

LOOKAHEAD(move) a 2 THEN

best-move = move best-liberties = liberties END

LOOKAHEAD(move): place black stone at move CALL COUNT(move,black) remove black stone RETURN count of liberties

PATS:

FOR each white stone DO IF there is a pattern in the table centered on that white stone THEN

get suggested black move y CALL EVAL(y,2) EXIT END END

white stone. Three-stone patterns have either four or eight orientations, depending on their lateral symmetry. The program trades table space against program space by performing 180° rotations automatically. Thus, two or four table entries representing different orientations of each pattern are needed to account for all possibilities.

Pattern matches are checked last, because they almost always take priority over moves arising from the earlier phase of counting the liberties of groups. Pattern-match moves are associated with an artificial figure of two liberties to set their priority. Thus, if Wally can capture a white group, or avoid the capture of a black group having one liberty, he will do so despite any pattern matches. The priorities of the patterns are determined by the order in which they are checked, since the first match found is returned.

Ghost Stones

The edge of the Go board is strategically important because it helps to wall off areas. An attempt by white, for example, to invade be

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tween a black stone and the edge of the board should be defended against. The first five patterns in figure 7 already defend against threatened connections; why not use them to protect the connection between a stone and the edge of the board? Imagine that there is an additional row of black "ghost" stones all around the board. As figure 8 shows, a white move near the edge can then invoke a pattern. This idea was implemented in the pattern match by allowing offboard positions to count as black stones tested for in each pattern.

Edge Moves

One of the most startling improvements in Wally's performance resulted from a simple observation in the first few games. Groups on the edge of the board, when attacked, often extended fruitlessly along the edge, as in figure 9. A prohibition against edge moves, except to capture or on a pattern match, was added. Wally's play began at that moment to take on the character of an opponent to be reckoned with.

Handicaps

Go has a handicap system that allows an expert to play an even and interesting game with a novice. Black is given a head start of two to nine stones on designated points—the ones marked with black spots on the board (see figure 1). The handicap stones are placed symmetrically like die spots, except that a handicap of three stones is placed on three corners. Additional handicap points, for a total of up to seventeen stones, were added for Wally's benefit, since it was not expected that he would be a strong player. Each additional handicap stone accounts for roughly 10 points difference in score.

The handicap stones help to make up for Wally's lack of overall strategy. The handicap points are good points to occupy early in the game, so a large handicap solves much of the strategy problem.

Eyes and Life

Wally has a blind spot that costs him dearly against experienced players: he does not understand that any group, no matter how large, will be captured unless it has two "eyes," or sufficient space to make them. An eye is an unoccupied point or connected group of points. A group enclosing two eyes is immune from

114 April 1981 © BYTE Publications lnc

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BYTE April 1981 115

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116 BYTE April 1981

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BYTE April 1981 117

4& 4&$t^

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:<ft$= =t^$=

<v;

w

Figure 7: Patterns. In each of these seven configurations, the black move marked x is suggested when the white stone and the two other black stones are already present. These patterns are applied in all orientations.

capture, because a group cannot be captured unless it can be brought down to only one liberty. A group with two eyes will always have at least two liberties. The opponent cannot fill either eye because such a move would fill all the liberties of his invading stone, and hence is illegal. Figure 10 illustrates this.

Wally does surprisingly well despite a fundamental ignorance of the facts of life. Captures and pattern

matching moves tend to create eyes more or less automatically.

Play Experience and Improvements

Wally plays like a beginner; however, he does play better than people just introduced to the game. Experienced players are surprised by the reasonableness and apparent skill of some of Wally's moves but are quick to discover that he does not

know about forming two eyes.

Along the present lines, there is no room for significantly improving Wally within the 1 K-byte memory that my K1M-1 has. With a memory (d) extension, the first improvement that

springs to mind for the future is a fullsized board. The Rule of Ko is not hard to implement and should be included. Many more patterns ought to be added, and the pattern-matching mechanism could be more general.

Wally should be taught something about ladders, if only to avoid them. A ladder, illustrated in figure 11, is a sequence of moves that ends in disaster for one side or the other, depending on conditions several moves ahead.

The most challenging problem for a Go-playing program is how to recognize when a group does or does not have the potential to form two eyes.

Looking ahead down the move tree as a general approach, as is done in chess-playing programs, has two obstacles: the sheer number of possible moves at each turn, and the need to first develop a way to evaluate the board configuration. The best candidate for an evaluation function is

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(Modi Min 32K 2-drive system. Mod II 64K 1-drive. Mod III 32K 1-drive

• •NEW** DISCAT (32K 1-drive Min) Mod I, III $50.00

This comprehensive Diskette Cataloguing/Indexing utility allows the user to keep track of thousands of programs in a categorized library. Machine language program works with all TRSDOS and NEWD0S versions. Files include program names and extensions, program length, diskette numbers, front and back, and diskette free space.

• •NEW* • KFS-80 (1 -drive 32K Min — Mod II 64K) Mod I, III $100.00; Mod II $175.00

The keyed file system provides keyed and sequential access to multiple files. Provides the programmer with a powerful disk handling facility for development of data base applications. Binary tree index system provides rapid access to file records.

• •NEW** MAILLIST (1-drive 32K Min - Mod II 64K) Mod I, III $75.00; Mod II $150.00

This ISAM-based maillist minimizes disk access times. Four keys — no separate sorting. Supports 9-digit zip code and 3-digit state code. Up to 30 attributes. Mask and query selection. Record access times under 4 seconds!!

**NEW** LPSPOOL(32K 1-drive Min) Mod I $75.00

LPSP00L — Add multi-tasking to permit concurrent printing while running your application program. The spooler and despooler obtain print jobs from queues maintained by the system as print files are generated. LPSP00L supports both parallel and serial printers.

UTILITY PACKAGE (Mod II 64K) $150.00

Important enhancements to the Mod II. The file recovery capabilities alone will pay for the package in even one application! Fully documented in 124 page manual! XHIT, XGAT, XC0PY and SUPERZAP are used to reconstruct or recover date from bad diskettes! XC0PY provides multi-file copies, 'Wild-card' mask select, absolute sector mode and other features. SUPERZAP allows examine/change any sector on diskette include track-0, and absolute disk backup/copy with I/O recovery. DCS builds consolidated directories from multiple diskettes into a single display or listing sorted by disk name or file name plus more. Change Disk ID with DISKID. XCREATE preallocates files and sets 'L0F' to end to speed disk accesses. DEBUGII adds single step, trace, subroutine calling, program looping, dynamic disassembly and more!!

DEVELOPMENT PACKAGE (Mod II 64K) $125.00

Includes RACET machine language SUPERZAP, Apparat Disassembler, and Model II interface to the M'ciosofl 'Editor Assembler Plus' software package including uploading services and patches for Disk I/O.

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118 April 1981 © BYTE Publications Inc

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Now the power, speed and compactness of MMSFORTH drive a major applications program for many of YOUR home, school and business tasks! Imagine a sophisticated database management system with flexibility to create, maintain and print mailing lists with multiple address lines, Canadian or the new 9-digit U.S. ZIP codes, and multiple phone numbers, plus the speed to load hundreds of records or sort them on several fields in 5 seconds! Manage inventories with selection by any character or combination. Balance checkbook records and do CONDITIONAL reporting of expenses or other calculations. File any records and recall selected ones with optional upper/lower case match, in standard or custom formats. Personnel, membership lists, bibliographies, catalogs of record, stamp and coin collections—you name it! ALL INSTANTLY, without wasted bytes, and with cueing from screen so good that non-programmers quickly master its use! With manual, sample data files and custom words for mail list and checkbook use.

Technical: Handles data as compressed indexed sequential subfiles of up to 25K characters (9K in 32K RAM). Access 1-4 data diskettes. Modified Quicksort. Optionally precompiles for 5-second program load. Selfadjusts for many routine mods. Structured and modular MMSFORTH source code ideal for custom modifications.

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?' Y H

Figure 8: Ghost stones. The black move at x is suggested by the pattern in figure 7d because there is an imaginary black stone at point Y, off the edge of the board, for purposes of pattern matching.

Figure 9: Running along the edge. Before the program was modified, black would move at x, white could respond just above x, and the process would be repeated until the black "worm" reached the edge of the board and was captured. Edge moves are now prohibited except for captures and pattern matches.

Figure 10: A safe group with two eyes. White cannot capture black because both eyes, marked x, would have to be filled. But white can make only one move at a time, and a move in either point is illegal.

Figure 11: A ladder. White threatens to capture black by moving at 1. When black attempts to escape at 2, white moves at 3, and so on. The black stones form a staircase that eventually reaches the edge of the board and is captured by white 9. If there were a black stone at 6, however, black would escape, and white would be left in a vulnerable position.

an estimate of the area controlled by each player. When an area is only loosely surrounded, however, or an invasion is in progress, it is very difficult to determine the ownership of many points. A possible approach is the perceptual-grouping heuristic method developed by Zobrist (reference 3). Move tree searching is probably the only way to find the best move in confined tactical situations, like those that appear in Go problem books.

Another improvement suggested by chess programs is to include some of the countless known corner openings, or "joseki." Joseki are useful anywhere in the board, and should be implemented as an extension of the pattern matching.

After a move that leaves an opponent's group with only one liberty, one is supposed to say "atari" to warn him that his group is about to be captured. Wally says nothing, and I have lost large groups by failing to notice an impending capture. "Atari" goes in next.B

References

1. Ryder, J. "Heuristic Analysis of Large Trees as Generated in the Game of Go." Stanford University: Ph D Thesis, 1971.

2. Wilcox, B. "Computer Go." American Go Journal, 1979.

3. Zobrist, A. "A Model of Visual Organization for the Game of Go." AFIPS Spring Joint Computer Conference, 1969, pages 103 thru 112.

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Build Your Own Turing Machine

James E Willis

Lawrence Berkeley Lab

1 Cyclotron Rd

Building 4

Berkeley CA 94720

In 1936, Alan M Turing gave the following description of a computing machine:

The machine is supplied with a "tape" (the analog of paper) running through it, and divided into sections (called "squares"), each capable of bearing a "symbol." At any one moment there is only one square, say the rth, bearing the symbol G(r) which is "in the machine." We may call this square the "scanned square." The "scanned symbol" is the only one of which the machine is, so to speak, "directly aware." However, by altering its m-configuration, the machine can effectively remember some of the symbols which it has "seen" (scanned) previously. The possible behavior of the machine at any moment is determined by the m-configuration g(n) and the scanned symbol G(r). This pair g(n), G(r) will be called the "configuration." Thus, the configuration determines the possible behavior of the machine. In some configurations in which the scanned square is blank (ie: bears no symbol) the machine writes

down a new symbol on the square; in other configurations, it erases the scanned symbol. The machine may also change the square which is being scanned, but only by shifting it one space to right or left.

A Turing Machine

consists of three parts:

a tape, a program, and

a device.

Turing's description has become the definition of computability. That is, if a Turing Machine can work the problem, then the problem is said to be computable. If no Turing Machine can eventually find an answer to the problem, then the problem is not computable. John von Neumann and others have tried to establish a relationship between a Turing Machine and human neural networks. (See Michael Arbib's book, listed in the references at the end of this article.) An overview of these concepts along with some history of the problem is given in an article by Jeremy Bernstein (reference 2). An example of a

hardwired version may be found in Jonathan K Millen's article (reference 3).

As with other problems involving computing machines, the first step is to carefully define the problem or task. Once a careful definition has been given that defines and limits the scope of the project, we may then attempt a solution. The solution may take on many forms depending on the intended use of the project.

In this article, I will describe a finite (theoretical) Turing Machine (TM) and the implementation of a Practical Turing Machine (PTM) in hardware, in a program for the 6800 microprocessor, and in a FORTRAN program. These implementations are equivalent in that they accept the same input and, for that input, produce the same output.

Turing Machines—a Definition

A Turing Machine consists of three parts: a tape, a program, and a device. The tape consists of an infinite array of Is and 0s. The device writes on the tape and moves the tape according to the program. (See figure la.)

Text continued on page 128

122 April 1981 © BYTE Publications Inc

Circle 84 on Inquiry card.

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And by operating like any other modern, well-run business enterprise, United Way succeeds in delivering the maximum in human services for the dollars that are collected.

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Cook" a Public Servi

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Apple World

-^B^3-D ANIMATED COLOR GRAPHICS Y ""Written in machine code.

The program made lamous on national T.V.! v by Paul Lutus

"^B^ APPLE WORLD turns your Apple into a sophisticated f graphics system capable of creating animated

three-dimensional color images, projecting them in k true perspective on the screen, rotate them, move

_^m£ them closer, further away, and many other exciting and

^^B^ imaginative things.

Draws objects with 65.000 points per side.

,^MW A powerful screen-oriented text editor is included to ^^^^ facilitateimage fomation. This program was recently

* featured on Tom Snyder's Prime Time Saturday TV Show and is now available for sale.

~^mZ APPLE WORLD'S powerful editor is so easy to use thai ^^^ children will love it. You can now "sketch" your dream

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^^^ until the screen is filled with a doorknob. You could .^^^W then go inside and mnve from room to room ^l^^k examining furniture placement as your screen rotates

* within the room. Images or specific parts of images can easily be saved to disk or printer.

.^MW Does all this sound like science fiction"? ^^^^ You won't think so after you have visited Apple World.

INTRODUCTORY PRICE $59.95

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^m^ or Atari screen with true 3 dimensional perspective, "^W^ Have rocket ships fly out at you in this incredible high

V ""* speed graphics package. 3-D SUPERGRAPHICS" is

a 6502 machine language program that will ^ interface to your Basic or machine language

_^mm programs or games using simple "DOS-like" commands.

f Features include:

• Simple image entry through editor w • Objects up to 256 points per side

^W& • Uses all hi-res coiors

"^B^ • Allows mixed colored text & graphics

V for prompts and captions

• Translates on 3 axes L^ • Individual axis scales

_^^W • 21 different commands "^•^ • Rotate object 1.4° to 360" r increments at machine speeds

^ FOR 48K APPLE II OR PLUS WITH "^V DISK II $39.95 FOR DISK

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124 BYTE April 1981

Relational Query System For Management

By Ken German & Toby Zweifach

DATABASES: You've Heard The Hype Before... The Truth IS...REQUEST DELIVERS!

DATABASE MAINTENANCE —

• Uses sophisticated screen formatting & data entry, like on IBM 3270's!

• Generates it's own screens automatically!

• Handles records up to 4K in length, using multiple screen "Pages"!

• Automatic data compression for increased disk capacity

• Uses Superkram (See below) access method for incredibly fast access, LESS THAN .2 SECOND FOR A RECORD!

• Automatic index creation/maintenance

• Automatic maintenance capabilities

• "Goof-Proof" error handling

• Input can come from VISICALC1" or SOURCE'"

DATABASE SELECTION—

• Uses screen masks to form query

• Provides extensive search capabilities

• Search arguments can include arithmetic/boolean functions, multi-field comparisons

• Queries can generate input for automatic database maintenance

• Queries can be stored in "Query Library" and executed from menu on demand

• Any number of fields can be queried concurrently

• Query output can be routed to disk, CRT report formatter, VISICALC™ or SOURCE'"

ONLY $225

DATABASE REPORTING—

• Automatic headlines

• Automatic field editing

• Report fields can be calculated, sub-totaled & cross-footed in any manner desired.

• Optional counter breaks may be set

• Automatic grand totals

• Automatic statistics

REQUIREMENTS

Superkram (see below) and: Commodore Pet 32K (40 or 80 col.) and 2040/4040/8050 disk OR Apple II 48K with Applesoft or language system and 2 disk drives or CORVUS.

SUPERKRAM

Now With Multi-Key

Capabilities

For Apple & Pet

by Ken Germann

Since KRAM™ was introduced in 1979 it has fast become known as the quickest and most powerful access method for serious Apple and Pet users. Now, after hundreds of requests we have added MULTI-KEY, MULTI-INDEX, functions, as well as increasing processing speed.

IBM/370 users have VSAM (Virtual Storage Access Method) to provide fast, flexible keyed-access lo their data. Now SUPER KRAM (Keyed Random Access Method), from United Software of America, gives Apple and Pel users the same flexibility, substantially increasing the processing power of the Apple and Pet.

Until SUPER KRAM the only "random access" capability in the Apple and Pet consisted of a crude form of "relative record" processing. While this is usable for very simple applications, it falls lar short of the needs of today's business and analytical applications. Using SUPER KRAM records may be processed by any one of multiple "Key" values, which may consist of any kind of data: numbers, letters, special characters, etc. Even Apples's longawaited DOS 3.3 doesn't have anything like this!!

KRAM™ 2.0 Regular Features

• Written in 6502 machine code Basic compatible

• Create/Open a dataset

• Put record by key

■ Add & delete records by key

• Get any record by Full/Partial key

• Access by any key in as little as 2 sec

■ Supports multiple disks

• Read next or previous record

• Dynamic space allocation

• Dynamic space reclamation

• Dynamic index compression

• Files never need reorganization

• Compatible with language systems

th Corvusdisk)

KRAM™ 2.0 Only $99.95 SUPER KRAM™ Only $175

ATTENTION-EXISTING KRAM USERS.

Send $15 with original disk and ROM to United Software for improved version ol Kram.

SUPER KRAM'S™ Added Features

• MULTIKEY SUPPORT — Allowing simultaneous access to a KRAM file by more than one key field.

• HI-SPEED READ — This feature allows increased I/O speed up to 60% faster during processing of SUPER KRAM read next, read previous, put and delete requests.

• IMPROVED INDEX ARCHITECTURE - Allowing faster index searchers and more efficient disk space utilization.

• INTEGRATED BASIC COMMANDS — Allowing SUPER KRAM'" commands to be coded in-line with Basic, providing easier usage of KRAM than ever before.

• USER-SPECIFIABLE BUFFER POOL - Allowing the user to specify how many KRAM files are allowed open at one time; will support any number of KRAM files.

• LOGICAL RECORDS (KEYS MAY BE NON-UNIQUE) — Records added to the KRAM files are immediately accessible by any of the defined keys for the file (Automatic Upgrade)

• KRAM 2.0 files are totally compatible with SUPER KRAM

a UNITED ^r= SOFTWARE OF AMERICA

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Look for the RED-WHITE-BLUE United Software Display at your local computer dealer, or send check or moneyorder, plus $3.00 shipping to:

DEALER INQUIRIES INVITED

REQUEST & KRAM are trade marks ot United Software of America

(la)

STM.

R = 0

R'l

COMMENTS

NUMBER

W

0

ADR

w

D

ADR

0

0

1

1

1

2

CHECK FIRST BIT

1

0

3

1

1

4

CHECK SECOND BIT

2

0

4

1

1

3

3

1

5

1

1

5

WRITE A 1

4

0

5

0

1

5

WRITE A 0

5

0

0

6

1

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(HALT)

6

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1

1

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TAPE

Waiting On Delivery ofADECLA120?

Avoid the hassle by upgrading your LA36 for 1200 baud operation with a DS120 Terminal Controller.

The Datasouth DS120 gives your DECwriter® II the high speed printing and versatile performance features of the DECwriter® III at only a fraction of the cost. The DS120 is a plug compatible replacement for your LA36 logic board which can be installed in minutes. Standard features include:

•165 cps bidirectional printing

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• 110-4800 baud operation •1000 character print buffer •X-on, X-off protocol

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( START J

(lb)

YES

YES

WRITE ZERO

YES

WRITE ONE

( STOP J

Figure 1: Model of a Turing Machine and an example. Figure la presents a symbolic representation of a Turing Machine divided into three principal components: a program, a tape, and a mechanism or device for executing the program. The current instruction being executed is pointed to by the Turing program counter (TPC), the register R holds the contents of current tape position. The index I points to the character that is currently under the tape head. The program given in figure la reads 2 bits from the tape and writes a third bit to give the three characters odd parity (an odd number of Is among them). The program has an initial state given by statement 0 and a final or halting state given by the infinite loop of statements 5 and 6. The flowchart in figure lb shows the logic of this program, with the numbers beside each box being the statement number associated with that position within the flowchart.

126 April 1981 © BYTE Publications Inc

Circle 85 on inquiry card.

grragggg

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• •* i • • ■ 11 • • . iti i « ,

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Turn your Apple into the world's most versatile personal computer.

The SoftCard™ Solution. SoftCard turns your Apple into two computers. A Z-80 and a 6502. By adding a Z-80 microprocessor and CP/M to your Apple, SoftCard turns your Apple into a CP/M based machine. That means you can access the single largest body of microcomputer software in existence. Two computers in one. And, the advantages of both.

Plug and go. The SoftCard system starts with a Z-80 based circuit card. Just plug it into any slot (except 0) of your Apple. No modifications required. SoftCard supports most of your Apple peripherals, and, in 6502-mode, your Apple is still your Apple.

CP/M for your Apple. You get CP/M on disk with the SoftCard package. It's a powerful and simple-to-use operating system. It supports more software than any other microcomputer operating system. And that's the key to the versatility of the SoftCard/Apple.

Circle 86 on inquiry card.

BASIC included. A powerful tool, BASIC-80 is included in the SoftCard package. Running under CP/M, ANSI Standard BASIC-80 is the most powerful microcomputer BASIC available. It includes extensive disk I/O statements, error trapping, integer variables, 16-digit precision, extensive EDIT commands and string functions, high and low-res Apple graphics, PRINT USING, CHAIN and COMMON, plus many additional commands. And, it's a BASIC you can compile with Microsoft's BASIC Compiler.

More languages. With SoftCard and CP/M, you can add Microsoft's ANSI Standard COBOL, and FORTRAN, or

Basic Compiler and Assembly Language Development System. All, more powerful tools for your Apple. Seeing is believing. See the SoftCard in operation at your Microsoft or Apple dealer. We think you'll agree that the SoftCard turns your Apple into the world's most versatile personal computer.

Complete information? It's at your dealer's now. Or, we'll send it to you and include a dealer list. Write us. Call us. Or, circle the reader service card number below.

SoftCard is a trademark of Microsoft. Apple II and Apple II Plus are registered trademarks of Apple Computer. Z-80 is a registered trademark of Zilog. Inc. CP/M is a registered trademark of Digital Research, Inc.

/HCflQSOfT

V CONSUMER^ PRODUCTS^

Microsoft Consumer Products, 400 108th Ave. N.E., Bellevue, WA 98004. (206) 454-1315

Text continued from page 122:

The device first reads position / of the tape through the tape head, then places the value it finds into its register, R. If R contains a zero, the device executes the left side of program statement number Turing Program Counter (TPC). If R contains a 1, the device executes the right side of program statement number Turing Program Counter.

Each side of each program statement contains a value for the variables W, D, and ADR. The symbol W indicates what is to be written on the tape. The symbol D indicates the direction to move the tape head: if D = 0, the tape head is moved one space to the left; if D = l, the tape head is moved one space to the right. The symbol ADR is the address of the next program statement to be executed. Briefly, the device reads the tape, writes on the tape, moves the tape head, and transfers control to another program statement. The program presented in figure lb is a parity checker—that is, the machine reads two binary digits and writes a third to

give the total 3 bits an odd number of Is—that is, odd parity.

[It should be noted that the previously mentioned notation for a Turning Machine is not the one usually encountered in classrooms and textbooks. A more formal definition defines a Turning Machine with the program expressed as a set of 5-tuples of the .following form:

(current state, character being read, character to write over current character, next state, direction to move tape)

where the particular 5-tuple to be applied is the one that is given by the current state and the character being read. It can be seen that each line of the notation used in this article can be rewritten as two 5-tuples of the above form; therefore, the two notations are equivalent .... GW]

The operation of a Turing Machine may be represented by a flowchart, as in figure 2. Suppose that the variables W, D, and ADR are contained in

D(R,TPC) = 1 ? I

I I

f START J

1

.

READ TAPE INTO REGISTER R R = TAPE (1 )

WRITE CHARACTER

TO TAPE

TAPE(I ) = W(R,TPC)

_/'direc

""N. = Rl

TION\YE

s

GHT v?

NO

MOVE TAPE HEAD LEFT 1 = 1-1

MOVE TAPE HEAD RIGHT 1= 1 + 1

'

\

GET ADDRESS OF NEXT INSTRUCTION TPC = ADR { R ,TPC)

Figure 2: Flowchart for the Turing Machine algorithm. In this algorithm, written primarily for a hardwired or assembly-language implementation, the only allowable characters that can be written are 0 and 1. The only allowable movements for the tape head are left and right. The algorithm does not end as such, but a final or halting state can be implemented by the addition of two program lines that unconditionally loop to each other, denoting the end of the algorithm. This is done in the example of figure la.

three arrays, each two-dimensional: W(R,TPC), D(R,TPC) and ADR (R,TPC). The first subscript corresponds to the value contained in register R, while the second subscript refers to the program statement number. (In the example of figure 1, W(l,3) = 0, D(l,3) = l, and ADR(1,3)=3.) The variable I refers to the position of the tape. Hence, the tape is represented by a one-dimensional array, TAPE(Z). The variable TPC represents the Turing program counter—that is, the line of the Turing program being referenced. These variables, along with the description, of the operation of a Turing Machine, are utilized in the flowchart of figure 2.

So far, no restrictions have been placed on the values of TPC or the tape index /. Turing assumed that the program and tape were indefinitely large. In a practical Turing machine, the variable TPC takes on values up to and including the maximum number of program statements. The tape index / may take on values up to and including the number of spaces on the tape. It is usual to assume that when the value of / exceeds the length of the tape, it returns to the first position on the tape, so that the tape then becomes finite and connected to form a loop. We call such a restricted machine a practical Turing Machine (PTM). With these restrictions it is possible to construct a PTM from discrete digital components.

A Hardware Version

A hardwired version of a PTM utilizing integrated circuits can be readily constructed as described in the Millen article (see reference 3). In the present implementation, the program is stored in a 128 by 8-bit programmable memory circuit. (See figure 3.) The variables are the same as those used in the flowchart. The temporary register holds the value of ADR(R,TPC). Register TPC points to a program statement. Register R selects the left or right side of the program statement. The value of I is held in a 12-bit binary up-down counter. The tape is represented by 4096 bits of programmable memory. The boxes labeled "address selector" operate like double-throw switches and facilitate loading and execution of programs. A maximum of sixtyfour program statements may be

Text continued on page 136

128 April 1981 © BYTE Publications Ire

Circle 87 on inquiry card.

r • *' -

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a

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SBfc"

Unretouched CAT 400 display. 242x256k 16 bits per pixel 128K byte imaae buffer Partial picture shown here to highlight detail quality Imao Analysis Systems, Inc . 999 McMillan St. N W. Atlanta. Ca

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DIS

IC25

555

TRG THR

OUT RST

3

1

4

. 2

IC22 7400

^E^^

OCK IN

O.OOljiF

m

14 12 6 1 2 8

K CK CK PR C

IC23 7476

15 9

16 4

11

+ 5V

■IK

RESET

C CK CK J

IC24 7476

14 12

11

10

0 _0_ 0 0 0 0

SINGLE CLOCK 1 RESET CLOCK 2 CLOCK 2 CLOCK 3 CLOCK 4

STEP

Figure 3: Schematic diagram for the hardwired Practical Turing Machine. The device is designed to be built on three small circuit cards, figures 3a thru 3c. In figure 3a, the clock board, IC23 and IC24 produce a four-phase clock used by the other boards.

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35.00 52.00

8.00 7.50 TMS 9900 27.00 25.00

LS00 .25

LS02 .25

LS04 .25

LS08 25

LS10 .25

LS20 .25

LS30 .25

LS32 .35

LS38 35

LS42

LS5I LS54 LS73 LS74 LS85 1.15 LS86 .40 LS93 .65 LS95 .75

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130 April 1981 © BYTE Publications Inc

Circle 88 on inquiry card.

Circle 89 on Inquiry card.

A s175 Program

That Makes your Microcomputer

Worth Its Weight In Gold.

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The Denver

Software Company has developed, with the assistance of a Big Eight accounting firm, a financial package for microcomputers which accommodates the needs of both the very smallbusinessman and the household budget manager, and costs far less than you would imagine.

The FINANCIAL PARTNER™ contains all essential accounting functions, and yet is easy to use. It also has built-in flexibility: Programming expertise and valuable time are not needed to get the FINANCIAL PARTNER™ ready to use. And most important, this is a complete package, containing the programs, language, operating system, and supplies. The beauty of the FINANCIAL PARTNER™ is that you don't have to be a professional bookkeeper or accountant to use it. Controller Jim Vogt says, "It is one

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The FINANCIAL PARTNER™, which operates from menu selections, collects and organizes information for all of the standard categories: Assets, liabilities (including accounts payable), normal living expenses, deductible expenses (including all six deductions for personal Federal Income Tax returns), earned income (for both the wage earner and the

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The FINANCIAL PARTNER™ is available for Apple, Atari, Commodore, Ohio Scientific, Texas Instruments, Radio Shack, Zenith, and most other microcomputers.

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a. co

imii

*- s *

a: o

Figure 3b: 77ie processor card. 1C1 is the Turing program memory; the lines coming into AO thru A6 of IC1 are the Turing Program Counter (TPC). IC7 stores the R (direction) bit, and IC9, IC10, and ICll store the Turing program address at which the program will start execution. The left/right switch designates which half of the Turing program word is written (switch open = left half) when the RUN/PROGRAM bit is set to PROGRAM.

132 April 1981 © BYTE Publications Inc

HAVE WE

GO! A PROGRAM

FOR YOU IN 111

Attend the biggest public computer shows in the country. Each show has 100,000 square feet of display space featuring over 50 Million Dollars worth of software and hardware for business, industry, government, education, home and personal use. You'll see computers costing $150 to $250,000 including mini and micro computers, software, graphics, data and word processing equipment, telecommunications, office machines, electronic typewriters, peripheral equipment, supplies and computer services.

All the major names are there including; IBM, Wang, DEC, Xerox, Burroughs, Data General, Qantel, Nixdorf, NEC, Radio Shack, Heathkit, Apple, RCA, Vector Graphic, and Commodore Pet. Plus, computerized video games, robots, com\puter art, electronic gadgetry, and computer music to entertain, enthrall and educate kids, spouses and people who don't know a program from a memory disk. Don't miss the Coming Of The New ComputersJ, Show Up For The Show that mixes business with pleasure. Admission is $5 for adults and $2 for children under 12 when accompanied by an adult.

Ticket Information

Send $5 per person with the name of the show you will attend to National Computer Shows, 824 Boylston Street, Chestnut Hill. Mass. 02167. Tel. 617 739 2000. Tickets can also be purchased at the show.

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Circle 90 on inquiry card.

BYTE April 1981 133

(3c)

THREE UP/DOWN COUNTERS

FOUR IK BY 1 BIT PROGRAMMABLE MEMORIES

DIRECTION

CLOCK 3

Figure 3c: The memory card. 1C12, IC13, and IC14 store the pointer I to the Practical Turing Machine tape, while IC15 thru IC18 store the tape itself.

6 0 t

TAPE TAPE CLOCK 2

BIT BIT

WRITE READ

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134 April 1981 © BYTE Publications Inc

Circle 91 on inquiry card.

Circle 92 on inquiry card.

MULTIUSER

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Display videotape segments then automatically switch to computer text.

Display multiple-choice options at each stage of the presentation, then, depending on the choice made, replay any portion of text and/or video, or move on to new material.

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If you checked D, contact us for more information on Cavri Interactive Video. We offer a reasonably priced, sophisticated system that links an Apple* or an RS-232 interfacing computer with a Sony or Panasonic VCR and TV screen — with no modification. Included are simple, straightforward instructions for writing your programs. Plus frame-accurate stops and switches with no accumulated error.

Write or call today and join the many companies, large and small, that are improving their audiovisual training and testing with the new technology pioneered by Cavri.

Training, of course, is only one application. Now you can catalogue anything — for example, a museum can videotape its paintings, sculptures, and artifacts, then show them by artist, subject, date, or any other grouping, regardless of the sequence in which they were recorded on the videotape. Tell us your application, and we can help by supplying the system and guidance on programming and videotape or videodisc production.

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"TM — Apple Computer Co. 136 April 1981 © BYTE Publications Inc

(3d)

PIN 18 ,.i—v, OF IC1 A5 I—>

PIN 19 ..r—v, OF IC1 A4 I—->

PIN20 r—-^

OF IC1 A31_^>

TIL209

TYPICAL 330J1

FOR 7 TYPICAL

J» FOR 7

PIN 21 OF IC1

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PIN22 ..r-^ OF IC1 All_>

PIN 23 |

OF IC1 *0l_>

IC27 7404

o'fN,C87 E^>0i @^

+ 5V

MOST SIGNIFICANT BIT (MSB)

TURING

)PR0GRAM

COUNTER

LEAST SIGNIFICANT BIT(LSB)

REGISTER R

Figure 3d: This simple front panel for the PTM displays the address being pointed to by the Turing Program Counter and the value in the R register.

Text continued from page 128:

stored in 128 8-bit locations. Programs are stored by:

Number

Type

+ 5 V

GND

IC1

MCM6810

24

1

IC2

7475

5

12

IC3

7475

5

12

IC4

7475

5

12

IC5

74157

16

8

IC6

74157

16

8

IC7

7400

14

7

IC8

7400

14

7

IC9

7476

5

13

IC10

7476

5

13

IC11

7476

5

13

IC12

74191

16

8

IC13

74191

16

8

IC14

74191

16

8

IC15

2102

9

10

IC16

2102

9

10

IC17

2102

9

10

IC18

2102

9

10

IC19

7400

14

7

IC20

7400

14

7

IC21

7400

14

7

IC22

7400

14

7

IC23

7476

5

13

IC24

7476

5

13

IC25

555

8

1

IC26

7404

14

7

IC27

7404

14

7

Table 1:

Power-wiring

table for figures

3a, 3b,

and 3c.

• single-stepping the programming counter to the desired statement number,

• selecting the proper side of the statement with the L/R switch,

• loading the values for W, D, and ADR via the programming switches, and

• depressing the "write" button.

This sequence is repeated until all of the program has been entered. Execution is initiated by:

• single-stepping the starting location of the Turing program into register TPC, and

• switching to RUN mode.

Timing signals are provided by a 4-phase clock through the inputs labeled clock 1 thru clock 4.

This representation offers a relatively fast execution time of about 2 fis per cycle. Changes in the length of the tape or in the maximum number of program statements are extremely difficult to make. Output is limited only by the imagination and

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Our Distributed Processing Operating System, dpc/os resides in the Service Processor, establishing a CP/M environment for each user and managing access to the shared system resources. Multiuser facilities are provided for print spooling, for interprocessor communication and for private, public and shared-update files. Several processors can be employed concurrently by a single user via the enhanced batch submit facilities. And with DISCOVERY all CP/M compatible programs will execute without modification, thus protecting your software investment

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means of the user. In my prototype, a row of light-emitting diodes (LEDs) displays the contents of register R and register TPC (see figure 5). Components for this hardwired representation of a PTM cost about $80.

An Assembly-Language Version

Another implementation of a Practical Turing Machine is with a microprocessor. The code given in listing 1 is designed to run with only 512 bytes of memory and a Motorola 6800 microprocessor. The main program, as written, uses monitor routines available on the Heathkit ET-3400 Trainer. The tape index / is represented by the contents of locations 12 and II. The variable II points to an 8-bit word in the tape array. The 3 least significant bits of the contents of the location 12 point to a bit within that word. A maximum of thirty-two program statements may be stored in 64 bytes of memory.

Subroutine RUN is divided into five parts:

•statements 0000 thru 0016 (hexadecimal) load R with the value of TAPE (/)

STM#

R

= 0

R = l

0

0080

00A0

1

0081

0OA1

2

0082

00A2

3

0083

00A3

•

•

•

•

•

•

•

•

•

31

009F

00BF

WD — ADR — 7 6 5 4 3 2 10

Bit locations

Figure 4: Memory map of assemblylanguage implementation of a Practical Turing Machine. Memory locations hexadecimal 0080 thru 00BF are used to store a program of up to thirty-two steps, with 2 bytes being used to store each statement line. The character to be written, W, is in bit 7 of a given byte. The direction of tape head movement, D, is in bit 6. The statement number of the next statement to be executed is stored in bits 4 thru 0 of the byte. Bit 5 is unused.

•statements 0017 thru 001C (hexadecimal) establish an offset for finding the proper half of a Turing program statement •statements 001D thru 002F (hexa

decimal) print W(R,TPC) on the TAPE

• statements 0030 thru 0044 (hexadecimal) increment or decrement /

• statements 0045 thru 0049 (hexadecimal) restore TPC to the next program statement number

The main program provides output through the ET-3400 monitor routines and LED displays.

Details of storage of the Turing program appear in figure 4. Each side of each program statement is stored in a separate memory location. The value of W occupies the most significant bit and the value of D occupies the next most significant bit. The value of ADR is stored in the 5 least significant bits of a Turing program statement location.

Program statements are entered directly into memory locations using monitor routines available on the trainer.

Execution is initiated by:

entering the starting location of the irine nroeram into the location

Turing TPC,

program into the location

Text continued on page 146

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138 April 1981 © BYTE Publications Inc

Circle 95 on Inquiry card.

ALL

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from OSBORNE/McGraw-Hill

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PET/CBM Personal Computer Guide Second Edition by Adam Osborne and Carroll Donahue #55-1. $15. □

The PET/CBM Personal Computer Guide is a step-by-step guide that assumes no prior knowledge of computers. If you can read English, you can use this book. This revised second edition provides even more useful material than the popular first edition. It covers the most recent CBM products: the CBM 8000 and 4000 series computers, the 2040 and 8050 disk drives, and programmable printers. Adam Osborne co-authored this new edition. He has re-writien it to be a step-by-step BASIC tutorial. So if you don't know BASIC, don't worry. This book will teach you both BASIC and CBM BASIC. If you're thinking about buying any personal computer, this book will show you what the PET can do for you. If you've just bought a PET or CBM. this is the book you must have to really understand your computer. By using the examples found in this book you'll quickly get your PET/CBM up and running. These examples are thoroughly documented so you can learn how and why the programs work. It's the "how" and "why" that are important in learning to make the PET work efficiently for you. The PET Personal Computer Guide covers everything you'll need to be master of your PET.

"PET and CBM are both trademarks of Commodore Business Machines.

%

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"D

c

(0

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c

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CP/M User's Guide by Thorn Hogan «44-6$i2 99D

If you haven't yet purchased CP/M for your system, the CP/M User's Guide will make your first use of CP/M easy. If you already have CP/M, this book will help you modify your system and let you "jockey your disks "like an expert. The CP/M User's Guide describes types of CP/M and their compatibility. It includes a discussion of conventions used lo create file names and command lines. Numerous sample screen displays for each version of CP/M graphically explain each operator command and computer response. CP/M's Assembly Language Utilities are described for the non-technical reader who wants maximum use of CP/M's capabilities. The book also discusses how application packages, high level languages, solution programs, and other support programs combine with CP/M to answer a user's individual needs. You'll also find an explanation of MP/M and CP/NETas well as the technical aspects of CP/M's internal structure which will permit you to make simple modifications. A full glossary and several useful appendices are included. -CP/M is a trademark ot Digital Research Corporation.

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Make check payable to: {f\ OSBORNE/McGraw-HIII

630 Bancroft Way, Berkeley, CA 94710 Dept. B14 Phone Orders:(415) 548-2805

IS

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Signature _

Listing 1: Listing for implementation of the Practical Turing Machine in 6800 machine code. The program uses routines from the Heathkit ET-3400 microprocessor trainer at hexadecimal locations 0058 and 005B.

MICRO-TURING PRACTICAL TURING MACHINE SIMULATOR FOR USE WITH A 6800 MPU AND AT LEAST 512 BYTES OF RAM.THE MAIN PROGRAM USES MONITOR ROUTINES AVAILABLE ON HEATHKIT"S MODEL ET-3400 MICROPROCESSOR TRAINER.WRITTEN BY JIM WILLIS PHYSICS DEPT. UNC CHAPEL HILL. CHAPEL HILL , NC. 27514.

MICRO-TURING

COMMENTS

" READ TAPE

" SET UP TAPE MASK FROM (12)

A=00000001

B = I2

B=00000111 .AND. B

IF (B=0) GO TO NEXT

A=2*A

B=B-1

GO TO FIRST

R=B(=0)

" LOAD R WITH TAPE(12,11)

X=I1

IF ((A.AND.TAPE(Il)).EQ.O) Z=1,ELSE Z=0

IF (Z=l) GO TO ENDR

B=B + 1

R=B(=1)

" LOAD B WITH TURING PROGRAM STM(R,TPC)

B=TPC

B=B+$20

TPC=B

X=TPC

B=TURING PROGRAM STM(R,TPC)

X=I1

" WRITE ON TAPE

IF((B.AND.10000000).EQ.O) Z=1,ELSE Z=0

IF (Z=l) GO TO WZERO

A=A.OR.TAPE(Il)

GO TO ENDW

A=.NOT.A

A=A.AND.TAPE(I1)

TAPE(I1)=A

" MOVE TAPE POINTER

X=$004A

IF((B.AND.01000000).EQ.O) Z=1,ELSE Z=0

IF (Z=l) GO TO DEC1

" INCREMENT (12,II)

11=11+1

IF(I1.NE.-128) GO TO ENDR

12=12+1

GO TO ENDD

" DECREMENT (12,11)

11=11-1

IF(I1.NE.127) GO TO ENDD

12=12-1

" TPC=ADR(R,TPC)

B=B.AND.00011111

TPC=B

RETURN

MEM.

LOC.

OP.

CODE

LABEL

MNEMOMIC

0000

86

01

RUN

LDA

A # $01

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D6

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B 12

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B # $07

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A $00,X

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27

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B

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0019

CB

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B # $20

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" VARIABLES

12

II

Listing 1 continued on page 142

140 April 1981 © BYTE Publications Ire

Circle 101 on inquiry card.

The largest selection of software from the world's largest software publisher.

UCt

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Write for our catalog with full program descriptions and specifications.

DISK OPERATING SYSTEMS

CP/M CONFIGURED FOR: APPLE II

DIGITAL MICROSYSTEMS FDC3 DURANGO F-85 HEATH H8 AND H89 ICOM MICRO DISK ICOM 3712 ICOM 3812

ICOM 4511/PERTEC O3000 INTEL MDS

MICROPOLIS FLOPPY DISK M ITS/ALTAI R MOSTEKMDX NORTH STAR 0SIC3

PRO-TECH HELIOS TRS-80 MODELI TRS-80 MODEL II TRS-80 MODEL III ZENITH Z89 MP/M FOR INTEL MDS

HARD DISK INTEGRATION MODULES

CORVUS WITH APPLE II SOFTCARD CORVUS WITH S100 AND TRS-80

MODEL II ICOM 4511/PERTEC D3000 KONAN PLUS CDC PHOENIX XCOMP SM/S PLUS CDC PHOENIX XCOMP DFC10 FOR PERTEC D3000

SYSTEMS TOOLS

BUGANDuBUG

TRS-80 MODEL II

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CP/M

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EDIT

UNLOCK

EDIT-80

WORD-MASTER

FILETRAN

XASM-18

IBM/CPM

XASM-48

MAC

XASM-65

MACRO-80

XASM-68

PASM

XMACRO-86

PLINK

ZDT

RAID

Z80 DEVELOPMENT

RECLAIM

PACKAGE

SID

ZSID

TELECOMMUNICATIONS

LANGUAGES

ALGOL-60

muSIMP

APL/V80

NEVADA COBOL

BASIC-80

PASCAL/M

(COMPILER)

PASCAL/MT

BASIC-80

PASCAL/MT +

(INTERPRETER)

PASCAL/Z

BDSCCOMPILEF

PL/l-80

CBASIC-2

SMAL/80

CIS COBOL

S-BASIC

COBOL-80

TINYC

FORTRAN-80

WSMITHSC

KBASIC

COMPILER

muLISP

XYBASIC

LANGUAGE AND APPLICATIONS

TOOLS

BASIC UTILITY

MDBS.RTL

DISK

M/SORT FOR

DATASTAR

COBOL-80

FABS

PEARL

FORMS 2 FOR

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STRING BIT

MAGSAMIII

STRING/80

MAGSAM IV

SUPER-SORT

MDBS.DRS

ULTRASORTII

WORD PROCESSING SYSTEMS

AND AIDS

MAGIC WAND

TEX

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TEXTWRITER III

MICROSPELL

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ANALYST FPL

muMATH

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OTHER SPECIALIZED APPLICATIONS

BSTAM

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DATEBOOK

ESQ-1

MASTER TAX

PAS-3 DENTAL

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APL-AN INTERACTIVE APPROACH ACCOUNTS PAYABLE & ACCOUNTS RECEIVABLE-CBASIC 8080/Z80 ASSEMBLY LANGUAGE THE CP/M HANDBOOK THE C PROGRAMMING LANGUAGE FIFY BASIC EXERCISES GENERAL LEDGER-CBASIC

ACCESSORIES

DC 300 DATA CARTRIDGE HEAD CLEANING DISKETTE FLIPPY DISK KIT FLOPPY SAVER

Program names and computer names are generally trademarks or service marks ol the author or manufacturing company.

All software products have specific requirements for hardware and additional associated software (e.g. operating system or language).

All products are subject to terms-and conditions of sale.

Copyright <c; 1981 Lifeboat Associates. No portion ol this advertisement may be reproduced without prior permission.

Ordering Information

COMPUTERS SUPPORTED WITH MEDIA FORMAT ORDERING CODES.

ADDS Multivisicin

AVL Eagle

Altair8800

Alios

Apple CP/M 13 Sector

Apple CP/M 16 Sector

BASF Syslem 7100

Blackhawk Micropolis

Mod II

Blackhawk Single Density

CDS Versatile 3B

COS Versatile 4

COMPAL-80

CSSN Backup

Cromemco System 3

Cromemco Z2D

Delta Systems

Digi-Log Microterm II .

RT Digital Microsystems A1

RB DurangoF-85 RL

B1 Oynabyle DB8/2 R1

A1 Dynabyte DB8/4 A1

R6 Exidy Sorcerer * Lifeboat

RR CP/M 02

RD Heath H8 + H17/H27 disk . P4 Heath H89 * Lileboal CP/M P4

02 Heath H89 • Magnolia

Q3 CP/M P7

01 Helios II B2

02 ICOM 2411 Micro Floppy ... R3

02 ICOM 3712 A1

T1 ICOM 3812 A1

A1 ICOM 4511 5440 Cartridge

R6 CP/M D1

A1 ICOM 4511 5440 Cartridge

RD CP/M D2

RA

IMS 5000 IMS 8000 IMSAI VDP-40 R4

IMSAI VDP-42 R4

IMSAI VDP-44 R5

IMSAI VDP-80 .. A1

ISC Intecolor

8063/8360/8963 A1

Intertec Superbrain DOS 0.1 R7 Intertec Superbrain DOS 0 5 RJ Intertec Superbrain DOS 3 x RK Intertec Superbrain 00 RS

Kontron PSI-80 RF

MITS 3200-3202 81

MSD5.25in RC

MecaDelta-15 25in P6

Micromation A!

Micropolis Mod I 01

Lifeboat Associates, 1651 Third Avenue, N.Y, N.Y. 10028 (212) 860-0300 Telex: 640693

pi

Micropolis Mod II

Morrow Discus

Moslek

North Star Single Density

North Star Double Density P2

North Star Quad Density P3

Nylac Micropolis Mod II

Nylac Single Density

Ohio Scientific C3

Onyx C8001

PettecPCC2000 Processor Technology

Helios II

Quay 500

Quay 520

RAIR Single Density RAIR Double Density

02 03

A3 T2 A1

B2 RO RP R9 RE Research Machines 5.25 in RH

Research Machines Sin

Rex

SD Systems 5 25 in

SD Systems 8 in

Sanyo 7000 5 25 in Spacebyte .....

TEI5 25in

TElBin

TRS-80 Model I

STANDARD TRS-80 Model I * FEC

Freedom

TRS-80 Model I +

Micromation TRS-80 Model I t Omikron

5.25 in RM

TRS-80 Model I f Omikron

8 in

TRS-80 Model I ♦

Shuflleboard TRS-80 Model II TRS-80 Model III Vector MZ

Vector System B

VistaV-805 25in. Single

Dens

Vista V200 5 25 in. Double

Dens

Zenith Z89 +Heath CP/M P7 Zenith A89 + Lileboal CP/M P4 Zenith Z89 + Magnolia

CP/M P7

boat Associates

SOFTWARE

In Germany, x

Intersoft GmbH, Schlossgartenweg 5,

D-8045 Ismaning Telephone 089/966-444 Telex: 5213643 isof

In Switzerland,

Lifeboat Associates GmbH, Aegeristr. 35, CH6340 Baar,

Telefon: 042/31 2931, Telex: 865265 MICO CH

Listing 1 continued:

004E XX 004F XX

TPC R

0054 8D AA 0056 96 4F 0058 BD FC QC 005B BD FE 3C 005E 01 01 01 0061 20 F0

MAIN

(TPC) (R)

BSR RUN

LDA A # R

JSR REDIS

J3R OUTHEX

NOP

BRA MAIN

TPC R

" MAIN

BRANCH TO SUBROUTINE RUN

A=R

" SET UP DISPLAY ADDRESS

" DISPLAY CONTENTS OF A

" SPACE FOR ANOTHER JSR

GO TO MAIN

" END MAIN

0030

00

(0,0)

0081

81

(0,1)

00A0

81

(1.0)

00A1

00

(1,1)

0100

XX

THRU

XX

01FF

XX

" LOCATIONS $0080 THRU $00BF

" RESERVED FOR TURING PROGRAM

" STATEMENTS

" (1,0)=(R,TPC)

" TAPE

" TAPE

" TAPE

XX= LOCATION FILLED JUST PRIOR TO EXECUTION

Listing 2: Listing for implementation of the Practical Turing Machine in FORTRAN.

:l.00 " TURING

110 " UNIVERSAL TURING MACHINE SIMULATOR.JIM WILLIS > PHYSICS DEPARTMENT

120 " UNIVERSITY OF NORTH CAROLINA » CHAPEL. HILL NORTH CAROLINA,

130 " DESIGNED TO RUN ON UNCCC'S VERSION OF IBM'S 360/370 CALL-OS

140 " TURING

ISO DIMENSION 17'APE < 128 )

160 INTEGER *2 W(2r64) nB<2»64> >ABR<2i>64) i-TAPE<128) t TPC > WI yDI» ADR 11 T

170 DATA Y/'YV

180 1000 WRITE(3»100)

190 100 FORMAT( ' HOW MANY SPACES IN THE TAPE? 128 MAX. ' )

200 READ<1*#) MTAPE

210 IF(HTAPE,GT,128) MIAPE~128

220 1001 WRITE(3v102)

230 102 F0 RMAT<' IN PU T TURIN0 PR0 0 R A M,W 0»D 0»A DR01W11D11A DR1.W 0 «2 1" 0 END ' )

240 NSTM'-O

250 1 NDEX-NSTM-fl

260 WRITE (3»103)NSTM

270 103 FORMAT(' STM.NO. '*I2)

280 READ(1t#)W(1»NDEX)vD(1,NDEX)tADR(1.NDEX)»U(2»NDEX)>HH2>NDEX)rADR <2 »NDEX)

290 IF(N STM,E0.64)00 T0 2

3 0 0 I! F (W (1 r H D E X ) . G T ♦ 1) (3 0 T 0 2

310 NSTM^NSTM-fl

320 GOTO 1

330 2 WRITE<3»104)

340 104 FORMAT(' NO. WO DO ADRO Wl Dl ADR1')

350 DO 3 I~1»NSTM

360 N-I-l

370 WRITE<3»105)N»W<1»2)»D<1»I)»A0R(1»I)nW(2»I)tBi2>I)tADR<2»I)

380 105 FORMAT'-' ' »4I4 r ' \ ' v3I4)

390 3 CONTINUE

400 WRITE (3 1-106)

410 106 F0RMAT(' INPUT FIRST TURING PR0GRAM STM. NO,')

420 READ ( l.J *) TPC Listing 2 continued on page 144

142 April 1981 © BYTE Publications Inc

Circle 97 on inquiry card.

SYBEX BREAKS THE

LANGUAGE BARRIER

NTRODUl WM v.

PA5CBC

■i

Let the chips fall where they may. These two books on BASIC assure comprehension and competence.

by Richard Mateosian teaches interactive game design and BASIC programming through thorough analysis of eight different kinds of computer games. Programs are presented in Microsoft BASIC with versions for PET/CBM, TRS-80 and APPLE II. 350 pp., 120 illustr., Ref. B245, $13.95

by I. P. Lamoitier provides the surest way of learning BASIC—actual practice. Graduated exercises, each containing a detailed explanation, flowchart and sample run, develop skill and competence rapidly. Applications include mathematics, business, operations research, statistics and more. 256 pp., 194 illustr., Ref. B250, $12.95

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)y Rodnay Zaks is a simple yet comprehensive guide to standard and UCSD Pascals: step-by-step presentation with exercises for beginners, complex concepts and extensive appendices for experienced programmers. An indispensable book for everyone who wants to learn Pascal programming.

pp., 100 illustr., Ref. P310, $14.95

by lacques Tiberghien is an easy-to-read, easy-to-use dictionary containing all the features for most existing versions of Pascal (Standard, Jensen-Wirtli, OMSI, UCSD, HP1000, Pascal/Z). Over 180 entries, arranged alphabetically; each includes definition, description, syntax diagram, details of implementation, variations and examples. The perfect reference tool for any Pascal user. 500 pp., 150 illustr., Ref. P32C

MAIL TO: SYBEX DEPT. B41

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Scientists and engineers involved in significant work have been delayed by having to reinvent algorithms for a new computer language. No more.

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6502 GAMES by Rodnay Zaks 304 pp., 140 illustr., Ref. G402, $12.95

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PROGRAMMING THE Z8000

by Richard Mateosian

312 pp., 124 illlustr., Ref. C281, $15.95

THE CP/M HANDBOOK (With MP/M)

by Rodnay Zaks

336 pp., 100 illustr., Ref. C300, $14.95

□ SEND ME YOUR FREE CATALOC

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Circle 98 on inquiry card.

WHAT'S

BETTER

THAN AN

ISAM

And Will Turn

MICROSOFT'S

BASIC

COBOL

FORTRAN

DIGITAL'S PL/i-80

CBASIC

PASCAL/MT+

S-BASIC

CROMEMC016K BASIC

into first class application languages?

MICRO B+

The first and most complete implementation of B-TREE index structures for microcomputers. B-TREES eliminate index file reorganization,

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An index of over

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Available in Language C

Fair Com

2606 Johnson Onve Columbia MO 65201 (314)446-3304

«' 1980 fair Com

Shipping $4 USA / $8 Foreign We accept VISA and MASTERCARD

Ft/l-80 Is o trademark of Digital Research C8ASIC is a trademarii of Compiler Systems. Inc. S-BASIC Is a trademark of Topaz Programming PASCAL/MT* Is a trademark of MTMIcroSystems

Listing 2 continued:

430

440 107

450 460

4 70 .1:1.9 480

490 120

5 0 0

510

5 2 0 530 ' 540 ' 550 ' 560 570 580 590 600 6.10 620

6 3 0 64 0

6 50 660 670 680 690 700 710 720 730

7 40 750 760 770 ' 780 ' 790 ' 800

S10

820

830

840

850

860

870

880

890

900

910

920

930

940

950

960

970

980

990

1000

1010

1020

1030

1040

121

18

»00

201

202

7 7

03

.09 110

144 April 1981 © BYTE Publications tac

WRITE (3 I- 107)

FORMATC HOW MANY TIMES THROUGH THE TAPE?')

READCI. vUOMIT WRITE(3.119)

F 0 R M A T ( ' IN P U T C H A R A C T E R F 0 R Z E R 0 ♦' ) READ (1> 120) J.ZERO

FORMAT(A1) WRITE(3v121)

F 0 R M A T ( -' IN P U T C H A R A C T E R F 0 R 0 N E . "' ) READCU 120) I ONE

INITIALIZE TAPE TO ZERO

HO 4 j>l vMTAPE TAPE(I)=0

CONTINUE KIT«0

TAPE LIST ROUTINE

KT APE** 1

KIT»KIT+i DO 32 N»l yMTAPE ITAPECN)~IZERO IF(TAPE(N).EQ*0)G0T0 32 ITAPE(NXi:0NE

CONTINUE

W RIT E (3 >• 113) (IT A P E (I) »I»1, M T A P E)

FORMAT(128A1) IF(KIT,ECU MIT)GOTO 99

RUN

CONTINUE TPOTPC+1 T-TAPE CRT APE) + 1

D:i>Dnvrpo

TAPE(KTAPE)~W<T»TPC)

IF <D I* E0M )G0TG 201

KTAPE-KTAPE-1

IF ( KTAPE J...T.1) KTAPE-MI APE

GOTO 202

KTAPE=KTAPE+1 IF(KTA PE.BT.MTAPE)K T APE =1

TPC = ADR<T'vTPC) !i:F < KTAPE . EQ«M')"APE ) G0T0 9 GOTO 200

WRITE (3i-lOS)

FORMAT< ' WANT TO CHANGE THE TAPE LENGTI READ(1,109)ANSWER IF (A N S W E R , E Q ♦ Y ) GO T 0 10 0 0

FORMAT (AD WRITE(3v110)

F0 RM A T(' WANT T0 REPR 0GR AM?') READCI. * 109) ANSWER IF (A N S W E R . E Q , Y) G 0 T 0 10 01 GOTO 2 END

Circle 99 on inquiry card. >

4.4 MEGABYTES

FOR YOUR APPLE

1 ■—• ■

jH^'

Double-Sided, Double-Density 8-Inch Drive Capability is Here ... Now!

The new LOBO DRIVES Model LCA-22 Double Density Floppy Disk Controller has been specifically designed to match your APPLE® to the new double-sided, double-density 8-inch floppy disk drives. Now, you can add up to four 1.1 Megabyte drives (4.4 Megabytes total) and realize all the power and potential of your APPLE computer.

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clock „ JLIUUUULnJLILILIl

CLOCK 4

CLOCK 3

CLOCK 2

CLOCK 1

CLOCK SIGNAL

J~l

J~~L

1_

TIME

Figure 5: Timing diagram for the four-phase clock. The signals shown here are generated by IC23 and 1C24 in figure 3a. Note that within the schematic of figure 3c, the inverted counterparts of clock 2 and clock 3 are also used.

Text continued from page 138: • entering the DO-0054 command into the trainer (this begins program execution at hexadecimal location 0054).

The value of R is displayed continuously on the leftmost LED of the trainer.

The microprocessor representation of the PTM is easier to implement than the hardwired version. Changes in the length of the tape or the maximum number of program statements are relatively easy to make, but the microprocessor is very slow compared with the hardwired version. Subroutine RUN requires about 150 /is per cycle as compared with 2 lis for the hardwired version.

A FORTRAN Version

One of the most useful and comprehendable representations of a PTM is one written as a high-level language program. Listing 2 is a source listing for an interactive FORTRAN program that can be used to simulate a PTM. The run section of this program follows the flowchart in figure 2.

The program is stored in three arrays dimensioned W(2,64), D(2,64), and ADR(2,64). The maximum length of the tape is 128 characters. A shift is made in the subscripts to allow R=0 and TPC=0. Output characters for the tape are chosen by the user rather than being restricted to 0 and 1. Program statements are entered as six-component vectors and can be readily changed. The most important variables are available interactively to the user.

Summary

We have implemented the Practical Turing Machine in three forms—as a hardwired circuit, a 6800 machine code program, and a FORTRAN program. We have found that the hardwire version is the fastest but the most difficult to run or modify, and that the FORTRAN version is the easiest to modify but the slowest in execution. The microprocessor version is a compromise in both speed and utility. ■

Acknowledgments

/ would like to thank Tom Ainsworth for his help in the design of the hardwired version, Dr W ] Thompson for his guidance during the project, and Alice Glenn for her help in the preparation of the manuscript. The research for this article was supported in part by the United States Department of Energy.

References

1. Arbib, M. Brains, Machines, and Mathematics. New York, McGraw-Hill Book Company, 1964.

2. Bernstein, J. "When the Computer Procreates." New York Times Magazine, February 15 1976.

3. Millen, J K. "A Universal Turing Machine." December 1976 BYTE, pages 114 thru 119.

4. Minsky, M L. Computation: Finite and Infinite Machines. Englewood Cliffs NJ: Prentice-Hall, 1967.

5. Munnecke, Thomas. "Designing a Universal Turing Machine: a Software Approach." December 1979 BYTE, pages 26 thru 30.

6. Turing, A M. "On Computability with an Application to the Entscheidungproblem." Proceedings of the London Mathematical Society, Volume 42, 1936, pages 230 thru 265.

146 April 1981 © BYTE Publication! Inc

Circle 100 on Inquiry card.

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System Notes

A Relocatable Bootstrap for the Tarbell Disk Controller

Hector M Smith

9852 Dandelion Ave

Fountain Valley CA 92708

Some Z80 microprocessors do not work properly with the Tarbell disk-controller ROM (read-only memory). For example, Ithaca Intersystems recommends that the bootstrap program be relocated to high memory and that a power-on jump to it should be executed. You can make the program independent of memory location by using the Z80 relative-jump instruction.

Listing 1 is a relocatable version of the Tarbell bootstrap loader. Relative jumps are included at hexadecimal locations 0010 and 0016. A test bit instruction is located at hexadecimal 000E.

The original 8080 code is shown in listing 2. In the

code, at hexadecimal locations 000E and 000F, ORA resets the sign flag if the MSB (most significant bit) of INTRQ is 0. If this is the case, JP jumps to RDONE.

Because the Z80 does not have a relative jump instruction activated by a positive test, BIT 7,A is used to check if bit 7 (INTRQ) is 0. If it is, a jump relative to RDONE is executed. At hexadecimal location 0016, a jump relative to RLOOP and NOP was substituted for the original jump.

The modified bootstrap (listing 1) can be located anywhere in memory. A jump to it will boot the CP/M operating system. ■

Listing 1: A Z80 relocatable bootstrap program for the Tarbell disk controller. The mnemonics are TDL Assembler.

ADDR MACH

LABEL

ASY

LANGUAGE COMMENTS

CODE

0000 DB FC

BOOT:

IN

WAIT

WAIT FOR HOME.

0002 AF

XRA

A

COMPLETE.

0003 6F

MOV

L,A

SETL = 0.

0004 67

MOV

H,A

H&L = 0.

0005 3C

INR

A

SET A = 1.

0006 D3 FA

OUT

SECT

SECTOR = 1.

0008 3E 8C

MVI

A.8CH

READ SECTOR.

O00A D3 F8

OUT

DCOM

O00C D2 FC

RLOOP:

IN

WAIT

WAIT FOR DRQ OR INTRQ

000E CB 7F

BIT

7,A

TEST BIT 7

0010 28 07

JRZ

RDONE

DONE IF INTRQ

0012 DB FB

IN

DDATA

READ A BYTE OF DATA.

0014 77

MOV

M,A

PUT INTO MEMORY.

0015 23

INX

H

INCREMENT POINTER

0016 18 F4

JMPR

RLOOP

DO IT AGAIN

0018 00

NOP

FILLS EMPTY SPACE

0019 DB F8

RDONE:

IN

DSTAT

READ DISK STATUS.

001B B7

ORA

A

SET FLAGS.

001C CA 7D 00

JZ

07DH

IF ZERO, GO TO SBOOT.

001F 76

HLT

DISK ERROR, SO HALT.

WAIT

=

OFCH

SECT

=

OFAH

DCOM

=

OF8H

DDATA

=

OFHB

DSTAT

=

OF8H

sting 2: Original

8080 code before

modification

for the Z80 microprocesso

000E

B7

OR

A A

000F

F2 19 00

IP

RDONE

0016

C3 0C 00

JM

P RLOOP

148 April 1981 © BYTE Publications Inc

Circle 102 on inquiry card.

Lifelines*

The serious publication for the serious software user.

March 1981 Vol. 1 Issue #10

From the Software Evaluation Group: A Review of the Configurable Business System

Osborne/McGraw-Hill's General Ledger, a Tutorial by One of Its Authors.

BASIC Comparisons: An Introduction to SBASIC.*

Details on Volume 48 from The CP/M Users Group.*

Some Biting Comments on the Industry from the Mysterious Zoso.

Lifelines is the publication dedicated to keeping you up-to-date on happenings in the explosive microcomputer world.

Lifelines specializes in news about software for CP/M* and similar operating systems.

Lifelines does it with a guarantee of high level, in-depth analysis of software uses and capabilities.

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'SBASIC is a trademark of Topaz Programming * CP/M is a trademark of Digital Research, Inc. The CP/M Users Group is not affiliated with Digital Research, Inc.

■^Ms^n l^M^^ft

A Closer Look at the TI Speak & Spell

Congratulations to Michael Rigsby on his article "Dissecting the TI Speak & Spell" (September 1980 BYTE, page 76). He is not alone in desiring an economical voice-output device for his computer, and the Speak & Spell is an excellent choice. Economy is one reason, and the circuitry of this device has features that make it potentially one of the most flexible and comprehensive speech synthesizers available.

The problem is how to interface the Speak & Spell to a computer. Mr Rigsby's approach is the first step, but it allows only a spelling computer, not a talking one. In order to achieve more, it is necessary to know something about the workings of the device. This information is difficult to obtain. Texas Instruments has not been very informative, although considering the investment it has in speech technology this is perhaps understandable. Thus, the Speak & Spell is an irresistible challenge to the experimenter.

Mr. Rigsby has, however, made one fundamentally incorrect assumption: the TI Speak & Spell is most definitely not based on the SN76477N complex-sound generator, nor does it store words, or even phrases, as individual pulses in memory. As I will show, it uses an entirely different technique.

The Heart of the Unit

The TMC0281NL is a proprietary Texas Instruments integrated circuit that is virtually an entire digital signal processor, with timing and decoding circuits, a 10-pole digital lattice filter, and a D/A (digital-to-analog) con

Peter Vernon

31 Georgina St

Newtown NSW 2042

Australia

verter. All of this is contained on a tiny piece of silicon just 44 mils square. This is the heart of the speech synthesizer.

Also on the board is the controller, the TMC0271NL, which is a member of the TMS-1000 microprocessor family. The TMC0271 shares the same basic architecture as the TMS-1000 used in TI's calculators, but it has been modified to enhance its BCD (binary-coded decimal) arithmetic capabilities. It also has an expanded instruction set and an output multiplexer to reduce the number of pinouts required in its role as a controller for the speech synthesizer IC (integrated circuit).

The Speak & Spell is an

irresistible challenge to

the experimenter.

As Mr Rigsby guessed, the other two integrated circuits on the board are high-density ROMs (read-only memories). The TMC0350 family are 128 K-bit ROMs, organized as 16 K by 8 bits. They incorporate an internal 18-bit address counter/register and two 8-bit output buffers, with the four high-order bits of the address driving a l-of-16 device-select decoder and the other 14 bits addressing the ROM array directly.

Linear Predictive Coding

The circuitry is only part of the story. The real secret of the Speak & Spell and other Texas Instruments speech-synthesis devices is a tech

nique called LPC {linear predictive coding). This technique makes it possible to encode a complex speech waveform with relatively little data. A speech signal is highly redundant, made up of a few basic waveforms that are repeated to produce speech sounds. Essentially, LPC eliminates the redundancy inherent in the speech signal and retains only the data required to drive the speech synthesizer.

The TMC0281 can be thought of as an electronic model of the human vocal tract. The data input is a description of the filter parameters necessary to model the vocal tract as its characteristics change over time. Codes for twelve synthesis parameters are stored in the ROMs. These parameters are ten filter coefficients, and pitch and energy information.

The filter parameters are derived from samples of actual speech and are encoded by a complex mathematical algorithm that makes it possible to predict a speech waveform based on information derived from previous waveforms. Because of the finite-time response of the human vocal tract, only a fixed number of speech sounds can follow a particular vocalization.

To produce speech, the controller specifies the starting point of a string of data stored in the ROMs. The ROM output provides the pitch, amplitude, and filter parameters from which the synthesizer constructs the speech waveform.

The input to the filter is either a periodic or random sequence of pulses. A random sequence of pulses is used to recreate unvoiced sounds,

150 April 1981 © BYTE Publications Inc

Circle 103 on inquiry card.

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such as "[" or "s," while a periodic sequence creates voiced sounds such as "a." The pitch information either varies the frequency of the periodic pulses or, if all the bits are zero, selects random noise as the input to the lattice filter. An amplification factor is also input to the synthesizer and adjusts the amplitude of the excitation source to produce sounds of varying intensity.

The lattice filter of the synthesizer has ten stages. Each stage carries out two multiplications and two additions on its two digital inputs before passing the results backward and forward to its neighbors. The operations of the ten stages are carried out sequentially, as are the operations within each stage. Through careful consideration of timing and the use of a pipeline approach, only one adder and one multiplier are needed to carry out the mathematical operations. Each separate arithmetic operation requires only 6 fis.

Figure 1 is a block diagram of the basic elements of the TMC0281. The multistage lattice filter uses the parameters Kx thru K„ to digitally filter the amplified excitation signal, and passes its output to a D/A converter connected to the speaker.

The coefficients of the filter are updated approximately every 20 ms. However, because of the redundancies in speech patterns, a complete set of parameters is not always required. Sections of the data stream may be replaced by a single "repeat" bit, cutting the data required to control the filter from a maximum of 49 bits to a minimum of 4, thus conserving memory space.

During speech the TMC0281 accesses the ROMs directly until it receives an end-of-phrase command and returns control to the TMC0271 controller. Five lines are used to transfer data and commands within the system. One of these lines is the processor data clock, which determines when the data on the other four lines is valid. These are the five lines mentioned by Mr Rigsby.

Timing

Timing for the synthesizer is based on a 50 Hz frame rate—so a new speech segment is read from the ROM every 20 ms. The speech patterns coded in the ROM are sampled at a rate of 10 kHz, which corresponds to the maximum bandwidth of speech—5

152 April 1981 © BYTE Publications Inc

Circle 104 on inquiry card.

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BYTE April 1981 153

Circle 106 on Inquiry card.

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:;

WHITE 1 ■ ■ ' .■'■■•■!

NOISE

PERIODIC I I I I PULSES

UNVOICED

VOICED*

PITCH

AMPLITUDE

LATTICE FILTER

VOCAL TRACT MODEL

SPEAKER

D/A CONVERTER

-<

FILTER

COEFFICIENTS

<Kl-Kn>

Figure 1: Block diagram of the heart of the TI Speak & Spell—the Texas Instruments TMC0281NL integrated circuit. The TMC0281NL is a proprietary circuit that is virtually an entire digital signal processor and can be thought of as an electronic model of the human vocal tract. It includes timing and decoding circuits, a 10-pole digital lattice filter, and a D/A converter. Speech synthesis takes place through a process called LPC (linear predictive coding), which makes it possible to encode a complex waveform with relatively little data. Either pseudo-random noise (for unvoiced sounds) or periodic pulses (for voiced sounds) are amplified and fed to the lattice filter, which models the vocal tract in accordance with coefficients stored in two external 16 K by 8-bit ROMs (read-only memories). A maximum of 49 bits is needed to specify each sound pattern, which is updated every 20 ms. This results in an overall data rate of 2400 bps (bits per second). The TMC0281NL is controlled by a TI TMC0271 microprocessor, a specialized member of the TMS-1000 microprocessor family.

kHz. (The maximum bandwidth for telephone-quality speech is 3.5 to 4.5 kHz.) An 800 kHz oscillator is divided by four to produce the major system clock. This four-phase clock controls the transfer of data within the system. The individual bit patterns in each 20 ms frame are clocked into the synthesizer at a rate corresponding to the sample frequency of 10 kHz. It is this clock which produces the 0.1 ms pulses measured by Mr Rigsby.

A maximum of 49 bits is needed to specify the sound pattern that will be produced every 20 ms. This is an overall data rate of about 2400 bps (bits per second). One hundred seconds of speech time thus requires the storage of 240,000 bits of information, which corresponds well with the 256,000 bits of storage provided by the two TMC0351 ROMs.

Capabilities and Challenge

Because the Speak & Spell reconstructs speech sounds from a constant-excitation signal filtered under digital control, it is potentially capable of reproducing any sound at all. The challenge for the experimenter is to determine what information needs to be input to create a particular sound. Trial and error seems to be the only approach. With

much work it would be possible to determine which combinations of data are needed to produce each phoneme of the English language. (All words are made up of combinations of particular sound units called phonemes. About 42 phonemes are used in the English language.) These phoneme patterns could be stored in memory and arranged to produce any word. At 49 bits per phoneme and 42 phonemes, only 2058 bits are required. The problem is, of course, to find the right bits.

Perhaps the best place to start would be the connector provided for the attachment of expansion modules. The module-select key on the keyboard of the Speak & Spell is used to signal the controller that an expansion module is in place and that it should instruct the synthesizer to access this module rather than the ROMs on the main circuit board. By using this signal it is possible to force the synthesizer to accept data that is input on the module connector. The system clock can be used to govern the rate of this data input. Experimenting with this approach produces a weird and wonderful series of sounds. At present, my computer (an Exidy Sorcerer) can only grunt and squeak, but after all, that's how we all started IB

154 April 1981 © BYTE Publications Inc

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SSS FORTRAN Specifics

SSS FORTRAN makes full FORTRAN IV available to microcomputers. SSS FORTRAN meets and exceeds the ANS11966 FORTRAN standard. The compiler supports many advanced features not found in less complete implementations, including: complex arithmetic, character variables, and functions. SSS FORTRAN will compile up to 600 lines per minute! Recursive subroutines with static variables are supported. ROMable ".COM" files may be generated.

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Code generation: ROMable ".COM" files or intermediate code files (saves disk space). External routines may be called.

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Errors: Over 200 distinct compiler error messages, precision and

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Interrupts: FORTRAN programs may be interrupted at any time: the stack

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• • D E ATLCIM3 • m

SSS RATFOR

RATFOR is a preprocessor that compiles to SSS FORTRAN. SSS RATFOR allows the use of contemporary loop control and structured programing techinques. SSS RATFOR is similar to FORTRAN 77 in that it supports such things as: REPEAT ... UNTIL WHILE IF ... THEN ... ELSE

Begin End Brackets Macro Defines

SSS RATFOR is supplied with source code. The source code is distributed in both RATFOR and SSS FORTRAN. Not only does this prevent obsolescence, but allows the user to add enhancements as desired.

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SSS FORTRAN requires a 32k CP/M system. Z80 only. SSS FORTRAN with RATFOR: $325.00 SSS FORTRAN alone: $250.00

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BYTE April 1981 157

Clubs and Newsletters

Zips 00000—10000

1. Syntax ZX80

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3. Ann Zevnik, Editor, (617) 456-3661

5. News about the Sinclair ZX80 microcomputer.

1. Gosub TRS-80 Users Group

2. POB 712 Worcester MA 01613

3. Jim Mercanti, (617) 845-1851, (617) 458-7263

4. Gosub TRS-80 Users Group Buffer

5. Noncommercial.

1. TRUGEM (TRS-80 Users Group of Eastern Massachusetts)

2. 3 Driscoll Dr, Framingham MA 01701

3. Ronald M Egalka, Secretary, (617) 877-4520

4. The TRUGEM Newsletter

5. TRS-80 hardware and software; peripherals from Radio Shack and independents; Programs Exchange Library (noncommercial); demonstrations and sales of commercial hardware and software encouraged.

1. New England Computer Society

2. POB 198 Bedford MA 01730

3. Bob Waite, President (617) 448-6351 home; (617) 897-3221, ext 2499, work

4. NECS Newsletter

5. User Groups: PET, Apple, 6800, Digital Group, and TRS-80. CBBS (Computerized Bulletin Board System), (617) 864-3819.

1. The Boston Computer Society

DIRECTORY

The following is the fourth BYTE Clubs and Newsletters Directory. The directory was compiled from information supplied by the various clubs listed. A form was sent to all clubs and newsletters listed in the third directory requesting up-todate information. If the form was not returned, we deleted the club from the fourth directory. In addition, the listing was correlated with back issues of the magazine and materials on file in the BYTE offices. If information is missing in one or more categories, it means the data was not provided. We will be keeping the file available and updating it for the next directory; so, if there are errors, omissions, or if you have a new club that has just been formed, send the information to Charley Freiberg, Clubs and Newsletters Editor, BYTE Publications Inc, POB 372, Hancock NH 03449.

The listing follows this form: 1. Name of organization or name of publication; 2. Mailing address; 3. Contact person and telephone number; 4. Newsletter or publication; 5. Special interests.

2. 3 Center Plz, Boston MA 02108

3. (617) 720-0597

4. The Boston Computer Society Update (an enormous publication with nationwide industry exclusives and news of New England)

5. User Groups: PET, Sorcerer, OSI, North Star and others. Subgroups: education, business applications, Pascal and beginner tutorials.

1. Classroom Computer News

2. POB 266, Cambridge MA 02138

3. Lloyd Prentice, (617) 787-0420

5. This bimonthly newsletter is interested in education, curriculum development, and related topics.

1. Technical Education Research Centers

2. 8 Eliot St, Cambridge MA 02138

3. Robert Tinker, Director or Susan Warner-Mills, Assistant, (617) 547-3890

4. Hands On!(A Forum for Science and Technology Educators)

5. Applications to education, especially science.

1. RICH (Rhode Island Computer Hobbyists)

2. POB 599, Bristol RI 02809

3. Emilio D Iannuccillo

4. Yes

5. We are an active group dedicated to keeping abreast of current technology, plus lending a hand to each other regarding hardware and software. We also give help and advice to newcomers into the world of microprocessors.

1. PIE (PET Information Exchange)

2. 27 Leicester Way, Pawtucket RI 02860

1. SNAC (Southern New Hampshire Apple Core)

2. Computerland of Nashua, 419 Amherst St, Nashua NH 03060

3. Don Fairchild, Treasurer, (603) 434-5626

4. S.N.A.C.

5. This group is involved in all aspects of home computing using Apple systems.

1. Manchester Users Group

2. 346 S Taylor St, Manchester NH 03103

3. Scott, (603) 624-0089

4. Yes

5. TRS-80s.

1. Southern Maine TRS-80 Group

2. 15 Mountain View Rd, Cape Elizabeth ME 04107

3. Douglas Stewart, (207) 767-2351

4. Byte Babble

5. TRS-80s.

1. Doctor's Computer Club

2. 42 E High St, East Hampton CT 06424

3. Dr Aziz Ghaussy, (203) 267-2400

4. Medical Computer Journal Newsletter

5. Application of computers in medical practices.

1. The Pocket Computer Newsletter

2. POB 232, Seymour CT 06483

1. Computers in Psychiatry/Psychology

2. 26 Trumbull St, New Haven CT 06511

3 Marc D Schwartz, MD, Editor, (203) 562-9873

5. This publication is for professionals interested in the use of computers in their work.

1. Connecticut Computer Club

2. 18 Ridge Ct W, West Haven CT 06516

3. Leo Taylor, Secretary

4. CCC Newsletter

5. We have two talks per meeting; generally one on software and one on hardware. The club does not specialize in any one machine.

1. API Market Newsletter

2. POB 5314, Mt Carmel CT 06518

3. Raymond C Jordan, (203) 288-0283

158 April 1981 © BYTE Publications Inc

Circle 107 on inquiry card.

Corvus Lowers the Price of Admission to the Winchester Club

■

Here's the price breakthrough you've been waiting for on Winchester disk systems. It's our new5'i-inch 5-million byte Winchester that adds cost effective mass storage to over 15 of the most popular microcomputers. Now everyone can enjoy the improved reliability, increased storage capacity, and faster speed of sealed-environment Winchester technology.

You can start with 5 million bytes, then expand the system with up to three add-on drives of 5. 10, or 20 million bytes. Our 5 million byte system has all of the advanced features of the larger capacity Corvus systems, including our low cost MIRROR backup and multi-user CONSTELLATION network that allows up to 64 computers to share the Corvus data base and peripherals such as printers.

Want the full story? Contact your local computer store.

\I

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Clubs and Newsletters,

1. Amateur Computer Group of New Jersey

2. 1776 Raritan Rd, Scotch Plains NJ 07076

3. Sol Libes, (201) 277-2063

4. ACG-NJ News

5. User Groups: 8080/Z80, 6800, KIM-1, TRS-80, PET, CP/M, 1802, S-100, Apple, and Pascal. We also have software libraries and tutorials.

1. OSI Users Group

2. 4 Swimming River Rd, Lincroft NJ 07738

3. Bob Childs, (201) 747-8888

1. Data Processing Club

2. c/o Dennis M Lloyd, Business Studies Division, Gloucester County College, Tanyard Rd, Sewell NJ 08080

3. (609) 468-5000, ext 242

4. Interested in microcomputer programs inside and outside of the classroom.

Zips 10000—20000

1. New York Amateur Computer Club

2. POB 106, Church Street Sta, New York NY 10008

3. Garry Sawyer, (212) 864-4595.

4. New York Amateur Computer Club Newsletter

5. Anything to do with computers.

1. Computer Careers News

2. 135 W 50th St, New York NY 10020

3. Connie Winkler, Editor, (212) 582-9617

5. Careers publication for processing professionals.

1. Feedback From Fujitsu

2. c/o Ruder & Finn Inc, 110 E 59th St, New York NY 10022

3. Darrell J Aherin, (212) 593-6317

5. News of the Japanese

• TRS-80 •

APPLE 2 • ATARI • SCORCERER

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INTERNATIONAL

A DIVISION OF SCOTT ADAMS. INC

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computer, telecommunications, and electronics industries.

1. Lifelines

2. 1651 Third Ave, New York NY 10028

3. Mary Anna Feczo, (212) 722-1700

5. This publication is for CP/M users.

1. Association for Computers and the Humanities

2. Queens College, Flushing NY 11367

3. Joseph Raben, (212) 520-7407

4. ACH Newsletter

5. Humanities applications.

1. Small Computer News

2. Edwards Publications, 78-56 86th St, Flushing NY 11385

3. (212) 441-4082

1. D G Independent User's Group

2. POB 316, Woodmere NY 11598

3. Lloyd Kishinsky, (516) 374-6793

4. Bridge

5. Digital Group computers.

1. Long Island Computer Association

2. 3788 Windsor Dr, Bethpage NY 11714

3. A M Stone, Editor, (516) 731-1649

4. The Stack

5. User Groups: S-100, TRS-80, and 6502.

1. Digiac Corporation

2. 175 Engineers Rd, Smithtown NY 11787

3. James D Gobetz, President, (516) 273-8600

4. MAPS Digest

5. For MP/M users.

1. CAMS (Capital Area Micro Computer Society)

2. POB 348, Ridge Rd, RD #1, Scotia NY 12302

3. Stanley L Mathes, (518) 372-3767

4. Occasional

— Circle 108 on inquiry card.

Subgroups for Apple (associated with International Apple Corps), TRS-80, S-100, and other groups.

1. Sphere Microcomputer Group

2. 2 Tor Rd, Wappingers Falls NY 12590

3. Jeffrey Brownstein, DDS, (914) 297-3950

4. Sphere Newsletter

5. 6800 microcomputers.

1. CHIP-S Microcomputer Club

2. POB 504, Syracuse NY 13201

1. Mohawk Valley Microcomputer Club

2. 706 Lee St, Rome NY 13440

3. Rich Weaver

4. Micros Along the Mohawk

5. Several special interest groups: 6800, 8080/Z80, and beginners.

1. RAMS (Rochester Area Microcomputer Society)

2. POB 90808, Rochester NY 14609

3. Erwin Rahn, (716) 473-3184

4. Memory Pages

5. Special interest groups: UFORTH (University of Rochester FORTH) and 6800/6809/68000. Users groups: North Star and CP/M.

1. Monroeville Apple Users Club

2. Dr G J Harloff

3. 579 Carnival Dr, Pittsburgh PA 15239

1. Central Pennsylvania Computer Club

2. 3263 Bull Rd, York PA 17404

3. Cletus Hunt III, (717) 764-4977

4. Data Dump

5. Special interests: SS-50 bus and TRS-80 systems.

1. Wyoming Valley TRS-80 Club

If you write software, write Digital Research.

bring your products to market.

Independent Software Vendors (ISV's) are the key to solving the software crunch in the 1980's. To help you bring your products to market, Digital Research introduces the ISV Support Plan — designed to assist you in: Developing Your Product D With the fast and powerful

PL/I-80™ Programming

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programming

retting Esta Your Market

ISV Seminars cover:

□ Designing a marketing strategy

□ Advertising

□ Writing Manuals

□ Assuring software security

□ Supporting and updating products

On-Going Support Includes.

□ Legal and technical information

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□ Printing facilities

□ Free product listing in our Applications Software Catalog

s the world s largest software marketplace -— the GP/M® customer base.

So why do it alone? Write Digital Research. We'll send you our free brochure detailing the ISV Support Plan.

ED DJGiTflL RESEARCH'

P.O. Box 579 Pacific Grove, CA 93950 (408) 649-3896 TWX 910 360 5001

WTTTTT

Visit us at the W

heNCC

Circle 109 on inquiry card.

BYTE April 1981 161

Clubs and Newsletters,

2. 302 Wyoming Ave, Kingston PA 18704

3. Art Prutzman, (717) 287-1014

5. Special interests: TRS-80 uses and modems.

1. Delaware Valley Computer Society

2. POB 651, Levittown PA 19058

3. Howard Kalodner, (215) 742-6612

4. DVCS Newsletter

5. TRS-80 users group.

1. PACS (Philadelphia Area Computer Society)

2. POB 1954, Philadelphia PA 19105

3. Dick Moberg, Eric Hafler; Hot line (215) 925-5264

4. The Data Bus

5. Users groups for all major microcomputers, courses on languages, computers for children, and other groups.

Zips 20000—30000

1. Buss: The Independent Newsletter for Heath Company Computers

2. 325-B Pennsylvania Ave SE, Washington DC 20003

3. Charles Floto, (202) 544-0484

5. News on items that are hardware- and softwarecompatible with Heath Company computers and Zenith Data Systems.

1. Battery Lane Publications

2. POB 30214, Bethesda MD 20014

3. Eric Balkan, (301) 770-2726

4. Computer Consultant

5. Information of interest to free-lance and corporate consultants.

1. Washington DC CP/M Users Group

2. 7315 Wisconsin Ave,

The WORKSHEET Problem-Solving Language

Want to play "What-if"? Want to do Real Estate Analysis, Family Budgeting, Taxes, Company Cash Flow; want to simulate complex and interrelated processes'? WORKSHEET is a powerful language designed for the purpose of writing programs to solve these and all other problems that involve a row-column "spreadsheet". Even novice programmers are solving complicated problems on the first day!

WORKSHEET is not a hybrid text editor or a toy. It is a complete, self-documenting model-building system. List the assumptions that went into your budget with the SHOWF1L program—even the boss will understand!

Change the assumptions, the relationships, or the data, and produce a new spreadsheet, neatly captioned, in minutes.

Model too big to fit on a single page? Format it dynamically— one page of 12 (or any number) columns, or 2 pages of 6 columns, or whatever tells your story best.

Conditional evaluation of a variable? Reference to variables in different rows, several columns back? No problem!

Sample models include portfolio valuation, real estate evaluation, iterative solution of a Diophantine equation, family budget, product profit based on exponentially damped growth of sales.

Use it for tough, professional jobs—it's the only CP/ M modeling system that can handle them!

Requires 48K CP/M system and Microsoft Basic . C Basic or North Star Basic running under CP/ M with Matchmaker 11.

WORKSHEET Language disk (5" or 8" CP/M) $199.95

(specify version) 80-Page Manual only $ 19.95

The SoHo Croup

140 Thompson St., Suite 4-B

New York, NY 10012

Note: CP. M, Microsoft, and North Star arc registered trademarks of Digital Research. Microsoft, and North Star Computers, respectively.

Washington DC 20014 3. Winston Riley III, (301)

986-1234 5. Public-domain software exchange, review of operating systems, languages, and packages.

1. WACS (Washington Amateur Computer Society)

2. 4201 Massachusetts Ave, #168, Washington DC 20016

3. Robert Jones, Director

4. ]WACS

5. Interested in I/O Selectric conversions; inexpensive terminals and personal systems; 9900, 6800, 8080/Z80 hardware and software.

1. Washington Apple Pi

2. POB 34511, Washington DC 20034

3. Bernie Urban, (301) 229-3458; club phone (301) 468-2305

4. Washington Apple Pi

5. Education, medical, Pascal, assembly language, games, helping neophytes in computer programming.

1. TI Programmable Calculator Club

2. 9213 Lanham Severn Rd, Lanham MD 20801

3. Maurice E T Swinnen, Editor

4. TIPPC Notes

5. All AOS system programmable calculators.

1. PEEK(65)

2. POB 347, Owings Mills MD 21117

3. Al Peabody, (301) 268-0561

5. This is a journal for OSI users.

1. CHUG (Capital Heath Users' Group)

2. POB 341, Fairfax VA 22030

3. Dale Grundon, Secretary

4. >CHUG

5. Interested in all Heath computers and related equipment.

1. AMRAD (Amateur Radio Research and Development Corporation)

2. 1524 Springvale Rd, McLean VA 22101

3. Paul L Rinaldo, (703) 356-8918

4. AMRAD Newsletter

5. Special interests: amateur radio and computers, computers and communications devices for the deaf, amateur computer networking.

1. WAKE (Washington Area KIM Enthusiasts)

2. 5112 Williamsburg Blvd, Arlington VA 22207

3. Ted Beach

4. Monthly

5. KIM and other 6502 single-board computers.

1. The Microcomputer Investors Association

2. 902 Anderson Dr, Fredericksburg VA 22401

3. Jack M Williams, (703) 371-5474

4. The Microcomputer Investor

5. Use of microcomputers to assist in making and managing investments.

1. Delmarva Computer Club

2. POB 36, Wallops Island VA 23337

3. Jean Trafford, (804) 824-3400

4. Peek-n-Poke

5. Special interests: 6502 processors, computer aids for the handicapped, education, business, and entertainment programs.

1. Tidewater Computer Club

2. 677 Lord Dunmore Dr, Virginia Beach VA 23464

3. C D Yeoman, (804) 420-6379

4. Hard Copy

1. Triad Heath Users Group

2. 424 Cliff dale Dr, Winston-Salem NC 27104

3. Hughes Hoyle, (919) 378-1050; Steve Minor, (919) 765-7717

162 April 1981 © BYTE Publications Inc

Circle 110 on inquiry card.

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4. 32K of fast static RAM (w/IEEE 24 bit extended addressing)

5. Sorcim's powerful PASCAL/M *-8086 software on disk

6. Digital Research's CP/M *-86 software on disk

7. I/O and Disk Controller cables, plus full documentation on all hardware and software

* PASCAL/M is a trademark of Sorcim: CP/M is a registered trademark of Digital Research

Total Package Price: $2495

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ELECTRONICS

Terms: Calilornians add tax. Allow for shipping (excess refunded). VISA and Mastercard orders call i415) 562-0636, Circle 111 on inquiry card.

ude street address lor UPS

BYTE April 1981 163

WESTICO... Because getting good software fast is hard.

To get your software tomorrow, call Westico todav. (203) 853-6880.

Westico understands your microcomputer software needs. We know you want a good selection of software without the hassle of hunting all over for it., .We know you want it f ast... And we a Iso know you wa nt a product Packed by service. With Westico you get all three.

We have an extensive list of

guality software products for the serious microcomputer buyer — accounting, professional time accounting, text processing, planning and analysis, telecommunications, data management, development^ tools. And the list is growing.

Dial-up the 24-Hour Hotline (203) 853-0816 (300 baud)

It's an on-line catalog, updated each day! See displays of all products and the latest version numbers and prices. Build a trial order without any obligation. Complete the order only if you wish. We also offer 24-hour delivery service. Call, write, Telex or dial-up today. C.O.D.,Master Card and VISA accepted.

ASCOM program for time sharing and data transfers. • Transfers files between computers • Conversation mode controls remote computers

• Batch mode by command files

• Commands to display directories and type files

ASCOM can log-on a time sharing system to retrieve stock exchange data for storage and analysis. Batch mode can make the log-on, password, data guery, and storage automatic. ASCOM can transmit program files to another micro running ASCOM — locally, or remotely through a modem.

MINIMODEL™ Financial Planning' Tool — does big financial planning jobs at micro prices — for cash flow projections, financial forecasting, venture analysis, project planning and risk analysis. • Model size limited only by disk file size. •Operating results can be fed into models.

• Time horizon advances to eliminate old data • Consolidates models into higher level models

• Consolidated models are processed u nder thei r own ru le set • Report content and format totally under user control.

■

CP/M™ programs for TRS-80 Model II, Apple with SoftCard,™ Vector Graphic, iCom, Cromemco, North Star, Micropolis, Ohio Scientific, SuperBrain and more.

GENERAL LEDGER Peachtree7"

$550

$40

A,D,I,L

ACCOUNTS RECEIVABLE Peachtree

550

40

A,D,I,L

ACCOUNTS PAYABLE Peachtree

550

40

A,D,I,L

INVENTORY CONTROL Peachtree

650

40

A,D,I,L

PAYROLL Peachtree

550

40

A,D,I,L

CLIENT WRITE-UP Peachtree

990

40

A,D,I,L

PAS-3 MEDICAL Artificial Intelligence

990

40

A.CI,

PAS-3 DENTAL Artificial Intelligence

990

40

A.C.I

PROPERTY MANAGEMENT Peachtree

990

40

A,D,I,L

PTA Asyst Design

595

40

A.C.I

PTA Demo Asyst Design

75

40

A,C,I

ESQ-1 Legal Micro Information

1495

50

A,C,I,L

ESQ-1 Legal Demo Micro Information

75

50

A,C,I

DATEBOOK'" Organic Software

295

25

A,l

WOR DM ASTER™ MicroPro

145

25

A,K,L

WORDSTAR'" MicroPro

450

40

A.F.K.L

MAIL-MERGE'" MicroPro

125

25

A,F,K,L

WORDSEARCH'" Keybits

195

40

A,F

TEXTWRITER Organic Software

125

20

A

MINI MO DEL Financial Planning

495

50

A,C,I,L

STATPAK NW Analytical

500

40

A.D.I

MILESTONE™ Organic Software

295

25

A.I

ASCOM DMA

125

10

A,T

CBS DMA

395

40

A,F,K

CBS LABEL OPTION DMA

80

10

A.F.K

MAGSAM III MAG

145

25

A.CorD.F

MAGSAM IV MAG

295

25

A,C,F,K

SELECTOR IV Micro-Ap

395

25

A.CG.K

PRISM/IMS MAG

495

55

A,C,F,K

PRISM/ADS MAG

795

55

A,C,F,K

PL/l-80'" Digital Research

500

35

B.F.L.P

BASIC-80 Microsoft

350

25

A,F,L

BASIC COMPILER Microsoft

395

25

A,F,L

S-BASIC" Topaz

295

25

A,F

NEVADA COBOL Ellis Computing

150

25

A

CBASIC-2™ Compiler Systems

120

15

A

PASCAL/M'" Sorcim

175

20

A,G

GENERAL SUBROUTINE PAK Asyst Design

295

30

A.C.K

APPLICATION UTILITIES Asyst Design

495

30

A,C,K

PASCAL/MT*-™ MT Microsystems

425

30

A,G

SUPERSORTI MicroPro

225

25

A,L

SURVEYOR Peachtree

550

40

A,D,I,L

STRING BIT'" Keybits

65

15

A

STRING/80'" Keybits

95

15

A

STRING/80 SOURCE Keybits

295

n/a

A

ULTRASORT II'" CCS

165

15

A

All software has specific requirements for proper operation such as computer type, equipment configuration and support software.

Check the following codes for system requirements to be certain your system will accept the software offered.

(A) CP/M version 1.4 or higher. (I) Business system: 48K memory. 200K

(B) CP/M version 2.0 or higher. dual disk drives, cursor addressable

(C) CBASIC-2. terminal, and 132 column printer.

(D) MBASIC version 4.51. (K) Cursor addressable terminal.

(E) BASIC-80 version 5.0 or higher. (L) signed license required for shipment.

(F) 48K memory or greater. (O) specify 8080. Z80, or CDOS. (G)56K memory or greater. (P) give CP/M serial number. (H) 64K memory. (T) serial port and modem

(Z) Z80CPU.

Specify disk format: North Star Single or Double, Micropolis Mod I or Mod II, 8" single density, Ohio Scientific,SuperBrain or Apple. Prices do not include shipping or C.O.D. In CT add 7%% sales tax. "Manual price will be credited against later purchase or software. Dealer inquiries invited. Copyright t 1981 Westico. Inc

WESTICO

The Software Express Service

25 Van Zant Street • Norwalk, Connecticut 06855 (203) 853-6880 • Telex 643-788

1. Carolina Apple Core

2. FOB 31424, Raleigh NC 27612

3. Joseph H Budge, (919) 489-4284

4. From The Core

5. Apple computer users group.

1. TRS-80 Users Group

2. 7554 Southgate Rd, Fayetteville NC 28304

3. R Gordon Lloyd

4. TRS-80 Users Group Newsletter

5. We are interested in all aspects of the TRS-80.

1. TIPS Users Group

2. 101 Brookbend Ct, Mauldin SC 29662

3. Fred Holmes, (803) 288-5664

4. TIPS Newsletter

5. Special-purpose standalone systems and homebrew computers.

Zips 30000—40000

3.

4.

Digital Publications Inc

3169 Holcomb Bridge Rd,

Suite 307, Norcross GA

30071

John Rapp, Publisher,

(404) 451-1156

Mini-Micro, free software

exchange

Software exhanges and

publications for Data

General, IBM, and DEC

PDP-11 and PDP-8

systems.

1. Culpepper and Associates Inc

2. 4922 Heatherdale Ln, Atlanta GA 30360

3. Warren Culpepper, (404) 451-3797

4. Salt 'ri Pepper

5. Special interests: software product management.

1. CSRA Computer Club

2. POB 284, Augusta GA 30903

3. Jim Graves, President, (404) 738-1378

4. CSRA Computer Club Newsletter

April 1981 © BYTE Publications Inc 165

T5€:HfiRDSID€

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COLOR COMPUTER $359.

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MODEL III $919.

TRS-80 COMPUTERS

Mod I, 64K RAM (#26-4002) $3599.00

Mod III, 16K RAM (#26-1062) $919.00

Mod III, 48K RAM (#26-1062 + ) $1039.00

Pocket Compw/lnter (#26-3501+) — $259.00

Color Comp, 4K RAM (#26-3001) .. Color Comp, I6K RAM (#26-3001+) Color Comp, Ext BASIC (#26-3002)

.$359.00 .$399.00 .$529.00

MODEL I DISK DRIVES

HARDSIDE 40-track Dr(#7-40) $329.00

PERC0M TFD-40 Dr(#7-99) $379.00

PERC0M TFD-100 Dr (#7-100-1) $399.00

HARDSIDE 80-trackDr (#7-80) $449.00

PERC0M Dual TFD-100 Dr (#7-100-2).. $799.00

PERCOM Data Sep (#7-03) $29.95

PERCOM Doubler(#?-07) $199.95

HARDSIDE Ext Cable (#7-02) $15.95

HARDSIDE 2-Dr Cable (#7-04) $29.00

HARDSIDE 4-Dr Cable (#7-05) $39.00

MODEL I PERIPHERALS

COMM-80 Interf (#4-80) $159.00

CHATTERBOX Interf (#4-81) $239.00

DISK-80 Interf, 16K RAM (#4-82) .... $339.00 DISK-80 Interf, 16K RAM (#4-83).... $369.00

BUSY BOX Interf (#4-01) $99.95

LYNX Communications Interf (#19-80). $229.00 RS Expan Interf 32K RAM(#26-H40-32) $399.00 16K Memory Kit TRS-keypad(#6-no2-i) $59.00 16K Memory Kit, TRS-lnterf (#5-1102).. $59.00

Dual Joysticks for Color Comp (#26-3008)$24.95 VISTA Model II 8" Disk Dr 1 (#7-4001). $939.00 VISTA Model II 8'' Disk Dr 3 (#7-4002)$1795.00

0RCHESTRA-80(#i5-03) $79.95

Upper/Lower Mod Kit (#15-02) $24.95

CPU Speed-up Mod kit (#15-04) $37.50

Video Reverse Mod kit (#15-05) $23.95

2-port TRS-BUS Ext (#15-12) $29.95

3-port TRS-BUS Ext (#15-13) $39.95

TRS-80 Model I Dust Cover Set (#16-01)..$7.95 TRS-80 Model I Carrying Case(#i7-201)$109.00 TRS-80 Monitor Carrying Case (#17-202)$84.00

CTR-80A Cass Recorder & Cable(#26-1206)$59.95 TRS-80 Model III Dust Cover (#16-05) ... $7.95

TERMS: Prices and specifications are sub|ect to change. HARDSIDE accepts VISA & MASTERCARD. Certified checks and Money Orders; Personal checks accepted (takes 3 weeks to clear). HARDSIDE Pays all shipping charges (within the 48 states) on all PREPAID orders OVER $100.00. On all orders under $100 a $2.50 handling charge must be added. COD orders accepted (orders over $250 require 25% deposit) there Is a $5.00 handling charge. UPS Blue Label, and Air Freight available at extra cost. TRS-80 Is a trademark of Tandy Corp.

5. Users groups: TRS-80, Apple, and 6800.

1. Albany Computer Club

2. Albany Junior College, 2400 Gillionville Rd, Albany GA 31707

3. Dr Donald Cook, (912) 439-4205

5. Our interest covers all microcomputers.

1. Level II Club

2. 4406 W Lawn Ave, Tampa FL 33611

3. D Griffith

5. We are interested in trading original software.

1. ASCII, Sol User's Group

2. POB 10325, Tampa FL 33679

3. J Brockway, (813) 837-4655

4. ASCII

5. Sol computers.

1.

CAMS (Central Alabama

Microcomputer Society)

6375 Pinebrook Dr,

Montgomery AL 36117

Lewis E Garrison, (205)

272-8462

READY

TRS-80 hardware and

software.

National Association of Computer Stores

2. 3255 S US 1, Ft Pierce FL 33450

3. Steven W Koerner, Executive Director, (305) 465-9450

4. Monthly newsletter

Zips 40000—50000

1. ACSCO (Amateur Computer Society of Central Ohio)

2. 215 Delhi Ave, Apt J, Columbus OH 43202

3. Paul Pittenger, President, (614) 267-3412

4. I/O

5. Graphics and personal networks.

166 April 1981 © BYTE Publications Inc

Circle 112 on inquiry card.

Circle 113 on inquiry card.

V

The next

generation of business software

% v v

If you've been searching for a complete line of quality software for your small business computer, your search is over. Designer Software is pleased to announce Phoenix'", the first line of business software to include both professional word processing and general accounting. Word Processing

We designed Phoenix'" Word Processing to compete with high-priced, dedicated word processors. It is completely new from top to bottom and is unlike any other word processing software currently available. Phoenix'" is more powerful than WordStar1", more flexible than Magic Wand™ and easier to use than either. We built "human engineering" into the product to make it easy for non-technical personnel to use. The commands are simple and logical; the documentation is well-written and organized; and the training program is something that, frankly, you'll have to see to believe.

Accounting Phoenix'" Accounting includes the five general applications and a growing number of specific applications. Each accounting package was designed by CPA's and written in COBOL with an underlying assembly-language database for

Designer Software

HOUSTON

speed. All of the general accounting packages — General Ledger, Accounts Payable and Receivable, Payroll and Inventory —have been field-tested, some for as long as two years. Specific applications include Fixed Assets Accounting, Mailing List Maintenance, Tenant Processing, Financial Projection, and Time/Billing. We are developing more all the time.

Documentation for Phoenix'" Accounting is as revolutionary as it is for Phoenix'" Word Processing. We don't just teach you which buttons to push and leave it at that. We take the time to explain the accounting principles behind the packages, because we think that you can use our products better if you understand why we ask you to do certain things. And we've made a special effort to make the manuals entertaining as well as informative so that you will want to read them.

See us at the Faire

We are unveiling Phoenix''" at the Sixth Annual West Coast Computer Faire. If you are planning to attend, we hope that you will drop by booth 1018-20 to see us. If you can't make it this year, write, call or contact Us via The Source and we'll send you more information.

Designer Software only sells through dealers. Dealer inquiries invited.

3400 Montrose Boulevard • Suite 718

Houston. Texas 77006

(713) 520-8221 • SOURCE TCU671

Circle 113 on inquiry card.

BYTE April 1981 167

MICROMAIL HAS WHAT YOUR SYSTEM NEEDS.

DIABLO

630

The Diablo Model 630 is a reliable, high quality, fullcharacter serial printer for anyone who is seeking superior print quality at a low cost. This is the first Diablo printer to offer complete interchangeability between metal and plastic print wheels. And the sophisticated and discerning user does not sacrifice print quality to obtain this versatility. Every aspect of the Diablo 630 design has been focused on maintaining outstanding print quality. Terminals also have self-test, extensive internal diagnostics and automatic bidirectional printing.

$1,999.00 With Adjustable Forms Tractor add $200.00

ANADEX

Standard features include expanded and compressed print, underlining, true lower-case descenders, RS-232C, Parallel, and 20mA interlaces, last bi-directional printing, and highresolution graphics.

DP-9599 $1299.00

DP-9501

2K Expanded Buffer Option $70.00

TEXAS INSTRUMENTS

Fast, reliable, and widely supported, the T.I. 810 has proven itseli to be a solid printer for business or industry.

810/2 $1,549.00

(includes upper/lower case option)

810/2VFC/CP $1,679.00

(includes u/1 case, forms control & compressed print)

Prices good through May 15,1981

PRINTERS

C.R.T.'s

ANADEX

Tele Video

DP9000 DP-9001

$1199 $1199

Just like the 9500/9501. but 5 inches narrower. Uses paper up to 9.5 inches wide.

DIABLO

1640RO $2525

Uses plastic daisywheels, prints up to 45 c.p.s.

1650RO $2675

Uses metal daisywheels, prints up to 40 c.p.s.

912C $ 725

920C $ 795

950 $ 995

NEW! Features a detachable keyboard & programmable function keys.

SOROC

IQ.120 $ 689

IQ.140 $1099

IQ.135 $ 849

NEW! Microprocessor controlled, programmable function keys.

C. ITOH

CITIOO DEC

$1625

VT-lOO

$1650

TELEPRINTERS

DEC

LA 34 $ 969

Dot-matrix, 30 c.p.i. Adjustable character sizes & line spacing.

LA34AA $1099

Includes programmable forms length control.

TELETYPE

43 $ 999

Very reliable 30 c.p.s. teleprinter. Ideal for use with 300-baud acoustic couplers or modems.

DIABLO

1640KSR $2830

Uses plastic daisywheels, prints up to 45 c.p.s.

1650KSR $2940

Uses metal daisywheels, prints up to 40 c.p.s.

i:MJCRaMflJL.,

MICROMAIL • BOX 3297 • SANTA ANA, CA 92703 (714) 731-4338

To Order: Send check to MICROMAIL. P.O. Box 3297, Santa Ana. CA 92703. Personal or company checks require two weeks to clear Visa/MasterCard accepted. C O.D. requires a 15% deposit. Handling: Add 3% to orders less than 3750, 2% to orders $751 ■ S2.000. 1% to orders over $2,000 NOTE: Handling charges are waived on orders pre-paid in advance by check Shipping: We ship FREIGHT COLLECT via UPS or Motor Freight Air and Express delivery is available.

1. Midwest Affiliation of Computer Clubs

2. POB 20205, Columbus OH 43220

3. Douglas Troughton, (614) 574-8152

4. MACC-Pack, and Cotnputerfest

5. Promoting personal computing by helping member clubs in any way possible.

1. TI 99/4 Users of Cincinnati

2. 8075 Spring Garden Ct, West Chester OH 45069

3. Larry Morrow, (513) 777-7042

5. Exchange of information and ideas concerning the TI 99/4.

1. DMA (Dayton Microcomputer Association)

2. c/o Dayton Museum of Natural History, 2629 Ridge Ave, Dayton OH 45414

3. Gary Turner, (513) 848-6911

4. Data Buss

5. Numerous special interest groups and help for beginners.

1. Apple-Dayton Users Group

2. 4819 Leafburrow Dr, Dayton OH 45424

3. Dick Peschke, Secretary,

Gone

with the

wind.

We could lose

our national symbol . . .

the majestic bald eagle.

Once man drives eagles out of their nesting areas, they rarely return. Today there are only about 900 pairs of eagles known to be nesting in the lower 48 states.

We can save the eagle by establishing eagle preserves. You can help. Join the National Wildlife Federation, Department 102, 1412 16th Street, NW,

.Washington, DC 20036. Let's keep the eagle £5^3 around another hundred years.

168 April 1981 © BYTE Publications Ire

Circle 114 on inquiry card.

Circle 115 on inquiry card.

£ ■

/ A

y > ////

osy ,.;.

/•■; ?t

'!:':•: I:

i : llll .-.:--v'L- .

//'ii

/ SAVE $50

We design and manufacture a complete line of industry compatible microcomputer assembled and tested boards and kits for your system. All are S-100 bus compatible and use the Z-80 microprocessor.

With over 25,000 boards and hundreds of computer systems installed throughout the world, SD Systems offers you both proven and state-of-the-art products! We provide you with a complete family of kits for all your systems needs —

SBC 100/200 — A 2.5/4 megahertz range of single board computers which are effective standing alone or combined with the complete SD board range.

ExpandoRAM till — For use with 250/200 nanosecond \ RAM, these high density boards offer 16 to 64K memory; \ the ExpandoRAM II can achieve RAM capacities up to ' 256K using 64K chips.

' Versafloppy //// — A floppy disk controller for up to four

drives, supporting single/double density and single/double-sided disk formats.

VDB-8024 — A full function visual display board with a Z-80 controller that adds display capabilities to your system.

Z-80 Starter Kit — A low-cost entry into the world of microcomputers designed primarily for education and experimentation.

Prom 100 A specialty board of SD Systems which allows you to program 2708/2716/2732 proms.

SD SYSTEMS

P.O. Box 28810 • Dallas, Fexas 75228 • Telex 6829016

y<*\ ':■■■ ■-'

" N V V

YOU CAN SAVE $50

when you purchase any two SD Systems board kits from participating DEALERS and present coupons included in any two kits to participating DEALERS listed below. Coupons must be presented to participating DEALERS by 10-15-81.

A.S.A.P. COMPUTER PRODUCTS

SlqnalHill, Ca. 213-595-6431

Q. T. COMPUTER SYSTEMS, INC.

I awndale, Ca, 213-970-0952

f COMPUTERS, ETC

i Dallas, Texas 214-644-5030

v JADE COMPUTER PRODUCTS

Hawthorne, Ca. 800-421-5500

COMPUTER CENTRE

Swansea, England, U.K. 44-792-460023

ARCON ELECTRONICS LTD Toronto, Ontario, Canada 416-868-1315

RATIONAL SYSTEMS

Buckinghamshire, U.K. 0908-611349

ALPHA BYTE STORES

Calabasas, Ca. 213-883-8594

ARISIA MICRO SYSTEMS Mississauga, Ontario Canada 416-274-6033

SIRTON PRODUCTS

Surrey, England, U.K. UK-OI-660-5617

V.\»

GIFTS FROM PROMETHEUS

NEW for APPLE II

Advanced products at

Down-to-Earth

PRICES

DUAL SERIAL CARD-1.

All functions of two independent serial cards on one board-plus more. Provides Apple ll(1) users with two simultaneous asynchronous serial channels. DSC-1 appears as two separate logical serial cards to the Apple ll(1). Fully software compatible with all Apple ll's(1) and Microsoft software. 2716 EPROM used for easy driver modification. In addition, the second serial channel supports these extra features: • Strapable DCE/DTE. • Secondary RS-232 handshake functions (DCD, DTR, DSR) • Strapable logical slot location and hardware looks like it's another slot. Order: PP-DSC-1 @ $189.00 each

DUAL SERIAL/PARALLEL CARD-1. As with the Dual Serial Card-1 (above), the Dual Serial/Parallel-1 provides Apple users with simultaneous use of one full serial port and one parallel port. Both ports strapable for any Apple peripheral slot. Fully compatible with all Apple and Softcard (CP/M) software. Drivers for serial interface and Centronics parallel interface are contained in modifiable industry standard EPROM. Serial port is configured like DSC-1. Order: PP-DSP-1 @ $189.00 each.

MEMORY EXPANSION MODULE-1. Expand your Apple ll<1>to afull64K RAM system with highest quality 16K dynamic RAMS. Fully buffered to provide reliable operation - even with fully loaded Apples. Total compatibility with Microsoft Softcard(2)/CP/M(3) and all Apple software. Supplied complete with installation instructions and test program.

Order: PP-MEM-1 @ $149.50 each. PASCAL MT+ MEM-1. A modular native Z-80 code Pascal compiler. ISO standard. Includes a MEM-1 (detailed above). Have a full Pascal compiler at half the Apple price. Requires a Microsoft Softcard<2) and two disk drives. Note that the Pascal MT+ alone is normally $250.00.

Order: PP-PMT-1 @ $299.00 each.

16K RAM ADD-ON rOTS. For TRS-80 and Apple ll(1). Eight (8) fullspecification industry standard 16K RAMS. These are not seconds.

Order: PP-RAK-16 @ $29.00 each.

All Prometheus boards are completely tested and burned-in prior to shipment. One-year warranty covers parts and labor. MONEY BACK GUARANTEE: Order now without risk. Boards may be returned, in good condition, after up to 10 days df trial for a full and prompt cash refund. California: add 6% tax; BART Counties, 61/2%. Orders under $150, add $3.00 postage, for handling charge. Freight allowed on orders over $150. Dealer inquiries invited. Quantity discounts available.

PROMETHEUS

PROMETHEUS PRODUCTS INCORPORATED

4509 Thompson Ct. • Fremont, CA 94538 • (415)791-0266

Registered Trade Marks: (1) Apple Computers, Inc. (2) Microsoft Consumer Products (3) Digital Research. Inc.

VfSA

i

7*t

(513) 236-3619 Apple-Dayton Newsletter

1.

2.

TRI-STATE Computer Club

2669 Highmeadow Ct,

RT 1, Wheelersburg OH

45694

Douglas Troughton, (614)

574-8152

Yes

Special interests: TRS-80,

Apple, OSI, KIM,

PDP-11, and 6800

systems.

AIM-65 User's Group R R#2, Spencerville OH 45887

Donald Clem, (419) 647-6576 Target

Special interests: AIM-65and 6502-related information.

1. Apple One Library

2. 51625 Chestnut Rd, Granger IN 46530

3. Joe Torzewski, (219) 272-4670

5. We actively support the Apple I computer.

1.

1.

Northern Indiana Computer Hobbyist Exchange

927 S 26th St, South Bend IN 46615 Eric Bean, (219) 288-2101 NICHE Newsletter

Evansville Computer Club

2. c/o National Sharedata Corporation, POB 3895, Evansville IN 47737

3. Robert Heerdink

5. Special interests: S-100, TRS-80, Bally, and Apple systems.

1. The Midwest Buss

2. 441 E Bemhard, Hazel Park MI 48030

3. Art Blundell, (313) 547-3011

5. Special interests: our buy-and-sell forum and swapping news from club to club.

1. Sorcerer's Apprentice Computer User's Group

170 April 1981 © BYTE Publications Inc

Circle 116 on inquiry card.

If you are the owner of an Apple, Pel, Atari, orTRS-80 ami also have a disk drive, we have some of the those systems u/ith sound capability, our games have Crystalsonics — a newly developed concept in tone generation. For Apple and Atari (here are some truely superlative hires graphics. In fact, Sands of Mars offers 3-D graphics and flight simulation landing. It includes over 186 full screen hires maps of Martian terrain.

••***••****

We now serve over 30 countries around the world. Dealership and distrihutor inquiries are welcome. Special rates are available on larger orders. We have 48 hours delivery to anywhere in the continental United States. We are also looking for experienced programmers and new game software. Our royalty terms are extremely generous. If you have what you consider to be a quality product that you would like to have marketed please give us a call. If you would like to be a member of the Crystal User's Club and be eligible to receive free user contributed software, please submit a program of any type and a $10.00 membership fee. In return you will receive a Crystal Membership Card, a copy of The House of Usher, and a year's subscription to Crystal Vision.

HOUSE OF USHER — Wander through a haunted house. Rooms and scenery in 15 color lo-res graphics. We offer a $100.00 prize to the first person to solve the mystery. Over 200 monsters, objects and perils. $24.95

GALACTIC QUEST — Crystalsonics - hires graphics -the ultimate space adventure. Vegan warships attack and fire in real time simulation. Land on and trade with over 64 star systems in 3 galaxies. Allow 6-12 hours for play. $29.95

SUMER — Travel back through time to ancient Sumeria in the middle cast. You are given 10 years as king to restore this kingdom to prosperity. Plant, war, consult the astrologers - very hard to beat! $19.95

LASAR WARS — Crystalsonics - hires graphics - protect the planet earth from a full scale alien invasion. Over three types ol invading craft and hundreds of approach simulations. The games speaks for itself. $29.95

WORLD WAR III — Crystalsonics - hires graphics - for you war game freaks, this is it! Iran and Irag - nuclear missiles - hires 3 scene battlefield - demolition squads - tanks - strategy. Custom designed for two arm chair generals. Save the world from nuclear holocaust! $29.95

BENEATH THE PYRAMID - Crystalsonics - hires graphics - brand new! Explore the pyramids and miles of winding secret tunnels beneath I hem. Enter at the Sphinx and find the hidden treasure chamber. All in hires with very aggressive monsters and many many perils. To win you must find the golden cat and your way out!!! $29.95

LITTLE CRYSTAL — Especially designed anthology for children from ages 5 to 80. Includes Mr. Music which turns your Apple into an organ ul sorts, gunk where two weird monsters shoot it out and many other educational as well as entertaining programs for children. True unique addition for kids who always feel left out of Dad or Mom's computerizing. $39.95

SANDS OF MARS — What we at Crystal believe to be the fittest advettlure game available to dale. In addition to hires graphics and super tone routines where the user's system will support it, this game provides landing simulation, animation, and revolutionary 3-D graphics. It is the ultimate in space adventure and may takeseveral weeks or months to play. It istheOydessy of the Slarship Herman on its maiden flight to Mars. Hie initial liltoff is animated and paddle controlled. The flight through space is in Hires 3-D Graphics with many animated scenarias. You must land your slarship on Mars, it will lack enough fuel and supplies for a return voyage. You must lead your party through hundreds of Hires maps of Martian let rain and subterrainian passages. You then will secure adequate resources for take off, navigate your ship back to earth and attempt a successful touchdown. There is a mystery buried in the ancient city of Lemuria beneath the sands of Mars. We offer a $100.00 prize to the first space gamer to discover it. Good luck! $39.95

For more information you may write or call: Crystal Computer, 12215 Murphy Avenue, San Martin, California 95046 (408) 683-0696

atMicrohouse

Spring Qeanirig

Sweep up savings on leading hardware and software!

We at Microhouse would like to thank you worldwide for your tremendous response to our wide range of discounted hardware and software. To serve you better, call or write us anytime for your hardware and software needs. If you don't see it, ask!

We will attempt to meet or beat any advertised price!

Software Manual List & Manual/Only

Software

D WORDSTAR The premier word processing, software from MicroPro S49S.00 $322/840

:_■ MA1LMER0E option for Wordstar 2 X S150.00 $110/825

D WORDMASTER by MicroPro.

S150.00 $118/825

D SUPERSORT I by MicroPro. Can be used as a stand-aJone program or can be linked to programs with a Microsoft format $250.00 $189/825

O SUPERSORT II A stand alone-only version of above. ...$200.00 $18S/$25

D DATASTAR by MicroPro.

$350.00 $289/535

O SPELLGUARD checks 20 pages of copy for spelling mistakes and typos In less than a minute. Can be used with many CP/M® word processors (including WordStar). Lets operator review words It judges as potential errors. Operator may then change the suspect word or add if to SPELLGUARDs 20.000 word dictionary (dictionary size limited onty by disk space). $295 $230/$20

D dBASE II, the assembly-language re lalional Database Management System for CP/M* . No need for host language Handles up to 65.000 records (up to 32 fields of 1K each). English-like commands. Report generator with user-definable fun-screen operation. Win read existing ASCII files ..$700 S628/J20

D TCS/AManta INTERACTIVE ACCOUNTING SYSTEM for small businesses New release. Each package can be used atone or post automatically to the General Ledger. Available in complied version (no support language needed) or in source (MBASIC required). Needs 48K RAM. 132-col. printer. 24x80 CRT and CP/M*

COMPARE AT UP TO J530/pkg.

GENERAL LEDGER $757125

ACCOUNTS RECEIVABLE .. $757$25

ACCOUNTS PAYABLE $75/825

ACCOUNTS PAYABLE $75/825

PAYROLL $7S/$25

ALL FOUR »259/$25

SAMPLE PRINTOUT BOOK of ALL

FOUR $15

D STRUCTURED SYSTEMS ACCOUNTING SYSTEM (Requires CBASIC2. 2 dsk drives, 24xS0 CRT. 132-cokjmn width printer). . . LIST: $1250.00 each

GENERAL LEDGER $899/840;

ACCOUNTS RECEIVABLE .. $689/840

ACCOUNTS PAYABLE $6>0/$40

PAYROLL $698/840

INVENTORY $337/$40

□ BASIC 80 by Micro. Version 5.2 and 4.51 Included.... $350.00 $299/130

D BASIC COMPILER by Microsoft. Language compatible with MBASIC. Includes MACRO 80 assembler $395.00 $33<V$30

D COBOL N Compter by Microsoft. $750.00 $«40/$30

O MSORT by Microsoft $138/815

D COBOL 80 wfMSORT. Saving by buying both at the same time. $759/$40

Q Whtte.mrth'1 "C" COMPILER. Conforms to fuR UNIX* version 7 C language $630.00 CALL/130

D STACKWORKS FORTH. For Z80 or 8080 CPU (specify). Suppled in source Assembler included If 75.00$1257$30

D FORTRAN 80 by Microsoft.

$500.00 $390/$30

D MACRO 80 by Microsoft Assembler for 8080 and Z80$200.00 $140/$20

D PASCAL/M compter by SORCIM Ful Wrln implementation. Produces P-corJe. $175.00 $139/$20

□ PASCAL/Z compter by ITHACA INTERSYSTEMS. Produces Z80 native assembly code $395.00 $359/$30

D UCSD PASCAL . ..$350.00 $299/$50

D muStMP/muMATH by Microsoft muSIMP Is a fast, efficient interpreter for sophisticated mathematical functions of up to 611 digits. muMATH is a package of programs written In muSIMP. Requires 40K ... $250.00 S225/J25

D NAD (Name 8 Address).

$100.00 $68/820

□ OSORT by Structured Systems.

$100.00 J68/J20

□ ANALYST by Structured Systems. $250.00 $195/120

D CBS • Configurable Business System. Requires no support language! $383/$40

D DIAGNOSTICS I by Supersoft.

$75.00 $48l$20

D DIAGNOSTICS II.

$100.00 $82.50/820

DTERM $150.00 $94/*20

D DATEBOOK by Organic Software $295.00 $25B/$25

D EDIT 80 by Microsoft

$/20.00882/820

H TEXTWRITER III by Organic Software

$125.00 $110/820

D LETTERIGHT by Structured Systems.

$200.00 $138/820

D MAXELL 8" SINOLE-slded Double Density Diskettes (Box 10). $57.50 $43.75

D MAXELL 8" DOUBLE-slded Double Density Diskettes (Box 10). $87.50 $88.25

D MAXELL 5%" SINQLE-sided Double Density (Box 10) ... $55.50 $37.50

O MAXELL 5 V." DOUBLE-skted Double Density (Box 10) ....$82.50 $82.80

D WABASH 8" SJNOLE-slded. slngtedensrty(BoxlO) $29.51 $27.24

D WABASH 8" DOUBLE-slded. doubteden«Jty(Box 10) $49.79 848.98

D SCOTCH HEAD CLEANING DISKETTES Includes two diskettes and bottle of cleaning solution. For single or double sided drives $30.00 $20.70

Hardware

D EPSON MX80 DOT MATRIC PRINTER with its ingenious removable printhead. bidrectional and logic-seeking, adjustable tractor, fine print quality and standard features make this a real bargain Parallel interface S645 00 $519.00

D SERIAL or IEEE 488 INTERFACE for

the MX80 $55.00 $43.70

D APPLE INTERFACE CARD for the MX80 (when ordered with the MX80) $85.00 $88.75

D TRS-80 EXPANSION CABLE.

(for MX 80) $35.00 $30.60

DAPPLE CABLE $25.00 $21.90

(for MX 80)

D EPSON MX70, pUn-Jane version of the MX80. Monodi-ectional. 80 cps. Graftrax II Graphics included. Adjustable tractor. Parasel version only. $450 $376.00

i ! DIABLO 630 RO PRINTER uses plastic and metal print wheels. Fewer working parts mean less down time. Speed: 40 cps bidirectional, logicseeking $2185.00 $1999.00

D IDS PAPER TIGER 860, the 15" tiger. 150 cps. bidirectional, logic-seeking. 9-wire staggered printhead. Fixed A proportional text, automatic text justification. Up to 220 col. Paratel 8 serial Interfaces $1695 $1484

D IDS PAPER TIGER 460.

$1295.00 $1072.00

D C. rrOH STARWRITER I letter quality printer. Uses Diablo pnnrwheei and ribbons. 25 cps. Bidirectional logic seeking. Son-tost. Friction feed. Parasol Interface $1895 $1431

I STARWRITER I Serial version $1980 $1502

D TELEVIDEO 950C, the newest and smartest Tetevideo Al features of the 920C plus detachable keyboard, smooth scrolling, sptt screen, graphics characters, 25th status Ine, 19.2 kilobaud max speed, buffered aux. port. $1195 $995

D ANADEX 9500 or 9501.

$1437.00 $1380.00

D ANADEX DP6000 . $995.00 $776.00 D CENTRONICS 704-1.

$2280.00 $1838.00

D CENTRONICS 737-1.

$995.00 $770.50

' : BIG DISCOUNTS ON DYNABYTE, CROMEMCO, NORTHSTAR AND IMS SYSTEMS. Call or write for prices!

ASK FOR YOUR FREE DISKETTE CASE WITH YOUR SPRING ORDER!

PflCES AND SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE.

CALL OR WRITE FOR FREE CATALOG

CP/M la a registered trademark of Digital

Research.

UNIX is s registered trademark of Bed

Labs.

APPLE Is a registered trademark of

Apple Computers.

Ill

511 North New Street Bethlehem, VA 18018 (215)868 8219

medicine, dentistry, health sciences, and micro- and minicomputers.

1. ICC A (International Computer Chess Association)

2. ICCA, Vogelback Computing Center, Northwestern University, Evanston IL 60201

3. B Mittman, (312) 492-3682

4. ICCA Newsletter

5. Computer chess.

1. CHICATRUG (Chicago TRS-80 Users Group)

2. 203 N Wabash, Rm 1510, Chicago IL 60601

3. Emmanuel B Garcia Jr

4. CHICATRUG News

5. TRS-80s.

1. Quad City Computer Club

2. 4211 7 Ave, Rock Island IL 61201

3. John Greve, (309) 786-8187

5. General-interest club.

1. SCAMPUS (SC/MP Users Society)

2. POB 132, Knob Noster MO 65305

3. Tom Bohon, Coordinator, (816) 563-2650

4. SCAMPUS Newsletter

5. Anything to do with National Semiconductor's SC/MP I and II integrated circuits (systems, controllers, etc).

1. Financial Systems Report

2. c/o Syntax Corporation, 4500 W 72nd Ter, Prairie Village KS 66208

3. Vernon K Jacobs, (913) 362-9667

4. Financial Systems Report

5. This 8-page monthly newsletter provides information about computer systems for financiers.

1. Lincoln Micro-Computer Club

2. 1209 Garber Ave, Lincoln NE 68521

3. Hubert Paulson Jr, (402) 435-1507

174 April 1981 © BYTE Publications Inc

Circle 119 on inquiry card.

Clubs and Newsletters,

2. POB 1131, Troy MI 48099

3. Don Gottwald, (313) 792-3867

4. Sorcerer's Apprentice

5. This club is interested in any topics concerning the Exidy Sorcerer microcomputer.

1. OSI-MUG (OSI Michigan Users Group)

2. 3247 Lakewood Ave, Ann Arbor MI 48103

3. (313) 761-5358

1. SEMCO (South Eastern Michigan Computer Organization)

2. POB 02426, Detroit MI 48202

3. Information number, (313) 775-5320

4. Data Bus

5. Special interests: networking, TRS-80, Atari, 6800, 650X, Heath, Digital Group, CP/M, S-100, and any aspect of computing.

1. Detroit Interact Group

2. 15356 Prevost, Detroit MI 48227

3. Stephen Cook, (313) 272-7594

4. Interaction Newsletter

5. Special interests: the Interact computer.

1. Flint 6500 Users Group

2. POB 4310, Flint MI 48504

3. R Riley, (313) 695-1117, 7-8 PM weekdays

1. ERCC (Educational, Recreational Computer Club)

2. POB 325, Owasso MI 48867

3. John Horvath, (517) 725-2835

4. ERCC Newsletter

5. Emphasis on educational, recreational, business, and scientific uses of computers.

1. Battle Creek Area Microcomputer Club

2. 8587 Q Dr N, Battle Creek MI 49017

3. Jeff Stanton, (616) 763-9685, evenings

4. Yes

5. Special interests: mostly the TRS-80.

Heath User's Group

Hilltop Rd, St Joseph MI

49085

Bob Ellerton, (616)

982-3463

REMark

Heath hardware and soft

2.

3.

Microcomputer Users International

c/o Jack Decker, 1804 W 18th St, Lot #155, Sault Ste Marie MI 49783 Jack Decker, (906) 632-3248; in Ontario, Canada, Phil Barton or Frank Gardner, (705) 942-1363 Northern Bytes Serving microcomputer users in Sault Ste Marie Ontario/Michigan area. We wish to exchange

newsletters with other clubs.

Zips 50000—60000

1. Eastern Iowa Computer Club

2. POB 1189, Cedar Rapids IA 52406

3. Sam Dillon, (319) 377-0889

4. Bimonthly

FOR ALMOST A DECADE...

. AND STILL HOLDING

5V at 3A with Built-in OVP

Model HB5-3/OVP $24.95 Single Qty.

New 1981 Product Catalog... plus our new Tour Guide. Phone or write for your copies today!

wmiwsir

Power One's Case models started at $24.95. Over 200,000 models later, they're still only $24.95!

■ 115/230 VAC Input

■ OVP Built-in

■ .05% Regulation

■ 2-Year Warranty I 2-Hour Burn-in ■ UL Recognized

■ CSA Certified

Get all the details on our 125 standard linear and switching power supplies.

**©

XJr'

"PRODUCT

,1m.

@pauierane*

o.c. power supplies

Power-One, Inc. • Power One Drive • Camarillo, CA 93010 (805) 484-2806 • (805) 987-3891 • TWX 910-336-1297

SEE OUR COMPLETE PRODUCT LISTING IN EEM & GOLDBOOK

Circle 117 on inquiry card.

April 1981 © BYTE Publications Inc 171

CPU's &

SUPPORT

CHIPS

RAM's

B251

B259

a257(AM9517)

Z80A S10

9275

FD1791

UART's

AY5-1013 - 3.75

TRJ602B - 3.95

AY3-85O0 -"XSS

PT1482B - 3.25

INTERFACE & DRIVERS

2.50 2.50 2.50 2.50 2.00 2.00 2.00 2.00

21141-3

4116-3

411 B-a

21L02-3

21Q2-4

MK4027-3

MK4096-11

TMS4045-25

MS4050NL

2101-1

21078(5280

MM5270

MK4008P

- 3.95 -3.75 -6.75

-3.50

- 2.95 6.50

- 3.95 -2.45

- 1.75 -3.45

ROM's

4029

4030 4034 4036 4040 4042

4046 4049 4050 4061 4052 4053 4066

55 4076

.35 4099

74C0D

74C02

74C04 ■

74C08

74C10

74C20 74C32 74C73

74C74 74C76

70

74C83 - 1

30

7JC85 - 1

10

74CS6

50

90

96

74C161 - 1

75

75

20

15

74C163 - 1

15

74C165 - 1

25

74C173 - 1

30

74C174 - 1

30

74C192 - 1

50

74C926 -- 6

95

2516 2532 8223 82S23 82S112 825115 82S123 82S126 82S129 82S130 82S131 AM9218C

- 29.95 -3.95

- 2.95 -7.95 -6.95

- 4.95 -2.95

- 3.25 -3.45

- 3.95 -6.95

SHIFT REGISTERS

MM 1402 MM 1403 MM 1404 MM5013 MM5016 MM5055 MM5056 MM5057 MM5058 MM5060

-1.75 -2.50 -2.50 -2.50 -2.50 2.50 -2.50 -2.50

PRINTED CIRCUIT BOARD

4" x 6" DOUBLE SIDED

EPOXY BOARD 1/16" thick

60 ea 5/S2.60

EPOXY GLASS VECTOR BOARD

1/16" thick with 1 /10" spacing

4%"x6%" $1.95

SPECIALS

4116-3 RAM'S - 8/$24.00

15% ALL74LS SERIES LEADER OSCILLOSCOPES

WE CARRY A FULL LINE OF HIGH QUALITY,

LOW PRICED OSCILLOSCOPES WITH

A TWO YEAR WARRANTY.

COMPARE PRICE & FEATURES.

LB0517 50 MHz D.T. CAL. DELAY

$1950.00

OSCILLOSCOPES

LBO-302

LBO-308S

LBO-310A

LQO-507A

LBO-508A

LB0 511

L80 513

L8Q-514

LB0-515B

LBO-520

10 MHz, D.T., 3" Compact 20 MHz, D.T.. 3" Portable AODC 4MHi, S.T. Recur. Sweep

20 MHz, S.T.,5"

20 MHz. D.T., 5"

10MHz,S.T.,5"

1QMH2.S.T,. I my Sens. .

790.00 950.00 .275.00 .610.00 .835.00 .420 00 .495.00 .645.00 30 MHz. D.T. Ciii. Delayed Sweep 1,530.00

30 MHz, D.T. w/Dolay Lino . .1,100.00

SPECIALS GOOD THRU APRIL 1981

CRYSTALS $3.45 ea.

6.144 MHz 8.0O0MH;

DATEL'S DAC-08BC

"8bitDAC - $9.95

74S00 74S02 74S03 74S04 74S05 74S08 74S10

.30

74S74

.30

74S86

.40

.45

74S133 1

.40

74S135 1

.30

74S133 1

.36

74S139 1

.40

74S140 1

.40

74SI53 1

.40

.40

74S157 1

74S175 74S194 74S257 74 S 258 74S260 74S280 74S373 74S374

7 WATT LD 65 LASER DIODE IR $8.95

25 watt Infra Red Pulse (SG 2006 equiv.) Laser Diode (Spec sheet included) s„4 gc

2N3820 P FET $ .45

2N5457NFET $ .45

2N2646UJT $ .45

ER 900 TRIGGER DIODES 4/$1.00

2N 6028 PROG. UJT $ .65

TTL REED RELAY - SPST 5V 20ma $1.00

CLOCK CHIPS

MM5387AA $5.95

MM5314 $4.75

MM5316 $4.95

TANTALUM CAPACITORS

.22UF35V 67*1.00 10UF10V -$ .40

.47UF35V 5/$1.00 22UF10V -$ .30

.68UF35V 5/$1.00 15UF16V 3/$1.00

1UF35V 5/$1.00 30UF6V B/$1.00

2.2UF20V 5 $1.00 33UF20V $ .60

ff «H" 100UF15V $-70

4.7UF15V 5/$1.00 1 cm ip 1 K\/ <: QR

6.8UF35V 3/51.00 150UF15V $ -95

SANKEN

AUDIO POWER AMPS

Si 1010G 10WATTS .. 5 7.50 Si 1020 G 20 WATTS .. $11.00 Si 1030 G 30 WATTS .$13.50 Si 1050 G 50 WATTS .$25.00

200 PRV 1A LASCR .95

RS232 CONNECTORS

DB25Pmale $3.25

DB 25S female ... $4.25 HOODS $1.50

2.000 MHz 4.000 MHz 3.000 MHz 3.57 MHz 5.000 MHz 6.000 MHz

10.000 MHz 18.000 MHz 18.432 MHz 20.000 MHz

RIBBON CABLE

FLAT (COLOR CODED)

#30 WIRE

16cond. - .40/perfoot 40 cond. - .75/per foot 50cond. - .90/perfoot

MINIATURE MULTI-TURN TRIM POTS 100, 5K, 10K, 20K, 250K, ... $.75 each .

NO. 30 WIRE WRAP WIRE SINGLE STRAND

100' $1.40

ALCO MINIATURE TOGGLE SWITCHES

MTA 106 SPOT $1.05

MTA206DPDT $1.70

MTA 206 P-DPDT CENTR OFF $1.85

MSD 206 P-DPDT CENTER OFF LEVER SWITCH $1.85

SCR's

600

TRIAC's

PRV

1A

10A

2SA

100

.45

.80

1.55

200

.84

1.30

2.10

400

1 30

1.90

3.10

600

2.00

2.75

4.30

FP 100 PHOTO TRANS $ .60

RED, YELLOW, GREEN OR AMBER LARGE LED's.2" 6/51.00

RED/GREEN BIPOLAR LED's $ .55

MLED92 R LED $ .75

MRD14B PHOTO DARL. XTOR $ .75

TIL-118 OPTO-ISOLATOR $ .75

IL-5 OPTO-ISOLATOR $ .80

1 WATT ZENERS: 3.3, 4.7, 5.1, 5.6, 6.8, 8.2, 9.1, 10,

12,15,18, or 22V 6/$1.00

SFC3301 - 50 PRV30A FAST RECOVERY DIODE (35ns) . .$2.25 20KV250MA DIODE $1.90

SILICON POWER RECTIFIERS

PRV 1A 3A 12A 50A 125A 240A

.20 .40 1.30 4.25 12.00

.25 .65 1.50 6.50 15.00

.30 .80 2,00 8.50 18.00

.35 1.00 2.50 10.50 22.00

.45 1.25 3.00 12.50 26.00

IN4148(IN914) 15/$1.0Q

.1 or .01 uf 25V ceramic disc. caps. 16/$1.00, 100/$5.00

7 SEGMENT DISPLAYS

FSC 8024-4 digit DL-707 C.A. .3"... . $.75

C.C. 8" display.... $5.95 DL747 C.A. .6" ... .$1.50

FND503C.C. .5".. $ .85 HP3400 .8"CA.... $1.95

DL-704-.3"C.C... $ .85 HP3405 ,8"CC .... $1.95

^ i> 'i ^iaflh

TRANSISTOR SPECIALS

2N1307PNPGETO5

2N404APNPG£T0 5

HEPG6Q14 -PNPGETC3

TIP121 - NP\S SW.TCHING

2N6233-NPN SW Ti MING POWER.

MRF-BOOtaCi'lii l-.'.NSis'nflNPN... $ .

2N3772NPNS TO-3. ... . $1.

2N4908PNPR TO 3. $1.

2N50B6PNPS H)92 4/$1,

2N3137NPNSi=1r- . . . $ .

2N3319 NPN S. TO 3 PF .. $1,

2N1420NPN ~<TJ; 3:$1.

2N3767NPNS1 fO 66 $ .

2N2222NPN!; rO-18 Si$1.

/;;-:.Hi/1 irj -.; is 4/81.

MPS

PNE

TIP 34 P

JPRi

SiUB

TTLIC

SERII

7400

.17

7450

.17

74161

7401

.1/

7472

.:lh

74162

7402

.17

7473

.35

74163

7403

.17

7474

47

74164

7404

?4

7475

41

7416b

7405

?4

7476

45

74166

7406

.33

7480

.45

74167

7407

:i<o

7483

.60

74170

7408

77

7485

,7a

74173

7409

74

7486

AV

74174

7410

17

7489

.60

7417b

7411

77

7490

.b0

74176

7412

,77

7491

,bb

74177

7413

47

7492

.60

74190

7414

m

7493

.SO

74181

7416

33

7494

,m

74190

7417

37

7495

m

74191

7420

17

7496

,60

74192

7425

3fi

74107

,3b

74193

7426

aa

74121

.!tb

74194

7427

3S

74122

,39

74195

7430

17

74123

.«

74196

7432

77

74125

.4b

74197

74126

4b

74279

7438

?7

74145

,75

74325

74148

1 Ml

7441

K>

74150

1.10

74363

7442

.50

74151

.6b

7445

/()

7446

,75

75154

1.10

7447

.75

74155

.7b

7448

,75

74157

.lib

8T98

FULL WAVE BRIDGE

PRV

2A

6A

25A

100

1.40

200

.80

1.30

2.20

400

1.00

1.6S

3.30

600

1.30

1.90

4.40

DIP SOCKETS

SPIN .17 22PIN .30 14 PIN ,20 24 PIN .3b 16PIN .22 28PIN .40

18PIN .25 40PIN .60

74LS SERIES

74LS01

74LS02

74LS03

74LS04

74LS05

74LS08

74LSD9

74L5I0

74LS11

74LS12

74LS13

74LS14

74LSI5

74LS2D

74LSZ1

74L522

74LS26

74LS27

74L528

74LS3Q

74LS32

74LS37

74LS74 74LS75 74LS76 74LSB3 74LS85

74LS96 74LS107 ■

74LSI09 74LS11274LS113 74LE114 74LS123 74LS125 74LS126 74LS132 74LSI36 74LS138 74LS139

74LS151 - 1.19 74LS153-1.19 74LS155-1.19

LINEAR CIRCUITS

136- .! 900 - .! M307 M30a M324

LM348 - .90 LM358 - ,70 LM361 - 1.7! LM377 LM382 LM336 LM3B7 LM553 LM555 - .45 LM553

,60

- 2.25

566

- 1.25

CA758 CA3018 CA3046 CA3078 CA3080 CA30B6 CA3094 NE540L

REGULATORS

74LS157

74LS160

1.00

74LS1B1

74LS163

LOO

74LS16.1

1.00

74LS16B■

1.25

74L5169

.75

74LS170

74LS173

.90

74LS174

1.00

74LS175

;.00

74L5181

2.50

a

74LS191

74 LSI 92

.90

74LS193

74LS194

1.10

74LS195

.90

74 LSI 96

1.00

74LS197

.90

7JLS241

1.60

74LS242

1.60

;.'.i S2'ji

1.28

1.00

74LS258

.90

74LS259

74LS273

74LS283

.80

74LS290

71LS293

.80

74LS365

74LS3G7

74LS373

74LS38r,

.50

74LS393

1.50

LM1B10 - 2.20 Ml 88

LM317T...

LM337

323K-bV3A. 73HGKC-5V;

..,.$2.50 ... $2.50 ... .$5.75 5A $6.95

LM305G $

340K-12,15or24V S 340T-5, 6, 8, 12, 15

POSTAGE ADD 10% FOR ORDERS UNDER $20.00 RATES ADD 5% FOR ORDERS BETWEEN $20.00 AND $50.00

ADD 3% FOR ORDERS ABOVE $50.00

TERMS: FOB CAMBRIDGE, MASS. SEND CHECK OR MONEY ORDER. MINIMUM TELEPHONE. C.O.D. PURCHASE ORDER OR CHARGE $20.00 MINIMUM MAIL ORDER $5.00.

SEND 5.25 FOR OUR CATALOG FEATURING TRANSISTORS & RECTIFIERS. 145 HAMPSHIRE ST., CAMBRIDGE, MASS. 02139

SOLID STATE SALES

P.O. BOX74B

SOMERVILLE, MASS. 02143

TEL. (617)547-7053

WE SHIP OVER 95%

OF OUR ORDERS WITHIN

24 HOURS OF RECEIPT

TOLL FREE 1-800-343-5230

1. H8SCOOP

2. 2918 S 7th St, Sheboygan WI 53081

3. Henry E Fale, (414) 452-4172

5. Special interests: Heathkit H-8 and H-89 computers.

1. Fox Valley Crab-Apples

2. Mathematics Department, University of Wisconsin—Oshkosh, Oshkosh WI 54901

3. John Oman, (414) 424-1362

5. Use of the Apple II in the classroom.

1. MICRO

2. 335 W Prospect St, Appleton WI 54911

3. John Ensley, (414) 731-7183

4. Yes

5. Special interests: computer networks, graphics, and educational uses.

1. Mini 'Apples

2. 13516 Grand Ave S, Burnsville MN 55337

3. D Buchler, President, (612) 890-5051

4. Mini 'Apples Newsletter

5. Apple II users group. Special interests: Pascal, education, personal, business, and industrial applications.

1. XXX-11

2. POB 2017, Fargo ND 58107

3. C R Corner, (218) 233-7894

4. XXX-11 Newsletter

5. Special interests: languages.

Zips 60000—70000

1. Dental Computer Newsletter

2. 1000 North Ave, Waukegan IL 60085

3. E Neiburger, Editor, (312) 244-0292

4. Monthly

5. Special interests:

172 April 1981 © BYTE Publications lnc

Circle 118 on inquiry card.

2716 (5V) $8.95

4116

200NS

$3.50

2114L

300NS

$3.75

NEW! IT TALKS "FAST TALKERS S-100"

LOW DATA RATE S100 SPEECH BOARD

• UNLIMITED SPEECH POSSIBILITIES

• S100 INTERFACE

• USES TEXAS INSTRUMENT TMS 5200 V.S.P

• SOFTWARE. VOICE DATA ASSEMBLER

• 32 WORD VOCABULARY INCLUDED

• AUDIO AMP W/SPEAKER

• ASSEMBLED AND TESTED

NEW TECHNOLOGY SPEECH PROCESSOR

ALLOWING UNLIMITED SPEECH POSSIBILITIES

DELIVERY FROM STOCK

TMS-5200 VOICE SYNTHESIS PROCESSOR

Chip with Data Sheet $69.00

$329.

"CONTROL TALKER II"

110V 50/60 HZ

32 INPUT LINES

(TTL)

32 10 AMP (50V)

OUTPUT LINES

Z80 BASED

SYSTEM

8K PROM

(SOCKET)

1K RAM

VOICE OUTPUT

SINGLE BOARD

STEPPING MOTOR

CONTROL (UP TO 8)

Control Talker II can be used to control stepping motors, relays, counters, etc., and support a variety of uses including robotics, telephone dialer, digital access, security, aulo drilling, measuring, counting and virtually unlimited applications with added speech output to advise

of status etc. Put one to work for you today!

$550.

Double Sided QUME DRIVES DATATRAK 8

°RU,RCE $540.00

(Regularly) $808.00)

CALIFORNIA COMPUTER SYSTEMS

Order

Number 2032A 32K Sialic 20338 32K Sialic 2032C

32K Sta

EM450NS

EM-300NS EM-2C0NS

I MEM-200NS

2065C 6a K Dy 2116A igk Static MEM-450NS

2M6B

16K Slahc MEM300NS

21I6C

16K Sialic W6M-20ONS

2116X

16K BD oniy

22C0A

Mainframe 110.60

2422A

Floppy Controller

2710A

4-Porr Serial I/O

271BA

SciauParaiiei I/O

2720A

4-Port Parallel HO

2810A

2 80 CPU BD

APPLE BDS:

1560 00 640 00 649 00 569.00 257 00 26100 290 00 67 00 386 00 320 00 279,00 290 00 200.00 235 00

7470A

AID Converter

7490A

GP1B IEEE 4KB

77 IDA

Serial Asyncrt 9(

77I2A

Serial Syncn Ba

7720A

S 63 00 103 00

90 00 97 00 230 00 127 00 152 00 99 00 I 99 00

329 00

79L

VOLTAGE REGULATORS

art" Case Price

,i 05 J 092 45

IL12 I"092 45

ItS T092 45

T092 65

TQ92 65

T092 65

TO220 1 20

TO220 1 20

TO220 1 20

TO220 1 25

TO220 1 25

TO220 1 25

79U5 7805 P 7B12P 78I5P 7905 P 7912P 7915P 7805K 7812K 78I5K 7905K 7912K 7915K 309M 309K 317P 317K 323K 337P 337K 350K

I03 T03

T039

T03

T022U

T03

T03

TO220

T03

T03

CRYSTALS

(Parte Includes Iraquoncy In MHZ)

Parl#

SYi

SYI 8432

SV2

SY2.4576

SY3.579

SY4

SY5 068

SY6

SY6 144

SYS

Price

575 5.75 5.75 5.75

5.75 4.50 450

CERAMIC DISC

CAPACITORS 50V

Value 1 + 25+100 +

4 7pf 07 06 04

lOpI 07 06 04

22pf 07 06 04

33pf 0/ 06 04

39pl 07 06 .04

47p( 07 06 04

68pl 07 06 .04

100pl 07 .06 .04

150pf 07 06 04

220pl 07 06 .04

270pl 07 06 04

330pt 07 06 .04

,0022ml 0033ml 0047ml

DIODES

Switching

IN914 12*1 00

1N414S 12S100

LOW-PROFILE SOLDER TIN

PartW 1 + 25+100 +

S8LT 15 n 08

SI4LT 18 16 14

S16LT 2t 18 16

S18LT 26 22 18

S20LT 31 26 20

S22LT 33 28 22

S24LT 35 29 24

S28LT 41 34 26

S40LT 53 4 7 40

WIRE-WRAP SOLDER TIN

Part* 1 + 25+100 +

SBWT 37 33 30

S14WT 48 43 39

S16WT 53 -18 -»3

S18WT 61 55 50

S20WT 65 77 69

S22WT 69 80 72

S24WT 96 86 77

S28WT 1.22 111 99

B40WT l 75 '57 1 40

WIRE-WRAP GOLD

Pari* S8WG S14WO

SI6WG S18WG S20WG S22WG S24WG S28WG J.".J0vVG

SOLID DIPPED TANTALUM CAPACITORS 20%

ValuB Volls 1 + 25+100 +

2 2ml

3 3ml

4 7m)

T.55 1 29 1 05

V* WT &

5

VaWT CARBON I % RESISTORS

2.2K

2.4K

2.7K

3K

3.3K

3.6K

3.9K

5.1K 5.6<

6.2< 6.8 <

2O0K 220K 240K 270K 300K 330K 360K 390K 430K 470K 5I0K 560K 620K 680K 750K 820K

2.2M

2.4M

2 7M

3M

3.3M

3.6M

3.9M

MINIMUM ORDER PER TYPE: 5 pes—any qty 5 pack @ $.25

MINIMUM ORDER PER TYPE:

100 pes

Price Per 100 Pk:

QTY 'AWT '/.WT

100 up 51.70 $1.80

1,000 up 1.50 1.60

5.000 up 1.30 1.40

10.000 up 1 10 1.20

ZENER DIODES

Vi WT Part# Price

1N5231B 1N5239B 1N5242B 1N5245B 1N5248B 1N5250B 1N5252B IN5255B

1 WT

1N4733A 1N4739A 1N4742A 1N4744A 1N4746A IN4747A 1N4749A

POLYESTER

CAPACITORS

+ & - 10%

TOLERANCE 50V

Valui

OOtrn'

0012ml

0015ml

OOlBmf

0022ml

0027 ml

0033ml

,0039ml

0047ml

0056ml

0068ml

.0082fnl

.01ml

012ml

015ml

018ml

.022ml

,027ml

,033ml

,039ml

047ml

.056ml

068ml

0B2ml

.27ml .33ml 39ml 47ml

H

100 +

TRANSISTORS

2N2219A S .35

2N2222A .25

2N2905A ,30

2N2907A .25

2N2369A 25

2N3904 20

2N3906 20

PN2222A 19

PN2907A 19

RECTIFIERS (1A)

1N4001 1N40O2 IN 4003

1N4004

12100 12100 12/1.00 121.00

1N40O5 10/1.00 08 IN40O6 11/1.00 08 1N4007 10(1.00 08

74 LS

Part U Price

74LS00 32

74LS01 32

74LS02 32

74LS03 32

74LS04 32

74LS05 32

74LS08 .32

74LS09 .35

74LSIO .3B

74LS11 38

74LSI2 39

74LS13 32

74LS14 65

74LS15 35

74LS20 32

74LS21 36

74LS22 36

74LS26 35

74LS27 39

74LS28 37

74LS30 36

74LS32 40

74LS37 36

74LS3B 36

74LS40 36

74LS42 95

74LS47 1 15

74LS48 1 15

74LS51 .32

74LS54 .38

74LS55 .34

74LS73 49

74LS74 49

74LS75 63

74LS76 55

74LS83 95

74LS85 125

74LS86 .55

74LS90 79

74LS92 75

74LS93 75

74LS95 .99

74LS107 50

74LS109 .50

74LS112 52

74LSU3 52

74LS114 .52

74LS123 1.05

74LS125 70

74LS126 .70

74LS132 .95

74LS136 53

74LS13B 85

74LS139 .85

74LS148 1.75

74LS151 79

74LS152 79

74LS153 79

74LS154 2 05

74LS157 1 15

74LS15B 115

74LS160 85

74LS161 85

74LS162 .85

74 LS 163 95

74LS164 1 10

74LS165 1 10

74LS166 255

74LS170 1.90

74LS173 135

74LS174 l 25

74LS175 95

74LS1B1 235

74LS190 I 15

74LS191 1.15

74LSI92 1.15

74LS193 1 15

74LS194 1 15

74LS195 1 15

74LS196 99

74LS197 99

74LS221 .95

74LS240 1 05

74LS241 1 05

74LS242 1.45

74LS243 1.45

74LS244 1 05

74LS245 2 15

74LS251 129

74LS253 .99

74LS255 99

74LS257 1 15

74LS25B 1.15

74LS260 .95

74LS261 249

74LS266 65

74LS273 165

74LS283 1.05

74LS365 .85

74LS366 85

74LS367 85

74LS368 85

74LS373 1 65

74LS374 1 45

74LS375 99

74LS377 1.15

74LS3B6 59

74LS390 I 75

74LS393 1 75

81LS95 1.35

81LS96 135

81LS97 135

81LS9B 135

4000 CMOS

Part -i Price

4000

4001

4002

4006

4007

4008

4009

4016 4017 4018 4019 4020

4025 4026 4027 4028 4029 4030 4034 4035 4040

4043 4044 4046 4047

4052 4053 4060 4066

4072 4073 4075 4076 4077 4078 4081 4082 4093 4503 4508 4510

SERIAL PORT CARD WITH 4 PORTS $289 WITH 2 PORTS $260

MIN ORDER: $10.00 SHIPPING: ADD $2.00 GA RESIDENTS ADD 3% SALES TAX

MASTERCARD AND VISA WELCOME

MAILORDERSSOUTHERN SEMICONDUCTORS INC.

BOX 986

LAWRENCEVILLE, GA. 30246 PHONE ORDERS:

OEM AND INSTITUTIONAL INQUIRIES INVITED (404) 963-3699

Circle 120 on inquiry card.

BYTE April 1981 175

ENTREPRENEURS

Imli1™!™! WmU I MORE THAN EVER IN THE MICROIVkkl#hll# COMPUTER INDUSTRY.

The shortage of knowledgeable dealers/distributors is the «1 problem of microcomputer manufacturers Over 300 new systems houses will go into business this year but the number falls short of the 1200 needed It is estimated thai the nal "in wide shortage of consultants will be over 3000 by 1981 The HOW TO manuals by Essex Publishing are /out best guide lo start participating in the continued microcomputer boom

(36

HOW TO START YOUR OWN SYSTEMS HOUSE

6th edition March 1980

Written by the lounder of a successful systems house, this

tai Milled 220-page manual covers virtually all aspects of

starting and operating a small systems company It is abundant

with useful, real-lite samples contracts proposals, agreements

and a complete business plan are included in lull, and may be

used immediately by the reader

Proven, field-tested solutions lo the many problems lacing the

small systems house are presented

From the contents:

• New Generation of Systems Houses • The SBC Marketplace

• Marketing Strategies • Vertical Markets & lAPs • Competitive Position/Plans ot Major Vendors • Market egment Selection & Evaluation • Selection ol Equipment & Manufacturer • Make or Buy Decision • Becoming a Distributor • Getting Your Advertising Dollars Worth • Your Salesmen Where to Find Them • Product Pricing • The Selling Cycle • Handling the 12 Most Frequent Objections Raised by Prospects • Financing foi the Custom©! • I easing • Questions You Will Have to Answer Before the Prospect Buys • Producing the System • Installation, Acceptance, Collection • Documentation • Solutions to the

Service Problem • Protecting Your Product • Should You Start Now'' • How to Write a Good Business Plan • Raising Capital

HOW TO BECOME A SUCCESSFUL

COMPUTER CONSULTANT

HOW TO BECOME A SUCCESSFUL COMPUTER CONSULTANT

by Leslie Nelson, 2nd revised edition Jan 1981 Independent consultants are becoming a vitally important factor in the microcomputer field filling the gap between the computer vendors and commercial/industrial users The rewards ol the consultant can be high treedom, more satisfying work and doubled or tripled income HOW TO BECOME A SUCCESSFUL COMPUTER CONSULTANT provides comprehensive background information and step-by-step directions for those interested to explore this lucrative field

• Established consulting markets* How to get started • Itemized start-up costs • Are you qualified7 • Beginning on a part time basis • The Marketing Kit • Should you advertise? • Five marketing tips • Getting free publicity • How much to charge

• When do you need a contract9 • Sample proposals • Which |Obs should be declined • Future markets • The way to real big

money • Avoiding the legal pitfalls • How consultants'associations can help you • The National Register of Computer Consultants • How others did it real-life sample cases «and much more.

ESSEX PUBLISHING

$28.

No, 16

FREE-LANCE SOFTWARE MARKETING 3rd edition. June 1980 Writing and selling computer programs as an independent is a business where • you can get started quickly, with little capital investment • you can do it full time or part time • the potential profits are almost limitless Since the demand lor computer software ol all kinds is growing al an explosive rate, the conditions lor the small entrepreneur are outstanding

This manual will show you how to sell your own computer programs using these proven techniques • direct to industries • through consulting firms • through manufacturers of computer hardware • in book form • mail order • through computer stores It will show you how to profitably sell and license all types of software ranging from sophisticated analytical programs selling lor thousands of dollars, down to simple accounting routinesand games for personal computers

The book will guide you step by step through the process ol S30. No. 32 marketing, advertising, negotiating a contract, installing software,

training users and providing maintenance and support It also contains sample software contracts that have been used in actual software transactions Also included are tips on how to negotiate with a large corporation ways of avoiding personal liability techniques for obtaining free computer time and hints on how to run a free-lance software business while holding a full-time job

ESSEX PUBLISHING CO. Dept «■

;J«.'j nioomlield Avenue • Caldwell, N.J 07006 I- ■ I

" lei books by numt lend hei I m • • . • lei i ■ r Ma ite e ». Publ rier pa

i riipping ForUPS di| ping IA only) addSLOOpei I idd ! pei book in

II i 11 '' i nd Central America , I i N .... iiesta

DNo 10 ONo 16 ONo32 □ Che iss OUPS OAir

Name

A Ho

State

Card H r

F or taster shipment on credit card orders call (2011 783-6940 between 9 and 5 Eastern lime

. Exp

Zip

5. We have an ABBS

(Apple Bulletin Board System) on (402) 423-8086.

Compusers

POB 2064, Hastings NE 68901

Rocky Friend, President; or Dorothy Friend Secretary (..orrijiusers

We have a number of different makes ot microcomputers and are interested in all subjects concerning computer use.

3.

Zips 70000—80000

1

99 4 Home Computer

Users Group

'

POB 95148, Oklahoma

City OK 73143

.'..

Charles LaFara, (405)

787-8521

4.

Monthly newsletter

5.

We have a program ex

change and are looking

fi 'i more information on

TI BASIC.

1.

The Tulsa Computer

Society

2,

POB 1133, Tulsa OK

74101

3.

Mike Parr, (918)

492-8292

■i

I i I Port

5.

Everything!

Theatre Computer Users Group

104 N St Mary, Dallas

TX 75214

Mike Firth, (214)

827-7734

TCUG Notes

Spec ial interests: the use

of computers in live

drama.

1. FWAUG (Fort Worth Apple Users Group)

2. 1401 Hillcrest Dr. Arlington TX 76010

3. Lee Meador, (817) 461-1981

4. FWAUG Newslettri

5. Apple hardware and software.

176 April 1981 = BYTE Publication* btc

Circle 121 on inquiry card.

GgGgGgGgGgGgGgGgGg

GgGgGgGgGgGgGgGgGg

GgGgGgGgGgGgGgGgGg

GgGgGgGgGgGgGgGgGg

HhHhHhHhHhHhHhHhHhl

HhHhHhHhHhHhHhHhHhH

HhHhHhHhHhHhHhHhHhHl

HhHhHhHhHhHhHhHhHhHh

IgGgGgGgGgGgGgGgGgGgGgGg

gGgGgGgGgGgGgGgGgGgGgGg

^GgGgGgGgGgGgGgGgGgGgGg

GgGgGgGgGgGgGgGgGgGgGg

ihHhHhHhHhHhHhHhHhHhHh

. iHhHh'HhHhHhHhHhHhHhHh

^HhHhHhHhHhHhHhHhHhHh

m 'HhHhHhHhHhHhHhHhHh

APPLE H Computer now with genuine upper/lower case

We used to think the sophistication of the Apple 11/ PLUS could not be improved upon. With increasing availability of business software capital letters on the screen are not sufficient. Especially for wordprocessing and the PASCAL editor the lack of lower case was disturbing.

After searching for a better solution we developed a new keyboard-encoder to implement upper and lower case in the keyboard and on the screen.

• typewriter mode or ALPHA-LOCK mode operation

• all keys with AUTOREPEAT

• four character sets including FULL ASC II, and EUROPEAN sets

• no soldering, no wiring

• simply replace the plug-in encoder-board

Fix your system today, so tomorrow you're not stuck with just capital letters.

Ask your Apple dealer for the new keyboard-encoder from BASIS. For S 125,00 you save time and get a new clear screen.

INCORPORATED

Apple II is the registered trademark of apple computer, inc.

BASIS, Inc., P. O. Box 2029, Los Gatos, CA 95030

Clubs and Newsletters,

1. Club 1802

2. POB 985, Dickinson TX 77539

3. John L Hubisz, (713) 938-4098

4. Newsletter

5. Our activities are for beginners in microcomputing. We use ELFs and other 1802-based boards that employ simple controls,

1. High Plains TRS-80 Users Group

2. POB 30545, Amarillo TX 79120

3. Tom Whittenburg, (806) 374-971J

1. Permian Basin Amateur Computer Group

2. c/o Ector School District, POB 3912, Odessa TX 79760

3. John Rabenaldt, (915) 697-4607 (after 6 PM) or (915) 332-9151 (9 AM to 5 PM)

5. Special interests: Selectric interlaces, color displays,

MECA tape, and Altair 8800 systems.

Zips 80000—90000

1.

2.

3. 5.

Apple it

415 E 43rd, Odessa TX

79762

Larry Brown

Apple 11 microcomputers.

1. 2. 3.

Denver Amateur Computer Society

POB 1235, Englewood

CO 80150

Lam,' Costa, (3031

1. 1. 3. 5.

Permian Basin TRS-80

Users Group

Rt #4, POB 1455, Odessa

TX 79763

Allan D Emert, (915)

381-3138

TRS-80 Model 1.

4. 5.

1

428-2929

INTERRUPT

We are a broad-interest

dub.

Southern Colorado Computer Club

* WRITE OR CALL FOR FREE CATALOGUE *

CALIFORNIA COMPUTER SYSTEMS Hir.HlNQU Mil) /< WIN PRh i 7.80 CPU 4 Mli/, wiili one serial port 12 slut S too mainframe disk controllei oil. Dynamic Ram, CP M2.2" $1,645.

Interfaced to 2 Shugarl 8*, single sided double density drives mounted in our own beautiful MAX BOX with power suppl) and fan $1,250.

A complete S-100 system for under $3,000 ("HE BES1 BLh ON ["HE MAR1 I I

IMS 5000 and 8000 Systems

Outstanding long term reliability and performani e I hese systems Feature a '80A < I'l' S 100 bus; ill ml ilc density drives (eithei single or double sided), DMA disl conti oiler, 64K RAM, 2 serial .s; I parallel port. Prices include the verj finest implementation <>l I I' \P available in the entire industry Hard disk .in<l multi usei software options. Desk top or desk enclosed 5000 111 with dual, single sided mini di $3,225.

80001.11 with dual single sided 8 drivi 54,755.

PER SCI— THE h INC AND QUI 1 \ I >/ DRIVES!

Model 299B: Dual headed drives total I 2 MB unformatted $2,300.

Model 277: I )iul 8 mcli drives voice coil positioned IBM compatible 16001 BYTES

pel drive unformath d Si .210.

Slimline abinel and power Foi eithi \ ' 7oi '■"! $ (00

DRIVES

[lie MAX BOX: Manufactured bj lohnD Owens \ iciates. 8 dual drive cabinel complete with powei supply .^ fan Will holdQumes Shugartsoi Siemen Excellent design and engineering ... S 325.

With 2 Shugarl 800R drives St,250. With 2 QUME Doubli sided drives St,650.

MPI 1551

$265.

B52

U

Bsi2

S500. Shugarl $ 450.

HAZELTINE 1500

1510

S925. si 030

AMPEX DIALOGUE 80 CRT saso. Removable keyboard, 2 page memory

M optional) bloi I- h ansinil

CENTRONICS 737 $ '80

Same as I RS 80 Model IV Apple serial parallel interface $195.

EPSON MX801S

$ ISO

IMS MEMORY u- K t.,tn $350.

32 K si.in, $650.

64 K Dynamic with parity $755.

TEI MAINFRAMES, S 100

12 slot, table top $500.

22 slot, table top $670.

Hack moiinls add $ 50.

50 Hj ' v volts add S 50.

TELEVIDEO CRTs

s>12 $780. s>20 $850. 950 $1,050.

\AW CYPnDT Overseas Callers: TWX 710 588 2844 WttATUKi: Phone 212 448-6298 or Cable: OWENSASSOC

JOHN D. OWENS

Associates, Inc.

12 Schubert Street

Staten Island, New York 10305

212 448-6283 212 448-2913 212 448-6298

Computer Shack, 1635 S

Prairie, Pueblo CO 81005

Tom Thomas, (303)

564-3545

Monthly newsletter

1. Utah Computer Association

2. 378 E 9800 S, Sandy UT 84070

3. Lawrence N Barney, (801) 571-9661

4. UCA Bits

5. Special interests: advanced software, hardware, CP/M, and Pascal.

1. SNPCS (Southern Nevada Personal-Computing Society)

2. 1405 Lucilee St, Las Vegas NV 89101

3. Cy or Edna Wells, (702) 642-0212

4. Hard Copy

5. Both hardware and software; exchange id iiiim mation and experience; and guidance and encouragement for new hobbyists. We participate in fairs and exhibitions.

Zips 90000—99999

1. Poly 88/8813 Users Group

2. 13022 Psomas Way, Los Angeles CA 90000

3. Pat or Roger Lewis

4. Poly 88/8813 Users Group Newsletter

5. Software exchange.

1. LA Apple Users Group

2. 9513 Hindry PI. Los Angeles CA 90045

3. Philip A Wasson, (2131 649-1428

178 April 1981 S BITE Publications In<

1. The San Fernando Valley 6502 Users Club

2. 3816 Albright Ave, Los Angeles CA 90066

3. Larry Goga, (213) 398-6086

5. This club is open to all owners of 6502-based computers including KIM, SYM, and AIM. PET and Apple owners are also welcome.

1. SuperLetter

2. Abrams Creative Services, 369 S Crescent Dr, Beverly Hills CA 90212

3. (213) 277-1588

5. Newsletter for SuperBrain users.

1. OSI Users Independent

2. 6061 Lime Ave #2, Long Beach CA 90805

3. Charles Curley, (213) 422-3673

4. OSI Users Independent Newsletter

5. OSI computers and software.

1. ELF of the Valley

2. 2670 Calle Abedul, Thousand Oaks CA 91360

3. Richard Cox, (805) 492-4128

5. RCA 1802 microcomputers.

1. Compucolor/Intecolor Users Group

2. 5250 Van Nuys Blvd, Van Nuys CA 91401

3. Stan Pro, (213) 788-8850

4. Bulletin

5. We are an international group of color-computer users, with over 1000 programs in our library.

1. The Cursor Group

2. POB 266, North Hollywood CA 91603

4. The Cursor

5. User group of the Bally Arcade.

1. ET-3400 Users Group

2. 11231 Oak St, El Monte CA 91731

3. Charles Van Dyke, (213) 443-2237; CompuServe acct 70250,413

1. San Diego Heath User's Group

2. 12202 Kingsford Ct, El Cajon CA 92021

3. Jim Quinn, President, (714) 561-2540; Cliff Dudley, Secretary, (714) 697-8796

4. Coming soon

5. Special interests: the exchange of ideas, information, and assisting Heath computer users.

1. CIE (Computer Informa

tion Exchange)

2. POB 158, San Luis Rey CA 92068

3. Bill McLaughlin, (714) 757-4849

4. CIE People's Software News

5. Special interests: TRS-80.

1. Apple for the Teacher

2. 9525 Lucerne St, Ventura CA 93004

3. David Miller, Editor,

(805) 647-1063; Ted Perry, President, (916) 961-7776

4. Apple Educators' Newsletter

5. Education using Apple II microcomputers.

1. International Apple Core

2. POB 976, Daly City CA 94017

3. Ken Silverman, (415) 878-5382

4. The Apple Orchard

* TELETYPE MODEL 43 INVENTORY SALE *

TELETYPE

Model 4320 AAA $ 885.

220V. model with transformer installed

inside cabinet $ 985.

Model 43ASR, 8 level, 1" tape . S2,595. Limited supply of Model 45 available.

TELEBUFFER 43 ASR $945.

Circuit card designed for internal installation in the Model 43 Teletype. Changes the 43 into a buffered send/ receive device, enabling it to function as a Telex without paper tape. Provides from 4K to 16K bytes of internal memory for storage of message. Contents of memory may be edited and manipulated in preparation for transmission. Options include forms control and answer back.

IBM 3101 CRT Model 10 51,195.

Model 20 $1,395.

Selectric-like, detached keyboard. 9x16 dot matrix. Maintenance contract from IBM only $70 per year

ITHACA INTERSYSTEMS

Full S-100 IEEE Compatibility! Full 24 address bits. DMA disk controller. SYSTEM 2A includes 20 slot mainframe with front panel, 64K Dynamic RAM. Z80 CPU, 4 MHZ, extended addressing capability. 4 parallel, 2 serial I/O floppy controller. Our discounted price, $3,415.

MARINCHIP SYSTEMS M9900

Elegant 16 bit CPU, S-100 compatible, multi user, multi processor operating system. BASIC, FORTH, META, PASCAL, Word processor, text editor. CPU kit and software package . $ 550.

Assembled $ 700.

Complete system, 64KB,

two drives $4,995.

MICROANGELO $2,280.

High resolution graphics system. 15", 22MHZ, green phospher screen, 72 key keyboard; includes complete cabling and software. From SCION. S-100 Graphics card $ 960.

GRAPHICS SOFTWARE

On line, real time, for the M9900 to drive the Microangelo. For use in design of PC board masks, IC masks and other applications $1,000.

CORVUS HARD DRIVES

We are the S-100 CORVUS dealer in the New York area.

MODEL 11, Hard Disk System $4,820. Mirror Backup System $ 715.

TARBELL

Double density controller $420.

Cables $ 40.

Complete TARBELL Product Line Available.

UPGRADE DEC LA 35/36 . $750.

Increases baud rate to 1200. Microprocessor controlled. Many options available. Enthusiastic user response. Longterm reliability. From DataSouth.

Communications Software from from Hawkeye Grafix

Enables communications from a micro to a terminal or to another micro, mini or maxi computer. Object Code $75. Source Code $250.

3M SCOTCH" Diskettes

5 BOXES 1 BOX Price of len per box

Model740,8" single sided,

single density. .$29.00 $26.50 Model741,8" single sided,

double density. 38.00 35.00 Model 743,8" double sided

double density. 46.50 42.50 Model744,5'/T soft sectored single sided,

single density. . 29.00 26.50

CAT from NOVATION

Originate/Answerback $175.

CAT-D $185.

Connects directly to telephone line with a plug-in jack. Eliminates need for acoustic coupler. AUTO-CAT $240.

WE OFFER A FULL RANGE OF EXPERT CONSULTING SERVICES

JOHN D. OWENS

Associates, Inc. SEE OUR AD ON FACING PAGE

April 1981 © BYTE Publications Inc 179

Clubs and Newsletters

5. Apple hardware and software.

1. Homebrew Computer Club

2. POB 626, Mountain View CA 94042

3. Robert Reiling, (415) 967-6754

4. Homebrew Computer Club Newsletter

5. Information exchange on all systems.

1. Proteus

2. 1690 Woodside Rd, 219, Redwood City CA 94061

1. FORTH Interest Group

2. POB 1105, San Carlos CA 94070

3. Roy Marteus, (415) 962-8653

4. FORTH Dimensions

5. The FORTH language.

1. San Francisco Apple Core

2. 1515 Sloat Blvd, Suite 2, San Francisco CA 94132

3. Randy Fields, (415) 775-7965

4. Cider Press

5. Apple computers.

1. CUssP

2. POB 784, Palo Alto CA 94302

3. Dave Dameron, Editor

4. CUssP Newsletter

5. Cromemco computers and systems.

INSUA (International North Star User's Association)

2. POB 1318, Antioch CA 94509

3. William Banaghan

4. The Compass

5. For North Star computer users.

1. Arcadian

2. 3626 Morrie Dr, San Jose CA 95127

3. R Fabris, (408) 742-6048 (8 AM to 4 PM) or (408) 258-4586 (6 to 10 PM)

5. For the Bally/AstroVision Arcade.

1. CUE (Computer-Using Educators)

2. Independence High School, 1776 Education Park Dr, San Jose CA 95133

3. Don McKell, (408) 926-7378

4. Bimonthly newsletter

5. Computers in education.

1. Pascal/Z Users Group

2. 7962 Center Pky, Sacramento CA 95823

5. The purpose of our

group is to encourage the use of Pascal.

1. 68XX(X) User Group

2. POB 18081, San Jose CA 95158

3. Ray Boaz, (408) 269-9522 5. All 68XX(X) microcomputers and related hardware and software.

1. SYM-1 Users Group

2. POB 315, Chico CA 95927

3. H R Luxenburg, (916) 895-8751

4. SYM-Physis

5. Graphics, voice, music, word processing, and intercomputer communications for the SYM-1.

1. Group/380

2. POB 1131, Mt Shasta CA 96067

3. Mokurai Cherlin

4. Group/380 News

5. IBM 370-compatible microcomputers.

1. The Aloha Computer Club

2. POB 4470, Kailua HI 96734

3. Roger Wickenden, President, (808) 262-4673

4. The Debugga

5. Anything to do with microcomputers.

1. Z80 Microfans—A Sorcerer Users Group

2. POB 12504, Portland OR 97212

3. C Douglas Auburg, Editor, (206) 694-7769, evenings

4. Z80 Microfans Newsletter

5. Special interests: sharing problems, tips, and solutions in the use of the Exidy Sorcerer.

1. Portland Computer Society Inc

2. POB 17371, Portland OR 97217

3. Neal J Bonome, (503) 654-5932

4. Portland Computer Society Newsletter

5. Information exchange for

all types of microcomputers.

1. Salem Area Computer Club

2. POB 7715, Salem OR 97303

3. Kenneth Ernst, (503) 393-1173

4. SACC Newsletter

5. Users groups: Apple, TRS-80, PET, and VisiCalc.

1. Home Computers

2. POB 616, Silverton OR 97381

5. General information on personal computers.

1. Atari Computer Enthusiasts

2. 3662 Vine Maple Dr, Eugene OR 97405

3. M R Dunn, Editor,

4. A.C.E. Newsletter

5. This group is dedicated to the use of Atari microcomputers.

1. Hex Users Group

2. 36012 Military Rd S, Auburn WA 98002

3. Charles Worstell, (206) 927-6038

4. Newsletter on an irregular basis

5. Special interests: 6800 and 6809 small systems.

1. PN HUG (Pacific Northwest Heath Users Group)

2. c/o POB 993, Bellevue WA 98009

3. Jan N Johnsen, (206) 464-5666

VAK-4 16K STATIC RAM BOARD

• Designed specifically for use with the AIM-65, SYM-1, and KIM-1 microcomputers

• Two separately addressable 8K-blocks with write protect.

• Designed for use with the VAK-1 or KIM-4* motherboards

• Has provisions for mounting regulators for use with an unregulated power supply

• Made with 1st quality 2114 static ram chips

• All IC's are socketed

•' Completely assembled, burned-in, and tested We manufacture a complete line of high quality expansion boards. Use reader service card to be added to our mailing list, or U.S. residents send $1.00 (International send $3.00 U.S.) for airmail delivery of our complete catalog. "Product of MOS Technology

VAK-4 DUAL 8K-RAM $Wfc6fr $325.00 plus shipping VAK-2 8K-RAM (Vi populated) $239.00

Special thru 4/30/81 VAK for $299.00

^Jrnb>

ENTERPRISES

INCORPORATED

2951 W. Fairmount Avenue • Phoenix, AZ 85017 • (602) 265-7564 Please note new address

180 April 1981 © BYTE Publications Inc

Circle 122 on inquiry card.

This

printer

costs less

than $450.

Beat that...

if you can.

Epson

This is the Epson MX-70. The lowest priced dot matrix printer you can buy. Now, that in itself should make it very attractive to a lot of people. But you ain't heard the half of it.

To begin with, the MX-70 has a lot more in common with our now-famous MX-80 than just the name. Like unequalled Epson reliability. And technological breakthroughs like the world's first disposable print head. But frankly, the MX-80 packs a lot more power than some people need. So we built the MX-70 to be a no-frills printer. At a no-frills price.

But the MX-70 is still a great little printer. We give you 80 CPS unidirectional printing. Top-of-form recognition. Programmable line feed and form lengths. Plain paper printing. An easy-to-read 5x7 matrix. Self test. And an adjustable tractor feed.

That's what you'd expect

from a basic little printer. But here's something you wouldn't expect: the finest graphics package on the market today. Free.

We call it GRAFTRAX II. And it means 480 dots across the page, resolution to 60 dots per inch, and a graphic image free of the jitter and overlap that plagues other printers. You get cleaner grays and finer point resolution.

So now you've got a choice. You want more power and extra functions, you buy the MX-80. You want a basic little printer that prints, and keeps on printing, you buy the MX-70. They're both at your dealer now.

But at this price, you'd better hurry.

EPSON

EPSON AMERICA, INC.

23844 Hawthome Boulevard • Torrance, California 90505 • (213) 378-2220

Circle 123 on inquiry card.

BYTE April 1981 181

Clubs and Newsletters,

4. Newsletter published every other month

5. Special interests: Heath H-8 and H-89 microcomputers.

1. NW PET Users Group

2. 2565 Dexter N #203, Seattle WA 98109

3. Richard Ball, (206) 284-9417

4. Newsletter

5. PET users group.

1. Apple Puget Sound Program Library Exchange

2. 304 Maine Ave S, Suite 300, Renton WA 98055

3. Dick Hubert, (206) 271-4514

4. Call-A.P.P.LE.

5. Everything related to the Apple II.

1. SPOHUG (Spokane Heath Users Group)

2. RFD #1, Box 676, Spokane WA 99204

3. Charles K Ballinger, President, (509) 448-9727

4. SPOHUG Newsletter

5. Special interests: Heath H-8 and H-89 computers.

Foreign Clubs and Newsletters

1. Computer Education Group of Victoria

2. POB 245, Niddrie, Victoria 3042, Australia

3. Greg Johnstone, (03) 336-1855

4. COM-3

5. Educational uses of computers.

1. Brazilian Microcomputer Club

2. Rua Sambaiba, 516, Leblon, Rio de Janeiro 22450, Brazil

3. Douglas Gilson, 274-2439 5. Special interests: exchanging programs and ideas with other clubs.

1. Apple's British Columbia Computer Society

2. #101-2044 W 3rd Ave, Vancouver, British Columbia, V6J 1L5, Canada

3. Gary Little, (604)

731-7886

4. Applegram

5. Apple II microcomputers.

1. Apple-Can

2. POB 696, Station B, Willowdale, Ontario, M2K 2P9, Canada

3. Louis H Milrad, (416) 961-6691 or 223-0599

4. Yes

5. All areas concerning microcomputers.

1. Association of Computer Experimenters

2. c/o B Murphy, 102 McCraney St, Oakville, Ontario, L6H 1H6, Canada

3. B Murphy, (416) 845-1630

4. Ipso Facto

5. Special interests: CDP 1802 microprocessorbased hobby computers.

1. I-SUG

2. POB 1542, St Catharines, Ontario, L2R 7J9, Canada

5. Interested in Exidy

Sorcerer microcomputers.

1. Kitchener — Waterloo Microcomputer Club

2. Reading Room — E2-3354, Electrical Engineering Department, University of Waterloo, Waterloo, Ontario, N2L 3Gl, Canada

3. Roger Sanderson, work (519) 885-1211, ext 3815

5. Special interests: 6800 and 6809 SwTPC systems.

1. OSMIE (Ontario Society for Microcomputers in Education)

2. Unit for Computer Science, McMaster University, Hamilton, Ontario, L8S 4K1, Canada

3. N Solntseff, (416) 525-9140, ext 4689

5. All educational uses of microcomputers.

1. The Ottawa Computer Group

2. POB 5691, Station F, Ottawa, Ontario, K2C 3M1, Canada

3. John Mainwaring, President, (613) 725-9441; or Dennis Tubie, Secretary, (819) 561-1645

4. OCG Newsletter

5. Special interests: microprocessors and computer bulletin board.

1. TRACE (Toronto Region Association of Computer Enthusiasts)

2. POB 6922, Station A, Toronto, Ontario, M5W 1X6, Canada

3. Ross Cooling, (416) 488-3314

4. TRACE

1. CPE (Central Program Exchange)

2. Department of Computing & Mathematical Sciences, The Polytechnic, Wulfruna St, Wolverhampton, WVI 1LY, England

3. Judith Brown, 0902 27371, ext 93

4. Program Exchange

5. Microcomputer usage in schools and educational computer-aided learning.

1. North London Hobby Computer Club

2. c/o D.E.C.E. Polytechnic of North London, Holloway Rd, London N7 8DB, England

3. Robin Bradbeer, 01-607-2789

4. Gigo

5. Special interests: business, homebrew, and games workshops. PET users group.

1. Microtel—Club

2. 9, rue Huysmans 75006 Paris, France

3. M Perdrillat, 33 (1) 544 70 23

4. Microtel-Infos

5. This group is interested in microcomputers and telecommunications.

Bower-Stewart Si Associates

SOFTWARE AND HARDWARE DESIGN

$GOLD DISK$ CP/M Compatible Z-80 Software

Available for all 8-5" SS-SD IBM format systems including TRS-80®, Northstar, SD Systems. Also available on 5" double density Superbrain."

$175.

ppd

Un-can your canned software!

Z-80 Disassembler Feel couped up with your canned software? Our Z-80 Disassembler recreates assembly language source files from absolute code enabling users to easily tailor programs to meet their specific needs. The Preconditioner works with the Disassembler to decode ASCII.

Credit cards Immediate service, free 24 hr phone - we will credit invoice Checks. M.O.'s: Ten workday hold CA res Add tax

$50.

ppd

^B -^g

Great looking letters & reports!

E-Z Text A unique word processor organized around user-created text files, embellished with simple control commands, which supports such 'BIG GUYS' features as Automatic Footnoting, Table Spacing, Heading, Paging, Left & Right Margins, Proportional Spacing and MORE, at a 'LITTLE GUYS' price tag.

State system & controller Allow time for surface mail Trademarks Digital Research. Radio Shack. Intertec

POST OFFICE BOX 1389 HAWTHORNE, CALIFORNIA 90250 213 / 676-5055

182 April 1981 © BYTE Publications Inc

Circle 124 on inquiry card.

The PRACTICAL MICROCOMPUTER PROGRAMMING™ books. .

WHAT DO THE CRITICS SAY?

BYTE: "It was apparently Mr. Welter's goal from the beginning to present the fundamental concepts of assembly language programming in a completely nonthreatening way. He has accomplished this better than any other author to date.. . Practical Microcomputer Programming is a very powerful series. It is well written and full of essential techniques for the assembly language programmer.".. . "The authors know the difference between a novice and a ninny. They never talk down... on every page the authors spot and clear up the small ambiguities of technical jargon that can block understanding."

Kilobaud: "A powerful plus for this book is the author's determination to demonstrate why and how to use each instruction, not merely to explain how it works. . .At no point do the authors resort to rehashing material available from the manufacturer. .. but instead choose a less theoretical, more practical approach."

Leventhal:

pies, and topics."

". . .large numbers of documented, well structured exama clear readable style, a logical development of major

Digital Design: "This book is the best and most lucid introduction to Z80 programming that we have seen."

CACHE: "This is an EXCELLENT book.. .dirt cheap for such great software and documentation."

IF YOU'VE TRIED THE "CHEAPIES" AND AREN'T SATISFIED WITH WHAT YOU GOT, IT'S TIME TO TRY THE REAL THING, THE ACKNOWLEDGED WORLD STANDARD OF TECHNICAL EXCELLENCE IN ASSEMBLY LANGUAGE PROGRAMMING INSTRUCTION—THE PRACTICAL MICROCOMPUTER PROGRAMMING BOOKS.

- FOR THE 6502 ■ PRACTICAL MICROCOMPUTER PROGRAMMING: THE 6502 toy W. J. Weller $32.95

20 chapters, 6 appendices, 475 page Smythe sewn hardcover covering all fundamental assembly language techniques for the 6502 processor. The text explanation is re-enforced with 118 verified, real world programming examples that run on real computers. An extended 6502 language, supported by a new editor/assembler which comes with the book, circumvents many of the problems which have made the 6502 so difficult to program in the past. In addition to the fundamental technique chapters, there are special chapters covering simple graphics, elementary cryptography and random number generation and use. The source texts of both the editor/assembler and a powerful new debugging monitor for the Apple II and Apple II + included in appendices. The object code for this software is supplied FREE to book purchasers on Apple cassette or for $7.50 on disk when the licensing agreement from the book is returned to the publisher. The editor/assembler is also available on paper tape for users of other 6502 based systems.

- FORTHEZ80PRACTICAL MICROCOMPUTER PROGRAMMING: THEZ80 toy W.J. Weller $32.95

18 chapters, 4 appendices, 481 page Smythe sewn hardcover which details assembly language technique as applied to the Z80processor. The Z80 is treated as an 8080 superset in an 8080 extension language, which means that you don't have to discard your hard won 8080 knowledge to program the 180. In addition to the fundamental chapters there are chapters on graphic output and full four function decimal arithmetic. The text explanation is re-enforced with 104 tested, verified programming examples. A powerful editor/assembler and debugging monitor, in source form, are provided to support the language used in the book. This software will run on any 280 based computer with 10K RAM beginning at 0. Object code for both editor/assembler and debugging monitor is sent to book purchasers FREE on paper tape or, in modified form, on TRS-80 Level II cassette when the coupon from the book is returned to the publisher.

■ FOR THE 8080 PRACTICAL MICROCOMPUTER PROGRAMMING: THE INTEL 8080 toy Weller, Shatzel and Nice $23.95

18 chapters, 3 appendices, 318 page Smythe sewn hardcover which applies fundamental assembly language technique to this most popular of processors. The text is supported by 84 separate programming examples. The book includes a special section on the handling of complex peripheral devices and exotic typefaces. Appendices give the source for an 8080 resident debugging monitor and a minicomputer cross assembler for the 8080. Also available (not shown above) are a workbook for use with this text ($9.95) and Mi EDITOR/ASSEMBLER SYSTEM FOR 8080/8085 BASED COMPUTERS ($15.95) which supports the language used in the text. These three books together make a complete teaching package for the 8080.

• FOR THE 6800 ■ PRACTICAL MICROCOMPUTER PROGRAMMING: THE M6800 toy W.J. Weller $23.95

16 chapters, 2 appendices, 299 page Smythe sewn hardcover text which details the application of fundamental assembly language technique to the 6800. 104 separate programming examples re-enforce the text explanation. Contains in addition special chapters on low precision trigonometry and random number generation and use. A resident debugging monitor for 6800 systems is included in an appendix.

NO GAMES, NO NONSENSE, NO RE- | PRODUCTIONS OR REHASHES OF | MANUFACTURER'S DATA SHEETS, | JUST TESTED, ACCURATE, RELE- | VANT PROGRAMMING INFORMA- | TION BACKED UP BY REAL EXAMP- | LES THAT RUN ON REAL COMPUT- | ERS-THE PRACTICAL MICROCOM- | PUTER PROGRAMMING BOOKS, i THERE IS NOTHING ELSE AS GOOD i ANYWHERE, AT ANY PRICE.

Mail to: Northern Technology Books, Box 62, Evanston, IL 60204

□ Practical Microcomputer Programming: The 6502

□ Practical Microcomputer Programming: TheZ80

□ Practical Microcomputer Programming: The Intel 8080

□ Practical Microcomputer Programming: The M6800 D Workbook for Practical Microcomputer Programming: The Intel 8080

□ An Editor/Assembler System for 8080/8085 Based Computers

$32.95 $32.95 $23.95 $23.95 $ 9.95 $15.95

D Check enclosed (U.S. funds only)

Name

Street

City

D Money order enclosed

. State

-Zip

Illinois residents add 5% sales tax

The time has come for computers to talk and listen

^

Introducing COGNIVOX series VIO, the affordable voice I/O peripherals

If you have a

PET - TRS-80 - APPLE II AIM 65 - SORCERER

or any Z-80 CPU based system with at least 16K ol RAM, COGNIVOX will add a whole new dimension to your computer.

Imagine being able to use your voice for entry of commands and data and then listen to the computer talk back to you! This exciting possibility has now become a reality at a very affordable price.

COGNI VOX. series VIO, is a family ol voice input and output peripherals especially designed for personal computers that are easy to use and have excellent software support. You need only plug in COGNIVOX, load one ol the programs provided and you will be able to have a voice encounter with your computer1

COGNIVOX can be trained to recognize words or short phrases from a vocabulary of up to 32 entries of your choice, with an accuracy of up lo 98%. The voice response vocabulary can also have up to 32 entries chosen by the user. COGNIVOX requires that your computer has at least 16K of RAM. If it has less memory or if you are only interested in recognition, ask us about our SR-100 series of voice input peripherals

COGNIVOX comes complete with microphone, power supply, (as required), built-in amplifier/speaker and extensive user manual. What makes COGNIVOX truly unique, though, is the software that comes with it on cassette. Some of the programs included are: DIALOG, a program that lets you conduct a dialog with your computer (or translate from one language to the other); VDUMP, a vocal memory dump that reads the memory contents out loud; VOTH, a voice operated talking board game and VOICETRAP, a voice operated video game.

Adding voice I/O to your own programs can be done very easily too. All that is needed to have your computer recognize a word or say a word is a single USR statement in BASIC. No machine language programming is necessary.

With all these features, you'd expect COGNIVOX to cost a small fortune (after all, even talking chess games sell for over $300), yet it only costs $149 (add $4.50 fcr shipping in the U.S., 10% ol order overseas. CA res. add 6% tax). This low price has been made possible by innovative hardware and a technological breakthrough in recognition algorithm design that uses powerful non-linear pattern matching techniques and adaptive learning.

COGNIVOX is simply the most (un, most exotic peripheral you can buy for your computer. Write or call (805) 685-1854 for more information. giving us the make and model of your computer Or better yet. order a COGNIVOX today and bring your computer to life.

VOICETEK

Dept B, P.O. Box 388 Goleta, CA 93116

Clubs and Newsletters,

1. Japan Microcomputer Club

2. Rm 313, 3-5-8, Shibakoen, Minato-Ku, Tokyo 105, Japan

3. Keigo Aono, Director 03-438-1869

4. Microcomputer Circular

5. This is the largest, nonprofit, nationwide group in Japan. An English-language version of the club's newsletter is available.

Microcomputer Club

Fte de Quijote §5,

Tecamachalco, Mexico

10-D F, Mexico

Alfredo Buzali, (905)

589-2279

Bulletin

Primarily concerned with

the Apple computer.

1. HCC (Hobby Computer Club)

2. Christinastraat 171, 5 615 RK Eindhoven, Netherlands

4. Hobby Computer Club Nieuwsbrief

5. The goals of the HCC are to increase contacts between computer amateurs and to exchange ideas and experiences.

1. Club de Computation Lampas de Carabobo

2. Apartado 716, Valencia, Venezuela 2001A, Venezuela

5. Use of microcomputers in civil engineering, basic sciences, and administration. ■

A

nswers to

Micro

Shakespeare Quiz

1 -m

2-j 3 -a 4-f 5-h

6 7

8

9 10

0

b

q

l

s

11 -i 16 -e

12 - c 17 - t

13 - r 18 - k

14 - g 19 - n

15 - p 20 - d

Number of Correct Matches

MicroShakespeare Rating

20

Hit "START" with confidence.

17- 19

One short debug session and you're home free.

13 - 16

Check your system monitor.

9-12

Must have mixed up the pinouts.

5 -8

Blame it on a power surge.

4 or fewer

Back to collecting stamps.■

184 April 1981 © BYTE Publications Inc

Circle 14 on inquiry card.

SOLVE THE STORAGE

SHORTAGE

with ten multi-user megabytes

CompuStar's 8-inch Winchester

CompuStar Cable Assembly

If you could think of just one way to improve our phenomenally popular SuperBrain, what would it be? More disk storage? Well, we already thought about it. And for only a few thousand dollars for a whopping 10 megabytes of lightningfast storage, it's nothing short of another major breakthrough! From the company that wrote the book on price/performance . . . Intertec.

Our New CompuStar™ 10 Megabyte Disk Storage System (called a DSS) features an 8 inch Winchester drive packaged in an attractive, compact desktop enclosure. Complete with disk, controller and power supply. Just plug it into the Z80 adaptor of your SuperBrain and turn it on." It's so quiet, you'll hardly know it's there. But, you'll quickly be astounded with its awesome power and amazing speed.

'Some models require hardware/software modification.

The secret behind our CompuStar DSS is its unique controller/multiplexor. It allows many terminals to "share" the resources of a single disk. So, not only can you use the DSS with your SuperBrain, you can configure multiple user stations using our new series of CompuStar™ terminals, called Video Processing Units or VPU's™.

Four CompuStar VPU's are available. At prices starting at less than $2,500. Some models are designed to operate as stand-alone microcomputers, with internal disk storage. Just like your SuperBrain. Each model features its own 64K of RAM and can be "daisy-chained" into a powerful multi-user network. Just connect one VPU into the next. Using easy-toinstall cable assemblies. Connect up to 255 users in a single system. One at a time. As you need them.

Whether you need an extra 10 megabytes for your SuperBrain or an enormous multi-user network, the CompuStar™ DSS solves your storage shortage problems. Sensibly. And economically. Plus, your investment is protected by a nationwide service network with outlets in most major U.S. cities. Providing efficient on-site or depot maintenance.

Get a demonstration of this extraordinary new system today. Call or write now for the name and address of your nearest CompuStar dealer.

j= INTERTEC

Cdata s systems.

2300 Broad River Rd. Columbia. S.C. 29210 (803) 798-9100 TWX: 810-666-2115

THE EGYPTIANS LOVED LARGE NUMBERS, AND...

ts

THE GREEK-5CAME UP WITH A WHOLE 5ET OF VARIABLES:

THE ALPHABET loo^zoei/) (wov?)j

PEOPLE COULD NOW HAVE A HARD COPY OF ANYTHING. IT WAS EVEN USED BY OUR

FOUNDING FATHERS.

BUT WHEN REPLACING TUBES BECAME MORE COSTLY THAN THE FIGURING WAS WORTH, SOLID STATE TECHNOLOGY TOOK OVER. SO INSTEAD OF MASSIVE COMPUTERS FILLING UP AN ENTIRE FLOOR,THEY WERE BUILT TINY. ABOUT THE SIZE OF A REFRIGERATOR.

FINALLY CAME THE

IN VENT I ON OF THE

MICRO- PROCESSOR!

BACK IN PRE-HISTORIC TIME55CAVEMEN DID ALL THEIR FIGURING ON THEIR FINGERS. BUT THE ONLY TROUBLE WAS 10 WAS AS HIGH AS THEY COULD COUNT

LET5 5E£ WOW. TWEy/M »s...UH,HMM .W/ELL.ITMuoTBE 10 *

SO THEY INVENTED A CRUDE ADDING MACHINE

COUNTING REMAINED THAT WAY UNTIL SOME GREAT SUMERIAN DISCOVERED THAT NUMBERS] CAN EXIST HIGHER THAN lO.

IT EVEN HAD ITS OWN SET OF GRAPHIC CHARACTERS.

AS TIME PROGRESSED 50 DID MAN'S NEED FOR I EVEN MORE COMPLICATED)

NUMBER WORK.

o,

THE CHINESE PUT IT TO IMMEDIATE (J5E

THEN PASCAL INVENTED THE BUILT IN POWER SUPPLY.

WITH THAT, THE FIRST TRUE DIGITAL C0MPUTER5 WERE BUILT. THEY WERE GIANT AND USED MILLIONS OF TUBES.

G-UTENBERG INVENTED THE F/R5T MOVABLE PRINT. HEAD

- OO 0 0 0 o

o o 0 o a o

0 0 O 0 0 4

% % \\f %

rare

#88®

DESPITE THEIR SMALL SIZE, THEY STILL WERE

NOT QUITE SMALL ENOUGH

--FOR HOME USE.

GET THAT TWINS Ol/T OF M* HoWE'

WHICH MADE IT POSSIBLE -H FOR MICRO-SIZE COMPUTERS WflWi/jniH»«n///fJ»||| f|| "

AND NOW OUR 5MALL

PORTABLE COMPUTERS

ARE THOUSANDS OF TIMES

MORE POWERFUL AMD C05TT

THOUSANDS OF TIMES LESS.

r—^

* FACT: BfN FRANKLIN COINED THE ELECTRICAL TEftMJ "POSITIVE AND N64ATIVE''

30 NOW IT IS EASIER THAN EVER TO WRITE A COMPLICATED PRO&Ri

186 April 1981 © BYTE Publications Inc

Circle 127 on inquiry card.

Orange micro

CENTRONICS 737 (

RADIO SHACK \ LINE PRINTER IV )

Word Processing Print Quality

• 18 x 9 dot matrix; suitable tor word processing • Underlining • proportional spacing • right margin justification • serif typeface • 50/80 CPS • 9V2" Pin Feed/Friction feed • Reverse Platen • 80/132 columns

CENTRONICS 737-1 (List $995) $765

CENTRONICS737-3 (List $1045) $815

EPSON MX80

I

Low-Priced Professional Print Quality

• 9 x 9 dot matrix • Lower case descenders

• 80 CPS • Bidirectional, Logic seeking • 40,66, 80,132 columns per line • 64 special graphic characters: TRS-80 Compatible • Forms handling • Multi-pass printing • adjustable tractors

EPSON MX80 EPSON MX70

.(List $645) .(List $495)

OKIDATA MICROLINE SERIES

TRS-80 Graphics Compatibility

• 9 x 7 dot matrix • 80 CPS • 80, 132 columns — 64 shapes for charts, graphs & diagrams • Double wide characters • 6/8 lines per inch • Up to 3 part copy • Friction & pin feed • 200 M character head warranty

OKIDATA MICROLINE 80 (List $800) $520

OKIDATA M82 Bidirectional, Forms handling (List $960) $750

OKIDATA M83 Wide carriage, 9 x 9 dot matrix (List $1260) Scall

IDS PAPER TIGERS

Dot Resolution Graphics, quality print

• 7 wire printhead (445); 9 wire printhead (460) with lower case descenders • Over 150 CPS • bi-directional, logic seeking (460) • 8 character sizes; 80-132 columns

• Adjustable tractors • High-resolution dot graphics • Proportional spacing & text justification (460).

IDS445G 7 wire printhead, graphics (List $895)

IDS460G9wire printhead, graphics (List $1394)

$ 795 $1150

CALL FOR FREE CATALOG

(800) 854-8275

CA,AK, HI (714) 630-3322

At Orange Micro, we try to fit the right printer to your application. Call our printer specialists for free consultation.

'SPECIALIZING IN PRINTERS AND CRT'S"

VISTA — C. ITOH

Daisy Wheel Letter Quality

• 25 CPS (Optional 45 CPS) • Typewriter quality • Centronics parallel • RS 232 Serial (Optional) • Proportional spacing • Bidirectional • Programmable VFU • Self test • Diablo compatible • Friction feed (Optional tractors) • 136 printable columns. • Manufactured by C. ITOH.

VISTA V300 (C. ITOH) (List $1895) $ Call

ANACOM

Low Cost, High Speed, Wide Carriage

• 9 x 9 dot matrix • Lower case descenders • Wide carriage • Adjustable tractors to 16" • 150 CPS, Bidirectional, Logic Seeking

ANACOM 150 (List $1350) S Call

ANADEX

Dot Graphics, Wide Carriage

• 11 x9dot matrix; lower case descenders • Dot resolution graphics

• Bi-directional, logic seeking • Up to 200 CPS • RS 232 Serial & Parallel • Forms control • X-ON/X-OFF* Up to 6 part copy. ANADEX9501 (List$1650) $1450

NEC SPINWRITER

High Speed Letter Quality

• 55 CPS • Typewriter quality • Bidirectional • Plotting • proportional spacing.

5510-5 RO, Serial, w/tractors (List $2995) $2625

5530-5 RO, Parallel, w/tractors (List $2970) $2599

QUANTITY PRICING AVAILABLE

TELEVIDEO CRT'S

PRICES SLASHED!

TVI912C TVI920C TVI 950

}

Please Call Toll Free Prices are too low to advertise

PRINTERS

MALIBU 165 wide carriage, graphics, letter quality .. (List $2495) $1975 QUME 5/45 typewriter quality (List $2905) $ 2559

INTERFACE EQUIPMENT

CCS APPLE PARALLEL Interface & cable $ 150 |

APPLE II- EPSON MX80

parallel graphics intertace board & cable $ 110

SSMAIO BOARD Apple Serial/parallel interface (List $225)$ 175

MICROTRONICS Atari parallel interface $ 69 I

ATARI 850 Interface module, serial/parallel $ 199

TRS-80 CABLES to keyboard or Exp. interface * Ca"

NOVATION D-CAT direct connect modem $ Call

TELEPHONE ORDERS: Mon.-Fri. 8:30 - 5:00

The Orange Micro Printer Store (Retail):

Mon. -Fri. 10:00 - 6:00, Sat. til 4:00

*Ss

Phone orders WELCOME; same day shipment. Free use of VISA & MASTERCARD. Personal checks require 2 weeks to clear. Manufacturer's warranty included on all equipment. Prices subject to revision.

Oronge

fTlfCrO, Inc.'

3148 E. La Palma, Suite E Anaheim, CA 92806

Software Review

Three Versions of APL

Gregg Williams, Senior Editor

BYTE POB 372

Hancock NH 03449

When BYTE magazine published its APL language issue in August 1977, APL was far beyond the capabilities of any microcomputer. To show how rapidly things have evolved since then, the Digital Group, in that same issue, was advertising a 32 K-byte static-memory board for $995, and another advertisement began, "Introducing Apple II...." Times have changed: 32 K bytes of dynamic memory, now commonly used in several major microcomputer lines, can be bought for less than $120—and Apple is one of the oldest computer lines in the industry.

Times have changed for APL as well: several companies have announced software and hardware supporting this unique programming language. This review compares three versions of APL: Softronics APL, Ramware APL80 for the Radio Shack TRS-80, and Vanguard APL/V80. (For additional information, see the "At a Glance" boxes. Tables 1 thru 4 give timing comparisons and further information.)

Softronics APL: I/O Options and Documentation

Softronics APL runs on any Z80-based computer that supports at least 44 K bytes of memory and the CP/M operating system. It was written by Eric Mueller of Softronics, who, in 1977, authored a subset of APL called EMPL for 8080-based microcomputers. Softronics APL (Version 2.3C), which sells for $350, has both good and bad features; a summary is given in table 2.

The most welcome feature of Softronics APL is the ability to use it with several types of keyboards and display devices. The default mode of operation is for the software to respond to a standard ASCII (American Standard Code for Information Interchange) terminal through standard CP/M input and output routines. Three other modes allow the user to use an assortment of APL-type devices.

For those of us who do not have several thousand extra dollars to spend on an APL-type I/O (input/output) device, the ASCII mode of Softronics APL is very welcome. In this mode, all APL characters that are not on a normal keyboard are replaced by either a single key (eg: an underline character to replace the APL assignment arrow) or a 3-character mnemonic (eg: $TP for the transpose operator or $RO for the Greek rho symbol). Although some users object to this arrangement, my reaction to running Xerox APL for an extended period, using such mnemonics, was one of gratitude—better this

APL than no APL at all.

Listing 6 shows the output of the APL function CIRCLE. Listing 3a shows the output with slight changes in regular APL notation. I have also found that by changing the value of the system variable DCS, you can cause the APL mnemonics to be displayed with angle brackets around them instead of the preceding dollar signs—on printout only (ie: not input). For example, you will still have to type in $RO for the APL reshape operator, but it will be displayed to the screen or printer as < RO> . This is a nice feature that adds to the readability of APL programs printed in ASCII mode.

Provisions are also made for using Softronics APL with the two most prevalent types of APL terminals (bitpairing and typewriter-pairing terminals). Softronics APL begins executing in the ASCII mode but can be converted to APL terminal mode by assigning a new value to the system variable DCS, or it can be modified to begin executing in terminal mode by making a 1-byte patch to the APL.COM machine-language file. Nonstandard terminals or video boards can be interfaced by adding usersupplied input and output machine-language subroutines. The manual explains what routines need to be written and where they should be placed in memory.

Finally, the manual gives documentation on still another I/O option: the use of APL input and output through a video board with a programmable character generator. The documentation includes the software driver (which works with an Objective Design Inc character generator), a Kent-Moore Alpha-VDM-II video display board, and a listing that defines all APL special characters for a character generator as a series of hexadecimal numbers. All this code is included in the APL.COM file.

The ease with which I understood these four display options is an indication of the quality of the documentation. The Softronics APL documentation is the best of the three packages reviewed here. It includes a short tutorial on APL for the complete novice, a description of all functions, sample programs (including APL defined functions that simulate certain APL operators not defined in machine language), and several useful appendices. One section of the documentation, "Bugs and Common Perplexing Error Messages," is a great time saver. It is extremely helpful in explaining some quirks of Softronics APL and how to circumvent them. This section saves the user from

188 April 1981 © BYTE Publications Inc

Circle 128 on inquiry card.

The VP-111 hobby computer: Start programming for only $99.

$99.

New! VP-111 Microcomputer Assembled* and tested.

Features:

• RCA 1802 Microprocessor.

• 1K Bytes static RAM. Expandable on-board to 4K. Expandable to 32K Bytes total.

• 512 Byte ROM operating system.

• CHIP-8 interpretive language or machine language programmable.

• Hexidecimal keypad.

• Audio tone generator.

• Single 5-volt operation.

• Video output to monitor or modulator.

• Cassette interface—100 Bytes/sec.

• Instruction Manual with 5 video game

listings, schematics, CHIP-8, much more!

Ideal for low-cost control applications.

Expandable to full VP-711 capability with

VP-114Kit.

'User need only connect cables (included), a

5-volt power supply and speaker.

*199.

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95

20

15

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O VP-601 Keyboard—128-character ASCII

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Asynchronous serial output $ 99

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□ VP-616 Keyboard—Same as VP-606 plus 16-key numeric keypad $119

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D VP-3303 Interactive Data Terminal

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« Enclosed is $_

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spending quite a bit of time swearing that the language "just doesn't work right."

SofIronies APL: Some Problems

Despite its excellent performance in other areas, Softronics APL (Version 2.3C) has a number of deficiencies that range from minor annoyances to critical defects. The most serious defect is that Softronics APL does not notify the user of an error situation. Any computation that has a result over 9.2 X1018 is replaced by a seemingly random value between 1018 and 1019. The low limit on computation size is not what makes this error dangerous; rather, the danger lies in the language substituting an inaccurate answer and not stopping the computation with an error message.

A second problem with Softronics APL is that it responds with the message SYNTAX ERROR to any number over 7 digits long. I feel that the inability of this language to accept a longer number by rounding it off and, when necessary, putting it into scientific notation is a serious defect.

Many numeric operations that should come out "even" result in numbers ending in ...9999 or ...9997. For example, any variable assigned either the value 0.1 or 1/10 is printed as .099999. The dyadic power function has, for integral exponents, a cumulative round-off error that results in some incorrect answers. For example, 5s is calculated to be 390,622 (it is 390,625) and 312 is calculated to be 531,436 (it is 531,441), with higher powers also being incorrect.

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WHEN ORDERING SPECIFY DISK OR TAPE

SCIENTIFIC ENGINEERING LABORATORIES

11 Neil Drive • Old Bethpage, NY 11804 Telephone: (516) 694-3205

'Trademark of Tandy Corp.

There is no affiliation between Scientific Engineering Laboratories and

Tandy Corp. or Radio Shack.

When using the power function for fractional powers, such as square roots, the results seem to be one or two units off in the least significant digit. Even though 6 significant digits are given in all calculations, I would recommend using only 5 significant digits when using the dyadic power function to calculate a root.

The trigonometric functions, such as sine, cosine, tangent, and arctangent, agree with the results found in the Chemical Rubber Company's CRC Standard Mathematical Tables. However, the arctangent function seems to work with a scalar (ie: a single value) but not with a vector (ie: a one-dimensional array of values).

Softronics APL still lacks several useful functions that are found in the more expensive Vanguard APL: arccosine, arctangent, and all hyperbolic trigonometric functions; rotation on three-dimensional and higher matrices; the grade-up and grade-down functions; and the deal (ie: dyadic question-mark) function. Other,

Name

Language Used

Softronics APL, Version

8080 machine language

2.3C

Computer Needed

Type of Software

An 8080-, 8085-, or

Package

Z80-based computer with

Version of APL program

at least 44 K bytes of

ming language

programmable memory,

running the CP/M

Manufacturer

operating system

Softronics, 35 Homestead

Ln, Roosevelt NJ 08555

Documentation

112 pages, 22 by 28 cm

Price

ifiVi by 11 inches)

$350

Audience

Format

APL users, programming

8-inch standard CP/M

language enthusiasts

floppy disk

Name

Computer Needed

APL80 (by Phelps Gates)

Radio Shack TRS-80

Model I with one floppy

Type of Software

disk drive, Level II

Package

BASIC, and 32 K bytes

Version of APL program

of memory

ming language

Documentation

Manufacturer

Twenty pages, 13 by 20

Ramware, 6 South St,

cm (5 by 73A inches)

Milford NH 03055 (603)

673-5144

Audience

APL users, programming

Price

language enthusiasts

$39.95

Comments

Format

Cassette-tape version

5-inch floppy disk

with 25% fewer features

available for 16 K

Language Used

TRS-80 at $14.95

Z80 machine language

190 April 1981 © BYTE Publications Inc

Circle 129 on inquiry card.

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Circle 96 on inquiry card.

more advanced operators that are also missing are not mentioned here. See table 2 for a more complete definition of the language.

Ramware APL80

In its version of APL for the Radio Shack TRS-80 Model I, Ramware of Milford, New Hampshire, has made available a remarkable product. When I first saw the advertisements for the tape version of APL80, its low price ($14.95) led me to dismiss it as some kind of toy, probably written in BASIC and too slow to be useful. Even though the tape version has about 25% fewer features than the more expensive disk version ($39.95), it is still written in Z80 machine language and is a fairly usable version of the language. Author Phelps Gates has reason to be proud of this package.

Table 3 lists the operators available within APL80. The fullness of the language is due to the use of the ROM (read-only memory) modules implementing Level II BASIC. Because the author was able to use the numerical routines from Level II BASIC, much of the work of creating an entire programming language had been done for him, and he could concentrate on making it behave like APL. (APL80 has been tested and found to work on the newer TRS-80s that have Level II BASIC in two rather than three ROM devices. Until a correction can be made to the current version of APL80, however, the down-arrow symbol used for the APL drop and gradedown operations must be displayed by simultaneously Text continued on page 196

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Name of System

Features

Vanguard APL/DTC

APL/ASCII keyboard

(desk-top computer)

and 12-inch APL/ASCII

memory-mapped video

Manufacturer

display of twenty-four

Vanguard Systems Cor

80-character lines housed

poration, 6812 San

in separate video terminal

Pedro, San Antonio TX

enclosure; display of all

78216 (512) 828-0554

APL characters

Price

Software Included

$7995

CP/M operating system,

APL/DTC software

Terminal Dimensions

32 by 45.5 by 53.5 cm

Hardware Options

(12 Vi by 18 by 21

Communications option

inches)

(Hayes Microcomputer

Products Micromodem

Computer Dimensions

plus special software);

19 by 51 by 43 cm {7V%

high-resolution

by 20 by 17 inches)

(256-by-240 black-and

white or 128-by-120

Processor

sixteen-gray-level)

Z80, 8-bit

graphics; letter-quality

APL/ASCII printer, real

System Clock Frequency

time clock.

4 MHz

Software Options

Memory

APL * PLUS file system

80 K bytes of static

simulator

memory (34 K bytes left

for APL workspace)

Audience

APL users, programming

Mass Storage

language enthusiasts

Two quad-density 5-inch

floppy-disk drives

Name

mable memory; a Z80

Vanguard APL/V80

processor card; at least

one floppy-disk drive

Type of Software

Package

Documentation

Version of APL program

Seventy-six pages, 22 by

ming language

28 cm (8V2 by 11 inches)

Manufacturer

Audience

Vanguard Systems Cor

APL users, programming

poration, 6812 San

language enthusiasts

Pedro, San Antonio TX

78216 (512) 828-0554

Features

APL defined functions

Price

(programs) simulate some

$500

APL functions, APL *

PLUS file system, and

Format

other functions

CP/M or CDOS

operating system, 5-inch

Comments

or 8-inch disk

This version is identical

to the software reported

Language Used

on for the APL/DTC

Z80 machine language

computer, except for the

reduced workspace size

Computer Needed

and the availability of the

Computers with at least

inner product function as

48 K bytes of program

a defined function.

192 April 1981 © BYTE Publications Inc

Circle 130 on inquiry card.

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Listing 1: Listing of the APL function SETUP. This routine defines certain variables used in the execution of benchmark programs.

V SETUP [10] A-i-10 lOpilOO [20] B*M [30] OlOxloiM [40] D+-A*(°2)ilOQ [50] E+llO

[60] F+-1000 365 24 60 60 [70] RA^,A [80] RB+.B [90] M3D<-2 5 lOpRA V

Listing 2: Listing of the APL function TIME. When this routine is used as a benchmark program, the function to be tested replaces each occurrence of the phrase (EXP) on lines 10 thru 60. (See table 1.)

V TIME N;LP [10] LP+0 [20] BGN-.(EXP) [30] (EXP) [40] (EXP) [50] (EXP) [60] (EXP)

[70] ^(N>LP^LP+1)/B0N [80] 'DONE ';/Jx5;' TIMES' [90] 'UNIT TIME IS '; (4ffx5)x[];

1 SECONDS PER ITERATION' V

Listing 3: Listing and sample execution of the APL function CIRCLE. Listing 3a shows the function, which has the purpose of adding a set value to all matrix elements that fall within an imaginary circle with a given center and radius. Listing 3b shows a 10 by 10 array filled with zeros and, below it, the same circle after execution of the statement B—(6 5 4 8) CIRCLE A. On one of the printers used to generate these listings, the backarrow character, —, appears as an underscore,

VB+-AR CIRCLE A ;RD;ROW;COL [10] AR CONTAINS: ROW COORD, COL COORD, RADIUS, VALUE ADDED [20] B^A

[30] BCW*-/!fl[l]-/lJ?[3] + l [40] NEXTROW: ROWi-ROW+1 [50] CO/>vli?[2]-/«?[3] + l [60] NEXTCOL: C0L*C0L-H

[70] ->(ARl3~]<(((ROW-ARlll)*2) + (COL+ARL2'})*2)*Q.5'i/ENDLP [80] BlROW;COL1*BLROW,C0L]+/lfl[4] [90] ENDLP:-+(COL<ARl2~]+ARt3l)/NEXTCOL [100] ->-(0,NEXTROW)[l+ROW<ARlll+ARl3HV

0

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5

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CIRCLE

A

B

0

0

0

0

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0

8

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8

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8

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8

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8

8

8

8

8

8

8

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8

8

8

8

8

8

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194 April 1981 © BYTE Publications Inc

Circle 131 on inquiry card.

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Listing 4: Listing and sample execution of the APL function TRANS. Listing 4a shows the function, which translates a numeric array similar to the one in listing 3b to a character array that reflects the contents of the numeric array. Listing 4b shows the result of executing TRANS B, where B is the matrix in the lower half of listing 3b.

1B*-TRANS A ;AA ;MX ;MN ;MAXX; CHAR

[10] CHAR+-'LMNOPQRSWVWX¥Z-123UttlB<3ABCDEF+*#'

[20] MN*-L/AA*-,A

[30] MXH/AA

[40] UAXXHMX[-MN)ilb

[50] AM.0.5tl6+AH*iU2

[60] BHpA)pCHAR\_AA] V

—FFFFF

-FFFFFFF— -FFFFFFF— FFFFFFFFF-FFFFFFF— -FFFFFFF— —FFFFF

Listing 5: Listing of the APL function IVER. This function, written by Kenneth Iverson (the inventor of APL), will generate a vector of all prime numbers up to and including the scalar A. (A must be greater than or equal to 7.)

V B*-IVER A

B«-(2=+/<90 = (i/4)°.| \A)/\A V

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*1k

I Calculate odds on HORSE RACES with ANY COMPU TER using BASIC.

I SCIENTIFICALLY DERIVED SYSTEM really works. TV Station WLKY of Louisville. Kentucky used this sytem to predict the odds of the 1980 Kentucky Derby See the Wall Street Journal (June 6. 1980) article on Horse-Handicapping. This system was written and used by computer experts and is now being made available to home computer owners. This method is based on storing data from a large number of races on a high speed, large scale computer 23 factors taken from the "Daily Racing Form" were then analyzed by the computer to see how they influenced race results. From these 23 factors, ten were found to be the most vital in determining winners NUMERICAL PROBABILITIES ol each of these 10 factors were then computed and this forms the basis of this REVOLUTIONARY NEW PROGRAM

I SIMPLE TO USE: Obtain "Daily Racing Form" the day before the races and answer the 10 questions about each horse. Run the program and your computer will print out the odds for all horses in each race. COMPUTER POWER gives you the advantage!

I YOU GET: f) TRS-80 (Level II) or Apple Cassette

2) Listing of BASIC program for use with any computer

3) Instructions on how to get the needed data from the "Daily Racing Form"

4) Tips on using the odds generated by the program.

5) Sample form to simplify entering data for each race

MAIL COUPON OR CALL TODAY

3G COMPANY, INC. DEPT. BT (503)357-9889 RT. 3, BOX 28A, GASTON, OR 97119

Yes. I want to use my computer for FUN and PROFIT Please send me programs

at $24.95 each. ^gm

I need a □ TRS-80 Cassette or G Apple Cassette. ^P'

Enclosed is: n check or money order □ Master Charge □ Visa

Card No. NAME

Exp. date

ADDRESS. CITY

START USING YOUR COMPUTER FOR

FUN and PROFIT!

Listing 6: Listing of the APL function CIRCLE as generated by Softronics APL using a non-APL video terminal. APL functions can be printed on a standard printer through the use of mnemonic phrases, which begin with a $ sign. The backarrow appears here as an underscore.

[i]

[2] [3] [4]

[5] [6] [7]

[a]

[9] [10]

[11] [12]

SDL B_AR CIRCLE 5LP

A;RD;ROW;COL

AR CONTAINS: ROW £, COL COORD, RADIUS, VALUE ADDED

(EG: (6 5 4 9) CIRCLE VALUE 9 AND RADIUS 4,

A ADDS TO ARRAY A CIRCLE OF WITH CENTER AT (6,5))

5LP SLP SLP 5 LP B_A

ROW_AR[1]-AR[3]+1 NEXTROW:ROW_ROW+l

COL_AR[2]-AR[3]+l NEXTCOL:COL_COL+l SGO ((AR[3]*2)<((ROW-AR[l])«2) + ( COL-AR[2])*2)/ENDLP B[R0W;C0L]_B[R0W;C0L]+AR[4] [13] ENDLPiSGO (C0L$LE AK[2]+AR[3])/NEXTC0L [14] SGO (0,NEXTROW)[1+ROW<AR[1]+AR[3]] $DL

Text continued from page 192:

pressing three keys: the shift key, the down-arrow key, and the Z key.)

Because Ramware APL80 has almost all the capabilities of Level II Disk BASIC, it has some functions and features that the other versions reviewed here do not; several examples are: single-precision or double-precision variables, inverse trigonometric functions, exponents, logarithms, and character editing within a line. Even in the benchmarks (see table 1), this version does fairly well against the other two versions when you consider the differences in price ($39.95 vs $350 and $500) and in processor speed (the TRS-80 is running at 1 MHz, while the other two are running the same type of Z80 processor, but at 4 MHz).

The method used to represent APL on an unmodified TRS-80 is odd, but it is probably the best way that could

Text continued on page 204

OPERATION

UNIT TIME TO PERFORM OPERA TION, SECONDS

SOFTRONICS APL

RAMWARE APL80

VANGUARD

APL/DTC

SOFTWARE

Q — A *B

0.79

4.6

1.2

Q~A>B

0.48

0.42

0.091

Q-B

0.059

0.051

0.012

Q—20D

5.0

2.9

8.6

Q —$C

140.

11.

3.1

Q~FT100000000

NA

0.61

0.13

Q — _50tRA

0.086

0.18

0.014

q-ODni

180.

NA

66.

Q — 4<t>[l]M3D

NA

0.74

1.8

Q—E°.+ E

0.41

0.31

0.082

Q—+/C

0.25

0.25

0.19

CIRCLE

160. *

230. *

150.

TRANS

9.0 *

28. •

11.

IVER

28.

160. «

120.

Table 1: Timing results of APL benchmark details on this and tables 2 thru 4, see the Benchmarks" text box on page 204.

programs. For 'Notes on APL

196 April 1981 © BYTE Publications Inc

H

&

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CQMPJTRQNICS

N

EVERYTHING FOR YOUR TRS-80* • ATARI* • APPLE* • PET* •

•TRS-60 is a trademark of the Radio Shack Division of Tandy Corp. - 'ATARI is a trademark of Atari Inc. - 'Apple is a trademark of Apple Corp. - *Pet is a trademark of Commodore

BUSINESS PAC 100

100 Ready-To-Run Business Programs

* 30-Day money °« Software

(ON CASSETTE OR DISKETTE) Includes 110 Page Users Manual 5 Cassettes (Or Diskettes)

Inventory Control Payroll Bookkeeping System Stock Calculations

Checkbook Maintenance.....Accounts Receivable.....Accounts Payable

BUSINESS 100 PROGRAM LIST

1 RCILE78

2 ANNU1

3 DATE

4 DAYYEAR

5 LEASE1NT

6 BREAKEVN

7 DEPRSL

8 DEPRSY

9 DEPRDB

10 DEPRDDB

11 TAXDEP

12 CHECK2

13 CHECKBK1

14 MORTGAGE/A

15 MtlLTMON

16 SALVAGE

17 RRVARJN

18 RRCONST

19 EFFECT

20 FVAL

21 PVAL

22 LOANPAY

23 REGWTTH

24 S1MPDISK

25 DATEVAL

26 ANNUDEF

27 MARKUP

28 SINKFUND

29 BONDVAL

30 DEPLETE

31 BLACKSH

32 STOCVAL1

33 WARVAL

34 BONDVAL2

35 EPSEST

36 BETAALPH

37 SHARPE1

38 OPTWRrTE

39 RTVAL

40 EXPVAL

41 BAYES

42 VALPRINF

43 VALADINF

44 UTILITY

45 SIMPLEX

46 TRAMS

47 EOQ

48 QCIEUEl

49 CVP

50 CONDPROF

51 OPTLOSS

52 FQUOQ

NAME

53 FQEOWSH

54 FQEOQPB

55 QC1ECJECB

56 NCFANAL

57 PROFIND

58 CAP1

Circle 133 on inquiry card.

Interest Apportionment by Rule of the 78's

Annuity computation program

Time between dates

Day of year a particular date falls on

Interest rate on lease

Breakeven analysis

Straightline depreciation

Sum of the digits depreciation

Declining balance depreciation

Double declining balance depreciation

Cash flow vs. depreciation tables

Prints NEBS checks along with dairy register

Checkbook maintenance program

Mortgage amortization table

Computes time needed for money to double, triple.

Determines salvage value of an investment

Rate of return on investment with variable inflows

Rate of return on investment with constant inflows

Effective interest rate of a loan

Future value of an investment (compound interest)

Present value of a future amount

Amount of payment on a loan

Equal withdrawals from investment to leave 0 over

Simple discount analysis

Equivalent & nonequivalent dated values for oblig.

Present value of deferred annuities

% Markup analysis for items

Sinking fund amortization program

Value of a bond

Depletion analysis

Black Scholes options analysis

Expected return on stock via discounts dividends

Value of a warrant

Value of a bond

Estimate of future earnings per share for company

Computes alpha and beta variables for stock

Portfolio selection model-i.e. what stocks to hold

Option writing computations

Value of a right

Expected value analysis

Bayesian decisions

Value of perfect information

Value of additional information

Derives utility function

Linear programming solution by simplex method

Transportation method for linear programming

Economic order quantity inventory model

Single server queueing (waiting line) model

Cost-volume-profit analysis

Conditional profit tables

Opportunity loss tables

Fixed quantity economic order quantity model

DESCRIPTION

As above but with shortages permitted

As above but with quantity price breaks

Cost-benefit waiting line analysis

Net cashflow analysis for simple investment

Profitability index of a project

Cap. Asset Pr. Model analysis of project

59 WACC Weighted average cost of capital

60 COMPBAL True rate on loan with compensating bal. required

61 DISCBAL True rate on discounted loan

62 MERGANAL Merger analysis computations

63 FINRAT Financial ratios for a firm

64 NPV Net present value of project

65 PRINDLAS Laspeyres price index

66 PR1NDPA Paasche price index

67 SEASIND Constructs seasonal quantity indices for company

68 T1METR Time series analysis linear trend

69 T1MEMOV Time series analysis moving average trend

70 FUPR1NF Future price estimation with inflation

71 MAILPAC Mailing list system

72 LETWRT Letter writing system-links with MAILPAC

73 SORT3 Sorts list of names

74 LABEL I Shipping label maker

75 LABEL2 Name label maker

76 BCJSBCJD DOME business bookkeeping system

77 TTMECLCK Computes weeks total hours from fimeclock info.

78 ACCTPAY In memory accounts payable system-storage permitted

79 INVOICE Generate invoice on screen and print on printer

80 INVENT2 In memory inventory control system

81 TELDIR Computerized telephone directory

82 TIMUSAN Time use analysis

83 ASSIGN Use of assignment algorithm for optimal job assign.

84 ACCTREC In memory accounts receivable system-storage ok

85 TERMSPAY Compares 3 methods of repayment of loans

86 PAYNET Computes gross pay required for given net

87 SELLPR Computes selling price for given after tax amount

88 ARBCOMP Arbitrage computations

89 DEPRSF Sinking fund depreciation

90 (JPSZONE Finds GPS zones from zip code

91 ENVELOPE Types envelope including return address

92 ACJTOEXP Automobile expense analysis

93 INSF1LE Insurance policy file

94 PAYROLL2 In memory payroll system

95 DILANAL Dilution analysis

96 LOANAFFD Loan amount a borrower can afford

97 RENTPRCH Purchase price for rental property

98 SALELEAS Sale-leaseback analysis

99 RRCONVBD Investors rate of return on convertable bond

100 PORTVAL9 Stock market portfolio storage-valuation program

D CASSETTE VERSION D DISKETTE VERSION

$99.95 $99.95

NEW

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□ TRS-80* MODEL D VERSION $149.95 (Outside ^'Nfi

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Scalar Dyadic Operators, Softronics APL

s <

COMMENTS

ADD

0

0

SUBTRACT

E

0

MULTIPLY

0

0

DIVIDE

0

0

EXPONENT

0

0

LOGARITHM

0

0

FLOOR

0

0

CEILING

0

0

Dyadic version innaccurate in last decimal place; see text.

a: o

H <

cr

L±J

0O

LU

s <

z

o

Q

<

Z

o

S

O

o <

> a

1

RESIDUE

0

0

1

1

FACTORIAL

0

0

o

CIRCLE

0

0

< < > >

LESS THAN, ETC.

0

= *

EQUAL TO, NOT EQUAL TO

0

AV

AND, OR

0

AV

NAND, NOR

0

COMMENTS

Gamma function missing.

Only sin, cos, tan, arctan implemented.

Nondyadic Scalar and Mixed Operators, Softronics APL

~

NOT

0

?

ROLL

0

0

i

IOTA (INDEX)

0

0

p

RHO(RESHAPE)

0

0

•

RAVEL

0

0

XT

DECODE,ENCODE

0

H

TAKE, DROP

0

f

MEMBERSHIP

0

H

GRADE-UP GRADE-DOWN

0

s

MATRIX DIVIDE OR INVERSE

0

0

COMMENTS

Dyadic available as defined function only.

Catenation for vectors only; no lamination.

Available as defined function only.

Both available as defined function only.

tr

LU

a. o

UJ

<

Z

<

z o

S

a <

>~

Q

s

TRANSPOSE

0

0

(D

ROTATE OR REVERSE

0

0

e

ROTATE

0

0

/

COMPRESS

0

i

COMPRESS

0

\

EXPAND

0

\

EXPAND

0

<}>

EXECUTE

0

?

FORMAT

0

COMMENTS

Dyadic "diagonal" transpose

missing.

Dyadic function available for vectors and two-dimensional matrices only available as defined function.

Available as /[1] only.

Converts a vector or array to a character string (with embedded carriage return) for printing.

Composite Operators, Softronics APL

IE

O

1<

a:

UJ

m

<

HI

SE

<

O

<

>

o

z

<

•/

REDUCTION

0

fr

REDUCTION

0

-I to <

3 > <

fg

INNER PRODUCT

0 OUTER PRODUCT [7]

Notes:

"Y" and "N" mean that a given operator is either present in all its forms or totally absent from this verion of APL. "Y*" means that the operator is only partially present in this version. "N*" means that the operator is not present in this version but that part or all of it is available through an APL defined function supplied with this version. Further information explaining "Y*" and "N*" is given in the "Comments" column.

A scalar is an object (number or character) with no dimension. A vector is a string of objects that have one dimension. An array is a matrix of objects that have two or more dimensions.

Other features: standard APL commands, system functions, and system variables; line editing only of defined functions; PEEK and POKE functions; 8080-type port IN and OUT functions; shared variable mechanism for interaction with disk files (sequential read and write only, in standard CP/M format); mixing of APL data structures (arrays, vectors, scalars) in records of same file; user choice of standard terminal, APL terminal, or video board with programmable character generator; and good documentation.

Other limitations: several much-needed operators are missing (see body of this table) and there is no random access to disk files' character-editing of defined functions.

Table 2: Summary of Softronics APL features.

198 April 1981 © BYTE Publications Inc

E

CQMPUTRQMCS

N

• • EVERYTHING FOR YOUR TRS-80™ • •

MODEL III

* All orders processed within 24-Hours * 30-Day money back guarantee on all TRSDOS Software • Add $2.00 for shipping in UPS Areas • Add $4.00 for COD. or NON-UPS Areas * Add $5.00 outside U.S.A., Canada & Mexico •k We will match any bonafide advertised price in any of the Major Computer Magazines

TUS-Mh l trademark ol Tandy Com.

) GENERAL LEDGER, ACCOUNT8 RECEIVABLE, ACCOUNT8 PAYABLE, PAYROLL,

INVENTORY CONTROL AND INVOICING (Small Business Group) an extensive business

system for the serious user can be used one module at a time or as a coordinated system

$198.95 per module $1199.95 for the complete system.*

!) MASTER PAC 100 100 essential programs BUSINESS PERSONAL FINANCE

STATISTICS MATH GAMBLING GAMES includes 125 page manual and 5 diskettes

$59.95

i) BUSINESS PAC 100 100 essential business programs INVENTORY CONTROL PAYROLL BOOKKEEPING SYSTEM STOCK CALCULATIONS CHECKBOOK MAINTENANCE ACCOUNTS RECEIVABLE ACCOUNTS PAYABLE includes 125 page manual

and five diskettes $99.95

l) INFORMATION SYSTEM (The Bottom Shelf) An in-memory information system for small

mailing lists, inventories (i.e. books, articles, records, program reference files) Can be used

for anything that you would use rolodex or index card files Up to ten user define fields

Programmable printouts for rolodex cards, mailing labels, etc Will identify all records that

contain a group of characters you've entered even if that group is in the middle of a line Sorts

data base by any field $49.50*

I) DATA MANAGER II (The Bottom Shelf) RANDOM ACCESS Disk based DATA MANAGEMENT SYSTEM (Similiar to INFORMATION SYSTEM above but RANDOM ACCESS

STORAGE expands the amount of storage space available) Used to replace index cards for

medium sized mail lists, inventories, personnel records, sates prospects, etc Uses up to four

disk drives on line Up to twenty user defined fields, programmable printouts for rolodex

cards, etc will identify all records that contain a group of characters you've entered even if

that group is in the middle of a line maintain up to 5 changeable presorted "key" files

variable length random records (the smaller the record you define, the more records yu can store) $99.95*

i) BUSINESS MAIL SYSTEM (The Bottom Shelf) Handles large mailing lists (up to 150.000

names) supports 3 or 4 line addresses files automatically in zip code order, alphabetical

within zip code formats for 1 to 4 across mailing labels supports quick disk location of

single or multiple names meets all industry and postal standards numeric code fields

included for printing selected records $125.00*

') ANALYSIS PAD (The Bottom Shelf) A Columnar Calculator for financial analysis, line item

budgeting, cost analysis, sales analysis and almost any financial function (and many statistical

functions) create matrixes of 29 * 39 make all entries at one time either by row or column

add. delete, move or switch columns and rows edit any data from full screen display add.

subtract, multiply and divide one column by another and put results in designated column (up to six calculations can be made and placed in designated column) define columns as constants save calculations and formulas on disk results can be printed in a variety of report

formats $99.95*

i) CHECKBOOK II (The Bottom Shelf) A complete in memory checkbook balancing and

reconcilliation program five column keyboard input with 5 characters for check number. 16

for payee. 4 for code numerical sort routine $49.50*

I) CHECK REGISTER ACCOUNTING SYSTEM (The Bottom Shelf) A complete random access

checkbook system set and define up to 60 accounts with as many income accounts as you

choose complete checkbook balancing and reconcilliation single entry input where

transaction can be dispersed over several accounts enables user to make a 64-character note

on each transaction printout your own check after data entry prints monthly summaries of

each account with month and year-to-date totals create a suspense file to remind you of

coming expenses Reports generated included Check Register (for any month), notes to

Check Register, Income/Expense Distribution Report. Statement of Selected Accounts. Bank Reconcile Statement, Suspense File and Full Account Distribution Statement $74.95*

l) LIBRARY 100 (The Bottom Shelf) 100 Programs on a broad range of topics Finance

Education Graphics Home Games CASSETTE VERSION $49.50

DISK VERSION $74.95

) ADVENTURE (by Scott Adams) A series of games (for ages 10-99) wander through enchanted worlds seeking treasures 1. Adventureland 2. Pirate's Adventure 3. Mission

Impossible Adventure 4. Voodoo Castle 5. The Count 6. Strange Odyssey 7. Mystery

Fun House 8. Pyramid of Doom 9. Ghost Town (#1 and #2 recommended for the movie

adventure) Each adventure $14.95 (jon cassette) Diskette versions sold in groups of three

at $39.95 per three programs (#1 - #3. #4 - #6, #7 - #9).

I) HORSE SELECTOR II (Dr. Hal Davis) New simplified version of the original Horse Selector

(for flats) The first Horse Selection System to actually calculate the estimated offs for each

horse easy to follow rules uses 4 factors (speed rating, track variant, distance of the

present race, distance of the last race) calculated estimated odds FREE DUTCHING

TABLES allows betting on 2 or more horses with a guaranteed profit $50.00

I) MON-3 and MON-4 (Howe Software) Powerful utility programs enabling you to interact

directly with your TRS-80 in MACHINE LANGUAGE The monitor comes with complete

40-page instruction manual making it useful for both the beginner and advanced programmer....

simple commands make it easy to use functions include DISPLAY, DISASSEMBLE, MOVE

and COMPARE, SEARCH. MODIFY, RELOCATE. PRINT, READ and WRITE. UNLOAD, SAVE

and READ, INPUT and OUTPUT, SEND and RECEIVE MON-3 $39.95 (for cassette)

MON-4 $49.95 (for disk).

(14) SMART TERMINAL (Howe Software) enables your TRS-80 to be used as a remote terminal

to a time sharing computer system $69.95

(15) FA8T 80RT (Howe Software) a series of machine-language subroutines to sort data from

BASIC programs data may be alphabetic (string) or numeric easily interfaced with your

BASIC programs (no machine language knowledge is necessary) $9.95

(16) MAILING LIST (Howe Software) maintains mailing lists of over 1000 names commands

allow adding, changing, deleting, and finding names. Sorting is done in machine language subroutine labels printed in 1, 2 or 3 columns $69.95

(17) HOME BUDGET (Howa Software) combines the maintenance of your checkbook with

analysis of your income, expenses and monthly bills. Handles data including bills, income, deposits, checks and debits to your checking account, and cash expenses. Computes checkbook balance, list of unpaid bills, monthly and year-to-date summaries of income and expenses

showing income tax deductions All output printed on video display or line printer comes

with complete instructions manual $49.95*

(16) SMALL BUSINESS ACCOUNTING (Howe Software) Based on the DOME BOOKKEEPING

SYSTEM keeps track of all income, expenditures and payroll for a small business of up to 16

employees income and expenditures can be entered on a daily, weekly or monthly basis

computes monthly and year to date totals manual contains complete instructions for customization Cassette version $29.95 Diskette version $49.95

(19) REMODEL-PROLOAD (Racet Computes) Renumber program lines move statements from

one part of a program to another $34.95

(20) GSF (Racet Computes) Lightning fast in-memory machine language sort utility that can be

made part of your BASIC progams without any machine language knowledge includes

several other utilities to speed up your BASIC programs no machine knowledge necessary

to use GSF in your BASIC programs $30.00

(21) DOSORT (Racet Computes) includes GSF (above) extends the in memory sort to sorts

on multiple disk drives $45.00*

(22) COPSYS (Racet Computes) allows the user to make copies of machines language cassettes

without any knowledge of machine language $20.00

(23) COMRPOC (Racet Computes) an auto load program for disk users allows the user to

insert a diskette into their MOD-HI and have the computer take over all loading load a

machine language program, BASIC, RUN a certain program all without pressing a single button

allows your computer to perform 10. 20. 30 or more functions without pressing a single

button $30.00*

(24) INFINE BASIC (Racet Computes) adds a variety of machine language subroutines to your

BASIC programs (without any machine language knowledge) fast sorts matrix operations

compress and uncompress data and more $60.00

(25) INFINITE BUSINESS (Racet Computes) an add on package to INFINITE BASIC adds a

variety of routines important to the businessman (increase accuracy of calculations and more)

$30.00

(26) DMS (Racet Computes) lightning fast machine language sort sorts up to 4 disk drives of

information $90.00*

(27) BLINK (Racet Computes) allows you to RUN new programs without losing the variables

stored in your previous program line many programs together without losing important

variables $30.00*

(28) KFS-80 (Racet Computes) now you can use ISAM (Index Sequential Access Files) on your

MOD-MI using ISAM in your BASIC programs allows instant access of your items in your

data files use with mail programs inventory programs etc. $100.00*

(29) MAIL LIST (Racet Computes) all routines are in machine language allowing for quick

access $75.00

• for disk only Circle 134 on Inquiry card.

•CQMPLITRQNICS:

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NEW TOLL-FREE

ORDER LINE

(OUTSIDE OF NY. STATE)

(800) 431-2818

HOUR

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(914) 425-1535

Scalar Dyadic Operators, Ramware APL80

+

ADD

m

h

SUBTRACT

0

0

X

MULTIPLY

E

0

*

DIVIDE

0

0

*

EXPONENT

0

0

®

LOGARITHM

0

0

L

FLOOR

0

0

r

CEILING

h

0

0

o

<

o 2

>

Q

COMMENTS

1

RESIDUE

0

0

1

FACTORIAL

0

0

Gamma function missing.

o

CIRCLE

0

0

Hyperbolic and hyperbolic inverse not defined.

< < > >

LESS THAN, ETC.

0

= *

EQUAL TO, NOT EQUAL TO

0

AV AV

AND, OR NAND, NOR

0 0

Assumes nonzero values are equivalent to 1 or true (nonstandard).

H i

H a

Nondyadic Scalar and Mixed Operators, Ramware APL80

1 5

NOT (T)

? ROLL 0] [T]

i IOTA (INDEX) 0| 0|

p RHO (RESHAPE) [7] W\

RAVEL \T\ [7T]

IT DECODE, ENCODE 0j

TAKE, DROP (Tj

MEMBERSHIP |Tj

COMMENTS

Catenation for arrays, vectors, along last coordinate only; no lamination.

Right argument of encode limited to scalars only.

grade-up nr\

GRADE-DOWN LU

MATRIX DIVIDE OR INVERSE

0 0

o

Q

0

0

/ / \ \

¥

COMMENTS

transpose (yTI [771 Monadic transpose is nonstan

L-11 —' dard for 3-dimensional or larger

ROTATE OR REVERSE

ROTATE

COMPRESS

COMPRESS

EXPAND

EXPAND

EXECUTE

FORMAT

Sr—n arrays; dyadic "diagonal' I—I transpose missing.

[n*] 0 Available as (A [1] only.

0

0 Available as / [1] only.

0

0 Available as \ [1].

Fl

Sets field width and number of decimal places for future output.

Composite Operators, Ramware APL80

o

f/ REDUCTION

(■/■ REDUCTION

< COMMENTS

<

0

0 Available as f/[1]

fg

INNER PRODUCT OUTER PRODUCT

CO <

>

0

Notes:

"Y" and "N" mean that a given operator is either present in all its forms or totally absent from this version of APL. "Y*" means that the operator is only partially present in this version. "N*" means that the operator is not present in this version but that part or all of it is available through an APL defined function supplied with this version. Further information explaining "Y*" and "N*" is given in fhe "Comments" column.

A scalar is an object (number or character) with no dimension. A vector is a string of objects that have one dimension. An array is an matrix of objects that have two or more dimensions.

Other features; five tutorial programs on APL included in package; standard APL commands, automatic execution of latent expression; tracing of function execution; choice of single (6-digit) or double (15-digit) precision in output; real-time clock, line and character editing of defined functions; print formatting and system control variables(APL l-bar functions); positioning of screen output (equivalent to PRINT @ in BASIC); use of periods and dashes in variable names; PEEK, POKE, and CALL functions; random or sequential access of file records; updating of file records; and mixing of APL data structures (ie: arrays, vectors, scalars) in records of same disk file.

Other limitations: only one assignment operator per line; maximum of thirty-two functions per workspace and 255 lines per defined function; arrays limited to sixty-three dimensions; uses one-letter substitutions for APL operators (but these substitutions are differentiated from normal text).

Table 3: Summary of Ramware APL80 features.

200 April 1981 © BYTE Publications Inc

The Hard

Facts About

Software

I THREADED INTERPRETIVE LANGUAGES

9 by Ronald Loeliger Threaded languages (such as FORTH) are compact, giving the speed of assembly language with the programming ease of BASIC. They combine features found in no other programming languages. This book develops an interactive, extensible language with specific! routines for the Zilog Z80 microprocessor. With the core interpreter, assembler, and i * data type defining words covered in the text, it is possible to design and implement programs for almost any application and equivalent routines for different processors.

£ Threaded Interpretive <M1g(U3gQS

0f

«y

2

272 pages ■*,

hardcover

illustrated ISBN 0-07-038360-X

BASIC SCIENTIFIC SUBROUTINES, VOLUME I

by Fred Ruckdeschel

Designed for the engineer, scientist, experimenter, and student, this book presents a complete scientific subroutine package in BASIC. Volume I covers plotting, complex variables, vector and matrix operation, random number generation, and series approximations. This volume features routines written in both standard Microsoft and North Star BASIC, extensive appendices, and subroutine cross-references.

VOLUME I 336 pages hardcover illustrated

ISBN 0-07-054201-5

Circle 135 on inquiry card.

BEYOND GAMES: System's Software For Your 6502 Personal Computer

" by Kenneth Skier

At last, a complete programming guidebook for owners of personal computers utilizing the 6502 microprocessor. A self-contained course in structures programming and topdown design, this book presents a powerful set of tools for building an extended monitor, disassembler, hexadecimal dump routine, and text editor programs. Pro grams are thoroughly explained, with clear instructions for modifications.

ISBN 0-07-057860-5 440 pages softcover illustrated

Circle 135 on inquiry card.

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Scalar Dyadic Operators, Vanguard APL

a. o h<

UJ

a. o

LU

<

Z

o o <

O

S

o

<

>

+

ADD

m

E

SUBTRACT

s

0

X

MULTIPLY

m

0

*

DIVIDE

e

0

•

EXPONENT

h

0

®

LOGARITHM

0

0

L

FLOOR

0

0

r

CEILING

0

0

< a.

I

o

< < > >

= * AV AV

RESIDUE

COMMENTS

0 0

factorial 0 (Tj Gamma available as a defined

function.

circle FTI (yTI Hyperbolic, inverse yjQ2- 1,

LESS THAN, ETC.

EQUAL TO, NOT EQUAL TO

AND, OR NAND, NOR

0 0 0 0

VB=n not defined.

Nondyadic Scalar and Mixed Operators, Vanguard APL

Q. O

<

z

O S

>

Q

~

NOT

0

?

ROLL

0

0

I

IOTA (INDEX)

0

0

P

RHO(RESHAPE)

0

0

•

RAVEL

0

0

XT

DECODE,ENCODE

0

u

TAKE, DROP

0

i

MEMBERSHIP

0

H

GRADE-UP GRADE-DOWN

0

B

MATRIX DIVIDE OR INVERSE

0

0

COMMENTS

Catenation for arrays, vectors, along all coordinates; lamination available as defined function. Right argument of encode limited to scalars only.

Both available as defined function only.

o

s

(D

0 / t \ \ & ?

TRANSPOSE

ROTATE OR REVERSE

ROTATE

COMPRESS

COMPRESS

EXPAND

EXPAND

EXECUTE

FORMAT

0 0

0 0

0 0

0

COMMENTS

Monadic transpose for arrays

available as defined function

only.

Both forms work for vectors

only; for all arrays, available as

defined functions only.

0 Available as / [1] only.

0

0 Available as \ [1] only.

0

Left argument is print width and |T| number of decimal places; right argument is vector or array to be formatted.

a. o

l<

UJ

n. hi _i to

<

-I

LU Q. O

S < z

<

5

COMMENTS

'/

REDUCTION

0

.r

REDUCTION

0

Available as f / [1] only.

Composite Operators, Vanguard APL

p 3

< <

£ uj -l

uj S <

Q- < >

O Z <

f.g INNER PRODUCT 0

o.f OUTER PRODUCT [7|

Notes:

"Y"and "N" mean that a given operator is either present in all its forms or totally absent from this version of APL. "Y*" means that the operator is only partially present in this version. "N*" means that the operator is not present in this version but that part or all of it is available through an APL defined function supplied with this version. Further information explaining "Y*" and "N*" is given in the "Comments" column.

A scalar is an object (number or character) with no dimension. A vector is a string of objects that have one dimension. An array is a matrix of objects that have two or more dimensions.

Other features: standard APL commands, system functions, and system variables; line editing only of defined functions; shared variable mechanism for interaction with disk files (sequential and random access); mixing of APL data structures (arrays, vectors, scalars) in records of same disk file; the ability to share with any Z80 I/O port.

Other limitations: only way to use this software with a non-APL terminal or video board uses one-letter substitutions of a standard ASCII character for APL operators (plus these substitutions are not differentiated from normal text); documentation is adequate but terse; no character editing of defined functions.

Table 4: Summary of Vanguard APL/DTC software features.

202 April 1981 © BYTE Publications Inc

"WITH THE UCSD p-SYSTEM; WE CAN WRITE ONE APPLICATION THAT GOES FROM APPLE TO ZENITH!'

HARRY BLAKESLEE, President, Denver Software

UCSD p-System and UCSD Pascal are trademarks of the Regents of the University of California.

Our business is bigger and better than ever. A lot of the credit for that goes to the UCSD p-System software from SofTech Microsystems. It's given us ten times the market we used to have.

We can write a single, sophisticated applications program with the UCSD p-System—like our financial management package—and it just keeps on running. On Apple, Commodore, Ohio Scientific, Texas Instruments, Zenith, and more. That's the real beauty of the UCSD p-System. Any program you write for one microcomputer runs on others, both today and tomorrow. You protect your software investment, without restricting your hardware options.

And with the UCSD p-System,you can use the language of your choice-UCSD Pascal,™ FORTRAN-77, BASIC, or assembly language. All are backed by SofTech Microsystems, a leading system software company who's been around for over a decade, who knows how to develop professional quality software, and who's committed to delivering it.

Get a head start on tomorrow. With the microcomputer software that goes from "A" to "Z." Distribution licensing and single copies available. Write or call for details, so you can start going places, too.

micposvsTems

(=» 5USSIDIRHV OF SOFTECH

For the software that's going places.

9494 Black Mountain Road, San Diego,

CA 92126. (714)578-6105

TWX: 910-335-1594

Circle 136 on inquiry card.

BYTE April 1981 203

Notes on APL

The following information specifies the tests that are run on all versions of APL that are examined at BYTE magazine. Defined function SETUP, shown in listing 1, creates the APL variables that will be used in the tests shown in table 1. A and B are 10 by 10 matrices used in tests like A + B to perform an operation 100 times with one statement. C is a ten-element vector giving the values from it to 10ir. D is a 10 by 10 matrix of trigonometric values. E is a ten-element vector of the values from 1 to 10 (used to test the outer product operator). F is a vector used to convert seconds to years, days, hours, minutes, and seconds in the test F T 100000000, using the encode (i) operator. RA and RB are 100-element vectors made from the elements of matrices A and B. Finally, M3D is a threedimensional array used to test rotation around a nondefault axis.

The function TIME in listing 2 was used in timing the performance of a function. Statements 20 thru 60 are performed N times, with the (exp) in each line replaced by the function being tested (for example, Q—A-r-B). Statement 80 displays the total number of times the function has been performed, while statement 90 requests the number of seconds used in the test (timed by a stopwatch) and displays the time used to perform the function once. Each function is per

Benchmarks

formed five times within TIME to maximize the time spent executing the function when compared to the time spent executing statement 10 and repeatedly executing line 70 N times. In addition, the TIME function was performed with increasing values of N until the unit time agreed to three significant places. The timing values in table 1 are rounded to two significant places.

Three short APL functions, CIRCLE, TRANS, and IVER, are used as benchmarks to grade the performance of an APL implementation in less abstract terms. (See listings 3, 4, and 5.) CIRCLE takes a numeric matrix and adds a set value to all matrix elements in an imaginary circle with a given center and radius. (This function was used to set up a "picture" matrix of geometric shapes in a pattern-recognition algorithm.) The TRANS function transforms a matrix of numbers into a matrix of symbols, with the individual symbols used to reflect the value of the corresponding numeric matrix entry. The IVER function was presented by Dr Kenneth Iverson in the article "Understanding APL" (August 1977 BYTE, page 36). When given a right argument of seven or larger, it returns a vector containing all the prime numbers up to and including that number. (For example, IVER 11 returns the vector 2 3 5 7 11.)

Notes:

• All of the above tests are performed on either 10 by 10 matrices or 100-element vectors; in addition, the tests were carried out to minimize the amount of time outside the operation being timed.

• In some cases, a version of APL could not operate on a given size matrix. An asterisk denotes an estimated entry made by adjusting the time an operation took for a smaller matrix.

• CIRCLE, TRANS, and IVER (shown in listings 3 thru 5) are APL defined functions used to compare the versions of APL in a working environment.

• All numbers here are given to 2 significant digits.

• In the cases where a version of APL gives the user an APL defined function (a short program written in APL) to use when the operation is not in the machinecode version of APL, the defined function is used in the above timing tests. For example, none of the above

versions of APL incorporate matrix divide in their versions, but Softronics and Vanguard supply an APL defined function to do the same operation.

• NA means the function is not available in a given version of APL.

• The Ramware APL80 was run on an unmodified Radio Shack TRS-80 Model I with one disk drive and 48 K bytes of memory. The TRS-80 runs at 1 MHz; all timing figures should be halved for users running modified TRSSOs at 2 MHz.

• The Softronics APL was run on a Cromemco Z2D with 56 K bytes of memory, running at 4 MHz.

• The Vanguard APL/DTC software was run on an APL/DTC computer with 80 K bytes of memory, running at 4 MHz. Users buying the Vanguard APL/V80 software should expect slightly decreased performance varying with the amount of memory in the system.

Text continued from page 196:

be devised. APL operators that normally do not appear on the keyboard have a 1-character substitution. For example, the character % replaces the APL division operator +, and parentheses () replace the square brackets [] used in APL to denote subscripts. Other characters are represented by a shifted keyboard letter; for example, shift-q is used for the APL character □ (a quad), and shift-i is used for the APL iota operator t. On the TRS-80 video screen, these characters are displayed as their uppercase alphabetic equivalents (because an unmodified TRS-80 has no lowercase letters) with a little graphic dot just below and to the left of the uppercase let

ter. This, plus one space on the left of the single letter substitution, makes this system more readable. (See photo 1 for the APL80 equivalent of the CIRCLE function of listing 3a).

Many other Level Il-related features make Ramware APL80 a usable product and certainly the best buy dollar-for-dollar. Several other features that must be mentioned are sequential and random access of APL disk files and access to the real-time clock; other features are listed in table 3.

Vanguard APL/DTC Computer and Software

Two of the 'At a Glance" boxes describe the last ver

204 April 1981 © BYTE Publications Inc

circle 737

'nquiry

card.

Ste-Julie. Quebec Canada JOL 250

(514)649-6185

BYTE

April

1981

205

The ZVX4 MEGABYTER is for the APPLE II user who wants to DOUBLE file size, expand the capability of existing business software, and make other SERIOUS applications more viable.

Now you can have compatibility with IBM, INTEL, CP/M*, Z80 Softcard*, UCSD Pascal, and others.

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• Gain automatic single/double density operation

• Change to double sided drives with one switch

Available at your Apple dealer. Call or write today!

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SORRENTO VALLEY ASSOCIATES

1722 SORRENTO VALLEY ROAD SAN DIEGO, CA 92121 (714) 452-0101

* CP/M trademark of Digital Research, Inc. Z80 Softcard trademark of Microsoft, Inc.

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Photo Is The APL function CIRCLE as presented by Ramware APL80. In this version of APL for the TRS-80 Model I, nonstandard APL characters are replaced by either a 1-character substitution or by a single letter marked by a graphics dot below and to the left of the letter.

Photo 2: The Vanguard Systems Corporation APL/DTC. The system includes: the APL/DTC (desk-top) computer, on the left; its associated APL terminal, on the right; and, on top of the computer, documentation and two floppy disks of software—customized CP/M and Vanguard APL.

sion of APL, which was reviewed as a computer/software combination called APL/DTC. The computer and software have been optimized for each other, creating a version of APL that is slightly more powerful than its stand-alone software counterpart, APL/V80.

The APL/DTC system, which carries a label of the same name (see photo 2), is actually a Vector Graphics microcomputer with modifications made at Vanguard Systems Corp. (One modification results in the computer holding 80 K bytes of memory.) Its associated terminal, which displays all APL characters (as shown in photo 3) has an APL keyboard and is a Vector Graphics "Mindless Terminal" (a keyboard and video display that connects to a memory-mapped video board inside the computer proper). Its associated video board has a PROM (programmable read-only memory device) that generates the APL character set. The APL/DTC computer runs CP/M as customized by Lifeboat Associates and Vanguard. The

206 April 1981 © BYTE Publications Inc

Circle 138 on inquiry card.

Start learning and computing for only $129.95 with a Netronics 8085-based computer kit. Then expand it in low-cost steps to a business/development system with 64k or more RAM, 8" floppy disk drives, hard disks and multi- terminal I/O.

THE NEW EXPLORER/85 SYSTEM

Special! Full 8" floppy, 64k system for less than the price of a mini! Only $1499.95!

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Imagine — for only $129.95 you can own the starting level of Explorer/85, a computer that's expandable into full business/development capabilities — a computer that can be your beginner system, an OEM controller, or an IBM-formatted 8" disk small business system. From the first day you own Explorer/85, you begin computing on a significant level, and applying principles discussed in leading computer magazines. Explorer/85 features the advanced Intel 8085 cpu, which is 100% compatible with the older 8080A. It offers onboard S-100 bus expansion. Microsoft BASIC in ROM, plus instant conversion to mass storage disk memory with standard IBM-formatted 8" disks. All for only $129.95, plus the cost of power supply, keyboard/ terminal and RF modulator if you don't have them (see our remarkable prices below for these and other, accessories). With a Hex Keypad/display front panel. Level "A" can be programmed with no need for a terminal, ideal for a controller, OEM, or a real low-cost start.

Level "A" is a complete operating system,perfect for [beginners, hobbyists, industrial controller use. $129.95

LEVEL "A" SPECIFICATIONS

Explorer/85's Level "A" system features the advanced Intel 8085 cpu, an 8355 ROM with 2k deluxe monitor/ operating system, and an advanced 8155 RAM I/O . . . all on a single motherboard with room for RAM/ROM/ PROM/EPROM and S-100 expansion, plus generous prototyping space.

PC Board: Glass epoxy, plated through holes with solder mask. • I/O: Provisions for 25-pin (DB25) connector for terminal serial I/O, which can also support a paper tape reader . . . cassette tape recorder input and output . . . cassette tape control output. . . LED output indicator on SOD (serial output) line .. . printer interface (less drivers) . . . total of four 8-bit plus one 6-bit I/O ports. • Crystal Frequency: 6.144 MHz. • Control Switches: Reset and user (RST 7.5) interrupt. . . additional provisions for RST 5.5, 6.5 and TRAP interrupts onboard. • Counter/Timer Programmable, 14-bit binary. • System RAM: 256 bytes located at F800, ideal for smaller systems and for use as an isolated stack area in expanded systems . . . RAM expandable to 64K via S-100 bus or 4k on motherboard.

System Monitor (Terminal Version): 2k bytes of deluxe system monitor ROM located at F000, leaving 0000 free for user RAM/ROM. Features include tape load with labeling . . . examine/change contents of memory. . . insert data .. . warm start.. . examine and change all registers . . . single step with register display at each break point, a debugging/training feature ... go to execution address . . . move blocks of memory from one location to another . . . fill blocks of memory with a constant . . , display blocks of memory . . . automatic baud rale selection to 9600 baud .. . variable display line length control (1-255 characters/line) . .. channelized I/O monitor routine with 8-bit parallel output for high-speed printer . . . serial console in and console out channel so that monitor can communicate with I/O ports.

System Monitor (Hex Keypad/Display Version): Tape load with labeling . . . tape dump with labeling .. . examine/change contents of memory . . . insert data . . . warm start . . . examine and change all registers . . .

Full 8" disk system for less than the price of a mini (shown with Netronics Explorer/85 computer and new terminal). System features floppy drive from Control Data Corp., world's largest maker of memory storage systems (not a hobby brand/,)

Level "A" With Hex Keypad/Display.

single step with register display at each break point. . . go to execution address. Level 'A" in this version makes a perfect controller for industrial applications, and is programmed using the Netronics Hex Keypad/ Display. It is low cost, perfect for beginners. HEX KEYPAD/DISPLAY SPECIFICATIONS Calculator type keypad with 24 system-r'efined and 16 user-defined keys. Six digit calculator-type display, that displays full address plus data as well as register and status information. LEVEL "B" SPECIFICATIONS Level "B" provides the S-100 signals plus buffers/ drivers to support up to six S-100 bus boards, and includes: address decoding for onboard 4k RAM expansion selectable in 4k blocks . . . address decoding for onboard 8k EPROM expansion selectable in 8k blocks . . . address and data bus drivers for onboard expansion . . , wait stalegenerator(jumperselectable). to allow the use of slower memories . . . two separate 5 volt regulators.

LEVEL "C" SPECIFICATIONS Level "C" expands Explorer/85's motherboard with a card cage, allowing you to plug up to six S-100 cards directly into the motherboard. Both cage and card are neatly contained inside Explorer's deluxe steel cabinet. Level "C" includes a sheet metal superstructure, a 5-card. gold plated S-100 extension PC board

thai plugs into the motherboard, number of S-100 connectors.

Just add required

LEVEL "D" SPECIFICATIONS

Level "D" provides 4k of RAM, power supply regulation, filtering decoupling components and sockets to expand your Explorer/B5 memory to 4k (plus the origi

nal 256 bytes located in the 8155A). The static RAM can be located anywhere from f&ffl to EFFF in 4k blocks.

LEVEL "E" SPECIFICATIONS Level "E" adds sockets for 8k of EPROM to use the popular Intel 2716 or the TI 2516. It includes all sockets, power supply regulator, heat sink, filtering and decoupling components. Sockets may also be used for 2k x 8 RAM IC's (allowing for up lo 12k of onboard RAM). DISK DRIVE SPECIFICATIONS

• 8" CONTROL DATA CORP. • Data capacity: 401.016 bytes professional drive. (SD). 802,032 bytes (DD).

• LSI controller. unformatted.

• Write protect. • Access time: 25ms (one

• Singleordoubledensity. track).

DISK CONTROLLER/I/O BOARD SPECIFICATIONS

• Cont.,olsuptofour8"drives.

• 1771A LSI (SD) floppy disk conl roller.

• Onboard data separator (IBM compatible).

• 2 Serial I/O ports

• Autoboot lo disk system when system reset.

• 2716 PROM socket included for use in custom applications.

• Onboard crystal controlled.

• Onboard I/O baud rate generators to 9600 baud.

• Double-sided PC board (glass epoxy.)

DISK DRIVE CABINET/POWER SUPPLY

• Deluxe steel cabinet with individual power supply for maximum reliability and stability.

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Please send the items checked below:

□ F,xplorer/85 Level "A" kit (Terminal Version)... SI29.95plus $3 post. & insur.

□ Explorer/65 Level "A" kit (Hex Keypad/Display Version). . . $129.95 plus $3 post. & insur.

D 8k Microsoft BASIC on cassette tape. $84.95 postpaid. D 8k Microsoft BASIC In ROM kit (requires Levels "B", "D" and E").. . $99.95 plus $2 post & insur.

□ Level "B" (S-100) kit... $49.95 plus $2 post. & insur.

D Level "C" (S-100 (Hard expander) kit $39.95 plus $2 post

& insur. 0 Level "D" (4k RAM) kit . . $69.95 plus S2 post. 8. insur. D Level "E" (EPROM/ROM| kit. . . $5.95 plus 50c p&h.

□ Deluxe Steel Cabinet for Explorer/B5 . . . $49.95 plus $3 post. & insur.

D Fan For Cabinet .. . SI5.00plus $1.50 posl. & insur. D ASCII Keyboard/Computer Terminal kit: features a full 128 character set. u&l case: full cursor control: 75 ohm video output: convertible lo Baudot output: selectable baud rale. RS232C or 20 ma. I/O, 32 or 64 character by 16 line formats, andean be used with either a CRT monitor or a TV sel (if you have an RF modulator) . . . $149.95 plus $3.00 post. & insur. □ DeLuxe Steel Cabinet for ASCII kcyboara/lerminal . . . $19.95 plus $2.50 post. & insur.

□ New! terminal/Monitor: (See photo) Same; features as above, except 12" monitor with keyboard and terminal is in deluxe sinfile cabinet; kit . . . $399.95 plus $7 posl. & insur.

D Hazelllne terminals:Our prices too low lo quole— CALLUS D Lear-Slgler terminals/printers: Our prices loo low to quote:

CALL IS

□ Hex Keypad/Display kit $69.95 plus S2 posl. & insur.

□ AP-1 Power Supply Kit ±8V ® 5 amps) in deluxe sleel cabinet .. . $39.95 plus S2 post. & insur.

□ Gold Plated S-100 Bus Connectors. $4.85each, postpaid.

□ RF Modulator kit (allows you louse your TV set as a monilor)

...$8.95 postpaid.

□ 16k RAM kit (S-100 hoard expands lo 64k). . . $199.95 plus $2 posl. & insur.

□ 32k RAM kit $299.95 plus $2 posl. 8. insur.

□ 48k RAM kit $399.95 plus $2 posl. 8, insur. D 64k RAM kit. . . $499.95 plus $2 post.* insur.

□ 16k RAM Expansion kit (lo expand any of Ihe above in 16k hlocks up lo 64k) . . . $09.95 plus $2 posl. & insur. each.

r :■ Intel 8083 cpu Users' Manual.. $7.50posipaid.

□ 12" Video Monitor (10MHz bandwidth)... $139.95 plus $5 posl. & insur.

□ Beginner's Pak (see above) $169.95 plus $4 post. & insur.

□ Experimenter's Pak (see above) . . . $219.95 plus $6 posl. & insur.

D Special Microsoft BASIC Pak Without lermlnal (sra above). $329.95 plus $7 post. & insur.

□ Same as above plus ASCII Keyboard Terminal With Cabinet, Gel Free RF Modulator (see above). . . $499.95 phis $10 posl. & insur.

□ Special 8" Disk Edition Explorer/85 (see above). . $1496.95

plus $26 posl. & insur.

□ Wired & Tested... $ 1799.95 plus $26 post. & insur.

□ Extra R" CDC Floppy Drives... $499.95 plus $12 posl. & insur.

□ Cabinet & Power Supply For Drive $69.95 plus $:t post. & insur.

□ Drive Cable Set-up For Two Drives... $25 plus $1.50 post. &

□ Disk Controller Board With 1/0 Ports. . $199.93 plus $2 posl. & insur.

□ Special: Complete Business Software Pak (see above) $699.96 postpaid.

SOLD SEPARATELY:

□ CP/M 1.4... $IOOposlpaid.

□ CP/M2.0... $l50poslpaid.

□ Microsoft BASIC. .. $325 postpaid.

□ Intel 8085 cpu User Manual . $7.50 postpaid.

□ Level "A" Monitor Source Listing... $25 postpaid.

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Photo 3: Lisfmg o/ f/ie API function CIRCLE on the APL/DTC terminal screen and, below, a listing of special APL characters as they appear on the APL/DTC terminal. The last row is composed of characters that are created using an overstrike.

price tag of $7995 is rather steep for an APL machine, but a large body of CP/M software, including other computer languages, is available for the machine, somewhat mitigating the expense.

The language itself, called APL/V80 and available for $500 in a variety of formats, is the undisputed winner in every category except cost and documentation. The fact that it is more expensive is reasonable; after all, it does offer a faster APL that implements more operators. However, its weakness in the documentation, though slight, is disturbing.

POCKET/? TERMINAL

Here's $395 worth of convenience for anyone working with digital systems. Carry it anywhere in a pocket, valise or toolkit to enter and retrieve data, run diagnostics, change constants, test aata links, etc.

Look at its facilities:

•Transmits 128 I ASCII codes • Can display last 30 characters received • Displays full 64-character ASCII set on deariesegment LEDs 25-line RS232/C compatible interface I •Single 5V supply required at 400mA typical 110 or 300 baud transmission selectable • Parity codes, stop bits settable to your standard , •Obeys bell, cursor and

data format control codes Phone or write us tor more details now: GR ELECTRONICS, ,v...-- 1640 Fifth Street,

rr " Santa Monica, CA 90401. |

Telephone: (213) 395-4774. Telex: 65-2337 (BT Smedley SNM).

Because its documentation is not of the same caliber as the rest of the package, the software must stand on its own merits. (Fortunately, it does.) The documentation is terse, sometimes cryptic. Much of the language is defined in charts that give only the name of the operation being performed. Only one or two examples are given for each operator, far too few to be able to generalize. Comparing the Vanguard documentation to the Softronics documentation (which takes up to a half page to describe an operator and includes examples), I can summarize by saying that the Softronics documentation is much more "friendly" and much more useful as both a tutorial and a reference.

On the positive side, APL/V80 includes information on customizing the software and on building and using auxiliary processors (software) that allow the language to interface to custom external devices through Z80 I/O ports. In addition, Vanguard provides a set of APL defined functions (in both printed and disk file form) that implements almost all of the functions not in its APL. Data files can be accessed either sequentially or randomly through a mechanism called shared variables; this method is used by the IBM 5100 computer and other computers to provide an APL-like mechanism for interacting with disk files.

Vanguard has solved the problem of using its APL/V80 on an unmodified ASCII computer. According to Dr John Howland of Vanguard Systems Corporation, a defined function is included in the APL/V80 package that, when executed, allows the user to edit and list APL functions using mnemonic substitutes of any length for the APL characters that are not on a regular ASCII keyboard. Although I have not seen this system at work, it sounds like a viable solution.

Several notes are in order in relation to tables 1 and 4. The information in these tables is based on the APL software supplied with the APL/DTC computer, not the APL/V80 software. Again, according to Dr Howland, the APL/V80 software should run at the same speed as the software running on the APL/DTC computer (assuming that the Z80 board of the host computer runs at 4 MHz, the system clock frequency of the APL/DTC). This means that the timing figures of table 1 are valid for the APL/V80. In addition, the software features in table 4, listed as available on the APL/DTC, are also in the APL/V80 software, with the exception of the inner product function (available as a defined function in APL/V80). The APL/DTC allows an APL workspace of 34 K bytes, while the APL/V80 software allows a workspace of about 27 K bytes when running on a 64 K-byte CP/M system. The additional memory space used by the APL/DTC software is devoted to the implementation of hardware-related features (such as access to the real-time clock and a machine-related security function).

Conclusions

Versions of APL are available to fit every budget. The Ramware APL80 is a usable version of APL for the TRS-80, and it is quite a bargain at $39.95. Softronics APL, although it does have some serious limitations, is in a medium price range at $350. Vanguard APL/V80, at $500, is the fullest and fastest APL. Your needs and the amount of money you can spend will determine which version is best for you.B

208 April 1981 © BYTE Publications Inc

Circle 139 on inquiry card.

Finally, there is a

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Get onto onComputing. Call 800-258-5485.

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+

•#\tr>\

mv-::

7

«T

RAM 17 T1*^^

-the memory that took 18 months to hatch!

18 months ago, we designed RAM 17 around a brand new 16K static RAM from Hitachi that not only had the reliability and speed of static memory, but also consumed less power than dynamics.

Unfortunately, pricing on this VLSI chip back then was such that we didn't feel RAM 17 would meet our tough standards for cost-effectiveness. In the past few months, however, volume production has lowered chip prices to where RAM 17 now represents an exceptional value in S-100 memory.

Features include a stunningly low 250 mA typical power consumption, guaranteed operation (no wait states) at 6 MHz with CPU Z and 10 MHz with CPU 8085/8088, full compliance with all IEEE 696/S-100 specifications (including 24 bit addressing and standard board size), four optional 2K windows to accommodate memory mapped disk controllers, pinout compatibility with 2716 EPROM (allows RAM/ROM mix on a single board), plus all the other features that make CompuPro memory the first choice of system designers world-wide.

$1595 CSC (2 year limited warranty), $1395 A/T (1 year limited warranty), $1095 Unkit.

These features may appear to be those of a dream memory of the future... but CompuPro is delivering RAM 17 now at finer computer stores near you.

CompuPro™

#

division of

(OjlBB i

"ELECTRCmI :,

OAKLAND AIRPORT, CA 94614 (415) 5620636

MEMBER

on

CompuPro computers don't JUST work:

they WORK, and WORK, and WORK, and WORK, and

If there's anything more important than throughput, it's reliability: that's why CompuPro System Components are painstakingly engineered not just to work, but to keep on working. Say goodbye to unexplained system hardware glitches - CompuPro products conform to all IEEE696/S-100 specifications, thereby ensuring well integrated (and predictable) system performance. Also, should a system malfunction ever occur, the bus oriented nature of S-100 machines allows you to simply pull out the bad board and plug in a replacement.. .and when you depend on a computer, you know what it means to minimize down time.

All CompuPro products meet the most demanding mechanical and electrical standards, and are backed with one of the best warranties in the business (1 year limited warranty on all products, 2 year limited warranty with exchange program for products qualified under the Certified System Component program).

Sure, computers can be great intelligent toys; but for scientific, industrial, and commercial applications, toys aren't good enough. You need a computer that works, works right, and keeps on working: you need CompuPro system components.

NEW! DISK 1: THE ULTIMATE

a/t $495, csc $595 DISK CONTROLLER.

Finally, a disk controller worthy of the CompuPro name. This state of the art design uses properly implemented DMA with artibration, meaning that Disk 1 can co-exist - without any conflict whatsoever-on the same bus as other DMA devices. And because Disk 1 has 24 bit DMA addressing (not memory mapped), you have access to a full 16 megabyte memory map.

What about speed? Disk 1 transfers data independently of CPU speed, allowing operation with 6 MHzZ80s®* . Versatility? Disk 1 handles up to four 8" or 5.25" floppy disk drives (including 96 track high density minifloppies), single or double sided, single or double density (soft sector). Convenience? Disk 1 includes BIOS for CP/M-80®* ■, as well as on-board boot for automatic startup and on-board serial port for system initialization startup. Compatibility? Disk 1 is compatible with MP/M®* , OASIS, CP/M-80, and CP/M-86. Reliability? Uses industry-standard, third generation controller chips and the same design excellence that is a part of every CompuPro product.

We weren't going to put out another me-too disk controller... and we didn't. The CompuPro Disk Controller is here.

SYSTEM SUPPORT 1 MULTIFUNCTION BOARD

$295 Unkit, $395 A/T, $495 CSC This multi-purpose S-100 board provides sockets for4K of extended address EPROM or RAM (2716 pinout) with one battery backup socket; battery backup month/day/year/time crystal clock with BCD outputs; optional math processor (9511 or 9512); full RS-232 serial port; three 16 bit interval timers (cascade or use independently); two interrupt controllers service 15 levels of interrupts; power fail indicator; and comprehensive owner's manual with numerous software examples. Conforms fully to all IEEE 696/S-100 standards. (Add $195 to the above prices for the optional 9512 math processor.)

SOFTWARE

8088/8086 MONITOR-DEBUGGER: Supplied on single sided, single density soft-sector 8" disk. CP/M®* compatible. Great development tool; mnemonics used in debug conform as closely as possible to current CP/M®* DDT mnemonics. $35.

PASCAL/M* FROM SORCIM: PASCAL-easy to learn, easy to apply - can give a microcomputer with CP/M®* more power than many minis. We supply a totally standard Wirth PASCAL/M* 8" diskette

and comprehensive manual. Specify Z-80* or 8080/8085 version. $175.

Most CompuPro products are available in Unklt form, Assembled/Tested, or qualified under the high-reliability Certified System Component (CSC) program (200 hour burn-in, more). Note: Unkits are not intended for novices, as de-bugging may be required due to problems such as IC infant mortality. Factory service is available for Unkits at a flat service charge.

r\

<j

XJ>

COMPUTER ENCLOSURE 2

Introductory price: $795 (specify rack mount or desk top version) Includes fused, constant voltage power supply ( + 8V at 25 Amps, ±16V at up to 6 Amps); 20 slot shielded/active terminated motherboard; and deluxe enclosure with dual AC outlets on rear, heavy-duty line filter, circuit breaker, quiet ventilation fan, and reset switch. Rack mount version includes slides for easy pull-out from rack frame.

Also available: COMPUTER ENCLOSURE 1. Same as above, but less power supply and mortherboard. $289 desktop, $329 rack mount.

PRICE BREAKTHROUGH ON 16K MEMORY EXPANSION - 8 RAMS/S29

These top quality, low power, high speed (200 ns) 16K dynamic RAMs expand memory in TRS-80* -I, -II, and -III computers (color model too) as well as machines made by Apple, Exidy, Heath H89, newer PETs, etc. Backed by 1 year limited warranty. Add $3 for two dip shunts plus TRS-80* conversion instructions. Limited quantity.

S-100 MEMORIES FROM THE MEMORY LEADER

CompuPro memories feature fully static design to eliminate dynamic timing problems, full conformance to all IEEE 696/S-100 specifications, high speed operation (4/5 MHz Unkit, 10 MHz A/T and CSC), low power consumption, extensive bypassing, and careful thermal design.

Unkit A/T CSC

8K RAM2A $159 $189 $239

16K RAM 14(extended addressing) $279 $349 $429

16K RAM 20-16

(extended addressing and bank select) $319 $399 $479

24K RAM 20-24

(extended addressing and bank select) $429 $539 $629

32K RAM 20-32

(extended addressing and bank select) ...$559 $699 $799

NEW! 64K STATIC RAM 17 . Amazingly low power in a 64K fully static RAM board: less than 500 mA maximum, 250 mA typical! It's fast, too; runs with 6 MHz Z-80®* CPUs, or 10 MHz 8080-family CPUs (8085, 8088, etc.). Uses IEEE extended addressing protocol, and may optionally turn off 2K windows from EOOO to FFFF in order to accommodate North Star or Morrow disk controllers (the CompuPro disk controller can use the full 64K since it employs properly implemented DMA techniques). $1095 Unkit, $1395 A/T, $1595 CSC.

TERMS: Prices shown do not include dealer Installation and support services. Cal res add tax.

Allow at Ieast5%shlpping; excess refunded. Orders under $15 add $2 handling. VISAW and Mastercard® orders {$25 min) call our 24 hour order desk at (415) 562-0636. Include street address (or UPS delivery. Prices are subject to change without notice.

FREE CATALOG: Want more information? Then send for our free catalog. For fast 1st class delivery, add 41 cents in stamps; foreign orders add $2 (refundable with order).

•LEGAL CORNER: 280A is a registered trademark ot Zilog; TRS-80 is a Irademark of the Tandy Corporation. PASCAL/M is a Irademark of Sorcim; CP/M and MP/M are registered trademarks of Digital Research.

COMPUPRO PRODUCTS ARE AVAILABLE AT FEVER COMPUTER STORES WORLD-WIDE. . .CALL (415)562-0636 FOR THE STORE NEAREST YOU.

Circle 140 on inquiry card.

CompuPro"

division of

pi»EJiJ

ELECTRONICS^

OAKLAND AIRPORT, CA 94614 (415) 562-0636

BYTELINES

News and Speculation About Personal Computing

Conducted by Sol Libes

Jony Enters Word-Processing Arena: The Sony Corporation is a real innovator. First, it decided to enter the word-processing market. Then it introduced a new concept in word processing that's surely a winner. Called the Typecorder, it consists of a small keyboard/ microcassette unit [about the size of two issues of BYTE. ...CW] that has a microcomputer and 1-line LCD display; it costs $1400. Small enough to fit into your briefcase, it permits you to create text, edit it, and store it on tape. The tape can be run off on a companion printer, available for $800, or through a word-processor system due later this year. You can transmit the text over telephone lines via an optional acoustic-coupler modem, or you can process the text through a non-Sony system. Typecorder lets you mix audio and digital information on cassette, so you might devise some interesting computer-assisted software.

I have no doubt that Sony's concept, features, and low price will be popular and will lead to applications beyond word processing.

^Hk Close Look At The IBM Olsplaywrlter: IBM is

now delivering its new lowcost Displaywriter word-processing system; it's only $1000 more than the Radio Shack TRS-80 Model II, and it's really a general-purpose microcomputer that uses the Intel 8088 microprocessor.

IBM rents word-processing software for $50 per month, which sounds rather steep; however, consider the TRS-80 owner who uses WordStar. WordStar costs $500, plus another $150 for the CP/M operating system.

Further, MicroPro International issues WordStar updates about four times a year at $25 to $40 apiece. Hence, WordStar can cost a user about $850 for the first year of operation.

My point is that the price difference between a wordprocessing system using an IBM (or Wang, Lanier, etc) and a Radio Shack system is really not that great. Add to this IBM's terrific service and its promises of extended I/O, communications, and applications packages for the Displaywriter, and you'll see that IBM is competing aggressively in the microcomputer marketplace.

W.

ord-ProcessIng Prices Dropping: Wordprocessing-system prices are dropping. Following on the heels of IBM's new low-cost word-processing system, Wang Laboratories has introduced a new stand-alone system for $7500, with discounts offered on multiple units. Lanier Business Systems is expected to introduce an inexpensive system. A B Dick is planning a $7500 system that includes software (the others do not), and is drawing up plans for a local-network system that shares a printer, which will further reduce costs.

Vomputer Hobbyists Gather For Huge Flea Market: On Saturday and Sunday, April 25th and 26th, several thousand computer hobbyists will flock to Trenton State College, Trenton, New Jersey, for the Trenton Computer Festival, the world's largest personal-computer-equipment flea market. This annual outdoor event is now in its sixth year. A multitude of swap and seller tables covering more than 5

acres of real estate feature everything from complete computer systems to tiny electronic parts. There will be speakers, user-group meetings, an indoor exhibition area, and a banquet on Saturday night.

The Festival is sponsored by the Amateur Computer Group of New Jersey, the Philadelphia Area Computer Society, and the Trenton State Computer Society. The funds raised help support these nonprofit organizations and their activities. For information, call (609) 771-2487, or write to TCF-81, Trenton State College, Trenton NJ 08625.

Wredlt Cards With Intelligence? The Battelle Memorial Institute is studying the feasibility of a credit card with a built-in microprocessor. Such a card has already been developed in Europe and will soon be tested. It is expected that intelligent credit cards will provide added security without requiring large computer networks.

H

ome-Inform at Ion Market Takes Shape:

Several tests are underway to determine the best way to capture the lucrative homeinformation market. In the meantime, there's a battle brewing for control of the market, and the major contestants are the telephone companies, principally AT&T (American Telephone and Telegraph) and the cable-television companies.

By 1983, AT&T is expected to launch its home-information systems. A user will probably have to buy a special video-display terminal, about $250, plus pay a monthly service fee in the $4 to $8 range.

The cable-television companies plan to provide the same two-way services. Companies such as Westinghouse, General Electric, and American Express are snatching up cable-television outfits. Several cabletelevision home-information systems are already in operation. However, the real battle is at least two years away when AT&T actually enters the market.

I he Terminal You May Have Been Waiting For: Hewlett-Packard has introduced a super-intelligent terminal, called the Model 2626A. It displays 119 lines with 160 characters per line; moreover, the display can be divided into four windows. There are two independent I/O ports, so that you can simultaneously communicate through separate windows with two different computers. There are user-programmable keys, and the bell has fifteen pitches, sixteen intensities, and two volumes—which means that you can play decent-sounding music on it.

I Icrosoft And DEC Join Forces: Microsoft's first software product was a 4 K-byte BASIC interpreter, which used keywords similar to DEC's (Digital Equipment Corporation's) BASIC-Plus. It launched Microsoft on the road to success with expanded BASICs and other language packages. DEC has now adopted Microsoft BASIC for its GIG I (general imaging generator and interpreter) color-graphics system. Microsoft's BASIC is contained in ROM (readonly memory) in a microprocessor-based unit. GIGI is used with the PDP-11 and VAX-11 systems.

212 April 1981 © BYTE Publications Inc

Whether the job is building a home or a world MILESTONE helps...

With today's concerns about increasing costs and declining productivity it is true more than ever that any project worth doing deserves careful planning. Whether your're planning a construction project or the opening of a new retail store, you must carefully schedulue your manpower, dollars and time in order to maximize productivity.

MILESTONE is a critical-path-network-analysis program. It runs on a desktop microcomputer, is inexpensive and simple enough for anyone to use.

MILESTONE'S design is a product of many years of experience in the "real world" of small-project management. In such an enivornment the primary purpose of planning is to help the project leader clarify the task at hand and to help him communicate his ideas to his subordinates and superiors. For these two reasons the designers of MILESTONE stressed it's interactivity and comprehensive reporting.

Most of the design effort was put into eliminating unnecessary or redundant operator input and to checking all entries for validity. By organizing the project data for you, you can interactively modify your project plan leaving MILESTONE to perform the tedious calculations and to display the results.

Internally, MILESTONE treats your project as a series of activities. Each activity has a name, duration, capitol cost, mix of manpower, and an associated list of other activities that must be completed first. The list of associated activities (or prerequisites) provides a thread that MILESTONE uses to link all the jobs together into an overall project schedule. Every time you add a new activity or make a change to an existing one, the entire schedule is recomputed and the results are immediately redisplayed on the screen.

For MILESTONE a project is simply any task made up of steps that must be performed in sequence. After dividing a project into it's composite steps, MILESTONE can help you plan, schedule and control the project.

Specifically here are some of the things you can do,

Find out which activities are time critical and can't be delayed

Discover which activities have slack time and can be delayed without delaying the entire project Prepare a detailed cost estimate based upon a summation of each activity's individual equipment and manpower expenses Change an activity and instantly see the impact on the overall project schedule Investigate tradeoffs between manpower, dollars, and time

Keep track of your project's progress by periodically updating the schedule to reflect changes in the plan and completed activities

MILESTONE requires 54K RAM and CP/M, Apple Pascal, or UCSD Pascal. CP/M versions need no support language. All Apple II versions require 24 x 80 video card. Formats: 8" single denisty IBM softsectored, NorthStar DD, Micropolis Mod II, Superbrain 3.0, Apple II. Price is $295. Manual alone - $30. Add $7.00 for shipping.

SOFW/1RE SOFTWARE DIGITAL AMRKETING

DIGITAL/MARKETING

2670 CHERRY LANE

WALNUT CREEK • CALIFORNIA 94596 • (415) 938-28BO

MILESTONE trademark Organic Software CP/M trademark Digital Research Apple Pascal Trademark Apple Computer UCSD Pascal trademark Regents University California

Circle 141 on inquiry card.

BYTE April 1981 213

BYTELINES

diagnostic Disk Troubleshoots Your Disk Drive: Dysan Corporation will introduce a floppy disk that checks disk-drive operation. It contains software and geometric patterns that test radial positioning, linearity, hysteresis, eccentricity, index timing, skew, relative head positioning, azimuth, drive rpm (revolutions per minute), head load, access time, and head/ media compliance. The first model to be introduced will be a $40 IBM 3740-compatible 8-inch disk.

w.

ord-Processor Dictionary Introduced:

IBM's new Displaywriter word-processor system features an optional dictionarysoftware package that checks the spelling of up to 70,000 words. Similar packages will soon be available for other systems. The first is Microspell, to be distributed by Lifeboat Associates. It checks the spelling of any ASCII-text file stored on disk under CP/M. Thus, the program can be used with files created by WordStar, WordMaster, Magic Wand, and other word-processing packages.

I

BM Status Report:

Many critics want you to believe that IBM's dominance in the data-processing market is eroding rapidly. Don't believe it, because more than a third of the $60 billion 1980 computer market was IBM's. In all industry, IBM's $23 billion in sales ranked eighth, and its $3 billion in total profits was third. By contrast, the second largest computer maker, Burroughs, had $2.83 billion sales and $305.5 million in profits.

IBM is not always the technological leader. Rather, it has used marketing clout to establish dominance in any market it enters. For example, IBM sells 70% of the large mainframe computers in the USA.

However, during the last few years, DEC (Digital

Equipment Corporation), Data General, Wang Laboratories, and Amdahl have grabbed an increasing share of the computer market. Several Japanese companies, such as Fujitsu, Hitachi, and NEC (Nippon Electric Company), are also moving in on IBM's territory. On the horizon, IBM faces strong competition from AT&T, Xerox, and Exxon, as they move into local and interoffice data-communication network markets.

These factors have had a serious impact on the value of IBM's stock. In the 1960 s, it sold for as much as 66 times earnings; it now sells for 15 to 20 times earnings.

IBM's strategy for the 1980s is based on a coming generation of mainframes that will set new levels in price versus performance and emphasize telecommunication networks. In addition, IBM has opened retail stores and is entering several new markets via joint ventures, such as a videodisk project and satellite communications. However, it is likely that these projects will be a minor part in the whole IBM strategy for the 80s. Although IBM will become more involved in data networking, its focus will continue to be large central data-processing operations.

IM,

lew 8-Inch Winchester Has 136 Megabytes: Ontrax Corporation has unveiled the largest capacity 8-inch Winchestertype disk drive to date. It stores 136 megabytes on five platters using sixteen read/ write heads. With a controller, the drive sells for $5000 in quantity. That's 0.004 cents per byte, compared to about 0.2 cents per byte for a typical single-density floppy-disk drive.

R,

random News Bits:

Computerland, High Technology, and The Computer Store plan to stock at least one Japanese-made personal computer. Japanese sup

pliers currently being considered are NEC, Casio, Canon, Sharp, and Panasonic. ...Tandy Corporation and the Professional Farmers of America (PFA) have introduced Instant Update, a data-base service that uses TRS-80 videotext terminals (actually TRS-80 Model II). Via telephone connections, the service provides information affecting commodity prices and crop yields and gives access to Washington Watch News. Commodity prices are updated every 10 minutes. The service costs $95 per month. ...Sony has introduced a 3'/2-inch microfloppy-disk drive. (Editor's note: See this month's editorial.) It is currently being marketed to OEMs and systems houses; its capacity is reputed to be over 800 K bytes (unformatted) per disk. ...Two teenagers have been charged with masterminding a scheme that shut down DePaul University's computer during enrollment week. The shutdown cost DePaul $22,252 in computer time, repairs, and manpower. The teenagers said they did it to disprove the school's claim that it couldn't be done. ...Intel Corporation announced its figures on net income and revenues for the year that ended December 31, 1980. Net income was $96.7 million, up 24% from the previous year, and revenues were $855 million, up 29% from 1979. Most of the growth occurred in the first half of the year....

R,

random Rumors: Informed sources say that Tandy will lower the price of its Videotext terminal to compete with AT&T's projected home-information terminal. ...Apple Computer is developing a new microcomputer using the 16-bit Motorola 68000 microprocessor. ...At least one software-development house has leaked that it is seriously negotiating with Apple on a disk operating system for a machine called the Apple IV. ...Look for a lower-priced version of Hewlett-Packard's HP-85

desk-top computer—maybe less than $2000—to be called the HP-83. It lacks some of the HP-85's features, but it has a plug-in disk-drive option. ...Exxon's Kylex division is developing a 40-row by 80-character LCD (liquidcrystal display) for computer-display terminals. ...Sony might be developing a personal-computer system for this year's market. Sony may include an interface for its new Typecorder wordprocessor terminal. ...Digital Equipment Corporation is developing a new line of personal-computer products with extensive software support, including an operating system based on RT-11 with VAX-compatible BASIC...

WOBOL For The 8086 Announced: The software picture for 8086-based 16-bit microcomputer systems keeps improving. Seattle Computer Products has announced an 8086 version of Microsoft BASIC. Now Microsoft has COBOL-86, which runs under the CP/M-86 operating system.

The projected execution time of these packages is three times as fast as the 8080/Z80 versions. As a result of the 8086's multitasking capabilities, the packages will be better suited for multiple-user systems than the 8-bit versions.

MAIL: I receive a large number of letters each month as a result of this column. If you write to me and wish a response, please include a stamped, self-addressed envelope.

Sol Libes POB 1992 Mountainside NJ 07092

214 April 1981 © BYTE Publications lnc

ALL THESE FEATURES... IN THIS SMALL SPACE...

AT THIS LOW PRICE!

Greater computer power. . . fewer separate components . . . larger capability . . . simpler to operate . ... modular maintenance . . .

These are the unique benefits of the Quasar Data QPD-100 Floppy Disk Computer. . . plus unsurpassed reliability...plus 12-month warranty on all PC boards.

Its highly reliable, industry-standard MFE drive is compact. Accepts both single AND double-sided disks.

Upgradeable from the Z-80® microprocessor-based system to our ZSOOO^ microprocessor-based system by simply plugging in extra PC cards. Hard disk and multi-user systems available.

As your requirements grow, your QDP-100 can grow to fit them.

The Quasar Data QDP-100H is a larger version with 6-megabyte capacity; includes one double-sided floppy and one 51/t microwinchester hard disk.

Both the Quasar Data QDP-100 and QDP-100H are fully compatible with all standard terminals.

Phone or write for descriptive bulletin and specifications. And ask for a demonstration. Dealer inquiries invited.

QUASAR DATA'S QDP-100 COMPUTER SYSTEM.

4,695

18" wide 16%" deep 11" high

Complete systems available

'" Z-80 and Z-8000 are trademarks of Zilog Corporation

~CP/MandMP/M

are trademarks of Digital Research Corp

Circle 142 on inquiry card.

10330 Brecksville Road, Brecksville (Cleveland), Ohio 44141

Phone: 216/526-0838 / 526-0839

Telex: 241596

BYTE April 1981 215

SiiperSofft's

Gallery of CP/M Ma§{erwork§

u

SUPER-M-LIST: A complete, easy to use mailing list program package. Allows for two names, two addresses, city, state, zip and a three digit code field for added flexibility. Super-M-List can sort on any field and produce mailing labels direct to printer or disk file for later printing or use by other programs. Super-M-List is the perfect companion to TFS. Handles 1981 Zip Codes! Requires: 48K CP/M Supplied with complete user manual: $75.00 manual alone: $10.00

TFS-Text Formatting System: An extremely powerful formatter. More than 50 commands. Supports all major features including:

• left & right margin justification • userdefined macros

• dynamic insertion from disk file * underlining and backspace TFS lets you make multiple copies of any text. For example: Personalized form letters complete with name, address & other insertions from a disk file. Text is not limited to the size of RAM making TFS perfect for reports or any big job. Text is entered using CP/M standard editor or most any CP/M compatible editor. Requires: 24K CP/M

Supplied with extensive user manual: $85.00 manual alone: $20.00 Source to TFS in 8080 assembler (can be assembled using standard CP/M assembler) plus user manual: $250.00.

TEXT PROCESSING

R

DIAGNOSTICS I: Easily the most comprehensive set of CP/M compatible

system check-out programs ever assembled.

Tests:

• Memory • CPU (8080/8085/Z80) • Terminal • Disk • Printer To our knowledge the CPU test is the first of its kind anywhere. Diagnostics I can help you find problems before they become serious. A good set of diagnostic routines are a must in any program library. Minimal requirements: 32K CP/M. Supplied with complete user manual: $75.00 Manual alone: $15.00

DIAGNOSTICS II: Includes all of Diagnostics I, plus:

• Every test is "submit"-able

• A complete Spinwriter/Diablo/Qume test has been added (Serial Interface only)

• Output may be logged to disk

• Expanded memory test

• Expanded terminal test Expanded disk test

Diagnostics ll provides the next level in system maintenance.

Requires: 32K CP/M

Price: $100.00 Manual only: $15.00

SYSTEM MAINTENANCE

A ititi tuti t A A A * * i A * * A A faA

'TINY' PASCAL II: We still call it Tiny' but it's bigger and better than ever! This is the famous Chung-Yuen 'Tiny' Pascal with more features added. Features include:

• recursive procedures/functions • integer arithmetic * CASE

• FOR (loop) • sequential disk I/O • 1 dimensional arrays

• IF...THEN...ELSE • WHILE • PEAK & POKE

• READ & WRITE ■ REPEAT...UNTIL • more

Tiny' Pascal is fast. Programs execute up to ten times faster than similar BASIC programs. SOURCE TOO! We still distribute source, in Tiny' Pascal, on each discette sold. You can even recompile the compiler, add features or just gain insight into compiler construction.

Requires: 36K CP/M. Supplied with complete user manual and source on discette: $85.00. Manual alone: $10.00

STACKWORK'S FORTH: A full, extended Forth interpreter/compiler produces COMPACT, ROMABLE code. As fast as compiled FORTRAN, as easy to use as interactive BASIC. SELF COMPILING: Includes every line of source code necessary to recompile

itself. EXTENSIBLE: Add functions at will. Z80 or 8080 ASSEMBLER included. Single license, OEM licensing available. Please specify CPU type: Z80 or 8080 Supplied with extensive user manual and tutorial: $175.00 Documentation alone: $25.00

SSS FORTRAN: The SSS FORTRAN compiler is fast, efficient, and complete (full 1966 ANSI standard with extensions). The RATFOR compiler compiles into FORTRAN allowing the user to write structured code while retaining the benefits of FORTRAN. The FORTRAN supports many advanced features not found in less complete implementations, including: complex arithmetic, character variables, and functions. Complete sequencial and random disk I/O are supported. SSS FORTRAN will compile up to 600 lines per minute! Recursive subroutines with static variables are supported. ROMable ".COM" files may be generated. SSS RATFOR allows the use of contemporary loop control and structured programming techniques. SSS RATFOR is similar lo FORTRAN '77 in that it supports such things as:

• REPEAT...UNTIL " WHILE • IF..THEN...ELSE SSS RATFOR is supplied with source code in FORTRAN and RATFOR. System Requirements & Prices:

SSS FORTRAN requires a 32K CP/M system. SSS FORTRAN with RATFOR: $325.00 SS FORTRAN alone: $250.00

RATFOR alone: $100.00

(Sold only with valid SSS FORTRAN license)

i

^f*1 ♦ **$** ♦ W ♦ "*♦ **1 PROGRAMMING LANGUAGES fr** f w f" j M j w f'"^

UTILITIES I: A collection of programs that you will find useful and

maybe even necessary in your daily work (we did!).

Includes:

GREP: Searches files for a specified string

SORT: In core sort of variable length records

CMP: Compare two files for equality

PRINT: Formatted listings to printer

PG: Lists files to CRT a page at a time

. . . plus more . . . Requires: 24K CP/M Supplied with manual on discette: $60.00

UTILITIES II: Many new programs not available elsewhere. Includes these "file" utilities:

DIFF: Source comparitor

PR: Powerful multicolumn output formatter

CAT: Concatenate files

RPL: Substitute strings in files

. . . plus more . . . Requires: 24K CP/M $60.00 Supplied with manual on discette

UTILITIES

TERM: A complete intercommunications package for linking your computer to other computers. Link either to other CP/M computers or to large timesharing systems. TERM is comparable to other systems but costs less, delivers more and source is provided on discette! With TERM you can send and receive ASCII and Hex files (COM too, with included convertion program) with any other real time communication between users on separate systems as well as acting as timesharing terminal.

• Engage/disengage printer • errorchecking and auto retry

• terminal mode for timesharing between systems

• conversational mode • send files • receive files Requires: 32K CP/M

Supplied with user manual and 8080 source code: $150.00 Manual alone: $15.00

^INTERCOMPUTER COMMUNICATIONS!

Mii

ANALIZA: An amazingly accurate simulation of a session with a psychiatrist. Better than the famous "ELIZA" program. Enlightening as well as fun. An excellent example of Artificial Intelligence. Requires: 48K CP/M, CBASIC2 Cost: $35.00

ENTERTAINMENT

ft

, ,..- : , ::;:,-, "■"'.;- , '"■■.;,',;. '" :;

u

Cl>

Z8000CROSSASSEMBLER:Supports:

full Z8000 syntax, segmented and

:,:

unsegmented mode, full 32-bit arithmetic, hex output, listing output,

U-.

'■>.-'

"downloader".

V.

:""'.

Requires: 56K CP/M $500.00

1 year maintenance $300.00

W

:'l"i

manual alone $ 50.00

;

$

>.;--■,_'■ - - A zeoootoo! J - :< =; ^

^

ENCODE/DECODE: A complete software security system for CP/M. Encode/Decode is a sophisticated coding program package which transforms data stored on disk into coded text which is completely unrecognizable. Encode/Decode supports multiple security levels and passwords. A user defined combination (One billion possible) is used to code and decode a file. Uses are unlimited. Below are a few examples:

• databases • payroll files • programs • tax records

Encode/Decode is available in two versions:

Encode/Decode I provides a level of security suitable for normal use. Encode/Decode II provides enhanced security for the most demanding needs. Encode/Decode I: $50.00 Encode/Decode II: $100.00 manual alone: $15.00

^^ SOFTWARE SECURITY f

On line "Help" system provided with every program package.

SuperSoft

First in Software Technology

CP/M Formats: 8" soft sectored, 5" Northstar, 5" Micropolis Mod II, Vector MZ, Superbrain DD/QD

All Orders and General Information:

SUPERSOFT ASSOCIATES

P.O. BOX 1628

CHAMPAIGN, IL 61820

(217)359-2112

Technical Hot Line: (217) 359-2691

(answered only when technician Is available)

CP/M REGISTERED TRADEMARK DIGITAL RESEARCH

SuperSofffs DIAGNOSTICS I & II for CP/M

Since the beginning, programs have been written to verify the correctness of computer systems. This task has usually fallen on the manufacturers of computer equipment. However in the case of microcomputers, the manufacturers have been reluctant to supply such programs along with their hardware. First, because they often are not the ones called on to fix that hardware, and second, because the low cost of such systems often does not allow for such a large programming effort. The tremendous number of CP/M systems have made it possible for us to offer both DIAGNOSTICS —I & II at an affordable price, since we do not have to deal with a myriad number of console devices and disk systems, we simply use the standardized system calls.

Both packages perform tests on the five critical areas of your computer system: • Memory • CPU • Printer • Terminal • Disk drive

DIAGNOSTICS-I provides an excellent level of testing. DIAGNOSTICS —II is simply the finest set of system maintenance routines ever written for microcomputers. DIAGNOSTICS —II includes all of DIAGNOSTICS —I. but goes much further in providing the user with even more checks, tests, and reports.

DIAGNOSTICS-I Features

The MEMORY TEST allows every byte of user memory to be tested. Both a quick test as well as a walking bit' test are included. Error reports summarize errors by bit as well as address.

The CPU TEST interprets a program that is designed to execute all single instruction sequences and many multiple instruction sequences. After each instruction sequence, the program tests all of the CPU registers to see that the proper registers changed correctly, and only those registers changed. This will detect, for instance, if storing into the A register affects the B register. The CPU test will automatically recognize the type of CPU you have. To the best of our knowledge, nothing as powerful as the CPU test is available anywhere else.

The PRINTER TEST prints a one line pattern, then rotates the pattern one character and prints again. This barber pole' scheme is simple, yet elegant, since it checks that every printable character can be printed in every printer column, and does so in a manner that makes any error obvious at a glance.

The TERMINAL TEST prints a 'barber pole' and then exercises cursor positioning, foreground, background, eraseall, erase-to-end-of-line, erase-foreground, and erase-background. If some of these features are not available on your terminal, they can be skipped. The test can be used with any terminal; many standard types are supplied pre-patched. any other can be patched by the user.

The DISK TEST writes a unique pattern in each sector, and then does a pseudo-random seek/read test within the file area.

DIAGNOSTICS-II Features

Every test is "submit'-able. In fact, a sample submit file is provided with each disk. This means that the user can run a series of tests without operator interaction. To further decrease the need for the user to "baby sit' the tests, the output of tests may be logged to disk for later review. This makes overnight testing very easy yet informative.

We started with DIAGNOSTICS —I and added all the features that users wanted as well as some of our own. Below is a description of some of the enhancements.

MEMORY TEST:

• Default to size of CP/M TPA • Bank select (a necessity for more than 64k)

• Memory map of system displayed • Memory speed test • Burn in test

PRINTER TEST:

• Spinwriter, Diablo, Qume test which checks all head and carriage motions as well as ASCII printing features. (This is a very thorough test!)

DISK TEST:

• Writes a unique pattern to each sector on disk, verifying as it runs.

• User defined seek patterns allowed (This is great for drive allignment and testing!)

• Tests user specific user defined sectors.

The TERMINAL TEST is the same as for DIAGNOSTICS —I except that it is submit -able.

The CPU TEST is the same except that it is "submit -able and output may be logged to disk.

Also, a QUICK TEST has been added which willcheckthe memory, disk drives, and CPU in your system in less than four minutes! The test is, of course, not as thorough as the ones described above, but provides a measure of confidence. It is particularly useful if used every time the system is powered up.

SISSIES !i $I?£?™ *» Orders and General Information:

DIAGNOSTICS II: $100.00 Cfm*rOi# P^S^ SUPERSOFT ASSOCIATES

DIAGNOSTICS II: $100.00 ft/rwCV/ F^S^ SUPERSOFT A

(manual only): $15.00 JUJjXLSf^i \mmm* P.O. BOX 1628

Both require 32K cp/m First in Software Technology

CHAMPAIGN, IL 61820

(217)359-2112

Technical Hot Line: (217) 359-2691

__,.._ „„ _,„„.., „,,., (answered only when technician Is available)

CP/M Formats: 8 soft sectored, 5 Northstar, 5 Micropo

lis Mod II, Vector M2, Superbrain DD/QD -civmnEosre»fDtiudem»mhhgit«l heseauch

An Introduction to Data Compression

Harold Corbin

11704 Ibsen Dr

Rockville MD 20852

Even though the cost of data storage continues to decrease fairly rapidly, there are still a number of situations where it is desirable to squeeze more data into a physical storage device. Often the typical microcomputer has limited memory, small disks, or slow cassettes. With any of these storage limitations, data compression may offer a method of using the existing device to store larger quantities of data or to provide improved access time to the data. The use of data compression can also provide significant improvement in the transmission of data over communication networks since there are fewer bits to send in order to convey the information.

ASCII code does not consider that

the frequency of the characters in

the file is not uniform.

The basic idea in data compression is to use more efficient codes to represent the information in a file or to remove redundant and unnecessary information from the file. With data compression in effect, the system stores or sends only the minimum data necessary to convey the original information.

In a typical file, the individual characters are represented by fixed-length codes such as ASCII (American Standard Code for Information Interchange). This representation does not consider that the frequency of occurrence of the characters in the file is not uniform. In typical English text, E is the most common letter and Z is the least frequently used letter. Table 1 presents a frequency analysis for letters in English text. Using a code such as ASCII for storing or transmitting text means that

the same number of bits is used for the most frequently occurring letter as well as for the least frequently occurring letter. This method of encoding data uses more bits to represent the information in the file than is necessary. In this article, I will illustrate ways to store data more efficiently.

Encoding the data in a more efficient form is called data compression. There are a variety of methods that have been used to compress data, but all of them attempt to reduce the redundancy of the original data. Most large data-processing systems provide some form of file compression, since storage costs money. Also, it is often less expensive to pay for the computer time to compress and expand the data than to pay for mass storage. The user of a large system usually has PACK and UNPACK commands available to allow compression and expansion of his files.

Typical data-processing systems use some form of zero or space suppression to do their data compression. This method is easy to implement and not very expensive to run, and produces fairly good compression for many types of data. The efficiency of this compression method is dependent upon how many spaces or zeros occur in the file. Typically, a source file of assembly-language statements is a good candidate for data compression. Fifteen to twenty percent compression of an assembly-language source file is not uncommon.

Data-Compression Methods

A space-compression capability can be implemented in several ways. Two common ones are bit mapping and recurrence coding. In the bit-mapping scheme, a bit map exists that is long enough to match one bit of the bit map to each byte of data in the original file. In the map, a 0 is stored for each byte in the data that is a space, and a 1 is

218 April 1981 © BYTE Publications tac

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NOW AVAILABLE! 256KB memory on a dual height board only $1925. CHRISLIN INDUSTRIES now offers state-of-the-art 64K RAM Memory system designs. Like our recently introduced 512KB MULTIBUS® compatible single card memory our 256KB LSI 11/23 memory is an industry first.

Free up critical and expensive backplane space. Saves you 3 dual slots.

Addressable in 4K increments up to 4 Megabytes.

On board parity generator checker totally DEC hardware and software compatible.

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Battery back-up capability. 256KB unit draws less than 300 ma at 5 volts in battery back-up mode.

Tested and burned in. Full year warranty.

DON'T ASK WHY WE CHARGE SO LITTLE, ASK WHY THEY CHARGE SO MUCH.

£

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Computer Products Division 31352 Via Colinas • Westlake Village, CA 91362 • 213-991-2254

Multibus is a trademark of the Intel Corp LSI II is a trademark of Digital Equipment Corp

Circle 143 on inquiry card.

BYTE April 1981 219

stored in the map for each corresponding byte in the data that is not a space. This way, the data can be stored with all spaces removed and still be easily reconstructed by first examining the bit map to determine where the expanded file needs to have a space or spaces inserted as the next data byte.

Recurrence coding takes a string of more than two repetitive characters and replaces the string with a special character. It is then followed by the count of how many occurrences of the repeated character are being compressed. A variation of this method is used in the IBM VM/370 Operating System with the PACK option of the COPYFILE command.

If the string "ABbbbbCD" (where b is a space) were to be compressed using the bit-mapping technique, 5 bytes would be required to store the data and the bit map. The map would be 11000011 (1 byte) and the data would be "ABCD" (4 bytes). Since only 5 bytes are required to store the original data in compressed form instead of 8 bytes, the data is compressed to 62.5% of its original length. Storing the same string using recurrence coding would result in a compressed string of "AB*4CD", where "*4" replaces the four spaces. In this case, the data is compressed to 75% of its original length. You can see that the efficiency of a given method is dependent upon both the method itself and the characteristics of the data's redundancy.

Another method of compression is known as pattern substitution. In this method, each occurrence of a specific pattern is replaced by a unique code. For example, in the above text, the pattern "compression is" could be replaced by a single 8-bit byte — say, 11111001. This would compress each occurrence of the 14 ASCII bytes in the pattern to a single byte. Obviously, if there were more than 256 patterns, the code pattern would have to be bigger than 8 bits to maintain uniqueness.

Variations of this method could mix the ASCII code and the pattern code. One scheme would place a unique code — for example, the ASCII ESC (escape) character — ahead of the pattern code. When the PACK routine encounters the ESC character, the next byte is replaced with its equivalent pattern.

Another scheme that would permit ASCII and pattern codes to be mixed would tag the pattern codes by setting the high-order bit to 1. This would restrict the ASCII to 128 codes and the patterns to 128 codes.

The efficiency of the pattern-substitution compression methods can be very useful if the pattern is long and its number of recurrences is high. Some compression systems based upon this method have sophisticated programs that search the data for patterns and assign codes to the patterns in an optimal manner.

Some compression methods are data-value dependent. One of these methods is difference compression. For example, if succeeding records had a field with the following values:

1,732,517 1,732,217 1,732,200 1,732,190

either the difference between succeeding fields or the difference from a base value could be stored as the com

pressed data. In the first case, the values

1,732,517 300 17 10

would be stored. Obviously, if the field is of fixed length, nothing is gained by compression. However, if a variable field-length capability exists in the system, some space savings can be achieved with this compression method. Again, the amount of compression is highly dependent upon the data and its characteristics.

Another compression method makes use of the statistical properties of the occurrence of the data to be compressed. In this method, shorter codes are used for the more frequently occurring data elements. Longer codes are used for less frequently occurring data elements. One code used in data compression that optimizes the encoding values is the Huffman code. There

Letter

Frequency (%)

E

13.0

T

10.5

A

8.1

0

7.9

N

7.1

R

6.8

1

6.3

S

6.1

H

5.2

D

3.8

L

3.4

F

2.9

C

2.7

M

2.5

U

2.4

G

2.0

Y

1.9

P

1.9

W

1.5

B

1.4

V

0.9

K

0.4

X

0.15

J

0.13

Q

0.11

Z

0.07

Table

1: Relative fre

quency

of the alphabet in

the English language. In

most ch

aracter codes (in

eluding

the common 7-bit

ASCII),

every letter is

represer

ted by the same

number

of bits. But one

method

of data compres

sion assigns shorter codes

to the frequently used let

ters (ie:

E, T, and A) and

longer

codes to seldom

used letters (ie: Q and Z).

A message stored in this

kind of

code should be

significantly shorter in bits

than th

e same message

stored in ASCII.

Letter

Huffman Code

E

100

T

001

A

1111

0

1110

N

1100

R

1011

1

1010

S

0110

H

0101

D

11011

L

01111

F

01001

C

01000

M

00011

U

00010

G

00001

Y

00000

P

110101

W

011101

B

011100

V

1101001

K

110100011

X

110100001

J

110100000

Q

1101000101

Z

1101000100

Table 2: A Huffman code.

There

are many Huffman

codes;

this is the one that

is used in figure 2 and

listings

1 thru 4. Note that

the shorter codes are used

for frequently occurring

letters,

and that no code is

a beginning substring of a

longer

code.

The

average number of

digits

used to represent a

letter

can be reduced

toward the entropy limit

H if

the Huffman tech

nique

is used to encode

blocks

of letters rather

than individual ones.

220 April 1981 © BYTE Publications Inc

A

TO GROWTH

A year ago, the course for Marot Software Systems, Inc. was clear. We were on our way to becoming the world's best source for software. And we were going to accomplish that by distributing only the operating system and the application software that brought out the best in microcomputers. That was our course... and, in all modesty, we were most successful.

That's when something funny happened. The dealers, consultants and computer users with whom we had relationships began asking— and then demanding—that we at Marot apply our expertise and follow-through to the supply of reliable, quality-oriented hardware and complete computer systems. Systems that could solve specific problems in data-based management and analysis for business, law, medicine, science and government.

Here's the hardware we now distribute:

ONYX —Extremely powerful and reliable 5-user Z80-based micro, with 10 or 20 Mb hard disk and integral tape subsystem. Also available: 16 bit Z8000 operating UNIX™ Version 7, with up to 1 Mb RAM for as many as 8 users. 10 or 18 Mb hard disk with integral tape subsystem and additional storage available.

ALTOS —Cost-effective floppy disk system, 208 K RAM for up to 4 users. Expansion to 58 Mb hard disk with tape backup available.

The marketplace told us of the need for support, too. Of the gap that existed in matching hardware, operating systems and software to application requirements. And of the need for assistance in evaluating options available to meet those requirements.

So, we thoroughly searched and found the best hardware we could distribute.

As a result, Marot Software Systems, Inc. has become Marot Systems, Inc. It's the one company you can rely on to handle total computer needs: from hardware, software, operating systems and support to total computer solutions.

If you're a computer dealer or a computer consultant, Marot's total backup and support could be the special something you need to make your operation grow. Call or write us today.

Here are the products distributed by Marot Systems, Inc. Please check items of interest and return this coupon to:

Marot Systems, Inc.

310 Madison Avenue, Suite 408

New York, New York 10017

(212)661-8550

Please send me more information on the following: Operating System

□ OASIS® — The mini-like single and multi-user machineindependent operating system for Z80 commercial applications and serious programmers.

Name

MAROT SYSTEMS YOUR EASTERN SOURCE

Software

□ MAGIC WAND™ —The most usable fullfeature word processing system with extremely powerful text-formatting features.

□ MAROT'S MAILING LIST PROGRAM — Maintains up to 65,000 entries

in zip and name order, by ISAM files.

□ COMPLETE BUSINESS PACKAGES —In standard ANSI 74 COBOL. Five module accounts receivable, accounts payable, general ledger, payroll, order entry/inventory plus financial modeling and job costing.

□ ESQ-1™ —Time and billing system for the legal profession.

D MAROT'S OFFICE APPOINTMENT SCHEDULER —Maintains complete office diary, with ability to compare schedules.

Title

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Address

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Hardware

□ ONYX

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ESQ-1 is a trademark of Micro

Information Systems, Inc. TRS-80 is a trademark of Tandy Corp, OASIS is a product of Phase One

Systems. MAGIC WAND is a trademark of

Small Business Applications Inc.

Circle 144 on inquiry card.

BYTE April 1981 221

are actually many Huffman codes, but they are similar in structure.

Before explaining how to construct a Huffman code, I will describe a typical Huffman code and how it works. The code that is used in the two compression programs in this article is given in table 2.

To compress the word "compression", the appropriate

CODE LENGTHS L ARRANGED IN ASCENDING ORDER

I

. IS NEW

CODE SAME ] LENGTH AS F I LAST CODE |

ADD 1 TO LAST CODE

TACK ON ZEROS EQUAL TO THE DIFFERENCE IN CODE LENGTH ONTO RIGHT-HAND END OF CODE

( END J

Figure 1: Flowchart for assignment of Huffman codes. This algorithm will produce a series of codes (Huffman codes) with the following two characteristics: the length of the code (in bits) is inversely proportional to the relative frequency of the symbol being encoded; and no code is a beginning substring of the Huffman code of another symbol. Together, these properties define a code with a unique decoding that uses the smallest number of bits to encode an average message.

binary code is assigned to each letter, which produces the

binary string:

, 01000111000011110101101110001100110101011101100, \ AAA A A A A A A A /

COM

R E S S I O N

A quick count shows that 47 bits were required to encode the word "compression" with Huffman coding as compared to the 88 bits required with ASCII code. This gives a compressed text that is 53.4% of its original length. This level of compression is not too surprising since it is well known that the English language is highly redundant.

Of course the above example is a very short one. A larger piece of data should be used to find a more exact value of the amount of compression that can be expected from using Huffman coding. The actual efficiency can also be determined mathematically, but an explanation of that method is beyond the scope of this article. Using the program code described above with English text, approximately 4.18 bits would be required for each letter. Compared to 8-bit ASCII code, the compressed text is compressed to 52.2% of its original length.

Earlier in this article I mentioned that Huffman codes are optimized based upon the probability of the occurrence (ie: frequency) of the data element being encoded. In the program-code table (table 2), the more frequently occurring letters have the shorter codes, (eg: an E is coded with 3 bits). The number of bits, b, needed to encode a letter can be determined by the following formula:

b = /(-log2 p)

where p is the probability of occurrence of the letter, and f(x) is the closest integer greater than or equal to x.

From table 1, the probability of occurrence of an E in English text is 0.13; since — log2 0.13 = 2.94, the integer length is 3. If you were to continue to compute the code lengths from the probabilities in table 1, the lengths would differ from the code lengths used in the programs. This is because the program code lengths were determined from text that differs slightly in frequency from the text used to prepare table 1.

There are several ways the actual codes can be constructed. One method is shown in figure 1. To use the algorithm in figure 1, the letters must be arranged by

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222 April 1981 © BYTE Publications Inc

Circle 145 on inquiry card.

If you want a choice in print wheels,# there's only one choice

in printers.

The Diablo 630.

It's the only printer that lets you use either metal or plastic print wheels. So you can choose the print wheel that's just right for the job.

The 630 works as well with a 96-character plastic daisy print wheel as it does with an 88-, 92-, or 96-character metal daisy print wheel. In over 100 different type styles.

Every 630 has fewer moving parts than competitive printers, which makes it more reliable. And it offers unsurpassed print quality. Compatibility with Diablo supplies. And bi-directional printing capability.

The 630 is the only printer in the world that uses both metal and plastic wheels.

So if you want to change your print wheels, you'll just have to change your printer.

To a Diablo 630 printer.

saw*-*'

I

Diablo Systems

XEROX

Diablo* ami XEROX® arc trademark of XEROX CORPORATION.

Circle 146 on inquiry card.

BYTE April 1981 223

Stack Work's

A full, extended FORTH interpreter/compiler produces COMPACT, ROMABLEcode. As fast as compiled FORTRAN, as easy to use as interactive BASIC.

SELF COMPILING

Includes every line of source necessary to recompile itself.

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V G U M

Figure 2: Binary tree for a Huffman code. The Huffman code for a letter is defined as the sequence of binary digits encountered when tracing the path from the root node, *, to the letter. Thus, the code for G is 00001, and the code for E is 100. This is the code used in the programs of listings 1 thru 4. Although this code cannot be produced by the algorithm of figure 1, it is a valid Huffman code (there are many) that can be validly used to illustrate the structure and implementation of Huffman codes in general.

ascending code length. Then the letter with the shortest length is assigned a code consisting of all Os. Execution of the algorithm will result in the assignment of a unique code to each letter.

With any set of codes that are constructed, it is important that no code has a shorter code as part of its beginning. For example, if E is 100, then 10010 cannot be the code for another letter. This is because in scanning the bit stream from left to right, the decoding algorithm would think that 10010 is E (100) followed by 10 and not the different letter that was intended.

Regardless of the method used to construct the codes, the full set of binary Huffman codes can be represented as a binary tree. Figure 2 shows the binary tree that is equivalent to the Huffman code used in the programs of listings 1 thru 4. (These codes were not produced by the algorithm of figure 1.) This code structure allows the code to be uniquely decoded by simply starting at the top of the tree and walking down the tree, taking each branch that corresponds to the bit value, 1 or 0, as the coded data stream is scanned from left to right. This is the way the expansion program recreates the original data.

It is possible to combine various compression methods to increase the storage efficiency even more than when working with single letters. For example, Huffman codes could be assigned to patterns. Instead of working with the frequency of letters, you would use the frequency of the patterns. Thus, the pattern "code" might be represented by 010 and the pattern "data compression" might be represented by 10110. Obviously, a lot of compression could be achieved, particularly if single-letter and pattern methods are combined and certain patterns have a high frequency of occurrence.

Sample Programs

Two versions of both the compression and the expan

224 April 1981 © BYTE Publications Lie

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BYTE April 1981 225

sion programs have been prepared to demonstrate two different uses of data compression. The compression program, COMPl, demonstrates the basic concept. (See listing 1.) Characters are entered from the keyboard and the output of the program is a serial bit stream that could be sent to a cassette for storage of the compressed data. Such a scheme could result in reduced writing time and faster access to the data. The tradeoff involved is the usual one in many data-processing situations; namely, storage space saved versus computer time used to encode and decode the data.

The amount of compression is

highly dependent upon the data

and its characteristics.

Since COMPl is for demonstration purposes only, the program is simplified somewhat by storing the serial data 1 bit per byte of memory. This is just a convenience that simplifies the expansion program, EXPl. (See listing 2.) If the data were actually being sent to a serial output port, only minor changes in the code would be required.

The second compression program, COMP2, uses the same basic compression method as COMPl. (See listing 3.) However, the resulting serial bit stream is broken into 8-bit bytes for use by a parallel storage medium such as programmable memory. This provides maximum compression in a fixed-word-length computer. The program

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EXP2 expands the compressed text created by COMP2. (See listing 4.) The description of the compression and expansion programs emphasizes the table structure, since both programs use tables to facilitate changing codes.

COMPl Description

This program takes characters entered via the keyboard, checks for a legal character, finds the Huffman code corresponding to the entered character, and stores the bit stream sequentially in memory. Each bit is stored in the lowest-order bit of a byte for demonstration convenience and for interfacing with EXPl. The first two words of the output buffer contain a count of the number of bits that are stored in the remainder of the buffer. This information is used by EXPl to stop the decoding process on the bit stream. The input need not come from the keyboard and could be from another buffer, simply by changing a few lines of code related to the input function.

The heart of the program's operation is the table lookup and the shifting function. Based upon a letter's ASCII code, an index is computed that is then added to the base address of the encoding table. This table has the following format: two 8-bit words are required for each letter to be encoded; the low-order 4 bits of the first word in memory contain a count of the number of bits required to encode the letter. The remaining 12 bits, 8 in the second byte followed by 4 in the top half of the first byte, are used to store the compressed code. (Note that the word order in the source statement and in memory is reversed because of the assembler's treatment of the DW (Define Word) instruction. The code is stored leftjustified in the 12-bit area. This format makes processing simple when the two words are loaded into the D and E register pair for shifting.

With the compressing code located, it is serialized by shifting left according to the count in the 4-bit part of the table. The DAD (add register pair to H and L) instruction effectively shifts the DE register pair's high-order bit into the carry register. As each bit is shifted out, the total bit count in the buffer is updated. The processing of the input stream continues until a period is detected, and control returns to the system monitor.

It should be noted that the only characters that are encoded are the twenty-six alphabetic letters. Any other characters (including blanks) are ignored. In a nondemonstration environment, spaces, punctuation, and other symbols would have to be included; this would require enlarging the lookup table to include the representation of the new symbols.

EXPl Description

The expansion program, EXPl, operates on the bit stream prepared by COMPl. (See listing 2.) It expects this data to be in the buffer defined by COMPl, with the bit count in the first two words and the data bit in the lowest bit of each byte. This program is also table-driven; but the table is more complex than the encoding table and the processing is more involved. Basically, the program searches a binary tree to decode the bit stream. The binary tree shown in figure 2 is converted to a table. The program then steps through the table, selecting the appropriate branch in the tree structure depending upon the value of each bit in the data stream. The data in the table

Text continued on page 246

226 April 1981 © BYTE Publications Inc

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Listing 1: COMF1 text-compression routine. This routine takes only alphabetic text entered from the keyboard and converts it to the Huffman code given by the tree in figure 2. The Huffman code is stored 1 bit per byte. The routine is written in 8080 machine code.

7 500

?5oo

->500

9500

9500

?500

7500

?5no

9500

2500

7500 31

00

00

7503 21

00

no

■7506 ??

00

41

7509 21

02

41

250C 22

8C

25

?50F DB

08

7511 OF

251? Da

OF

?5

2515 DB

0\

2517 FE

2E

2519 CA

OC

00

251C CD

00

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251F E6

7F

2521 D6

41

2523 DA

OF

25

2526 FE

l.A

2528 D2

OF

25

252B 87

252C 4F

252D 06

00

252F 21

58

2.5

2532 09

9 53 3 5E

2 534 73

■?535 56

7536 7B

2537 E6

OF

7539 47

7 53A EB

753B AF

253C 29

253D 17

253E E6

01

2560 E5

2541 2A

8C

25

2544 77

2545 23

7546 22

8C

25

2.549 2A

00

41

754C 23

754D 22

00

41

2550 El

2551 05

2552 C2

3B

25

2.5*5 C3

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25

7558

7558

2558

2558 04

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255A 06

70

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40

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80

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48

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0001 0002 0003 0004 0005 0006 0007 0010 0011 0012 0020 0021 0077 0023 0024 0040 0041 0042 0043 0060 0070 0073 0075 0080 0082 0084 0086 0090 0100 0110 0120 0130 0140 0150 0160 0170 0180 0185 0187 0190 0192 0200 022.0 0225 0226 0228 0229 0231 0232 0235 0236 0238 0260 0270 0300 0305 0306 0307 0310 0320 0330 0340 0350 0360 0370 0380 0390 0400 0410 0420

*THIS ROUTINE TAKES TEXT, (LETTERS ONLY)

*AND COMPRESSES THEM USING HUFFMAN CODING. FOR

*TEST PURPOSES THERE IS ONE BIT PER BYTE IN THE

*DATA BUFFER. THE FIRST TWO BYTES IN THE DATA BUFFER

*ARE THE BIT COUNT. ENCODED DATA IS STORED IN DBUF AS 1 BIT

*PER BYTE FOR TEST PURPOSES. NORMALLY DATA WOULD BE PACKED

*OR OUTPUTTED SERIALLY.

ECHO: EQU 0C500H ;OUTPUT DRIVER

SP: ECU 6

MON: ECU OCH

LXI SP,0 LXI H,0 SHLD DBUF

•.MONITOR RETURN

INCH:

;END OF TEXT ;NO MORE

;CLEAR PARITY ;COMPUTE INDEX

A'+l

COMPRESSED BIT COUNT

LXI H.DBUF+2

SHLD DADD ;NEXT BIT LOCATION

IN 8

RRC

JC INCH

IN 10

CPI ' .'

JZ MON

C-\LL ECHO

.AN I 07FH

SUI 'A'

JC INCH

CPI 'Z'-'

JNC INCH

.ADD A

MOV C,A

MVI B,0

LXI H,TABL

DAD B

MOV E,M

INX H

MOV D,M

MOV A,E

.AN I OFH

MOV B,A

XCHG

XRA A

DAD H

RAL

AN I 1

PUSH H

LHLD DADD

MOV M,A

INX H

SHLD DADD

LHLD DBUF

INX H

SHLD DBUF

POP H

RCR B

JNZ NEXT

JMP INCH ♦ENCODE TABLE FORMAT- LOW ORDER 4 BITS ARE NUMBER OF BITS *IN ENCODED CHARACTER. REMAINING 12 BITS .ARE FOR CODE. *CODE IS LEFT JUSTIFIED. E.G., AN M IS 00011

;MULT IPLY BY 2

; INDEX

;GET ENCODE VALUE

GET BIT COUNT MASK COUNT KEEP COUNT

NEXT:

SHIFT OUT BIT

MSB FIRST

SETUP OUTPUT BIT

;STORE BIT

.UPDATE BIT COUNT

[REDUCE COUNT

STREAM

TABL:

DW 0F004H DW 7006H DW 4005H DW 0DR05H DW 8003H DW 4805H DW 805H DW 5004H DW 0A004H DW 0D009H DW 0D189H DW 7805H

228

April 1981 © BYTE Publications Inc

Listing 1 continued on page 230 Circle 150 on inquiry card. >

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listing

l con

tinued

2570

05

18

2572

04

CO

2574

04

EO

2576

06

D4

2578

4A

Dl

257A

04

BO

257C

04

60

257E

03

20

2 580

05

10

2582

07

D2

2584

06

74

2586

89

DO

258*

05

00

2 58 A

0A

Dl

258C

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00

258E

4100

0430

DW

1805H

M

0440

DW

0C004H

N

0450

DW

OE004H

0

0455

DW

0D406H

P

0460

DW

0D14AH

0

0470

DW

0B004H

R

0480

DW

6004H

S

0490

DW

2003H

T

0500

DW

1005H

U

0510

DW

0D207H

V

0520

DW

7406H

W

0530

DW

0D089H

X

0540

DW

5H

Y

0550

DW

0D10AH

Z

0600 DADD:

DW

0

N

0605

ORG 4100H

0610 DBUF:

DS

1000

NEXT BIT LOCATION

Listing 2: EXP1 text-expansion routine. This routine takes the output of COMP1, information expressed in a Huffman code, and decodes it using the binary tree of figure 2. The decoded character is displayed via a user-supplied subroutine named DISP. The routine is written in 8080 machine code.

3000

3000

3000

3000

3000

3000

3000

3000

3000

3000

3000

01

00

00

3003

21

02

41

3006

22

97

30

3009

21

00

41

300C

4E

3 OOP

23

300E

46

300F

C5

7010

21

4B

30

701?

E5

3014

3 A

97

30

3017

4E

3019

23

3019

06

00

301B

3?

97

30

301E

El

301F

09

30?0

7E

30?1

17

3022

DA

32

30

3025

IF

3026

5F

3037

16

00

3039

19

3 03 a

CI

303B

CD

44

30

303E

C5

302F

C3

13

30

3032

IF

3033

E6

7F

3035

5F

3036

16

00

3038

19

3039

7E

303A

CD

00

C5

30 3D

ri

3 03E

CD

44

30

3041

C3

OF

30

0000 0001 0002 0003 0004 0005 0006 0007 0008 0009 0010 0020 0030 0040 0050 0060 0070 0080 0090 0100 0110 0120 0130 0140 0150 01*0 0170 0180 0190 0200 0205 0210 0220 0230 0240 0250 0270 0280 0290 0294 0296 0297 0298 0299 0305 0310 0320 0330

*THIS PROGRAM ACCEPTS DATA PREPARED BY THE DATA COMPRESSION ♦(HUFFMAN CODE) PROGRAM.THE DATA BUFFER HAS THE BIT COUNT *IN THE FIRST TWO BYTES.THE PROGRAM RUNS UNTIL ALL BITS *HAVE BEEN PROCESSED. THE PROCESSING CONSISTS OF ADDING A *DATA BIT TO THE TABLE ENTRY POINT, GETTING AN INCREMENT *VHICH POINTS TO THE NEXT 0-1 PAIR AND CONTINUING UNTIL *A TAG IS FOUND IN BIT 7. THIS SIGNIFIES THAT THE NEXT *TABLE ENTRY IS THE DESIRED CHARACTER.IN A NON-TEST MODE *DATA WOULD BE EITHER PACKED IN 8 BIT BYTES OR ARRIVING *VIA A SERIAL PORT.

EXP:

NEXT:

OUTCH:

LXI SP,0 LXI H.DBUF+2 SHLD DADD LXI H.DBUF MOV C,M INX H MOV B,M PUSH B LXI H.XTAB PUSH H LHLD DADD MOV C,M INX H MVI B,0 SHLD DADD POP H DAD B MOV A,M RAL

JC OUTCH RAR

MOV E,A MVI D,0 DAD D POP B CALL DECB PUSH B JMP NEXT RAR

AN I 7FH MOV E,A MVI D,0 DAD D MOV A,M CALL DISP POP B CALL DECB JMP EXP

;FIRST BIT

;NEXT DATA ADDRESS

;BIT COUNT

;DECODE TABLE

;DATA VALUE

;TABLE + DATA BIT GET POINTER

;TABLE+DATA BIT + POINTER

:REDUCE BIT COUNT

;REMOVE TAG

;GET DECODED CHARACTER

Listing 2 continued on page 232

230 April 1981 © BYTE Publications Inc

The Text Solution for APPLE II®

Now APPLE II® Owners Can Solve Text Problems

With VIDEOTERM 80 Column by 24 Line Video Display

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7X12 MATRIX 18X80 OPTIONAL

I'MII ' t }*♦■- ./

1123456 789 i j < = >? CABCDEFSHIJKLHNO POBSTUVUXYZI\]t_

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7X9 MATRIX 24X80 STANDARD

VIDEOTERM lists BASIC programs, both Integer and Applesoft, using the entire 80 columns. Without splitting keywords. Full editing capabilities are offered using the ESCape key sequences for cursor movement. With provision for stop/start text scrolling utilizing the standard Control-S entry. And simultaneous on-screen display of text being printed.

Installation of VIDEOTERM in slot 3 provides Pascal immediate control of the display since Pascal recognizes the board as a standard video display terminal and treats it as such. No changes are needed to Pascal's MISC.INFO or GOTOXY files, although customization directions are provided. All cursor control characters are identical to standard Pascal defaults.

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VIDEOTERM's on-board asynchronous crystal clock ensures flicker-free character display. Only the size of the Pascal Language card, VIDEOTERM utilizes CMOS and low power consumption ICs, ensuring cool, reliable operation. All ICs are fully socketed for easy maintenance. Add to that 2K of on-board RAM, 50 or 60 Hz operation, and provision of power and input connectors for a light pen. Problems are designed out, not in.

The entire display may be altered to inverse video, displaying black characters on a white field. PROMs containing alternate character sets and graphic symbols are available from Videx. A switchplate option allows you to use the same video monitor for either the VIDEOTERM or the standard Apple II" display, instantly changing displays by flipping a single toggle switch. The switchplate assembly inserts into one of the rear cut-outs in the Apple II' case so that the toggle switch is readily accessible. And the Videx KEYBOARD ENHANCER can be installed, allowing upper and lower case character entry directly from your Apple II' keyboard.

Firmware 1K of on-board ROM firmware controls all operation of the VIDEOTERM. No machine

language patches are needed for normal VIDEOTERM use.

Firmware Version 2.0

Characters 7x9 matrix Display

Options 7x12 matrix option;

Alternate user definable

character set option;

Inverse video option.

Want to know more? Conlact your local Apple dealer today for a demonstration. VIDEOTERM is available through your local dealer or direct from Videx in Corvallis, Oregon. Or send for the VIDEOTERM Owners Reference Manual and deduct the amount if you decide to purchase. Upgrade your Apple II' to full terminal capabilities for half the cost of a terminal. VIDEOTERM. At last.

Advanced Hardware Design

Available Options

24 x 80 (full descenders)

18 x 80 (7 x 12 matrix with full descenders)

Apple II* is a trademark of Apple Computer Inc.

ROMWnter* is a trademark ol Mountain Hardware Inc.

Micromodem II* 15 a trademark ot D C. Hayes Associates Inc.

Softcard' is a trademark ol Microsofl

EasyWriter" is a trademark ol Information Unlimited Software Inc

PRICE: • VIDEOTERM includes manual $345

• SWITCHPLATE $ 19

• MANUAL refund with purchase.... $ 19

• 7x12CHARACTERSET $ 39

• MICROMODEM FIRMWARE $ 25

APPLE II® OWNERS!

introducing the

KEYBOARD & DISPLAY

ENHANCER

■ PUT THE SHIFT AND SHIFT LOCK BACK WHERE IT BELONGS ■ SEE REAL UPPER AND lower CASE ON THE SCREEN •ACCESS ALL YOUR KEYBOARD ASCII CHARACTERS

Videx has the perfect companion for your word processor software: the KEYBOARD AND DISPLAY ENHANCER Install the enhancer in your APPLE II and be typing in lower case just like a typewriter. If you want an upper case character, use the SHIFT key or the CTRL key for shift lock. Not only that, but you see upper and lower case on the screen as you type. Perfectly compatible with Apple Writer and other word processors like, for example. Super-Text.

If you want to program in BASIC, just put it back into the alpha lock mode; and you have the original keyboard back with a few im

provements. Now you can enter those elusive 9 characters directly from the keyboard, or require the Control key to be pressed with the RESET to prevent accidental resets.

KEYBOARD AND DISPLAY

ENHANCER is recommended for use with all revisions of the APPLE II. It includes 6 ICs. and EPROM and dip-switches mounted on a PC board, and a jumper cable. Easy installation, meaning no soldering or cutting traces. Alternate default modes are dip-switch selectable. You can even remap the keyboard, selecting an alternate character set. for custom applications.

PRICE • KDE-700 (REV. 7 or greater) $129.

» KDE-000 (REV. 6 or less) $129.

Apple II'" is a trademark of Apple Computer. Inc.

ffl B

VIDEX 897 N.W. Grant Avenue Corvallis, Oregon 97330 Phone (503) 7580521

Circle 151 on inquiry card.

BYTE April 1981 231

Listing 2

3044 3045 3046 3047 304A 304B 3 04B 304B 3 04B 3 04B 304B 306B 3 04C 304P 304E 3 04F 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 305A 305B 305C 305P 305E 305F 3060 3061 3 062 3 063 3 064 3065 3066 3067 3068 3069 3 06A 306B 306C 306D 3 06E 306F 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 307A 307B 307C 307D 307E 307F 3080 3081 3082 ■'083 ''084 3085 3086 3087

continued:

OB 79

BO

CA OC 00

C9

2A 01 02 08 82 02 45 82 82 49 52 06 01 82 82 4F 41 82 02 4E 03 81 44 03 81 50 03 81 56 02 05 82 82 4A 58 03 81 4B 82 82 5A 51 02 OE 03 81 54 02 05 82 82 59 47 82 82 55 4D 02 08 03 81

0340 0350 0360 0365 03 70 4000 4010 4020 4030 4040 4050 5000 5010 5020 5030 5040 5050 5060 5070 5080 5090 5100 5102 5104 5106 5108 5110 5120 5130 5140 5150 5160 5170 5180 5190 5200 5210 5220 5230 5240 5250 5260 5270 5280 5290 5300 5310 5320 533 0 5340 5350 5360 5370 5380 5390 5400 5410 5420 5430 5440 5450 5460 5470 5480 5490 5500 5510 5520 5530 5540 5550 5560

DECB: DCX B

MOV A,C

ORA B

JZ MON

RET *THE DECODE TABLE HAS *THE TABLE VALUE IS T *NEXT 0-1 PAIR AS THE *THE TABLE VALUE JUST *SET IN BIT 7, IN ADD *THAT THE NEXT VALUE XTAB:

;REDUCE BIT COUNT

THE FOLLOWING FORMAT: HE INCREMENT NECESSARY TO GET TO THE

PROGRAM STEPS THROUGH THE DATA.

PRECEEDING A CHARACTER HAS A TAG IT ION TO THE INCREMENT, TO INDICATE IA A CHARACTER.

DB

42

DB

1

DB

2

DB

8

DB

130

DB

2

DB

'E'

DB

130

DB

130

DB

•I'

DB

'R'

DB

6

DB

1

DB

130

DB

130

DB

'0'

DB

•A'

DB

130

DB

2

DB

iNi

DB

T

DB

129

DB

•D'

DB

3

DB

129

DB

ipi

DB

3

DB

129

DB

'V

DB

2

DB

5

DB

130

DB

130

DB

•J'

DB

'X'

DB

3

DB

129

DB

'K'

DB

130

DB

130

DB

'Z'

DB

• Ql

DB

2

DB

14

DB

3

DB

129

DB

i f i

DB

2

DB

5

DB

130

DB

130

DB

•Y«

DB

'G'

DB

130

DB

130

DB

>U'

DB

'M'

DB

2

DB

8

DB

3

DB 129

0

0

1

1

2

0

3

1

4

0

5

1

6

7

0

8

1

9

10

11

0

12

1

13

0

14

1

15

16

17

0

18

1

19

20

0

21

1

22

23

0

24

1

25

26

0

27

1

28

29

0

30

1

31

0

32

1

3^

34

35

0

36

1

37

38

0

39

1

40

41

42

0

43

1

44

0

45

1

46

47

0

48

1

49

0

50

1

51

52

53

0

54

1

55

56

57

0

58

1

59

0

60

1

Listing 2 continued on page 234

232 April 1981 © BYTE Publications Inc

DIGITAL HARMONY

A new synthesis

of sight and sound

Digital Harmony by John Whitney

Digital Harmony lays the foundation for the whole new field of audio-visual art made possible by microcomputers. John Whitney, a pioneer of the special effects technology used in STAR WARS and 2001: A SPACE ODYSSEY, explains the special union of computer graphics and music. His computer-generated visual art graphically depicts the laws of harmonic motion common to all music.

Digital Harmony includes a complete description of Whitney's computer, peripherals, and film techniques. Colorful illustrations are included, as well as the program listings that generated them. The descriptions are sufficient for anyone to begin to explore this new territory as a composer and computer experimenter — transforming the small computer into an ideal instrument for creating compositions in aural and visual art.

'John Whitney is on the Faculty in the Department of Art at the University of California, Los Angeles.

ISBN 07-070015-X $21.95

Please remit in U.S. funds or draw on a U.S. Bank

Please send □ copies of

Digital Harmony

Available Now

Toll Free # 1-800-258-5420

Name

Title

Company

Street

City

State/Province

Code

□ Check enclosed in the amount of $

D Bill Visa □ Bill Master Charge

Card No

Exp. Date.

Add 75c per book to cover postage and handling.

H V I K 70 Main Street

R'l'IVI Peterborough, New Hampshire 03458

Circle 152 on inquiry card.

BYTE April 1981 233

Listing

2 continued

3088

48

3089

82

308A

82

308B

43

308C

46

308D

82

308E

02

3 08F

53

3090

03

3091

81

3092

4C

3093

82

3094

82

3095

42

*09*5

57

''097

02 41

309">

4100

44E8

44E8

44E8

5570

DB

•H' ;

61

5580

DB

130

62

0

5590

DB

130

63

1

5600

DB

iCi

64

5610

DB

• pi

65

5620

PB

130

66

0

5630

DB

2

67

1

5640

DB

■S'

68

5650

DB

3

69

0

5660

DB

129

70

1

5670

DB

'L'

71

5680

DB

130

72

0

5690

DB

130

73

1

5700

DB

■B'

74

5710

DB

.Wi

,75

5720

DADD:

DW

DBUF+2

NEXT DATA ADDRESS

5909

ORC

■ 4100H

6000

DBUF:

DS

1000

9000

DISP:

EQL

0C500H

DISPLAY A CHARACTER

9010

MON

ECU

0OOCH

MONITOR RETURN

9020

SP:

ECU

0

Listing 3: COMP2 text-compression routine. This routine is identical to COMP1 (listing 1) except that the Huffman code information is packed and stored 8 bits to the byte. The routine is written in 8080 machine code.

2600

0001

♦THIS

! ROUTINE TAKES TEXT (LETTERS ONLY)

2600

0002

*AND

COMPRESSES THEM USING HUFFMAN CODING.

2600

0004

*THE

FIRST TWO BYTES IN THE DATA BUFFER

2600

0005

*ARE

THE BIT COUNT. ENCODED DATA IS STORED IN

DBUF

2600

0006

*1N A PACKED FORM, 8 BITS TO THE BYTE.

2600

0010

ECHO:

ECU 0C500H

;OUTPUT DRIVER

2600

0011

SP:

EQU 6

2 600

0012

MON:

ECU OCH

• MONITOR RETURN

2600

31

00

00

0020

LXI SP,0

2603

21

00

00

0021

LXI H,0

2606

22

00

41

0022

SHLD DBUF

•.COMPRESSED BIT COUNT

2609

21

02

41

0023

LXI H,DBUF+2

260C

22

BA

26

0024

SHLD DADD

;NEXT BIT. LOCATION

260F

AF

0025

XRA A

2610

32

BC

26

0026

STA POS

2613

DB

08

0040

INCH:

IN 8

; INPUT CODE

2615

OF

0041

RRC

2616

DA

13

26

0042

JC INCH

2619 DB

OA

0043

IN 10

261B

FE

2E

0045

CPI '.•

;END OF TEXT

261D

C2

37

26

0047

JNZ PROS

2620

2A

BA

26

0050

LHLD DADD

;CLEAN UP PARTIAL BYTE

2623

3A

BC

26

0052

LDA POS

2626

47

0054

MOV B,A

;COMPUTE SHIFT COUNT

2627

3E

08

0056

MVI A,8

2629

90

0058

SUB B

262A

E6

07

0060

ANI 7

262C

47

0062

MOV B,A

;KEEP SHIFT COUNT

262D

7E

0064

MOV A,M

;GET PACKED BYTE

262E

CA

OC

00

0066

SHFT:

JZ MON

; FINISHED

2631

17

0068

RAL

2632

05

0070

DCR B

2633

77

0071

MOV M,A

•.REPLACE PACKED BYTE

2634

C3

2E

26

0072

JMP SHFT

2637

CD

00

C5

0073

PROS:

CALL ECHO

263A E6

7F

0075

ANI 07FH

•.CLEAR PARITY

263C

D6

41

0080

SUI 'A'

;COMPUTE INDEX

263E

DA

13

26

0082

JC INCH

2641

FE

1A

0084

CPI 'Z'-'A

+1

2643

D2

13

26

0086

JNC INCH

2646

87

0090

ADD A

;MULTIPLY BY 2

2647

4F

0100

MOV C,A

2648

06

00

0110

MVI B,0

264A

21

86

26

0120

LXI H.TABL

264D

09

0130

DAD B

; INDEX Listing 3

continued on

page 236

234 April 1981 © BYTE Publications Inc

THE ADVANTAGES OF THE FUNCTIONAL GROUP

Diversity of projects.

Varied technical challenge.

Involvement from concept through implementation.

Broadinteraction and cooperation between software and hardware.

We've got it all at Harris Composition Systems in Melbourne, Florida.

We're pioneers in word processing. And the world's first and leading supplier of total word processing systems for use in the newspaper industry.

And we're now extending that "system-oriented" approach into the office systems field—integrating data processing, word processing,

electronic mail, advanced communications and networking. With an ambitious program representing the largest investment Harris Corporation has ever made to develop a new product.

That means the opportunity for personal participation and immediate contribution— across the board—in both newspaper word processing and office systems.

For experienced professionals with expertise in

□ Real Time Software and Hardware/Firmware Development □ Digital Design

□ Analog Design □ Applications Programming.

All supported by a billion dollar, Fortune 500 corporation. All in a modern, stimu

lating work environment. All in beautiful, affordable Melbourne, Florida—on the shores of the deep blue Atlantic.

Send your resume and salary history to: Daphne Cumberland, Composition Systems Division, Dept. BT, P.O. Box2080, Melbourne, Florida 32901. Or call COLLECT (305) 242-5321, in Florida. Outside Florida call 1-800-327-1493.

Share the advantages with;

COMMUNICATION AND INFORMATION PROCESSING

An Equal Opportunity Employer M/F/V/H.

Listing 3 continued:

264E 5E 264F 23

2650 56

2651 7B

2652 E6 OF

2654 47

2655 EB

2656 AF

2657 29

2658 17

2659 E6 01 265B E5

265C 2A BA 26 265F 57

2660 3A BC 26

2663 5F

2664 7E

2665 17

2666 B2

2667 77

2668 1C

2669 7B 266A FE 08 266C C2 74 26 266F AF

2670 23

2671 22 BA 26 2674 32 BC 26 2677 2A 00 41 267A 23

267B 22 00 41 267E El 267F 05 2680 C2 56 26 2683 C3 13 26 2686 2686 2686

2 686 04 FO 2688 06 70 268A 05 40 2 68C 05 D8 268E 03 80 2690 05 48 2692 05 08 2 694 04 50 2696 04 AO 2698 09 DO 269A 89 Dl 269C 05 78 269E 05 18 2 6A0 04 CO 26A2 04 EO 26A4 06 D4 2 6A6 4A Dl 2 6A8 04 BO 26AA 04 60 26AC 03 20 26AE 05 10 26B0 07 D2 26B2 06 74 26B4 89 DO 26B6 05 00 26B8 OA Dl 26BA 00 00 26BC 26BD 4100

0140

MOV E,M

GET ENCODE VALUE

0150

INX H

0160

MOV D,M

0170

MOV A,E

GET BIT COUNT

0180

AN I OFH

MASK COUNT

0185

MOV B,A

KEEP COUNT

0187

XCHG

0190

NEXT:

XRA A

0192

DAD H

SHIFT OUT BIT STREAM

0200

RAL

,MSB FIRST

0220

AN I 1

;SETUP OUTPUT BIT

0225

PUSH H

0226

LHLD DADD

0228

MOV D,A LDA POS

0229

0231

MOV E,A

.KEEP CURRENT POSITION

0233

MOV A,M

;GET OLD PACKED DATA

0235

RAL

.MAKE ROOM

0237

ORA D

.PACK

0239

MOV M,A

.PUT IT AWAY

0240

INR E

.UPDATE POSITION

0242

MOV A,E

0244

CPI 8

;FULL BYTE?

0246

JNZ STOR

0248

XRA A

[INITIALIZE POSITION

0250

INX H

[UPDATE DADD

0252

SHLD DADD

0258

STOR:

STA POS

0260

LHLD DBUF

02 62

INX H

jUPDATE BIT COUNT

0264

SHLD DBUF

0266

POP H

0268

DCR B

.REDUCE COUNT

0270

JNZ NEXT

0300

JMP INCH

0305

♦ENCODE TABLE FORMAT- LOW ORDER 4 BITS

0306

*IN ENCODED CHARACTER.REMAINING 12 BITS

0307

*CODE

IS LEFT JUSTIFIED. E.G., AN M IS

0310

TABL:

DW 0F004H

;A

0320

DW 7006H

;B

0330

DW 4005H

,C

0340

DW 0D805H

;o

0350

DW 8003H

;E

0360

DW 4805H

;F

0370

DW 805H

;G

03 80

DW 5004H

;H

0390

DW OA004H

;I

0400

DW 0D009H

;J

0410

DW 0D189H

;K

0420

DW 7805H

;L

043 0

DW 1805H

;M

0440

DW 0C004H

;N

0450

DW OE004H

;0

0455

DW 0D406H

,P

0460

DW 0D14AH

;Q

0470

DW 0B004H

R

0480

DW 6004H

,S

0490

DW 2003H

J

0500

DW 1005H

U

0510

DW 0D207H

V

0520

DW 7406H

w

0530

DW 0D089H

X

0540

DW 5H

Y

0550

DW 0D10AH

Z

0600

DADD:

DW 0

;NEXT BIT LOCATION

0603

POS:

DS 1

.BIT POSITION

0605

ORG 4100H

0610

DBUF:

DS 1000

ARE NUMBER OF BITS ARE FOR CODE.

236 April 1981 © BYTE Publications Inc

IF YOU CAN VAIT A MINUTE,

WE CAN S/yE

YOU HJ

iii

With the Storwriter™ Daisy Wheel 25 cps printer from C. Iron.

A business letter, written on a 45 cps word-processing printer, might take about two minutes to print.

With the Starwriter, it might take closer to three.

The typical 45 cps printer retails for about$3,000.

But the Starwriter 25 retails for about $1,895—thus saving you about $1,000.

And therein lies the biggest difference between the Starwriter 25 and the more expensive, daisy wheel printers.

The Starwriter 25 comes complete and ready-to-use, requiring no changes in hardware or software. It uses industry-standard ribbon cartridges, and it's "plug-in" compatible to interface with a

wide variety of systems, to help lower system-integration costs.

Using a 96-character wheel, it produces excellent letter-quality printing on three sharp copies with up to 163 columns, and offers the most precise character-placement available, for outstanding print performance.

Cltoh's warranty;

3 months on parts and labor, supported by one of the best service organizations in the industry.

1000 OFF

Leading Edge Products, Inc., 225 Turnpike Street, Canton, Massachusetts 02021

Dear Leading Edge:

I'd like to know more about the Starwriter, and how spending a minute can save me a grand. Please send me the name of my nearest dealer.

NameTitle

Company.

Street

State

Jip_

Phone: Area CodeNumber

LEADING EDGE.

Leading Edge Products, Inc., 225 Turnpike Street, Canton, Massachusetts 02021

Dealers: For immediate delivery from the Leading Edge Inventory Bank™call toll free 1-800-343-6833

In Massachusetts, call collect (617)828-8150. Telex 951-624

Listing 4: EXP2 text-expansion routine. This routine takes the output of COMP2, information expressed in a packed Huffman code, and decodes it using the binary tree of figure 2. The decoded character is displayed via a user-supplied subroutine named DISP. The routine is written in 8080 machine code.

3000

3000

3000

3000

3000

3000

3000

3000

3000

3000

3000

3000

3000

3000 31

00

00

3003 21

02

41

3006 22

CO

30

3009 21

00

41

300C 4E

300D 23

300E 46

300F 3E

01

3011 32

C2

30

3014 C5

3015 21

74

30

3018 E5

3019 2A

CO

30

301C 3A

C2

30

301F 47

3020 7E

3021 17

3022 05

3023 C2

21

30

3026 3E

00

3028 17

3029 4F

302A 06

00

302C 22

CO

30

302F El

3030 09

3031 7E

3032 17

3033 DA

43

30

3036 IF

3037 5F

3038 16

00

303A 19

303B CI

303C CD

55

30

303F C5

3040 C3

18

30

3043 IF

3044 E6

7F

3046 5F

3047 16

00

3049 19

304A 7E

304B CD

00

C5

304E CI

3 04F CD

55

30

3052 C3

14

30

3055 OB

3056 79

3057 BO

3058 CA

oc

00

305B 3A

C2

30

305E 3C

305F 32

C2

30

3062 FE

09

0000 0001 0002 On 03 0004 0005 0006 0007 0008 0009 0010 0011 0012 0015 0020 0030 0040 0050 0060 0070 0074 0076 0080 0090 0100 0110 0120 0122 0124 0126 0128 0130 0132 0134 0136 0140 0150 0160 0170 0180 0190 0200 0205 0210 0220 0230 0240 0250 0270 0280 0290 0294 0296 0297 0298 0299 0305 0310 0320 0330 0340 0350 0360 0365 0370 0380 0385 0390

*THIS PROGRAM ACCEPTS DATA PREPARED BY THE DATA COMPRESSION •(HUFFMAN CODE) PROGRAM THE DATA BUFFER HAS THE BIT COUNT *IN THE FIRST TWO BYTES. THE PROGRAM RUNS UNTIL ALL *BITS HAVE BEEN PROCESSED THE PROCESSING CONSISTS OF •ADDING A DATA BIT TO THE TABLE ENTRY POINT, GETTING AN •INCREMENT WHICH POINTS TO THE NEXT 0-1 PAIR AND CONTINUING *UNTIL A TAG IS FOUND IN BIT 7 THIS SIGNIFIES THAT THE *NEXT TABLE ENTRY IS THE DESIRED CHARACTER. *THIS IS THE PACKED VERSION WHICH PROCESSES DATA FROM *8 BIT BYTES, MSB FIRST.

DISP: EQU 0C500H MON: ECU OOOCH

SP: EQU 6

LXI SP,0 LXI H.DBUF+2 SHLD DADD LXI H.DBUF MOV C,M INX H MOV B,M MVI A,1 STA POS EXP: PUSH B

LXI H.XTAB NEXT: PUSH H

LHLD DADD LDA POS MOV B,A MOV A,M BIT: RAL

DCR B JNZ BIT MVI A,0 RAL

MOV C,A MVI B,0 SHLD DADD POP H DAD B MOV A,M RAL

JC OUTCH RAR

E,A D,0 D B CALL DECB PUSH B JMP NEXT RAR

7FH E,A D,0 D

A,M CALL DISP POP B CALL DECB JMP EX" DECB: DCX B

MOV A,C ORA B JZ MON LDA °OS INR A STA POS CPI 9

;DISPLAY CHARACTER ;MONITOR RETURN

OUTCH:

MOV MVI DAD POP

AN I MOV MVI DAD MOV

FIRST BIT NEXT DATA BIT COUNT

ADDRESS

{INITIALIZE POSITION

;DECODE TABLE

;GET BIT POSITION

;GET ;GET

DATA DESIRED

BIT INTO CARRY

;RESTORE SINGLE BIT -.DATA VALUE

;TABLE + DATA BIT ;GET POINTER

;TABLE+DATA BIT + POINTER ;REDUCE BIT COUNT

;REMOVE TAG

;GET DECODED CHARACTER

{REDUCE BIT COUNT {UPDATE BIT POSITION

;8 BITS PROCESSED?

Listing 4 continued on page 240

238 April 1981 © BYTE Publications Lie

DYNACOMP

Quality software for^:

ATARI

PET

APPLE II Plus

TRS-80 (Level II)* NORTH STAR CP/M 8" Disk

GAMES, SIMULATIONS, EDUCATION and MISCELLANEOUS

BRIDGE 2.0 (Available for all computers) Price: $17.95 Cassette/SI 1.95 Diskelle

An all-inclusive version of this mm! popular of card games. This program bolh BIDS and PLAYS either :ontracl or duplicate bridge. Depending on the contract, your computer opponents will either play the offense OR defense. If you bid loo high, the compuler u ill double youi contract! BRIDGE 2.0 provides challengint entertainment for advanced players and is an eicellenl learning tool for the

Price: $14.95 Cas.seII*/SIS.95 Diskette game. Hearts is a trick-oriented game in which the purpose is no! lo :r opponents who are armed with hard-lobeal playing strategies

Price: SI 1.95 DuMtle/S 15.95 Diskelle

en nip

iet(

alsll

e cards one

alalimc

and you (and ilie compu

cr) bet on what you s

c. The

if Oil Lis

Ho

s bluffs

Also included is a fivee

ird draw poker beltin

6K ATARI

Colo

. graphics

sound.

HEARTS 1.5 (Available for all computers)

An exciting and entertaining compuler version of this popular c; take any hearts or the queen of spades. Play againsl two comp

STUD POKER (ATARI only)

computer does not cheat and usually bets lice program. This package will run on a

POKER PARTY (Available for all computers) Price: S17.95 CasMfte/S21.95 Diskette

POKER PARTY is a draw poker simulation based on the book. POKER, by Oswald Jacoby. This is Ihe mosi comprehensive version available for microcomputers. The party consists of yourself and six olhcr (computer) players Each or these players (you will gel lo know them) has a different personality in ihe form of a varying propensity lo bluff or fold under pressure. Practice with POKER PARTY before going lo thai expensive game lonight! Apple Cassette and diskette versions require a 32 K (or larger) Apple II.

VAI.DEZ (Available for all computers) Price: S14.95 Cassette/SIB. 95 Diskette

A simulation of supertanker navigation in the Prince William Sound and Valdci Narrows. The program uses an extensive 256X256 dement radar map and employs physical models of ship response and tidal patterns. Chan youi own course through ship and iceberg traffic. Ant standard terminal may be used for display.

FLIGHT SIMULATOR (Available for all computers)

ion of take-off, flight and landin

>fa real airfoil. Yoi

d flyer ei

o perform loops, half-ri

nilar acrobatic

Price: 517.95 Cause lie/$21.95 Diskette

The program ulili/cs aerodynamic equations and the galion using radials and compass headings. The more

Price: $14.95 Cassetle/SIB.W Diskette

ed version of the classic card game, cribbogc. It is an eicellenl program for the cribis the beginner wishing to learn Ihe game, in particular ihe scoring and jargon. The K ihe top of the display (utilizing the TRS-80's graphics capabilities), with ihe cards loints using the (radilionil phrases.

CRIBBAGE 2.0 (TRS-80 only)

This is a well-designed and nicely execute bage player in search of a worthy oppont standard cribbage score board is continu; shown underneath. The compuler auton

CHESS MASTER (North Star and TRS-80 only I price: $19.95 Cassette/$23.95 Diskette

This complete and very powerlul program provides five levels of play. It includes castling, en passant captures and the promotion of pawns. Additionally, the board may be preset before ihe start of play, permitting the examination of "book" plays. To maximize execulion speed, ihe program is written in assembly language (by SOFTWARE SPECIALISTS of California). Full graphics are employed in Ihe TRS-80 version, and two widths of alphanumeric display are provided lo accommodate North Star users.

SIA KTREK 3.2 (Available Tor all computers)

This is Ihe classic Startrek simulation, but wiih several new features. For example, il warning while also attacking starbases in olher quadranls. The Klingons also attack v. shot at! The situation is hectic when the Enterprise is besieged by three heavy cruisers a

Price: S 9.95 Cass* I le/S 13.95 Diskette

Klingons now shooi at the Enterprise without h bolh light and heavy cruisers and move when la starbaseS.O.S. is received! The Klingons gel

Price: $10.95 Cass* t le/S 14.95 Diskelle lie TV screen to "roll" a ball into a hole in the screen. Sound simple? Not when the hole gels smaller and smaller! A built-in timer allows you to measure your skill againsl others in this habit-forming action game.

GAMES PACK I (Available for all computers) Price: $9.95 Casaelle/S 13.95 Diskette

GAMES PACK I contains the classic computer games or BLACKJACK. LUNAR LANDER. CRAPS. HORSERACE. SWITCH and more. These games have been combined into one large program for ease in loading. They are individually accessed by a convenient

GAMES PACK II (Available for all computers) Price: $9.95 Cassette /SI 3.95 Diskette

GAMES PACK II includes Ihe games CRAZY EIGHTS, JOTTO. ACEY-DUCEY, LIFE. WUMPUS and others. As with GAMES

PACK I, all the games are loaded as one program and are called from a menu.

Why pay 17.95 or more per program when you can buy a DYNACOMP collection for jusl J9.95?

NOM1NOES JIGSAW (ATARI and TRS-M oily)

NOMINOES JIGSAW is an intriguing and sophisticated graphical puzzle. The jigsaw c( domly chosen shapes (nominees), of which there are 60 types. By knowing thai the shi Ihe shape at each location, all the nominocs may be eventually deduced. Scoring is basei

MOVING MAZE (Apple only)

MOVING MAZE employs ihe games paddles lo direct a puck from one side of a (and randomly) buill and is continually being modified. The objective is lo crosr Scoring is by an elapsed time indicator, and three levels of ploy are provided.

Price: $16.95 Ciuwette/S20.9S Diskette

siits of a 9 by 9 board partially filled with ranis must be legally connected, and by guessing

Price: $10.95 Cassette/S 14.95 Diskette o Ihe other. However, Ihe maze is dynamically iaze without touching (or being hit by) a wall.

BLACK HOLE (Apple only)

This is an exciting graphical simulai

that the tidal stress destroys i

Price: $14.95 Cassetle/S 18.95 Diskette

n of the problems involved in closely observing a black hole with a space probe. The object is lo nc, an orbil close to a small black hole. This is to be achieved without coming so near the anomaly -. Control of the craft is realistically simulated using side jets for rotation and main thrusters for

mploys Hi-Rcs graphics

TEACHER'S PET I (Available for all computers) Price: $ 9.95 Caiselte/S 13.95 Diskelle

This is the first of DYNACOMP's educational packages. Primarily intended for pre-school to grade ), TEACHER'S PET provides ihe young student with counting practice, letter.word recognition and three levels of math skill exercises.

Price: S 9.95 Cassette/S 13.95 Diskelle

n used in local

CRYSTALS (ATARI onlyl

A unique algorithm randomly produces fascinatii two patterns are the same, and Ihe combined eff

CRANSTON MANOR ADVENTURE (Norlh Star only)

At last! A comprehensive Adventure game for the Norlh Star. CRANSTON MANOR ADVENTURE lakes you into myslerious CRANSTON MANOR where you attempt (o gather fabulous treasures. Lurking in the manor arc wild animals and robots who will not give up the treasures without a Tight. The number of rooms is greater and the associated descriptions are much more elaborate than Ihe H popular series of Adventure programs, making ihis game (he lop in its class. Play can be stopped ai any lime and the status

Price: $19.95

:. Rcqui:

i J2K.

NORTH STAR SOFTWARE EXCHANGE (NSSE) LIBRARY DYNACOMP now distributes ihe 20 • solume NSSE library. Mosl of (hese diskel

Price $9.95 Diskette

Circle 154 on inquiry card.

Availability

DYNACOMP software is supplied with complcli TRS-HOlLevel III and Apple (Applesoft)cassette

alien containing clear explanations and example! :e (ATARI requires 24K). Except where noted, programs d diskette as well as North Star single density {double den rd (IBM format) 8" CP/M floppy disks for systems m

Ml Olherwise specified, all vailableon ATARI, PET. impaiiblOdiskette.Addiunder M8ASIC.

BUSINESS and UTILITIES

MAIL LIST II (Apple and North Star diskettes only)

This many-featured program now includes full alphabetic and lip code sorting as well as Til defined code, client name or Zip Code. The printout format allows the use of standard size i thin 1100 entries (single density Norlh Star or Apple DOS 3.2; over 2200 with double dc:

Price: $24.95

meiging. Entries can be retrieved by userIdress labels. Each diskette can store more ily North Star or Apple DOS 3.3)!

EORM LETTER SYSTEM (FLS) (Apple and North Star diskette only) price: $17.95

FLS may be employed to generate individually addressed form letters. The user creates the address Tile and separately composes the letter. FLS will ihen print form letters using each address. FLS is completely compatible with MAIL LIST II. which may be used lo manage your address Tiles.

FLS and MAIL LIST 11 are available as

TEXT EDITOR I (Letter Writer)

suited for composing letters and is quile

combined package for 137.9S.

Price: $14.95 Cass*lle/SlS.95 Diskette

widths and simple paragraph indexing. This text editor is ideally arger jobs. Available for all computers.

Price: $34.95 Diskette

iplify your personal finances. Features payee; optional priming of

Price: $19.95

; name). Commer

Rcference records

PERSOMAL FINANCE SYSTEM (ATARI only)

PFS is a single disk menu oriented system composed of 10 programs designed to organize a include a 300 transaction capacity: fas! access; 26 optional user codes; data retrieval by reports: checkbook balancing; bar graph plotting and more. Also provides on the diskelle is ATARI DOS 2.

FINDIT (North Star only)

This is ■ (hree-in-one program which maintains information accessible by keywords of three types: Personal (eg: la cial (eg: plumbers) and Reference (eg; magazine articles, record albums, elc). In addition to keyword searches, [he niversary and appointment searches for Ihe personal records and appointment searches for the c are accessed by a single keyword or by cross-referencing two or three keywords,

DFILE (North Star only)

This bandy program allows North Star users to maintain a specialised data base o variably accumulates. DFILE is easy lo set up and use. It will organize your disks gram.

COMPARE (North Star only) Price: $12.95

COMPARE is ■ single disk utility software package which compares two BASIC programs and displays Ihe Tile sizes of the programs in byres, the lengths in terms of the number of slalemenl lines, and [he line numbers at which varioui listed differences occur. COMPARE permits the user lo examine versions of his software to verify which are the more current, and lo clearly identify ihe changes made during develop men l.

COMPRESS (North Star only)

COMPRESS is a single-disk utility program which re BASIC programs. The source Tile is processed one

-. File ci

Price: SI 2.95

ves all unnecessary spaces and (optionally) REMark statements from North Star at a time, thus permitting very large programs to be compressed using only a of 20-50* are commonly achieved.

GRAFIX (TRS-80 only) Price: $12.95 C*ia«lle/$16.95 Diskette

This unique program allows you lo easily create graphics directly from the keyboard. You "draw" your figure using the program's extensive cursor controls. Once the figure is made.it is automatically appended to your BASIC program as a siring variable. Draw a "happy face", call il HI and then print il from your program using PRINT HSI This is a very easy way lo creale and save graphics.

TIDY (TRS-80 only) Price: $10.95 Cass*lt*/$ 14.95 Diskette

TIDY is an assembly language program which allows you to renumber ihe lines in your BASIC programs. TIDY also removes unnecessary spaces and REMark statements. The result is a compacted BASIC program which uses much less memory space and executes significantly faster. Once loaded. TIDY remains in memory; you may load any number of BASIC programs without having to reload TIDYI

STATISTICS and ENGINEERING

DATA SMOOTHER (Not available for ATARI) Price: $14.95 CasMtte/$18.95 Diskette

This special data smoothing program may be used to rapidly derive useful information from noisy business and engineering data which are equnlly spaced. The soflware features choice in degree and range of fit, as well as smoothed first and second derivative calculation.

FOURIER ANALYZER (Available for all computers) Price: $14.95 Cassetie/$18.95 Diskette

Use this program to examine the frequency speclra of limited duration signals. The program features automalic scaling and plotting of the input data and results. Practical applications include Ihe analysis of complicated patterns in such fields as electronics, communica

TFA (Transfer Function Analyzer)

This is a special soflware package which may be used lo evaluate the in examining their response (o pulsed inputs. TEA is a major modifica □rienled decibel versus log-frequency plol as well us data editing featuri

miHc u

. TFA is

n engineering tool. Available for all computers.

Price: $19.95 Casselle/S23.95 Diskette

sfer functions of systems such as hi-fi amplifiers and Tillers by in of FOURIER ANALYZER and contains an engineerings FOURIER ANALYZER is designed for educational

HARMONIC ANALYZER (Available for all computers)

HARMONIC ANALYZER was designed for the spectrum analysis of repetitive editing and storage/retrieval as well as data and spectrum plotting. One particula equally spaced or in order. The original data is sorted and a cubic spline intcrpolat: algorithm.

Price: S24.95 Cass*I le/S2*.95 Diskelle

waveforms. Features include data file generation, y unique facility is that the input data need not be n is used lo create Ihe data file required by ihe FFT

REGRESSION I (Available for all computers) Price: $19.95 Cas*ette/$23.9S Diskelle

REGRESSION I is a unique and exceptionally versatile one-dimensional least squares "polynomial" curve fitting program. Features include very high accuracy; an automalic degree delermination option; an extensive inlerno! library of filling functions; data editing; automalic dala and curve plotting; a statistical analysis (eg: standard deviation, correlation coefficient, elc.) and much more. In addition, new Ills may be tried without reentering the dala. REGRESSION I is certainly Ihe cornerstone program in any data analysis soflware library.

REGRESSION II (PARAFIT) (Available for all computers) Price: $19.95 Caiselle/S23.95 Diskette

PARAFIT is designed to handle those cases in which Ihe parameters are imbedded (possibly nonlinearly) in Ihe filling function. The user simply inserts the functional form, including the parameters (A(l), A(2), elc.) as one or more BASIC statement lines. Data and nipulated and plotted as with REGRESSION I, Use REGRESSION I for polynomial Tilling, and PARAFIT for [hose

ariablcs. Besides perfor

MULTILINEAR REGRESSION (MLR) (Available Tor all computers)

MLR is a professional soflware package Tor analyzing dala sets containing two or more linearly indc;

ing the basic regression calculation, (his program olio provides easy to use data entry, storage, relri

[ion, [he user may interrogate ihe solution by supplying values for the independent variables. The r

limited only by the available memory,

REGRESSION 1, II and MULTILINEAR REGRESSION may be purchased together for 149.95 (three cassellcs) or 161.95 [three

diskette*).

BASIC SCIENTIFIC SUBROUTINES, Volume I (Not available for ATARI)

DYNACOMP is ihe exclusive distributor for Ihe software keyed lo the text BASIC Scientific Subroutines. Volume I by F. Ruckdeschel (see ihe BYTE/McGraw-Hill advertisement in BYTE magazine. January 1981). These subroutines have been assembled according to

cclion II: Chapter cction Hi Chapter cclion «: Chapter

2 and 3: Dala and function plotting, complex variables I: Matrix

operal:

Random number generaiors, series approximations : $14.95 Cajselte/JI8.9J Diskelle All three collections arc available (or S39.95 (three cassettes) and 149.9! (three diskettes). Because the text is a vital pari of the documentation, BASIC Scientific Subroutines, Volume I is SI9.95 plus 75* postage and handling.

a DYNACOMP for

ROOTS (Available for all computers)

In a nutshell, ROOTS simultaneously

of the polynomial, and because Ihe proccdi

and the calculated roots are substituted bu

Price $9.95 Cus«tte/$13.95 Diskette

ill the zeroes of a polynomial having real coefficients. There is no limit on the degree eralive, [he accuracy is generally very good. No initial guesses are required as input, the polynomial and ihe residuals displayed.

ATARI. PET. APPLE II. TRS-ftO. NORTH STAR. CP/M and II

! registered trade n

Ordering Information

1 orders are processed and shipped postpaid within 48 hours. Please enclose payment with o . by VISA or Master Card, include all numbers on card. For orders ouiside North Ameri

Add 12.50 to diskelle price for 8" floppy disk (IBM format sofi sectored, CP/M. Mict •TRS-80 diskettes are nol supplied with DOS or BASIC.

Deduct 10% when ordering 3 or more programs.

a add 10% for shipping and handling.

e for detailed descriptions of these and other programs from

DYNACOMP, Inc.

1427 Monroe Avenue

Rochester, New York 14618

24 hour mail order phone: (716)586-7579

Office phone (9AM-5PM EST): (716)442-8960

Nct, York Stal* roMrati pkuc *rfd 7* NYS ufe. in.

Listing

i continued:

3064

CO

3065

3E 01

3067

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23

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22 CO 30

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0400 0410 0420 0430 0440 0442 0444 0450 0460 4000 4010 4020 4030 4040 4050 5000 5010 5020 5030 5040 5050 5060 5070 5080 5090 5100 5102 5104 5106 5108 5110 5120 5130 5140 5150 5160 5170 5180 5190 5200 5210 5220 5230 5240 5250 5260 5270 5280 5290 5300 5310 5320 5330 5340 5350 5360 5370 5380 5390 5400 5410 5420 5430 5440 5450 5460 5470 5480 5490 5500 5510 5520

;RESET POSITION

;UPDATE BYTE ADDRESS

RNZ

MVI A,l

ST A POS

PUSH H

LHLD DADD

INX H

SHID DADD

POP H

RET *THE DECODE TABLE HAS THE FOLLOWING FORMAT: *THE TABLE VALUE IS THE INCREMENT NECESSARY TO GET THE *NEXT 0-1 PAIR AS THE PROGRAM STEPS THROUGH THE DATA *THE TABLE VALU JUST PRECEEDING A CHARACTER HAS A TAG *SET IN BIT 7, IN ADDITION TO THE INCREMENT, TO INDICATE *THAT THE NEXT VALUE IS A CHARACTER. XTAB:

DB

42

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1

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2

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130

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0

0

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1

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0

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1

4

0

5

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6

7

0

8

1

9

10

11

0

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1

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0

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1

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0

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56

Listing 4 continued on page 244

240 April 1981 © BYTE Publications Inc

For $4,995*you not only get a word processor.

Automatic screen prompting guides user through operations.

Familiar, typewriter-like keyboard. Powerful, versatile userdefined keys reduce many word processing jobs to just two keystrokes.

Word Processing software is only $500. Optional List Processing software, with the powerful conditional select fea lure, is only $400. Optional Accounting software is available through Digital's Computer Stores.

Communications options let you transmit information electronically. Communicate with other computer systems. Flexible text editing features, easy to learn, easy to use. Boilerplate library of commonly used text. Abbreviation (or short-hand) library.

Dual 8" floppy disk drive. Convenient storage with flexible diskettes.

Standard 30 cps draft printer. (Select optional Letter Quality Printer instead of draft printer and system price becomes $7295:)

You also get the Digital factor.

At $4,995, Digital's Word Processing has to be the best value in the industry.

Value which includes immediate delivery. Special discounts on 3-pack systems.

And the Digital Factor. What's that? Read on.

Since we're the world's largest maker of small computers, you get the benefits of our considerable size and experience. Benefits such as a 14,000-person customer service organization 111 Sales Offices, complete training at any one of the 25 Computer Stores or 6 regional training centers, and a 30-day money-back guarantee.

That's the Digital Factor.

For a personal demonstration, call 800-528-6050, ext. 1276. In Arizona, 800-352-0458. For $4,995, you get a lot more than a word processor.

'Software and destination charges not included. Prices quoted apply in U.S. only.

We change the way the world thinks.

In Canada, call Digital Equipment of Canada Ltd., Kanata, Ontario, Tel. 613-592-5111. In Europe, call Digital Equipment Co. Ltd., Reading, England, Tel. (0734) 85131.

Into computers? Want to get started?

What is The Computer Book Club? An exciting new concept that puts hobbyists and businessmen on top of the fast-paced, dynamic world of computers. CBC will bring you info on software, hardware, applications, and theory... at savings up to 75% on hundreds of fact-packed volumes.

CBC is not just another book club! You can get in on Members' Bonus Benefits, like discounts on practical software packages, games, cassettes and disks, plus extra-value book dividends, and much, much more!

This introductory membership offer is for a limited time only. Join today!

1205 List $15.95

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1187 List $14.95

1062 List $12.95

1111 List $14.95

More books to pick from...

• The Complete Handbook of Robotics.

List$12.95.No. 1071

• 57 Practical Programs & Games in BASIC. List$10.95.No. 1000

• Illustrated Dictionary of Microcomputer Terminology. List$13.95. No. 1088

• Handbook of Remote Control & Automation Techniques. List $16.95. No. 1077

FREE when you join.

iOMPt,rERisrs handy

DATABOOK DICTIONARY

242 BYTE April 1981

List $4.95

Circle 155 on Inquiry card.

Take 4 exciting books

IOr Ip .Uy (valuesto $70.75)

... and get one FREE!

1141 List $12.95

1160 List $12.95

1203 List $14.95

1241 List $12.95

7 very good reasons to try The Computer Book Club...

• Reduced Member Prices. Save up to 75% on books sure to increase your know-how

• Satisfaction Guaranteed. All books returnable within 10 days without obligation

• Club News Bulletins. All about current selections—mains, alternates,extras—plus bonus offers.Comes 10 times a year with dozens of up-to-the minute titles you can pick from

• "Automatic Order". Do nothing, and the Main selection will be shipped automatically! But ... if you want an Alternate—or no books at all—we'll follow the instructions you give on the reply form provided with every News Bulletin

• Continuing Benefits. Get a Dividend Certificate with every book purchased after fulfilling Membership obligation, and qualify for discounts on many other volumes

• Extra Bonuses. Take advantage of added-value promotions, plus special discounts on software, games, and more

• Exceptional Quality. All books are first-rate publisher's editions, filled with up-to-the minute info

THE COMPUTER BOOK CLUB Blue Ridge Summit, PA 17214

Please accept my Membership in The Computer Book Club and send the 4 volumes circled below, plus a free copy of Computerist's Handy Databook/Dictionary. I understand the cost of the books selected is $1.00 (plus shipping/ handling). If not satisfied, I may return the books within ten days without obligation and have my Membership cancelled. I agree to purchase 4 or more books at reduced Club prices during the next 12 months, and may resign any time thereafter.

1000 1111

Name _

1045 1141

1050 1160

1055 1169

1062 1187

1071 1191

1077 1203

_Phone_

1088 1205

1095 1241

Address. City

-Zip_

State

(Valid for new members only, I-'oreign and Canada add 20%. Orders outside U.S. must be prepaid witb international money orders in U.S. dollars.) BY-4H1

Circle 155 on Inquiry cara.

BYTE April 1981 243

Listing

i continued

3 0AD

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DADD:

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NEXT DATA ADDRESS

5990

POS:

DS

1

BIT POSITION

5999

ORG 4100H

6000

DBUF:

DS

1000

Listing 5: BASIC frequency-analysis program FREQ. Written in Microsoft BASIC, this program receives text entered by the user and prints the frequency distribution of all letters and symbols. One symbol that does not appear by itself in a line of text is defined as marking the end of text; the symbol, defined in line 100, is presently "%".

LIST FREQ (FREPUENCY ANALYSIS PROGRAM)

10 CLEAR 3000 12 D=45 15 S=0

20 DIM B$(2550) 30 DIM C(D) ^0 DIM L$(D) 50 FOR N=0 0 TO D 60 L$(N)='"%" 70 NEXT N

75 PRINT "ENTER ANALYSIS TEXT, TERMINATE WITH %" 80 FOR N=0 TO 10 90 INPUT B$(N) 100 IF B$(N)=""/o" GOTO 120 110 NEXT N 120 F=N-1 125 FORN=0 TO F 130 L=LEN(B$(N)) 140 FOR K= 1 TO L 150 A$=MID$(B$(N),K,1) 160 FOR J=0 TO D 170 IF L$(J)=A$ GOTO 220 180 NEXT J 190 L$(S) = A$ 200 C(S)=C(S)+1 205 T=T+1 210 S=S+1 215 GOTO 230 220 C(J)=C(J)+1 225 T=T+1 230 NEXT K 2^0 NEXT N 2^5 M=l

250 FOR K=l TO S-2 25 5 FOR N=l TO S-M 260 IF C(N-l)c=C(N) GOTO 274 262 T$=L$(N-1) 264 U=£(N-1) 266 L$(N-1)=L$(N) 268 C(N-1)=C(N)

Listing 5 continued on page 246

244 April 1981 © BYTE Publications Inc

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Listing 5 continued:

2 70 L$(N)=T$ 272 C(N)=U 274 NEXT N 276 M=W+1 278 NEXT K

291 PRINT "LETTER FREOJENCY ANALYSIS"

292 PRINT

2°3 PRINT "LETTER","COUNT","PROBABILITY"

?9A PRINT "

295 PRINT

?0n FOR N= 0 TO D

'10 PRINT L$(N),C(N),C(N)/T

320 NEXT N

OK

Text continued from page 226:

is uniquely dependent upon the code being used. However, the basic structure and program can be used with any Huffman code.

There are three parts to the table structure: the index values that allow the program to step through the appropriate number of table entries (ie: tree branches) as the data-stream bit values are serially examined; the decoded character that results from the search; and a flag to indicate to the program that the next table entry found is a character and not an index value. The index values are always in pairs, with separate index values for a 1 or a 0 bit-stream value. Therefore, as the program scans through the table at each pair of index values, one or the other is selected, depending upon whether the bit in the

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data stream is a 1 or a 0.

The table-scanning process consists of adding the data bit to the current table address. This gives a new address whose contents, an index value, is added to the address of the index value itself. This new table address is the address of the next node in the tree of figure 2.

This process continues until a flag is detected, indicating that the next entry is the desired letter. This test is performed each time an index-value address has been computed. The flag is the most significant bit in the table entry. The remaining 7 bits are interpreted as an ASCII character if the flag is on (logical 1) or as an index value if the flag is off (logical 0). This limits the index value to 127, the maximum distance in the table that can be skipped when processing 1 data bit. To help explain this process, a portion of the table is shown in figure 3.

In the Huffman code used in this program, the letter "I" is 1010. The decoding program identifies the corresponding letter by using the data bit stream and the decoding table previously described. The first data bit is added to the table address, TAB, giving a new address, TAB + 1.

TABLE

TABLE

DATA

ADDRESS

ENTRY

FLAG

BIT

B to

42

OFF

0

\

+ l

ADD 1

fTi

OFF

m

> CHOOSE FIRST BIT

U->

J

♦ ,J

ADD 2

r^i

OFF

a

^

&

) CHOOSE SECOND BIT

+ 3 1

8

OFF

i

J

♦4

130

ON

0

1

* 5

ADD 2

r"?l

OFF

B

) CHOOSE THIRD BIT

\£)

J

+ 6

E

OFF

130 ■ I2B + 2

ON

a

1

■ 130

) CHOOSE FOURTH BIT

♦ 8

130

ON

i

/

+ 9

ADD 2

■

1010

1

DECODED

+ 10

R

+ 11

6

0

+ 12

1

1

Figure 3: Use of the binary tree tables in programs EXPl and EXP2. This annotated table interprets the first 13 bytes of the lookup table in both the code-expansion routines. It corresponds to the part of the binary tree in figure 2 that leads to the letters E, I, and R. This figure shows the process by which 1010 is decoded as the letter I.

246 April 1981 © BYTE Publications Inc

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The index value here, a 1, is added to the previous result, giving TAB+ 2. The first bit has now been processed.

Beginning on the second bit, 0 is added to the previous result and the new index value pointed to is 2. This is added to the previous result, giving a new address of TAB+ 4.

The second bit has now been processed. The next data bit, a 1, is added to the previous result, giving the address TAB+ 5. Adding the index value at this location, a 2, gives the new address, TAB+ 7. The third bit has now been processed.

Adding the last data bit, a 0, gives the entry 130. The fact that this value is greater than 128 proves that it is really an index value of 2 with the flag bit set; 130 = 128 +2. This tells the user that the next entry, two locations further, is the desired character. Adding the index value of 2 points you to the letter "I". Since a letter was found, the process is repeated from the beginning, continuing with the next bit in the data stream (providing that the supply of data has not been exhausted).

Shorter codes are used for the more

frequently occurring data elements,

and longer codes are used for less

frequently occurring data elements.

COMP2 Description

The COMP2 program, given in listing 3, is similar to COMPl except for one significant difference—the serial bit stream that results from the encoding process is packed and stored 8 bits to the byte. This provides true compression and is useful when the compressed file is stored in main memory or when the mass-storage device requires an 8-bit word. An interesting occurrence in using a compression scheme like this is that a low degree of data encryption occurs automatically when the bit stream is broken into 8-bit bytes. Referring back to the example where the word "compression" was represented by 47 bits, you can see that the 8-bit bytes look like the following:

(Binary)

(Hexadecimal)

(ASCII Meaning)

01000111

47

G

00001111

OF

SI (Control character)

01011011

5B

Left bracket

10001100

8C

Not defined in 7-bit ASCII

11010101

D5

Not defined in 7-bit ASCII

1101100

D(?)

Insufficient data

If someone looked at this data, it would not be immediately obvious that this is the word "compression". Some knowledge about the processing method or some effort in decoding it would be necessary to retrieve the original word.

EXP2 Description

The EXP2 program, given in listing 4, is similar to EXP1 except that it expects to find the data to be decoded in a packed form of 8-bit bytes. It works in conjunction with COMP2. As in EXPl, the decoded data is sent to some sort of terminal device. Any other destination could be used with a slight code change.

248 April 1981 © BYTE Publications Inc

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Listing 6: Listing of the execution of program FREQ (listing 5). This listing is the result of running the FREQ program, using eight lines of BASIC code as the text to be analyzed.

OK

RUN OF FREQUENCY ANALYSIS PROGRAM

ENTER ANALYSIS TEXT, TERMINATE WITH % ? "120 f=n-l"

? "125 forn=0 to f"

? "130 l=len(b$(n))"

? "140 for k= 1 to 1"

? "150 a$=mid$(b$(n),k,l)"

? "160 for 5=0 to d"

? "170 if l$(j)=a$ s°to 220"

? "ISO next j"

? %

LETTER FREOJENCY ANALYSIS

LETTER COUNT PROBABILITY

3 A M 6 7 G 8 X 5 E B K A I D

» R

J

2

L T ( ) F N $

O

0

1

7.75194E-03

7.75194E-03

7.75194E-03

7.75194E-03

7.75194E-0?

7.75194E-0''

7.75194E-0''

7.75194E-03

7.75194E-0-5

2

1.55039E-02

2

1.55039E-02

2

1.55039E-02

2

1.5c;039E.02

2

1.55039E-02

2

1.550"59E-02

2

1.55039E-02

2

1.5I>039E-02

•?

2.o2558E-02

3

2.32558E-02

4

3.10078E-02

4

3.10078E-02

5

,.87597E-02

5

3.87597E-02

5

3.87597E-02

6

4.65116E-02

6

4.65116E-02

6

4.65116E-02

7

5.42636E-02

8

6.20155E-02

10

7.75194E-02

11

8.52713E-02

21

.162791

0

0

Line

Operation Performed

10

Assign string space.

12

Maximum number of unique sym

bols expected.

15

Number of unique symbols

entered.

20

Text working buffer.

30

Symbol count array.

40

Symbol array.

50 thru 110

Entry of text to be analyzed.

80

Loop control for number of lines

(may be increased).

120

F is number of text lines entered.

125 thru 180

Input line is transferred to text

buffer.

190 thru 240

Count number of each type of

symbol; T is total count; C is

count of corresponding symbol in

symbol array.

245 thru 278

Sort symbols by count in ascend

ing order.

291 thru 320

Computer probability and output

results.

Table 3: Operations performed by lines of code in the

BASIC program

FREQ of listing 5.

FREQ Description

To aid in doing frequency analysis, a small program, FREQ, was written in Microsoft BASIC. (See listing 5.) This program counts the occurrence of symbols (letters, spaces, punctuation marks, etc) that have been entered

and prints the frequency analysis. In order to include spaces in the count, the input array should be initialized to be filled with a symbol not occurring by itself in the text stream. The same symbol can be used to terminate the text-entry operation: I used a percent sign (%).

The size of the text block to be analyzed is limited only by available memory. To get a reasonably accurate analysis, the text block should be more than several hundred characters and be representative of the entire text. It is not necessary to do a frequency analysis every time a code is constructed. However, the closer the code lengths correspond to the frequency of occurrence, the more efficient the resulting compression will be.

A sample run of FREQ is shown in listing 6 with the text input being part of the program itself. By comparing this output with the figures of table 1, you can see how the letter frequency for a BASIC source program compares to that of plain English text.

Finally, since there are no remarks in the FREQ program, the information in table 3 will help you understand the program. ■

References

1. Hoffman, L J, Modern Methods for Computer Security and Privacy, Prentice-Hall, 1977.

2. Huffman, D A, A Method for Construction of MinimumRedundancy Codes, Proceedings of the Institute of Radio Engineers, September 1952.

3. Tao, W Y, A Firmware Data Compression Unit, University of Illinois, January 1974.

4. Williams, Gregg and Rick Meyer, "The Panasonic and Quasar Hand-Held Computers: Beginning a New Generation of Consumer Computers," BYTE, January 1981, pages 34 thru 45.

250 April 1981 © BYTE Publications Inc

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BYTE April 1981 251

Build an Intercomputer Data Link

Mike Wingfield

93 Pine Hill Rd

Bedford MA 01730

Have you ever wanted to share a program or data with someone, but had no way to get it from your machine to his without typing it by hand? While this facility is lacking on most microcomputers, it is so necessary to scientific and business computers that it has long been taken for granted. The power of a computer is greatly enchanced when it can communicate with geographically distant computers. Computers can attain increased efficiency by sharing both resources and data, or by distributing the work load among connected computers. These capabilities also increase the versatility of the computer as a tool, and make possible such services as electronic mail and quick access to data. These and similar advantages will become available to the hobbyist and the small businessman through the use of intercomputer data links.

This article describes a specific implementation of a connection be

About the Author

Mike Wingfield graduated from the University of California at Los Angeles in 1972 with a PhD in computer science. Presently, he is working for the computer consulting firm of Bolt, Beranek, and Newman in Cambridge, Massachusetts, where his specialty is the design and implementation of intercomputer communication software. His hobbies include gardening and experimentation with 6800- and 6809-based microcomputers.

The power of a computer is greatly enhanced when it can communicate with geographically distant computers

tween two computers that provides a symmetrical facility for terminal linking and memory-to-memory file

USER A

1

TERMINAL

COMPUTER

transfers. Terminal linking implies that the output from each terminal is echoed on the remote terminal. File transfer implies the error-free transmission of a block of data from one computer to the other. The purpose of this article is to provide insight into the requirements of largescale network design through an examination of one specific implementation.

System Overview

As presented in figure 1, each end

USER B

COMPUTER

TERMINAL

DATA LINK

Figure 1: Typical data-link system configuration. Although the connection between the terminal and the computer is hardwired (ie: a direct electrical connection), the data link between computers (bridging a large distance) is usually accomplished via radio or telephone link.

252 April 1981 © BYTE Publications Inc

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□ Personal Check □ Money Order/Cashier's Check

D VISA □ Master Charge (Bank No. )

Acct. No. Exp. Date

Signature

Print

Name

Address

City

State Zip

ISMVETRONICS

RESEARCH & DEVELOPMENT, LTD, 333 Litchfield Rd„ New Milford. CT 06776

v....

Computers can attain

increased efficiency by

sharing both resources

and data.

of the connection consists of a computer and a terminal (such as a teletype or a video display terminal). The local computer is connected to the remote computer via a data link that is implemented by an asynchronous serial hardware interface and the software necessary to support data transfer. The data link may be hardwired if the distance between computers is short; or, it may consist of a pair of modems connected by a telephone line if a hardwired line is inconvenient. Figure 2 illustrates the

hardware configuration of each computer—in this case, a 6800-based system. Two ACIAs (asynchronous communications interface adapters) provide the necessary interfaces to the terminal and to the line. The software involved occupies approximately 700 bytes of memory.

The user interface can be defined as the view the user has of his computer. The interface to the data-link software was designed to be as simple as possible (to reduce the amount of software), and yet provide the user with two capabilities:

• Echoing of characters typed by one terminal on the other terminal. This feature enables two persons to communicate with each other. This is the transparent or linking mode, which is the default state of the software.

• Initiation of a file transfer from one

6800 MICROPROCESSOR

t

c

c

c

0

Ul

READ-ONLY MEMORY

0

u.

PROGRAMMABLE MEMORY

3Jl

ASYNCHRONOUS COMMUNICATIONS INTERFACE ADAPTER (ACIA)

.TO OTHER /\/ COMPUTER

0

Ul

ASYNCHRONOUS COMMUNICATIONS INTERFACE ADAPTER (ACIA)

TERMINAL

DATA BUS

ADDRESS BUS

Figure 2: Hardware configuration of a 6800-based computer. The computer communicates across the data link by means of the ACIA, which converts the 8-bit bytes of information to a continuous (serial) stream of bits. This serial bit stream is transmitted by use of the modem, which translates between the binary signal and a signal that can be carried across telephone lines.

254 April 1981 © BYTE Publications Inc

FOR OVERWORKED COMPUTER OPERATORS, OUR SLC-1 MAKES THE PERFECT ASSISTANT.

Your computer may lose track of things once in a while. The time, for example. When it does, your operator has to make sure it gets things right again - which costs you time and money. If they make a keying error, these costs go up.

That's one good reason to get your computer a smart new assistant like the SLC-1. It listens to everything your computer says. When it recognizes a key phrase, it flashes back the answer instantly. A battery backup system keeps the SLC-1 running, come power failure or system crash. And unlike your regular operator, the SLC-1 doesn't make mistakes.

Plus the SLC-1 does a lot more than timekeeping. It also provides instant answers to a variety of mainframe questions. You pick the key phrase it looks for, and type in the responses. Then-for example-if your computer goes

down, it can be automatically re-booted back into action under the SLC-1's supervision.

The SLC-1 does all this because it's driven by its own computer, a 6502 microprocessor. So when you want to use your main computer for something else, you still have - for backup - the SLC-1, with its own 1K bytes of RAM (expandable to 12K).

But even with its optional 10-digit display, the SLC-1 is inexpensive to hire. And it's simple to train. Just plug it into the RS-232 or 20-mA current loop serial link between your computer and terminal, enter your message responses, and you're all set.

So give yourself a break: talk to our personnel counselor today at Digital Pathways, 1260 L'Avenida, Mountain View, CA 94043. Or contact us at (415) 969-7600. TWX 910379-5034. We'll introduce you to a new assistant that doesn't talk back. Except to your computer.

7T

MEET THE ASSISTANT COMPUTER OPERATOR THAT NEVER TAKES A COFFEE BREAK.

Ciicioii-ition inquiry card.

GENERAL FRAME FORMAT

DLE

STX

(OPC)

ETX

(CHECKSUMHIGH)

(CHECKSUMLOW)

DATA BYTES

Figure 3: Frame format for data transmission. A frame is information that will be transmitted across the data link as a unit and checked for accuracy upon receipt. For the purposes of transmission accuracy, the data is preceded by a header and followed by a trailer. DLE and STX are both 1-byte ASCII characters. (OPC) stands for opcode, which is a 1-byte quantity that tells the receiver what kind of data follows. A running 2-byte total of the data bytes is kept. This is deposited as a checksum, high byte first, and is used by the receiving computer as a check against transmission errors.

(o) ADDRESS FRAME:

DLE

STX

30

(ADDRLOW)

(ADDRHIGH)

DLE

ETX

(CHECKSUMHIGH)

(CHECKSUMLOW)

(b) DATA FRAME:

DLE

STX

31

DLE

ETX

(CHECKSUMHIGH)

(CHECKSUMLOW)

DATA BYTES

(c) ACKNOWLEDGE FRAME:

DLE

STX

32

DLE

ETX

(CHECKSUMHIGH )

(CHECKSUMLOW)

DLE

STX

33

DLE

ETX

(CHECKSUMHIGH)

(CHECKSUMLOW)

(d) NEGATIVE

ACKNOWLEDGE FRAME:

Figure 4: Frame formats for different types of data. The third byte in each frame dictates the type of data sent in that frame. A hexadecimal 30 means that the current frame contains a 2-byte hexadecimal address, sent high byte first: this is an address frame, with format as illustrated in figure 4a. A hexadecimal 31 denotes a data frame, which is the only frame that has a variable length. (See figure 4b.) Because the end of the data is marked by a DLE ETX sequence, a DLE within the data byte area is transmitted twice to indicate that it is data, rather than the end of valid data. A hexadecimal 32 denotes an acknowledge or A CK frame (figure 4c), while a hexadecimal 33 denotes a negative acknowledge or NAK frame (figure 4d). The address and data frames are sent to the computer that is receiving data. The ACK and NAK frames are sent from the receiving computer to acknowledge error-free or faulty transmission of the previous frame, respectively.

computer to the other. This is done by specifying a local starting address of the file, the remote loading-start address, and the byte count of the file. This is accomplished by a simple command interpreter that asks for these three parameters and initiates the transfer. Data blocks are transmitted by one computer, and their reception acknowledged by the other. This is the file-transfer mode of the software.

The following information outlines the sequence of events leading to the transfer of a file between computers. User A dials up user B over the telephone and both computers are connected via modems. (See figure 1.) User B tells user A, via the link, the

name and loading location of the desired file. The file can be a BASIC program, an assembly program, a letter, or any other kind of file.

User A types a control-F that initiates the local command interpreter, resulting in "S:" being displayed. User A keys in four hexadecimal digits (representing the source address) and a carriage return. The command interpreter types "D:" and waits for four more hexadecimal characters and a carriage return (representing the destination address).

Finally, a "#:" directs user A to type in the byte count and a carriage return; this begins the file transfer. When the transfer is complete, user A's computer returns to the linking mode. Further file transfers can then

be negotiated before the telephone connection is manually broken.

During specification of the addresses and byte count, a backspace erases the previously typed character and a control-X aborts the command interpretation and returns the computer to the linking mode. Any illegal hexadecimal characters typed are ignored and the terminal bell is sounded for each occurrence.

Communication Protocol

To insure correct interpretation of a sequential stream of bytes, a communication protocol that imposes meaning on the data stream must be specified. Computer protocols, like human protocols, are those modes of behavior agreed upon between

256 April 1981 © BYTE Publications Inc

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j£?ndfiyst car) be modified to suit your needs because we sufefify the source Joe the commar)us.kou can arbWcaxily alter the befiavior jf wy commdydf

One year's suffiort is included—we (\orft imveyou tojeydfovjowesejfi^fyft our tfjorougf), readable documentation fjas received high aedaimjeom our usecs.rJAmettjyst comes wily Tye,3}>D& C compiler

systems

Amethyst $350 (less C compiler $250) manual $35

Mince (Amethyst text editor) $125 manual $15 demo disk $10

Scribble (Amethyst text formatter) $125 manual $15

Mince and Scribble ordered together $175

D

48K CP/M required. Available on 8" soft sector diskettes. Mince and

Amethyst require a cursor-addressable terminal. Dealer, site, OEM,

and **NIX versions and licenses available.

Mark of the Unicorn, P.O. Box 423, Arlington, MA. 02174 (617)489-1387

Circle 164 on Inquiry card. BYTE April 1981 257

The days of complicated, unreliable, dynamic RAM are gone:

the ultrabyte memory board

6lfln QK I complete kil \

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Netronics consistently offers innovative products at unbeatable prices. And here we go again —with JAWS, the ultrabyte 64K S100 memory board. ONE CHIP DOES IT ALL JAWS solves the problems of dynamic RAM with a state-of-the-art chip from Intel that does it all. Intel's single chip 64K dynamic RAM controller eliminates high-current logic parts . . . delay lines . . . massive heat sinks. . . unreliable trick circuits. REMARKABLE FEATURES OF JAWS Look what JAWS offers you: Hidden refresh ... fast performance . . . low power consumption . . . latched data outputs ... 200 NS 4116 RAMs . . . on-board crystal. . . 8K bank selectable . . . fully socketed . . . solder mask on both sides of board . . designed for 8080, 8085, and Z80 bus signals. . . works in Explorer, Sol, Horizon, as well as all other well-designed S100 computers.

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□ JAWS 16K RAM kit, No. 6416, S199.95.*

D JAWS 16K RAM fully assembled, tested, burned in, No. 6416W, S229.95.*

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□ Expansion kit, JAWS 16K RAM module, lo expand any of the above in 16K blocks up to 64K, No. 16EXP, $129.95.*

'All prices plus S2 postage and handling. Connecticut residents add sales lax. Total enclosed: S

□ Personal Check □ Money order or Cashiers Check

□ VISA □ MASTER CHARGE (Bank No )

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Signature :

Prim Name

Address

City

State Zip

H Send me more information

parties. Bridge-bidding sequences are an example of a human protocol, although the complete protocol agreement between partners must be negotiated. Computers require precisely specified protocols.

To encode meaning into a data stream, the concept of a frame must be introduced. A frame is a stream of bytes with a beginning-of-frame mark, a coded portion (which determines the use of the data), the data, and an end-of-frame mark. To enable more reliable communications along a noisy channel, a checksum is appended to the end of the frame; this is used by the receiver to verify that no bits have been dropped. Figure 3 presents the structure of the frames selected for this file-transfer application.

Computer protocols, like human protocols,

are those modes of

behavior agreed upon

between parties.

Since each byte in a stream can assume any one of 256 values, a special technique is used to denote the beginning and ending of a frame. One particular byte is selected to be the data-link escape (DLE), to signify that the next byte is to be interpreted as either start of frame (STX) or end of frame (ETX). The receiver, when seeing a DLE and a STX in series, knows that a frame has begun. When the DLE ETX pair is received, it knows that the end of frame has been reached and that the next 2 bytes contain the checksum. To preclude the appearance of a DLE STX or DLE ETX pair within the data portion of the frame, all DLEs in a data frame are doubled—that is, transmitted as DLE DLE. The receiver, seeing two sequential DLE bytes, simply discards one of them to restore the frame to its original length.

The byte following the DLE STX is assigned the function of an operation code (ope) that is used to give meaning to the data portion of the frame. Four types of frames are defined: an address frame (hexadecimal 30), a data frame (hexadecimal 31), an acknowledge frame (hexadecimal 32),

and a negative acknowledge frame (hexadecimal 33). These four frames represent the minimum set required to successfully get a file transferred from one computer to another in a simple, yet reliable fashion.

One design possibility not used here would put the address field in the data frame so that the start-load address for each frame would be available just before its associated data. This would have eliminated the necessity for the address frame; however, it would require a buffer in the receiver equal to the length of the frame. The buffer would be used to hold the data until the checksum verified that the received data is perfect. If the data were not buffered, but was simply stored at the address specified, then an error in the address bytes would cause the data to be stored in the wrong portion of memory. With a separate address frame, the address will be verified as correct before the data arrives so that no receive buffering is required.

Following receipt of the address or data frame, the receiver returns either an acknowledge (ACK) or a negative acknowledge (NAK) frame, thus indicating whether the frame received is perfect. The sender uses this information to decide whether or not to retransmit the frame. Thus, both computers must communicate to get the whole file transferred without error.

Figure 4 illustrates the structure of each of the four types of frames. Data bytes corresponding to the code for DLE are doubled only in the data frame, which has variable length. This is unnecessary in the other three frames because they have a predefined length.

The checksum is simply a 16-bit sum of all the bytes in the frame (except the first DLE and the trailing ETX). This provides an undetected bit-error rate which is adequate for this application.

The frame structure is used only in file-transfer mode; in linking mode, each character is sent immediately; no error checking is considered to be necessary.

The lowest level of protocol involves the hardware interface between the two computers. In this application, the two computers are connected over an asynchronous bitserial channel. This technique was selected for several reasons. A serial

258 April 1981 © BYTE Publications Inc

NEECO

Qt commodore

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4016 "B" (16K RAM 4.0 Basic - 40 Column) .... 995

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2022 Tractor Printer 795

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8010 IEEE Modem 395

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PET - IEEE Cable 40

IEEE-IEEE Cable 50

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NEECO also carries all available ATARI software

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I

Circle 165 on inquiry card.

BYTE April 19B1 259

NEW!!! THE *

ELECTRIC MOUTH

for SlOO, Elf II, Apple, TRS-80 Level II*

From $99.95 kit Now— teach your computer to talk, dramatically increasing the interaction between you and your machine.

That's right: the ELECTRIC MOUTH actually lets your computer talk! Installed and on-line in just - inutes, it's ready for spoken-language use in office, business, industrial and commercial applications, in games, special projects, R&D, education, security devices — there's no end to the ELECTRIC MOUTH's usefulness. Look at these features:

* Supplied with 143 words/letters/ phonemes/ numbers, capable of producing hundreds of words and phrases.

* Expandable on-board up to thousands of words and phrases (just add additional speech ROMs as they become available).

* Four models, which plug directly into SlOO. Apple, Elf II and TRS-80 Level II computers.

* Get it to talk by using either Basic or machine language {very easy lo use, complete instructions with examples included).

* Uses National Semiconductor's "Digitalker" system.

* Includes on-board audio amplifier and speaker, with provisions for external speakers and amplifier.

* Adds a new dimension and excitement to programming; lets you modify existing programs and games to add spoken announcements of results, warnings, etc.

* Installs in just minutes.

Principle of Operation: The ELECTRIC MOUTH stores words in their digital equivalents in ROMs. When words, phrases, and phonemes are desired, they are simply called for by your program and then synthesized into speech. The ELECTRIC MOUTH system requires none of your valuable memory space except for a few addresses if used in memory mapped mode. In most cases, output ports (user selectable) are used,

second d

space f speed g

Spoken Material Included!

one eighteen m dollar inches numl

iwo nineteen cancel down is df

Ihree Iwenty case equal U <>■■

four 'n'rty cenl error kiln on

five forty 400het1z lone feet left oul

six BBS eoherlz lone flow less over

seven s'xIy 20ms silence fuel lesser parenthesis start i z

eight seventy 40ms silence gallon limil percent slop j

nine eighty nflms silence go low please than k

tan !!'nej^Lj I60™5 silence gram lower plus ihe |

eleven hundred azfJms silence great mark point time m

twelve thousand camj greater meter pound Iry n

thirteen million check have mile pulses up o

fourteen zero comma high milli rale volt p

fifteen again control higher minus re weight q

sixteen ampere danger hour minuli; ready a r

seventeen and degree in near right b s

*"EJ/ JJ" ond "The EJeciric Mouth" are reg. trademarks 0/ Netronics R&D Ltd. "Apple" is a reg. trademark of Apple Computer Inc. "TRS-80 Level JJ" is a reg. trademark 0/ Tandy Corp.

Continental U.S.A. Credit Card Buyers Outside Connecticut

CALL TOLL FREE 800-243-7428

To Order From Connecticut Or For Technical Assistance, Etc.,

Call (203) 354-9375

NETRONICS R&D LTD.DePtB4

333 Litchfield Road, New Milford, CT 06776

Please send the items checked below:

□ S100 "Electric Mouth" kit soo.tir.

□ Elf II "Electric Mouth" kit S99.95

U Apple "Electric Mouth" kit $110.95

D TRS-80 Level II "Electric Mouth" kit SI 19.05

Add $20.00 for wired & tested units. All plus $3.00 postage & insurance. Conn res. add sales tax.

Total Enclosed S

D Personal Check D Cashier's Check/Money Order

□ Visa □ Master Charge (Bank No. |

Acct.No.

Signature

Print

Name

-Exp. Dale.

Address

City

State

260 April 1981 © BYTE Publications Inc

.JZhi_

SIGNAL LEVEL

START BIT

DO

Dl

D4

D5

D7

STOP BIT

Figure 5: Serial transmission of data. When transmitting data between two computers on an asynchronous serial line, the data is transmitted 1 bit at a time with each byte of data (8 bits) framed by a start bit and a stop bit; a parity bit usually comes between the last data bit (D7) and the stop bit but is omitted in this application due to the error checking already provided. Here, the byte being transmitted is binary 11010011 (read from right to left).

COMPUTER A

COMPUTER B

SEND FILE

SEND

SERIAL

LINE

RECEIVE

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Figure 6: The interconnection of send and receive software modules. When computer A sends a data frame to computer B, the receive module of computer B tells its send module to transmit an ACK frame (if the data agrees with the checksum) or a NAK frame (if it does not). This acknowledge frame is received by computer A, which then informs its send module to transmit new data, or retransmit the previous frame, as necessary.

channel uses few wires when a direct connection is possible. For longer distances, the link can be made by a telephone line and standard modems. Also, there are integrated circuits interfacing directly to the microprocessor that can handle this format very well. Figure 5 demonstrates how 8-bit bytes are transmitted along with their start and stop bits. To improve efficiency, no parity bit is used since the checksum provides error control.

Software Description

The software is organized into three cooperating modules: the send routine, the receive routine, and the command interpreter. The send and receive modules are used mainly for file transfer. The conceptual connection of these two software modules in both computers is detailed in figure 6. The send routine of computer A sends to the receive routine in computer B, and vice versa.

When the send module in A sends a frame, the receive module in B

verifies the checksum and tells the send module in B to send either an ACK or a NAK back to A. The send module in B sends the ACK or NAK to A's receive module, which then informs A's send module that an ACK or a NAK was received. Thus, two flags are necessary for communicating between the send and receive modules: one commanding "send ACK or NAK," and the other stating "received ACK or NAK." A "send file" flag to the send module of A initiates the file transfer.

Note the symmetry. Because the send and receive sections in each computer are independent, and because they communicate by flags, the send output can be fed directly into the receive input in the same computer for test purposes during debugging. Files can be moved from one place in memory to another within the same machine, simulating the actions of two coupled machines.

The third module of code is the command interpreter, which is used to specify the source starting address,

Text continued on page 266

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Circle 166 on inquiry card.

BYTE April 1981 261

( IOINT J

NO /CHARACTER

^\ ? ^/^

PRINT AND SEND CHARACTER

Tyes

PRINT "S."ON CONSOLE

( RETURN J

KBSTATE=1

f RETURN J

KBSTATE= 0

( RETURN )

DECREMENT KBBUFF POINTER BY 1

f RETURN )

O

PUT CHARACTER

IN BUFFER;

PRINT CHARACTER

f RETURN J

GET CHARACTER

ACTER \ YES RETURN,

0

f RETURN J

CONVERT KBBUFF TO BINARY VALUE

BYTECNT^VALUE

XMITFILE = 1

KBBLOCK=1

( RETURN j

SRCADDR*VALUE

PRINT "D:" ON CONSOLE

KBSTATE = 2

f RETURN J

DESTADDR = VALUE

PRINT "H:" ON CONSOLE

KBSTATE= 3

( RETURN J

Figure 7: Flowchart for the command interpreter, IOInt. This routine gathers the information necessary to initiate the transfer of a given block of information between computers. An interrupt from the keyboard causes this routine to be executed (from the beginning) every time a key is pressed. The value of KBSTATE (keyboard state) causes the routine to ask for the starting address of the block to be sent (with the prompt "S:"). This is followed by a request for the destination address for the first byte (prompted with "D:"), and the number of bytes to be transferred (prompted with "#:"). Once this information has been given, the routine disables the keyboard from further input (KBBLOCK = l) and sets a flag that tells the software send module to begin sending the block of data (XMITFILE=1).

262 April 1981 © BYTE Publications lnc

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Circle 167 on inquiry card.

BYTE April 1981 263

( XMITLOOP J

I WAIT""! ' LOOP I

0

XMITFILE=0

YES /RECDAClO = 0

?

RECDACK=0

YES

■©

RING BELL

BLOCKKB=0

RETRANS=3

SEND ADDRESS FRAME: SEQUENCE IS: DLE.STX, 30,DESTADDRH,DESTADDRL DLE,STX,CHECKSUMH, CHECKSUML

XMITLOOP

WAIT FOR"ACK RECEIVED" SIGNAL (RECDACK=1)

©

YES

WAITFLAG=0

XMITACK\ YES

( RETURN J

SEND NAK FRAME

XMITACK=0

0

RETRANS=RETRANS-1

PRINT ERROR MESSAGETRANSMISSION OF DATA FRAME FAILED

Figure 8: Flowchart for the send module. This routine, when activated by the condition XMITFILE=1, causes the computer to transmit a block of data in the form of an address frame, followed by a data frame. It waits in a loop until XMITFILE is set to 1, signaling that a block of data is ready to be transmitted. It then sends the address data frames, waiting after each for an ACK frame response from the receiving computer. If either frame is received imperfectly, the process begins again with the address frame. Software limits repetition to a total of three tries. All numbers used in this figure are hexadecimal. Also, the variables ADDRESS, BYTECNT, CHECKSUM, DESTADDR, INDEX, and SRCADDR are all 2-byte variables. The subscripts H and L refer to the high and low bytes, respectively, of a 2-byte variable. If the block to be transmitted is more than decimal 256 (hexadecimal 100) bytes long, it is transmitted in blocks of 256 bytes.

On Flowcharting Interrupt-Driven Routines

The perceptive reader may notice that the flowchart of figure 9 (on page 266) does not have a return or end block. Although it may not be immediately obvious, the same is true of the flowchart in figure 8. (The one return block that does exist is used only when the XmitLoop routine is returning from calling itself.) The reason for this and other seeming omissions has to do with the function of interrupts in the data-link routines.

When the data-link software (see listing 1) is running, it is usually in the XmitLoop routine, repeating the wait loop marked in the flowchart of XmitLoop. (See figure 8.) If an interrupt comes from the keyboard, control transfers to the IOInt routine, flowcharted in figure 7, and returns to the routine that was executing before the interrupt.

If an interrupt comes from the serial line, control transfers to some location within the Linelnput routine, but, instead of starting at

the beginning of the routine (as is done with the IOInt routine), control transfers to the instruction directly after the "bsr GetByte" (branch to GetByte subroutine) instruction most previously executed. (See figure 9.) This can be accomplished because the GetByte subroutine stores the return address in the variable ACIAState; it is this address that is jumped to upon a serial line interrupt (see routine IOInt in listing 1).

264 April 1981 © BYTE Publications Inc

Circle 168 on inquiry card.

SEND BEGINNING OF DATA FRAME; SEQUENCE IS: DLE, STX.31

YES

INDEX* BYTECNTL

INDEX = 100

ADDRESS —SRCADDR

GET MEMORY BYTE, UPDATE CHECKSUM, AND SENDONE BYTE OF DATA FROM BODY OF DATA FRAME

YES

UPDATE CHECKSUM AND SEND SECOND DLE

INDEX = INDEX -1 ADDRESS = ADDRESS+1

SEND END OF DATA FRAME, SEQUENCE IS: DLE, ETX, CHECKSUMH, CHECKSUML

XMITLOOP

WAIT FOR "ACK RECEIVED" SIGNAL (RECDACK*!)

BYTECNT=BYTECNT -100 DESTADDR= DESTADDR+100 SRCADDR= SRCADDR+100

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April 1981 © BYTE Publications Inc 265

(line INPUT J

Text continued from page 260:

the destination starting address, and the byte count. This code is activated by a control-F character depressed on the keyboard. The final carriage return sets the XMITFILE flag, which is polled by the background send routine.

Command Interpreter Structure

Figure 7 presents the flowchart for the command interpreter, IOInt, which is driven by interrupt signals received from the keyboard.

Each character from the keyboard generates an interrupt, which starts the command interpreter. If the send module is currently sending a file, as evidenced by the relation "BLOCKKB > 0", then the character is to be ignored and is merely echoed as a bell.

0

STORE BYTE AND INCREMENT ADDRESS

GET CHECKSUMu ANDCHECKSUML

NO /tHECKSUrrOK

XMIT ACK=1

I

RECDACK= -1

Figure 9: Flowchart for the receive module, Linelnput. Whenever an incoming byte on the serial line causes an interrupt to occur, control of the program transfers to a point within this routine just after the previous "get byte" request, and executes until another "get byte" request is encountered. Control then returns to the routine that was running before the serial line interrupt (usually the wait loop marked in figure 8) until another serial line interrupt causes the Linelnput routine to resume execution where it stopped. This routine stops for every byte of an ACK, NAK, address, or data frame.

266 April 1981 © BYTE Publications Ire

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BYTE April 1961 267

The operation of the interpreter is a function of the state variable, KBSTATE. If the state is zero, the transparent mode case, the character is echoed locally and sent to the remote computer. Otherwise, the character is tested for being a carriage return (CR).

The carriage return causes the keyboard buffer (which collects address or byte-count hexadecimal characters) to be converted to a binary value. If the character is a control-X, the interpreter mode is aborted and KBSTATE is returned to zero.

If the character is a BS (backspace), the pointer into the keyboard buffer is decremented (after first checking for underflow). If none of the above is true, the character is checked for being a proper hexadecimal character and is then put in the keyboard buffer (after checking for overflow). The keyboard buffer holds as many as four hexadecimal characters, which is the largest buffer needed to specify a 16-bit address or a byte count.

The sequence of characters echoed on the terminal following the carriage return, as well as the location of the

binary value, are dependent on the current state of the interpreter. After each carriage return, the state is incremented to ensure that the correct control path is executed for each of the three parameters collected. Finally, the last carriage return after the byte count specification sets the BLOCKKB flag and the XMITFILE flag. The BLOCKKB flag prevents any keyboard characters from appearing on the line during a file transfer. The XMITFILE flag tells the send module to begin sending the specified file.

Send Routine Structure

The send module, XmitLoop, is responsible for sending address, data, ACK, and NAK frames to the remote receive module. Figure 8 shows the flowchart for the program flow of the send routine. This routine operates in background mode, testing three flags to see if any work is pending. If the XMITACK flag is -1, a NAK frame is sent; if it is +1, an ACK frame is sent.

If the RECDACK flag is not zero, and the send routine is waiting for an ACK or a NAK, then a return is made

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to the data transfer routine to complete the data or address frame transfer. (This will be explained in more detail later.) If the XMITFILE flag is non-zero, then file transfer begins.

As explained earlier, the address frame is sent first so that no buffering in the receiver is necessary in case of an address error. Once the address is correctly received and acknowledged, a data frame is sent. If the data frame is acknowledged, the next address and data frames are sent, and the process is repeated.

If a NAK frame is received, then the address frame received in error is retransmitted and verified before the data block is retransmitted. When sending either an address or a data frame, the send routine employs the same mechanism in waiting for an ACK or NAK. When the wait for an ACK or NAK signal is necessary, the send module XmitLoop calls itself by storing the return address on the stack and branching to the beginning of the routine. When the send routine finds that the RECDACK flag is set, control is returned to the proper location in the send routine via an RTS (return from subroutine) instruction. The RECDACK flag indicates whether a new frame should be sent or the old one retransmitted.

A retransmission index is maintained and decremented each time a frame retransmission is necessary, and no more than three retransmissions are allowed. (The number of retransmissions allowed is a parameter that is easily changed.) If more than three failures occur, an error message is typed on the sender's console and control returns to the transparent mode. When all of the file has been successfully transmitted, control returns to transparent mode and the keyboard is enabled.

In data frames, data bytes that happen to have the same hexadecimal value as the DLE code are doubled (repeated) so that a false end of frame is prevented; the receive routine drops the second DLE so that the data is received correctly. In the worst case, this has the effect of doubling the length of the frame.

Receive Routine Structure

The flowchart for the receive program, named Linelnput, is shown in figure 9. This routine handles the in

Text continued on page 286

268 April 1981 © BYTE Publications Inc

Circle 169 on inquiry card.

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Circle 170 on inquiry card.

BYTE April 1981 269

Listing 1: Software for data transfer between two 6800-based systems linked by a serial line. The software here consists primarily of a data-sending routine (labeled XmitLoop), a data-receiving routine (labeled Linelnput), and a command interpreter (labeled IOInt). All numbers preceded by a dollar sign ($) are hexadecimal numbers. Also, references to '0, '1, '2, and '3 are actually to the characters "0", "1", "2", and "3". These characters, when represented in ASCII, have values of hexadecimal 30, 31, 32, and 33 and are referred to in text and in flowcharts as such. Flowcharts 7 thru 9 correspond to the code given in this listing.

rr*9i'

rile

eau

Ppfti

et x

e«u

H9B2

St X

equ

"(1710 7

bel 1

equ

OH! 1ft

*X

equ

P0P6

*F

equ

PP08

bs

equ

P90D

C r

equ

00 1 ft

IOPt P

eou

F9Pn

Ac 1 aCsM

equ

Fq01

Ac 1 aOat al

eau

F902

AciaCsr?

equ

F933

Ac 1 aOat a2

equ

OV5P

SayeOpc

equ

("051

Aci aStat e

equ

ansa

S re Arjdr

equ

0056

DestAddr

equ

0058

BvteCnt

equ

0(?«5B

ninVal

eau

a 050

KbPt r

eau

01 rt S F

KbBuif f

equ

3362

KbF.nd

eau

00.63

ChkSun.

eau

;i?6^>

ReedChk

eau

0-lbA

KbState

equ

0 0 6 B

RecdAc k

eau

i!06C

Xmi t Ack

eau

03 6 0

X m i t F i 1 e

eau

006F

W a i t F 1 a q

eau

H;"6F

BlockKb

equ

7V-7S

SaveSu"

equ

(.''17 7

XChkSum

eau

fl?79

Address

eau

$9ti

$83

$82

7

M«

6

6

$d

S 18

$f 900

$f901

Sf9P2

$f 903

$50

S51

$5U

$"5b

$S8

$5h

$5d

ISf

$62

$b3

$b5

th.i

$bb

$bC

$bd

$6e

*6<

$75

$77

$79

die c^ar

et x char

91 x char

belt char

control X

control F

backspace

c a r r i age return

I/O Interrupt vector

Ac 1 a to terminal

A c 1 a to modem

place to save ope

state of ac 1 a fsm

ftp sou ret address

ftp destination addr

ftp byte count

place to save number

ot r into KbBuf f

U char buffer

end of hu f fer

xmit checksum, recv side

reed checksum, recv side

state of kh handle r

f1aq - reed ac k

flag - send ac k

f1aq - send file

flag - wait for ack/nack

flag • blocks kb act i v

olace to save checksum

i«i 11 ed checksum

r e c v store address

100 0

org

I 1 (J 3 0

* Entry point

1000 1 PIP?

1005 1008 10PA 1000

1010

1013 1015 1018 101A 101C 101r1021 1022 1023 1025 1028 102A 1028

8b B7 B7 86 B7 H7 CE OF CE DF Bb CE bF !)8 4 4 26 CE DF 01 HE

03

F90tf

F902

96

F q 0 0

F902

lien 51

IIP?

18 06

0^6A P0

FA

005F

5D

Start

i n i) o o o

Ida s t a st a Ida st a s t a Idx

St X

1 dx stx Ida idx cl r i nx dec bne idx stx nop cl i

«3

Aci aCs r1

Ac * aCsr2

»$9b

Ac i aCsr1

Ac i aCsr2

*InzAci a

Aci aState

•IOInt

IOPtr

*6

SKbState

x

i n?1oop #KbBuff

KbPtr

reset Acia's

/6U, 8 bits, interr

set up ac i a2 entry

clear start

the f1ags of area

in* the buffer ptr

* Background routine

checks event entries

1P2C 102E 1030 1033 1035

9b 2b CE 9b 2b

6D

2A

l?b7

6C

PF

Xm1tIoop

1037 D6 6ft

1 da a

bne Idx 1 da a bne 1 da b

Xmi tF 1 1 e I nzAddr *Nac kr r« Xm1tAck GoAc k RecdAck

xmlt file event?

ptr to Nack frame xmit ack/nack event?

reed ack/nack event?

Listing 1 continued on page 272

270 April 1981 © BYTE Publications Inc

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Epson MX-80 $579

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Daisy Wheel s1,799

Save 5% Off wirh Purchase of MOD III System or Disk Drive

New low cost internal disk kit available to expand your storage capability. With this kit, now, you may expand your Model III computer up to four MTI 40 track disk drives, giving 175,000 bytes of storage per drive for a total of 700K.

The kit includes one 40 track disk drive, controller, power supply, cables, mounting hardware and installation documentation.

Manufacturer Direct Price ONLY

*649

fiR

MICROCOMPUTER TECHNOLOGY, INC

3304 W. MACARTHUR, SANTA ANA, CA 92704 • PHONE (714) 979-9923 • TELEX #678401 TAD IRIN

*Uses MTI Memory, Disk Drives & Components

® TR5-80" IS A REGISTERED TRADEMARK ^ OF TANDY CORPORATION

VISA

ALL PRICES CASH DISCOUNTED

FREIGHT FOB FACTORY

ASK FOR FREE CATALOG

Circle 171 on inquiry card.

BYTE April 1981 271

Listing 1 continued:

039

03B

030 03F 0<J 1 0'JU

?a5

0U8

piaB

cion

0«F

05? (*$3

pis y

056 058

H5* 050

061 063 0frU 066 068 06A 06C 06F

070

072

073 07U

076 077 079 ?7B

07C 07E 080 082

08 a

085 087 088 ,*8A 08C 08E 090 091 092 09U

096 097 098 09* 09C 09E M> 1 0A4 0A7 0A9 AAA 0AC 0AF

27 97 96

27 7F 1 7 39

2B CE C6 A6 BO 28 5A 2b D7 20

6B 6E FB 0C6ET

0 3

126,1 07 0F

i tie 4

F7 6C D2

306D 58

7F DE 27 51 C6 83 37

C6 30 80 52 96 56 80 73 96 57 80 6F 80 59

33

to

2R 33

37

C6 31 80 3F 5F

96 58 26 3? 06 59 OF 5'J 37

A b g p 33

80 55

81 9.i 26 02 8D «F »8

5A

26 F0 80 35

33

00 2B 96 27 7A 7C 7C 2*1 5A 26 CE BD

0F 58 1<I

00 58 cn56 0P5O

Hi

H7 126E

1 IB?

hea st a Ida bea Cl r tba rt s

Xm i t Loop WecdAck ^ a i t F 1 a g Xmi tLoop

Wa i t F1aq

clear the event

clear the flag

reg a is ack/nack f 1 ag

return to waiting routine

* Routine for sending Ack/Nack ipame

GoAc k

Skpldx F rmLooP

F i n4

bmi Idx 1 da 1 da Isr inx dec bne st a bra

Skpldx

*AckF rn>

#7

x

SendChar

F rmLoop Xmi tAck Xm i t Loop

send nac k? send ac k1 frame bvte count get bvte send out

clear the pvent

* Routine for sending Address frame

Inz Add r

GoAddr

* there

c! r ldx beg Ida b psh b Ida b bsr 1 da a bsr 1 da a bsr bsr is a wait pul b t st a bmi

XmitF ile ByteCnt LastB!k #3

clear

c hec k

flag for null

i ndex

ret ransm i ss ion save it opcode byte send dle,st x,ope send out addr bytes

*»0

SendHdr

DestAddr

UpdtChk

OestAddr*1

UpdtChk

SendTl send d1e,etx,cc - wait for ac k/nac k he re

get ret pans i ndex check ack/nack flag

RetryBlk branch if ack

* Routine

G o F i l e

Skipl.d SendByt es

F i n 0 o U n

there

RetryBlk

F r ror

for PSh

Ida bsr Cl r b 1 da a bne Ida b Idx psh h 1 da a pu 1 b bsr cmp a bne bs r i nx dec b bne bsr is a wait pu 1 b t st a hm i Ida a beg dec i nc i nc bra dec b bne 1 dx Isr

sending block of data b

b

SendHdr

ByteCnt SkipLd ByteCnt+1 S rcAddr

UpdtChk #dle FinOoub UpdtChk

save retrans index

opcode

send dle,stx, opc

in* byte count index

chk upper hyte

< 256 bytes left

save i t

get byte

restore

update checksum, send

check for die

update checksum, send

check byte count

SendByt es

SendTl send dle,etx,cc ■ wait tor ack/nack here

get ret rang i ndex check ack/nack flag check for failure check for done

Ret rvBlk

ByteCnt

LastBlk

ByteCnt

Oest Addr

SrcAddr

InzAddr

decrease i nc rease i nc rease

bv

by by

256 256 256

bytes bytes byt es

GoAddr

*ErrorMsg print error msq

0 u t T e x t

Listing 1 continued on page 274

272 April 1981 © BYTE Publications Inc

LOWEST PRICE - BEST QUALITY

NORTH STAR

North Star Horizon 2

2-51/4 Disk Drives 32K Double Den Factory assem. & tested Factory guaranteed List 3095

only

$2274

POWERFUL NORTH STAR BASIC FREE SUPERB FOR BUSINESS & SCIENCE

FACTORY ASSEMBLED & TESTED LIST ONLY

HORIZON-1-32K-DOUBLE DEN $2695 $1980

HORIZON-2-32K-QUAD DENSITY 3595 2674

HORIZON-2-64K-QUAD +HARD DISK 9329 7149

HORIZON RAM ASSM 16K=$389. 32K = $579

HORIZON RAM KIT SALE! 16K = $314 32K = $469

HORIZON DISK DRIVE SALE DOUB DEN SAVE! 315

NORTH STAR HARD DISK 18 Mb 4999 $3929

PASCAL-PLUS 14,18 OR 36 DIGIT PRECISION 249

SUPERBRAIN

ZENITH

SUPERBRAIN QD 64K

List $3995 only $2995

Z-89 48K List $2895 only $2299

TERMINALS Z-19 $725

INTERTUBEIII omy$725

DIP-81 PRINTER omy$395

MICROTEK $675

NEC PRINTER $2569 TRACTOR, THIMBLE, RIBBON

InterSystems

ITHACA INTERSYSTEMS 2A

List $3595 You Pay Only

Z-80A CPU 4 MHz 64K Dynamic RAM Front panel V I/O—with interrupts FDCII Disk Controller 20 slot motherboard

$2795

PASCAUZ + THE FASTEST PASCAL $375 GET READY FOR ITHACA'S Z-8000

8086 16 BIT CPU & SUPPORT CARD SEATTLE $575

MORROW 8" DISK

DISCUS 2D + CP/M® 600K ONLY $938 DISCUS 2 + 2 + CP/M® 1.2 MEGA B. $1259 ADD DRIVES 2D = $650 2 + 2 = $975 2D-DUAL + CP/M® ONLY $1555

MORROW HARD DISK

26,000,000 BYTES!!

LIST $4995 ONLY $3995

CP/M® IS INCLUDED!

SAVE ON MEMORY AND PROGRAMS

SYSTEMS MEMORY 64K AST 4mHz

$599 SYSTEMS MEMORY 64K BANK SELECT $789 CENTRAL DATA 64K RAM $599

ITHACA MEMORY 8/16-bit 64K $845

SEATTLE MEMORY 8/16 BIT 16K 4Mhz $275 SSM KITS Z-80 CPU $221

VIDEO BROV83 4Mhz $412

ANADEX PRINTER DP-9500-1 $1349

CAT NOVATION MODEM $169

TARBELL DISK CONTROLLER DD $445 ECONORAM2A8KASSM $179

NSSE 1-22 & P01 TERRIFIC PROGRAMS ONLY $10. EACH NORTHWORD 294 MAILMAN 234 INFOMAN $364

TARBELL COMPUTER-PHONE

RCA-COSMAC VP-111 99 RCA-COSMAC VP-711 $199

COLOR! RAINBOW 385 SPECTRUM $289

EZ-80 Machine Language Tutor $25 EZ-CODER Translates English to BASIC $71 ECOSOFT FULL ACCOUNTING PKG

$315 BOX OF DISKETTES $29

SECRETARY WORD PROCESSOR

The Best! $99 TEXTWRITER III Book Writing Program

$112 GOFAST NORTH STAR BASIC Speeder Upper $71 Which Computers are BEST? BROCHURE FREE

North Star Documentation refundable w/HRZ $20

AMERICAN SQUARE COMPUTERS BEATS ADV. PRICES

square

American [0] Computers

919-889-4577 KIVETT DR. JAMESTOWN N.C. 27282 919-883-1105

CP/M is a registered trademark of Digital Research, Inc.

Circle 172 on inquiry card.

BYTE April 1981 273

Listing I continued:

10B2 fi6 P7 LastBlk Ida a «beH ring the bell

10BU 80 H\ nsr SendTerm send bell to term

10B6 07 6F sta b BlockKb unlock the kh

1WBfl 20 9E F4n2 bra Fin4 end of file xfer

* Subroutine which sends out dle.stx, unci in? checksum 10BA 86 90 SendHdr Ida a *dle die char

108C 80 2C bsr SendChar send die

lPlRE IF c 1 r a

10BF 97 77 sta a XChkSum In? checksum

10C1 97 78 sta a XChkSum+1

1BC3 86 8? 1 da a * st x

10C5 8D 18 bsf UpdtChk send stx

10C7 17 tba

10C8 80 IS bsr UpdtChk send opcode

10CA 39 rts

* Subroutine whicK sends out dle,etx»ccl#ce2

* and sets up wait for ack/nack 10CB 8b 9a SendTl Ida a «dle

1 0 C 0 9 7 6 (-. sta a wgitHaq indicate waiting ack/nack

10CF 80 0£ bsr UpdtChk send out die

1001 86 83 Ida a «etx

1003 80 IS bsr SendChar send out etx

1005 96 77 Ida a XChkSum

1007 80 11 bar SendChar send high bytp

10D9 96 78 Ida a XChkSum+1

10DB 80 00 bsr SendChar send low byte

10DO ?£' 09 bra Fin2 go to idle 1 non

10OF 56 UpdtChk PSh a

10E!l 9B 78 add a XChkSgm+1

10E2 2 4 «3 bec SkpH

1 0 E 4 7CP;,77 inC XChkSum

I WE 7 97 78 SkpH sta a XChkSum+1 10F9 3? pul a

10EA 37 SendChar psh r> save it

10FB F6 F90? Ida b AciaCsr2 aet status

10tE C a ? 2 and h a 2 tent for ««it reaOV

10F0 27 F9 beg SendChar+1

10F2 H7 F9B3 sta a AciaData?

10F5 33 Pul b restore req

10F6 39 rts

10F7 r 6 F 9 01-1 SendTerrr Ida b AciaCsrl aet status

10FA C4 02 a"d b «2 test for transmit rnv

10FC 27 F9 bea Send Term wait for readv

10FF 87 F901 sta a AciaDatal

1101 39 rts

* Entry Doint for the I/C interrupt

1102 &6 F902 IOInt Ida a AcieCsr2 aet status

1105 2A 07 bpl Kblnt chk for acia interr

1107 B6 F903 Acia2Int Ida a AciaData2 get l|ne data

110A DE 51 ldx AciaStete

110C 6E 00 jmp x go to ACIA routine

110E 86 F90) Kblnt Ida a AciaDatal get kb data

1111 By 7F and a #$7f kill parity bit

1113 D6 6F Ida b BlockKb Chk if sending file

1115 27 05 beg ChkCli

1117 86 07 OutBell Ida a «bell

1119 80 0C OutTerm bsr SendTerm send char to term 111B 3B rti return

111C D6 6A ChkCli Ida b KbState

II IE 26 13 bne CI I

1120 81 06 emp 3 #*F 1122 27 05 bea StartCl i

1124 8D 01 bsr SendTerm send char to term

1126 8D C2 bsr SendChar

1128 3B rti return

1129 CE 1278 StartCl i Idx #SrcTxt output S? Listing 1 continued on page 276

274 April 1981 © BYTE Publications Inc

32K Board Pictured Above

Why Not the Best?

From The Dynamic RAM Company.

2MHz

4MHz

16K—$249

$259

32K—$375

$395

48K—$500

$530

64K—$625

$665

We have now been shipping our 2MHz dynamic RAM boards for over two years. Hundreds of 4MHz boards have been going out every month since early 1979. Our reliability is proven in the thousands of systems which contain our board. Many qualityminded systems houses across the country and overseas are using our boards for their equipment.

Our prices still beat all. Despite rising 1 6K memory chip prices (at least from reputable suppliers), Central Data continues to give you the best buy in memory today. Nobody offers a board with a capacity of 64K, assembled, tested, and guaranteed for a full year at the price we do.

Circle 173 on inquiry card.

Deselect around PROMs. Our

boards have the important deselect feature which lets you overlap any fixed memory in your system with no interference.

Our features make the board easily used and expanded. You address our boards on 16K boundaries with mini-jumps (small shorting plugs that slide over wirewrap pins) near the top of the board for easy access. If you want to expand your board after you have purchased it, all that you need to do is add memory. We can supply you with expansion packages ($1 50-2MHz, $160-4MHz) which include eight RAMs that you can depend on as well as two mini-jumps for addressing. And of course, our board never generates wait states.

Low power consumption keeps your computer running cool and reliable. The total power consumption of our 16K board is typically less than 4 watts ( + 8V @ 300ma, +1 6V @ 1 50ma and

-16V @ 20ma). Boards with additional memory typically increase power consumption only 1 watt per 1 6K!

Standard S-100 Interface. Our board is designed to interface with any standard S-100 CPU. All of the timing of the board is independent of the processor chip, and the board is set up for different processors by changing two plugs on the board.

Call or write us today. That will guarantee a fast response with more information on the board. Or make an order — you'll probably have the board in two weeks! If you're interested, also ask for a catalog on our Z8000 16-bit processor board designed for the MULTIBUS. All of these products are available to your local dealer, also.

Central Data Corporation, 713 Edgebrook Drive, PO Box 2530, Station A, Champaign, IL 61820. (217) 359-8010

Central Data

BYTE April 1981 275

Listing 1

J12C 11 2F 1132 1133 1135 1137 1139 1 13B 1130 113F 11UC? 1142 1 t«4 1116 11^8 111A 1 14C llflE 115? 1152 115a

1157 1159 1156 H5C 115F H5F 1161 1 162 1 16« 1167 1169 U6B

continued:

8D HB2

7C «P»6A

3B

81

27

81

27

81

27

36

8tf

2B

fl!

2F

81

2B

81

2E

ea

Dfc" 8C 27 A7 08 OF 32 20 32 20 CE 8D 97 CE

0D 46 18 29

32

ID

HA

31

15

36

11

27

5D

51063

H8

(53

5D

BS

B3

1275 49 6A

005F

CI i

CharDK

BadChar

Cancel

InzPtr

i nc

pti

emp beq

Cffp

bea

emp bea pen. sub bm1 Cmp

ble

emp bml cup bgt

sub

ldx

CPU

bea st a 1 nx stx pul bra pul bra ldx bsr st a ldx

OutText KbState

#CP

Convert

**X

Cancel tfbs BackUp

*$30

BadChar

«9

CharOK

tt$31

BadChar

»$36

BadChar

#$27

KbPtr

#KbEnd+l

BadChar

x

KbPt r

Out Term

OutBel1 *CRLF OutText KbState SKbBuff

return check for CR

Check for ctrl x check for backspace

save for display

check for valid hex char

check for overf1ow

qet original char echo for dl9plav pull off stack

out put a c r# If

clr KbState

Listing 1 continued on page 278

To Place An Order

From Outside Texas

1-800-231-3680

Questions & Answers

& Orders Texas 1-713-392-0747

MARYMAC INDUSTRIES, INC.

(Radio /hack)

Store #Q-189

AUTHORIZED SALES CENTER

BRAND NEW IN CARTONS DELIVERED. Marymac Industries owns & operates Radio Shack® dealership in Katy, Texas. Warranties will be honored by all company owned Radio Shack8 stores, & participating franchisees and dealer authorized sales centers. Save State Sales Tax. Texas Residents Add Only 5% Sales Tax. Open Mon.-Sat. 9-6 . We pay freight and insurance. No extra charge for Master Charge & Visa. Call us for reference in or near your city. Ref: Farmers State Bank, Brookshire, Texas. Write or visit us at, 21969 Katy Fwy, Katy (Houston), Texas 77450.

WE OFFER ON REQUEST

Federal Express

Houston Intercontinental Airport Delivery

U.P.S. BLUE

References from people who have bought computers from us probably in your city

ED McMANUS

0

0

0 0

10% 15%

OR MORE

Model III

In stock TR8-80 Modal II and III

No Tax on Out of Texas Shipments!

WE ALWAYS OFFER

0 NO extra charge for Master Charge or Visa

0 We always pay the freight and insurance

0 Toll free order number

0 Our capability to go to the giant Tandy Computer warehouse 5 hours away, in Ft. Worth, Texas, to keep you in stock.

JOE McMANUS

RadM Jhaek

In Stock

276 April 1981 © BYTE Publications Inc

Circle 174 on inquiry card.

MODEL II

$ DISCOUNT $

TRS-80®.

MODEL

RA301

26-4002

64K 1 Drive

$3440.00

26-4160 1 Drive EXP $1035.00

26-4161 2 Drive EXP 1575.00

26-4162 3 Drive EXP 2115.00

26-4501 Gen. Ledger 180.00

26-4502 Inventory 180.00

26-4503 Payroll 360.00

26-4554 Acct. Rec 180.00

26-4701 Fortran 270.00

26-1157A Daisy Wheel. . .2290.00 26-1158 Daisy Wheel II. . .1799.00

COMPUTER SPECIALISTS

26-1155 Quick Printer II $187.00

26-1145 RS-232 Board 84.00

26-1140 "O" K Interface 249.00

26-1141 "16" K Interface 359.00

26-1 142 "32" K Interface 469.00

26-1160 Mini Disk - Drive 0 419.00

26-1161 Mini Disk - Additional 419.00

26-1154 Lineprinter II 699.00

26-1165 Line Printer V 1710.00

26-1159 Lineprinter IV 859.00

26-1166 Line Printer VI 1080.00

26-1563 Scripsit - Disk 79.00

26-1566 Visicalc 83.00

26-1562 Profile 72.00

26-1061 4KI $630.00

26-1062 16K III 888.00

26-1063 32K III

2-Drives, RS232 2225.00

COLOR

ALL OTHER R.S. SOFTWARE

FURNITURE, STANDS, CABLES

AND ACCESSORIES AT

DISCOUNT FROM

CATALOG PRICE.

26-3001 4K $360.00

26-3002 16K 540.00

26-3010 Color Video 360.00

26-1206 Recorder 54.00

26-3008 Joysticks 22.50

CEriTROniC5

Fast 100 CPS Centronics

730 Printer 577.00

Text Quality Centronics

737 Printer 737.00

Novation Cat Modem. .$149.00 CCA Data Management

System 72.00

Adventure Games

Games 1-9 each 14.00

Q

Acorn

Software Products, Inc.

Model II Cobol Compiler

$360.00 Cobol Run Time Package

$36.00

Pocket Computer

■jv • • • " ' *'

fgtpc ioono!

CD CO G3 CD CO S3 S3 G3 C3D

aaaaa

26-3501 1.9K P.C $225.00

26-3503 Cassette l/F 45.00

14-812 Recorder 72.00

GAMES:

Alien Invasion $9.00

Stock Market 9.00

Star Trek 9.00

Block Em 9.00

Ting-Tong 9.00

UTILITIES:

System Savers 14.00

EDUCATION:

Language Teacher 18.00

FREE: COMPUTER CATALOG UPON REQUEST

1-800-841-0860 Toll Free Order Entry

MICRO MANAGEMENT SYSTEMS, INC.

No Taxes on Out Of State Shipments

Immediate Shipment From Stock on Most Items

DOWNTOWN PLAZA SHOPPING CENTER

115CSECONDAVE.S.W.

CAIRO, GEORGIA31728

(912) 377-7120 Ga. Phone No.

-TRS-80 It a reglitered trademark of th* Tandy Corp.

R.S. 90 Day Limited Warranty F-48 Form Provided

Largest Inventory In the S.E. U.S.A.

Circle 175 on inquiry card.

BYTE April 1981 277

Listing 1

116E

1170

1171

1173

1176

1178

1179

117B

1170

1180

U82

U8U

1186

1188

118A

118C

118E

1190

1192

1195

1197

1199

1198

119D

11A0

11A2

11*5

11A7

11A9

1 1 AC

11AE

1 1BPI

continued: DF 5D 3B

DE 5D 8C 005F 27 9F 09

DF 5D 20 9C CE 005F 8D 3A 97 58

80 36 97 5C DE 5B

96 6A

81 01 26 07 DF 5a CE 127D 20 09 81 0? 26 0C DF 56 CE 128? 8D IP 7C 0f"6A 20 Ca DF 58 7F 0PI6A

97 6D 97 6F 2<* B9

BackUp

Convert

Trv2

CM spText

Trvi

stx

rti ldx

cpx bea dex stx bra ldx bsr st a bsr st a ldx Ida cmp bne stx ldx bra cmp bne stx ldx bs i" i nc bra stx cl r st a st a bra

KbPt p

KbPt r *KbBuff OutBel1

KbPt

OutT

«KbH

Bvte

BinV

Byte

BinV

BinV

KbSt

*1

Trv2

SrcA

#Des

D i sp

#2

Trv3

Dest

#RCn

OutT

KbSt

InzP

Byte

KbSt

Xmi t

Bloc

InzP

r epm

uf f

al

al + 1

al

ate

ddr tTxt

Text

Addr

tTxt

ext

ate

t r

Cnt

ate

File

kKb

t r

ini pt r

return

check for underflow

deer KbPtr

point at buffer qet a byte Put in ins byte qet a byte

qet binary nu»ber check fsm state

display D s

display » «

s ave byte count

set send file event 1ock the kb

11B2 11B4

A6 27

13

Out Text

Ida bea

Retnfa

qet char

Listing 1 continued on page 280

Big Savings On Atari & PET!

No Risk - No Deposit On Phone Orders - Shipped Same Day You Call0 - C.O.D. or Credit Card

* On all in stock units

Atari® 800

List $1080

only $759

ATARI*

400 8K 400 16K .

410 Recorder

815 Disk

810 Disk

822 Printer

825 Printer

830 Modem

850 Interface Module

CX852 8KRAM

CX853 RAM

CX70 Light Pen

CX30 Paddle

CX40 Joystick

CX8100 Blank Diskettes (5/box)

62

1199

489

359

779

159

179

94

149

64

18

18

22

CXL4104 Mailing List $17

CX4107 Biorhythm 13

CXL4007 Music Composer 45

CX4110 Typing 20

CX4101 An Invitation to

Programming 17

CXL401 5 TeleLink'" 20

CXL4004 Basketball S 30

CX4105 Blackjack 13

CXL4009 Chess 30

CXL4011 Star Raiders'" 45

CX4111 Space Invaders 18

CXL4006 Super Breakout" 30

CXL4010 3-DTic-Tac-Toe 30

CXL4005 Video Easel" 30

Please Call Between 11AM & 6PM (Eastern Standard Time)

(800) 233-8050

To Order:

Phone orders invited (800 number is for order desk only). Or send check or money order. Equipment shipped UPS collect. Pennsylvania residents add 6% sales tax. Add 3% for Visa or MC. Equipment is subject to price change and availability without notice.

Computer Mail Order 501 E. Third St. Williamsport, PA 17701

£* commodore

4032N $1090 CBM 2022 Printer.

4032B. 8032...

NEW

VIC-20

1090 1499

$299

CBM 4040 Drive. CBM 8050 Drive. CBM C2N Drive . PET-IEEE Cable.. IEEE-IEEE Cable.

675

1090

1420

87

37

46

Software

E186 279

WordPro 3 (40 col.) WordPro 4 (80 col.) WordPro 4 Plus

(80 col.) 339

Visicalc - Apple 122

Visicalc - Atari 163

Visicalc-PET 163

Commodore

Tax Package 399

Microtek - for Atari

Microtek 16K RAM ... 99.95 Microtek 32K RAM ...189.95

Disks

Sycom 51A" Single Density Box of 10 $29

Maxell 5'A" Floppy

MD1 Single Density

Box of 10 34

MD2 Double Density Box of 10 44

Printers

Trendcom 200 489

Epson MX-80 539

Commodore Tally 8024... 1679

(717) 323-7921

278 April 1981 © BYTE Publications Inc

Circle 176 on inquiry card.

Circle 177 on inquiry card.

16 BIT 8086 MICRO SYSTEM

Tec ■ 86™ Basic ■ 86 ™ CP/M - 86 ™

IEEE S-100 Bus - Available Now Complete system up and operating 8086 System with Dual Floppy Disks Available Now for only $3990 CP/M-86™ only $250 Basic-86™ only $350

Tec-86 / 8086 System

$3990

■

Complete 8086 System for CP/M-867

CP/M-86 Available Now - $250 • IEEE 696 S-100 Compatible • 5 MHz 8086 CPU (Optional 4 or 8 MHz) • Vectored Interrupts • 24 Parallel I/O lines (three 8 bit ports) • Two RS-232 Ports • Baud rates from 50 to 19200 baud • Independent baud rate generator for each serial port • 32 Kilobytes of static RAM (Expandable) • ROM boot for CP/M86™ • Dual 8-inch Shugart floppy disks with controller • Attractive, all metal desk top enclosure

Optional 64K Dynamic RAM - Available Soon Basic-86™ Available Now

EC RR

eqistered tradeMark ■ Microsoft

Data Acquisition Systems and Video Digitization Systems Available 23414 Greenlawn • Cleveland, OH 44122

TECMAR, INC.

(216)382-7599

CPM" registered tradeMark • Digital Research

Listing 1 continued: 1B6 BO 1 OF 7 1B9 08 1BA 20 Ffc

1BC 1BE 1BF 1C(5 1C1 1C2 1C3 lCu 1C6 1C7 1C8 1C9

1CA

1CD 1CF 1D1 10*1 \Ob )D8 ID* IDC 1DD IDF 1E1 1E3 U5 1E7 If

A6 H8 48 <JB 48 48 3b A6 "8 33 IB 39

BD 81

Pi P)

30

1?4F 9H

27 ^5 8D t^F7 20 F«

80 77

81 8? 2b 6P 5F

D7 b3 D7 bU 8D bC 97 5F 8] 3? 27 ?IE 81 31

Byte

Hetnb * Rout < ne which Lmelnogt jsr InzAe i a cmp a

beq

Out Isr

bra

FrameSt bsr

cmp a bne cl r b sta b st a b bsr sta a cmp a beg cmp a

jsr

SendTerm

send char

to

term

Inx

bra

OutText

Ida

a

X

< nx

as 1

a

as 1

a

asl

a

as 1

a

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a

Ida

a

X

(UK

PUl

b

aba

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handles incoming ACIA characters GetByte get next char tfdle check for die char F rameSt

SendTerm send char to term Li nelnput GetByte

#stx check for stx char ErrNack

ChkSum

ChkSum+l zero the checksum

GetBvte

SaveOpc save opcode

M'Q check for addr frame

AddrF ru

*M check for data frame

Listing 1 continued on page 282

J

THE

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280 April 1981 © BYTE Publications Inc

Circle 178 on inquiry card.

Important New Salary Data

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The 1981 Computer Salary Survey and Career Planning Guide has been compiled by Source Edp, North America's largest recruiting firm devoted exclusively to the computer profession Since 1966, our annual Survey has helped thousands of computer professionals make the best decisions for their future. And now, at the threshold of sweeping changes in the industry, this new Survey can be of particular importance to you.

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(When writing, please be sure to indicate home address and current position title )

Circle 179 on inquiry card.

BYTE April 1981 281

Listing 1 11EB ItfD lifcF

1 IF 1

11F3 1 1FS 11F7 1 1F9 1 ! FB 1 1FD 1 IFF

wet

1203 12P5 12P7

12P9

I2?e

1200 120F 1211 1213 1215 1217 1218 1214 121C 121E 121F 1221 1223 122S 1227

1228 122A

continued:

27 «3

81 32

27 BE

81 33

27 0A

2H b?

80 S6

97 79

80 S2

97 7A

80 HI

80 UC

DE 63

OF 75

80 46

97 65

80 H2 97 66 C6 HI DE 65 9C 75 27 01 50

96 5?

8U «12

27 0E 50

2B ^7

96 50

81 32 27 01 5?

07 63

20 9F

AddrF pm

VerChk VeMfy

beq cmp a beq cmp a beq bra bsr st a a bsr st a a bsr bsr ldx stx bsr st a bs r st a a Ida b 1 dx

CPX

beq neg b S kpC rt I da a and a bea t st b bml 1 da a cmp a beq neq b * RecdAck: W => Set;J*ck sta b F i r.3 bra

a

Dat aF rm

»•?

VerChk

#'3

VerChk

ErrMack

GetBvte

Address

GetBvte

Address*1

GetBvte

GetBvte

ChkSum

SaveSum

GetBvte

RecdChk

GetBvte

RecdChk+i

*1

RecdChk SaveSum SkpCrt

SaveOpc

*2 SendAck

check for ack frame

check for nack frame

bad f pa»e

get upper addr bvte

get lower addr bvte

aet die net et x save the checksum

get upper checksum

get lower checksum

1 => Ack

-1 a> Nack

get opcode Ignore bit 0

error -> reed Nack

get opcode

check for reed Ac*

SetRAck SaveOpc

SetRAck

-1 s> reed Nack nop, 1 s> reed Ack, -1 s> reed Nack RecdAck

Linelnput

Listing 1 continued on page 284

Combine accurate flight characteristics with the best in animation graphics and you'll have SubLOGIC's

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282 April 1981 © BYTE Publications Inc

Circle 180 on inquiry card.

Pascal

from beginning to...

The BYTE Book of Pascal

Edited by Blaise W. Liffick

This newly reprinted edition, compiled from articles, language forums, and letters from BYTE Magazine, provides a comprehensive introduction to Pascal. In addition this book contains important software, including two versions of a Pascal compiler —one written in BASIC and the other in 8080 assembly language; a p-code interpreter written in both Pascal and 8080 assembly languages; a chess playing program; and an APL interpreter written in Pascal. $25.00 Hardcover pp. 342 ISBN 0-07-037823-1

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end

Circle 181 on inquiry card.

BYTE April 1981 283

Listing 1 continued:

122C D7 6C SendAck sta b XmitAck

* XmitAck: 0 = > nop, 1 => xmit Ack, -1 => xmit ^ack 122E 20 9A bra Unelnput

123P1 flD ID DataFrm bsr GetBvte

1232 81 90 cmp a »dle check for doubled die

123a 27 09 beo ChkDble

1236 DE 79 OkOble 1 dx Address

1238 A7 gip sta a x store byte

123A 08 inx

123B OF 79 stx Address

123D 2*3 Fl bra DataFrm

123F 80 0E ChkDble bar GetByte throw away first die

1241 Si 99 cmp a #dle

1213 27 Ft beo OkOble

1215 8l 83 cmo a *etx check for frame end

1217 27 BA beq Verify frame error

1219 86 FF F-rrNeck Ida a *-l send Mack event

121B 97 6C Sta a XmitAck

12«D 2a OB bra Fin3

* Exit routine which saves the return address,

* undates the checksum, and does rti 121F 30 GetByte tsx

1250 EE "0 Idx x qet entry point 1252 OF 51 stx AciaState save return aodess

1251 3) ins

1255 3i ins get off stack

1256 9B 61 add a ChkSum+j 1258 2u 03 bcc SlepUpper 125A 7C 0063 inc ChkSum 125D 97 61 SkpUpner ata a ChkSum+1

125F 3B rti return

1260 90 AckFrm fcb dl e» st x , • 2 , d 1 e, e t x, 1, S« 'J

1261 82

1262 32

1263 90 1261 83

1265 01

1266 1U

1267 9? NackFrm fcb rtl e, st x, ' 3» dl e# et x, 1 , S«5

1268 82

1269 33 126* 90 126B 83 126C 01 126D 15

126E 20 ErrorMsn fee / Failed/ 126F 16

1270 61

1271 69

1272 6C

1273 65 1271 61

1275 00 CRLF fcb $d,Ja,0

1276 0A

1277 00

1278 20 SrcTxt fee / S» /

1279 53 127A 3A 127B 20

127C 00 fcb 0

1270 20 OestTxt fee / D: / 127E uu 127F 3A

1280 20

1281 00 fcb 0

1282 20 BCntTxt fee / *l /

1283 23 1281 3A

1285 20

1286 00 fcb 0

end

284 April 1981 © BYTE Publications Inc

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BYTE April 1981 285

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Text continued from page 268:

put from the serial line; it detects frames, parses them, and performs the appropriate action. The state of the receive program is saved whenever calls to GETBYTE are made. (It is conceptually easier to imagine that a call to GETBYTE results in a wait followed by a return with the next input byte from the line. Actually, a call to GETBYTE results in the storing of the return address in ACIASTATE and the execution of a return from interrupt instruction. The next line input interrupt then causes a branch to the address in ACIASTATE, which reenters the receive routine at the right place to process the next incoming byte.)

Incoming bytes are first checked sequentially for the presence of DLE bytes. If a byte is not a DLE, it is printed on the local terminal. Otherwise, the DLE signals the beginning of a frame, and the STX and opcode bytes are received and checked.

An opcode of hexadecimal 30 implies that the next 2 bytes are to be stored in ADDRESS, high-order byte first. The checksum is then tested. If it is correct, the XMITACK flag is set to 1; otherwise, the XMITACK is set to —1. The send module will eventually notice this work request and issue either an ACK or a NAK frame.

An opcode of hexadecimal 31 implies a data frame. Since the start address has already been verified in the address frame, data bytes are stored in their proper memory locations as they arrive. When a DLE DLE is detected, only one DLE is stored. If, however, a DLE ETX is detected (denoting an end of frame), the checksum is verified and and XMITACK flag is set accordingly.

An opcode of hexadecimal 32 implies receipt of an ACK frame, and an opcode of hexadecimal 33 implies receipt of a NAK frame. Both are verified for accuracy by comparing the computed checksum to the received checksum, and the RECDACK flag is set accordingly. This informs the send module whether the next address or data frame may or may not be sent.

At the end of each frame, control returns to the beginning of the receive program so that the next frame (or stream of keyboard characters) may be properly interpreted.

Debugging

Debugging is best accomplished if the code can be separated into modules that can be tested independently. As indicated earlier, there are three major modules: the command interpreter, the send routine, and the receive routine. I have found the following order to be the easiest way to debug the program routines:

• the transparent mode routine

• the receive routine

• the command interpreter

• the send routine

The computer was connected to itself, as described earlier, for testing purposes; this was done by connecting the transmit line of the send routine to the receive line of the receive routine. In this way, I was able to confine bugs to only one machine.

Proper operation of the transparent mode code is verified by the double echo on the terminal. Each character typed in is echoed on the console from the send routine. The character is then sent on the line, where it is received by the receive routine and again typed on the same console. When two separate computers are connected, of course, only one character is typed on each console.

The receive routine can be debugged independently by keying in protocol frames on the keyboard and observing what the receiver does with them. Normally, the DLE, STX, and ETX characters are defined with the high-order bit on, which precludes their generation by the keyboard. (This is to ensure that keyboards cannot accidentally send a protocol frame.) During debugging, however, the value of the DLE, STX, and ETX bytes can be changed to keyboardgenerated characters, thereby allowing frame synthesis through the keyboard for debugging purposes only.

The send routine must be disabled during this stage of debugging by changing the BNE INZADOR at hexadecimal location 1045 to BRA XMITLOOP. This ensures that the XMITACK flag from the receive module does not cause an ACK or NAK to be sent, thus clearing the flag.

First, an acknowledge frame is

286 April 1981 © BYTE Publications Inc

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keyed in to test the receive routine's response. The RECDACK byte, as a result, should be set to a value of +1. Next, a NAK frame is keyed, which should get the RECDACK byte to

— 1. If these received frames do not result in the proper setting of the flags, then either the receive routine is faulty, or the frame was keyed incorrectly.

After a proper address frame is typed, the XMITACK flag should be set to 1; otherwise, it should be set to

— 1. Also, a proper address frame should put the address types in the 2-byte variable ADDRESS.

Finally, frames of varying length and content should be typed in, and memory should be checked to ensure that the data has been properly stored. Of course, the keyboard cannot generate bytes with the highorder bit on, but this should not affect the debugging process. A proper data frame should set the XMITACK flag to 1, while a bad frame should set it to — 1.

The command interpreter is debugged next by typing a control-F character and noticing that an "S:" is typed on the console. Typing in four hexadecimal characters and a carriage return should result in a "D:" being typed on the console. The command interpreter checks for valid hexadecimal characters, which in this implementation are lowercase "0" thru "9" and "a" thru "f." Either typing in a bad character, or typing more than five characters, results in the ringing of the terminal's bell.

After the destination address is keyed, a "#:" should be typed on the console. When the byte count and a carriage return are typed, the user should cause system reset and go to the computer's monitor program (in my case, a Motorola MIKBUG). Locations SRCADDR, DESTADDR, and BYTECNT should contain the proper values of the three parameters just typed in. Also, the XMITFILE flag should be nonzero. If any of the above information is not correct, the command interpreter has errors and must be debugged.

The debugging of the send routine is the last and most difficult task. The patch introduced to disable the send routine must be deleted and the original code restored. The command interpreter is then used to set up the addresses and a byte count; a carriage return is struck to initiate the send

Prices subject lo change without notice.

routine. Normally, the send routine will send out an address frame and wait for the RECVDACK flag to indicate proper receipt of the frame. It will then send a data frame and again wait for the RECVDACK flag. Since the transmit line is connected to the receive line during these tests, a more complicated interaction occurs.

The interaction is as follows—the sender issues an address frame and the receiver, in turn, sets the XMITACK flag. The sender sees the XMITACK and sends an ACK frame, and the receiver receives the ACK and sets the RECVDACK flag. The sender, noticing the RECVDACK flag, sends a data frame. Errors result in up to three retransmissions before the file transfer is aborted and the computer returns to transparent mode. This sequence of events can be verified by disabling various portions of code and watching the flags change using a debugging routine (there is usually one in the computer's monitor program).

Once the software routines have been independently debugged as described above, there should be few problems when a final test is made with two computers linked by a serial line.

Final Notes

Reliable data transmission between two computers over a noisy channel is a primary concern of communication engineers, who have developed a spectrum of elaborate protocols to ensure that errors are detected and corrected. The simple data link described here is not overly robust. For example, the computer will "hang up" waiting for a valid response when an ACK or a NAK is received in error and discarded. One solution is to include a timeout interrupt that causes the send routine to retransmit its data if an ACK or NAK is not received within a certain period of time. Although the routines shown here were written with simplicity and minimal software in mind, the reader is encouraged to add this feature.

The protocol presented here is computer independent and could just as well be implemented in the machine language of any microprocessor. As long as there is agreement on the electrical interface and on the data-transfer protocol, a computer can pass data of any kind to any other computer. ■

288 April 1981 © BYTE Publications Inc

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BYTE April 1981 289

Three-Dimensional Computer Graphics, Part 2

Franklin C Crow

Department of Computer

and Information Service

Ohio State University

2036 Neil Ave Mall

Columbus OH 43210

Last month, in Part 1, we examined almost every algorithm needed to display three-dimensional line drawings that represent solid objects modeled by polygons. I attempted to keep the procedures concise, at the occasional sacrifice of clarity or efficiency.

Listing 1 contains a complete Pascal program that incorporates the individual graphics procedures presented in Part 1. I have used this program with the Heath/Zenith H-19 video terminal (which has limited semigraphics) and the UCSD (University of California, San Diego) Pascal system. I have also used it (very satisfactorily) with a 500-line raster graphics display and a Pascal interpreter running under the UNIX operating system on a DEC (Digital Equipment Corporation) VAX 11/780 computer.

The program includes facilities for all of the basic functions necessary for three-dimensional representation:

• acquisition of machine-readable data

• transformation to the proper perspective

• scaling

• elimination of hidden lines and faces

In presenting this program, I have assumed that your display system can draw lines, as most systems that are capable of full graphics provide appropriate software. However, scanconversion software is included to support the Heath/Zenith H-19 video terminal, and the routines Moveto and Drawto can be easily modified

for any other raster display. area of three-dimensional graphics

As designers continue to simplify software will be the next to receive the use of personal computers, the significant attention. ■

Listing 1: Complete UCSD Pascal three-dimensional graphics program that incorporates the ideas and procedures put forth in Part 1 (see March 1981 BYTE, page 54).

Program Hi deLines

const DotsA«ross = 79!

IJotsDown = 47;

MaxPts = 200;

MaxPois ■= 200;

MjxVt;: = 800;

MaxSides - S; (* main mum sides on a polygon *)

(* main mum si des 0. . MaxVtx;

t y p e c 0 u ri t e

Point, = record X, Y, I : real end; Vertex = 0 MaxPts;

Polygon • record NumVt:-; : Vertex; Start UnePoly = array Ci. . MaxSi des] of Point,

Polygons ■ array C1. . MaxPol S3 of Polygon;

Vertices ; array [J. . MaxVtxJ of vertex;

OutPolys : array Ci. . MaxPols] of Polygon;

OutVtces ■ array CI. . MaxVtx] of Point; EyeSpace Matrix;

Window : UnePoly;

*)

± y e p o i n t a n d

LyePt. Cntr I nt : Poi nti (*

ScreenSeal e, ScreenCtr : Point; SereenX, ScreenV : real; Screen ■ packed array CO. . DetsAcri NumPols, NumWtees, NumPts, Wi ndowSiz< IM u m LJ i s p 1 a y» N u m V t ;■: 0 u I ■ counter;

CiiidChar char; h i 1 eName : ftlri ng; lion- : boolean;

* ++-M-+-+++4-+++++ uetPlanes ++++++++++++++++++-» irocedura GetPUnesI var Poly ; OnePoly; NuillPts >ar liLstl : counter;

TinpPoly ■ OnePoly;

(-Jf o i" i g i r; a 1 pol y g o n s

I * original v e r t i ce 5

(# displayed polygons »)

(* displayed points #i

(■* eye space transform #)

<# display window #)

• nter

5 f i n t e r c

is, 0. . DotsDownl of boolean; I c. 0 u n t e r ;

4-H- + + + H

c 01.1 n 11

h e g 1 11 ' 3 c om p u t e p 1 a n e e q u a t i ;

Lsti : = NumPts; for I: ~i to NumPts do begin

with PolyCI] do b e g i n

"ImpPolyCl J. X : = V ■» PolyCLstll. 2 - 7 » Pol I'mpPolyCn. Y ; = Z * Pol y [Lsti II. X - X # Pol ImpPoiyi: I 3. 7 := X * PolylLslll. Y - Y * Pol end; Lstl : = 1, end; (* for 1 oop * )

for I :-■■.! to NumPts do £* copy back to input

with TinpPolyCI J do

begin PolyCIl. X: -X; Pol y L I ]. Y: -Y; PolyLi end; (# GetPlanes #)

3 e f f 1 c 1 e n t s

yL l

yCL.

p 01 y g o n e d c

,tll. Y; ; 11 j '.'., ; 111 x,

;edure

I ;

c reenScai i

Listing 1 continued on page 292

290 April 1981 © BYTE Publications lnc

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Listing 1 continued:

MaxX, MinX, MaxY, MinY : real;

begi

MaxX f o r

...i 11 h b

l

MaxX

i f M than

else S e r e S c r e end;

n

: =0. 0*

[:=L t.

Window eg in f X/2 f X/2

f Y/Z

f Y/Z

ndi

Ma axY > S c r e

Scree

nScal

nSeai

<*

MinX: =0. Oi MaxY:=0. Oi MinY:=0. Ol (» window must, include Z-axis

W i ndowS i ze d o £13 do

> MaxX then ttaxX :- X/?.; ■C MinX then MinX : = X/Zi

> MaxY then MaxY : ■ Y/Zi < MinY then MinY : » Y/Z;

X - MinX; MaxY :» MaxY - MinY;

(0. 73 * MaxX) (* standard display is 3 units high by 4 uidr- *)

nScale. Z : = (MaxY * 4 / 3 ) nScal e. Z : = MaxXi

e. X : - DotsAcross / ScreenSeal e. Zi

e. Y := ( DotsDown * 4 / 3 ) / ScreenScale. Z;

0atScre e nScale #)

begi n

Hone : = false;

NumPols : = 01

Numjjispj ay : - Oi NumVtees ;= Oi NumPts : =; 0i mith EyePt do begin X:

w.ith Cntrlnt do t Jin

X: -0. Oi

z

= 16

Oi

end

z

= 16

Oi

end

?

=16

Oi

end

z

■ 16

Oi

end

Y: =DotsDown/2i

Wi ndowSj ::e : = 4;

with Window!!] do begin X:=-4. Oi Y: —3. Ol

with WindowE21 do begin X:=-4. 0; Y: = 3.0;

with WindowC3J do begin X: = 4.0; Y: = 3.0;

with WindowC43 do begin X:= 4.0; Y:=-3. 0;

LietSc reenS'cal e;

GetPlanest window* WindowSize );

with ScreenCtr do begin X:=DotsAcross/2i

en di (* Initialize *)

(# ++++++ start +++++++++++++++++++ *) p r o c e d u r e S t art; var I, J : counter; begin (* clear screen *) tor 1 :-- 0 to DotsAcross do for J := 0 to DotsDown do Screen! I, J 1 end; (# start «•)

var I, J : counter; begin

write(chr(27>,-F ' ); (* put terminal into graphics mode ») wri Te( chr (27), ■'p*'); (* put terminal into reverie, video ■& i wri te(ehr(27), 'W >i <» no wraparound at end of line *) ...I : = DotsDown; while J > 0 do b eg i n for I :o 0 to DotsAcross do

if Screen!, I, ..I] and ScreenEI,d-i] then write('q-) else if ScreenLI, .J-n then wr 1 t e ( ' 1 ' )

else if SereenEI, J] then writet-o-> else write! " ' )| if J > 1 then J : - J - 2 (# count down by two--, #)

else J : - 01 if J > 0 then writelni (* CR/LF unless last line ») end; readln, (* await CCR> before continuing (preserves screen) write( chr(27), -Q' )i (# exit graphics mode *) wri tefchrC?/>,■■'.:;■')i C* exit reverse video ») endi (* Finish #)

(# +++++++++++++++ Moveto ++++++++++++++++++++ *)

procedure Movatof X.Y : real )i

begi n

ScreenX :- Xi ScreenY :- Y;

endi (* Moveto *)

(* ++++++++++++++++++ rirawto +++•+-++++++++++++++ #) procedure Drawtol X,Y : real >; var I : counter) Dxi Dy, Length- StepX, StepY, Xpos, Ypos : reali

begin (* Drawto *)

Dx := X - ScreenX; Dy ;= Y - ScreenY;

> abs(fly) then Length := abstDx! else Length : = abs(Dy); 1.0; (« catch zero-length lines #)

if Length

1. 0 then Length

Listing 1 continued on page 294

292 April 1981 © BYTE Publications Inc

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Listing 1 continued: StepX ■ = Dm i Length; Xpos : ~ ScreenX;

StepY : = Dy / Length; Ypos : = ScreenY;

for I := 0 to trunc(Length! do begin S c r c >"■■ n C r o u n d < X p o s ). r o u n d ( Y p o s) 1 ■. = t r u a ;

Xr. s :- Xpos + StepXj Ypos := Ypos + StepY;

end;

ScreenX : = X; ScreenY ; = Yi

end; t* Dr-Aiut *)

(■it +++++++++++++++++ ReaoUbjeet +;■+++++++++++++++++++++ #)

procedure ReadQbjectl FileName : string >; (* read in object from disk

vsr PtsObj. PolsDbj, PtsPol , 1 , J : counter;

Xposi Ypos, If s ■ real;

D-bjf- i le : til<,- of ehsri

begin

...ir i If i -I' vititm for ■', F i 1 eNanle, ' X Y I : ' ) , r eadl r, ( X pos, Ypos, ?. pos > ;

reseUObjFiie, F ileNamei ; (* open object file *)

r e a d 1 n l 0 b j F 11 e, p I s0 b j, P o 1 sO b j )i

for I =1 to PtsObj do with Poi nts[. L+NumPts] do begin

r e,-:d] mObjhj J e, ,J, X, Y. /'. ) ,

X ;■=> X + Xpos, Y : = Y + Ypos; 7. :.= I + Z p o si end;

for .1 : =1 to PolsOb j do begin

l eadlUbjFi le, PtsPol ); <-t

for J ;= l to PtsPol do

: d p o 1 y g o n v e r t e:: p 01 I

beg i n

read'Ob.iF i i e, Ver 11 .:: es 1 .J+NumV t c es] ),

Ver fi eesPJ+NuiriVtces .1 := Verti cesPJ+NumVtees] + NumPt; e 11 j; eaglmfU,jf i 1 ei, (* reed past end of line *) oifh Polygons!I+NumPois] do begin'"

Start : = NurnVtces; N1.1 in VI :■: : = Ptsf-'ol, e n a;

NurnVtces :- NurnVtces + PtsPol;

end; Nun.Pts := NumPts + PtsObj; NumPols : = NumPols + Polsubj, end; (* Readubjeet #)

(■a- +++++++++++++++++++ MakePicture +++++++++++++++++++++++•+-++ #) procedure MakeF'i c t ure; £« transform and clip, then display poiyg-: v a r 1, ,J, N umC 1 p : c o u n t e r; TmpPoly : OnePoly;

(■tt- +++++++++++++ DotF'rod ++++++++++++++++++++ it)

function OotProdC Ptl,Pt2 : Point ) ; real;

begi n

DotProd : » Pti. X » Pt2. X + Ptl. Y # Pt.2. Y + Ptl Z • Pt2. Z ;

end; (* DotF'rod #>

(# +++++++++++++++++++-+- I dent +++++++++++++++++++++++#)

p r o c e d ure I d e n t ( v a r M t x : Matru; ); (» initialize matri x » )

v a r I, J : c o u n t e r;

b e q i n

for I;=1 to 4 do

for ,J: --=L to 4 do

if 1 - J then MtxCI.J] : = 1.0 else Mt>.[I,.Jl : =•■ 0.0; end; (# I dent *)

(*, +1- + ++++ + + + + + + ++++++++ flfttri aMuI t H-H-+H-+H- + + +++ + + + + + it)

procedure Matri xMul t ( Mtl,Mt2 : Matrix; var Result : Matrix );

va r 1, .J, K counter;

begin

for I: =1 to 4 do

for U:=l to 4 do

begin

H65i.ll TCI, .J] : = 0. 0,

for K: -=1 to 4 do

Result!],.Jl := Resul t [ I, J1 + M t i UK, J]*I1 t.2L 1, Kl, end; end; (* MatrixMult *)

<-h- ++++++h--i-+++h-+++++-i- Transform +-n-++++++++++H-f+++-i-++-<-++++4-i- #) procedure Transform; Pt : Point; Mtx : Matrix; var NewPt . point begi n

NewPt. X := Pt. XitMtxEJ., 11 + Pt. Y#M1 xt 1 , 2] + Pt. X*MfxL.i

NewPt. Y := Pt. XitMtxf.2, 1J + Pt. Y*MtxC2, 21 + Pt. Z*Mt;:C

NewPt. 7 .= Pt. X#Mt;:C3, 1] + pt. Y#MtxC3. 23 + Pt. Z*MtxC5

end; (if Trans for in *)

J + M t >■ [ i., 4 :l; 1 + MtxC ', 4 l, J + Mtx[3, 43,

Listing 1 continued on page 296

294 April 1981 © BYTE Publications Ire

Computer experts (the pros) usually have big computer experience. That's why when they shop system software for Z80 micros, they look for the big system features they're used to. And that's why they like Multi-User OASIS. You will too.

DATA INTEGRITY: FILE & AUTOMATIC RECORD LOCKING

The biggest challenge for any multi-user system is co-ordinating requests from several users to change the same record at the same time.

Without proper co-ordination, the confusion and problems of inaccurate or even destroyed data can be staggering.

Our File and Automatic Record Locking features solve these problems.

For example: normally all users can view a particular record at the same time. But, if that record is being updated by one user, automatic record locking will deny all other users access to the record until the up-date is completed. So records are always accurate, up-to-date and integrity is assured.

Pros demand file & automatic record locking. OASIS has it.

SYSTEM SECURITY: LOGON, PASSWORD & USER ACCOUNTING

Controlling who gets on your system and what they do once they're on it is the essence of system security.

*1 [I I

(THEN COMPARE.)

Without this control, unauthorized users could access your programs and data and do what they like. A frightening prospect isn't it?

And multi-users can multiply the problem.

But with the Logon, Password and Privilege

Level features of Multi-User

OASIS, a system manager can specify for each user which programs and files may be accessed — and for what purpose.

Security is further enhanced by User Accounting —a feature that lets you keep a history of which user has been logged on, when and for how long.

Pros insist on these security features. OASIS has them.

EFFICIENCY: RE-ENTRANT BASIC

A multi-user system is often not even practical on computers limited to 64K memory.

OASIS Re-entrant BASIC makes it practical.

How?

Because all users use a single run-time BASIC module, to execute their compiled programs, less

memory is needed. Even if you have more than 64K, your pay-off is cost saving and more efficient use of all the memory you have available —because it services more users.

Sound like a pro feature? It is. And OASIS has it.

AND LOTS MORE...

Multi-UserOASIS supports as many as 16 terminals and can run in as little as 56K memory. Or, with bank switching, as much as 784K.

Multi-Tasking lets each user run more than one job at the same time.

And there's our BASICa compiler, interpreter and debuggerall in one. An OASIS exclusive.

Still more: Editor; Hard & Floppy Disk Support;

Keyed (ISAM), Direct & Sequential Files; Mail-Box; Scheduler; Spooler; all from OASIS.

Our documentation is recognized as some of the best, most extensive, in the industry. And, of course, there's plenty of application software.

Put it all together and it's easy to see why the real pros like OASIS. Join them. Send your order today.

OASIS IS AVAILABLE FOR

SYSTEMS: Altos: Compucorp: Cromemco Delia Producls: Digital Group: Digital Microsystems: Dynabyte: Godbout. IBC. Index: Intersyslems: North Star: Onyx: SD Systems: TRS 80 Mod II Vector Graphic. Vonmex

CONTROLLERS: Bell Controls; Cameo Corvus: Konan: Micromation: Micropolis: Tarbell: Teletek: Thinkertoys: X Comp

Write for complete.

free Application Software D

rectory

PLEASE SEND ME:

Price

with

Manual

Product

Manual

Only

OPEHATING SYSTEM

(Includes:

EXEC Language

File Management:

User Account ng;

Device Drivers;

Print Spooler;

General Text

Editor, etc )

SINGLE-USER

St 50

S17.50

MULTI-USER

350

17.50

BASIC COMPILER/

INTERPRETER/DEBUGGER

too

15.00

RE-ENTRANT BASIC

COMPILER/INTERPRETER/

DEBUGGER

150

15.00

DEVELOPMENT PACKAGE

(Macro Assembler:

Linkage Editor;

Debugger}

150

25.00

TEXT EDITOR &

SCRIPT PROCESSOR

150

1 5 00

DIAGNOSTIC S

CONVERSION UTILITIES

(Memory Test.

Assembly Language:

Converters: File

Recovery: Disk Test

File Copy Irom

other OS; etc )

100

15.00

COMMUNICATIONS

PACKAGE

(Terminal Emulator

File Send & Receive)

PACKAGE PRICE

(All ot Above)

SINGLE-USER

500

60.00

MULTI-USER

850

60.00

FILE SORT

100

15.00

COBOL-ANSI 74

750

35.00

Order OASIS from:

Phase One Systems, Inc.

7700 Edgewater Drive, Suite 830

Oakland, CA 94621

Telephone (415) 562-8085 TWX 910-366-7139

NAME_

STREET (NO BOX

rr)

CITY

STATE AMOUNTS

ZIP

(Attach system description;

add S3 for shipping;

California residents add sales tax) ■

□ Check enclosed □ VISA

□ UPS COD. □ Mastercharge

Card Number

Expiration Date

Signature

MAKES MICROS RUN LIKE MINIS

Circle 191 on inquiry card.

BYTE April 1981

295

Circle 192 on inquiry card.

MBC Systems, Inc.^

(203) 342-2747

NORTH STAR HORIZON:

HRZ-2-32K-D-Factory ASM$2275 HRZ-2-32K-Q-Factory ASM$2675 64K DD or Q Also Available

HDS-18-F $4449

Northword DQ $ 359

INFO-Manager $ 365

Mail Manager $ 269

General Leger $ 775

ACC. REC. OR ACC. PAY..$ 445

Word Star $ 350

Medical-Dental SYS $2500

■siimmm am

COMMODORE (PET):

2001-32K-BorN Keyboard $1090 16K Also in Stock....$859!!! 8032 (80 Column Screen)$1599 2040 Dual Floppy Drive $1090 8050 Dual Floppy (1MEG)$1599 2022 Tractor Printer...$ 749

Word PRO IV $ 290

VISICALC $ 195

APPLE II PLUS Call For Price!

ATARI 800 $ 849

TI 99/4 Console&Monitor.. $990 INTERTEC SUPERBRAIN:

32K RAM $2595

64K RAM $2695

PRINTERS

Letter Quality: NEC 5510 or 5530

NEC 5520 KSR

DIABLO 630

C. ITOH

Dot Matrix:

CENTRONICS 73 0.. 737-1 799..

EPSON MX-80

PAPER TIGER 460G BASE II MST

,$2550 ,$2950 ,$2390 ,$1690

, $ 599 , $ 799 ,$ 999 .$ 599 ,$1250 ,$ 649

DISPLAY TERMINALS

HAZELTINE 1420 $ 949

" " 1500 $ 999

INTERTUBE III $ 775

TELEVIDEO 920C $ 849

Since 1977 complete sales and service. Most items in stock, prices are subject to change. Visa and Master Charge welcome Most items shipped by UPS.

MBC Systems, Inc.

Multi Business Computer Systems, Inc.

2 8 MARLBOROUGH STREET PORTLAND, CONN. 06480

(203)342-2747 TWX 710-428-6345 M-F 9-6 SAT.9:30-3:00

Listing 1 continued:

(ft +h--i-+++++++++++++ procedure Get-EyeSpa var Mtx : Matrix*

C1,C2 : PotntJ

hi y p o t ertus a, C o s A i S i nA

GetEyeSpace +++++++++++■+•+++++++++++++++ ft) < EyePt. Cntrlnt : Point >i

real;

(ft lead eyepoint translation ft)

beyin

lderit(EyeSpace>i with EyePt. do

begin EyeSpaceCl, 43: =-Xl EyeSpaceC.2, 41: = -Y: EyaSpaceC3. 4] : = -Zi transform ( Cntrlnt, EyeSpace, CI ); (ft translate ctr. of interest. ft)

1 derit(Mtx> l (» load rotation about Z-axis »> with CI do Hypotenuse := sqrt.( X»X + Y*Y )i if Hypotenuse > 0.0 then

begi n

CosA := Ci. Y / Hypotenuse) SinA := Ci. X / Hypotenuse!

MtKLl.i: := CosA; Mt!-:C2, 11 := SinA;

Mtx[.i,2] :=-—SinA; MtxC2, 23 := CosA;

MatrixMult< EyeSpace, Mtx, EyeSpace );

endi Transform! Cn trl nt, EyeSpace, C2 ); (ft rotate ctr. of interest »)

IdenUrHx); (« load rotation about X-axis ft) with C2 do Hypotenuse := sqrt( Y»Y + 2*7. ); if Hypotenuse > 0.0 then b e ci i n

/ Hypotenuse;

CosA :-■ C2. Y / Hypotenuse; SinA := -C2. Mtx[2,2j := CosA; MtxI3, 2] :■ SinA; MtxC2,33 :=-SinAl r1txC3, 33 : = CosA; MatrixMult< EyeSpace, Mix, EyeSpace ); end;

Ident(Mtx); (ft load switch between Y and Z axes *) MtxC2,2] ;= 0.0; Mt::C3, 3J r= O.O; Htxf.2' 31 :« i.O; MtxE3i23 := i.O; Matri xMul t ( EyeSpace, Mtx, EyeSpace >; end, C* GetEyeSpace ft)

(ft ++++++++++++++++++ MakeDispleyabla +++++++++++++++++++++ ft)

procedure MakeDi spl ayar.l e ( var Pt : Point ); (ft take to sere

b egi n

Pt. X := ScreenScal e. X ft Pt, X / Pt. Z + ScreenCtr. X;

Pt Y := ScreenScale. V » Pt. Y / Pt. Z + ScreenCtr. Yi

end; (ft MakaDisplayeb] t ft)

space »)

«-++++++++++++ PacesEye 5Eye( Poly : OnePoly )

b o o 1 £

f+ + + + + -H + + + 4

var TmpPt Point)

T m p P o I y : O n e P o J. y;

begi wi tr

Tm pp TmpP TmpP TmpP TmpP TmpP GetP i f D

olyL gi n yCl'J yti:

yen

yL21 y[2I yI2I nes( Prod en F se F

'J do TmpPt. X: =X;

TmpPt. Y: ^Y; TmpPt.

X : = PolyClI. X - Poiyr.2:. X

Y : - PolyCil Y - Polyt2I. Y Z : = PolyCi:. Z - PolyL2J. Z X : = PolyLSl. X - Polyl2I. X

Y := Poly[3J. Y - Po.lyC2], Y Z : = PolyLS]. Z - Polyt?!. 7; TmpP'ol y, 2 );

TmpPt, TmpPolytl 1 > O 0.0 acesEye := false . cestye : « true; FacesEye ft)

(ft ++++++++++-*-++-»-++■+•+++++ CLipln +++++++++++++++++++++++++++++ ft) procedure Clipln(var Poly : OnePoly; var NumPts : counter), var I, ,J, Lst-J, TmpPts : counter;

D1.D2, A : real;

TmpF'oly ; OnePoly)

begi ■I" o r

(ft for each window edge »)

1: =1 to WindowSiza do if NumPts > O then b eg i n

Oi :=» DotProdt Pol yCNumPts 3 , Wi ndowL I 1 )i Lst.J : = NumPts; ImpPts : = 0;

for ,J:=i to NumPts do (ft for each polygon edge ft)

begin

if Dl > 0.0 then (ft is leading vertex inside? »)

begi n

TmpPts : = TmpPts + .1; with TmpPolyC TrnpFtsJ do

begin (ft copy leading vertex ft)

X: =PolyCLst.JJ. X; Y: ^PolyCLst-Jj. Y; I: =Pol vl Ls t ,J3. Z:

end;

Listing 1 continued on page 298

296 April 1981 © BYTE Publications Inc

PMC-80 Expanded

Use all standard peripherals and existing software

When you buy PMC-80 you get hardware and software compatibility with the most popular microcomputer system in the world —that means thousands of disk and cassette based programs and all kinds of peripherals are instantly available!

PMC-80 has configurations that give the computer enthusiast a way to grow from a STARTER system in affordable increments. Begin at a low $675 for the basic 16K level II system and grow to the complete 48K memory system pictured above with two floppy disks for less than $3000.

FASTLOAD option inputs short programs as fast as "disk" from ordinary,

standard format cassettes. Fast, reliable and economical!

PMC-80 COMMUNICATOR option provides interface to modems and parallel port printers. Take your pick of peripherals for communication with electronic bulletin boards and low cost timeshare services via phone lines from your home or business.

PMC-80 EXPANDER option provides the most powerful configuration with a total of 48K memory, provision for 4 mini-floppies, printer interface, RS232C communications interface, plus a slot for the popular S-100 boards.

Sold through computer stores.

Personal Micro Computers, Inc.

475 Ellis Street, Mountain View, CA 94043 (415) 962-0220

Circle 193 on inquiry card.

BYTE April 1981 297

Circle 194 on inquiry card.

A MICROPROCESSOR TRAINING SYSTEM FOR:

EDUCATION INDUSTRY

AND MORE!

THE

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• On Board RAM/ROM

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• 8 Character Display

• Serial/Parallel Interface

• KC Standard Cassette Interface

• TBUG. Monitor

• Comprehensive Teaching Documentation

AND MUCH MORE...

THE OMNIBYTE TRAINER IS DESIGNED TO LEAD YOU FROM BASICS TO A FULL UNDERSTANDING OF MICROPROCESSORS!

Expands into a full development system; or stand alone in a variety of applications

(312)231-6880 jjjjjj) 245 W. ROOSEVELT RD.

WEST CHICAGO, IL 60185

Omnibyte Corporation

298 April 1981 © BYTE Publications Inc

Listing 1 continued:

e rnJ;

<» if leading vertex inside *)

D2 := DotProd< PolyCJH, Window! I 1 >j

if Dl * D2 C 0.0 then t* doe;, edge straddle win

beg i n

A : = Di / < D1 - D2); TmpPts : = rmpPts + 1; uji i.h TmpPolyCTmpPts: do

begin

X :- A * PulyLJ]. X + «. 1. 0 - A) * PdlylL-.t.

Y ; .= A * l-'oly[.J], Y + (1. 0 - A) * PolyCLst

/ i m A * PolyL.Jl. Z + (1. 0 - A) # PolyCLst

end; endi

Lst.J : » Ji Dl : = D2,

end; (» NumPts loop *)

for J:=J to TmpPts do <* copy polygon back to input. with TmpPolyCJa do

begin Pol yl Jl. X: =Xi PolyCJ], Y: =Yi PolyCJl. Z: NumPts ! » rmpPtaj e n dl (* W i n d owS i z e 1 o.:. p * )

(* C1 i p I n * )

n. Yi

M. Z;

= Z; endi

h++++++++++++++++++++ In: :adure JnsertSortl Poly : 11 J i k c o u n t e r;

AvDepth : real:

ertSort +++++++++++++++++++++++++++ #) OnePolv i NumPts : counter );

begin (* binary insertion sort, on average depth *)

AvDepth : = 0. Oi

for I:=1 to NumPts do

wi th Po 1 yL1.1 do <* a tore and find average depth * )

begin

t.iutVtcesCNumVtxOut+1+1]. X :- X;

QutVtcesCNumVtxOut+I+13. Y := Yi

CiutVtcestNumVtxOut+I+J:. Z := Z;

AvDepth :- AvDepth + Z;

end, AvDept-h := AvDepth / NumPts. Out.VteesCNumVtxOiJt+J II. Z :■ AvDepth,

J :~ <>; (** initialize for insertion seari

I :» (NumDisplay + 1) div 2;

K

*)

NurnDi sp.L ,?.y;

while (J O I) do <* binary search for insertion point *)

it AvDepth < GutVtcesI. Out.Pol ysC 11. Start. 1.1

then begin K := I; I := ( I + J ) dlv 2; end else begin J : « I ; I:=(I+K+l)div2l end; for J:=NumDisplay downto 1+1 do

begi n

OutPolyst.J+i J. Start ;= Ou tPolysCJl. Start;

uutPo 1 ystJ+l 1 NurnVt.x■ = 0utPo 1 ys[J1. NurnVtx;

end; OutPolys! 1 + 1 J Start. ;= NumVtxOut + li OutPolysCI+U, NumVtx: = NumPts; NumVtxOut := NumVtxOut + NumPts + 1; NumDi spj ay - NumDi splay + 1; end, C* InsertSort *)

( « +++++++++++++++++++++++ ClipOut H--I- + + + + + + H- + + + + + ++++++++++++ + H- »)

procedure ClipOut.f Poly : OnePoly; var NumPts : Vertex; Place ; counter"), var Ir Lstl, NumDrawn ; counter;

Ptl, Pt2 : Point;

Drawn : boolean)

(# ++++++++++++++++++++ ClipAfter ++++++++++++++++++++++ #) procedure CI i pAf ter ( Index : counter; Ptl,pt,2 ; Point); var I counter;

Dl, D2, A : real;

Out : boolean;

Pt3 : Point;

begin (* recursively check polygons for overlap with input edge #) if Index < Place oi- is polygon closer than edge? #) then with Out.Pol ysl I ndexl do begin

I := Start + NumVtx; Out : --- false;

repeat <# for each polygon edge *) Dl := DotProdl P t.i , OutV tcesT I 1 )j U2 := DotProd( pt.2, uutVteesLi:i ), if 101 <= 0. 0) and (D2 <■ 0. 0) then begin (# both points visible #> Out := true;

ClipAfter( Index+1,Pti , Pt2 >; end else if Dl * U2 < O. 0

then begin (* one point visible *) A : «= Dl / (HI - D2);

Listing 1 continued on page 300

Nestar Is Growing a Local Network for You.

Centralized data processing is under pressure. Managers compete for computer time and complain about the lengthy justification process for new applications. Individual users at their terminals are frustrated by unacceptable response times. When the system goes down, everybody's DP-dependent work grinds to a halt.

High Productivity

Nestar's Cluster/One, Model A is a local network of Apple" computers that lets people get on with productive work instead of waiting in line, Since every user station is a computer in itself, response time is fast, and downtime problems are restricted to single individuals. The net result: productivity grows as your network grows.

More for Less

Nestar's Cluster/One is a true local network, not merely a limited function shared disk system. This means your company enjoys the benefits of shared data, station-tostation communication (including electronic mail), and the reduced costs of shared peripherals. Since Cluster/One is

" Apple is a registered trademark of Apple Computers. Inc. Circle 195 on inquiry card.

microcomputer-based, its cost-per-station is dramatically lower than other systems with similar capabilities, including mini-based systems. And the more people on the network, the greater your savings!

We're Growing Our List of Applications

Cluster/One is working right now — in banking, manufacturing, the travel industry, schools, and many other institutions and businesses. Software for the application you have in mind may also exist right now — literally thousands of programs have been written for Apple.

Plant One Now!

We're ready to ship immediately. So if you're working on the problems of DP overload, consider the Cluster/One from Nestar. It's a solution that grows on you. For more information, contact us at: Nestar Systems, Inc., 2585 East Bayshore Road, Palo Alto, CA 94303, 415/493-2223

AESEV?

Circle 196 on inquiry card.

Mil stocks 'em all for faster delivery.

No hidden charges. Prices include delivery.

Ask about our" QED " d iscounts.

VISA and MasterCard orders accepted.

VIDEO TERMINALS

VT100 DECscope $ 1635

VT132 DECscope 1995

ADM-3A (dumb terminal) 795

ADM-3A+ (dumb terminal) 875

ADM-5 (dumb terminal) 945

ADM-31 (2 page buffer) 1185

ADM-42 (8 page buffer avail.) 2035

1410 (Hazeltine dumb terminal) 825

1420 (dumb terminal) 895

1421 (Consul 580 & ADM-3A comp.l 850

1500 (dumb terminal) 1045

1510 (bufferedl 1145

1520 (buffered printer port) 1395

1552 (VT52 compatible) 1250

GRAPHICS TERMINALS

VT100 with graphics pkg 3160

ADM-3A with graphics pkg 1995

ADM-3A+ with graphics pkg 2075

300 BAUD TELEPRINTERS

LA34-DA DECwriter IV 1045

LA34-AA DECwriter IV 1125

LA36 DECwriter II 1295

Teletype 4310 1045

Teletype 4320 1195

Diablo 630 RO 2295

Diablo 1640 KSR 2775

Diablo 1650 KSR 2835

Tl 743 (portable) 1190

Tl 745 (port/built-in coupler) 1485

Tl 763 (port/bubble memory) 2545

Tl 765 (port/bubble/b.i. coupler) 2595

600 BAUD TELEPRINTERS

Tl 825 RO impact 1450

Tl 825 KSR impact 1570

Tl 825 RO Pkg 1625

Tl 825 KSR Pkg 1795

1200 BAUD TELEPRINTERS

LA 1 20 RO (forms pkg.) 2295

LA 120-AA DECwriter III (forms pkg.) 2350

LA 180 DECprinter I 1695

Tl 783 (portable) 1645

Tl 785 (port/built-in coupler) 2270

Tl 787 (port/internal modem) 2595

Tl 810 RO impact 1760

Tl 810 RO Pkg 1950

Tl 820 KSR impact 2025

Tl 820 RO 1850

Tl 820 KSR Pkg 2195

TI820ROPkg 2025

2400 BAUD

Dataproducts M200 (2400 baud) 2595

DATAPRODUCTS LINE PRINTERS

B300 (300 LPM band) 5535

B600 (600 LPM band) 6861

2230 (300 LPM drum) 7723

2260 (600 LPM drum) 9614

2290 (900 LPM drum) 1 2655

ACOUSTIC COUPLERS

A/J A242-A (300 baud orig.) 242

A/J 247 (300 baud orig.) 315

A/J AD342 (300 baud orig./ans.) 395

A/J 1234 (Vadic compatible) 895

A/J 1245 (300/1200 Bell comp.) 695

MODEMS

GDC 103A3 (300 baud Bell) 395

GDC 202S/T (1200 baud Bell) 565

GDC 212-A (300/1200 baud Bell) 850

A/J 1256 (Vadic compatible) 825

A/J 1257 (triple modem w/phone) 975

CASSETTE STORAGE SYSTEMS

Techtran 816 (store/forward) 1050

Techtran817 (store/for/speedup) 1295

Techtran 818 (editing) 1795

Techtran 822 (dual) 2295

MFE 5000 (editing) 1495

FLOPPY DISK SYSTEMS

Techtran 950 (store/forward) 1395

Techtran 951 (editing) 1995

mti

Applications Specialists & Distributors Great Neck. New York/Cleveland. Ohio.

N.Y.: 516/482-3500 & 212/895-7177 800/645 8016. Ohio: 216/464-6688

Listing 1 continued:

pt.2. Z: --1: end.

Fas. X : = A * F't2. X + (1. O-A) * Ptl. X; Pt.3. Y : = A # Pt2. Y + (1. O-A) * Ptl. Yj Pt3. Z :- A * Pt2. Z + (1. O-A) * Ptl. I,

i f i.ii < o. o

then bagin C* Ptl visible *> ClipAfterC Index+1, Ptl, Pt.3 )• mi th Pt.3 do

begin Ptl. X:*-Xi Ptl. Y:=Y; Pt end else begin (* Pt? visible »)

C1 i pA fter ( I ndex+1, P13, P12 ). with Pt.3 do

begin Pt2. X:«Xi Pt-2. Y: =Y; end: endl (* one point visible *> I := I-li until Out or (1 = Slfrtli <* all visible or edge end else begin f# reached end of list of closer polygons Makaflisplayabiel Ptl >; MakeDisplayable< Pt2 ) Movetoi Ptl. X, Ptl. Y h Drawtoi Pt2. X, Pt,2. Y )i Drawn := true; (* mark as displayed #) end; end, (* ClipAfter *)

(* ClipUut procedure body #)

begin (* clip each poly edge by all closer polys, draw whats left #)

MumLirawn : = Oi

L si,I : » NumPtsi

for !:-! to NumPts do

beqi n

with PolyCLstl 3 do begin Ptl. X:-Xi Ptl. Y: =Yi Ptl. Z:=Zi endi

with PolyLlJ do begin Pt2. X:=X; Pt.2. Y: =Yi Pt2. Z: »Zl end;

Ilrawn : « fai sei

ClipAfterC l,Ptl,Pt2 ); <» check closer polys, then display »)

if Drawn then NurrrDrawn :- NumDrawn + 1;

LstI : = li

end; <» for loop *) if NumLirauin = O then NumPts : =- O; (* mark as hidden *) end; (# Cli puut #)

begin (» MakePicture procedure body »)

GetEyeSpacei EyePt, CntrI nt ); (* get eyespace matrix *) NumDisplay : «• 0; NumVtxOut. :- O; (* set. output counters *) f or I: = 1 to NumP01 s do mith PolygonsCIJ do beg i n

for .J: > I to Nun.Vtx do (* get. polygon #) b e g i n with Point si. Vertices! Start + J 1 1 do

begin ImpPolyE JJ. X: =X; rmpPol yC.J:. Y: =Y; TmpPol yt Jl. Z : -Zi end Transform* ImpP'oJ y[..l], tyeSpace, lmpPolyCJJ ); !* transform *) end; if PscesbyeC TmpPoly ) then begin'

NumClp := NumVtxi (* protect original data #) Clipln( CmpPoly, NumCl p ); (# clip to view window *) if NumClp > 0 then J nsert.Sort ( TmpPoly. NumClp );

<# store in sorted order for display #) end, end; (* loop for each polygon #) (tt display surviving polygons, clipping each by closer polygons *) Start; (* initialize and clear display ■») f or I:=1 to NumDisplay d o wi th OutPolysCI] do b e g i n for J:=l to NumVtx do

with Gut.Vt.cesf. Start + J 1 do

begin TmpPoiyCJX X: =Xi TmpPolyLJJ. Y: =Y; TmpPolyLJl. Z: =Z, end; ClipOuU TmpPoly. NumVtx. I ); (* clip and display *) if NumVtx > 0 then

b e gin

GetPlanesC 1mppoly. NumVtx ), (* convert to planes #) for J: «1 to NumVtx do <* copy back for later clipping *) with OutVtcesL Start + ...I 1 do

begin X: =TmpPolyCJ3. Xi Y: =lmpPoly[.Jl. Y; 7 : =TmpPolyL.JJ. 7.; end; end; end; (* for loop <1 to NumDisplay) ») Finish; (* finalize picture #) end; (» MakePicture *)

begin (# main program #)

Initialize; (# set up default view parameters #)

w hi1e n ot 0one d 0

Listing 1 continued on page 302

300 April 1981 © BYTE Publications Inc

Move Up to Tarbell

The Serious Business Machine

Do you have a small computer system that operates with mini-floppies and has limited storage capacity? Then it's time to move up to the Tarbell Empire Series System. Tarbell starts where small systems leave off, providing storage from 1 to 20 megabytes. This means Tarbell is capable of growing right along with your business. (It also makes sense to start with Tarbell if you're a firsttime computer buyer.)

Tarbell is the serious general purpose business machine, backed by years of experience with disk systems. It gives you word processing, inventory control with bill of materials, mailing lists — all in addition to accounting applications: general ledger, payables, receivables, payroll with cost accounting and order entry. Whatever your need may be, Tarbell can provide the working software that gets the job done.

With the Tarbell System you get a Z80 4 Mhz CPU with memory management, timer and full interrupt capability, 2 RS-232 serial ports with handshaking, 64 K bytes of random-access memory, double density floppy disk interface, 2 double density floppy disk drives, cabinet, power supply, and cables.

The software includes: CP/M™ 2.2 disk operating system, Tarbell Disk BASIC, Tarbell Database System, and all manuals and documentation.

Tarbell also offers the MP/M™ Multi-User Operating System and 4 additional RS-232 serial ports.

The Tarbell Empire Series is delivered assembled, tested, and with a FULL six-month warranty on parts and labor.

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Circle 197 on inquiry card.

BYTE April 1981 301

Listing 1 continued:

b e g i n

nin tel n( -Tread object, eyepoint, center of interest, start over.

, -' Hi l n d cm, pic t urs, q U1 t 1 ' ) i read! n (CrcidChar ) ; case CmdC h a r ot

-r' begin writef'fils name : '); readl n(Fi 1 eName) i

ReadObject(Fi leName;; end; -e- i begin wri te( ■' eyepoint, X Y Z : -') i

with EyePt do readlni X,Y, Z ); end; ■- c ■' t. e 9 i n '...' r i t e (-' c. e n t. e r o f i n t • r e 31, X Y ? : ' ); with Cntrlnt do readln< X, Y, Z ), end; -s' -. begin NumPols ■. - 0; IMumPts :- Oi

end; 'W begin write<'display window : how many sides? '); r e a dl n (W i n d owS i z e ); for I: =] to Windows'] ?e do b e o i n

write<-'X Y > : ' ); w i t h W i n d cw C I : d o r a a d 1 n I X, Y, t > . end; CietScreenScale; <# get window to screen scale *)

GetPlanesI Window, Wi ndowSi 26 ); i# get clipping plane end; -' p' ■ MakePi c t ure; -' >:j- : Done : = true; end; (# case statement »)

end; (* while loop #)

end. (* ruein program *)

BYTE's Bugs

Adventurous Bugs

As expected, many people called our offices with questions about the two Adventure programs in the December 1980 BYTE, "Pirate's Adventure" (by Scott Adams, page 192) and "Lost Dutchman's Gold" (by Bob Liddil and Teri Li, page 268). Although the authors found only two errors per se, the following notes are in order:

In listing Adventure," 1240 says:

2 of "Pirate's page 210, line

1240 IF D O-ITHEN 1330 ELSE INPUT "READY DATA TAPE. HIT ENTER"; K$

while line 1330, the last line given in the listing, says simply:

1330 REM

Photo 1: Jon Swanson, BYTE drafting editor, finds a bug (shown in right hand) at the entrance to the Lost Dutchman Mine.

According to Scott Adams, the listing is correct as stands, because D is set to — 1 in line 20 of listing 2 (page 202) to denote a cassette-based program. The lines following line 1330 were deleted by Scott from an earlier version of the program, because they referred to disk commands only. Thus, the variable D should retain the value —1 throughout this program, thereby preventing a branch from line 1240 to line 1330.

There is an error in "Pirate's Adventure," but it affects you only if you tried to combine listings 1 and 2 into a single program for a 32 K-byte TRS-80 (as suggested in column 2 of page 212). The problem occurs when statements in what used to be listing 2 try to read the data directly from the DATA statements that used to be in listing 1. The full directions are:

1. Delete lines 6510 to 6790 of listing 1.

2. Append the remaining DATA statements from listing 1 to the end of listing

2, changing all occurrences after line 1240 of INPUT#D to READ.

3. In listing 2, change line 1280 to:

1280 FOR X = 0TO CL:FOR Y = 0TO 1:READ CA(X,Y):NEXT Y,X

4. In listing 1290 to:

2, change line

1290 FOR X = 0 TO NL:FORY=0TO 1:READ NV$(X,Y):NEXT Y,X

In the listing for "Lost Dutchman's Gold," the lack of a closing quote at the end of line 36 (page 268) caused some confusion. However, the program will run without the quote, so that is not a problem. One occurrence of the invisible Control-D that editor Gregg Williams missed mentioning is on line 4130 (page 280), just before the first letter in the word DELETE.

The error in "Lost Dutchman's Gold" is in the last line of line 1287 (page 274). Change the part that reads "7$(J,3)" to read "O$0,3)"the character before the dollar sign is capital O.

Thanks to Bob Liddil, Scott Adams, and several other BYTE readers for calling these problems to our attention. ■

302 April 1981 © BYTE Publications Inc

computer Li products, inc.

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Cabinet size: 20"w x 23"d x 7.5"h. Cabinet painted dove grey, Irani panel Is black Mounting lor 2 eight-inch Shugan SAB01R Floppy Disk Drives (or mechanical equivalent) Drive mounting brackets supplied. Drives not supplied. 70CFM1an, 6' three-wire line cord, power switch, line fuse, EMI litter and clamped Hat cable exit on rear panel P794 power supply: + 5{5?4A. +24@5A-6A peak.-5(3.75A All voltages regulated Powef supply is a removable module

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Cabinet size: 17"w x 20.5"d x 7.5"h. Cabinet painted dove grey, troil panel is black (other color schemes optioial) 15-position IEEE compatible motherboard (will accept T80I terminator kit. optional), card cage with all guides Resel switch □n tront panel Power switch, 8'DB25 cutouts, 2 BNC mounting holes. 70CFM (an, EMI filter. 6' power cord, line fuse, and clamped Mat cable exit on rear panel PBOO power supply ( + 8<315A. +16@3A. -16<33A) Power supply is a removable module Motherboard connectors optional

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Cabinet size 13 5"w x 23"dx 11 "h Cabinel painted dove grey, front aanel is black Mounting lor 2 afght-tlKh Shugan SA8Q1R Floppy Disk Drives [or mechanical equivaleni). Drive mounting brackets supplied Drives not supplied 70CFMlan. 6' three-wire line cord, power switch, line fuse. EMI filter and clamped flat cable en! on rear panel P794 power supply + 5f!i4A, + 24@5A—6A peak. -5@ 75A All voltages regulated. Power supply is a removable module

Circle 198 on inquiry card.

BYTE April 1981 303

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Technical Forum

An ADM-3 Emulator for the Hazeltine 1500

Charles Shoemaker

2725 E Maplewood Ave

Littleton CO 80121

All Hazeltine 1500 owners seem to agree on two things: it is a very nice terminal; and they are frustrated that a good deal of the software available that uses cursor control has been written for the Lear Siegler ADM-3 terminal; consequently, it will not run properly on the 1500.

In my particular case, the problem came to a head as I was attempting to modify for my terminal a graphics game written in 8080 assembly language. Some of the cursor-movement control was not at all obvious, and I wasn't really willing to take the time to follow the entire structure of the program through just to play a simple game.

This, coupled with the fact that I'd have to do the same (disassembling system software where no source code is provided) for every program written for the ADM-3, led me to write this routine.

This routine is a patch to my CP/M operating system BIOS (I/O driver module). It can be placed in ROM (read-only memory) or programmable memory, but, if it is placed in ROM, the two temporary locations, MODE and Y, will have to be relocated somewhere in programmable memory. The routine is entered with the ASCII (American Standard Code for Information Interchange) character to be sent contained in the C register and the parity bit low. It assumes that the output status has been checked and that the output port is ready for a character. Registers A and C are altered on exit. Since this routine needs to send as many as four characters (I will explain that in a moment), there's a subroutine to wait for output status, which will have to be customized for other systems.

If the character to be sent comes in another register, the MOV instructions to and from C (and the PUSH B and POP B instructions, if the register is B) can be easily altered. For example, if the program sends the character in A, the following routine can be used:

PUSHB

MOV C,A

CALL EMULATOR

POPB

RET

Note that in the 8080 instruction set, the PUSH B and POP B instructions also do the same to C.

The code is twisty, and a little bit devious, as described below. I first attempted to fit it into 128 bytes, so that it would fit in one disk sector. Unfortunately, I didn't quite make it. Users with Z80 processors can take advantage of

304 April 1981 © BYTE Publications Inc

Circle 199 on inquiry card.

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BYTE April 1981 305

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Adapt $ 69/$na

Ratfor $ 86/$na

SOHO GROUP

MatchMaker $ 97/S20

Worksheet $177/$20

STRUCTURED SYSTEMS

GL or AR or AP or Pay... $599/$40 Inventory Control $449/$40

• Analyst $199/$25

• OSort $ 89/S20

SUPERSOFT

• Forth (8080orZ80) $149/$25

• Diagnostic II $ 84/$20

Other less 10%

TCS

GLorARor APorPay. All 4

WHITESMITHS

"C" Compiler

Pascal (incl "C")

.$ 79/$25 .$269/$96

$600/$30 .$750/$45

DATA BASE

FMS-80 $649/$45

dBASE II $629/$50

Condor $599/$30

T.I.M $329/$35

"PASCAL"

• Pascal/MT+ $429/$30

• Pascal/Z $349/$30

Pascal/UCSD $299/$30

Pascal/M $149/$20

"WORD PROCESSING"

• SpellGuard $249/$25

Spell Binder $349/$45

• Magic Wand $289/$45

OTHER GOODIES"

Tiny"C" $ 89/$50

Tiny "C" Compiler . . . $229/$50

CBASIC-2 $ 89/S15

Nevada Cobol $129/$25

MicroStat $224/$ 15

Vedit $ 99/$ 15

• Prof Time Bill (Asyst).... $549/$40

• ESQ-1 $1349/$50

• MiniModel $449/$50

• StatPak $449/$40

• Micro B+ $229/$40

APPLE II

MICROSOFT

Softcard $292

• Fortran $179

Cobol $574

PERSONAL SOFTWARE

Visicalc $122

CCA Data Mgr $ 84

Desktop/Plan $ 84

Zork % 34

PEACHTREE

General Ledger $224/$40

Acct Receivable $224/$40

Acct Payable $224/$40

Payroll $224/$40

Inventory $224/$40

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Super-Text II $127

Data Factory $129

• DB Master $159

Ledger Plus $549

• Charles Mann less 15%

• STC less 15%

ORDERS ONLY-CALL TOLL FREE VISA • MASTERCHARGE

1-800-854-2003 ext. 823 • Calif. 1-800-522-1500 ext. 823

Overseas —add $10 plus additional postage • Add $2.50 postage and handling per each item • California residents add 6% sales tax • Allow 2 weeks on checks, C.O.D. ok • Prices subject to change without notice. All items subject to availability • (?) —Mfgs. Trademark.

THE DISCOUNT SOFTWARE GROUP

6520 Selma Avenue, #309 • Los Angeles, CA 90028 • (213)666-7677

Te<

im.

their relative-jump capabilities and easily crunch it into 128 bytes.

How It Works

On the ADM-3, cursor up, cursor right, home, and clear screen are simple control codes: 11,12, 30, and 26 in decimal, respectively. The control codes for the two terminals are shown in table 1. These codes are converted in the routine called NORM (see listing 1). Noncontrol characters are shunted to be transmitted directly at the label

Listing 1: The Lear Siegler ADM-3 emulator for the Hazeltine 1500. For a detailed explanation of the program, see the accompanying text.

SPECL! 0UTCHS

ORG

JMP

ORG

LDA ORA MOV JZ

JPE

CPI MVI STA JNZ MVI STA RET

CPI

JC

JNZ

MVI

JMP

CPI

JZ

CPI

JNZ

MVI

JMP

CPI

JNZ

MVI

STA

RET

CPI

JNZ

INR

INR

MVI

CALL

MOV

PUSH

IN

ANI

JZ

POP

GUT

RET

JM

MOV STA MVI STA RET

PUSH

MVI

CALL

POP

MOV

SUI

CPI

JNC

ADI

CALL

XRA

STA

LDA

JMP

HE DB

7FB4H ENTRY

8000H

MODE

A

A,C

NORM

XY

A,0

MODE ZAP

30

NTH0ME

ZAP

Cr 18

SPECL

11

SPECL-1

12

NTRGHT

A.16

ZAP

27

NTESC

A.l

MODE

26

DUTCH

C

C

A,126

ZAP

A,C

PSU

10H

OUTCH+2

PSU

11H

Y

ArOFPH

MODE

C.17

SPECL

6

ArC

32

31

SENDX

96

OUTCH+1

A

MODE

Y

OUTCH+1

0 0

FIX CPM DUTCH ROUTINE TO JUMP HERE

PUT AFTER BIOS

ARE WE IN THE MIDDLE OF SOMETHING?

GET CHARACTER TO SEND. FOR COMPARES

ORDINARY

IF JUMP TAKEN, NORM CONTAINS EITHER 3 OR 255

MIDDLE OF XY ADDRESS SEOUENCE PRESET ERROR CONDITION

SOMETHING'S WRONG—PRINT IT AND GIVE Up

FIX UP

TELL US NEXT TIME

AND BACK

TEST FOR HDME CHARACTER

NOT A CONTROL CHARACTER—SEND IT GET HAZEL'S HOME CHARACTERDO IT

IS IT UP-CURSOR? QUICK TRICK IS IT RIGHT-CURSOR?

NO

HAZEL'S RIGHT-CURSOR

IS IT ESCAPE-ADDRESS CURSOR?

TELL US NEXT TIME THROUGH

IS IT CLEAR SCREEN?

NO, MUST BE SOME OTHER CONTROL CHARACTER MAKE 2B, HAZEL'S CLEAR SCREEN CHARACTERGET HER ATTENTION

SEND THE FIRST CHARACTER RIGHT AWAY RETRIEVE ORIGINAL CHARACTER STOW IT AWAY GOTTA CHECK STATUS

GET IT BACK

SEND IT

FINALLY, RETURN TO CALLER

WE KNOW WE HAVE 'ESC ' = ' SEQUENCE

SEE IF THIS IS X OR Y CHARACTER

TAKE THE JUMP IF THIS IS X

JUST GET Y CHARACTER

AND SAVE IT

LET US KNOW WHAT TO DD NEXT TIME

AND BACK

SAVE X CHARACTER A MINUTE GET HAZEL'S ATTENTION

GET'M BACKGET X COORDINATE GET RID OF ADM-3 BIAS FIX HAZEL'S BIAS OK AS IS

HAZEL LIKES THIS BETTER SEND X FIX MODE UP—BACK TO NORMAL

ADM-3 BIAS OK FOR HAZEL SEND IT AND GO HOME

306 April 1981 © BYTE Publications Inc

Circle 201 on inquiry card.

dBASE II vs. the Bilge Pumps.

by Hal Pawluk

We all know that bilge pumps suck.

And by now, we've found out—the hard way—that a lot of software seems to work the same way.

So I got pretty excited when I ran across dBASE II, an assembly-language relational Database Management System for CP/M. It works! And even a rank beginner like myself got it up and running the first time I sat down with it.

If you're looking for software to deal with your data, too, here are some tips that will help:

Tip #1: Database Management vs. File Handling:

Any list or collection of data is, loosely, a data base, but most of those "data base management" articles in the buzzbooks are really about file handling programs for specific applications. A real Database Management System gives you data and program independence (no reprogramming when data changes), eliminates data duplication and makes it easy to turn data into information.

Tip #2: Assembly Language vs. BASIC:

This one's easy: if you're setting up a DBMS, you're going to be doing a lot of sorting, and Basic sorts are s-l-o-w. Run a benchmark on a Basic system like S*-IV against a relational DBMS like dBASE II and you'll see what I mean. (But watch it: I've also seen one extremely slow assembly-language file management system.)

Tip #5: Relational vs. Hierarchal & Network DBMS.

CODASYL-like hierarchal and network systems, around since the 1960's, are being phased out on the big machines so why get stuck with an old-fashioned system for your micro? A relational DBMS like dBASE II eliminates the predefined sets, pointers and complex data structures of a CODASYL-type DBMS. And you don't need to be a programmer to use it.

dBASE II vs. everything else.

dBASE II really impressed me. Written in assembly language (with no need for a host language), it handles up to 65,000 records (up to 32 fields and 1000 bytes each), stores numeric data as packed strings so there are no roundoff errors, has a superfast multiple-key sort, and supports ISAM based on B* trees.

You can use it interactively with English-like commands (DISPLAY 10 PRODUCTS), or program it (so when you've set up the formats, your secretary can do the work). Its report generator and userdefinable full screen operations mean that you can even use your existing forms.

And if all this makes your mouth water, but you've already got all your data on a disk, that's okay: dBASE II reads your ASCII files and adds the data to its own database.

Right now, I'm using dBASE II with my word processor for budgeting, scheduling and preparing reports for my clients.

Next come job costing, time billing and accounting.

An Unheard-of Money-Back Guarantee.

dBASE II is the first software I've seen with a full money-back guarantee.

To check it out, just send $700 (plus tax in California) to Ashton-Tate, 3600 Wilshire Blvd., Suite 1510, Los Angeles, CA 90010. (213) 666-4409. Test dBASE II doing your jobs on your computer for 30 days. If, for some strange reason, you don't want to keep it, send it back and they'll refund your money.

No questions asked.

They know you don't need your bilge pumped.

AshtonTate

©Ashton-Tate 1980

Circle 202 on inquiry card.

blTTE April 1981 307

CROSS-COMPILE

FORTH !

Nautilus Systems' Forth Cross-compiler is now in use by individuals, universities, and major companies around the world.

USES:

• To produce a modified or tailored version of Forth on a host computer.

• To produce Forth systems for computers that have none.

• To produce applications that use the minimum required nucleus code.

• To do all the above in a ROM/RAM environment.

FEATURES:

• Written entirely in high level fig-Forth.

• Automatic forward reference to any word or label.

• Cross-compiles to any location in the host for any base address in the target.

• Cross-canpiles to any screen in the host for any base address in the target.

• Cross-canpiles vocabularies.

• Can produce headerless code.

• Can produce romable code.

• Load map that shows address, type of symbol and name. The map appears in readable column format, and page width and length are selectable.

• A comprehensive list of undefined symbols is produced showing undefined CFAs, DOES> pointers, labels and words on a vocabulary-by-vocabulary basis.

MACHINE READABLE VERSIONS FOR THE FOLLOWING SYSTEMS:

TRS-80 NORTHSTAR

APPLE CP/M

H-89 LSI-11

Each includes an executable version of fig-FORTH model 1.0, Cross-compiler, cross-compilable source, utilities, and documentation. (This program is not intended for newcomers to FORTH)

Price $150.00 (Includes shipping). Calif, residents please add sales tax.

NAUTILUS SYSTEMS

P.O. BOX 1096 SANTA CRUZ, CA. 95061

FOR THE SERIOUS FORTH USER

TRS-80 is a trademark of Radio Shack, a division of Tandy Corp.

APPLE is a trademark of Apple Computers Inc.

CP/M is a trademark of Digital Research.

LSI-11 is a trademark of Digital Equiptment Corp.

COPYRIGHT ° 1981 NAUTILUS SYSTEMS

HOST — TARGET

Te<

im,

Action

Cursor Up Cursor Down Cursor Left Cursor Right Clear Screen Cursor Home

ADM-3

11 (Control-K) 10 (line teed) 8 (backspace) 12(Control-L) 26 (Control-Z)

H-1500

126, 12 (-, Control-L) 10 (line feed) 8 (backspace) 16 (Control-P)

126, 28 (-, Control-shift-L)

30 (Control-shift-N) 126, 18 (~ , Control-R)

Table 1: The control codes for the Lear Siegler ADM-3 and the Hazeltine 1500 terminals. The numbers are the decimal values for the ASCII codes shown in parentheses.

ZAP. The control codes are detected with a series of compare operations, and the proper code for the Hazeltine placed in the C register. The Hazeltine's 126 functionlead-in code is sent, if necessary, by the jump to SPECL. Other control codes (carriage return, line feed, backspace, etc) fall through and are sent unchanged.

The two-coordinate direct cursor addressing is more complicated. For both terminals, X is the horizontal position, from 0 thru 79, and Y is vertical, from 0 thru 23. The ADM-3 must receive the sequence ESC (ASCII 27), " = " (ASCII 61), Y + 32, and X + 32. The H-1500 requires the tilde (~, ASCII 126), ASCII 17, then X, then Y + 32. In addition, if X is in the range 0 thru 31, then 96 should be added, although the terminal will accept 0 thru 31.

The routine collects all four characters from the host software, then sends the Hazeltine control sequence. Since the emulator is called four times before it can complete the direct-cursor addressing sequence, we need some way to know where we are in the sequence and what action needs to be taken in each case. The temporary byte, MODE, is the key to what happens. Its four states are as follows:

• MODE = 0: We are not in the middle of a directcursor-address sequence. NORM gets control. If NORM detects ESC, it sets MODE to 1 and returns.

• MODE = l: ESC has been detected. If "=" is the current character, MODE is set to 3 and the routine returns. Otherwise, MODE is reset to 0 and the character is sent.

• MODE = 3: This character is the Y coordinate. The byte is stored in variable Y, and MODE is set to 255.

• MODE = 255: The byte to be sent is the X coordinate. The byte is processed for the Hazeltine and the lead-in and control bytes are sent. X is recovered and sent, then Y is recovered. No processing for the 1500 is needed here. MODE is reset to 0 and Y is transmitted.

These values for MODE were chosen so that a fourway branch could be taken from one test, the ORA A instruction at the top of the routine. The zero flag is tested first, and the jump-on-zero instruction branches to NORM. The 1 condition is separated by the JPE, as it is the only condition with odd parity. The 3 and 255 are differentiated with the sign flag.

The kind of multiway branching I've used here is worth a little study. It could be useful in a number of applications.!

308 April 1981 © BYTE Publications Inc

Circle 203 on inquiry card.

Ahml ^mt mtk Licenced by Sinclair Research Ltd. ^_

Microcomputer

for everyone at a Micro Price

J* \ The LMicroficeJ

The unique

and valuable

components of the MicroAce

The MicroAce is not just another personal computer. Quite apart from its exceptionally low price, the MicroAce has two uniquely advanced components: the powerful BASIC interpreter, and the simple teach yourself BASIC manual.

The unique versatile BASIC interpreter offers remarkable programming advantages:

• Unique 'one-touch' key word entry: the MicroAce eliminates a great deal of tiresome typing. Key words (RUN, PRINT, LIST, etc.) have their own single-key entry.

• Unique syntax check. Only lines with correct syntax are accepted into programs. A cursor identifies errors immediately. This prevents entry of long and complicated programs with faults only discovered when you try to run them.

• Excellent string handling capability takes up to 26 string variables of any length. All strings can undergo all relational tests (e.g. comparison). The MicroAce also has string input to request a line of text when necessary. Strings do not need to be dimensioned.

• Up to 26 single dimension arrays.

• FOR/NEXT loops nested up 26.

• Variable names of any length.

• BASIC language also handles full Boolean arithmetic, conditional expressions, etc.

• Exceptionally powerful edit facilities, allows modification of existing program lines.

• Randomise function, useful for games and secret codes, as well as more serious applications

• Timer under program control.

• PEEK and POKE enable entry of machine code instructions, USR causes jump to a user's machine language sub routine.

• High resolution graphics with 22 standard graphic symbols.

• All characters printable in reverse under program control.

• Lines of unlimited length.

'Excellent value' indeed!

For just $149.00 {including handling charge) you get everything you need to build a personal computer at home... PCB, with IC sockets for all ICs; case; leads for direct connection to a cassette recorder and television (black and white or color); everything!

Yet the MicroAce really is a complete, powerful, full-facility computer, matching or surpassing other personal computers at several times the price.

The MicroAce is programmed in BASIC, and you can use it to do quite literally anything, from playing chess to managing a business.

The MicroAce is pleasantly straightforward to assemble, using a fine tipped soldering iron. It immediately proves what a good job you've done: connect it to your TV ... link it to the mains adaptor ... and you're ready to go.

Fewer chips, compact design, volume production-more power per Dollar!

The MicroAce owes its remarkable low price to its remarkable design: the whole system is packed on to fewer, newer, more powerful and advanced LSI chips, A single SUPER ROM, for instance, contains the BASIC interpreter, the character set, operating system, and monitor. And the MicroAce 1K byte

- a new generation of miniature computers

A COMPLETE COMPUTER for $149.00 for 1K Kit

Post and Packing FREE

(Add 6% Tax for Shipments inside California)

RAM (expandable to 2K on board) is roughly equivalent to 4K bytes in a conventional computer typically storing 100 lines of BASIC. (Key words occupy only a single byte.)

The display shows 32 characters by 24 lines.

And Benchmark tests show lhat the MicroAce is faster than all other personal computers.

No other personal computer offers this unique combination of high capability and low price.

The MicroAce teach-yourself BASIC manual.

If the features of the BASIC interpreter mean little to you don't worry. They're all explained in the specially written book free with every kit! The book makes learning easy, exciting and enjoyable, and represents a complete course in BASIC programming from first principles to complex programs. (Available separately purchase price refunded if you buy a MicroAce later.) A hardware manual is also included with every kit.

The MicroAce Kit:

$149.00 with IK COMPLETE

$169.00 with 2K

Demand for the MicroAce is very high: use the coupon to order today for the earliest possible delivery. All orders will be despatched in strict rotation. If you are unsuccessful in constructing your kit, we will repair it for a fee of $20.00, post and packing FREE. Of course, you may, return your MicroAce as received within 14 days for a full refund. We want you to he satisfied beyond all doubt and we have no doubt that you will be.

Z80 A microprocessor chip, widely recognised

as the linsl ever made.

Sockets for TV, cassette recorder, power supply,

SUPER

ROM.

Your MicroAce kit contains...

Printed circuit board, with IC sockets for all ICs. Complete components set, including all ICs-all manufactured by selected world leading suppliers. New rugged keyboard, touch-sensitive, wipe clean. Ready-moulded case. Leads and plugs for connection to domestic TV and cassette recorder. (Programs can be SAVEd and LOADed on to a portable cassette recorder.) Mains adaptor of 600 mA at 9VDC nominal unregulated. FREE course in BASIC programming and user manual.

JOIN THE REVOLUTION - DON'T GET LEFT BEHIND - ORDER YOUR MICROACE NOW!!

Send Check, Money Order or quote your Credit Card No. to: MicroAce 1348 East Edinger, Santa Ana, California, Zip Code 92705. or phone (714) 547 2526 quoting your Credit Card Number.

Quantity

Description

Unit Price

TOTAL

MicroAce Kit 1K

$149.00

MicroAce Kit 2K

$169.00

Manual

$10.00

1K Upgrade Kit

$29.00

Shipmen add 6%

ts inside California TAX

TOTAL

Amex. Diners Check

Money Order Master Charge Visa

Card No.

Exp. Date_

AddressCity

.Zip.

Circle 204 on inquiry card.

BYTE April 1981 309

Technical Forum

Challenger Writes on Comprint

Edward H Carlson, 3872 Raleigh Dr, Okemos MI 48864

I use an Ohio Scientific C2-4P for word processing and text editing. I selected the Comprint 912 as a printer because of its legibility (9 by 12 dot matrix), speed (3 lines per second), quietness (electrostatic printing, not impact), and low cost. The choice of the parallel-interface model reduced costs further. I want to show you a 6502 assembly-language program that interfaces a 6522 VIA (versatile interface adapter) parallel port to the Comprint 912.

The Model 500 main processor board of an OSI Challenger II has a provision for a 6820, a 6520, or a 6521 PIA (peripheral interface adapter) containing two 8-bit parallel ports. The 6522 VIA enhances the PIA functions with extra handshake options and two timers. I had already added a 6522 to my processor board in the space for the PIA. A little extra work was required because six pins have different functions on the 6522. I made the modification by changing only four lines on the Model 500 processor board. The price was a nonstandard naming of the address lines to the sixteen registers of the 6522.

The address conversions needed are noted at the bottom of listing 1. The 6522 resides at hexadecimal location F7xx in memory.

The Comprint has several parallel I/O (input/output) options. I've used the wide strobe/acknowledge mode, enabled by pulling a jumper pin from the Comprint circuit board. Besides the seven lines of ASCII (American Standard Code for Information Interchange) data, there are three control lines. DAV is the strobe signal sent by the computer telling the printer that valid data is on the data lines. NDAC is the acknowledge signal sent by the printer telling the computer that the data has been accepted. NRFD is the busy line that the printer sets high when its data buffer is full and unable to accept further data.

At the 6522 end, the lines are assigned as follows: DAV is CB2, put high and strobed low when the 6502 processor writes data to port B of the 6522 VIA. It must be set high again before the next ASCII character is sent. NDAC is CBl, configured to detect the trailing edge, low-to-high transition, of the acknowledge signal sent from the printer. NRFD is pin PB7 of the eight-line parallel data. One wants to detect the high or low state of this line, not an edge as it makes a transition.

Listing 1: After installing the 6522 VIA in the Model 500 processor board of the OSI Challenger II, this 6502 assembly-language program interfaces the 6522 parallel port to the Comprint 912.

10 cooo

* = $CO00

20 COOO

PARALLEL ' '

30 COOO 48

OUTCHR

PHA

A CONTAINS CHARACTER

40 C001 A902

LDA #$02

ENABLE B PORT OF 6522

50 C003 8D0EF7

STA $F70E

60 C006 A97F

LDA #$7F

DATA DIRECTION

70 C008 8D08F7

STA $F708

80 C00B 8D07F7

STA $F707

CLEAR INTERRUPT FLAGS

90 C00E A990

LDA #$90

READY STROBE, PERIPHERAL CON

100 CO 10 8D03F7

STA $F703

CBl TO GO LOW ON WRITE, DAV

110 C013 AD00F7

BUSY

LDA $F700

READ B PORT INPUT

120 CO 16 2980

AND #% 10000000

BIT 7 IS NRFD OF COMPRINT

130 CO 18 30F9

BMI BUSY

BUSY IF BIT 7 IS HIGH

140 C01A 68

PLA

150 CO IB 49FF

EOR #$FF

INVERT, DATA ACTIVE LOW

160 CO ID 8D00F7

STA $F700

OUTPUT TO PRINTER

170 C020 AD07F7

ACK

LDA $F707

LOOK FOR NDAC ON CB2

180 C023 2910

AND #$10

NDAC IS ACKNOWLEDGE FROM

190 C025 C910

CMP #$10

COMPRINT

200 C027 D0F7

BNE ACK

IF NOT FOUND, LOOK AGAIN

210 C029 A9F0

LDA #$F0

RESTORE CBl TO HIGH, END DAV

220 C02B 8D03F7

STA $F703

230 C02E 60

RTS

235 C02F

Standard

Mine

240 C02F

B Port I/O Register

00

00

250 C02F

Auxiliary Control Register

0B

0E

260 C02F

Peripheral Control Register

oc

03

270 C02F

Interrupt Flag Register

0D

07

310 April 1981 © BYTE Publications Inc

Volume II

CiarcicTs Circuit Cellar

Steve Garcia, described as a "technological treasure," is BYTE's most popular writer. His innovative circuit designs are ingenious, timely, practical, easy-to-build, and—they work.

Ciarcia's Circuit Cellar, Volume II is more than a series of hardware designs: it is a ready reference and workbook of related projects, now available as a single source.

Volume II features 19 articles, including 14 that were voted by BYTE's readers as the best articles of the month, such as: Build a Computer-Controlled Security System, Communicate On a Light Beam (laser communications), Anyone Know the Real Time? (real time clocks), The Intel 8086, Add Nonvolatile Memory to Your Computer, Computerize a Home (AC remote control from your computer), A Computer-Controlled Wood Stove, Ease Into 16-Bit Computing (The Intel 8088), and I/O Expansion for the Radio Shack TRS-80: Parallel and Serial Ports.

Special offer: Buy both Volume I and Volume II now and get Volume I for one-half price. Offer valid through April 15th. All orders must be postmarked by that date.

Volume I contains a collection of more than a year's worth of the popular series Steve writes for BYTE magazine. Included are six winners of BYTE's On-going Monitor Box (BOMB) award voted by the readers as the best articles of the month: Control the World (a four-channel digital-to-analog converter for controlling appliances and other devices); Memory Mapped I/O; Program Your Next EROM in BASIC; Tune In and Turn On (a computerized wireless AC control system); Talk To Me (add a voice to your computer); and Let Your Fingers Do the Talking (a touch panel for your video display).

Buy these books at your favorite computer bookstore or direct from BYTE.

Use our toll-free number (1-800-258-5420) and order your copies today.

Please send L! Please send I Please send I J

. copies of Ciarcia's Circuit Cellar, Volume I, $8.00 . copies of Ciarcia's Circuit Cellar, Volume II, $12.95

. special offer—the complete set of Ciarcia's Circuit Cellar, Volumes I & II, $16.95

(Hurry-offer expires April 15, 1981)

Name

Title

Company

Street

City

State/Province

Zipcode

□ Check enclosed in the amount of $

□ Bill Visa □ Bill Master Charge Card No.

Add 75<t per book to cover postage and handling.

KrJfL, ?; 70 Main Street

KLIllniS Peterborough, New Hampshire 03458

Exp. Date .

Circle 205 on inquiry card.

BYTE April 1981 311

Technical Forum ..^—____-^__

The subroutine to write one character to the printer is given in the listing 1. When called, accumulator A contains the character to be sent. The Comprint expects inverted data (ie: 1 to be low and 0 to be high). A hardware modification can be made to the Comprint 912 to accept noninverted data, but I elected to do the inversion in software with an exclusive-OR (XOR) instruction.

First, port B is enabled. Then data lines PBO thru PB6 are assigned to output the ASCII character, and data line PB7 is assigned to input the busy signal. The interruptflag register is cleared (by writing Is to it) so that it can detect transitions in CBl.

Next, a mask is written to the peripheral control register, which does two things:

1. requests an interrupt flag to be set for low-to-high transitions of the acknowledge line CBl;

2. requests CB2 to go low when the processor writes to

ORIGINAL

500 BOARD (a)

the 6522, to make the beginning of the strobe signal DAV.

Port B is now ready to see if PB7 is high, denoting a busy signal. If not, the data is sent and the interrupt-flag register is repeatedly read to await the acknowledge signal before continuing. (Bit 4 is set by an active transition of CBl, not bit 3 as given in the old edition of the Osborne and Associates book An Introduction to Microcomputers.) This flag is reset by the next write to Port B.

Finally, the DAV line is set high again, to end the wide strobe pulse, and the subroutine is exited.

Some options that could be tried are: use of the narrow-strobe/acknowledge mode of the Comprint 912, use of port A of the 6522, or use of a PIA instead of the VIA. In each case, the program would need modifications.!

IRQA

IRQB

RSO

RSI

cso

R/W

38

♦—O IRQ

36

-O A°

-O Al

22

-O +5V

21

-O R/W

MODIFIED

500 BOARD (b)

COMPRINT

CABLE

SIGNALS

b$l£

PINS

10

PBO RSO

38

3

11

PBl RSI

37

* r*—1 ii

5

12

PB2 RS2

36

13

PB3 RS3

35

<• 1 nl

14

PB4

500

4

15

PB5

Aboard

SIGNALS

6

16

PB6

13

17

PB7

15

18

CBl

11

19

CB2 R/W

22

*

IRQ

21

* i—^

1 > IRQ

J

Figure 1: The hardware modification that enables the Comprint 912 printer to work with the OS1 Challenger II. When the 682,0 position on the Model 500 processor board is modified to take the 6522 VIA, the four marked lines must be cut (the lines to pins 21, 22, 37, and 38, see figure la). New lines must be attached to these pins (denoted by asterisks in figure lb). Note the nonstandard addressline assignments after the rewiring is completed.

AMS

ADVANCED MICRO SYSTEMS • 26188 ADAMOR ROAD • CALABASAS, CA. 91302 OPEN MON.-FRI. 10-8 SAT. 10-6 Tel.: (213) 880-4670

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312 April 1981 © BYTE Publications Inc

Circle 206 on inquiry card.

SOFTWARE

NEW! HISTOGRAPH (Boyd) A calendar-based histogram or bar-graph production system. Allows the user to enter numeric data that relates to a date, and reproduces that data as a high-resolution histogram. 09009. Apple II Disk. $29 95

NEW! DATA-GRAPH (Boyd) Aids in the preparation of graphs and charts. Numeric data can be entered into Data-Graph and used to create colorful one-, two-, or four-quadrant graphs. 09109. Apple 11 Disk. $49.95

NEW! DOUBLE PRECISION FLOATING POINT FOR APPLESOFTTM (S-C Software) Extends the accuracy of the arithmetic available on the Apple from nine digits to a full 21-digit precision on all functions in Applesoft compatible format. 09409. Apple II Disk. $49 95

ORDER NOW!

Hayden Book Company, Inc.

50 Essex Street, Rochelle Park, NJ 07662

Send me Ihe software checked below A check or money order is enclosed i understand that Hayden pays shipping and handling cosls and thai I can return any disk or tape within 10 days if il is defective or [ am dissatisfied wilh it for any reason Residents of NJ and CA must add sales tax Offer good in US only Name of individual ordering must be filled in B 4/81

a 07004

□ 07009

□ 07101 O 07103 D 07301

□ 08609 D 09009 D 09109

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NEW! OP-AMP DESIGN (Gabrielson) Provides the necessary values for your design and will suggest appropriate op-amp types. Includes a choice of six op-amps, and the program will then determine if your selection of an op-amp will be acceptable within your chosen parameters Can be updated to accommodate future op-amps. 09704. Apple II tape. $16.95

LINE & VARIABLE CROSS REFERENCE GENERATOR (Johnson) Provides a cross-reference of line numbers and variable names. 07301. PET tape. $16.95

APPLESOFT UTILITY PROGRAMS (Gilder) Increase your BASIC programming speed and flexibility. Contains 9 useful subroutines: 1. REM Writer 2. PRINT Writer 3. POKE Writer 4. Hexadecimal/Decimal Converter 5. Line Counter 6. Renumber 7, Append 8. Byte Counter 9. Slow List/Stop List 03504. Apple I! tape, $29-95

RENUMBER & APPEND: Utility Programs for the Apple (Gilder) Renumber your Applesoft program and append a second program to the one in memory. 03804. Apple II tape. $14 95

REVIVE (Gilder) When a program is accidentally erased. REVIVE searches through memory and finds the information that enables it to restore the pointers that have been changed. 03604. Apple II tape. $19 95

SLOW LIST/STOP LIST: Utility Programs for the Apple (Gilder) Start, stop, and controfthe speed of your program with Apple ll's game paddles. 03904,

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PSEUDODISK (Neuschatz) This money-saving program simulates a disk memory system for Integer BASIC programs. It allows multiple programs in memory at the same time which can be run from a catalog. 04804,

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6502 DISASSEMBLER (Stamm) Produce assembly language source files with labeled subroutines and references from programs already in memory. It is compatible with Haydens ASSEMBLY LANGUAGE DEVELOPMENT SYSTEM. 08609. APPLE II Disk, $39.95

DATA MANAGER: A Data Base Management System and Mailing List (Lurus) Store information < a floppy disk, and retrieve it quickly and easily by specific names, or by category. 04909. Apple 11 Disk Version. $49 95

Apple is a trademark of Apple Computer Company, Inc.. and is nol affiliated with Hayden Book Company. Inc.

F1NPLAN: A Financial Planning Program for Small Businesses (Montgomery) Allows you to enter data from a balance sheet into the program, to make assumptions about the future growth of business, and to have the computer project results for up to a five year period based on those assumptions. And if you change any data, the program revises all resulting data automatically. The disk version can be used only with TRSDOS Version 2.3. 05103. TRS-80 Level II tape, $69.95, 05108. TRS-80 Level II Disk Version. $74.95

SARGON II (Spracklen) The Champ of champs, "...an excellent program which will provide a true challenge for many players...Save your money and buy SARGON II..." '80 Software Critque. 03403. TRS-80 Level II; 03404. Apple II; 03410. OSI C1P-. 03440. OSI C4P. each tape $29.95. 03408. TRS-80 Level II Disk-. 03409. Apple I! Disk; 03414. OSI C1P Disk; 03444. OSI C4P Disk; 03484. C8P Disk; each $34.95

BLACKJACK MASTER: A SImulatorfTutor/Game

(Wazaney) A serious game that performs complex simulations and evaluations of playing and betting strategies. 05303. TRS-80 Level II tape. $24.95. 05308, TRS-80 Disk Version. $29.95

REVERSAL (Spracklen) Winner of the software division of the First International Man-Machine OTHELLOTM Tournament, this version of the 200-year old game Reversi.

features 27 levels of play and high-resolution color graphics. 07004. APPLE II tope. $29 95. 07009. APPLE II Disk. $34 95

ROYAL FLUSH: Competitive Poker Solitaire

(Wazaney) A game you can play alone or with any number of players. High score wins in this poker-based, fun-filled card game. Choose from possible game variations. 07101. PET. 07103. TRS-80 Level II. each tape. $14.95

STARCLASH (Walton) An exciting game of galactic strategy for one or two players. 05903. TRS-80 Level 11 tape. $16.95

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50 Essex Street, Rochelle Park, NJ

07662 Book Company, Inc.

Circle 207 on inquiry card.

BYTE April 1981 313

KILL SURGES LIKE LIGHTNING!

AC power line surges are destructive, can cost you money, and can't be prevented. But you can stop them from reaching your sensitive electronic equipment with a Surge Sentry.

Surge Sentry acts in picoseconds to dissipate up to a 1,000,000 W, lOOju, second surge. Triggers at 10% above nominal peak voltage. Works in parallel with the power line. Is easy to install for immediate protection. No complicated wiring or special tools required.

Several different models to choose from, including an OEM version. Call or write today for a free brochure.

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DEALER INQUIRIES INVITED

Technical Forum

On the Use of Fourier Transforms to Explore Biological Rhythms

A J Owens, Bartol Research Foundation, University of Delaware, Newark DE 19711

In his editorial "Is Pseudoscience Done by Computer Pseudo-Computer-Science?" (November 1979 BYTE, page 6), Carl Helmers encouraged the analysis of numerical data to test the validity of the biorhythm hypothesis: that our lives are dominated by a few quasisinusoidal cycles. He suggested taking data on our personal lives, perhaps rating each day on a scale of 1 to 10, and then analyzing the time series using the fast Fourier transform (FFT).

Coincidentally, motivated by some biorhythm proponents in an introductory astronomy class that I was teaching, I have been carrying out exactly that program since January 1977. Through November 1979, my data set consisted of 1024 consecutive daily ratings of my personal well-being, recorded by me each evening on a scale of 1 to 10.

While reading Mr Helmers' editorial, I decided to program my AIM-65 microcomputer to analyze the data. (I had previously analyzed 256- and 512-day subsets of the data as they became available, using a FORTRAN program run on a minicomputer.)

With only 4 K bytes of user memory, my AIM-65 could barely run the program to analyze 256 data points

About the Author

A ] Owens is a research physicist and professor at the Bartol Research Foundation of the Franklin Institute, which is located at the University of Delaware. He received his postgraduate degrees from the California Institute of Technology in the field of theoretical physics. Although he uses mainframe computers for his astrophysical research, he claims to be a novice in dealing with microcomputers, having graduated downward from time-sharing systems and minicomputers. He currently uses a Rockwell AIM-65 linked to a BETA-1 digital cassette system.

Technical Forum is a feature intended as an interactive dialog on the technology of personal computing. The subject matter is open-ended, and the intent is to foster discussion and communication among readers of BYTE. We ask that all correspondents supply their full names and addresses to be printed with their commentaries. We also ask that correspondents supply their telephone numbers, which will not be printed.

314 April 1981 © BYTE Publications Irtc

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BYTE April 1981 315

GET THE

SOFTWARE THAT'S

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You want a copy of the exciting software system that's going places. Professionals everywhere are using the UCSD p-System. Now, you can have it. The UCSD p- System offers: a complete software development system, your choice of languages, and a portable system that runs on your microcomputer today and tomorrow. Send in the coupon below and join the pros today. Phone orders accepted with Visa or Master Card.

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□ Send me more information (general)

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□ Send information on the availability of systems for the 6800,6809, and/or 9900 processors

My system has: (check only one)

□ CP/M " Version 1.4

□ CP/M Version II.O with 128-byte sectors

□ 8080 or Z80 processor without CP/M (requiring some assembly language programming)

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□ PDP-11 with □ RX01 □ RX02 (check one)

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NOTE: [pertaining to two items above) For availability of RK05 and RL01 disk drivers, contact SofTech Microsystems.

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□ Check or money order enclosed

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(UCSD p-System and UCSD Pascal are trademarks of the Regents of the University of California. CP/M is a registered trademark of Digital Research Corporation. LSI-11 and PDP-11 are trademarks of Digital Equipment Corporation.)

Technical Forum,

—in fact, the comments had to be deleted to fit the program into the memory. The FFT algorithm used here was originally written for a Digital Equipment Corporation time-sharing computer, and the only modifications are the small input routine and the calculation of the power spectrum at the end. The fast Fourier transform routine for 256 data points takes about 3 minutes to run.

It is of crucial importance in any time-series analysis to understand (and report) details concerning the statistical uncertainty in the results that are obtained. Otherwise, the importance of an insignificant wiggle in the Fourier transform at the "right" place can be blown far out of proportion. Fortunately, information scientists have studied the problem of extraction of signals from noise, and the basic concepts are not too difficult to grasp. For a complete (and technical) account, I suggest reading Random Data: Analysis and Measurement Procedures, by J S Bendat and A G Piersol (Wiley-Interscience, New York, 1971).

Suppose that you begin with N data points, each a sample from some process that is random or noisy. Obviously, no matter how you "massage" the data, you have only N independent samples. In the fast Fourier transform, the N data points sampled at intervals of time separated by At are transformed into N Fourier coefficients in the frequency domain, one each for the sine and the cosine terms corresponding to frequencies 1/NAf, 2/NAf, . . . , (N/2-1 )/NAf, l/2Af. For random data, the Fourier coefficients have random phases, so one usually reports the power spectrum, which is the sum of the squares of the sine and the cosine terms (altered by a multiplication constant used to normalize the result). The original N data points give N/2 power spectral estimates in frequency space, each with two degrees of freedom— one each from the sine and cosine terms.

Inasmuch as each raw-power spectral-density estimate has only two degrees of freedom, it is rather poorly determined. In only two-thirds of the cases can one expect the "true" power spectral level to be in the interval between zero and two times the measured power spectrum.

To improve the accuracy of the estimates, one averages the power spectrum. One method of doing this, the one that I applied, is to divide the total data set into smaller groups of points, calculate the power spectrum for each subset, and then average the power spectra from each group. For example, my set of 1024 days was divided into four groups of 256 points each. Power spectra for each of the four groups were calculated, and the resulting four spectra were averaged at each of the 128 power spectral points in frequency space.

A second approach is to calculate the power spectrum of the entire record (eg: 1024 days). One then averages the several adjacent frequency bins (eg: four) to get a smaller number of more accurately known power spectral estimates.

In either case, averaging four spectra (or frequency bins), each with two degrees of freedom, gives power spectral estimates with eight degrees of freedom. As a result, we expect that, in two-thirds of the cases, the "true" power spectrum at a given frequency will then lie between 0.5 and 1.5 times the measured value. In general, the fractional uncertainty in each estimate is ±y/(2/D),

316 April 19B1 © BYTE Publications Inc

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BYTE April 1981 317

SORCERER SOFTWARE

from QUTILfry SOFTWTIRe

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The latest of Quality Software's great arcade games for the Sorcerer is ARROWS AND ALLEYS, by Vic Tolomei. You drive your car in a maze of alleys. Your task is to eliminate a gang of arrows that constantly pursues you. You have a gun and the arrows don't, but the arrows are smart and they try to stay out of your sights and will often attack from the side or from behind. Eliminate the arrows and another, faster gang comes after you. Four levels of play. Requires 16K or more of RAM. $17.95

BEDIT by Ernest Bergmann. A BASIC editor. This short and easy to use program is a machine language routine that loads in low memory and allows you to edit your BASIC programs by modifying text on the video screen. No more retyping a long line just to change one character. A few cursor movements make the necessary modifications. Even renumbering lines is easy to do. This program is a real limesaver. Runs on any size Sorcerer. $11.95

FORTH for the Sorcerer. Now Sorcerer owners can en|oy the convenience and speed of the fascinating FORTH programming language. Based on fig-FORTH and adapted for the Sorcerer by James Albanese, this version uses simulated disk memory in RAM and does not require a disk drive. Added to standard fig-FORTH are an on-screen editor, a serial RS-232 driver, and a tape save and load capability. Numerous examples are included in the 130 pages of documentation. Requires 32K or more of RAM.

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GRAPHICS ANIMATION by Lee Anders. This package provides the BASIC programmer with a powerful set of commands for graphics and animation. The program is written in machine language but is loaded together with your BASIC program and graphics definitions with a CLOAD command. Any image from a character to a large graphic shape may be plotted, moved, or erased with simple BASIC commands. Encounters of plotted character sets with background characters are detected and background images are preserved. Contains a medium resolution plotting routine. A keyboard routine detects key presses without carriage returns. Includes a separate program for constructing images. Runs on any size Sorcerer. $29.95

QS SMART TERMINAL by Bob Pierce. Convert your Sorcerer to a smart terminal. Used with a modem, this program provides the capability for you to communicate efficiently and save connect time with larger computers and other microcomputers. The program formats incoming data from time-sharing systems such as The Source for the Sorcerer video. Incoming data can be stored (downloaded) into a file in RAM. Files, including programs, may be saved to or loaded from cassette, listed on the video, transmitted out through your modem, or edited with an on-board text editor. Interlaces with BASIC and the Word Processor Pac. $49.95

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Technical Forum.

where D is the number of degrees of freedom.

The BASIC computer program shown in listing 1 is quite simple. The routine in lines 100 thru 180 allows the data to be entered. Because the input data are real (ie: they have no imaginary component), they are stored in the one-dimensional array X, and the one-dimensional

Listing 1: Power spectrum calculation program. This program was used to calculate the data points plotted in figures 1 and 2.

1 REM

2 REM

3 REM

6 REM

PROGRAM FFTPOU

POUER SPECTRUM USING FFT

A. J. OWENS 16-N0V-79 REAL PART OF FUNCTION IN X> IMAG IN Y

10 DIM X<256>,Y<256> 20 REM

INPUT ROUTINE GIVES DATA X AND Y AND NUMBER OF DATA POINTS. Nr A POUER OF 2. INPUT ROUTINE IS IN LINES 100-199. FFT CALCULATION ROUTINE IS IN LINES 200-590. PRINTOUT OF THE POUER SPECTRUM IS IN LINES 591-800. INPUT ROUTINE

25 REM 27 REM

29 REM

30 REM 32 REM 34 REM 100 REM 150 N=256

160 FOR 1=1 TO N

170 INPUT X<I)

175 Y<I>=0

180 NEXT I

200 REM BEGIN FFT CALCULATION

202 G=INT<L0G<N>/L0G<2)-rl.00000E-06>

203 P=2*3.14159/N

204 FOR L = 0 TO G-l 206 G1=2"(G-L-1) 20(3 M=0

210 FOR 1=1 TO 2"L

220 K1=INT(M/G1)

230 GOSUB 530

240 Y1=C0S(P*K2>

250 Y2=-SIN(P*K2>

260 FOR J=l TO Gl

270 Y3=X<M+G1+1>*Y1-Y<M+G1+1)*Y2

280 Y4=X(M+G1+1)*Y2+Y(M+G1+1)*Y1

290 X(M+G1+1>=X(M+1)-Y3

300 Y<MhGl+l)=Y(M+l)-Y4

3.10 X<M+1)=X<M+1)+Y3

320 Y(M+1)=Y(M+1)+Y4

330 M=M+1

340 NEXT J

350 M=M+G1

360 NEXT I

370 NEXT L

3EI0 FOR 1=0 TO N-l

390 K1=I

400 GOSUB 530

410 IF K2>=I THEN 480

420 K3=X<I+1>

430 X<I+1)=X<K2+1)

440 X(K2+1)=K3

450 K3=Y<I+1>

460 Y( IH )=Y(K2+1)

470 Y(K'2+1)=K3

480 NEXT I

499 GO TO 591

500 REM STATEMENTS 500 TO 510 PRINT OUT RESULTS

501 REM OF THE FFT ITSELF; SKIPPED HERE

502 FOR 1=0 TO N-l

504 PRINT i;X(I+l>;'+I'»Y(I+1>

S06 NEXT I

520 GO TO 591

530 K2=0

540 FOR K=l TO G

550 K3=INT(Kl/2)

560 K2=2*<K2-K3)+K1

570 K1=K3

580 NEXT K

590 RETURN

591 REM PRINT OUT POUER SPECTRUM

593 PRINT 'STEP BETUEEN DATA POINTS'* 595 INPUT T

599 PRINT 'NUMBER OF POINTS AVERAGED'!

600 INPUT M 605 PRINT

610 PRINT ' FREQUENCY POUER'

620 0=2*T/<M*N)

630 FOR J=0 TO N/2 STEP M

640 S=0

650 FOR 1=1 TO M

660 S=S+0*(X( J+I + 1)*X( J+I + l)+Y( J+I + l)*Y(J + I-fl)>

670 NEXT I

680 F=(2*J+M)/(2*N*T>

690 PRINT F.S

700 NEXT J

800 GO TO 599

999 END

318 April 1981 © BYTE Publications Inc

Circle 215 on inquiry card.

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Circle 217 on inquiry card.

800-323-1780

• Ribbons for: Diablo, Qume, IBM, Wang. NEC, All Data Printers and Typewriters.

• Printwheels, Elements and Thimbles.

• Magnetic Media: Floppy disks, mini-floppy, Tape, Packs and Cassettes.

• Disc storage systems, Quietizers, Anti-static mats, Ink rolls and much more.

• Terminals and accesories.

• TO ORDER •

Phone orders invited, using credit cards. Or send check, cashiers check or money order that draws on a U.S. bank. Please add 3% (S5.00 Minimum) lor handling, shipping and insurance. Illinois residents add 5%% sales tax. Mail order pricing only. Catalog mailed upon request.

DISKETTES

• 100% Certified

• 2 Year Warranty

• 10 Million Passes

• Human Engineered

• EZ View Box

• The Best Disk Available Today.

5V4" (Soft Sector) 5'/«" (10 Sector) 5V4" (16 Sector)

8" Single SideSingle Density 8" Single Side Reversible 8" Single Side Double Density 8" Double Sided Double Density

Box of 10 29.95 29.95 29.95

32.50 52.50 50.00 52.50

m

"Run With the Thoroughbreds" Satisfaction Guaranteed

NCE Supply Corp. 915 W. Liberty Drive

Wheaton, IL60187

Phone: 800-323-1780 Toll Free

*312-682-0001 Within Illinois

TELEX 724389ATT NCE • Distribution Worldwide •

THE FORTH SOURCE

Specializing in printed material for the FORTH language. Send for listing of current material.

Installation Manual

$10.00

8080 Listing

10.00

6502 Listing

10.00

6800 Listing

10.00

6809 Listing

10.00

PDP-11 Listing

10.00

PACE Listing

10.00

Alpha Micro Listing

10.00

more coming

Using FORTH, manual

$25.00

fig-FORTH Cross Compiler

30.00

PDP-11 User's Guide

20.00

Tiny Pascal in fig-FORTH

10.00

more coming

Foreign orders add 30% for Airmail.

Dealer inquiries invited.

Write for complete listing FORTH material.

MOUNTAIN VIEW PRESS

PO Box 4656

Mt. View, CA 94040

of

A REFURBISHED "SELECTRIC" ASCII TERMINAL FOR THE SMALL BUSINESSMAN OR SERIOUS HOBBYIST.

The AJ 841 I/O terminal. Now available from dealers nationwide.

Demand for our AJ 841 I/O computer terminal has been great. And now it's getting even greater. So call your local computer shop dealer right away. Supply is limited! You may never have another opportunity like this one to buy your own professional terminal.

The AJ 841 features:

• Choice of serial RS 232 or parallel interface

• ASCII code

• 14.9 cps printout

• High quality Selectric printing

• Heavy-duty Selectric mechanism

• Off-line use as typewriter

• Documentation included

• 30-day warranty on parts and labor (details available on request)

Call toll-free now

For location of your nearest AJ dealer, call toll-free:

800/538-9721

California residents call collect 408/263-8520. Extension 263.

Available only in the continental United States

ANDERSON JACOBSON

See us at the NCC booth 1608

Circle 218 on inquiry card.

BYTE April 1981 319

for TRS-80 Models I &

SuperSoft LISP allows the TRS-80 to become a complete Artificial Intelligence laboratory! It is the tool that takes you to the frontier of Computer Science.

The SuperSoft LISP is a complete and full implementation. (It is NOT a subset!) It contains an efficient garbage collector which optimizes the usage of user RAM, and supports the TRS-80 graphics. Below are some features:

• Runs in 16k level II (with only 6K overhead)

• Fully implements atom property list structure.

• PROG is supported.

• FUNARG device is implemented.

• Efficient garbage collection.

• Complete with LISP editor and trace.

• Allows complete range of single precision numeric data.

• Works with old as well as new ROMs.

• Contains 97 functions.

• Sample Programs.

The LISP package is supplied on tape or discette and with a complete user manual.

cassette version: (requires 16K level II)

Disk version: (requires 16K disk)

(manual only: $15.00)

$75.00 $100.00

All Orders and General Information:

SUPERSOFT ASSOCIATES

P.O. BOX 1628

CHAMPAIGN, IL 61820

(217)359-2112

Technical Hot Line: (217) 359-2691

(answered only when technician is available)

SuperSoft

First in Software Technology

TRS-80 TRADEMARK TANDY CORP

Technical Forum.

<

5 o

Q

10

1

1 1

1 1 1 1

5

- \ /

\ A A f\ A

2

\ / A V t \ /

\ \l t \/

2

0-40 DAYS

7 DAYS

0.5

1

i i

i i i i

10 20

FREQUENCY IN (256 DAYS!

30 -1

40

Figure 1: A power spectrum chart averaging four periods of 256 days each. This figure of the low end of the full-power spectrum graph shows the relative intensities of sine waves of various frequencies. The range of values bracketed by the arrows labeled "20-40 days" represents the power of sine waves with periods between 20 and 40 days. If biorhythms were present in this power spectrum, they would have appeared as significant peaks at certain points within this range. The vertical line at frequency = 15 shows the possible variation of the point on the graph and is a measure of the possible error in measurement at that point.

10

<

Q

et

iu 2

o

Q

1 "

1 1

t

l i

^\t

•

f-0.5^^ #

"T

• >^ • • •

_

•

_

> t

,

••*

• •

.

20-40 DAYS

7 DAYS

i i

i i

•

0.05 0.1

f (DAY-1)

0.2

0.5

Figure 2: A modified power spectrum chart. The data of figure 1 was averaged over four frequency bins, giving a more accurate set of data points, and plotted using logarithmic scales for both the frequency and power axes. The notation used is described in the caption for figure 1.

array Y is set to zeros. Lines 200 thru 590 perform an N-point fast Fourier transform:

F„= E

Zk exp (—2-jrikn/N)

where Zk = Xk + iYk is the (complex) input vector and F„ is the complex Fourier transform (i = ^J — 1 and is the unit measure along the imaginary axis when dealing with complex numbers). The real (cosine) part of F is placed in X and the imaginary (sine) part in Y by the routine. The nth frequency, corresponding to the Fourier coefficient F„, is /„ = n/(NAt). The power spectrum is calculated in

320 April 1981 © BYTE Publications lnc

Circle 220 on inquiry card.

PHiooqrq

Modem Kit

300 Baud Acoustic Coupler

$69.00

Includes: Power Supply Speakers

Printed Circuit Board All Integrated Circuits,

Resistors & Capacitors Instruction and Trouble

Shooting Book

Order Direct or Call for the Location of the Closest Dealer

Add $4.00 for Shipping Charge. Ohio Residents add 6.5% for Sales Tax

I

f*

MASTERCHARGE

oho oqrs products coqpORsrnon

14600 Detroit Avenue • Cleveland. Ohio 44107 • (216) 221-9000

Allow 6 weeks lor Delivery

I I

I

Circle 221 on inquiry card.

SPEED UP YOUR SYSTEM!

Fortran or Compiled Basic 3 times faster using the

Memtech Arithmetic Processing Unit Interface.

'£**W

This interface enables any S-100 buss microcomputer to communicate with the AMD 9511 APU. It can perform a Floating Point Multiply in 56 MS vs. 3000 /xS in software. Trigonometric and exponential functions are also performed (41 in all).

Assembled with 3MHz 9511 $460 (with 2MHz $390) Library for Microsoft Fortran $100, Basic $100

Memtech Co.

665 Shelter Creek,Suite237,San Bruno, CA 94066

California residents add 6°» sales tax. Price includes shipping lo any point in U.S. and sockets for all Ic'a.

THE FIRST TRS-80 COMPATIBLE COMPUTER WITH HIGH DENSITY COLOR GRAPHICS!

LNW80

LNW RESEARCH introduces the LNWfiO, a high performance color computer, compuliole with the TBS-80™ Model I. The fully integrated LNW80 is a sophisticated and versatile microcomputer with the following powerful

features.

COMPATIBILITY

Hardware and software compatible to the Kadio Shack TRS-80™ Hodel I computer, provides the widest software base of any microcomputer. cassette Interface*! expansion bus

DISPLAY

Quality upper and lower case display.

Two modes of color graphics, high resolution graphics, 384 x 192 in eigne colors - higher density than the Apple II'. Low density color graphics of 128 x 192 are also available in einht colors.

iii-ju resolution - black and white qraphics text and TRS-80™ standard graphics. Reverse video, composite video RF output,

PERFORMANCE

The LNWao utilizes the fast Z-8QA microprocessor which executes at a

speed of 4 MHZ - over twice the speed n\' the TRS-80™ Model I.

of 384 x 192 mixed with

PC BOARD

$89.95

LNW RESEARO

Ask about our : Keyboard

N

EXTERNAL DATA SEPERATOR

caDlnet L««d«i VIMO 100-BO

1

W

LNW RESEARCH 14661 ■ C MYFORO RD TUSTIN CA 92680(714)552-8946

ORDERING INFORMATION

VISA

SYSTEM EXPANSION

AT

A^O" | PC BOARD A ]

9Q7 LUSER MANUAL J

• SERIAL RS232C 20mA I/O - FLOPPY CONTROLLER

• 32K BYTES MEMORY

• PARALLEL PRINTER PORT

• DUAL CASSETTE PORT > REAL-TIME CLOCK

• SCREEN PRINTER BUS ONBOARD POWER SUPPLY SOFTWARE COMPATIBLE SOLDER MASK,SILK SCREEN

Circle 222 on inquiry card.

BYTE April 1981 321

6809 SOFTWARE

im

BY MICROWAREc"

OS-9™ MULTIPROGRAMMING OPERATING SYSTEM

/m true multitasking, real time operating system for / % timesharing, software development, database, A m process control, and other general applications. This versatile OS runs on almost any 6809-based computer.

■ UNIX'" -like file system with hierarchical directories, byte-addressable random-access files, and full file security. Versatile, easy-to-use input/output system is hardware independent and expandable.

■ Powerful "shell" command interpreter features: I/O redirection, multiple job stream processing, and more. Includes a complete set of utility commands.

■ OS-9 Level Two uses hardware memory management and can address over one megabyte of memory. Also includes pipes and filters for inter-process data transfers.

■ OS-9 Level One runs on systems without memory management hardware having up to 56K memory.

DOS-9 Level Two $495* □ Level One $195

BASIC09™ PROGRAMMING LANGUAGE SYSTEM

Extended BASIC language compiler/interpreter with integrated text editor and debug package. Runs standard BASIC programs or minimally-modified PASCAL programs.

■ Permits multiple named program modules having local variables and identifiers. Modules are reentrant, position independent and ROMable.

■ Additional control statements for structured programming: IF ... THEN ... ELSE, FOR ... NEXT, REPEAT . .. UNTIL, WHILE ... DO, LOOP . .. ENDLOOP, EX/TIF .. . ENDEXIT.

■ Allows user-defined data types and complex data structures. Five built-in data types: byte, integer,

9 digit floating-point, string and boolean.

■ Runs under OS-9'" Level One or Level Two. D$195*

OTHER OS-9" FAMILY SOFTWARE

■ Stylograph™ Screen-Oriented Word Processor

■ Interactive Assembler ■ Macro Text Editor

■ Interactive Debugger

BAS1C09 and OS-9 are trademarks of Microware" and Motorola. UNIX is a trademark of Bel! Laboratories.* Most software is available on ROM or diskette in versions for many popular 6809 computers. Contact Microware® for specific availability.

^m MICROWARG*

Microware Systems Corp., Dept. B2

_==- 5835 Grand Avenue, Des Moines, Iowa 50304

gg. (515) 279-8844 • TWX 910-520-2535

Technical Forum.

Frequency in (256 days)-1

log,,, (Power)

1

1.00

2

1.20

3

0.83

4

0.59

5

0.10

6

0.76

7

0.94

8

0.91

9

0.61

10

1.00

11

0.29

12

0.79

13

0.65

14

0.16

15

0.13

16

0.79

17

0.62

18

0.44

19

0.26

20

0.56

21

0.39

22

0.73

23

0.52

24

0.12

25

0.17

26

0.58

27

0.08

28

0.62

29

0.53

30

0.42

31

0.72

32

0.47

33

0.74

34

0.57

35

0.27

36

0.70

37

0.48

38

0.49

39

0.12

40

0.49

Table 1: Table of values for

the power spectrum chart of

figure 1. The second column of numbers is the base-10

logarithm of the value of the

power. For example, for point

20, 10°■" equals 3.63

which is

the value plotted in figure 1 at

the point frequency =

--20. The

marks for 7, 20, and 40 days in

figure 1 correspond

to frequency values (with units of (256

days)") of 36.6, 12.8

and 6.4,

respectively. The logarithm of

the variation of the

error mark at frequency = 16 is +0.18

and —0.30 from the recordec

value of 0.79.

lines 591 thru 800, using the relation:

P„ = (2Af/N)|F„|2

The program allows averaging of the power over any specified number of frequency bins. If M frequency estimates are averaged, the number of degrees of freedom in the single power spectrum is D = 2M and the fractional statistical uncertainty is ±V(2/2M) = ±V(1/M).

As mentioned above, I scored 1024 consecutive days on a scale of 1 to 10 and analyzed the data in 256-day groups. The average scores for the four groups were 5.1, 4.6, 4.5, and 4.6, indicating a mean near 5 with a hint of a long-term decline. The day-to-day variation (standard deviation) was close to 1 for each of the four periods.

Averaging the power spectra for the four periods, I ob

322 April 1981 © BYTE Publications Inc

Circle 223 on Inquiry card.

Circle 224 on inquiry card.

[

NEW!

CHfcCKBOOK CHECKWRITER

PROGRAM FOR:

TRS 80CC '■' TRS 80 LEVEL II"1

ATARI 8O0'M APPLE llIM

HEATH H-89'v

CASSETTE TAPE S9.95

or LISTING 55.95

5»

Circle 225 on inquiry card.

S

IMOW. . .Continuous Checks

That Can be Used With or Without Your Computer!/ The Best in A Home Checking System

That's right Continuous Checks fan-folded in a 3-to-a-page desk set design And they can be computer primed, handwritten or typewritten — whichever suits the quantity or situation.

SPECIAL DESIGN

Our checks are not a high-volume business form adaptation. They're specially designed Computer/Manual Checks for the home or low volume user. And Programming is Easy. All stub and check information is un the same line No need to change tractor width when loading either Our checks are the same QW width as standard tractor feed printer paper Tear down 8U8 is the same as the classic personal sued check issued by all banks.

COMPLETE HOME SYSTEM

With this system you can print the bulk of your monthly checks on your computer. Your checks and slubs can then be stored in our attractive Data Ring Binder Checkbook. Later, if you have a tew checks to write, there's no need lo load them into a printer - just write a check at your desk as shown above. And you can mail your checks in our dual windowed envelopes to eliminate addressing

ChOreS. 1R&HU- l.nU,, l,x M.iiBOO -SlAMH ine. Appl.ll'»

UNIQUE

You won't find checks like these anywhere.

And. our special small quantity printing process will give you excellent quality and appearance. Standard color-coordinated imprinting and encoding is as shown above (logo can be omitted) on blue, grey, tan, or green checks.

PRICED RIGHT

Two Hundred checks are just $29.95 {envelopes S13.95). Five Hundred checks are S49.95 (envelopes S27.95) Data Ring Checkbooks are only S6.95.

Special "ORDER NOW" Offer If you order directly from this ad. we'll send you a monthly Checkbook-Checkwnting program FREE on cassette tape for any one of the computers listed above. You'll save 59.95. Just enclose a voided check (for encoding information) with your payment (VISA MasterCard orders must show signature. expiration date, and account number). Or. send today for samples. Sorry, we can't make [his Free Offer unless you order directly from our

SYNERGETIC 4715 shepherd rd. SOLUTIONS MULBER?I86Fn

PHONE- (6131 646-6557 JJOOU

Complete AIM 65 Expansion

For complete AIM 65 expansion, Forethought Products brings you the AIMMate Series, quality expansion products with price, performance and versa tility that puts them in a class of their own.

AIM-Mate Series expansion, including RAM (to 48K), PROM, I/O, video and floppy disk interface, STD BUS interface, parity protection and more, lets you configure the kind of system you need.

The compact AIM-Mate case puts it all together in a sturdy, portable, desk top unit.

Write today for complete details on the AIM-Mate System- AIM 65 expansion products for the professional.

jFORETHOUGHT

l^SPRODUCTS

87070 Dukhobar Road, Eugene, Oregon 97402 (503) 485-8575

The DataTrak" 5 Floppy Disk Drive The DataTrak" 8 Floppy Disk Drive

from Qlime. Distributed by asap

The DataTrak 5 double-sided double-density drive uses state-of-theart technology to give you superior data integrity through improved disk life, data reliability, and drive serviceability using SlAM media.

Quine's independent head load yields wear characteristics far superior to competitive drives. This superior wear performance produces savings on both diskette usage and drive maintenance.

Improved data reliability, resulting from superior amplitude and bit shift characteristics, optimizes operator efficiency and reduces processing time for end-users.

And Data Irak's unique modular design means simplified field servicing for you and your customers.

Design Features

Expanded storage capacity •Two-sided, double density Proven head carriage assembly •Ceramic head with tunnel erase •Dual-head flex mounting arrangement

•Superior head bdd dynamics

Precise lead screw actuator

•past access time - 20 ins irack-lo-track

•Low Iriclion and minimum wear

•Low power dissipation

Additional features

•Industry standard 5V4" media format

•ISO standard write protect

•Door lock out (or media protection

•Requires DC voltage only

•Daisy Chain up to 4 drives

•Heads load oil command independent of loading media

Product Specifications

Performance Specifications

Capacity Unformatted: 437.5K or 50UK bytes Qume Formatted: 286 7 K or 327.7K bytes

Recording Density: 545b BPi

Track Density 48 I'PI

Cylinders: 35 or 40

Tracks' 70 or 80

Recording Method: FM or MFM

Rotational Speed: 300 RPM

Transfer Rate: 250K bits/second

Latency (avg .): 100 ins

Access Time: Track-to track 20 ms Settling 15 ms

Head Load Time: 50 ms

The DataTrak™ 8 double-sided, double-density drive uses state-of-the-art technology to give you superior data integrity through-improved disk life, data reliability, and drive serviceability.

Qume's innovative approach to controlling head load dynamics yields wear characteristics far superior to competitive drives. In independent evaluation. DataTrak 8 is setting industry standards for tap test performance. This superior wear performance produces savings on both diskette usage and drive maintenance.

Improved data reliability, resulting from superior amplitude and bit shift characteristics, optimizes operator efficiency and reduces processing time for end-users.

And DataTrak's unique modular design means simplified field servicing for you and your customers.

Design Features

Expanded storage capacity

•Two sided, double density Fully IBM compatible •IBM 3740 and System 32 drives •IBM 3600 and 4964 drives

• IBM Sytem 34 drives

Proven head carriage assembly •Ceramic head with tunnel erase •Dual-head flex mounting arrangement •Superior head load dynamics Fast, precise steel belt drive

• Fast access time-3 ms track-to-track

•Low friction and minimum wear • Low power dissipation Additional features •ISO standard wrile protect

•Programmable door lock

•Negative DC voltage not required •Daisy Chain up to 4 drives •Side-by-side mounting in standard 19" RETMA rack Product Specifications Performance Specifications Capacity Unformatted l.b Mbytes/disk

IBM formal 1 2 Mbytes/disk Recording Density 6816 BPI Track Density. 48 TP1 Cylinders 77: Tracks. 154 Recording Metliod: MFM Rotational Speed- 360 RPM Transfer Rate: 500K bits/second Latency (avg.): 83 ms Access Time: Track-to-track 3 ms Settling 15 ms Average 91 ms Head Load Time: 35 ms Disk: Diskette 2D or equivalent

computer 3S3p products, inc.

1198 E. Willow Signal Hill, CA 90806

AUTHORIZED DISTRIBUTOR FOR QUME

CALL FOR PRICE AND DELIVERY

(800) 421-7701 Or (213) 595-6431 (In California)

Circle 226 on inquiry card.

BYTE April 1981 323

HELPING THE SMALL COMPUTER ENTREPRENEUR

How To books and seminars from Essex Publishing Company

SYSTEM5

HOUSE

#10. HOW TO START YOUR OWN SYSTEMS HOUSE. Leslie Nelson. Practical step-by-step guide for the HDP professional or small businessman. Covers all aspects of starting and operating a small systems business. $36.00

#35. SOKTWARE WRITER'S MARKET. Bernard Korites. 1800

places tosellyoursoftware. Ifyou are in the suit ware business this directory is your key to profits. $45.00

#130. HOW TO START & OPERATE A MAIL-ORDER BUSINESS.

Julian Si/nan. Indispensible for those selling software, equipment or supplies by mail. 3rd revised edition. 544 pages. $24.95

#290. HOW TO FINANCE YOUR SMALL BUSINESS WITH GOVERNMENT MONEY. R.S. Hayes and J.C. Howell. Amazingly, one of the best sources of start-up and expansion capital is Uncle Sam. This book shows you in detail how to go about it. $14.95

#211. HO W TO START AND PROMOTE YOUR OWN NEWSLETTER. Howard L Shenson. Newslettering is a high profit business. This detailed, step-by-step seminar shows you how you can do it. Includes cassettes, written materials and binder $59.00

#291. HOW TO SUCCEED IN YOUR OWN BUSINESS. W.R. Park and S.C. Park. Gives the first-time, untested entrepreneur a look at what to expect. Brings a wealth of specific operating data for over KO kinds of businesses. $19.95

ESSEX PUBLISHING CO.

285 Bloomfield Avenue • Caldwell. N.J. 07006 Ordei Hooks bv number;

i i

Send cheek, money order (US S). VISA or Master Charge fl. Publisher pavs4lh class shipping. I For UI'S shipping (U.S. A. only) add S1.00 per book. For Air Mail shipping add $2.50 per book '

in the U.S.A.. S6.00 in Mexico and Central America. SI 2.00 per book elsewhere. N.J. residents I

add 5'r sales rax.

D Cheek enclosed D Credit Card

□ 4th Clas

a lips

□ Air

Name

Address

City SI

Card U 1

for faster shipment on credit card orders call (201) 783-6940 between 9 and 5 Eastern time.

Zip

Exp, Date

Technical Forum,

Point Number log10(f)

log10 (Power)

1

-2.01

0.96

2

-1.60

0.78

3

-1.39

0.75

4

-1.25

0.53

5

-1.14

0.49

6

-1.06

0.50

7

-0.99

0.43

8

-0.92

0.55

9

-0.87

0.61

10

-0.82

0.42

11

-0.78

0.39

12

-0.74

0.45

13

-0.70

0.24

14

-0.67

0.22

15

-0.64

0.45

16

-0.61

0.26

17

-0.59

0.24

18

-0.56

0.24

19

-0.54

0.11

20

-0.51

-0.07

21

-0.49

0.30

22

-0.47

0.06

Table 2:

Table of values for modified power spectrum of

figure 2.

Here, both columns of numbers

are the base-10

logarithms of their respective values as

plotted in figure 2.

For example, for point 2, lCr'M and Iff3*

give values of

0.025 and 6.026, which can be read off

the horizontal and

vertical axes of figure 2. The marks for 7

20

and 40 days in

figure 2

correspond to frequency values

(with units of

(days)-')

of 0.141, 0.050, and 0.025,

respectively. The

logarithrr

of the variation of the error

ma

rk as shown in

figure 2 is +0.10 and -0.12.

tained the power spectrum, the low-frequency part of which is shown in figure 1. Note that the power spectrum's vertical axis is logarithmic; this makes the size of the statistical uncertainty in each point the same. A typical error flag at frequency = 15 is shown. A few relevant cyclic periods are shown, including the week (seven days) and the canonical biorhythm periods (twenty to forty days).

The safest thing to say is that there is no evidence whatsoever for enhancements above the background noise level in the biorhythm range. Even if all the variation in the six power spectral points in the twenty- to forty-day range is attributed to biorhythms, the contribution is only about fifteen percent of my total variance from day to day. But there is no evidence for any periodicities in this region, and the noise in the biorhythm range looks similar to that at both lower and higher frequencies.

The perceptive reader may notice that the power spectrum shown in figure 1 is not flat, as would be the case for perfectly "white" or uncorrelated noise. This implies that there is some temporal structure in my day-to-day feeling of well-being. To investigate this more closely, I averaged the data in figure 1 over four adjacent frequency bins, to give power spectra with thirty-two degrees of freedom. The results are shown in figure 2, given as a log-log plot. The solid line shows that the power spectrum is well fit by a power law spectrum, P(f) oc f-°s. This is an unusual power spectrum. White noise has a flat spectrum, and random-walk noise has a f'2 spectrum. Electrical "flicker

324 April 1981 © BYTE Publications Inc

Circle 227 on inquiry card.

Circle 228 on inquiry card.

Circle 229 on Inquiry card.

New Low-cost Modem MA-50

• Answer/Originate

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noise" has an /"1 spectrum. My biorhythms, instead of producing quasi-periodic "music of the spheres," seem to be more in the nature of a slightly colored and unique random hisslB

Biorhythms and Fourier Transforms

Proponents assert that the relative strength and weakness of mankind in areas roughly described as "physical," "emotional," and "intellectual" vary in cycles of twenty-three, twenty-eight, and thirty-three days, respectively, with each of the curves approximating sine waves of equal amplitude. Of course, the effects of each influence are added together, so that an overall index of a particular day's merit (as the author recorded by assigning each day a number between 1 and 10) would not readily show the presence (or absence) of these sinusoidal waves.

This is where Fourier transforms (either fast or discrete) come in. In theory, any complex periodic waveform can be shown to be the sum of a number of sine waves of differing frequencies and amplitudes. The Fourier method transforms an amplitude-versustime waveform into its equivalent amplitude-versusfrequency waveform—ie: the transformed waveform tells the relative strengths of the different frequency sine waves that, when added together, will give the original amplitude-versus-time waveform.

Once this is understood, it becomes apparent that, if a specified waveform contains definite twenty-three-, twenty-eight-, and thirty-three-day cycles, these cycles should cause visible peaks in the appropriate places on the frequency (horizontal) axis of the transformed waveform. The lack of such peaks would indicate that these frequencies contribute no more to the overall waveform than other frequencies do. A transformed wave that is roughly a flat horizontal line indicates that sine waves of all frequencies contribute equally to the original waveform. Such a waveform has no dominant frequencies. A signal consisting of random components with no discernible dominant frequencies is known as white noise.

Another verification of the transformed wave is concerned with the amplitude of existing peaks. In this situation, those peaks that correspond to the biorhythm cycles should be of equal amplitude, because the three biorhythm cycles are defined as being of equal amplitude.

Response by Carl Helmers

This article suggests an approach to verification of any biological cycles hypothesis. It is not a controlled scientific experiment, and any conclusions are thus applicable only to this particular individual's characteristics.

By applying techniques of signal analysis to a broader population of individuals, it might be possible to design a scientifically valid experiment.

References Bendat, J S, and A G Piersol, Random Data: Analysis and Measurement Procedures, Wiley-lnterscience, New York NY, 1971. Stanley, W D, and S J Peterson,"Fast Fourier Transforms on Your Home Computer," December 1978 BYTE, pages 14 thru 25.

326 April 1981 © BYTE Publications Inc

Circle 231 on Inquiry card.

Circle 233 on inquiry card.

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Ask BYTE

Conducted by Steve Ciarcia

4116 Pointers

Dear Steve,

Being an ardent do-it-yourselfer, I'm currently in the process of designing a homebrew computer system. Since the 16 K-bit type-4116 dynamic memories are cheap, compact, and use little power, I have decided to use them as my main memory components. Designing the interface is no problem, but I'm all too aware of the 4116's cantankerous nature with respect to circuit-board layout, power-supply fluctuations, and so forth. What should I know about these devices? Ken McDonald Yellowknife, NWT, Canada

The most important thing to remember when designing any computer that uses 4116s is that the power-supply volt

ages have to be turned on and off in sequence. To keep from blowing the 4116 on powerup, the —5 V supply must be turned on before the +5 V and +12 V supplies. On power-down, the — 5 V has to remain on while the + 5 and +12 are removed.

In lower-current power supplies (such as you will probably use), the sequencing can be accomplished through the time constants of the power supply itself; this technique is used in the TRS-80. By giving the -5 V section a very fast time constant compared to the other two supplies, it appears to come on first. On powerdown, the sequence is reversed. Because the —5 V has such a low-current draw on it, it will stay up long after the other voltages have dropped.

Other than that, use prime components and stay away from surplus devices. For more information on refresh timing signals of dynamic memories, refer to my article in the March 1981 BYTE "Build the Disk-80: Memory Expansion and Floppy-Disk Control," on page 36... .Steve

Any Port In a Storm

Dear Steve,

I'm not sure if I understood the little that I read of your article "I/O Expansion for the TRS-80, Part 2: Serial Ports." (See the June 1980 BYTE, page 42.) Can I use the modem on my Radio Shack RS-232C port and my serial (Diablo) printer on your RS232C port or vice versa? If so, are there any tricks to it7 Stan via The Source

You say that you already have an RS-232C interface, so I'll presume it is Radio Shack's TRS232, which is installed inside the TRS-80 Expansion Interface. Normally, only one interface can be accommodated, and it is hardwire-addressed as port hexadecimal E8. Because the COMM-80 has selectable addressing, it can be added to your system and set for one of fifteen other addresses. With a software driver that directs any output to this second serial port, you can plug your Diablo into it and use both ports without conflict.

What you really need is a CHATTERBOX, which is a COMM-80 with an acoustic modem installed in the same enclosure. It is designed so that, when the modem is in use, the characters being transmitted and received are

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328 April 1981 © BYTE Publications Inc

Circle 235 on Inquiry card.

sent out through the RS-232C connector. You can plug your Diablo directly into the CHATTERBOX and have a modem with a printer output. Absolutely no changes in any software are needed. ...Steve

TRS-80 Tape Formats

Dear Steve,

The TRS-80 has more software created for it than any other system. This software is usually transferred on a cassette that is readable only on

Table 1

Tape Formats

BASIC Tape Format

Leader

256 zeros followed by an A5 sync byte

D3 D3 D3

BASIC header

XX

Single-character file name

LOB (low-orde

r byte)

Next line's address

HOB (high-order byte)

Pointer

LOB

Line number

HOB

XX ...

XX

Line contents

00

End-of-line marker

00 00

End-of-file markers

System Tape Format

Leader

256 zeros followed by an A5 sync byte

55

System-format header byte

XX XX XX

XX

XX XX

6-character file name

3C

Data header

XX

Data length, 00 = 256 bytes

LOB

Loading

HOB

Address

XX ... X>

Actual line contents

XX

Checksum of line bytes and load address

78

End-of-file marker

LOB

Entry

HOB

Address

Editor/Assembler

Source

Tape Format

Leader

256 zeros followed by an A5 sync byte

D3

Source header

XX XX XX

XX

XX XX

File name

d1 d2

d3

d4 d5

5-digit line number in ASCII (bit 7 is set)

20

Data header

XX ... XX

Line (128 bytes maximum)

0D

End-of-line marker

1A

End-of-file marker

BASIC Statement Storage

Format in Memory

LOB

Address of

HOB

next line

LOB

Line number in

HOB

binary form

XX ...

XX

Line contents

00

End-of-line marker

00 00

End-of-file marker

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MASTERCHARGE

Circle 236 on Inquiry card.

April 1981 © BYTE Publications Inc 329

Ask BYTE

a TRS-80. For people with other computers, this vast amount of software is unusable. Please tell me the data-storage format used by Tandy for its TRS-80. Paul Shields Victor Harbor, S A, Australia

Table 1 on page 329 shows the various TRS-80 Model I cassette-recording formats....Steve

Problem With Light Controls

Dear Steve,

It seems that a lot of BYTE readers are interested in home control via the BSR System X-10. I've fooled around with computerized home-control devices for some time, and I think BYTE readers should be aware of one rather distressing trait of the light-control modules.

When an incandescent bulb burns out, the filament in the bulb falls across its supports creating a momentary

short circuit across the A C line. I have had three BSR units damaged when a bulb has gone out. Once it involved a single table lamp with a 70-watt bulb. Another time the failure occurred in a wall-switch module controlling my outdoor-perimeter circuit of 400 watts.

This seemingly practical and low-cost method of home control becomes something of a folly when you find that you must replace a $16 control module because a $0.69 bulb has burnt out. I have not been able to return modules for replacements, because the salespeople accuse me of overloading the module.

In the future, I hope that the design of these modules will include protection against the surge that occurs when a light bulb fails. Until then, 1 don't think they are all that practical and probably should not be committed to serious uses (for which they are advertised), such as a

burglar deterrent. Chris Gundlach Huntington VW

/, too, have noticed that situation, and I've mentioned it to BSR. They are aware of the problem, but there isn't much that can be done to totally eliminate "zapping" the module except installing a 50 A Mac (the cost would be prohibitive). There aren't too many ways to achieve foldback current-limiting in a triac.

Don't feel too bad. I've lost seven modules and a controller because of various problems, such as transients and blown bulbs. While the BSR unit is still cost-effective in consumer applications, I would be wary of it in critical control situations.

A few companies have asked me about using the BSR for industrial remotecontrol and solar-hearing systems, and I told them essentially what you have said to me. The application, of

course, determines the ultimate interface selection. When the alternative is a thousand-dollar computer front end, the BSR may still be the best choice—even if a receiver has to be replaced once in a while....Steve

The following is a letter sent to me concerning Mr Gundlach's problem, from BSR....Steve

BSR Responds to Criticism

Dear Mr Gundlach,

You are correct in your identification of the problem. All commercially available dimmers that contain triacs, as our lamp- and wall-switch modules do, are subject to zapping if a blown light-bulb filament falls in a "short circuit" position instead of open circuit.

Since the introduction of the System X-10 in the fall of 1978, all products have been updated and improved as necessary. We now use triacs

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330 April 1981 © BYTE Publications Inc

Circle 237 on Inquiry card.

that we feel are most resistant to zapping. Our overall return rate is quite low, and has steadily decreased with respect to blown triacs. This is substantiated in part by the fact that the major retail chains continue to buy our products in large quantities and would not do so if there were persistent problems.

We are shipping you replacements for your failed units at no charge. I would greatly appreciate any feedback on performance that you care to give...good or bad I

Sorry you had some difficulties. Peter A Lesser Vice President General Manager X-10 Division BSR Inc

The Two Can't Connect

Dear Steve,

I have an early (second year of production) Radio

Shack TRS-80 Model I 16 K-byte Level II computer that I'm having trouble adding peripherals to. I have a Quick Printer II, an Exatron Stringy Floppy, and a typewriter interface, each of which can be plugged into the expansion connector of the TRS-80 keyboard unit.

I also have a l-into-2 cable that should allow me to use two peripherals at once. However, if more than one peripheral is plugged into the cable, the computer randomly executes the initial powerup routine — destroying whatever I was working on.

It doesn't seem to matter which peripherals I try to combine, nor does it matter if one is off. I don't think the problem is in the cable, because it works well with each of the peripherals singly and in either connection.

What could this be? I'd like to use the system for text processing, but that's impossible right now. Ron Tye Long Beach CA

The TRS-80 Model I sometimes does strange things when cables are connected to the keyboard. The longer the cables, the more likely the problem you described. With one peripheral installed, it may work properly, but when the load of another is added, the bus signals become sensitive to noise. Keeping the cables as short as possible helps.

The solution is to either add a circuit that buffers all

the signals from the keyboard or, at the very least, actively terminate the extension cable. If you do not mind a little soldering, you can try terminating your present cable. At the end of the cable, from each signal, attach a 1 k-ohm resistor to +5 V and a 470ohm resistor to ground. You'll have to add a separate 5 Vsupply, since +5 Vis not available on the keyboard connector.... StcveB

In "Ask BYTE," Steve Garcia answers questions on any area of microcomputing. The most representative questions received each month will be answered and published. Do you have a nagging problem? Send your inquiry to:

Ask BYTE

c/o Steve Garcia

POB 582

Glastonbury CT 06033 If you are a subscriber to The Source, send your questions by electronic mail or chat with Steve (TCE3I7) directly. Due to the high volume of inquiries, personal replies cannot be given. Be sure to include "Ask BYTE" in the address.

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Circle 238 on inquiry card.

April 1981 © BYTE Publications Inc 331

Event Queue

April 1981

April-June

Microprocessor Software, Hardware, and Interfacing,

various cities throughout the United States. This hands-on course provides a foundation in the skills required for the design, programming, and real-world interfacing of microprocessor applications. For further details and a schedule of meeting places and times, contact Integrated Computer Systems Inc, 3304 Pico Blvd, POB 5339, Santa Monica CA 90405, (213) 450-2060.

April-October

Computer Sales-Marketing Workshops, various cities throughout the United States. These workshops are designed for retail salespeople and computer-marketing managers and their staffs. For a schedule of times and loca

tions, contact Datasearch Inc, 4954 William Arnold Rd, Department C, Memphis TN 38117, (901) 761-9090.

April 1-2

Communications in the Twenty-First Century, Philip Morris Operations Center, Richmond VA. This conference will focus on technological advances and their economic, political, social, and psychological implications. Elie Abel, Professor of Communications at Stanford University, and Lord Briggs, provost of Worcester College, Oxford, England, are the keynote speakers. For information, contact the manager of Media Relations, Philip Morris Inc, 100 Park Ave, New York NY 10017.

April 1-3

Assuring Quality in Electronic Data-Processing Applications, McCormick Inn Hotel, Chicago IL. The objec

What is a

CLOCALPEEP?

Another name for the CCB-II, which is:

• a clock

hour, minute, second

• a calendar

day, day of week, month, year

• an audio alarm

All on one board foryour

TRS-80 Model II

It includes a pacemaker battery which will give over 8 years of continuous timekeeping.

From the folks who brought you the best CP/lvT forthe Model II.

$175 plus shipping Prepaid, COD, Mastercharge or Visa orders accepted. California residents add 6% sales tax.

TRS-80 is a trademark of Tandy Corp. CP/M is a registered trademark of Digital Research Inc.

Kg

«5>SF

PICKLES & TROUT

P.O. BOX 1206, GOLETA. CA 93116. (805) 967-9563

Warning: Installation requires opening the Model II. which may void its warranty. We suggest that you wait until the warranty period has expired before installing the CCB-II.

tive of this conference is to explain the methods, tools, and techniques that are valuable in improving the quality of computerized applications. Tutorials cover the areas of quality assurance; managing structured design; and designing, implementing, and enforcing application standards. Contact DPMA Quality Assurance Conference, 12611 Davan Dr, Silver Spring MD 20904, (301) 622-0066.

April 3-5

The Sixth West Coast Computer Faire, Civic Auditorium, San Francisco CA. The Faire, a major personal-computing event, has continually attracted larger and larger numbers of exhibitors and attendees. A full program of talks plus a large display of hardware and software are featured. For more information, contact Computer Faire, 333 Swett Rd, Woodside CA 94062, (415) 851-7075.

April 4

The Third Annual RAMS

Spring Computer Show,

Perinton Square Mall, Fairport NY. This event is sponsored by the Rochester Area Microcomputer Society. For more information, contact RAMS, POB D, Rochester NY 14609.

April 7-8

Top Secrets '81, Pointe Resort, Phoenix AZ. Honeywell's annual computer security and privacy conference. Many data-security authorities will discuss the business and legal impact of the latest incidents in computer crime and abuse. The conference fee is $500. Contact the Security Symposium Registrar, Honeywell Information Systems, M/S T-99-4, POB 6000, Phoenix AZ 85005, (800) 528-5343; in Arizona (602) 249-7954.

April 7-9

Computerized Office Equipment Expo—Midwest '81, O'Hare Exposition Center, Rosemont IL. This exposition

has exhibits and seminars on the use of computers and related equipment in business environments. For details, contact Industrial & Scientific Conference Management Inc, 222 W Adams St, Chicago II 60606, (312) 263-4866.

April 7-9

Electro/81, New York Coliseum and Sheraton Centre Hotel, New York NY. Electro/81 will feature computers and computer-related equipment, plus seminars on components, devices, and materials; computer communications; memories; office automation; speech; and more. Contact Electronic Conventions Inc, 999 N Sepulveda Blvd, Suite 410, El Segundo CA 90245, (800) 421-6816; in California (213) 772-2965.

April 9-12

Southwest Computer Show and Office Equipment Exposition, Market Hall, Dallas Market Center, Dallas TX. Hardware and software for business, education, government, home and personal use will be featured. Mini- and microcomputers, office machines, supplies and services, graphics equipment, and word processing will also be exhibited. Contact National Computer Shows, 824 Boylston St, Chestnut Hill MA 02167, (617) 739-2000.

April 10-11

The Eleventh Annual VCUC Conference, Sheraton Red Lion Inn, Blacksburg VA. The VCUC (Virginia Computer Users Conference), a division of the ACM (Association for Computing Machinery), and the Computer Science Department of the Virginia Polytechnic Institute and State University are holding this conference. The themes are "Personal Computing" and "System Performance." Write to ] Rosow or S Haldeman, VCUC 11, 562 McBryde Hall, VPI and SU, Blacksburg VA 24061.

332 April 1981 © BYTE Publications Inc

Circle 239 on Inquiry card.

Circle 240 on inquiry card.

Circle 241 on inquiry card.

DIGITAL DATA RECORDER MODEL CC-9B

For five years now, the CC series recorders have been the industry NRZ Asynchronous recorder standard. Now the D series sets a new standard in stability and reliability with its tachometer feedback LC stabilized motor circuit.

• 4800 or 9600 Baud

(3" or 6" per second)

• lCf8 Error Rate

RS232 or TTL In and Out

• RTS motor start

• CTS Data start

• DB 25 or special

connector optional

• 110/220- 50/60 Hz

• Wow & Flutter ± .3%

• Speed Stability (long

term) + .l%

DC1 Model Price $275.00 DC2 Model Price $285.00

NATIONAL MULTIPLEX CORPORATION

260 Lackland Drive East

Middlesex, New Jersey 08846

Tel. (201) 356-9200 TWX 710-997-9530

EVADA

ForCP/M

Powerful subset of ANSI-74

Why wait?

All the elegant simplicity

of COBOL la now affordable!

$

DISK

99

95

5^ J

REQUIRES only 16K RAM. Available on 8" CP/M standard single density or SW diskettes for North Star, TRS-80 Mod I and Superbraln. Other formats tool Manual alone $24.95. >

<*e> Ellis Computing

^^ 600-41 >t Avenue

San Francisco, CA 94121 U.SJL.

These powerful, easy to use COBOL APPLICATION PACKAGES

are also available:

1. BUDGET PLAN REPORT GENERATOR

Fantastic time saver and planning aid for beginning or established businesses.

2. PERSONAL FINANCIAL REPORTING

Eye-opening Insights of personal spending.

3. LABELS for mailing lists.

4. PRECOBOL (a preprocessor).

ALL 4 In one BOOK!

73 pages with complete COBOL source code listings and super documentation.

$24

95

WE WELCOME CO.D.'s

/^ffl-^^

(415) 751-1522

la CA add »•!•» t*». CP/M trada mark of Wflltal Hataarch. TR8-80 trade mack ot Tandy Corp.

REFURBISHED TERMINAL SALE!

A limited offer from Data Access Systems, Inc., in addition to their full line of new products.

MFR/MODEL

SALE PRICE

DESCRIPTION

Lear Siegler ADM-3

$525

Video terminal.

Texas Instruments 725

$300

Portable thermal printer with built-in coupler

735

$650

Portable thermal printer with built-in coupler.

745

(limited ASCII keyboard)

$1175

Portable thermal printer with built in coupler.

745

(lull ASCII keyboard)

$1225

Portable thermal printer with built-in coupler.

735 KSR

$600

Desktop thermal printer.

Digital Equipment LS-120

$1450

132 column 180 CPS printer.

LA-36

$750

132 column 30 CPS printer with E.I.A.

ADDS Regent 20 (new)

$595

Video terminal.

Regent 25 (new)

$775

Video terminal.

All units are DASI factory refurbished and in good working condition. Includes 30-day parts and labor warranty, on site. Call your local DASI office, or toll free: (800) 257-7748. In N.J. (800)232-6510.

Corporate Offices: Cole Rd. & Camden Ave.. P.O. Box 1230. Blackwood. NJ 08012. (609)2280700. Toll Free (800) 257-7748. In New Jersey. (800) 232-6510.

District Ottlcti: Atlanta (404) 449-5435. Austm-(512) 474-9643. Boston-1617) 769-6420. Chicago-OH) 9670440. Cincmnati(513) 793-9714. Cleveland-(216) 473-2131. Dallas(214)256-5536. Denver(303) 741-2922. Detroit(313)S89-1409. Hartlord(203)674-1697. Houston-(713) 682-5965. Los Angeles-(213) 618-0400. Milwaukee-(414) 963-9006. Mmneapolis-(S12) 854-4466. New Jersey-(201) 227-8880. New York City (212) 564-9301. Orange County-(714)979-21S7. Philadelphia(215) 667-8315. Phoemx-(602) 263-5034. Portland(S03) 644-8600. Rochester(716) 377 2090. St. Louis(3U) 576-2804. San Antomo-1512) 655-3274. San Francisco(415) 872-1811. San Jose-(408) 244-3772. Seattle-(20€) 251-5070. Washington. DC (301) 459-3377.

*

D/fl

*S;

DATA ACCESS SYSTEMS INC

Computer I j Programmirtf t BASIC / «

i'.\.- -:-■.■■" y*:'.---m t9*liE5}*

t V-iiZ**

Computer \

Programming in1

BA

tsum

war *

Computer

Programming

BASIC

Microcomputers are coming — ride the wave! Learn to program with a new course written for the beginner. Learn BASIC the language of the small computer and the most easy-to-learn computer language in widespread use. A self-instruction course that takes you from complete ignorance to real proficiency with a unique style of graded hints. 60 illustrated lessons teach the five essentials of good programming: problem definition; flowcharting; coding the program; debugging; clear documentation. And you don't even need a computer! Price: $22.95

Send check with order to:

Cambridge Learning Inc.,

1 Judith Drive

North Reading, MA 01864

or call (617) 664-3657 with

Mastercard or VISA

Mass. residents add 5% Sales Tax

Also available:

Digital Computer Logic and

Electronics

This course is designed as an introduction to digital electronics and is written at a pace that suits the raw beginner. No mathematical knowledge is assumed other than the use of simple arithmetic and decimals, and no electronic knowledge is expected at all. The course moves painstakingly through all the basic concepts of digital electronics in a simple and concise fashion: questions and answers on every page make sure that all the points are understood. Price: $14.95

Design of Digital Systems

Written in a similar question and answer style to Digital Computer Logic and Electronics, this course moves at a much faster pace and goes into the subject in greater depth. Ideally suited for scientists or engineers wanting to know more about digital electronics, its six A size volumes lead step by step through number systems and Boolean algebra to memories, counters and arithmetic circuits and finally to an understanding of calculator and computer design. Price: $19.95

$5.00 discount for orders over

$30.00.

All prices include surface shipping

For Airmail add $10.00

CAMBRIDGE LEARNING INC.

Circle 243 on inquiry card.

BYTE April 1981 333

Event Queue.

April 13-14

The Executive Computer Conference, Washington DC. The theme of this 2-day meeting is "Improving Organizational Productivity through Systems Technology." Special emphasis will be placed on management's perspective of the contributions the computer has made to organizational productivity. For information, contact Kendall E Burroughs, The Executive Computer Conference, 1730 N Lynn St, Suite 400, Arlington VA 22209, (703) 521-6209.

April 13-16

The Fifteenth International Symposium on Minicomputers and Microcomputers, MIMI '81, Sheraton Hotel, Mexico City, Mexico. The scope of this symposium covers hardware, software, distributed processor architecture, computer networks, telecommunications, real-time applications, education, and more. Contact Ing. Jorge Gil, Academic Secre

tary, MIMI Symposium, IIMAS-UNAM, Apartado Postal 20-726, Mexico 20 D F, Mexico.

April 14-16

The Seventh Annual Federal DP Expo, Sheraton Washington Hotel, Washington DC. This conference and exposition is for computer-system users in the US government. More than 150 exhibitors and over 100 speakers will highlight the event. Contact The Interface Group, 160 Speen St, Framingham MA 01701, (800) 225-4620; in Massachusetts, call (617) 879-4502.

April 25-26

Trenton Computer Festival,

Trenton State College, Trenton NJ. This annual flea market and swap meet of personal-computer equipment also features speakers, user-group meetings, and an exhibit of commercial products. It is sponsored by the Amateur Computer Group of New Jersey, the Philadelphia Area Computer Society, and

Selectric® Interface System

EiASILY interfaced to any IBM Selectric I, II, or III.

OTOP spinning your wheels. Letter quality at an affordable price.

CONNECTS via Parallel or RS-232, accommodates varied handshaking.

o

N

NLY S575 to $599. Dealer inquiries invited.

EW design provides added features.

ESCON Products, Inc.

12919 Alcosta Blvd.

San Ramon, Ca., 94583

(415) 820-1256

the Trenton State Computer Society. Contact TCF-81, Trenton State College, Trenton NJ 08625, (609) 771-2487.

April 26-30

Saudibusiness '81, Riyadh, Saudi Arabia. This show has been designed for the fastgrowing Saudi Arabian business community. Pavilions by the United States, the United Kingdom, West Germany, France, Italy, and approximately fifteen other countries will be featured. For more information, contact Donald Ryan, Project Manager, Rm 3200, US Department of Commerce, Washington DC 20230, (202) 377-4652.

April 27-30

National Design Engineering Show and Conference, Mc

Cormick Place, Chicago IL. The theme of this show is "Computers Throughout the Design Function." Additionally, the principal areas of consideration are design management, computeraided design, materials, mechanical components and systems, and electronics. Contact Clapp & Poliak Inc, 245 Park Ave, New York NY 10167, (212) 661-8410.

April 30-May 1

An Assessment and Forecast of Computer Graphics, Saddle Brook Marriott, Saddle Brook NJ. This annual conference will assess the present state of computer graphics and will evaluate hardware, software, systems services, and applications. The impact of new technologies on computer graphics and the role of graphics in business will be discussed. Contact Bob Sanzo, Frost & Sullivan Inc, 106 Fulton St, New York NY 10038, (212) 233-1080.

May 1981

May 2

National Computer ProblemSolving Contest for Junior and Senior High School Students, throughout the US. Small teams of junior and senior high school students

will compete for two hours on computer systems to solve five programming problems. Winners will be judged on whether their programs run properly using the test data supplied in the problem, are easy to read, and are logical, imaginative, and creative.

To receive a copy of the 1981 contest problems, local school directors should contact the University of Wisconsin—Parkside by April 4. Directors must agree to keep the problems confidential until the day of the contest. After that, any organization can use the problems to conduct its own contest. Local contest winners can enter the national and international contest. A national and worldwide ranking will be determined by a team of judges from the University of Wisconsin—Parkside. All interested schools or organizations can share the 1981 contest problems.

For additional information, write Dr Donald T Piele, Associate Professor of Mathematics, University of Wisconsin—Parkside, Kenosha WI 53141.

May 4-7

National Computer Conference, McCormick PI, Chicago IL. Approximately 90,000 people are expected to attend this year's National Computer Conference (NCC). The use of robots and artificial intelligence will be among the program sessions at the Personal Computing Festival during the NCC. This will be the first time that personal-computing exhibits have joined the rest of the conference in the main exhibit area. Over thirty technical sessions will be held. All major companies will be represented. Contact the American Federation of Information Processing Societies Inc, POB 9658, 1815 N Lynn St, Arlington VA 22209, (703) 558-3617.

May 5-8

INTELCOM 81/Paris, Paris, France. INTELCOM (International Telecommunications and Computer Conference and Exhibition) 81/Paris is

334 April 1981 © BYTE Publications Inc

Circle 244 on Inquiry card.

part of a program to promote an international dialogue on vital subjects in the telecommunications field. This conference attempts to guide the evolution of the computer and its technology by combining the efforts of private companies, government, and equipment users. For information about attending, presenting a paper, or exhibiting at INTELCOM 81/Paris, contact the Conference Affairs Group, Horizon House, 610 Washington St, Dedham MA 02026, (800) 225-9977; in Massachusetts (617) 3268220.

May 33-23

Fourth Annual Rosen Research Personal-Computer Forum, Playboy Resort, Lake Geneva WI. This forum features guest speakers from all the major personal-computer hardware and software companies. The Rosen Forum is one of the most prestigious and important seminars in the industry. For further details on this 3-day session, contact Rosen Research Inc, 200 Park Ave, New York NY 10166, (212) 586-3530.

May 23-13

Custom Integrated Circuits Conference, CICC'81, Americana Hotel, Rochester NY. The CICC aims to bring together designers, producers, and users of custom integrated circuits to discuss recent developments and future directions in the field. Papers will be read on applications, algorithm-implementing integrated circuits, fabrication techniques, interfaces and interconnects, computer-aided design, and testing and qualification. Contact Dr Rajinder Khosla, General Chairman, Research Laboratories, B-81, Eastman Kodak Company, Rochester NY 14650, (716) 722-2525.

May 11-13

The Thirty-First Electronic

Components Conference,

Colony Square Hotel, Atlanta GA. Papers will be read on semiconductor-processing technology, optoelectronic devices, manufacturing technology, materials, hybrid

microcircuits, discrete components, interconnections, reliability, and connectors. Contact T G Grau, Bell Laboratories, Whippany Rd, Rm 3B-312, Whippany NJ 07981; or Electronics Industries Association, 2001 Eye St NW, Washington DC 20006.

May 34-26

The Tenth ASIS Mid-Year Meeting, Fort Lewis College, Durango CO. The American Society for Information Science's (ASIS's) theme for this year's meeting is "Using Information." Among the topics to be addressed are user studies, decision making, organizational change, government, education, management, access to information, and designing information systems for use. For information, contact ASIS, 1010 16th St NW, Washington DC 20036, (202) 659-3644.

May 27-20

Expo '81, Loew's Anatole Hotel, Dallas TX. Expo '81 is a combination of exhibits and technical sessions. The exhibits cover everything from graphics systems to industrial computer-control systems. The technical sessions range from tool design, design engineering, and robotics to numerical control. For more information, contact Numerical Control Society, 519 Zenith Dr, Glenview IL 60025, (312) 297-5010.

May 20-22

Joint Conference on Easier and More Productive Use of Computing Systems, University of Michigan, Ann Arbor MI. This conference intends to combine the insights of the social sciences, humanities, computer science, and human-factors engineering. Contact Gregory A Marks, 4258 Institute for Social Research, University of Michigan, Ann Arbor MI 48106, (313) 763-3482.

May 20-22

Videotex '81, Royal York Hotel, Toronto, Ontario, Canada. Videotext information systems allow users to call up information, make

VERSION 3.0

It keeps getting better and better!

Starting over a year ago with the original set of programs from Osborne & Associates, we have gradually developed a selfinstalling, reliable business package. A partial list of our enhancements:

No-Hassle Installation.

You simply select your desired configuration from a series of menus and go. There is no recompiling necessary, except for some state payroll tax routines.

CRT Independence.

We support 16 terminal types directly, and provide a method for specifying more. We can make it run with your CRT - or your money back.

File Access.

Our GL account file lookups are much faster than the original. And now — with version 3.0 — we have doubled the number of accounts, customers, and vendors that can reside on a disk.

There are many other improvements — send for details.

We believe our product to be the best Osborne-based business package available for CP/Mbased microcomputers. We are committed to the ongoing support of our users, through both a tech-support phone line and a generous upgrade policy.

Vandata has been supplying applications software for over eight years. Quality and support are our way of doing business.

Our 30-day money-back guarantee speaks for itself.

General Ledger with Cosh Journal $295

Accounts Receivable $295

Accounts Poyable $295

Payroll with Cost Accounting $295

All Fout Pockag.j (GL, AR, AP, PR) $995

Magic Wand (Super Word Processor!!) $345

Peorl Level III (best prog tool available) $645

CBASIC2 $110

TRS-80' MOD II CP/M- 2 2 (P 8, T) $185

H89/Z89CP/M- 2 2(Mognolia) $199

Formats Std. 8". 5" NorthStar DD, TRS-80 MOD ll» H89/Z89 Manuals (or GL, AR/AP, and PR are not included in price - odd $20 per manual desired (AR/AP are in one manual). CP/M and CBASIC-2 reguired to run accounting sofrwore Users must sign licensing agreement. Dealer inquiries invited.

To order call: (206)542-8370 or write VANDATA

17541 Stone Ave. N.

Seattle, WA 98133

CP/M" ts a registered trademark of Digital Research TRS-80" is a registered trodemark or Rodio Shack, Inc

■

"in.

Circle 245 on inquiry card.

April 1981 © BYTE Publications Inc 335

Event Queue.

reservations, pay bills, exchange electronic mail, read an electronic newspaper, shop, and play video games. This conference will review videotext developments in Europe, Japan, and North and South America. Demonstrations of videotext systems will be given. Seminars on standards, legal aspects, and economic issues will be featured. Contact Videotex '81, 316 Lonsdale Rd, Suite 3, Toronto, Ontario, M4V 1X4, Canada, (416) 598-1981.

May 21-23

Annual Conference of the Educational Computing Organization of Ontario,

Sheraton Centre and the Ontario Institute for Studies in Education, Toronto, Ontario, Canada. Exhibitions on the use of computers in schools and discussions on how to locate suitable educational materials will be featured. Contact the Conference Office, OISE, 252 Bloor St W, Toronto, Ontario, M5S 1V6, Canada.

June 1981

June 6-9

Atlanta Small Computer Show, Atlanta Hilton, Atlanta GA. Producers of small computers, peripherals, sup

plies, and services will be exhibiting at this show. Business owners, corporate and government executives, dataprocessing managers, doctors, lawyers, and other professionals are expected to attend. Obtain additional information from The Atlanta Small Computer Show, 4060 Janice Dr, Suite C-l, East Point GA 30344, (404) 7679798.

June 9-11

Understanding and Using Computer Graphics, Chicago IL. This seminar covers the latest in graphic-system technology, including hardware, software, and applications. Contact Bob Sanzo, Frost & Sullivan Inc, 106 Fulton St, New York NY 10038, (212) 233-1080.

June 14-18

The Second National Conference of the National Computer Graphics Association,

Baltimore Convention Center, Baltimore MD. Computer-graphics demonstrations, exhibits, and workshops will be held. Contact the National Computer Graphics Association Inc, 2033 M Street NW, Suite 330, Washington DC 20036, (202) 466-5895.

June 16-18

NEPCON East '81, New York Coliseum, New York NY.

This exposition is aimed at engineers, prototype developers, production specialists and testing personnel. Technical programs will be presented. Contact Industrial & Scientific Conference Management Inc, 222 W Adams St, Chicago IL 60606, (312) 263-4866.

June 17-19

National Educational Computing Conference, North Texas State University, Denton TX. This conference will provide a forum for individuals and institutions interested in educational computing. Computer literacy, computer education for teachers, and computers in education are some of the topics to be covered. Contact Dr Jim Poirot, NECC-81 General Chairman, Computer Sciences Department, North Texas State University, Denton TX 76203.

June 20-22

The Fifth Annual Computerfest, Franklin University, Columbus OH. Talks on robots and calculators will be featured. Microcomputers and small-business systems will be presented. This show is being sponsored by the Midwest Affiliation of Computer Clubs and Franklin University. Contact Computerfest '81, Paul Pittenger, 215

Delhi Ave, Apt J, Columbus OH 43202, (614) 224-6237.

June 29-July 1

The Nineteenth Annual Meeting of the Association for Computational Linguistics, Stanford University, Stanford CA. Syntax, parsing, and sentence generation, computational semantics, discourse analysis and speech acts, speech analysis and synthesis, machine and machineaided translation, and mathematical foundations of computational linguistics are some of the topics to be discussed. Contact Don Walker, Artificial Intelligence Center, SRI International, Menlo Park CA 94025, (415) 326-6200, ext 3071. ■

BYTE's Bits

Atari Slashes Prices

Atari Inc has reduced the price of the Atari 400 computer with 8 K bytes of memory to $530. The 16 K expanded version of the 400 is now selling for $630. Atari also reduced the Model 810 5V4-inch floppy-disk drive to $599.95.

On another front, Atari plans to begin selling a $150 word-processing program later this year.B

REAL TIME CLOCKS

SciTronics

introduces ... with full Clock/Calendar Functions

The Worry-free Clocks for People Who Don't Have Time to Worry!!

What makes them worry-free?

• Crystal controlled for high (.002%) accuracy

• Lithium battery backup for continuous clock operation (6000 hrs!!!)

• Complete software in BASICincluding programs to Set and Read clock

• Clock generates interrupts (seconds, minutes, hour) for foreground/background operation

Applications:

• Logging Computer on time

• Timing of events

• Use it with the SciTronics Remote Controller for Real Time control of A.C. operated lights and appliances

Versions available for:

• S-100 bus computers

• Apple II computer

• SciTronics RC-80

RTC-100 $159

RTC-A $129

RC-80CK $109

send SciTronics Inc.

Check or 523 s ciewell St., P.O. Box 5344 orderyio Bethlehem, PA 18015 (215) 868-7220

Please list system with which you plan to use controller • Master Charge and Visa accepted. COD's accepted. PA residence add sales tax.

336 April 1981 © BYTE Publications Inc

Circle 246 on inquiry card.

Circle 247 on inquiry card.

Circle 248 on inquiry card.

■

fciiHieierstiii

Boards forS-100 BUS from S.C. Digital

"CPUI-Z80"

Advanced Z8DA based CPU board S219 Assembled and Tested S149 Kit *(less Interrupt)

Features: Model CPUI-Z80

• 2/4 Mhz SW selectable. • Built in 8 Prioritized Vectored Interrupts with 8 possible levels

ot Nested Interrupts using powerful Mode 2 of Z80, all done in Hardware, expandable with

external ckt. • Vector Jump on RESET, in 4K increments. • Supports 2K of EPROM (not

supplied), DMA. dynarmic RAM refresh . . . many more.

'Kit comes with all parts except chips connected to Interrupts.

"INTERFACE: 1"

I/O, Memory Interface Board

S229 Assembled and Tested SI69 Kit

Features: Model 3SPC

• 3 Serial w RS232C or 20ma Current Loop, 1 Parallel. • 4K of EPROM/ROM and 4K of RAM (ROM/RAM not supplied). • Built in Kansas City Standard Cassette interface usable to 1200 Baud. • Generates all popular baud rates up to 19.2Kbaud, including 110 Er 134.5. *> SW settable Address, Baud Rates, Ports.

"UNISELECT" 16K Static RAM with universal Bank Select Model 16KUS S235 A ft T. with 200 nsec memory chips.

All boards meet IEEE-S100 standards. Fully socketed, solder masks, gold contacts, and

guaranteed for one full year. Kit guaranteed parts, only.

Delivery: from stock to 72 hours. Ordering: You may call for M.C., VisaorC.O.D. orders.

(Add S4.00 for COD.) Personal checks ok., butM.0. speeds shipment. Takes? to 15 days to

clear personal checks before shipping.

Undamaged boards can be returned within 10 days for full refunds. Illinois residents add 5Vi%

cajpc tav

OEM. PRICING AVAILABLE, DEALER INQUIRY INVITED

Sf\ r>" "4. I P.O. Box 906 Phone:

.L». Uigital Aurora, IL 60507 (312)897-7749

MAIL ORDER DISCOUNTS

tipple computer

Sales and Service

APPLE II PLUS 48K

$1,175

APPLE III CALL FOR PRICES

ACCESSORIES

DISK II DRIVE & CONTROLLER (DOS 3,3)

....525

MICROSOFTZ-80SOFTCARDSYSTEM ..

.290

DISK II DRIVE ONLY

455

MICROSOFT 16K RAM CARD

169

INTEGER BASIC FIRMWARE CARD

.149

VIDEX 80 COLUMN BOARD & SWITCH

.330

APPLESOFT II FIRMWARE CARD

...149

HAYES MICROMODEM II

.315

M&RSUP-R-MODRF MODULATOR

... 30

LEEDEX 12" B&W MONITOR

.149

CENTRONICS PRINTER INTERFACE CARD .179

SANYO 12" GREEN MONITOR

265

HIGHSPEED SERIAL INTERFACE CARD

145

SILENTYPE PRINTER W/INT CARD

535

SSM AIO SERIAUPARALLEL I/O CARD

. .185

EPSON MX-80 PRINTER

620

LANGUAGE SYSTEM WfPASCAL

....420

MPI88G PRINTER

695

DAN PAYMAR LOWER CASE ADAPTER .

.... 45

QUME SPRINT 5(45 PRINTER

2,550

SOFTWARE

APPLE DOS TOOLKIT

.... 65

APPLE FORTRAN

.159

APPLE PLOT

.... 60

APPLEWRITER

. . 65

TAX PLANNER

... 99

DOW JONES PORTFOLIO EVALUATOR

45

APPLE PILOT

. .125

DOW JONES NEWS & QUOTES REPORTER

85

VISICALC

.119

THE CONTROLLER BUSINESS SYSTEM

. 515

DESKTOP PLAN

... 79

SUPER INVADER (DISK)

23

CCA DATA MANAGEMENT

.... 85

BASF 5'/." DISKETTE (10)

.. 30

TO ORDER: Please send cashier's check, money order or personal check (allow 10 business days to clear). VISA and Master Card credit card service add 2%. American Express credit card service add 5%. Shipping, handling and insurance in U.S. add 3% (minimum $3). California residents add 6% sales tax. Foreign orders add 10% for shipping. Equipment is subject to price change and availability. All equipment carries factory warranty. TELEX: 697120 DATAMAX-SDG

computer age. inc.

Authorized Apple Dealer & Service Center 4688 CONVOY ST., SUITE 105, SAN DIEGO, CA 92111 (714) 565-4062

~ " Clock/Calendar

ComputeiWateh

Now available on Three Buses

Features *APPLE II

• 12/24 Hr. Format

• Month-Day-Year

• Day of Week *TRS-80

• Leap Year Bit

• 4 Interrupts

• +-30 Sec. Adjust1

• Battery Backup S1l

• Simple to Program,

S^ 50 FOB ' Apple is a Trademark of

Apple Computer Co. COmpUTJm© " TRS80 is a Trademark of Tandy Corp.

Dealer Inquire (714) 536-5000

P.O. Box 5343 Huntington Beach, CA 92646

Circle 249 on inquiry card.

•8*

Model EP-2A-87

EPROM Programmer

NEW - CRT ENTRY MODE

f°ni*u;" ■-■ The Model EP-2A-87

S Tc?2">&ai «,c i EPROM Programmer has an

RS-232 compatible interface

and includes a 2K or 4K

f.."fe-° t^jB M buffer During the ON-LINE

Mf m mode, another computer

can down-load to the buffer. Only two easy-to-implement commands are available to an external computer. (Load buffer and read buffer.)

In the OFF-LINE mode, the EP-2A-87 will program, verify, test buffer, and load the buffer from the EPROM socket. During the programming cycle, the EPROM is checked before programming to insure that it is erased and after programming it automatically verifies that programming is correct. Power requirements are 115 VAC 50/60 Hertz at 15 watts.

Pari No. Description Price

EP-2A-87-1 Programmer with 2K buffer $575 00

F.P 2A-87 2 Programmer with 4K buffer 650.00

Non standard voltage option (220 v. 240 v. 100 v) 15,00

PM0 Personality Module, programs TMS 2708 18 00

PM 1 Personality module programs 2708 18.00

PM 2 Personality module programs 2732 34.00

PM 3 Personality module, programs TMS 2716 26.00

PM 4 Personality module, programs TMS 2532 34.00

PM5 Personality module, programs 2716. TMS 2516 18.00

PM6 Personality module, programs 2704 18(10

PM 7 Personality module, programs 2758. TMS 2508 18 00

PM 8 Personality module, programs Motorola MCM68764 36.00

Optimal Technology, Inc.

r Blue Wood 127 **"*

Earlysville, Virginia 22936 Phone (804) 973-5482

Circle 250 on inquiry card.

BYTE April 1981 337

Circle 251 on inquiry card.

Introducing

The

Benchmark

WORD

PROCESSING

SYSTEM

THE BENCHMARK software system sets new standards in word processing. First, it canbedeliveredtorunontheCP/M<BortheNorthStarDOS.sotheremaybenoneed to buy a special operating system. Second, it has all the features of systems costing thousands of dollars more. Third, the price is as low as, or lower than, most word processing systems.

Anyone can learn to run and use THE BENCHMARK in one day of self training. Completely self-prompting in English. THE BENCHMARK is a full capability word processor, has been thoroughly tested in an off ice environment and proved to meet the needs of the most sophisticated user.

• Multi-operating system

• Changes terminal drivers

• Customized to utilize all the features of terminal S. printer

ONLY

$499

• Overtype - erases, corrects

• Variable, electronic decimal tab

• Screen menus simplify operation

• Block move and get

plus tax where applicable

THE BENCHMARK is distributed by RSB Computer Systems. Dealer inquiries are invited.

kp Computer

1954 E. University 1-800-528-7385

Systems

Tempe, Arizona 85281 AZ-602-968-7101

THE BENCHMARK is a trademark of Metasoft Corporation CP/Misa registered trademark ot Digital Research

• €p'^aocitetm' ore than

a°d. «l 10,000 s^ ^ jobUst* ana

mcnoNAe

ENGUS4

Books Received

/Iduanced Micro Devices Condensed Catalog. Sunnyvale CA: Advanced Micro Devices Inc, 1981; 18 by 24.5 cm, 147 pages, softcover, no ISBN, free of charge.

COBOL, A Vehicle for Information Systems, Robert T Grauer. Englewood Cliffs NJ: Prentice-Hall Inc, 1981; 19 by 24.5 cm, 432 pages, hardcover, ISBN 0-13-139709-5, $18.95.

The Creative Kid's Guide to Home Computers, Fred D'Ignazio. Garden City NY: Doubleday & Company Inc, 1981; 16 by 24 cm, 130 pages, hardcover, ISBN 0-38515313-9, $9.95.

Digital Electronics Troubleshooting, Joseph J Carr. Blue Ridge Summit PA; Tab Books Inc, 1981; 13 by 21 cm, 350 pages, softcover, ISBN 0-8306-1250-5, $9.95; hardcover, ISBN 0-83069677-6, $16.95.

The Effective EDP Manager, Michael R Frank. New York: AMACOM, 1980; 16 by 23.5 cm, 197 pages, hardcover, ISBN 0-8144-5635-9, $17.95.

Experiments in Amplifiers, Filters, Oscillators, and Generators, Morris Tischler. New York: McGraw-Hill Book Company, Gregg Division, 1981; 22 by 28 cm, 170 pages, softcover, ISBN 0-07-064780-1, $6.95.

Experiments in General and Biomedical Instrumentation, Morris Tischler. New York: McGraw-Hill Book Company, Gregg Division, 1981; 22 by 28 cm, 201 pages, softcover, ISBN 0-07064781-X, $8.95.

Experiments in Telecommunications, Morris Tischler. New York: McGrawHill Book Company, Gregg Division, 1981; 22 by 28 cm, 186 pages, softcover, ISBN 0-07-064782-8, $7.95.

The FORTRAN Cookbook, Thomas P Dence. Blue Ridge Summit PA: Tab Books Inc, 1980; 13 by 21 cm, 334 pages, softcover, ISBN

338 April 1981 © BYTE Publicarions Inc

Circle 252 on Inquiry card.

MICROSTAT NOW AVAILABLE FOR CBASIC2*

MICROSTAT is the statistics package for microcomputers, and is proving itself to users around the world, including:

Stanford, Harvard, Johnson & Johnson, Duke, University of Washington, UCLA, Lockheed, University of Pennsylvania, Oklahoma State, U.S. Geological Survey, Monsanto, University of Toronto, Sweden's National Central Bureau of Statistics, Utah State, Butler University, SUNY, Van Camps, Texas ASM, University of Wisconsin

and a growing list of other organizations. MICROSTAT's Data Management Subsystem (DMS) makes creating your own data files easy and includes numerous editing and transformation capabilities. Files produced by DMS can then be used to generate statistics in all common statistical areas (e.g., descriptive statistics, ANOVA, correlation, multiple regression, probability and hypothesis tests, nonparametrics and others) plus some not so common ones. Whether pure reserch or industrial quality control, MICROSTAT is the statistics package for you.

MICROSTAT sells for $250.00 and is supplied on 8" SD or 5<A" (North Star) disks. The user's manual sells for $18.00 and includes sample data and printouts. Please specify version when ordering. Foreign inquiries, please write directly to us.

Circle 253 on Inquiry card.

ECOSOFT

P.O. Box 68602

Indianapolis, IN 46268

(317) 283-8883

* CBASIC2 is a registered trade mark of Software Systems

TEXAS COMPUTER SYSTEMS

Radio /haek

Authorized Sales Center

All Radio Shack merchandise available at a discount Ask for our price list

MODEL II 64K $3349

All accessories lor Model H available -- disk expansions, printers and software

(Plus shipping)

EPSON MX-80 HE

Letter quality matrix tlmllar to (tie Une Printer IV ind Hie Centronics printer but rial full LlSt 5645 xrftwere control of 40,10, M, or 132 columns, 00 epi bidirectional printjnt tractor feed, drspoteble printneed. S300 leu then the nearest comoetlthe printer, ifi Hie belt dpi In e letter ouollti miirtl-etriee printer. Oar price hi too jge tcedwrttM

* Anadex 9500/9501 * Line Printer V * The New Daisy Wheel II

* Payment Money Order Cashier s Check. Certilied Check Personal Checks require 3 weeks to clear VISA MASTERCHARGE Add 3%

» Prices suoiect to change at any lime

* No lax out ol stale TX add 5

* All items new guaranteed Oy manufacturer

* Delivery subject to availability

TEXAS COMPUTER SYSTEMS

An Authorized RADIO SHACK* Sales Center F70I

Box 1174, Brady, Texas 76825

TOLL FREE Number 800-3511473

Texas Residents 915-597-0673

reformaTTer

With REFORMATTER ™ disk utilities you can read and write IBM 3740 and DEC RT-11 single density formatted diskettes on your CP/M » system.

REFORMATTER enables you to access large system databases, improve data exchange with other organizations, increase program development capabilities, and use your micro in distributed processing.

REFORMATTER programs feature bi-directional data transfer and full directory manipulation. ASCII/EBCDIC conversion provided with CP/M ^-» IBM. MPIM is now fully supported.

Program Data Sheets, Application Guides, and Machine Compatibility Guides available.

Each program $195.00 from stock. Specify CP/M ** IBM or CP/M +* DEC. Order from MicroTech Exports, Inc., 467 Hamilton Ave., Suite 2, Palo Alto, CA 94301 □ Tel: 415/324-9114 □ TWX: 910-370-7457 MUH-AUOS □ Dealer and OEM discounts available.

mmim CP/M* is a registered trademark of Digital Research. vtfl

Circle 254 on inquiry card.

DECLSMl Components

Dependable service at discount prices

Domestic and Export

mini

Computer Suppliers, inc.

25 Chatham Rd., Summit, N.J. 07901

Since 1973

(201) 277-6150 Telex 13-6476

©Mini Computer Suppliers, Inc. 1979

Circle 255 on Inquiry card.

BYTE April 1981 339

Circle 256 on inquiry card.

If you're looking for

the best prices in the U.S.A. on

TRS-80

MICROCOMPUTERS

We have consistently offered the TRS-80 line at savings up to 20%, which means you can save $150 to $1500 by buying directly from Computer Discount of America.

TRS-80 Model II, 64K System, with disc drive only $3385.00

Other TRS-80 Model II, or Model III computers and systems, Color Computers, and Pocket Computers are in stock at similar savings.

Our savings are as big on expansion interfaces, printers, diskettes everything for your TRS-80 System.

ATARI

MICROCOMPUTERS

We have the full line of ATARI personal computers and systems, including Models 400 and 800. The computers, accessories, and hardware are brand new, in factory sealed cartons, and carry a full factory warranty. Most models are in stock for immediate delivery (usually within 7-10 days), and a price quote is as near as your phone. So if you're looking for the best prices in the U.S.A., for microcomputers and accessories, call Computer Discount of America, Inc., West Milford, New Jersey 07480. 201-728-8080. NO TAX ON OUT-OF-STATE SHIPMENTS.

TOLL FREE 800-526-5313

Computer

of America

Authorized TRS-80 dealer, store B-282.

340 April 1981 © BYTE Publications Inc

Books Received.

0-8306-1187-8, $8.95; hardcover, ISBN 0-8306-9914-7, $14.95.

Guide to Microcomputers, Franz J Fredericks. Washington DC: Association for Educational Communications and Technology, 1980; 15.5 by 23 cm, 152 pages, softcover, ISBN 0-89240-038-2, $11.50.

How to Build Your Own Working Microcomputer, Charles K Adams. Blue Ridge Summit PA: Tab Books Inc, 1980; 13 by 21 cm, 308 pages, softcover, ISBN 0-83061200-9, $9.95; hardcover, ISBN 0-8306-9684-9, $16.95.

Introduction to Computer Design and Implementation, S Imtiaz and Kwok T Fung. Rockville MD: Computer Science Press Inc, 1981; 16 by 23.5 cm, 271 pages, hardcover, ISBN 0-914894-11-0, $19.95.

Introduction to Computers and Data Processing, Gary B Shelly and Thomas J Cashman. Fullerton CA: Anaheim Publishing, 1980; 21 by 27 cm, 498 pages, softcover, ISBN 0-88236-115-3, $15.95. Accompanying the textbook are a Teacher's Guide and Answer Manual, Test Bank, and transparency masters. Student Workbook and Study Guide for above, 21 by 27 cm, 247 pages, softcover, ISBN 0-88236-116-3, $5.95.

Introductory Structured COBOL Programming, Gary S Popkin. New York: Van Nostrand Reinhold Company, 1981; 19.5 by 24 cm, 471 pages, harcover, ISBN 0-442-26771-1, $18.95.

The MC6809 Cookbook, Carl D Warren. Blue Ridge Summit PA: Tab Books Inc, 1981; 13 by 21 cm, 176 pages, softcover, ISBN 0-83061209-2, $6.95; hardcover, ISBN 0-8306-9683-0, $11.95.

Microprocessor Background for Management Personnel, James Arlin Cooper. Englewood Cliffs NJ: Prentice-Hall Inc, 1981; 16 by 23.5 cm, 163 pages, hardcover, ISBN 0-13-580829-4, $14.95.

Microcomputer Interfacing Handbook: A/D & D/A, Joseph J Carr. Blue Ridge Summit PA: Tab Books Inc,

Circle 153 on inquiry card.

/ STRICTLY jCipplG

AUTHORIZED DEALER NO. 9D80

APPLE II PLUS: YOU SAVE

16K $1049 22%

48K $1099 29%

64K $1269 27%

Apple III Call

All are 1981 model with Apple RAM. >64K unit is 48K unit with Microsoft 16K RAM board.

IMPORTANT NOTE: We will repair all Apple equipment regardless of where you purchased it. Disk II & Controller 3.3 Disk II

Moniters,Sanyo9" B&W 12"B&W 12"Grn. 13" Col. RF Modulator, M&R Silentype printer Qume Sprint 5 45RO Serial Interface Card Apple Writer program Visicalc 80 Column Video:

Apple Smarterm

M&R, SupeRterm

Videx,

Language/Pascal Sys. Apple Plot Apple Pilot Microsoft:

Z80 Softcard

16K RAM Card Paper Tiger printer Tiger to Apple cable Epson MX 80 W/lnterface DC Hayes Micromodem 16K Expansion RAM Kit 10 Memorex 5" disks 10 3M Scotch 5" disks 10 Maxell 5" disks Accounting Sofware,

"Insoft Accountant" $ 365 66%

(a full professional quality integrated GL.A/R.A/P, Payroll package with hotline support). Send for free sample printouts.

Above prices for mail orders only Mail Order Dept. located in Jacksonville. OR. Our store showroom is at 126 NE F St., Grants Pass, OR. Store prices include service and will differ. No mail order sales at store. CALL ORDER DESK:

(800)547-1289

TECHNICAL & OREGON: (503) 899-7297

ORDERING INFORMATION: Minimum order $100. Money Orders, Cashier Checks or Bank Wire Welcomed. Visa and MC orders add 3%. Personal checks accepted (allow up to 20 days to clear). All orders add 3% for shipping, handling and insurance. Include your telephone number. No COD's. Prices subject to change without notice. Order desk hours are 9 to 6 PST. 10 to 3 Saturdays

COMPUTER EXCHANGE

MAILORDER DEPARTMENTOF

,<SCOMPUTER STORE

PO BOX 1380 Jacksonville, OR 97530

$ 499

23%

$ 439

16%

$ 169

30%

$ 249

21%

$ 299

21%

$ 449

20%

S 25

38%

$ 499

22%

$2499

20%

$ 129

35%

$ 59

21%

$ 119

21%

$ 299

17%

$ 319

14%

$ 249

18%

$ 379

24%

$ 55

21%

$ 119

21%

$ 250

28%

$ 169

16%

Call

Call

S 19

46%

Call

Call

$ 299

23%

$ 39

74%

$ 25

45%

$ 35

33%

$ 39

33%

Circle 258 on Inquiry card.

Circle 257 on Inquiry card.

hGSPQc nnocrncnn

p h

Q

n □

p

@

Q Q

a □

L.2DPLO! PACKAGE L20 & L3P PACKAGES

MAURO PHOAC MP 250 PLOTTER

i 160 00 *160 00 S695 00 S 795 00

S950 00

MAURO PLOTTER

APPLE TR5 80 and RS 232 .nirrlace ea

LEAPAC SOFTWARE Cemfllela iv,oiJimpnsio"»l a<

Ixcwnt obioleted ai you upgrade voui plotting eflu<[ lining I.BrarifilLBOj lor MICROSOFT comparable prod MACRO BOor.8 CP M at ft NOFt'HSTAR TRS 8

120 PACKAGE Two dimensional plol package th<n C arable calls Such n P10T5 PLOT WHERE FACTOR I 13P PACKAGE Pe.specuve pi IhtM rJ.mens.nnai p ION ZOOMING FLV BYS and ANIMATION ire DUtl

g efroi ai plotting ipewH o' up iq 2 p

ttiOMty Store Rrqun ■•% only 5 b.t* pi a pai ( ploiin lui 8080 Z80 fi502 t. 6800"

»nt TnP suKwa'f il swppt.ea a\ 8060 280 -elat is FORTRAN 80 COBOL 80 COMPILER BASIC a or HEATH B9 compatible diskenei

1 .nloiir

af 6 uu

pages i

InnrunwK HIPLOT DMP 3 4 6 &? plollfs anc DIABLO 1620 & 16^0 OUME SPRINT 5 ana NEC 5&10 & 5520

cp m .s j r»gi*w

HIPLOT & DMP a

TRS 80 is a

P

b

Q

n □

□

p p

3 Q

a

□

LINE VOLTAGE TRANSIENT CLIPPING

Features Parallel Operation

PROTECTS:

•Computers

•Micro-Computer Systems •Word Processors •Cash Registers • Power Supplies

5000 Hits/Second

PROTECTS AGAINST.

•High Energy Voltage Transients •On-Off Switching •Lightning Induced Transients • Inrush of On/Oft Power

MARC

INDUSTRIES, INC.

TRANSIENT VOLTAGE

SURGE SUPPRESSOR LISTED

0/HF

®

7133 Rutherford Rd. Baltimore, Md. 21207 , (301)298-3130 800-638-9098 ,

REMOTE MONITORING AND CONTROL

FOR THE APPLE II COMPUTER Real time clock/calendar included

Connects directly to and communicates thru the AC power line. OUTPUT Operates up to 256 BSR System X - 10 remote control modules. Also operates intelligent control modules and alarm and voice output modules, soon to be available from ICS. INPUT Use the BSR Command Console to send commands to your computer. Monitor the status of security and temperature remote input modules, and the status of ICS output modules. CLOCK The clock provides sec, min, hour, date, day of week, mo, year, plus 4 selectable interrupt rates for background operation of control programs. On board battery backup. SOFTWARE On board software is provided to handle the remote 1/0, set and read clock, run background control schedules, and simulate the BSR Command Console. Easy access from BASIC. TRADEMARKS-APPLE II: Apple Computer , Inc. , Sys tern X-10: BSR Ltd. SEE YOUR DEALER OR ORDER FROM ICS FOR $185 (+$5 Ship./hand.)

INTELLIGENT CONTROL SYSTEMS, INC.

PO BOX 14571 MINNEAPOLIS, MN 55414 (612)699-4342

CATCH THE S-100 INC. BUS!

Morrow Designs "Thinker Toys" Switchboard I/O A&T

Central Data 16K Dynamic RAM

expandable to 64K A&T Mullen TB-4 Extender Card

w/Probe Kit Ithaca Intersystems MPU-80

Series II A&T SSM I0/4 with 2P&2S Kit North Star Floating Point Board

A&T

OUR

LIST

SPECIAL

PRICE

CASH

PRICE

259.00 207.00

259.00 220.00

59.00

395.00

210.00

50.00

316.00 178.00

399.00 339.00

Subject to Available Quantities • Prices Quoted Include Cash Discounts. Shipping & Insurance Extra.

We carry all major lines such as

S.D. Systems, Cromemco, Ithaca Intersystems. North Star,

Sanyo, ECT, TEI, Godbout, Thinker Toys, SSM.

For a special cash price, telephone us.

S-fDD,inc.

7 White Place, Clark, N.J. 07066 201-382-1318

Hours: Mon. - Fri. — 10 a.m. to 6 p.m.

Circle 259 on Inquiry card.

BYTE April 1981 341

Circle 261 on inquiry card.

GET IT

OFF THE

FLOOR

Now that you have a shiny new computer terminal, what are you going to put it on? Computer Furniture and Accessories«makes a variety of furniture for a wide range of computer applications. In combinations of six widths, three depths, and three heights. With "L" shaped returns, Micro shelves, data shelves, RETMA mounting, and printer stands. With optional drawers, doors, CRT turntables, and casters. Sizes, shapes and colors designed to fit your office or computer room environment. Reasonably priced and shipped from stock.

Call CF&A. We'll get your system up where you can really put it to use.

CF*A

Computer Furniture and

Accessories, Inc.

1441 West 132nd Street

Gardena, CA 90249

(213) 327-7710

342 April 1981 © BYTE Publications Inc

Books Received

1980; 13 by 21 cm, 350 pages, softcover, ISBN 0-83061271-8, $8.95; hardcover, ISBN 0-8306-9704-7, $14.95.

Motorola Optoelectronic Device Data, Motorola Technical Information Center. Phoenix AZ: Motorola Inc, 1980; 17.5 by 23.5 cm, 302 pages, softcover, no ISBN, $3.25.

Operating Systems, Harold Lorin and Harvey M Deitel. Reading MA: Addison-Wesley Publishing, 1981; 17 by 24 cm, 378 pages, hardcover, ISBN 0-201-14464-6, $19.95.

People and Project Management, Rob Thomsett. New York: Yourdon Press, 1980; 15 by 23 cm, 106 pages, softcover, ISBN 0-91707221-9, $10.50.

PET/CBM Personal Computer Guide, Second Edition, A Osborne and Carrol S Donahue. Berkeley CA: Osborne/McGraw-Hill, 1980; 16.5 by 23.5 cm, 501 pages, softcover, ISBN 0-93198855-1, $15.

The PLL Synthesizer Cookbook, Harold Kinley. Blue Ridge Summit PA: Tab Books Inc, 1980; 13 by 21 cm, 279 pages, softcover, ISBN 0-8306-1243-2, $7.95; hardcover, ISBN 0-8306-9707-1, $13.95. ■

This is a list of books received at BYTE Publications during this past month. Although the list is not meant to be exhaustive, its purpose is to acquaint BYTE readers' with recently published titles in computer science and related fields. We regret that we cannot review or comment on all the books we receive; instead, this list is meant to be a monthly acknowledgment of these books and the publishers who sent friem.

WANTED:

APPLE, PET, TRS-80, CP/M

SOFTWARE

Westico is a publisher and distributor of professional software for microcomputers. If you have a new program ready for distribution or want your existing prog rams to reach a larger market, contact

Phillip Woellhof, V.P. Mktg.

Westico. inc.

25 Van Zant Street

Norwalk, CT 06855

(203) 853-6880 To increase your profits, take advantage of Westico's worldwide promotion and distribution.

WESTICO

The Software Express Service

LETTER QUALITY

ASCII

KSR

TERMINALS

$1600

t-ELMER CAROUSELS: I butler, lull ASCII. R5-?32

4027, 2104, 4096 75C

INTERSIL 4Kil DYNAMIC RAM: 300ns. c»ri power P/N 7005-13. pquiv lo 4027, 210-1 40% I'3 the usual nobby pnce. Luge OEM o>

6 OUTPUT POWER SUPPLY FLOPPY, EPROM, CPU ETC.

BWAND NEW NORTH: 13670 IMled t>0'»S Ono us.vi .n NCn coil.it terminals. SV/3A, 24V/1 ?A, 16W28A (nil adjustable, w/ov prol ft cm limiting): 12V/0 1A. -24V/0.3A ihoih »/OV prnr | -W0 1A (,id| I Ful requlalpd consiTVEilivp linear op*ian partially ?nc1 W/SCM) assy (twigs tbeofy'5<?>«ire docs 3 5*55* 14 115VAC Ru"sa"fl lloppy m drop the It lo 13V and run ?-3 mimtloppies r,uiiianlwKl S35 e» ■ I? It'i UPS

Writ

I tor

atgmn

',i.|>llll.-'S mi-'iv.ry . Ii

TERMS: UPS COD, \ NJ .wid sal'?* tax

ELECTRAVALUE INDUSTRIAL

PO BOX 157-B Pyfl

MORRIS PtAINS. NJ 07<150 r'Ak,

201/267-1117

wabash

When it comes to

Flexible Disks, nobody

does it better than

Wabash.

MasterCard. Visa Accepted. Call Free: (800)235-4137

PACIFIC EXCHANGES

100 Foothill Blvd San Luis Obispo. CA 93401 (In Cal call (80S) 543-1037]

Circle 263 on inquiry card.

Circle 265 on Inquiry card.

Of Your HP-85 or Commodore System Building Blocks

the POWER

Pet/CBM With TNW's IEEE-488 Bus

TNW-2000

TNW's RS-232 SERIAL INTERFACES

Connect your PET/CBM to any RS-232 Serial Printer. Plotter. Terminal. Modem, or other device.

CRT

TNW-10Q0 TNW-2000 TNW-232D

ONECHANNEL OUTPUT ONLY

ONECHANNEL INPUT AND OUTPUT

TWO CHANNELS. INPUT & OUTPUT 12 RS-232 CONTROL SIGNALS

$129 $229 $369

TURN YOUR PET INTO A TERMINAL

Access Timesharing Systems and Bulletin Boards with TNW's Pterm Software and full service telephone modem:

TNW-103

AUTO ANSWER/AUTO DIAL USE WITH DAA

$389

Pterm also works with acoustical couplers and other modems interfaced to the PET with the TNW-2000 or TNW-232D. Electronic mail and TWX Terminal programs also available. All units are addressable IEEE-488 devices, complete with power supply cabinet, full documentation and one year warranty.

TNW CORPORATION

3351 Hancock St. • San Diego, CA., 92110(714) 225-1040

TWX910-335-1194

Visa/Mastercharge Welcome • Dealer inquiries invited

DIGIAC

MAPS 1000

MP/M'S

HARDWARE

PARTNER

'The Dlglac MAPS-1000 MP/M" Universal Support Module has been designed to meet the total demands required by Digital Research's MP/M multi-user, multi-tasking operating system. All Input/output, Interrupt generation tor task switching, and disk bootstrapping are resident functions on the MAPS-1000.

'The MAPS-1000 has been designed with all the following powerful features:

• Four (4) independent RS-232C Serial Communication channels • One 8 bit TTL parallel port • On-board phantom controlled disk boot prom/monitor • Power on jump capability • Crystal controlled MP/M interrupt generation Logic • On board extended memory bank switching Logic

• MAPS-1000 fully assembled and tested price. . . S425.00

DIGIAC CORPORATION

175 Engineers Road Smithtown, New York 11787 Phone (516) 273-8600 MP/M is a trademark ot the Digital Research Corporation

Apple en castellano

Tercer Medio presenta su sistema administrative) (T.M.A.) para Apple ][

Disenado de acuerdo con los principios contables aceptados en todos los pai'ses de habla hispana.

APLICACIONES COMERCIALES YCIENTIFICAS

• CONTABILIDAD • CUENTAS GENERAL PORCOBRAR

Diario General Resumen del Diario Consulta parcial al Diario Mayor General Balance de Comprobacion Balance General Ganancias y Perdidas Catalogos de Cuentas Consultas por pantalla

Catalogo de Cuentas Listado de Transacciones Antiguedad de Saldos Saldos por Veneer Relacion de Cobranzas Relacion de Pagos Estado de Cuentas Consultas varias por pantalla

INVENTARIO Y FACTURACION

CONTROL DE BANCOS

PERT/CPM

CUENTAS A PAGAR

CONTROL DE COSTO DE OBRAS

VENTAJAS DEL SISTEMA T.M.A.

Son completamentes conversacionales.

El chequeo de la informacion es instantaneo.

Los reportes impresos o por pantalla guardan

los formatos generalmente aceptados.

Estan pensados para adaptarse a cualquier

empresa.

Toda la informacion esta instantaneamente

disponible.

Precision Expandida.

Numeros de hasta ± 999.999.999.99

a

Tercer Medio

Sistema de Informacion C.A.

APARTADO DE CORREOS 62533 CARACAS 1060-A - VENEZUELA TELEX: 27.876 - CPBTH -VE. TELEFONOS: 283.60.88 - 284.74.68

'Apple esmarca reqistrada pot APPLF COMPUTER INC

Circle 266 on Inquiry card.

Circle 267 on Inquiry card.

BYTE April 1981 343

Software Received

This following is a list of software packages that have been received by BYTE Publications during the past month. The list is correct to the best of our knowledge, but it is not meant to be a full description of the product or the forms in which the product is available. In particular, some packages may be sold for several machines or in both cassette and floppy-disk format; the product listed here is the version received by BYTE Publications.

This is an all-inclusive list that makes no comment on the quality or usefulness of the software listed. We regret that we cannot review every software package we receive. Instead, this list is meant to be a monthly acknowledgment of these packages and the companies that sent them. All software received is considered to be on loan to BYTE and is returned to the manufacturer after a set period of time. Companies sending software packages should be sure to include the list price of the packages and (where appropriate) the alternate forms in which they are available.

Apple

ABM, graphics arcade game for the Apple II. Floppy disk, $24.95. Muse, 330 N Charles St, Baltimore MD 21201.

Action Sounds and Hi-Res Scrolling, sound and graphics utility for the Apple II. Floppy disk, $15.95. AvantGarde Creations, POB 30161, Eugene OR 97403.

Animal Bingo, nonviolent strategy game for the Apple II. Floppy disk, $9.95. AvantGarde Creations (see above).

Apex Handy Disk #1, disk utilities for the Apex Operating System (on the Apple II). Floppy disk, $39. Apparat Inc, 4401 S Tamarac Pky, Denver CO 80237.

Asteron, game for the Apple II. Floppy disk, $27.50. Western Microdata Enterprises Ltd, POB 633, Postal Station G, Calgary, Alberta, T3A 2G1, Canada.

Courseware Magazine, education programs and documentation for the Apple II. Cassette, $12.95 for a single issue or $50 for 5 issues. Courseware

Magazine, School of Business, California State University, Fresno CA 93740.

CRAE 2.0 (Co-Resident Apple Editor 2.0), Applesoft program editor for the Apple II. Floppy disk, $24.95. Highlands Computer Services, 14422 S E 132nd St, Renton WA 98055.

The Creativity Life Dynamic Book, graphics-, music-, and poetry-generation game for the Apple II.

Floppy disk, $19.95. AvantGarde Creations (see above).

Jungle Safari, graphics game for the Apple II. Floppy disk, $9.95. Avant-Garde Creations (see above).

Masterdisk, disk-examination utility for the Apple II. Floppy disk, $29.95. Masterworks Software Inc, POB 7000-285, Rolling Hills Estates CA 90274.

MCAT 2.0, disk-catalog utility for the Apple II. Floppy disk, $19.95. Highlands Computer Services (see above).

The Meaning Life Dynamic, graphics-game package for the Apple II. Floppy disk, $15.95. Avant-Garde Creations (see above).

The Mine Fields of Normalcy, strategy game for the Apple II. Floppy disk, $9.95. Avant-Garde Creations (see above).

Mystery Code, strategy game for the Apple II. Floppy disk, $9.95. Avant-Garde Creations (see above).

Oldorf's Revenge, fantasy game for the Apple II. Floppy disk, $19.95. Highlands Computer Services (see above).

Personal Property Inventory, cataloging utility for the Apple II. Floppy disk, $14.95. Hayden Book Company Inc, 50 Essex St, Rochelle Park NJ 07662.

The Prisoner, strategy game for the Apple II. Floppy disk, $29.95. Edu-Ware Services Inc, 22035 Burbank Blvd, Suite 223, Woodland Hills CA 91367.

Sentence Diagramming,

teaching program for the Apple II. Floppy disk, $19.95. Avant-Garde Creations (see above).

Star Avenger, graphics arcade game for the Apple II. Floppy disk, $27.50. Western Microdata Enterprises Ltd (see above).

Tarturian, fantasy game for the Apple II. Floppy disk, $24.95. Highlands Computer Services (see above).

VU #3, VisiCalc-based utility for the Apple II. Floppy disk, $69.95. Progressive Software, POB 273, Plymouth Meeting PA 19462.

XPLO, programming language for the Apple II. Floppy disk, $79. Apparat Inc (see above).

TRS-80

Attack Force w/Sound, graphics arcade game for the TRS-80. Cassette, $14.95. Big Five Software, POB 9078185, Van Nuys CA 91409.

Beef Cattle Least-Cost Ration Program, cost-analysis program for the TRS-80. Cassette, $5. Agricultural Software Consultants Inc, 1706 Santa Fe, Kingsville TX 78363.

Blackjack Master, blackjack strategy game for the TRS-80. Hoppy disk, $24.95. Hayden Book Company Inc, 50 Essex St, Rochelle Park NJ 07662.

Galaxy Invasion, graphics arcade game for the TRS-80. Cassette, $14.95. Big Five Software (see above).

Personal Property Inventory, cataloging utility for the TRS-80. Floppy disk, $14.95. Hayden Book Company Inc (see above).

Starclash, strategy game for the TRS-80. Floppy disk, $16.95. Hayden Book Company Inc (see above).

CP/M

Communications Software Package, utility for CP/M systems. Floppy disk, $60. Datastat Systems Inc, 631 B St, San Diego CA 92101.

Datastar, key-to-disk dataentry program for the CP/M

operating system. Floppy disk, $350. MicroPro International Corporation, 1299 Fourth St, San Rafael CA 94901.

Pascal/M, programming language for the CP/M system. Eight-inch floppy disk, $175. Sorcim, POB 32505, San Jose CA 95152.

Supersort I, record-sorting utility for the CP/M operating system. Floppy disk, $250. MicroPro International Corporation (see above).

WordMaster, video-based text editor for the CP/M operating system. Hoppy disk, $150. MicroPro International Corporation (see above).

WordStar, word-processing program for the CP/M operating system. Floppy disk, $495. MicroPro International Corporation (see above).

Other Computers

Budget Manager, personalutility program for the APF Imagination Machine. Cassette, $19.95. APF Electronics, 1501 Broadway, New York NY 10036.

Full Screen Editor, textmanipulation program for the Heath H-89. Floppy disk, $24.95. Heath Company, Benton Harbor MI 49022.

Jinsam 8.0, data-base-management program for the Commodore CBM 8032. Floppy disk, $175. Jini MicroSystems Inc, POB 274, Kingsbridge Sta, Bronx NY 10463.

Personal Business Machine, personal-utility program for the APF Imagination Machine. Cassette, $29.95. APF Electronics (see above).

Ramscan, memory diagnostic test for the Atari 800. Floppy disk, $15. Axlon Inc, 170 N Wolfe Rd, Sunnyvale CA 94086.

Space, Size, and Surface Guide, personal-utility program for the APF Imagination Machine. Cassette, $29.95. APF Electronics (see above). ■

344 April 1981 © BYTE Publications Inc

BYTE's Bits

Results of "What Is It?" Contest

In the April 1980 BYTE, we announced a contest. In the 'What's New?" section, on page 247, we printed a picture of an anonymous mechanical device and challenged readers to identify it. The first person to respond with the correct answer was to receive the device as a prize.

Tony Caloggero of Nahant, Massachusetts, won the contest. It is called Stepdozer, a product of the Gakken Company of Japan. The Stepdozer is part of a line of mechanical toys known as Space Mechanimals.

Other readers sent in varying descriptions of the beasty. Several readers stated that it was part of a cash register. One reader gave a specific description as a 1903 C L Smith adding machine, with

the battery pack thrown in as a "red herring." Another reader guessed several possibilities: "a doughnut dunker, an automatic pitchfork, or a piece of my spaceship." Yet another suggested that it was a model of an oil pump. These descriptions were slightly off the mark.

Several readers came closer, by describing it generically as "a walking machine." One reader said that he recognized it instantly as a "Rien de Toot," and we received one letter identifying the device as a "mechanical Trojan horse."

Finally, we would like to quote extensively from a reader in University, Alabama, who wrote:

Good heavens, any economist worth his salt knows the answer—it's a portable widget, with a selfcontained power source. It's

used as a product example in almost every freshman economics course in the country. Get with it—you folks are slipping! Next time, show us

something really hard to guess, like an inversely truncated framistan!

Only if we can find one.B

Photo 1:

got it.

A Stepdozer for Tony Caloggero. He guessed it, he

f

Radio/hack

PROGRAMS

<ft G$ Graph

/> - VV Snace-y

ic Games

Space-Action-Invaders

Programmer's Tool Kit

Write your own programs easier

rr

Many, many more!

Books • Memory • Accessories

Shipping from stock

Call or Write:

COMPUTERWARE

I

6809 Specialists

Dept. C • Box 668 Encinitas, CA 92024

(714) 436-3512

Computerware is a trademark of Computerware. Radio Shack is a registered trademark ol Tandy Corp.

DISK DRIVE WOES? PRINTER INTERACTION? MEMORY LOSS? ERRATIC OPERATION?

Don't

Blame The Software!

Power Line Spikes, Surges &

Hash could be the culprit!

Floppies, printers, memory & processor often interact! Our unique

ISOLATORS eliminate equipment interaction AND curb damaging

Power Line Spikes, Surges and Hash.

• ISOLATOR (ISO-1) 3 filter isolated 3-prong sockets; integral Surge/Spike Suppression; 1875 W Maximum load, 1 KW load any socket $62.95

• ISOLATOR (ISO-2) 2 filter Isolated 3-prong socket banks; (6 sockets total); Integral Spike/Surge Suppression; 1875 W Max load, 1 KW either bank $62.95

• SUPER ISOLATOR (ISO-3), similar to ISO-1 except double filtering & Suppression $94.95

• ISOLATOR (ISO-4), similar to ISO-1 except unit has 6 Individually filtered sockets $106.95

• ISOLATOR (ISO-5), similar to ISO-2 except unit has 3 socket banks, 9 sockets total $87.95

• CIRCUIT BREAKER, any model (add-CB) Add $ 8.00

• CKT BRKR/SWITCH/PILOT(CBS) Add $16.00

Master-Charge, Visa, American Express

Order Toll Free 1-800-225-4876

(except AK, HI, MA, PR & Canada)

A&J Electronic Specialists, Inc.

171 South Main Street. Natick. Mass. 01760 Technical & Non-800: 1-617-655-1532

Circle 269 on inquiry card.

Circle 270 on inquiry card.

April 1981 © BYTE Publications Inc 345

k^

V

w THE CONFIGURABLE BUSINESS SYSTEMIM is a parameter-driven information manager that makes the business of applying computers easier and more efficient. A pre-defined framework gives you the tools to design and implement your own well-documented system, including:

• sophisticated data entry

• concise data-based management system

• user customized job streams and menus

• personalized report generation

User training and support is minimized by a comprehensive operating manual. CBS Disks can fit any 8080 or Z80 computer with CP/M*

Disks and manual, $395; Manual only, $40.

Your DMA representative can tell you about DMA.DOS, our CP/M compatible operating system, and ASCOM, an Asynchronous Communication Control Program.

DMA • WE SPEAK YOUR LANGUAGE

This publication is available in microform.

University Microfilms International

Please send additional information

for.

Name

Street

City

State

Zip

300 North Zeeb Road 30-32 Mortimer Street

Dept. PR. Dept. RR.

Ann Arbor, Mi. 48106 London WIN 7RA

U.S.A. England

346 BYTE April 1981

Circle 65 on inquiry card.

The business information you need at the turn of a key.

Datadex is a new interactive business management system designed for the Apple personal computer. It's from IUS, the people who brought you EasyWriter™ and who are bringing you new products for office automation, education, and development systems.

Datadex is short for data index. It lets you put all your business data into your Apple the way you like to see it and manipulate it any way you want. II adapts to your way of doing business.

Want to generate a sales report? Just press four keys and fill in the blanks. That puts your sales data into the computer. Now, your report: Datadex designs it for you, based on what you've entered. Nothing to it. That's power!

You can do the same with phone lists, mailing lists, dealer names or inventories.

PUT OATAOGX

IN YOUR

APPLE.

They all enter Datadex and form your own personal data base.

Want to find a company but don't know how to spell its name? Try something that sounds close, and our Soundex routine will find it. It is very forgiving on typos and extra spaces.

-< CHECKBOOK >■

OLOISIUS ZUKRZAWSK1

mMOUHT I 923 77 CROSS I 523.7?

Soundex helped us find Mr. Zuki7,awski when we were balancing our checkbook. We weren 't sure how to spell Al's name, so searched for Al Z and found him. Instantly. The check register and several other applications are free with Datadex.

Want a specific piece of information, like sales for January 14-21? Inquire Datadex and the answer comes up on the screen right now. And right.

Want a report of all sales in ZIP code areas starting with 9? Sure. Just ask it to print a report.

But seeing is the only way to believe. Get a demonstration of Datadex at your local Apple dealer. See the personal computing power it can bring to your office and home. If you've looked at a VisiCalc-type program, see Datadex before you buy.

By the way, about IUS. We're the Apple of software. We got there by giving you great products and super support. We provide customer service over the phone. Professionally written documentation. And products that are never outdated, only updated. Information Unlimited Software, Incorporated,

281 Arlington Ave., Berkeley, CA 94707. (415) 525-9452.

Datadex is a trademark of Sonnma Softworks. EasyWriter is a trademark of Cap'n Software. Apple is a trademark of Apple Computer Inc. VisiCalc is a trademark of Personal Software, Inc

PADDLES

Interfacing with Modular Breadboards

Roger ] Combs and Paul E Field

Department of Chemistry

Virginia Polytechnic Institute

and State University

Blacksburg VA 24061

Often, microcomputer interfacing is a simple task requiring only a basic knowledge of digital electronics. The availability of breadboarding sockets has made building and testing of digital electronics circuits relatively easy. (Breadboard sockets considered here are the E & L Instruments SK-10 and the AP Products Super Strip.) The ease of digital-circuit testing with breadboards can be extended to microcomputer interfacing by use of functional modules which plug into these breadboards. We call these modules PADDLEs (Peripheral Analog/Digital Device-Logic Extensions).

Breadboarding sockets have made building and testing digital electronics relatively simple.

The various PADDLE modules perform the following functions: address decoding for device selection, D/A (digital-to-analog) conversion, A/D (analog-to-digital) conversion, displaying data, and debouncing switches. Once you have built these circuits in modular form, you will not have to build them from scratch for every breadboard project, and you will not have to use valuable breadboard space that could otherwise be delegated to the project at hand.

It is best to avoid constructing modules so complex that their use becomes cumbersome and their utility limited. For this reason, we shall consider building PADDLEs to perform only those functions which are often called for in digital circuits and which are easily integrated into prototype interface circuitry.

We have found a minimum configuration of five PADDLEs most useful both for interfacing projects and for instruction. These consist of (1) a set of three switchdebouncing circuits, (2) a set of eight logic switches having a latched-pulse output for interrupt generation, (3) a dual seven-segment display, (4) an A/D-D/A converter and comparator for either analog-to-digital or digital-toanalog conversion, and (5) a device decoder capable of generating eight unique outputs from an 8-bit input.

A single 8-bit address decoder PADDLE can be used to select devices, provided the microcomputer uses accumulator I/O (input/output). In order to decode a 16-bit memory address, two decoder PADDLEs would be necessary. Though the PADDLEs can be used with other microprocessors, our focus is on the 8080 family. In the following text we consider each of these PADDLEs in terms of function and design.

Pulser PADDLE

This PADDLE (see figure 1) generates a digital pulse, either positive or negative, that is devoid of the bouncing (momentary intermittent contact) always found in mechanical switches. This is done by the use of an RS (set-reset) flip-flop. Often an RS flip-flop is constructed from two NAND gates; however, the same result can be obtained by the use of two inverters. Either a positive or negative pulse is available at the output of each RS flipflop. With a single type-7404 hex inverter, three RS flipflops can be constructed (rather than two using a single 7400 quad NAND gate).

The operation of an RS flip-flop constructed from either inverters or NAND gates is controlled by the current-sinking ability of a TTL (transistor-transistor logic) device output, since a floating input connected to an output that is low will also be pulled low. These pulsers are a means of manually generating signals that can be used to enable or clear such devices as monostable multivibrators (one-shots), counters, latches, and so on.

Logic Switch PADDLE

As the name implies, the device in figure 2 allows definition of a logic 1 or 0 on each of eight parallel lines. A single-pulse switch is also provided to generate an interrupt pulse that is latched by a 7474 D-type latch. Each of the eight lines is three-state buffered and enabled by the same external pulse that clears the D latch. Used with an 8080A microprocessor, the output line marked P can be tied to INT (the processor's interrupt line) and the input-enable signal, labeled E, can be connected to the microprocessor's interrupt-acknowledge line, INTA. This allows the PADDLE to function as an interrupting device. Once INT has been accepted, INTA will gate the instruction defined by the logic switches (usually a special-restart subroutine call, RST X) onto the data bus.

348 April 1981 © BYTE Publications Inc

Number Type +5V GND

IC1 7404 14 7

£

SW2 _6NC

O 0V "L

O 0V

OOV "L

O ov J"

OOV "L

O>0V J"

Figure 1: Schematic of a PADDLE for manually producing bounceless pulses. SW1 thru SW3 are momentary-contact switches; A thru F are sections of a 7404 hex inverter integrated circuit.

Octal

BOC

377

7.7.

246

4.6

135

3 5.

012

1 2

Table 1: Examples of BOC (binary/octal code) coding using two seven-segment displays and their decimal points to represent an 8-bit number.

A short program to test this function using RST 4 is given in listing 1. Alternately, the PADDLE can be used as an input device to the accumulator (by properly using E with device decoding), or E can be tied to ground and the logic switches used as individual switches.

Display PADDLE

This device (see figure 3) displays an 8-bit word on seven-segment LED (light-emitting diode) displays in either the BCD (binary-coded-decimal) format or a BOC (binary/octal-code) format. The BCD format is actually the hexadecimal display obtained with the 7447 sevensegment decoder. Since the upper six digits of this code are not particularly useful, or at least not easily memorized, we have devised the BOC format in order to display an 8-bit word using the two seven-segment displays and their associated decimal points.

Number

Type

+ 5V

GND

IC1

7474

14

7

IC2

74368

16

8

IC3

74368

16

8

GND

A N I

N 0

N C NORMALLY CLOSED N 0 NORMALLY OPEN

* <3 E

-O D7

O D6

-O D5

-O D4

0» 03

O D2

O Dl

O DO

CHERRY MICROSWITCHES

Figure 2: This PADDLE circuit permits the sending of 8 bits of data to a processor by functioning as either an interrupt or an input device. Switch C is of the momentary variety, while the eight data switches are SPST (single pole, single throw).

Listing 1: Routine to exhibit function of the Logic Switch PADDLE as an interrupt device. An indefinite delay is generated by use of EI (enable interrupts) followed by HLT (halt). Each time an interrupt is generated the display will increment by one.

SUB A /CLEAR ACCUMULATOR AGAIN, INR A OUT DISPLAY EI HLT /INTERRUPT IS ENABLED

000 040, POP H /RESTORE STACK POINTER

JMP /RST 4 MUST BE JAMMED ON DATA BUS

AGAIN /AT TIME OF INTA" IN ORDER TO RETURN

PAGE /TO NEW DELAY

April 1981 © BYTE Publications Inc 349

+ 5V

DO O

Dl O D2 C^ D3 O

o

D4 [Z>

D5 \Z>

D6 O

D7 [~>

ID

2D

3D

IC1 7475

10 2Q 30

4D

15

16

IC2 7475

ID

2D

4D

1Q 20 3Q 30 40 40

DIP PLUG JUMPERS

BCD

8 GND

8 GND

DIP SOCKET

03

RD

Q4

LA

Q5

LB

06

LC

06

RP

07

LD

Q7

LP

BOC

LP 16

LD 15

RP 14

GND 13

LC 12

LB 11

LA 10

RD 9

NC -NO CONNECTION

Number

Type

+ 5V

GND

IC1

7475

5

12

IC2

7475

5

12

IC3

7447

16

8

IC4

7447

16

8

Figure 3: Binary data on lines DO thru Dl can be displayed on two seven-segment LED (light-emitting diode) displays in either BCD (binary-coded-decimal) or BOC (binary/octal-code) format (see text) using the Display PADDLE. Resistors Rl thru R16 are 240-ohm Vt W.

Binary/octal-code format is binary in the sense that the two most significant bits are displayed on the decimal points, and it is octal since the remaining six bits are displayed as two octal digits on the seven-segment displays. BOC represents a substantial advantage over normal numeric display because only two rather than three displays and decoders are required. Although one could monitor the eight lines using alphanumeric hexadecimal displays, these are much more expensive than seven-segment displays with decimal points.

The ability to use the displays in either a BCD or BOC format is selected by using one of two jumper-wired dualinline plugs inserted into a 14-pin DIP (dual-inline package) socket. The eight data-input lines, DO thru D7, are brought to a pair of 7475 quad D latches. The outputs of the latches, Q0 thru Q7, Q6, and Q7, are routed via the DIP plug to obtain the selected display format. In either configuration, signals from Q0 thru Q2 bypass the DIP plug and connect directly to the three least significant inputs of the 7447 decoder-driver for the right-hand display.

In the BCD configuration, the DIP plug directs Q3 to the MSB (most significant bit) input of IC3, the righthand 7447, and Q4 thru Q7 to the appropriate inputs of

IC4, the left-hand 7447. The decimal points of the displays are not connected.

In the BOC configuration, the DIP plug directs Q3 thru Q5 to IC4, grounds the MSB inputs of both 7447s, and connects Q7 and Q6 directly to the left- and right-hand decimal points of the FND 507 LED displays. Use of the logical complements of Q6 and Q7 is necessary because the FND 507 is a common-anode display.

On the PADDLE module, the gating inputs to the 7475 quad D latches are tied together and labeled E (enable). When E is at logic 1, the data present on lines DO thru D7 is displayed; on the l-to-0 transition it is latched. In this manner the Display PADDLE can be used as an output device (provided proper address decoding is implemented to allow the 7475s to latch the data bus at the correct time).

A/D-D/A PADDLE

The PADDLE in figure 4 can be used as either an A/D (analog-to-digital) converter or a D/A (digital-to-analog) converter. It consists of the following: a 7404 hex inverter, two 7475 quad D latches, a 1408L8 8-bit D/A converter, a 741 operational amplifier (op amp), and a 311 voltage comparator. Because the latter three devices re

350 April 1981 © BYTE Publications Inc

K5V

E O

D7 \Z>

D6 O

D5 O

D4 [3>

D3 O

02 ODl |Z>

DO O

IC1 7475 4D 40

3D

2D ID

30

2Q 1Q

16

10

IC2 7475

4D 3D 2D ID

4Q 30

20

1Q

15

IC6 ^ 74368

;ik

n^

10

11

12

IC3

RC

Vref(-)

MC1408L8 Al VREFW

A2

A3 A4 A5 A6 A7 A8 COMPEN VEE

'0

16

15pF

15

+ 5V

IK -*wv

2.2K *

>680J1

IK _vv/v

<OvAi

200JI

Ro

a

5.IK -VW—

-1Z>vao

Figure 4: Analog-to-digital and digital-to-analog conversion of data is performed by the A/D-D/A PADDLE in conjunction with the SAP program in listing 2. VA! and VA0 are the analog input and output lines, respectively. The asterisk indicates the voltage reference point; jumper ] allows generation of negative output voltages. IC 6 is one section of a 74368 integrated circuit.

Number

Type

+ 5V

GND

-12V

+ 12V

IC1

7475

5

12

IC2

7475

5

12

IC3

MC1408L8

13

2

IC4

LM741

4

7

IC5

LM311

1

4

8

IC6

74368

16

8

quire +12 V and —12 V, wire-insertion sockets labeled + V and —V are provided on the PADDLE for connection to an external power supply.

Let us fiFst consider the use of this PADDLE as a D/A converter and note its limitations. The PADDLE is designed so that once an 8-bit word is latched by the 7475s, the 1408 D/A converter converts this byte into a proportional current. The 741 operational amplifier connected to the output of the D/A converter serves as a current-to-voltage converter. When the jumper shown in figure 4 is not inserted, the D/A converter is in a unipolar mode and can generate voltages between 0 and the positive external power-supply voltage. In the unipolar mode, the voltage range is dependent upon the reference current supplied to the D/A converter and the amplifier feedback resistance at the output of the D/A converter. The calculation of this voltage is based on the digital value of the 8 bits DO thru D7:

VAO =

v„

R,(

DO

, Dl D2 , D3 D4

+ — + — + — + —

2

4 8 16 32

+

D5

64

+

D6 128

+

D7 256

where Rref is the resistance provided by a 1 k-ohm potentiometer and Rf is 5.1 K-ohms (from the amplifier feedback resistor). Note that Vref at the node labeled with the asterisk in figure 4 is determined by the voltage-divider circuit and is calculated to be 1.18 V. As Rref is reduced to zero, the voltage output goes to a minimum value of approximately + 4.0 V. Based on the previous equation, we can infer that an impedance of about 500 ohms exists at pin 14 of the 1408L8.

To use the D/A converter in a bipolar mode requires insertion of a jumper on the PADDLE. This jumper connection is made between two wire-insertion sockets. It introduces an offset current via R0 that permits negative output voltages to be obtained. Note that Rre( as defined can be interpreted as a scaling factor because it approximately defines the range of voltage values possible at the output VAo

This only approximately defines the range in the bipolar mode because of the parallel resistance of R0 introduced into the voltage-divider circuit. Because the inverting input of the operational amplifier is at virtual ground, the resistance from Vref to ground now becomes the 2.2 k-ohms of potentiometer R0 in parallel with the 680-ohm resistor. Introducing the offset current (Vref/R0)

April 1981 © BYTE Publications lnc 351

Number

Type

+ 5V

GND

IC1

74138

16

8

IC2

7400

14

7

IC3

7404

14

7

A7 O

A6 C>

A5 O

A4 O

A3 O A2 £> Al O

A0 E>

Figure 5: Jumpers located at C allow the 8-Bit Address Decoder PADDLE to decode any eight consecutive addresses out of a possible 256.

yields the bipolar voltage: V„,„ / DO Dl

AO R„f V 2 4 8 16

D3 16

D4 32

+

D5_ 64

+

D6 128

+

D7 256

)

v„

Rn

R,

As a result of the reference voltage's dependence on R0, both the offset and scaling potentiometers must be adjusted to give a voltage symmetric about 0 V. The resolution of the D/A converter in either unipolar or bipolar mode is one part in 256, or 0.4%.

Now let us consider use of the PADDLE as an A/D converter. This is accomplished by using a software routine in conjunction with the D/A converter and the

Listing 2: SAP, the successive-approximation program. Also see figure 6.

SAP,

ADC,

SUB A

LXIB

O00Q

200Q

MVID

010Q

ORAB

MOV C,A

OUT

DAC

IN

FLAG

ANI

200Q

JNZ

WAIT

PAGE

NEXT,

WAIT,

MOV A,B

XRAC

MOV C,A

MOV A,B

RAR

MOV B,A

MOV A,C

DCR D

JNZ

ADC

PAGE

RET

NOP

IMP

NEXT

PAGE

voltage-comparator integrated circuit. The 311 voltage comparator compares the analog input voltage, VAI, to a reference voltage, VAO, supplied by the D/A converter, derived from a program-generated digital input. The selection of inputs to the voltage comparator with VAI at pin 3 and VAO at pin 2 of the LM311 (IC5) is based on impedance matching (ie: pin 2 is a high-impedance input and avoids loading the analog-signal source).

Now the two voltages are compared in relative magnitude and the result is reflected in the output (pin 7) of the comparator. If VA1 is greater than VAO the output will be at the negative saturation voltage; conversely, if VAI is less than VAO, the output will be at the positive saturation voltage. Because the LM311 has an opencollector output, the output voltage is made TTLcompatible by adding a pull-up resistor tied to +5 V.

The output is tied to D7 of the data bus through a three-state buffer, thus allowing the signal to be monitored by SAP (a successive-approximation program, given in listing 2, with the flowchart shown in figure 6). A logic state of 1 at D7 indicates that an output byte (ie: VAO) is too low, while a logic 0 indicates that the byte is too high.

SAP starts with the most significant bit and either sets or clears it depending upon the status of D7. This process of setting or clearing successive bits is continued until all 8 bits have been tested. Therefore, if the analog input voltage is constant over the duration of the SAP execution time, it can be measured to within 0.4%. SAP takes eight steps to adjust VAO regardless of the value of VA1. Thus, the rate of conversion is constant in this particular software version of an A/D converter. Calculating the maximum rate of conversion requires computation of the SAP execution time because each SAP step allows sufficient settling time for the D/A converter.

352 April 1981 © BYTE Publications lnc

8-Bit Device Decoder PADDLE

This PADDLE uses one 7404 hex inverter, one 7400 quad NAND gate, and a 74138 3-to-8-line decoder (see figure 5). It allows generation of device-select pulses for use in accumulator I/O typical of the 8080 family of microprocessors. As a decoder, the PADDLE provides unique decoding for eight adjacent device codes from XX0 to XX7 over the range of 256 devices. This is done by

CSAP )

SUBA I XI B 000Q 200Q

MVI D 010Q

CLEAR A AND C; PUT TEST PATTERN IN B = 200Q

SET D FOR BIT COUNT

■ »10

0RA B

MOV C,A

OUT DAC IN FLAG

ANI

200Q

JNZ

WAIT

PAGE

NOP JMP NEXT PAGE

SAVE ALL '1' BITS FROM A AND B IN A

STORE AS CURRENT VALUE IN C

COMPARE CURRENT VALUE TO UNKNOWN

yS 1

S >v

NO

VAI y~

? /

DECREASE CURRENT VALUE:RESET TEST BIT= 0

WAIT EQUAL NUMBER OF CLOCK CYCLES

,1

'

SHIFT TEST BIT TO NEXT LESSER DIGIT FOR NEW B

RESTORE A TO CURRENT VALUE

B

MOV A XRA C MOV C,A

MOV A,B RAR MOV 8, A

MOV A,C

DCR D JNZ ADC PAGE

f RETURN J

RET

Figure 6: A flowchart of SAP, the successive-approximation program of listing 2. The 8080 code is shown with each flowchart step.

jumpers in wire-insertion sockets on the PADDLE, which select unique decoding for A7 thru A3 (or A15 thru All) of the address bus lines.

Once a device code is generated, it must be ORed (off of the PADDLE module) with either I/OR (referred to as IN ) or I/OW ( OUT ) to create_a device-select pulse for input or output, respectively. IN and OUT are obtained by NANDing the appropriate latched status bit with the control pulses DBIN (input) or WR (output) on an 8080 processor. In terms of the S-100 bus, IN is defined as sINP (pin 46) NANDed with pDBIN (pin 78), while OUT is PWR (pin 77) inverted and NANDed with sOUT (pin 45).

Construction Details

The printed-circuit layouts for the five PADDLEs are presented in figure 7. Each board is 3 inches long and either IVi or 2 inches wide. The extra section of the Display PADDLE which supports the seven-segment display at a comfortable viewing angle is 1% inches long.

The component layouts for the PADDLEs are given in figure 8. Because the layouts are for single-sided copper foil, all jumpers, as well as all other components, were run parallel to the edges of the PADDLE, with none of the jumper wires crossing. Note that the pins for power and ground must be carefully aligned for insertion into the breadboard. The power bus is assumed to be the outer strip on the breadboard.

All circuit-board holes were drilled with a #65 drill bit (with the exception of holes for wire-insertion sockets; these required a #55 drill bit). The small switches used for the pulsers required that slots be cut with the wheel-cutter blade of a Dremel tool. Marks are provided on the switch pads for guide holes to be drilled at each end of the slots.

It was found convenient to mount the Display, 8-Bit Address Decoder, and A/D-D/A PADDLEs on the side of the breadboard away from the experimenter, while the Logic Switch and Pulser PADDLEs were plugged into the breadboard on the side nearest the experimenter (see photo 1). This accounts for the manner in which the PADDLEs were labeled in figure 7.

With this arrangement, switches and pulsers are close at hand and easy to manipulate, while the display is positioned to face the experimenter and the wire-insertion sockets and their associated jumpers are out of the way.

Once the circuit boards are etched, drilled, and tinplated, the following steps provide the most systematic approach for assembly:

1. Spray-paint the component side of the board with enamel.

2. Label component side with transfer letters.

3. Spray labels with clear acrylic coating.

4. Insert wire jumpers; solder and trim leads.

5. Insert resistors; solder and trim leads.

6. Insert and solder IC sockets.

7. Insert and solder potentiometers.

8. Insert capacitors; solder and trim leads.

9. Using either wire-wrap posts or #24 gauge wire, mount breadboard-insertion pins so that they extend 0.3 inches below the board, solder, and trim flush on component side.

10. Insert and solder wire-insertion sockets.

Text continued on page 356

April 1981 © BYTE Publications Inc 353

Pef 1979

o ------ 0

(a) Pulser PADDLE

/S&lililHIil

o o

o ©

iioiDisioioiEgii

&BA

(b) Logic Switch PADDLE

(c) Display PADDLE

c Pef 1979

(d) A/D-D/A PADDLE

o

(e) 8-Bit Address Decoder PADDLE

Figure 7: Full-size printed-circuit-board patterns for the five PADDLEs.

354 April 1981 © BYTE Publications Ire

Circle 271 on inquiry card.

1 0

1 C

10

7404

•

*■

E P

7474

"

I

74368 74368

a •

I,,,,

(a) PULSER PADDLE

(b) LOGIC SWITCH PADDLE

R1-R16

FND507

FND507

M

CQ

a a □ a

/ /

DIP PLUG

7475

7475

(c) DISPLAY PADDLE

2K

IK

680fi IK

2.2K

<■© V ©- 0 @ A ©I

120pF 200J1 100 K

IK 15pF

©©©©©©©© 0 7

© © ©

74138

7400

7

© © ©

O G ®

<=

3

© 1 ©C ©0

7404

-0

(d) A/D-D/A PADDLE

(e) ADDRESS-DECODER PADDLE

Figure 8: Component view of the individual PADDLEs.

GTC-101 Terminals

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Visa/MasterCard/Diners Club Accepted.

TO ORDER: Send check, money order or credit card number and exp. date to Computer Technology Associates, 5812 Cromo Drive, Suite 102. El Paso, Texas 79912. Personal or company checks require two weeks to clear. Credit card users can call with card information.

SHIPPING: We ship terminals prepaid by motor freight. Air and express delivery are available on all products.

There is no handling charge.

April 1981 © BYTE Publications Inc 355

$5.93 0.18 0.20 1.85

$2.37 0.35 0.69 0.20 0.22

$7.87 0.59 0.49 0.99 0.70 0.22 0.38 0.05 $14.10 0.49 0.69 0.90 0.35 5.75 0.22 0.23

0.05

0.05 0.05 0.05 0.05 1.35 1.35 $7.17 0.16 0.18 0.69 0.20 0.22 0.23

Table 2: Components necessary for each PADDLE and their approximate costs.

Pulser PADDLE: Total

1

7404

1

14-pin IC socket

3

Cherry Microswitch

Logic Switch PADDLE: Total

1

7474

2

74368

1

14-pin IC socket

2

16-pin IC socket

Display PADDLE: Total

2

7447

2

7475

2

FND507

2

DIPplugs(16pin)

5

16-pin IC sockets

1

24-pin IC socket

16

240-ohm, V4 W resistors

A/D-D/A PADDLE: Total

2

7475

1

74368

1

LM311

1

741

1

MC1408L8

5

16-pin IC sockets

6

wire insertion sockets

Resistors

1

680 ohm, Va W

1

1 K, V* W

1

2.2 k-ohm, V* W

1

5.1 k-ohm, V* W

1

100 k-ohm, V* W

1

1 k-ohm potentiometer

1

2 k-ohm potentiometer

Device Code PADDLE: Total

1

7400

1

7404

1

74138

2

14-pin IC sockets

1

16-pin IC socket

24

wire insertion sockets

Listing 3: Program to log 256 points of an analog signal by calling SAP and then display the resultant conversions, used in conjunction with the PADDLE setup in figure 10.

LAD,

DISC,

STALL,

LXIH

TABLE

PAGE

CALL

SAP

PAGE

MOV M,C

INRL

JNZ

LAD

PAGE

MOV A,M

MVID

1DH

OUT

DAC

DCR D

JNZ

STALL

PAGE

INR L

IMP

DISC

PAGE

/INITIAL ADDRESS OF DATA TABLE

/CONVERSION SUBROUTINE /RETURN WITH VALUE IN C

/PUT POINT IN TABLE /NEXT TABLE POSITION /LOGGED 256 POINTS? /NO

/YES:GET POINT FROM TABLE /SET DELAY FOR DISPLAY

/DISPLAY POINT

/COUNTDOWN /DELAY DONE? /NO

/NEXT TABLE POSITION /ENDLESS DISPLAY

Photo I: Complete PADDLEs mounted on a breadboard socket. Starting at bottom center and moving counter-clockwise: Pulser, Logic Switch, Display, 8-Bit Address Decoder, and A/D-D/A.

Text continued from page 353:

Table 2 lists the components necessary for each PADDLE module and their approximate costs.

Experiments Using PADDLES

This quintet of PADDLEs defines a set of circuitry that is indispensable for most interfacing projects. Cost is minimal compared to the benefit derived from the modules. As stated above, usually only a few additional logic gates are required in order to use the PADDLEs as peripheral devices. Although we leave their applications to the needs and imagination of the user, a few elementary applications are described here. We have already discussed how to implement the Logic Switch PADDLE as a vectored-interrupt device to enter an RST instruction.

A second application for a simple I/O circuit can be constructed using the Address Decoder, Display, and Logic Switch PADDLEs as shown in figure 9. This circuit requires only four additional gates and an inverter for device-select-pulse generation. A program to test the circuit would contain a loop with instructions to receive input from the Logic Switch and send output to the Display.

A third application uses the A/D-D/A and Address Decoder PADDLEs to log and display 256 points of a 4 V peak-to-peak sine wave (100 Hz, see figure 10). A main program and subroutine are given in listing 2 and listing 3. Note that the successive-approximation program of listing 2 uses a subroutine that is discussed under the A/D-D/A PADDLE. The conversion rate from analog to digital can be found by calculating the execution time per point of the log-analog-data program. With an 8080A microprocessor operating at 2 MHz, this time is calculated to be 0.41 ms per point. (Displaying this signal on an oscilloscope in an undistorted digital form requires the same rate of display as conversion; this is done by use of the D register as a delay counter in the displayconversion program. )■

356 April 1981 © BYTE Publications Inc

ADDRESSDECODER PADDLE

A![>

DISPLAY PADDLE

£>J

E>^

-Odo -Odi -Odz O"

-C>D4 -C>D5

-C>C>6 HZ>D7

E D7

DO

LOGIC

SWITCH

PADDLE

Figure 9: Configuring three PADDLEs as an I/O (input/output) device for an 8080-type system requires a single 7402 inverter.

O>°SCILL0SC0PE

ADDRESSDECODER PADDLE

^C^

ASO

AiOA2(I^

A1|Z^ A0(^>

outC^ inO^

-<^AUDIO

OSCILLATOR

A / D - D /A PADDLE

£>U

^E^3Z^

k>c

-Q3>D2

-Ow

-OD4 HZ>05 -OD6 -0>D7

Figure 10: PADDLE configuration to convert the output of an audio oscillator to digital form and back to analog for display on an oscilloscope.

MICROSETTE CASSETTES

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C-10 C-20

COMPUTER CASSETTES

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• "■

ii.,...

oi*«

1

• •

£

., J

C-60 C-90

AUDIO CASSETTES

Microsette, the undisputed industry leader in short cassettes for microcomputer applications also offers equally high grade audio cassettes at budget prices. Credit card buyers may phone (415) 968-1604.

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April 1981 © BYTE Publications Inc 357

META TECHNOLOGIES

26111 Brush Avenue, Euclid Ohio 44132 CALL TOLL FREE 1-800-321-3552 TO ORDER

IN OHIO, call (216) 289-7500 (COLLECT)

FILE BOX

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'RINGS' & THINGS

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CLEANING KIT for 51/." drives $24.95

Single Sided, Soft-Sectored 5'/i-inch, (for TRS-80™) Mini-floppy

DISKETTES $21

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(not shown) An economical form of storage for 10 to 15 diskettes, and is suitable for your bookshelf! Case opens into a vertical holder for easy access.

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and Offerings subject to

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358 BYTE April 1981

Circle 273 on inquiry card.

What's New?

PUBLICATIONS

UPTREND

UPTREND is written and designed to help owners of Personal Software's programs increase their productivity. It includes how-to articles on program usage, questions and answers, information on the programs themselves, and letters and interviews with program users. The publication is sent to owners of Personal Software's programs, and it is available at computer retail stores selling the company's products. Contact Personal Software Inc. 1330 Bordeaux Dr, Sunnyvale CA 94086, (408) 745-7841.

Circle 400 on inquiry card

1980 APL Users Meeting Proceedings

The proceedings of the October 1980 APL users meeting are available from I P Sharp Associates. The book is comprised of 52 papers read at the meeting. The subjects covered are APL resources, APL for financial applications and economic forecasting, international networks, personneland record-handling systems, inhouse APL timesharing services, APL techniques and programming tools, teaching APL, and more. The price is S 18 per copy. Contact I P Sharp Associates Ltd, Publications Department, 145 King St W, Toronto, M5H 1J8, Canada, (416) 364-5361. In the US, address I P Sharp Associates Inc. 1200 First Federal Plz, Rochester NY 14614, (716) 546-7270.

Circle 401 on inquiry card

Music and

Microprocessors

Hal Chamberlin's Musical Applications of Microprocessors provides coverage of digital microprocessorsound and music synthesis. This book discusses linear techniques for microprocessor applications, musical applications for 16-bit microprocessors, and all phases of waveform shaping and filtering. Waveform charts, nomographs, and sample control and generation programs written in BASIC are provided to inspire experimentation and application. It is published by Hayden Book Company Inc. 50 Essex St, Rochelle Park NJ 07662, (201) 843-0550. The cost is S24.95.

Circle 402 on inquiry card

H H Smith Catalog

H H Smith Inc, a manufacturer of electronic components and hardware, has published Catalog 810 for design engineers and purchasing agents. Printed-circuit board supports, cable clamps, and spacers are among the items featured. Contact H H Smith Inc, 812 Snediker Ave, Brooklyn NY I 1207, (212) 272-9400.

Circle 403 on inquiry card

Micro Media Magazine

This bimonthly magazine provides software reviews, graphic art, advertisements, articles, and more for the Heath H-8, -88, -89, and Zenith Z89 computers. The magazine comes in an interesting format: on a floppy disk.

Subscriptions are $ I 1.95 for a single issue and S55 for a year. Micro Media supports its subscribers by making the magazine available in both Benton Harbor and Microsoft BASIC, as well as HDOS or CP/M disk formats. Contact Micro Media at POB 402286, Garland TX 75040, (800) 527-4830, ext 101; in Texas (800) 442-4884, ext 101.

Circle 404 on inquiry card

TRS-80 Users Software Mews

CIE People's Software News is free to TRS-80 users. The publication has news of the activities at People's Software, where public-domain software is distributed for a copying charge. The price for a cassette of programs is $10.95. The current 5-tape library contains 206 programs, for $54.75. Contact the Computer Information Exchange Inc, POB 159, San Luis Rey CA 92068, |714) 757-4849.

Circle 405 on inquiry card

H-8 Programming for Beginners

This book, written by Don Inman, Ron Santore, and Bob Albrecht, is designed for Heathkit H-8 users. Computer terms are defined for beginners, and each chapter tests the reader's knowledge by challenging him or her to write a short program or subroutine. The book is a short programming course that explains assembly language and serves as an introduction to Benton-Harbor BASIC. It is available for $8.95 from the Dilithium Press, 30 N W 23rd PI, Portland OR 97210, (503) 243-1 160.

Circle 406 on inquiry card

Software Buyer's Guide

The Official Software Buyer's Guide is published each January and July. It contains listings of software for business applications, word processing, operating systems, games, and general programs for many microcomputers. For information on space deadlines, advertising rates, and availability, contact OSBG, Listing Department, POB 18278, Reno NV8951 1, (702) 356-8400.

Circle 407 on inquiry card

Where Do New Products Items Come From?

The information printed in the new products pages of BYTE is obtained from "new product" or "press release" copy sent by the promoters of new products. If in our judgment the information might be of interest to the personal computing experimenters and homebrewers who read BYTE, we print it in some form. We openly solicit releases and photos from manufacturers and suppliers to this marketplace. The information is printed more or less as a first-in first-out queue, subject to occasional priority modifications. While we would not knowingly print untrue or inaccurate data, or data from unreliable companies, our capacity to evaluate the products and companies appearing in the "What's New?" feature is necessarily limited. We therefore cannot be responsible for product quality or company performance.

April 1981 © BYTE Publications Inc 359

What's New?

SYSTEMS

Small Business System from Systel

The REPORT/80 is a portable business system for less than 510,000. It combines the 8085 and Z80 microprocessors. 64 K bytes of memory, a keyboard; a 12-inch, 80-column by 25-line video display, two 5-inch floppy-disk drives, a 9 by 7 dot-matrix printer, and two RS-232C serial ports in a single unit. CP/M is included. Systel offers a selection of business programs as an option. The Model 11 has a suggested retail price of $8950, and includes two double-sided, double-density drives. The Model 15 has two double-sided, guad-density drives, and costs $9950. For more information, contact Systel Computers Inc. 20370 Town Center Ln, Cupertino CA 95014, (408) 253-0992.

Circle 408 on inquiry card

6800/6809 Development

Systems Can Offer

2-Megabyte Storage

The Scoutsystem development systems from SSB (Smoke Signal Broadcasting) are for 6800/6809 microprocessors. They provide 2 megabytes of floppy-disk storage and up to 64 K bytes of programmable memory. The series features a video display, dual 5- or 8-inch disk drives, plus SSB's Hunter debugging package, which allows memory, register, and stack contents to be inspected and changed. Software includes a macroassembler that provides relocatable code. An MDOS conversion package permits files generated under it to be read by SSB's DOS68 or DOS69 and vice versa. A text editor and text processor are available. The EPROM (erasable programmable read-only memory) programmer can handle 1 K-, 2 K-, or 4 K-byte EPROM s. An optional in-circuit emulator allows the host system to be tied into the target system. The Scoutsystem series also contains a diagnostic routine for identifying failed integrated circuits. Prices for the Scoutsystem series range from under $5700 to $7745. Contact Smoke Signal Broadcasting, 31336 Via Colinas, Westlake Village CA 91362,(213)889-9340.

Circle 409 on inquiry card

Systems from Zeda

The 520 series of portable microcomputers feature a Z80A microprocessor, a video display, floppy-disk drive, and detachable keyboard. The series can be powered by standard 1 10 VAC current, 12 VDC, or optional internal batteries. You can order your system with either a 5-, 9-, or 12-inch video screen (ie: the Models 525, 529, or 522, respectively). The series has 48 K bytes of programmable memory, 2 K bytes of video programmable memory, a double-density floppy-disk-drive controller, and a 200 K-byte drive. A 400 K-byte guad-density drive is available. Up to three drives can be added to the system. A Centronics printer port, an RS-232C serial port, and a bar-code-reader port for a HewlettPackard HEDS-3000 digital wand are provided. The CP/M-compatible

ZEDOS operating system has all the CP/M and CDOS + system calls, plus ZEDOS calls. A status line displays a program counter; disk-error information; a low-power indicator; a typeahead buffer; system idle, screen frozen, and printer activated flags; and disk status. The prices are $4495 for the 522, $3995 for the 525, and $4195 for the 529. Contact Zeda Computers International Ltd, 1662 W 820 North, Provo UT 84601, (801) 377-9948.

Circle 410 on inquiry card

6809 Board for the Apple II

The Mill is a 6809 microprocessor board that plugs into the Apple II. It can be used in manufacturing or laboratory process-control monitoring and concurrent programming tasks. Users can run existing 6502 programs, 6809 programs, or any software reassembled for the 6809 from existing 6800 source code. In operation, the 6809 and 6502 run concurrently, with the 6809 acting as the bus master during the 6502's bus accesses. Typically, the 6809 commands 80% of the available bus time for memory accesses and data transfers. The 6502 can stop the 6809 for time-critical I/O operations. Sections of 6502 programs can be recoded into 6809 machine language. The FLEX operating system can be employed with the Mill. The Mill features directly addressable stacks and the position independence of code, and it allows the Apple II to be used in a multiprogramming mode. The Mill is available from Stellation Two, POB 2342, Santa Barbara CA 93120, for $275.

Circle 411 on inquiry card

16 Megabytes of Storage on the QT

QT System + can be used for accounting, word-processing, and scientific applications. It features a Z80 microprocessor, two 8-inch floppydisk drives, a controller for doublesided, double-density 5- and 8-inch drives, and a Televideo 920C video terminal. There are 48 K bytes of dynamic programmable memory (expandable to 64 K bytes), a 2 K-byte monitor program and Disk BIOS (Basic I/O Subsystem) on an EPROM, two RS-232C ports, two parallel ports, a real-time clock, and the CP/M 2.2 or the MP/M operating systems.

The QT System + comes in two versions. The I-megabyte, singlesided, double-density system sells for $4295. The 2-megabyte, doublesided, double-density unit is priced at $4995. For complete details, contact QT Computer Systems Inc. 15620 S Inglewood Ave, Lawndale CA 90260, (800) 421-5150; in California (213) 970-0952.

Circle 412 on inquiry card

360 April 1981 © BYTE Publications Inc

What's New?

PERIPHERALS

Voice-Entry Terminal for the Apple II

The VET/2 voice-entry terminal plugs into any slot of a 48 K-byte Apple II. A direct keyboard link allows the user to choose keyboard or voice input at any time. Once a word has been entered into the program, whenever it is spoken, the function is performed. The VET/2 is supplied with preprocessor, interface board, software with demonstration programs, noise-canceling headset microphone, and a user's manual. The price is S895 from Scott Instruments, 815 N Elm, Denton TX 76201, (817) 387-9514.

Circle 413 on inquiry card

Connect Your Selectric to a Computer

The Escon interface system includes all the electronics, connectors, and instructions necessary to convert an IBM Selectric typewriter into an output printer. Units have been designed for S-100 systems, and RS232C serial, parallel, and IEEE-488 interfaces. No drilling or modification is reguired. The typewriter can still be used in a normal fashion, and its eligibility for IBM warranty and service will not be affected. Printing speed is 15 cps (characters per second), which is approximately 160 words per minute. Prices range from S595 to S675. For details, contact Ipex International Inc. 16140 Valerio St, Van Nuys CA 91406, (213) 781-0020.

Floppy-Disk Drives from Commodore

The 8060 series of 8-inch floppydisk drives includes the CBM 8062, which can store 3.2 megabytes of data, and the CBM 8061, which handles up to 1.6 megabytes. The 8061 reads and writes one side of the disk, while the 8062 handles both sides. The drives and operating system are compatible with the IBM 3740 format and Commodore's other drives. For more information, contact Commodore Business Machines Inc. 950 Rittenhouse Rd, Norristown PA 19403, (215) 666-7950.

Circle 415 on inquiry card

Circle 414 on inquiry card

Video Terminal from Perkln-Elmer

The Perkin-Elmer Model 550S is a block mode/editing video-display unit. Three modes allow for conversational timesharing, transaction processing, and test manipulation or software development. The 550S offers an optional second page of scrolling memory. The 24-line screen windows into 48 lines by 80 columns of text. The standard keyboard has 83 keys, including a numeric pad and four program function keys. A serial printer port is standard, as well as automatic on/off host control over terminal block transmissions and half intensity, blink, nondisplay, and protected features. Transmission types included are: send all, send unprotected only, send line, send page, and send from home to stop code. The 550S is priced at SI 189. Contact Perkin-Elmer, Terminals Division, 360 Rt 206 South, Flanders NJ 07836, (201) 229-6800.

Circle 416 on inquiry card

Pitch Analyzer for Speech Synthesis

The Visi-Pitch extracts and measures vocal pitch in real time. The device provides visual or numerical descriptions of pitch variability, speech rhythm, and intonation contours. It can be used in the testing of speech synthesis and recognition systems, and in speech therapy. The Visi-Pitch interface can transfer frequency or period information to 8-bit parallel inputs. The period data is generated after each pitch period, and frequency data is generated every 0.5 seconds. The data output is 3-state 8-bit parallel. The price for the unit is S2410 from Kay Elemetrics Corporation, 12 Maple Ave, Pine Brook NJ 07058. (201) 227-2000.

Circle 417 on inquiry card

16 K-Byte Memory Card for the Apple II

RAMCard provides the Apple II 48 K computer with 16 K bytes of programmable memory. It's compatible with Microsoft's SoftCard. It can be used with all software available for the SoftCard, but it cannot be used in addition to the Apple Language Card. The price of the RAMCard is $195. For more details, contact Microsoft Consumer Products, 400 108th Ave NE, Suite 200, Bellevue WA 98004, (206) 454-1315.

Circle 418 on inquiry card

April 1981 © BYTE Publications Inc 361

What's New?

PERIPHERALS

Vldeodlsk-toApple Interface

TheColoney VAI-1 interface board fits inside the Apple and allows complete control of the DiscoVision industrial videodisk player. In addition, the package provides circuitry to switch computer- or disk-generated video on a single television monitor. The packages sells for S525, and includes a manual, a controller card, junction box for video connections, control subroutines in assembly language and Pascal, cables, and a demonstration program. For additional information, contact Coloney Productions, 1248 Blountstown Hwy, Tallahassee FL 32304, (904) 575-0691.

Circle 419 on inquiry card

MicrocomputerCompatible Temperature Probes

Tempsens provides direct temperature input for a variety of microcomputers, including the PET, the Apple II, and the TRS-80. Operating within a temperature range of -24°C to 72°C (-10°F to + I60°F), each Tempsens module provides two temperature probes to the CmC (Connecticut microcomputer) AIM 16 analog input module using a CmC MANMODI. The MANMODl will accept input from up to 8 Tempsens modules, for a total of 16 individual probes. The suggested retail price of a 2-probe Tempsens is $49.95. Contact Connecticut microcomputer Inc, 34 Del Mar Dr. Brookfield CT 06804, (203) 775-4595.

Circle 420 on inquiry card

Light Pen for OSI Computers

The L C S Light Pen Kit designed for OSI (Ohio Scientific) computers features a coiled cord and an easily disconnected plug. The light pen is manufactured by Lewis Computer Systems, and is distributed by Faragher Associates Inc, 7635 W Bluemound Rd, Milwaukee Wl 53213, (800) 558-0870. The suggested list price is $29.95.

Circle 421 on inquiry card

Color-Graphics

Board for

Heath Microcomputers

The HA-8-3 color-graphics board can be used with the Heath H-8 and All-in-One computers. The board uses a TI-9918 color video-display-generator integrated circuit. An AY-3-8910 programmable sound-generator circuit is also included. Four X,Y joystick consoles can be used with the board; each console has 4 bits of parallel I/O.

A socket is provided for an AMD9511 arithmetic processor circuit. The HA-8-3 can be used with most video monitors as well as other video accessories utilizing NTSC composite color video. Demonstration software on a 5-inch floppy disk is included. The board sells for $395. Contact Heath Company, Department 350-590, Benton Harbor Ml 49022, (616) 982-3210.

Circle 422 on inquiry card

362 April 1981 © BYTE Publications Inc

This Black-Hole Diode Is User-Transparent

INPUT [~_>

-©

-<CD INPUT

Another new addition in the smallcomponents market is the 7N-oo BHD (black-hole diode). This device has two inputs and no output. Care must be taken to shield this component appropriately or it may absorb the unit it is placed in. The 7N-oo will accept any voltage or current value. It is useful for Gl (garbage-in) applications. Due to the light-absorption qualities of the device, we could not provide a photograph. Contact Spatial Regression Ltd, POB 463, Paulborough NH 03458.

Circle 423 on inquiry card

Software for the Hayes Mlcromodem II

Datacomm is a data-communications-software package for use with the Hayes Micromodem II for Pascalequipped Apple II microcomputers. Datacomm consists of a terminal program that allows data and program exchange. It uses the Apple's Pascal routines for ease and accuracy, and Hayes Micromodem II routines are used so that a programmer can include data-communications commands in his or her Pascal program. Datacomm is available in retail computer stores for $50. Contact Hayes Microcomputer Products Inc. 5835 Peachtree Corners E, Norcross GA 30092, (404) 449-8791.

Circle 424 on inquiry card

What's New?

MISCELLAMEOUS

Low-Power

16 K-Byte Memory

Board for S-100 Systems

This 16K-byte programmable memory board for S-100-bus systems uses 650 mA at +5V, 90 mA at + 12V, or 16 mA at -5V. Each 4 K-byte block is addressable to any 4 K boundary. The board uses NEC (Nippon Electric Company) UPD 410 D integrated circuits. This static memory board costs S350 in kit form, or $385 assembled. Contact Shell Electronics Company, M/S 1429, Sun Valley CA 91352. (213) 767-5597.

Circle 425 on inquiry card

S-100 ErrorCorrecting Board

This 4 MHz S-100 error-correcting board monitors 64 K bytes of existing system programmable memory and intervenes to correct bus data before it is accepted by the microprocessor. The board corrects I-bit memory errors and flags all 1- or 2-bit errors. All operations are performed through onboard hardware. The board immediately corrects memory problems, and latched displays show the address and bit in error. The price is $ 1295 from Correlation Systems, 81 Rockinghorse Rd, Rancho Palos Verdes CA 90274.

Circle 426 on inquiry card

Z80 Monitor

in an EPROM

SSM Microcomputer Products has a Z80 monitor in a single-voltage 2716 EPROM. Supporting SSM's CB2 Z80 microcomputer board, the monitor allows operators to display, substitute, or fill memory; perform hexadecimal arithmetic; establish two program breakpoints; set and examine registers; assign I/O devices; and input and output data to or from a port. The monitor can scan its memory and set its stack to avoid replacement or reprogramming of the EPROM. Documentation and software listings are provided with the monitor, which is priced at $89. Contact SSM Microcomputer Products, 2190 Paragon Dr, San Jose CA 95131, (408) 946-7400.

Circle 427 on inquiry card

Apple II Display Board

The Apple II Display Board has a run-stop, single-step switch that simplifies identification of shorted lines between address or data bits and shows individual steps for teaching computer logic. The board has 16 address LEDs (light-emitting diodes), 8 data LEDs, and 1 ready LED. All lines are buffered. The board sells for $49.95 assembled and tested, $42.95 for the kit, and $25.95 for the bare board. Contact John Bell Engineering, POB 338, Redwood City CA 94064, (415) 367-1137.

Circle 428 on inquiry card

Serial-Communications Card for S-100 Systems

Cromemco's Quadart serial-communications S-100 interface card has four serial channels. Any channel can support asynchronous or synchronous byte- or bit-mode communication protocols under software control. Handshaking is provided. The Quadart can connect an S-100 microcomputer and an IBM-type machine using Bisync or SDLC protocol. A loopback feature provides the capability to connect data from one channel or modem to another, or allows any modem/channel combination to be used. Data rates range from 0 to 300 k bps (bits per second). The interface supports the interrupt structure of the Z80A microprocessor. The Quadart has real-time clocking capability. Control for the board is from the C-Bus provided by Cromemco's Model IOP processor computer. The Quadart serial-communications board is available for $595. The IOP costs $695. For information, contact Cromemco Inc, 280 Bernardo Ave, Mountain View CA 94043, (415) 964-7400.

Circle 429 on inquiry card

WordCheck Spots

Misspellings in

Documents and Letters

WordCheck interacts with WordPro 3 or 4 word-processing programs and checks every word for spelling or typographical errors. The program contains approximately 2000 of the most commonly used words and suffixes. Words that do not match this list appear on the screen. If you wish, these words can then be added to a 1000-word auxiliary spelling list. WordCheck is available for CBM and PET 32 K-byte microcomputers with floppy-disk drives. The list price is S200 from Micro Computer Industries Ltd, 1520 E Mulberry, Suite 1 10, Fort Collins CO 80524, (303) 221-1955.

Circle 430 on inquiry card

April 1981 © BYTE Publications Inc 363

What's New?

MISCELLANEOUS

Copy Stands for Computer Terminals

The Keyboard Companion copy stands keep work directly in front of the operator. They fit most terminals with detachable keyboards, including the Apple II. The units can support a telephone book and other heavy reference manuals or manuscripts. Installation is quick and easy. Prices begin at $ 19.95 for the 16-inch model. For information, contact PKay Corporation, POB 11463, Costa Mesa CA 92627, |714] 548-2081.

Circle 431 on inquiry card

Zilog's New Microcomputer Systems

The MCZ 2/19 features a Z80A microprocessor, 64 K bytes of programmable memory, and 2.4 megabytes of floppy-disk storage that can be expanded to 4.8 megabytes with additional disk drives. The MCZ 2/49-1 system includes the MCZ 2/19 plus a video-display terminal, Zilog's RIO 3 operating system, and COBOL or BASIC. Zilog also has PLZ and a variety of business-application software packages available. In 50-unit quantities, the MCZ 2/49-1 costs S5890, and the MCZ 2/19 is S5270. For details, contact Zilog, 10340Bubb Rd, Cupertino CA 95014, (408) 446-4666.

Circle 432 on inquiry card

Noise-Emlttlng Diode from LOUD

The 3N120DB NED (noise-emitting diode) is a new development in indiscreet electronics. It is pictured in a DO-4 case. It is a low-voltage, highpower device with a + 3dB signal-tonoise ratio. The NED is available from LOUD Electronics, POB 463, Wheelborough NH 03458.

Circle 433 on inquiry card

Memory Board for SS-50 Bus Works with 1-Megabyte Memory Systems

A 24 K-byte static programmable memory board for SS-50 bus systems, the M24SS is available in 8 K-, 16 K-. and 24 K-byte configurations. The board is organized in 8 K-byte segments that can be located at any 8 Kboundary of a 64 K-byte memory space. The board uses standard 2114 integrated circuits. Access time is 300 ns. The 8 K-byte configuration is $199.95, the !6K- is $349.95, and the 24 K- is $499.95. A memory expansion kit is available for SI39.95. For complete details, contact Percom Data Company, 211 N Kirby, Garland TX 75042, (800) 527-1592; in Texas (214) 272-3421.

Circle 434 on Inquiry card

Control AC

Circuit Devices

from Your Apple II

This I/O (input/output) interface board for the Apple II can operate up to 256 BSR System X-10 AC control modules. Input communications come from the X-10 command console and temperature and security input modules, which will soon be available from Intelligent Control Systems. On-board software is provided to handle the AC I/O. The software also coordinates the background schedule-control process and sets, reads, and displays the real-time clock. Four selectable interrupt rates allow the simultaneous running of machine-language programs in the background and other programs in foreground. A rechargeable battery powers the clock when the Apple is off. The price is $ 185 from Intelligent Control Systems Inc, POB 14571, Minneapolis MN 55414, (612) 699-4342.

Circle 435 on inquiry card

Multitasking System for Dynabyte 5000 Microcomputers

DOS Level 4 is a multitasking operating system for Dynabyte's Series 5000 microcomputers. This CP/Mand MP/M-compatible system is available on all Dynabyte microcomputers. It can handle up to 8 terminals and 16 printers, and any single terminal can run up to 8 simultaneous jobs. Any printer can be accessed from any terminal, and each terminal can have or share a single system spooler. Memory capacity is 400 K bytes.

DOS Level 4 supports MBASIC, CBASIC, COBOL, FORTRAN, PL/I, and Pascal. The package includes interfacing software, a driver for a modem, and a utility to help programmers create interface drivers for special peripherals. For information, contact Dynabyte Inc, 115 Independence Dr, Menlo Park CA 94025, (800) 227-8300; in California (415) 329-8021.

Circle 436 on inquiry card

364 April 1981 © BYTE Publications Inc

Release Wire Ties

Courtesy Plastics has wire ties that feature release levers molded into locking heads. Squeezing this lever allows the tie to be adjusted or removed without damaging it. The tie can be reused later. These ties may be installed by hand or machine. They come in sizes for bundles up to 5 cm (2 inches) in diameter. The Release Wire Tie has a tensile strength of 50 lbs. For complete details, contact Courtesy Plastics, 250 Alice St, Wheeling IL 60090, (312) 541 -7900.

Circle 437 on inquiry card

Apple Users' Work Collected in Catalog

The Special Delivery Software Catalog program offers a selection of user-written programs for the Apple computer. This catalog program is designed by Apple to encourage people outside the company to develop software and to make their applications programs available to other Apple users. The first catalog contains 12 programs, including a personal-finance manager, a BASIC teaching program, stepwise multiple regression, programs for learning geometry and measurement, games, a Pascal animation package, a Pilot animation program, electronic music, and a US geography package. Software prices are in the S35 to $150 range. Apple plans to update the catalog three times annually. To order the free catalog or the software from it, call (800) 538-3088; in California call (800) 662-9256. To submit programs for evaluation by Apple, write to Special Delivery Software, 10260 Bandley Dr, Cupertino CA 95014.

Circle 438 on inquiry card

What's New?

MISCELLANEOUS

Color Graphics Printer

The Model IS800I is a color graphics printer produced by PrintaColor Corporation. The device contains a microprocessor and features a twelve-nozzle, three-color ink-jet printhead that can print seven colors using two- or three-color overlays. The print head has a resolution of 100 dots per inch. The microprocessor enables the unit to present minimal burden to the host computer. The IS8001 can print on l47/a-inch paper with 70 characters per line. For further details on this S6000 color printer, contact PrintaColor Corporation, 5965 Peachtree Corners E, Norcross GA 30071, (404) 448-2675.

Circle 439 on inquiry card

Touch-Sensitive Kits for Video Displays

Interaction Systems Inc's touchsensitive add-on kits can be attached to any 12- or 15-inch (diagonal) video screen. Data can be entered on the screen by touching the appropriate area of the screen. The kits utilize a capacitance-sensitive faceplate, which is mounted in front of the video screen. Software and firmware allow the computer to identify and interpret the changes in capacitance. The faceplate interface uses a Z80 microprocessor. Custom configurations are available. The kits are priced under $300 in OEM (original equipment manufacturer) quantities. Contact Interaction Systems Inc. 24 Munroe St, Newtonville MA 02160, (617) 244-6825.

Circle 440 on inquiry card

Inexpensive Dot-Matrix Printer

The GP-80M is an 80-column, 5 by 7 dot-matrix printer having an upperand lowercase ASCII (American Standard Code for Information Interchange) set, double-width characters, and dot graphics modes. The printhead life is 30 million characters. Print speed is 30 cps (characters per second), with original-plus-two copies capabilities and adjustable tractors to accommodate paper widths up to 8 inches. It measures 171 by 328 by 127 mm (7 by 13 by 5 inches) and weighs 2.5 kg [5'A lbs). Parallel and serial interfaces are available. The suggested retail price is $425. Contact Watson, Burton, and Associates, Port POB 122, Yokohama 231-91, Japan, Telex 3822596.

Circle 441 on inquiry card

Plug Centronics 737 Printer into the H89/Z89

This interface board allows the Centronics 737 printer to be used with the Heath/Zenith H89/Z89 microcomputer. It plugs into either machine's internal bus, and can use any of the four decoded I/O ports. The HDOS device driver provides access to the printer's features, which include underscoring; elongated, proportional, condensed, or standard print fonts; sub- and superscripting; backspace; and half or full, forward or reverse line feeds. The interface and HDOS device driver together are $64.95. Separately, the driver is $14.95, and the interface is $54.95. Order from FBE Research Company Inc. POB 68234, Seattle WA 98168.

Circle 442 on inquiry card

April 1981 © BYTE Publications Inc 365

What's New?

MISCELLANEOUS

Universal Peripheral Controller for the Z8000

Zilog's Z8090 Universal Peripheral Controller (Z-UPC) is designed for distributed processing and multitasking applications. The Z-UPC does arithmetic tasks, translation and formatting of data, and controls I/O (input/ output] devices. It features 2 K bytes of internal ROM [read-only memory), externally expandable from 2 to 4 K. Also included is a 256-byte register file, three programmable 8-bit I/O ports, two counter/timers, and six levels of internal prioritized interrupts. The device is offered in four other versions, and all are priced at SI 17.36 each, in sample quantities of 10 to 99. For additional details, contact Zilog, 10340 Bubb Rd, Cupertino CA 95014, (408) 446-4666.

Circle 443 on inquiry card

Atari 400 and

800 Screen Printer

The Macrotronics screen-printer package enables users to print an Atari 400's or 800's screen display onto a Trendcom 200 or IDS 440G Paper Tiger printer. Text, giaphs, and drawings can be printed, and the image can be printed in gray-scale, black-and-white, and reversed image. LPRINT and LIST"P:" commands are used to print. The package includes a connector assembly with a cable and a 3 K-byte auto-loading program on floppy disk and cassette. Listings of sample programs are included in the user's manual. The package is priced at S 139, from Macrotronics Inc. 1 125 N Golden State Blvd. Suite G, Turlock CA 95380, (209) 667-2888.

Circle 444 on inquiry card

Novation Has LSI Modem Modules

These modem modules can operate at rates up to 1200 bps (bits per second) and are designed for building-block applications within computers or terminals. The modules can provide Bell 202 half-duplex, Bell 103 answer/originate, CCITT European Standards V.21 or V.23, ViewData European Network, and interface with the deaf teletypewriter (TTY) network. Contact Novation, 18664 Oxnard St, Tarzana CA 91356, (213) 996-5060.

Circle 445 on inquiry card

Extremely Fast

Schottky PROMs

Using a titanium/tungsten technique. Monolithic Memories Inc has developed a series of fast Schottky I K- and 2 K-bit bipolar PROMs (programmable read-only memories). These devices use a programming technique that doesn't require a separate programming pin. Available in 256- by 4-bit, and 5 16- by 4-bit configurations, the PROMs feature PNP inputs for low-input current, full Schottky clamping, and three-state or open-collector outputs. They operate

at 45 ns for commercial and 55 ns for military devices. In lots of 100, each 63S140/I commercial I K-bit PROM costs $5; the military 53S140/1 is S7.50. In similar quantities, the 2 K-bit PROMs are S7.50 and SI 1.25 each. Contact Monolithic Memories Inc, 1 165 E Arques Ave, Sunnyvale CA 94086, (408) 739-3535.

Circle 446 on inquiry card

Tl Extended BASIC and Memory Expansion Unit

Tl Extended BASIC is an expanded version of the resident BASIC in Texas Instruments' TI-99/4 microcomputer. It features ACCEPT AT and DISPLAY AT statements, sprites (programmable moving objects), subprograms, and error-handling functions. Multiple statements can be written on the same line with tail-end remarks. Complex IF...THEN...ELSE statements can also be written.

The Memory Expansion Unit is exclusively designed for use with Extended BASIC or UCSD Pascal, Version IV, which is newly available. The unit adds 32 K bytes of programmable memory to the 16 K bytes resident in the TI-99/4. For more information, contact Texas Instruments Inc, Consumer Relations, POB 53, Lubbock TX 79408, (800) 858-4565; in Texas (800) 692-4279.

Circle 447 on inquir

ry card

Fujitsu America's

8-Inch

Winchester Disk Drives

The Model 2311 8-inch Winchester disk drive stores 48 megabytes and the Model 2312 84 megabytes; both feature a 20 ms access time. The 2311 uses two hard disks for storage, and the 2312 stores its 84 megabytes on four disks, utilizing 589 cylinders at 20 K bytes per track. An SMD interface with data-separation circuitry and internally selectable fixed- and variablelength sector formats are provided. The price of the 48-megabyte 2311 is $3195 in OEM (original equipment manufacturer) quantities of 100, and the 84-megabyte 2312 drive is S3795 in the same quantities. The Fujitsu Model 2301 floppy-disk drive stores 11.7 megabytes and is priced at $ 1660 in OEM quantities of 100. The 2302 floppy-disk drive stores 23.4 megabytes and is priced at S2095 in OEM quantities. For additional information, contact Fujitsu America Inc, 2945 Oakmead Village Ct, Santa Clara CA 95051, (408) 727-4300.

Circle 448 on inquiry card

366 April 1981 © BYTE Publications Inc

DIGITAL RESEARCH COMPUTERS

(214)271-3538

32K S-100 EPROM CARD NEW!

Blank PC Board - $34

ASSEMBLED & TESTED ADD $30 SPECIAL; 2716 EPROM's (450 NS) Are $11.95 EA. With Above Kit.

7. Any or all EPROM locations can be disabled.

8. Double sided PC board, solder-masked, silk-screened.

9. Gold plated contact fingers

10. Unselected EPROM's automatically powered down for low power.

11. Fully buffered and bypassed.

KIT FEATURES

1 Uses+5V only 2716 (2Kx8) EPROM's.

2 Allows up to 32K of software on line!

3. IEEE S-100 Compatible.

4. Addressable as two independent 16K blocks.

5. Cromemco extended or Northstar bank select

6 On board wait state circuitry if needed. 12 Easy and quick to assemble.

32K SS-50 RAM

$37900

KIT

For 2MHZ Add $10

Blank PC Board $50

For SWTPC 6800 - 6809 Buss

Support IC's

and Caps

$19.95

Complete Socket Set

$21.00

Fully Assembled,

Tested, Burned In

Add $30

At Last! An affordable 32K Static RAM with full 6809 Capability.

FEATURES:

1. Uses proven low power 2114 Static RAMS.

2. Supports SS50C - EXTENDED ADDRESSING.

3. All parts and sockets included.

4. Dip Switch address select as a 32K block.

5. Extended addressing can be disabled.

6. Works with all existing 6800 SS50 systems.

7. Fully bypassed. PC Board is double sided, plated thru, with silk screen.

16K STATIC RAM KIT-S 100 BUSS

16K STATIC RAM SS-50 BUSS

PRICE CUT!

~»a£ I2iBt'"_~ri.

$19995

KIT

111 Mil IIS III 111

...............I

PRICE CUT!

FULLY STATIC!

BLANK PC BOARD W/DATA-$33

LOW PROFILE SOCKET SET-$12

SUPPORT IC'S & CAPS-$19.95

KIT FEATURES

1 Addressable as four separate 4K Blocks.

2 ON BOARD BANK SELECT circuitry (Cromemco Standard1) Allows up to 512K on line!

3 Uses 2114 (450NS) 4K Static Rams

4 ON BOARD SELECTABLE WAIT STATES

5 Double sided PC Board, with solder mask and silk screened layout Gold plaled contact fingers

6 All address and data lines fully buflered ASSEMBLED & TESTED-ADD $35

7 Kit includes ALL parts and sockets

8 PHANTOM is jumpered to PIN 67

9 LOW POWER under 15 amps TYPICAL from the +8 Volt Buss

10 Blank PC Board can be populated as any multiple of 4K

FOR 2MHZ ADD $10

i i1|1Ii1i1111III illliiiillill.il 111

FOR SWTPC 6800 BUSS!

OUR #1 SELLING RAM BOARD!

ASSEMBLED AND TESTED - $35

KIT FEATURES

1 Addressable on 16K Boundaries

2 Uses 2114 Static Ram 3. Fully Bypassed

4 Double sided PC Board Solder mask and silk screened layout

5 Ail Parts and Sockets included

6 Low Power Under 1 5 Amps Typical

BLANK PC BOARD—$35 COMPLETE SOCKET SET—$12

SUPPORT IC'S AND CAPS—$19.95

H0NV STEREO! «£*

S-100 SOUND COMPUTER BOARD

COMPLETE KIT! $8495

(WITH DATA MANUAL)

At last, an S-100 Board that unleashes the full power of two unbelievable General Instruments A Y3-8910NM OS computer sound IC's Allows you under total computer control to generate an infinite number of special sound effects tor games or any other program. Sounds can be called in BASIC. ASSEMBLY LANGUAGE, etc. KIT FEATURES: » TWO Gl SOUND COMPUTER IC'S

* FOUR PARALLEL I/O PORTS ON BOARD » USES ON BOARD AUDIO AMPS OR YOUR STEREO. « ON BOARD PROTO TYPING AREA.

* ALL SOCKETS. PARTS AND HARDWARE ARE INCLUDED » PC BOARD IS SOLDERMASKED. SILK SCREENED, WITH GOLD CONTACTS.

* EASY QUICK AND FUN TO BUILD WITH FULL INSTRUCTIONS

* USES PROGRAMMED I/O FOR MAXIMUM SYSTEM FLEXIBILITY Both Basic and Assembly Language Programming examples are included

SOFTWARE:

SCL'" is now available! Our Sound Command Language makes writing Sound Effects programs a SNAPI SCL'" also includes routines for Register-Examine-Modify, Memory-Examine-Modify. and Play-Memory. SCL'" is available on CP/M' compatible diskette or 2708 or 2716 Diskette $24.95 2708 - $19.95 2716 - $29.95. Diskette includes the source. EPROM'S are ORG at E000H

BLANK PC BOARD W/DATA $31

4K DYNAMIC RAM BLOWOUT!

SAME AS INTEL 2107B!

4K RAMS AT AN UNBELIEVABLE 50C EACH!!!

Prime, new, National Semi., 1979 date coded, full spec, parts. NS. #MM5280-5N. Same as INTEL 2107B-4, T.l. TMS4060, NECuPD411, etc. We bought a HUGE QTY. from a West Coast Distributor at truly DISTRESS PRICES! One of the most popular and reliable RAM's ever made. These parts have been used by almost all Major Computer Main Frame Mfg. the world over! Arranged as 4K x 1, 270 NS Access Time, 22 Pin Dtp. These units DO NOT use multiplexed addressing, thus making REFRESH and other timing very simple. See INTEL MEMORY DESIGN HANDBOOK for full application notes. The NAT. SEMI. MEMORY DATA BOOK is available at most Radio Shack Stores. Prime units in original factory tubes!

#5280-5N 4096 BITS X 1 270 NS ACCESS 8 FOR $4.95 32 FOR $16

FACTORY CASE (450 PCS) — $180 Sockets Special: 22 Pin Low Profile (With Purchase of 5280's) 8 FOR $1.

COMPUTER PARTS SPECIALS

74LS175- .99 8035 Intel Single Chip CPU 6.95

74LS240 - 1.19 Signetics 2901 4 Bit Slice - 6.95

74LS241 - 1.19 AMD 2903 4 Bit Super Slice - 12.50

74LS244 - 1.19 AMD 29705 Dual Port RAM - 8.95

74LS373 - 1.29

Intel 2716-1 (350 NS) - 12.95

NEW! G.I. COMPUTER SOUND CHIP

AY3-8910. As feaiured in July. 1979 BYTE1 A fantastically powerful Sound & Music Generator. Perfecf for use with any 8 Bit Microprocessor Contains: 3 Tone Channels. Noise Generator. 3 Channels of Amplitude Control 16 bit Envelope Period Control. 2-8 Bil Parallel I/O 3 D to A Converters, plus much more' All in one 40 Pin DIP. Super easy interface to the S-100 or other busses $11.95 PRICE CUT!

SPECIAL OFFER: $14.95 each Add $3 for 60 page Data Manual.

Digital Research Computers

9 (OF TEXAS) '

P.O. BOX 401565 » GARLAND, TEXAS 75040 " (214) 271-3538

TERMS: Add $1.50 postage. We pay balance. Orders under $15 add 75<t handling. No COD. We accept Visa and MasterCharge. Tex. Res. add 5% Tax. Foreign orders (except Canada) add 20% P & H. Orders over $50, add 85$ for insurance.

•TRADEMARK OF DIGITAL RESEARCH.

WE ARE NOT ASSOCIATED WITH DIGITAL RESEARCH OF CALIFORNIA, THE SUPPLIERS OF CPM SOFTWARE.

BYTE April 1981 367

What's New?

SOFTWARE

CP/M for Heath Microcomputers

Heath H-8 and H-89 All-ln-One computers can now have the CP/M operating system. Three operating system modules (BIOS, BDOS, CCP) are included with Heath CP/M. Utilities included are a two-pass 8080 assembler; a text editor; an 8080 debugger with traced execution and disassembly; a file dump; system generation and relocation; programs to display file sizes and disk usage, set file class, assign physical and logical devices, display system parameters, copy files between devices, and convert internal HEX files into memory images. Full source code is provided. The Heath CP/M operating system comes on 5- and 8-inch floppy disks for S150. For details contact, Heath Company, Department 350-620, Benton Harbor Ml 49022, (616) 982-3210.

Circle 449 on inquiry card

Accountant's Software

DATAWRITE is a CP/M-based client-write-up program for accountants. It supports floppy- and harddisk drives and incorporates expanded account-number structures, several journal options, and complete report-writing capabilities. For details on DATAWRITE, contact Dataword Inc. 1404 140th PI NE, Bellevue WA 98007, (206J 643-2050.

Circle 450 on inquiry card

Interface CBASIC With AssemblyLanguage Programs

CBASIC, Version 2, incorporates a function that allows assembly-language packages to be interfaced with CBASIC programs. It permits trace outputs to the console when a lineprinter statement is in effect. It provides for 255 characters to be entered in response to an input statement. A backslash within a data statement is treated as a literal character rather than a continuation character. CBASIC features 14-digit accuracy for business applications, and is implemented as a compiler. It allows a text editor to be used. CBASIC, Version 2, was developed by Compiler Systems, POB 145, Sierra Madre CA 91024, (213) 355-1063.

Circle 451 on inquiry card

Crlbbage for the TRS-80

Cribbage Master plays a strong game, pegging its own points in play and never missing an opportunity to score—especially on points you miss. The program shows the order of the cards as played for in-play pegging. All entries are made by a single keystroke. Cribbage Master is designed for the TRS-80 16 K-byte Level II. It is available from Manhattan Software, POB 35, Pacific Palisades CA 90272, (213) 454-8290, for SI 2.95.

Circle 452 on inquiry card

Software for Z80, 8080, and 8085 Systems

The ZAPS software system has assemblers and disassemblers for Z80, 8080, and 8085 systems. An editor, loader, and the use of Intel and ZilogMostek mnemonics are also featured. The system requires any Z80 processor with a North Star floppy-disk drive, and 48 K bytes of programmable memory. The price is $100 from Conentropy, POB 316, Yonkers NY 10704.

Circle 453 on inquiry card

6800 Diagnostics and Disk Repair

Technical Systems Consultants Inc has a memory-diagnostic and disk-repair package for the 6800 microprocessor. The programs run under the 6800 FLEX operating system. Included in the memory diagnostics are a 0s and Is test, a random pattern test, walking bit tests, a dynamic programmable-memory dropout test, and a convergence test.

The disk-repair portion contains utilities that operate on a FLEX-formatted floppy disk. There are three diagnostic utilities that report unreadable sectors and structural inconsistencies among files, two utilities for recovering data, a utility to remove bad or intermittent sectors from the free space, a program to retrieve deleted files, a single-sector read/write/modify routine, and a copy utility which ignores CRC (cyclic redundancy check) errors. This package is available on 5or 8-inch floppy disk for $75. Contact Technical Systems Consultants Inc, POB 2570, 1208 Kent Ave, West Lafayette IN 47906, (317) 463-2502.

Circle 454 on inquiry card

Three Versions of

FORTH for OSI

Starstruck Software has fig- (FORTH Interest Group) compatible FORTH for OSI (Ohio Scientific) C8P dual floppydisk-drive systems. A line editor, commands for the OS65D operating system, and a record of unused dictionary space are featured. This version costs $79.95. Contact Back to Basic Computer Center, #43 Cross Keys Shopping Center, Florissant MO 63033, (314) 873-4495.

OSI-FORTH 2.0 runs under the OS65D3 operating system, and has access to all commands and resources. A 6502 assembler and a text editor are included. OSI-FORTH 2.0 runs on C2, C3, C4, and C8 systems. It is supplied on 5- or 8-inch floppy disks, and has a suggested price of $79.95. For details,. contact Technical Products Company, POB 12983, University Sta, Gainesville FL 32604.

TEK-AIDS' OS65U fig-FORTH uses the OS65U operating system and runs coresident with BASIC, allowing FORTH modules to be integrated into existing programs. OS65U will run on OSI 48 K-byte systems with dual disk drives or hard-disk and multi-user configurations. The price for this system is $250. Contact the Software Federation Inc, 44 University Dr, Arlington HtsIL 60004, (312) 259-1355.

Circle 455 on inquiry card

New Games for the Apple II

The Apple now has three new high-resolution-graphics games written in machine language: Asteron, Star Avenger, and Shooting Gallery. They run on the Apple II under all versions of DOS (disk operating system) and on the Language System. Each game is supplied on a disk and requires 48 K bytes of memory. Shooting Gallery costs $22.50, and the others are priced at $27.50. Contact Western MicroData Enterprises Ltd, POB G33, Postal Station G, Calgary, Alberta, T3A 2G1, Canada.

Circle 456 on inquiry card

368 April 1981 © BYTE Publications Inc

VISTA

Your Supermarket For Add-ons and Peripheral Products

Vista

V-300 Daisy Wheel Printer

Letter Quality

The Vista V80/800/8000

Family Disk Drive System

Full compatible with TRS-80,

Heath/Zenith

120 Day Warranty

40 Track Patch at NO CHARGE

V-80 Single drive system (102K) .... $ 395.00

V-80 Two drive system (204K) S 770.00

V-800 Single drive. B52 drive (204K) . S 595.00

V-B00-2 Double dirve. B52 drives (408K) S1175.00

V-8000 Single drive. B92 drive (408K) S 775.00

V-8000-2 Double drive B92 drives (816K) $1450.00

• Print Wheel — Industry standard 96-character Daisy Wheel (Including the extended-life dual plastic wheels)

• Printable columns (136)

• Proportional, bi-directional printing

• Interface — Industry standard parallel (RS232-C optional)

• Service - Prompt maintenance/service agreements available nationwide

• Warranty - 90 days parts and labor, one year parts only

V-300-25 $1895.00

V-300-45 $2195.00

Tractor Option $ 300.00

Vista V-100 Printer $745.00

• 9x7 dot matrix

• 125 cps bi-directional print speed

• 136 column

• Industrial quality

The Vista Model II

Totally Compatible with the TRS-80* Model II

Provides one, two or three drives

Adds up to 1.5 million bytes of on-line

storage

120 day warranty

Does everthing Radio Shacks

expansion system will do. . . for less!

Single drive (non-expandable) .... $900.00

Single drive expansion system .... $1000.00

Two drive expansion system $1550.00

Three drive expansion system .... $2100.00

Additional drives alone $525.00

Vista Music Machine 9

NEW! Uses latest State of the Art

LSI Technology

Requires only one slot for 9 voices!

Uses three AY3-8910's to produce 9 voices

Plays music generated by the ALF

board

APPLE II™ compatible

ALF™ software reauired

Price:

$129.95

MPI B51 MPI B52 Siemens Siemens Shugart

Add On Drives

40 Track, Double

Density 204K ., $275.00

'Dual Head, Double

Density 408K ... $375.00

FDD 100-5 40 Track Double

Density 204K $275.00

FDD 100-8 8" Single

Sided Drive.■...,. $448.00

801R Single Sided Drive

$448.00

Other Products

1. 16K RAM upgrade kits $ 49.95

2. NEW DOS 80 $149.00

3. LNW 80 (computer board) $ 86.95

4. LNW expansion board $ 66.95

5. H.C. Pennington books:

TRS-80 DISK AND OTHER MYSTERIES: $ 18.95

MICROSOFT BASIC DECODER AND

OTHER MYSTERIES - $ 27.95

The Vista V-1000 Floppy Disk Drive Subsystem

The Vista V-200 for Exidy

Completely packaged system, tested and ready to plug in

Includes: power supply, two 40 track drives, case, double density controllers, and all cabling and total CP/M™ documentation. Storage capacity from 400K to 1.2 meg. System software-VISTA CP/M DiskOperating System and BASIC-E Compiler recorded on 5'A" diskettes Price: Starting as low as

$1199.00

S-100 version as low as $699.00

Deluxe chassis with internal slide allows easy access for drive positioning and mounting.

Built to mechanically and electrically accomodate single sided drives, double sided drives — including, the most popular 8-inch Winchester and Shugart floppy disk drives, and 8-inch streaming tape cartridge units.

Storage capacity from 0.5 to 40 megabytes

Industrial quality cabinet with die cast

front bezel

Meets all UL and OSHA standards

Additional Savings! Front and rear retma

rail mounts provided at no extra charge

(no external slides)

Desk or rack mountable

Features modular construction with

removable sub-assembly that allows easy

cabinet positioning and mounting

Drives pull out for easy service and

maintenance

Cabinet $ 395.00

Cabinet with (2) single sided drives $1595.00 (Includes power supply and cable) Cabinet with (2) double sided drives $2295.00 (Includes power supply and cable)

WffS

The Vista Computer Company

1317 E. Edirtger Avenue, Santa Ana, California 92705,(714)953-0523

CALL TOLL-FREE 800-854-8017

'TRS-80 is a registered trademark of Radio Shack, a Tandy Corporation

™ Apple Is a registered trademark of Apple ComputerjCo.

™ CP/M Is a registered trademark of Digital Research ,

Circle 274 on inquiry card.

BYTE April 1981 369

N

TRANSISTORS

2N608A

2N666

2N657

2N881

2NBB2

2N683

2NG84

2N886

2N686

2N687

12.71 17.30 19.80

2r*6S9

2N690

2N691

2NB92

2N897

2N699

2N703

2N706

2N706A

2N706B

2N70B

2N711

2N711B

2N718

2N718A

2N720A

2N736

2N740

2NB34

2NB69A

2N910

2N914 1.60

2N915 1.40

2N91B 1.73

2N918 BO

2N929 .42

2N930 .42

2N930A 2.20

2N966

2NS98

2N1132 .40

2N1132A 3.G3

2N1695 1.7B

2.20 3.22 3-3B 3.33 1.66 2.66

5.69

11596

4.26

2N1697 2N159B 2N1B99 2N1613 2N1711 2N1B42 2N1B42A 4.33 2N1B43 4.40 2N1B43A 4.47 2N1844 4.77 2N1844A 484 2N184& 556 2N1845A 5.S3 2N1846 6.47 2N1846A 6.54 2N1847 7.41 2N1347A 7.48

2N1B>

B.01

2N1B48A 8.08

2N1849 9.52

2N1B49A 9.59 2N1B50A11.01 2N1B50A11.09

2N1890 9.04

2N1893 .45

2N1990 3.92

2n1991 7.36

2N2060 5.03

2N20B0A 4.26

2N2102 1.50

2N2180 1.60

2N2193 .76

2N221B .66

2N221BA 60

2N221S .66

2N2219A .SB

2N2221 .40

2N2221A .42

2N2222 .40

2N2222A 42 2N2223 2N2223A 2N2270 2N2297 2N2322 2N2323 2N2324 2N2325 2N2326 2N2327 2N2328 10.12 2N2329 13.33

2N2368 1.74

2N2369 .42

2N2369A 45

2N2405 2.86

2N2453 439

2*N2463A 4.62

2N2475 .60

2N2478 .60

2N2480 3.59

2N24BOA 3.86

2N2481 .73

2N2483 .39

2N2484 .45

2N2501 8.78

4.26

2.00 2.29 2.80 3.62 5.13 6.66 8.16

3.33 3.19 2.93 3.99 3.72 3.33

4.12 3 B6 B.05 1.80 3.19 286

2N2540 7.7B 2N2573 651 2N2S74 655 2N2575 7.99 2N2676 848 2N2577 10.09 2N2678 10.66 2N2579 12.46 2N2604 1.66 2N2605 .90 2N260B 180 2N2639 2N2640 2N2B41 2N2642 2N2843 2N2644 2N2646 2N2647 2N2652 3.B6 2N26G2A 4.79 2N26B7 2.B7 2N2688 3.33 2N26B9 7.04 2N2690 8.86 2N2713 .16 2N2720 4.52 2N2722 3.99 2N2723 2N2723 2N2785 2N2B00 2N2B57 2N2B94 2N2895 2N2896 2N2S97 2N2903 2N2903A 2N2904 2N2904A 2N2905 2N2906A 2N2906 2N2906A 2N2907 2N2907A 2N2913 2N2914 2N2915 2N2916 2N2917 2N2918 2N2919 2N2920 2M2924 2N2925 2N2944 2N2945 4,06 2N2946 4.59 2N2947 2691 2N2959 4.72 2N3009 2.99 2N3011 1.66 2N3012 2N3013 2N3014 2.06 2N3019 .75 2N3020 6.0S 2PJ3043 40.00 2N3044 34.00 2N3045 28.00 2N3046 37.00 2N3047 31.00 2N3048 28.00 2N3053 .48 2N30&3A 1.73 2N30S4 .90 2N3054A 1.69 2N3055 1.10 2N3055A 1.98 2N3073 1.40 2N3114 9.11 2N3133 7.52 2N3135 7.91 2N3137 3.02 2N3227 432 2N3244 23.87 2N3245 23.87 2N3249 7.58 2N3250 .70 2N32G0A .80 2N3251 .70

2N3261A .75 2N3252 2.06 2N3253 2.40 2N3297 55.10 2N3299 1.30 2N3300 1.66 2N3301 130 2N3202 1.70 2N3303 21.50 2N3307 16.70 2N3308 14.20 2N3330 1.30 2N3375 19.00 2N3390 .26 2N3391A .25 2N3414 .22 2N3416 .25 2N3425 4.50

2N3436

2N3437

2N3438

2N3439

2N3440

2N3441

2N3442

2N3444 18.20

2N3446 6.80

2N344S

2N3447

2N3448

2N3467

2N346B

2N3485

2N3485A 8.60

2N3486 9.60

2N3486A 10.50

2N3494 14.80

2N349S 19.30

3.33 3.72 10.64

6.59 4.66 6.32 6.59 6.99

4.32

2.73

1.90 2.00

1.40

2.10

630 7.40 7.90 3.70

3.80 8.20

2N3793 2N3796 2N3797 2N3798 2M3799 2N3B06 2N3B07 2N3808 2N3B09 2N3810 2N3B11 2N3811A 13.60 2N3B12 27.40 2N3813 27.40 2N3814 29.40 2N3816 31.00 2N381B 36.50 2N3B18A 43.10 2N3B17 43.10 2N3817A36.10

4.90 4.90 6.00 5.40

4.12

5.90 6.12 6.70

PREMIUM QUALITY

3.70

1.60 2.40 2.50

3.70 4.30

5.00 6.00

2.10

2.10

2N3496 15.70 2N3497 20.40 2N3498 9.40 2N3499 10.60 2 N 3500 16.00 2N3501 17.90 2N3506 17.70 2N3507 20.00 2N350B 8.60 2N3509 8.60 2N3510 1.90 2N3511 2.60 2N3546 2N3553 2N3563 2N3564 2N3565 2N3566 2N3567 2N3568 2N3569 2N35B3 2N3584 2N3585 2N3632 24.00 2N3B34 20.02 2N3636 21.95 2N3636 24.20 2N3637 21.80 2N363B .25 2N3638A .26 2N3640 .26 2N3642 .20 2N3643 .35 2N3646 .25 2N3647 2N3646 2N366B 2N3669 2N3670 10.20 2N3677 3.B0 2N36B7 2N3693 2N3694 2N3700 2M3702 2N3703 2N3704 .20

2N3706 .20

2N3706 .20

2N3707 .19

2N370B .19

2N3709 .19

2N3710 .19

2N3711 .19 2N3712 3.90 2N3713 1.80 2N3714 1.90 2N3715 1.80 2N3716 1.90 2N3719 7.10 2N3720 9.80 2N3721 .20

2N3724 .90

2N3725 1.46 2N3725A 1.68 2N3726 2N3727 2N3731 2N3734 2N3735 2N3736 2N3737 2N373B 2N3739 2N3740 2N3741 2N3742 2N3743 19.80 2N3762 8.0S 2N3763 16.50 2N3764 8.06 2N3765 16.50 2N3766 2.00 2N3767 2.30 2N3771 2.40 2N3772 2.50 2N3773 3.60 2N3789 1.B0 2N3790 1.80 2N3791 1.70 2N3792 1.80

9.98 5.30 3.60 3.26 6.46 7.00 7.00 2.20 2.70 2.20 2.00 19.80

1.06

2N3B19 2N3821 2M3B22 2N3923

2N3B24 1.20 2N3B26 23

2N3827 .19 2N383B 22.30

2 N 3839 2.25

2N3843 .60

2N3B59 .25

2N3B60 .20

2N3866 1.54 2N3866A 2.00

2N3867 1.80

2N3868 1.90

2N3870 5.00

2N3B71 6.30

2N3872 8.00 2N3B73 10.10 2N3877A .25 2N389B 2N3B97 2N3898 2N3B99

2N3903 .30

2N3904 .19

2N3905 .20

2N3906 .20

2N3909 1.33 2N3926 20.40 2N3927 21. BO

2N3933 1.60

2N3946 3.90

2N3947 3.60

2N394B 2.70 2N39SO 39.10

2N3957 2.55

2N3959 4.90

2N3960 5.80

2N3962 .51

2N3963 .67

2N3964 .68

2N3966 .6B 2N3968 2N3970 2N3971 2N3972 2N3980 2N3993 2N3994 2N4013 2N4014 2N4016 2N401B

2N4030 .69

2N4031 .76

2N4032 .81

2N4033 1.40

2N4036 .66

2N4037 .60

2N4068 .19

2N4O60 .20

2N4061 .19

2N4062 .19

2N4072 2 30

2N4091 1.14

2N4092 1.07

2N4093 1.05

2N4117 2,20 2N4117A 1.60

2N4118 1.90 2N4118A 1.50

2N4119 1.80 2N4119A 1.60

2N4123 .19

2N4124 .19

2N4125 .20

2N4126 .26

2N4141 .20

2N4142 .20

2N4143 .20 2N4167 2N41B8 2N41B9 2N4167

3.20 1.30 1.20 1.20 4.20 2. BO 2.90 2.70 2.80 10.12

6.36 6.44 6.70 636

2N4169 2N4170 2N4171

10.30 fl.30 6.35 6.60

2N4174 2N41B3 2M4184 2N4186 2N4186 2N41B7 2N418S 2N4189 2N4190 2N4199 6B.20 2N4200 35.20 2N4201 118.40 2N4202 162 50 2N4203 178.20 2N4204 208.00 2N4208 3.90 2N4209 2N4212 2N4213 2N4214 2N421B 2N4216 2N4217 2N421B 2N4219 2N4220 2N4220A 1.50 2N4221 1.60 2N4221A 1.64 2N4222 1.60 2N4222A 1.64 2N4223 1.5B 2N4224 1.50 2N422B .40

2N4231A 1.60 2N4232A 1.90 2N4233A 2.35 .2N4234 1.50 2N4235 1.65

7.10 7.55 850 10.30

4.80 2.10 2,60 290 3.80 5.00 5.70 8.30 12.40 1.40

2N485BA 1.94

2N4859 1.81

2N4860 1.81

2N4860A 1.90

2N48G1 1.90

2N4870 .94

2N4871 .84

2N4878

2N4890

2N4895

2N4895

2N4B97

2N489B

2N4899

2N4900

2N4901

2N4902

2N4903

2N4904

2N490G

2N490B

2N4912

2N4913

2N4914

2N4915

2N4918

2N4919

2N4920

2N4921

2N4922

2N4923

2M4924

2N4925

2N4926

2N4927

2N4928

2N4929

2 N 40 ISO

2N4931

2.38

1.14

2.10 2.80 3.10 .30

3.00

1.26

2N4236 1.80 2N4237 1.35 2N4238 1.50 2N4239 1.BO 2N4240 2.50 2N4248 .25 2N4249 .20

2N4250 .25 2N4256 .20 2N4258 .36 2N4260 1980 2N4261 23.20 2N4264 .66 2N4265 .72 2N4289 2N4339 2N4340 2N4341 1.50 2N4342 .76 2N4347 1.65 2N4348 2N4361 2N4352 2N4356 2N4358 2N4360 2N4391 2N4392 2N4393 2N4395 2N4398 4.40 2N4399 5.90 2N44O0 .20

2N4401 .20

2N4402 .20

2N4403 .20 2N4404 13.20 2N4405 14.30 2N4406 17.90 2N4407 20.35 2N4409 .31

2N4410 .36 2N4416 1.46 2N4416A 1.64 2N4425 .45

.2N4427 1.50 2N442B 2.70 2N4440 23.25 2N4441 2.07 2N4442 2N4444 2N4449 2N4453 2N4851 2N4852 2N4853 2N4854 2N4855 2N4858 2N4856A 1.40 2N4857 1.33 2N4857A 1,40 2N4868 1.30

2.23 4.77 6.0B 3.72 1.31 1.31 2.87 5.70 5.45 1.33

3.78 3.00

1.10

1.48

3.19 4.60 3.90 3.48 4.46 4.96 4.33 3.46

2N4937 11. B0

2N4938 4.02

2N4939 3.64

2N4940 22.00

2N4941 24.30

2N4942 21.70

2N4948 1.18

2N4949 3.07

2N4957 5.31 2N495B 2N4959 2N4983

2N49B4 1.50

2N49B7 .75

2N498B 1.20

2N4989 1.60

2N4991 .75

2N4993 1.80

2N4994 .30

2N5016 24.40

2N5022 1.40 2N5023 2N5032 2N503B 2N5039 2N5060 2N5051 2N5052 2N50G8 2NG059

2N5060 .59

2N5061 .60

2N5062 .69

2N6063 .73

2N50B4 .84

2N50B7 1.5B

2N50B8 1.79

2N5069 1.98

2N5070 24.40

2N5071 27.50

2N6086 .19

2N50B7 .19

2N5088 .19

2N50B9 .19

2N5090 18.30

2N5105 2.60

2N5108 4.60

2N5109 .40

2N5131 .25

2N5132 .20

2N5133 .20

2N6134 .26

2N5135 .20

2N5146 28.10

2N5160 4.B0

2N5161 16.04

2N6162 23.71

.2N5164 3.80 2N5165 2N5166 2N6167

2N516B 4.31

2N6169 4.74

4.18 5.60 7.26

1.40

STORES 00 NOT ACCEPT MAIL ORDERS

MAILORDER

P.O. BOX2208Y CULVER CITY, CA90230

PHONE ORDERS (213) 641-4064

Minimum Older SI 0 00 Add S2 00 io cover postage and handling Masie'Charge oral VISA welcomed Please include »Qi» charge card number, interbank number and eipirahon dale Some itenu are iubrecl lo piiw sale Mot responsible lor typos Store pricing may vary ham Mail Order puong We reserve the right to subsMute manufacture!

2N6170

2NG171

2N6172

2NE179

2NG190

2N5191

2N5192

2N6193

2N6194

2N6195

2N5198

2N620B

2N6209

2N6210

2N6219

2NG220

2N5221

2NB222

2NG223

2M6224

2N5225

2W5226

2N6227

2N5228

2N5229

2N5230

2N5231

2IM6232 .35

2NG232A 26

2M&241 17.82

2N5246 .72

2N6265

2N6266

2N6267

2NG268

2N5269

2M5270

2N6271

2N6294

2N529B

2NG301

2N5302

2N6303

2N5306

2N&308

2N6309

2NG320

2N5321

2NG322

2N5323

2NG336

2N5337

2N5338 4.60

2N6339 5.10

2N5344 10.40

2N5346 12.60

2IM5346 22.70

2N5347 25.70

2N5348 26.70

2N5349 32.60

2N6354 .40

2N5355 .40

2N53G9

2N5359

2N5360

2N5361

2N5362

2N5363

2N5364

2N5366

2N5367

2N536B

2N53B9

2N5397

2N5398

2N6400

2N5401

2N5415

2N5416

2N5418

2N5419

2N5420

2N5427

2N5428

2N5429

2N5430

2N5431

2N5441

2N5442

2 N 5443

2 N 5444

2N5445

2N544G

2N5447

4.52 5.39

6.44

3.60

307

3.88

3.60

2.21 2.16 2.16 2.02 2.15 2.16 2,78

1.80

2.49

1.07

18.00

1.60

2NS44B 2N6449 2N64B0 2N5461 2N5453 2N6457 2N545B 2N6469 2N6480 2N5461 2N5462 2N54B3 2N5464 2N6466 2N54B4 2N5485 2N6488 2N5490 2N5660 2N6551 2N6656 2N5835 2146636 2N6837 2060 2N6838 .70

2NG639 .63

2N6640 .70

2N5641 12.20 2 N 5642 14.60 2N5643 20.60 2N6645 1840 2N5646 27.60 2N5863 .67

2N66&4 63

2N566B 82

2N6669 .76

2N5670 .82 2N5871 10.50 2N6872 12.60 2N6769 .24 2N5770 .23 2N6772 .24 2N6777 .90 2N577B .90 2N6781 1.B5 2N6782 2N5783 2N6784 2N6786 1.35 2N5786 1.35 2N5817 .40

2N5822 .60 2N5824 .25

2N5B27 .30

2N582B 40

2N5828A 40 2 N 5830 .27

2N5831 .27

2N5835 3.86 2N5B36 4 60 2N5837 540 2N5B41 13.80 2N5842 11.60 2N5847 18.50 2N5848 20.60 2N6849 27.60 2NG862 76.50 2N5B75 135 2N5B76 1.47 2N6877 1.36 2N6B78 1.65 2N6941 30. BO 2N6944 12.30 2N6945 15.30 2N6946 19.30 2N6947 12.30 2N5961 .19

2N6974 2N5975 2N5976 2N6977 2N6978 2N5979 2N5980 2N5981 2N5982 2N59B3 2N5984 2N6985 2N59B6 2NG987 2N5988 2N59B9

2.71 3.05 3 60 2.48 2.80 3.30 3.40 3.90 4.70 2.60 2.90 3.60 3.70 4.10 4.50 3.50

2N6990 3.90 2N5991 4.30 2N6004 .70

2N6014 .70 2N6027 .60 2N6028 .60 2N6029 6.94 2N6030 7.30 2N6031 B.40 2N6032 24.00 2N6033 27.00 2NB034 1.20 2N6035 1.30 2N6036 1.40 2N6037 1.02 2N6038 1.10 2NB039 1.30 2N6040 2.80 2N6041 2NS042 2N6043 2N6044 2N6046 2N6049 2N6050 2N6061 2N6052 2N6053 2NG064 2N6055 2N605B 2N6057 2N605B 2N6059 2N606B 2N6069 2N6070 2N6071 2N6072 2N6073 2N6074 2N607G 2N6076 2N6077 2N6078 2N6080 2N6081 2N6082 2N6084 20.00 2N6094 14.70 2N6095 16.00 2N6096 21.00 2N6097 23.00 2N6099 .87

2N6103 2N6107 2N6109 .84 2N6111 .84

2N6116 1.61 2N6117 2.66 2N6118 3.20 2N6121 .90

2N6122 .90 2N6123 1.05. 2N6124 .90 2N8125 .90 2N6126 1.05 2N6129 1.23 2N6130 1.36 2N6131 1.51 2NB132 1.26 2NB133 1.41 2N6134 1.54 2N6136 29.10 2N6145 6.90 2NG146 2N6147 2N6151 2N6162 2N6153 2N6154 2N6155 2N6166 2N6167 2N616B 2N6169 2N6160 2N6161 2N6162 10.40 2N6163 8.80 2N6164 10.10 2N6165 12.10 2NS186 54.00 2N6167 5.35

3 00 3.30 2.50 2.70

3.00

2.30

2.30 2.60 2.80 1.50

3.96

6.44 12.30 13.BO 15.50

1.10

m

^gs

• 10%*

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Bring this TOI'IMIX into one of ourstores or mail to our Mail Order address shown below

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^Coupons accepled

7.80 9.30 2.86

3.93

4.83 6.70 7.30 7.10 B.42

2N616B 6.50

2N6169 7.30

2N6170 8.80

2N6171 6.45

2N5172 7.B0

2N6173 10.20

2N6174 12.10

2N61B6 36.60

2N61B7 40.60

2NB18B 40.50

2N61B9 63.00

2N6190 12.90

2N6191 19.00

2N6192 16.90

2N6193 21.70 2N6211 2N6212 2N6213 2N6220 2N6226 2N6227 2NB228 2N6229 2N6230 2N6231

2N6233 7.6B

2N6234 7.85

2NB235 B.14

2N6236 .94

2N6235 8.14

2NB236 .94

2N6237 1.00

2N6238 1.03

2N6239 1.16

2N6240 1.61

2N6241 2.74

2N6249 7.30

2N6250 8.66

2N6251 878

2N6265 2.80

2N6266 10.70

2N6257 2.58

2N6274 21.70

2N6276 26.00

2N6276 34.00

ZN6277 46.00 2NB282 2NB283 2N6384 2N6286 2N6286 2N6287 2N628B

2.48 2.98 3.40 .60 1.68 1.BB 2.19 2.98 3.56 4.36

5.30 5.90 5.90 6.30

6.90

2 N 62 90

2 N 62 92

2N6294

2N6295

2N6296

2NB297

2N6298

2N6299

2N6300

2N6301

2N6303

2N6304

2N6305

2N6306 3.80

2N6307

2N6308

2N6312

2N6313

2N6314

2N6315

2N6316

2N6317

2N631B

2N6326

2N6327

2N632B

2N6329

2NB330

2M6331

2N633B

2N6339

2N6340 17.90

2 N 6341 20.90

2N6342 1.60

2N6342A 2.06

2N6343 2.10

2N6343A 2.40

2N6344 2.90

2N6346 6.60

2N6345A 6.20

2N6346 1.90

2N6346A 2.20

2N6347 2.26

2N6347A 2.60

2N6348 3.00

2N6348A 3.60

2N6349 5.80

2N6349A 6 60

2NB354 5.40

2N6368 38 50

2N6370 3B.60

2N6377 22.70

2N637B 30.80

2.20 2.40 9.80 2.10

6.00 1.60 1.80 2.30 1.70 1.90 2.10 21.5 3.20 3.60 4.10 3.60 4.00 4.40 B.50 9.90

CAPACITORS • CAPACITORS • CAPACITORS

ALUMINUM ELECTROLYTIC

H

MFD 10V 16V 25V 35V 60V

21 .23 2B

220 .23 26

22 24 .30 24 .26 .32 .30 .36

35 40 .50 40 .45 .55 45 60 .80 65 80 1.20 30 1.60 2.50

ZENER DIODES

500 mW — 5%

1N5240B 16 .22

1N5247B 17 .22

1N524BB 18 .22

1N6249B 19 .22

1N5250B 20 22

1N5261B 22 .22

1N5262B 24 22

1NS253B 26 .22

1N52&48 27 22

1N52658 28 .22

V Pi 1N5256B 30 1N5257B 33 1N5258B 36 1N6259B 39 1N5260B 43 1N5261B 47 1N5262B 51 22 1N5263B 56 22 1N5264B 60 .22 1N5265B 62 22

V Pricn

1N52B6B B8 .22

1N6267B 76 .22

1N6223B 27 22

1N5224B 2.8 .22

1N5225B 3.0 .22

1NS226B 33 22

1N5227B 3.6 .22

1N622BB 3.9 .22

1N5229B 4 3 22

1NG230B 4.7 .22

1N5231B 5.1 22

1N52328 5 6 22

IN5I33L! 5.0 .22

1N5234B 6.2 22

V Prico

1N5235B 6.B .22

1NG230B 7.5 .22

1N6237B 8.2 22

1N5238B 8.7 22

1N5239B 9.1 .22

1N5240B 10 .22

1N6241B 11 .22

1NG2428 12 .22

1N5243B 13 .22

1N5244B 14 .22

1N5245B 16 .22

50V CERAMIC DISC—$1.00 Per Pack

9/pkg 9/pkg 9/pkg 9/pkg 8/pkg 8/pkg B/pkg 8/pkg 8/pkg 7/pkg

5p(

7/pkg

iepf

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27pl

7/pkg

47pf

7/pkg

6Sp[

7/pkg

100 [>f

9/pkg

150 pf

9/pkg

220pf

9/pkg

270pf

9/pkg

300pf

330pf

390pl

470pf

560 pf

eSOpf

.001 mtd

.0015mtd

O022mfd

OOSmtd

9/pkg 9/pkg 9/pkg B/pkg 8/pkg 8/pkg B/pkg 7/pkg 7/pkg 6/pkg

.0047mfd 005 mid

01 mid .016 mid

.02 mid .022 mid

03mld .039mld .047 mid

ELNA DIPPED TANTALUM

10.0

10.0

35

16.0

20

16.0

35 1.

22.0

16

33.0

20 1.

47.0

20 1.

68.0

16 1.

PLESSEY POLYESTER (MINI-BOX)

001

1000

.14

.012

0012

1000

.14

.015

0015

1000

.14

.016

0018

1000

.14

.022

0022

1000

.14

.027

0027

1000

.14

.033

0033

1000

.14

039

0039

630

.14

.047

0047

630

.14

.056

0056

630

.14

.068

0068

630

.14

.082

0082

630

.14

2N6379 44.70

2N63B3 2.10

2N63B4

2N63B5

2N6386

2N63B7 1.17

2N638B 1.26

2N6394 1.80

2N6395 1.82

2N6396

2N6397

2N639B

2N6399

2M64O0

2N6401

2N6402

2N6403

2N6304

2N64Q5

2N6420

2N6403

2 N 6304

2N6420

2N6421

2N6422

2N6423

2N6424

2NB425

2N6426 .63

2N6427 .61

2N6428 .76

2N6428A 1.00

2N6429 .76

2N6429A 1.00

2N6430 2.60

2N6431

2N6432

2M6433

2N6436

2N6437 16.00

2N643S 20.40

2N6439 56.00

2N6466 1.11

2MB487 1.20

2N6488

2N6489

2N6490

2N6491

2N6497

2N649B

2N6499

2NB501 2B.00

2N6603 23.10

2.36 2.64 1.05

2.80 2.60 2.80 9.90

1.29 1.11 1.20 1.29

2.79 3.40

4.90

2IM6504

2N6505

2N6506

2N6507

2IM6508

2N6509

2N651S

2AI6516

2N6517

2N6518

2N6619

2N6520

2N6530

2N6531

2N6532

2N6533

2N6S42

2N6543

2N6544

2N6545

2N6546

2IM6547

2N6548

2N6549

2N6551

2NB552

2N6553

2N6564

2N6555

2N6556

2N6557

2N6568 1.13

2N6559 1.33

2N6569 1.12

2N6691 1.13

2N6592 1.26

2N6593 140

2N6603 13.60

2N6604 13.60

2N6609

2N6648

2N6649

2N6666

2N6667

2NSB68

2N6671

2N6672

2N6673

2N6674

2NB675 900

3N83 1.80

3N84 1.80

3NB5 3.00

1.26 1.36 1.60 1.60 3.20 4.30 6.40 5 50

1.00

1.17

460 2.20 2.50

600 6.80 7.50

C PLESSEY

ZENER DIODES 1 WATT — 5%

V Price

1N472BA 3 3 40

1N4729A 3.6 .40

1N4730A 3.9 40

1N4731A 4.3 .40

1N4732A 4.7 .40

1N4733A 5.1 .40

1N4734A 5.6 .40

1N4735A 6.2 .40

1N4736A 6.8 .40

1N4737A 7.5 .40

1N473BA 8.2 .40

1N4739A 9.1 40

1M4740A 10 .40

1N4741A 11 .40

1N4742A 12 40

1N4743A 13 .40

1N4744A 15 .40

1N474BA 16 40

1N4746A 18 .40

1N4747A 20 .40

1N4748A 22 40

1N4749A 24 40

1N4750A 27 .40

1N4751A 30 40

1N4762A 33 40

1N4753A 36 .40

1N4754A 39 .40

1N4755A 43 .40

1N4766A 47 40

1N47&7A 61 ,40

1N4768A 56 40

1N4759A 62 40

1N4760A 6B 40

1N4761A 75 57

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ATLANTA

3330 Piedmont Rd. N.E.

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CULVER CITY

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Culver City, CA 90230

|213) 300-3595

HOUSTON

2649 Richmond

Houston, TX 77098

(713) 529-3489

PORTLAND

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Portland, OR 97220

(503) 254-5541

SANTA ANA

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Santa Ana, CA 92705

(714) 547-8424

SUNNYVALE

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Sunnyvale, CA 94087

(408) 243-4121

TUCSON

4518 E. Broadway

Tucson, AZ 8571 1

(602) 881-2348

370 BYTE April 1981

Low Profile — TIN

1-24 25up SOup 1

17 S .16 S 15 S

A8ZT-TI A14ZT-TI

A16ZT-TI .22 .21 .20 .19

A18ZT-TI .29 .28 .27 .26

A20ZT-TI .33 .32 .31 .30

A22ZT-TI .36 35 34 33

A24ZT-TI .37 .36 .35 .34

A28ZT-TI .43 .42 41 .40

A40ZT-TI 46 .45 .44 43

Standard Soldertail — TIN

A22T .72 .71 .70 69

A24T .52 .51 50 .49

A2BT .78 .77 76 .75

A36T 83 .82 81 80

A40T 1.0B 1,07 1.06 1.05

Standard Soldertail—Gold

1-24 25up 50up 100up

A16G A18G A22G A24G A28G A36G A40G

SOCKETS

WIRE WRAP Level 3

A8WG A10WG A14WG A16WG A18WG A20WG A22WG A24WG A28WG A36WG A40WG

1.35 1.43 1.83 1.95 2.43

1.22 1.21 1.20

Wire Wrap — TIN

A8WT-TI A14WT-T! A16WT-TI A18WT-TI A20WT-TI A22WT-TI A24WT-TI A28WT-TI A36WT-TI A40WT-TI

* MICROPROCESSOR CRYSTALS •

2.4SJB 3.I7II

3.S7I

CASE

P/N

PRICE

HC33

CY1A

J9.50

HC33

CD1A

9.50

HC31

CV2A

■ 75

HC]J

CY2B

125

HC3J

CT3I

60S

HCJJ

CT3D

6 00

KCH

CY3»

SOB

HC1I

CV4C

5.00

KCtl

CVIB

B.OO

HC18 CY5A

HC18 CV7A

HC1S CY5B

HC1B CB5C

HC1I CY5B

HI 18 CY6C

HC18 CY8G

HC1B (

12A

14.11918 HC1B CY14A 4 75

IRBO

MKi) CASE P/N I

I5.B0 HC18 CY15A :

18.00 HC1B CY19A

IB 432 HC18 CY19B

19 66BB KCia CY70A

20.00 KC1B CY72A

21.684 HC1B CY23B

7700 HC1B CY27A

37.00 HC1B CY37A

[lil DO HC1B CY100A

FIBER OPTICS from MOTOROLA

The Link Kit

Only....

Aqq f~.fi ^-Wjjjmmjt^M • provides an optical link capable of

I x-mittingdataat NRZrateto20 mb/s

• allows familiarity with fiber optics

^Kv while experimenting with

actual circuits fcr systems

• has basic design

^ equations and examples

• illustrates general applications

of fiber optics

Flasher LED

FRL-4403 Red LED and Flasher IC Chip ONLY

in One Package QOp

LED BAR GRAPH ARRAYS AND DRIVER

GL-112R3 LEO Array is a red LED arrangad in a 12 dot bar graph configuration. When used in combination with tho IR-2406, linear luvel indications can be generated. GL-112M2 LED Array same as above except dot graph is arranged as 8 green and 4 red positions.

IR-2406 LED Driver is an integrated circuit

LED driver with 12 outputs. Each successive

output turns the LED's an in steps equal to:

VraffrVtOM.} - VroffMln.)/1 3

\

OEM Prices

GL-112R3 $4.80

GL-112M2 $4.80

IR-2406 $4.80

The Bright TWO-COLOR LED

Both Red-orange and Green LEDs in E D95

the eame package. Color mixing can 1-24 — $1.60

be accomplished due to separate anodes. H si -in

74LS...Series

74LS00N $ .21

74LS03N .23

74LS04N .26

74LS08N 27

74LS10N .24

74LS1 IN

74LS20N

74LS22N

74LS26N

74LS27N

74LS32N

74LS37N

74LS40N

74LS42N

74LS73N

74LS74N

74LS86fg

74LS90N

74LS93N

74LS109N

74LS1I2N

74LS123N

74LS12SN

74LS126N

74LS132N

74LS136N

74LS138N

74LS139N 74LS145N 1.20

74LS151N

74LS152N

74LSI53N

74LS160N

74LS161N

74LS162N

74LSI63N

74LS164W

74LS170N 2 65

74 LSI 74N 74LST75JJ 74LS181N 2.30 74 LSI90N 1.20 74LS19IN 89 74LS193N .89 74LS194N .85 74LS195N .65 74LS221N .85 74LS240N 95 74LS241N .90 74LS243N 99 74LS244N .95 74LS245r\ 2.20 74LS251N 2.20 74LS253N .59 74LS257N .60 74LS258N 65 74LS260N .65 74LS266N 48 74LS273N 1.35 74LS299N 2.60 74LS365N 75 74LS366N 79 74LS367N 70 74LS373N 1.45 74LS374N 1 40 74LS377N 1.40 74LS381N 2.90 74LS490N 1.80

VOLTAGE REGULATORS

LM300H

LM300N

LM304H

LM305H

LM309H

LM309K

LM317H 1.70

LM317-To220 1.60

LM3I7K 2.45

LM320-5K 2.20

LM320-6K

LM320-8K

LM320-12K

LM320-15K

LM320-18K

LM320-24K

LM323K

LM340-5K

LM340-6K

LM340-8K

1.45

2.20 2.20 2.20 2.20

2.20 4.70 1 35

1.35 1.35

LM340-12K 1.3J

LM340-15K 1.3!

LM340-18K 1.3!

LM340-24K 1.3:

LM350K

LM353-5

LM353-8

LM353-12

LM353-15

LM353-18

LM3D3-U

LM723CH

LM723CN

78L05ACP

78L05CP

78 LOSACP

78L08CP

78L12ACP

78L12CP

78L15ACP

VOLTAGE REGULATORS

To220 (Plastic)

7815CP 7818CP 7824CP

To220 (Plastic)

7905CP $.9!

7912CP .9!

7915Ca .9!

7918CP .9!

7924CP .9! (Dire

SILICON GENERAL

Linear IC and Voltage

Regulator Databook

214 pages $4.50

RF

TRANSISTORS MRF207 S 1.61 MRF208 16.06 MRF209 19.27 MRF212 22.48 MRF215 40 15 MRF216 43.29 MRF221 15.22 MRF222 17.67 MRP223 18.50 MRF224 21.65

MRF314 28.91

MHF314A 28.91

MRF454 26.53

MRF454A 26.53

MRF455 22.34

MRF455A 22.34

MRF475 4 05

MRF901 3.00

MRF904 3.21

MRF911 2.89

MRF8003 2.44

MRF8004 2.93

1.00

1.00

1.00

1.00

78L15CP 78L18ACP 78L18CP 78L24ACP 78L24CP 79L03ACP 79L03CP 79L05ACP 79L05CP 79L12ACP 1.50 79L12CP 1.00 79L15ACP 1. 79L15CP 79L18ACP 79L18CP 79L24ACP 1 50 79L24CP 1.00 MC1463G 4.90 MC14661 9.90 MC1468G 5.90 MC1469G 4.90 To220 Case 78M05CT S .85 78M06CT 1,45 78M08CT 1.45 78M12CT 1.45 78M15CT 1.45 78M18CT 1.45 78M20CT 1.45 78M24CT

1.45

Motorola's Complete Opto Triac Driver Line J* JJf

Typ. m« VoIt

MOC3009 15 251

MOC3O10 8 251

MOC3011 5 251

MOC3020 15 401

MOC3021 8 401

MOC3030' 15 251

MOC3031* 8 25t

11 H

m

-E&;

*io%* •

DISCOUNT COUPON

Bring this COITMIN into one of ourstores or mail to our Mail Order address shown below

and receive a 10% IHM OIXT

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Offer riVI'l HIS on April SO. I Oil I

S=

ANCRONA HAS INTERSIL ICs

Z-80

SERIES

2.5 MHz Z-80-CPU $ 8.95 2-80-CTC 6.50

Z-80-P10 6.50

'-DART 15.45

'-DART-9 13.50 Z80-S10/0 24.40 Z-80-S10/9 18.20

-DMA 20.10

4.0 MHz Z-80A-CPU S 9.95 Z-80A-CTC 7.95

Z-80A-P10 7.95

Z-8QA-DART 18.85 Z-80A-DART-9 16.50 Z-80A-S10/0 30.50 Z-80A-S10/9 23.40 Z-80A-DMA 24.90

IM610D-1PL

IM6102-1PL

ICM7038-A1PA

ICM7038-C1PA

ICM7045

ICL71C03-ACP1

ICL7106-CPL

ICL7107-CPL

1CL7116-CPL

ICL7117-CPL

ICM7201-1DR

ICM7205-1PG

ICM7206-CJPE

1CM7207-A1PD

ICM7208-1PI

ICM7209-1PA

ICM7211-1PL

S13.95 14.50 3.00 3.00 14 95 13.80 15.50 15.00

2.25 13.00 5.15 6.60

ICM7213-1PD

1CM7215-1PG

ICM7216-A1J1

ICM7216-B1P1

ICM7216-C1J1

ICM7216-D1P1

ICM7217-A1P1

ICM7217-B1J1

ICM7217C1P1

ICM7217-1J1

ICM7218-C1J1

ICM7223-1PL

JCM7224-IPL

ICM72251PL

ICM7226-A1J1

ICM7226B1PL

1CM7227-A1P1

SS.36 13.95 32.00 28.65 26.65 21.40 11.25 12.40 10.35 12.40 10.76

7.90 11.26

8.60 32.00 28.65 12.40

ICM7227-B1J1

ICM7227-C1P1

ICM7227-1J1

ICM7240-1JE

1CM7241-1PA

ICM7242-1JA

ICM7250-1JE

ICM72G0-1JE

IC>%r17270-1PL

1CM7555-1PA

ICM7556-1PD

ICL7G60-CP.A

ICL8038-CCJD

ICL8048-CCPE

ICLB069-CCQ

ICL8211-CPA

14.48 12.40 14.46 4.90 3.40 2.05 6.00 5.26 5.8S 1.20 2.25 3.00 4.70 21.60 2. BO 2.60

6800

SERIES

MC6800P S 5.90

MC6801L1 65.84

MC6802P 1 1.50 MC6805U2P2 30.72

MC6808P 13.90

MC6809P 36.50

MC6821P 3.46

MC6828P 9.90

MC6840P 12.22

MC6843P 45.39

MC6844P 45.39

MC6845P 22.00

MC6846P1 39.90

MC6846P3 66.50

MC6847P 16.06

MC6850P 3.40

MC6852P 3.50

MC6854P 32.26

MC6859L 277.90

MC6860P 10.80

MC6862P 11.80

MC6875L 6.90

MC6880AP 3.14

MC6881 P 8.91

MC6882AL 6.13

MC6885P 2.72

MC6886P 2.72

MC6887P 2.72

MC6888P 2.72

MC6889P 3.14

IS BETTER

2114L3 $

4116 (200ns) 2708 2716 (5 V) 2732 (450ns) 2732 (350ns)

1-10

3.90 3.90 5.90 9.90 24.90 26.90

10 up

> 3.20

3.20

5.30

9.30

23.90

25.90

100 up

$ 3.00

3.00

5.00

9.00

22.90

24.90

Our Very Special 64K Dynamic RAM

HM4864 $65.00 $63.00 $59.00

ANCRONA

Stocks

Only

FIRST QUALITY!

6502 SERIES

P6502 S 6.40

P6502A(2MHj!| 7.90 P6502B|3MHJ) 13.50 P6503 970

P6503A 10.70

P6504 9.30

P6504A 10.70

P6505 9.30

P6505A

P6506

P6506A

P6507

P6507A

P6512

P6512A

P6513

P6513A

P6514

P6514A

PG515

P6515A

P6520

P6520A

P6521

P6521A

P6522

PG522A

P6532

PS532A

13,70

9.70 10.70 3.70

10.70

10.70

S16.60

9.70

10.70 9.70

10.70 9.70

10.70 5.90 G.40 6.20 6.80 6.40

11.90 7.80

10.20

8080A—8085A and Support ICs

P80B0A S5.00

P8085A 10.00

P8212 2.30

P8212B 4.50

P8216 2.10

8224 PC 3.10

P8226 2 40

8228PC 5.80

P8237 22.00

8238PC 6.00

P8251 6.40

P8253 13.00

P8255A 6.10

P8257 1 1.90

P8279 15.90

DP8303N 3.90

DP8304BN 3.90

DP8307N 3.90

DP8308N 3.90

Z8000 SERIES

Z8001 DC S150.00

Z8002DC 140.00

Z8065DC 99.00

Z8073PC 25.20

Z8104PC 4.90

Z8107PC 4.90

Z8108PC 4.90

Z8120DC 5.60

Z8121 PC 3.65

Z8127DC 19.60

Z8133PC 2.50

Z8136PC 5.20

Z8140PC 3.00

Z8144PC 3.60

Z8148PC 3.00

Z8164BPC 24.40

Z8165PC 7.65

Z8166PC 7.65

Z8173PC 2.10

RS232 CONNECTORS

DB25P male 2.95 DB25S female 3.60 HOODS 1.75

SET

7.50

NMOS MICROPROCESSOR MC68000L S347.73 MC63000L4 291.87 MC68000L6 319.80 MC68488P 19.80 MC68705P3L1 11.72

NMOS EPROM

MCM68708CS 32.26 MCM68764C 309.89 MCM68766C 309.89

gU California Uj" Computer

mJI Systems For Commodore Computers 32K STATIC HAM MODULE

(ASSEMBLED AND TESTED) 2032A 450ns HAM $710.OD

20328 30Dns RAM. 795.00

2032C 200ns RAM. . B30.00

64K DYNAMIC HAM MODULE

(ASSEMBLED AND TESTED} 20B5C 200ns RAM. S700.00 I6K STATIC RAM MODULE

(ASSEMBLED AND TESTED) 2116A 450ns RAM S349.95

211GB 300ns RAM 383.95

2116C 200ns RAM 399.95

MAINFRAME 2200A Assy and Tested $399.95 2200 K Complete Ht... 349.95 Nnle: Spec, color-Black,Blue. Brown, Office Cream, or Grey. FLOPPY DISK CONTROLLER Z422A AssyE>Tested. . . S400.00 4-Port Serial I/O Inlerfaco 2710A Assy ErTested. . S340.00 Sorial/Parallel I/O Interface 2718A Assy&Tesled... $360.00 4-Porl Parellel I/O Interface 2720A Assy&Tesled. . $2511.00

z-ao~ cpu

2810A Assy&Tesled. . . $300.00

For Apple Compute

7440A Assembled and Tested .

PROGRAMMABLE TIMER

PARELLEL INTERFACE

7720A Assy Blest cable &s!d firmware. . . $119.95

77208 Assembled and tested: cable & CenKanics-lype

firmware included. SI 19.95

STORES DO PJDT ACCEPT MAIL ORDERS

MAILORDER

P.O. BOX2208Y CULVER CITY. CA90230

PHONE ORDERS (213) 641-4064

mm Order SIOQO Add S2 00 lo co.er postage and handling MasierCnaige and VISA welcomed Please include yem charge card number interbank number and narration date Some cams are subtect to prror sale Not responsible for ttpos State pricing may vary Irom Marl Order pricing We reserve the light to substitute

ABITHMETIC PROCESSOR

7811B Assembled and tested; CCsoll diskette included [Comualibte with Apple II" computers with a disk dtivel S399.95

781 IC Assembled and tested; CCsult ROM included (Compatible with Apple II PLUS * compu lets and Apple II" computers with an Applesoft'" card) . S399.95

7424A Assy & Tested Less ball

ASVNCHROIMUS

SERIAL

INTERFACE

771DA Assy h tested; cable included. . . S159.95

CALENDER/ CLOCK MODULE

SYNCHRONUS

SERIAL

INTERFACE

7712A Assy b tested cable included . SI 79 95

GPIB IIEEE-48B) INTERFACE

7490A Assy b tested; cable included S300.00

CENTRONICS" PRINTER INTERFACE

7728A Assy& tested; cable not in

ANCRONA HAS MOTOROLA ICs

BFR90 BFR91

CA3054

CA3059

CA3079

MBD101

ME3D102

MBD201

MBD501

MCE63P

MC664P

MC665P'

MC6S7P

MCG68P

MC677P

MC678P

MC6BOP

MC6B4P

MC830L

MCB32L

MCB35L

MCB36P

MC837P

MC839L

MC839P

MC840P

MC846P

MC84BL

MC866P

MC857L

MC857P

MC862L

MC958L

MC1013P

MC1302P

SI 8B

2.42

1.54

3.34

2.23

.73

,2B

1.03

1.57

3 20

3.20

1.91

3.20

1.91

2.05

2.05

2.05

5.10

227

227

2.46

1.50

585

3.56

1.50

1 36

3.17

2.14

2.46

1.50

2,27

2.46

,50

3.72

MC1309P MC1310P

MC1330A1P

MC1349P

MC1350P

MC1351 P

MC1352P

MC1355P

MC13S7P

MCI 358 P

MC1364P

MC1372P

MC1373P

MC1391P

MC1403AP

MC1403AU

MC1403UDS

MC1405L

MC140BL6

MC140BL7

MCI 408 LB

2,10

2.01 2.10 1.55 1.50 2.01 6.48 6,19 1.44 3.78 11.07 4.23 1S.28 2.94 4.75 4.64

MC140BPB 4,40

MC1413P 1.33

MC1436CU 7.99 MC1437L 3 99

MC1437P 3.14

MC1439G 4 99

MC1439L 4.62

MC1439P1 3.97

MC1445G 4.20

MC1445L 4.15

MC1445P1 .72

MC1445UDS 1.77 MC1456G 2.25

MC1456P1 1 96

UC1458CL MC1458CP1

MC1458P1

MC1458P1S

MC1469G

MC1469R

MC1488L

MC1489AL

MC1489L

MC14B9P

MC1494L

MC1495L

MC1496G

MC1B04L

MC180BP

MC1B09P

MC1810P

MC3062L

MC3302L

MC3302P

MC3303P

MC3325P

MC3340P

MC3360P

MC3370P

MC3403P

MC3405P

MC3408L

MC3416L

MC3423P1

MC3438L

MC3448AP

MC3470P

MC3476P1

MC3S03L

MC4016P

MC4024P

MC4026P

MC4044P

MC4316L 1

MC455BNCP1

MC8311 P

MC9819P

MC1O104P

MC10109L

MC10116L

MC10116P

MC10123L

MC10124L

MC10125L

MC10131P

MC10137L 2

MC10159P

MC10189L

MC10195L

MC10198P 3

MC10216L

MC10231P

MC12O40P 1

MC120B1P

MC14410P 2

MC14411P 1

MC14412VP 1

MC14436VP 1

MC14457P

MC14458P 1

MC14490FP

MC1449DVP

MC14495P

MC34004P

VISIT A STORE NEAR YOU TODAY - We stock a large selection uf Technical Boohs, Discrete Components. Integrated Circuits, Test Equipment and Electronic Supplies.

ATLANTA

3330 Piedmont Rd. N.E.

Atlanta, GA 30305

(404) 261-7100

CULVER CITY

1 1080 Jefferson Blvd.

Culver City, CA 90230

(213) 390-3595

HOUSTON

2649 Richmond

Houston, TX 77098

(713) 529-3489

PORTLAND

1 125 N.E. 82nd Ave.

Portland, OR 97220

(503) 254-5541

SANTA ANA

1300 E. Edinger Ave.

Santa Ana, CA 92705

(714) 547-8424

SUNNYVALE

1054 E. El Camino Real

Sunnyvale, CA 94087

(408) 243-4121

TUCSON

4518 E. Broadway

Tucson. AZ 8571 1

(602) 881-2348

Circle 275 on inquiry card.

BYTE April 1981 371

DATA PRECISION

A DIVISION OF ANALOGIC CORPORATION MODEL DESCRIPTION PRICE

175 3'/. Digit Portable D.M.M. S219.00

245 4-/2 Digit Portable D.M.M. 385.00

248 4V, Digit Portable True RMS D.M.M. 385.00

100-Hour Mini-Portable 41/2-Digit LCD Multimeter

• 25 Ranges, including five each AC and DC. both voltage and current, plus five resistance rangesl • Sensitivities of 1(V(V. 10nA. lOOmfi. and maximum readings of 100 volts (500 AC), 2A. 20 megohms! • Basic accuracy of ±0.03%. supportod by lab-grade T.C. — typically. ±(0.003% rdg. + 0.001% rng.)/ "C • Rechargable 100-hour battery portability, plus line operation (while charging) • Big. clear, high-contrast 0.43" high LCD readout, readable anywhore you can see to work . . . including bright sunlight! MODEL 255 $295.00

258 4Vi Digit Portable True RMS D.M.M.

585 8 Digit Portable 250MHz Frequency Coi

385.00 395.00

3Vi Digit- LCD Display DIGITAL MULTIMETER

• Unique Audible "Eyes-Off" multi-testing • Fast testing without taking your eyes off the circuit you're probing. • Continuity Test works on three lowest resistance ranges. • Repetitive Alarm warns of AC overload or accidental applications of AC voltage to OHMS input. • Single-tone alarm on negative DC overvoltage. • Also tests logic levels - logic transistors — relay or switch opening and closing — diode and transistor junctions — ev

MODEL 936 $190.00

Capacitance Meter

• Easy to use-plug in capacitor, push range button and read the value to 0.1%

• 0.5 in. liquid crystal display

• Exclusive "Acharge/Avolt" measurement circuit (patent pending) holds ±0.1 %

basic accuracy for a full year.

• Up to 200 hra operation on standard 9V Batt.

• 8 easy pushbutton ranges cover 0.1 pf 1999 microfarads.

• Best of all it's easy on the budget - only

MODEL 938

$185

0.1° Resolution, LCD Display TEMPERATURE METER

• WIDE-RANGING — [~l 65°C to + 150°C»(-)85o to 302°F • ACCURATE — ± .40C/±0.7°F over most of range • FAST— 8 seconds to 99% of final change in reading • VERSATILE — switch-selectable resolution (0.1° or 1") and degrees C or F • HANDY — easy to carry, hold, use. read

• TOUGH — takes everyday field usage yet maintains calibration. • COMPLETE — includes fullmeasurement range probe. • USED EVERYWHERE — internal 9V battery or line operation (115AC, 47 - 63 Hz) with optional battery eliminator. MODEL 940 $195.00

1350

1351

1750

2480

2480 R

5740

5800

5801

5845

3'/) Digit Bench D.M.M.

3VS Digit Bench D.M.M. with 20A

3Vi Digit Bench/Portable True RMS and dB D.M.M.

4'/j Digit Bench/Portable D.M.M.

4Vz Digit Bench/Portable True RMS D.M.M.

7 Digit 100MHz Multifunction Counter

8 Digit 520MHz Bench/Portable Frequency Counter 8 Digit 520MHz Bench/Portable Frequency Counter 8 Digit 150MHz Multifunction Counter

215.00 205.00 360.00 330.00 350.00 325.00 485.00 525.00 340.00

SIGNETICS

The Instructor 50

$350oo

Desktop Computer rery thing you need to and debug machine

Red. Our Price

Pan No. DP1002-2 32K 81395.00 $1016.00

HHM

10 Megahertz

HM307

SINGLE TRACE OSCILLOSCOPE IDEAL SERVICE INSTRUMENT TIME BASE 0.2 /is - 2.0 s/cm LPS-TRIGGER ■ COMPACT BUILT-IN COMPONENT TESTER

NO DISCOUNT COUPON FOR ITEMS ON THIS PAGE

CALL FOR QUOTE ON QUANTITY DISCOUNTS

Only S404.25

20 Megahertz

HM312

DUAL TRACE OSCILLOSCOPE I 10 x 8 cm DISPLAY I LPS-TRIGGERING

■ BANDWIDTH DC — 20MHz

■ TRIGGERING up to 30MHz

■ FULLX- Y OPERATION

Only S58O.0O

50 Megahertz

HM512

DUAL TRACE OSCILLOSCOPE SWEEP DELAY DELAY LINE BRIGHT DISPLAY BANDWIDTH DC — 50MHz TRIGGERING up to 70MHz AFTER TRIGGER DELAY LINE OVERSCANNING INDICATION IDEAL FOR COMMUNICATIONS AND DATA PROCESSING

Only $1485.00

KEITH LEY

3V2 Digit Hand-Held DIGITAL MULTIMETER

MODEL 130 —0.5% basic DCV accuracy • 25 ranges and 5 functions: DC volts, AC volts. DC amps. AC amps and ohms • Auto zero and auto polarity • Low battery indicator and much much more $11 5.00

MODEL131 —0.25% basic DCV accuracy • 25 ranges and 5 functions: DC volts, AC volts. DC amps, AC amps and ohms • Diode test • Auto zero and auto polarity • Low battery indicator and much more $134.00

4!/2 Digit LCD Hand-Held DIGITAL MULTIMETER

0.05% DCV accuracy • 4V4-digit resolution • 5 functions • Easy to read. 0 6" LCD display • 100hour life from an akaline battery • Annunciator warns user when 10% of battory life remains • Reliable rotary switches clearly display range and function • Fully protected from overload: 1000V max DCV. 1000V peak ACV and 300V max Ohms • 10A current range • ACV bandwidth to 20KHz MODEL 135 $219,00

4Vi Digit Bench/Portable DIGITAL MULTIMETER

MODEL 176—0.5% accuracy below 20VDC and20KHzAC • 20000 count

display • 0.6" LCD display • 5 Functions: DC volts. AC volts, DC amps, AC amps and ohms • Function and range annunciators • 1000 hour battery life typical MODEL 176 $249.00

MODEL 1 78 — 0.04% basic accuracy • 20000 count display • 0.6" LED display • 1400V input protection • Easy to use • 3 Functions: DC voiys, AC volts, ohms $249.00

1 304 Carrying Case $1 0.00

1 766 Battery Eliminator 40.00

1 788 Rechargeable Battery Pack 79.00

50 Megahertz

HM812

DUAL TRACE STORAGE OSCILLOSCOPE

■ 50 MHz DUAL TRACE PLUS VARIABLE PERSISTENCE

■ DELAYED SWEEP WITH AFTER DELAY TRIGGERING

■ STORAGE OF SINGLE-SHOT-SIGNALS "AUTOMATIC STORE"

■ LED INDICATION FOR OVERSCAN, SINGLE SHOT, TRIGGER ACTION DELAY MODE, "AUTOMATIC STORE" Only $4035.00

4V4 Digit LCD

Bench/Portable

DIGITAL MULTIMETER

• 2000 count display • 0.6" LCD display

• Function and range annunciators • 5 Functions; DC volts, DC amps, AC volts,

AC amps and ohms • Fully protected • 1-year battery life from alkaline

battery • Quality and performance

The K Oft Way 169 provides full capability for many genera I purpose applications.

Seldom-used functions have been eliminated to keep the price/performance

ratio high.

MODEL 169 $169.00

Universal Oscilloscope Probe

S— $36

:oo

SWITCHABLE XI and X10 Attenuation Factor

KEY ADDITIONAL FEATURES: • 100MHz bandwidth • Heavy duly tip • Break resistant center conductor • Slender, flexible cable

• 6ft. cable length • Wide compensation range • Fits all scopes

• Ground reference can be activated at tip • Includes SPRUNG HOOK, l.C. TIP, BNC ADAPTOR. INSULATING TIP and TRIMMER TOOL ACCESSORIES.

STORES 00 NOT ACCEPT MAIL ORDERS

MAILORDER

P.O. BOX2208Y CULVER CITY, CA90230

PHONE ORDERS (213) 641-4064

Minimum Order SID 00 Add S'l OD to cover postage and handling Master Charge and VISA welcomed Please include your charge card nomber, interbank number and etptralmn date Some ilcms are suli|er.l to nrioi sale Nol responsible lor lypus Store pricing may vary from Mail Order pricing. We reserve the right to substitute

THANDAR

Pulse Generator

(lott c

bottom)

• Independent Period and Pulse Width Controls

• Period Range 200ns — 200fts (5MHz — 5Hz)

• Pulse Width Ranga 100ns — 100/is

• Varible 5011 and Fixed TTL Outputs

• TTL Output Capable of Driving 20 Standard TTL

• Can Be Operated in Triggered. Gated. Manual OneShot or Manual Gated Modes

• Complement Switch Inverts Both Outputs

TG105 Only $219,00

Frequency Meter (

eft c

■°P)

• 10Hz — 200MHz (Resolution Ippm across measurement range • 5 Selectable Gate Times • Input Better than 30mV rim Across Full Range and Better than lOmV rms from 20Hz — 100MHz • W 8-Digit LCD Display • Automatically Positioned Decimal Point

• Totalise Mode For Frequencies Up To 20Mhz

• 1 M Hz Int. Timebase Available via Rear Panel Socket

• Indicates Units Being Measured (KHz or MHz)

TF200 Only S394.00

TP600 600MHz Proscaler Only $98.00

VISIT A STORE NEAR YOU TODAY - We stock a large selection of Technical Books, Discrete Components, Integrated Circuits, Test Equipment and Electronic Supplies.

ATLANTA

3330 Piedmont Rd. N.E

Atlanta, GA 30305

(404) 261-7100

CULVER CITY

1 1080 Jefferson Blvd.

Culver City, CA 90230

(213) 390-3595

HOUSTON

2649 Richmond

Houston, TX 77098

(713) 529-3489

PORTLAND

1125 N.E. 82nd Ave.

Portland, OR 97220

(503) 254-5541

SANTA ANA

1300 E. Edinger Ave.

Santa Ana, CA 92705

(714) 547-B424

SUNNYVALE

1054 E. El Camino Real

Sunnyvale, CA 94087

(408) 243-4121

TUCSON

451 8 E. Broadway

Tucson, AZ 8571 1

(602) 881-2348

372 BYTE April 1981

HICKOK

DIGITAL MULTIMETERS

LX-304 LX-303

S7995

Dual Trace Oscilloscope HITACHI 30 MHz

• TV sync-separater circuit

• High-sensitivity 1mV7div (5MHz)

• Sweep-time magnifier (10 times)

• Z-axis input (Intensity modulation)

• Signal delay line

• X-Y operation

• Trace Rotation

Model V302B

$995

DMM + VARI-PITCH + LOGI-TRAK =

MX-333

s235

© PLESSEY

Metallized Polyester Capacitors

Series 160

I "^MINIBOX

SAMPLER

S26.00

AP PRODUCTS

923101..S 79.95

923102. . . 124.95

923103. . . 124.95

MARK IV LED POWER LEVEL INDICATOR

R>po« • Display Range -36dB to+5dB

<IT $31.50 • Floating or Gradual Output Indicating

• Kit includes transistors, leds, capacitors, resistors, PC Board, and silk screened metal front panel

THE NEW NLS TECHNOLOGY

TOUCH/TEST 20

I 3

TOUCH/TEST 20 comes com

9 with lesi leads, tempera

i lure probe, component test

adaptor, batteries and charger

| unit. Order yours TODAY!

I ORDER NO. PRICE

NLSTT20 LEATHER S43S

NLSTT20B CARRYING S467

NLS-41-140 CASE 45

Intersil LED or LCD

3% DIGIT PANEL

METER KITS

BUILD A WORKING DPM IN *A HOUR WITH THESE COMPLETE EVALUATION KITS

Tesl these new parts for yourself with Intersil's low cost prototyping kits, complete with A/D converter and LCD display |7106| or LED display (7107). Kits provide all materials, incl PC board, for a functioning panel meter. ICL7106EV [LCD). . . . S34.4S ICL7107EV (LED) .... Mt.70

I #

SD SYSTEMS

ZOA STARTER ■OU SYSTEM

The Z80 Starter Kit by SD Systems uses the powerful Z80 microprocessor as the heart of the complete microcomputer on a single board, Learn a step-by-step introduction to microcomputers with a keyboard and display, audio cassette interface, PROM programmer, wire-wrap expansion area, 4channel Counter Timer and on Board RAM and PROM. Complete Opperation and Instruction Manual included. ZBUG Monitor in ROM.

27004 kit

$399 38007 assam/T.. $531

STORES DO NOT ACCEPT MAIL ORDERS

MAILORDER

P.O. BOX220BY CULVER CITY, CA 90230

PHONE ORDERS (213) 641-4064

Minimum Older SI 0 00 Add $2 DO lo cover postage and handling. Maitu Chuga and VISA walcumsd Pleate includa your chaige card number, intarbank number and eipjaton data Some itims are subject id prior tale. Nat responsible foi typos Stoic pricing. me> vary bam Mail Order pricing We leserve the Jig hi to substitute manufacturei

Quite Portable Very Affordable and Unbelievable

Versatile the PET computer may

very well be a lifetime investment

• Large Keyboard

• Separate Numeric Pad

• Graphics on Keys

commodore

16KS

Professional Keyboard Kits!

Models 753 Er 756 ASCII Keyboard Kits For Hobby or OEM Microprocessor Users

• Full 128 Character ASCII (756) • 53 Keys, popular ASR-33 format (753| • Rugged G-10 P.C. Board •Tri-mode MOS ancoding. • Two Key Rollover | MOS/TTL/OTL Compatible outputs • Shift and Alpha Lock(756) • Level end Pulae Strobo(756)

• Custom Keycaps • 3 User Dafinable Keyi(763) • Selectable Parity • Low Bounce Keyswitchat* And Much Morellf

753K 63 Key phona style keyboard-Kit. . . $65.95

753A Same as above assembled $79.95

756K 50 Key Full ASCII keyboard kit $69.95

756A Same as above assembled $82.95

701 Plastic enclosure for 753/756 $15.00

702 Steel enclosure (or 753/756 $29.95

753MF Mounting Frame for 763 $6.95

756MF Mounting Frame for 756 $6.95

CARBON FILM RESISTORS

FULL LEAD • HIGH QUALITY • 5%TDL

10 33 100

11 36 110

12 39 120

13 43 130 IB 47 150 16 51 160 18 56 180 20 62 200 22 68 220 24 75 240 27 82 270 30 91 300

330 1.0K

360 1.1K

390 1.2K

430 1.3K

470 1.5K

510 1.6K

660 1.8K

620 2.OK

680 2.2K

750 2.4K

820 2.7K

910 3.OK

3.3K 3.6K 3.9K 4.3K 4.7K 5.IK 5.6K 6.2K G.8K 7.5K 8.2K

10K 33K 100K

11K 36K 110K

12K 39K 120K

13K 43K 130K

15K 47K 160K

16K 51K 160K

18K 56K 180K

20K 62K 200K

22K 68K 220K

24K 75K 240K

27K 82K 270K

30K 91K 300K

330K 1.0M

360K 1.1M

390K 1.2M

430K 1.3M

470K 1.5M

510K 1.6M

560K 1.8M

620K 2.0M

680K 2.2M

750K 2.4M

820K 2.7M

910K 3.0M

3.3M 3.6M 3.9M 4.3M 4.7M 5.1M 5.6M 6.2M 6.8M 7.5M 8.2M 10.OM

% Watt $1.69 per C Vfc Watt $1.79 per C

ORDER ONLY IN MULTIPLES OF 100 PIECES PER VALUES

CfcQ 1C 2 WATT

M*Ci lw 10 P/Pack

$2.10

1 WATT

20 P/Pack

AVAILABLE IN THE FOLLOWING VALUES IN OHMS

3.3 ISO 300 560 1.5K 3.0K 5.6K 20K 47K 180K 680K

10 180 330 680 1.8K 3.3K 10.0K 22K 56K 220K 1.0M

47 200 390 820 2.OK 3.9K 12.0K 27K 68K 330K 2.2M

100 220 470 1.0K 2.2K 4.7K 15.OK 33K 100K 390K 4.7M

120 270 510 1.2K 2.7K 5.1K 18.OK 39K 150K 470K 10.OM

31/2-Digit, LCD-Display DIGITAL MULTIMETER

• HANDY — easy to hold, to carry, to use. to read. • ACCURATE — basic 0.1% DC accuracy

• TOUGH — built to tnke rough everyday field usage and electrical overload . . . yet maintain its calibration • VERSATILE — big, clear, high contrast 3'/i-dig it LCD display, readable anywhere... a full 0.5 " high. • PORTABLE — Palm-si*ed. lightweight operates up to 200 hours an a single 9V transistor alkaline battery. • EXPANDABLE — uses standard DMM accessories to extend ranges even further.

MODEL 935 $175.00

POWER SUPPLY

5 Volt 3 Amp APS 5-3

1-9... S37.25 10 up. .. $35.55 25 up.. $34.04

XR2206KB FUNCTION GENERATOR KIT

OPERATES ON EITHER: SINGLE 12V J-.6V SPLIT SUPPLY

INCLUDES ALL PARTS TO BE MOUNTED ON PC BOARD

Only $19.95

POWER SUPPLY NOT INCLUDED

m

• 10%*

DISCOUNT COUPON

Bring this COUl/OBt into one of our stores or mail to our Mail Order address shown below

and receive a I 0% DISCOUNT on purchases from this page of $50.00 or more. Otter EXPIRES on April .10. I»» I

NAME

ADDRESS.

CITY STATE

PHONE NO

Coupons accepted only with full name and address fille

91

PORTABLE thondor

OSCILLOSCOPE

• DC-IOMHz

• 2" Diagonal CRT

• SMALL SIZE

(10"xS.8"x(2")

• ULTRA LOW POWER CONSUMPTION

Only $369

LIGHT

WEIGHT |2 ib.)

AUTOMATIC CIRCUIT POWER DOWN FOR UNUSED SECTIONS

HIGH QUALITY CARBON FILM

RESISTOR KITS

% Watt — 5% Tolerance

EACH SET CONTAINS 840 RESISTORS 20 each of the following values (in ohms|

i .on i on i oon i .OKn i OKn 1 ooKn i.oun i .5n i sn 15on i .5Kn 15Kn 150Kn i .5Mn

2.2n 22fi 220« 2.2Kn 22Kn 220Kn 2.2MH 3.3n 33H 3300 3.3Kn 33Ktt 330Kn 3.3Mn 4.7n 47H 470n 4.7Kn 47Kn 470Kn 4.7Mn

6.an 6Bn6son 6.8Kn 68Kn 660Kn ,68n

RS-14-25 Complete w/StorogB Bin$2490

NEW 30 MEGAHERTZ

PORTABLE, DUAL TRACE MINI-SCOPE

30MEGAHERT2

MS-230 Du.t T>*a $649.00

15 MEGAHERTZ

MS-215 DU.ir,ac8' S497.00

MS-15 Single, !..-.= ., $389.01)

PORTABLE and LIGHT WEIGHT

EXAR

XR-032CP XR-083CP XH-084CP

1-24 25up100up i 1.39$ 1.11 $ .93

XR-C

4CP

XR-095CP

XR-096CP

XR-246P

XR-346CP

XR-346-2CP

XR-205CN

XR-210CN

XR-215CN

XR-C240

XR-C262

XR-C277

XR-320P

XR-5ESCP

XR-L555CP

XR-556CP

XR-L556CP

XR-558CP

XR-559CP

XR-567CP

XR-L567CP

XR-U5BCP

XH-U68CN

XR-1488P

XR-1489AP

XR-1524M

XR-156BN

XR-2200CP

XR-220! CP

XR-2202CP

1.58 1.30

4.80 4.00

3.38 2.81

3.38 2.81 ■

4.22 10.22

9.28 7.43 6.19 8.06 6.45 5.38

XR-2203CP

XH-2204CP

XR-2206CP

XR-2207CP

XR-2208CP

XR-2209CP

XR-2211CP

XR-22I2CP

XR-221BCP

XR-2228CP

XR-2240CP

XR-2242CP

XR-2271CP

XR-227 2CP

XR-2276CP

XR-2284CP

XR-2268CP

XR-2524P

XR-2556CP

XR-2567CP

XR-3403CP

XR-3524CP

XR-4136CP

XR4151CP

XR-4195CP

XR-4212CP

XR-4558CP

XR-4741CP

XR-5533P

XH-5533AP

XR-5534CP

XR-5534ACP

XR-6118P

XR-6128P

XR-8038CP

XR-13600CP

.94 .79

4.22 3.28 2.79 2.63 4.93

.94

.79

3.38 2.81

2.63 2.19

2.23 1.86

2.10 1.75

3.94 3.29

3.45 2.88

2.57 2.14

2.23 1.86

1.59 1.33

1.53 1.27

I.IB 1.99 3.66 8.72 4.03

1.59 1.33

2.93 2.44

6.98 5.81

3.22 2.69

11 2.49 2.07

1.94 1.61 2.50 2.09 1.59 1.33

2.64 2.25 2.25 3.75 1.82

VISIT A STORE NEAR YOU TODAY - We sleek a large selection of Technical Books. Discrete Components, Integrated Circuits, Test Equipment and Electronic Supplies.

ATLANTA

3330 Piedmont Rd. N.E.

Atlanta, GA 30305

(404) 261-7100

CULVER CITY

1 1080 Jefferson Blvd.

Culver City, CA 90230

(213) 390-3505

HOUSTON

2649 Richmond

Houston, TX 77098

(713) 529-3400

PORTLAND

1 125 N.E. 82nd Ave.

Portland, OR 97220

(503) 254-5541

SANTA ANA

1300 E. Edinger Ave.

Santa Ana, CA 92705

(714) 547-0424

SUNNYVALE

1054 E. El Camino Real

Sunnyvale, CA 94087

(408) 243-4121

TUCSON

4518 E. Broadway

Tucson, AZ 8571 1

(602) 881-2348

Circle 276 on inquiry card.

BYTE April 1981 373

o

LOWEST PRICES

ON THE

Pan onthe^J; Jj^

American Electronics

a

Radio /hack

Computers For Business, Learning and Entertainment

INCORPORATED

For More Information Call

TOLL FREE ORDER NUMBER

800-531-7466

Texas & Principal NUMBER

512-581-2765

Telex Number 767339

Dept. B, 1117 Conway

Mission, Texas 78572

o

o

00

cippkllplu/

With 48Kof s memory!

51195

With the purchase ol the APPLE Hi select Irom the below1 SPECIAL PRICING!

8ase~2 printer. S59901 DIsklMconl ...585'

Distill 475">

Ser.PrinlerCd... 179^

SupRIUod 23"

3waylK3Select.. 33"

videotex)tz:.... m

FirmwareCard. 179"° 'MFtoRCACabl^°°^

74LS00 .26 74LS155 1.15

74LS02 .26 74LS158 75

74LS03 26 74LS160 95 74LS04 .26 74LS161

74LS08 .28 74LS162 95

74LS09 .26 74LS163 160

74LS10 .26 74LS164 65

74LS20 .26 74LS165 65

74LS21 28 74LS170 175

74LS22 .26 74LS174 75

74LS26 .49 74LS175 .75

74LS27 26 74LS190 75

74LS30 .28 74LS193 .95

74LS32 .32 74LS195 .95

74LS38 .32 74LS196 85

74LS42 65 74LS221 1.40

74LS48 .78 74LS240 165

74LS51 25 74LS241 1.65

74LS54 .35 74LS243 145

74LS74 .38 74LS244 1.45

74LS75 .60 74LS245 2 25

74LS83 44 74LS253 95

74LS85 .95 74LS257 .95

74LS86 95 74LS258 .95

74LS90 .69 74LS259 2 85

74LS93 .69 74LS279 44

74LS107 45 74LS283 100

74LS112 38 74LS293 1.85

74US113 .48 74LS298 120

74LS122 48 74LS366 95

74LS123 .95 74LS367 .55

74LS126 .69 74LS368 .55

74LS138 69 74LS373 1.39

74LS151 .44 74LS374 139 74LS153 .44 74L!

kll/oppkllpki/

With64Kpf memory!

51389

flw>u inTERPflcc ennw

cinmonKf MnTu i m

commuiwuTioni <•**•**.■<•**• m

MIHIICOmHOUM <».•.*.).J Mt

MKM UUMUMf NKHMI 4W

COLOR

$397*

EPROMS 2708 Ik x 8 5.95 8 FOR 40.00 2716 2k x 8 9.95 single p.s 8 FOR 80.00 2732 4k x 8 24.95 2716 2k x 8 6.96 tnpte p.a.

L—d«x Corp

appk ckxk, cakA<ki(

*12495

On board batteries with one year He.

UsosMSMSa32-crystalcontroled

California Computer Systems

S038C

NE555V

7905.

7908 .

7915

7918

7805

7806

7808 .

7812

MC1330AIP

MC1350P

MC1358P

LU380N

NE565H

MC1458P

IS410 SCR

IT410 TRIAC 2114 200ns 2114L 300ns 2114L 200ns 4116 300ns 4116 200ns

BUY FIVE OR MORc

1.60 1.15 1.50 1.75 1.25 .50 .95 .95

$16.95 each

CARRY

Tbar

SWITCHES

COHCORD

COfflPUTCR

componenn

1971 SOUTH STATE COLLEGE

ANAHEIM, CALIF. 92806

VisiCalc

For the Apple and Atari

$129.00

(N7400N SN7402N SN7404N SN7408N SN7410N SN741 2N SN7413N SN7414N SN7416N SN7417N SN7423N SN7425N SN7430N SN743/N SN7438N

.20 SN7440N

22 SN7442N .22 SN7443N .24 SN7445N .22 SN7451N .28 SN7454N .35 SN7474N

49 SN7475N .29 SN7482N 29 SN7492N

28 SN7493N .25 SN7495N

23 SN7496N

29 SN74122N

24 SN74136N

.22 SN74141N

57 SN74151N

.78 SN74153N

78 SN74154N

.20 SN74155N

20 SN74157N

32 SN74160N

32 SN74161N

1.05 SN74163N

.50 SN74164N

.48 SN74165N

.60 SN74174N

.70 SN74175N

.39 SN74180N

.95 SN74181 N

.69 .65 .65

1.25 .80 .69 .95 .65 .85 .87 .87 95 .69 .75

1.15

MSM5832 i-7AK

MICROPROCESSOR l*° REAL-TIME CLOCK

The MSM583? » a monolith* muitl-gaie CMOS integrate

provide arH'essable 4-bir I. 0 Qua ol SECONDS MIN HOURS DAV-OF WEEK DATE MONTH »na VEAH

TRS80

IGK MemrxyWdDn

•4395

KIT CONTAINS DIP SWITCHES

AND DETAILED INSTRUCTIONS

No"GHtches",Surges Or Interference

THE MPDTT7 TURNS AH

ORDINARY OUTLET INTO A CONTROL LED FILTERED POWER SOURCE FOR UP TO EIGHT DEVICES.

374 BYTE April 1981

DMa©®Q0©OK]

□ □□

INTRODUCTORY M PRICE ONLY ^"»

REGULAR $3250.00 LIST

INCLUDING CP/M2.2® (Last Month At This Price)

320K

MINI DRIVES SHOWN, 8"

and 5J4" 10MB HARD DISK OPTIONAL

IMMEDIATE DELIVERY!

1 YEAR PARTS WARRANTY!

(90 DAYS ON DRIVE PACKAGE, KEYBOARD AND LABOR)

MR MICRO SALES

S-100-8

©HUSK "UTKI

TERMINAL

• Feather Touch Capacitance Keyboard

• 60 Key Standard ASCII PLUS + Hex Keypad

PLUS + 8 Special Function Keys PLUS + 20 Screen Editing Keys

♦ SOROC Type Screen Attribute Set

♦ Half Intensity

OPTIONS:

♦ Dual 514" Double Sided MPI B51 (640K) add $225.00

♦ Dual 51/4" Double Sided MPI B91 (1.2MB) add $360.00

♦ Dual 8" SIEMANS FDD120-8 Drives (1MB) add $250.00

♦ Dual 8" QUME Double Sided Drives (2MB) add $625.00

COMPUTER

8 SlotS-100

64K Dynamic Ram

4MHZ Z-80

Serial Printer Port (150 -19.2K)

Double Density Disk Controller

Programmable Baud Rate

Programmable Keyboard Set

0

□

DISK STORAGE

Dual Double Density 514 Single Sided Drives

DOUBLE SIDED Option

Double Sided, 77 Track, Option

Color Matched Enclosure Self Contained Power Supply

w W i^f MICRO

. SALES

11 EDISON DRIVE * NEW LENOX. ILLINOIS 60451 ~k (815)485-4002

CP/M2.2 is a Registered Trademark of Digital Research Inc.

Circle 279 on inquiry card.

Circle 280 on Inquiry card.

BUILD YOUR OWN LOW COST MICRO-COMPUTER

POWER SUPPLIES

FOR S-100 BUS, FLOPPY DISKS, ETC.

POWER TRANSFORMERS (with mounting brackets)

ITEM NO.

USED IN KIT NO.

PRI. WINDING TAPS

SECONDARY WINDING OUTPUTS 2x8 Vac 2x14 Vac 2x 24 Vac

SIZE WxDxH

UNIT PRICE

T3

0V,110V,120V 0V, 110V, 120V 0V,110V,120V 0V, 110V, 120V 0V, 110V, 120V

2 X 7.5A 2X12.5A 2x9A 2x4A 2x3A

2 X 2.5A 2 X 3.5A 2X2.5A (28V, CT) 2x2A

2x2.5A 48V, CT, @3A

POWER SUPPLY KITS (open frame with base plate, 3 hrs. assy, time)

ITEM USED FOR @+BVdc (H>-9Vdc @ + 16Vdc @-16Vdc @+28Vdc

3y4"x35/„"x3'/8" 33/."x4f x3/," 3V4"x4f*x3%" 3V*"x3%"x3%" 3"x3"X2'/2"

SIZE WxDxH

21.95 27.95 29.95 22.95 14.95

UNIT PRICE

KIT 1 15 CARDS SOURCE 15A

KIT 2 SYSTEM SOURCE 25A

KIT 3 DISK SYSTEM 15A

1A

2.5A 3A 2A

2.5A 3A 2A

4A

12"x5"x4'/a" 12"x5"x4'/a" 14"X6"X4'/,"

52.95 59.95 67.95

DISK SYSTEM PWR SUPPLY S3 assy. & tested, open frame, size to"(W)x6"(D)x4%"(H) 92.95

UNREGULATED OUTPUTS: +8V@12A, ±16V@3A.

REGULATED OUTPUTS: +5V@4A, -5V@1A, +24V@4A, SHORTS PROTECT. IDEAL FOR THE SYSTEM WITH 10SLOTS MAINFRAME & TWO 8" DISK

DRIVES, SUCH AS SHUGART801R OR SIEMANS FDD 100-8. (OPTION: OVP for +5V @ ADD $5.00)

DISK DRIVE POWER SUPPLY "R3" assy. & tested, open frame, size 9"(W)x6y< "(D) x4%"(H) 67.95

SPECS: +5V @ 5A REGUL, OVP, - 5V @ 1A REG., + 24 @ 5A REG., SHORTS PROTECT. OPTIONS: 1. REPLACE + 24V BY +12V

2. ADD ± 12V @ 1A, $12.00 MORE. IDEAL FOR 2 SHUGART 801/851 OR SIEMANS FDD 100-8/200-8 DISK DRIVES & ROCKWELL AIM-65. SHIPPING FOR EACH TRANSFORMER: $4.75. FOR EACH POWER SUPPLY: $5.00 IN CALIF. $7.00 IN OTHER STATES. CALIF. RESIDENTS ADD 6% SALES TAX. OEM WELCOME.

MAILING ADDRESS: P.O. BOX 4296 TORRANCE, CA 90510

SUNNY INTERNATIONAL

(TRANSFORMERS MANUFACTURER)

(213) 328-2425 MON-SAT 9-6

SHIPPING ADDRESS: 22129V2 S. VERMONT AVE TORRANCE, CA 90502

et:

Yes! We supply

IMSAI

y

compatible products.

NOTE: "Original" IMSAI parts were purchased at the closing business sale of IMSAI Manufacturing Corp. WW Components also distributes S-100 buss IMSAI compatible parts and boards. As supplies of "original" parts are exhausted, WW reserves the right to supply equivalent compatible parts not made by IMSAI. All items listed as "Assembled & Tested" have been assembled by WW Components and carry a 1 year warranty.

1-8080 S-100 THE ORIGINAL IMSAI: Mainframe with blue cover, cardguides and hardware

ENCLOSURE spaced for PS-28D Power Supply, up to 22 slot motherboard.

Sheet Metal Kit Kit of all metal parts and hardware w/docs $115.00

Thinker Toys WunderBuss20 for above w/o conn. $79.00

Complete 8085 based CPU including: serial RS-232 port, parallel I/O port 3 MHz operation, 256 bytes memory, ROM monitor, 3 timers, and more.

Assembled & Tested $250.00

Mounts in the I-8080 enclosure, supplies +8V @ 28A, +/- 16V @ 3A, kit includes board, transformer, documentation, and all components.

KIT $95.50

The complete 8085 system, includes MPU-B, RAM III, 10 slot terminated motherboard, PS-28D, and jump start front panel. A complete 64K system!

Assembled & Tested $1250.00

NOW AVAILABLE - CP/M for the IMSAI floppy disk system. Version 2.2 is available for the DI0-C 8" controller. Others on request. Docs. incl.

8" Diskette & Manuals $175.00

Ask about documentation, repair service, firmware and software for your system.

MPU-B SBC 8085 CPU

PS-28D Power Supply Parts Kit:

1-8015 Complete System w/MPU-B

CP/M ® 2.2 for IMSAI

TERMS: (1) PREPAID Send check or M.O. for merchandise amount only - we pay the shipping in USA only. (2) UPS COD or bankcard orders by phone or mail - shipping charges added. California Residents add 6.5% Sales Tax.

85 5

B

5 1

ft

376 BYTE April 1981

Circle 281 on Inquiry card.

yc/t

P.O. Box 4430X Santa Clara, CA 95054

ELECTRONICS

INTEGRATED CIRCUITS

Will calls: 2322 Walsh Ave. (408) 988-1640 TWX 910-338-2139

Same day shipment. First line parts only. Factory tested. Guaranteed money back. Quality IC's and other components at factory prices.

74Q0TTI

740QN

7402N

7404N

7409N

7«tON

74 UN

7420N

7422N

7430N

7442N

7445N

JAA7U

7448N

M50K

7474N

7475N

7485N

74B9N l

7490N

7492IJ

7493N

7495N

74I00N I

74I07N

74121N

74123K

74125N

74145N

741MN I

74151N

741 bW l

74157N

7416IN

74162N

M1B3N

74174N

7417SN

7419DN 1

74192N

741 BUN

7422 IN 1

?msn 1

74365N 74366N 74367N

74LS00 TTl 74LSDQN 74LS02N 74LS04N 74LS05H 74LS08N 741SKW 74LSI3N 74LSI4N 74LS20N

74LS22N 35

74LS28N 35

74LS30N 35

74LS33N 60

74LS38N 50

74LS74N .45

74LS75N 65

74LS90N 60

74LS93N 75

74LS95N 1 00

74LS107II 45

74LS1I2N 45

74LS113N 45

74LSI32H 99

74LSl36fl 50

74LS151H 75

74LS155N 79

74LS157N I ID

74LS162N I 10

MLS163N t 10

741S174H I 15

74LS190II 1 25

74L5221N 1 25

74LS256H 1 00

74LSM7PI 69

UHEAR

CA3Q45 90

CA3046 1 10

CA30B1 I 80

CA3082 1 90

CA30B9 3 40

IM301ANAH 35

LM305H 87

LM307N 35

LM308S 1 00

LM309K 1 25

LM311HH 90 LM317T LM317K

LM320K-5 1 35

LM320K-12 1 35

LM320K-15 135

LM320T-5 95

LM320T-8 95

LM320T-12 95

LM320T-15 95

LM323K-5 5 95

LM324N 1 00

LM339N I 00

LM340K-5 1 35

LM340K-8 ) 35

LM340K-12 135

LM340K-15 I 35

LM340K-24 I 35

LM34QT-5 85

LM340T-8 85

LM340T-12 85

LM340M5 B5

LM340T-18 85

LM340T-24 65

LM350 5 50

LM377 2 95

LM379 5 00

LM380N I 00

LM381 160

LM382 1 GO

LM709H

LM723H N

LM733H

LM741CH

LM741N

LM747H N

LM748N

LM1303N

LM1304

LM1305

LMI307

LM13I0

LM145B

LMIB12

LMI889

LM2111

LM2902

LM3900N

LM3905

LM3909N

MC1458V

NE550N

NE555V

NE556A

NE565A

NE566V

NE567V

NE570B

78L05

78L08

78M05

75108

75491CN

75492CN

75494CN

22 00

LM31B

1 50

B700CJ B7Q1CN

B750CJ 13 95

LD130 9 95

9400CJV F 7 40

ICL7103 9 50

ICL7107 14,25

CMOS

CD4000 25

CD 4001 35

CD4002 35

C04006 1 10

CD40O7 35

CD4008 1 20

CD4009 45

CD4Q'0 45

CD4011 35

CD4012 28

C04013 47

C04014

CD4015

C04016

CD4017

CD4018

CD4019

CD4020

CD4021

C04D22

CD4023

CO4024

CD4025

CDJ026 CD4027 CD402B CD4029 CD4030 CD4035 CD-1040 CD.1042 C[}.:u.l3 CD4044 CD4046 CD4049 CD4050 CD4051 CDJ060 CD 4066 CD4066 CD4069 CD4070 CD4071 CD4072 CD4Q73 CD4075 CD4076 CD407B CD4081 CO4082 CD4116 CSJ4490 CO4507 CD4506 CD4S10 CD4511 CD4515 CD4516 CD4518 CD4520 CD4527 CD452B CD «53 CD4566 CDJ5B3 CD4535 CD40I92 74CO0 74C0J 74C1Q 74CH 74C20 74C30 74C48 74C74 74C76 74C90 74C93 74C154 74C160 74C175 74C192 74C221 74C905 7JC905 74C914 74C922 Ft 74C923 74C925 74C926 74C927

2 50 21 ML -150ns 4 00

66 4116 200ns 4 50

65 8-4116 200ns26 95

I 35 MM5262 40

45 MM5280 3 00

1 00 MM5320 9 95

1 35 MM5330 5.94

85 PD4110-3 4 00

B5 PD41ID-4 5 00

.85 P5101L B 95

167 4200A 9.95

45 82325 2 90

60 91L02A 1 50

I 13 HD0165-5 695

1 42 MM57100 4 50 71 GIAY3850O-I 9 95 40 MCM66751A 9 95 40 9368 3 50 50 4100 10.00 45 416 16 00

f, CLOCKS

•W MM5311 5 50

'■g MM5312 3 90

« MM5314 3.90

« MM5369 2 10

35 MM5841 14 45

-tl MM5865 7 95

?.™ CT7010 B9S

1*89 CI7015 8 95

2 =■? UM537SAA/N 3 90 1 ™ MMS375AGN 490

-« 7205 16 50

2,% im

IC SOCKETS Solder Tin Low Pralim PIN 1 UP PIN 1UP

WIRE WRAP LEVEL 3

53 -e, ASCII ieytraatd kit Fully assembled

Enclosure Plaslic

Metal Enclosure

70 00 14 95 29.95

7208

S 7209

9f DS0026CN

IJ DS0056CN

?0 MM5310J

18 67 40

CRYSTALS

1 MHl 2MHl 4 MM; 5MHi 10 MH: 18 MH; 20 MKj32MHi 32768 Hi I t 8432 MH; I 3 5795 tAHl I 2 0100 MH; ! 2 097152 Mil; 1 2 4576 MH; 1 3.2768 MH; 1 5 068B MH; 5 185 MH;

5 7143 MH;

6 5536 MH; 14 31B18MH;

40 6802

35 6820

B9 6B50

35 8080A 35

3 95

12 95

75 00

8096 8097 8098 BT09 8T10 8T13 BT20 BT23 8T24 8T25 BT26 ST28

95 8086

85 Z80 133

1 25 280A 11 95

1 25 82'2 2 90

1 25 8214 3 95 3 50 8216 2 90

2 75 8224 3 45 1 35 8228 4 95 1 65 8251 6 95 1 90 8253 15 00

6 00 8255 5 75 75 8357 10 95

1 95 B259 14 95

5 00 IB02CP nlas 13 95

5 50 !802DPplas 17 95

7 50 1861P 9 50 kqs COP1BQ2CD 28 95 em CDP1B02D 35 00

CDP1B16P 7 95

55 UART7FIF0

65 AY5-1013 5 50

65 AY510I.'

65 3341

1 25

450 PROM

3.00 I702A 4.95

5 50 270B 6 10

3 10 271611 18 00 3 50 2716 5 Won 10 50 3 20 B 2716 5 Vol! B9 00 169 2732 29 50

2 75 2756 19 50

KEYBOARD ENCODERS

AY5-2376 SI2 50

AY5-3600 17 95

AY5-910O 10 50

AY5-9200 16 50

74C922 5 50

74C923 5 50

HD0165 5 6 95

AYS-9400 10 50 0 Connecton RS232

DB25P 3 62

OB25S 5 20

Cover l 67

0E9S 195

0A15P 2 10 0A1SS Complete Set

6 95

9 50

HJckok 3^ Dlgll LED mul

llmitif S9.95

SlapwUch Kit 26.95 Aulo Clock XII 17.95 Olgldl Clock KI1 tl.95

IK-'IBKEprom Kit

(less PROMS) SB9 00 Molherhoird $39 00

Eilender Baud $15 00

28 8T98 t 69 8748

47 8748-8

1 25 B755A

1 00 MOS/MEMOfiY RAMNB2S23

55 2101-1 3.85 NB2S123

I 05 2102-1 95 N82S126

94 2I02AL-4 1 45 N82S129

45 2102AH-2L 165 N82S131

1 02 2104A-4 4 95 NB2S136

1 35 2T07B-4 3 75 N82S137

1 10 2111-1 3 75 DMB577

28 2112-2 3.95 8223

75 2114 3 75

28 2114L300ns425

RESISTORS '<

wait 5«

10 oer type 25 per lyuc 100 oer lyoe

03 025 015

1000 per type

350 oiece M

5 pet type

012 6 75

'7 win 5'. pe

type 05

Televldio Termlnil Model 912 $785 00 Model 920 S8B5 00

Tlirr BltlC Fiyi-.-l.-i-cr.l::'! HI

110. DO

LEDS

Red TOIfi 15

Green. Yellow T01B 2D

Jumoo Ret) 20

Green. Orange. Verio* Jumoo 25

Clisiiie LED Mounting Clips 3S1 25 (specrly reO amber green, yello*. Clurl

COHTINEHTAL SPECIALTIES In itoclt Complete line ot DreaoooarO teat egurp Max-100 B digit Frag. Clr. 1149.95

Complete line ot *P Products In ate

SPECIAL PRODUCTS

MM5B65 Slop.atcn T.mer

with 10 pg spec a

PC noaro I

SarlteAea '.torn Puanounoo

3 poa slide Encoder HD01655 «

Parilronica Moflel 10 Trigger

EapanOer Kit S22l

Model 150 Bus

Grabber Krl S36S

Clock Calandar Kit S2r

2.5 MHa Fieguency

Counter Kit 131

30 MH; Fraguancr

Couniar all HI

TRANSFOHMEOS

5V 300 ma !

12 Voll 300 ma transformer ' l2 6VCT600ma !

12V 250 ma wall plug 1

12V CT 250 ma wall plug 24V CT 100 ma :

10V I 2 amp wall plug ■

12V 5 amp IS

12V 500 ma wall plug '

12V 1 amp wall plug I

10 15 VAC B 15 VA wall plug <

DISPLAY LEDS

MANl

MAH3

MAH72 74 C

DL704

DL707 DL707R

DL727 728 C

DL747.750 C

FFID359

FND500507

FNQ5O3 5I0

FIID800B07

3 Orgil Bubble

10 Oign Orspia

7520 Clarre. c

TIL311 He.

MAN3540

MAW610

MAW4640

MAN4710

MAN4740

MANB540

MAII6710

MAN6740

CCCA I

CC CA I CCCA I

MA1007A. C. E

MA1012A

I02P3 tranalormer

MA10I2A Tltnalormar

DIP Swllcttea

4-0054100 S 95

5-position 1 00 6-posmnn 1 00

B-obsmon

1 D5

Cbmplole lino ot Kooby-Bloa sol

oeness OreaOboanJs In stock IC Starlei Pack S5.95

Discrete Component Starter Pack S8.S7

PROM Eraser

assembled. 25 PROM capacity $37.50 (with timer $69.50). 6 PROM capacity OSHA/ UL version $69.50 (with timer $94.50).

Z80 Microcomputer

16 hit I/O, 2 MHz clock, 2K RAM, ROM Breadboard space. Excellent for control. Bare Board S28.50. Full Kit $99.00. Monitor $20.00. Power Supply Kit $35.00. Tiny Basic $30.00

S-100 Computer Boards

8K Static Godbout Econo IIA Kit 149.00 16K Static Godbout Econo XIV Kit 269.00 24K Static Godbout Econo XX-24 Kit 414.00 32K Static Godbout Econo XX-32 Kit 537.00 16K Dynamic RAM Kit 289.00

32K Dynamic RAM Kit 328.00

64K Dynamic RAM Kit 399.00

Video Interface Kit $139.00

80 IC Update Master Manual $39.00

Comp. IC data selector, 2700 pg. master reference guide. Over 51,000 cross references. Free update service through 1980. Domestic postage $3.50.

Modem Kit $60.00

State of the art, orig., answer. No tuning necessary. 103 compatible 300 baud. Inexpensive acoustic coupler plans included. Bd. only S17.00.

LRC 7000 -Printer 5389.00

40/20 column dot matrix impact, std. paper.

Interlace all personal computers.

64/40/32/20 version $405.00. Optional cables available.

LRC 7000 printer interface cable for Super Ell Willi software $35.00

NiCad Battery Fixer/Charger Kit

Opens shorted cells that won't hold a charge and then charges them up, all in one kit w/full parts and instructions. $7.95

Rockwell AIM 65 Computer

6502 based single board with full ASCII keyboard and 20 column thermal printer. 20 char, alphanumeric display, ROM monitor, fully expandable. $405.00. 4K version $450.00. 4K Assembler $85.00, 8K Basic Interpreter $100.00.

Special small power supply for AIM65 assem. in frame $54.00. Complete AIM65 in thin briefcase with power supply $499.00. Molded plastic enclosure to fit both AIM65 and power supply $47.50. Special Package Price: 4K AIM, 8K Basic, power supply, cabinet $625.00.

AIM65/KIM/VIM/Super Elf 44 pin expansion board; 3 female and 1 male bus. Board plus 3 connectors $22.95.

60 Hz Crystal Time Base Kit $4.40

Converts digital clocks from AC line freguency to crystal time base. Outstanding accuracy.

Video Modulator Kit $9.95

Convert TV set into a high quality monitor w/o affecting usage. Comp. kit w/full instate.

Multi-volt Computer Power Supply

8v 5 amp, »18v .5 amp. 5v 1.5 amp. -5v .5 amp, 12v .5 amp, -12v option. ±5v, ±12v are regulated. Basic Kit $29.95. Kit with chassis and all hardware $43.95. Add S4.00 shipping. Kit of hardware $14.00. Woodgrain case $10.00. $1.50 shipping.

RCA Cosmac 1802 Super Elf Computer $106.95

Compare features before you decide to buy any other computer. There is no other computer on the market today that has all the desirable benefits of the Super Ell for so little money. The Super Ell is a small single board computer that does many big things. It is an excellent computer for training and for learning programming with its machine language and yet it is easily expanded with additional memory, Full Basic, ASCII Keyboards, video character generation, etc. Before you buy another small computer, see if it includes the following features: ROM monitor; State and Mode displays; Single step; Optional address displays; Power Supply; Audio Amplifier and Speaker; Fully socketed for all IC's; Real cost of in warranty repairs; Full documentation. The Super Ell includes a ROM monitor for program loading, editing and execution with SINGLE STEP for program debugging which is not included in others at the same price. With SINGLE STEP you can see the microprocessor chip operating with the unique Quest address and data bus displays before, during and after executing instructions. Also, CPU modeand instruction cycle are decoded and displayed on 8 LED indicators. An RCA 1861 video graphics chip allows you to connect to your own TV with an inexpensive video modulator to do graphics and games. There is a speaker system included for writing your own music or using many music programs already written. The speaker amplifier may also be used to drive relays for control purposes.

plus load, reset, run, wait, input, memory protect, monitor select and single step. Large, on board displays provide output and optional high and low address. There is a 44 pin standard connector slot for PC cards and a 50 pin connector slot for the Quest Super Expansion Board. Power supply and .sockets for all IC's are included in the price plus a detailed 127 pg. instruction manual which now includes over 40 pgs. of software info, including a series of lessons to help get you started and a music program and graphics target game. Many schools and universities are using the Super Elf as a course of study. OEM's use it for training and R8aD. Remember, other computers only offer Super Elf features at additional cost or not at all. Compare before you buy. Super Ell Kit $106.95, High address option $8.95, Low address option $9.95. Custom Cabinet with drilled and labelled plexiglass front panel $24.95. All metal Expansion Cabinet, painted and silk screened, with room for 5 S-100 boards and power supply $57.00. NICad Battery Memory Saver Kit $6.95. All kits and options also completely assembled and tested.

Questdata, a software publication for 1802 computer users is available by subscription for $12.00 per 12 issues. Single issues $1.50. Issues 1-12 bound $16.50. Tiny Basic Cassette $10.00, on ROM $38.00, original Elf kit board $14.95. 1802 software; Moews Video Graphics $3.50. Games and Music $3.00, Chip 8 Interpreter $5.50.

A 24 key HEX keyboard includes 16 HEX keys

Super Expansion Board with Cassette Interface $89.95

This is truly an astounding value! This board has been designed to allow you to decide how you want it optioned. The Super Expansion Board comes with 4K ol low power RAM fully addressable anywhere in 64K with built-in memory protect and a cassette Interface. Provisions have been made for all other options on the same board and it fits neatly into the hardwood cabinet alongside the Super Elf. The board includes slots for up to 6K of EPROM (2708, 2758, 2716 or Tl 2716) and is fully socketed. EPROM can be used for the monitor and Tiny Basic or other purposes. A IK Super ROM Monitor $19.95 is available as an on board option in 2708 EPROM which has been preprogrammed with a program loader/ editor and error checking multi file cassette read/write software, (relocatable cassette file) another exclusive from Quest. It includes register save and readout, block move capability and video graphics driver with blinking cursor. Break

Quest Super Basic V5.0

A new enhanced version of Super Basic now available. Quest was the first company worldwide to ship a full size Basic for 1802 Systems. A complete function Super Basic by Ron Cenker including floating point capability with scientific notation (number range I.17E38). 32 bit integer ±2 billion; multi dim arrays, string arrays; string manipulation; cas

points can be used with the register save feature to isolate program bugs quickly, then follow with single step. If you have the Super Expansion Board and Super Monitor the monitor is up and running at the push of a button. Other on board options include Parallel Input and Output Ports with lull handshake. They allow easy connection of an ASCII keyboard to the input port. RS 232 and 20 ma Current Loop for teletype or other device are on board and if you need more memory there are two S-100 slots for static RAM or video boards. Also a 1K Super Monitor version 2 with video driver for full capability display with Tiny Basic and a video interlace board. Parallel 1/0 Ports $9.85, RS 232 $4.50, TTY 20 ma l/F $1.95, S-100 $4.50. A 50 pin connector set with ribbon cable is available at $15.25 for easy connection between the Super Elf and the Super Expansion Board. Power Supply Kit for the complete system (see Multi-volt Power Supply).

Ohio Scientific Computers

CIP Series 2 $455.00. Like an Apple at less than half the price! CIPMF Series 2 $1199.00. Minifloppy version with additional RAM/ROM. Complete software and peripherals available. Send for free brochure.

Gremlin Color Video Kit $69.95

32 x 16 alpha/numerics and graphics; up to 8 colors with 6847 chip; 1K RAM at E000. Plugs into Super Elf 44 pin bus. No high res. graphics. On board RF Modulator Kit $4.95

1802 16K Dynamic RAM Kit $149.00

Expandable to 32K. Hidden refresh w/clocks up to 4 MHz w/no wait states. Addl. 16K RAM $63.00 Tiny Basic Extended on Cassette $15.00

(added commands include Stringy, Array, Cassette I/O etc.) S-100 4-Slot Expansion $ 9.95 Super Monitor VI.I Source Listing $15.00

sette I/O; save and load, basic, data and machine language programs; and over 75 statements, functions and operations. New improved faster version including renumber and essentially unlimited variables. Also, an exclusive user expandable command library.

Serial and Parallel I/O included. Super Basic on Cassette $55.00.

Elf II Adapter Kit $24.95

Plugs into Elf II providing Super Elf 44 and 50 pin plus S-100 bus expansion. (With Super Expansion). High and low address displays, state and mode LED's optional $18.00.

Super Color S-100 Video Kit $129.95

Expandable to 256 x 192 high resolution color graphics. 6847 with all display modes computer controlled. Memory mapped. 1K RAM expandable to 6K. S-100 bus 1802,8080,8085, Z80etc. Dealers: Send lor excellent pricing/margin program.

Editor Assembler $25.00

(Requires minimum of 4K lor E/A plus user source)

1802 Tiny Basic Source listing $19.00

Super Monitor V2.0/2.1 Source Listing $20.00

TERMS: $5.00 min. order U.S. Funds. Calil residents add 6% tax.

$10.00 min. BankAmericard and Master Charge accepted. $1.00 insurance optional. Postage: Add 5%. COO. $10.00 min. order.

FREE: Send lor your copy ol our NEW 1980 QUEST CATALOG. Include 48c stamp.

Circle 282 on Inquiry card.

BYTE April 1981 377

Circle 283 on inquiry card.

Add-On

Disk Drive

Subsystems

FOr Apple, TRS-80, S-100 Based Computers

Expansion and enhanced capabilities are key words in achieving full utilization of your computer system. Our complete line of LOBO disk drive subsystems are the ideal, cost-effective way to provide the expansion capabilities you need to meet your system growth reguirements. All of our subsystems are complete, thoroughly-tested, 100% burned-in, and feature a 1 year 100% parts/labor warranty.

APPLE

3101 Minifloppy, 31011 Minifloppy w/interlace card

8101CA One SA800 in cabinet w/power, DDC* Controller, cable and manual 8202CA Two SA800 in cabinet w/power, DDC* Controller, cable and manual 5101CA One SA850 in cabinet w/power, DDC* Controller, cable and manual 5202CA Two SA850 in cabinet w/power, DDC* Controller, cable and manual "Double Density Controller

S-100 BASED COMPUTERS

MODEL NO. DESCRIPTION

4101C SA400 in cabinet w/power

821 2C Two SA801 in cabinet w/power

521 2C Two SA851 in cabinet w/power

GENERAL

MODEL NO. DESCRIPTION

8212 Two SA801 in cabinet

8212C Two SA801 in cabinet w/power

5212 Two SA851 in cabinet

5212C Two SA851 in cabinet w/power

TRS80

MODEL NO. DESCRIPTION MODEL NO

4101C SA400 in cabinet w/power C808

8101C II One SA800 in cabinet w/power lor Mod. II LX80

8202C II Two SA800 in cabinet w/power lor Mod. II RS232

C802 CableforMod.il 16K

C805 Cable lor TRS80 Minifloppy VTOS

DESCRIPTION

Cable lor TRS80 Eight-inch Floppy

Double-density expansion interface

Dual Serial Port Option

16K Byte RAM lor LX80 (32KB max.)

4.0 Disk Operating System

INVENTORY CO.,

P.O. Box 185, Santa Y»iez,Ca., 93460 (805) 688-8781

STANDARD RS232 CABLES

PART NO.

DESCRIPTION

PRICE

RS232MM9

Male to male 9 ft. cable

24.00

RS232MM18

Male to male 18 ft. cable

29.00

RS232MF9

Male to female 9 ft. cable

29.00

RS232MF18

Male to female 18 ft. cable

34.00

RS232FF9

Female to female 9 ft. cable

34.00

RS232FF18

Female to female 18 ft. cable

39.00

RS232M09

Male to open 9 ft. cable

18.00

RS232M018

Male to open 18 ft. cable

23.00

RS232F09

Female to open 9 ft. cable

24.00

RS232F018

Female to open 18 ft. cable

29.00

DISK DRIVE POWER CABLES

PART NO.

DESCRIPTION

PRICE

PDC-5

5%" DC PowerConnector24" lonq

6.00

PAC-8

8" AC Power Connector 24" lonq

6.00

PDC-8

8" DC Power Connector 24" long

7.00

PAC-8D

8" AC Power Connector for Double Density Disk Drives

6.00

ALL ASSEMBLED - NOT A KIT

DISK DRIVE SIGNAL CABLES

CLOCK/CALENDAR FEATURES

Single 5V*" Drive Cable Dual 5'/-" Drive Cable Quad 5'/-" Drive Cable Single 8" Drive Cable Dual 8" Drive Cable Quad 8" Drive Cable Please state type connector: card-edge or socket.

26 Pin Card-edge Connector to DB25S 2' long $19.00

$24.00 $29.00 $34.00 $24.00 $32.00 $40.00

4116 —

8/$30.00

(200 ns)

2708 —

$6.00

2716 (5V) —

$9.00

2732 —

$25.00

2114L3 —

8/$28.00

12/24 Hr. Format Month-Day-Year Day of Week Leap Year Bit 4 Interrupts +-30 Sec. Adjust Battery Backup Simple to Program

S-100 Clock

A&T $150

Kit $100

Bare Bd. $ 60

Apple Clock

A&T Kit Bare Bd.

TRS-80

A&T Only

$150 $100 $ 60

$150

WE ACCEPT MASTER CHARGE, VISA & AMERICAN EXPRESS

LAX COMPUTER PRODUCTS

4728 Manhattan Beach Blvd. Lawndale, CA 90260 (213) 542-4505

Apple is a Trademark of Apple Computer Co.

TRS80 is a Trademark of Tandy Corp.

TERMS: Cash, checks, money orders, credit card. C.O.D. under $100.00 add $2.00 C.O.D. charge. Minimum shipping & handling charge $3.00. Prices subject to change without notice. All sales in American dollars only.

378 BYTE April 1981

Circle 284 on inquiry card.

6502, Z80, 8080 AND 8085 USERS

JOHN BELL

ENGINEERING'S

6502 AND Z80

MICROCOMPUTERS

ARE DEDICATED COMPUTERS DESIGNED FOR CONTROL FUNCTIONS.

THESE BOARDS FEATURE:

• 2048 BYTES EPROM

• 1024 BYTES RAM

• ALL BOARDS INCLUDE COMPLETE DOCUMENTA TION

• 50 PIN CONNECTOR INCLUDED IN KITS AND ASSEMBLED UNITS

• 2716 AVAILABLE SEPARATELY

JOHN BELL ENGINEERING'S 6502 MICROCOMPUTER, 2716 EPROM PROGRAMMER AND APPLE II PARALLEL INTERFACE PLUS THE APPLE II MICROCOMPUTER — A COMPLETE DEVELOPMENT SYSTEM.

6502 MICROCOMPUTER FEATURES:

• 1024 BYTES RAM

• 2048 BYTES EPROM

• USES ONE 6522 VIA (DOC. INCL)

• 2 8 BIT BIDIRECTIONAL I/O PORTS

• 2 16 BIT PROGRAMMABLE TIMER/ COUNTERS

• SERIAL DATA PORT

• LATCHED I/O WITH HANDSHAKING LOGIC

• TTL AND CMOS COMPATIBLE

80-153 ASSEMBLED $ 110.95

BARE BOARD $24.95 KIT $ 89.95

USE YOUR 6502 OR Z80 MICROCOMPUTER TO CONTROL EVERYTHING!

JOHN BELL ENGINEERING'S NEW Z80 MICROCOMPUTER FEATURES:

• Z80 CPU SOFTWARE COMPATIBLE WITH Z80, 8080 AND 8085 MICROPROCESSORS

• 2048 BYTES EPROM

• 1024 BYTES RAM

• SINGLE 5V POWER SUPPLY AT 300MA •CLOCK FREQUENCY IS 2MHZ, RC CONTROLLED

» Z80 PIO (DOC. INCL)

• 2 8 BIT BIDIRECTIONAL I/O PORTS

• LATCHED I/O WITH HANDSHAKING LOGIC

• TTL AND CMOS COMPATIBLE

80-280 BARE BOARD

ASSEMBLED $129.95 $29.95 KIT $119.95

• YOUR HOME SECURITY SYSTEM

• HEAT CONTROL

• LIGHT CONTROL

• SOLAR HEATING AND POWER SYSTEMS

• AUTOMATIC CONTROL OF TAPE RECORDERS

• TRAFFIC LIGHT CONTROL

• IRRIGATION SYSTEMS

• AUTOMATIC CONTROL OF VIDEO RECORDERS

• ROBOT CONTROL

• AUTOMATIC DIALER

• AUTOMATED SLIDE SHOW CONTROL

• COMMUNICATION SYSTEMS FOR THE DISABLED

• THE WORLD

John Bell Eivgiiveeriivg

VISA

ALL PRODUCTS ARE AVAILABLE FROM: JOHN BELL ENGINEERING

P.O. BOX 338 • REDWOOD CITY, CA 94064 • (415)367-1137 "SEND FOR OUR COMPLETE CATALOG! ADD 6% SALES TAX IN CALIFORNIA. ADD 5% FOR SHIPPING AND HANDLING.

MASTER CHARQE

Circle 285 on inquiry card.

BYTE April 1981 379

Circle 286 on inquiry card.

CALL TOLL FREE

228 4097

Call Toll Free For

"Unbelievable"

Low Low

Prices On These

Lines:

APPLE —ATARI —BASE 2

CENTRONICS COMMODORE —DC HAYES

HAZELTINE —LEEDEX MACROTRONICS — MAXELL

MOUNTAIN HARDWARE

NORTH STAR —PANASONIC

SANYO —SYNCOM

TOUR

CUCTftONICS lf^LA>7Ci®PIMi

1840 "O" Street Lincoln, Nebraska 68508 In Nebraska Call (402) 476-7331

| MicroCompEquip 1

DISCOUNTS & DEALER OVERSTOCKS

ALL ITEMS BELOW SOLD AS IS

- NO RETURNS / NO REPAIRS

CALL FOR AVAILABILITY: LIMITED QUANTITIES

NEW EQUIPMENT

Sell For

List Price

Polymorphic Systems

A.l. Cybernetics Speechboard

260.00

380.00

8K Assembled 8K Memory Board

289.00 225.00

385.00 300.00

CALL FOR

Anadez 40 Column Printer

641.00

855.00

Poly KBD

169.00

225.00

OUR LOW PRICES

Base 2 8K Memory Board Assembled

211.00

262.00

8813

2880.00

3250.00

Commodore 2001-8 8K PET

550.00

795.00

System 0

378.00

525.00

FOR THE FOLLOWING

Craig M-100 Translaler

122.00

199.95

88-System 2

529.00

735.00

Dajen Cassette Interlace

88.00

120.00

System 12 Kit

846.00

1128.00

MANUFACTURERS:

Dynabyte Naked Terminal

245.00

350.00

System 6

1134.00

1575.00

Digital Systems Dual 8" Single Density

2293.00

2732.00

Video Card

210.00

280.00

Dutronics Poly Z-80 Upgrade Kit

123.00

169.95

Processor Tech

APPLE

Dutronics Jmsai Z-80 Upgrade Kit

116.00

159.95

Cuts BD Assembled

139.00

199.00

Eclectic Corp. Su" ^rchip for Apple II

75.00

95.00

8K Dynamic Ram

175.00

250.00

ATARI

Fidelity Electronics Ltd.

16K Dynamic Ram

300.00

429.00

Level 1 Chess Challenger

120.00

75.00

64K Dynamic Ram

878.00

1350.00

CROMEMCO

Level 4 Checker Challenger

100.00

115.00

Extended Basic Cassette

21.00

45.00

Level 2 Checker Challenger George Riak Inc. Pet Keyboard

40.00 176.00

40.00 250.00

SOL 20 W/O Memory System II Kit

1270.00 1262.00

1895.00 1905.00

VECTOR GRAPHIC

Imsai CPU Board

125.00

175.00

Panasonic Monitor

143.00

210.00

Icom Micro Peripherals 5" Disk Drive

821.00

1095.00

SD Sales 32K Dynamic Ram Board Kit

332.00

475.00

Intertec Data Intertube Terminal Kent Moore 8K RAM 450NS

595.00 148.00

874.00 197.50

Solid State Music 16K Static Ram Board Kit Southwest Technical (SWTPC)

300.00

325.00

Kent Moore Alpha Display Module Mountain Hardware

80.25

107.00

MF-68 Dual 5" Floppy Graphics Terminal

796.00 79.00

995.00 98.50

MicroCompEquip

AC Control Apple

132.00

189.00

Technical Design Labi. (TDL-Xitan)

PO BOX 195

AC Remote

95.00

149.00

I/O board - SMB-II

257.00

395.00

S-100 AC Control Kit

104.00

149.00

32L Series K Memory Board

559.00

799.00

CROWNSVILLE, MD 21032

AC Remote Kit

67.00

99.00

Fortran IV Ser.37

279.00

349.00

AC Control- Apple Kit Micromation Dual Memorez 8" disk drive

104.00 1467.00

145.00 1990.00

Fortran IV Ser.41 Xitan Alpha 1.5

279.00 823.00

349.00 1138.00

Micromation Dual Density disk controller Card MS Corp. Apple PR-40 Interlace

310.00 87.00

500.00 87.00

Xitan Alpha 1 Xitan Alpha 3

576.00 854.00

769.00 1181.00

VISA / MC / CHECK

National Multiplex Digital Cassette Recorder

150.00

200.00

Xitan Alpha 1.5

571.00

868.00

Novation 1200 Baud Modem (4202T) Radio Shack TRS-80 Disk Drive

274.00 399.00

375.00 499.00

Video Board Technico Super Starter Assembled

277.00 293.00

369.00 300.00

PHONE ORDERS:

TRS-80 16K Computer

479.00

599.00

Technico Super Starter Kit

199.00

299.00

(301) 261-1859

TRS-80 Expansion Interlace

239.00

299.00

Trace Elec. 32K RAM Board Assem

599.00

999.00

380 BYTE April 1981

Circle 287 on inquiry card.

1858 Evergreen Street, Duarte,

DIGITAL INC.

INSULATION DISPLACEMENT SOCKETS

RIGHT ANGLE HEADERS

' « '£. 1 S 1 * 1;

Pins

10 20 26 34 40 50

IDH10SR -80 IDH20SR1-25 IDH26SR 1-85 IDS34SR 2.15 IOH40SR 2.50 IDH50SR 3.15

EJECTOR EARS .25

IDH10WR 1.75 IDH20WR 2.75 IDH26WR 3.60 IDH34WR 4.15 IDH40WR 4.90 IDH50WR 6.15 EACH

25 PIN "D" CONNECTORS

.•--■:

m>

Slyl. Part •

SOLDER STYLE Male DB25P .2.25 Female DB255 3.00 Hood DB25C 1.10

INSULATION DISPLACEMENT Male IDC25P 4.95 Female IDC255 5.25 Hood IDC25C 1.35

CARD EDGE CONNECTORS

m

Pins

Part No.

10

IDE10

3.25

20

IDE20

3.50

26

IDE26

4.05

34

IDE34

4.85

40

IDE40

5.65

50

IDE50

5.90

SOCKETS

Ptna Part No. 10 IDS10

20 26 34 40 50

IDS20 IDS26 IDS34 IDS40 IDS50

1.25 2.02 2.65 3.50 4.05 5.06

Slain Rail*)

.25

.25

.25

.25

.25

.25

Conductors: Solid Color

Color Coded

10 14 16 20 24 26 34 40 50

10 ft. 2.90 3.40 3.70 4.40 5.00 5.40 6.80 7.80 9.50

toon. 17.00 23.80 27.20 34.00 40.80 44.20 57.80 68.00 85.00

ton.

4.00

5.00

5.60

7.00

8.00

8.60

11.00

13.00

16.00

toon.

30.00

42.00

48.00

60.00

72.00

78.00

102.00

120.00

150.00

CABLE PLUGS

^-T^^^^^^T^

Pins Part No.

14 IDP14 1.25

16 IDP16 1.40

24 IDP24 2.25

40 IDP40 3.65

WIRE WRAP WIRE

WIRE KITS

Length 100/Bag 500/Bag 1K/Bag

Length 100/Bag 500/Bag 1K/Bag

Kit No. 1

$9.95

Kit No. 3

$32.95

2.5" $1.25 $3.58 $ 6.19 3.0" 1.30 3.86 6.78 3.5" 1.37 4.15 7.37 4.0" 1.42 4.44 7.94 4.5" 1.48 4.74 8.54 5.0" 1.54 5.04 9.13 5.5" 1.58 5.38 9.72 6.0" 1.65 5.66 10.31

6.5" $1.92 $6.44 $11.81 7.0" 1.99 6.76 12.44 7.5" 2.08 7.07 13.09 8.0" 2.14 7.38 13.73 8.5" 2.18 7.69 14.36 9.0" 2.24 8.11 15.01 9.5" 2.30 8.32 15.65 10.0" 2.39 8.71 16.28

250 250 100

3"

3'/2"

4"

100 100 100

4'/2'

5"

6"

500 2'/2' 500 3" 500 3V4' 500 4"

500 4'/2" 500 5" 500 5'/2" 500 6"

Kit No. 2

$24.95

Kit No. 4

$59.95

250 500 500 500 250

2'/2"

3" 3Vt" 4" 4'/4'

250 100 250 100 100

5"

5Vi"

6"

6'/2"

7"

1000 2'/2' 1000 3" 1000 3%" 1000 4"

1000 4'/2" 1000 5" 1000 5" 1000 6"

Kynar precut wire. All lengths are ov Colors and lengths cannot be mixed fo Red, Blue, Black, Yellow, White, Gre

erall, including 1" strip on each end. r quantity pricing. Choose from colors an, Orange, and Violet.

ORDERING INFORMATION:

• Orders under $25 include $2 handling

• All prepaid orders shipped UPS Ppd.

• Visa, MC & COD's charged shipping.

• Ail prices good through cover date.

• Most orders shipped same day.

• Byte must be mentioned to get sale price.

Write or call for 1981 catalog

• IC Sockets

• Vector Board & Pins

• Bishop Drafting Aids

• OK Tools

• RN IDC Crimp Connectors

"NEW" WIRE WRAP SOCKETS

FEATURING A SELECTIVE PLATING METHOD THAT WILL SAVE YOU

MONEY BY HAVING GOLD ONLY WHERE IT COUNTS.

GOLD PLATED CONTACTS

TIN PLATED TAILS

3 Level closed entry.

RN Side Wipe contact design gives twice the contact area for high reliability.

Size Quantitv/Tube Price ee.' Price/Tube

B

52

.41

21.32

14

30

.47

14.10

16

26

.51

13.26

18

23

.70

16.10

20

21

.87

18.27

22

19

.94

17.86

24

17

.96

16.32

28

15

1.25

18.75

40

10

1.70

17.00

•FOR REFERENCE. MUST BE ORDERED IN TUBE QUANTITIES.

Circle 288 on inquiry card.

TOLL FREE ORDERING NUMBER 1-(800,-423-7144

Z-80 FORTH $50.00

Fast, Interactive, and flexible language well suited for real time applications. Full flg-FORTH" and FORTH-79vocabularies, plus extensions for access to all CP/M*' functions. Uses standard CP/M compatible random access flies for screen storage. Eight-inch soft-sectored single density diskette includes: interpreter/compiler, line editor, screen editor, Z-80 assembler, decompiler, utilities, and demonstration programs. 60 page user manual supplied. Requires Digital Research CP/M 2.x or MP/M 1.x. Price Includes tax and shipping by first class mail or UPS.

Laboratory Microsystems

4147 Beethoven Street Los Angeles, CA 90066

* Forth Interest Group.

* * CP/M Is a trademark of Digital Research,

inc.

COMPUTERS

C1P SERIES II - $479 00

OUR price - $399.00

other OSI discounts available

CALL NOW TOLL FREE

1-800-558-0870

COMPUTERS PLUS, INC.

2 749 S. 108th St.

MILWAUKEE, Wl 53227

(414) 321-1770

IN WISCONSIN

P~ QUARTZ CRYSTALS *«$

1 , 3218 S

5.2428-B

9.9336 B

20OO0-B 36.2886-6

42.8518 8

468 126-8 I

1 535011

5.610 B

9.96408 B

2049B8B 363636-8

4287688

473768-B ' ,

, ' 1 000 A

5.7143-8

9.98960-B

22.1184-8 379628 B

429258 8

4 78336 B 4

| 1.8432-A

5.955-B

I0OO0-B

226256 B 3B3768-B

42.962B-6

46O00 B , '

1 . 1.8437-8

5.982-B

ID2458-B

2E.3556-B 38.4448-6

4300086

48.3006-B |

1 ' 2.000<A

6.000-B

I0.4966-B

26.50066 366268-6

43.0378-B

48.6668-8 <

. r 2.0971 -A

6.144-B

I0.7755B

26.6706 B 38.9258-8

43.0748-8

■18 7006-8 4

' > 2.4576A

5.15030!

10.8255-8

27 000-B 39.3128-B

43.1858 B

4B.B768-B . 1

1 . 2.500-A

6.297B0!

10.8386-8

27.0006 B 39.5038 B

43.25968

49.7O0E-B ' ,

, • 2.6657-8

64MB

11.1360 B

21 6506 B 39 66688

43.3338-8

49.7338-B ^

1 2.9950-B

6.5536-B

11.155 8

28 4006-6 39.7536-B

4337088

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1 | 3.000-A

6.72530-1

112186-8

2B6276-B 39J768-B

43.4078 8

502505 B 1

| 3.067-8

6.75840-1

11.2890 B

28.7538 8 399628 8

43437BB

SI0556-B ' .

. 1 32MB

6.9003-6

11.4776 B

29.B758B 40.4448 8

43 44-18 8

5131288 |

| 3.276BA

7.0063-6

II.6566-B

29.9376-8 40.5928 B

43.5558-6

SI.7776B . f

1 . 3 500 II

7.0336-6

II.6B16-B

30O646-B 40.BI2B-B

43.62988

51.8506 8 ' |

, ' 3.570-B

7.0916-8

12.440 B

30.36066 40.8336 11

43.6668-8

52.8128-B *

) 4.000 B

7.1636-8

14JI82-B

3002586 40.8758-3

43.77788

56.7506-B , '

* . 4.10434

7.2586-B

14.43D8-B

30S76BB 40B88B-B

43812B-B

60.6006B 1

| ' 4.M26B

B.0OO-B

15000-B

31.4378-8 40.9258-8

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60.7508-8 ' ,

1 4 4803 B

8.0556 B

15.4408 B

31.7538-8 41.0008-B

438518 B

66.7506-B {

' > 4.6103 8

8.1416-B

15.5066 B

3I9006B 4I.I666-B

438888-8

70.4006-B , 1

1 4.6503 B

8.1818-8

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32.000-8 41.3768-8

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75 0005 B |

, ' ■! 8303-3

8.3303-B

18.3848 B

33.2006-B 41.9378 B

44.O008B

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17.2248 B

33.6258-8 4Z.00O8-8

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34.5558 8 42.5636-8

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100 6668 B . 1

| 5.06B8-B

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34.7538-B 42.6268 8

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101.4666-6 ' ,

, ' 5.1203-B

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184320 B

34.9776 8 -12.7005 8

45.1256-8

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1 5.IB50-B

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359256 B 42.7538 B

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4 . 5.1B56 8

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360008 4281438

46.70068

I04991B-B f

< ALL A

.2.99

ALL B -11.99

0 OR MORE DEDUCT 5== ' |

ADD SI.00 SHIPPING

CAL

RES. ADD 6% SALES TAX

FREE OSCILLATOR SCHEMATICS

WITH ANY ORDER

l| QUALITY COMPUTER PARTS |l

1 P.O

BOX 743 / CHATSWORTH, CA 91 311 I

Circle 341 on inquiry card.

Circle 342 on inquiry card.

Circle 343 on inquiry card.

□(TiPUTLF? CDIhPDnETS

LUQUR

Q.T. AND GODBOUT COMPONENTS FROM SLUDER

Assembled & Tested List

2 floppy 6JXS»Jlom 275

Gooaouf compupro phoducts assembled s tested

INTERFACE!) 1 or !AIT 24

:ivr,r[HM,r-Pon:ii«;c:c:. Serial etc 395

COMPLETE WOHD PROCESSING AND ACCOUNTING PACKAGE QT Syst8mComnul<i:.vitriZBOA 64KRAU 2 Spr.jl poili. Dual 8" II!

CPM2 2. Wpil'i:..' C'.:l:V,Z :. ,-..r.-..,./.-■ i'nj .'(liJAP/Afl.'Piyrol in0 ill ann NEC SilQ 5Din*nnii includu 80"2» lo'mir>al 89W

CALL OR WniTEFORC

D ITEMS NOT LISTED an Cnochs, or Poslal Mor

IKjotSOO. ANDSIiOOonSySlom^ Calilopnia F*n3iUrri1r.ii:l!i t"-i Salcl

All Pi:tu^ Ltitijucl luClianoeWiinoijl Nolice

f REE ACCOUNTING PACKAGE TO END USERS ON O T. SYSTEMS

■ PQ BQ* RBI

• iVE5TTt-\ir\srE.R u.f\ qaJuQl

— 71H BRS 17Mb

CP/M 68XX

CROSS-SOFTWARE including source code in "C"

ASSEMBLER FEATURES:

J 2-pass absolute assembly

) Full instruction set, Motorola-compatible

S Free-format input

^Unlimited length labels

>Arithmetic expressions in operands

) Sorted symbol table output

> Intel format hex output

(PACKAGE A6800. . . MC6800/MC6802/MC6808

I PACKAGE A6801 MC6801/MC6803

1 PACKAGE A6809 MC6809

18" soft-sectored disk format, w/manual ... S100.00

■ 5" North Star disk format, w/manual S100.00

J Manual and listing alone S 85.00

(Wisconsin residents please add 4% tax)

Introl corp<

647 w. Virginia St. visa and

Milwaukee, Wl 53204 Master Charge

(414) 276-2937 Accepted

:■#*#»#»**■

*****

••COMPUTER SURPLUS**

*******************

Used micro computer systems 100% functional, $600 to $1500. Video terminals & keyboards, $50 to $700. Stringy floppy units-brand new, $300. All the above with documentation. Computer cabinets, 19" rack, $50 to $100. Power supplies, capacitors, ribbon cable, cooling fans, misc. components & hardware. Also deal in IBM & Univac.

CALL VIC CLOUGH at (216) 473-0866

DATA HARDWARE

701 Beta Dr. #4 Cleveland Ohio 44143

************************

DEALERS WELCOME

Circle 344 on inquiry card.

Circle 345 on Inquiry card.

Circle 346 on inquiry card.

O Dysan

^CORPORATION

Solve your disc problems, buy 100% surface tested Dysan diskettes. AD orders shipped from stock, within 24 hours. Call toll FREE (800) 235-4137 for prices and information. Visa and Master Card accepted. All orders sent postage paid.

PACIFIC EXCHANGES

100 Foothill Blvd. San Luis Obispo, CA 93401. (InCal. call (805) 543-1037.)

Pascal and C for hire

Experience in:

□ systems software

□ real time applications

□ business applications

□ scientific applications

□ data reduction

McHenry Associates

P.O. Box 2700 Huntington Beach, CA 92647

(714) 962-6019

CONVERT ANY TV

TO A HIGH QUALITY MONITOR

- *»

Hi CH DUAL 1TY

TTTTTTT V V T y V T V V T

HOD -- KITS

• • • • •

Hot Chassis or Transformer sets* 64-80 characters per line By-passes tuner & I.F. Normal viewing unaffected Safe—Easy kit installation

ACVM Hi-resolution $34.95 ppc Referenced to neutral

1.

V.A.M.P. INC.

Box 29315, Los Angeles, CA 90029

Calif. Residents add 6% Sales Tax

Circle 347 on inquiry card.

Circle 348 on Inquiry card.

Circle 349 on Inquiry card.

m

CROPROCiSSOi

RS

UPPORT I.C'S

WE GUARANTEE FACTORY PRIME PARTS

We are going to become the largest supplier of prime

MEC 16Kx1 DYNAMIC RAM 200 N.S.

microprocessor

support I.C.'S. We guarantee that our I.C.'S

These

are prime 4116's from one of the

best

are purchased from manufacturer authorized distributors.

MOS RAM manufacturers in the world.

This is the only

way to deliver prime parts at the lowest

4116 200ns

possible prices.

Dur committment is to offer the best price

and the fastest

delivery to our customer. We give many

8 for $25.00 32 for 96.00

thanks to our va

ued customers who have helped us grow.

Only prepaid orders on this special.

8080A CPU

4.95

2708 EPROM 1Kx8 4.95

NEC 1Kx4 STATIC RAM 250 N.S.

8085A CPU

8.95

2716 EPROM 2Kx8 8.95

These

are prime low power static ram's

NEC

8086 CPU

99.95

2732 EPROM 4Kx8 21.00

for the finest in MOS MEMORY.

8088 CPU

44.95

4118 STATIC 1Kx8 15.00

2114L 250ns

Z-80 CPU

10.50

4164 200ns 64Kx1 Call

8 for $25.00 32 for $96.00

Z-80A CPU

12.95

Z80B CPU 21.00

Only prepaid orders on this special.

Z80-P10 7.75

8289 49.95

4050 .69

4531

.99

74C925 6.95

74LS107 .45

74LS244

1.95

Z80A-P10 9.75

4000 .35

4051 1.10

4532

1.25

74LS00 .35

74LS109 .45

74LS245

4.95

Z80-CTC 7.75

4001 .35

4052 1.10

4539

.99

74LS01 .28

74LS112 .49

74LS247

1.10

Z80ACTC 9.75

4002 .35

4053 1.10

4543

1.99

74LS02 .28

74LS122 .55

74LS248

1.10

Z80-DMA 22.25

4006 1.39

4055 3.95

4553

3.50

74LS03 .28

74LS123 1.19

74LS249

1.69

Z80A-DMA 27.75

4007 .29

4056 2.95

4555

.75

74LS04 .39

74LS125 1.35

74LS251

1.79

Z80-S10/0 24.95

4008 1.39

4059 9.95

4556

.75

74LS05 .28

74LS126 .89

74LS253

.98

Z80A-S10/0 29.95

4009 .49

4060 1.39

4581

1.99

74LS08 .39

74LS132 .79

74LS257

.98

Z80-S10/1 24.95

4010 .49

4066 .75

4582

1.01

74LS09 .39

74LS136 .59

74LS258

.98

Z80A-S10/1 29.95

4011 .35

4068 .35

4584

.55

74LS10 .28

74LS138 .89

74LS259

2.95

Z80-S10/2 24.95

4012 .29

4069 .35

4585

.99

74LS11 .39

74LS139 .89

74LS260

.69

Z80A-S10/2 29.95

4013 .49

4070 .49

4702

9.95

74LS12 .39

74LS145 1.25

74LS261

2.49

3205 3.45

4014 1.39

4071 .35

74C00

.39

74LS13 .47

74LS148 1.49

74LS266

.59

3242 10.00

4015 1.15

4072 .35

74C02

.39

74LS14 1.25

74LS151 .79

74LS273

1.75

8155 11.25

4016 .59

4073 .35

74C04

.39

74LS15 .39

74LS153 .79

74LS275

4.40

8185 29.95

4017 1.19

4075 .35

74C08

.49

74LS20 .26

74LS155 1.19

74LS279

.59

8185-2 39.95

4018 .99

4076 1.29

74C10

.49

74LS21 .38

74LS156 .99

74LS283

1.10

8202 45.00

4019 .49

4078 .35

74C14

1.65

74LS22 .38

74LS157 .99

74LS290

1.29

8205 3.45

4020 1.19

4081 .35

74C20

.39

74LS26 .39

74LS158 .75

74LS293

1.95

8212 2.00

4021 1.19

4082 .35

74C30

.39

74LS27 .39

74LS160 .98

74LS295

1.10

8214 3.95

4022 1.15

4085 1.95

74C32

.99

74LS28 .39

74LS161 1.15

74LS298

1.29

8216 1.85

4023 .38

4086 .79

74C42

1.85

74LS30 .26

74LS162 .98

74LS324

1.75

8224 2.65

4024 .79

4093 .99

74C48

2.39

74LS32 .39

74LS163 .98

74LS347

1.95

8226 1.85

4025 .38

4099 2.25

74C73

.85

74LS37 .79

74LS164 1.19

74LS348

1.95

8228 5.00

4026 2.50

4104 1.99

74C74

.85

74LS38 .39

74LS165 .89

74LS352

1.65

8238 5.45

4027 .65

4501 .39

74C85

2.49

74LS42 .79

74LS166 2.49

74LS353

1.65

8243 4.65

4028 .85

4502 1.65

74C89

4.95

74LS47 .79

74LS170 1.99

74LS363

1.49

8251A 5.55

4029 1.29

4503 .69

74C90

1.85

74LS48 .79

74LS173 .89

74LS365

.99

8253 9.85

4030 .45

4505 8.95

74C93

1.85

74LS51 .26

74LS174 .99

74LS366

.99

8255A 5.40

4031 3.25

4506 .75

74C95

1.85

74LS54 .35

74LS175 .99

74LS367

.73

8255A-5 5.40

4032 2.15

4507 .95

74C107

1.19

74LS55 .35

74LS181 2.20

74LS368

.73

8257 9.25

4033 2.15

4508 3.95

74C151

2.49

74LS73 .45

74LS190 1.15

74LS373

2.75

8257-5 9.25

4034 3.25

4510 1.39

74C154

3.50

74LS74 .59

74LS191 1.15

74LS374

2.75

8259A 7.30

4035 .95

4511 1.39

74C157

2.10

74LS75 .68

74LS192 .98

74LS375

.69

8271 60.00

4037 1.95

4512 1.39

74C160

2.39

74LS76 .45

74LS193 .98

74LS377

1.95

8275 32.95

4040 1.29

4514 3.95

74C161

2.30

74LS78 .65

74LS194 1.15

74LS385

1.95

8279 10.80

4041 1.25

4515 3.95

74163

2.39

74LS83 .99

74LS195 .95

74LS386

.65

8279-5 10.80

4042 .95

4516 1.69

74164

2.39

74LS85 1.19

74LS196 .89

74LS390

1.95

8282 6.70

4043 .85

4519 .99

74173

2.59

74LS86 .45

74LS197 .89

74LS393

1.95

8283 6.70

4044 .85

4520 1.39

74174

2.75

74LS90 .75

74LS221 . 1.49

74LS395

1.70

8284 5.85

4046 1.75

4522 .99

74C175

2.75

74LS92 .75

74LS240 1.95

74LS399

2.95

8286 6.70

4047 1.25

4526 1.15

74C192

2.39

74LS93 .75

74LS241 1.90

74LS424

2.95

8287 6.70

4048 .99

4527 1.75

74C193

2.39

74LS95 .88

74LS242 1.95

74LS668

1.75

8288 25.40

4049 .69

4528 .99

74C195

2.39

74LS96 .98

74LS243 1.95

74LS670

2.29

MAIL

ORDERS SHOULD BE SENT TO:

HANLEY ENGINEERING

P.O. Bo

x 21432 Seattle, Washington 98111

RETAIL STORE

Telepho

ne Orders & Inquiries (206) 453-0792

1644 116th NORTHEAST

Minimu

m Order $10.00 Add $3.00 Shipping

BELLEVUE, WASHINGTON 98005

FOR T

HE FINEST IN MICROF

>RO<

ZESSOR SUPPORT I.C

s

Circle 291 on inquiry card.

BYTE April 1981 383

$94.20*

Single Board Computer

► ortcs. nuKlet MCLi i

6800 MPU, serial I/O. parallel I/O, RAM, EROM, 44-pin AW x 6 V PCB

EXPANSION MODULES

RAM, ROM, CMOS RAM/battery, analog I/O, serial I/O, parallel I/O. counter/ timer, 488 GPIB, EROM programmer, power tail detect/power on reset

IVINTKK

Circle 292 on Inquiry card.

ISIPERLETTERJ

Is For

SuperBrain' People!

Now, owners and operators of Intertec SuperBrain computers around the world have a special newsletter to call their own! Superletter is packed each month with important technical news, accessory ideas, and CP/M software designs for the SuperBrain.

Regular monthly features include Technical Corner, Q & A Forum, Intertec Factory News, Guest Interview, and Super Classifieds. For subscription info and ad rates, contact:

SIPERLETTER

Abrams Creative Services

P.O. Box 3121

Beverly Hilts, CA 90212

(213)277-2410

MULTIPLE TERMINALS WITH CP/M®!

Irvine Computer's NEW Model 100 Transaction Multiplexer lets you construct CP/M®-based, multi-terminal, transaction-oriented applications without- requiring additional system memory, serial interfaces, or a multi-user operating system!

The Model 100 connects to your computer in place of your existing RS-232 console terminal. Up to seven (7) RS-232 terminal devices can then be connected to the Model 100. When the computer is busy, the Model 100 buffers all terminal input data until the application program asks for it.

NO CP/M® mods, hardware mods, nor assemblylanguage code is required. Applications can be written in high-level languages. Loaded with features! S1495, quantity one, F.O.B. Costa Mesa, CA. Limited manufacturer's warranty. For more information, call or write:

EASTERN U.S. AND FOREIGN:

Wright Marketing Company, Ltd.

19104 Rhodes Way

Gaithersburg, MD 20760 (301)840-1928

WESTERN U.S.:

Irvine Computer Corporation (mfgr.)

3001 Red Hill Avenue, 6-103

Costa Mesa, CA 92626 (714) 557-5292

CP/M® is a registered trademark of Digital Research.

Circle 293 on Inquiry card.

Circle 294 on inquiry card.

Write for FREE sample or tend $2.95 for a package of 10 holders plus S .75 for shipping and handling.

FILING SYSTEM FOR COMPUTER DISKETTES

A non-glare clearplis page hiving two pockets on one side to house one 8" diskette plus a top pocket to store in index card to record disk data. The pages are three-hole punched for convenient and economical storage in standard three-ring binders.

C||

1 aiMINEtt INFORMATION

: ttrrmn

BIS. INC.. P.O. BOX 969. BRENTWOOD. TN 37027 • (615) 373-Z3U

ATARI OWNERS

SCREEN PRINT INTERFACE

Obtain hardcopy of any screen image (graphics and / or text) on either a TRENDC0M 200 or IDS 440 Paper Tiger printer. Simply attach the supplied parallel printer cable and load the software from cassette (moy be transferred to Disk). Obtain a ' 'picture" of the screen on your printer under direct (CTRL?) or program (XI0) control Works In all graphics / text modes as well as LPRINT and LIST "P;" . . _ _

Only $139

Parallel Printer Interlace tor the ATARI 400 / 800

Connects to controller jocks 3&4 works with BASIC / DOS / ASSEMBLER Three printer connectors available

ATARI 400 I 800 TRENDCOM100/ 200 A4P-1 A8P-1 CENTRONICS 730 I 737 A4P-2 A8P-2 CENTRONICS 36 PIN' A4P-3 A8P-3

69.

95

CA sales add 6% tax

MC / VISA accepted

"Fits all other parallel Centronics plus Anodex. Base 2,

Epson. Comprint and Microtek Order by part number,

ATARI is a recognized trademark o( ATARI. Inc

AMCROTOONLCS, inc.

1125 N. Golden State Blvd. I Suite G

Turlock, CA 95380 (A) (209) 667-2888 / 634-8888

HEADERS

34 PIN HEADER 3M 3413-1003 St. 25 EA 40 PIN HEADER ALPHA SI.50EA

50 PIN HEADER

3M 3433-1002 SI. 75 EA

40 PIN CONNECTOR

3M 3417 $1.50 EACH

22/44 EDGE CONNECTOR

TIN SOLDERTAIL .1S6'x .200"

7-17vdc S.S. BUZZER

Sound output 70aa (a 20 cm

$1.25 each

FLAT LEVER HANDLE

'MINI TOGGLE

5 PDI RATED

6 AMPS (£0 !3S V

I 4 ■ JO BUSHING

|J SI 00 each

10 for $8 50

Litronix FRL-4403

♦JFLASHER LED

d,^,.,, ,,„,,„

with built in Hashing unit

T 1 '.package pulse rata 3hi u 5v20ms.

LARGE QUANTITIES AVAILABLE $1.35eac.fr. 1Q(orS12.50

ALL CLKTROflKS CORP.

905 S. Vermont Ave. terms

Los Angeles, Calif. 90006 ■ o.»«,i».. i ,m,„.,i (213) 380-8000 ■Min otf»$«M»

Mon.-Fri. Saturday '""p?™usa 9 AM■5 PM 10 AM • 3 PM •Calil "•»■«« 6°'

• Prompt Shipping

SEND FOR FREE CATALOG

Circle 295 on Inquiry card.

Circle 296 on Inquiry card.

Circle 297 on Inquiry card.

LISP

Interpreter for the TRS-80*

See the August, '79 issue of byte to find how easy it is to

USE LISP.

■ Includes more than 30

FUNCTIONS flt PREDICATES.

■ Coded for high-speed operation.

■ Full arithmetic capability.

■ User's Manual.

■ Supplied on cassette for 1 6K

64K LEVEL II.

Send $50 in checkor money order to:

Cyber Innovations World Trade Center

P. O. BOX 58657 Dallas, Texas 75258

•trademark of Tandy Corporation

LOWEST COST

LIGHTNING, RFI, STATIC, AND TRANSIENT VOLTAGE PROTECTION

SOLVES diBc drive errors memory loss

intermittancies short lifetimes

USED FOR small computers medical equipment stereos, tv's word processors

"CIRCUIT-SAFE"

2 INDIVIDUALLY FILTERED BANKS OF 3 SOCKETS (6 TOTAL 3-PRONG SOCKETS)

1875 WATT MAX LOAD.... $26.95 ppd.

try one for 15 dayal

HORIZON. INC.

COMPUTER PRODUCTS DIV,

BOX 454

PALATINE. IL. 60067

ENCLOSING CHECK MONEY ORDE;

VISA MASTERCHARGE(BANK NO.

EXPIRES SIGNED

ACCT. NO.. NAME

A ATARI"

COMPLETE LINE OF ATARI COMPUTER PRODUCTS 20-25% OFF

Alari 800 wrth 16K $810 Atari B10 Disk Drive $460

Atari 400 with 8K $399 Alari 410 Cassette Player $69

Visicalc $170 Kurta Graphics Tablet $560

Ramcram 32K Modules (upgrade 400 or 800} $256

ALL ATARI SOFTWARE 20% OFF BIT BUCKET SOFTWARE FOR ATARI: Utilities Disk with Disassembler, Basic Renumberer, Character Generator, Cruncher

Utility (requires 24K) $45

Games: Mastercode, Mr. Simon, City

Bomber (each) $12.95

Hex, Cryptogram,

Flying Saucers (each) $14.95

Any 3 Ot above $30.00. (specify disk or cassette)

ALSO: Commodore Pet at Similar Savings PLUS: Centronics, NEC. Zenith, Intertec, and More!

^ The Bit Bucket

fp tfflr Hardware. Software. Consulting

'%qW 168 North Beacon Streel

'fcjlL .P.O Box 365

Y~Tl Newlon Highlands. MA 02161

^—J Phone:(617)783 3144

Circle 298 on Inquiry card.

Circle 299 on Inquiry card.

Circle 300 on Inquiry card.

DOWN-TO-EARTH PRICES ON

OUT-OF-THIS-WORLD PERSONAL

COMPUTERS AND COMPONENTS.

Look at this!

Ohio Scientific Superboard II

• It's the first complete computer system on a board.

• Superboard II uses the ultra powerful 6502 Microprocessor

• 8K Microsoft BASIC-in-ROM

• 4K static RAM on board, expandable to SK

• Full 53-key keyboard, with upper and lower case. Plus user expandability.

• Video interface and audio cassette interface.

The Ohio Scientific Superboard II at $299 — in today's economy — has got to be the best buy by far. It will entertain you with spectacular graphics made possible by its ultra high resolution graphics and super fast BASIC. It will help you in school or industry, as an ultra powerful scientific calculator. Advanced scientific functions and a built-in "immediate" mode allow you to solve complex problems without programming.

The Superboard II can be expanded economically, for business uses, or to remotely control your home appliances and security. Even communicate with other computers.

Read what's been written about Superboard II:

"We heartily recommend Superboard II for the beginner who wants to get into microcomputers with a minimum cost. A real computer with full expandability." —POPULAR ELECTRONICS, MARCH 1979

"The Superboard II is an excellent choice for the personal computer enthusiast on a budget.11

—BYTE, MAY 1979

Look at these easy hardware prices:

610 Board For use with Superboard II and Challenger 1 P.

8K static RAM. Expandable to 24K or 32K system total.

Accepts up to two mini-floppy disk drives. Requires + 5V

@4.5 amps. S 298

Mini-Floppy Disk Drive Includes Ohio Scientific's PICO DOS

software and connector cable. Compatible with 610

expander board. Requires + 1 2V @1.5 amps and +5V @

0.7 amps. [Power supply S. cabinet not included.] 299

630 Board Contact us for important details. 229

AC-3P 12" combination black and white TV/video monitor. 159

4KP 4K RAM chip set. 79

PS-005 5V 4.5 amp power supply for Superboard II. 45

P8-003 12V power supply for mini-floppies. 45

PF Modulator Battery powered UHF Unit. 35

CS-900B Metal case for single floppy disk drive and power

supply. [While stock lasts.] 49

AC-12P Wireless remote control system. Includes control console, two lamp modules and two appliance modules, for use with 630 board. 175

AC-17P Home security system. Includes console, fire

detector, window protection devices and door unit for use

with 630 board. 249

C1P Sams C1P Service manual 8

C4P Sams C4P Service manual 16

C3 Sams Challenger III manual 40

Ohio Scientific and independent suppliers offer hundreds of programs for the Superboard II, in cassette and mini-floppy form.

Freight Policies All orders of $100 or more are shipped freight prepaid. Orders of less than $100 please add $4.00 to cover shipping costs. Ohio residents add 5.5% Sales Tax.

IBBB>Bi| r^MBkl Hours: Call Monday thru Friday.

VISA (tflSfi, 8.00 AM to 5:00 PM E.O.T. I 1 I^^BJ TOLL FREE: 1-800-321-5B05

Guaranteed Shipment

Cleveland Consumer Computers S. Components guarantees shipment of computer systems within 48 hours upon receipt of your order. Our failure to ship within 48 hours entitles you to 835 of software, FREE.

TO Order: Or to get our free catalog CALL 1-800-321-5805 TOLL FREE. Charge your order to your VISA or MASTER CHARGE account. Ohio residents cail: [216) 464-8047. Or write, including your check or money order, to the address listed below.

CLEVELAND CONSUMER COMPUTERS & COMPONENTS

P.O. Box 46627 Cleveland, Ohio 44146

■ SB SSI SSI BBS BBS ■

P.O. Box 46627 . COMPONENTS Cleveland, Ohio 44146

□ Superboard II $299. □ RF Modulator $35. D 610 Board $298. □ AC-3P 1 2 " BAA/ Monitor $159.

□ Mini-Floppy Disk Drive $299. □ D1P Sams Manual $8. [Attach separate sheet for other items.)

NAME

ADDRESS:

CITY:

I"!nrlor> Cnrm> Cleveland consumer

UlUCl fUl lie COMPUTERS SCOMPONI

I

I I

I

I

I

IUrders or less than anuu. please add $4.uu to cover shipping costs. Urders will be accepted fronrvU.S. and Canada only. All prices quoted are U.S., date of publication, standard UPS shipping FOB the factory. B _

. STATE:

.ZIP:.

MASTER CHARGE

MONEY ORDER

PHONE:

Payment by: VISA

Credit Card Account #_ Expires

TOTAL CHARGED OR ENCLOSED $ rOhio Residents add 6.5% Sales Tax]

Orders of less than £100. please add $4.00 to cover shipping costs. Orders will be accepted fronrvU.S. and Canada only. All prices quoted are U.S.. date of publication, standard UPS shipping FOB the factory.

. Interbank #[Master Charge)

Circle 301 on inquiry card.

BYTE April 1981 385

Close Out

Desk Top Computer

This unit is a computerized Electronic Secretary. It keeps time. date, calendar, message, and meeting files. Originally sold thru a major mail order house for over $450.

Technically, it's a 6507 MICRO, ROM, RAM, Panaplex Alpha Display, Ni-Cad battery, Power Supply. Keyboard, Wood and Aluminum Case with Schematic and operating instructions.

Most of these Computers are warranty returns. We are offering Refurbished, like new, units for $99.95 and AS IS {most have minor problems) units for $44.95. Add $4.95 for shipping and handling. AH units are complete as described. All sales are final. California Residents add 6.5% sales tax.

Send Payment with order or call our Order Line 408-272-2320 and use your MC or VISA card.

Solid State Surplus

P.O. Box 32418/San Jose, CA 95152

SOFTWARE DESIGN ENGINEER

BSEE/BSCS. minimum 3 years programming experience. Realtime systems programming and software development for electronic switches is a plus. Experience with PASCAL or C or Assembly language required. Call collect or send resume to Kenneth W. Cooper, Harris Corporation, RF Communications Division, 1680 University Avenue, Rochester, NY 14610, (716) 244-5830, EXT 3356.

I-LAJRRIS

An Equal Opportunity Employer M/F

^TVTVl

8035 SYSTEMS

A compact modular set of PC Boards for implementing test instruments, measurement and control systems, badge readers, data communications, data entry, games or home security systems.

CPU Board. 8035. 2716

1K RAM, 40 I/O Lines

SIO Board. 38251 A, RS232

Dr/Rec. 6 LEDs

PIO Board. 2 8255 PIOs.

KIT A&T

$99 S125 99 125 99 125

2 or 3 Slot Mother Boards ... Power Supply. 5V. 12V&-12V Diagnostic EPROM and Listing

Bare Boards, Schematics and Parts Lists, each ...

50

55 65 40

S19.95

Boards are A" by 7". 80pms. 156 centersedge connector. Development Tools available on CPM.

Make check payable to:

SKP Electronics

221 1 Caper Tree Dr Justin. CA 92680

(7141832-1732 California residents add 6°o sales tax Please arid S3.00 tor shipping and handling

Circle 302 on Inquiry card.

Circle 304 on Inquiry card.

Scotch'

DISKETTES

SAVE 40% complete list.

5%"Sgl. Dens. 26.70/10

Specify soft, 10 or 16 hard sectors

8"Sgl. Dens. 27.30/10 8"Dbl. Dens. 35.80/10

Specify soft or 32 hole hard

Add $2.00 shipping - Michigan add 4% tax

LYBEN COMPUTER SYSTEMS

27204 Harper Ave.

St. Clair Shores, Ml 48081

Authorized Distributor Information Processing Products

FLOPPY DISKS

8"& 5V4"

OPUS-$26.00/boxoho 3M-$32.00/box of io iv/li-ir-i PO Box 5059

06460 (203)877-3610

We carry a full line of computer supplies

Send for free cata log.

VISA- MASTERCHARGE-CHECK

BUY WHOLESALE!

Sale thru 4/30/81 on Zenith/Heath Z-89 64K system, listing for $3045

Anyone may buy 1 for $2375

or 2 for $2284 each or 3 for $2193 each

Gill or write for prices on other Zenith. North Star, and other Z-80 based computer svstenis, modules, peripherals, and supplies at New England's oldest independenl computer store.

Computer Mart, Inc.

1395 Main Street Waltham, MA 02154

(617) 899-4540

Circle 305 on inquiry card.

Circle 306 on Inquiry card.

Circle 307 on Inquiry card.

OKIDATA

MICROLINE 80

PRINTERS

479.00

80 CPS • Up to 3 part copy '9X7 dot matrix • 80,132 columns - 64 shapes for graphs or charts • 6 or 8 lines per inch • Friction feed standard - Tractor feed optional • Quantity discounts available. Charge card orders add 3%.

m

American Business Computers

118 South Mill Street

Pryor, OK 74361 sassa

918-825-4844

A classified ad magazine run by a computer...

With AD-LINE". a menu-driven computer program, one phone call will immediately compose and expertly index your ad. Prompts will insure inclusion of all pertinent details. AD-LINE* will answer all questions and take all subscription information.

Use your terminal and any 300 baud coupler for instant communication with our computer.

If you don't have a terminal to access AD-LINE* mail your ads to:

PO Box 15642 Philadelphia, PA 19103

micrc

CISICfl CMlSUTririTS

1 Bit through 32-Bit Machines

We handle concept

through production

prototypes with

complete documentation.

HARDWARE - 916/723-1050 David Jenkins

7214 Springleof Court Cirrus Heights. CA 95610

SOFTWARE-916/381-1717 Richard Lerseth - LEAPAC

0245 Mediterranean Way Sacramento. CA 95626

Circle 308 on Inquiry card.

Circle 309 on Inquiry card.

Circle 310 on Inquiry card.

THE STAR MODEM

From Livermore Data Systems

RS232 MODEM IEEE 488 MODEM RS232 CCITT IEEE 488 CCITT

SALE $135

SALE $245

$170

$280

STAR Modem is the price performance leader with a full 2 YEAR FACTORY WARRANTY.

WE CARRY THE BLACK APPLE

Belle, Howell

apple computer inc.

EBS Business System for PET/CBM

Extremely comprehensive package for small business. Fully integrated inventory and accounts receivable system including invoices, packing slips, mail labels, statements, bank deposit slips, and 17 reports.

Paper-Mate Word Processor $29.95

PET/CBM full featured 60 command system by Michael Riley. Uses either tape or disk and any printer. Includes in-text commands, floating cursor, scrolling, etc.

FLEX-FILE Diti Bise lor CBM/PET $60

Random file handling system with Report Writer and Mail Label Handler. By Michael Riley

KMMM Pascal lor PET $75

Subset of standard Pascal with true machine language translator for faster execution. 16K with tape or disk.

EARL lor PET (disk file based) $65

Editor, Assembler, Relocates Linker to generate relocatable object code.

MIF0RTH+ for PET/CBM $65

A full-featured FORTH with extensions conforming to Forth Interest Group standards. Includes assembler, string processing capabilities, disk virtual memory multiple dimensioned arrays, floating point and integer processing.

MIPLOT Intelligent Plotter by Watanabe Instruments (Dlglplot)

SPECIAL $1145

Has all intelligent functions for producing graphs and drawings including 8 vector and 4 character commands. Solid and broken lines can be specified. Character generator for alpha, numeric, and symbols. C haracters can be rotated in 4 orientations, and can be 16 sizes. Coordinate axes drawn by specifying graduation Interval and number of repetitions Parallel ASCII interface, 11x17 paper.

SPECIALS

EPSOM MX-aO Priitir

Call

EPSON MX-70 Mater

Call

STARWRITER Daisy Wheel Printer

$1500

Centronics 737 Printer

790

NEC Spinwriter

2500

XYMEC Hl-Q 1000 Intelligent Daisy Wheel

2150

Leedex Video 100 12" Monitor

129

ZENITH DATA SYSTEMS

Z19 Video Terminal (factory assera)

735

Z89 with 48K (factory assem.)

2150

SYM-1

209

SYM BAS-1 BASIC or RAE-1/2 Assembler

85

KTM-2/80 Synertek Video Board

349

Seawell Motherboard - 4K RAM

195

Seawell 16K Static RAM - KIM, SYM, AIM

320

6502 6502A 6520 PIA 6522 VIA 6532

7.45 8.40 5.15 6.45 7.90

2114-L200 ns RAM

2716 EPROM(5volt) TMS 2532 EPROM 4116-200 H RAM S-100 Wire Wrap

10/6.95 50/6.55 100/6.15

10/7.95 50/7.35 100/6.90

10/4.90 50/4.45 100/4.15

10/6.10 50/5.75 100/5.45

10/7.40 50/7.00 100/6.60

3.75 20/3.50 100/3.25

9.90 5/9.45 10/8.90

23.50

6 fir 29.00

2.65

commodore

CBM-PET SPECIALS

,<V Up to $235 FREE ,^ merchaidlsi with purchase of * one of following CBM-PET Itimil

CASSETTES - AGFA PE-611 PREMIUM

High output, low noise, 5 screw housing, labels. C-10 10/5.65 50/25.00 100/48.00

C-30 10/7.30 50/34.00 100/66.00

All other lengths available. Write for price list.

$1

FREE 795 236 795 236 795 76 995 160 295 206 295 205 795 100 95 12 395 60 CALL

4 PART HARMONY MUSIC SYSTEM lor PET

Allows you to easily enter, display, edit, and play 4 part harmony music. Includes whole notes thru 64ths (with dotted and triplets), tempo change, key signature, transpose, etc. The KL-4M unit includes D to A converter and amplifier (add your own speaker). KL-4M Musk Beerl wfta VMM Praaram S50.00

8032 32K - 80 column CRT

8050 Dual Disk Drive - 1 megabyte

8N Full size graphics keyboard

16K Business or Graphic Keyboard

32K Business or Graphic Keyboard

2040/4040 Dual Disk Drive - 340K

2022 Tractor Feed Printer

C2N External Cassette Deck

CBM Voice Synthesizer

Used CBM/PET Computers

WHITE FOR SYSTEM PRICES

♦"EDUCATIONAL DISCOUNTS***

Bay 2 PET/CBM Cenaatera, main 1 FREE

WordPro 3+ 32K, disk, printer 250

WordPro 4+ 8032, disk, printer 385

OZZ Data Base System for CBM 8032 335

VISICALC for PET, ATARI 170

BPI General Ledger, A/P, A/R for PET/CBM 270

EPROM Prairaaiaar far PET 72.00

Programmers Toolkit - PET ROM Utilities 34.90

2 Meter IEEE to IEEE Cable 43.00

PET Spacemaker Switch 24.90

Dust Cover for PET 6.90

IEEE-Parallel Printer Interface for PET 110.00

IEEE-RS232 Printer Interface for PET 120.00

The PET Revealed 17.00

Library of PET Subroutines 17.00

Source Hookup over 1000 programs/services 88

DISK SPECIALS

SCOTCH (3M) 5%" 10/2.

SCOTCH (3M) 8" 10/2

Verbatim 5%" 10/2. (add 1.00 for 5'A" Verbatim

Verbatim 8" Dbl. Dens 10/3

BASF 5'A" soft 10/2

BASF 8" soft 10/2

Maxell Disks In stock

Diskette Storage Pages Disk Library Cases 8"

.90 50/2.80 100/2.70

95 50/2.85 100/2.75

.45 50/2.40 100/2.35 plastic storage box)

.45 50/3.35 100/3.25

.60 20/2.50 100/2.40

65 20/2.55 100/2.45

writs for prices

10 for 3.95 -2.85 5"-2.15

A

ATARI 800 $777

All Atari Modules 20% OFF

ATARI EDUCATIONAL PLAN Write far details.

A P Products 15% OFF APHobby-Blox 15% OFF

ALL BOOK led SOFTWARE PRICES DISCOUNTED

The 8086 Book (Osborne) 14.00

Z8000 Assembly Language Programming 16.90

PET Personal Computer Guide (Osborne) 12.75

PET and the IEEE-488 Bus (Osborne) 13.60

6502 Assembly Language (Osborne) 14.45

Programming the 6502 (Zaks) 10.45

6502 Applications Book (Zaks) 10.45

6502 Software Cookbook (Scelbi) 9.45

CP/M Handbook (w/ MP/M) Zaks 11.85

Practical BASIC Programs (Osborne) 13.60

Some Common BASIC Programs (Osborne) 12.75

Montgomeryville. PA 18936 215-699-5826 A b llOITipUlGrS

WRITE FOR CATALOG.

Add SI 25 per order for shipping We pay balance ill UPS surface r:h,

mi all prepaid orders Prices listed are on cash discount basis He' puces slightly higher

Circle 311 on Inquiry card.

BYTE April 1981 387

H-89

I/O EXPANSION KITS

1. Decoder interface (H-89-1): This board plugs into the CPU board of the H-89 and gives an additional 64 I/O ports (0 to 77Q) plus a socket for another 64 ports defined by the user 539.95

2. Parallel I/O board (H-89-2): This board contains 2 of 8255A chips plus a circuit for an optional 2716 EPROM and 74S470 decoder burner. It will be compatiable with the expasion box to be announced later $59.95

3. PROM burner kit (H-89-3): This kit contains all the parts and software to complete the (H-89-2) inio a 2716 EPROM and 74S470 PROM burner....$49.95

The price includes shipping and handling within U.S.A 6% tax for Illinois residents. 10% off before May 31, 81.

MICROFLASH CO.

4916 B CAROL

SKOKIE. ILL. 60077

(312)677-4928

COMPUTER INTERFACE

for the

IBM Electronic Typewriter

The MED1AMIX ETI1 "will allow you to connect an IBM ET Model 50, 60 or 75 to any computer that has a Centronics type parallel port. Features include a Z 80 Microprocessor, 2000 bytes RAM, user definable codes £ characters, right justification and access to all of the tricks these typewriters are capable of.

MEDIAMIX

PO Box 67B57 dept.B Los Angeles, CA. 90067

213-475-9919 tmnta

MAGIC WAND™ $325

This powerful word processor is in stock for most CP/M compatible systems, including Radio Shack, North Star, Vector Graphics, Cromemco end APPLE [with Z-HO cerd @ $295 end Videx BD column board @ $295). We will custom configure your diskette if you will specify: CPU, tarminel, printer.

Our fully interactive

MAIL MAGIC™

mail menagement softwere, with 14 user defined fields and full merge and sort capability is available for $149.

We will also quote on all specific hardware and software for APPLE, PET and Vector Graphics.

Computer City ^gr

P.O. Box 60284 B ^™

Houston TX 77205 (713)821-2702

Magic Wand is a registered trademark of

Small Business Applications Meil Magic is a registered trademark of Computer City

Circle 312 on Inquiry card.

Circle 313 on Inquiry card.

Circle 314 on Inquiry card.

Tired of BASIC? Try S/S PASCAL!

for CP/M* users

■Powerful subset of Standard PASCAL.

■ Integers,Reals,Strings,Text Files,etc... ■INTERRACTIVE COMPILER 1! m Correct your errors during compilation !

■ Your- source on disc is compiled in fast efficient Pcode directly stored gn disc.

■ Complete and detailed manual.

■ No knowledge of PASCAL required.

S65 on cassette

SCOTIA °r525;dT

S10 manual only

SOFTWARE

1964,Beech St.,Halifax N.S.

B3H 4B8 , CANADA

Kequirerrent:24K with CP/M*

CP/M is a Trademark of Digital Research

Cancer

dies with the patient

Heart Disease

dies with the patient

Huntington's

Disease

kills on and on and on.

NATIONAL HUNTINGTON'S DISEASE

ASSOCIATION

Suite 501.1441 Broadway New York. NY 10018 212-966-4320

THIS SPACE CONTRIBUTED BY THE PUBLISHER

793

HARDWARE SPECIALS

PRINTERS

CENTRONICS 730-1 $ 575

CENTRONICS 737-1 S 720

DIABLO 630 S2075

TERMINALS

TELEVIDEO 920C S B35

TELEVIDEO 912C $ 775

NORTH STAR HORIZON MICROPROCESSORS Fully Tested Liberal Return Policy

NS HORIZON II QUAD DENSITY, 32K DOUBLE DENSITY, 32K UPGRADE TO 64K CP/M* FOR NORTHSTAR

$2938 $2524 S 520 S 150

GREAT DEALS ON SOFTWARE

MICROPRO

WORDSTAR'" S 325

MAILMERGE" $ 100

DATASTAR'" S 230

SUPERSORT V $ 165

SUPERSORT II'" $ 130

SMALL BUSINESS APPLICATIONS, INC.

MAGIC WAND'" $ 275

20S OFF CP/M*WITH NS HORIZON II 10% OFF ALL OTHER SOFTWARE WITH NS HORIZON II J**v

DWP InC. P0?)241-2910 -£

123 Rowdl Court , Falls Church. Virginia 22046

Circle 315 on Inquiry card.

Circle 317 on Inquiry card.

* UP TO 50% Off *

* * 16K RAM MEMORY KIT * * * UPGRADE V'OUR COMPUTER IU 5 MINUTES 4116 chips — Garanteed PRIME

ADD 200ns 16K CI SET OF 8) $3 10 SETS OR MORE ONLY $ 29.95

** CENTRONICS 101A PRINTER - ONLY $895

SAVE HUNDREDS OF DOLLARS OFF MODEL II AND MODEL III

* TAP THE SOURCE OR HICRNET *** HUGE DATABASE WITH IIAZELTIHE 1000 terminal

AND MODEM ONLY $499.00

-COMPUTER SYSTEMSTANDARD AND CUSTOMIZED , WORDPROCESSING , DISTRIBUTED AND MANY MORil. • DATAPOINT,ALPHASPRINT

REPAIRS

OUR IN-HOUSE EXTENSIVE ELECTRONIC REPAIR SERVICE REPAIRS DISK DRIVES TERMINALS —PRINTERS AND MUCH MORE.

BEWEHKE I'EuIfHE'KftLii 41 SH588S pLAIn

BETHEL CT. 06S01 PHONE (203) 743-5583

We're the MAGNOLIA people you've been looking for...

Add the CP/M® disk operating system to your Zenith/Heath '89 All-in-One Computer. Easily installed hardware and software proven by reliable service for more than a year. Supports 8-inch, double-sided 5-inch, and hard disk drives. Only $195. Ask your local dealer; or

MAGNOLIA H

MICROSYSTEMS

2812THORNDYKEAVE. WEST SEATTLE, WASHINGTON 98199

[206) 285-7266

CP/M" is a registered trademark of Digital Research. Inc.

?? APPLE*-ITIS ??

Hardware or Software Problems?

Save time and money by having your own diagnostic disk. Determine immediately if you have a hardware problem.

XPS's APPLE*-CILLIN can

help you cure your problems fast and easily.

Order APPLE*-CILLII\I for

$29.95**

UPS

UtC.

323 York Road Carlisle, PA 17013

•trademark of Apple Computer Inc. •*PA Residents add 6% sales tax Requires 48K and one Disk II*

Circle 319 on Inquiry card.

Circle 320 on Inquiry card.

WE WILL NOT BE UNDERSOLD

DISK DRIVES

FOR TRS-80* Model I

CCMOOTEAC 51/i",40Track(102K) $314

CCI-100 MPI 5V.T, 40 Track (102K) $319

CCI-280 5Va",80Track(204K) $429

PRINTERS

I ADD-ON DRIVES FOR ZENITH Z-89

CCI-189 5V*", 40Track (102K)

CCI-289 51/4", 80 Track (204K)

Z-87 Dual 5V*" system

External card edge and power supply included. 90 day warranty/one year on power supply.

NEC Spinwriter

Letter Quality High Speed Printer

R.O.

R.O. with tractor feed

KSR with tractor feed

$394 $499 $995

$1795

RAW DRIVES 8"SHUGART801R $425

5'/4"MPI,TEACorTANDOM $CALL

MORROW DESIGNS/THINKER TOYSTM

DISCUS 2D 1 DRIVE $ 938 2 DRIVE $1635

DISCUS 2 + 2 1 DRIVE $1259 2 DRIVE $2245

DISCUS Hard Disk M26 $3990 M10 $2999

DEI CARTRIDGE TAPE BACKUP

For your hard disk. With either S-100 control card

or piggy back board for single board Z-80 computers. IS^S-GO $2995

DISK OPERATING SYSTEMS

PATCHPAK#4byPercomData $8.95

CP/M- for Model I, Zenith $145 for Model II, Altos $169

NEWDOS Plus 40track $79 NEWDOS 80 $135

DISKETTES — Box of 10 with plastic library case

5'/4" Scotch $35 Maxell $40 BASF/Verbatim $24

8" Scotch $50 Maxell $55 BASF/Verbatim $36

CLEAR PLASTIC CASE-Holds505V*" diskettes $19

C.ITOH Starwriter

EPSON MX-80 PAPER TIGER

IDS 445 Graphics &2K buffer

IDS 460 Graphics & 2k buffer

IDS 560 Graphics

ANADEX DP-8000 $849

OKIDATA

Microline 80 Friction & pin feed

Microline 80 Friction, and pin & tractor feed

Microline 82 Friction & pin feed feed

Microline 83 120 cps, uses up to 15" paper

Starwriter I

DP-9500/01

CENTRONICS 730 $ 595

737 $ 780

779

EATON LRC 7000 T

TI-810

TRS-80* software, compressed print & vert, form control

$2395 $2595 $2895

$1995 $CALL

$ 699 $1050 $1599 $1345

$ 499 $ 599 $ 719 $ 995 $ 969 $ 269

$1865

16K RAM KITS 2 for $56 $30

200 ns for TRS-80*, Apple II, (specify): Jumpers $2.50

S-100 CALIFORNIA COMPUTER SYSTEMS

COMPLETE SYSTEMS

ARCHIVES

$CALL

ALTOS

ACS8000 Series

SCALL

APPLE

II-16K $1075

Call for other Apple products

III-96K

$3749

TRS-80*

H-64K $3499

III-16K

$ 899

ZENITH

48K, all-in-one computer

$2395

ZENITH

Z-19

$ 795

TELEVIDEO

920C $ 748

950

$1049

IBM

3101 Display Terminal

$1195

ATARI

400 $ 479

800

$ 795

APF

Game Only $ 95

System

$ 489

MATTEL

INTELLIVISION

$ 229

Used TRS-80'

Model I Computers, tested and guaranteed

SCALL

MONITORS

APF

9"B&WTVM-10

$120

BELL&

HOWELL

9"B&WBHD911

$220

LEEDEX

12"B&W $129

13" Color

$389

SANYO

9"B&WVM4509

$155

SANYO

12" B&W DM5012

$226

SANYO

12" Green Screen DM5112

$238

SANYO

13" Color DMC6013

$416

ZENITH

13" Color

$350

TELECOMMUNICATIONS

LIVERMORE STAR MODEM 2-year guarantee

$129

UNIVERSAL DATA SYSTEMS UDS-103

$179

D-CAT HARD WIRED DIRECT MODEM

$189

AUTO-CAT A

jto Answer, Direct Connect Modem

$249

MAINFRAME Model 2200A $349

Z80CPU Model 2810 $269

MOTHERBOARD Model 2501 $CALL

16K STATIC RAM, 200ns Model 2016BC $309

32K STATIC RAM, 200ns Model 2032C $619

64K DYNAMIC RAM Model 2065A $599

FLOPPY DISC CONTROLLER Model 2422A $359

EXTENDER BOARD Model 2520 $ CALL

2P + 2SI/0 Model 2718 $ CALL

ACCESSORIES

Z-80SOFTCARD $299.00 SCOTCH HEAD CLEANING DISKETTE: Cleans drive

Read/Write head in 30seconds; specify5Vi"or8". $ 25.00 FLOPPY SAVER: Protection for center holes of 51/4"

floppy disks. Installation tools and rings for 25 diskettes. $ 11.95

Re-orders of rings only $ 6.95

VIDEX BOARD 80 Column, U/L case conversion card $279.00

CRT FILM: Helps eliminate external glare, 9" $ 29.00

RF MODULATOR: Adapts video to TV $ 29.00

TRS-80 & OTHER MYSTERIES $ 18.95

NEC SPINWRITER THIMBLE $11.95 RIBBON $ 6.00

CCS CARDS: Parallel or serial printer interface cards $115.00

RS232: For Radio Shack Interface. $ 89.00

DISK-DRIVE EXTENDER CABLES: Fits all mini-disk drives. $ 16.95

SIX (6) PRONG ISOLATOR: ISO-2 $ 54.00

AC FILTER/6 PRONG POWER STRIP $ 39.00

DISK DRIVE CABLES: 2 drive $29.00 4 drive $ 35.00 For fast delivery, send certified checks, money orders or call to arrange direct bank wire transfers. Personal or company checks require two to three weeks to clear. All prices are mail order only and are subject to change without notice. Call for shipping charges.

dealer (national/international) inquiries invited Send for FREE Catalogue

The CPU SHOP

TO ORDER CALL TOLL FREE 1-800-343-6522

TWX: 710-348-1796 Massachusetts Residents call 617/242-3361

5 Dexter Row, Dept. B04M

Charlestown, Massachusetts 02129

Hours 10AM-6PM (EST) Mon.-Fri. (Sat. till 5)

Circle 321 on inquiry card.

Technical Information call 617/242-3361 Massachusetts Residents add 5% Sales Tax Tandy Corporation Trademark/' Digital Research

^^^^^^^^

VtSA*

[master charge]

BYTE April 1981 389

EVERY MONTH

BUY, SELL OR TRADE ALL TYPES OF COMPUTER EQUIPMENT AND SOFTWARE (pre-owned and new) among 20,000 readers nationwide in BIG (11x14") pages. Classified ads are only 10' per word and are indexed for easy and fast location. Subscription: $10 a year/ 12 issues. Money back guarantee. Sample copy, $1.50.

campursR SHOPPER

P.O. Box F-14

Titusville, FL 32780

(305) 269-3211

MasterCard or VISA subscription orders only,

call TOLL FREE 1-800 528 6050 Ex. 184 .

BELOW DEALERS COST!

NorthStaf^

North Star Horn

32KDD -2265.00 32K QUAD-2600.00

Immodiaio Delivery Application Sotlwarp

North St>r Pascal NorlhWord General Ledge;

COD CASH IN ADVANCE VISA/ MASTER CHARGE'

•ADD 4 PERCENT ON CHARGE ORDERS

CUSTOM BUSINESS COMPUTERS

103 ATLANTIC AVENUE, LYNBROOK. NEW YORK 11563»(516)8873340

list xref sort col print and more

Fine Software Tools in C

The Toolbox

prints that missing source listing cross reference C programs alphabetize by all or part ot text line arrange text in columns on page paginates text (or hard copy

All programs are in portable Whitesmith C xref and list are compatible with the compiler's error listing Title lines on list and print output includes the date on RT-11 systems Source code on 8" floppy and manual available immediately for $45 (lax and shipping included} Specify RT-11 or CP/M format

The Toolsmith

Dept. BYTE

P. O. Box 22511

San Francisco, CA 94122

RT-11 is a trademark of Digital Equipment Corp CP/M is a trademark of Digital Research

Circle 322 on inquiry card.

Circle 323 on inquiry card.

Circle 324 on inquiry card.

SMARTNET

-Automatic spooling and despooling. -Levels 1-15 of the hub computer are

password protected. -No modifications needed to the BIOS

or XI05. -Block data transfer with checksum. -Low memory requirements. -Complete source code provided.

REQUIREMENTS

-Hub comuuter must be running KP/K*. -imartnet requires CF/tf* 2.2, 20k of

memory and at least one disk drive. -Dumbnet requires at least 16k of memory. Disk drives not needed.

PRICE

JKARTNET C150.00 DUHB.'ET 3 175.00 PURCHASE TOGETHER .3500.00

LIMMAR

541 Ingraham Ave.

Calumet City, IL. 60409

"512-868-4 866 Ask for Mark

* Trademark of Digital Research,

SURPLUS ELECTRONICS

ASCII

ASCII

TRS-80* COMPATIBLE, IBM SELECTRIC- BASED I/O TERMINAL

with ASCII conversion installed: $645.00

Many Other Items Available: Tape Drives; Cable: Cassette Drives; Wire; Power Supplies (5 volt 35 amp, others); Displays; Cabinets; Transformers; Heat Sinks; Printers; Components.

Send lor Free Catalog

WORLDWIDE ELECTRONICS, INC.

130 Northeastern Blvd.

Nashua, N.H. 03062

Phone orders accepted using VISA or MC

Toll Free 1-800-258-1036

in NH 603-889-7661

'TRS-80 is a trademark of the Radio Shack

Division of Tandy Corporation.

MEMOREX

Floppy Discs

Lowest prices. WE WILL NOT BE UNDERSOLD!! Buy any

quantity 1-1000. Visa Mastercharge accepted Call free (800)235-4137 for prices and information. All orders sent postage paid.

PACIFIC EXCHANGES

100 Foothill Blvd San Luis Obispo. CA 93401 (In Cal. call (805)543-1037)

Circle 325 on Inquiry card.

Circle 326 on inquiry card.

Circle 327 on Inquiry card.

No TRS-80© Word processor

is complete without

PROOFREADER

Let your TRS-80 proofread your SCRIPS1T, Electric Pencil or other documents. Proofreader uses a 38,000 word dictionary and lists misspelled words on a file, screen, or printer. (Requires 32K, 1 disk. MODEL!) $34.00

RATFOR

Rational Fortran preprocessor allows structured programming using Fortran. One of the best versions available, with full manual. (Requires Fortran, 48K, 2 disks, MODULI) $49.00

SOFT-TOOLS are professional quality software tools developed for the TRS-80 by a PhD in Computer Science. Versions for MODEL-III available soon.

Order Postpaid:

SOFT-TOOLS

MHE Box 14 Tijeras, NM 87059

Know The Reasons Why

The FORCE-80 is your

"Best Buy."

FORCE-80 The computer protector

• Power dropout protection

• Suppresses transient voltages

• Suppresses RFI

• Disc protection

• Factory warranty

• Satisfaction guaranteed

• Direct from factory

FORCE-80

Only $121.50 plus $5.00 shipping & handling

Check, Mastercharge, Visa accepted (5% discount lor cash) ^^^m

No C O D 's please ^^—

P&S Electronics, Inc.

P.O. Box 23014 Dept. B Nashville, TN 37202

Allow 6-8 weeks for delivery. Add 14 days for personal checks.

Double Side Disk Drives

- a

Disk Drive Subsystem with Dual Double Side Drives, Power Supply and Cable. Total Capacity 2.4 M-Byte. Fully Assembled and Tested.

Only t!

1. Table Top Version $1,695.00

2. Rack Mount Version 1,695.00

3. Pair of Slides with Attachment

4. S100 Disk Controller (handles single & double density in 256, 512 & 1024 byte sectors, single & double side) 350.00

5. Double Side Disk Drives (1.2 mb) 535.00

(Qume DT/8)

Call Now (408)496-6910

OSM Computer Corporation 2364 Walsh Avenue Santa Clara, CA 95051

Circle 328 on inquiry card.

Circle 329 on inquiry card.

Circle 330 on Inquiry card.

electronic components fffl^w TTL i%*

One-Stop Component Center (™;

This is a partial listing of over 500 items available from 500 authorized Jim-pak Distributors:

7400 2/.85

7402 2/.85

7404 2/.85

7406 2/1.19

7407 2/1.19

7408 2/.S9

7410 2/.85

7414 99

7417 2/1.10

7420 2/.85

7447 1.19

7474 69

7475 79

7476 69

7485 1.19

7486 2/1.19

7489 2.99

7490 85

7493 85

74100 2.25

74109 2/1.19

74121 69

74123 99

74150 1.95

74154 1.95

74157 99

74161 1.19

74164 1.59

74174 1.59

74175 1.49

74192 1.19

74193 1.19

74367 99

74393 1.95

POTENTIOMETERS

2 Watt @ 70°C

7/8" Slotted Shaft

Linear Taper

1K 5K 10K 25K 50K 100K

1 Meg

CMU . . $2.95

3/4 Watt @ 70°C 15 Turn Pot. Linear Taper

100n 500ft 1K 5K 10K 50K 100K 500K 1Meg

830P. .$1.79

ffi^ CMOS ^*

4000 4001 4002 4006 4009 4010 4011 4013 4016 4017 4018 4020 4023 4024 4027

.69

.69

.69

1.95

.89

.85

.69

.85

.85

1.49

1.49

2.19

.49

1.29

.89

4030 . . .

. . . .79

4040 . . .

. . . 1.95

4044 . . .

. . . 1.39

4046 . . .

. . . 2.49

4047 . . .

. . . 2.75

4049 . . .

. . . .89

4050 . . .

. . . .89

4051 . . .

. . . 1.95

4066 .. .

. . . 1.19

4069 . . .

. . . .79

4070 . . .

. . . .79

4071 . . .

. . . .79

4081 . . .

. . . .69

4093 . . .

. . . 1.19

4511 . . .

. . . 1.95

CONNECTORS

DB25P D-Subminiature Plug 3.95

DB25S D-Subminiature Socket 4.95

DB51226 Cover for DB25P/S 2.25

22/44SE P.C. Edge 2.95

UG88/U BNC Plug 2.19

UG89/U BNC Jack 3.95

UG175/U UHF Adapter .59

S0239 UHF Panel Recp. 1.49

PL258 UHF Adapter 1.95

PL259 UHF Plug 1.95

UG260/U BNC Plug 2.39

UG1094/U BNC Bulkhead Recp. 1.49

WW LINEAR ffiffi*

LM301N.

LM305H.

LM307N.

LM308N.

LM309K.

LM310N.

LM311N.

LM317T.

LM318N.

LM319N.

LM320K-5

LM7905T

LM7912T

LM7915T

LM323K.

LM324N.

LM337T .

LM339N.

.59 1.39

.75 1.19 2.25 2.69 1.49 2.29 2.95 2.95 2.25 1.75 1.75 1.75 5.95 1.29 2.29 1.29

LM7805T LM7812T LM7815T LM380N. LM384N. LM555N. LM556N. LM565N. LM566N. LM567N. LM723N. LM741N. LM1310N LM1458N LM1488N LM1489N LM1800N 76477 N. .

1.75 1.75 1.75 1.49 2.49

.69 1.49 1.95 1.95 1.79

.79

.65 2.95

.99 1.59 1.59 4.49 3.95

GRAB BAGS

GB100 Cer. Caps. (100) 2.95

GB101 Mylar Caps. (60) 4.95

GB102 Electrolytic* (60) 4.95

GB103 Tantalums (40) 4.95

GB108 TTL IC's (50) 4.95

GB110 Asst. LEDs (100) 5.95

GB113 Trimmers (30) 4.95

GB116 Vsw Resist. (200) 2.95

GB117 V2W Resist. (200) 2.95

G8120 SlideSwitch(25) 3.95

GB123 Heat Sinks (30) 3.95 GB127 Transistors (100) 3.95 GB137 Chokes (50) 3.95

GB139 Term. Strips (40) 3.95 GB140 Spcr/Stndff(150) 2.95 GB141 Washers (200) 2.95

GB145 Lugs (100) 2.95

GB154 l&2w Resist. (100) 2.95 GB162 7-Seg.Dsplys.(50) 5.95 GB173 3/8" Pots. (100) 5.95

REGULATED POWER SUPPLY KIT

Uses LM309K. Heat Sink _ provided. PC board construction. Provides a solid 1 amp (s> 5 volts. Can supply up to±5V, ±9Vand ±12Vwith JE205 Adapter. Includes components, hardware and instructions. 3y2"x5"x2"H

JE200 $14.95

DESK TOP ENCLOSURES

DTE-8 (Pictured) $31.95

DTE-11 (Pictured) 34.95

DTE-14 36.95

DTE-HK (Case for JE600) 47.95

DTE AK (Case for JE610) (Pictured) ... 52.95

JOYSTICKS

JS-100K 100K Linear Taper Pots $5.49

JVC-40 40K (2) Video Controller 5.95

V

TOOLS

PCB-3 P.C. Board Vise $12.49

WS-150 5"WireStrip./Cut. (12-24AWG). . 3.99

SG-30 10" 110-120V30W Solder Iron. . 7.50

SG-TIP Replacement Tip for SG-30 S. Iron 1.25

WALL TRANSFORMERS

AC250 DV9200

250mA 12VAC 200mA 9VAC

(117V/60Hz). (117V/60Hz).

$3.95 3.95

WW LS Schottky WW

74LS00 55 74LS109 79

74LS02 55 74LS123 .... 1.95

74LS04 69 74LS138 .... 1.49

74LS08 55 74LS139 .... 1.49

74LS10 55 74LS154 .... 2.49

74LS14 1.09 74LS157 .... 1.49

74LS30 55 74LS161 .... 1.79

74LS32 69 74LS174 .... 1.79

74LS38 69 74LS175 .... 1.79

74LS42 1.49 74LS192 .... 1.89

74LS47 1.49 74LS193 .... 1.89

74LS48 1.79 74LS221 .... 1.95

74LS73 79 74LS244 .... 2.49

74LS74 79 74LS245 .... 3.49

74LS75 99 74LS367 .... 1.29

74LS85 1.95 74LS374 .... 2.49

74LS90 1.09 81LS97 2.49

SOCKETS

Low Profil

8 pin LP . 14 pin LP . 16 pin LP . 18 pin LP . 20 pin LP . 22 pin LP . 24 pin LP . 28 pin LP . 36 pin LP . 40 pin LP .

e Wire Wrap

2/.59 14 pin WW tin .75

2/.69 14 pin WW gold 1.09

2/.79 16 pin WW tin .79

2/.89 16 pin WW gold 1.19

2/.99 24 pin WW gold 1.69

2/1.09 40 pin WW gold 2.75

.79 14 p. plug/cover 1.29

.82 16 p. plug/coverl.39

.99 24 p. plug/cover 1.95

1.19 Also, The Molex Line

DIODES & TRANSISTORS

IN751 . IN757 . IN1188. IN 3600. IN4001. IN4004. IN 4007. IN4148. IN4733. IN4734. IN4735. IN4742. IN4744.

. 2/.59

. 2/.59

. 2.69

. 5/.99

. 4/.59

. 4/.69

. 4/.79 .10/. 99

. 2/.69

. 2/.69

. 2/.S9

. 2/.69

. 2/.69

2N2219A. . . .2/1.19 2N2222A. . . . 2/.89 2N2907A. . . . 2/.89

2N3055 99

2N3772 2.25

2N3904 2/.69

2N3906 2/.69

2N4401 2/. 79

2N4403 2/. 79

2N5129 2/.69

2N5139 2/.69

2N5210 2/.79

2N5951 2/1.29

CAPACITORS

Dipped Tantalum ELECTROLYTIC

.lmfd@35V

.47mfd@35V

lmfd@35V

2.2mfd@25V

3.3mfd@25V

4.7mfd@25V

10mfd@25V

33mfd@25V

100V MYLAR .OOl-.Olmfd 4/.79

.022mfd 4/.89

.047mfd 4/.99

.lmfd 4/1.19

.22m fd 4/1.29

2/. 8

2/.89

2/.S9

2/1.09

2/1.19

2/1.39

1.19

3.95

lmfd@50V

4.7mfd@50V

10mfd@50V

22mfd@50V

47mfd@50V

100mfd@50V

220mfd@50V

1000mfd(°>25V

2200mfd@16V

50V CERAMIC 10pf-.022mfd 4/.59 .047mfd 4/.69

.lmfd 4/.79

3/.69

2/.59

2/.69

2/.79

2/.89

.59

.69

1.19

1.39

MICROPROCESSORS

Z80A CPU (4MHz) 14.95

MC6800 8 Bit MPU 14.95

8080A CPU 7.95

8212 8 Bit I/O Port 3.95

8216 Bi-Directional Bus Driver 4.49

2513/2140 Character Generator 12.95

8T97 Tri-State Hex Buffer 2.25

AY-5-1013 30K Baud UART 6.95

AY-5-2376 88-Key Keyboard Encoder 13.95

2114-3 4K Static RAM (300ns) 9.49

MK4116 16K Dynamic RAM (250ns) 9.95

2708 8K EPROM 10.95

2716 16K EPROM (+5V) 19.95

12VDC AUTOMOTIVE/ INSTRUMENT CLOCK MODULE

s ® © ®—a^' ^

.300 GREEN DISPLAY

MA1003 $19.95

Circle 331 on inquiry card.

BYTE April 1981 391

!! REAL TIME !

11

The TIME MACHINE from ALPHA OMEGA COMPUTER SYSTEMS isn't just another digital clock chip surrounded by interface circuitry. It's an intelligent microcomputer based peripheral device.

The TIME MACHINE communic itej with your computer via a serial I/O port at a user selectable data rate between 300 and 2400 baud. RS-232, RS-422, or current loop communication may be used.

Battery protection against power loss is included. The TIME MACHINE automatically computes day ot the week and leap year. Buffered output oulses at one second, one minute, and one hour intervals are provided.

Dimensions are 2.5 x 4."'5 x 7.5 inches. Batteries, power supply, and communication cable are included.

Price Is only $450 single lot and quantity discounts are available. Dealer inquiries invited. Off the shelf delivery.

ALPHA

OMEGACOMPUTM I9STIMI, INC.

P O Bo. T27 / Cdivalht. Cgon 07330

: <nx

ZAS Z-8000

SOFTWARE DEVELOPMENT PACKAGE

A professional Z-8000 assembly language package now available for 8060 & Z-80 based microcomputers which use the CP/M* orlSIS-IJ* operating system. The package includes:

yPAQful featured relocatable cross assembler. ^A%0 uses Zllog syntax, supports segmented and non-segmented code, symbol names to 64 characters. 26directives, including nested conditional assembly, "include" files, and named program, data and absolute sections. Outputs: object and listing files.

"71 W ^ask Guilder. The most powerful linker you've LLi\ ever used! Sections can be combined in any order and optionally "located" at fixed address. ZLK can also handle complicated overlay arrangements. 71 r^Obiect Loader. Loads an absolute object file £-Xm\J for execution by a Z-8000 CPU on the bus. Includes host OS interface.

ZAS, ZLK, ZLD CP/M* .$395 Waa// isis-ii" ..$495

\fjjj Manual Only $25

WESTERN Supplied on Single Density 8" Disk

WARES CP(M» Digital Research, Inc. ISIS-II* Intel Corp.

Box 48 Placervllla, CO 81430

Worth Star

BASIC UTILITY SET

■ EDITOR —Create & edit a Basic program using 26 commands, including GLOBAL locate & change.

■ BPRT — Print & cross reference a Basic program.

■ BPAK — Pack a Basic program.

■ RE — Rename a disk file.

(ten plus $1'50 shiPP'n9. vpby Calif. Res. add 6%.

/^^\ Check, VISA, M/C

(m) Software Systems

1269 Rubio Vista Road. Altadena, Calif. 91001 (213) 791-3202

Circle 332 on inquiry card.

Circle 333 on inquiry card.

Circle 334 on inquiry card.

■ PEX NEW!

interface Converts

Your Typewriter

Into Printer

• Finest print quality • Low cost

• Easy installation • Quick delivery

• Fits IBM SELECTRIC® typewriter with no modification.

• For trs-80\ Apple*, or any parallel or RS232 port.

• write or phone for more Information, today!

%

— U.S. and worldwide sales —

EX

INTERNATIONAL INC. 16140 valerlo St.

Van NUVS.CA 91406 USA TEL: 213/781-0020 TLX/TWX: 910-495-1767

New Senslbiy-Priced Paper Tape Reader

A new, smaller, less expensive Stand-Alone Paper Tape Reader Model 605 reads at 150 CPS, has a parallel TTL output and is bidirectional. It stops on character, is completely self-contained and has automatic taut-tape sensing.

The new reader has 5 voll DC and 24 volt DC output power available and an optional internal clock. The desk-top model is priced at $495 (or one unit, a saving of about 25% of the price of the larger Model 612. Contact Louis Doshay, Addmaster Corporation, 416 Junipero Serra Drive, San Gabriel 91776; telephone (213) 285-1121

A NEW WIRELESS AC REMOTE CONTROL INTERFACE for the Sears and BSR X-10 home control system. Use your present TRS-80 Level It, Apple II or SlOo computer to provide complete home security through control of lights, appliances and motors with a few simple BASIC commands.

As featured in: "COMPUTERIZE J HOME" BYTE. January 1980

Busy Box - Assembled & tested

For TRS-80 ..(109.95

ForSlOO .... 119.95

For Apple II...114.95 Realtime control software -TRS-80 19.95 To order call (516) 374-6793 or write: The MicroMind Inc. 917 Midway. Woodmere.NY 11598

DEALER INQUIRIES INVITED

BUSY BOX

Circle 335 on Inquiry card.

Circle 336 on Inquiry card.

OAE's PP-Series EPROM Programmers plug directly into any vacant EPROM socket and allow you to transfer data directly from RAM to EPROMs. No additional power supplies are required. All timing & control sequences are handled by the programmer. Each unit includes internal DC to DC switching regulator, ZIF socket and 4 ft. ribbon cable terminated with a 24 pin plug. Programmers are available for all EPROMs from 2708's thru 2532's.

Oliver Advanced Engineering, Inc.

676 W. Wilson Ave.. Giendaie, CA 91203

(213) 240-0080 or Telex 194773.

PP SERIES PROGRAMMERS

See us at NCC, booth 770

DISK DRIVES

REMEX

Compatible with IBM and Shugart. Double sided, Double Density

1600 KBytes.

RFD4000 $595

Double Sided, Double Density

800 K. Bytes

RFD2000 $395

For fast delivery, send certified checks, money orders or call to arrange direct bank wire transfers. Personal or companychecks require two weeks to clear. California Res. add 6% sales tax. Minimum shipping charge $10.00. NoC.O.D. Electronic Equipment Unlimited 3845 Birch Street Newport Beach, CA 92660

PH: (714) 540-5231 Pricing and availability subject to change without notice.

MEDICAL BILLING

for APPLE II

• 7000 ACCOUNTS

• 2000 TRANSACTIONS

$995

3604 Foothill. LaCrescenta, CA

(213) 248-2884

Circle 338 on Inquiry card.

Circle 339 on inquiry card.

Circle 340 on inquiry card.

ANOTHER FAMOUS PRIORITY 1 ELECTRONICS

TRUCK LOAD PURCHASE

10 MHZ 16K A&T STATIC S-100 RAM

FROM

(onfipuProM

division of

(8(9®®%

^ ELECTRONICS^

UST „

&h

%£

llllllll

''i«fcC8BBSBP?

<km':::::::* i 33l

I

.I,,,,, p,!,!!.,,.

,..-:.i;:rv

The RAM 14 provides 16K X 8 of reliable, totally static RAM storage. Conforming fully to the IEEE 696/S-100 bus standard, RAM 14 not only provides 24 address lines for 16 megabyte extended addressing capability, but also includes a number of features you would only expect to find in memory boards costing considerably more. Here's a partial listing of what makes RAM 14 your best choice!

Operates up to 10 MHZ (70 ns Ram Chips)

Assembled & Tested

Meets or exceeds all IEEE 696/S-100 specifications (including timing).

Fully static design eliminates the timing problems associated with dynamic memories.

Switch selectable choice of 24 address lines conforming to the IEEE 696/S-100 extended addressing specifications, or 16

address lines as used in older S-100 systems.

Ideal for multi-user installations.

Board is addressable as one 16K x 8 block on any 4K boundary.

Switch selectable PHANTOM disable and write protect.

+ 5 Volt operation (requires no other supply voltages).

Low power operation (900 mA typical, 1200 mA maximum).

1 year Factory Warranty

GBT-143A

$199.00

Quantities are limited so hurry!

&$&&<*»■

PRIORITY ONE ELECTRONICS

° 16723 B ROSCOE BLVD. • SEPULVEDA, CA 91343

Terms: Visa, MC, BAC, Check, Money Order, U.S. Funds Only. CA residents add 6% sales tax. "Sales Prices are for prepaid orders only. Credit card orders will be charged appropriate freight.

Circle 290 on inquiry card.

TO »f SKS? micro

Xtim SALES

DEALS □ Df>4AS D D£>US

SHOP HERE AND

(7 10

(MINIMUM ORDER $10.00)

7M « ABSOLUTELY the LOWEST PRICE EVER for a Hi Speed (300 NS) LO-LO Power 32K RAM.{ 4K by 1 Chips are organized in Selectable Banks,

* Extended Address Lines A16 - A17 * Phantom Line * 9 Regulators

SCHOOLS

DIP SWITCHES pos. prc

4 .88

5 .92

6 .95

7 .99

8 1.05

9 1.15

10 1.19

JK ' EX

PINS PC WW

8 14 16 18 20 24 28 40

.10 .26

.13 .29

.16 .32

.18 .34

.22 .32 .34 .45

.38 .48 .50 .61

AMP - Need we say more? There is a difference in sockets! These aren't the lowest prices you can find. But, if you've been"burned" before by bad connections in your computer, a few pennies for the best is worth it!

RESISTORS .02 ea!

(100 PACK) %W

1.0 4.7 6.8

10

15

22

27

33

47

68

75 100 150 220 330 470 680 1K 1.5K 2.2K

2.7K

3.3K

3.9K

4.7K

6.8 K

10K

12K

15K

18K

20K

22 K 24 K 27K 33 K 39 K 47 K 68 K 100K

220K

330K

470K

680 K

1M

1.5M

2.2M

4.7M

150K 10M

WIRE WRAP WIRE

Packed in 500 Lot Bundles

(Length includes 2" x 1

Color - R, Bu, G, Y,

50 ft. $1.65- 100 ft. $3.00

2.5-3.25 3.0-3.35 3.5-3.50

4.0-3.75 4.5-4.00 5.0-4.50

' Strip)

Bk, W 500 ft. $9.50

6.0-4.75

7.0-5.00

8.0-5.50

10.0-6.50

OK WIRE WRAP TOOL $5.95

ST21 ST22 ST23 ST24 ST25 ST26

6 Amps 125 VAC

7 Amps 30 VDC

$1.25 ea.

DPDT STANDARD TOGGLE

(ON-NONE-ON)

(ON-OFF-ON)

(MOM ON-OFF-MOM ON)

(ON-OFF-MOM ON)

(ON-NONE-MOM-ON)

(ON-ON-ON)

HOBBIEST

LM323K 5V 3A.

REGULATOR

$5.50

TAB MOUNT

7805 +5V 1A

7905 -5V 1A

7812 +12V 1A

7912 -12V 1A

HEAT

SINKS

49$

$1.25

♦ GOLD ♦

S-100-CONNECTOR Tl or Better

$2.50 $3.25

DIP PLUGS

PART* PINS

PRICE

08 DP 14DP 16DP 24DP 40DP

14 16 24 40

.40 .55 .58 .95 1.50

Socket and Dip Plug priced based on gold not exceeding $700 per ounce.

CONNECTORS

DUAL ROW .100

CARD EDGE

PINS

PRICE

PINS

PRICE

20

2.35

20

3.35

26

3.00

26

3.80

34

3.85

34

4.65

40

4.50

40

5.50

50

5.50

50

5.90

RIBBON - 20 to 34 @ 1.00 ft. 40 & 50 @ 1.30 ft.

CRIMPING 2.00 / CONNECTOR

OEM'S

Z-80-A

$6.95

4MHZ Beastie with extra instructions!

Z-80 SUPPORT

CTC - $6.55

SIO - $25.50

PIO - $6.50

DMA - $18.75

All 4MHZ (who wants 2MHZ?)

74LSXX

74LS0O 74LS01 74LS02 74LS03 74LS04 74LS05 74LS06 74LS07 74LS08 74LS09 74LS10 74LS11 74LS12 74LS13 74LS14 74LS15 74LS20 74LS21 74LS22 74LS26 74LS27 74LS28 74LS30 74LS32 74LS33 74LS37 74LS38 74LS40 74LS42 74LS47 74LS48 74LS35 74LS54 74LS55 74LS73 74LS74 74LS75 74LS76 74LS78 74LS83 74LS85 74LS86 74LS90 74LS92 74LS93 74LS95 74LS96

.33 .33 .33 .33 .59 .39 .39 .39 .59 .39 .29 .39 .39 .69

1.25 .49

1.95 3.7 .29 .39 .49 .39 .49 .95

1.95 .75 .39 .25

1.39 .79 .79 .25 .25 .70 .79 .59 .79 .79 .49 .95

1.49 .95 .75 .75 .95

1.29

1.29

74LS107 74LS109 74LS112 74LS113 74LS114 74LS122 74LS123 74LS124 74LS125 74LS126 74LS132 74LS133 74LS136 74LS138 74LS139 74LS145 74LS148 74LS151 74LS154 74LS155 74LS156 74LS157 74LS158 74LS160 74LS161 74LS162 74LS163 74LS164 74LS165 74LS166 74LS168 74LS169 74LS170 74LS173 74LS174 74LS175 74LS181 74LS189 74LS190 74LS191 74LS192 74LS193 74LS194 74LS195 74LS196 74LS197

.59

.59

.59

.59

.49

.59

1.19

1.49

.89

.89

.79

1.19

.69

.99

.99

1.25

1.49

.79

2.49

1.49

1.49

1.49

1.49

.75

1.99

1.25

1.25

2.15

1.49

2.49

2.95

1.95

1.95

1.25

1.49

1.49

2.15

6.95

.99

1.95

1.95

1.95

1.49

.95

.95

1.95

74LS221 74LS240 74LS241 74LS242 74LS243 74LS244 74LS245 74LS247 74LS248 74LS249 74LS251 74LS253 74LS257 74LS258 74LS259 74LS260 74LS266 74LS273 74LS275 74LS279 74LS283 74LS289 74LS290 74LS293 74LS295 74LS298 74LS324 74LS352 74LS353 74LS365 74LS366 74LS367 74LS368 74LS373 74LS374 74LS377 74LS378 74LS379 74LS38 6 74LS390 74LS393 74LS395 74LS490 74LS668 74LS669 74LS670

2.95 2.95 2.49 1.95 1.95 2.95 8.95 1.19 1.19 1.69 1.79 .95 1.95 1.95 2.95 .75 1.15 1.75 4.39 .79 1.49 5.75 1.29 1.95 1.95 1.29 1.75 1.65 1.65 .95 .79 .99 .99 2.95 3.95 1.95 1.95 1.95 .59 1.95 1.95 1.95 4.95 1.69 1.89 3.55

394 BYTE April 1981

DEALS □ DEALS □ 0£>US

OUR BUYERS ARE IN

CONTACT WITH EVERY MAJOF

SUPPLIER AND O.E.M.

BUY HERE AT 1000 PIECE

QUANTITY PRICES

ALL MERCHANDISE 100%

GUARANTEED! 15 DAY FULL

CASH REFUND!

JUST HOT STUFF

POWER SUPPLIES

If you can beat these prices we will be truly amazed. OEM's at 500 lot pay more than this. Call or write for full spec, sheets.

DISK POWER SUPPLIES

PRIAM-SHUGART-CENTURY-MICROPOLIS

+5V@9A |-5V@.8A |+24V@7A | US-384 189.00

SHUGART-SIEMANS-MPI 514"

+5V@.5A

+ 12V(s>.9A

US-340

33.50

+5V@2A

+ 12V@4A

US-323

56.25

SHUGART - SIEMANS - CDC 8"

+5V@1A

-5V@.5A

+24V @ 1.5A

US 205

52.50

+5V@2A

-5V@.5A

+24V0 3A

US-206

69.00

+5V@3A

-5V@.6A

+24V <i> 5A

US-162

89.00

+5V@ 1.7A

-5V@ 1.5A

+24V @2A

US-272

69.00

+5V@2A

+ 12V@.4A

-12V@.4A

US-HTAA

37.50

TELEVIDEO 912C

SOROCIQ120- $675.00 Televideo 912C- 665.00 Televideo 920C- 720.00 ADDSR-25 - 710.00

Also have 920C, SOROC, HAZELTINE, etc. What we don't have is room on this page. Call Toll Free 800 number for prices.

C-ITOH PRINTER $499.00

Look closely at the

photo and see other

adds in this rag at

$995.00. Perfect units,

warranteed. Only 500 pes. Same story,

manufacturerer had too many.

S-100 CARD EXTENDER

$12.50

(Gold Contacts)

As long as there is a price war, we will fight your battle. Compare at your local Dept. store and buy U$ MICRO.

MEM0REX - VERBATUM - WABASH

BASF FLOPPIES

BOX OF 10 ONLY:

554" 554" 514"

8"

SOFT HARD 10 HARD 16 SOFT 1D SOFT 2D SOFT2DDS

$2.65 ea' 2.65 ea. 2.65 ea. 3.25 ea. 3.85 ea. 5.00 ea.

Wf

664 N. MICHIGAN AVE. * SUITE 1010 * CHICAGO, ILLINOIS 60611 CALL TOLL FREE: 1-800-435-9357 * MONDAY thru SATURDAY (ILLINOIS RESIDENTS CALL: 815-485-4002) * 8:00a.m. to 6:30p.m.

TERMS: Prepayment - C.O.D. up to $100.00 - M/C Visa $5.00 Processing and Handling added to each order PLUS Shipping Charges. Please allow personal check to clear before shipment.

SPECIAL OF THE QUARTER SPECIALS OF THE MONTH

S1-MOD (KIT) ^ntgTi

$189.00c»jr jTjfcft

Complete S-100 12 Slot Computer. Ample system power with regulated power for drives. Excellent for Subsystem or Hobby use. 4 hours to build. (6 conn, incl., less fans)

DUAL DRIVE SUBSYSTEM

$995.00

$195.00 w/no Drives

)

I

4

If this looks like a Lobo ft

Drive System, don't be

fooled. Just because it 2 SHUGART 801R

looks like one, works like POWER SUPPLY

one, smells like one, and tastes like one (?)

doesn't mean it has to cost like one!

TWIN VERTICAL DRIVES 5" $550.00 - 8" $980.00

Attractive, convenient and compact Two Drive Mass Storage includes Power Supply, Drives, Cabinets and Cables. Double Sided, Double Track available too!

Z-80 CPU (KIT)

The first time this

world popular CPU

offered in Kit. 2 serial,

3 parallel, CTC, EProm

Z-80 at 4 mhz. Software

buad rate, etc. (less Prom & cable)

$212.00

EXPANDABLE RAM

*SPECIAL*SPECIAL*SPECIAL*

This is the best all around 64K board you can buy. If after you see it, you don't agree return for full refund. Bank Select by extended address lines or I.O. 40H.

1|; '='as» "■■' 'SfflilP'ii* m

• $389.00 A&T*

U$ - D$K $255.00

Double Density 8" and 5" Disk Controller disigned for S-100 IEEE standards. Uses Western Digital 1795, 1691 2143 Chip Set.

FANS $1495

9

These are brand new,

in the box fans. Not

noisey bearing pullouts,

Never again at these low prices!

3 1/8'

4-5/8"

4116s

Expansion 16K Dynamic RAMs for Apple, TRS-80 S-100 systems. T.I., Mostek Intel, Call for manufacturer.

$2.95

200 NS

DIP-80 $399.00

Don't be mislead by this _

LOW price. This is a rug- J|

ged 100% Duty Cycle

7 by 7 Dot Matrix Printer. ^^^^^^^—

Brand new, factory warr. i

• RS 232 ADD $65.00 • TRACTOR FEED ADD $70.00

2114s

One of the world's two

most popular STATIC

RAMs. Factory prime

tested units. Sold in lots of 8 only.

FUJITSU, HITACHI, etc.

$3.45

200 NS

TMS-4044 MM-5257 INTEL 2147

$4.25

250 NS

The other of the world's most popular STATIC RAMs. This one is 4K by 1 organization. Don't buy Gold, buy these, the price won't last!

2716s 2708s

$9.50 (450 NS) $6.95 (450 NS)

Remember when 2716s were $50.00 and hard to get? These units are so beautiful it's hard to part with them. But we will, for a small price. Guaranteed!

SHUGART DRIVE 8" 801R

$395.00

Manufacturer had

too many, buys at 8" 851 R $585.00

1000 piece rate,

sales dropped, so we got'em. Fantastic buy, get

them while they last! Full warranty.

SIEMANS DRIVE

8" 120-8 k,TO/w> $375.00

Very Special Price on ^ "

these BRAND NEW current production units

Add $10.00 for Extended 1 Year Warrantee!

Circle 350 on inquiry card.

BYTE April 1981 395

SALE SALE SALE

Disk Drives

JADE's new dual disk sub-assemblies include: Handsome metal cabinet with proportionally balanced air flow system, rugged dual drive power supply, cooling fan, cable kit, lighted power switch, approved fuse assembly, line cord, NeuerMar rubber feet, and all necessary hardware to mount 2-8" disk drives ■ it's all American made, guaranteed for six months, and it's in stock! Dual 8" Sub-Assembly Cabinet

END-000421 Cabinet kit $225.00

END-000420 Bare cabinet $59.95

Single sided, double density disk drive sub-system END-000423 Kit w/2 8" drives .... $975.00 END-000424 A & T w/2 8" drives $1195.00

Double sided, double density disk drive sub-system END-000426 kit w/2 8" drives .... $1495.00 END-000427 A & T w/2 8" drives $1695.00

JADE DISK PACKAGE

Double density controller, two 8" double density floppy disk drives, CP/M2.2 (configured for controller), hardware and software manuals, boot PROM, cabinet, power supply, fan. & cables Special package price $1395.00

8" Disk Drive Sale

Highly reliable double density floppy dish drives Shugart 801R single sided, double density

MSF-10801R SA-801R $425.00

Special Sale Price 2 for $790.00

Siemens FDD100-8D2 single sided, double density

MSF-201120 6 mo warranty $385.00

Special sale prie'e 2 for $750.00

Real Double-Sided Drives

8" Double-Sided Double-Density Sale

it-********************************

* Shugart SA-851R double-sided, double-density *

* only $625.00 ea 2 for $1190.00 *

a********************************

MFE M701 8" double-sided, double-density drives only $525 ea 2 for $1040.00

Qume Data Track 8 double-sided, double-density drives only $575.00 2 for $1100.00

Printers

CENTRONICS 737-1

i) x N dot matrix, letter quality, proportional spacing

PRM-15737 Parallel...' $795.00

With interface for Apple $895.00

MX-80 - Epson

132 column. 9 x 9 dot matrix, multiple fonts

PRM-27080 Save $100.00 $545.00

Interface for Apple $110.00

SPINWRITER - NEC

65 cps, bi-directional, letter quality printer with deluxe tractor mechanism, both parallel and serial interfaces onboard. 16K buffer, ribbon, print thimble, graphics, micro space justification, data cable, and self test'diagnostic ROM.

PRD-55511 without 16K buffer ... $2795.00 PRD-55512 with 16K buffer $2895.00

S-100 Systems

S-100 SYSTEM - Calif Computer Sys

Complete S-100 system including 12 slot mainframe. -I MHz Z-80 CPU. 64K RAM memory, double density dish controller, RS-2D2 cable, 8" & 5'/," disk drive cables, Cl'/M 2.2. manuals, auto boot ROM. completely assembled & tested.

2210A Integrated & tested $1995.00

2210B Not integrated $1795.00

S-100 Memory

64K RAM - Calif Computer Sys

4 MHz bank port / bank byte selectable, extended addressing. 16K bank selectable, PHANTOM line allows memory overlay, 8080 / Z-80 front panel compatible. MEM-64565A A&T $449.95

MEMORY BANK - Jade

/ MHz. IEEE S-100. hank selectable. ,S or 16 bit

MEM-99730B Hare board $55.00

MEM-99730K Kit. no RAM $219.95

MEM-16730K 16Kkit $249.95

MEM-32731K S2K kit $289.95

MEM-48732K 18K kit $324.95

MEM-64733K 64K kit $359.95

Assembled & tested add $50.00

EXPANDORAM USD Systems

I Mlh RAM hoard expandable from IKK to 15KK

MKM-16630K 16Kkit $275.95

MEM-32631K H2K kit $295.95

MEM-48632K 18K kit $315.95

MKM-64633K 64K kit $335.95

Assembled & tested add $50.00

32K STATIC RAM - Jade

■> or I Mil; expandable sialic HAM hoard uses 211 il/s

MEM-16I51K IKK-l Mite kit $169.95

MKM-32151 K T2K I Mite kit $299.95

Assembled & tested add $50.00

16K STATIC RAM - Cal Comp Sys

2 or 4 MHz 16K static RAM board, IEEE S-100, bank selectable. Phantom capability, addressable in 4K blocks MEM-16160A 16K 2 MHz A&T ... $286.95 MEM-16162A 16K 4 MHz A & T ... $289.95 MEM-16160B Bare board $50.00

PB-1 - S.S.M.

2708, 2716 EPROM board with built-in programmer

MEM-99510K Kit $154.95

MEM-99510A A&T $229.95

PROM-100 - SD Systems

271)8, 2716, 27112, 2758, & 2516 EPROM programmer

MEM-99520K Kit $219.95

MEM-99520A Jade A&T $269.95

S-100 Video

VB-3 - S.S.M.

80 characters x 21 lines expandable to 80 X 48 for a full page of text, upper & lowercase, 25S user defined symbols, WQx 192 graphics matrix, memory mapped, has key board inpu t.

IOV-1095K 4 MHz kit $375.00

IOV-1095A ■/ MHz A&T $450.00

IOV-1096K HO x 48 upgrade. $39.95

VIDEO BOARD - Jade

(vt characters x Ifi lines, 7 x 9 dot matrix, full upper lower case ASCII character set. numbers, symbols, and greek letters, normal .'reverse blinking video. S-100.

IOV-1050K Kit $99.95

IOV-1050A A&T $125.00

IOV-1050B Bare board $19.95

S-100 CPU

2810 Z-80* CPU - Cal Comp Sys

2, 1 MHz Z-80A* CPU with RS-2:i2Cserial 1 Oport and onboard MOSS 2.2 monitor PROM, front panel compatible. CPU-30400A A&T $269.95

THE BIG Z* - Jade

2 or 4 MHz switchable Z-80" CPU with serial 1 O. accomodates 2708, 2716, or 2732 EPROM. baud rales from 75 to 9600

CPU-30201K Kit $145.00

CPU-30201A A&T $199.00

CPU-30200B Bare board $35.00

CB-2 Z-80 CPU - S.S.M.

2 or 4 MHz Z-80 CPU board with provision for up to 8Kof ROM or 4K of RAM on board, extended addressing. IEEE S-100, front panel compatible. CPU-30300A A&T $229.95

SBC-200 - SD Systems

•; MHz Z-80* CPU with serial & parallel 1 Oports, up to 8K of on-board PROM, software programmable baud rate generator. 1K of on-board RAM. Z-80 CTC.

CPC-30200K Kit $339.95

CPC-30200A Jade A&T $399.95

S-100 Disk Controller

DOUBLE DENSITY - Cal Comp Sys

B'/i" and 8" disk controller, single or double density, with on-board boot loader ROM, and free CP M 2.2* and manual set. IOD-1300A A&T $369.95

DOUBLE-D - Jade

Dou ble density controller with the inside track, on-board Z80A*, printer port, IEEE S-100, can function on an interrupt driven buss

IOD-1200K Kit $299.95

IOD-1200A 8" A&T $389.95

IOD-1205A 5>A" A & T $389.95

IOD-1200B Bare board $65.00

VERSAFLOPPY II - SD Systems

Neic double density controller for both 8" & 5' "

IOD-1160K Kit.'. $379.95

IOD-1160A Jade A&T $439.95

Motherboards

ISO-BUS - Jade

Silent, simple, and on sale - a better motherboard

6 Slot (5VS" x 8V»")

MBS-061B Bare board $19.95

MBS-061K Kit $39.95

MBS-061A A&T $49.95

12 Slot (9"i" x 8%")

MBS-121B Bare board $29.95

MBS-121K Kit $69.95

MBS-121A A&T $89.95

18 Slot (H'/' x 8V)

MBS-181B Bare board $49.95

MBS-181K Kit $99.95

MBS-181A A&T $139.95

Card Cages

S-100 CARD CAGE - Jade

Metal cage with card guides & fan mounting ENX-106001 Six slot $29.95

S-100 CARD CAGE - Vector

/.'/" rack mimntahlv. adjustable, hold* 21 cards

VCT-CCKIOO Anodizvd A! $49.95

SALE SALE SALE

S-100 I/O

S.P.I.C. - Jade

Our new I, () card with 2 SIO's, 4 CTC's. and 1 PIO IOI-1045K 2 CTC's, 1 SIO, 1 PIO .. $199.00

IOI-1045A A&T $259.00

IOI-1046K 4 CTC's, 2 SIO's, 1 PIO $259.00

IOI-I046A A&T $319.00

IOI-1045B Bare board w/manual ...$59.95 IOI-1045D Manual only $20.00

1/0-4 - S.S.M.

2 serial I/O ports plus 2 parallel I/O ports

IOI-1010K Kit $179.95

IOI-1010A A&T $249.95

IOI-1010B Bare board $35.00

TERMINATOR - S.S.M.

Active terminator for S-100 bus

TSX-195K Kit $29.95

TSX-195A A&T $54.95

TSX-195B Bare board $22.95

S-100 EXTENDER - Cal Comp Sys

Put those problem boards (the ones you probably bought from one of our competitors) within easy reach. TSX-160A A&T $37.95

S-100 PROTO BOARD - Jade

Universal design, plated thru holes, gold fingers TSX-140B Bare board $24.95

TERMINATOR & EXTENDER - CCS.

Can he used as both an S-100 extender and terminator TSX-150K Kit $43.95

Diskettes

DISKETTES - Jade

Bargain prices on magnificent magnetic media

5'/i" single sided, single density, box of 10

MMD-5110103 Soft sector $27.95

MMD-5111003 lOsector $27.95

MMD-5111603 Kisector $27.95

5'/i" douhle sided, double density, box of 10 MMD-5220103 Soft sector $39.95

8" single sided, single density, box of 10 MMD-8110103 Soft sector $33.95

8" single sided, double density, box of 10 MMD-8120103 Soft sector $39.95

8" double sided, double density, box of 10 MMD-8220103 Soft sector $49.95

Video Monitors

9" B & W MONITOR - A.P.F.

High quality, high resolution video monitor VDM-750900 9" monitor $159.95

13" COLOR MONITOR - Zenith

The hi res color you've been promising yourself VDC-201301 $449.00

12" GREEN SCREEN - NEC

20 MHz. PHI phosphor video monitor with audio, exceptionally high resolution - A fantastic monitor at a very reasonable price VDM-651200 12" monitor $259.95

Mainframes

MAINFRAME - Cal Comp Sys

12 slot 3-100 mainframe with 20 amp power supply

ENC-l 12105 Kit $359.95

ENC-112106 A & T $419.95

DISK MAINFRAME - NNC

Holds 2 8" drives and an 8 slot S-100 system. Attractive metal cabinet with 8 slot motherboard, power supply, fan, key switch, and other professional features ENS-112320 with 30 amp p.s $699.95

Accessories-Apple/TRS-80

16K MEMORY UPGRADE

Add 16K of RAM to your TRS-80. Apple, or Exidy in just minutes. We've sold thousands of these 16K RAM upgrades which include the appropriate memory chips (as specified by the manufacturer), all necessary jumper blocks, fool-proof instructions, and our 1 year guarantee.

MEX-16100K TRS-80 kit $29.00

MEX-16101K Apple kit $29.00

MEX- 16102K Exidy kit $29.00

DISK DRIVE for APPLE

,5'/;" disk drive with controller for your Apple MSM-12310C with controller ...... $499.95

MSM-123101 w/out controller $375.00

DISK DRIVES for TRS-80

23% more storage, tf times faster, 40 track with free patch, 120 day warranty, includes case, power supply, and cable MSM-12410C Save $125.00 !!! ' $299.95

DOS 3.3 UPGRADE - Apple

Upgrade your old DOS to the improved 3.11 IOD-2233A Complete kit $64.95

APPLE STICK - Micromate

Joy stick with pots for Apple 11 SYA-1510A A&T $35.95

Z-80* CARD for APPLE

Z-HO" CPU card with CP/M 2.2 for your Apple CPX-30800A A&T $279.95

AIO - S.S.M.

Parallel & serial interface for your Apple

IOI-2050K Kit $155.95

IOI-2050A A&T $194.95

PRINTER INTERFACE - CCS.

Centronics type I/O card w/ firmware IOI-2041A A&T $99.95

APPLE CLOCK - Cal Comp Sys

Real time clock w battery back-up IOK-2100A A&T $109.95

Modems

•••••••••••••••••••••••■a-*

LEX-11 MODEM - Lexicon

A real star.' 300 baud, answer/originate, HS 232C

IOM-5511A Best buy!!! $128.00

• ••••••••••••••••-A-*******

NOVATION CAT

800 baud, answer'originate acoustic modem IOM-5200A 7 year warranty $179.00

D-CAT .100 baud, direct connect modem IOM-5201A Special sale price $189.00

AUTO-CAT Auto answer'origiate. direct connect IOM-5230A Special sale price $239.95

MICROMODEM - D.C. Hayes

Auto answer dial modem card for Apple or S-100

IOM-2010A Apple modem $349.95

IOM-1100A S-100 modem $375.00

MICRONET MODEM - Micromate

Direct connect with extra features - a best buy IOM-2020A Best Apple modem .... $275.00

• Z-80, Z-80A, and the letter Z are recognized trademarks of Zilnf*. Inf. *CP/M is a registered trademark of Digital Research Corp. *CBASIC is a trademark of Compiler Systems, Inc.

Circle 351 on Inquiry card.

Single Board Computers

AIM-65 - Rockwell

6502 computer with alphanumeric display, printer, & keyboard, and complete instructional manuals

CPK-50165 IK AIM $374.95

CPK-50465 4K AIM $449.95

SFK-74600008E 8K BASIC ROM ...$99.95 SFK-64600004E 4K assembler ROM $84.95

PSX-030A Power supply $64.95

ENX-000002 Enclosure $49.95

4K AIM, 8K BASIC, power supply, & enclosure Special package price $625.00

Z-80* STARTER KIT - SD Systems

Complete Z-80" computer with RAM. ROM. I/O. display, keyboard, manual, and kluge area.

CPS-30010K Kit $369.95

CPS-30010A Jade A&T $459.95

MICROPROCESSORS

Z-80 10.95

Z-80A 12.95

8502 11.50

6800 11.95

B802 17.95

(5809 39.95

8035 24.00

8080A 6.59

8085 15.95

8748 59.95

Z-80 SUPPORT

3881 PIO 9.50

3881-4 PKUMHz 14.50

3882 CTC 9.50

3882-4 CTC-I MHz 14.95

3883 SIO 29.50

3884 SIO 49.50

BAUD RATK GENERATORS

MC14411 10.00

1.843 MHz xtal 4.95

UARTS

AY5-10I3A 5.25

AY3-1014A 8.25

TR1602B 5.25

TMS6011 5.95

IM6402 9.00

6800 SUPTORT

6821P 5.95

6828P 11.95

6H34P 22.50

6840P 18.75

6850P 4.80

6852P 5.79

68751. 7.40

084H8P 25.00

PROMS

2708 -toOns 6.25

10 for $4.90 ea

2716 12f,v 11.95

2716 ,5i> 11.95

10 for $8.90 ea

2532 .5i> 39.95

2T.ti St) 39.95

2758 So 9.95

RAMS

21UK2 2 MHz 1.25

21U12A / MHz 1.50

2I14L 2 MHz 3.75

2114LA -I MHz 3.95

4116 4.25

4164 MK.xl 59.95

5257 2 MHz 675

5257A / MHz 7.25

MK4118 IR95

SUPPORT DEVICES

8212

8214

8216

8224

8224-:

8226

8228

8238

824.3

8250

8251

8253

8255

8257

8259

8275

8279

3.25 4.65 2.95 3.25 . 5.75 3.85 4.95

4.95

,. aoo

14.95 6.50 17.95 6.50 19.95 17.95 49.95 15.95

PLACE ORDERS TOLL FREE

Continental U.S. Inside California 800-421-5500 800-262-1710

For Technical Inquiries or Customer Service call

213-973-7707

Computer Products

4901 W. Rosecrans, Hawthorne, Ca 90250 TERMS OF SALE: Cash, checks, credit cards, or Purchase Orders from qualified firms and institutions. Minimum order $15.00. California residents add S% tax. Minimum shipping and handling charge $H.0fl Pricing and availability subject to change without notice.

SN74O0N SN7401N SN7402N SN7403N SN7WN SN7405N SN74Q6N SN7407N SN7408N SN74Q9N SN7410N SN7411N SN7412N SN7413N SN7414N SN7416N SN7417N SN7420N SN7421N SN7422N 5N7423N SN742SN SN7426N SN7427N SN7428N SN7430N SN7432N SN7437N SN7438N SN7439N SN7440N SN7441N SN7442N SN7443N SN7444N SN7445N SN7446N SN7447N SN7448N SN7450N SN74S1N SN7453N SN7454N SN7459A 5N7460N SN7470N

74LS0O 74LS01 74LS02 74LSQ3 74LS04 74LSOS 74LS08 74LS09 74LS10 74LS11 74LS12 74LS13 74LS14 74LS15 74LS20 74LS21 74LS22 74LS26 74LS27 74LS28 74LS30 74LS32 74L533 74LS37 74LS33 74LS40 74LS42 74LS47 74LS48 74LS49 74LS51 74LS54 74L555 74LS73 74LS74 74LS75 74LS76 74L578 74LS83 74LS85 74 L 586 74LS90

74S00 74S02 74S03 74S04 74S05 74508 74S09 74S10 74S1I 74S15 74S20 74S22 74S30 74S32 74S40 '4551 74S64 74565 74S74 74S86 74S112 745113 74 SI 14 * LIM

7400

SN7472N

SN7473N

SN7474N

SN7475N

SN7476N

SN7479N

SN7480N

SN7482N

SN7483N

SN7485N

SN74B6N

SN7489N

SN7490N

SN7491N

SN7492N

SN7493N

SN7494N

SN749SN

SN7496N

SN7497N

5N74100N

5N74107N

SN74109N

SN74116N

SN74121N

SN74122N

SN74123N

SN74125N

5N74126N

SN74132N

SN74136N

SN74141N

SN74142N

SN74143N

SN74144N

SN74I45N

SN74147N

5N7414BN

SN74150N

SN74151N

SN74152N

SN74153N

5N74154N

5N741S5N

3.2S 3.49 3.49

74LS

74LS92 74LS93 74LS95 74LS96 74LS107 74LS109 74 LSI 12 74LS113 74LS114 74LS122 74LS123 74L5125 74LS126 74LS132 74LS133 74LS136 74LS138 74LS139 74LS151 74LS153 74L5154 74LS155 74LS156 74LS157 74LS158 74LS160 74LS161 74LS162 74LS163 74LS164 74LS165 74LS16B 74LS169 74LS170 74L5173 74LS174 74LS175 74LS181 74LS190 74LS191

74S

74S133 74S134 74S135 74S136 74S13S 74 S139 74 S140 745151 74S153 745157 745158 74S174 745175 74S188 74S194 74S195 745196 745240 745241 74S242 74S243 'TED AVAILABILITY

74LS192 74LS193 74LS194 74LS195 74LS197 74LS221 74LS240 74LS241 74LS242 74LS243 74LS244 74LS245 74LS247 74LS248 74LS249 74LS2S1 74LS253 74 L 5257 74LS258 74LS260 74LS2S6 74LS273 74LS279 74LS283 74 L 5290 74L5293 74LS29B 74LS352 74LS3S3 74LS36S 74LS366 74LS3G7 74LS368 74LS373 74LS374 74LS375 74LS386 74LS393 74LS399 74LS67Q 81LS95 81LS97

74S244

745251

74S253

74S257

74S258

745260

745280

74S287*

74S288*

745373

745374

745387*

74S471*

74S472*

745473*

74S474*

745475*

74SS70*

74SS71*

745572*

74S573*

74S940

745941

ESE PR

1.15 1.15 1.15

1.95

1.95 1.95

2.49 2.49

2.49

5.95 19.95 19.95 19.95 21.95 21.95

7.95

7.95 19.95 19.95

3.15

CA3013H CA3023H

CA3039H CA3046N CA3059N CA3060N CA3080H

CA-LINEAR

CA3081N CA3082N CA3Q83N CA3086N

2.00 2.00 1.60

CA3089N CA3096N CA3I30H CA3140H CA3160H CA3401N CA3600N

CD4000 CO4001 CD4002 CD40O6 CD4007 CD4009 CD4010 CD4011 CD4012 CO4013 CD4014 CD4015 CD4016 CD4017 CD4018 CD4019 CD4020 C D402I CD4022 CD4023 CD4024 CD4025 CD4026 CD4027 CD4028 CO4029 CD4030 CD4035 CD4040

CD-CMOS

CD4041 CD4042 CO4043 CD4044 CD4046 CD4047 CD4048 CD4049 CD4050 CD4051 CD4052 CD4053 CD4056 CD4059 CD4060 CD4066 CO4068 CD4069 CD4070 CD4071 CD4072 CD4073 CD4075 CD4076 CD4078 CD4081

CD4082

CD4093

CD4098

CD4506

CD4507

CD4508

CD4510

CD4S11

CD4514

CD4515

CD4516

CD4518

CD4519

C D4S20

CD4526

CD4528

CD4529

CD4543

CD4562

CD4566

CD4S83

CD4723

C D4724

MC14409

MC14410

MC14411

MC14412

MC 14419

M C14433

1.79 1.79 1.95 2.79 11.95 2.79

1,95 14.95 14.95 14.95 11.95

4.9S 13.95

LITRONIX DISPLAY SALE

MULTI-DIGIT R

DL-4500 DL-4507 DL-4520A DL-4120A

LECTOR

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LECTOIl ARRAYS

OLJ3MIII.ni

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DISCRETE LEDS

XC556R .200" red

XC5S6G .200" green

XC556Y .200" yellow

XC556C .200" clear

XC22R .200" red

XC22G .200" green

XC22Y ,200" yellow

MV10B .170" red

S/Jl 4/J1 4/S1 4/S1 S/Sl 4/$l 4/$l 4/J1

MV50 .085" red

XC209R .125" red

XC209G .125" green

XC209Y .125" yellow

XC526R .185" red

XC526G .185" green

XC526Y .185" yellow

XC526C .185" clear

6/$l 5/$l 4/11 4/S1 5/$l 4/(1 4/$l 4/$l

XC111R .190" red 5/(1

XC111G .190" green 4/S1

XC111Y ,190" yellow 4/$l

XC111C .190" clear 4/$l

^^Tc'BM RED LEO METAL

RL-2 . .$.39ea.or3/$1.00

CA. - Common Anode DISPLAY LEDS CC' - Common Cathode

Typa

MAN 1 MAN 2 MAN 3 MAN 52 MAN 54 MAN 71 MAN 72 MAN 74 MAN 82 MAN 84 MAN 3620 MAN 3630 MAN 3540 MAN 4610 MAN 6610 MAN 6630 MAN 6640 MAN 6650 MAN 6660 MAN 6710 MAN 6750 MAN 6780 DLO304 DLO307 DLG500

Polarity C.A.—red

5x7 D.M.—red

CC—red

C.A.—green C.C.—green C.A.—red C.A.—red C.C—red C.A.—yellow C.C—yellow CA.—orange CA.—orange ± 1 C.C—orange C.A.—orange C.A.—orange—DD . C.A.—orange z 1 C.C—orange—OD . C.C—orange ± 1 C.A.—orange C.A.—red—DD C.C—red ± 1 CC—red C.C—orange CA.—orange C.C—green

Type

DLG507

DL704

DL707

DL728

DL741

OL746

DL747

DL750

DL0847

OLO850

DL33B

FND358

FND359

FND503

FND507

HDSP-3401

H DSP-3403

5032-7751

5082-7760

5082-7300

5082-7302

5082-7304

4N2B

LIT-1

MOC3010

Ht

.500 .300

Polarity

C.A.—green

C.C—red

CA.—red

C.C—red

C.A.—red

C.A.—red ± 1

C.A.—red

C.C—red

CA.—orange

C.C—orange

C.C—red

C.C. ± 1

C.C.

C.C. (FNDSOO)

CA. (FND510)

C.A.—red

C.C—red

C.A.,R.H.D.—red .430

C.C.R.H.D.—red .430

4x7 591. dig. RHD .600

4x7sgl.dlg. LHD .600

Ouernge. char. (±1) .600

Photo XslstorOpto-lsa

Photo Xslstor Opto-lsc

Optically Isol.TrlacDrl'

.800

22.00 22.00 19.95

POTENTIOMETERS ^

$2.95 each

2 Watt SO 7 0°C ± 10% 7/8" Slotted Shaft Linear Tepar Meets Mil-R-94

RV4NAY SD- 102A RV4NAY SD - 502A RV4NAY SD - 103A RV4NAY SD - 2S3A RV4NAY 5D - 503A RV4NAY SD - 104A RV4NAY 5D • 105A

IK 5K

10K 25 K

50 K 100K lMeg

LOW PROFILE (TIN) SOCKETS

8 pin LP

14 pin LP 16 pin LP 18 Pin LP 20 pin LP 22 pin LP 24 pin LP 28 pin LP 36 pin LP 40 pin LP

SOLDERTAIL (GOLD) STANDARD

24 pin SG 28 pin SG 36 Pin SG 40 pin SG

$1.35 each

Part No.

830P- 50ohrr

B30P-100ohrr

830P-600ohrr

B30P-1K

830P-2K

830P- 5K 830P-10K 830P-20K

630P-50K

830P-100K 830P-200K 830P-500K B3aP-lMeg

SOLDERTAIL STANDARD (TIN)

14 pin ST 16 pin ST 18 pin ST 24 pin ST 28 pin ST 36 pin ST 40 pin ST

WIRE WRAP SOCKETS (GOLD) LEVEL #3

8 Pin WW 10 pin WW 14 pin WW 16 pin WW 18 pin WW 20 pin WW 22 pin WW 24 pin WW 28 pin WW 36 pin WW 40 pin WW

1.23 1.14

1.38

1/4 WATT RESISTOR ASSORTMENTS -5%

ASST

T

5ea.

10 Ohn 27 Ohn

i 12 Ohm i 33 Ohm

15 Ohrr 39 Ohrr

18 Ohm 47 Ohm

22 Ohm 56 Ohm

50 pes.

$1.95

ASST

2

5ea.

68 Ohn 180 Ohn

i 82 Ohm 220 Ohm

100 Ohnr

270 Ohrr

120 Ohm 330 Ohm

150 Ohm 390 Ohm

50 pes.

$1.95

ASST

3

5 en.

470 Ohn 1.2K

560 Ohm l.SK

680 Ohrr 1.8K

820 Ohm 2.2K

IK 2.7K

50 pes.

$1.95

ASST

4

5ea.

3.3K 8.2K

3.9 K

10K

4.7K

12K

5.6K

15K

6.BK

1SK

50 pes.

$1.95

ASST

5

5ea.

22 K 56K

27K 68K

33 K B2K

39K 100K

47K 120K

50 pes.

$1.95

ASST

6

5aa.

1S0K 390 K

180 K 470 K

220K 560 K

270 K 680 K

330 K 820K

50 pes.

$1.95

ASST

7

5fl3.

1M 2.7M

1.2M 3.3M

1.5M 3.9M

1.8M 4.7M

2.2M 5.6M

50pcs.

$1.95

ASST. 8R

Includes Resistor Assts. 1-7 (350 pes.)

$10.95 ea.

S10.00 Min. Order - U.S. Funds Only Calif. Residents Add 6% Sales Tax Postage —Add 5% plus51 Insurance

rcAT&ss*

J a EEHH33H11

Spec Sheets - 25rf

Send 41rf Postege for your

FREE 19B1 JAMECO CATALOG

PHONE

ORDERS

WELCOME

(415) 592-8097

MAIL ORDER ELECTRONICS - WORLDWIDE 1355 SHOREWAY ROAD, BELMONT, CA 94002 PRICES SUBJECT TO CHANGE

-\

Part No. Function Price

7045IPI CMOS Precision Timor 14.95

7045EV/KH* Stopwatch Chip, XTL 22.95

7106CPL 3ft Digit A/D (LCD Drive) 16.95

7106EV/KU* IC. Circuit Board, Display 34.95

7107CPL 3V; Digit A/D (LED Drive) 15.95

7107EV/KU* IC, Circuit Board, Display 28.95

7116CPL 3>fc Digit A/D LCD DIs. HLD. 18.95

7117CPL 2Vi Digit A/D LED DIs. HLD. 17.95

7201IDR Low Battery Volt Indicator 2.2S

7205IPG CMOS LED Stopwatch/Timer 12.95

7205EV/Klt* Stopwatch Chip, XTL 19.95

7206CJPE Tone Generator 5.1S

7206CEV/KU* Tone Generator Chip, XTL 9.95

7207AIPD Oscillator Controller 6.50

7207AEV/KU* Preq. Counter Chip, XTL 11.10

7208IPI Seven Decade Counter 17.95

7209IPA Clock Generator 3.95

7215IPG 4 Func. CMOS Stopwatch CKT 13.95

7215EV/KU* 4 Func. Stopwatch Chip, XTL 19.95

7216AIJI 8-Diglt Univ. Counter CA. 32.00

7216CIJI 8-Dlglt Freq. Counter C.A. 26.95

7216DIPI B-Dlglt Freq. Counter C.C. 21.95

7217IJI 4-Diglt LED Up/Down Counter 12.95

7218CIJI 8-Diglt Univ. LED Drive 10.95

7224IPL LCD4Va Digit Up Counter DRI 11.25

7226AIJL 8-Dlglt Univ. Counter 31.95

7226AEV/KU" 5 Function Counter Chip, XTL 74.95

7240IJE CMOS Bin Prog. Timer/Counter 4.95

7242IJA CMOS Dlv|de-by-256 RC Timer 2.05

7250IJE CMOS BCD Prog. Timer/Counter 6.00

7260IJE CMOS BCD Prog. Timer/Counter 5.25

7555IPA CMOS 555 Timer (B pin) 1.45

7556IPD CMOS 556 Timer (14 pin) 2.20

761IBCPA CMOS Op Amp Comparator 5MV 2.25

7612BCPA CMOS Op Amp Ext. Cmvr. SMV 2.95

7621BCPA CMOS Dual Op Amp Comp. 5MV 3.95

7631CCPE CMOS Trl Op Amp Comp. 10MV 5.35

7641CCPD CMOS Quad Op Amp Comp. 10MV 7.50

7642CCPD CMOS Quad Op Amp Comp. 10MV 7.50

7660CPA Voltage Converter 2.95

B069CCQ 50ppm Band—GAP Volt Ret. Diode 2.50

8211CPA Volt Ref/lndlcator 2.50

8212CPA Volt Ref/lndlcator 2.50 * INTERSIL'S EVALUATION KITS

74C00 74C02 74C04 74 COB 74 C10 74C14 74C20 74C30 74C42 74C48 74C73 74C74 74C6S 74C86 74C89 74C90 74C93 74C95

1.59

74C

74C195 74C221

74C240

74 C106

.75

74C244

74C107

1.89

74C373

74C151

2.95

74C374

74C154

3.95

74C901

74C157

2.25

74C903

74 C160

1.69

74C911

74 C161

1.60

74C912

74 C162

1.49

74C915

74C163

1.69

74C917

74C164

1.59

74C922

74 C173

1.39

74C923

74 C174

1.39

74C925

74C175

1.39

74C926

74C192

1.69

80C95

74 C193

1.69

80C97

1.59

1.95 2.25 2.25

2.49 2.59

10.95 5.49

5.75

.79

LH0002CN 6.85

LM10CLH 4.50

LM11CLH 4.75

LH0070-OH 6.05

TL071CP .79

TL072CP 1.39

TL074CN 2.49

LH0082CD 35.80

TL082CP 1.19

TL0B4CN 2.19

LH0094CD 36.80

LM300H .99

LM301CN .35

LM302H

LM304H

LM305H

LM307CN

LM308CN

LM309H

LM309K

LM310CN

LM311H

LM312H

LM317MP

LM317T

LM317K

LM31BCN

LM319N

LM320K-5

LM320K-12 1.35

LM320K-15 1.35

LM320T-5 1.25

LM320T-12

LM320T-15

LM323K-5

LM324N

LM329DZ

LM331N

LM334Z

LM33SZ

LM336Z

LM337T

LM337MP

LM338K

LM339N .99

LM340K-5 1.35

LM340K-12 1.35

LM340K-15 1.35

1.95

1.00

1.15 1.75 3.95

1.95

5.95

3.95

6.95

LINEAR

LM340T-5 1.25

LM340T-12 1.25

LM340T-15 1.25

LM341P-5 .75

LM341P-12 .75

LM341P-I5 .75

LM342P-5 .69

LM342P-12 .69

LM342P-15 .69

LM348N

LM350K

LF351N

LF353N

LF355N

LF356N

LM358N

LM359N

LM370N

LM373N

LM377N

LM380N

LM381N

LM382N

LM3B4N

LM3S6N-3

LM3B7N

LM389N

LM392N

LF398N

LM399H

TL494CN

TL496CP

NE510A

NE529A

NE531H

NE536H

NE540H

NE544N

NE550A

NE555V

LM556N

NE564N

LM565N

LM566CN

LM567V

S.7S

4.00

6,00 4.95 3.95 6.00 6.00

4.95

29

2.75

NE570N

LM702H

LM703CN

LM709N

LM710N

LM7UN

LM723N .69

LM733N 1.00

LM739N 1.19

LM741CN .35

MC1741SCG 3.00

LM747N .79

LM748IN .59

LM1014N

LM1310N

LM1458CN

LM1488N

LM1489N

LM1496N

LM1556 V

LM1800N

LM1877N-9

LM18B9N

LM1B96N

LM2002T

LM2877P

LM2B78P

LM2896P-1

LM3189N

LM3900N

LM3905CN

LM3909N

LM3914N

LM3915N

LM3916N

RC4136N

RC4151NB

RC4194TK

RC4195TK

KB4428

KB4429

LM45O0A

ICL8038B

LM13080N

LM13600N

75138N

75450N

75451CN

4.95

CAPACITOR CORNER

50 VOLT CERAMIC DISC CAPACITORS

Value 1-9 10-99 100+ Value 1-9 10-99 100+

10 pf .08 .06 .05 .OOluF .08 .06 .05

22 pf .08 .06 .05 .0047uF .08 .06 .05

47 pf .08 .06 .05 .Oliii .08 .06 .05

100 pf .08 .06 .05 .022mF .09 .07 .06

220 pf -08 .06 .05 -047uF .09 .07 .06

470 pf .OB ,06 .05 .UiF .15 .12 .10

100 VOLT MYLAR FILM CAPACITORS

.OOlmt .12 .10 .07 I .022m f .13 .11 .08

,0O22mf .12 .10 .07 .047mf .21 .17 .13

.0O47mf .12 .10 .07 .lmf .27 .23 .17

.Olrnf .12 .10 .07 I .22mf .33 .27 .22

+20% DIPPED TANTALUMS (Solid) CAPACITORS

-1/35V . 15/35V -22/35V .33/35V .47/35V .68/35V 1.0/35V

.39 .34 .39 .34

.37

.29

.41 .51

.53 .47 .37

.63 .56 .45

.79 .69 .55

1.39 1.25 .95

.79 .69 .55 MINI. ALUMINUM ELECTROLYTIC CAPACITORS

1.5/35V 2.2/3SV

3.3/25V 4.7/25V 6.8/25V 15/25V 22/6V

-47/50V

1.0/50V

3.3/50V

4.7/2SV

10/25V

10/50V

22/25V

22/50V

47/25V

47/50V

100/2SV

100/50V

220/25V

22O/50V

470/25V

1000/1SV

220O/16V

Axial Lead

.19 .16 .12 .17 .15 .11

.79 .69 .61

.47/2SV .47/50V 1.0/16V 1.0/25V 1.0/S0V 4.7/16V 4.7/25V 4.7/50V 10/16V 10/25V 10/50V 47/SOV 100/16 V 100/25V 100/SOV 220/16V 470/25V

Radial Lead

.16 .14 .13

.25 .21 .19

398 BYTE April 1981

sSSduoterClock Modules

12VDC

AUTOMOTIVE/

INSTRUMENT

CLOCK

APPLICATIONS:

• In-dash autoclocks

• A*tor-rnarket auto/ RV clocks

• Aircraft-marine elks.

• 12VDC oper. Instru.

• Portable/battery powered instrumnts.

Features: Bright 0.3" green display. Internal crystal timebase. i0.5 sec/day accur. Auto.display brightness control logic. Display color filterable to blue, blue-green, green & yellow. Complete—just add switches and lens.

MA1003 Module $16.95

MAI 023 .7" Low Cost Digital LED Clock Moduli 8.95 MA1026 .7" Dig. LED Alarm Clock/Thermometer 18.95 MAS036 .3" Low Colt Digital LED Clock/Timer 6.95 MA1002 .5" LED Display Dig. Clock & Xlormer 9.95

2 National Semiconductor

RAM SALE

MM5290N-4 (MK4116/UPD416) . . $4.95 each

16K DYNAMIC RAM (250NS)

(8 EACH $39.95) (100 EACH $450.00/lot)

MM5290J-2 (MK4116/UPD416) . . $6.95 each

16K DYNAMIC RAM (150NS)

(8 EACH $49.95) (100 EACH S550.00/lotl

MM5298J-3A $3.25 each

8K DYNAMIC RAM [LOW HALF OF MM5290J) 200NS (8 EACH $23.95) (100 EACH $250,00/Jot)

MM2114-3 $5.95 each

4K STATIC RAM (300NS)

(8 EACH $43.95) (100 EACH S450.00/lot)

MM2114L-3 $6.25 each

4K STATIC RAM (LOW POWER 300NS) (8 EACH $44.95) (100 EACH S475.00/lot)

EPROM Erasing Lamp

• Erases 2708. 2716, 1702A, 5203Q, 5204Q, ate.

• Erases up to 4 chips within 20 minutes.

• Maintains constant exposure distance of ona inch.

• Special conductive foam liner eliminates static build-up.

• Built-in safety lock to prevent UV exposure.

• Compact - only 7-5/8" x 2-7/8" X 2"

■ Complete with holding tray for 4 chips.

UVS-11E.......... ..$79.95

Jumbo 6-Digit Clock Kit

• Four ,630"ht. end two .300"ht. common anode displays

• Uses MM5314 clock chip

• Switches for hours, minutes and hold functions

• Hours easily viewable to 30 feet

• Simulated walnut case

• 115VAC operation

• 12 or 24 hour operation

• Includes all components, case and wall transformer

• Size: 6M"x 3-1/8" X 1K"

JE747 $29.95

6-Digit Clock Kit

• Bright .300 ht. comm. ca' ode display

• Uses MM5314 clock chip

. for hours,

linutes

and hold modes

• Hrs. easily viewable to 20 ft. ■ Simulated walnut case

• 115 VAC operation

• 12 or 24 hr. operation

• Incl. all components, case & wall transformer

• Size: &V<" x 3-1/8" x 1M"

JE701 $19.95

m^ JE215 Adjustable ISpr Dual Power Supply

General Description: The JE215 is a Dual Power Supply with independent adjustable positive and negative output voltages. A separate adjustment for each of the supplies providesthe user unlimited applications for IC current voltage requirements. The supply can also be used as a general all-purpose variable power

supply.

FEATURES:

■ Adjustable regulated power supplies, pos. and nog. 1.2VDC lo 15VDC.

• Power Output (each supply): SVDC !s> 500mA, 10VDC@ 750mA, 12VDC@ 500mA. and 15VDC@ 175mA.

• Two, 3-terminal adj. IC regulators with thermal overload protection.

• Heat sink regulator cooling

• LEO "on" indicator

• Printed Board Construction

• 120VAC input

• Size: 3-1/2"w x 5-l/16"L x 2"H

JE215Adj. Dual PowerSupply Kit (asshown). . $24.95

(Picture not shown but similar in construction to above)

JE200 Reg. Power Supply Kit (5VDC, lamp) .. $14.95

JE205 Adapter Brd.(to JE200) ±5,-9 & -12V. $12.95

lwJE210Var.Pwr. Sply.Kit, 5-15VDC,to1.5amp. $19.95

MICROPROCESSOR COMPONENTS

INSBOWA

DP1212

DPBU

8080A/8080A SUPPORT DEVICES

CPU

S-BU Insut/Outdut Priority Interrupt Conirol Bl-Diii

OPSHS INS1M3 INSB250 DPS2S1 DP8253 OP8255 OPS257 DPJ259

opaan Dmn

DPB30O DPB303 DPS 304 OPB307 DP830S

But DrUsr Syit«m Contrc

ar/Orli

. I/O IUSART)

■ral i/o (ppi) lontiot Dl Control

ira/Diiol»y intomce

Sytum Timing Elemsnt 8-Blt BI-Olrectlon»l Recalv S-BIt Bl-Oliectlonil Racelv B-BIt BI'Dlcecllonil Raeelv

6800/6800 SUPPORT DEVICES

MC6800 MPU

MCSM'CP MPU wlln ClocK *n0 HAM

MC6BIQAPL l?8xl Slilic RAM

IMccnS]

MCU21

MCS828

MCSUOU

MC68S0

MCM52

MC«60

MC6KZ

MC6M0A

zta (tsoc)

Z&OA (ISO-l)

cdpibot. aso

IOM2901AOC

MC56502 NSB03SN-* NSBOMN-6 NSBWON-6 NS8070N

P808S NSSWO rMSWOOJL

0*MD0i Oigltil MODEM

2400opt r/odulitoi

Quad 3-Slite But. Tr»nj. (MCSTM)

MICROPROCESSOR CHIPS —

MPU : CPU-«-B<t Slice (Com. T« MPU w/ClQCh (65K Bytes MPU-S-BIt [6MHi| CPU -Sgl.ChlD S-BIl (128t» CPU (Z5S eytes RAM) CPU-W Bytes RAM CPU w/BiSIC Micro Interi CPU

CPU-16-Bit MPU—16-6 It

—SHIFT REGISTERS

DuilS-BI! Dynamic DualSO-BH Dynamic Dual 100-Bit Static Dual M-BII Accumulator 256-Bit Dynamic

MM500H MM503H IM50EH

M1402 MM5013

MMM16M 5O0/S12-BH Dyi

MMS034N Octal (0-BII

IM503SN Octal W-B11

(l««A) 1K4-BII Dynar

2S1BN ?SHV

2525 V 252'V

2521V 2529V 2SJ2N

x 12.Bit Stat Dual 133-Qlt St. S12-BU Dynaml 1024. BH Dynam Dual2Si-Blt St. Dual 290-Bit Si.

-DATA ACQUISITION

O-ICN

AFI21-1CJ .FI22-1CJ MJMAH

LMJ14Z

L.MJ35Z

LF3S6N

LFMBN

LM399H

ADC08WLC

DAC0806LC

Temo.Comn. Proc. Rel. (.SDpm/i I 8-Blt A/D Converter (I |_SB) I B-BIt D/A Convenor (0.7B\ Lin.)

DATA

ADCU09CCN AOCMI7CCN DACIMOLCN DAC10MLCN DACIQ20LCN

DACI222l.CN

CD40SIN

AY-S-101J

ACQUISITION (CONTINUED)

a-BIt A/O Converter (1-Ch. Multl.) ! 1-Bll A/D Converter lli-cn. Multl.) it 10-Blt D/AConv. Micro. ComrJ. (0.05%). 13 10-Blt D/A Conv. Micro. Comp. (0.20T.) t 10-Blt D/A Converter (o.OSv. Lin.) !

10-Blt D/A Converter (0.10% Lin.) !

12-BltD/A Converter (0.2OX Lin.) 5

4 Sill

1300m

w Pow

MM 5262 MM 5280/? 10 7 MM5J90J-2(4116) MM529U-1A

c 300m Low Power 16,3M«lDyn»mlcS50n» (nomamarked 16K Dynamic 2S0m 409Gxl Fait TOnt Z46x4 Static

1034x1 Dynamic Fully Oecoaed 2Kxl Dynamic 409£x) Dynamic ISK Dynamic ISOns (UPD415) »K Dyn. 200nt (lower 1ft ol MM5290J)

Static

P ROMS /E P ROM S

Ele PROM

!K

S2S23I74SIB8I 82S12JP*S2W)

2513(2140) 2513(3021) 2S16N MM52MIM

I6K EPROM (-SV, +5V, .12V) I ISK EPROM (Single *5V)

32K EPROM

BK EPROM («S0nsl (Single *5V

2041 PROM

32x8 PROM (Open Collector)

4096 Bipolar PROM

32KB Trl-Stata Bipolar PROM

BK PROM -ROM'S

Clara

ir Gen<

SCP 128x9x7 Alpna. Control CMar. Gen.

-MICROPROCESSOR MANUALS

DSO025CN DS00XCN INSiniN-1 IN526SIN MMM167N MM58174N CO P402N

COP402M\

■ SPECIAL FUNCTION

« Driver (SMZ] Dual MOS Clock Drivel (SMZ) Floppy Disc Controller Communication Chip

Microcontroller with 64-Dlnlt RAM and Direct LED Drive Microcontroller with 64-Dlglt RAM t. Direct LED Drive w/N Bull Int. 32-Sog.VAC Fluor. Driver (20-pln pkg.)

LEPHONE/KEYBOARD CHIPS

Putn Button Telephone Dialer Ropertory Dialer CMOS Clock Generator

74C922 J4C923 MM53190N

Keyooara Encoaer pujU But 96/144- Ko;

f (16 key I) (16 k

/I)

DESIGNERS' SERIES Blank Desk-Top Electronic Enclosures

' High strength epoxy molded ena pieces in mocha brown finish.

1 Sliding rear/bottom panel for service and component accessibility.

1 Top/bottom panels.080 thk alum. Alodine type 1200 finish (gold tint color) for best paint adhesion after modification.

' Vented top and bottom panels for cooling efficiency.

1 Rigid construction provides unlimited applications.

CONSTRUCTION;

ThB "DTE" Blank DeskTop Electronic Enclosures are designed to blend and complement today's modern computer equipment and can be used in both industrial and home. The end pieces are precision molded with an internal slot (all around) to accept both top and bottom panels. The panels are then fastened to V*" thick tabs inside the end pieces to provide maximum rigidity to the enclosure. For ease of equipment servicing, the rear/ bottom panel slides back on slotted tracks while the rest of the enclosure remains intact. Different panel widths may be used while maintaining a common profile outline. The molded end pieces can also be painted to match any panel color scheme.

Enclosure Model No.

Panel Width

PRICE

DTE-8

8.00"

$29.95

DTE-11

10.65"

$32.95

DTE-14

14.00"

$34.95

$10.00 Nlin. Order - U.S. Funds Only Calif. Residents Add 6% Sales Tax Postage —Add 5% plusS1 Insurance

Spec Sheets - 25c!

Send <11 ii Postage for your

FREE 19B1 JAMECO CATALOG

nnsnssEm

PHONE

ORDERS

WELCOME

(415) 592-8097

MAIL ORDER ELECTRONICS - WORLDWIDE

1355 SHOREWAY ROAD, BELMONT, CA 94002

PRICES SUBJECT TO CHANGE

JOYS

JS-5K I

ICKS

JS-5K 5K Linear Taper Pots $5.25

JS-100K 100K Linear Taper Pots $4.95

JVC-40 40K (2) Video Controller in case . . . S5.95

AC and DC Wall Transformers

Part No.

AC 250 AC 500

AC1000 AC1700 DV 9200 DC 900

Input

117V/60HZ 117V/60Hz

117V/60HZ 117V/60Hz 117V/60Hz 12QV/6QHZ

Output

12 VAC 250i 12 VAC 500i 12 VAC 1

9 VAC 1.7 ai 9 VDC 200rr 9 VDC 500rr

Price

S3.9 5 S4.95

S5.95 $6.95 $3.25 $3.95

CONNECTORS

0825P D-Subminiature Plug $2.95

DB25S D-Subminiature Socket S3.50

DB51226 Cover for DB25P/S $1.75

22/44SE P.C. Edge 122/44 Pin) $2.95

UG88/U BNC Plug $1.79

UG89/U BNC Jack $3.79

UG175/U UHF Adapter $ .49

S0239 UHF Panel Recp $1.29

PL258 UHF Adapter $1.60

PL259 UHF Plug $1.60

UG260/U BNC Plug $1.79

UG1094/U BNC Bulkhead Recp SI.29

TRS-80 16K Conversion Kit

Expand your 4K TRS-80 System to 16K. Kit comes complete with:

*8 Ba. MM5290 (UPD416/4116) 16K Dyn. Rams <"NS)

* Documentation for Conversion

TRS-16K2 -150NS $49.95

TRS-16K4 -250NS $39.95

JE610 ASCII Encoded Keyboard Kit

The JE610 ASCII Keyboard Kit can be interfaced Into most any computer system. The kit comes complete

with an Industrial grade keyboard switch assembly (62-keys), IC's, sockets, connector, electronic components and a double-sided printed wiring board. The keyboard assembly requires +5V (? 150mA and —12V @ 10 mA for operation. Features: 60 keys generate the 126 characters, upper end lower case ASCII set. Fully buffered. Two user-define keys provided for custom applications. Caps lock for uppar-case-only alpha characters. Utilizes a 2376 (40-pin) encoder read-only memory chip. Outputs directly compatible with TTL/DTL or MOS logic arrays. Easy interfacing with a 16-pln dip or 18-pin edge connector. Size: 3'/a"H x 14«"W x 8K"D

JE610/DTE-AK (as pictured above). . .$124.95

IFfim l<ri+ 62"Kev Keyboard, PC Board, * 7Q QrJUO I U l\ll &. Components {no case) q> /o.»D

K62 62-Key Keyboard (Keyboard only) . . .$ 34.95

DTE-AK (case only-3Vi"Hxll"Wx8V«"D)$ 49.95

JE600 Hexadecimal Encoder Kit

FULL 8-BIT lflL^A \

LATCHED OUTPUT ^ft VHfc \

19-KEY KEYBOARD ^ -- \

The JE600 Encoder Keyboard Kit provides two separate hexadecimal digits produced from sequential key entries to allow direct programming for 8-bit microprocessor or 8-bit memory circuits. Three additional keys are provided for user operations with one having a bistable output available. The outputs are latched and monitored with 9 LED reedouts. Also included Is a key entry strobe. Features: Full 8-bit latched output for microprocessor use. Three user-define keys with one being bistable operation. Debounce circuit provided for all 19 keys. 9 LED readouts to verify entries. Easy Interfacing with standard 16-pln IC connector. Only +5VDC required for operation. Size: 3'/."H x 8'ri"W x 8«"D

JE600/DTE-HK (as pictured above) .... $99.95

.renn ■/■■* 19-Key Hexadec. Keyboard, acq qc

JbbUU Kit PC Board tCmpnts. (no case). .*oy.yo

K19 19-Key Keyboard (Keyboard only) .... $14.95

DTE-HK (case only—3Vi"HxaV4-WxaV4"D) $44.95

Circle 352 on inquiry card.

BYTE April 1981 399

CAlifORNIA DiqiTA

Post Office Box 3097 B • Torrance, California 90503

FREE PLASTIC LIBRARY CASE INCLUDED WITH THE

PURCHASE OF EVERY BOX OF DISKETTES

■ivale labeled for California Digital by one of

c most respected producers of magnetic media, i ich diskette is certified double density at 40 acks. To insure extended media life each dlsI kette is manufactured with a reinforced liub-Jiole. I And of couthc, a plastic library case Is included | with every box of diskettes. MMO-CDS(OIHIO) ise specify computer or required sectors.

■I I. BOX

Ten boxes $22.75

MINIDISKETTES

One hundred boxes $21.50

10 boxes S2y.oo

EIGHT LNCH

Scotch

„vv

10 bx

Dysan

box 10

"

MUX box

Ohl

Single

■skWMllgte

dm.

740-0

MM.

$33.

3740/1

MO. $

IV.

3060

Single

side/ double

dm

741-0

4h.

3740/1 (

75.

/H.

3090

87,

35.

.Single

side/32 sec

740-33

Hfi.

33.

nouble

side/ doubt

D U.

743-0

Kb.

59.

na.

3115

49.

45.

SCOTCH brand he

ad c

eaning kit. $24.35

MMA-CK{

KB) pi

as

specify

81/

B"

Prices

available o

n request for

tap

ridges, dl

kpadta

volumn dl

akeltcs.

NEW

from

Shugart

Technology

s

Megabyte Hard Disk Drive

Packaged in the same physical size as the industry standard 5 1/4" minifloppy disk drive. The micro-Winchester stores thirty times as much data (6.38 megabytes unformatted), accesses data twice as fast {170 milliseconds) and transfers data twenty times faster (5.0 megabits per second. )

The ST506 is factory sealed to protect the media from environmental contaminates. Requires only DC voltage. enclosure, felCAA

SURPLUS

Dual California Digital 5 1/4" ST506 drive and power supply.

Shugart Associates SA400 removable media disk drive for above package, add: S-100 & Apple controller scheduled for spring release.

rvi

TRS-80 • APPLE II

16k memory (8)4116's

Installation is simple. Anyone who has ever changed a spark plug should be able <. to up-grade his microcomputer. How can California Digital offer these memory up-grade sets at 25% below our competition? Simple, we buy in volume, wholesale to dealers and sell the balance directly to owners of personal microsystems. These 16K dynamic memory circuits are factory prime and unconditionally guaranteed for one full year. NOW, before you change your mind, pick up the telephone and order your up-grade memory from California Digital. Add $3 for TRS80 jumpers.

STATIC

21L02 450nS. 21L02 250nS. 2114 1KX4 450 2114 1Kx4 300 4044 4Kxl 450

4044 4Kxl 250

4045 1Kx4 450 4045 1Kx4 250 5257 low pow.

1-31 1.19 1.49 5.95 8.95 5.95 9.95 8.95 9. 95 5.95

32-99 100-5C -999

1K+

1.39 5.50 8.50 5.50 9, 50 8. 50 9.50 5.50

5. 25 8. 00 5. 25 9.00 8. 00 9.00 5. 00

4.80 4.60

2716 EPROM

We have slashed price in an effort to reduce our over stocked inventory. These are single five volt EPROMs ] manufactured by one of the Worlds largest producers of semiconductors. All are first, quality prime devices. Ceramic 450 nS.

IUlTR/vVioUTProcIucts LVSHE

UV EPROM ERASER

With purchase of FORTY

2716 EPROM's

*/V value

*300

2

;piit

2

Split

^' S-IOO

■*-,J>9VDC

|p- 22V, ct jT~ 24V disk

Cl5V. f 15V. £ Fan

POWER

SUPPLY

KIT

$

59

801/ R Disk Drive 15 lbs

Shugart 801/R with CP306 power mipply, muffin c.

plcte in dual enclosure with .ill the necessary ham

Documentation included. 3fi pounds, MSIJ- 1B01

Same as .ibove but Willi two Shujjart 801H disk drives.

SO pounds. MSD-2H0!

Disk dtiV« cahle. 6 fee! .i0 conductor with edge card connec

at both ends. WCA-S50S $25,00

, 220V. 50MHsi add $50.00 per dink driv

The new jpplianct iating Sy

HSR timer runs yo 8 while your away tem X-10 device's

2&

S£

llku cloc Couplet

ely

rk

Tu

E

onl with

amps and

USB Tim Muster c Ultras on

er eight channel c Controller

$65.00 34.05

Appliance Module 500 W Lamp Moduli 300 Watte NEW full control wall sv.

$13.05

13.f)5

ich 14.50

Rotron Wisper Fan

$1477

115 VAC. 7 Watts WR2A1

Factory fresh Muffin fans NOT pull-outs. EMF-4M

S-100 .125'

Imsni soldi

tmaai wire wrap (I'D

Sullins Hi-Rel. .250'

Sullins Hi-Rel. WAV

Sullins/AJlatr - HO" ,156" Ccr

ird)

22/44 Kim Evolot 2.50 2.

36/72 Digital Group S/T 5.05 5.

36/72 Digital Crimp WAV 6.fit) C.

43/86 Motorola 0800S/T 6.BD 6.

43/86 Moto. 6B0O WW 7.00 6.

BCTBGRATED CIRCUIT SOCKETS

IJB hood 2IP 1.38 DC371' male 4.20 PC37S female ti.00

B.OO H.00

RIBBON CABLE CONNECTORS 17/34 5" disk 4.85 4.15 3.05 20/40 TltS-80 5.65 5.05 4.70 23/50 8" disk 5.90 5.15 4.U0

It contains fi vi- hii;h eiii-rmt lirii!(:i- rectifier* livi- i:oiii|puii-r cradc electronic capacitors and a 700 ' w.itt split primary transformer (11(1/220V.) he supplv is capable of supporting 9 full 30 Amp S-100 svstein along with 12)

lectrolytic capacitors consist of: one each HJ.000 ul / l.iV; IH.OOU til-MUV;

6,CI00uW.H)V; Hid TWO 1 2.0007 30V.

,11 components lire new surplus acquired from aXCOSS Inventory of the

luiional Cub Register Company,

li'.ise place vmir Order e.irlv, at thin low price *tt expect this kit i" !••■ .

nick sell out. SPC-PW10O. . ..Shipping: east Of Mississippi add SI5.00

□ATA INPUT TERMINAL

This Keyst

quired froi

Corporation. I

' a dire

tlyo

iriglnally designee

The svsten; in comprised of ,i prer-.tui-.. c;ist aj-.m.im-.i:ti .uid fiber,']..ss enclosure.

.tlong'with a Honeywell .' Microswitch hall effect keyboard. Thirty diapt-iy lamps

iidvise tile operator of tin: systems tit.itus. Four inch loud speaker aekamdedges

acceptance of data and alerts the operator of pending problems.

Hut most of all this "USED" terminal, with a little imagination, can be engineered

to make the perfect home for an S-100 computer and video display; or attli sll£h!

mollification will accept the Rockwell A1.M-5S micro/computer.

!■ Ive volt regulated power supply is available for .in additional ISO. (Bee June Byte

All units are In excellent condition. Original acquisition Deer S7O0. 22 lb*.

H39.50 J m

E DATA ENTRY SVSTEM

PORTABLE DATA ENTRY SYSTEM

These used data terminals were Originally desirned for retail store order en'. syaturns. The operator enters the inventory control number, merchandise ot hand and the unit price. After all pertinent data has been entered, the main v house 1b telephoned, the handset is placed in the acoustic coupler an ail [lie recorded information is transmitted hack the master computer.

Each system includes: Cassette drive unit; Removable hex keyboard with LED display; Five Gould "D" NiCads with charger; Acoustical coupler and DB29 cable. All units removed from service In working condition. Original cost over $2,500.

Regulated

Power Supply

5 VOLT 5AMP

$U?5

isior regulation outputs ttve volts at ■■ TTL hobby applications. SPC-PS1

Sankyo Magnetic Card Transport

fhis Snnkyu card transport is capable of storing I M\d retri.-vim: over .100 characters of d " ,• sinele '_■ t^1 IIP style matmetie data Motorized mechanism palls the magnetic card across ihefoor channel r hi:ad in under two seconds. Ideal for any data processing application »h amounts of Information must be randomly retrieved. Original cost over Documentation and sample card Included. New surplus. SPC-SCR

WESTER^ UMO^

ENCLOSURE

Thei

ufac

tured for Western Union by Universal Technology, The enact purpose of the product is still » mystery but the enclosure Is Ideally suited for an S-100 motherboard wilh shielded power supply. Removable hood and plexielas front make this enclosure .in attractive home for any Iiobbv product. New surplus in fuclurv boxes supplied 22/44 edge connectors; UB 2SS coniinu foot grounded power cord and more 10 1/2" nQ 7/8" Shipping weight H lh

$24.95^

All merchandise sulci by California Oigital is premium ^racle. Shinning; First five pounds $2.00; e;ich additional udd $.40

i orders 10% shipping. Kxcess will be refunded, ^tuuurnia residents add 6% sales lax. COD's discouraged. Open accounts extended to state supported educational institutions and companies with a "Strong Dun & Uradstrect. " Warehouse: 15608 Ingle wood Blvd. Visitors by appointment.

TOLL FREE ORDER LINE

800)421-5041

TECHNICAL & CALIFORNIA

213)679-9001

CAliFoRNiA DiqiTAl

Post Off if a Box 3097 B • Torrance, California 90503

'1J!

MEMOREX

i MEMOREX j

MEMOREX MEMOREX

MEMOREX B ■MEMOREX

SUPER BUY

NEW

from INTEGRAL DATA

Paper Tiger

GRAPHICS *ll7U

| The 460 Paper Tiger uses B do! ma cement of the dots overlap bath J

[ spondunce quality printing.

I rite printer a nine-wire print bead uses staggered needle rows to create the vei tleally overlappinc dots. The head Is driven bi-directionally under microprocessor control by a stepper motor driven mechanism. ' Two K " buffer allows the printer to accept the entire content of a 3.920 charac

| CUT screen. With (;raphics suggested retail price S1.39S 27 lbs. PRG-460G

HEWLETT PACKARD

2650

This self contained package

THP

1VEC Spin writer 551(3 P/S

*2"79

['he woni processing quality Sptnwrlier prints at speeds upio 15 one utters per second. The Model SSH P/S is supplied with both parallt md H5-332 serial tat or fasten, Use Included is the tractor feed me

im.-tm, .ilonj; with print thimble mi! ribhon. FHh-561BPfl 70 lb:

ievboard lh.SH> Model fif.20 I'/S available i'2U:i:j. FUN-."i52f) 1'S 75 lb:

JEC V-300

"Word Processing

Daisy Wheel Printer

♦1595

in ably priced letter quality prlntei S characters per second. Full 130 prim posilit '130"1 horizontal. 1/48" vertical. sea standard Dlahlo brand interchang-ibl.- deia] in-1 limj'j CPU iiii,-;i-i.iprticetisor controlled. Iiiti onnector. Shipping 5B lbs. PRV-300.

TELETYPE MODEL43

4320 KEYBOARD MODELS

TTL aerial output AAA $ 995

RS232 serial AAK 1050

Friction 80 column AAE 1100

Friction 80 RS232 AAL 1195

Bell 103 Modem AAB 1495

Tat?

EPSON

MX-80 *495

misti. adjusts to accept ten

It ivide eonuiiuniis paper. Uei.uiren "Eight bit"

nies type parallel Interftcing. PRE-MXB0 17I.li

CEnTRDniC5

730 $595 737 $750

Centronics; 730 and the 737 are capable Of accep-.in,

Office letterhead or pin feed continuous forms. it resolution the 737 Implements a nine wire dot irlnl head. Parallel Interfacing. Add SBS for PRC-730P (S). PRC-737P (S) 17 lbs.

26 Megabyte Hard Disk Drive

from

George Morrows

Thinker Toys

Qher .'.lorro* Products. HJluonal hard disk S3SSU

sens 2l> 1 drive DSD

seus 2D :• drives lti27

SCU1 2*2 1 drive 1330

Dis: Jockcv 21' controller l)is< Jockey 1 Controller

Wit herd dish Controller Switchboard interface "New" Multiboard M-in iv.i Meg ibyte hard

AMPEX

DIALOGUE 80 CRT TERMINAL

5995

from"ilie Ampex Corporation. The Dialogue BO features removable keyboard ayable two pages (four optional) dual program keys, half intensity protected

fields "and status line. Transmits data either block, line or character mode.

Excellent value. VDT-D80 shipping 47 lbs.

BMC

VIDEO MONITOR

$259

ISphOl

< Mill

somposit video input make the BMC KG-12C ..n ideal monitor for anyone requiring ■ugh resolu'ion 12" display, iiact plastic enclosure assures that the BMC monitor is a ragged where instrument, lor added protection the unit is equipped with removable smoked non-glare olexit'las screen. VUM-HMC 18 lbs.

direct connect

Your Choice

MODEM $169

Direct connect modems eliminate loss of Information due to the car Don compress! associated With acoustic modems. Choose either of these two j;reat units.

Tin- Universal Data Systems 1031.1' is switch selectable b-Kween answer and ort taatc o s. lullv Hell 10.1 compatable. Directly connects lo the new modular telephone |nek. mo ! powered from the telephone line. No need to locate modem proximity to AvC power receptlclo. MOD-1Q3LP 3 pounds.

V/SA

All merchandise sold by Calif onShipping: First five pounds $2.00 Foreign orders 10% shipping. E) California residents add G% sale? Open accounts extended to state i

ia Digital is premium grade.

each additional add $.40 cess will be refunded.

tax. COD's discouraged, jpporled educational institu

tions and companies with a "Strong Dun & liradstreet. Warehouse: ir>608 Inglewood Rlvd. Visitors by appointn

Circle 353 on inquiry card.

nt.

ACCESSORIES FOR THE

COMPUTER

CALIFORNIA COMPOTEH SYSTEMS Arithmetic Processor 7811 B/C $319

Asynchronous serial interface 7710 129

Centronics Interface card 7728 95

12K PROM Module 7114 69

Calender/Clock. Bat. back-up 7424 99

Parallel interface 7720A 99

Programablo Timer 7740A 99

Analog/Digital converter 7470A 99 MICROSOFT PRODUCTS

Apple to Z-80 CPU card 379 D. C HAYES PRODUCTS

Micromodcm for Apple 319 COMPUTER STOP PRODUCTS

Double Vision I B0 Column Video 250 INTERACTIVE STRUCTURES

10 Channel A/D card AIO/2 275

MOUNTAIN COMPUTER PRODUCTS Intro X-10 system for BSR J2;

Intro X-10 card onlv II

IS channel All/DA 8 bit 3!

Apple Clock batten' back-up 21

Supertalker SD200 %'

ROM Plus with alter H

ROM Writer/Programmer 1

APPLE BRAND PRODUCTS Apple Language card Floppy disk with controller Floppy disk without controller Apple parallel interface SSM MICROCOMPUTER Dual serial parallel interface AiO SORRENTO VALLEY ASSOCIATES 8" floppy controller (Pascal)

450

S-100 BOARDS

Assembled • Tested • Burned-in

MEASUREMENT SYSTEMS Dynamic memory IJMB-6400 S770

Dynamic memory DMB-8206 700

GODBOUT/COMPUPRO Dual B088/B085 16 bit CPU 375

Z-flO CPU 24 bit address 4 MHz 239 Sialic RAM 32K (Alpha Micro) 575

Spectrum color graphics board 329

Interfacer II I/O board 199

SEATTLE COMPUTER PRODUCTS 8086 16 bit CPU 2 card set /86 dos 595 CALIFORNIA COMPUTER SYSTEMS S-100 Mainframe 220OA 329

Disk controller/2.2 CPM 2422 329

Z-80 CPU 4 MHz DMA 2B10A 250

DIGITAL RESEARCH 32K 2716 EPROM board 99

EPHOMS for above 2710 16 req. 13 CALIFORNIA DATA CORPORATION A/1) board 10 channel 12 bits QT COMPUTER SYSTEMS Real time clock/calendar 135

MORROW/THINKER TOYS

Multiboard "NEW" Daisy wheel port,

real time clock, power on jump,

program interrupt com'I 3P/3S $37

Switchboard interface 4P/2S 21

Disk Jockey 1 disk controller 19

Disk Jockey II double density 37

SD SALES

PROM-100 programmer

Video display board 8024

Versafloppy 3740 controller

MULLEN PRODUCTS

Extender board/LorIc probe (kit) 4

Relay Opto/control board 14

D. C HAYES PRODUCTS

Micromodcm s-ioo FCC register 37

ARTEC ELECTRONICS

Wire Wrap proto board WW/100 2

General Purpose prolo GP /100 I

CALIFORNIA DIGITAL

(10B6 CPU 4K on board static RAM4!

TELETEK

SINGLE BOARD COMPUTER FLOPPY DISK CONTROLLER

1-lJC-l features the X.-B0 CPU I with the NEC 765 floppy ilisk •oiler. The board SURpOrtS both e or double density 9 1/4 or 8" drives. Two serial (4r>-960Qbd) wo parallel pons add to the Qex

uiilli; board computer, features are realtime

nip to monitor, sectored ■oiling ;

■\ this _•;

f.able nf (.

■nal 3

Winchester hai

jwer Supply the 16 El'RUMS.

s695

S-100 Mother Board $35

Quiet Buss

8803-18 18 slot IMSAI

TOLL FREE ORDER LINE

(800)421-5041

TECHNICAL & CALIFORNIA

213 679-9001

7400

SN7400N

SN7401N

SN7402N

SN7103N

SN7404N

SN7405N

SN7406N

SN7407N

SN7408N

SN7409N

SN7410N

SN7411N

SN7412N

SN7413N

SN7414N

SN7416N

SN7417N

SN7420N

SN7421N

SN7422N

SN7423N

SN7425N

SN7426N

SN7427N

SN7429N

SN7430N

SN7432N

SN7437N

SN7438N

SN7439N

SN7440N

SN7441N

SN7442N

SN7443N

SN7444N

SN7445N

SN7446N

SN7447N

SN7446N

3N7450N

SN745IN

SN7453N

SN7454N

SN7459N

SN7460N

SN7470N

SN7472N

SN7473N

SN74 74N

SN7475N

SN7476N

SN74 79N

SN7480N

SN7481N

SN7482N

SN7483N

SN748SM

SN7466N

SN7489N

SN7490N

SN7491N

SN7492N

SN7493N

SN7494N

SN7495N

SN7496N

SN7497N

SN74100N

SN74107N

SN74109N

SN74116N

SN74121N

SN74122N

SN74123N SN74125N SN74126N SN74128N SN74132N SN74136N SN74139N SN74141N SN74142N SN74143N SN74144N SN74145N SN74147N SN74148N SN74150N SN74151N SN74152N SN74I53N SN74154N SN74155N SN74156N SN74157N SN74158N SN74I60N SN74161N SN74162N SN74163N SN74164N SN74165N SN74166N SN741G7N SN74170N SN74I72N SN74173N SN74174N EN74175N SN74176N SN74177N SN74179N SN74180N SN74181N SN74182N SN74184N SN74I85N SN74186N SN74188N SN74190N SN74191N SN74I92N SN74I93N SN74194N SN7A195N SN74196N SN74I97N SN74I98N SN74199N SN74221N SN74251N SN74273N SN74279N SN74283N SN74264N SN74265N SN74290N SN74298N SN74365N SN74366N SN74367N SN74368N SN74390N SN74393N SN74490N

CD4000 CD400I CD4002 CD4006 CD4007 CD40O8 CD4009 CD4010 CD4011 CD40I2 CD4013 CD40I4 CD4015 CD4016 CD40I7 CD4018 CD4019. CD4020 CD4021 CD4022 CD4023 CD4024 CD4025 CD4027 CD4026 C04029 C04030 CD4031 CD4032 CD4034 CD4035 C04037 CD4040 CD4041 CD4042 CD4043 CD4044 CD4046 CD4047 CD4048 CD4049 C04050 CD4051 C04052 CD4053 CD4055 CD4056 CD4059 CD4060 CD4066 CD4069 CD4070 CD4071 CD4072 CD4073 CD407S C04076 CD4077 CD4078 CD4081 CD4062 CD4085 CD4089

1.10 3.95 2.95

CD4093

CD4094

CD4098

C04099

MCI 4408

MC14409

MCI4410

MC14412

MC14415

MC144I9

CD4501

CD4502

CD4503

CD4505

CD4506

CD4507

ZD4508

CD4510

CD451I

CD4512

CD4515

C04516

CD4518

CD4520

CD4555

CD4556

CD4566

74CO0

74C02

74C04

74C08

74C10

74C14

74C20

74C30

74C32

74C42

74C48

74C73

74C74

74C85

74C89

74C90

74C93

74C95

74C107

74C151

74C154

74C167

74C160

74C181

74C1B3

74C164

74C173

74C174

74C175

74C192

74C193

74C195

74C922

74C923

MM80C95

MM80C97

74LS00

CMOS

99 295 2.49

2.25 12.95 12.95 12 95 12 95 8.95 4 95

1.39 3.95 1 69

1.65 1.85 1 19 2.49 3.50 2.10 2.39 2.30 239 2.39 2.59 2.75 2.75 2.39 2.39 2.39 7.95 6.95 1.50 1.25

74LS00N

74LS01N

74LS02N

74LS03N

74LS04N

74LS05N

74LS08N

74LS09N

74LS10N

74LS1IN

74LS12N

74LS13N

74LS14N

74LS15N

74LS20N

74LS21N

74LS22N

74LS26N

74LS27N

74LS28N

74LS30N

74LS32N

74LS37N

74LS38N

74LS40N

74LS42N

74LS47N

74LS48N

74LS51N

74LS54N

74LS55N

74LS73N

74LS74N

74LS75N

74LS76N

74LS78N

74LS83AN

74LS85N

74LS86N

74LS90N

74LS92N

74LS93N

74LS95N

74LS96N

74LS107N

74LS109N

74LS112N

74LS113N

74LS114N

74LS122N

74LS123N

74LS124N

74LS125N

74LS126N

74LS132N

74LS136N

74LS138N

74LS139N

74LS145N

74LS148N

74LS151N

74LS153N

74LS154N

74LS155N

74LS156N

74LS157N

74LS156N

74LS160N

74LS161N

74LS162N

74LS163N

74LS164N 74LS165N 74LS166N 74LS16BN 74LS169N 74LS170N 74LS173N 74LS174N 74LS175N 74LS181N 74LS190N 74LS191N 74LS192N 74LS193N 74LS194N 74LS195N 74LS196N 74LS197N 74LS221N 74LS240N 74LS241N 74LS242N 74LS243N 74LS244N 74LS245N 74LS247M 74LS248N 74LS349N 74LS251N 74LS253N 74LS257N 74LS258N 74LS259N 74LS260N 74LS261N 74LS266N 74LS273N 74LS275N 74LS279N 74LS283N 74LS290N 74LS293N /4LS295N 74LS298N 74LS324N 74LS347N 74LS348N 74LS352N 74LS353N 74LS363N 74LS365N 74LS366N 74LS367N 74LS368N 74LS373N 74LS374N 74LS375N 74LS377N 74LS385N 74LS386N 74LS390N 74LS393N 74LS395N 74LS399N 74LS424N 74LS668N 74LS670N 81LS95N B1LS96N 81LS97N 81LS98N

LINEAR

78H05

78M06

78M.G.

LM105H

LM108AH

LM300H

LM301CN/H

LM304H

LM305H

LM306H

LM307CN/H

LM308CN/H

LM309K

LM310CN

LM311D/CN/H

LM312H

LM317T

LM318CN/H

LM319N/H

LM320K-XX

LM320T-XX"

LM320H-XX'

LM323K

LM324N

LM339N

LM340K-XX

LM340T-XX'

LM340H-XX'

LM344H

LM348N

LM358CN

LM360N

LM372N

LM376N

LMG77N

LM380CN/N

LM381N

LM3B3T

LM386N

LM387N

LM390N

NE531V/T

NE555V

NE556N

NE561T V

NE5G2B

NE565M7H

NE566H/V

NE567V/H

NE592N ;

LM702H

LM709N/H

LM710N/H

LM711N/H

LM715N

LM723N/H

LM733N/H

LM739N

LM741CN/H

LM741CN-14

LM747N/H

LM748N/H

LM760CN :

LM1310N

LM1458CN/N

MC1488N

MC1489N

LM1496N

LM1556N

LM1800N

LM1820N

LM1850N

LM1889N

LM2111N

LM2900N

LM2901N

LM2917N

CA3013T

CA3018T

CA3021T

CA3023T

CA3035T

CA3039T

CA3046T

LM3053N

CA3059N

CA3060N

CA3062N

LM3065N

CA3080N

CA30B1N

CA3082N

CA3083N

CA3086N

CA3DB9N

CA3096N

CA3097N

CA3130T

CA3140T

CA3146N

CA3160T

CA3190N

CA3401N

MC3423N

MC3460N

SG3524N

CA3600N

LM3900N

LM3905N

LM3909N

RC4131N

RC4136N

RC4151N

RC4194

RC4195

ULN2001

ULN2003

SN75450N

SN75451N

SN75452N

SN75453N

SN75454N

SN75491N

SN75492N

SN75493N

SN7 5494N

ADW\NCED

COA\PUTER PRODUCTS

BECKMAN

Digital Multimeters

p9

%

The TECH 300 nas .i D S»i Voc ,i«urjcy im an

dtluc leaWM (ml willwiil insl?-Ohms'" rriHyluncl-on ui the 10 UpMlM ^rv^-:.

*

I

TECH 300 Dignai MuRmwhi TECM 310 Digital Mullimnlei TECH 330 Digilnl Mullimolor VC-201 Vmyl Carrying Case DC-202 De-iu.e Carrying Case HV-211 High Vollage Probe HP-221 RPProt* Cl-231 AC CurtWll Clamn DL-24 1 Deluio Inst Lead Kil 7L-242 Spare Tesl Leads

S100

SI 30 $189

■ffWM VISTA

LiTlrl COMPUTER

yra^aa company APPLE™ 40 CHARACTER TYPE-AHEAD BUFFER

Hi-Speed Serial UO Centronics Pfniet I/O Applesoll II Firmware Apple dock Introl X-10 System Inlrol X-10 Controller AH Music Synthesizer 16 Ch Analog Input 2 Ch Analog Output 13-Key Keypad Visi-Calc

• Apple® II16K Apple® II Plus $11

DISK SYSTEM SPECIAL

Apple II Plus W/48K Supermod Video Modulator

Disk II w/Controller Integer Based ROM Card.

ACP PRICE S1969.00

0S65 Oigi-Seclo* $349 00 Integer ROM Card

Apple Graphics Tablet 67500 Prolo Card

OC Hayes Modem il 34995 HSR Modulator

Or:* II WCrnlrUw 4 Po$33

S18900 180.00 18900 26900 17995 26995 25995 24995 164 95 11995 12500

Disk II

Pa«a' Lang System Parallel Printer Card Communicanons Card Business SoilwarePkg Corvus 10 Megaoyle Drive

4625 00

459 00 450 00 16500 189 00 625 00

16K Upgrade K>\

Desktop Plan

8 Floppy Controller

Heuristics SpeecWab

Ron .plus + Supe'lalkei Cashier

50

SI 8900 2195

2995 . 54.95 54 95 9B00 35000 179 00 169 00 27900 25000

Jappkz^$3gg5 A

• Apple III Option A; Apple II 96K. „ _ . _ „ Inlormation Analyst Package. • APPle 'I' Option C: Same as 12" B/W Monilor $3995.00 Option A Pius: Disk II for Apple 111,

• Apple III Opiion B: Same as Silentype Thermal Pfinter $4785.00

Option A Plus: Disk II lor • To substitute 128K Apple III tor

Apple III $4395.00 96K Apple III Add $450.00

NEW APPLE PRODUCTS

■ AFVLE FAN" - Cures thermal rjrotiems (rom mttaoHtea

•nadires designed specifically lor Anne $49 95

• 'BIT 3' - New 80 > 24 Video Board lor Apple Completely

compaieie with Pascal S3?9 95

• "BAH WAND" hcwlctl Packard HEDS-3000 Bar Code

inlolacal lo Apple S19900

• "SEC APPLE A/0" - 6 Channel A/D inlertace comDrei^y

assemored and lesied S9950

t "APPLE FORTdAN" S175D0

■ "APPLE CRyPIEXT lot data cncryplion and

seewty M490C

"B2/A2" GfapflKa Inlertace Card by Base 2 S15995

B" Disk Drws tor Apple Controller, DOS. Two B"

flrwes cab.net anJ cade J145000

MOOMODEM - DC Hayes $31995

"D1GISECT0R" Converts video input to HfRes

qraphes S34995

Can r of ma Ml crop rod ucl*

i/iilC*rC KnypaOi Numtwrtc koypid with «p«ce. wwco ESC - and ■ lay* lot VWOale compallBIHty SI 69.00

• DOS 3 3 Upgrade Kits 23% more suxaoe m 16-secux

lor mat 165 00

• Mcuntan Hardware Muse Board best yet

16 channels 155000

• Conlroiier 11 Revtsion m 20°^ overall processing

speed release and supports standard printed Hnliced

disk handing Addilronal error erecting

Imcvoved nanuai Vendor hie eipanded $14500

• Pascal Revision Kit Adds eiecutrve and

ctuimnp capabililies lo Pascal environment $6500

• Mountain Hardware Eipansion chassis 8 more Sims

lor Apple Hardware or software selectable

Includes cower supply Avarl Soon

• Smart Term Appte 80 > 24 Vtfec Card 1619.00

• Symie. X-10 $34900

• Apple Siienlype With Apple inteHoem iniedace Card $54900

• NEW CaMorria Compuier Sysiems APPLE dock Orty $124 95

• NEW 2-80 Soflcard to APPLE CPH 22 & M BASIC 50 J32500

RETAIL STORES OPEN MON-SAT

mammm

P.O. Box 17329 Irvine, Calif. 92713

Direct Order Lines: (714) 558-8813

(800) 854-8230 or (800) 854-8241

POttft'BLACrUACK ROULETTE HORSE HACIMG SUBBATTlf ARMOfi (UTILE SPACE BATtLE SEA BAntE ABCAOC

FOR INTERNATIONAL ORDERS: 1310 E. Edinger (714) 953-0604 Santa Ana, CA92705 TWX: 910-59S-1565

402 BYTE April 1981

AEWVNCED^—

COMPUTER QDUCTS

"V-DRIVE"

THE LAST WORD IN 8" Fiom-OISK ENCLOSURES

s-ren MmMH re 9ifl«! law M cruse, «i frrefi starring an i«a • S orate

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• Mm

NOW SAVE ON

TRS 80 ADD-ON

ONLY $299.00

! DRIVE CABLE 29.95 2 roR 279.00 ,

I DRIVE CABLE 39.95

MINIATURE COMPUTER

LMkrOfkCj Computer

BAjto1KKI1 149.00

\ 2KKIT 169.00

' Manual 10.00

ATTENTION VIDEO HOBBYISTS!!!

* BOX BUILDERS

* USE AS REMOTE TUNER/TIMER

* FULL SCHEMATICS AVAILABLE

* FOR ONLY $5.90! - FREE W/PURCHASE

A RflCnH Sc«oal Puirnas* Allows Us To Present The Foltovunq

NEW. UNUSED COMPONENTS

FriB Til Raimti ll*M Cimtti Ricirdir

I IJHF.VHF Iutp SuMSSenYJy *ajl a« MM

anil ViJ.ii Df nortiHalot ill rng

? Hf Mooiiiaio *ifiAua«*V«jH)ini.,ii MU. run

CtonnH 3 or 4 OuDul

3 OfftH rice!- Module AM7PM Fluoresce-"

Re**iit (Green)

4 3M0»ifnlo'irinmMi1cfw^

74

95

MeMEitXOTl«95 Call FOf Volume Discounts

FLOPPY

LOW cost

DISK SUBSYSTEM

Siemens FDD 120-B (21 VISTA Floppy Controller (S-100). Case. Power Supply*. Cable CP/M Disk Operating System Assembled 4 Tested

-'..:■■■■ ■.'.-■■.. -i ■;,.■;-■ . *14M.0O

.CHECK Dim floftt 1111 ra.ciHG on this rut* SAVE S300.00 (SI 79900 VALUE)

WATANABE MIPLOT

RAM BOARDS SPECIAL 10K AJUIr Mil. Dynamic RAM Hoards

Aeaem. 1 TitWd 11 10.05 Untested J05 OO

16K

FLOPPY DISK DRIVES

TandomTMIOO-1 5W." DM Drtva 249.95

MPIBai-5V.*0irme*a 239.85

Shugarl SA4O0-SW 35 tracks 20*00

Shugarl BOO/601 R 8" 440.00

Stamens Shugart Compatible Mode FOD-120-80 42900

PERSCI Modal 277 Dual 119500

WANQO/SIEMENS5*-Ortve 200.00

MP1 062 B\d*Doal 348.00

WANQO/SIEMEMS 282 Oirral 5V 306.00

WANQO/9IEMENS82 200.00

MPI 91 Double Tree* Oanalty S-ng-a SkM. 80 Track*. 379O0 MPI 02 Double Trick Penalty DoubK Side. 1 BO Track... ■ 478.00

9601 9602 9603 9604

9605

9616

9617

9620

9622

9627

9629

9629A

9630

9640

96»

9655

96103

96702

16 Slol Mother Board

Card Cage

B Slot Mother Board

Power Supply

DC Input Power Supply

Utility Prolo Board

Anlh. Proc/Memory Module

Buttered Utility Prolo Board

32K EPROM/RAM Module

EPROM Programming Head

16 Channel Parallel i/O Module

Serial-Parallel I/O Module

16K Sialic RAM Module 470ns

32K Static RAM 450ns

32K Static RAM 200ns

Card Extender

Multiple Programmable Tuner

8 Channel Duple* Serial I/O Mod.

Intelligent Tape Controller

32/32 I/O Module

Contact Closure Module

175 00

75.00 100.00 275.00 32500

39.00 49500

49.00 250.00 250 00 29500 325.00 39500 695 00 895.00

68.00 395 00 39500 550 00 27500 350.00

The Vista V30O Printer

SUnOiMJ tb in

•Ilsr" $1895°°

THE VISTA V-20O FOR EXIDY

Price Slaning as low as 11199.00

Stan* onrt Unaka thai Cajtotf CatnaKmx •**>■ Pita

VPQ0E20 «00 ?Bmt ?5itK 119900

Smote Hon WOO (■?? 800 2 pn* 75 % 154900

Oouw Head

VTOOEJO 600 ] Dnvt 32l«, f.7400

Single Hrarj V200E3? t?MSG 30n«e Jj Urs 199900

Doutrerwa]

EXPANDORAM II MEMORY KITS

* Bank Selectable + Uses 4116 200 ns

* Write Prolect _«,* Power BVDC ±16VDC

* Phantom HgSets *■ Ud to 4 MHz

Expando 64 Kil (4116) Assem & Tested Add S50. 16K $249.00 48K S435.00

32K $289.00 64K $505.00

"^3?9^Rs5o7aPPLE^39!9^

memory expansion kits.

4116's. 16K (200/250 ns.) B pes lor S30.95

w/in5tructions 8 jumpers Call For Volume Pricing

* Special TRS80 Schematic S 4 95

* Expansion Interlace Schematic S 4.95

* Exoansion Interface Conneclor 7 95

CENTRONICS PRINTER

Modal 737

• Centronics complete printer ■

• The 737 has everything. Check and compare the leatures

• New low price $835.00

32K STATIC RAM BOARD

S-100

16K 4MHi KIT 159.0!

16K4MHzAAT .217.951

32K 4MHz KIT ...289.95 I

•J [ 32K 4MHz AiT 348.05 I

H Bare Board 30.05 I

-.m.^wilnuii^ 00.05 |

BASE II PRINTER^ ^TTc!!

a 60 Lmos Per Minute flS Mlmo;

a 115/230 VAC. SO Jk\% .——-3>-^

or 60 Hj f^» ~~~~"^&~^

• 72. 80. 96, I 20 or P"*ajtL-^«l**^^--^

•&8SSS* ^^-^1 BEG1799O0|

WtTH ALL OPTIONS ACP PRICE $699.00 |

Option "M" Terminal Screen Butler 11920 Cha' I J50 00

Option V High Speed Paper Advance 8 Graphics 50 00

Opuon 'T Tracio- Feed 5000

UV "Eprom" Eraser

. Model UVs-11 E $60.95

) Holds 4 Eprom s at a lime I Backed by 45 years

experience

Modal S-52T... S325.0O Professional Industrial Model

S-100 MOTHERBOARD SPECIAL

8 slot expandable w/9 conn.

rgfl $69.95 NOW $52.95

SHUGART DRIVE

449.00

ACOUSTIC MODEM

NOVATION CAT"" O3O0 BauC

'D' CAT MODEM

NOW AVAILABLE SI 00.00

MONITORS

Uanyo VM 4509 9"BAV

Sanyo VM 4212 1 5" B/W

Sanyo 6013 13" Color

DATA BOOKS • COMPUTER BOOKS

19S0 IC Master INTEL Daia Book ..

INTEL MCS 85 Manual -

SALE a OIBOBWf BOOK* a IALE Inlro to M.. .,>■■ Vol 0 Intro to Micros Vol. I 8080A Prog.ramming 6800 Programming

Z80 Programming

Vol II Some Heai Mcoprocessors w/8-ncer

Vol. Ill Some Real Suppon Devices w/Bmdor Intro lo M.c'os Vol "'

BOB6 Programming

Z8O00 Programming

Inlro. lo PaacaJ

750 tela 12SO 1250

1250 1250 1600 27 50 27.50 IB 50 14 95 14 05 14 95

SALE • SYBEX COMPUTER BOOKS • SALE

6502 Games . SI 2 95

tnlro to Personal A Business Compuling 12.95

Mircoorocassors From Chips to Systems 12.95

Microo'ocossor Iniertaciog Techniques 12.95

Programming the Z80 .. 12.95

Programming Iho 28000 . . 1295

Programming Iho 6502 12 95

6502 Applica Irons Book .... 12.95

CPMHandbook 12.95

FIRST TO OFFER PRIME PRODUCTS TO THE HOBBYIST AT FAIR PRICES!

1. PrOVeil Quality Factory tested products only.

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3. Over $1,000,000.00 Inventory

1981 CATALOG NOW AVAILABLE

Send S2.0O for your copy of the most complete catalog of computer products. A must for the serious computer user. MICROPROCESSORS

zao

Z60A

F-6 138501

2650

TD1B02

BOBOA

BOBOA^MHi

SALE 8085...

1695 1895 1395

2901 290W

2903 40il Sup

TMS 9900JL

CPI600

6502

6502A

IM6I0O

29 95

49 95 39 95

6800B2 0MH;

6802P

8035

8039

8755 8748 6809

19.95

19 95

1995

49 95 69 95 37 95 69 95

ADVANCED SUPPORT

AM95I I Anlti Procr

9512 Anin Processor

9513 Linn Timing AM9517 DMAContrr. AM9b'9Univers.

I 75.00 175 00 79 95 18 95 1895

Z-80 SUPPORT CHIPS

Z80PIO

Z80A.PIO

Z80CTC

Z80A-CTC

Z80-DMA

Z80A-0MA

Z80-SIO/0

Z80A-SIO/0

2 5 MHi 4 0MHi 2 5 MHi 4 0MHr 2 5 MHl 40MHI 2 5 MHz 4 0 MHZ 2 5 MH;

8 75 12.95 29 95 36 95 35.95 39 40 35 95 39 40

Z80-SIO.M Z80A-SIO/1 Z80-SIO/2 2 5MHt 280-SI0/2 4 0 MHi

8080/8085 SUPPORT

24 95

39 40

HI !!.!„■« I 56 I/O (1755 I/O With Eprom 8202 Dyn Ram Com 8205/748 '38 Decoder 82i2 8bni/o

8214 Pr.or.ly Inl 8216 Bus Driver . 8224 Clock Gen 8224^4 (4MHi| 8226 Bus Driver 8T26 Bus Driver . . H22H !?ys Control. B23B Sys Conl 8251 Prog I/O 8253 Inl Timer 8255 Prog I/O 8257 Prog DMA 8259 Prog Int 8275 CRT Conl roller Prog KeyDoard

64 95 34 95 3 95 2 75 5 25 2 75 2 95 9 75 395 2.95 5 50

5 50

6 95 1295

650 16 95 17.95 49.95 15 95

SBOO SUPPORT CHIPS 5810 128x6 Ram. 4 75

6820 PIA 5 95

6821 PlA 6 50 6828 Priority Int 19.95 6834-1 51 2 i B Eprom 16 95 6845/MP46505 CRT Com. 39 95 6847 Color CRT 49 95 6850 AClA 5 95 6852 Serial Adapter 5 95 6860 Modem 1095 6862 Modulator . 11.95 E371A IOMHiOSC 2595 6875 . . 6.95 6880 Bus Driver 2.95 MC6848B 19 95 68047 24 95

SHIFT REGISTER SALE

2504V 1 49 2525 1 49

2507V 1 49 2527 . 1 49

2517V . 1 49 252B.. 1 49

2524V 1 49 2529 l 49

2533-. 149 0902 SUPPORT CHIPS

6520 PIA 7 50

6522 Mull 11 95

6i30O02.003.004.005 21 95

6532 1995

6S51 19.95

PROMS

2708 450 ns B 25

2708'G650n5 7 50

1702A 4.95

2732 44.95

2716-5V 14.95

2716-SV. 12V 19.95

2758-5V 1995

S203AQ 1395

5204AO 14 95

IM5610 3.90

B2S115512 x8(TS) . 16.95

82S12332 x8 . 4 90

82S126256«4 4.90

82SI292S6x4(TS).. . . 4.90

825130 512«4(OC) 6 50 B2S23 695

825131 14.95

82S137 1495

745387 8.50

745471 12.96

74S472 12.95

74S570 14.95

74S571 14.95

NOTE: WE PROGRAM PROMS

CHARACTER GEN.

2513O01 (SV) Upper 9 50

2513005I5V) Lower . 1095

2513.ADM3)5V)Lower. ... 14,96

MCM6571 11.75

MCM6571A . II75

MCM6574 14.50

MCMGS75 14.50

MCM8874 14.05

UARTS/BAUD RATE

TRI602BI5V 12VI 3 95

AYV013I5V 12VI 495 1

AY5'014A/16I2(5-14V| 6 95

AY5I01SA/1863I5VI 695

TMS60H 15V 12V| 553

IM6102 795

IM6403 8.95

2350 USRT 9 95

l671BAstros 24 95

KALI TK14T3B O.OB

MC14411 11.95

4702 14 95

WD 1941 9 95

COM5016 ...16.95

AMI18S3 7.05

INS 8250 15.86

KEYBOARD ENCODERS

AYS-2376 13.75

AY5-3600 13.75

MD0165 9.95

74C922 9.95

STATIC RAMS

2IL02 450ns /tBA*A 1 30 1 25 21L02 7S0ns 1 ^0» ) ' ?9 ' 5S 2112-1 V£9'295 ?8S

99

155

?65

2101-1 290 27(

;tl4L250ns [40461 6 50 5 91

Zl l4L-4Mm (4045) 5 50 5 25

4.7S

4044 4SOni 5 gs 595

EMM4200A 9 75 8 ?5

7 95

EMM4402 '95 7 25

AMD9U0r31 1295 1195 1101 1 95 ' 7S P2'25-9J4?Sl4bnsi 995 8 35

'0 25

8 25

B5lfl IK . t CMOS 795 795

7 25

Zi47LnwPo»er4KSianc t995 t895 1695

93415 995 895

8 50

TMS.10.1li 1 1 95 1095

10 50

DYNAMIC RAMS

JI6/4tlf, l6Ktl6P.nl

Seio<B4iGs

49 95

4l158KHGPml

6 95

4050 4K . 1 08 Pint

4060 4K . 1 [22 Pirn

4027 4K . 1 |16 Pirtl

4 95

5261 1 95 cau H03

> 95

"bo all RAMS 66°4

5?w i?45$159.95soo:'

'95

1 50

SOCKETS

■ Pin.

[ WIr. Wr.D

3 linl

M

20

38

62

20 ?2

29

79

110

43

JO

60

MO

169

ZERO INSERTION FORCE

16P" S550 24 Pj.i S7 50 JOF'.n

SHI .'5

FLOPPY DISK I/O

LED READOUTS

OtMM

10D Hod

Currm And*

FND157

1J7 Hal

CHTfTi CillW*

FND501

SOD RM

M)0 Had

fh(i:>;i;i',ii)

IjOO RM

Ccmm AfKd

IHBbM

500 RM

Comra AruHel-Hl

FNtJiJC

S00 Own

Conn Ciwor

rrjDSbO

fNDa03l8W)

800 nw

FND807(BI0

800 RU

HPS087 7Mt

600 BM

HPSoa2 7KX

600 U

4 1 7 Sql Dfll BHP

HP50B7 773I

300 R«

TIL305

nra

IIL308

270 RM

NitntnrjJ DrsWi

ComrTi Anrbp Lftt 01

100 Orttn ttwTll» C* Irt DP 300 Gy««i Ccnm CiNdc FUgnt DP 300 YNIO* Conm Aixiof Ri^it UP

IC SPECIAL PURCHASE

LF 13508 JFET Analog Multi 8 btl 8 95

ICM 7045 Precision SioDWaich 23.95

CMOS LED Stopwcich/Timer 19.95

ICM 7207 Oscillator Conlrollar 7.50

Seven Decade Counter 1 B.95

ICM 7209 Clock Generator 6 95

ICL 7107 3'i Digil A/D (LEO) 14 95

MC1 4433P 31 j Digil A/0 Converter 1 3 95

ICL 8211 Voiiage fleierence 1 95

LM 1B50N G'Ound Fault IC 3/1 00

LM 290ON Quad Amplifier 2/1 CO

LM 2917N F.eq 10 Voll Conv 2/1 99

AY-3-3550 4'. digit DMM 24 95

AY-5-3507 40MH' DVM 9 95

MEM 4963 Mostel Smoke Deleclpr 11 95

27S08 32 . 8 Prom |IM 56001 2 95

G1 15M 6 channel Mostet 1 49

ULN 2003A 7 channel Driver .99

2101AL-4 195

MCM 14505 64 On Sialic Ram 695

MOC 1003 (4N28)Oolo Coupler 3/1.00

SPX33 OpIO Coupler 3/1.00

IH 5045 CMOS Switch DBST . ,450

VA 3045 Trans Array . 1,25

TR 1402A UART 1.85

MR 1007 Dyn Mem Shrtt Reg ,, .395

5736 Calc. Con CtrOuH . 2/1.90

5763 Cite, Con Circuit 1.96

5318TVCh. Dlap CUCuN - 4 50

BOBOA 8 Bit CPU 4 95

82S21 32 x 2 Static RAM 2/1.99

8700 CJ 8 Bit A/D 90S

2758 5V-2708 EPROM 12,95

MM5280/VPD411/C2 107/TMS 4060/

4I01 Dynamic 22 Pin RAM 1.76

6604/VPD 414/402 7/2660/MK 4096/

4Kx1 Dynamic 16 Pin. 1.95

New Nallonal Clock MM 58187

Real Tlma 19.&C

7520/25 50 LM 387 I 25

1488/1489 2/1 99 LM 3302 3/1 99

MK50'4Calc 3/199 LM 4558 LM323K 4.95

MC1372 . 8.95

MM5298-4A/B . 2.95

RC 4136 PC 4131

DAC100 15.95

VERBATIM DISKETTES

100% CERTIFIED ERROR-FREE1

1771-01 8"4 Miniltoppy uPd372 Nec Floppy 1781 Dual Floppy 179101 Dual Floppy uPd 765rioppy

A/D CONVERTERS

8700 8 Oil Binary

Sol: StciorM IRS 80 elc IQMMr; MarrlHS Apr* at 15 Mac Hard Mciopoki

(2S.05

tn*s

52501

52S-10 525- IE

• 40 & It IMCX IHIILE BENtlTY- IIIBIE 5101 O

ItA'WIWI "HKFflMHMN, "INC 577 01 Soil StciorM IRS BO etc S32

577-10 10 Hole Hud NS Apple etc 32

577-16 16HoltHnid Wcrcoots 32

a ig nu.cn Muni hied bouile Kilini%

55001 Salt Sectored SA 450 MPI 52 8M

550-10 10 IHt HarrJ 8ASF. WAHGCO PJ

550-16 IGHrieHjrrJ Mcro> •" a r lHSCEITll-IEItlUETTEl

FDBOO-OI Soil S>nc* Densily. 3740 S33

FDflOO-32 32 Hard Single Density Srug 33

FD8020T Soli OojDIe Oensrly 3740 44

FD85001 Soil Double SOW. Doit* Density 3740 49 VOLUME DEALER PRICING AVAILABLE MH *t JO 8TTTt*rf ITYIAN OAII

24 95 4995 2995 36 95

49 95

8701

8703 8 b.l TS

9400 Voll toFreq Con,

8750 3'rOigil BCD

140BL6 6bil 3

l40BL6 8 0il 5

DACOI D to A S.

DAC08 9

DAC 100 15

TV CHIPS/SOUND

AY3B500-1 G Games B/W 4

AY38515 Color Converter 2

AY38603-1 PoadraceGame B

AY38606-1 Wipeoul Game 9

AY38607-1 Shooiing Gallery 8

AY3B910 Sound Generator 12

SN76<17?7ISoundGeneiator 3

MM5320/2 1 TV Synch Gen 9

MM5369 Prescaler 3

LMI8B9 RF Modulalor 3

MM57100 NSC Color TV 6 104CH

13 50 2200 1350

./Audio

8 Hb

29.9:

RF

MSR Moduiat

WAVEFORM GEN.

B038 Function Gen 3 95

MC4024VCO 295 LM566 VCO 1 95

XR2206 Funclion Generator 5 25

SHIFT REGISTERS

MMSOOH Dual25 .50

MM5056N Dual 256 .2 95 MM5060N Dual 128 2 95

2510ADual 100 1 95

2847 Quad 80 . 4.95

3341 Dual 80 4 95

3351 40x9FIFO 17 95 3357 Quad 80 6 95

9403 16 i 4 FIFO 9408 lOBn Seoul 3347

24 95 9 95 5 95

CTS DIPSWITCHES

CTS206-2 CTS206-4 CTS206-S CTS206-6

75 CTS206-7

75 CTS206-8

75 CT5206-9

75 CTS206-10

CONNECTORS (GOLD)

DB25P1RS232) D825S Female Hood

Set w/Hood. Sale 22/44 W/W. S/T. KIM 43/86 W/W, S/T. MOT 50/1 CO S-100 Connector « 50/100 S-100 Connector'.

S750 2 95

650

NAKED PC

S-100 Sound Board S34.05

Z-80CPU/(ithaca). . 34.95

8O80ACPU 34 95

16K Stale RAM (2114) 29.95

32K Static RAM (2114) 39.95

BK Eprom (2708). 24.95

1702 Eprom Board 30.00

270B/2716 Eprom 34,95

RBHltime Clock, 34.95

ACP Prolo Bd. (3M Conn.)... 27.95

Vector 8800 Proto 22.20

Vector 8803 11 slol MB.... 29.05

ACP Extender w/Conn. 18.95

13 Slol MolherBoard(WMQ 32.95 3 Sioi Mot herBoardfWMC)..29.95 8 Slol Mother (Exoandabta).. 34.95 Proc-Tech Bare Boards. CALL

■VMC FloopvPCB 34 95

floppy PC8 IB'SHUGART) 30 B5

COMPUTER SPECIALS

MSCO'

tfUl*

LIST SALE

995 'BS,

Apple II Plu PET 2001-1 Ejudy Sccer Cromemco Sys II! 6990 6290 Hornon I w/32K CALL

Pascal Microengme 1995.1595 IPSI 1620 Diablo RO 3295 2695 Anade«DP8000 995 875

CemromcsMicroS-1 595 525 Soroc IO 120 995 795

Teletype Model 43 1349 1150 HiPIOI Plolli H.PIol Digili

Alan 800 Alan 400 TI99/4

Laedei 12" Monitor Centronics W Trancom T-100 Trencom T-200 Sanyo 9" Monitor Sanyo 15" Monitor Sanyo 13' Monitor

795. 735

895 784.

999. 825.

549. 449. 1150.1025

189. 140.

995 899.

375 349

595 525

SOCKET SPECIALS

14Plrtw/w2L I .36

20 Pin w/w-2L 76

IB Pin art 18

22 Pin art 16

MPWiart 100/12,00

18 Pin art -....100/13.00

Cat lor vohinta orldna

TERMS: Use check. M/C, VISA. AMEX, CB. or COD. COD requires 25% deposit. Charge Orders please include expiration dale. Foreign pay U.S. Funds. Order by phone, man or TWX. MINIMUM 110.00 Please Include magazine issue and phone no. SHIPPING USA add S2O0 lor first 2 lbs For surface add 30* lor additional lbs. For air add 70« for additional lbs FOREIGN: Add 10% shipping and handling COCsJI.eiexIr*. N01 raaponsible lor typoa. Soma Hems subfacl to prior sale. We reserve hghl lo limrt quantities, soma Hems subject 10 predoua metal adder. Retail pricing may vary from Mai1 Order. We reaerve The right to sub

RETAIL STORES OPEN MONSAT

P.O. Box 17329 Irvine, Calif. 92713

Direct Order Lines: (714) 558-8813

(800) 854-8230 or (800) 854-8241

FOR INTERNATIONAL ORDERS: 1310 E. Edlnger (714) 953-0604 Santa Ana, CA92705 TWX: 910-595-1565

Circle 354 on inquiry card.

BYTE April 1981 403

<*

COMPUTER SYSTEMS

J INC.

15620 South Inglewood Avenue l.avtndale. California 90260 (213) 970-0952

SYSTEM+ (8")

QT SYSTEM +

MINI

SYSTEM+

(5V4")

The QT System+ is designed for both businessmen and engineers in accordance with the latest IEEE standards. Among other functions, it can be used for accounting and word processing, as well as a variety of scientific applications. The system will soon be available with MP/M® to allow multiuser, multi-tasking operations. This means, for example, that an engineer could be working on scientific applications in the lab while an accountant is writing payroll checks in the office. QT also offers a full line of business

and applications software, ranging from a business package to word processing.

Technical specifications: 4MHz Z-80A CPU • Dbl-sided, dbl-den. 5V4" & 8" floppy disk controller (handles both drives simultaneously) • Two 8" dbl-den., sgl. or dual sided disk drives, expandable to 4 floppy drives • CP/M® 2.2 included • 64K RAM • Comes complete in single mainframe • EPROM/ROM in any combination to 8K •

Two RS232C serial I/O ports • Two parallel I/O ports • Hard disk compatible • Real time clock • Std. 2K monitor program & disk routines included on ROM • Poweron/Reset jump to monitor program • 2716 (5V) EPROM programmer (software incl. on monitor ROM)(ext. 25.5V @ 50ma req.) • Uses Z-80A CPU vectored interrupts • Assembled, tested & burned •Documentation included.

With Terminal 920C Add $900.00

SYSTEM + I (1MB+)

SYS+SS Computer System with 8" Single Sided Drives (801R) without Terminal

A&T (6 slot) $3595.00

A&T (8 slot) $3695.00

A&T (12 slot) $3795.00

SYSTEM + II (2MB+)

SYS+DS Computer System with 8" Dual-Sided Drives (Qume DT-8) without Terminal

A&T (6 slot) $4495.00

A&T (8 Slot) $4595.00

A&T (12 slot) $4695.00

MINI-SYSTEM + I (V2MB+)

Computer System with 5V4" Single Sided Drives (uses B-51 Disk Drives) No Terminal

A&T (6 slot) $2495.00

A&T (8 slot) $2595.00

A&T (12 slot).

$2695.00

w

MINI-SYSTEM + II (1MB+)

Computer System with 5'A" Double Sided Drives (uses B-52 Disk Drives) No Terminal

A&T (6 slot) $2795.00

A&T (8 slot) $2895.00

A&T (12 slot) $2995.00

DISK DRIVE PRODUCTS

V

QT DISK PACKAGES

DDC-88-1 Dbl Den Controller, A&T, two 8" dbl den drives (801R) CP/M® 2.2,cabinet, power supply & cables SPECIAL $1495.00

DDC-88-2 Two 801R disk drives with cabinet, power supply, fan & cables $1200.00

DDC-88-22 Two DT-8 Qume drives with cabinet, power supply, fan & cables $1600.00

DDC-88-3 Cabinet with power supply, fans

& cables $ 275.00

DDC-88-4 Cabinet only $ 75.00

DISK DRIVES 8"

Shugart 801R Sgl/Sided Dbl/Den $ 450.00

Qume Datatrak 8" Dbl/Slded Dbl/Den

QME-8DS (851R) compatible $ 650.00

Pkg of two $1250.00

SVa"

MPI-B51 MPI B-51 $ 235.00

Sgl Sided Sgl/Dbl Den MPI-B52 MPI B-52 $350.00

Sgl Sided, Dbl Den MPI-B91 MPI B-91 $ 375.00

Sgl Sided, Dbl Den. 77 tracks

Shugart SA400 SHU-SA400 $ 250.00

Sgl Sided, Dbl/Den

S-100 PRODUCTS

Double Density - Cal Comp Sys

5%" or 8" disk controller with free CP/M 2.2 CCS-2422A A&T $374.95

Expando RAM II - SD Systems

4 MHz RAM board expandable from 16K to 256K

SDS-RAM216K 16K kit $289.95

SDS-RAM216AT 16K A&T $339.95

SDS-RAM232K 32K kit $329.95

SDS-RAM232AT 32K A&T $379.95

ITHACA AUDIO REV 2.0 Z-80 BD

Bare Board $35.00 each

10 for $300.00

SEALS ELECTRONICS 32K STATIC BD

Uses TMS-4044 or 5257L $35.00 each

SDS-RAM248K 48K kit $369.95

SDS-RAM248AT 48K A&T $419.95

SDS-RAM264K 64K kit $409.95

SDS-RAM264K 64K A&T $459.95

PROM-100 - SD Systems

2708, 2716. 2732, 2758 & 2516 EPROM programmer

SDS-PROM-100K kit $220.00

SDS-PROM-100AT A&T $275.00

QT MEMORY EXPANSION KITS

TRS-80 •APPLE* EX ID Y

4116 200 ns 8 for $32.00

2716 (5V-450 ns) $ 9.00

2716 (5 & 12V-450 ns) $ 9.00

2732 (5V) $40.00

2114L 300 ns 8 for $36.00

100 - $3.50 ea.

PARTS

MICROPROCESSORS Z80 (2MHz) .. . $10.95 Z80A (4MHz) . . $12.95

6502 $11.25

6800 $12.50

6802 $18.00

8035 $20.00

8080A $ 3.50

8085A $20.00

8086-4 $60.00

8088 $60.00

8748 $60.00

TMS 9900 JL $29.95

8080A SUPPORT

8212 $ 3.50

8214 $ 4.50

8216 $ 2.95

8224 $ 4.00

8228 $ 6.00

8238 $ 6.00

8243 $ 5.00

8251 $ 7.00

8253 $19.00

8253-5 $20.25

8255 $ 6.25

8257 $17.95

8257-5 $19.00

8259 $19.95

8275 $69.95

8279 $17.50

8279-5 $18.00

8295 $16.50

KEYBOARD CHIPS

AV5-2376 $13.75

AY5-3600 $13.75

BAUD RATE GENERATORS

MC14411 1.8432 XTAL

$11.00 $ 4.95

s^z

DISK CONTROLLER

1771B01 $24.95

B01 $37.95

EPROMS

1702A $ 4.95

2708 $ 6.25

2516 (5V) $ 9.00

2716 (5V) $ 9.00

2716 (5 & 12V) $ 9.00

2758 $19.95

2532 $40.00

2732 $40.00

USRT S2350 $ 7.95

MISCELLANEOUS OTHER COMPONENTS

N8T20 $ 3.25

N8T26 $ 2.50

N8T97 $ 2.00

N8T98 $ 2.00

1488 $ 1.25

1489 $ 1.25

D3205 $ 3.00

D3242 $14.00

P3404 $ 6.75

TMS5501 $19.00

DM8131 $ 3.00

UARTS

TR1602B $ 4.50

AY5-1013A $ 4.50

CHARACTER

GENERATORS

2513 $10.95

UP CASE (5&12V) 2513 $10.95

LWR CASE (5&12V) 2513 $ 9.75

UP CASE (5V) 2513 $10.95

LWR CASE (5V)

6800 PRODUCTS

6802P $18.00

6821P $ 5.25

6B40P $18.25

6845P $22.00

6850P $ 4.80

6860P $11.55

6875P $ 7.40

SBC+2/4 SINGLE BOARD COMPUTER

Features: 1K RAM (which can be located at any 1K boundary) plus one each Parallel and Serial I/O parts on board • Power on jump to on-board EPROM (2708 or 2716) • EPROM addressable on any 1K or 2K boundary • Full 64K use of RAM allowed in shadow mode • Programmable Baud rate selection, 110-9600 • 2 or 4MHz switch selectable • DMA capability allows MWRT signal generation on CPU board or elsewhere in system under DMA logic or front panel control • Two programmable timers available for use by programs run with the SBC+2/4 (timer output and controls available at parallel I/O connector; parallel input and output ports available for use on CPU board).

Bare Board $ 60.00

Kit $190.00

^A&T $295.00^

V!

Z+80 CPU

Features: Power on jump to on-board EPROM (2708, 2716 or 2732) • EPROM addressed on any 1K or 2K boundary: also shadow mode allows full 64K use of RAM • On-board USART for Synchronous or Asynchronous RS-232 Operation (Serial I/O port) • Programmable Baud rate selection, 110-9600 • Switch selectable 2 or 4 MHz • MWRITE signal generated if used without front panel • Front panel compatible.

Bare Board $ 50.00

Kit $150.00

A&T $210.00

RAM+16

Features: S-100, 16K x 8 bit static RAM • 2 or4. MHz • Uses 2114 1K x 4 static RAM chip • 4K step addressable • 1K increment memory protection, from bottom board address up or top down • Deactivates up to six 1K board segments to create "holes" for other devices • DIP switch selectable wait states • Phantom line DIP switch • Eight bank select lines expandable to 'h million byte system • Data, address and control lines all input buffered • Ignores I/O commands at board address.

Bare Board $ 35.00

4Mhz Kit $190.00

4Mhz A&T $225.00

RAM* 65

•S-100, 16K x 8 bit static RAM «2 or 4MHz • Uses 2114L(300NS) CHIP'Addressable in 4K steps 'Memory protection in 1K increments, from bottom board address up or top down • May deactivate up to six 1K segments of board to create "holes" for other devices • DIP switch selectable wait states • Phantom line DIP switch 'Features bank selection by I/O instruction using any one of 256 DIP switchselectable codes—allows up to 256 softwarecontrolled memory banks.

Bare Board $ 35.00

4MHz Kit $210.00

^4MHz A&T $250.00,

\

f\ COMPUTER f«J SYSTEMS ^flU I INC.

I 15620 South IngJewood Avenue I l.awndale. California 90260 J (21.1) 970-0952

QT PRODUCTS

EXPANDABLE* REV II DYNAMIC MEMORY BOARD

Features: Runs at 4MHz • 3242 refresh controller with delay line • Four layer PC board insures quiet operation • Supports 16K, 32K, 48K or 64K of memory • 24 IEEE-specified address lines • Optional M1 wait state allows error free operation with faster processors • Optional Phantom disable • Uses Z-80 or onboard refresh signal • Bank on/off signal selected by industry standard I/O port 40 (Hex) • Convenient DIP switch selection of data bus bits determines bank in use • 3 watts low power consumption • Convenient LED indication of bank in use.

Definitely works with Cromemco and North Star

Bare Board $ 75.00

^

KIT No RAM .... $230.00

16K $280.00

32K $360.00

48K $480.00

64K $525.00

A&T

16K $350.00

32K $450.00

48K $575.00

64K $675.00

J

CLOCK/CALENDAR* FOR APPLE II, S-100 OR TRS-80

Features: Date/Month/Year • Day of week • 24 hour time or 12 hour (a.m./p.m.) selectable • Leap year (perpetual calendar) • 4 interval interrupt timer: 1024Hz (approx. 1 millisec), 1 sec, 1 min., 1 hr. • On-board battery backup • Simple time and date setting • Simple software interface • Time advance protection while reading.

Battery Included S-100 or Apple TRS-80

A&T $150.00 A&T Only ... $150.00

Kit $100.00

Bare Bd $ 60.00

WATCH FOR THE FOLLOWING NEW BDS:

4 Port Serial Bd (APR) E-PROM Programmer (MAY) Floppy Disk Controller (JUN) Hard Disk Controller (JUN) Color Video Bd (AUG)

INDUSTRIAL GRADE I/O BD

Has two serial Sync/Async ports (RS-232, current loop or TTL) with individual Xtal controlled programmable baudrate generators • Four 8-bit Parallel ports; one latched input port and other three can be programmed in combinations of input, output or bidirectional • Also, has three 16-bit Programmable Timers and an 8-level Programmable Interrupt Controller w/Auto restart (8080 / Z80) • Other features include; on-board clock divisor for timers, completely socketed, wire wrap posts for easy port configuration plus more.

Bare Board $ 70.00

Kit $200.00

A&T $375.00

PLACE ORDERS TOLL FREE

1-800-421-5150

(CONTINENTAL U.S. ONLY)

fEXCEPT CALIFORNIA)

Apple is a trademark of Apple Computer, Inc. CP/M and MP/W are trademarks of Digital Research. TRS-80 is a trademark of Radio Shack. Circle 355 on inquiry card.

SILENCE+ MOTHERBOARDS

These motherboards are among the quietest on the market. A unique grounding matrix — with each line completely surrounded by ground shielding — eliminates need for termination and gives high crosstalk rejection • They're customer-proven, without crosstalk sometimes operating at 14MHz • A LED power indicator helps eliminate zapped circuits • IEEE S-100 std. compatible, available with 6,8, 12,18 or 22 slots* (The 22 slot board fits Imsai chassis and has slot for front panel.)

V

6 Slot

Bare Board .. $ 25.00

Kit $ 40.00

A&T $ 50.00

8 Slot Bare Board .. $ 27.00

Kit $ 55.00

A&T $ 70.00

12 Slot

Bare Board .. $ 30.00

Kit $ 70.00

A&T $ 90.00

18 Slot Bare Board .. $ 50.00

Kit $100.00

A&T $140.00,

QT MAINFRAMES

MF+ 5V<" Disk Mainframe with 25A Pwr Sup

MF+MD12 (12 slot M/B) $500.00

MF+MD8 (8 slot M/B) $475.00

MF+MD6 (6 slot M/B) $450.00

MF+MD w/o M/B $400.00

Q.T. Mainframe

MF+12 (12 slot M/B) $450.00

MF+18 (18 slot M/B) $500.00

MF+22 (22 slot M/B) $600.00

y

MAINFRAME+ DISK DRIVE

V

Includes cabinet, 25 amp power supply, IEEE S-100 compatible 6, 8 or 12 slot motherboard and dual 8" disk drive with disk drive power supply.

MF+DD6 $625.00

MF+DD8 $650.00

MF+DD12 $675.00

DDC-8 SINGLE 8" DISK CABINET

Accepts one 8" disk drive (Shugart, Remex, PerSci, Siemens, etc.) • Fan cooled, with data cable and AC line filter to eliminate EMI • Operates from 100-125VAC/200-250VAC at 50-60HZ • Disk drive NOT included.

DDC+8 $195.00

TERMS OF SALE: Cash, checks, money orders, credit cards accepted. Also C.O.D. orders under $100.00. Minimum order S10.00. California residents add 6% sales tax. Minimum shipping and handling charge S3.00 Prices subject to change without notice. International sales in American dollars only. ^^^^_, .

VIS* ]

BITS & PIECES

TRS-80/APPLE

MEMORY EXPANSION KITS ^ 4116's RAMS

8for*2900%

ADD S3.00 FOR PROGRAMMING JUMPERS FOR TRS-80 KEYBOARD

4116's 100 pes & UP $3.00 each 1000 pes & UP $2.75 each

2114-3L

| 4096 BIT (1024x4) 300ns | LOW POWER STATIC RAM

8/s3000

100 + s300

5257-3L

(TMS 4044)

4096x1 300ns

LOW POWER STATIC RAM

8/s5000

100 pes. + s475

2732

2716

450ns 5 Volt only 16 KEPR0M

s1195 each

or 8/s6800

2708

450ns 8K EPR0M

s850 each or 8/s5400

$25.00

450ns 5 Volt only &/$1gQQQ 32 K EPR0M 8x4K

B1232 and "D" SUB-MINIATURE

ffi^CONNECTORS fy.v.v.-.v.y.-^

—I FEMALE —1—

c aim

llOOIJBUUUBnBIJH

= Plug, Male Type - S | PART NO.

: Socket, Female Type - C = Cover, Hood

CND-0E9P CN0-DE9S CN0-DE9C CN0-DA15P CND-DA15S CND-DA15C CND-DB25P CND-OB25S CND-DBS1212 CND-P25H CND-DB51226 CND-DC37P CND-DC37S CND-DC37C CND-DD50P I CND-DD50S CND-DD50C CND-D20418

CND-RS2328F

CND-5730360

DESCRIPTION

9 PIN MALE 9 PIN FEMALE 9 PIN COVER 15 PIN MALE 15 PIN FEMALE 15 PIN COVER 25 PIN MALE 25 PIN FEMALE

1 PC. GREY H000

2 PC. GREY H000 2 PC. BLACK HOOD

37 PIN MALE

37 PIN FEMALE

37 PIN COVER

50 PIN MALE

50 PIN FEMALE

50 PIN COVER

HARDWARE SET 2 PR

RS232, DB25P, EIA

CLASS 1 CABLE 8 CON.

8 FT. CENT. 700 SERIES

PRINTER CONNECTOR

1-9 $ 2.10 $ 2.70 $ 1.50 $ 2.75 $ 3.95 % 1.50 i 3.50 i 4.60

1.60

1.50

1.90

5.80

8.70

1.80

$ 8.75

$11.65

S 2.00

S 1.00

S19.95

S 9.00

PRICE 10-24 S 1.90 S 2.40 S 1.25 S 2.45 $ 3.60 S 1.30 $ 3.25 % 4.35

1.45

1.25

1.65

5.10

7.70

1.55

7.75

$10.25

i 1.80

S .80

$17.95

$ 7.50

25-99 $ 1.70 $ 2.10 $ 1.10 $ 2.15 $ 3.20 $ 1.10 $ 3.00 $ 4.20 $ 1.30 $ 1.10 $ 1.45 $ 4.45 $ 6.70 $ 1.30 $ 6.70 $ 6.90 $ 1.60 $ .70

$15.95

$ 6.00

21 pairs of nylon guides

furnished for snap-in mounting

on .25" multiples

wi. VCT-CCK10O $4980 P1^ wibs.

RACH MOUNTABLE CAGE

Especially designed to accommodate S100 size Plugboards, Motorola Exorcisor,™ and Micromodule™ Plugboards. Cage has .081" thick anodized aluminum side walls. Will accommodate Plugboards 4.0" to 8.5" long and 10.0" to 11.5" wide by 1/16" thick. Cages assemble quickly.

CENTRONICS® 737-1

LETTER QUALITY DOT MATRIX

PRINTER

LIST $995.00 SALE

$725.00

CEN737

fc3.Shugart

SA801R SALE

SHU-SA8I 2 OR MORE

$395

$41000

00

ea.

version 2.2

LIST $400.00

SALE

California Computer Systems CCS2422A FLOPPY DISK CONTROLLER „ WITH CP/M VERSION 2.2 $375.00

IEEE S-100 COMPATIBLE SINGLE/DOUBLE DENSITY

5V4'78" DISK DRIVES

SINGLE/DOUBLE HEADED

ASSEMBLED &

TESTED

CCS-2810 Z80 CPU 2/4 MHZ CPU W/Serial I/O

List Price SALE CCS-2810 A&T $300.00 $275.00

V

s^L S-100

MOTHERBOARDS

GBT-153U GBT-153A GBT-154U GBT-154A GBT-155U GBT-155A

UNKIT 6 SLOT A & T 6 SLOT UNKIT 12 SLOT A & T 12 SLOT UNKIT 20 SLOT A & T 20 SLOT

LIST PRICE

$129.00 $169.00

$214.00

OUR PRICE $ 89.00 $119.00 $129.00 $149.00 $174.00 $189.00

MODEM SALE

$129.00

THE STAR

MODEM

from LIVERMOR

FEATURE

FITS GTE HANDSETS!

2 YEAR WARRANTY

EXCLUSIVE ACOUSTIC CHAMBERS

The exclusive triple seal of Livermore's new flat mounted cups locks the handset into the acoustic chamber yielding superior acoustic isolation and mechanical cushioning. Designed to adapt to most common handsets used throughout the world, the STAR offers the utrqost in flexibility and transmission reliability.

the utmost in tie:

Specifications:

• Data Rate: 0 to 300 baud

• Compatibility: Bell 103 and 113: CCITT

• Frequency Stability: ±0.3 percent. Crystal controlled

• Receiver Sensitivity: -50 dBm ON, -53 dBm OFF

• Modulation: Frequency shift keyed (FSK)

• Carrier Detect Delay: 1.2 seconds ON; 120 msec OFF ■ EIA Terminal Interface: Compatible with RS 232

specifications

• Teletype Interface: 20 milliampere current loop

• Optional Interfaces: IEEE 488; TTL; TTY 43

• International (CCITT) frequencies available

• Switches: Originate/Off/Answer; Full Duplex/Test/Half Duplex

• Indicators: Transmit Data, Receive Data, Carrier Ready, Test

• Power: Supplied by 24 VAC/150 MA UL/CSA listed wallmount transformer. Input 115 VAC, 2.5 waits. (A 220 VAC, 50 Hz adaptor is available upon request.)

• Dimensions: 10" x 4" x 2"

• Weight: 1.74 lbs. (3 lbs. shipping weight including AC adaptor.)

• Warranty: Two years on parts and labor, excluding the AC adaptor which carries the manufacturer's warranty

List SALE

Part No. Description Price PRICE

LIV-STAR RS232, TTL Modem $199.00 $129.00

LIV-STAR2UM RS232. 20MACurrent Loop S199.00 S129.00

LIV-STAR-V21 CCITT European Standard $229.00 $209.00

LIV-IEEE IEEE 488 Standard $395.00 $249.00

LIV-IEEE-V21 IEEE 488, CCITT Standard VS465.00 $388.00

CABLES

Part No. Description

CND-RS2328FRS232 8Cond8~ LIV-I2I IEEE to IEEE 2 Meter ,, LIW-I2PET IEEE to Pet 2 Meter.

tandard V $465.00 $388.00 ■

ES jd 99

-^Vl^^. Price ^M

. ■ ~ $19.95 ^J

1 S59.95 9M

$59.95 ^^

PROTECT YOUR INVESTMENT PROTECT YOUR DATA WITH

ISDBflR

GOF-IBAR46

LIST PRICE SALE PRICE

s7995 53995

GOLD S-100 CONNECTORS

PRIORITY ONE distributes the Tl S-100 Card Edge

Connectors at tremendous volume for prices

others only wish they could duplicate.

JTfrn. SOLDER TAIL PRICE

PartNo. V^Ol-9 10-24 25-99 100-249

TI-S100 STG^* 3,20 2.90 2.50 2.20

WIRE WRAP PRICE Part No. 1-9 10-24 25-99 100-249

TI-S100WWG 4.00 3.75 3.50

3.25

PRIORITY ONE ELECTRONICS

16723 B ROSCOE BLVD. • SEPULVEDA, CA. 91343

Terms: Visa, MC, BAC, Check, Money Order, U.S. Funds Only. CA residents add 6% sales tax. Minimum order $15.00 Prepaid U.S. orders less than $75.00 include 5% shipping and handling. MINIMUM $2.50. Excess refunded. Just in case ... please include your phone no. Prices subject to change without notice. We will do our best to maintain prices thru April, 1981'. (213) 894-8171 •SOCKET and CONNECTOR prices based on GOLD, not exceeding S.700 per oz. 'Sale Prices are for prepaid orders only. Credit card orders will be charged appropriate Ireight

ORDER TOLL FREE 1-800-423-5633 ORDER TOLL FREE 1-800-423-5633

S-100 HEADQUARTERS

THE DUAL PROCESSOR BOARD IS HERE!

GBT161 8085 CPU BOARD GBT1612 8085/8088 CPU BOARD

• 8088 & 8085A CPU

• S-100 IEEE COMPATIBLE ■ SWITCHABLE CPU'S

• 5 MHZ OR 2 MHZ SWITCHABLE

• POWER ON JUMP TO ANY 256 BYTE BOUNDARY

• POWER ON JUMP CAN BE DISABLED

• CPU CAN JUMP ON POWER ON ONLY OR POWER ON AND RESET.

• 24 BIT EXTENDED ADDRESSING

• IMSAI FRONT PANEL COMPATIBLE

• AVAILABLE WITH 8085A ONLY

BOARD WITH 8085 ONLY

List Price Our Price CBT161A Assembled & Tested $325.00 S305.00

BOARD WITH 8085 & 8088

GBT1612A Assembled & Tested $425.00

S399.00

ENHANCED Z80 S-100 CPU BOARD

GBT160 Z80 CPU

• 4-6 MHz Z80 CPU

• IEEE S-100 Bus Compatible

• On Board Prom Sockets For Up To 8K Prom

• Power On Jump Start To Any 256Byte Boundary

• On Board Memory Manager For Direct Addressing For Up To 16M-Bytes

• Fully Maskable Vectored interrupts

• Wait State Generation For All Machine Cycles

■ Bypassing Of All Supply Line To Suppress Transients

• All ICs Are Socketed

List Price Our Price

(225.00

S295.00 $280.00

G8T160U Unkit

GBT160A Assembled & Tested

SPECTRUM S-100 COLOR GRAPHICS BOARD

• Uses the MC6847 LSI IC

• Uses 1372 color encoded/generator

• Alphanumeric/graphics in 8 colors

• Ultra dense 256 x 192 full graphics

• 8K bytes, on-board low power RAM

• One full duplex parallel I/O port with attention, enable & strobe bits with power for running joysticks, keyboards, etc.

• A parallel port for graphics mode control | • Board may be used as a 4MHz RAM for program storage

LIST PRICE QUA PRICE

GBT144U UNKIT

GBTI44A A&T S399.00

GBT2D SUBL0GIC UNIVERSAL GRAPHICS INTERPRETER SOFTWARE

$299.00 $349.00

$35.00

INTERFACER I

Our I/O board gives.you inparalleled flexibility and operating convenience. We include such features as:

• 2 independently addressable serial ports (dip switch selectable addresses)

• Real LSI Hardware UARTs for minimum CPU housekeeping

• RS232C. current loop (20mA). & TTL signals on both ports

• Precision, crystal-controlled Baud rates up to 19.1 KBaud (Individually dip switch selectable)

• Transmit & receive interrupts on both channels, jumperable to any vectored interrupt line

• Industry standard RS232 level converters with five RS232 handshaking lines per port

• Optically isolated current loop with provisions for both onboard & off-board current sources

• UART parameters, interrupt enables. & RS232 handshaking lines are software programmable with power-on hardware default to customer specified hard-wired settings for maximum flexibility

• Port connectors mate directly to ribbon cable & DB25 connectors in standard pinouts

• RS232 lines will conform to either master or slave configurations

• Board gives full feature operation with both 2 & 4 MHz systems

• Low power consumption: *8V @450mA: • 16V @ 150mA: -16V f3>70mA max.

• No soltware initialization required for board operation, although board parameters may be altered by software

LIST PRICE OUR PRICE GBT133U UNKIT S199.00

GBT133A A&T $249.00 $219.00

INTERFACER II 3PTS

1 independently addressable serial port

RS232C: 20mA current loop, & TTL signals

Precision crystal controlled Baud rate generator

Up to 19.2K Baud

Transmit and receive interrupts, jumperable to and vectored

interrupt line

Five RS232 handshaking lines

Optically isolated current loop

3 parallel I/O

Utilizes LSTTL octal latches for latched I/O data with 24mA

drive current

Enable & strobe bits on each port (each with selectable

polarity) < Interrupts for each input port ■ Separate 25 pin connector with power lor each channel and a

status port for interrupt mask & port status

LIST PRICE OUR PRICE

ECONOROM 2708

Has provisions for wait states for 4MHz operations. Configured as four 4K blocks—each independently addressable and disababie. Power-on jump. Does NOT include 2708s. Includes all support chips, sockets, regulators. heat sinks, etc. Sold in UNKIT form only. Shipping Weight 2 lbs. GBT125U Unkit $85.00

*NEW!*

DISK 1 HIGH

PERFORMANCE

FLOPPY DISK

CONTROLLER

Finally, a floppy disk controller worthy of bearing the CompuPro name is now available for integration into your S-100 system. The DISK 1 floppy controller incorporates numerous features that were previously unavailable on a DMA floppy disk controller board. DISK fully complies with the IEEE 696 bus standard, INCLUDING DMA ARBITRATION!

Third generation INTEL 8272/NEC 765A LSI floppy

disk controller.

High speed cycle stealing DMA interface for processor independent data transfer between system

memory and flexible disk.

Handles up to four 8 or 5.25 inch floppy disk drives.

Single or double density / single or double sided

capability.

Supports IBM 3740 soft sectored formats.

24 bit DMA addressing with data transfer across

64K boundaries for data transfer throughout the

16Mbyte memory map.

I/O mapped interface allows contiguous system

memory. (DISK 1 occupies no memory space)

On board Phantom boot EPROM for automatic

startup.

On board serial port for initial system startup.

Board compatible with MP/M, OASIS, CP/M-80 and

CP/M-86.

Board supplied with BIOS for CP/M-80

CP/M-80 and CP/M-86 available for DISK 1.

CPU speed independent data transfer for operation

up to 10MhZ.

Fully arbitrated DMA interface as per IEEE 696 for

allowing multiple DMA devices without conflict.

May be interrupt driven for multi-user environments.

Up to 600K bytes per side (8 inch drive) for an on-line

total of up to 4.8M bytes (4 drives - double sided

-double density)

LIST PRICE OUR PRICE GBT-171BA Disk 1 A&T $495.00 $445.00

SYSTEM SUPPORT 1 MULTIFUNCTION BOARD

This multi-purpose S-100 board provides your computer with the most needed system support functions -at less cost than buying numerous single function boards. Includes sockets for 4K of extended address EPROM or RAM (2716 pinout), 1 socket with battery backup; crystal controlled month/day/year/time clock with BCD outputs; optional high speed math processor (9511 or 9512); full RS-232 serial port; three 16 bit interval timers (cascade or use independently); two interrupt controllers service 15 levels of interrupts; power fail indicator with provision to switch CMOS memory to battery backup; and comprehensive owner's manual with numerous software examples. Conforms fully to all IEEE 696/S-100 standards.

Want to make your S-100 system more versatile? System Support 1 is the answer.

LIST PRICE OUR PRICE GBT-162U unKit 5295.00

GBT-162A A&T $395.00 $360.00

GBT-9512 Match Clip $195.00

Static S-100 Memory

PRIORITY ONE ELECTRONICS (2i3i

16723 B ROSCOE BLVD. • SEPULVEDA, CA. 91343 '

32K ECONORAMXX

32K Bank Select. IEEE S-100 compatible. Features one 32K block that can be addressed on 4K boundaries. Compatible with the IEEE proposed standard of 24 address lines as well as all currently used bank select configurations. Any or all of the eight 4K byte blocks may be disabled to create as many windows in memory to avoid any system memory conflicts.

List Price Our Price

GBT164A16 16K RAM A & T $399.00 $329.00

GBT164A24 24K RAM A&T $539.00 $455.00

GBT164A32 32K RAM A&T $699.00 $569.00

894-fti

CA residents add 6% sales tax, ®lf1

Terms: Visa, MC. BAC. Check, Money Order, U.S. Funds Only.

Minimum order $15.00 Prepaid U.S. orders less than $75.00 include 5% shipping and handling.

MINIMUM $2.50. Excess refunded. Just in case ... please include your phone no. Prices subject to

change without notice. We will do our best to maintain prices thru APRIL, 1981

'SOCKET and CONNECTOR prices based on GOLD, not exceeding $700 per oz.

•Sale Prices are for prepaid orders only. Credit card orders will be charged appropriate freight

ORDER TOLL FREE 1-800-423-5633 ORDER TOLL FREE 1-800-423-5633

Circle 356 on inquiry card.

IMAGINE THE STOI AN 8 INCH FLOPPY

315K BYTES PER SIDE ON 5 1/4" OF COURSEI Micropolis. the worlds largest manufacturer of high density 51/4" disk drives, has been doing it for years. Arid reliably at that.

An ordinary 5 1/4" floppy provides just 35/tracks per side and stores only 70K bytes; This is not nearly enough for anything useful, so instead, Micropolis uses 77 tracks per side. Each track is then formatted with 16 sectors (hard) at 256 bytes per sector yielding an impressive 315K bytes per side.

Micropolis drives have a larger capacity than many 8" disk drives, though it only occupies the "space of a 5 1/4" floppy The 315K byte capacity is roughly 4 times the capacity of a standard 5 1/4" drive. This is what we call QUAD DENSITY.

To achieve the high density capability, you may think Mcropolis had to sacrifice speed or reliability. NOT SO! The track to track access firhe is only 30ms with a high speed data transfer rate of 250,000 bits per second,

By creating this high density format, Micropolis is able to keep your initial subsystem costs to a minimum. Your cost is less than $.002 per byte. Thats a BIG VALUE in a small package.

MICROPOLIS disk subsystems are expandable to keep up with your ever increasing needs. Up to four drives/heads may be daisy-chained on one S-lOO controller board. With all four drives/heads in operation, you have access to over 1.2 MEGABYTES of on-line storage.

WITH MICROPOLIS, complete means COMPLETE, Each subsystem comes complete with controller interface, cable, and software. The software Includes the MDOS operating system extended basic, assembler and editor. Everything you need to get "On Line" In one complete package.

MICROPOLIS provides total Integration which means they control everything from beginning to end. The result is a better drive for you, backed by a full 120 day factory guarantee.

Anyone can cut price.by cutting out capacity or valuable features. But there's no long term advantage in it. Not for the user. Or the builder.

MICROPOLIS takes a better approach, even though it's harder, using advanced design to provide more capability while also lowering cost,

For example, most 51/4-inch floppy disks cut costs by using a cheap, less accurate plastic cam or cam follower to position the read/write head. Most 8-inch floppy disks use a better approach, with a rolled steel lead screw for this function.

We go them one better and use an all-steel system, with a precision-ground steel lead screw and" steel follower. It costs more but gives us greater storage capacity with lower cost per thousand bytes. Not so incidentally, our steel construction (compared to plastic) significantly increases reliability, too. There's even a built-in File Protect feature that prevents accidental loss of valuable data. (A file protected diskette cannot be written on.)

Heat can cause numerous read and write errors that can become hazardous to your data. The major heat producing power supply components are mounted to a large heat sink, external to the cabinet, by the power switch and fuse (located at the rear of the cabinet), This design is to assure that the drive components are kept as cool as possible to assure reliable data recovery.

MICROPOLIS has a reputation for getting along with most everybody. Compatabllity is not a problem with MICROPOLIS. Their disk drives and/or subsystems can be easily integrated into systems such as Polymorphic, Cromemco, CCS, Ithica Intersystems, Godbout, Northstar, Jade Big Z, QT SBC 2/4, and many others. Many OEM manufacturers rely on MICROPOLIS to get the job done efficiently. Companies like Commodore, Exldy, Harris, and Vector Graphics to name just a few. Years from now, you can look back with a secure feeling knowing you made the best choice. MICROPOLIS.

HGE CAPACITY OF IN 5 1/4" FORMAT

THIS

/VtKtf*OT5C^»JKi

NOT THIS

minimi

Because of our incredible purchasing power, PRIORITY ONE ELECTRONICS is able to buy MICROPOLIS disk drives by the thousands and receive special pricing. That special pricing we receive is passed on to you in the form ot tremendously discounted prices. Now all thai remains is for you to take advantage of this truly incredible buy.

MODEL

MCP-1053-4 MCP-1053-2 MCP-1043-2 MCP-1041-2 MCP-1042-1 MCP-1041-1

DESCRIPTION

S-100 SUBSYSTEMS

LIST

1.2 MB 2 HEAD DUAL

630 KB DUAL

315 KB SINGLE

315 KB SINGLE, NO PS

143 KB SINGLE

143 KB SINGLE, NO PS

$2605.00 $1895.00 $1145.00 $1045.00 $795.00 $695.00

SALE PRICE

$1395.00 $995.00 $695.00 $639.00 $625.00 $595.00

COMPLETE W/S-100 CONTROLLER, CABLES, MANUALS AND MICROPOLIS MDOS AND BASIC

ADD-ON DRIVES

MCP-1033-2 MCP-1023-2 MCP-1021-2 MCP-1022-1 MCP-1021-1

630 KB DUAL

315 KB SINGLE

315 KB SINGLE, NO PS

143 KB SINGLE

143 KB SINGLE, NO PS

$1395.00 $645.00 $545.00 $545.00 $445.00

$895.00 $495.00 $475.00 $375.00 $360.00

REQUIRES ACCESSORY ADD-ON CABLES

GOOD NEWS FOR TRS-80* OWNERS

We now have a complete line of TRS-80* Model 1 compatible MICROPOLIS add on drives in matching colors. These drives simply plug into the expansion interface via a disc data cable.

197K BYTES PER SIDE FOR YOUR TRS-80*, that's easy! Just order a 77 track add on drive and the New DOS-80 operating system. Among the many features of New DOS-80, is its ability to control any mix of 35, 40, or 77 track drives on the same cable.

TRS-80® DISK DRIVES

MCP-1027-1 MCP-1037-1 MCP-1027-2 MCP-1037-2

APP 395M

PR1-34CEEE-2 PR1-34CEEE-4

35 TRACK SINGLE 35 TRACK DUAL 77 TRACK SINGLE 77 TRACK DUAL

$545.00 $1195.00

$645.00 $1395.00

ACCESSORIES

NEW DOS/80 TRS-80®

35 thru 77 SUPPLIED

TRACK OPERATING 35 TRACK

SYSTEM $149.00

Two Drive Data Cable Four Drive Data Cable

GOOD THRU APRIL 1981

$279.00 $695.00 $439.00 $795.00

ON

77 TRACK

$159.00

$29.95 $39.95

THIS COULD BE THE START OF SOMETHING SMALL.

SEE US AT THE WEST COAST COMPUTER FAIR

AND PICK UP YOUR DRIVES.

1-800-423-5633 PRIORITY ONE ELECTRONICS

16723 B ROSCOE BLVD. • SEPULVEDA, CA. 91343

(213)894-8171

Terms: Visa, MC, BAC, Check, Money Order, U.S. Funds Only. CA residents add 6% sales tax, Minimum order $15.00 Prepaid U.S. orders less than $75.00 include 5% shipping and handling. MINIMUM $2.50. Excess refunded. Just in case ... please include your phone no. Prices subject to change without notice. We will do our best to maintain prices thru April 1981. 'SOCKET and CONNECTOR prices based on GOLD, not exceeding $700 per oz.

*Sale Prices are for prepaid orders only. Credit card orders will be charged appropriate freight

•TRS-80 is a registered trademark of Tandy Corp.

Circle 357 on Inquiry card.

Best Prices and Delivery!

i

SUPERBRAIN by Intertec

Self-contained computer with duat disks and two RS232C ports. Complete with CP'M' 2.2 and BASIC. ......

32K Double Density, List $2995 . YtUOU

64K Double Density, List $3345 $2883

64K Upgraded to Quad Density w/Special MiniMicroMart Warranty SPECIAL $3395

VIDEO TERMINALS

/VflrVEMULATOR (Intertec), List $895$ 749 NEW INTERTUBE IHList $895 ... ONLY $ 749 SOROC 120, List $995 SPECIAL $ 729

1Q140, List $1495 SPECIAL $1149

PERKIN-ELMER 550, List $997 $ 799

with anti-glare screen, $1027 $ 829

HAZELTINE 1410, List $900 $ 749

1420 $ 849

1500, List $1225 $ 879

1510, List $1395 $1089

1520, List $1650 $1389

LEAR SIEGLER ADM3A, Assembled . . $ 849

TELEVIDEO 912C, List $950 $ 789

920C. List $1030 $ 849

950C, List$1195 NEWS1039

ANADEX DP-8000 $ 849

DP-9500, List $1650 $1399

DP-9501. List $1650 $1399

PAPER TIGER IDS-445, List $995 $ 695

w/graphics op., incl. buffer, $1195 .. $ 789

PAPER TIGER IDS-460, List 1149

PAPER TIGER IDS-460G List 1199

NEW IDS PAPERTIGER 460 . List 1295 SH49 NEW IDS PAPERTIGER 460G List $1394 $1199

NEC Spinwriters Call for Price

TELETYPE 43 KSR $1087

CENTRONICS 730-1 parallel interface .. NEW LOW $ 649 737 parallel interface . SUPER VALUE $ 829 779 w/Tractor, List $1350 $1049

703 w/Tractor, VFU, List $2975 $1695

704 w/Tractor, VFU, List $2350 $1595

Tl 810 Basic, List $1895 $1695

810/serial & Centronics-style

parallel interface. List $1940 $1735

810 w'full ASCII (U/LC), Vertical Forms Control, Compressed Print . . $1895

Tl 820 KSR, List $2165 $1895

Tl 745 w/full ASCII, List $1695 $1399

COMPRINT 912 w/parallel interface . . $ 559

912 w/serial interface, List $699 $ 589

AXIOM IMP I $ 699

MICROTEK, List $750 $ 675

OKIDATA Microline 80, List $949 $599

Tractor Feed Option $109

RS232 Serial Interface $ 99

NORTH STAR HORIZON"

HORIZON 1 ASSEMBLED & TESTED

32K, Double Density, List $2695 .... $2279 32K, Quad Density, List $2995 $2539

HORIZON 2 ASSEMBLED & TESTED

32K, Double Density, List $3095 $2619

32K, Quad Density, List $3595 $3049

48K, Double Density, List $3590 $3039

48K, Quad Density, List $4090 $3469

64K, Double Density, List $3830 $3239

64K, Quad Density, List $4330 $3669

FLOPPY DISK SYSTEMS

NORTH STAR MDS-A

Assembled, List $899 . .

MORROWTHINKERTOYS- Discus2D,

List $1199 OUR PRICE $ 998*

Discus 2D, dual-drive. List $1994 $1694*

Discus 2 + 2, A&T, List $1549 $1319*

Dual Discus 2 + 2, A&T, List $2748 . . . $2335* "Now includes CP/M" 2.2

Prom Programers

SSMPB1 Kit List $125 $106

SSM PB1 A&T List $190 $161

SD Computer Prom 100 Kit $236 $201

SD Computer Prom 100A&T List $311 . . $264

FLOPPY DISK CONTROLLER BOARDS

NORTH STAR, DD,

Assembled, List $499 $399

MORROW Disk Jockey 1, A&T ($213) . $189

Disk Jockey 2D, A&T, List $479 $429

SD Versafloppy 1, Kit, List $284 $239

Versafloppy II, DD Kit, List $413 $349

Versafloppy II, DD, A&T, List $507 . . . $429

DELTA double density A&T ($385) $345

CONDUCTOR, double density A&T . . . $269 INTERSYSTEMS FDC-2, A&T, $495 . . . $439 MICROMATION Doubler, DD, A&T . . . $429 TARBELL Floppy Disk Interface Kit ... . $199

double density, A&T, List $495 $444

CPU BOARDS

(assembled unless noteai NORTH STAR Z80A IZPB-A'AI, $299 $254 CROMEMCO 4 MHz (ZPU-W), List $395 $335

4 MHz (SCC-W), List $450 $382

INTERSYSTEMS (formerly Ithaca Audiol new Series II Z-80, 4 MHz. List $395 . . . $349

SSM CB1 8080 A&T List $252 $214

CBIAKit, List$183 $156

CB2 Z-80, A&T, List $344 $289

CB2 Kit, List $60 $221

DELTA Z-80, with I/O $289

SD SBC-100, List 413 $349

SBC-100 Kit, List $341 $289

SBC-200, List $471 $399

SBC-200 Kit, List $373 $317

MEMORY BOARDS

specials 719 32K SD ExpandoRAM Kit

CALL FOR PRICES

ESCON CONVERSION FOR IBM SELECTRIC

Complete w/microprocessor controller and power supply. Factory built. User installs solenoid assembly or it can be done at Escon factory at nominal cost. Parallel (TRS-80, Sorcerer, etc.), $575 $514

RS232 Standard Serial, List $599 534

IEEh-488 (for PET), List $660 584

TRS-80 Cable 25

CALIFORNIA COMPUTER SYSTEMS

Z80 CPU BOARDS List $299 $269

DISK CONTROLLER 2422 List $399 .... $359

16K Static, A&T, List $349.95 $259

32K STATIC List $71 0 $599

64K DYNAMIC BOARD List $699 $589

NORTH STAR 16K Dynamic RAM Board,

A&T (RAM-16-A/A), List $499 $42(

32K A&T (RAM-32/A), List $739 $62C

CROMEMCO 16KZ-W, List $495 $419

64KZ-W, List $1795 $1269

MEASUREMENT SYSTEMS & CONTROLS

(Guaranteed performance, incl. labor/parts 1 yr DM6400 64K Board w/all 64K, $795 . . . $65'

DM4800 with 48K, List $695 $65(

DM3200 with 32K, List $595 $50!

DMB6400 64K Board w'all 64K $85!

DMB4800 with 48K $78!

MORROW SuperRAM - all static, all A&T

16K, 4 MHz or 2 MHz, List $349 . $299

32K, 4 MHz, List $699 $629

16K Memory Master, List $399 $339

24K Memory Master, List $549 $465

INTERSYSTEMS (formerly Ithaca Audio)

8K Static 2 MHz, A&T, List $165 $149

8K Static 4 MHz, A&T, List $195 $176

16K Static 2 MHz, A&T, List $475 $427

16K Static 4 MHz, A&T, List $495 $445

64K Dynamic, List $995 $895

CALIFORNIA COMPUTER

16K Static, A&T, List $349.95 $259

I/O Mapped SD COMPUTER VDB-8024, kit, List $437 . 369

Assembled, List $556 $469

XITEX SCT-100K, Kit ONLY $169.95

SCT-100A Assembled $189.95

SSM VB2 I/O, Kit, List $199 $169

Assembled & Tested, List $269 $229

Memory Mapped

SSM VB1C, 16x64, Kit, List $179 $152

Assembled & Tested, List $242 S206

SSM VB3, 80-Char.,4MHz,Kit.List$425- • $359

4 MHz, A&T, List $499 $424

INTERSYSTEMS, Ibxba, A&T, List $1bb $149 "Subject to change.

NEW CROMEMCO 16FDC DOUBLE DENS

0ISK CONTROLLER List $595 OUR PRICE

SHIPPING AND INSURANCE: Add $2.50 for boards, $6 for Selectnc Converter or Floppy Disk Drives, $7 50 for Floppy Disk Systems, $15 for Horizon. SHIPPED FREIGHT COLLECT SuperBram, Centronic

and T.I. printers. Contact us for shipping information on other terminals and printers.

Mjove prices reflect a 2% cash discount (order prepaid prior to shipment) Add 2% to prices for credit card orders, C.O.D.'s, etc. Prices are subject to change and offers subject to withdrawal without notice

MiniMicroMart, Inc.

1618 James Street, Syracuse NY 13203 (315)422 4467 TWX 710-541-0431

If North Star or Cromemco offer it..

WE HAVE IT!!

Immediate Delivery at Discount Prices

NORTH STAR Horizon 2

32K Double Density

Assembled and Tested

LsXl5y$2619

S3

ASSEMBLED

HORIZON 1. DD $2279 32K. QD, List $2995 2539

HORIZON 2, 32K, DD $2619

32K. QD. List $3595 3049

48K, DD, List $3590 3039

48K, QD, List $4090 3469

64K, DD, List $3830 3239

64K, QD, List $4330 3669

NORTH STAR APPLICATIONS SOFTWARE

(Exclusive lor use with North Star Disk Systems — specify Double or Quad Density)

NORTHWORD, List $399 $339

MAILMANAGER, List $299 249

INFOMANAGER, List $499 419

GENERALLEDGER, List $999 799

ACCOUNTSRECEIVABLE, List $599 499

ACCOUNTSPAYABLE, List $599 499

NORTH STAR HARD DISK HD 18

18 megabytes, plugs into parallel port of North Star Horizon. Utilizes tried-and-proven 14" Century Data Marksman. List $4999. QUR pR|CE $41gg

NORTH STAR MDS-A - Double (or Quad)

Density Disk System, Kit, List $799 . OUR PRICE $669 Assembled and Tested, List $899 SPECIAL $719

NORTH STAR MEMORY BOARDS

16K Dynamic RAM (RAM-16-A/A), Assembled. List $499 $420

32K IRAM-32/AI, Assembled, List $739 $620

INTRODUCTORY SPECIALS ON ...

PREMIUM QUALITY BASF DISKS CERTIFIED FOR QUAD SYSTEMS

5V DOUBLE DENSITY DOUBLE SIDED usi$57.50 8" DOUBLE DENSITY DOUBLE SIDED ust$75.00 . Shipping $2 50 - Free Shipping In Multiple 01 Two Boi i

(Box of ten)

., $38.95 . . $47.49

/MEW System 3

by CROMEMCO

Now with Dual

Double Sided

Double Density

over 2 megabytes

of Storage)

64K of RAM

List $7995

LIMITED TIME

$6395

CROMEMCO SYSTEM 2 — Now double Density with Double Sided Drives, Quad Capacity mini floppy disc drives. List $4695 Only $3899

CROMEMCO Z-2H

Ful

11-megabyte Hard Disk system. Fast Z-80A 4 MHz processor, two floppy disk drives, 64K RAM memory, RS232 special interface, printer interface, and extensive software available. List $9995

our price $8489

NEW DOUBLE DENSITY CONTROLLER BOARD From Cromemco

With built-in diagnostics — 16 FDC Controller List $595 OUR PRICE $505

Z-2 COMPUTER SYSTEM List $995 $845

SINGLE CARD COMPUTER - SCC-W 4 MHz. List $450 $382

NEW COLOR GRAPHICS INTERFACE - SDI List $595 OUR PRICE $505 CROMEMCO HOD — 11 /22-megabyte Hard Disk for use with existing systems. DMA controller. Transfer rate of 5.6 megabytes/second.

H00-11. List $6995 OUR PRICE ONLY $5939

HDO-22. List $11,995 $10,189

SHIPPING AND INSURANCE: Add $15 or Horizons, $2.50 fo Advertised prices are for prepaid orders. Credit card and CO subject to withdrawal without notice.

r Boards and Software. Hard Disk Systems and Cromemco systems shipped freight collect. D. 2% higher. Deposit may be required on C.O.D. All prices subject to change and offers

WRITE FOR FREE CATALOG

MiniMicroMart, Inc.

1618 James Street, Syracuse, NY 13203 (315)422-4467 twx 710-541-0431

master charge

Circle 358 on Inquiry card.

Computers, Disk System

YfHiza I data

I systems

Z89-FA

List $2895

OUR PRICE $2395

Z-89GA

List $2595 $2149

A-87 Two Drive

Minifloppy System List $1195 $989

Z-47DA $3695

8" Two Megabyte List $3695 $3059

INTERSYSTEMS

formerly ITHACA AUDIO

The new Series II CPU Board features a 4 MHz Z-80A CPU and a full-feature front panel. 20slot actively terminated motherboard, with 25 amp power supply (50/60 Hz operation, incl. 68cfmfanl. DPS-1, List $1795

$1495

COMPLETE SYSTEM with InterSystem 64K RAM, I/O Board w/priority interrupt and double density disk controller board. Full 1-year warranty, List $3595

$2995

NEW! CR0MEMC0 SYSTEM ZERO

List $995 OUR PRICE $849

NEW! CROMEMCO SYSTEM ZERO/D

A complete 64K Computer with Double Density Disk Controller List $2995

OUR PRICES2545

Companion Disk drive for above —

Quad Density — Total of 780 Kilobytes of

storage on the two drives List $1295

OUR PRICE $1099

Only $3644 for a complete 64K Disk System

SUPERBRAIN

BvlNTERTEC

64K Double or Quad Density units available. Uses two Z-80 CPU's. Commercial-type terminal with 12" monitor. Dual double density minifloppies. Over 350 kilobytes of storage (twice that with quad density drives). Two serial RS232 ports, I/O ports standard. Expandable with optional S-100 S-100 interface. Comes with CP/MTM 2.2 operating system. MiniMicroMart can supply a wide range of CP/M development and application software.

w/64K Double Density, List $3495 .. $2869 W/64K Quad Density, List $3995 $3395

HEWLETT PACKARD

HP-41CV

HP-41 System I-$399.

(The HP-41CV and HP82104A Card Reader) List $495. HP-41 System II—$679.

(The HP-41CV andHP82104A Card Reader, HP82143A Printer/Plotter) List $ 840.

HEWLETT-PACKARD

HP-85A DeskTop

Computer

MORROW

THINKER TOYS® DISCUS M26™

26 megabytes of formatted storage List $4,995

$4,199

List $3250

$2749

THINKER TOYS® DISK SYSTEMS

Now includes CP/M® 2.2

Discus 2D, List $1199 $1019

Discus 2D, dual-drive, List $1994 $1694

Discus 2 + 2, Assem., List $1549 $1319

Dual Discus 2 + 2, Assem., $2748 $2335

All Morrow systems now include CP/M' 2 2

MORROW

Discus 2D's IN STOCK

NEW! CR0MIX FROM CROMEMCO

A New UNIX Like Disk Operating System,

With true multi-user,

multi-tasking capabilities

List $295 OUR PRICE $249

NEW! DOUBLE DENSITY CONTROLLER BOARD

FROM CROMEMCO

With built-in diagnostics 16 FDC Controller, List $595 OUR PRICE$505

RADIO SHACK TRS-80™

10% OFF!,

Terminals and Printer

Intertec

EMULATOR

Software compatible with a Soroc IQ-120, Hazeltine 1500, ADM-3A or DEC VT-52. Features block mode transmission and printer port; 12" anti-glare screen; 18-key numeric keypad; full cursor control. List $895

OUR PRICE $749

NEW INTERTUBE III

List $995 ONLY $749

12" display, 24 x 80 format, 18-key numeric keypad, 128 upper/lower case ASCII characters. Reverse video, blinking, complete cursor addressing and control. Special user-defined control function keys, protected and unprotected fields. Line insert/delete and character insert/delete editing, eleven special line drawing symbols.

TELEVIDEO TVI-912C

T,'.y.;.i.i.!.i.!.!.!.i.lH

Upper and lower case, 15 baud rates: 75 to 19,000 baud, dual intensity, 24 x 80 character display, 12 x 10 resolution. Numeric pad. Programmable reversfole video, auxiliary port, self test mode, protect mode, block mode, tabbing, addressable cursor. Microprocessor controlled, programmable underline, line and character insert/delete. "C" version features typewriter-style keyboard. List $950

OUR PRICE $789

HAZ

1500 ONLY

$879

PAPER TIGER

1410 w/numeric keypad, List $900 $749

1420 w/lower case and numeric pad 849

1510, List $1395 1089

1520, List $1650 1389

SOROC

IQ-120

List $995

SPECIAL

729

IQ-140 List $1495 SPECIAL $1149

CENTRONICS

PRINTERS

NEW 730, parallel, friction, tractor . . . $679

NEW 737 parallel, friction, tractor $849

779-2 w/tractor (same as TRS-80 Line

Printer I), List $1350 1049

702 120 cps, bi-direct., tractor, VFU .... 1995

703 185 cps, bi-direct., tractor, VFU .... 2395

704 RS232 serial version of 703, $2350 . . $1995

NEC SPINWRITER ™

Terminal/Keyboard as well as

RO Printer Only models available.

CALL FOR PRICES!

IDS 455 Paper Tiger, List $995 $895 w/graphics option, incl. buffer, $1194 . . $989 TRS-80 cable 45

NEW IDS 460

QUALITY PRINTING AT MATRIX

SPEED-LOGIC SEEKING

PROPORTIONAL SPACING

w/auto text justification

NEW IDS PAPERTIGER 460List $1295 . $1099 NEW IDS PAPERTIGER 460G List $1394 $1149

TI-810

TI-810 Basic Unit, $1895 . ONLY $1595 TI-810 w/full ASCII (Lower case), vertical

forms control, and compressed print . $1795 TI-745 Complete printing terminal with acoustic coupler, List $1695 .... $1399

RNFID6X

DP9500/DP9501 PRINTCRS

DP-9500. List $1650 $1349

DP-9501, List $1650 $1349

ANADEX 80-Col. Dot Matrix $849

OKI DATA

Microline80 ONLY $599

Tractor Feed Option $109

Serial interface $ 99

AXIOM IMP I $699

COMPRINT 912 w/parallel interf $559 912 w/serial interface, List $699 $589

MICROTEK, List $750 $675

920C (with 11 function keys, 6 edit keys and Above prices reflect a 2% cash discount (order prepaid prior to shipment). Add 2% to prices for credit 2 transmission mode keys. List $1030 card orders, C.O.D.'s, etc. Prices are f.o.b. shipping point. Prices are subject to change and offers

ONLY $849 subject to withdrawal without notice. WRITE FOR FREE CATALOG.

MiniMicroMart, Inc.

1618 James Street, Syracuse NY 13203 (315) 422-4467 TWX 710-541 -0431

Circle 359 on Inquiry card.

Unclassified Ads

UNCLASSIFIED POLICY: Readers who are soliciting or giving advice, or who have eguipment to buy, sell or swap should send in a clearly typed notice to that effect. To be considered for publication, an advertisement must be clearly noncommercial, typed double spaced on plain white paper, contain 75-words or less, and include complete name and address information.

These notices are free of charge and will be printed one time only on a space available basis. Notices can be accepted from individuals or bona fide computer users clubs only. We can engage in no correspondence on these and.your confirmation of placement is appearance in an issue of BYTE.

Please note that it may take three or four months for an ad to appear in the magazine.

FOR SALE: Apple Pascal language system. Never used, still in original packing with factory warranty for $400. M Antonovich, Box 6020, Wyomissing PA 19610.

FOR SALE: Moving, must sell; complete Texas Instruments 9900 minicomputer. Processor board with operating system in prom, 2 K cache programmable memory, 9900 processor, and I/O interface. Memory board with 32 K bytes of programmable memory and complete buffering. Cassette interface and 9600 bps digital cassette player/recorder. Complete system software: Assembler, Linking Loader, Text Editor, Super BASIC, and lots of games. All contained in a fan-cooled chassis. Total price for entire hardware/software computer system is $1800. Bernard H Penney, 31 Wheeler Dr, Peekskill NY 10566, (914)945-1044 day/(914) 528-1612 night.

FOR SALE OR TRADE: Kenwood amateur radio equipment: TS520S transceiver, frequency readout, AT200 tuner, 6- and 2-meter transverters, and variable frequency oscillator. All service manuals and cables included. Will sell or trade for Heath H-89 or H-8 computer system. Edward H Hill Sr, 3046 Stuart St, Indianapolis IN 46218, (317)545-8886.

FOR SALE: PDP-11. DEC PDP-11/05 processor boards with 4 K core memory, 16 to 64 K programmable memory, and parity controller. All working. Also, Tl Silent 743 (new) with full ASCII keyboard. Sell all, separately, or trade for line printer or what have you. Make offer. Jack Kreska, 1429 Warwick St, Garland TX 75042, (214) 495-2680.

FOR SALE: Microcomputer magazine collections. BYTE 10/76 (#14) to 12/80 (51 issues) for $50. Kilobaud Microcomputing 1/77 (#1) to 12/80 (all 48 issues published) for $70. Interface Age 7/76 (#8) to 8/80 (48 issues plus several original SCCS journals) for $35. All plus book rate postage. John Cameron, POB 1517, Palo Alto CA 94301, (415)327-0341.

HELP: I need any information at all about a Compucord 1210 digital cassette tape transport made by Compucord Inc of Waltham, Massachusetts. The company no longer exists, at least in Waltham. Any information regarding this device, the manufacturer, or any source of documentation is eagerly sought. I will be happy to pay for copying, or copy and return all material by return mail. Fred Goldberg, 29 Clearview Rd, E Brunswick NJ 08816, (201)257-8753.

MUST SELL: One slightly used Cray-1—too big for my apartment. Hardware included: light-dimmer interface, toaster interface, one homebrew 64-bit parallel I/O port with Nixie-tube indicators, coat hangers, extra buffing powder for instruction buffers, one box of bootstraps. Software included: CAL assembler on thirteen cassette tapes in Kansas City format, Morse-code trainer, tic-tactoe game, 8080 emulator. Price is negotiable. A Pri.fiil, POB 463, Peanutbutter NH 03458.

FOR SALE: TI-59, PC-100A (in perfect working condition), three modules (Master, Statistics, Mathematics and Utilities), eight specialty packettes (Engineering, Science, Securities, Marketing, etc), 20-roll paper for PC100A, and many finance utility programs. If brand new, you would pay $640. Now all can be yours if you send a . cashier's check for $460. C M Chen, 120 Columbus PI. Stamford CT 06907, (203) 322-7857.

WANTED: MMD-1 microprocessor trainer in operating condition. Please state asking price in first offer. D C Shoemaker, 2000 A Foxridge, Blacksburg VA 24060, (703) 552-5764.

FOR SALE: 48 K Apple II plus complete with two paddles, some programs, and cassette recorder with interface jack. Only three months old and in great condition. $1300. Eric Podell, 14949 Wellwood Rd, Silver Spring MD 20904.

FOR SALE: Sold system, must sell software at super reduced prices. Dozens of CP/M, languages, business s/w (G/L, A/R, A/P, etc). Send SASE for complete list and prices. Dee B Moser, Box 638, Great Bend KS 67530.

WANTED: June 1977 and October 1980 issues of BYTE. Will pay cash or trade March 1978, July 1980. August 1980, September 1980 issues. Also, I have for sale a Godbout 8 K S-100 4 MHz programmable memory board, assembled and working; $50. Thomas Kryst, 5242 E 24th St Apt D, Anchorage AK 99504.

HICKOK DIGITAL MULTIMETERS

MX-333

Model LX303

6950

MlZ Tech DMM 3V2Digit LCD Readout

MDdel WD 747 $7Q95

Beckman DIGITAL MULTIMETERS

Model TECH 300 1 09 Model TECH 310 140 Model TECH 330 1 99

Simjuon DIGITAL MULTIMETERS

Model 462 Model 463 „__

f19995$16995

iSo

260 Meter~~

Model 260-7

$QC Complete with nickelY"* cadmium batteries, AC

charger/adapter, test leads

Magnifier Lamp

Precision ground and polished magnification lens

Model LFM-1A

Casio Calculator Calendar Watch

Model C-atj

$4250

Watclr

BSSSSMJ 15MHzMiniscope

■ Rise time 11.7 nS or less ■ Built-in signal delay line ■ Flat

Dual Trace

ffl5" 30 MHz ^Triggered Scope

Model 1479A

Digital

Pulsar Probe Model dp-ido

50 MHz

Pulsar Probe Model dp-so

L*J

.© i

__ i * •

y©.|

Model 1420

Autoranging DMM

3V2-Digit 0.1% Digital A Capacitance Meter

| Model 3001 $233^^

Function Generator

Model 2001 $"] 5795

Proto Boards

Fully assembled

*5995

Logic Monitor

• Automatically

displays static and

dynamic logic •

Works with DTL, Model LM-1

HTL.TTL. and

CMOS

*5995

Touch/Test 20 Multimeter

15 MHz Dual Trace Triggered

M Miniscope

X*fl Model MS-215

30 MHz Dual Trace Triggered

MiniSCOpe Model ms-23o

PK400 ™ ™ ^:*™ „ $7/199

4 Pc Standard Starter Kit -One I Ij Standard Command f f Console ■ Two (2] Lamp Modules ■ One (1] Appliance Module

PK500 5 Pc Ultrasonic Starter Kit «0ue 11] Deluxe tAAQC

Ullrascnic Command Consult; ■ One . 11 Hand Held Remote *HHM Unit ■ Two |2) Lamp Modules ■ One (!) Appliance Uoil

LM501 Lamp Module S13.95

AM6D1 Appliance Module WS701 Wall Switch MorJuleS13. WS7I1 Wall Switch Module

Willi independent On-Olf pQWfll billions S1Q.95

»! The Timer $5Q95

Miniature High Fidelity 3-Way Stereo Speakers

$5Q95

Chess Challenger 7 $7995,3

Sensory Chess Challenger$110,

Voice Sensory Challenger 24995

WAHL

Cordless Soldering Iron $2995

Ttwtimo£-Sp.ot

Circuit Tester

Finds faulty components JJ quickly and easily

$2995 Model 5800

MURAPH0NE Cordless Telephone System

Model $1-1 ft 300 I ■ V.

Welter*

WTCPN Controlled Output Soldering Station

ModelWTCPN $5750 (

Service Master Tool Kit $4995

Soldering Station

l'MHil §upef6ase

Model 70260

24995

In-Dash Car Stereos

8-Track AM/FM $EO50

Model JCS 420 *"■

Cassette AM/FM $5750

Model JCS 505

Digital Cassette AM/FM

With ClOCk Model JCS 607

Graphic Equalizer

Model GE 5000 $3995

US

6x9 3-Way$-|295ea.

Speakers ■ 20 oz magnet' Model BP2000-69 TRD

855 Conklin St. Farmingdale, N.Y. 11735

■ Master Charge

■ BankAmericard

■ VISA ■ COD

■ Money Order

■ Check

NY. Slate residenis add appropriate

ADO FOR SHIPPING AND INSURANCE

to I 250.00 i 3.50

SZ51.00 to 500.00 5.0O

501.00 to 750.DD 7.50

751.DO la 1000.00 10.00

over 1000.00 12 50

sxtra

414 April 1981 © BYTE Publications Inc

fr°elel(800)645-9518

in N.Y. Slate call (516) 752-0050 ^^^^m Circle 289 on inquiry card

FOR SALE: Speak & Spell with Speak-2-Me-2 installed by Percom Data. 230-word vocabulary plus program to form words from parts of vocabulary words. Complete with modified printer interface cable, user's manual, and driver programs. Set up for TRS-80 Level II with 16 K. Instructions for other computers. Worth $200, sell for $150. Joseph Wear, Rt 1 Box 83A, New Egypt NJ 08533, (609) 758-7193.

FOR SALE: Okidata Model CP-110 friction-feed line printer, with RS-232 serial interface and uppercase/ lowercase character set. Prints 80 columns bidirectional at 110 cps. Uses 8V2-inch roll paper. Excellent condition. Cost $1349, asking $650. Virgilio DeCarvalho, ColumbiaPrinceton Electronic Music Center, 632 W 125th St, Room 318, New York NY 10027, (212) 280-3050.

FOR SALE: H-8, serial I/O board, 20 K programmable memory, cassette, Extended BASIC. Up and running, all documentation included. First $600 takes. I ship. M H Endres, Box 8, Spirit Lake ID 83869, (208) 623-5911.

FOR SALE: Magic Wand for TRS-80 Model II. Original disk and manual; $200. A A Schwartz, 6454 Camino Teatro, La Jolla CA 92037.

FOR SALE: Burroughs Series B9352 video terminal. Has printer output, uppercase, and full cursor control. $300 plus freight. Steve Nelson, Box 150, Webster MN 55088.

FOR SALE: PET 8 K computer with Soundware sound for PET, five tapes with programs including Microchess 2.0, and COMPUTE magazine for the PET. Original PET cost over $800, will settle for $675. Also, have ELF II computer complete with documentation and newsletters. Cost over $200, would like to trade for HP-41C card reader. Am interested in HP-41C equipment, willing to negotiate with PET and ELF II. Shaji Jacob, B27 Lincoln, Fort Morgan CO 80701, (303) 867-8162.

FOR SALE: Tl #751 Silent 700 type printer. 10, 15, 30 cps, thermal, Baudot code, receive-only. Complete, but needs electrical work. With five rolls of paper and complete documentation. $100, you pay shipping, or trade for Heath H-9 terminal. Tom Hamilton, 1405 Washington, Birmingham Ml 48009, (313) 647-5420 after 5 PM ET.

FOR SALE: OSI Superboard with expansion, 18 K programmable memory, 8 A power, 9-inch Sanyo monitor, and full enclosure; $650. 12-slot S-100 motherboard with 15 A power supply and termination; $150. Microdiversions Screensplitter 46 by 80 video display for S-100, brand new; $350. Plus much used equipment. Glenn Barnas, 280 Carmita Ave, Rutherford NJ 07070, (201) 935-0271.

FOR SALE: SwTPC CT-64 terminal; $300 or best. AC-30 cassette interface, works on any 300 bps RS-232 line; $80 or best. MP-A2 6800 processor card with SWTBUG; $120 or best. All assembled and tested. USR-310 modem; $130. Keyboard; $50. Must sell soon. Charles Duff, 7007 N Sheridan #317, Chicago IL 60626, (312) 386-0311 leave message.

FOR SALE: Multiterm printer Model T-4000: 55 cps, Diablo Hytype mechanism, tractor feed, ribbons, print wheels, many additional features, auto-underline, etc. $1700 or offer. Also, two Centronics 306C printers. $1200 each or offer. Michael Sloat, POB 982, Loma Linda CA 92354,(714) 796-2757.

FOR SALE: PET owners, I have sixteen 4108 programmable memory circuits guaranteed good. Will sell for $2.50 each or the entire lot for $35. Also, if your PET uses 4108s and they are in sockets, and you would like to upgrade to 32 K inexpensively, send $1 plus SASE for guaranteed instructions. I am also looking for an inexpensive printer with 40/80 lines and Centronics-type parallel input. Harry E Leggans, Box 1179, APO New York 09023.

FOR SALE: Alpha 16 mainframe includes processor, clock/controller, teletypewriter interface, 4 K memory, floppy-disk controller, and power supply. Also, much software and all manuals. $500 or offer. Edwin Karlow, Department of Physics, Loma Linda University, Riverside CA 92515, (714) 785-2143.

FOR SALE: Siemens FD100 mini floppy-disk drives with manuals, power supplies, and cases. $250 each or best offer. Western Digital 1771 floppy-disk controller circuits. $B each. Marcy Durkee, 10265 Meadowwood Ln, Overland MO 63114.

WANTED: Used computer-science books. Reasonably priced, in good condition; for personal use—only one copy of a title wanted. Examples: programming languages, Knuth (volume 2), programming techniques, compiler design, applications, etc. J R Berman, 494 Forest Ave, Teaneck NJ 07666.

FOR SALE: TRS-80 Model I, Level I, 4 K. Like new, hardly used. $500. Also, Apple games for trade—Invader, Asteroids, Sargon, etc. Randy Strouth, RR 5 Box 63, Faribault MN 55021, (507) 334-6585.

FOR SALE: Digital Group Z80, Diskmon, Business BASIC, 64-character, 26 K dynamic; $1200. Two 8-inch disk drives and Digital Group controller; $1600. Keyboard (needs repair) and 9-inch monitor; $250. Whole system for $2800. Wayne Dirks, 801 E 10th, Hutchinson KS 67501, (316) 663-3998 days.

FOR SALE: TRS-80 Model III computer with 48 K programmable memory, brand-new condition. Complete documentation plus several TRS-80 books. $950. Also, HP-41C programmable calculator with card reader plus blank cards, four memory modules, and MATH and STAT modules. $500. Alan J Grant, 530 44th St, Brooklyn NY 11220, (212) 436-1714 weekends or after 6 PM weekdays.

FOR SALE: Commodore PET 2001 computer with 8 K programmable memory and new 2.0 read-only memories. Has on-board cassette and small keyboard. $50 deposit for shipping by UPS collect, balance due of $475. Dan Rubis, 19713 Alger, St Clair Shores Ml 48080, (313) 771-1392.

BOMB

)naoina Monit

or Box

Author|s)

BYTE'

sC

Article #

Page

Article

l

20

Recurrence in Numerical Analysis

Davidson

2

36

Build a Low-Cost Logic Analyzer

Ciarcia

3

46

The MicroAce Computer

Searls

4

66

Digital Minicassette Controller

Kahn

5

94

A Reformatter for CP/M and IBM Floppy

Disks

Lehman

6

102

Programming the Game of Go

Millen

7

122

Build Your Own Turing Machine

Willis

8

150

A Closer Look at the Tl Speak & Spell

Vernon

9

188

Three Versions of APL

Williams

10

218

An Introduction to Data Compression

Corbin

11

252

Build An Intercomputer Data Link

Wingfield

12

290

Three-Dimensional Computer Graphics,

Part 2

Crow

13

348

PADDLES: Interfacing with Modular

Combs and

Breadboards

Field

WANTED: User's manual for Processor Technology 32KRA memory board. Steve Grant, 6055 E Washington Blvd, Suite 1035, Commerce CA 90040, (213) 725-1563.

FOR SALE: Heath H-8, dual-drive H-17, H-9 video terminal, three 8 K programmable memory cards, serial/ cassette interface. Entire system for $1500 or sell in parts. Richard Berhain, 142 Jefferson Ave, Hasbrouck Heights NJ 07604, (201)288-1693.

FOR SALE: North Star 2 system. Double-density, 48 K, with D C Hayes modem. Two serial and one parallel ports, SOROC IQ 140 terminal, and Centronics 779 tractor printer. Includes $2000 in business software. Six months old, in original boxes. $4895 or best offer. Also, DC Hayes modem 100; $325. Don, (615)526-7651.

FOR SALE: Heath H-9 terminal; Heath H-10A reader/ punch; Tl 9900 single-board 16-bit microcomputer. Complete manuals and software included. Best offer. D Montgomery, Box 27, Oakland FL 32760, (305) 656-4293.

FOR SALE: Super ELF with expansion board, 4 K static programmable memory, two I/O ports, Super Monitor, ASCII keyboard, 4-slot expansion case, power supply, RF modulator, Tiny BASIC cassette, and manuals; $250. Electric Crayon l/O-driven color graphics unit with 2 K memory, graphics firmware, manual, and built-in RF modulator. Alphanumerics and graphics expandable to 256 by 192. $200. Brent Elder, 7422 N Campus #7, Cornell University, Ithaca NY 14853, (607) 256-6750.

FOR SALE: Model 33 ASR teletypewriter with manuals, paper-tape reader and punch, and stand. Mint condition, less than 100 hours on usage meter. $595 plus shipping. Automatic motor control installed and tested is $30 extra. Ken Brand, 421 Fairview Ave, Winchester VA 22601, (703) 662-0665 after 6 PM.

WANTED: January and May 1979 BYTE. May and June 1978 Creative Computing. January, May, July, and December 1978 Kilobaud Microcomputing. Name your price. Robert Lansdale Jr, 18 Ashfield Dr, Etobicoke Ontario, M9C 4T6 Canada.

January BOMB Results: Hand-Held Computers

Readers responded to our January theme by voting top honors for "The Panasonic and Quasar Hand-Held Computers: Beginning a New Generation of Consumer Computers" by Gregg Williams and Rick Meyer (January 1981 BYTE, page 34). Because Gregg is an employee of BYTE, the S100 prize will go to Rick.

Steve Ciarcia captured second place for his article "Electromagnetic Interference," page 48 and receives $50.

Third place was taken by Teri Li for his article "Whose BASIC Does What?" Fourth place went to Michael Keith and C P Kocher for their article "The NEC PC-8001: A New Japanese Personal Computer."

With the January issue, we began to collect votes for the BOMB (BYTE's Ongoing Monitor Box) through responses on one of the reader-service cards. This resulted in an increased number of votes and many favorable comments from readers.■

April 1981 © BYTE Publications Inc 415

Reader Service

Inquiry No.

Page No.

311 AB Computers 387

189 ABM Products 292

293 Abrams Creative 384

56 Ackerman Digital 82

' Action Computer 137

18 Adaptive Data & Energy Sys 23

336 Addmaster 392

49 Advanced Access 72

354 Advanced Comp Prod 402, 403

206 Advanced Micro Sys 312

108 Adventure Int'l 160

* ALF Products 78

40 Alpha Byte Storage 59

297 ALL Electronics 384

332 Alpha Omega Systems 392

308 American Busn Comp 386

172 American Square Comp 273

275 Ancrona 370, 371

276 Ancrona 372, 372

218 Anderson Jacobson 319

63 Anderson Peripherals 94 237 Apparat 330

10 Apple Computer 13

198 ASAP 303

226 ASAP 323

202 AshtonTate 307

188 Automated Equip Inc 291

* Avocet Sys Inc 294 156 Axiom 245

159 BASF 249

* Basis Microcomputer GMBH 177 285 John Bell Engineering 379

* Beta Comp Devices 315 295 BIS Inc 384

300 Bit Bucket, The 384 13 BIZCOMP 16

82 BMC 119

124 Bower-Stewart & Assoc 182

* BYTE Back Issues 246 135 BYTE Books 201

152 BYTE Books 233

181 BYTE Books 283

205 BYTE Books 311

17 Calif Comp Systems 21

353 Calif Digital 400, 401

243 Cambridge Learning Inc 333

93 Cavrl Systems 136

173 Central Data 275

143 Chrislln Industries 219

301 Clev Con Comp & Compnts 385 32 Colonial Data 50

248 Computer Age Inc 337 210 Computer Case Co 315 314 Computer City 388

20 Computer City Canada Inc 25

256 Computer Disc of Am 340

* Computer Factory, The 247 261 Computer Furn & Access 342 176 Computer Mall Order 278

104 Computer Marketing Corp 152

307 Computer Mart Inc 386

322 Computer Shopper 390

57 Computer Specialties 84, 85 271 Computer Tech Assoc 355

" Computer Warehouse 93

51 Computers R Us 74, 75 342 Computers Plus Inc 382

52 CompuMart 76, 77

80 CompuServe 116, 117

269 Computerware 345

183 Computex 286

249 COMPUTIME337

45 Compuview Products Inc 67

278 Concord Comp Components 374

51 Consumer Computers 74, 75

107 Corvus Systems 159

130 Coval 192

235 Cover Craft 328

* CPM User's Group 60 321 CPU Chop, The 389

1 Cromemco 1, 2

118 Crystal Computer 173

323 Custom Business Comp 390

298 Cyber Innovations 384

* Cybernetics Inc 138 242 Data Access 333

* Data Discount Center 146 346 Data Hardware 382

64 Datasouth Computer Corp 95 85 Datasouth Computer Corp 126

178 Datek280

84 Delta Products 123

89 Denver Software Co, The 131

113 Designers Software 167

146 Diablo (Dlv of Xerox) 223

266 Digiac Corp 343

75 Diglcomp110

* Digital Equlpmt Corp 241

87 Digital Graphic Systems 129

141 Digital Marketing 213

163 Digital Pathways 255

109 Digital Research 161

* Digital Research Computers 367 201 Discount Sftw Grp, The 306

65 DMA 346

168 Dual System Control Corp 265

258 Dymarc Ind 341

361 Dyna Byte C III

154 Dynacomp 239

317 DWP 388

252 Ecosoft 339

* Electravalue Industrial 342 74 Elron Computers Ltd 108

* Efficient Mngmt Sys 327 286 Electronic Center 380

22 Electronic Control Tech 28

339 Electronic Equip Unltd 392

270 Electronic Specialists 345

241 Ellis Computing 333

123 Epson 181

236 ER Hardins Mltry Madness 329

244 Escon 334

121 Essex Publishing Co 176

227 Essex Publishing 324 36 Exatron Inc 55

29 Eyring Research Inst 45

98 Faircom 144

213 Farnsworth Comp Center 317

289 Fordham Radio Supply 414

225 Forethought 323

25 Frederick Comp Prod 32

294 Frederlcktowne Comp 384

' General Peripherals 388

111 Godbout Electronics 163

140 Godbout Electronics 210, 211

70 Mark Gordon Computers 104

139 GR Electronics Ltd 208

132 H & E Computronics 195

133 H & E Computronics 197

134 H & E Computronics 199 291 Hanley Engineering 383 207 Hayden Book Co Inc 313

48 Hayes Microcomp Prod Inc 71

31 Heath Company 49

27 High Technology Inc 34

39 Hobbyworld Electronics 58

299 Horizons Inc 384

53 Houston Instrument 79

54 Houston Instrument 79 15 IMS International 17

* Info Unltd Software 347 190 Innovative Sftw Appl 293

58 Integral Data Sys 87

59 Integral Data Sys 89 212 Integrand 317

259 Intelligent Control Sys 341

34 Intertec Data Systems 53

14 Intertec Data Systems 185

345 Introl Corp 382

335 Ipex Int'l Inc 392

5 Ithaca Intersystems 8

6 Ithaca Intersystems 9

351 Jade Computer Prod 396, 397

352 Jameoo Electronics 398, 399 230 JDR MICRODEVICES 325 331 Jlm-pak391

283 JR Inventory 378

30 Kern Publishing 48

105 Key Tronic 153 125 Konan Corp 81

341 Lab Microsystems 382

■ Lanier 27

284 Lax Computer 378

* Leading Edge 237 257 Leapac Services 341 310 Leapac Services 386 232 Lee Products Co 317

88 Leo Electronics 130

101 Lifeboat 141

102 Lifelines 149 325 Linmar 390

106 Livermore Data Sys Inc 154 222 LNW Research 321

99 Lobo Drives Int'l 145

137 Logo Computer Systems 205

305 Lyben Comp 386

348 McHenry & Assoc 382

* McMillan Book Club 193 296 Macrotronics Inc 384

319 Magnolia Microsystems 388

103 Madbu Electronics 151 164 Mark of the Unicorn 257

144 Marot Software Systems Inc 221

174 Marymac Industries Inc 276

77 Mauro Engineering 112

100 Maxell Data 147

* Medlamlx 388

* Meas Sys & Controls 29, 121 221 Memtech 321

228 Meta Research 325

273 Meta Technologies Corp 358

169 MFJ Enterprising Inc 268

204 Micro Ace 309

38 Micro Age Computer Store 57

199 Micro Business World 304

20u Microbyte 305

* Micro Comp Discount Co 114 73 Micro Data Base Sys 107

To get further information on the products advertised in BYTE, fill out the reader service card with your name and address. Then circle the appropriate numbers for the advertisers you select from the list. Add a 15<ent stamp to the card, then drop it in the mail. Not only do you gain information, but our advertisers are encouraged to use the marketplace provided by BYTE. This helps us bring you a bigger BYTE. The index is provided as an additional service by the publisher, who assumes no liability for errors or omissions. "Correspond directly with company. o

312

Micro Flash 388

208

*

Micro Focus 109

81

119

Micro House 174

41

175

Micro Management Sys 277

*

'

Micro Mint 392

43

160

Micro Pro International 251

128

47

Micro Works, The 70

122

287

MIcroCompEqulp 380 Microcomputer Store 340

7

153

238

33

MIcroDaSys 51

234

114

Micromail 168

*

214

MICROMATE 317

55

78

MICRO-SCI 113

247

*

Microsette 357

129

86

Microsoft (Cons Prod Dlv) 127

2

254

MioroTech Exports 339 Mlcroware 322

60

223

246

165

Mlkos 259

315

83

Miller Microcomputer Serv 120

*

255

Mini Computer Suppliers 339

115

306

Mini Computer Suppliers 386 Mini Micro Mart 410

304

358

344

358

Mini Micro Mart 411

11

359

Mini Micro Mart 412

136

359

Mini Micro Mart 413

211

50

Morrow Designs 73

328

16

Mountain Computer Inc 19

131

217

Mountain View Press 319

110

161

mpl 253

MT Micro SYSTEMS 83

*

*

302

171

MTI Inc 271

179

196

MTI Inc 300

138

192

Multi Business Comp Sys 296

209

158

MUSYS 248

120

203

Nautllls Systems 308

360

182

NCC '81 285

166

216

NCE Supply Corp 319 NEBS 326

8

231

176

12

NEC America Inc 15

180

165

NEECO 259

280

90

National Computer Show 133

•

240

National Multiplex 333

37

195

Nestar Systems Inc 299 Netronics 207, 254, 258, 260

97

*

Northern Tech Books 183

224

220

Ohio Data Products Corp 321

170

362

Ohio Scientific InstrC IV

334

338

Oliver Advanced Eng 392 Olympic Sales Co 100

155

68

197

9

Omega Micro Computers 12 Omega Sales Co 156, 157

149

61

71

62

Omlkron 92

177

194

Omnlbyte 298

44

*

onComputlng 96, 209

267

250

Optimal Technology 337

253

127

Orange Micro 187

*

95

Osborne/McGraw-Hill 139

76

167

OSM 263

72

330

OSM 390

265

•

Owens Associates 18, 178, 179

324

187

Pacific Exchanges 289

309

347

Pacific Exchanges 382

233

327

Pacific Exchanges 390

112

263

Pacific Exchanges 342

*

288

Page Digital 381 Palomar Computers 287

35

184

350

277

Pan American Elec 374

279

*

Pan American Airlines 267

150

91

Passport Designs 134 PCD Systems Tnc 6

145

3

349

4

Percom Data 7

245

28

Percom Data 35

46

363

Percom Data 91

66

364

Percom Data 91

69

365

Percom Data 91

151

366

Percom Data 91

42

367

Percom Data 91

274

368

Percom Data 91

126

193

Personal Microcomputers 297

*

24

Personal Software 31

333

191

Phase One Systems 295

19

239

Pickles & Trout 332

•

79

Piiceon 115

26

117

Power One Inc 171

67

290

Priority One 393

23

356

Priority One 406, 407

292

357

Priority One 408, 409

229

340

Professional Comp Store 392

326

116

Prometheus 170

281

329

P & S Electronics 390

320

185

Purchasing Agent, The 288 QT Comp Systems 404, 405

92

355

343

Quality Computer Parts 382

215

Quality Software 318

142

Quasar Data Products 215

148

Qantex 225

96

Quay 191

282 251

Quest 377

R & B Computer Systems 338

RKS Enterprises 314

Racet Computes 118

Radio Shack 61

Random House 338

RCA Solid State 64

RCA Solid State 189

RNB Enterprises 180

Rochester Data 10

Roland's Song Sftwr 331

S & M Systems 327

S-100 Inc 341

Howard W Sams Co 80

SC Digital 337

Scientific Engineering 190

Scion Corp 5

SclTronics Inc 90

SciTronics Inc 336

Scotia Software 388

Scottsdale Systems 62

SD Systems 169

SKP Electric 386

Sluder 382

Small Business Applications 14

Softech Microsystems 203

Softech Microsystems 316

Soft Tools 390

Software-To-Go 194

SoHo Group, The 162

Solid State Sales 172

Solid State Surplus 386

Source EDP 281

Sorrento Valley Assoc 206

Sorrento Valley Assoc 315

Southern Semiconductors 175

Southwest Tech Prod Corp CM

Spectrum Software 261

SSM 11

Stereo House 278

SubLOGIC 282

Sunny Int'l 376

SuperSoft 155, 216, 217, 224, 320

Super Star Int'l Corp 56

Sybex 143

Synchro Sound 69

Synergetlc Solutions 323

Systems Plus 269

SZ Software 392

Tab Books 242, 243

Tarbell Electronics 301

Tarco 226

Tech Sys Consultants (TSC) 105

TecMar Inc 279

Televldeo 65

Tercer Medio 343

Texas Comp Sys 339

3G Company 196

3M Company 111

Thunderware 106

TNW Corp 343

Toolsmlth, The 390

Trade-A-Computer 386

TransNet 327

TSE/Hardslde 166

United Software of Am 124, 125

Urban Software 54

US Micro Sales 394, 395

US Micro Sales 375

US Robotics 229

V.A.M.P. 222

V.A.M.P. 382

VANDATA 335

Vector Electronics 68

Vector Graphics 97

Verbatim 103

Videx 231

Vista Computer Co 63

Vista Computer Co 369

Voicetek 184

VR Data 88

Western Wares 392

Western Union 24

Westlco Inc 164, 165, 342

White Computer 33

Whitesmith's Ltd 99

Wild Hare Comp Sys 30

Wlntek Corp 384

Winterhalter & Assoc 325

Worldwide Electronics 390

WW Component Supply Inc 376

XPS Inc 388

Zobex 135

416 April 1981 © BYTE Publications Inc

Business Manager is a registered trademark of Dynabyte.

CP/M and MP/M are registered trademarks of Digital Research Corporation

Oir^la ^fi1 r\n inniiiru rarrl

"It's beautiful what your bucks will buy

from Ohio Scientific."

Ohio Scientific was first to add Winchester hard disk drives to microcomputers. This advanced technology allows low cost microcomputers to store over 100 times as much information on line as they could before.

"Our Challenger C3-B has been running almost 24 hours a day for the last 18 months keeping track of countless details of our business. The Challenger's real time clock allows repetitive jobs to be scheduled months in advance, and runs them without operator intervention when the time comes. For example, every morning at 3 AM our Challenger knows it is time to update all the day's accounting records including the P&L, General Ledger, and Payables. It knows when it is time to file a tax return, and it makes out the quarterly reports. When it is Jhrough with all of this, it writes the checks. Periodically it does a comprehensive advertising analysis and updates any other files that are necessary."

"Running our retail stores sure has been easier since our Challenger computer came to work for us. We use it for Accounts Receivable, Accounts Payable Payroll, General Ledger. It's most important in Inventory Control. We must know what we have and haven't. Now we do, daily. Terrific! Ohio Scientific!'

Henry Felkey, Division Manager, Schwartz-Klines New Philadelphia, Ohio

I

"Our Challenger gives us more control

of scrap from our blown film extrusion

operation. By putting shift reports

\ through the computer, we spot waste

j£v immediately. Whether the problem

is the extruder or the operator

■■S. it's corrected fast. Wasted

material is wasted money!'

Wayne Johnson, Controller, Wyard Industries, Cambridge? Minnesota

Ohio Scientific hard disk based microcomputers start at less than $10,000. And are sold by more than 400 dealers nationwide. For the one nearest you, call 1-800-321-6850, TOLL FREE.

w

##"

Circle 362 on inquiry card.

OHIO SCIENTIFIC

a A^J^ri Company 1333 SOUTH CHILLICOTHE ROAD AURORA, OH 44202 • [21 6] 831 -5600