Byte Magazine Volume 05 Number 01 - Domesticated Computers

This book was produced in EPUB format by the Internet Archive.

The book pages were scanned and converted to EPUB format automatically. This process relies on optical character recognition, and is somewhat susceptible to errors. The book may not offer the correct reading sequence, and there may be weird characters, non-words, and incorrect guesses at structure. Some page numbers and headers or footers may remain from the scanned page. The process which identifies images might have found stray marks on the page which are not actually images from the book. The hidden page numbering which may be available to your ereader corresponds to the numbered pages in the print edition, but is not an exact match; page numbers will increment at the same rate as the corresponding print edition, but we may have started numbering before the print book's visible page numbers. The Internet Archive is working to improve the scanning process and resulting books, but in the meantime, we hope that this book will be useful to you.

The Internet Archive was founded in 1996 to build an Internet library and to promote universal access to all knowledge. The Archive's purposes include offering permanent access for researchers, historians, scholars, people with disabilities, and the general public to historical collections that exist in digital format. The Internet Archive includes texts, audio, moving images, and software as well as archived web pages, and provides specialized services for information access for the blind and other persons with disabilities.

Created with abbyy2epub (v.1.7.0)

••;•*■', . »..'

If you have a problem that can be solved by a computer—we have a systems solution.

* Two central processors with maximum RAM capacities of 56K and 384 K bytes

* Three types of disk drives with capacities of 175K, 1.2M and 16M bytes

* Two dot matrix printers with 80 and 132 line capacity

A Selectric typewriter interface and a daisy wheel printer

Match these to your exact need, add one or more of our intelligent terminals and put togethera system from one source with guaranteed compatibility in both software and hardware.

Southwest Technical Products systems give you unmatched power, speed and versatility. Theyare packaged in custom designed woodgrain finished cabinets. Factory service and support onthe entire system and local service is available in many cities.

SOUTHWEST TECHNICAL PRODUCTS CORPORATION

219 W. RHAPSODY

SAN ANTONIO, TEXAS 78216 (512) 344-0241

Circle 233 on inquiry card.

LatchedOutputs

4 MHzCrystal Clock

On Card

Voltage

Regulation

ParallelI/O Port #1

\

ParallelI/O Port #2

/

8KR0MCapacity

^IIIIIIIIIIIIIIJI

IK RAM

Standard Bus

for System

Expandability

The single card computer

with the featuresthat help you in real life

COMPLETE COMPUTER

In this advanced card you get a pro-fessional quality computer that meetstoday's engineering needs. And it's onethat's complete. It lets you be up andrunning fast. All you need is a powersupply and your ROM software.

The computer itself is super. Fast4 MHz operation. Capacity for 8K bytesof ROM (uses 2716 PROMs which canbe programmed by our new 32K BYTE-SAVER® PROM card). There's also 1K ofon-board static RAM. Further, you getstraightforward interfacing through anRS-232 serial interface with ultra-fastspeed of up to 76,800 baud — softwareprogrammable.

Other features include 24 bits of bi-directional parallel I/O and five on-board programmable timers.

Add to that vectored interrupts.

ENORMOUS EXPANDABILITY

Besides all these features the Cro-memco single card computer gives youenormous expandability if you ever needit. And it's easy to expand. First, youcan expand with the new Cromemco32K BYTESAVER PROM card mentionedabove. Then there's Cromemco's broadline of S100-bus-compatible memoryand I/O interface cards. Cards with fea-tures such as relay interface, analoginterface, graphics interface, opto-isolator input, and A/D and D/A con-version. RAM and ROM cards, too.

Card Cage 32K BYTESAVER PROM card

EASY TO USE

Another convenience that makes theModel SCC computer easy to use is ourZ-80 monitor and 3K Control BASIC (intwo ROMs). With this optional softwareyou're ready to go. The monitor givesyou 12 commands. The BASIC, with 36commands/functions, will directly ac-cess I/O ports and memory locations —and call machine language subroutines.

Finally, to simplify things to the ulti-mate, we even have convenient cardcages. Rugged card cages. They holdcards firmly. No jiggling out of sockets.

AVAILABLE NOW/LOW PRICE

The Model SCC is available now at alow price of only $450 burned-in andtested (32K BYTESAVER only $295).

So act today. Get this high-capabilitycomputer working for you right away.

ra

Cromemco

^^^__^M Specialists in computers and peripherals

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

Circle 1 on Inquiry card.

BYTE January 1980

X

"

(

Z-2H

m

C Cromemco

Low-cost hard disk computers

are here

11 megabytes of hard disk and 64 kilobytes of fast RAM in a

Z80A computer for under $10K. Two floppy drives, too.

Naturally, it's from Cromemco.

It's a reality. In Cromemco's newModel Z-2H you get all of the aboveand even more. With Cromemco youget it all.

In this new Model Z-2H you getnot only a large-storage Winchesterhard disk drive but also two floppydisk drives. In the hard disk drive youget unprecedented storage capacityat this price—11 megabytes unfor-matted.

You get speed—both in the 4 MHzZ80A microprocessor and in the fast64K RAM which has a chip accesstime of only 150 nanoseconds. Youget speed in the computer minimuminstruction execution time of 1 micro-second. You get speed in the harddisk transfer rate of 5.6 megabits/sec.

EXPANDABILITY

You get expandability, too. Thehigh-speed RAM can be expanded to512 kilobytes if you wish.

And the computer has a full 12-slotcard cage you can use for additionalRAM and interface cards.

BROADEST SOFTWARE SUPPORT

With the Z-2H you also get thebroadest software support in the

microcomputer field. Software Cro-memco is known for. Software likethis:

• Extended BASIC

• FORTRAN IV

• RATFOR (RATional FORtran)

• COBOL

• Z80 Macro Assembler

• Word Processing System

• Data Base Management

with more coming all the time.

SMALL, RUGGED, RELIABLE

With all its features the new Z-2H,including its hard disk drive, is stillhoused in just one small cabinet.

Included in that cabinet, too, isCromemco ruggedness and reliability.Cromemco is time-proved. Ourequipment is a survey winner forreliability. Of course, there's Cro-memco's all-metal cabinet. Rugged,solid. And, there's the heavy-dutypower supply (30A @ 8V, 15A @+ 18 V, and 15A @ -18V) for cir-cuitry you'll sooner or later want toplug into those free card slots.

CALL NOW

With its high performance and lowprice you KNOW this new Z-2H isgoing to be a smash. Look into itright now. Contact your Cromemcocomputer store and get our salesliterature. Find out when you cansee it. Many dealers will be showingthe Z-2H soon—and you'll want tobe there when they do.

Hard disk drive at lower left can be inter-changed just by sliding out and disconnectingplug. Seven free card slots are available.Z-2H includes printer interface card.

PRESENT CROMEMCO USERS

We've kept you in mind, too. Askabout the new Model HDD DiskDrive which can combine with yourpresent Cromemco computer to giveyou up to 22 megabytes of diskstorage.

BYTE January 1980

G

Cromemco

incorporated

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

Tomorrow's computers now

Circle 1 on inquiry card.

W

In the Queue

W¥l January 1980Volume 5, Number 1

Foreground

page 74

28 COMPUTERIZE A HOME by Steve Ciarcia

Controlling appliances in your home is one of the many chores that may be delegated to a personal computer. Oneproduct that is readily available is the Sears Home Control System used in this month's Ciarcia's Circuit Cellar.

56 A COMPUTER-CONTROLLED LIGHT DIMMER, PART 1: DESIGN

by John H Gibson You can use your computer in conjunction with programmable timers to easily control alight dimmer. Since programmable timers simplify both hardware and software in such applications, you maythink of other applications.

74 A FURNACE WATCHDOG by Theron Wierenga

January is a month in which most of us show a greater than average concern for the state of our own homeheating systems. After moving into a new house Theron decided to let his computer keep track of the furnace.

122 TELEPHONE DIALING BY COMPUTER by Edward Joyce

Your computer can ease the burden of remembering and dialing telephone numbers. This computer-controlledinterface can dial your most frequently used numbers on Touch Tone telephone systems.

129 ANALYSIS OF POLYNOMIAL FUNCTIONS WITH THE TI-59CALCULATOR, PART 2 by Pierre Chance

This article describes the operation of the polynomial evaluation programs for the TI-59 given in part 1. One pro-gram calculates the roots of a sixth-order polynomial, while the other produces a plot of the function on the TIPC-100C printer.

156 ALPHA LOCK FOR YOUR ASCII KEYBOARD by Terry Conboy

This article presents a method to produce only uppercase letters from a keyboard capable of both uppercase andlowercase operation. Control and special characters are not shifted, and the shift lock can be easily turned off.

180 RELOCATING 8080 SYSTEM SOFTWARE by John Lipham

The ability to relocate programs in memory space is often helpful when you are changing from one system toanother, or adding a new program to your present system. John discusses some of the problems that are en-countered during relocation on the 8080 microprocessor and gives two programs that perform most of the work.

212 EIGHTEEN WITH A DIE, A LEARNING GAME PLAYER by Russell R Yost

People learn from their mistakes. Computers can too, if given the right program. Russell enabled his personal com-puter to learn how to win a simple game by writing the program described in this article.

Background

20 MAKING COLOR SLIDES WITH AN INTECOLOR MICROCOMPUTER

by Alan W GrogOUO An Intecolor intelligent color terminal (or other color-based computer) is used togenerate color images that can be directly photographed. Slide production from a video image is relatively cheap,and the image can be altered during the design process with a minimum of effort.

100 WHAT COMPUTERS CANNOT DO by T G Lewis

Designers constantly try to build better and faster computers. Recent technology has produced many advances, butthe question remains, "Is computing qualitatively better than when it first began?" T G Lewis discusses this issue.

118 INDIRECT ADDRESSING FOR THE 6502 by Kenneth Skier

The 6502 processor allows the user to perform certain indirect addressing operations. However, indirect addressingis not available for all instructions. Kenneth informs us of an easy way to perform indirect addressing on the 6502when it is not normally available.

136 THE PLOT CONTINUES by Leslie B Walter

The plotter described in this article is capable of being run by hardware and software drivers and gets around someof the physical difficulties, such as large torque and wobble factors, that confront some plotter designs.

160 A COMPUTER-GENERATED REMINDER MESSAGE by E M Pass

This article describes a system that can help you to remember important future events. The system, called Tickler,is helpful in remembering to perform actions that have to be repeated periodically.

Nucleus

NOTICE:

The 1980 Priority OneElectronics Engineering

Selection Guide

begins on page 80-C1

in this issue

6 Editorial: The Era of Off-the-ShelfComputers Has Arrived14 Letters115 BYTE News

148, 151 Technical Forum: Aids to theDirect Reception of Weather SatellitePhotographs;

An Improved Maze Program174, 206, Programming Quickies: APascal Checkbook Balancing Program; A

French-English Dictionary; Z80 User

Stack Emulation

176 Book Reviews

194 Clubs and Newsletters

195, 199 BYTE's Bugs

196, 150 BYTE's Bits200 Event Queue230 What's New?

271 Unclassified Ads

272 Reader Service, BOMB

January 1980 © BYTE Publications Inc 3

Publishers

Virginia Londoner, Gordon R WilliamsonAssociate PublisherJohn E HayesAssistant

Jill ECallihan

Editorial Director

Carl T Helmers Jr

Executive Editor

Christopher P Morgan

Editor in Chief

Raymond G A Cote

Senior Book Editor

Blaise W Liffick

Editors

Richard S Shuford, Gregg Williams

Assistant Editor

Bob Braisted

Editorial Assistants

Gale Britton, Faith Ferry

New Products Editor

Clubs, Newsletters

Charles Freiberg

Drafting

Jon Swanson

Production Director

Nancy EstleSenior Copy Editor

David William Hayward

Copy Editors

Faith Hanson, Warren Williamson,

Robin M Moss, Anthony J Lockwood

Art Director

Ellen Bingham

Production Art

Wai Chiu Li, Christine Dixon,

Holly Carmen LaBossiere, Deborah Porter

Typographers

Cheryl A Hurd, Debe L Wheeler,Sherry McCarthy

Advertising Director

Patricia E Burgess

Assistants

Ruth M Walsh, Marion Gagnon

Adv/Prod Coordinator

Thomas Harvey

Marketing Coordinator

Laura A Hanson

Circulation Manager

Gregory Spitzfaden

Assistants

Pamela R Heaslip, Agnes E Perry,

Melanie Bertoni, Barbara Ellis

Dealer Sales

Anne M Baldwin

Receptionist

Jacqueline Earnshaw

Traffic Department

Mark Sandagata, Thomas Yanni

Comptroller

Daniel RodriguesAssistantMary E Fluhr

National Advertising Sales Representatives:

Hajar Associates Inc

East

280 Hillside Av, Needham Heights MA 02194

(617)444-3946

521 Fifth Av, New York NY 10017

(212) 682-5844

Midwest

664 N Michigan Av, Suite 1010,

Chicago IL 60611 (312) 337-8008

West, Southwest

1000 Elwell Ct, Suite 227, Palo Alto CA 94303

(415) 964-0706/(714) 540-3554

ON THE COVER

The theme of this issue's cover illustration is "the domesticatedcomputer. " Robert Tinney has taken the idea of the remote con-trolled appliances suggested by Steve Ciarcia's article on page 28and combined it with some imaginative cabinetry in ahousehold setting. In the process, Robert used his artistic licenseto employ radio imagery with antennae and aetheric airbrushingas an alternative to ultrasonic techniques described by Steve.Either way, practical means of safely controlling 110Vappliances from the computer with total electrical isolation nowexist — both for the homebrewer and as practical productsadvertised in this issue.

Officers of McGraw-Hill Publications Company: Paul F McPherson, President; GroupVice President: Daniel A McMillan; Group Vice President-Planning and Development:James E Boddorf; Senior Vice President-Editorial: Ralph R Schulz; Vice Presidents:Robert B Doll, Circulation; James E Hackett, Controller; William H Hammond, Com-munications; Thomas H King, Manufacturing; Edward E Schirmer, International.

BYTE is published monthly by BYTE Publications Inc, 70 Main St, Peterborough NH03458, a wholly-owned subsidiary of McGraw-Hill, Inc. Address all mail except subscrip-tions to above address: phone (603) 924-7217. Address subscriptions, change ofaddress, USPS Form 3579, and fulfillment questions to BYTE Subscriptions, PO Box590, Martinsville NJ 08836. Second class postage paid at Peterborough NH 03458 and atadditional mailing offices—USPS Publication No. 102410 (ISSN 0360-5280). Subscrip-tions are $18 for one year, $32 for two years, and $46 for three years in the USA and itspossessions. In Canada and Mexico, $20 for one year, $36 for two years, $52 for threeyears. $32 for one year air delivery to Europe. $32 surface delivery elsewhere. Airdelivery to selected areas at additional rates upon request. Single copy price is $2.50 inthe USA and its possessions, $2.95 in Canada and Mexico, $4.00 in Europe, and $4.50elsewhere. Foreign subscriptions and sales should be remitted in United States fundsdrawn on a US bank. Printed in United States of America.

Address all editorial correspondence to the editor at the above address. Unaccep-table manuscripts will be returned if accompanied by sufficient first class postage. Notresponsible for lost manuscripts or photos. Opinions expressed by the authors are notnecessarily those of BYTE. Entire contents copyright © 1980 by BYTE Publications Inc.All rights reserved. v1t0

BYTE® is available in microform from University Microfilms International, o'/^sC^300 N Zeeb Rd, Dept PR, Ann Arbor Ml 48106 USA or 18 Bedford Row, Dept "//fcQPVv0PR, London WC1R 4EJ ENGLAND. Z^MW;*

Subscription WATS Line: (800) 258-5485Office hours: Mon-Thur 8:30 AM - 4:30 PM Eastern Time Friday 8:30 AM - Noon

January 1980 © BYTE Publications Inc

Circle 2 on inquiry card.

MICROANGELO

HIGH RESOLUTION INTELLIGENT GRAPHICS

Graphics boards have come and graphicsboards have gone. None have really givenyou all the features at a competitive pricethat you've wanted-UNTIL NOW!

.UTION 512 x 484 pixel display, from its own 32Krandom access memory.

Resident software emulates a terminaland also accepts high level commands for point,. line, region, and variably sized and oriented^ character generation.

ROCK SOUD DISPLAY No snow, no jitter, no

ropout. PERIOD.INDEPENDENi Z80 driven at 4 Mhz on its

own bus, so no address space fromyour host is used.

^ Direct MicroAngelo

via the light pen interface orhigh level software.

TALKATIVE High speedcommunication withyour host over inter-rupting parallel■ ports.

I EXTENSIBLERoomfor

up to 8K of PROM.

TIMELY 60 Hertz interrupting real time clock.

Drop it into any S-100 host and you're up andrunning.

VERSATILE Composite or direct drive output; provision forexternal sync for a 512 x 512 display.

895 dollars brings you the creative genius of

MicroAngelo.

MicroAngelo is available now. Call Jim Mather at(703) 827-0888 or write us at Micro Diversions, Inc., 8455-DTyco Road, Vienna, Virginia, 22180 and get creative!

BYTE December 1979 5

Look forSlmgart drives

in personal

computer systems

made by these

companies.

Editorial

Altos Computer Systems

2378-B Walsh AvenueSanta Clara, CA 95050

Apple Computer

10260 Bandley Dr.Cupertino, CA 95014

Commodore Business Machines, Inc.

3330 Scott BoulevardSanta Clara, CA 95050

Digital Microsystems Inc.

(Formerly Digital Systems)4448 Piedmont Ave.Oakland, CA 94611

Industrial Micro Systems

633 West Katella Suite LOrange. CA 92667

North Star Computer

2547 9th StreetBerkeley, CA 94710

Polymorphic Systems

460 Ward Dr.

Santa Barbara, CA 93111

Problem Solver Systems

20834 Lassen StreetChatsworth, CA 91311

Processor Applications Limited

2801 E. Valley View AvenueWest Covina.CA 91792

Technico Inc.

9130 Red Branch RoadColumbia. MD 21045

Texas Electronic Instruments

5636 EtheridgeHouston, TX 77087

Thinker Toys

1201 10th StreetBerkeley, CA 94710

^Shugart

The Era of Off-the-ShelfPersonal ComputersHas Arrived

Carl Helmets

This issue marks the beginning of a new decade: the 1980s. It may be ap-propriate at this time to pause and see how technology has progressed. At theturn of a previous decade, the only computers I could get my hands on werethose large and expensive behemoths of the 1960s, the IBM 360s, Univac1108s, and DEC PDP-6s, which I used during my occasional employmentswhile an undergraduate physics student. Those machines represented suchlarge capital investments that there was no way I could possibly own one.

At the time I knew that minicomputers existed. But they too were quite ex-pensive. The minicomputer of late 1969 was also very limited in peripheralsand systems software. At that time minicomputers were usually made byDigital Equipment Corporation, used a Teletype with paper tape for massstorage, and they may have had all of 8 K words of memory with 12 bits perword. It was an era in small computers when $30,000 might have purchasedthe hardware equivalent of today's $500 single-board engineering system; forexample, a Rockwell AIM-65 with some added memory and a power supply.(This single-board 6502-based computer includes printer, tape interface,systems software and keyboard. With all required purchases, it costs about$500 to $600. A system such as this is equivalent to (if not better than) one ofthe typical minicomputer "installations" of the late 1960s.)

As we entered the 1970s, the beginnings of the large-scale integrationmicrocomputer technology had been made. In existence at that time were 4-bitcomputers in high-technology calculator products, as well as such greataccomplishments as 1024-bit shift register memories (slow) and high-speed64-bit transistor-transistor logic (TTL) memories (power hungry). Massstorage on small machines in 1969, if it was electronic, was done on variousrandomly or serially addressable tape devices. These tape units were sold atprices comparable to the present-day retail price of a dedicated Winchestertechnology 10-million-byte hard disk drive. But the more common massstorage was mechanical, eg: the paper-tape reader and punch on a ModelASR-33 Teletype. As we enter the next decade, we find a much different pic-ture.

The 64-bit memory part of late 1969 has increased in size to today's latesttechnology 64 K bit dynamic memories. This is an increase in density of justover 3 decimal orders of magnitude (1024 & 103). The primitive 4-bit architec-tures of then current calculators have become the 32-bit architectures of cur-rent machines such as the Motorola 68000, which is now seeing its first limiteddeliveries to prototype laboratories. At the end product level, smart machineshave taken off in myriad directions, ranging from the dedicated controllersof computerized toys and microwave ovens, to the modern personal com-puter.

With the new extremely large-scale integration devices, the era of the 32-bitpersonal computer with high-resolution graphics display, main memory of256 K bytes and from 10 to 50 million bytes of hard disk capacity on line isnearly here. In 1980, such a system can be built with the central computer con-sisting of just 33 major parts: 32 memory chips and a 68000 microcomputer.

6 January 1980 © BYTE Publications Inc

"JtfyShugafollowed me li

FJT

<}

w

\

r

■£■!"■'■*

-■

^^1

1 1

1

i

■

^p^r 1

"After working all day with the computer atwork, it's a kick to get down to Basic at home. Andone thing that makes it more fun is my Shugartminifloppy™' We use Shugart drives at work, sowhen I bought my own system I made sure it had aminifloppy drive.

"Why? Shugart invented the minifloppy. Theguys who designed our system at work tell me thatShugart is the leader in floppy design and hasmore drives in use than any other manufacturer. IfShugart drives are reliable enough for hard-workingbusiness computers, they've got to be a goodvalue for my home system.

"When I'm working on my programs late atnight, I can't wait for cassette storage. Myminifloppy gives me fast random access and data

transfer. The little minidiskettes store plenty ofdata and file easily too.

"I made the right decision when I bought asystem with the minifloppy. When you lay out yourown hard-earned cash, you want reliability andperformance. Do what I did. Get a system with theminifloppy."

If it isn't Shugart,it isn't minifloppy.

^ Shugart

435 Oakmead Parkway, Sunnyvale, California 94086

See opposite page for list of manufacturers featuring Shugart's minifloppy in their systems.

TM minifloppy is a registered trademark of Shugart Associates

We'll pay the surface Ireight on all pre-paid productsfeatured in this ad to any of 18,000 U.S. tariffed loca-tions. No handling charges, add on costs, insurancefees or credit card fees!

Tl 99/4

Built in equation calculator, 13" colormonitor, 16-bit C.P.U., Tl Basic w/13 digitprecision, and more!CALL US FOR LOW PRICE!

Soroc IQ 120

High quality, professional text-editingterminal. 73-key board, built in 2K RAM.

$789

Hazeltine 1500

7X10 matrix, baud rates to 19,200; fullkeyboard with numeric pad, full functionCRT at a new low price! $950

Tl 810

Basic 150 cps serial. The industry leaderat a new low price! Save over $300.

$1589

Centronics 730

100 cps, parallel, 3-way feed,80-character buffer...the new leader insmall printers from Centronics. Save$100. $895

i mvMjem. I\ Comprint 912

Low priced electrostatic matrix printer,225 CPS' Serial $535

Parallel

499

North Star Horizon

Call us for our low prices onindustry's most popular C.P.U.

the

Tele video 912 $779

Centronics 704 $1685

Heath WH 14 $749

Over 2000 products from over 100 manufacturers. Prices subjectto change without notice, products subject to availability. FOBTempe, AZ (5% sales tax in Arizona)

toll-freeI -800-528-1418

1425 W. 12th PI. • Tempe, AZ 85281 • (602) 894-1193

Ancillaries, such as buffers and read-only memories,might double that count to 66. In a very approximatesystems sense, the manufacturing cost of an electronicsystem is proportional to the number of parts involved.This is exclusive of intangibles like software andaesthetics. So the manufacturing cost of such a devicetwo years from now will make it the typical personalcomputer.

But what of right now? Where would we stand if therewere to be no technological improvements in off-the-shelfpersonal computers? What is the state of today'stechnology? I am going to describe some of the criteriathat make up the design of a good modern personal com-puter system — and then I will make some commentsabout a particular system I just purchased and uponwhich I am creating this editorial. The fact that I havemade a particular choice reflects the necessity for choiceand not necessarily that other machines might not haveserved me as well. I will leave comments about this par-ticular machine until later while I go into more detailsabout what I see as the state of the art in small computersat the beginning of the 1980s.

The Personal Computer Circa 1980 . . .

As of this writing, October 1979, the state of the art inpersonal computing is such that the user is king. It ispossible to enter a computer store and witness the opera-tion of a typical modern system, try it out, then purchaseone just like it to take home and use. The discriminatinguser must pay attention to a number of technical pointsrelevant to the function of systems: areas of hardware,systems software, applications software, and plain old-fashioned idiosyncracies such as aesthetics and program-ming styles enter into a decision about which computer topurchase. But there is a core of minimum function whichmust be met in the contemporary small computer.

Starting this tour of function at the level of systemdesign, what are the characteristics of the processor andmemory required? First, remember the often overlookedpoint that the particular processor used is an arbitrary-consideration within a broad range. This is especially soin an era when high-level languages and systems softwarecan insulate the programmer from needless details of low-level code.

In present-day personal computers the processorswhich are typically used are 8-bit devices: 8080s, 6502s,Z80s, 8085s, 6800s, and 6809s. In raw performancestatistics, all of these are comparable within a factor of 2or 3 depending upon the benchmark chosen. Each has itsown strengths and weaknesses. The basic limitation ofpresent-era computers is the 8-bit bus, which cycles atonly a several megahertz rate (a typical system memoryaccess time is 200 to 500 nanoseconds). Transferring abyte at a time is often the most significant speed limi-tation.

Thus the processor choice is relatively unconstrainedamong the various off-the-shelf computers available to-day. What of memory? Whatever the processor, themore memory available, the better the system. I believethat the convenient and pleasurable use of the small com-puter as it exists today requires a bare minimum of 32 K(ie: 32,768) bytes. Of the computers I use regularly, twohave 64 K bytes and one has 53 K bytes. The primarycriterion for selecting memory technologies for a user of a

8 January 1980 © BYTE Publications Inc

Circle 3 on inquiry card.

Circle 4 on inquiry card.

At Intersystems,"dump" is an instruction.

Not a way of life.

[Or, when you're ready for IEEE S-100, will yourcomputer be ready for you?]

We're about to be gadflies again.

While everyone's been busytrying to convince you that largebuses housed in strong metalboxes will guarantee versatilityand ward off obsolescence, we'vebeen busy with something better.Solving the real problem with thefirst line of computer productsbu/7t from the ground up to con-form to the new IEEE S-100 BusStandard. Offering you extra ver-satility in 8-bit applications today.And a full 16 bits tomorrow.

We call our new line SeriesII™ And even if you don't need thefull 24-bit address for up to 16megabytes (!) of memory rightnow, they're something to thinkabout. Because of all the perform-

ance, flexibility and economythey offer. Whether you're lookingat a new mainframe, expandingyour present one or upgradingyour system with an eye to thefuture. (Series II boards are com-patible with most existing S-100systems and all IEEE S-100 Stan-dard cards as other manufacturersget around to building them.)

Consider some of the fea-tures: Reliable operation to 4MHzand beyond. Full compatibilitywith 8- and 16-bit CPUs, pe-ripherals and other devices. Eightlevels of prioritized interrupts. Upto 16 individually-addressableDMA devices, with IEEE Standardoverlapped operation. User-selec-table functions addressed by DIP-switch or jumpers, eliminating sol-dering. And that's just for openers.

The best part is that all thisheady stuff is available nowl Inour advanced processor—a fullIEEE Bus Master featuring MemoryMap™ addressing to a full mega-byte. Our fast, flexible 16K StaticRAM and 64K Dynamic RAMboards. An incredibly versatile and

economical 2-serial, 4-parallelMultiple I/O board. 8-bit A/D-D/Aconverter. Our Double-DensityHigh-Speed Disk Controller. Andwhat is undoubtedly the most flex-ible front panel in the business.Everything you need for a com-plete IEEE S-100 system. Availableseparately, or all together in ournew DPS-1 Mainframe!

Whatever your needs, whydump your money into obsoleteproducts labelled "IEEE timingcompatible" or other words peo-ple use to make up for a lack ofproduct. See the future now, atyour Intersystems dealer or call/write for our new catalog. We'lltell you all about Series II and thenew IEEE S-100 Bus we helpedpioneer. Because it doesn't makesense to buy yesterday's productswhen tomorrow's are already here.

&m

J

Ithaca Intersystems Inc.,

1650 Hanshaw Road/RO. Box 91,

Ithaca, NY 14850

607-257-0190/TWX: 510 255 4346

modern computer is that it be in the system, competentlyengineered, and reliable. Engineering jargon terms like"static" versus "dynamic" are meaningless once a producthas passed the design stage and becomes a reliable mass-produced product. The fact that nearly all mass-produced computers use dynamic memory is a statementabout the costs of various semiconductor engineeringtechnologies. When I buy a computer off the shelf, I careonly about the quantity of main memory available foruse as a resource.

In addition to the need for adequate main memory, thenext question is, what of magnetic mass storage? At abare minimum, the personal computer should have onthe order of 500 K bytes of on-line storage, preferably intwo or more drives. In today's technology, the mostprevalent magnetic medium is the 5- or 8-inch floppydisk, with single-, double- or quad-density recording.Although recently introduced in personal computers, thehard disk technology based on drive products, from firmslike Shugart, IMI and Micromation, is not nearly asprevalent as it will be in 1980 and beyond; the standardconfiguration for most small computers is two or morefloppy disk drives as 1979 draws to a close.

At the level of user interfaces, the standard displayhardware of a usable small computer is the 24 (or 25) lineby 80-character video display. In some machines this isbuilt in as a board in the system itself; on others it is pro-vided in the form of a high-speed serial link (typically19.2 kbps) to a video terminal. In either design, the ter-minal interface has a standard keyboard similar to atypewriter, and both upper and lowercase text are sup-

ported. In this era, when the marginal cost of a full upperand lowercase text capability is low compared to systemcost, there is no excuse for perpetuating primitive com-puters' use of only uppercase text. Still remaining at ahardware level, it is necessary to have a hard copy devicefor most effective use of a small computer (or a largecomputer for that matter). Rare is the person who canremember all the details of a program without hard copy;and rare is the computer system with sufficient redundantdisplays so that multiple independent pages of text can beconveniently viewed simultaneously. In a personal com-puter at prices within reason today, hard copy is anecessity.

What about the options and their availability? Doesthe computer in question have a de facto standard busdesign which is used by independent companies to designcompatible peripherals? At the present time, the personalcomputer world has four principal bus systems available— two that are represented by multiple computermanufacturers (S-100 and SS-50), and two that arerepresented by one computer manufacturer and many in-dependent compatible peripherals manufacturers (AppleII and Radio Shack TRS-80). These bus designs allowowners of small computers to mix and match peripheralsbeyond those of the standard variety every manufacturerprovides. Thus we can find music boards., modemboards, real-time clocks, and even hard disk memorieswhich plug into the bus definitions of one or more of thewidely used de facto standards.

Going on to the issue of software and its specifications,

Text continued on page 93

/

FINALLY, Apple II® software for the discerning computerist,and the not-so-discerning beginner

AppleAids™

Little Tricks™

A series of carefully explained subroutines containing a potpourri ofuseful programming techniques in Integer Basic and Applesoft, such asspecific key stroke identification, timing loops, disappearing questionmarks on input, no question marks on input, and many more.Cassette (16K) 14.95 Disk(32K) 19.95

Scroll Control™

Have you ever wondered why you cannot list an Integer Basic orApplesoft program one screen-page at a time? So have we, and wedid something about it! Our machine language Scroll Control, hiddenin RAM so as not to "bump" into your program, can be engaged or dis-engaged at a flick of the keyboard. Why be frustrated when instead youcan control the scroll? Cassette 9.95 Disk 14,95

Compulaw" Series

Alitax Estimator™

This Applesoft program, prepared under the supervision of an attorney,estimates disposable income after alimony and child support paymentsand federal taxes. For use by laymen and attorneys. 1980 tables.Cassette (24K) 9.95 Disk (32K) 14.95

Pensionner™

A companion to Alitax Estimator in Applesoft designed to calculate thepresent value of a pension in states in which a pension is subject todivision in marital dissolution cases.Cassette (24K) 9.95 Disk (32K) 14.95

N.J. res. add 5% sales tax

Apple II and Applesoft are registered

trademarks of Apple Computer, Inc.Add $1/item, shipping and handling•professional, but not a substitute for

legal advice

Form-It-Out™

A series of routines in Integer Basic and Applesoft containing detailedexplanation and examples of programming techniques necessary toprofessionalize your screen output. Included are right and center justi-fication, windowing, tabbing, cursor positioning among others.Cassette (16K). 14.95 Disk (32K) 19.95

Track & Sector List™

This is the ultimate disk utility. Instead of a catalog, have you ever seenthose dreaded words "I/O ERROR"? Is all lost? NO! Now your disk maybe saved. Also you can eliminate bad sectors, remove control charactersimbedded in file names, change the disk volume number, and more. Thismachine language program is supplemented by extensive tutorialdocumentation worth its weight in gold.Disk only (32K) 24.95

Hex and Decimal Learning Tree™My ABC's™

An early learning Integer Basic program using over one hundred and fiftyhigh resolution graphic letters and pictures in a drill-and-practice formatdesigned to develop identification of capital and small letters, andassociation of letters with pictures. Scoring capability allows monitoring.Child tested and teacher recognized. Cassette (48K) 14.95 Disk 19.95

Now I Can Rhyme™

A companion to My ABC's in Integer Basic. The child selects those highresolution pictures which rhyme. Score-keeping capability allowsmonitoring. Incorporates progressive levels of difficulty.Cassette (48K) 14.95 Disk (48K) 19.95

IMCORPORATED

P.O. Box 774MMorristown, NJ 07960(201)539-3770

10 January 1980 © BYTE Publications Inc

Circle 5 on inquiry card.

Circle 6 on inquiry card.

New from SSM.

/ L

■

,-sujum:

. /. /

.n JWtl.H

80 Character Video

With 80

interface for word processing.It produces a standard 80x24display of upper and lower casecharacters or as much as 80x51for a full page of text.The matrixfor graphic display goes up to160x204. And with optionalEPROM. as many as 256 userprogrammed characters orsymbols can be produced.

VB3 is memory mappedlor rapid screen updating. But itoccupies memory only whenactivated. So one or more VB.lscan be located at the sameaddress with a full 65K of mem-orj still available to the user.

It generates both U.S. andEuropean TV rates and meetsthe new IEEE S-100 standard.Other features include key-board input, black on white or\\ hite on black, one level of grey,underline, strike thru, blinkingchar., blank-out char., andprogrammable cursor. Softwareincludes a C'P M compatibledriver and a powerful terminalsimulator.

VB3 is available in several

.ie CB2 to assure thatit will be the most fully S-100compatible Z-80 CPU on themarket.

It operates at 2MHZ or4MHZ by DIP switch selectionand includes two sockets for2716/2732 EPROMs or TMS4016 2K RAMs. Memory sock-ets can be disabled. Separaterun/stop and single step switchesallow system evaluation withoutthe benefit of a front panel.

CB2 also features anM\\ RITE signal, firmwarevector jump, and an output portto control 8 extended addresslines lallow ing use of more than65K of memory). Jumper

W80 CPU

RAM has been increased from256 bytes to a full IK.

It also features an optional2K of 2708 EPROMs. power-onreset vector jump. MVYR1TE.parallel input port with statusand DIP switch addressing.

Retail price — $159 kit.S219 assembled.

211(S Walsh Avenue

Santa Clara. CA 95160 (408) 246-2-()'

S-100 signals to insure futureS-100 compatibility.

Retail price—$210 kit.

$275, assembled.

Our line. CPU.Video. 1 (>. RAM.I.PROM. EPROM Programmer.Music, Pn ti typing,Terminator,Extender, and Mother boards. 1

Available assembled i ft as kits.

Send lor our free brochure and findout why SSM has become the favorilof discerning Hobbyists and ()EMs.

igurattons. Ket<at $375 kit, $441

Microcomputing comes of age.

Ohio Scientific* 0S-65ULevel 3 operating systemsoftware brings newnetworking and distributedprocessing capabilitiesto microprocessor basedcomputer systems.

DUMBTERMINAL

DATABASE

INTELLIGENTTERMINAL

-|-ji^

iHH

B

Until now, the only alternative for lowcost multiple-user computerapplications was time-sharedsystems. However, a seriousdrawback of microcomputer or mini-computer multi-user time-sharesystems is the fact that under heavywork loads they slow down to a crawlsince the central processor time insuch a system is shared by all of theusers.

In a microprocessor based distributedprocessing system, using floppybased microcomputers as intelligentterminals (local systems) most of thework load is handled locally. Overallsystem performance does notdegrade under heavy job loads. Eachlocal system performs entry, editingand execution while utilizing thecentral data base for disk storage,printer output, and other sharedresources.

For more demanding applications it isdesirable to have several data bases,each with its own collection of localsystems. Such an inter-connected setof data bases is called a network.Each data base and its local intelligentand dumb terminals is called a cluster.

Level III

OS-65U Level 3 now supports thisadvanced networking and distributedprocessing capability as well asconventional single user operationand time-sharing. Level 3 nowsupports local clusters of intelligentmicrocomputer systems as well as

dumb terminals for the purpose ofutilizing a central Winchester disk database and other shared resources.Thesystem also has full communicationscapability with other Level 3 databases providing full network capability.

The system utilizes Ohio Scientific'slow cost, ultra high performancecomputer systems throughout for intel-ligent terminals as well as data bases.This general systems configurationprovides a cost/ performance rationever before attained in this class ofcomputer power.

Level 3 resides in each network database. A subset system resides in eachintelligent terminal. Each data basesupports up to 16 intelligent systemsand up to 16 dumb terminals.However, since dumb terminals canheavily load the system, they shouldbe kept to a minimum. Level 3 alsosupports a real time clock, printermanagement, and other sharedperipherals.

Data Base Requirements

Minimal requirements for a Level 3network data base are a C3-C or C3-Bcomputer system with 23 or 74megabytes respectively, consoleterminal, 100K bytes RAM and a CA-10X 16 port I/O board for network andcluster communications.

Intelligent Terminal Requirements

Any Ohio Scientific 8" floppy basedcomputer with 56K RAM and one database communications port.

Connections

Intelligent terminals and networkeddata bases are connected by low-costcabling. Each link can be up to 10,000feet long at a transfer rate of 500K bitsper second, and will cost typically 30<ta foot (plus installation).

Syntax

Existing OS-65U based software canbe directly installed on the networkwith only one statement change!Level 3 has the most elegantly simpleprogramming syntax ever offered on acomputer network.

File syntax is as follows:

DEVA.B.C.D. Local Floppies 1 unchanged Iromf single user andDEVE Local hard disks I limeshare systems

DEV K-Z Specific network

Data Bases

Each of up to 8 open files per user can

be from 8 separate origins. Specific

file and shared peripheral contentions

are handled by 256 network

semaphores

with the syntax Waite N

Waite N, close.

The network automatically prioritizesmultiple resource requests and eachuser can specify a time out onresource requests. Semaphores areautomatically reset on errors andprogram completion providing thesystem with a high degree ofautomatic recovery.

INVENTORYCONTROL

PURCHASING

RECEIVING

SHIPPING

AR/AP

an

CONTROLLER

c£HHdG—cG—

D8

74M

^■r^B

OB7*M

A Typical System

A typical system with two networkdata bases will have 148 megabytes ofdisk, four intelligent subsystemsequipped with dual floppies, two dumbterminals, a word processing printer, afast line printer, network data basemanager software and 1000 ft. of inter-connecting cable. Utlizing .7 MIPSprocessors throughout it will cost lessthan $50,000 plus installation. GToption computers (1.2 MIPS) can beutilized at a slightly higher cost.

One Step at a Time

Best of all, Ohio Scientific users candevelop distributed processingsystems economically one step at atime. A user can start with a singleuser floppy system, add a hard disk,then time-sharing, then a secondWinchester data base for backup andfinally cluster intelligent terminals toachieve a full network configuration.

For literature and the name of your localdealer, CALL 1-800-321-6850 TOLL FREE.

1333 SOUTH CHILLICOTHE ROADAURORA. OH 44202 • [216] 562-3101

The Microcomputersyou should take seriously.

The Challenger III Series is the micro-computer family with the hardware features,high level software and applicationprograms that serious users in businessand industry demand from a computersystem, no matter what its size.

Since its introduction in August, 1977,the Challenger III has become one of themost successful microcomputer systemsin small business, educational andindustrial development applications. Tensof thousands of Challenger Ill's havebeen delivered and today hundreds ofdemonstrator units are set up at systemsdealers around the country.

The Challenger III systems offerfeatures which make their performancecomparable with today's most powerfulmini-based systems. Some of thesefeatures are:

Three processors today, moretomorrow.

The Challenger III Series is the onlycomputer system with the three mostpopular processors— the 6502A, 68B00and Z-80. This allows you to takemaximum advantage of the OhioScientific software library and programsoffered by independent suppliers andpublishers. And all Challenger Ill's haveprovisions for the next generation of 16bit micros via their 16 bit data BUS, 20address bits, and unused processorselect codes. This means you'll be ableto plug a CPU expander card with two ormore 16 bit micros right in to yourexisting Challenger III computer.

Systems Software for threeprocessors.

Five DOS options including develop-ment, end user, and virtual data file singleuser systems, real time, time share, andnetworkable multi-user systems.

The three most popular computerlanguages including three types of BASICplus FORTRAN and COBOL with more

languages available from independentsuppliers. And, of course, completeassembler, editor, debugger and run timepackages for each of the system'smicroprocessors.

Applications Software for SmallBusiness Users.

Ready made factory supported smallbusiness software including AccountsReceivable, Payables, Cash Receipts,Disbursements, General Ledger, BalanceSheet, P & L Statements, Payroll, Per-sonnel Files, Inventory and Order Entryas stand alone packages or integratedsystems. A complete word processorsystem with full editing and outputformatting including justification,proportional spacing and hyphenation.

OS-DMS, the software star.

Ohio Scientific offers an InformationManagement system which provides enduser intelligence far beyond what youwould expect from even the mostpowerful mini-systems. Basically, it

The Challenger 111

Series

from Ohio Scientific.

C3-B

□ □

QQ

IIIUIHU »"

allows end users to store any collectionof information under a Data BaseManager and then instantly obtaininformation, lists, reports, statisticalanalysis and even answers toconventional "English" questionspertinent to information in the Data Base.OS-DMS allows many applications to becomputerized without any programming!

The "GT" option yields sub-microsecond microcomputing.

Ohio Scientific offers the 6502Cmicroprocessor with 150 nanosecondmain memory as the GT option on allChallenger III Series products. Thesystem performs an average of 1.5million instructions per second executingtypical end user applications software(and that's a mix of 8, 16 and 24 bitinstructions!).

Mini-system Expansion Ability.

Challenger III systems offer thegreatest expansion capability in themicrocomputer industry, including a fullline of over 40 expansion accessories.

Networking and DistributedProcessing

OS-65U level 3 now providesnetworking capabilities as well as timesharing ability allowing Challenger IIIbased systems to be expanded to meetthe most demanding businessapplications.

Prices you have to take seriously.

The Challenger III systems havephenomenal performance-to-cost ratios.The C3-S1 with 48K static RAM, dual 8"floppies, RS-232 port, BASIC and DOShas a suggested retail price of under$4000. 80 megabyte disk based systemsstart at under $13,000. Our OS-CP/Msoftware package with BASIC, FORTRANand COBOL is only $600, and otheroptions are comparably priced.

For literature and the name of your localdealer, CALL 1-800-321-6850 TOLL FREE.

Circle 7 on inquiry card.

C3-B wins Award of Merit atWESCON '78 as the outstandingmicrocomputer application forSmall Business.

ae

C3-S1

C30EM

1333 SOUTH CHILLICOTHE ROADAURORA, OH 44202 •[216] 562-3101

Letters

Tic Tac Rebuttal

In his letter to BYTE (October 1979,page 175), Mr Miller raises some inter-esting points. However, his commentsabout my Tic-Tac-Toe program (BYTEMay 1979, page 196) do require furtherexamination.

Apparently, aesthetics in program-ming is in the eye of the beholder; MrMiller found my table-lookup methodunappealing. It is more aestheticallypleasing to me to compute a move onlyonce, then use it, rather than to recom-pute the same move each time it is used.Since a Tic-Tac-Toe game is readilyrepresented as a decision tree, I felt thata table-lookup algorithm was the mostnatural implementation, and regrettedthe necessity of using more clumsymethods for the special cases.

A further advantage of a table-lookupmethod is its modularity; one move-logic block may be readily changed

without affecting other parts. You mayrecall that there was a logic bug in thepublished program (see "BYTE's Bugs,"August 1979, page 194). This was easilycorrected by changing only five numbersin the data table.

The concept is similar to that of achess program; the better ones use atable-lookup for the early moves of thegame, before things get too complicated.

As for taking advantage of the micro-processor's capabilities, it is morenatural for it to increment an address tofind a prestored number than to com-pute; its built-in computing power islimited to addition. More complicatedcomputing must be done by 'brute forceand awkwardness" in the machine-language programming of the BASICinterpreter.

Mr Miller did not like for the com-puter to always move first. As I statedin the article, I wanted the computer toplay an aggressive game. It is readily

5-10 times faster...and more!

Meet Pascal/Z,™ the fast, flexible compiler with"higher speed, greater efficiency and improved debugging:

■ True Z-80 native code Pascal compiler —5-10X fasterthan competing P-code implementations—no interpreterrequired.

■ The only multi-tasking Pascal —produces ROMablere-entrant code.

■ Optimized for fastest execution —recognizes andexploits special cases.

■ Easily transportable —all hooks to your system madethrough support library.

■ Includes IEEE standard floating point package.Single copy on CP/M-compatible disk includes compiler,companion macro-assembler & source of the library, $275.OEM licenses available. Write or call for more information.

n a nx\ A

\mmmmm\mmm

Ithaca Intersystems lnc.,1650 Hanshaw Road/PO. Box 91,Ithaca, NY 14850/607-257-019Q/TWX: 510255 4346

©1979 Ithaca Intersystems Inr

apparent that the computer cannot playan aggressive game if the user movesfirst; it can then play only a defensivegame, and wait for the user to blunder.Actually, I do have a user-first Tic-Tac-Toe program that uses a similar table-lookup method of play. While it playsthe best possible game within the limitsof a user-first game, it is still "curiouslylimited" and I felt that its inclusionwould detract from the performance ofthe published program.

To play a rational Tic-Tac-Toe game,it is necessary but not sufficient for theprogram to be unbeatable. A rationalprogram must not just respond to thecurrent situation, but it must be goal-oriented. To set a "trap" requires threemoves in the proper sequence. Thisplanning ahead is readily done with atable-lookup method, but I suspect thatit would be difficult to do by followingMr Miller's proposed system.

I suggest that Mr Miller submit a Tic-Tac-Toe program based upon his 9-stepstrategy. It is much more meaningful tocompare the performance of workingprograms than to compare a workingprogram with a theoretical one.

Delmer D Hinrichs2116 S E 377th AveWashougal WA 98671

UNIX-type File Available

We applaud Jim Howell's plea("Operating Systems: Let's Have SomeUNIX-Inspired Software," September1979 BYTE, page 82) for moresophisticated system software onmicrocomputers.

We would like to point out thatUNIX-style file systems are, however,available already for microprocessors (atleast the 6800s) in our SDOS product.

The SDOS file system supports fileswhich may be randomly addressed tothe byte; as many bytes as desired maybe read or written in a single systemcall. Sector sizes of the disk hardwareunderlying the file system are completelyinvisible to the application program.Disks with different capacities and sectorsizes can even be mixed on the samesystem. Regular I/O devices such as ter-minals and printers are treated identical-ly, with the result being that applica-tions object programs move unchangedfrom one SDOS hardware configurationto another.

14 January 1980 © BYTE Publications Inc

Circle 8 on inquiry card.

S. NTCOTC DMA SYSBK I SUPRBRAIN

■' ."' :' ,J '■ J ' l

The Honor Graduate

There's been a lot of talk latelyabout intelligent terminals withsmall systems capability. And, it'salways the same. The systemswhich make the grade in perfor-mance usually flunk the test inprice. At least that was the caseuntil the SuperBrain graduated withthe highest PPR (Price/Perfor-mance Ratio) in the history of theindustry.

For less than $3,000*, SuperBrainusers get exceptional performancefor just a fraction of what they'dexpect to pay. Standard features in-clude: two dual-density mini-flop-pies with 320K bytes of disk storage,up to 64K of RAM to handle eventhe most sophisticated programs,a CP/M Disk Operating Systemwith a high-powered text editor, as-

*Quantity one. Dealer inquiries invited.Circle 9 on inquiry card.

sembler and debugger. And, withSuperBrain's S-100 bus adapter, youcan even add a 10 megabyte disk!

More than an intelligent terminal,the SuperBrain outperforms manyother systems costing three to fivetimes as much. Endowed with ahefty amount of available software(BASIC, FORTRAN, COBOL), theSuperBrain is ready to take on yourtoughest assignment. You name it!General Ledger, Accounts Receiv-able, Payroll, Inventory or Word Pro-cessing . . . the SuperBrain handlesall of them with ease.

Your operators will praise theSuperBrain's good looks. A fullASCII keyboard with a numeric key-pad and function keys. A non-glare,dynamically focused, twelve inchscreen. All in an attractive desktopunit weighing less than a standard

office typewriter. Sophisticatedusers will acclaim SuperBrain's twinZ-80 processors which transfer datato the screen at 38 kilobaud! Inter-facing a printer or modem is noproblem using SuperBrain's RS-232C communications port. But bestof all, you won't need a PhD in com-puter repair to maintain the Super-Brain. Its single board design makesservicing a snap!

So don't be fooled by all the fresh-man students in the small systemsbusiness. Insist on this year's honorgraduate . . . the SuperBrain.

3

sinte3tecCdatas systems

2300 Broad River Road, Columbia, SC 29210(803) 798-9100 TWX: 810-666-2115

BYTE fcnuary 1980 15

Also, like UNIX, SDOS is completelyinterrupt-driven.

SDOS currently runs on seven manu-facturers' systems, handling over ten dif-ferent types of drives, including floppy,Winchester, and 10 M byte cartridgedrives.

We point out the obvious disadvan-tages of systems such as FLEX andCP/M; they are tied (and thus tie theapplication) irrevocably to the floppydisk hardware to which they wereoriginally attached. Further, file I/Ounder these systems requires a lot ofknowledge (ie: code) in the applicationto perform random access.

Yes, the industry does generally needmore sophisticated system software.

Ira D BaxterSoftware Dynamics2111 W Crescent, Suite GAnaheim CA 92801

A Stitch in Time?

Karen Wolfe's article in October BYTE"Power Helps Analyze Electric Bills,"(page 48) led me to analyze Karen's sew-ing power. With the assistance of a sew-ing machine and a pocket calculator,neither of them programmable, I reached

the following conclusions: For 100 hoursrunning time on the sewing machine sheprobably spends close to eight hours aday sewing, including cutting, pinning,etc.

In a month Karen sews about 21 miles— that's 25,000 double seams the fulllength of the kid's jeans. 50 miles ofthread speed through denim. Enough toweave 400 square feet of new cloth.

If Karen is ahead of the game and isin fact getting her stitches in in time, sheis saving 189 miles of sewing eachmonth. If she is not in time, she iswasting 18.9 miles of stitches, 45 milesof thread, and $1.38 of electricity.

Ken Bramham

apt 160, 15 rue Leon Bloy

92260 Fontenay-aux-Roses

FRANCE

Willard Irwin Nico1928- 1979

Personal computing pioneer andauthor Bill Nico passed away recently inHouston, Texas. Bill died of cancer July2, 1979 at the age of 50.

Bill Nico is perhaps most widelyknown for his writing. He wrote severalarticles for BYTE ("Shooting Stars,"

ANOTHER FIRST FROM MOUNTAIN HARDWARE.

SUPERTALKER.

FOR YOUR APPLE

SuperTalker is a peripheralsystem which permits theoutput of exceptionallyhigh quality human speechthrough a loudspeaker underprogram control. Initially words,sentences or phrases are digi-tized into RAM memory througha microphone. Speech data inRAM may be then manipulated likeany other data. The system consistsof a peripheral card, microphone, loudspeaker,and operating software. $279 assembled and tested.

83

Available through Apple dealers worldwide.

Mountain Hardware, Inc.

LEADERSHIP IN COMPUTER PERIPHERALS

300 Harvey West Blvd.Santa Cruz, CA 95060 (408) 429-8600

May 1976; "Sys SVi," January 1977;"Sweet Auto Line," February 1977) andwas author of Heath Company's bestselling, self-instructional courses BASICProgramming and Assembly LanguageProgramming. One of Bill's personalfriends was Robert Tinney, artist formany BYTE covers. Robert drew Bill onthe December 1977 cover.

Not so well known is the fact that BillNico was one of the first real computerhobbyists in the US. Bill's homebrew8080 computer built in 1974 had to beone of the first in the country.

Bill was also one of the best BASICand 8080 programmers around. Hecould get more out of his disk-basedIMSAI than anyone. He could writesystems software and languages, but feltjust at home with a small businesspackage or a real-time industrial controlprogram.

Bill was also pretty good at hardware.He was a professional logic designer anddid a fair amount of consulting in thisfield. His home was perhaps one of themost fully automated in existence. It wasa virtual electronic showplace. Bill wasalso an active amateur radio operator(W5PRZ).

It was only in recent years that Billdiscovered his talent for teaching. Billtaught frequently in Heath's computerclasses. His great empathy and personalawareness made him a gem of a teacher.His practical nature and down-to-earthapproach made him the favorite of everystudent. It was hard not to learn in hisclasses.

Bill Nico was born August 30, 1928 inLos Angeles. He graduated from Bur-bank High in 1946 and served in theArmy from 1950 to 1953. His electronicstraining came from Pierce College in LosAngeles. Bill worked in a variety of elec-tronic engineering and sales jobs inCalifornia and Texas from 1953 to 1969.He was manager of the Heathkit Elec-tronic Center in Houston from its open-ing in 1969 until 1975 when he left toform his own company. From 1975 to1979 he operated as a consultant andwriter from his Houston-based firm,Delta-t.

Those of us who knew and workedwith Bill will miss him greatly.

Lou Frenzel

1588 Oak Ter

St Joseph MI 49085

Marsport Forces Resurface

Mr Reiland made some commentsabout my "Marsport" article (April 1979,page 84) in his letter to BYTE (October1979, page 209). While I appreciate hiscompliments, I do differ with him on

16 January 1980 © BYTE Publicalions Inc

Circle 10 on inquiry card.

The easy way to learn about computers:

BUILD ONE

H14 Serial PrinterV

••«••

A H19 Smart

Video Terminal

a H8 Personal Computer^ with Dual Floppy System

H11A 16-bit Computer (DEC®PDP-11/03 compatible) withDual Floppy System £>

H89 All-in-One Computer

nr

Self-Instruction Programs forAssembly and BASIC Programming

Yes, you can do it. Heath makes it simplewith easy-to-build kits and step-by-stepassembly manuals that lead you from un-packing to final plug-in.And once you build your own computer,you'll know it inside-out. You'll know howto make it work for you.Software, designed especially for HeathkitComputers, includes innovative programs

for running your home or business, andexciting games your kids will enjoy.The Heathkit User's Group (HUG), madeup of owners of Heathkit Computers, willshare with you a library of over 400 pro-grams that they've written to make yourcomputer serve you in ways you neverimagined.Heathkit Computers may be low-cost kits.

But they're not playthings. They're power-ful, high-capacity computers designed forcomplex programming. You'll find com-plete systems — hardware, software, acces-sories—within the pages of the colorful,104-page, Free Heathkit Catalog. Andyou'll find service any time you need it at55 locations throughout the U.S. or at theHeathkit factory.

FREE

CATALOG

For complete descriptions of HeathkitComputers and nearly 400 other elec-tronic kits for your home, business orpleasure, send for the latest, freeHeathkit Catalog. Or you can pickup your catalog at a nearby Heathkit^Electronic Center.

If Coupon is missing write: Heath Co.,Dept. 334-612, Benton Harbor, Ml 49022

Heathkit Products are also sold and serviced at Heathkit ElectronicCenters (units of Veritechnology Electronics Corporation) through-out the U.S. See your white pages. DEC is a registered trademarkof Digital Equipment Corporation.

Circle 11 on inquiry card.

J Heathkit

Heath Company,

Dept. 334-612

Benton Harbor, Ml 49022

G YES Please send me my FREE Heathkit Catalog.I am not currently receiving your catalogs.

Address.

City.

-State.

CP-177

Zip.

L.r-i// *-ip g

BVTE January 1980 17

one point: he objected to my statementabout a circular orbit, 'The attraction ofgravity is exactly balanced by the cen-trifugal force at all times." All that I cansay is, if this is "confusion," I am ingood company. In the NASA bookSpace Mathematics (January 1972, page119), two forces are defined:

F, = mv'/rwhere:

F, = Centripetal force

m = Mass

v = Velocity

r = Radius from center

F2 = GMm/r2where:

F2 = Gravitational forceG = Universal gravitational constantM & m = Masses of the two bodiesr = Radius between centers

They then say, "The physical situation,if these two forces are equal, isrepresented in ... (a circular orbit)."(Emphasis added.) They further showhow, by setting these two forces equal,one can solve algebraically for the cir-cular orbit velocity. While their ter-minology is slightly different from mine,their meaning is obviously the same as Iexpressed.

One further point: Mr Reiland seemed

surprised that a three-dimensional land-ing simulation could be programmed ona programmable calculator. This pro-gram is far from the limit I I have sinceprogrammed a similar three-dimensionalrendezvous simulation, that keeps trackof two objects in their orbitssimultaneously. In it, the spaceship isinitially at rest on the surface of theprimary, while a target satellite is in arandom elliptical orbit. The user waitsuntil the satellite is in the best position,lifts off, matches orbits with the satellite,and rendezvous with it. To try this moredifficult exercise, send $1 to cover mycopying and postage costs for a 12-pagewrite-up and listing for the HP-67/97 (assubmitted to the Hewlett-Packard Users'Library). Include two blank magneticcards and I can record the program onthem.

Delmer D Hinrichs2116 S E 377th AveWashougal WA 98671

It Happened Again

It has happened again. Every time I

decide to let my BYTE subscription lapsebecause of the high price of themagazine, along comes an issue so jam-packed with well-written, informative,readable articles, that I am forced torenew my subscription again. The mostrecent issue, the one on LISP (August1979), just did it again.

The LISP articles simply coveredalmost everything one would want toknow in an introduction, and did itwell. In addition, there were excellentarticles on more advanced subjects —symbolic math systems and pattern-directed languages being the prime casesto point to — for those who want todelve deeper, or who already knew LISPand its implications and implementa-tions. All of these articles were well-written, tool

Amazing is the only word.

Dave Mellinger, LISP hackerc/o Datek Inc2336 Wilson BlvdArlington VA 22201

Elegant Input Recognizer

While working on a Star Trek pro-gram, I came across the problem ofcommand mnemonics. I wanted the userto be able to type commands asalphabetic mnemonics, not numbers (forexample, TRP for torpedo). Also, Iwanted him or her to be able to type inthe initial of the mnemonic, also for ex-pediency.

However, I did not want the remain-ing letters to be arbitrary (having thecomputer recognize only the first letterwould mean that THE PHASERS wouldwork for TRP). It's not easy tomemorize the mnemonics, so users couldeasily make mistakes in typing in com-mands, thereby moving two quadrantswest when they wanted to fire thephoton torpedo banks. I have seen thishappen on many occasions. So, I did alittle brainstorming, and came up withthis:

IF LEFT$("TRP",LEN(A$)) = A$THEN PRINT "TRP"

This works just as well for YES. Thisone-line comparison will allow "Y,""YE," or "YES," but not "YEAH,""ALYESKA," or even "YESNO." I agreethat it is really not necessary to put allthat user-input protection in a computer-assisted instruction (CAI) program, butif you want to use it, you can implementit very easily in any BASIC with LEFTSand LEN. It's also useful for other ap-plications, such as my Star Trek pro-blem.

Mils Hadeishi1460 W 182nd StGardena CA 90248 ■

18 January 1980 © BYTE Publications lnc

ALTOS COMPUTER SYSTEMS PROUDLY ANNOUNCES

AQ8000-6

E VERY FIRST

Double Density Z80 Micro-Computer

plus Twin 8" Floppies

plus 14.5Mb Winchester Disk

for under $9,500!And more! 4 user CP/M® for under $12,000!

^CP/M is a registered trademark of Digital Research, Inc

ALTOS COMPUTER SYSTEMS, LEADER IN SINGLEBOARD TECHNOLOGYDOES IT AGAIN WITH ITS SINGLEBOARD ACS8000-6. TOTAL BUSINESS COMPU1

HIGH TECHNOLOGY AGAIN

WINCHESTER MASS STORAGE

The new ACS8000-6 single board computer Is packedwith ultra-high technology: Z80 double-density computer,up to 208Kb of high speed RAM, Floppy-disk and Win-chester Hard Disk controllers, DMA, up to 6 serial/2Parallel I/O, optional 32 bit floating point processor. . .All on One Board, fully socketed, fully documented reliable and maintainable.

We're staying with Shugart for both floppies andWinchester hard disk. Why? Simple, low price, solidreliability and they're our next door neighbor. Our singleboard computer supports up to 4 Mbytes of floppies and58 Mbytes of Winchester running under AMEX.

ADVANCED MULTI-USER SOFTWAREOur new ALTOS Multi-User Executive(AMEX) supports four independentCP/M compatible programs in any of sixlanguages: Basic, Fortran, Cobol, PascalAPL, C, and a wealth of completebusiness application packages.

[ALEOS)

MINI PERFORMANCE FOR 1/2 COSTPrices you will love. Entry levelACS8000-6 Hard Disk System $9,4502 users $10,670, 4 users $11,960,AMEX separate at $250.

COMPUTER SYSTEMS

2338-A Walsh AvenueSanta Clara, Ca. 95050

AVAILABLE NOWI clrcle 12 on lnlulrV oardCall for your nearest Altos dealer. (408)244-5766. Telex 171562 ALTOS SNTA.

■■

Making Color Slides with anIntecolor Microcomputer

Slides are required for manydemonstrations and lectures. Instuc-tional slides often consist of a fewwords or a simple diagram or graphwhich the lecturer wishes to discuss.In recent years such slides have com-monly been prepared as a blue diazo(white writing on a blue ground).Even the simplest slide is subject toabout twelve processes: rough draft-ing, typing, checking, type setting,rechecking, photography, developingnegatives, brushing out imperfec-tions, diazo exposure, pickling, cut-ting, and mounting. Misunderstan-dings and interpretations mean that itis not uncommon for one or morestages to be repeated; the process ismoderately expensive, and a diazoslide tends to fade with time. This ar-ticle describes a quick, convenientmethod of preparing color slidesusing a computer.

Equipment

The computer employed is an Inte-color eight-color intelligent terminalequipped with BASIC and dualfloppy disk. The choice of cameraand film may depend on individualcircumstances, but the author sug-gests the following: a single-lensreflex (SLR) 35 mm camera, mountedon a tripod, with telephoto lens (toreduce barrel distortion). Close-up

Alan W Grogono

State University of New York

Upstate Medical Center

750 E Adams St

Syracuse NY 13210

la

DIFFICULTY VENTILATING(CAUSES AHO TREATMENT)

U l '.-iiMi,... (Suction l Po*iur*>

B foor R*l*x»ttar» t3*d*t* or P*r*1us«^n ducting <Qh*ng* Tub*. h\a.idilu>i ■* Mnk«d tub* CKroto*. ft*pa«tttan >H "■ i>wi or lull Obstruction h'i*,i i.<>l-<s) h rtn# tung intubation (Ulthdr*u * Cn*cfc>1 ?. Bronct*otp«»* <Ulthdr*u > N«llc«t*>9 PnMSMthQM* >Xr»U, fjw»t Tut*)

lb

1

10 mo] s I

0

1 moI / I

-3

1 • Kl / 1

-fi

I mlc mol-'l

-9

1 n ool'/ 1

Photo 1: Two examples of computer-generated slides containing color textmaterial.

lenses or close focusing attachmentsare essential.

The computer allows images to beformed on a high-resolution screenoffering eighty characters per line andeither forty-eight lines of small lettersor twenty-four lines of double-height

letters. Lines, bar graphs, vectorgraphics, and simple drawings canalso be constructed. The color for thebackground and for the foreground(the character or line) can beseparately selected from the eightavailable colors.

Software

A program called Menu is used to:

• prepare a new floppy disk for sav-ing images,

• prepare images,

About the Author

Dr Grogono is an Associate Professor ofAnesthesiology at the State University of NewYork, Upstate Medical Center, in SyracuseNew York. He trained in London, England,and emigrated to the United States in 1974. Heuses microcomputers with graphics for teach-ing, for recreation, and as described in theaccompanying article, for color slide making.He has written many scientific papers in hisspecialty, anesthesiology, and is author audi oreditor of several books. He is an active memberof the American Heart Association and directsthe Advanced Cardiac Life-SupportInstructor's Course in Syracuse NY. For theNew York State Society of Anesthesiologistsannual meeting in New York, he runs the panel"Research by New Investigators." He is also amember of the Icarus high-speed hydrofoil sail-ing project which set a B-Class. World Sailingspeed record in Weymouth, England, in 1976.

20 January 1980 & BYTE Publicalions Inc

"Our reputation rests on digits,

decimal points, and details,

Vfe wouldn't trust them to anything less

than Scotch Brand Data Cartridges?

Bill Birkett, Vice President,Trade Graphics, Inc.,Livonia, Michigan

The unique design of a datacartridge provides great reliability,high storage capacity and longtape life. And where could youpossibly get better data cartridgesthan Scotch Brand, made by3M, the people who invented thedata cartridge system itself?

3M controls every step in manu-facturing. Top quality magnetictape and precision components arepart of every Scotch Data Cartridge.Over twenty-five years of serviceto the computer industry assureyou of the utmost reliability.

Scotch Data Cartridges areavailable in miniature DC 100A,the standard-size DC 300A andnow, an extra-length DC 300XLwith 50% more storage capacity.They are compatible with mostcartridge systems includingHewlett-Packard, IBM, NCR,Tektronix and TI.

To find out where you can findScotch Data Cartridges or virtuallyany other data recording medium,call toll-free: 800-328-1300.(In Minnesota, call collect:612-736-9625.) Ask for theData Recording Products Division.

If it's worth remembering,

it's worth Scotch

Data Recording Products.

Circle 13 on inquiry card.

3M

BYTE January 1980 21

2a

• transfer the contents of the displaymemory onto the floppy disk

The program also places the com-puter into a suitable mode. The scrollmode is replaced by the page mode,and the screen image is made to cor-respond with the appropriatememory locations.

Image Preparation

Simple word slides are bestprepared in CRT mode (a modewhich allows direct user interactionwith the graphics display). Thekeyboard allows letters to be posi-tioned anywhere on the screen.Colored text, borders, and back-grounds are used for effect. Con-siderable rearrangement and adjust-ment is possible using the delete andinsert keys for characters and lines.When the image is complete, the diskis inserted and the AUTO key ispressed to run the storage program.The image is automatically transfer-red to the disk to be photographedlater. Examples of text slides preparedin this way are shown in photos laand lb.

More complicated slides may beproduced by employing a program toprepare the display (eg: to generate agraph or a histogram). Examples ofslides prepared in this way are shownin photos 2a and 2b. When such aprogram is being written, it is impor-tant to remember that the process oftransferring the image to disk uses aBASIC program that will replace thepreparation program in memory.

Color Selection

Color slides are usually most suc-cessful when the image or letters arebrighter than the background. Withthe bright foreground image, anyspreading due to light-scatter on thecathode-ray tube, the film or the pro-jection screen tends to enlarge a lineor a character instead of extin-guishing it. Therefore, of the sixty-four color combinations available,only about twenty are useful forslides.

If the alignment of the red, blue,and green electron beams in thecathode-ray tube is imperfect, thefocus of the screen image may suffer.This problem may be minimized byjudicious choice of foreground color.In such cases, use a color scheme inwhich the image is formed by turningonly a single beam on and off as it

Photo 2: Two examples of computer-generated slides containing colored graphicmaterial.

sweeps across the tube. For example,with white text on a magenta back-ground, only the green electron beamis modulated, and a good image canbe obtained even if the beam align-ment is poor.

Photography

The images are recalled forphotography using the same pro-gram. The program recalls the imagesone by one. Photographs must bemade in ambient darkness to avoidunwanted reflections. Certain colors

tend to require more exposure thanothers (eg: red and blue on blackbackgrounds).

Color film does not always repro-duce television images perfectly. Red,in particular, may appear somewhatbrown. A Kodak CC40R filter is sup-posed to correct this, but the ex-posure time required is doubled. Ihave prepared slides with and with-out the filter. I currently use KodakEktachrome 64 (ER-135) with nofilter. The films, filters, and ex-posures I used are shown in table 1.

A word of warning about returning

22 January 1980 © BYTE Publications In

The Paper Tiger.

At $995, why settle forless.

\^

*J

' v. ' --^ JTfe

y^**

>^v^

!29fl

^

VO

1

wx

v>

*«■**:

*</}

rfilJA

WCk tli.ll i , . . ojjx [

ln« OUmtard f>eu»-Bl totlwh MiUi

■ ■ ■ (Mill .1. -J

•<y '■'

jt4)

The Paper Tiger sets a new stan-dard for low-cost impact printers.More capability. More versatility.

■ Eight software-selectablecharacter sizes.

■ 80 and 132 column formats.

■ Full forms control.

■ DotPlot™ graphics option.

■ Connects directly to Apple II,TRS-80, and other personalcomputers.

Plus lots more. For a freebrochure, print sample, or thename of the Paper Tiger dealernearest you, write or call. IntegralData Systems, 14 Tech Circle,Natick, Massachusetts 01760.Call toll-free 800-343-6412.

In Massachusetts, Alaska, and Hawaiicall (617) 237-7610.

Circle 14 on Inquiry card.

Integral Data Systems, Inc.

Aperture f 3.5

Film

Speed(ASA)

Filter

ExposureSeconds

Kodak

Ektachrome

ER135

64

None

0.5

Kodak

Ektachrome

ER 135

64

CC40R

1

Kodak

Kodachrome

KM 135

25

None

1

Kodak

Kodachrome

KM 135

25

CC40R

2

Table 1: Exposures and films used tophotograph displays on the Intecolormicrocomputer.

films to the manufacturer for deve-loping and mounting: if slides have ablack background, an automatic filmcutter may be unable to recognize theframe boundaries. Several films havebeen returned irreparably damaged,sometimes with half of a slide in onemount and the other half in the nextmount. The use of colored back-

grounds is recommended for visualpleasure as well as preservation ofyour work. If you are in doubt, it isprobably wise to ask for your film tobe returned uncut.

Discussion

Slide preparation using a smallcomputer and color-transparencyfilm has a number of advantages;several colors can be used on a singleslide, the photography is simplified,and the color slides are more durable.In addition, when the computer issuitably located, the drafting andchecking are more convenient andmay even be reduced to a single step.I now find it easy to design a slide atthe keyboard. Decisions about spac-ing, positioning, and color can bemade, revised, and implemented asthe image is being prepared. This hasreduced the first five steps to two,namely drafting the image and savingit on disk. The photographic processis reduced to making the exposures,developing the film, and mountingthe slides — a considerable saving insteps and labor.

TRS-80/NORTH STAR

SOFTWARE

By J. Roehrig as seen in Byte, Kilobaud andPersonal Computing Magazines

1. Chess — written in Basic. Beats Microchess.

2. Scrabble — makes your computer a Scrabbleopponent.

3. Baseball — based on Major League results, keepsall statistics. Players perform true to life. Seen inJuly 1978 Personal Computing and November1979 Byte.

4. Bowling Secretary — keeps all necessary statis-tics. Seen in June 1978 Kilobaud.

5. Taxes — all new tax rates. Long form, short form,Schedules A, B, C and Income Averaging. Seen inMarch 1978 Personal Computing.

6. Accounting — double entry system producesJournal Entry Log, Balance Sheet and IncomeStatement.

7. Basketball — just like Baseball. Cover article fromJanuary 1979 Personal Computing.

8. Horse Racing — improved version of Decemberand January 1980 Byte article. Graphics, horsesrun true to form, past performances maintained.Realistic win, place and show payoffs.

9. Trotters — same as above but for Trotters.

10. Handicapper — a systematic way to evaluatewagers at the Track or OTB.

11. Games — 3D TIC TAC TOE as in April 1978Kilobaud, Boxing as in January 1978 PersonalComputing and Football as in February 1978Personal Computing.

12. Backgammon — a challenging opponent whouses the doubling cube. Very graphic.

NEW NEW NEW—TRS-80 Graphic Skill Games for 2 players or 1 against the computer:13. Baseball 14. Boxing 15. Football 16. Golf 17. Bowling 18. Horse Racing

All programs have been improved; each has its own instruction booklet andsells for: Cassettes $7, 6 for $40,12 for $75,18 for $105Diskettes $10,6 for $55,12 for $100,18 for $140

SEND ORDERS TO:

JJR DATA RESEARCHBox 74 Middle Village, NY 11379

or CALL C.O.D.'s TO: (516) 643-1931 (C.O.D.'s shipped within 48 hours)

The quality of slides produced inthis way is very pleasing. Audiencemembers inquire how the slides aremade and express appreciation of thecolor and the technique. Distortion isnegligible, and the quality of curvedand oblique graph lines is adequatefor lecture slides (for the graphs theresolution is 1 in 160 on the X axisand 1 in 192 on the Y axis).

The cost of making slides is hard toevaluate. The lecturer's time and thetime spent fetching, carrying, andchecking are often assumed by theorganization. However, even thosecosts that remain are significant. Be-tween $6 and $10 is probably theminimum cost of laying out thesimplest text and preparing a diazoslide. Slides for a one-hour lecturemay cost approximately $500.

Preparing slides on the computersimplifies the photographic process.This alone represents a saving ofabout $2 per slide. The time spentdesigning the slide and arranging thelayout can be reduced as well.However, any time spent employingthe additional choices of colors andlayouts may offset this potential sav-ings to some extent. The disks usedfor storing the images cost $5, orabout 50 cents per slide. However, thedisks are reusable and should there-fore not represent an appreciable costper presentation.

The greatest savings would be rea-lized by those illustration depart-ments that are frequently expected toprepare histograms, regressiongraphs, scatter diagrams and graphsof functions. A few appropriate pro-grams would allow numerical data ormathematical functions to be directlyconverted to color images. A finaladvantage is that Ektachrome pro-cessing is commonly availablecommercially on a same-day basis.Slides can be prepared, photographedand reviewed in twenty-four hours.

The computing equipment de-scribed in this article costs about$6000. Any illustration departmenthandling much slide preparation, par-ticularly that involving slides ofgraphs, should find it worthwhile toreview the type of material they han-dle and its cost. The Intecolor com-puter has now been used to preparehundreds of slides. A similar programwill also work on the Compucolor IIwith only slight sacrifice in definition,resolution, and color rendition. ■

24 January 1980 © BYTE Publications Inc

Circle 15 on inquiry card.

T

TSifc

&«B

■L

■

orw/s hasthe answer.

tl'lti1 |"^31ii"i*i*liil ,i:lil*(ir:il»Tt,l'[»l il •ViliM iu+Ti (Tr* uT3 iliMriT«l'«r7

the microcomputer—is now delivering the solution to backupfor less than $1500.

It's called the Corvus MIRROR®, a backup employing low-cost removable media with a total capacity of up to 100 millionbytes each. In approximately ten minutes, you can transfer anentire ten million byte disk without operator intervention.

Corvus is the company that gives you a complete systemssolution to the mass storage needs of microcomputers. Oursystems have fully compatible hardware and software for theApplet (including Apple Pascal), S-100 Bus, TRS-80 i, and nowthe LSI-11 and ALTOS computers. We utilize proven Winchestertechnology with IMI-7710 drives. Up to four eight-inch disks canbe used with our Z-80 based controller.

Interested in our new removable-media backup or our pacesetting Winchester systems? Both are available now. Call orwrite for full information.

CORVUS SYSTEMS, Inc.

900 S. Winchester BoulevardSan Jose, California 95128408/246-0461

t Apple Is a registered trademark ot Apple Computers, Inc.tTRS-80 Is a registered trademark of Radio Shack, a Tandy Co.

;ircle 16 on Inquiry card.

of the best valuescomputers is now

includes H8 Computer with 16K memory,four-port serial I/O and operating software, plus H17 FloppyDisk System (shown here with optional second drive) andH19 CRT Terminal —all in kit form.

• 8080A CPU has more softwarewritten for it than any other CPU

• 7 plug-in board positions for flexi-bility in configuring your system

• Up to 65K memory capacity

• Front panel keyboard for direct ac-cess to registers and memory

$289 kit purchased separately. Was$379. You save $90.$349.00 assembled

Includes interface controller board

$495.00 kit purchased separately$550.00 assembled

• Z80 microprocessor-controlled

• 25 x 80, upper and lower case

• Direct cursor addressing

• 8-user-function keys

$675.00 kit purchased separately$995 assembled

boards when purchased with the H8system.

Seven plug-in board positions on theH8 let you configure any combina-tion of memory and l/O's that suitsyou. Heathkit memory boards comein 16K, 8K and 4K increments. Inter-face boards are available for parallel,serial and cassette l/O's.

No computer system is better thanthe software that supports it. Thewide selection of H8 software in-cludes operating systems softwareand MICROSOFT1" BASIC.

Instant access to programs and data• 100K bytes storage area250 mS typical random access time

Special 5% discount applies to allsoftware, memory and interface

An extensive library of programs isavailable to owners of Heathkit Com-

-performance

*90 better.

imwwmmv \\\\\\\\\\\\\\\\\\1

osaar

puters through the Heath User'sGroup (HUG). The experience of thiscomputerite group can help you getthe most from your computer.

You get the most thorough documen-tation ever written when you buyyour Heathkit Computer. So it's easyto get your system assembled andoperating quickly.

And you get one of the most reliableservice organizations after you buy.More than 55 service locationsthroughout the U.S., plus a factoryservice phone give you fast access toexperts when you need them.

Computers, peripherals, software andaccessories —in kit or assembledform —you'll find them all at yourHeathkit Electronic Center. You'lleven find educational support like

Circle 17 on Inquiry card.

the special self-instruction programsthat teach you BASIC and Assemblylanguage programming.

Write for a FREE Heathkit Catalogcontaining the complete line of Heath-kit Computers, plus nearly 400 otherelectronic kits lor your home, work orpleasure.

Heath Company, Dept. 334-614Benton Harbor, Mich. 49022

Alexandria, VA New Orleans, LA

Anaheim, CA Norfolk, VA

Atlanta, CA Ocean, N|

Baltimore, MD Oklahoma City, OK

Boston, MA Omaha, NB

Buffalo, NY Philadelphia, PA

Chicago, II. Phoenix, AZ

Cincinnati, OH Pittsburgh, PA

Cleveland, OH Pomona, CA

Columbus, OH Providence, Rl

Dallas, TX Redwood, CA

Denver, CO Rochester, NY

Detroit, Ml Rockville, MD

El Cerrito, CA Sacramento, CA

Fair Lawn, Nl Salt Lake City, UT

Frazer, PA San Antonio, TX

Hartford, CT San Diego, CA

Houston, TX San lose, CA

Indianapolis, IN Seattle, WA

lericho, NY St. Louis, MO

Kansas City, KS St. Paul, MN

Los Angeles, CA Tampa, FL

Louisville, KY Toledo, OH

Miami, FL White Plains, NY

Milwaukee, Wl Woodland Hills, CA

Minneapolis, MN

•Units of Veritechnology Electronics Corporation, Prices stated here

are mail order and may be slightly higher at retail locations. CP-179

Prices subject to change without notice.

Giapcia's Circuit Gellsp

Copyright © 1980 by Steven A Ciarola. All rights reserved.

Computerize a Home

I anxiously glanced around the Cir-cuit Cellar. Devoid of the usualsounds of the stereo or television, theequipment fans imparted a distinctlyuneasy sensation of mechanicalpresence.

The room was totally dark exceptfor a few pilot lights and a videodisplay. There were no games, nofast-moving program listings; only asingle line was written on the screen.In the dim luminescence I could bare-ly distinguish the furniture from thebookcases. A little experience navi-gating in the dark would have beenuseful, but I opted for moderntechnology and reassuringly pattedthe flashlight in my pocket.

I pushed the button on my digitalwatch and noted the time. As itneared the prearranged hour, I turnedinstinctively to the terminal. Soon I'dknow which of us was in control!

Almost immediately the displaychanged and printed out "AUTO-MATIC CONTROL INITIATED."Simultaneously I could hear a high-pitched noise. It sounded almost likean insect chirp. There are no cricketsdown here; it must be a subharmonic.So far so good, but did it work?

"Steve, did you just blow a fuse?"My wife stood in the doorway andcalled down the stairs. It didn'tbother her that there weren't anylights on. After all, if you blow afuse, shouldn't the lights be off?

"The kitchen light went off and the

Steve Ciarcia

POB 582

Glastonbury CT 06033

bedroom light came on. Wait! Thebedroom light just went off and thekitchen light came back on. Nowthey're both off."

I grinned in a way that only aCheshire cat could appreciate."Sorry, Joyce, just experimenting onthe latest article." Chuckling softly, Icontinued. "I hope you don't mind,but the computer seems to have takenover."

"Can it make beds?" she replied.

I should have known that shewouldn't be taken in that easily."OK, I'll tell the computer to keep itssphere of influence to the cellar. I'll letyou know what the password islater."

As if by magic, the Circuit Cellarlights were activated. The test wassuccessful.

Security Versus Control

Even though it may seem true attimes, our house has not been takenover by a computer. I was simplytesting the latest addition to my homecontrol system.

In previous issues of BYTE, I pre-sented a series of articles on the con-struction of a home security system.(See "Build a Computer ControlledSecurity System for your Home":Part 1, January 1979 BYTE, page 56;Part 2, February 1979 BYTE, page162; Part 3, March 1979 BYTE, page150.) This was not a theoreticaldissertation. It was, in fact, an over-

view of the system installed in myhouse. The original concept was con-figured around a single-board 8085system and designed primarily as analarm controller. Even though itworks, it has definite limitations.

Eventually I became dissatisfiedwith just having a super burglaralarm. It seemed a shame to dedicateall that hardware and expense to afunction with such a limited capacity.The obvious step was to expand theconcept to be a "home control"system where security is but one ofmany possible applications. To dothis requires more memory; the singleboard has been replaced by a 26 Kbyte Z80-based computer with avideo display. Operating in eitherhigh-level or assembly language, it isas adept at keeping the checking ac-count straight as it is at scanning in-put ports searching for an intruder.Add to it the ability to activate andcommunicate with my large disk-based development system, and it isindeed a powerful tool.

The major difference between thetwo system concepts is the outputcontrol structure. As an alarm, thecomputer is strictly configured toscan and analyze a multitude of eventinputs, such as door switches andmotion sensors. Its decision process isimmediate, but its output control isrelatively limited. These generallyconsist of several lights, a siren, andan automatic phone dialer. Even in

28 January 1980 © BYTE Publications Inc

Get Word Power!

with

Daisy

WORD PROCESSOR

The best is noweven better...

New FeaturesNew CommandsNew CapabilitiesNew Manual

FeaturesEditor:

Formatter:

• Fully integrated with Editor

• On-screen Preview

• Extended Page, Margin and Indent control

• Hyphenation

• Super- and Sub-scripting

• Operator prompts and input

• Center, underline, bold face, red print

• Type face control, height, pitch,

• Header/footer lines

• Page number control

• Interactive editing with Dynamic Screen Imaging

• Direct insert with word wrap

• Extensive disk handling: DIR, ERASE,disk change, etc.

• Insert/Delete/Move

• Step by Character, Word, Line, Paragraph,Page, Screen

• 26 Temporary buffers

• Find/Replace with conditional test

Software for l/OS — TSA/OS — CDOS — SDOSother 8080/Z80 OS*M operating systems

Circle 18 on inquiry card.

HMI

m ■ IB

1

1

„

nnu

i

Jfll

l

^^^ M —

«;

■i ■■ §■ M

ii^^9 Eul

■l^^l

I

'iflH

!Ui»<. 1 It 1IV1I ( 1 )

-

■J t i ii « -.■.-. i i ivi

" ■'" B " B

H J

Photo 1: fiSi? X-10 system as marketed by Sears and called the Sears Home ControlSystem.

Photo 2: The internal electronics of the command-control console.

the sophisticated system I presented,these hardwired outputs were kept toa minimum to reduce costs.

Generalized home control extendscomputer control capability farbeyond the few outputs of the ori-ginal system. It is conceivable that allof the lights and AC outlets in thehouse could be affected. A few lightsoutside are barely enough. Lighting inthe bedrooms, kitchen, and garageshould be included, with the stereoand television thrown in for good

measure. If you live in a cold climateand use an automobile engine-blockheater, why not turn it on auto-matically before you get up in themorning? Tired of searching aroundin the dark for the light switch? Letthe door sensor from the alarmsystem trigger the lights as you walkinto a room. How about some softmusic ten minutes after you enter?The list is endless.

This expansion seems to be a con-tradiction considering my previous

concern over wiring costs. To accom-plish this feat, either every AC outletmust be directly wired to the com-puter through relays as in the originalsystem or the control capability mustbe added remotely to each light andappliance.

AC Remote Control

This latter suggestion is not asfarfetched as it might seem. Therehave been many technologicaladvances in the past year. One of themore significant achievements comesfrom BSR (USA) Ltd—specifically inthe area of AC remote control. TheBSR X-10 control system is shown inphoto 1. Clockwise from the center,the five components are: commandconsole, appliance module, cordlesscontroller, lamp module, and wall-switch module. With these units, low-cost AC control is a reality.

The BSR X-10, also marketed bySears as the Sears Home ControlSystem, operates through carrier cur-rent transmission from the commandconsole to the receivers. When a but-ton is pushed on the command con-sole to activate a remote receiver, acoded signal is sent through the housewiring. Each receiver monitors thesetransmissions and responds onlywhen its particular code is sent.

Figure la is a block diagram of the$39 command module and photo 2shows its internal electronics. Theheart of this, as well as the othersystem components, consists ofcustom large-scale integration (LSI)chips manufactured for BSR byGeneral Instrument Corp. In normaloperation the twenty-two-buttonkeypad is continuously scanned.When a key is pressed, this desig-nated function and a house code(previously set by a thumbwheelswitch on the bottom of the com-mand console) are combined into asingle message. The digital message isdirected to the transmitter section,where it modulates a 120 kHz carrier.The control signal appears on anoscilloscope as a series of pulsebursts. This is shown in photo 3.

There is a second method where thecommand console designates a con-trol function and transmits amessage. Each control console con-tains a ultrasonic receiver. In the pic-ture this is the metallic cylindricalcomponent with the two protrudingpins and shielded cable soldered onthem. The BSR X-10 system facilitates

30 January 1980 © BYTE Publications inc

Circle 19 on inquiry card.

MORE COLOR. MORE SOUND.MORE GRAPHICS CAPABILITIES.

OEEE DEffi

o

d j * i: m ■ — ■

/^/ffpffjf T^Pf ^yf^ry^yf ^^^ ^^^ ^X5 Q7 c^7 CP ^^9 c*^J

CUCUCSlCEJIS(~)lZIISCDeSeStBB

ATARI 400

Compare the built-in features ofleading microcomputers with the Ataripersonal computers. And go ahead,compare apples and oranges. Theirmost expensive against our leastexpensive: the ATARI8400:

Start with graphics capabilities. TheATARI 400 offers 128 color variations.16 colors in 8 luminance levels. Plus29 keystroke graphics symbols and 8graphics modes. All controlled from afull 57 key ASCII keyboard. With upperand lower case. And the system is FCCapproved with a built-in RF modulator.That's just for openers.

Now, compare sound capabilities.Four separate sound channels and a

{.Atari 1979

^yA Warner Communications Company

built-in speaker. With the optionaldigital recorder, you can add Ataril

'ith a high-speed serial I/O portthat allows you to add a whole family

unique Talk & Teach™ Educational System of smart peripherals. Including up tocassettes. four individually accessible disk drives.

Here's the clincher: Solid state (ROM) And a high speed dot-matrix impactsoftware. For home management, busi- printer. And, the Atari Program Recorderness and entertainment. Or just plug is included with the 800 system,

in an Atari 1 OK BASIC or Assembler Suggested retail price for the

language cartridge and the full power ATARI 800 (including recorder) isof the computer is in your hands. $999.99.

Memory? 8K expandable to 16K. — *""''" **" ■- «••« ««-««-.«»-.* .-•-«-And that's just for the ATARI 400 at asuggested retail of only $549.99.

The ATARI® 800~gives you allthat and much more.

User-installable memory to ATA I? I to other leading personal48K. A full-stroke keyboard. #%l#%l\i computers.

is included with the 800 system.Suggested retail price for theATARI 800 (including recorder) is$999.99.

Make your own comparison wher-ever personal computers are sold.Or, send for a free chart that

compares the built-in featuresI of the ATARI 400 and 800

mto other leading personalcomputers.

PERSONAL COMPUTER SYSTEMS

1265 Borregas Ave. Dept. C, Sunnyvale, California 94086. Call toll-free800-538-8547(in Calif. 800-672-1404) for the name of your nearest Atari retailer.

Photo 3: Oscilloscope picture ofcommand-control console transmissionon the AC line. (Photo courtesy of MarkScheffler.)

Photo 4: Handheld cordless controllershowing top and internal circuitry.

remote channel and function selectionthrough a handheld ultrasonictransmitter. This unit is shown inphoto 4 and diagrammed in figure lc.

When a key is pressed, it is encodedand transmitted as a series of 40 kHztone bursts. The command console,receiving this information through itsultrasonic receiver section, takes thisdata as if a button had been pushedon the command console. It then addsthe house code and simultaneouslytransmits the command message overthe house wiring.

The receiver part of the system isalso quite sophisticated, consideringthat each receiver costs less than $15.These receivers, shown in photos 5and 6, can be placed virtuallyanywhere. An overhead light can beaccommodated by replacing the stan-dard on/off wall switch with a wall-switch module. An appliance such asa dehumidifier is controlled throughan appliance module.

All receivers are basically the same.A block diagram of an appliancemodule is shown in figure lb. Thereceiver section monitors the AC linewaiting for a coded message cor-responding to its unique house (Athru P) and unit device (1 of 16) code.

40 kHzTRANSDUCER

40 kHz

ULTRASONIC

RECEIVER

1 '

22

BUTTONKEYPAD(SCANNED)

>

1

T

'

CUSTOM

LSI

IC

(24 PIN)

120 kHz

CARRIER CURRENT

TRANSMITTER

HOUSE

CODE

SWITCH

110VAC

cnHr 1—-i -

20V POWERSUPPLY (TO

ALL SECTIONS)

lb

15A 115VACSOLENOIDACTIVATEDSWITCH

"

120 kHz

CARRIER CURRENT

RECEIVER

CUSTOM

LSI

IC

(18 PIN)

—►-

HOUSE ANDDEVICE CODESWITCHES

110VAC

DC POWERSUPPLY (TOALL SECTIONS

60 Hz

1—"*i l

1 ' '

115VAC>OUTPUTTO APP-LIANCEOR LIGHT

lc

40kHzTRANSDUCER

40 kHz

ULTRASONIC

TRANSMITTER

CUSTOM

LSI

IC

(24 PIN )

f\

>

22

BUTTONKEYPAD(SCANNED)

V

i

I

1

i

9VBATTERY

Figure 1: Block diagrams of the integral parts of the BSR X-10. The block diagram forthe control console is given in figure la, the appliance module in figure lb, and theremote control transmitter in figure lc.

To turn on channel 10, simply press"10" and then the "ON" buttonsequentially. When the appliancemodule activates, it sounds like arelay engaging. In actuality, BSR usesan inexpensive solenoid to operate a15 A push-button Microswitch.

The lamp and wall-switch modulesuse a triac instead of this pseudo-relay. Unlike the appliance module,

which only operates as an on/offswitch, these units have the addi-tional ability to automaticallybrighten or dim when the correspon-ding function buttons are pressed onthe command console. Finally, allreceivers can be locally activatedwithout the command console. Toturn on a light or motor, simply flipthe power switch from on to off and

32 January 1980 © BYTE Publications Inc

onComputing

really makespersonalcomputerseasy tounder-stand."

Written in non-technical language,onComputing™ contains articles on thecapabilities of microcomputers, gettingstarted, latest reviews of personal com-puters, where to purchase and how to useyour computer.

xLm

lyone can learn the funda-mentals of using a computer.onComputing readers receivepractical advice and helpful hintson how to get the most out of apersonal computer, explanationsof computer terminology, and,periodically, an updated list ofactive computer clubs.

J5enefit from the experience ofother computer enthusiasts.Articles in onComputing arewritten by well known authorsas well as competent amateurs.They share their ideas on how touse the computer as a tool forbusiness, education, home enter-tainment, laboratory work andother applications.

womputer experts edit onCom-puting for the new user, not thecomputer professional. Theeditors combine their esotericknowledge of computer scienceand equipment to produce con-cise, non-technical materialwhich can be readily understoodby anyone interested in using acomputer—for fun or profit.

n

onComputing, Inc.

70 MainSt., Peterborough, NH03458Start your subscription today.

EVERY THREE MONTHSonComputing will bringthe latest develop-ments in the field ofpersonal computing:use, applications, books,selection—all in aneasy-to-read style.

© onComputing, Inc. 1979

1

onComputing Subscription Dept. P.O. Box 307, Martinsville, NJ 08836REGULAR subscription rate:

□ U.S. 1 yr. (4 issues) ® $8.50 □ Canada & Mexico, 1 yr. (4 issues) @ $10.00FOREIGN (to expedite service, please remit in U.S. funds drawn on a U.S. bank.)

□ Europe (and all other countries, except above), lyr.®! $12.00—surface delivery.D Start my subscription with current issue. □ Start with Vol. 1 Wo. 1

□ Bill Visa □ Bill Master Charge □ Bill me (North America only)

L

Card Number

Expiration

Signature

Name (please print)

Street/Apartment Number

City

State/Province/Country Code

7M89

J

Photo 5: The wall switch module replaces standard wall switch and allows remote con-trol. Two slotted-top rotary switches under the switch lever are for setting house anddevice codes.

Photo 6: The appliance module.

back to on again. This automaticallytriggers the receiver module into anon condition.

Controlling the BSR X-10

When I first started using the BSRX-10, I could hardly believe its ver-satility and low cost. The only pro-blem is that operation of the BSRX-10 is completely manual. The onlyway to use the control receivers isthrough the command console or

ultrasonic transmitter and byphysically pressing the buttons.

I would not say that I have a never-say-die attitude, but considering myoriginal security system, with anaverage cost of $250 per AC outputchannel, my future computer-controlled house depended heavily onless expensive input/output (I/O). Itwas absolutely necessary to find somemethod of utilizing the controlreceivers.

Three possible solutions came tomind:

• Directly synthesize the command-console waveform and transmit itdirectly onto the AC line.

• Brute force contact closure—at-tach either relays or comple-mentary-metal-oxide semiconduc-tor (CMOS) switches in parallelwith the push buttons and activatethe relays from the computer.

• Synthesize the waveform from theultrasonic controller and let thecomputer "talk" to the commandconsole.

Simulating the command-consoleoutput sounds simple in theory. (Thisis somewhat like estimating softwarecosts.) Simulating the device-controlcode and using it to modulate a 120kHz carrier frequency leads to con-tact with a hostile environment. Theoutput from the computer must beattached to the AC line. This requiresisolation through either transformersor optoisolators, plus many discretecomponents to properly match impe-dances. It is a shame to reinvent thewheel when BSR has already designedsuch an effective transmissionsystem. Although possible in theory,this approach is too messy to warrantfurther consideration.

The second alternative is bruteforce. This can usually work, but youmust be careful. In essence thismethod entails wiring relays orCMOS switches across the push but-tons and remotely, but still mechani-cally or electronically, closing thecontacts corresponding to a parti-cular button. Figure 2a illustrates thekeypad connections for both the com-mand console and cordless controller.The configuration is a 3 by 8 scanningmatrix. To turn on channel 6, simplyshort pins 28 and 18 together.Likewise, "dim" would be pins 25 and23. While twenty-two separate single-pole, single-throw switches could beused, figure 2b demonstrates an easieralternative.

Two CMOS switches can be usedin combination with the ultrasoniccontroller to provide this capability.Connected to 5 bits of a latchedparallel output port, the two inte-grated circuits channel the appro-priate lines together. To turn onchannel 12, a row-select code ofbinary 001 would be set on B2, Bl,

34 January 1980 © BYTE Publications Inc

THE MOST POWERFUL MICROCOMPUTERSOFTWARE EVER DEVELOPED IS ALSO „-

THE EASIEST TO USE ^ *g2f$?

\0&

MICROSYSTEMS INFORMATIONMANAGEMENT PACKAGE

fc\J5

-W

FOR USE ON

MICROCOMPUTERS

BUS-II

PUTS ANY OR ALL YOUR BUSINESS FILES INTO A POWERFULDATABASE.

CREATE VIRTUALLY ANY RELATIONSHIP YOU CAN THINK OF.

ENGLISH-SPEAKING REPORT GENERATOR.

POWERFUL USER COMMANDS NORMALLY FOUND ONLY INLARGE COMPUTERS. SELF-EXPLANATORY, EASY TO USE,SUCH AS "INPUT," "OUTPUT," "LIST," "PRINT," "CHANGE,""DELETE," "EXCLUDE," "INCLUDE," AND, PERHAPS MOSTIMPORTANT OF ALL, "HELP!"

STRAIGHTFORWARD INPUT AND EDITING ROUTINES— "IDIOT-PROOF."

OPERATOR'S MANUAL WITH FULL USER INSTRUCTIONS IS ON-LINE WITH HELP COMMANDS. PROBLEMS? JUST TYPE "HELP!"

COMMANDS CAN BE USED CONDITIONALLY ON ANY RECORDOR ON ANY FIELD WITHIN A RECORD.

IN-MEMORY SORT, OR, (FOR BIG FILES) DISK SORT.

ALL DATABASE FUNCTIONS ARE SUBROUTINES— CUSTOMPROGRAMMING SIMPLIFIED.

OPTIONAL CASH REGISTER POLLING AND CONTROL PACK-AGE AVAILABLE TO QUALIFIED BUYERS (REQUIRES INSTAL-LATION CONSULTATION).

OVER TWO YEARS' IN-FIELD TESTING. MIMP WORKS—FLAWLESSLY.

ONE YEAR SUBSCRIPTION TO APPLICATIONS NEWSLETTERFREE WITH PURCHASE.

TYPICAL APPLICATIONS: INVENTORY, CUSTOMER FILES,CASH REGISTER CONTROL (OPTIONAL EXTRA), DOCTOR/-DENTIST/LAWYER APPOINTMENTS OR CLIENT/PATIENT FILES,SALES RECORDS, MAILING LISTS.

INTRODUCTORY OFFER

$295

THE KEY TO THIS SOFTWARE IS ITS SIMPLICITY OF OPERATION.

CPA-APPROVED COMPLETE ACCOUNTING SYSTEM: GENERALLEDGER, ACCOUNTS PAYABLE, ACCOUNTS RECEIVABLE.

BRANCH ACCOUNTING HANDLES UP TO FIVE DIVISIONS.

COMPLETELY INTERACTIVE. SELF-UPDATING.

BATCH ACCOUNTING INSISTS ON BEING "IN BALANCE."

USER MENU. OPERATOR PROMPTING FOR CORRECT ENTRIES.

HIGHLY FLEXIBLE FORMATTING OF FINANCIAL REPORTS.

NO KNOWLEDGE OF DEBITS AND CREDITS REQUIRED (EXCEPTRECURRING JOURNAL ENTRIES— ASK YOUR ACCOUNTANT).

EXAMPLES OF REPORTS (FROM GENERAL LEDGER MODULE)

CHART OF ACCOUNTS

DETAILED GENERAL LEDGER

CASH RECEIPTS JOURNAL

CASH DISBURSEMENTS JOURNAL

JOURNAL ENTRIES JOURNAL

PROFIT-AND-LOSS JOURNAL

BALANCE SHEET

IDEAL FOR ACCOUNTING FIRMS AS WELL AS SMALLBUSINESSES.

PROVEN THROUGH YEARS OF USE.

THIS ACCOUNTING PACKAGE REQUIRES ONLY A HIGHSCHOOL-LEVEL UNDERSTANDING OF BOOKKEEPING.

ONLY

$295

DUAL EIGHT-INCH FLOPPY DISK DRIVES REQUIRED.

MIMP & BUS-II OPERATE ON ALL OHIO SCIENTIFIC 8-INCH OR WINCHESTER DISK MICROCOMPUTERS W/48 K RAM?USER-ORIENTED SYSTEMS NO PROGRAMMING REQUIRED

CREDIT CARD ORDERS

CALL(304) 291-5400

ALL ORDERS SHIPPED PREPAID WITHIN CONTINENTAL U.S. PLEASE DO NOT SEND CASH.OVERSEAS ORDERS PLEASE INCLUDE POSTAGE— 5 LBS. SORRY, NO C.O.D.

digital bechnologu

Inc.

ViSA

.^^.

master charge'

^^^^ ^^^*U

ROCKLEY ROAD MORGANTOWN. WV 26505

Circle 20 on inquiry cardl

2a

ll

28

BSR

CUSTOMLSI

INTEGRATEDCIRCUIT

25

23

1

DIM

16

5

22

ON

12

11

21

ALLOFF

14

13

20

OFF

4

3

19

BRT

8

7

18

ALLON

6

5

17

2

1

16

2b

£

BSR

CUSTOM

LSI

INTEGRATED

CIRCUIT

CMOS4-T0-1MULTI-PLEXER

B

A

OUT

22

21

20

19

18

16

INCMOS8-TO-lMULTI-PLEXER

CBA

<ZlB2

-Obi-Obo

PARALLELOUTPUTPORTCONNECTIONS

Figure 2: The keyboard in the BSR X-10 command console and remote control unit isconnected to a custom LSI integrated circuit. Figure 2a shows the keyboard in relationto lines coming from the BSR custom integrated circuit. The functional schematic infigure 2b could be used to replace the keyboard with an I/O port.

and BO, respectively, and a column-select code of binary 10 would be seton B4 and B3. The ON key would bea code of 11100 for bits B4 thru B0,for example.

The circuit of figure 2b will workonly with the handheld battery-controlled unit. The command-con-sole electronics, which run on —20 V,can use the same logical concept, butrelays must be substituted for theCMOS switches. The command con-sole is not isolated and its electronicsare floating at 120 VAC. To be totallysafe, it is best not to bother with it.

Hardwiring to the handheld unitkeyboard will work, but it also hassome detrimental features. In opera-tion, the ultrasonic unit consumes an

average of 30 mA, while peak cur-rents are about 100 mA. Alkaline bat-teries are a must. Short of direct con-nection to the computer's power sup-ply through a 9 V regulator, there isalways the hazard of battery brown-out. If I were depending upon thissystem, I would not have a criticalcomponent powered by battery.

Talking to the BSR X-10

The sensible alternative is to con-struct an interface that facilitatescordless communication between thecomputer and the BSR X-10 com-mand controller. Safety is theprimary consideration. There is nohazard in using the controller orreceivers as long as their cases are

intact. The BSR X-10 is Underwriters'Laboratories listed. Attachments be-tween the computer and the com-mand module must be done carefullyand only by experienced people. Bymaintaining the structural integrity ofthe components, you are not limitedto use with the computer. The com-mand console can be moved aroundthe house, and it is placed withinrange of the computer only whenautomatic control is desired.

Practical accomplishment of thisgoal is achieved using the ultrasonicreceiver found within the commandmodule. An interface is constructedthat formats function codes intomessage strings; these strings aretransmitted to the command consoleas 40 kHz pulses. In essence, the inter-face simulates the activity of acordless-controller unit.

Figure 3 describes in detail the com-munication between the two sub-system components. Each of thetwenty-two buttons has a unique5-bit code (listed in table 1). Forexample, channel 5 has a code of00010 with respect to bit positionsD8, D4, D2, Dl, and F. The ALLLIGHTS ON key generates the code00011.

The actual message that communi-cates this selection is approximately100 ms long and is composed of thir-teen 8 ms segments. Each segmentconsists of a burst of 40 kHz directedto an ultrasonic transducer. Data ispulse-width modulated. A logic 1 is a4 ms burst and a logic 0 is a 1.2 msburst.

To signify channel 5, the interfacefirst sends a start bit to alert thereceiver of the pending messagetransmission. This is a 40 kHz tonefor 4 ms. Next, the 5-bit selectioncode is sequentially transmitted as aseries of 1.2 and 4 ms bursts of 40kHz. This is followed by transmissionof the logical inversion of the 5-bitselection code and a 16 ms end-of-message tone. All messages use thesame format; only the 5-bit selectioncode varies.

Figure 4 is an interface specificallydesigned to send this message andfacilitate wireless remote control.Incorporating complete circuitry foraddress decoding and data storage, itappears to the computer as a singleoutput port. Turning on the tablelamp is as simple as sending a 1-byteoutput to the interface port. As with

36 January 1980 © BYTE Publications Inc

8/16 RAM

Goodthroughthe'80s

16K RAM for both 8-bitand 16-bit S-100 systems

The 16-bit micros are coming — fast!

1980 will be the year of the 16-bit microprocessor. With theirincreased speed, with their expanded instruction sets whichdramatically simplify programming, and with the sophisticatedlanguages and operating systems their architectures support, the 16-bit micros promise a many-fold increase in computing power. Here atSeattle Computer, we have been shipping our 8086 CPU card sinceearly November, but this is just the beginning for us. We plan toaugment the capabilities of our 8086 with sophisticated new hardwarefor the disk and for serial communications, and with our new interrupt-driven, multi-user disk operating system. All will be introduced by mid-year. Not that we are alone in the 16-bit world — Microsoft BASIC isavailable now for the 8086, with other languages in the works. Severalother firms have announced or are developing 8086 CPU cards, andno doubt systems using the Z8000 or 68000 will appear by the end ofthe year.

8/16 Fully Meets IEEE Standard

The 8/16 was designed to be in full compliance with the proposedIEEE Standard for the S-100 Bus. This Standard defines extensionswhich allow 16 data bits and 24 address bits while maintainingcompatibility with the original bus. The 8/16 fully implements theseextensions, and thus can be expected to interface smoothly with thesenew 16-bit machines.

How it works. . .

The 8/16 chooses a data path width of 8 or 16 bits by sampling thenewly-defined bus line over which the "Sixteen Request" signal issent. All 16-bit processors will use this signal. If it is present, the 8/16organizes itself as 8K by 16 bits. If it is absent, the 8/16 is 16K by 8 bitswide, just like any other 8-bit memory. Thus data path width selectionis automatic.

Write or check reader service

card for information about our

other 8086 products

Circle 21 on inquiry card.

For your 8-bit machine. . .

To use the 8/16 in your 8-bit machine, all you need to do is set theaddress of the board on its DIP switches and plug it into yourcomputer. The 8/16 offers "extended addressing" as proposed by theIEEE, which is an alternative to "bank select" in opening adress spacebeyond 64K. With extended addressing, memory can appear as asmooth, continuous block of up to 16 megabytes, any of which can beaccessed at any time. This contrasts with bank select in which blocksof up to 64K are switched on and off by special software. If your systemdoes not provide the 8 extra address lines required for extendedaddressing, this feature may be disabled and the extra lines ignored atthe flip of a switch. The 8/16 is fully static so there is no need forconcern over clocks or in applications using DMA. Our current one-year reliability on similar boards is 98% so you can expect years oftrouble-free service from your 8/16.

. . .and then 16-bits

This is what the board was designed for. It is guaranteed to run withour 8086 CPU set when the clock is at 8 Mhz. As it was designed to theIEEE Standard, there should be no trouble interfacing to anymanufacturer's CPU.

To order. . .

There are two ways to go. Check with your local dealer. If he doesnot have the 8/16 in stock, he can order it and have it for you in a fewdays. Or, you can order direct from the factory for $525. Bank cards,CODs okay. There is a 10-day return privilege on factory orders. Allboards are guaranteed for one year — both parts and labor. Availablefrom stock.

h

Seattle Computer Products, Inc.

1114 Industry Drive, Seattle, WA. 98188

(206) 575-1830

BYTE January 1980 37

COMPLETE MESSAGE

^START OF MESSAGE(LOGIC 1)

D8 D4 D2 Dl

D8 D4 D2 Dl

(

START

ims U

EACH DIVISION IS 8ms

H

24ms.40 kHz

D OR FLOGIC "1"

D OR FLOGIC "0"

4 ms p

8ms

1.2

OUTPUT PORT BITS

BOBlB2B3B4B5B6B7

INTERFACE FUNCTIONS

F

Dl

D2

D4

D8

N/C

N/C

TRANSDUCER OUTPUT ENABLE

Figure 3: Description of coded message sent from the cordless controller to the command console via ultrasonic communication. Thenecessary codes are shown in table 1.

the majority of my designs, it is bothprocessor and speed independent. Itworks equally well in BASIC orassembly language programs. Con-nected to port 9 (as in my examplesoftware), turning on a table lamp orthe hall lights in BASIC is a one-linecommand, OUT 9,5 (from the codelist of table 1). Turning it off is simplyOUT 9,7.

The circuit will work on virtuallyany computer, although the pindesignations in figure 4 refer speci-fically to the Radio Shack TRS-80Model I. All connections are madedirectly to the computer address anddata buses. In the TRS-80 this is donethrough the expansion connector. Ina computer such as an Apple II, thecircuit could be built to plug directlyinto the back-plane connector or tobe connected by a ribbon cable.

The electronics can be divided intothree subsystems: port latch andaddress decoding, pseudo pulse-width modulator, and messageserializer. Photo 7 illustrates the pro-totype of figure 4.

ICs 9 thru 13 make up the addressdecoding and data latch. For aTRS-80, I have arbitrarily chosen anaddress of 127 decimal (in my soft-ware examples, I use port 9). When

the address bus and OUT line (cor-responding to I/O WRITE on somesystems) indicate execution of an out-put command, the contents of thedata bus are stored in ICs 11 and 12.

CHANNEL NUMBER

BINARY CODE

DECIMAL OUTPUT TO

OR FUNCTION

D8

D4 D2 D1 F

INTERFACE CIRCUIT

1

0

110 0

12

2

1

110 0

28

3

0

0 10 0

4

4

1

0 10 0

20

5

0

0 0 10

2

6

1

0 0 10

18

7

0

10 10

10

8

1

10 10

26

9

0

1110

14

10

1

1110

30

11

0

0 110

6

12

1

0 110

22

13

0

0 0 0 0

0

14

1

0 0 0 0

16

15

0

10 0 0

8

16

1

10 0 0

24

ALL OFF

0

0 0 0 1

1

ALL LIGHTS ON

0

0 0 11

3

ON

0

0 10 1

5

OFF

0

0 111

7

DIM

0

10 0 1

9

BRIGHT

0

10 11

11

Table 1: Cordless controller push-button codes and decimal equivalents.

38 January 1980 © BYTE Publications Inc

For years many small business system buyersthought that in order to get "real" performanceand enough storage to be a "real" business systemthey would have to sacrifice the family jewels.

But with the introduction of the Smoke SignalChieftain series office computers a lot of people'sminds have been changed.

Because we designed the highly reliableChieftain small business system with the mostinnovative combination of performance and effi-ciency around.

At your fingertips there are 64,000 charactersof random access memory and you can addressanywhere from 740,000 characters to 2 millioncharacters with Smoke Signals's new double den-sity controller. For larger concerns, there's a 20Mbyte hard disk available.

At a time when other small computer manu-facturers tell you "you're on your own", SmokeSignal offers an abundance of easy-to-use softwareprograms such as order entry, inventory control,

accounts receivable, invoice entry, payroll, wordprocessing and much, much more. There's BASIC,COBOL and FORTRAN — even a multi-user BOS(Business Operating System) that allows fornumerous users simultaneously.

Chieftain systemsstarting at under $200.00per month display per-formance on par with sys-tems costing twice tothree times as much.

So call (213) 889-9340for your nearest autho-rized Smoke Signal dealer — he'll be glad todemonstrate the Chieftain's high reliability andease of operation. For dealers on,Yi clrcie 22.

All other inquiries, circle 63.

SMOKE SIGNAL

BROADCASTING

31336 Via Colinas. Westlake Village. California 91361. (213) 889-9340

•'<*».

y

Photo 7: Prototype of the circuit shown in figure 4. The ultrasonic transducer is remote-ly located, and ICs 9, 10, 11, 12, and 13 are contained on another board.

Bits 0 thru 4 will contain the functioncode (from table 1) and bit 7 is used toturn the transmitter output on andoff. For further information on ad-

dress decoding and output ports, Irefer you to Ciarcia's Circuit Cellarfrom BYTE Books and the article en-titled "Memory Mapped I/O," which

Make your own interface easily

for Apple 11' and Superkim2 with

Vector 4609 Universal Plugbord!

TTTTT

m%

ttmmzmimmi

mmiiiimummmmm,

m

COMPONENT SIDE

WIRING SIDE

saaaaaaaaaaaaaaaesi

|^i|IIIIIH**t^jJj|lTs0"siYs"7y"x'3T06'"". $21.50

HIGH CAPACITY:22 16-pin DIPs or 2 40-pin plus 18sixteen-pin DIPs.

VERSATILE.1 inch grid; .042 inch diameter holes.• Extra I/O connector—gold plated.

< tor easy cor

PMdtmcfconicCbtnpaiui

INCORPORATED ' '

Extended length! Extra area!No interference.

Wrap wire or solder.

Quick solder mounting of any ICsockets.

Hot tinned 2 ounce copper power& ground buses between IC leadsfor easy connection.

12460 Gladstone Avenue, Sylmar, California 91 342phone (213) 36S-9661, TWX (910) 496-153911 T. M. APPLE COMPUTER, Inc. 68067!) (5) T, M. MICROPRODUCTS

first appeared in the November 1977BYTE, page 10.

In figure 4, the 5-bit function code,as well as its logical inversion, areattached to a 16-to-l multiplexer,ICl. As the 4-bit counter IC7 in-crements, each of the input lines ofthe multiplexer is sequentially routedto the output, pin 10. With addressposition 0 permanently tied high andthe next ten addresses wired asfunction-code inputs, the output ofICl will reflect the first eleven 8 msmessage segments.

ICs 3, 5, 6, and 8 act as a digitalmodulator. If the output of ICl pin 10is a logic 1 (such as the start bit), a 4ms burst of 40 kHz will be routedthrough IC5 and appear at pin 6. Alogic 0 on pin 10 results in a 1.2 msburst. The timing of these events israther critical. The rate of clock one(IC8d) should be as close to 125 Hz aspossible (8 ms period), and clock two(IC8e and IC8f) should be similarlyset to 40 kHz. Use potentiometer Rl

As of the writing of this article,Mountain Hardware Inc (300Harvey West Blvd, Santa Cruz CA95060) has announced a plug-incard for the Apple II that, like thecontrol card described in this arti-cle, transmits to the B5R X-10Command Console. In addition,the company offers control soft*ware tailored to the Apple II withat least 32 K bytes of program-mable memory. Cost of the unit is$189 for the controller board aloneand $279 for the controller board,the X-10 Command Console, andthree remote modules.

The following items are availablefrom:

The Micromint Inc

917 Midway

Woodmere NY 11598

Telephone: (516) 374-6793

1. Assembled and tested interfaceboard and plastic encase $79.50

2. Cable and connector forTRS-80 $14.95

3. Cable and adapter board forApple II $29.95

4. Cable and adapter board for5-100 bus $34.95

5. 0.5 A power supply $9.95

New York residents please add 7%sales tax.

40 January 1980 © BYTE Publications Inc

Circle 23 on inquiry card.

A

-^

tu bo "i

COON

H2

KB

£<-vs<v

^e

-ne

CO 1

-A

•A

N lO ID

a ft luxOm

a

a

N <

<r _io>- ■

dS •

•y

a

a. fc

c

S B4

SI. *-

.0'

P O .

(DO

'Y

K

a

a u

2!§

1 ^ w

: a §- 5 <->

S N

S3

; S-o

1 O V.

I C *■

ft °°

Si

t. •»

o H

MS, 3*, ts

S B•a^^^

^2a ,§•

>3

So

cu

<u

9) .0

3 3

e

S -

M f—I

ft .

C.O

a

.1

cu"TS

C

p »>

5 +

fLT^

<»=!

2; <M c\j h- h- 1^ co o N. n- h- c\j co r^

0 *~r- <- *-■*-

>

10 I- ■* ■q- ■* -* co lo ^r «* rr 10 in f

+ W(Ni-i-i-t- I— T-1- 1-

CD

E

Moulin^-

OO CO OMNSO

Lr>irico^t"i-c\ico^t<Z)Mwww

■-■-ooinr-aioJJJJj

o t- cm co^wn^fLoiDNtoaiT-n-T-7-OOOOOOOOOOOOO

m ^ oj

^AAAA kkkk &

i A i A 'A & A

< CD

January 1980 © BYTE Publications Inc 41

Circle 24 on inquiry card.

k Your Computer

HERE'S WHAT THE DOCTOR

PRESCRIBES FOR YOUR

AILlNG MICROCOMPUTER:

muLISP from the Soft Warehouse

• Over 80 primitively defined LISPfunctions.

• Infinite precision integer arithmeticexpressed in any desired radix basefrom 2 through 36.

• Automatic dynamic memory manage-ment performed by an efficient gar-bage collector.

• Flexible but structured program con-trol constructs including an extendedCOND and multiple exit LOOP.

• Extremely fast execution speedachieved by the use of shallow bind-ing, address typing, and a closedpointer universe.

The Soft Warehouse can fill your pre-scription with the muLISP-79tm Soft-ware System. It is fully integrated intothe popular CP/Mtm Operating Systemand available for a number of differentdrives.

If Math Anxiety is your affliction,we also offer the muMATH-79tmSymbolic Math System. Read about itin the August '79 issue of BYTE.

Call or write us directly for more in-formation.

©Copyright The Soft Warehouse 1979

P.O. Box 11174, Honolulu, Hawaii 96828Telephone (808) 734-5801

42 January 1980 © BYTE Publications Inc

REAL-TIME

CLOCK

(OPTIONAL)

CIRCUIT CELLARTABLE LAMP

CIRCUIT CELLARHALL LIGHT

SPARE BEDROOMLIGHT

GARAGE CARHEATER

DEHUMIDIFIER

OUTSIDELIGHT #1

OUTSIDELIGHT #3

KITCHEN

MICROCOMPUTER

(APPLE, TRS-80ETC.

WIRELESSREMOTE CONTROLINTERFACE(FIGURE 4)

40 kHzTRANSDUCER

1 TO 20 FEET

#2

#4

LM

#6

AM

#8

#10

#12

ws

#14

#16

TYPICAL PLACEMENT OF 16RECEIVERS AROUND THE HOME

#1

#3

#5

CIRCUIT CELLARACCESSORIES PLUG

CIRCUIT CELLARSTAIR CASE

MASTER BEDROOMTABLE LAMP

#7

#9

#11

STEREO

PORCH LIGHT

MASTER BEDROOMTV

#13

#15

WS

OUTSIDELIGHT #2

GARAGELIGHT

EXISTING 115VACHOUSE WIRING

LM- LAMP MODULEWS- WALL SWITCHAM- APPLIANCE MODULE

Figure 5: A typical application of the wireless remote control. All of the modules areconnected over the house wiring.

to set the monostable multivibrator(or one-shot) IC6a to a period of 4ms. Use R2 to set the one-shot IC6b to1.2 ms.

The output of IC5 should generatethe first eleven segments of themessage. IC2, using the same tech-nique as IC1, adds a 16 ms end-of-message tone burst as segments 12and 13. The message is repeated in 24ms as the counter (IC7) loops to 0. Itwill send the same data as long as thecontents of ICs 11 and 12 have not

changed and the output-enable linehas not been brought high.

All of the components (except pos-sibly the 40 kHz transducers) arereadily available. Low-power Schott-ky transistor-transistor logic (TTL)devices should be used where speci-fied to properly interface with theTRS-80 or similar low-power bussystems.

One further note for prospectiveTRS-80 circuit builders. To use thisText continued on page 48Listing 1 on page 46

6809 PROCESSING POWER!

The Percom SBC/9. Only $199.95.

Fully compatible w th (he SSrequiring no modification of the'motherboard, memory oj-SBC/9™ is also a complete, single-board control computer with its ownROM operating] "System, -BAM,peripheral ports and a full-range baudclock generator.

Make the SBC/9 the heart of your computer and put to workthe most outstanding microprocessor available, the 6809.

the Mighty 6809

Featuring more addressing modesthan any other eight-bit processor,position-independent coding, special16-bit instructions, efficient argu-ment-passing calls, autoincrement/autodecrement and more, it's no won-der the 6809 has been called the "pro-grammers dream machine."

Moreover, with the 6809 you get amicroprocessor whose programs typ-ically use only one-half to two-thirds asmuch RAM space as required for 6800systems, and run faster besides.

And to complement the extraordi-nary 6809, the Percom design teamhas developed PSYMON™, an extraor-dinary 6809 operating system for theSBC/9™PSYM0N'"— Percom SYstem MONitor

Although PSYMON™ includes a fullcomplement of operating systemcommands and 15 externally callable

"trademark of Percom DatajCompany, Inc.

utilities, what really sets PSYMON™apart is its easy hardware adaptabilityand command extensibility.

For hardware interfacing, youmerely use simple, specific devicedriver routines that reference a table ofparameters called a Device ControlBlock (DCB). Using this technique, in-terfacing routines are independent ofthe operating system.

The basic PSYMON™ commandrepertoire may be readily enhanced ormodified. When PSYMON™ first re-ceives system control, it initializes itsRAM area, configures its console andthen 'looks ahead' for an optional sec-ond ROM which you install in a socketprovided on the SBC/9™ card. ThisROM contains your own routines thatmay alter PSYMON™ pointers andeither subtly or radically modify thePSYMON™ command set. If a secondROM is not installed, control returnsimmediately to PSYMON™

Provision for multi-address, 8-bit bidirec-tional parallel I/O data lines for interfac-ing to devices such as an encodedkeyboard.

A serial interface Reader Control outputfor a cassette, tape punch/reader or simi-lar device.

An intelligent data bus: multi-level databus decoding that allows multiprocess-ing and bus multiplexing of other busmasters.

Extended address line capability — ac-commodating up to 16 megabytes ofmemory — that does not disable the on-board baud rate clock or require addi-tional hardware in I/O slots.On-board devices which are fully de-coded so that off-card devices may useadjoining memory space.Fully buffered address, control and datalines.

The SBC/9™, complete with PSYMON™inROM, 1K of RAM and a comprehensiveusers manual'" costs iust $199.95.

PEFGOM

PERCOM DATA COMPANY, INC.

211 N KIRBY GARLAND. TEXAS 75042

12141272-3421

Percom peripherals for personal computing'

To place an order or request additional literaturecall toll-free 1-800-527-1592. For technical infor-mation call (214] 272-3421. Orders may be paid bycheck, money order, COD or charged to a VISA orMaster Charge account. Texas residents must add

5°/o sales tax. Circle 25 on inquiry card.

PRICES AND SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE

Welcome to Percom's Wide World

Each LFD mini-disk storage systemincludes:

• drives with integral powersupplies in an enamel-finishedenclosure

• a controller/interface with ROMoperating system plus extra ROMcapacity

• an interconnecting cable

• a comprehensive 80-page usersmanual

Circle 26 on inquiry card.

Low-Cost Mini-Disk Storage in the Size You Want

Percom LFD mini-disk drivesystems are supplied completeand ready to plug in the momentthey arrive. You don't even haveto buy extra memory. Moreover,software support ranges fromassembly language programdevelopment aids to high-speeddisk operating systems andbusiness application programs.

Mini-disk storage system prices:

The LFD-400®*1 and -400EX® systemsand the LFD-800® and -800EX® systemsare available in 1-, 2- and 3-driveconfigurations. The -400, -400EX drivesstore 102K bytes of formatted data on40-track disks, and data may be stored oneither surface of a disk. The -800, -800EXdrives store 200K bytes of formatted dataon 77-track disks.

The LFD-1000"* systems (not pictured)have dual-drive units which store 800Kbytes on-line. The LFD-1000® controlleraccommodates two drive systems so thata user may have as much as 1.6M byteson-line.

1-DRIVE

2-DRIVE

3-DRIVE

MODEL

SYSTEM

SYSTEM

SYSTEM

For the SS-50 Bus:

LFD-400®

$ 599.95

$ 999.95

$1399.95

LFD-800®

895.95

1549.95

2195.95

For the EXORciser* Bus:

LFD-400EX®

$ 649.95

$1049.95

$1449.95

LFD-800EX®

945.95

1599.95

2245.95

LFD-1000®

(dual) $2495.00

(quad) $4950.00

—

-flliUfli•Mil Nil I

A"*") J"1

'"ImlllllllHlJJlll

EXORciser* Bus LFD-400iXf> -800EX® Systems

Circle 241 on inquiry card.

Upgrade to 6809 Computing Power. Only $69.95

Although designed with the SWTP 6800 owner inmind, this upgrade adapter may also be used withmost other 6800 and 6802 MPUs. The adapter issupplied assembled and tested, and includes the6809IC, a crystal, other essential components anduser instructions. Restore your original system bymerely unplugging the adapter and a wire-jumpered

DIP header, and re-inserting the originalcomponents. Also available tor your upgradedsystem is PSYM0M® (Percom SYstem MONitor),the operating system for the Percom 6809single-board computer. PSYM0N® on 2716 ROMcosts only $69.95. On diskette (source and objectfiles), only $29.95.

Data Terminal & Two-CassetteInterface — the CIS-30+

RATE300

lEDMINAtUNE

r»fi

ON

1200

IOCAI

AUIO

COGOM

CIS-30 +

Circle 242 on inquiry card.

• Interface to data terminal and two cassette recorderswith a unit only 1/10 the size of SWTP's AC-30.

• Select 30,60 or 120 bytes per second casselteinterfacing; 300, 600 or 1200 baud data terminalinterfacing.

• Optional mod kits make CIS-30+ work with anymicrocomputer. (For MITS 680b, ask tor Tech MemoTM-CIS-30+-09.)

• KC Standard/Bi-Pfiase-M (double frequency) cassettedata encoding. Dependable self-clocking operation.

• Ordinary functions may be accomplished with 6800Mikbug* monitor

Prices: Kit, $79.95; Assembled, $99.95. Prices includea comprehensive instruction manual. Also available: TestCassette, Remote Control Kit (for program control ofrecorders), IC Socket Kit, MITS 680b mod documentationand Universal Adapter Kit (converts CIS-30+ for use withany computer).

of 6800 Microcomputing.

6800/6809 SOFTWARESystem Software

6800 Symbolic Assembler — Specify assembly optionsal time of assembly with this symbolic assembler. Source

listing on diskette $29.95

Super BASIC — a 12K extended random access disk BASICtor the 6800 and 6809. Supports 44 commands and 31 (unc-tions. Interprets programs written in both SWTP 8K BASIC(versions 2.0, 2.2 & 2.3) and Super BASIC. Features: 9-digitBCD arithmetic, Print Using and Linput commands, and muchmore Price $49 95

TOUCHUP'" — Modifies TSC's Text Editor and Text Pro-cessor for Percom mini-disk drive operation. Supplied on

diskette complete with source listing $17.95

Operating Systems

INDEX® — This easy-to-use disk-operating and tile man-agement system lor 6800 microcomputers is fast. I/O devicesare serviced by interrupt request. INDEX* accesses peripheralsthe same as disk files — new devices may be added withoutchanging the operating system. Other feafures: unlimitednumber of DOS commands may be added • over 60 systementry points • display only those files al or above user-specifiedfile activity level • versions available for SWTP MF-68, Smoke's

BFD-68 and Motorola's EXORciser*. Price $99.95

MINIDOS-PLUSX'" — An extension of the originalMINIDOS'* for LFD-400«' mini-disk systems, MINIDOS-PLUSX1" manipulates files by six-character names. Supportsup to 31 files. Resident commands include Initialize, Save,Allocate, Load, Files (directory list). Rename and Delete.Supplied on 2708 ROM with a minidiskette that includestransient utilities such as Copy, Backup, Create, Pack and Print

Directory. Price $34.95.

PSYMON'" — Percom SYstem MONitor lor the Percomsingle-board/SS-50-bus-compatible 6809 computer accom-modates user's application programs with any mix of peripher-als without modifying programs. PSYMON1" also featurescharacter echoing to devices other than the communicatingdevice, sophisticated register and memory dump routines and

more. Price (on 2716 ROM) $69.95.

WINDEX™ — Described in detail elsewhere on this page.Business Programs

General Ledger — For 6800/6809 computers using Per-com LFD mini-disk storage systems. Requires little or noknowledge of bookkeeping because the operator is promptedwith non-technical questions during data entry. General Ledgerupdates account balances immediately — in real time, and willprint financial statements immediately after journal entries. Userselects and assigns own account numbers; tailors financialstatements to firm's particular needs. Provides audit trail. Runsunder Percom Super BASIC. Requires 24K bytes of RAM.Supplied on minidiskette with a comprehensive users manual.

Price $199.95.

FINDER™ — This general purpose data base manager iswritten in Percom Super BASIC. Works wth 6800/6809 com-puters using Percom LFD-4001* mini-disk drive storage sys-tems. FINDER1"1 allows user to define and access records usinghis own terminology — customize file structures to specificneeds. Basic commands are New, Change, Delete, Find andPack. Add up to three user-defined commands. FINDER plusSuper BASIC require 24K bytes of RAM. Supplied on minidisk-ette with a users manual. Price $99.95

Mailing List Processor — Powerful search, sort, createand update capability plus ability to store 700 addresses perminidiskette make this list processor efficient and easy to use.Runs under Percom Super BASIC. Requires 24K bytes of RAM.Supplied on minidiskette with a users manual. Price $99.95.From the Software WorksDevelopment and debugging programs for 6800 u.Cs on disk-ette:

Disassembler/Source Generator $30.95

Reloc'tng Disas'mblr/Segmented Text Gen $40.95

Disassembler/Trace $25.95

Support Relocator Program $25.95

Relocating Assembler/Linking Loader $55.95

SmithBUG** (2716 EPROM) $70.00

1/2-Price Special on Hemenway Software!

CP/68? disk operating system $ 49.97

STRUBAL++ compiler $124.97

EDIT68 text editor $ 19.97

MACRO-Relocating Assembler $ 39.97

Linkage Editor (LNKEDT68) $ 24.97

Cross Reference utility $ 14.97

Circle 245 on inquiry card.!" trademark of Percom Data Company, Inc.' trademark of Motorola Corporation^Trademark of Hemenway Associates Company* 'SmithBUG is a trademark of the Software Works Company

And 'looking into' is just whatyou do with the ElectricWindow® as you peer rightinto memory space wherecharacters are being inputand manipulated. Displayis memory-resident,programmable and generatesup to 24 80-character lines.Other features include:

• standard charactergenerator plus provision foroptional special charactergenerator

• dual intensity, high-lightingalphanumeric display

• scrolling by a programmableregister • programmabledisplay positioning

• programmable interlaced ornon-interlaced scan

• descenders on lower caseletters • users manual withapplication instructions andlisting of WINDEX™'driver.

The Electric Window.®Worth Looking Into. $249.9$

WINDEX® is a fast video display driver program forthe Electric Window'*. WINDEX® also features:program and keyboard control of charactergenerators • displayable control characters — underprogram control • automatic scrolling • a driverroutine for the parallel input keyboard feature of thePercom 6809 Single-Board Computer, the SBC/9®• auto-linking to PSYMON®, the ROM operatingsystem for the SBC/9"-* • Prices: ROM version:$39.95; LFD-400® compatible diskette (source and

Object files): $29.95. Circle 243 on inquiry card.

Now Available! the SBC/9 MPU/Control Computer

(Single-Board-Computer/6809) — stands alone as a control computer, but alsocompatible with the SS-50 bus for use as an MPU card. Includes PSYMON® (PercomSYstem MONitor) in a 1K ROM and provides for additional 1K of ROM. Also includes 1Kof RAM. Features: Super Port — provision for multi-address, 8-bit bidirectional datalines • an intelligent data bus for multi-level data bus decoding • an on-board 110-baudto 19.2 kbaud clock generator • extended address capability — to 16 megabytes —without disabling baud clock or adding hardware. And much more. Supplied withPSYMON® and comprehensive users manual. Price $199.95.

See full page ad elsewhere in this magazine for all of the SBC/9™ features. Circle #244.

Full Feature Prototyping PC Boards

All of the features needed for rapid,straightforward circuit prototyping. Use14- 16-, 24- and 40-pin DIP sockets• SS-50 bus card accommodates 34- and50-pin ribbon connectors on top edge,10-pin Molex connector on side edge* 1/0card accommodates 34-pin ribbonconnector and 12-pin Molex on top edge

rPFrTi^TfSPPPTinF'

mrtnnfT!!!!

/O Bus Card: $14.95

SS-50 Bus Card: $24.95

• I/O card is l-'A inches higher thanSWTP 1/0 card • interdigitated powerconductors • contacts for power regulatorsand distributed capacitance bypassing

• use wire wrap, wiring pencil or solderwiring • tin-lead plating over 2-oz copperconductors wets quickly, solders easily

• FR4-G10 epoxy-glass substrate.

Circle 246 on inquiry card.

To place an order or request additional literature call toll-free 1-800-527-1592. For technical information call (214)272-3421. Orders may be paid by check, money order, COD orcharged to a VISA or Master Charge account. Texas residentsmust add 5% sales tax.

PRICES AND SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE.

PEHCOM DATA COMPANY, INC.

211 N. KIRBY GARLAND. TEXAS 75042

1214! 272-3421

Listing 1: Demonstration program for the Sears Home Control System.

.1ST

90 REM THIS PROGRAM ALLOWS DIRECT COMPUTER CONTROL OUER THE SEARS HOME CONTROL SYSTEM

92 REM

94 REM COPYRIGHT 1.979 STEUEN A- CI ARC IA

9 6 REM

9 3 REM

.1.00 REM SET UP TABLE OF CHANNEL /OUTPUT CODES

105 DIM CC20)*S<20)

110 DATA 12>28y4.20v2.J.8»:i.0v2dr 1 4 v 30

1.15 DATA 6,22*0*16»8»24

1.20 FOR X=l TO 16

1.25 READ C(X> {REM C(X) IS CHANNEL NUMBER

130 NEXT X

1.35 GO SUB 200 J GOTO 300

190 REM

1.95 REM

200 PRINT "CURRENT" STATUS IS J"

205 EOR X=l TO 1.6

210 PRINT "CHANNEL "SXi" IS "t {IF S<X>=1 THEN PRINT'ON" ELSE PRINT-OFF"

220 NEXT X

225 RETURN

300 PRINT "DO YOU WANT TO CLEAR ALL OUTPUTS TO ST ART"I INPUT A$

305 IE A$="YES" THEN F=l {GOSUB 90S0JF0R Z=l TO 16SS(Z>=0 {NEXT 2 {REM CLEAR BSR OUTPUTS

310 PRINT "SET CONTROLLER OUTPUTS BY ENTERING CHANNEL NO, AND FUNCTION"

315 PRINT"ENTER CHANNEL NO, (0 10 EXIT) "J J INPUT C

317 IE 00 THEN GOSUB 200 !GOTO 300

320 PRINT"CHANNEL "SC?" IS "i IIP S < C > = 1. THEN PRINT'ON" ELSE PRINT"OFT "

325 P RIN T " 0 N » 0 E E »N E X T i 0 R REVIEUI ) " i INPU1 A *

330 IE A*-'"ON" THEN S {C) = J. J X=C J GOSUB 9000 !F "=5 J GOSUB 9050 I GOTO 315 I REM TURN CHANNEL C ON

340 IF Ai|.^ "OFF" THEN S(C) =0 tX=CJGOSUB 9000! F=7JGQSUB 9050 {GOTO 31SSREM TURN CHANNEI C OFF

350 IF A«-"NEXT" THEN C ~+l{GOTO 320

360 GOSUB 200 (GOTO 315

8996 REM

8998 REM

9000 REM BSR HOME CONTROL DRIUER

901.0 REM C<X) IS CHANNEL CODE

9015 OUT 9,0(X) JREM SET CHANNEL

9020 GOSUB 9085

9025 RETURN

9050 REM FUNCTION BRIUER

9060 REM F■■-FUNCTION CODE

9065 OUT 9.F

90'0 GOSUB 9085

9075 OUT Vj.1.28 JREM BIT 7 SHUTS OFF TRANSDUCER OUTPUT

9080 RETURN

9082 REM

9084 REM

9085 FOR (TO TO 900 JNEXT 0 {RETURN JREM DELAY TIMER

READY

RUN

CHOOSE ONE OF THE FOLLOWING J

1. AUTOMATIC CONTROL SYSTEM ON

2, MANUAL CONTROL / CURRENT STATUS

3. PRINT THE CURRENT TIME

4, REVIEW DEFAULT SETTINGS AND ADD TO CONTROL LIST

YOUR CHOICE ? 4

DO YOU WANT TO REVIEW THE DEFAULT SETTINGS (Y/N)

1

.AT

2

HOURS

0 i-

ilNUTES

TURN CHANNEI...

1.0

9

. AT

.1.7

HOURS

0

MINUTES

TURN CHANNEL

10

3

.AT

1.8

HOURS

30

MINUTES

TURN CHANNEL

6

4

.AT

1.9

HOURS

2 5

MINUTES

TURN CHANNEL.

6

5

.AT

1.9

HOURS

40

MINUTES

TURN CHANNEL

6

6

• AT

20

HOURS

20

MINUTES

TURN CHANNEL

6

7 ,

.AT

20

HOURS

35

MINUTES

TURN CHANNEL

6

3

.AT

21.

HOURS

50

MINUTES

TURN CHANNEL

6

9

.AT

22

HOURS

0

MINUTES

TURN CHANNEL

6

10

.AT

2 3

; HOURS

50

' MINUTES-

TURN CHANNE

L i

11

.AT

1.

HOURS

50

MINUTES

TURN CHANNEI...

6

12

.AT

2

HOURS

45

MINUTES

TURN CHANNEL

6

ONOFFONOFFONOFFONOFF

ON

> OFFONOFF

Listing 1 continued on page 48

46 January 1980 © BYTE Publications Inc

WIRE

WRAPPING

TOOL

AWG30Wirei .025" Square Posts• Daisy Chain or Point lb PointNo Stripping or Slitting Required...JUST WRAP,• Built In Cut Off

Easy Loading of Wirei Available Wire Colors:Blue, White, Red & Yellow

U.S.A..FOREIGNPATENTS PENDING

IUST WRAP TOOL WITH ONE 50 FT. ROLL OF WIRE

COLOR

PART NO.

U.S. LIST PRICE

BLUE

WHITE

YELLOW

RED

JW-1B

JW1WJW-l-YJW1R

$14.9514.9514.9514.95

REPLACEMENT ROLL OF WIRE 50 FT.

BLUE

WHITE

YELLOW

RED

RJWBR-JW-WRJW YRJWR

$ 2.982.982.982.98

JUST WRAP-UNWRAPPING TOOL

JUW 1 $ 3.49

OK MACHINE & TOOL CORPORATION 3455 CONNER ST.,BRONX, N.Y. 10475 (212) 994-6600/TELEX125091

* MINIMUM BILLING $ 25.00/ADD SHIPPING CHARGE $ 2.00/NEW YORK CITY/STATE RESIDENTS ADD APPLICABLE TAX.

Circle 27 on inquiry card.

BYTE January 1980 47

Listing 1 continued:

13

.AT 16 HOURS 0 MINUTES TURN CHANNEL

1 ON

1A

.AT 22 HOURS 0 MINUTES TURN CHANNEL

1 OFF

15

.AT 23 HOURS 0 MINUTES TURN CHANNEL

A ON

16

•AT 0 HOURS 30 MINUTES TURN CHANNEL.

4 OFF

17

.AT 19 HOURS 30 MINUTES TURN CHANNEI

•5 ON

IB

.AT 21 HOURS 20 MINUTES TURN CHANNEI

. 5 OFF

19

.AT 22 HOURS 0 MINUTES TURN CHANNEL

5 ON

20

.AT 1 HOURS 0 MINUTES TURN CHANNEL

1......CHANGE LIST

2 ADD TO LIST

5 OFF

m rj

0 EXIT TO MENU

ENTER TIME tCHANNELt AND FUNCTION

ENTRY NO. 21 ? 2330(3*ON

ENTRY NO. 22 ? 0»0»0

1. .....CHANGE LIST

2......ADD TO LIST

? 0

0......EXIT TO MENU

CHOOSE ONE OF THE FOLLOWING I

1.

AUTOMATIC CONTROL SYSTEM ON

9

MANUAL CONTROL / CURRENT STATUS

3.

PRINT THE CURRENT TIME

4.

REVIEW DEFAULT SETTINGS AND ADD TO CONTROL

LIST

YOUR CHOICE ? 1AUTOMATIC CONTROL INITIATED23 HOURS 43 MINUTES

Listing 2: Program to compare the time from a real-time clock against a list of opera-tions to be performed at specific times. A sample run of the program demonstrates howthe entries may be varied.

RUNCURRENT

fATUS IS

CHANNEL 1

CHANNEL 2

CHANNEI... 3

CHANNEL 4

CHANNEI... 5

CHANNEL. 6

CHANNEL 7

CHANNEI... 8

CHANNEI... ?

CHANNEI... 10

CHANNEL 1 :l.CHANNEI...CHANNELCHANNEL.CHANNEI...CHANNEL

IS OFF

IS OFF

IS OFF

IS OFF

IS OFF

IS OFF

IS OFF

IS OFF

12

13

:l. 41516

IS OFF

IS OFF

IS OFF"

IS OFF

IS OFF

IS OFF

IS OFF

IS OFF

DO YOU WANT TO CLEAR ALL OUTPUTS TO START? YES

SE1 CONTROLLER OUTPUT'S BY ENTERING CHANNEL NO,. AND FUNCTIONENTER CHANNEL NO. (0 TO EXIT) ? 2CHANNEL. 2 IS OFFDN?OFF.NEXT?OR REVIEW -' ON

ENTER CHANNEL NO. (0 TO EXIT) ? 5CHANNEL 15 IS OFFON»OFFtNEXTtOR REVIEW 5? ON

ENTER CHANNEI... NO. (0 TO EXIT) ? 2CHANNEL 2 IS ONON»OFF»NEXT>OR REVIEW 5r NEXT

CHANNEI... 3 IS OFFONrOFF»NEXT*OR REVIEW i? REVIEW

CURRENT STATUS IS !CHANNEI... 1 IS OFF

Listing 2 continued on page 50

Text continued from page 42:interface properly, you must haveLevel 2 BASIC to address outputports. Also, in most Level 2 systems,+ 5 V on the expansion connector hasbeen disconnected at the factory. Itwill be necessary, therefore, to pro-vide a separate 5 V 300 mA powersupply for the interface electronics.

Using the Interface

A typical application is demon-strated in figure 5. The receivers canbe placed around the home to controla variety of appliances and lights.With the addition of the real-timeclock outlined in a previous CircuitCellar article ("Anyone Know theReal Time?" August 1979 BYTE, page50) you can add timed activation ofthese control functions as well.

Listing 1 shows a simple BASICprogram that demonstrates the inter-face capabilities. The command con-sole is plugged in and positionedwithin 20 feet on a direct unob-structed line with the interface outputtransducer. The program starts byasking if you want to clear all outputsand start fresh. Since the BSR X-10 isan open-loop control system, andyou have no way of knowing whichreceivers are activated, this is a pru-dent choice.

To turn on channel 6, simplyanswer the appropriate questionswith "6" and "ON". The status of allchannels can be reviewed at any time.

The program responds by calling acontrol output routine. Turningchannel 6 on requires two outputs tothe command console. One sets chan-nel 6 (as if pressing the 6 button), andthe other sets the "on" function (as ifpressing the ON button). To allowenough time for the command con-sole to respond, delay loops areinserted. The result is a 2-secondsignal to set device code 6 and a2-second message that tells it to turnon. The process can be reversed witha 6 and an OFF program command.All sixteen channels can be just aseasily cycled.

Listing 2 is the logical extension ofthis basic concept. Using a real-timeclock, you can create a list of pre-cisely timed events. It can be used tocontrol house lighting during vaca-tions or to turn the coffee maker on at6:30 AM. The program incorporatesa default list of data statements. Eachstatement is formatted as time, chan-

Text continued on page 54

48 January 1980 © BYTE Publications Inc

MicroPro International Corporation

zl.'iofessional LJualitii Ooflwa\e you (_ an Count Ori, J low!

MicroPro

T.M.

THE BEST GETS BETTER! Yes, in just a few months, thousands of users now know thatWORD-STAR™ is the word processing product that truly transforms the performance of Z-80,8085, and 8080 microcomputers into a class with systems costing far more. Look at theserecent enhancements: Print spooling; directory; foreign language adaptability; microspacejustification; mailing list merge; CP/M*1.4, 2.0 & MPM compatible, and more. Examine ourfeatures and order yours now!

MicroPro Price List:

Word-Star™-Word-Master™Tex-Writer™-

Software/Manual

$495/40

$150/25$ 75/15

Super-Sort I™-Super-Sort II™-Super-Sort III™-

Software/Manual

$250/25$200/25$150/25

For more information and the name of your nearest dealer, contact MicroPro International Corporation.

Dealer/Distributor/O.E.M. Inquires Invited

MICROPRO INTERNATIONAL CORPORATION1299 4th Street, San Rafael, California 94901Telephone (415) 457-8990 Telex 340388

•Runs under Digital Research CP/M or its derivatives, in 48K RAM

Note: Micro Pro offers a reward for reporting and successful prosecution of unauthorized copying.

Listing 2 continued:

CHANME

L 2

IS ON

CHANNE

L. 3

IS OFF

CHAN me:

1... 4

IS OFF

CHANNE

L 5

IS ON

CHANNE

L 6

IS OFF

CHANNE

1... 7

IS OFF

CHANNE

1... 8

IS OFF

CHANNE

1... 9

IS OFF

CHANNE

L :l. 0

IS OFF

CHANNE

1... :l. 1

IS OFF

CHANNE

1... 12

IS OFF

CHANNE

I... 13

IS OFF

CHANNE

I... 14

IS OFF

CHANNE

L 15

IS OFF

CHANNE

L 16

IS OFF

ENTER

CHANNE

1... NO,

(0 TO EXIT)

LIST

100110120130

140150160170

3 80190200210220230240250260270280290300310320330340350360370380390400410420430440450460470

4 BO490500H10520530540550560570580590600610620630640'650660670680

REM

REM

REM

REM

REM

REM COPYRIGHT 1979

REM

REM

GOSUB 350 {REM LOAD

REM PROGRAM OPTIONS

PRINT 8PRINTJ PRINT

PRINT

THIS PROGRAM PROVIDES REAL TIME CONTROL OF AC APPLIANCES

BY CONNECTING THE SEARS HOME CONTROL SYSTEM AND A REAL TIME CLOCK

TOGETHER.

STEVEN CIARCIA

DATA TABLES

ARE MADE THROUGH MENU SELECTIONS

"CHOOSE ONE OF THE FOLLOWING J"

AUTOMATIC CONTROL SYSTEM

MANUAL CONTROL / CURRENT

PRINT THE CURRENT TIME"

REVIEW DEFAULT SETTINGS AND ADD TO CONTROL LIST

ON"STATUS

:i

PRINT"1.PRINT'2.PRINT*3.

PRINT"4.

PR I NT-PRINT " YOUR CHOICE

IF Zl=l THEN PRINT

IF Zl=2 THEN GOSUB

IF Zl=3 THEN GOSUB

IF Zl«4 THEN GOTO

GOTO 200

REM

REM

REM SET UP TABLE OF CHANNEL/OUTPUT CODES

DIM C(20)»S(50)

DATA 12»28»4.20»2.ia

DATA 6>22tQrl6,8f2A

FOR X=i TO 16

READ C(X> J REM C(X)

NEXT X

REM WHEN PROGRAM IS INITIATED THE FOLLOWINGSETP0INT8 ARE STORED AS DATA STATEMENTSW=TOTAL NUMBER OF DATA STATEMENTS

"y I INPUT'AUTOMATIC CONTROL

740 J SOTO 810

1470 ! PR INT :PRINT940

10,26»14*30

IS CHANNEL NUMBER

INITIATED1

"THE PRESENT TIME

GOTO 1190

IS " . !G0SUB 1130 JG0T0 200

REM

REM

REM

DIM

W=20

DATA

DATA

DATA

DAI A

DATA

DATA

DATA

DATA

DATA

DATA

DATA

DATA

DATA

DATA

DATA

DATA

DATA

DATA

DATA

DATA

DATA TABI.IN THE FORM

CONSTITUTES THE DEFAULT CONTROLOF TIME » CHANN E L > AND FUN C T10 N

SETPOINTS

W(50)»A(50).B(50)»A$(SO) »L(50)REM W=TOTAL NUMBER OF DEFAULTS

0200»10."ON1

1700y10y"OFf1830»6i"ON"1923.6."OFF1

1940.6."ON"2020.6.

2035.6.215 0 y 6 y2200.6.2350y60150y6y0245.6.1600,12200,12300.4."ON0030.4."OF1930y5y"ON2120»5?"OFF"2200.3i"ON"0100.5."OFF"TO W JREAD

REM DEHUMIDIFIER

.'REM SPARE BEDROOM LIGHT!

•OFF'1 ON"'OFF'" ON""OFF1" ON"" OFF'

"ON", ..0FF.

{REM CIRCUIT CELLAR{REM CELLAR HALL{REM MASTER BEDROOM

"iCCE

PLUG

L=l

A (I... > j B C L ) * M < L.) { R E M 8 E T TIM E» C l-l ANN E I.... F U N C T10 N

Listing 2 continued on page 52

50 January 1980 © BYTE Publications Inc

OLIVETTI PRINTERS

AVAILABLE NOW!

For years we have been our own biggest customer.Until now you couldn't buy an Olivetti printer unlessyou bought a complete Olivetti calculator. Now, for thefirst time, our complete line of OEM printers is availablefor immediate shipment in any quantity. For use in cal-culators, electronic scales, cash registers, mini com-puters, CRT hard copy output, data loggers, medicaland scientific instruments, or any application where apaper tape printout is desired. Olivetti has a qualityOEM printer for you.

Fox Further Information Please Contact:

Olivetti Corporation20370 Town Center LaneCupertino, California 95014Telephone: 408/996/3867

PU184Q-

40 Column Thermal,Dot Matrix, Plotter

Features:

□ High Speed

□ Low Cost—The Best Really Can Cost Less!

□ Fewer Moving Parts

□ Proven High Reliability and Long Life

□ Over 3 Million In Use by Olivetti Alone

□ Lightweight and Compact—Extremely Versatile

□ Available With 6V or 18V Motor

□ Low Power Usage

□ Graphic Capabilities (PU1828 and PU1840)

□ All Printers are Available With or Without Interface Boards

-,i

m

•%■>

m*km

*, t'J^M

■ kftti

I*<mL

:

*§*

PU1828—

28 Column Thermal,

240 LRM.,

Dot Matrix, Plotter

PU1808—

16 Column Thermal, 120 L.RM.

PU1800—

20 Column Thermal, 120 LRM.

Coming Soon:

80 Column Thermal, 240 L.RM.Dot Matrix, Plotter

0

PU1100—

20 Column Impact, 120 L.RM.

Olivetti

Circle 28 on inquiry card.

Listing 2 continued:

690 NEXT I...

700 RETURN

71.0 STOP

720 REM

730 RE197 REM

740 PRINT "CURRENT STATUS IS I"

750 FOR X=l TO 16

760 PRINT "CHANNEL. "SXj" IS "5 (IF S(X>=1 THEN PRINT "ON" EI...SE PRINT "OFF"

770 NEXT X

780 RETURN

790 REM

800 REM

810 PRINT "DO YOU WANT TO CLEAR API... OUTPUTS TO START "J INPUT A$

820 IF A*="YES" THEN F=l SSOSUB 1380JF0R Z=l TO 16{S<7.>=0 {NEXT Z IREM CLEAR BSR OUTPUTS

830 PRINT "SET CONTROLLER OUTPUTS BY ENTERING CHANNEL. NO, AND FUNCTION"

8 4 0 P RIN T " E N T E R C H ANN E I... NO. < 0 T 0 E XIT ) "it IN P U T C850 II- C=0 THEN GOTO 200

860 PRINT "CHANNEL "JCS" IS " ■■ I IF S(C)==1 THEN PRINT" ON" ELSE PRINT "OFF"

870 PRINT"ONfOFF>NEXTrOR REVIEW »"{INPUT A*

880 IF A*~*ON" THEN S ( C ) = :l.I X=C I GOSUB 1330 I F=5 I GQSUB 1380 {SOTO 840JREM TURN CHANNEL C ON

890 IF A*-"OFF" THEN 8<C)-05X=C!QOSUB 1330; F=7{GOSUB 1380 i(30TO 840 IREM TURN CHANNEL C OFF

900 IF A$=="NEXT" THEN C=C + 1 I GOTO 860

910 GQSUB 740 I GOTO 840

920 REM

930 REM

940 PRINTS PRINT'BO YOU WANT TO REVIEW THE DEFAULT SETTINGS (Y/N) "${INPUT B*

950 IF B*<>"Y" THEN GOTO 1000

9 60 FOR L=l TO U970 L1==INT<A<L>/1.00,

980 PRINT L!"."S"AT "iL.15" HOURS " ", A (I... > -I... 1* 100 i " MINUTES ' } 'TURN CHANNEL " P B (I...) i " "SA$(L )

990 NEXT I...

1000 PRINTiPRINT" 1 ...... CHANGE I.. 1ST " SPRINT " 2......ABU TO LIST"

1010 PRINT" O......EXIT TO MENU" {INPUT Z2

1020 IF Z2=Q THEN GOTO 200

1030 IF Z2== I. THEN PRINT "RECORD ENTRY TO BE CHANGED"; ELSE 1080

1040 INPUT IS

1050 PRINT" PRESENTLY "5 A(Z3);B(Z3) ,A*(Z3)

1060 INPUT "TIME ,CHANNEL,AND ON OR OFF " iA<Z3)jB(23)vA$(Z3) J IF A(Z3>=0 THEN 1000

1070 PRINT "CHANGE ANOTHER Y/N "i {INPUT Z* (IF Z*s="Y" THEN GOTO 1030 ELSE 1000

1080 IF Z2<>2 THEN GOTO 1000

1090 REM START ADDITIONS AT END OF DEFAULT LIST

1100 PRINT" ENTER TIME «CHANNEL, AND FUNCTION"

1110 W=W+1 SPRINT'ENTRY NO."v U,l INPUT A(W) rB(.U> iA*(W) ! IF A<W>=0 THEN W=W-1 IGOTO 1.000

1120 GOTO 1110

1 :l 3 0 R E M 4 DIGIT F 0 R M A T R 0 U TIN E

1140 12 = I-11 * 10 + H 0 I T 3 - M1 * 10 + M 0

1150 PRI NT T 2 5 " l-l 0 U RS " 5 T 3 5 " MINU T E S " I R ETU R N

I160 REM

1:170 REM

.1.180 REM

1190 REM CONTROL. OUTPUT SUBROUTINE SETPOINT MONITOR

1200 T5»0

1210 GOSUB 1470 {REM GET TIME

1220 IF TJ.OT5 THEN GO SUB 1130 !TS=T1 {REM PRINT TIME

1230 FOR L=l TO U

1240 IF T:L=A(L) THEN X=B<L) {GOSUB 1330 IGOSUB 1280

1250 NEXT I...

1260 IF INP(0)O0 THEN GOTO 200 IREM CHECK KEYBOARD FOR INTERRUPT INPUT

1270 GOTO 1210

1280 IF A$<L)='ON" THEN F~5{S(B(L))=1 {GOSUB 1400

1290 IF A*<L)="OFF" THEN F^7 !S(B(L))==0 IGOSUB 1400

1300 RETURN

1310 REM

1320 REM

1330 REM BSR HOME CONTROL DRIVER

1340 REM C(X) IS CHANNEL CODE

1350 OUT 9»C<X) IREM SET CHANNEL.

1.360 GOSUB 1460

1370 RETURN

1380 REM FUNCTION DRIVER

1390 REM F-FUNCTIQN CODE

1400 OUT 9iF

1410 GOSUB 1.460

1.420 OUT 9 >.128 IREM BIT 7 SHUTS OFF TRANSDUCER OUTPUT

1430 RETURN

1440 REM

1450 REM

1460 FOR (3=0 TO 900 I NEXT 0 I RETURN IREM DELAY TIMER

Listing 2 continued on page 5452 January 1980 © BYTE Publications Inc

A FULL NETWORK DATA MANAGEMENT SYSTEM FOR MICRO COMPUTERS

© the Ultimate Software Tool:

v

AVAILABLE FROM

/Wlicrc Data Base Sustcms, inc.

MDBS IS A VERSATILEDATA BASE MANAGEMENT SYSTEM

• PROVIDES FLEXIBILITY OF A FULL NETWORK DATA

BASE SYSTEM

• EFFECTIVE REPRESENTATION OF COMPLEX DATA

STRUCTURES

• RECORDS CAN BE ORDERED ON VARIOUS SORT KEYS

• COMMANDS TO ADD, DELETE, UPDATE, SEARCH AND

TRAVERSE THE DATA BASE

• SORTED, FIFO, LIFO, NEXT AND PRIOR SET ORDER-

ING PROVIDED

• PROVIDES DATA PROTECTION

• STRAIGHTFORWARD USE OF ISAM-LIKE STRUCTURES

• COMPARABLE TO DATA BASE SYSTEMS PREVIOUSLY

AVAILABLE ONLY ON LARGER COMPUTERS

MDBS IS CODASYLORIENTED WITH EXTENSIONS

• EXPLICIT REPRESENTATION OF MANY-TO-MANY SETS

• RECORD TYPES MAY OWN OTHER OCCURRENCES OF

THE SAME RECORD TYPE

• DIFFERENT RECORD TYPES CAN PARTICIPATE IN A

SINGLE SET

• MULTIPLE LEVELS OF READ/WRITE PROTECTION

• NAMES OF DATA ITEMS, RECORDS, SETS AND FILES

ARE WHOLLY USER DEFINABLE

MDBS IS FOR THE SERIOUSAPPLICATIONS PROGRAMMER

• POWERFUL COMPONENT IN INFORMATION PROCESSING

• RELIEVES TEDIUM OF FILE HANDLING DETAILS

• OEMS CAN RAPIDLY AND INEXPENSIVELY DEVELOP

APPLICATION SOFTWARE

• USEFUL IN DISTRIBUTED PROCESSING ENDEAVORS

SOFTWARE DELIVERED ON MINI-OR FULL-SIZED FLOPPY DISKSUSING CP/M , NORTH STAR, OR TRS-80" COMPATIBLE FORMATS

• MDBS INTRODUCTORY OFFER $750.00

• USERS MANUAL (alone) $35.00

• Distributors and OEMS Contact MDBSfor Special Rates

• Application Programming Contractswill be Considered.

Indiana Residents Include 4% Sales Tax.

WE ACCEPT

CP/M is a registered trademark of Digital Research Corp.TRS-80 is a registered trademark of Radio Shack/Tandy Corp.

FEATURES

WRITTEN IN Z 80 CODE FOR MAXIMAL EXECUTIONEFFICIENCY AND MINIMAL MEMORY USAGE. (8080VERSION EXTRA).

ROUTINES ARE CALLABLE FROM BASIC (OR OTHERHOST LANGUAGES) TO FACILITATE FAST AND EASYAPPLICATION PROGRAMMING.

ROUTINES CAN BE ORGED TO SATISFY USER REQUIRE-MENTS.

SUPPORTS DATA BASES SPREAD OVER SEVERAL DISKDRIVES (MAXIMUM OF 8). DISKS MAY BE MINI- OR FULLSIZED FLOPPIES OR HARD DISKS.

I/O AND HOST LANGUAGE INTERFACE ROUTINES AREISOLATED FOR EASY ADAPTATION. PATCHES FORMANY COMMON OPERATING SYSTEMS/HOST LAN-GUAGE COMBINATIONS AVAILABLE, INCLUDING CP/M®WITH BASIC, FORTRAN AND COBOL, NORTH STAR DOSAND BASIC, ETC.

REQUIREMENTS

• Z-80 Based System (8080 Systems Extra,6502 Version Forthcoming)

• 8 to 16K Bytes (Depending on Options)in Addition to the Operating System,Host Language and Users Program.

PACKAGE INCLUDES

MDBS DDL DATA DEFINITION LANGUAGE ANA-LYZER/EDITOR. The user specifies data structures tobe used in a concise Data Definition Language (DDL).The MDBS Data Definition Language Analyzer/Editorallows the user to interactively create and edit DDLspecifications and to initialize the data base for usebased on these specifications.

250 PAGE USERS MANUAL with extensive documen-tation of the MDBS System.

MDBS DMS DATA MANAGEMENT ROUTINES. Theseare the routines callable from the host language (BASIC,PASCAL, etc.) which perform the data base operationsof finding, adding, and deleting records; fetching andstoring data items; and traversing the (possibly complex)data structure.

SAMPLE APPLICATION PROGRAMS written inNorth Star BASIC which illustrate various features ofMDBS.

MICRO DATA BASE SYSTEMS, INC

P.O.BOX 248 LAFAYETTE, IN 47902(317) 742-7388

Circle 29 on inquiry card.

BYTE January 1980 S3

Listing

1.4701.4801490500510152015301.540155015601570158015901600161016201630

2 continued:

REM THIS ROUTINE IS THE REAL TIME CLOCK INTERFACE DRIVER

REM HARDWARE DESCRIBED IN AUG. '79 BYTE

REM IT READS IN 2400 HR. FORMAT AND IS CONNECTED TO PORT 8

R0=0 tOUT 3«254 !REM TURN ON PANEL LIGHT

OUT 8»1 50UT 8*0 }T-INP<8> !D=T AND 16

IE D=l<4 THEN 1530 ELSE 1510

MO=T AND 15 ! GOSUB 1630

M:L='l AND 15 J GOSUB 1630

HO=T AND 15 tGOSUB 1630

H1=T AND 15 JGOSUB 1630

T1 = (H1 * 10+HO) * 100+ (M1 * 10 t-MO )

IE R0«*T1 THEN 1590 ELSE R0=T1

OUT 3»255 tREM TURN ORE PANEL

RETURN

REM T1«TIME

REM M1=TEN3 OF

OUT 8r I. !OUT 8

IREM TIME{GOTO 15:LIGHT

IN0

2400 FORMAT

I laTENS OP

MINUTES

HOURS HO^HOURMO-MINUTES

0 rr==INP(8) {RETURN

READY

...AND HOLDING

5V at 3A withBuilt-in OVP

Power One's B Case models started at$24.95. Over 100,000 models and fiveyears later, they're still only $24.95!

■ 115/230 VAC Input

■ OVP Built-in

■ .05% Regulation

■ 2-Year Warranty

■ 2-Hour Burn-inrjjS^ ■ UL Recognized■ CSA Certified

odel HB5-3/OVP

Get all the details on our 84standard open framesin our new 1978 catalog.

IN-STOCK NATIONWIDE...FOR IMMEDIATE DELIVERY

EASTERN REGIONAL SALES OFFICE: Schenectady, N.Y (518) 399-9200 ALA.: Huntsville, Rakes Engr. &Marketing Corp. (205) 883-9260 ARIZ.: Phoenix, PLS Assoc. (602) 279-1531CAL: Pasadena, A-F Sis. Engr. (213)681-5631; San Diego, A-F Sis. Engr. (714) 226-8424; San Jose, Richards Assoc. (408) 246-5860 COL.: Denver,PLS Assoc. (303) 773-1218 CT.: Litchfield, Digital Sis. Assoc. (203) 567-9776 FLA.: Orlando, OEM Marketing Corp.(305) 299-1000 GA.: Duluth. Rakes Engr. & Marketing Corp. (404) 476-1730 ILL.: Chicago, Coombs Assoc. (312)298-4830 IND.: Indianapolis, Coombs Assoc. (317) 897-5424 MD.: Wheaton, Brimberg Sis. Assoc. (301) 946-2670; Baltimore, Brimberg Sis. Assoc. (301) 792-8661 MASS.: Waltham, Digital Sis. Assoc. (617) 899-4300MICH.: Southfield, LH. Dickelman Co. (313) 353-8210 MINN.: Minneapolis, Engr. Prod. Assoc. (612) 925-1883N.J.: Whippany, Livera-Polk Assoc. (201) 377-3220; Marmora, Holdsworth (609) 398-4340 N.M.: Albuquerque,PLS Assoc. (505) 255-2330 N.Y.: Roslyn Hts., Livera-Polk Assoc. (516) 484-1276; Syracuse, C.W. Beach (315)446-9587 N.C.: Charlotte, Over & Over Inc. (704) 527-3070 OHIO: Cleveland, Marlow Assoc. (216) 991-6500;Dayton, Marlow Assoc. (513) 434-5673 OKLA.: Tulsa, Advance Technical Sis. (918) 743-8517 ORE.: Portland, Jas.J. Backer (503) 297-3776; Salem, Jas. J. Backer (503) 362-0717 PENN.: Pittsburgh, Marlow Assoc. (412) 831-6113;Newtown Sq„ Holdsworth & Co. (215) 356-8550 TEX.: Dallas, Advance Technical Sis. (214) 361-8584; Solid StateElectr. (214) 352-2601; Houston. Advance Technical Sis. (713) 469-6668; Solid State Eleclr. (713) 772-8483 UTAH:Salt Lake City, PLS Assoc. (801) 466-8729 WASH.: Seattle, Jas. J. Backer (206) 285-1300; Radar Elec. Co. (206)282-2511 WIS.: Milwaukee, Coombs Assoc. (414) 671-1945 EUROPE: Hanex, LA., CA (213) 556-3807 CANADA:Duncan Instr., Weston, Ontario (416) 742-4448; Winnipeg, Manitoba, Cam Gard Supply Ltd. (204) 786-8481

"Thinksabout

opou/ernne

D.C. POWER SUPPLIES

Power One Drive • Camarillo, CA 93010 • Phone; 805/484-2806 -TWX: 910-336-1297SEE OUR COMPLETE PRODUCT LISTING IN EEM & GOLDBOOK

Text continued from page 48:

nel, and function. To turn on a coffeemaker connected to a unit 6 appliancemodule simply write: DATA 0630,6,"ON". This technique allows us to setup a specific vacation or holidayrepertoire. Just load the program andrun it. The list of control data can beadded to while the program is run-ning. This allows specific actions suchas shutting off the television at 2 AMin case you fall asleep during the lateshow. Entries such as these are retain-ed only as long as the program is run-ning. They must be reentered if theBASIC program is terminated.

Conclusion

I always try to present interfacesand applications that I think will in-terest BYTE readers. I consider thisone is particularly significant con-sidering the cost advantages overearlier technology. I will not replacethe relay-controlled lighting in myhome, but further expansion of ACcontrol will use the hardware fromthis article. There are, of course,many situations where the BSR X-10is inappropriate, but considering thesophistication when it is connected toa computer, I am going to look a lotharder for ones that apply.

Next Month:

It is getting a little cold in Connec-ticut, and Venezuela is our oil con-nection. As a result, I have installed awood stove and have eight cords ofwood piled up in the backyard.Realize that not just any stove can beput in the Circuit Cellar, so nextmonth I will discuss my "Computer-Controlled Wood Stove."■

Call For Papers —

Association for

Computing Machinery

Conference

Papers are invited on any aspect ofcomputing. Papers must be receivedby February 18, 1980. For moreinformation, contact Gordon Sher-man, Technical Program Chair-man, ACM 80, University of Ten-nessee Computer Center, KnoxvilleTN 37916, (615) 974-6758.

54 January 1980 © BYTE Publications Inc

Circle 30 on inquiry card.

I

■ ' J*

1 Uj n

t

y/ i

• • If'*

♦

-

!i-'-

-'^.

■" •

— C^ wf

J^^

11 1

> T*

I

-^firfaL

BB^

We're looking for the most original useof an Apple since Adam.

What in the name of Adam do people do withApple Computers?

You tell us.

In a thousand words or less.

If your story is original and intriguing enough,you could win a one-week all-expense paid trip fortwo to Hawaii. Which is the closest we couldcome to paradise.

Win fabulous prizes forcreative writing.

To enter, drop by your nearest Apple dealer andpick up an entry blank. Fill it out. Then write anarticle, in 1000 words or less, describing the unusualor interesting use you've found for your Apple.

A jury of independent judges will cast thedeciding vote for the grand prize: a week for two,airfare included, in Hawaii.

The judges will also choose 16 additionalwinners, two each from eight categories:

Circle 31 on inquiry card.

graphics/music, entertainment, home, business,education, scientific, professional, and industrial.And each winner will choose from a long list oflonged-after Apple peripherals—from AppleDisk IPs to Graphics Tablets to printers.Or you can take a $250 credit towards thepurchase of any Apple product.

The contest ends March 31,1980. All winnerswill be notified by May 15.

Entry forms are available at your participatingApple dealer. Call 800-538-9696, (800-662-9238in California), for the one nearest you.

Mail the entry blank, your article and anyphotos to: Apple Computer, "What in the nameof Adam" contest, 10260 Bandley Drive,Cupertino, CA 95014. ^^f (^

And may the juiciestapplication win.

A Computer-ControlledLight Dimmer

Part 1: Design

John H Gibson

Physics Department

Alma College

Alma MI 48801

Microcomputer hobbyists are generally and looselyclassified as either software or hardware types, de-pending on where their dominant interests and fascina-tions lie. Software types find data manipulation a satisfy-ing end in itself. They dream of ever-expandingmemories, and they use their computers to organize theirfinances, keep kitchen records, and play complex videogames. Hardware types look for ever more interestingways to interface their microcomputers with the outsideworld. They lie awake at night devising new ways ofmaking their computers control lights, appliances, andmechanical devices. Their homes are filled with wires,relays, and remote sensors.

I am a hardware type. I love to make electrical andmechanical devices respond to automatic control. Mymost recent interest, which I would like to share withyou, has been in using a very simple microcomputer forlighting control.

Of all the control techniques developed by the micro-computer hobbyist, lighting control has remained themost primitive. Until recently, lighting control with amicrocomputer was usually restricted to simple on andoff switching. Proportional control, the controlled dim-ming of lights, required either expensive hardware or animpractically large software overhead and was thereforebeyond the reach of most microcomputer hobbyists.

The recent appearance of peripheral programmabletimers for microcomputers has changed all of this. Pro-portional lighting control with a microcomputer is nowboth inexpensive and easy to achieve.

Introduction to AC Phase Control

In traditional designs, lamp dimmers used either arheostat to regulate the current through the lamp, or an

autotransformer to adjust the voltage across it. Either ofthese inherently analog devices requires that a knob beturned to change the lamp brightness, and neither deviceis amenable to microcomputer control.

Modern lamp dimmers use the technique ofproportional AC phase control. A semiconductor switchin series with the lamp is opened and closed 120 times persecond. The switch's operation is timed to permit a cur-rent to flow through the lamp only during a controlledfraction of each half cycle of the 60 Hz alternating voltagesupplied by the power line. Because this is a switchingprocess, it is inherently digital, and it is therefore a readycandidate for microcomputer control.

The switching device most commonly used for ACphase control is the triac. A triac is a semiconductordevice that functions as a latching switch. Once turnedon, the triac remains on and cannot be turned off untilthe current through it drops to zero.

Figure la is a drawing of a triac, and figure lb shows itsschematic symbol. The terminals through which theswitched current flows are labeled MT1 (main terminal 1)and MT2 (main terminal 2). A third terminal, called thegate, is used to turn on the triac, that is, to establish con-duction between main terminal 1 and main terminal 2.Because of its latching property, once the triac is turnedon by the gate, it remains on until the current throughmain terminal 1 and main terminal 2 drops to zero.

Figure 2 illustrates the basic switching arrangement forAC phase control. A triac and a lamp are connected inseries with the 120 V, 60 Hz AC power line. A mecha-nical push-button switch in series with the triac's gate ispushed and released 120 times per second, or once duringeach half cycle of the 60 Hz alternating voltage applied tothe triac and lamp.

56 January 1980 © BYTE Publications Inc

f I

I

I i

M

.

la

"»*•

IF

■

^**.

-v

The RainBflWillUJO is the first ofa new generation in color periph-erals providing a cost effectivevay to upgrade to full color andilution graphics.By using standard RS 232 C communicationinterfacing, we made the Rainbow 2000 adapt-able to any existing mini or advanced system.A Built-in 6K RAM memory allows the Rainbow2000 to "stand alone" using just a keypad andcolor monitor, or it can be utilized with multi-

*TRS-80 is a registered trademark of Radio Shack, a Tandy Co.

ITRODUCING THE RAINBOW 2000.THE PERIPHERAL WITH THE BRIGHTEST COLORGRAPHICS SINCE VINCENT VAN GOGH!

terminal systems.

When we at Digitus designed the Rainbow2000, we had the industrial and scientific user inmind, so we didn't skimp on the specs. We testeach board extensively before it is packaged forsale, we use prime quality parts and we backeach board with a full one-year guarantee.

So whether you're plotting family expenseson your *TRS-80, or monitoring a factory withan *IBM 370, let the Rainbow 2000 be yourstep up to color graphics.

"IBM 370 is a trademark of International Business Machine Inc.

Circle 32 on inquiry card.

The Rainbow 2000, Vincent would havegiven his right ear for one!

FOR FURTHER INFORMATION CALL OR WRITE:

Digitus Corporation

RO. Box 10095

Towson. Maryland

21204

in Md. 301-467-3223

800-638-4259

DEALER INQUIRIESWELCOMED

BYTE January 1980 57

dBssm

(a)

METAL MOUNTING TAB

PUSHBUTTON

Figure 2: Basic switching arrangement for proportional ACphase control using a triac.

?MT2

(b)

Figure 1: Sketch of triac (la) and schematic symbol for a triac(lb).

I L T J I microcomputer11 L I 3 people®

computer martof new jersey

[Computer Mart of New Jersey

501 Route 27

Iselin, N.J. 08830

(201)283-0600

HOURS,

Openot 10 am,

Tuesday through Saturday

THE VITALINGREDIENT:

EXPERTISE

Before you buy your newmicrocomputer, chances oreyou hove o lot of questions.Important questions thatcould mean the differencebetween a working systemand a wasted system. Thevital ingredient Is expertise.The microcomputer people atComputer Mart are expert atanswering your questionsand helping you put togetherthe best system for yourapplication. Whether It's forbusiness, the home, or thelaboratory) come see theexperts at Computer Martof New Jersey. We have thevital Ingredient.

At the beginning of each AC half cycle, the triac doesnot conduct, so no current flows through it and the lamp.Then, a momentary (30 /xs) closure of the push-buttonswitch sends a current pulse into the triac's gate. This cur-rent pulse turns on the triac, establishing conduction be-tween main terminal 1 and main terminal 2.

Because the triac is a latching switch, it then remainson (even though the push button is released) until the endof the AC half cycle, when the current through it drops tozero. The triac then turns off and remains off until thenext momentary closure of the push-button switch.

The 380 ohm resistor limits the gate current pulse to avalue that will not damage the triac's gate.

Figure 3 illustrates when the current does and does notflow through the lamp during each AC half cycle. In thisillustration, the push-button switch is open (and the triacoff) for the first 5 ms of the 8.33 ms (1/120 second)positive half cycle. The push button is then momentarilyclosed.

At this time the triac turns on, and current flowsthrough it and the lamp until the end of the positive halfcycle, when the current drops to zero. The triac thenturns off and remains off until the next momentaryclosure of the push button. The next push-button closureoccurs during the negative half cycle, when the triacagain turns on and remains on until the negative halfcycle ends.

Current therefore flows through the lamp for only afraction of each AC half cycle. The size of that fractiondepends on how late in each half cycle the push button ismomentarily closed and the triac turned on. The longerthe delay in turning on the triac during each half cycle,the less power will be supplied to the lamp.

The simplified switching arrangement of figure 2 is forillustration only. Obviously, no mechanical switch canbe pushed and released with the speed and timingaccuracy needed to make this a reliable way of achievingproportional phase control of the power supplied to thelamp.

This does not mean that it is difficult to design circuitsthat will deliver properly timed trigger pulses to a triac.Many analog circuits that do this can and have beendesigned. They range in complexity from simple,manually adjusted resistor/capacitor phase-shift net-works used in household lamp dimmers to sophisticatedramp-and-pedestal circuits that provide AC phase con-

58 January 1980 © BYTE Publications Inc

Circle 33 on inquiry card.

Circle 34 on inquiry card. \

FOR THE VERY BEST INNORTHSTAR® COMPATIBLE SOFTWARE

DATA BASE MANAGERSSPECIAL!! $10.00 OFF of Selector-Ill C2

SELECTOR-MI C2: SuperSoft is proud to offer the Selector-Ill C2 at a special SI0.00discount. Selector III allows instant recall of any record using any information item in therecord. This makes Selector-Ill the most powerful Data Base Management System inmicro-computers todayl You can define a data format and begin entering your data inminutes. Helps bring applications on line in hours instead of months. (Note: Selector-Ill C2requires CP/M and C BASIC-2, not supplied - also 48K Ram required for some applications)Selector-Ill C2 is: $335.00 ($ 10.00 off list!). (Manual alone: $20,001

INSURANCE AGENTS

CRS - Client Record System. A complete program package for the Insurance agent. CRSwill provide you with very fast online access to your client records, print reports and maillabels, and give you all the information you will need to increase your sales through theuse of CRS as a MARKETING TOOL.

CRS stores a complete record for each client that includes the name, address, telephone#, as well as provisions for customer #, salesman ft and up to six policies (expandable, ifneeded). Write for details.

CRS comes with two(2) user's manuals, one for the owner, and one for office person-nel! (minimal system: one drive, 40K RAM starting 2000H) S250.00 (Manual: $40.00)

TEXT PROCESSORS

TFS -Text Formatting System. At last a full featured text processor for NorthStar that youcan rely onl TFS has left & right margin justification, page numbering, chaptering, pageheadings, centering, paged output & MORE. Supports powerful text manipulation inclu-ding: global & local 'search and change,' file merges and block moves. This means that

COMPUTER AIDED INSTRUCTIONMISS- Microcomputer Instructional Support System. A complete, self-contained CAIpackage applicable to home, school or business education. Includes everything needed tDcreate a sophisticated computer learning environment. MISS allows one to create any typelesson complete with wrong answer branching, re-test, and complete record keeping. Thestudent is prompted 100% of the way and need have no special knowledge. A specialfeature is the optional use of a unique algorithm which separates spelling errors from incor-rect responses. Absolutely no programming knowledge is required. MISS is completelyinteractive and maintains complete records on any number of students and lessons(limited only by disk space). MISS is a completely flexible system that will allow you toeither create lessons or to purchase pre-programmed lessons which run under MISS. Com-plete with user's manual....$40.00 {Manual alone: $10.00)

ASSEMBLERS

ARI AN - A complete 8080 assembler that interfaces directly to your DOS. ARIAN is com-pletely 'load and go'. Features include: dynamic file and RAM allocation, custom disk andRAM command capability, several library routines directly accessable by the user. Also, acomplete text editor, and system executive. ARIAN is both powerful and easy to learn anduse; it is an assembler that you can grow with. Comes complete with a 51 page user'smanual (ARIAN requires RAM from 0000H to 2000H) $50.00 (Manual alone: $10.00)ARIAN Utility Package - Several disk based utilities. Includes a complete DEBUGPackage: $50.00

PROGRAMMING LANGAUGES'Tiny' Pascal - This is famous Chung/Yuen 'tiny' Pascal. FAST - ELEGANT - STRUC-TURED. Local and global variables plus procedure and function independence make 'tiny'Pascal great for high speed applications. Compiles to 8080 code that executes up to 25

you can restructure your text file at any time to look the way you want it to, you can even times faster than BASIC. You also receive SOURCE to 'tiny' Pascal written in Pascal. This

'chain' files together from disk for documents larger than your current memory.

TFS is completely 'load and so' therefore you can start using it at once. You get two(2)user's manual: one is a Quick Start manual to get you going in minutes, the other is an indepth study of TFS. (TFS requires RAM from 0000H to 2000H) $75.00 (Manual only:$20.00)

SPEECH SYNTHESIZER SOFTWARE

'ANGLOPHONE' - Lets any 8080/Z80 computer convert ordinary English into phoneticcodes to drive Votrax, computalker, and TRS-80 Voice synthesizes. This is a hardworking,tested program suitable for use in the most demanding situations. (Details below). Inquirefor specific prices and media.

means that you can compile the compilerl Add features, relocate, etc. (you will need 36Kto do this) $40.00

UTILITIES

D E B E - (Does Everything But Eatl) This is a must for NorthStar user's. You can: COM-PACT & EXPAND BASIC programs. Compacting removes unnecessary spaces andremarks. This saves money and makes programs run faster. Expanding puts them backagain.

Cross-reference BASIC programs by variables and transfer statements.

Global substitutions of variables and transfer statements.

Formatted print outs of BASIC programs as well. $40.00

SPECIFY SINGLE OR DOUBLE DENSITY

TRS-80 COMPATIBLE SOFTWARE

'Tiny' Pascal FOR TRS-80

Now you too can have Pascall The famous Chung/Yuen 'tiny' Pascal has been speciallydesigned for the TRS-80! The full power and elegance of 'tiny' Pascal is at your command.Programs written in 'tiny' Pascal run at least 4 times faster than the same program inBASICI 'tiny' Pascal is also a great way to learn Pascal programming, & fun too.

Best of all, you only need a 1 6K Level II TRS-801 No disk is required. The 'tiny' Pascaloperating system is self-contained and very easy to use.

Tiny' Pascal is a subset of standard Pascal & includes: RECURSIVE PROCEDURE/FUNC-TION, IFTHEN ELSE REPEAT/UNTIL, 'PEEK' & 'POKE', WHILE DO, CASE, MORE! (Plus fullgraphics for your TRS-80).

You can save and load programs to and from tape in both source or compiler form.

You get all this and more, plus a user's manual for $40.00

SPEECH SYNTHESIZER SOFTWARE

'ANGLOPHONE': At last you can take complete advantage of your TRS-80 voice syn-thesizer. Forget about cumbersome phonetic codes. With 'Anglophone' you can simplyuse ordinary English. Completely interfaces with BASIC, or just about any other program-ming language. 'Anglophone' applies sophisticated pronunciation rules to transform nor-mal English spelling into speech using the TRS-80 Voice Synthesizer. Minimum hardware:Level II, 1 6K, Voice Synthesizer. Comes complete with user's manual and test program.....$45.00

Energy-Miser

Energy-Miser is a complete heating/cooling analysis program for your home, office orbusiness! With Energy-Miser you can calculate heat loss because of poor insulation, leakydoors and windows, poor planning and more. With Energy-Miser you can predict theannual savings on your utility bills for various improvements or modifications, including:use of solar power, better insulation, opening and closing drapery, etc.

But there is even more: Energy-Miser can also calculate your Return on Investment. Thatis, you can find your break point for converting to solar, for insulating better, etc. Energy-Miser even takes into consideration the Energy Tax Credit! Energy-Miser is a programdesigned to save your money!

Energy-Miser is a proven program written by a professional and includes a completeuser's manual for $22.50. (Minimum System 1 6K Level II, No Disk Required)

'TALKING TERMINAL': The 'Talking Terminal' program turns a TRS-80 into a talk-ing computer terminal. The 'Talking Terminal' program receives input from a remote com-puter and converts it to spoken words. Its many user options include: Instant Replay, spell-ed speech, silent or pronounced punctuation, and more. Minimum hardware: Level II, 1 6K,Voice Synthesizer, RS-232C board and expansion interface $145.00

1

.^^k ^^^h.

VISA

master charge]

ALL ORDERS PREPAID OR C.O.D.ILLINOIS RESIDENTS ADD 5% SALES TAX

(217) 344-7596

P.O. Box 1628Champaign, IL 61820

CONDUCTION

PUSHBUTTONCLOSED HERE

PUSHBUTTONCLOSED HERE

CONDUCTION

trol in response to an input analog voltage level.

Unfortunately, none of these analog circuits is easilycontrolled by a microcomputer. For microcomputer con-trol, something entirely different is needed.

Computer Control of the Triac

To begin, consider how to connect a microcomputer toa triac. Figure 4 shows a simple circuit for coupling amicrocomputer's output to a triac's gate. The couplingdevice is a Motorola MOC3011 optically isolated triacdriver. It consists of a light-emitting diode (LED) and anoptically coupled silicon bilateral switch (SBS).

In operation, each microcomputer-generated currentpulse through the LED produces a flash of light that trig-Figure 3: Graph of the current flowing through the triac andlamp. During each AC half cycle, the current begins to flowwhen the push-button switch is momentarily closed and con-tinues to flow until the current drops to zero. This exampleshows the push-button switch closed approximately 5 ms afterthe beginning of each 8.33 ms AC half cycle.

January 1980 & BYTE Publications Inc 59

M0C30II

o

n>

\

LED

SBS

-27

TRIACDRIVER

TRIGGER PULSE

FROM MICROCOMPUTER

Figure 4: Electrical isolation between the computer and the triacis achieved with a device containing an LED and a siliconbilateral switch (SBS).

Photo 1: Output of the synchronizer. The waveform wasrecorded with a vertical scale factor of IV per division and ahorizontal time base of lOOfis per division. Its zero is at the bot-tom line of the screen.

gers the silicon bilateral switch into momentary conduc-tion. This sends a current pulse into the triac's gate, turn-ing on the triac for the rest of that AC half cycle. The cir-cuit operates just like the push-button circuit describedearlier, except that the push button has been replaced bythe silicon bilateral switch, and the triac is now turned onby each microcomputer-generated current pulse.

Electrical isolation is an important feature of this cir-cuit. The MOC3011 permits the microcomputer to con-trol the 120-VAC lamp circuit while remaining electri-cally insulated from it.

How is the microcomputer to generate the properlytimed pulses needed to control the triac? ProportionalAC phase control requires 120 pulses per second, witheach pulse occurring at a controlled delay interval afterthe beginning of an AC half cycle. Part of this pulsegeneration can be performed by software, but there isalso an important hardware requirement. The microcom-puter can produce properly timed pulses only if it knowswhen each AC half cycle begins. That is, the microcom-puter must be synchronized to the AC power line.

This design problem has a two-step solution. The stepsare:

1. Design a circuit that generates a pulsed logic-levelchange at the beginning of each AC half cycle.

2. Use this pulsed logic-level change to signal themicrocomputer at the beginning of each AC halfcycle.

Figure 5 shows a synchronizing circuit that achieves thegoal of step 1. The circuit's output remains at logic 1(5 V), except when it goes to logic 0 for about 0.4 ms atthe beginning of each AC half cycle. This output is the

ZERO VOLTAGESWITCH

SYNCHRONIZER

OPT0ISOLAT0R

UNUSED

+ 5V FROM4 MICROCO

J—^T0

\ > MICROCOMPUTER

INPUT

ICROCOMPUTERGROUND

Figure 5: Synchronizer necessary to provide correct timing reference. 1C1 is a zero voltage switch that produces a current pulse (frompin 4) at the beginning of each AC half cycle. This current pulse is optically coupled through IC2 to pull a current pulse through R2,thus generating a momentary logic 0 at the synchronizer's output. For convenience and electrical safety, the circuit shown inside thedotted line should be built into a protected, insulated enclosure.

60 January 1980 © BYTE Publications Irrc

UUc

K'^U

MICROIPROCESi

>OR

INTERF>o

CI

TECHNIQUES

MG

TO ORDER

By Phone: (415) 848-8233. Visa,

MC, American ExpressBy Mail: Indicate quantity desired.

Include payment.Shipping: Add S1.50 per book

(UPS) or 75« (4th class- allow

4 weeks delivery).Tax: In California, add tax.

RODNAYZAKSAulsTINLESliA

Microprocessor interfacing is no longer an art. It is a set of techniques, andin some cases, just a set of components. This book introduces basic interfacingconcepts, and then presents in detail implementation techniques for bothhardware and software. It covers the essential peripherals, from keyboard tofloppy disk, as well as standard buses (SlOO to IEEE 488) and introduces basictroubleshooting techniques. Ref. C207,450pp., Third, (expanded) edition. SI 3.95

AVAILABLE AT BOOKSTORES AND COMPUTER STORES EVERYWHERE

SYBEX

Dept. Bl

2020 Milvia Street

Berkeley, CA 94704

Circle 240 on inquiry card.

BYTE January 1980 61

pulsed logic-level change required.

How is the microcomputer signaled, as required bystep 2? The answer to that question depends on how youplan to complete the design of the AC phase control.

One method is to connect the synchronizing signal toone of the microcomputer's interrupt inputs. Uponreceipt of each interrupt, the computer enters a program-timing loop to count off the desired delay. At the end ofthe delay, the program generates an output pulse to trig-ger the triac and then waits for the next synchronizing in-terrupt.

An interrupt-driven microcomputer using program-timing loops can handle very simple AC phase controlapplications, but this scheme becomes unworkable foreven moderately sophisticated programs. This is becausea wide-range power control capable of adjusting a lampfrom complete darkness to full brightness requires a tim-ing loop that runs nearly the full duration of each AC halfcycle, leaving almost no time to execute the rest of theprogram.

It would be much easier to let the microcomputer sim-ply compute a number representing the delay timerequired and leave it to a peripheral timing device toactually count off each delay time and trigger the triac.

Now such a peripheral timing device will be discussed.

The Programmable Timer

A programmable timer is a peripheral device designedfor connection to the microcomputer bus. It can be con-

FREE Catalog

New 4-way relief from problems withminicomputer supplies and accessories.

1. One-stop shopping.

I nmac (formerly known asMinicomputer AccessoriesCorporation) has a catalogof over 1000 products. Every-thing from racks and line-printer paper to connectorsand cables. Each designedto help keep your minicom-puter or word processingsystem up and running.

2. Hassle-free ordering.

I nmac lets you order bymail or phone. So keep this freecatalog close. It makes those once-tough tasks likeordering your magnetic media easy, fast and foolproof.

3. Fast shipment of just the quantity you need.Inmac ships your order within 24 hours from centers in

California, New Jersey and Texas. In a bind? Call us for themany special services that can get your products to yourinstallation even faster, with no minimum-order requirement.

4. Field-proven quality means precision performance.Inmac guarantees every product in these 70 pages for

at least 45 days. And even some for up to ten years.

JWl M Send tor your FREE

s3m mM~BfWH:U~m Inmac catalog or call^==? SSLSSJZ.SS^fJSx: (408) 727-1970 today!

2465 Augustine Drive, P.O. Box 4780, Santa Clara, CA 95051

® 1979 International Minicomputer Accessories Corporation

figured (by software) so that, driven by an external signal(ie: the synchronizing signal discussed earlier), itgenerates an output pulse after each input pulse. Itaccomplishes this with the interval between input andoutput pulses equal to a programmed delay.

This is just what is necessary for an AC phase control.A programmable timer can relieve the microcomputer ofall the processing required for delay timing and outputpulse generation. With a programmable timer attached,the microcomputer is free to run sophisticated programsthat need only load the timer with a new delay numbereach time a changed delay time is required.

To gain a closer look at the timer's operation, asimplified model will now be examined.

Figure 6 is a diagram of such a timer. In addition to itsconnections to the microcomputer bus, this timer also hasa gate input G and an output O. Inside the timer arethree addressable registers. They are:

• an 8-bit, write-only control register used toestablish the timer's operating mode (much as acontrol register configures the operation of aperipheral interface adapter (PIA));

• a 16-bit, write-only latch. Its contents are dividedinto two 8-bit bytes, called M, for the most signifi-cant byte, and L, for the least significant byte.These two bytes are placed in the latch by the pro-gram running in the microcomputer, and they maybe changed by the program at any time;

INPUT

GATE

PULSE

CONTROLREGISTER

LATCH

M L

1

>

COUNTING REGISTER

M 1 L

MICRO-COMPUTERBUS

-2 _TL

OUTPUTPULSE

Figure 6: Model of the programmable timer, showing gate inputG , output O, the connection to the microcomputer bus, and theaddressable registers. The arrows pointing from the latch to thecounting register indicate the data transfer that takes place at thebeginning of each count.

62 January 1980 © BYTE Publications Inc

Circle 36 on inquiry card.

I I * * .

^"^ 1 ■ ■ You may not have thought o

\^OmpUCOIOr JUL* personal computer. There

The personal computer forthe enterprising mind.:;:;;;;:;:;

reasons for buying a

ini'iii, household records.

sMS'rV1 That sanexceptive,and8K of user RAM

.Mile in .1 !>■

income-related applications. (ionsul

>lc, l he ii.i11

ROM. You cam

.il UOOllt .11 ions. VVl

To find <store. (ionipan

uetac "hiii)ir i<

iuxi

Programming is easy, with 16K Extended Disk MASK! capabilities storedcost software. OurSof-Disk™ programs cover a variety of exciting and

von (.in l>fii

• llll.ll I'll, ll.lll<ll<

s, and more

I Corporation

REoewnoH wlik suaaas. ramm

coupon Rflie uasza u.mwmmi

■;elo rate taim

book wlue ■statu ik 10 imim n

ACCUSED INTEREST ■■BM£||||ajFmn

fl9t ma

mama

1

(flU***1*1

>•»

Compticotor Corporation • Intecolor Drii

Pnrk/Atlnnta • Norcrosa, Georgia J0092 •Telephone 404/449«»996

Circle 37 on inquiry card.

BYTE January 1980 63

BUY ONE of these great professional books

when you join the

MINICOMPUTER SYSTEMS, Organiza-tion, Programming, and Applications.

By Richard H. Eckhouse, Jr. and L RobertMorris. 2nd Ed., 491 pp., illus. Updated, re-vised, and expanded, this is a book for everysystems programmer, systems designer,computer scientist, and application specialistwho wants to know more about microcomputerhardware, software, and design.787/026 Pub Pr., $21.95 Club Pr., $17.75

MICROELECTRONICS: Digital andAnalog Circuits and Systems. By JacobMillman. 807 pp., 700 illus. Exciting news forthe thousands of engineers who want a thor-ough refresher and updating on today's ICs.Will be welcomed by both digital and analogelectronics engineers at every level of profi-ciency.423/27X Pub Pr., $24.50 Club Pr., $19.50

AUTOMATIC DATA PROCESSINGHANDBOOK. Edited by The Diebold Group.976 pp., 269 illus. Written by a staff of interna-tionally recognized authorities on ADR thiscomprehensive handbook explains systems,programming and the languages, communica-tions processes, and the design and installa-tion of today's computers.168 /075 Pub Pr., $38.95 Club Pr., $25.75

THE Z-80 MICROCOMPUTER HAND-BOOK. By William Barden, Jr. 304 pp., illus.,paperbound. This book gives you the entire"state of the art" in microcomputer technologytoday. Arranged in three convenient and logi-cally developed sections, the book discussesarchitecture and interface signals, then power-ful interrupt sequences of Z-80 and interfacingexamples of I/O memory devices.784 /914 Pub Pr., $8.95 Club Pr, $7.60

BE SURE TO CONSIDER THESE IMPORTANT TITLES AS WELL—

APPLYING MICROPROCESSORS, New Hard-ware, Software, and Applications. Edited by L.Altman & S. E. Scrupski191 /603 Pub. Pr., $19.50 Club Pr, $15.50

57 PRACTICAL PROGRAMS & GAMES INBASIC. By K. Traclon784/957 Pub. Pr, $10.95 Club Pr., $9.30

MICROPROCESSOR ARCHITECTURE ANDPROGRAMMING. By W. F Leahy

784 /612 Pub. Pr, $19.95 Club Pr., $14.95

MICROPROCESSOR AND MICROCOMPUTERSYSTEMS. By G. V. Rao783/659 Pub. Pr., $24.50 Club Pr., $19.50

THE BASIC COOKBOOK. By K Tracton

786 /615 Pub. Pr., $7.95 Club Pr, $6.75

MICROPROCESSOR PROGRAMMING FORCOMPUTER HOBBYISTS, by N. Graham783/56X Pub. Pr, $12.95 Club Pr., $10.95

ILLUSTRATED DICTIONARY OF MICRO-COMPUTER TERMINOLOGY. By M. Hordeski

786 /631 Pub. Pr, $12.95 Club Pr, $10.95

HOME COMPUTER PROGRAMS. By J. W. Trudell,Jr. & M. Landberg

787 /042 Pub. Pr, $8.95 Club Pr, $7.60

FUNDAMENTALS OF COMPUTER AL-GORITHMS, by E. Horowitz & S. Sahni786 /380 Pub. Pr, $19.95 Club Pr, $15.95

ELECTRONICS DICTIONARY. By J. Markus404 /313 Pub. Pr, $24.50 Club Pr, $19.50

HANDBOOK OF OPERATIONALAMPLIFIER CIRCUIT DESIGN. By O F

Stout; edited by M. Kaufman. 434 pp., 223illus. Compact, concise, and highly concen-trated, this unique "one-stop" designer'shandbook contains an enormous amount ofinformation.617/97X Pub Pr., $29.65 Club Pr., $17.50

PRINTED CIRCUITS HANDBOOK.

Edited by C. F Coombs, Jr. 2nd Ed., 634 pp.,595 illus. Covering the subject of printed cir-cuits from the design's idea to final accep-tance, this enormously well-received work in-cludes double-sided plated boards throughprinted boards and also the major variationssuch as multilayer and flexible circuits.126/089 Pub Pr., $32.50 Club Pr., $24.50

PRINCIPLES OF INTERACTIVE COM-PUTER GRAPHICS. By William M. New-man and Robert Sproull. 2nd Ed., 544 pp.,illus. Now in a revised, updated Second Edi-tion, this is a volume that has long been THEstandard source of information for designers!463/387 Pub. Pr., $24.95 Club Pr., $19.95

PROGRAMMABLE CALCULATORS. By

Charles J. Sippl and Roger J. Sippl. 526 pp ,illus, 6Vi x 10 format, paperbound. Profuselyillustrated, this book analyzes pocket "pro-grammable" calculators. The authors concen-trate on the trade-up models that users willsoon be purchasing.784/493 Pub Pr., $13.95 Club Pr., $11.50

THE 8080A BUGBOOK: Microcomput-er Interfacing and Programming. By

Peter R. Rony, David G. Larsen, and JonathanA. Titus. 416 pp., with figures, charts, andtables, paperbound. Gives you the basic con-cepts of microcomputer interfacing and theassociated microcomputer I/O programmingto develop your own interfaces. For the 8080user, this book will be invaluable.783/845 Pub Pr, $9.95 Club Pr., $8.45

and GET ONE FREE (values up to $60.00)

COMPUTER PROFESSIONALS' BOOK CLUB.

ELECTRONICS ENGINEERS' HAND-BOOK. Editor in Chief, D. G. Fink. 2,704 pp.,2026 illus. Brings together in one instant-reference volume the essential principles,data, and design information known today onthe components, circuits, equipment, and sys-tems of all the various specialties that make upmodern electronics.209/804 Pub Pr, $52.50 Club Pr., S37.50

ELECTRONIC GAMES, Design,. Pro-gramming and Troubleshooting. By W.

H. Buchsbaum and R. Mauro. 335 pp., 338illus. Information you need to design, program,and troubleshoot electronic games is righthere in this widely popular hands-on guide.087/210 Pub Pr., $17.50 Club Pr, $14.00

MEMORY DESIGN: Microcomputers toMainframes Edited by LAURENCEALTMAN. 792 pp.. illus., 8V2 x 11 format Keepup" with memory chips, through this collec-tion of key articles from Electronics magazine.Data, diagrams, and discussions put all thetechnology to work for you in one authoritativebook—a volume so up to date, it's a pleasureto use.191/549 Pub. Pr., S18.50 Club Pr., S15.50

PROGRAMMING LANGUAGES. By AllenB. Tucker, Jr. 439 pp., illus. Gives you not onlythe principles of design but the applications ofsix major programming languages. Shows youtheir strengths and weaknesses in solving var-ious representative "benchmark" problems.654/158 Pub Pr, $22.00 Club Pr., $16.50

MICROCOMPUTERS/MICROPROCESSORSHardware, Software, andApplications. By John L. Hilburn and PaulN. Julich. 372 pp., illus. Expressly created forpeople involved in the design, use, or mainte-nance of digital systems using micro-computers. The authors describe the theoryand workings behind microprocessor architec-ture, read-only memory (ROM), random-access memory (RAM), and input/output in-terfacing methods.771/449 Pub Pr., $22.50 Club Pr., $16.50

LOGIC DESIGNER'S MANUAL. By JohnD. Lenk. 504 pp., illus. Written for logic ICusers rather than for designers of logic ICs,this book uses time-tested existing commer-cial logic ICs to solve all design and applicationproblems784 /671 Pub Pr., $18.95 Club Pr., $15.75

HOW TO DESIGN AND BUILD YOUROWN CUSTOM TV GAMES. By David L,Heiserman. 544 pp., illus. Shows you how tocreate and build TV games from scratch andmodify the ones you already have.786 /585 Pub Pr., $14.95 Club Pr., $11.95

MICROPROCESSORAPPLICATIONS MANUAL. By MotorolaSemiconductor Products, Inc. 720 pp., illus.,8V2X 11 format. With nuts-and-bolts practical-ity, this manual by the Motorola people (whoshould know) gives you detailed applicationsinformation on microprocessors and assumesno prior knowledge on your part about MPUs.435/278 Pub Pr., $38.00 Club Pr., $26.50

PERSONAL COMPUTING: Hardwareand Software Basics ELECTRONICBOOK SERIES. 224 pp., 175 illus., outsized8V2 x 11 format Gives you comprehensiveguidance to the present state of the art in per-sonal computers —an overall survey of thetechnology, and methods available to performvarious tasks, facts about the work others aredoing —and just how they are doing it.19V514 Pub. Pr., $14.95 Club Pr., $11.95

I (M/TH R

ENCYCLOPEDIA OF COMPUTER SCI-ENCE. Edited by Anthony Ralston and C. L.Meek. 7,500 pp., 60 illus., 100 charts, 7 x 70format. This first and only in-depth coverage ofthe entire field of computer science in a singlevolume is comprehensive and completely upto date.769/01X Pub Pr, $60.00 Club Pr., $39.95

ANALOG SYSTEMS FOR MICRO-PROCESSORS AND MINICOMPUTERS.

By Patrick H. Garrett. 248 pp., illus. Exploresall possibilities for analog systems in one ap-plications oriented volume —with many spe-cific examples.786/496 Pub Pr, $18.95 Club Pr„ $14.95

Choose any one of these books at the special club discount, andselect any other as your gift Free of Charge when you enroll.

Why YOU should join now!

• BEST BOOKS IN YOUR FIELD —Books are selected from a widerange of publishers by expert editors and consultants to give youcontinuing access to the latest books in your field.

• BIG SAVINGS —Build your library and save money too! We guaran-tee savings of at least 15% off publishers' list prices on every book.Usually 20%, 25% or even higher!

• BONUS BOOKS — You will immediately begin to participate in our

Bonus Book Plan that allows you savings between 70-80% off thepublisher's price of many books.

• CONVENIENCE -14 times a year you receive the Club BulletinFREE, fully describing the Main Selection and alternate selections,together with a dated reply card. If you want the Main Selection, yousimply do nothing —it will be shipped automatically. If you want analternate selection —or no book at all —you simply indicate it on theregular reply card and return it by the date specified. You will have atleast 10 days to decide. If, because of late mail delivery of the Bulletinyou should receive a book you do not want, just return it at the Club'sexpense.

As a Club member, you agree only to the purchase of four books(including your first selection) over a two-year period.

Computer Professionals' Book Club

P.O. Box 582, Hightstown, New Jersey 08520

Please enroll me as a member and send me tne two books indicated, oilling me tor my lirstselection only at the discounted members price, plus local tax. postage and nandhng 11not satisfied, I may return the books within 10 days and my membership will be canceled Iagree to purchase a minimum of 3 additional books during the next 2 years as outlinedunder the club pldn described in this ad Membership m the club is continuous butcancellable by me any time after the tour book purchase requirement has been fulfilled

Write Code # ol Write Code # of

FREE selection here FIRST selection hete

Orders trom outside the U S must be prepaid with international money orders in u S

dollars

Charge my I i VISA! I MASTER CHARGE-Exp Date

Credit Card # .

Signature

Name

Address

City. Slate. Zip .

•MC Bank #

Corporate Affiliation

This order subject to occeptonce by McGraw-Hill All prices subject to chonge withoutnotice Offer good only to new members A postage and handling charge 15 added to allshipments P39450

• a 16-bit, read-only counting register. A momentarylogic 0 at the timer's gate input causes this registerto be loaded with bytes M and L from the latch. Thecounting register then decrements on each cycle ofthe microprocessor clock. When the count reacheszero, a voltage pulse is delivered to the timer's out-put. Details of this operation will be describedshortly.

For this application, the synchronizing signal should beconnected to the timer's gate, and the timer's output usedto trigger the triac.

Now examine the timer in detail by stepping throughone cycle of its operation:

1. Upon receipt of a momentary logic 0 at its gate, thetimer loads its counting register from the latch(without changing the number stored in the latch). If itis not already low (logic 0), the timer's output goeslow.

2. The output remains low for an interval equal to(M + 1)L + 1 periods of the microprocessor's clock. At

the end of this interval, the timer's output goes high(logic 1).

3. The output remains high for L periods of themicroprocessor's clock. At the end of this time, theoutput again goes low.

4. The output remains low until another momentarylogic 0 at the gate starts the cycle again.

This timing sequence is illustrated in figure 7 and exampleoutputs are shown in the photo 2 sequence.

For this application, it is convenient to make L a fixedquantity and let M range from hexadecimal 00 to FF. Thischoice allows you (1) a fixed output pulse width LT,regardless of the delay chosen, and (2) program controlof the timed delay by specification of a single 8-bit byteM.

How is the size of L chosen? The time for one completecycle of the timer is:

Timer cycle = Delay time + Output pulse width= [(M+1)L + 1]T + LT= (M + l) (L+1)T

00

40

80

CO

FF

timer output pulses

hexadecimaltimer value

lamp voltage

Photo 2: This series of photos shows how the timer's output pulses lag behind those from the synchronizer and how the alternatingvoltage across the lamp is determined by the delay value contained in the timer latch. The numbers indicate the hexadecimal value.The top row of photos shows how the timer's output pulses lag those from the synchronizer by a time proportional to the delay value.The synchronizer's output is the series of negative pulses across the top half of the screen, while the timer's output is the series of briefpositive pulses (blips) across the bottom half. Both waveforms were recorded with a vertical scale factor of 2V per division and ahorizontal time base of 2ms per division. The synchronizer's output has its zero at the screen's horizontal center line, while the timer'szero is at the bottom line.

The bottom row of photos shows the alternating voltage across the lamp as determined by the delay value in the timer's latch. Thewaveforms were recorded with a vertical scale factor of 50V per division and a horizontal time base of 2ms per division.

-input

GATEPULSE

r

OUTPUTPULSE

-[IMtl)Ltl]T-

-LT-

Figure 7: Timer input and output pulses in the single-shot, dual8-bit operating mode. The output pulse begins at time t=[(M+l)L + ljT after the input gate pulse, where:

M= most significant byte loaded from the timer latch into

the counting register

L = least significant byte loaded from the timer latch into the

counting register

T= period of microprocessor clock

66 January 1980 © BYTE Publications Inc

Now...You, the small systems user can enjoythe advantages of HI-performancelo^c^ computer graphics

The perfect small system output device

Displays data in easy to read

graphical format

Both serial and parallel inputs

built-in.

Used standard 8Vi" x 11" paper

(DIN A4)

Plotting speed up to 2.4 Ips (60

mm per sec)

Resolution of both 0,01 and 0

The perfect small system Input device

Resolution and repeatability of0.005 In. (0.1 mm)Origin is completely relocatableRS232C and 8 bit parallel inter-face selectable at the connectorAccuracies of ± 0,015 in. (0.4 mm)Optional LC display shows a<

For complete Information contactHouston Instrument, One HoustonSquare, Austin, Texas 78753.(512)837-2820. For rush literature re-quests persons outside Texas calltoll free 1-800-531-5205. In Europecontact Houston Instrument,Rochesterlaan 6, 8240 GistelBelgium. Phone 059/27 74 45.

DIVISION OF MUMHSlOMlO

"the graphics • recorder company"

Circle 38 on inquiry card.

TM Trademark of Houston Instrument'U.S. Domestic Price Only

y Vgjr

If the maximum value of M is hexadecimal FF or decimal255, then the maximum time for one cycle of the timer is:

[Timer cycle ] = 256 (L + l) T

1 ' max

Each AC half cycle has a duration of 8333 /is. If youwish one cycle of the timer at maximum delay to justequal one AC half cycle, you must have:

8333 us = 256 (L + l) T

which requires that:

T _ 8333 us

256 T

- 1

The value picked for L clearly depends on the period Tof the microprocessor clock. For example, if the clockperiod is 2.5 us (for a 400 kHz clock), the computed valuefor L is:

8333 /is256 (2.5 us)

— 1 = 12 = hexadecimal 0C

Using this computed value for L does not work in prac-tice. This is because an intentional, small delay in thesynchronizer causes the timed cycle actually to beginabout 100 fis after the start of each AC half cycle, thusslightly reducing the time remaining in the half cycle forthe timer to operate. However, for this particular exam-ple, a value of L = 11 = hexadecimal OB does work well.

For this example, the timer's output pulse widththerefore is:

LT = 11 X 2.5/*s = 27.5us

Programmable Timer Module

Up to now you have been examining a slightly simpli-fied model of the programmable timer. Now concernyourself with a real device, the Motorola MC6840programmable timer module. Figure 8 is a pin-assign-ment diagram for the MC6840.

Each timer jn the MC6840 has its own gate input (pins

Gl, G2 and G3) and its own output (pins Ol, 02 and03). For this application, the synchronizing signal shouldbe connected to all three gate inputs, and the individualtimer outputs used to trigger three separate triacs. Figure9 shows how each timer output should be connected tothe AC circuit it controls. With the MC6840's three inde-

1

V CI

62 01

02 GlC2 D0

63 Dl

03 D2C3 03

28

2

27

3

26

4

25

5

24

6

23

7

22

8

21

RESET D4IRQ 05RSO 06RSI D7RS2 ENABLER/W CSIVcc CSO

9

20

10

19

II

18

12

17

13

16

14

15

Figure 8: Pin-assignment diagram for the Motorola MC6840programmable timer module.

AC PHASE CONTROL

+ 5V FROM

MICROCOMPUTER

MT2

TRIACSCI42B

FROM TIMEROUTPUT

R5

lOOil

■ C3*0.l/iF600V

<D

I20VAC60 Hz

I

LAMP

<J

Figure 9: Circuit for connecting one timer output to the AC circuit it controls. The AC phase-control circuit contained within the dot-ted lines should be built into a metal box, and the triacs isolated mounting tab securely fastened to the inside wall of the box.(Substitution of a different triac without the isolated mounting feature will require the use of special mounting hardware to electri-cally isolate the triac from the wall of the enclosure.)

68 January 1980 © BYTE Publications Inc

Circle 39 on inquiry card.,

26 MEGABYTES$4995.

Suddenly, S-100 microcomputer systems can easily handle 100 millionbytes. Because Morrow Designs™ now offers the first 26 megabyte hard diskmemory for S-100 systems-the DISCUS M26™ Hard Disk System,

It has 26 megabytes of useable memory (29 megabytesunformatted). And it's expandable to 104 megabytes.

The DISCUS M26™ system is delivered complete-a 26 megabyte hard disk drive, controller, cables and operating system-forjust $4995. Up to three additional drives can be added, $4495 apiece. !

The DISCUS M26™ system features the Shugart SA4008Winchester-type sealed media hard disk drive, in a handsome metal cabinetwith fan and power supply.

The single-board S-100 controller incorporates intelli-gence to supervise all data transfers, communicating with the CPU viathree I/O ports (command, status, and data). The controller has the ability togenerate interrupts at the completion of each command to increase systemthroughput. There is a 512 byte sector buffer on-board. And each sector can beindividually write-protected for data base security.

The operating system furnished with DISCUS M26™systems is the widely accepted CP/M* 2.0.

See the biggest, most cost-efficient memory ever intro-duced for S-100 systems, now at your local computer shop. If unavailablelocally, write Morrow Designs,™ 5221 Central Avenue, Richmond, CA 94804,Or call (415) 524-2101, weekdays 10-5 Pacific Time.

*CP/M is a trademark of Digital Research.

Q /MORROW DESIGNS™

Thinker Tbys

■EWBB

Registerselect Inputs

Operations

RS2

RS1

RSO

R/W = 0

R/W = 1

0

0

0

CR2 bit 0 clear:CR2 bit 0 set:

Write CR3Write CR1

No operation

0

0

1

Write CR2

Read status register

0

1

0

Write M buffer register

Read M of counter 1

0

1

1

Write L of latch 1

Read L buffer register

1

0

0

Write M buffer register

Read M of counter 2

1

0

1

Write L of latch 2

Read L buffer register

1

1

0

Write M buffer register

Read M of counter 3

1

1

1

Write L of latch 3

Read L buffer register

Table 1: Register selection in the MC6840 programmable-timermodule.

pendent timers, it is possible to control three different ACcircuits.

Each timer in the MC6840 also has its own external-clock input (pins Cl, C2 and C3) for use whentimer-counting frequencies different from that of themicroprocessor clock are needed. The external-clock in-puts are not needed in this application.

Table 1 describes register selection in the MC6840. TheMC6840 contains ten addressable registers. Nine of theseare the control registers, timer latches, and countingregisters for the three timers. The tenth is a status registercontaining interrupt flags. The status register will not beused.

The three register-select inputs RSO, RSI, and RS2should normally be connected to the microcomputer'slow-order address lines AO, Al, and A2 respectively.Because the control registers and the timer latches are allwrite-only registers, while the counting registers and thestatus register are all read-only registers, the R/W inputin effect serves as a fourth register select line. This featureprecludes the use on MC6840 registers of any MC6800processor instructions that operate directly on memory.Examples of such instructions are INC (increment), DEC(decrement), and CLR (clear).

The next section examines in detail how the MC6840 isprogrammed for proportional AC phase control.

System Power-Up

A system power-up or a momentary low-logic level onthe MC6840's RESET line causes the following actions:

• All three timer outputs are set low.

• All three timer latches are preset to hexadecimalFFFF, and the three counting registers are loadedfrom the latches.

• All three control registers are cleared, except thatbit 0 of control register 1 is set. Setting this bitcauses all three counting registers to be held in theirpreset state, so that the timers do not run.

Timer Initialization

The MC6840 is a versatile device with several

operating modes. This application requires that eachtimer in the MC6840 be configured for single-shot dual8-bit operation. The MC6840 is initialized for this appli-cation by loading hexadecimal B6 into control register 3(CR3), hexadecimal B7 into control register 2 (CR2), andhexadecimal B6 into control register 1 (CRl).

The order in which these registers are loaded is impor-tant. Control registers CR3 and CRl share a singleaddress space, with bit 0 of CR2 selecting whether controlregister CR3 or CRl is accessed (CR2 bit 0 cleared selectsCR3; CR2 bit 0 set selects CRl).

For example, if control registers CR3 and CRl shareaddress hexadecimal 8000 and CR2 occupies address8001, then (recall that CR2 bit 0 is cleared on systempower-up or RESET) an appropriate initialization se-quence is the following sequence of MC6800 instructions:

LDA A #$B6

LDA B #$B7

STA A $8000

STA B $8001

STA A $8000

Control word for CR3 and CRlControl word for CR2

Configure timer 3Configure timer 2Configure timer 1

Loading the Timer Latches

With the MC6840 initialized and the program running,the brightness of each lamp is controlled by the numberstored in its associated timer latch. If not disturbed, thesenumbers remain unchanged, and the lamps glow withconstant brightness. To change the brightness of anylamp, it is necessary only to load a new number into itstimer's latch.

It is important that the two bytes of each timer latch beloaded in the proper order. Although table 1 may leadyou to believe that the most significant bytes of the threelatches have three different addresses, in reality thesethree addresses lead to a single 8-bit buffer. To load aparticular latch, this buffer register must first be loadedwith the most significant byte. Then, when the leastsignificant byte is loaded into space L of the latch, thebuffer's contents are automatically transferred to thelatch's space M.

70 January 1980 © BYTE Publications Inc

I

Li

SO RELIABLE WE GIVE YOU

360 361 362 363 364

355 356 357 358 359

350 351 352 353 354

345 346 347 348 349

340 341 342 343 344

335

336

337

338

339

330

331

332

333

334

325

326

327

328

329

320

321

322

323

324

315

316

317

318

319

310

311

312

313

314

305

306

307302

308303

309

300

301

304

295

296

297

298

299

290

291

292

293

294

285

286

287

288

289

280

281

282

283

284

275

276

277

278

279

270

271

272

273

274

265

266

267

268

269

260

261

262

263

264

255

256

257

258

259

250

251

252

253

254

245

246

247

248

249

240

241

242

243

244

235

236

237

238

239

230

231

232

233

234

225 226 227 228 229

WARRANTY

TOTAL PEACE OF MIND.

We are business people, just like you. We wouldn't stick ourneck out unless we were certain we could back our claims andpromises to the last letter. We wouldn't offer a legally bindinglong-term warranty on our Microtek MT-80, unless we werepositive of Its solid reliability.

We are sure that our versatile, alphanumeric line printer willprovide you consistent, dependable performance. This is whywe give you,not the usuarSO-days in fine print, but an incredible365-days warranty. We stand behind every product we make.

LOADED WITH INNOVATIONS

• 40, 80 or 120 columns (software selectable)

• Non-thermal paper, pin feed

• 125 CPS, 70 lines per minute

• 9 x 7 dot matrix

• Vertical format unit

• 96-character ASCII (upper and lower case)

• Adjustable forms width to 9Vz"

• Parallel, serial (RS-232C), and IEEE-488interfaces available

OUR UNIT PRICE

$750. Parallel

$835. Serial (RS-232C)

$895. IEEE-488

For more information contact:

MICROTEK, Inc.7844 Convoy CourtSan Diego, CA92111Tel. (714)278-0633

Circle 40 on Inquiry card.

For example, suppose the three timer latches occupyhexadecimal addresses 8002 through 8007, and areassigned as follows-.

Ml: 8002LI: 8003

M2: 8004L2: 8005

M3: 8006L3: 8007

If you wish to load Ml, M2, and M3 with new delaynumbers DELAY1, DELAY2, and DELAY3 but leave Ll,L2, and L3 unchanged with hexadecimal IE stored ineach, the program sequence that would accomplish this

LDA A DELAY1

LDA B #$1E

STA A $8002

STA B $8003

Controlled Fading

Proportional AC phase control is most interestingwhen it is used to fade lamps on and off at controlledrates. This has application to theatrical lighting control,planetarium operation, and control of multiple projectorsin a slide show.

Controlled fading may be accomplished by using aprogram-timing loop to slowly increment or decrement adelay number toward some final value set by the pro-gram. The fading stops when the final value is reached.Fading up or down resumes when the program sets a newfinal value.

The basic timing element can be either the micro-processor's clock or a 120 Hz interrupt signal producedby the synchronizer. Of these two choices, I prefer thelatter, simply because it is much slower and thereforeeasily used to achieve slow fading rates.

But even 120 Hz is too fast. If the delay number isdecremented 120 times per second, a lamp fading fromcomplete darkness (DELAY = FF) to full brightness(DELAY = 00) will do so in only 2.1 seconds.

An intermediate register is needed, one which may beincremented or decremented 120 times per second and thecarry or borrow generated is used to increment or decre-ment the delay number.

LDA A DELAY2STA A $8004STA B $8005

LDA A DELAY3STA A $8006STA B $8007

It is important to understand that, even though Ll, L2,and L3 remain constant, it is not possible to avoidreloading a latch's least significant byte each time youwant to change its most significant byte. There is noother way to access the most significant bytes of the timerlatches.

Summary

You have been introduced to the basic principles ofproportional AC phase control; seen how a triac is usedfor this purpose and how a programmable timer may beused to drive the triac; and looked closely at theMotorola MC6840 programmable timer module con-figured for this application. A method of using a programtiming loop to slowly fade a lamp up and down inbrightness has been outlined. You now have all the infor-mation necessary to try this on your own.

In part 2 of this article I shall create a program and cir-cuit example on the Heathkit ET-3400 microprocessortrainer that will perform the lighting control functionsdiscussed so far.H

I The [

GIVE YOUR APPLE VISION FOR CHRISTMAS!

DS-65 Digisector® opens up a whole new world for your Apple II. Your computer can now be a part of the action, taking pictures to amuse youifriends, watching your house while you're away, taking computer portraits . .. the applications abound! The DS-65 is a random access video digitizer.It converts a TV camera's output into digital information that your computer can process. The DS-65 features:

• High resolution: 256 X 256 picture element scan• Precision: 64 levels of grey scale

• Versatility: Accepts either interlaced (NTSC) or industrial video input• Economy: A professional tool priced for the hobbyist

The DS-65 is an intelligent peripheral card with on-board software in 2708 EPROM.Check these software features:

• Full screen scans directly to Apple Hi-Res screen

• Easy random access digitizing by Basic programs

• Line-scan digitizing for reading charts or tracking objects

• Utility functions for clearing and copying the Hi-Res screen

Let your Apple see the world!

DS-65 Price: $349.95

Advanced Video FSII Camera Price $299.00

SPECIAL COMBINATION PRICE: $599.00

your I

APPLE SELF-PORTRAIT

P.O. BOX 1110 DEL MAR, CA 92014 714-942-2400

J

72 January 1980 © BYTE Publications Inc

Circle 41 on inquiry card.

ILL TO

Wmmmsimm]

im

Zinffl vds-ii

HilllllllllHI

SYSTEM INCLUDES:

2 Siemens 8" Disk Drives

- 1 Cabinet with Fan andPower Supply.

- 1 Tarbell Floppy Disk Inter-face, assembled & tested.

- 1 CP/M Disk Operating Sys-tem.

1 Tarbell BASIC.All Cables and Connectons.Complete User Documenta-tion.

Fully factory assembled andtested.

VDS-II Single Density . . .$1888VDS-IID Double Density $1999

^*&^

^^S^^%^^

TARBELL DOUBLE DENSITY INTERFACE FOR 8" FLOPPY DISK

Under Tarbell Double-Density CP/M, single and double density disks may be intermixed. The system automaticallydetermines whether single or double density is in place.

• Software select single or double density.•Phase-locked-loop and write precompensation for

reliable data recovery and storage.•On-board phantom bootstrap PROM is disabled afterbootstrap operation so all 64K memory address space isavailable to user.

• DMA in single or double density permits multi-user oper-ation.

• Extended addressing provides 8 extra address bits, per-mitting direct transfers anywhere in a 16 megabyteaddress range.

•Select up to 4 drives, single or double-sided.

• New BIOS for CP/M included with interface on single-density diskette.

Double Density Interface only, assembled & tested $425.

CP/M is a registered trademark of Digital Research.

950 DOVLEN PLACE -SUITE B • CARSON, CALIFORNIA 90746(213) 538-4251 • (213) 538-2254

Circle 42 on inquiry card.

BYTE January 1980

73

A Furnace Watchdog

Theron Wierenga

POB 2007Holland MI 49423

Having recently moved into a newhome and being a home computer en-thusiast, I naturally began looking foran application for my homebrewmicrocomputer. During the bigsnowstorm of January 26,1978,1 wassnowed in for four days. This situa-tion encouraged the development ofseveral ideas.

With forty-eight km (thirty mile)per hour winds producing 1.8 to 2.4m (six to eight foot) snowdriftsalongside of the house, and withemergency food source informationbeing broadcast on the local radio

station, it was natural that I began tothink about the heating system in thehouse. During a conversation withmy wife several questions arose, andwe dug out an information bookletthat had been supplied with the fur-nace. We also began to record the fur-nace on-off cycles.

More questions arose. How longwas the burner on? What were thecycle times? How much gas did itburn per cycle, and what was the costof this gas7 What would be the effectif I used my fireplaces for heating?How much would additional insula-

tion help, and did it really help toturn the thermostat down at night?

It became obvious that the onlyway to answer these questions wouldbe to monitor the burner cycles of thefurnace on a continual basis. Thisseemed to be an ideal task for myhomebrew 8080A microcomputer. Bythe time the storm had ended, mynotebook contained schematicdiagrams of all the additional cir-cuitry that would be needed to inter-face the furnace burner to the com-puter, and the first drafts of thenecessary software were written.

Photo 1: Interior of the gas furnace. The computer interface cir-cuit board is at the lower left, just to the right of the light greenpaper tag. The gas solenoid is slightly above the center of thephotograph.

Photo 2: The author's homebrew 8080A-based microcomputersystem. Two circuit boards of interest have been removed fromthe card cage and are displayed in the foreground. The real-timeclock and cassette interface board is on the left; the program-mable read-only memory board is on the right.

74 January 1980 © BYTE Publications Inc

About the Author:

Therein Wierenga is a thirty-four-year-oldassistant principal at Muskegon High Schoolwhere he formerly taught physics and com-puter science. His undergraduate degree inphysics is from Hope College, Holland MI. Hismaster's degree is in educational leadershipfrom Western Michigan University.

He has worked during summers atBrookhaven National Laboratory, and for thePLATO group at the University of Illinois atUrbana.

His recreational interests are early US postalhistory and electronics. He has designed andbuilt many electronic projects, including ahomebrew 8080A computer system and anAltair 8800 system. He is presently working ona Mite printer mechanism for a hard copy I/Odevice. His primary enjoyment comes frombuilding hardware.

Computer

The microcomputer which wasused is unique. It was assembled be-tween May 1977 and January 1978,and uses the 8080A microprocessor.The circuitry was packaged on fourAVi by 6 inch (11.43 by 21.24 cm)wire-wrap boards joined by amotherboard using standard 44-pin, double readout edge connectors on0.156 inch (0.402 cm) centers. Thefour boards consist of:

8080A central processor, busdrivers, and a serial I/O (input/out-put) port using the Intel 8251 pro-grammable communication interface.

4 K byte programmable memoryusing 21L02-type static memorydevices.

8 K byte programmable read-onlymemory using Intel 2708 circuits.

Real-time clock, Kansas City for-mat cassette interface, and a parallelI/O port.

After some effort and a little hairpulling, it was possible for me tosqueeze a copy of ProcessorTechnology's 5K BASIC into six2708-type programmable read-onlymemories. A monitor (which residesin another 2708) contains routines toload memory, display memory, jumpto a specified address, and begin pro-gram execution. The monitor can alsofill blocks of memory, move blocks ofmemory, set the real-time clock, readthe real-time clock, print the currenttime on the terminal, record pro-grams on cassette, and play back pro-grams from cassette.

UP TO 2400 MEGABYTESOF HARD DISK CONTROLFOR THE S-1OO BUS

SMC-100

CDC PHOENIXCDCMMD

Konan'm SMC-1OO la veraatlle, famt, coat efficient. It'a thedlak controller that brlnga 8-10O bua micro computeretogether with large capacity hard dlak drlvea.

Versatile

Interfaces S-100 bus microcomputerswith all fixed or removablemedia disk drives with storagemodule (SMD) interfaces. EachKonan SMC-100 will control up to 4drives ranging from 8 to 600megabytes per drive, including most"Winchester" type drives. Up to 2400megabytes of hard disk percontroller! And you can take yourpick of hard disk drives: Kennedy,Control Data, Fujitsu, Calcomp,Microdata, Memorex, and Ampex, forexample.

Faat

SMC-100 transfers data at fast, 6 to10 megahertz rates, with full onboardsector buffering and sectorinterleaving, and a DMA that's fasterthan other popularS-100 DMAcontrollers.

Coat efficient

SMC-100 is priced right to keep yourmicro computer system micro-priced.It takes advantage of low-cost-per-megabyte disk drive technology tomake the typical cost less than $80per megabyte.

The OEM/Dealer single quantity priceis only $1650, with driver ROM option.Excellent quantity discounts areavailable.

SMC-100 availability:

Off the shelf to 30 days in smallquantities. (Complete subsystemsare on hand for immediated delivery.)

Konan has the'answers. Talk to themtoday. Call direct on Konan's ordernumber: 602-269-2649. Or write toKonan Corporation, 1448 N. 27thAvenue, Phoenix, Arizona 85009.

1448 N. 27th Avenue • Phoenix, Arizona 85009 • 602-269-2649

Circle 43 on inquiry card.

January 1980 © BYTE Publications Inc 75

Circle 44 on inquiry card.

Pick yourApple indowntownChicago.

Mail order buying is fine for books.But here you get to work withactual machines, feel what they'relike, make a hands-on decision,and get instant delivery, to boot.

No waiting.

As one of Apple Computer's topnational dealers, we maintain acomplete stock of hardware, soft-ware, courteous help, servicewhen needed, and total supportall the time. We make sure yournew computer works right be-fore you take it home, that theinterfaces and peripherals work,that you understand the documen-tation, that the bugs are gone,and that you get everything youwant. It's all here. Right now.

English spoken.

We speak all the popular computerlanguages, except gobbledegook.We also happen to be especiallyskilled at the language of value.For your home or your business.

Money talks.

For instance, this month's specialis an entire Apple II Plus "BusinessManager's System" (Apple II is atrademark or Apple Computer,Inc.) for the price of the hardwarealone. It means you get the AppleII Plus computer with 48K ofRAM, two disk drives, a 9" videomonitor, a Centronics 779 printerand controller, plus all the top-quality turn-key business soft-ware in the "Controller" package,regularly $625. The whole $4,995value is yours for just $4,370!

REM PLENTY MORE.

In fact, you could think of all theApple II hardware and softwareadvertised elsewhere in this publi-cation as a kind of catalog for ourcomfortable new store. Thencome on in and check it all out inperson. (Too bad if you don't livein Chicago or the suburbs. Comeon vacation.) 106 E. Oak St.,Chicago, 111. 60611 (312) 337-6744.

THECOMPUTERROOM

MCT-20PT0IS0LAT0R

Figure 1: Electronic circuit that allows the computer to tell whether the furnace burner ison or off. The mercury switch is contained in the thermostat, and is connected in serieswith the gas solenoid and a source of 28 VAC electricity. The voltage difference be-tween the contacts of the mercury switch is 28 VAC when the switch is open (when thefurnace burner is off), and 0 VAC when the switch is closed (when the burner is on).When the furnace is off, the phototransistor in the optoisolator conducts in its saturatedmode. When the furnace is on, the phototransistor does not conduct.

' • 1 * • 111 i'i lYi'

The only additional necessaryhardware was a simple interface tothe furnace that the computer couldread to determine whether the burnerwas on or off.

Monitoring Hardware

The only information from the fur-nace needed by the computer iswhether the burner is on or off. Thiscould be supplied to the processorthrough 1 bit of a parallel input port.Since the computer has a real-timeclock, it can then calculate the lengthof time the burner is on and theamount of gas used. I timed the gasmeter over several long periods andfound that the furnace took seventeenseconds to burn a cubic foot (28.32liters) of gas. This measurement wasconfirmed by figures supplied by themanufacturer of the furnace.

Figure 1 shows how I obtained theone logical bit of information (on oroff) from the furnace circuitry. Thegas solenoid is connected to a 28 VAC source by the mercury switch inthe thermostat. The bimetallic coil inthe thermostat tips the switch on asthe room temperature decreases, andtips it off as the temperature in-creases. The contacts of the mercury

switch show 28 VAC when open (fur-nace burner off) and 0 VAC whenclosed (burner on).

When the burner is off, the 28 VAC signal is passed to a bridge rec-tifier made of diodes Dl thru D4. Thepulsed DC current is smoothed bycapacitor Cl and flows through thelight emitting diode (LED) in the op-toisolator (OPTO-1), saturating thephototransistor. When the mercuryswitch closes, no current flowsthrough the LED, and the phototran-sistor will be in the nonconductingstate.

If you have a parallel input portavailable (actually only one bit of an8-bit port is needed), you need onlyconnect point A of the circuit to theinput of the least-significant bit (LSB)of the port and point B to the systemground. A 1000 ohm pull-up resistorto the +5 V supply should also beconnected to the input. A twisted pairof wires can be used to connect thecircuitry in the furnace with the inputport on the computer.

My computer did not originallyhave a parallel input port, so I had toconstruct a simple one with aminimum of parts. Referring to figure2, an 8T95 three-state buffer was

76 January 1980 © BYTE Publications Inc

Micro DaSys Software™ -CP/M™ Compatible

The Pencil Sharpener™ - Now with subscripts and superscripts! Theform letter merge utility for the Electric Pencil II. $195. order code: psi.

Osborne Accounting Packages. Complete CBASIC 11 source disk-ettes of the best accounting software at the lowest price. AccountsPayable, Receivable, Payroll and General Ledger. $99 each, order codes:

APO,ARO,PCO,CLO.

6800 and 6809 Cross Assemblers for 8080 and Z80 CP/MSystems. Full Mnemonic assemblers with complete options specificationand output formatting. $89 each. Order codes: asm68, asm69.

For all software specify format: 8", 5" North Star, 5" Micropolis.

Wo NiMM.I Your lld-p!

An International Company Called Micro-

ys has designed a dynamite solution for thesmall businessman seeking a computer. We call it the"millie"TMp it's a system that combines the absolutebest business software available with fast, dependablehardware.

The "millie" is the smartest buy a smallbusiness can make, it comes with the most

powerful accounting, word processing and applica-tions software available. And to take advantage ofthat power, the "millie" uses the S-100 bus, eight inchdisk drives and the universal CP/M* operating system,It can be programmed in BASIC, FORTRAN, Pascaland dozens of other languages. Best of all, "millip"prices start at under $3000. The one illustrated in-cludes a reproduction-quality printer and full accoun-ting and word processing software for just Sf/vt-',"Millie" has been in use for over a year in the US,Europe, South America and Australia. It is a provendesign, regularly updated as the state-of-the-art ad-vances.

But an international company can't knock

on doors. Without branch offices in every city ofthe US (and the world) we have the same problem asdozens of other computer manufacturers, We simplycan't contact all of the small businessmen who couldbenefit from our "millie". That's where you come in,

We seek your help. Sell our "millie" as a com-plete, integrated system to your neighborhood busi-nesses, universities, writers and other professionals. If

you're reading this magazine you probably have allthe expertise required to demonstrate and sell"milties". All that's really required is the motivation toseek out prospective customers and the ability to pre-sent "millie's" features to them in a way most under-standable to them Put us in your customer's place.

We offer you a piece of the exciting computermarket, the chance to work with the most sophisti-cated software and hardware available, and best ofall, a handsome commission and no minimum pur-chase requirements (not even one!)

It's easy to sell "millies". You will be supportedby an international advertising campaign, a deperdable system made by a well known manufacturer,and the best documentation available. All you need isthe enterprise to seek out new customers and providethem with the support they need (perhaps earning yourown consulting fees) during and after installation. Wewill even supply you with potential sales leads in yourarea — Reader Service Questionaires, Direct Mail In-quiries, and Telephone Responses. Ihese are peolewho want you to sell them a "millie"1 All you need todo is act!

You've got nothing to lose! there are abso-lutely no strings, no minimum purchases, no specialdegrees or instruction required, no retail store neces-sary All that is required is the sincere desire to earnmoney selling our computers, join the fascinating fieldof computer sales now. The market is ready if you are!Write or call today for your introductory salespackage and complete info.

MicroDaSys S-100Products

8P2SM I/O Card. Eight 8-bit parallel I/Oports with handshaking, one serial RS-232 I/Oport, one modem I/O port. Kit $149,

Assembled $199. Order Codes 8P2SMK, 8P2SMA.

MD690a S-100 6800 CPU card, iok

PROM space, 1K RAM, 2400 baud cassette in-terface, 2 Parallel I/O Ports. Kit $198, Assembl-ed $258. Order Codes: MD690aK, MD690aA

New!

ColorMaster'" 80 x 25 Full Color

Memory-mapped Video Board. Kit $399,

Assembled $499. Order Codes: CMK. CMA.

4P4S I/O Card. Four 8 bit parallel I/O portswith handshaking, four serial RS-232 or TTLI/O ports. Kit $199, Assembled $249. Order

Codes: 4P4SK, 4P4SA.

Super Z™ - The amazing system on a board.Z80 Processor, two parallel I/O ports, serialRS-232 I/O port, counter/timer, 2708/2716EPROM, and 48K Dynamic Ram -All on onecardl Assembled only $950. Order Code: sz.Manuals for hardware and software are $15,creditable towards purchase.

6809!

Single Board Computer

S-100 Compatibility.6809 Computability

• 1K RAM • RS-232 level shifters

• 10K PROM space • 20 I/O lines

• Parellel keyboard input

• Memory-mapped video firmware

• Fully S-100 compatible(including 8080 type I/O)

• MONBUC II monitor included *

• 2400 baud cassette interface

$299 Assembled$239 Kit •

Order Codes:MD690bAMD690bK

For distribution in the Netherlands contact.Computer Programming lnterantion.il BVBurn Penstraat 1, Postbus 288. 3740AG Baarn,

t CP/M is a registered trademark of Digital Re

Circle 45 on inquiry card.

<r

Figure 2: A simple input port that can beused to transfer one bit of informationconcerning the furnace status to the com-puter. The address of this input port ishexadecimal OD, determined by the eight-input NAND gate and the inverter.

Number Type

+ 5V

GND

IC1

8T95

16

8

IC2

74LS30

14

7

IC3

74LS00

14

7

IC4

74L04

14

7

IC5

74LS02

14

7

PORTOD

*6 O

A40

12

«l[>

76~r Q>-

IC474L04

A[Z>

IC18T95

PROCESSORDATA IN

^

74LS02

2 I IC5a JO-

■O>D0

S-100BUS

INP 46

DBIN |78II

-| > I/O R

THIS GENERATES THEI/O R ON THE S-100 BUS

Listing 1: The "watchdog" program, written in Processor Technology 5K BASIC. Oncestarted, this program loops continuously, monitoring the status of the furnace andprinting summary data as required. A flowchart is shown in figure 3.

10

REM =

FURNACE

UATCHD0G

12

REM -

TO BE STARTED UITH

FURNACE OFF

20

DIM M

2(12)

22

19=0;

J9=0;G2=.

21149

24

PRINT

'INPUT M0NTHrDAY"

28

INPUT

M9,D9

30

PRINT

•LAST DOLLAR TOTAL1'

35

INPUT

K

40

PRINT

JPRINT

41

REM -

GET TIME

42

GOSUB

600

43

S2=S

44

REM -

STORE »

DAYS IN M0NTK

43

FOR C

=1 TO 12

4A

READ

M2(C)

48

DATA

31,28,31

30,31,30,31

,31,30,31,30,31

4?

NEXT

C

50

L=0

55

REM -

LOOP TO

READ INPUT

PORT 14

60

T=0

70

FOR C

=1 TO 10

80

Z=CALL<12074)

Listing 1 continued on page 80

used, as the data bus in the computeris bidirectional. A 74LS30 8-inputNAND gate and a single inverterdecode the input port address, whichis 0D hexadecimal or thirteendecimal. The I/O R signal from theIntel 8228 bus driver gates the inputsignal onto the bus. This I/O R signalcan be duplicated in an S-100 busmachine by NANDing the input in-struction (INP) signal from pin 46together with the DBIN signal on pin78.

Real-Time Clock

Before I begin to describe the soft-ware used, a few words about thereal-time clock will be useful. Thereal-time clock that is used is my owndesign, and is unique to this com-puter. Any type of real-time clockcould be used in the system. It makesno difference whether or not it usesextensive hardware, software timingloops, interrupts, etc— as long as theprocessor can obtain the time uponrequest and be able to convert this in-to the time of day in absolute dailyelapsed seconds (ie: time of day00:00:00 equals 0 seconds, time02:03:04 equals 2X3600 + 3X60 +4 = 7384 seconds and time 23:59:59equals 86,399 seconds). A subroutineis used in the BASIC program (inlisting 1) beginning at line 600 toderive the absolute time in secondsfrom the twenty-four-hour real-timeclock. Regardless of the type of real-time clock you use, some sort ofsubroutine will be necessary tocalculate the time in absoluteseconds. It is also very convenient tohave a routine that prints out the cur-rent time in traditional form on yourterminal.

Software

The main program used by thissystem (listing 1) is written in BASIC.The BASIC interpreter used is Pro-cessor Technology's 5K BASIC.Simply stated, the program con-tinually monitors the furnace burner'sstate, and each time it shuts off, thecomputer prints out a line of informa-tion on the furnace's last burn cycle.A burn cycle is defined as the intervalbetween two burner-off events.

To eliminate errors induced byswitch bounce, ten read operationsare done in sequence from the inputport. If all of the ten inputs representthe same on or off state, then the pro-

78 January 1980 © BYTE Publications Inc

Solve your personal energy crisis.

Software do the work.

With a calculator, pencil and paper you can spend hours plan-ning, projecting, writing, estimating, calculating, revising, erasingand recalculating as you work toward a decision.

Or with the Personal Software'" VisiCalc program and yourApple* II you can explore many more options with a fraction ofthe time and effort you've spent before.

VisiCalc is a new breed of problem-solving software. Unlikeprepackaged software that forces you into a computerizedstraight jacket, VisiCalc adapts itself to any numerical problemyou have. You enter numbers, alphabetic titles and formulas onyour keyboard. VisiCalc organizes and displays this infor-mation on the screen. You don't have to spend your timeprogramming.

Your energy is better spent using the results than get-ting them.

Say you're a business manager and want to projectyour annual sales. Using the calculator, pencil and papermethod, you'd lay out 12 months across a sheetand fill in lines and columns of figures onproducts, outlets, salespeople, etc. You'd cal-culate by hand the subtotals and summaryfigures. Then you'd start revising, erasingand recalculating. With VisiCalc, you simplyfill in the same figures on an electronic"sheet of paper" and let the computer dothe work.

Once your first projection is complete,you're ready to use VisiCalc's unique,powerful recalculation feature. It lets youask "What if?'/ examining new optionsand planning for contingencies. "What if"sales drop 20 percent in March? Just type inthe sales figure. VisiCalc instantly updatesall other figures affected by March sales.

Circle 46 on inquiry card.

Or say you're an engineer working on a design problem and arewondering "What if that oscillation were damped by another 10percent?" Or you're working on your family's expenses andwonder "What will happen to our entertainment budget if theheating bill goes up 15 percent this winter?" VisiCalc respondsinstantly to show you all the consequences of any change.

Once you see VisiCalc in action, you'll think of many moreuses for its power. Ask your dealer for a demonstration and dis-cover how VisiCalc can help you in your professional work andpersonal life.

You might find that VisiCalc alone is reason enough toown a personal computer.

VisiCalc is available now for Apple II computers withversions for other personal computers coming soon. TheApple II version requires a 32k disk system.

For the name and address of your nearest VisiCalc

dealer, call (408) 745-7841 or write to Personal Software, Inc.,

592 Weddell Dr., Sunnyvale, CA 94086. If your

favorite dealer doesn't already carry Personal

Software products, ask him to give us

, a call.

rt£8$

gOr

VisiCalc was developed exclusively forPersonal Software by Software Arts, inc.,Cambridge, Mass.

TM—VisiCalc is a trademark of

Personal Software, Inc.

'Apple is a registered trademarkof Apple Computer, Inc.

Listing 1 continued:

90 T=T+Z

100 NEXT C

110 IF T=L THEN 60

120 IF T=10 THEN 160

130 IF T=0 THEN 210

140 GOTO 60

150 REM - GAS ON ROUTINE

140 GOSUB 600

170 G=S

180 L=10

190 GOTO 60

200 REN - GAS OFF ROUTINE

202 REN - DO CALCULATIONS AND PRINT OUT LAST BURN CYCLE

210 GOSUB 600

215 REM - HAS TIME CROSSED MIDNIGHT

220 IF G<S THEN 250

230 I=86400-G+S

240 GOTO 260

250 I=S-G

260 J=(I/1700)*G2

262 19=19+1

264 J9=J9+J

265 K=K+J

266 REM - HAS TIME CROSSED MIDNIGHT248 IF S2<S THEN 274

270 D=86400-S2+S

272 GOSUB 500

273 GOTO 275

274 D=S-S2

275 R=(I/D>*100280 Q=CALL<6262)

288 PRINT TAB(1),M9,"/\D9,

290 PRINT TAB(11),"On",INT((I/60)*100)/100,"Min.,"r

292 PRINT TAB(27),INT(R*10)/10,"X of",INT((D/60)*100)/100,

294 PRINT TAB(43),"Mir>. cycle ♦",INT(<J+.005)*100)/100,

296 PRINT TAB<65),"«",INT((K+.005)*100)/100

298 S2=S

300 GOTO 50

499 REM - MON/DAY UPDATE

500 D9=D9+1

510 IF D9<=M2(M9) THEN 560

520 D9=1

530 M9=M9+1

540 IF M9<13 THEN 560

550 M9=1

560 print;print;print565 print"daily totals

548 18=19/1700

570 PRINT TAB(16),"Cost is $",INT(<I8*G2)*100)/100

575 PRINT TAB(16),INT(I8*10)/10,"CCF Used"

580 PRINTJPRINTJPRINT

585 I9=0JJ9=0

590 RETURN

599 REM - FETCH TIME IN SEC.

600 D1=CALL(12032)610 D2=CALL(12041)620 D3=CALL(12047)630 D4=CALL(12053)640 D5=CALL(12059)650 D6=CALL(12065)660 M=(10*D1+D2)*60+(10*D3+D4)670 S=M*60+(10*D5+D6)680 RETURN

Figure 3: Simplified flowchart of thewatchdog program given in listing 1.Once started, the program loops con-tinuously, checking the status of the fur-nace and printing summary data as re-quired.

- On",INT((I9/864)*10)/10,"r

( START J

INITIALIZECONSTANTSANDVARIABLES

GET CURRENT

TIME,

SET S2 = TIME

"-

READ INPUTPORT 13(DECIMAL)

/CHANGE^.<ClN BURNER>-

T YES

/burnerX.

v. on y

Tno

NO

*

ii%

GET CURRENT

TIME,

SET G = TIME

*j

GET CURRENT

TIME,

SET S = TIME

/^ NEW \s

\. day y

^ES

UPDATEMONTH/DAYPRINT DAILYTOTALS

NO

PRINT TIME,DATE ANDDATA FROMLAST CYCLE

gram accepts this as a true indicationof the burner's status. Figure 3 is asimplified flowchart of the program.Essentially the program loops con-tinually, looking for a change in theburner status. If there is a change,there are two different flow pathsdepending on whether the burner hasjust turned on or turned off. If theburner has just turned on, the currenttime is stored in the variable G. If ithas just shut off, the current time andthe value stored in G are used tocalculate how long the burner was onand the percentage of time the burner

80 January 1980 © BYTE Publications Inc

^7^?

Even at 5:12 a.m., its hard to quitplaying Personal Software"1 strategy games.

Gammon Gambler

A quick game before turning in can become an all-nightsession when you load any of the Personal Software'" strategygames into your Apple? PET* or TRS-80.* They'll challenge,teach and entertain you. And now there are two new games-Gammon Gambler'" and Checker King'"—joining BridgePartner,'" Time Trek'" and the best-selling Microchess.'"

Gammon Gambler is a sure bet. With ten levels of skill,you can begin a novice and becomean expert. Whichever level you play,the computer moves so quicklyyou don't have to wait. Theprogram follows U.Stournament rules, and in-cludes the doublingcube to spice up thegame. Written forthe Apple andPET by WillyChaplin.Checker King—you probably forgothow much fun it is! If you move andchange your mind, take it back and moveagain—without a peep from the computer.Play eight skill levels. Add and removepieces. Save three board positions for laterplay. And solve three challenging checkerpuzzles. Written by Michael Marks forthe Apple, PET and TRS-80.

Microchess, the most widely usedpersonal computer chess program, is anearly perfect chess opponent for the totalnovice or the advanced enthusiast. Writtenby Peter Jennings for the Apple, PET andTRS-80.

* Apple is a trademark of Apple Computer, Inc.; PET is atrademark of Commodore Business Machines, Inc.;TRS-90 isa trademark of the Radio Shack Division ofTandy Corp.

Circle 47 on inquiry card.

Bridge Partner. You against the computer in over 10 milliondifferent hands of contract bridge. You can even specify thehands' high card points. Written by George Duisman for the Ap-ple, PET and Level II TRS-80.

Time Trek is easy to learn, dif-ficult to master and impossible toforget. Take command of a starshipin real-time action to make the gal-axy safe again. PET version by BradTempleton. TRS-80 programby Joshua Lavinsky.

Personal Software, Inc.,

also produces the VisiCalc'"

program (the software that's

revolutionizing personal

computing), CCA Data Management Sys-tem, the Vitafacts series and other excitingsoftware for the Apple, PET and TRS-80.Now that you've read about the Per-sonal Software programs, go see ademonstration. For the name of yournearest Personal Software dealer, call(408) 745-7841 or write to PersonalSoftware, Inc., 592 Weddell Drive.,Sunnyvale, CA 94086.

Checker King

rtS3$

§Or

TWA**

STRATEGY CAUBS

Table 1: Use of variables in the BASIC program of listing 1. The physical items of datarepresented by each variable are shown here. During leap years (such as 1980), the ar-ray M2 must be modified to reflect the greater number of days in the month ofFebruary.

D Number of total seconds in the previous burner cycle, from last burner-off event to cur-rent burner-off event.

D1 Most significant digit (MSD) of current time; number of tens of hours.

D2 One digit of current time; number of units of hours.

D3 One digit of current time; number of tens of minutes.

D4 One digit of current time; number of units of minutes.

D5 One digit of current time; number of tens of seconds.

D6 Least significant digit (LSD) of current time; number of units of seconds.

D9 The current day of the month.

G Absolute daily elapsed time in seconds that the burner was on in the current cycle.

G2 Cost of gas in dollars for 100 cubic feet (2832 liters).

I Number of seconds the burner was on in the previous cycle.

18 Total number of units of gas used for the day, one unit = 100 cubic feet (2832 liters).

19 Accumulated number of seconds the burner has been on during the day.J Cost, in dollars, for the previous burner cycle.

J9 Accumulated cost of gas for the total day.

K Accumulated total cost of gas since the program was started.

L Set to zero if the burner is currently off, set to ten if the burner is currently on.

M Current time in minutes from 00:00:00.

M2 A subscripted array of twelve values containing the number of days in each month, ig-noring leap years.

M9 The current month.

R Percentage of time the burner was on during the previous burner cycle.

S Absolute daily elapsed time in seconds from 00:00:00.

S2 Time, in absolute daily elapsed seconds, that the burner was off in the previous cycle.

Z The value returned by a machine language subroutine, set to zero if the burner is off andto one if on.

was on during the last cycle. Acalculation of the cost of the gas usedis done, as well as the total running

cost. This information is then printedout on the terminal.

Table 1 describes the physical data

PASCAL/M

:\Jg\ ^t^ ■ /% I' fTmJm PASCAL M is on implementa

■^A^k ^^% 1 *■» I I \yf I lion of the Standard Pascal

«■> • • V^ ^k*^ • m JLrff A A programming language de-

A CP/M* COMPATIBLE PRODUCT signed by Nlklaus Wirth.

PASCAL/M does all input/output and file manipulation via calls toCP/M. The file interface Intrlnslcs were chosen to promote Pascalprogram transportability and to provide a bridge between CP/Mand the Standard Pascal language definition. In selecting anddefining extensions to PASCAL/M, heavy weight was given tocompatibility with other existing Pascal implementations. Over 40extensions to Standard Pascal support:

. Console Cursor Controls

Type String

Untyped files (formemory image I/O)

Segment procedures (memorysharing)

String and Character procedures tosupport insertion, deletion andreplacing of character data.

PASCAL/M provides single precision floating point (Type Real). Both in-teger (16 bit) and long integer (32 bit, 9 digit) arithmetic are sup-ported. An optional version will support the AMD 9511A or the Intel8231 math chips.

PASCAL/M requires 56K RAM and onefloppy disk. The package includes diskettewith P Code Compiler, Interpreter, andRuntime Library: Pascal User Manual andReport by Jensen and Wirth: and PAS-CAL/M User's Reference Manual. Thecost is $350. For manuals only - $35.Dealer inquires welcomed. Visa/MC

•CP/M is a trademark of Digital Research

2670 Cherry LaneWalnut Creek, CA 94596

Y AVAILABLE VERSIONS \

CP/M Type

CPU Type

Disk Size

1.4

SOSO/85

8"

1.4

ZSO

8"

Cromemco

CDOS

ZSO

8"

Northitar 2D

(Lifeboat)

ZSO

5-1/4"

2.0

8080/85

8"

2.0

ZSO

8"

MP/M l.O

SOSO/85

8"

MP/M t.O

ZSO

8"

DigitalMarketing

(415)938-2880

that the variables in the programrepresent. These descriptions shouldhelp in understanding the program'sdetails.

There are eight places where theCALL function is used in the BASICprogram. The CALL function bran-ches to a machine languagesubroutine in the following way. Anaddress (in decimal) is supplied as theargument, and program execution istransferred to that address. Anydesired value to be returned to theBASIC program is put in the variableto the left of the equal sign by placingit in the HL register pair beforereturning from the subroutine. ARETURN instruction at the end of themachine language routine returnscontrol back to the BASIC program.My machine language routines beginat hexadecimal address 2F00.

The CALL at line 80 simply readsinput port hexadecimal 0D andreturns either a logical zero or one todenote whether the burner is off oron, respectively.

The CALL at line 280 transfers con-trol to a machine language routinethat reads the real-time clock andprints the current time on the ter-minal in standard form. The variableQ is not used for any calculations,but rather just supplies the necessarysyntax for the BASIC interpreter. Asubroutine called TTOP, whichresides at hexadecimal address 189Din the monitor, is used within thisroutine as well as in the machinelanguage routines that begin at hex-adecimal memory location 2F00.TTOP reads the real-time clock andstores the 6-digit time (as ASCIIcharacters) beginning at hexadecimalmemory location 2254.

The six CALLs beginning at line600 are used to retrieve the individualdigits of the current time of day fromthe real-time clock. The six digits arethen used to calculate the absolutetime of day in seconds.

The machine language subroutinesare shown in listing 2 and are quitestraightforward. The subroutines Sithrough S6 each read a single digit ofthe time and return it to the BASICprogram in the HL register pair.Subroutine Si is always the first call-ed, and the actual clock-read opera-tion is done here just once. MASK isused to strip high-order bits from theASCII character representation of

82 January 1980 © BYTE Publications Inc

Circle 48 on inquiry card.

December 1, 1979

OregonSoftware

To the users of OMSI Pascal-1 for the PDP-11:

We are pleased to make available to you the new version (VI.2) of OMSI Pascal-1.VI.2 contains many enhancements and improvements, and you will find it easierto operate and even more reliable. The following overview outlines the mostsignificant changes incorporated in the new version. For details, please askfor the VI.2 Language Specification and User's Guide (s).

Extended precision real arithmetic: a compiler switch causes all real calcu-lations to be carried out with 15 digit precision (standard PDP-11 double pre-cision four-word format). Extended precision is supported on all PDP-11 andLSI-11 processors, and on all operating systems. The precision of the libraryfunctions is also extended.

Debugger: the interactive debugger is now entirely Pascal-oriented, and isconversant with all user identifiers, types, scope rules, and the source pro-gram. The debugger has the capability, for example, to intercept a fatal errorand display the last executed statements, or to accept and store commands fordisplay of variables at a breakpoint.

Profiler: if you have ever wondered where your program spends its time, theProfiler can produce a listing and show you the number of times every line isexecuted.

Fatal error recovery: the system error procedure can be replaced by a Pascal-coded routine.

Direct access files: the procedure Seek(file,record) is a built-in procedure,and causes the file buffer to be positioned to any desired record.

File options: many enhancements have been made in file processing, allowing(for example) large buffers and spanned records on RSTS and RT11, and RSX fileattributes including variable-length records. The RSTS file support uses 24-bitblock numbers for RSTS V7 large file capability. All systems now support a fulldefault filename when opening files.

Fast MACRO: most of the compilation time is actually spent in MACRO and thelinking loader. On RSTS systems, a new utility (MAC) performs both of thesefunctions in one-third of the time.

String package: included with VI.2 is a set of procedures and functions forhandling dynamic length character strings. The package is written for portabil-ity in Standard Pascal.

Order information: to OMSI Pascal-1 licensees in warranty or extended support,VI.2 is available for the cost of handling, media, and shipping; other partiesplease contact Anne Smith, Vice-president for Sales.

Donald Baccus

Vice-president,"Software Engineering.

2340 SW Canyon Road Portland, Oregon 97201

(503) 226-7760 Cable: SOFTWARE TWX 910-464-4779Circle 49 on inquiry card. BYTE January 1980 83

Circle 50 on inquiry card.

ANDSTUFF

Computer terminals, business systems,lab components ... they all need desksand enclosures. That's what we're allabout. Computer Furniture and Acces-sories offers a standard line of furnituresuitable for a wide variety of applica-tions. Handsome, rugged, economicalfurniture in all shapes, sizes and colors.Basic models shipped from stock indays, not months. And we're nice peopleto deal with. What more could youask for?

CF*A

Computer Furniture and

Accessories, Inc.

1441 West 132nd Street

Gardena, CA 90249

(213)327-7710

Listing 2: Machine language subroutines that are called by the BASIC program of listing1, shown here in assembler for the 8080 processor. Routines Si through S6 each read asingle digit of the time from the real-time clock. The digit value is returned to the BASICprogram in the HL register pair. Si is always the first to be called, and the actual clockread operation is done only once. MASK strips the high-order bits from the ASCIIcharacter representation of the digit.

8080 MACRO ASSEMBLER, VER 2.0 ERRORS = 0 PAGE 1

FURNACE UATCHD0G

WRITTEN BY T. UIERENGA, FEB.

READ HOURS,MINUTES,SECONDS

1978

189D

TT0P

EQU

189DH

2F00

ORG

2F00H

2F00

CD9D18

SI:

CALL

TT0P

; READ CLOCK

2F03

3A5422

LDA

2254H

; STORE IN MEMORY

2F06

C3242F

JMP

MASK

; GET TENS HOURS

2F09

3A5522

S2:

LDA

2255H

J GET UNITS HOURS

2F0C

C3242F

JMP

MASK

2F0F

3A5622

S3:

LDA

2256H

; GET TENS MINUTES

2FI2

C3242F

JMP

MASK

2F15

3A5722

S4:

LDA

2257H

J GET UNITS MINUTES

2F18

C3242F

JMP

MASK

2F1B

3A5822

S5:

LDA

2258H

J GET TENS SECONDS

2F1E

C3242F

JMP

MASK

2F21

3A5922

S6:

LDA

2259H

; GET UNITS SECONDS

2F24

E60F

MASK

: ANI

00FH

2F26

AF

MOV

L,A

J RETURN VALUE IN H,L

2F27

2600

MVI

H,0

2F29

C9

RET

; READ INPUT PORT 13

(ODH)

; o=

FURNACE

OFF, 1=01*

2F2A

DB0D

IN

13

2F2C

E601

ANI

1

J LSB ONLY USED

2F2E

AF

MOV

L,A

; RETURN VALUE IN H,L

2F2F

2600

MVI

H,0

2F31

C?

END

RET

HO PROGRAM ERRORS

8080 MACRO ASSEMBLER, VER 2.0

ERRORS =

0 PAGE 2

SYMBOL

TABLE

* 01

A

0007

B

0000

C

0001 II 0002

E

0003

H

0004

L

0005 M 0006

MASK

2F24

PSU

0006

SI

2F00 * S2 2F09 *

S3

2F0F *

S4

2F15

* S5

2F1B * S6 2F21 *

SP

0006

TT0P

189D

!C B1B0

:102F0000CD9D183A5422C3242F3A5522C3242F3A78: 102F10005622C3242F3A5722C3242F3A5822C324BF»102F20002F3A5922E60F6F2600C9DBODE6016F2606:022F300000C9D6:0000000000

84 January 1980 © BYTE Publications lnc

THE

INFLATION

FIGHTE

You can't buy morecapability for less ... Butyou can buy less for more

MPI presents the perfect answer to your inflation-riddled printer budget. THE MODEL 88T DOTMATRIX PRINTER. The first in a series of new full-capability low-cost printers designed specificallyfor the general use computer market. The Model 88T is a fully featured printer with a dualtractor/pressure-roll paper feed system and a serial or parallel interface. The tractor paperfeed system provides the precision required to handle multi copy fanfold forms, ranging inwidth from 1 inch to 9.5 inches. For those applications where paper costs are important, thepressure-roll feed can be used with 8.5 inch roll paper. A long-life ribbon cartridge gives crisp,clean print without messy ribbon changing. The microprocessor controlled interface has 80,96or 132 column formating capability while printing upper and lower case characters bi-directionally at 100 characters per second.

With all of these features, plus quality construction, continuous duty print head and attractivestyling, the Model 88T would easily sell at the competition's "under $1000" (999 w) tag. But weare offering it for only $749; this should make you happy and several hundred dollars richer.

Write for complete specifications and pricing information.

Ampi

Circle 51 on inquiry card.

MICRO PERIPHERALS, INC. 2099 WEST 2200 SOUTH / SALT LAKE CITY, UTAH 84119 / (801) 973-6053

BYTE January 1980 85

Circle 52 on inquiry card.

Microprocessor Bosed

Reverse Video

Blinking, Underling

Tobbing

Numeric Keypad Standard

Upper/lower Case Standard

Protected and Conversation

Modes

Lear Siegler Code Compatible

Cight Different editing Features

One Page of Memory Standard

Single Unit Price $840.00(Quantity pricing available)

Rdd $60.00 for Serial Printer Port

Add $60.00 for Second Page

Memory

Add $20.00 Shipping

Illinois Residents Rdd Appropriate

Sales Tax

Send for additional information,check, money order or C.O.D.certified check to the addressbelow.

...add the

sound dimensionto your system

Soundboard Uses Two Gl AV3-8910 I.C.'s to Generate SoundEffects Under Software Control

S-100 Bus Compatible

Breadboard Area Allows €asyAdaptation to any System

On Board Audio Amplifier

Four 8-Bit I/O Ports

I/O Addresses are SwitchSelectable

PCB only, $34.95

Send for additional information,check or money order to:

AckermanDigital Systems, Inc.

110 North York Road • Suite 208

Elmhurst, Illinois 60126

Tel. 312-530-8992

Illinois Residents Add Appropriate State Sales Tax

Table 2: Example of the output produced by the BASIC watchdog program of listing 1.

01:50:25 2/22 On 9.78 Min.,

02:25:42 2 / 22 On 11.23 Mm.

03:00:45 2/22 On 11.31 Hit).

03:34:40 2/22 On 11.51 Min.

04:08:46 2/22 On 11.45 Min.

04:43:22 2/22 On 11.65 Min.

05:18:22 2/22 On 11.5 Min.,

3.4 7. of 285.41 Min. cycle * .07 $ 3.27

31.7 X of 35.43 Min. cycle * .08 t 3.3632.2 7. of 35.06 Min. cycle * .08 * 3.4433.9 •/. of 33.91 Min. cycle ♦ .09 t 3.53

33.5 V. of 34.1 Min. cycle $ .09 t 3.61

33.6 7. of 34.58 Min. cycle t .09 $ 3.7

32.8 X of 35.01 Hin. cycle % .09 * 3.79

05:53:31 2 / 22 On 12.33 Mm., 35.1 7. of 35.13 Min. cycle * .09 t 3.

07:23:36 2/22 On 65.9 Min.,09:56:08 2/22 On 10.1 Min..10:35:23 2 / 22 On 11.88 Mm.,

73.1 7. of 90.08 Min. cycle $ .49 % 4.376.6 7. of 152.53 Min. cycle * .08 t 4.45

30.2 7. of 39.26 Min. cycle » .09 $ 4.54

11:16:10 2/22 On 11.26 Mm., 27.6 7. of 40.78 Min. cycle * .08 $ 4.62

12:00:01 2/22 On 10.88 Min.12:44:40 2/22 On 10.5 Min.,

24.8 X of 43.83 Min. cycle « .08 t 4.7

23.5 X of 44.66 Min. cycle « .08 * 4.78

13:33:57 2/22 On 10.03 Mm., 20.3 X of 49.28 Min. cycle « .07 * 4.85

14:25:37 2 / 22 On 9.7 Min., 18.7 X of 51.66 Min. cycle « .07 « 4.93

15:27:48 2/22 On 9.28 Min.. 14.9 7. of 62.16 Min. cycle $ .07 $ 5

16:32:27 2/22 On 9.21 Hin., 14.2 X of 64.66 Min. cycle $ .07 $ 5.06

17:27:30 2/22 On 10.53 Min., 19.1 7. of 55.03 Min. cycle * .08 « 5.14

18:17:55 2/22 On 11.48 Min., 22.7 X of 50.43 Min. cycle * .09 $ 5.23

20:43:56 2/22 On 117.3 Mm., 80.3 X of 146.01 Min. cycle t .88 < 6.1

21:19:56 2/22 On 14.43 Mm., 40 7. of 36 Min. cycle $ .11 * 6.21

DAILY TOTALS -- On 28 7.

Cost is t 314.2 CCF Used

each number to yield the binary valuebefore it is returned to the BASICprogram.

The input subroutine begins at hex-adecimal memory address 2F2A.Only the least significant bit (LSB) ofthe byte input from input port 0D isused.

Some sample output from themainline program is shown in table 2.Although a large amount of data issupplied by this program, it is dif-ficult to visualize the trends in thedaily consumption of gas withoutsome additional analysis of the data.Therefore, a second BASIC programis used to produce a simple bar chart

of daily gas consumption.

The bar chart program appears aslisting 3. Several sets of data, eachconsisting of three numeric values, areobtained from the "watchdog" pro-gram of listing 1. These data sets areentered into the DATA statementsbeginning at line 500. Each set is readas the variables H, M, and T, whichare the hour and minute the burnershut off after each cycle, and thelength of time it was on. The numberof data sets should correspond to thenumber of burner cycles in the daybeing charted.

An array D of 144 entries iscreated. Each entry represents ten

86 January 1980 © BYTE Publications Inc

zT^ir.Trss

YOUNG AND BRILLIA

£ &

7

:m

'

DATA BASE MANAGEMENTVIRTUAL CODEDATA COMPRESSION

INDEXED FILES

SPOOLING

MULTI-TASKING

. "

Every so often an individual is born exhibiting extraordi-nary talent at a very early age. Often, they rise above themultitude establishing themselves as masters in their fields.These individuals are called prodigies.

The Prodigy computer is so advanced, it clearly estab-lishes itself as a master in the field of small businesscomputing.

Modular design and single board construction mean reli-ability, expandability, and ease of service. But it is SOFT-WARE which truly sets Prodigy apart. Unlike other compu-ters, software was a major design consideration rather thanan afterthought. Prodigy utilizes a highly advanced operat-ing system and the PROTEGE* to provides some very im-pressive features:

The result? Incredible speed and storage capacity,and economical systemsdevelopmentand maintenance.

... "Though it may look like many other microcompu-ter systems — ... Prodigy One literally speeds awayfrom them." — ... Max Schindler, Software Editor-ELECTRONIC DESIGN.

Your local Prodigy dealer maintains an extensive libraryof field proven application software. Available applicationsinclude General Ledger, Accounts Receivable, AccountsPayable, Payroll, Medical Billing, and a remarkable systemfor the Personnel Placement Industry. All are easy to use yetprovide a level of sophistication unheard of in its price class.And Prodigy also does word processing!

Prodigy systems are supported by a nationwide organiza-tion of thoroughly trained, experienced professionals. YourProdigy dealer is a SINGLE source for hardware, softwareand a level of service that continually insures effective, trou-ble free operation.

Speed, sophistication, and low cost; an incredible combi-nation for a small business computer. Would you expectless from a prodigy?

PRODIGYi

SYSTEMS, INC.

497 LINCOLN HIGHWAY • ISELIN, N.J. 08830 • (201) 283-2000

"Prodigy's easy to use compiler-based small business applications development language. Prodigy also supports other popular languages such as FORTRAN, COBOL, BASIC, and PASCAL.Circle 53 on inquiry card. byte January 1980 87

Circle 54 on inquiry card.

AN OPEN LETTER ON THETEXAS INSTRUMENTSTI-99/4 HOME COMPUTER

It's a fact that the new TI-99/4 Is themost sought after home computer on themarket today. However, the demand farexceeds the factory's ability to producethem, so they will be in short supply,for all dealers, for the foreseeablefuture.

As a practical and equitable solution,CTC has set up a priority shippingschedule for our customers.Here's how it works.You send us your order for a TI-99/4,with a $150 deposit (cash or creditcard). Upon receipt of your order anddeposit, we record your name and thedate it is received on our priority list,and send you a confirmation of itsreceipt and your position on the prioritylist by return mail.

As we receive our allocation of TI-99/4'swe will ship them to our customersaccording to their position on ourwaiting list. Simply stated, it's TirstCome, First Served.'Safeguards:

You may cancel your order any timeupon 30 days written notice and receivea full refund of your $150 deposit.You may call us at any time and we willtell you your position on the list, andour best estimate of when you canexpect delivery.

CTC'S DISCOUNT PRICE $ 1 UvJ U

f.—l_ „rJ The ComputerV&LlviZI People

San Diego's largest Discount Computer & CalculatorStore. 5560 Ruffto Road, San Diego, CA 92123

Please ship me the following merchandise

Tl HOME COMPUTER PRODUCTS

PHC004M

TI-99/4 Home Computer

Deposit

PHA2Q00

Dual Cassette Cable

PHP1100

Remote Controls (Pair)

PHP 1500

Speech Synthesizer

COMMAND MODULES

PHM30O0

Diagnostic

PHM30QI

Demonstration

PHM3Q02

Early Learning fun

PHM30D3

Beginning Grammar

PHM3D04

Number Magic

PHM30D5

Video-Graphs

PHM3006

Home Financial Decisions

PHM3O07

Household Budget Management

PHM3008

Video Chess

PHM3009

Football

PHM3D10

Physical Fitness

TOTAL

Shipping, add 3%

Cal. residents add 6% tax

Amount enclosed

{check oi money order)

Charge lo my □ VISA Q MASTER CH

Acct W

Rank *

29 95699529.952995199519.95299544 9569.9529.952995

(Requited if using credit caid)

Name-

Street or P.O.\ City

. State_

Zip-

Listing 3: BASIC program that prints bar graphs from data accumulated by the watch-dog program of listing 1. An example of the output of this program is shown in figure 4.

100 REM - BAR CHART PRINTOUT FOR

110 REM - FURNACE UATCH DOG

120 REM

130 DIM D<144)

135 REM - SET ARRAY TO ZERO

HO FOR 1 = 1 TO 144

150 D(I)=0

160 NEXT I

165 REM - READ TIMES

170 READ H,N,T

175 IF T=0 THEN 250

177 REM - CALCULATE PLACE IN ARRAY

178 REM - AND LENGTH OF TIME ON180 X=H*6+INT((M/10)+.5)

190 T=INT(<T/10)+.5)

200 IF T>0 THEN 220

210 T»1

212 REM - FILL ARRAY UHEN ON

220 FOR I=X TO X-T+1 STEP -1

230 D(I)=1

240 NEXT I

245 GOTO 170

250 RESTORE

252 GOSUB 400

254 REM - PRINT OUT ARRAY AS 144 BARS

255 FOR J=1 TO 144

258 REM - CR IF=0

259 REM - BAR IF=1

260 IF D(J>=0 THEN 300270 FOR K=1 TO 30

280 PRINT"X",

290 NEXT K

291 REM - PRINT TIME ON LAST BAR

292 IF D(J+1)O0 THEN 300294 READ H,M,T

296 PRINT" ,,,H,"HRS.",M,"MIN.\300 PRINT310 NEXT J315 GOSUB 400320 STOP

399 REM - PRINT LINE OF DASHES ROUTINE

400 FOR Z=1 TO 40402 PRINT"-",404 NEXT Z

406 PRINT

408 RETURN

500 DATA 1,50,9.78,2,26.11.23,3,1,11.31,3,35,11.51.4,9,11.45

510 DATA 4,43,11.65,5,18,11.5,5,53,12.33,7,24,65.9,9,56,10.1

520 DATA 10,35,11.88,11,16,11.26,12,0,10.88,12,45,10.5,13,34,10.03

530 DATA 14,26,9.7,15,28,9.28,16,32,9.21,17,28,10.53,18,18,11.48

540 DATA 20,44,111.3,21,20,14.43

999 DATA 0,0,0

minutes of time during the day. Avalue of one is assigned to an arrayentry if the furnace was on during themajor part of the corresponding tenminute interval, otherwise the valueis left at zero. This array is thenprinted as 144 lines, which are blank

if the array value is equal to zero andfilled in with Xs if the value is equal toone. The time is printed alongside thefilled-in bar corresponding to the timeinterval in which the burner shut off.A sample output of the program isshown in figure 4.

88 January 1980 © BYTE Publications Inc

3uW>rf!eds.

^L^TS^t

c^^V^eve

ci\sV- "

#^^

os^d*

oa\a:;; co^c\06©^:n va&

of ^chniC

stems

U^ _trade^

Circle 55 on inquiry card.

BYTE January 1980 89

The particular day shown in figure4 is February 22 1978. Several in-teresting features can be determinedfrom the output. The thermostat wasturned down sharply before mid-night, and the furnace did not comeon again until 1:50 AM. The furnacecycled smoothly about every halfhour until 5:53 AM. At about 6:30

AM when we arose for the morning,the thermostat was turned up. Theburner was on for about one hour.The heat accumulated during thishour was not completely wastedwhen we left for work at about 7:30AM, and the thermostat was againturned down. Notice that the burnerdid not cycle again for about 2Vi

Figure 4: Sample output of the bar chart program of listing 3. This provides a graphicrecord of data obtained from the watchdog program of listing 1.

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 12 hrs.o hin.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 12 HRS. 45 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 13 HRS. 34 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 1 HRS. 50 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 2 HRS. 24 MIN. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 14 HRS. 24 MIN.XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 3 HRS. 1 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 3 HRS. 35 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 4 HRS. 9 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 4 HRS. 43 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 5 HRS. 18 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 5 HRS. 53 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 7 HRS. 24 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 15 HRS. 28 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 14 HRS. 32 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 17 HRS. 28 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 18 HRS. 18 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 20 HRS. 44 NIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 21 HRS. 20 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 9 HRS. 54 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 10 HRS. 35 MIN.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX II HRS. 14 MIN.

hours. Between 9:56 AM and 6:18PM (18:18 in 24-hour style), the cycletime lengthened as the outdoortemperature rose, and less energy wasneeded to maintain a constanttemperature. At about 7:00 PM(19:00) we returned home and turnedthe thermostat up. The furnace ranfor about one hour and fifty minutes.After this time it cycled once morebefore the thermostat was turneddown for the evening. The furnacedid not cycle again until after mid-night.

The burner was on twenty-eightpercent of the time during this par-ticular day, and 40,210 liters (1420cubic feet) of gas was burned at a costof $3. The weather was quite harsh.A low temperature of -18° C (0° F)and a high of -3° C (29° F) wererecorded, and the winds were sixteento twenty-five km per hour (ten to fif-teen miles per hour).

A secondary fact that came out ofthe data concerns the use of afireplace in our home. This fireplaceis located in the living room, aboutsix meters (twenty feet) around a cor-ner from the thermostat. Wheneverthe fireplace is burning, evenmoderately, the living room area andnearby thermostat are kept warmenough that the furnace does not runat all. This encourages a considerablesavings, since we use the fireplaceoften on evenings that we are home.

Conclusion

This system provides an excellentstarting point for an individual in-terested in monitoring the consump-tion of energy used for heating. Anextension of this system might beuseful to a homeowner who adds asupplemental solar heating system tothe conventional heating systemalready present in the home. Asidefrom monitoring the energy used, thecomputer in this situation could alsomonitor the solar energy generated.In addition, the computer could alsooperate the two heating systems,turning on the conventional furnacewhen there is not enough availablesolar energy.

Individuals may desire differentspecific information from the furnacewatchdog, therefore they may haveto write their own software for asystematic analysis of the data ob-tained. ■

90 January 1980 © BYTE Publications Inc

- aK

y

COMPUTER INTO A GENIUS.

Bob admits he thought his computerhad reached the limit of its capabilities.Then he discovered the BASIC Compilerfrom Microsoft.

"It's incredibly fast;' he boasts. "Nothingwas as fast as my Microsoft BASIC inter-preter—yet this new compiler is actually3-10 times faster.

"And that's not all',' he beamed. "Mycompiler has the same language features asMicrosoft 5.0 BASIC and runs in my 40KCP/M system:'

Bob says, "When Microsoft comes outwith a new product, I know it's got to begood. And this BASIC Compiler is thewizard I've been waiting for.

"At last, I can generate relocatablemachine language modules from myMicrosoft BASIC programs—machinecode that's highly optimized. And becausethe Microsoft macro assembler and loadercome with the BASIC Compiler, BASICprograms are easily linked to assemblylanguage subroutines or Microsoft

FORTRAN and COBOL programs.Just like the pros!' smiled Bob.

"What's more, the compiler generatesa fully symbolic listing of the machinelanguage that's generated—a great way forme to learn assembly code on my own'.'

Bob believes in giving credit where creditis due. "Microsoft turned my BASIC com-puter into a genuis for $395, but I wassmart enough to recognize a good thingimmediately'.'

If you want to get the most out of yourcomputer and your BASIC programs, ask formore information on the Microsoft BASICCompiler. We know you'll compliment your-self on a very smart move.

10800 N.E. Eighth Suite 819Bellevue, Washington 98004206/455-8080 Telex 328945

We set the standard.

Circle 56 on inquiry card.

If you haven't, we'd be surprised ifyou're using your computer at any-where near its full potential. Be-cause if it won't determine the mostefficient assignment of resourcesand/or personnel, com-pute the yields of a bondover different periods,or calculate your incometaxes, you might just aswell have stuck with a padand pencil.

The fact of the matter isthat you just don't learn toprogram overnight. Whichis precisely why FolioBooks Basic SoftwareLibrary (BSL) was devel-oped. Using simple,straightforward BASIC language,the BSL leads you through every step necessaryto input hundreds of useful and entertaining

There are hundreds

of reliable, complete and

most of all useful programs in

the Basic Software Library

programs. Just punch it into your computerexactly as it appears in the BSL.

But just in case your BASIC may not use one ofour functions, we've included an appendix inVolume V which gives conversion statements for

19 different BASICS. Or, to

convert your favorite

program to Fortran or

Over 116,000

volumes already sold...

and two more editions

have just arrived!

APL or just about any

other language, the

appendix in Volume II

defines all the statements

and parameters used in

our programs.

Over 85% of the

programs listed in the first

five volumes can be

executed in most systems with

8K BASICS and 16K of free user RAM. If you only

have 4K of BASIC, you can still input 60% of the

first five volumes in only 8K of user RAM.

The Basic Software Library puts hundreds of reli-able, complete and most of all USEFUL programsat your fingertips. So don't wait any longer. Feedyour computer a good book and start using yoursystem the way it was meant to be used. Youwon't be alone—over 116,000 volumes of the BSLare already in use. Just take a look at all the pro-grams you could be feeding your system tonight— then CALL Folio Books at (800) 423-4864 (inCalifornia, call collect at (213) 795-5224) to orderyour own Basic Software Library.

It'll be the tastiest meal your system ever had.

These are just some of the programs contained in the BSL!

Volume I: Business ana' PersonalBookkeeping Programs $24.95Bond • Computes price and interesttor bond purchases.Building ' Analyzes the cost of build-ing design proposals.Compound • Computes effective com-pound interest rates.Decision 1 • Makes a lease/buy deci-sion for you.

Decision 2 ■ Makes the decision ofwhether to buy a component ormake it.

Depreciation * Calculates depreciationby four different methods.Efficient'Calculates the most efficientassignment of resources and/or per-sonnel.

Flow • Predicts your yearly cash flow.Installment • Performs monthly in-stallment accounting.Interest ■ Computes interest accrualsmonthly.

Investments • Computes annual ratesof return on investments.Mortgage * Makes a comparison ofmortgage terms.

Optimize * Optimizes the layout forplant, shop, office, etc.Order * Determines your economicorder quantity for inventory items.Rate • Computes true annual interestrates.Return 1 • Computes lessor's rate of

92 BYTE January 1980

return for uncertain assets.

Return 2 • Computes a lessor's rate of

return after taxes.

Plus 16games and HgrapUicprograms!

Volume II: Math and EngineeringPrograms $24.95Conv. • Calculates convolutions.Intensity • Calculates and plots RF orAcoustic intensities.Lola • Calculates longitude andlatitude from interstellar fix or dis-tance.

Macro * Simulates a language com-piler.

Max. Miu. • Calculates the maximumand minimum values of functionover a specific interval.Navaid • Calculates position from al-titude and azimuth of celestialbodies.

Planet'Calculates sun and moon pos-itions hourly.

PSD • Calculates Power SpectralDensities and FFT's.Rand 2 • Generates random integersbetween X and Y.

Solve • Solves polynomials byBairstow's Method.Sphere Trian • Solves any sphericaltriangle.

Track' Calculates course and distanceand incremental vectors.Variable' Finds all variables in BASIC

programs.

Vector * Calculates final position;given start and motion vectors.Plotting and Statistics ProgramsBinomial • Calculates binomial proba-bility distributions.Chi-Sq. • Applies the Chi-Square testto samples.

Coeff ' Calculates coefficients offourier series to approximate a func-tion.

Confidence 7 * Calculates confidencelimits on linear regressions.Confidence 2 • Calculates confidencelimits for a sample mean.Correlations * Performs auto and crosscorrelations with plots.Exp-Distri • Calculates exponentialdistribution for a sample.Paired * Compares two groups of datausing the rank test.Polynomial fit • Performs leastsquares polynomial fit.Stat I • Finds the mean, variance andstandard deviation.Stat 2 • Computes various statisticalmeasures for a variable.T-Distribution • Calculates normal andT-distributions.

Unpaired * Compares two groups ofunpaired data.

Variance Z ■ Analyzes a variance tableof one-way random design.XY • Plots functions of X and Y.

Appendix A: Basic Statement Defi-nitions

Volume III: Advanced BusinessPrograms $39.95

Billing • Performs posting and billingof accounts.

Inventory • Maintains data for inven-tory records.

Payroll * Computes payrolls with afull set of deductions.Risk* Performs a risk analysis on capi-tal investments.

Schedule 2 • Performs the most effi-cient scheduling of men and re-sources to location.Shipping ' Solves the problem ofscheduling and assignments.Stocks* Computes the value of stocks.Switch • Calculates the effects of abond switch.

Volume IV: General Purpose Pro-grams $9.95

Bonds * Computes the yields for abond over different periods.Fundsl -Calculateslong-term predic-tions of funds.

Funds 2 • Plots the results oi the pre-dictions above.

Go-Moku • Go-Moku: ancient Chi-nese game of chance.Life* Life: truly a battle for survival, areal challenge.Loans • Calculates annuities, loans

and mortgages.

Popul • Performs population projec-tions for defined areas.Profits • Determines the profitabilityof a firm's various departments.Qubic■ 3-Dimensional Tic-Tac-Toe.Rates • Calculates the effective annualinterest rate for stated interest.Savings * Computes savings plan pro-files.

Volume V: Experimenter's ProgramsS9.95

Baseball • Plays a full nine innings ofbaseball.

Compare * Compares two groups ofdata.

Confid 10' Determines the confidencelimits for normal population.Differ • Compares the difference ofthe means for data of equal variance.Fourier» Evaluates the fourier series.Integers * Computes integers as thesum of other integers.Logic • Determines conclusions fromlogic statements.

Primes ■ Factors numbers into theirprimes.

Quadrac • Solves quadratic equations.Regression 2 'Calculates linear regres-sions.

Roulette • Computerized "wheel offortune" plays roulette.Stat 10 • Calculates quantities for twogroups of paired data.Stat 11 • Computes sample statistics.Top • Computes cost for surfacingroad or driveway.

Vary Performs analysis of a variancetable; one-way random design.

Appendix B: Statement ConversionAlgorithms

Volume VI: A Complete BusinessProgram $49.95

Ledger * Maintains ALL company ac-counts and generates financial re-ports. Includes routines for: Pyrl, In-ventory, Depreciation, Accounts Re-ceivable, Accounts Payable.

Volume VII: Professional Programs

$39.95

Cliess • Designed to challenge the

average player.

Medbil • Complete patient billing

svstem for doctors, dentists. Also

permits the maintenance of a patient

history record.

Wdproc • Wordprocessing for law-yers, publishers, writers, etc. Write,store and change from rough draft tofinal copy in a variety of formats.

Volume VIII: Home Owners Pro-gram $19.95

1040-Tax • 1040 Taxpayer's return,itemized or standard deductions.Balance' Reconciles bank statements.Checkbook' Balances your checkbook.Instlo 78 • Computes real cost on fi-nanced items.

Deprec 2 * Computes depreciation,four methods, any time period.Appendix C: Favorite ProgramConversions

<&S^ 'VolumeIX:

v* Programs for the Traveler $19.95

Auto • Expense and mileage (kilo-meters) calculations.

Cypher • Codes and decodes private

messages.

Hurrtrac • Hurricane tracking and

projection program.

ID • Vehicle identification program.

Lorana • Loran "A" position program.

Navigate • Computes minimum time

courses.

Omega • Omega position program.

Patterns • Generates computer pictures.

Radar • Vehicle tracking program.

RDF ' Position location program.

.. Volume X:tcVN *A Comprehensive Business\S^ Program $69.95

The complete software program todeal with virtually any businessproblem. Contains the followingprograms:

• Accounts receivable.

• Accounts payable.

• Merchandise inventory.

• Check register.

• Fixed assets.

• Payroll.

• Balance and profit and loss sheets.

• Year-end reports.

• Building a data base.

• Sample data.

• ACBS 1 (use).

• Data sheets.

• Sample business forms.

• Tax updating.

• Basic statements.

• Source listings.

Order 3 or more volumes and receive a 10%discount; order 5 or more and we pay shippingand handling in addition to your 10% discount.

ORDERING INFORMATION: Call toll-free(800) 423-4864 M-F 11-5 p.m., Sat. 9-12 noonPacific Time. Mail order: include name, addressand telephone. M/C and Visa customers include:your name as it appears on your card, card #, ex-piration date. All orders add $1.00/volume forshipping and handling. California residents add6% sales tax. We ship UPS unless otherwiserequested.

(800)423-4864

In California call collect: (213) 7S/5_5224

Folio Books

P.O. Box 4100-H, Los Angeles, California 90041

BSL Also Available at Leading Computer Stores Everywhere.Circle 57 on inquiry card.

Editorial continued from page 10:

what are the typical criteria expected in the modern per-sonal computer? For one thing, systems software is re-quired to use the rich hardware capabilities of the smallsystem. The days of an integer subset of high-levellanguage X with a disk operating system capable of onlysimple data transfer operations are gone. The modernpersonal computer user at a minimum requires an extend-ed disk BASIC with files and strings and an operatingsystem with all the appropriate filing, editing and utilityamenities. Nearly all the widely advertised systems havethis kind of capability.

In what I consider to be the ultimate in usefulness forcurrent computers, we find the high-level language orien-tation of computers with manufacturer-independentPascal, C, ANSI standard FORTRAN, and BASIClanguages.

The particular case of the UCSD Pascal system ispioneering a machine independence never before seen incomputing. Users are driving the mass-produced com-puter market, with no single company having dominanceenough to dictate styles of languages. The success ofUCSD Pascal over the past two years as a machine-independent package available from numerous manufac-turers is one of the joys of present-day computing. I canedit, compile, and use the operating system on onemachine in a manner identical with my interactions onanother machine. I use three different computers withtotally different hardware processor designs — yet, withUCSD Pascal, the operating systems are functionallyidentical, so I do not have to switch personalities con-stantly.

I have demonstrated with friends that it is possible tosend object code produced by the UCSD Pascal compilerto other machines where it will execute and behave thesame way. The manner of transportation at the hardwarelevel is sometimes via disk media where compatibilityexists, and, where different disk formats are involved, wehave transferred files through the means of serialRS-232C compatible data connections.

This Pascal-based system is actively supported by anumber of manufacturers, now prominently includingpersonal computer manufacturers Apple and North Staras well as the integrated circuit manufacturer WesternDigital. UCSD Pascal is available in versions for DECPDP-11 minicomputer systems (upon which it wasoriginally developed), CP/M-based 8080 and Z80systems, Motorola 6800-based systems, and even theRadio Shack TRS-80. On all these diverse hardware con-figurations — with a working useful criterion of 500 Kbytes mass storage, 50 K or more bytes of memory — thesame operating system and compilers run, can pass filescompatibly between each other, and achieve systems per-formance sometimes missing from the minicomputersand behemoth computers of today and yesterday.

So with this in mind as the ultimate in off-the-shelftechnology, let's summarize: A desirable contemporarypersonal computer has 64 K bytes of memory, about500 K bytes of mass storage on line, any old competentlydesigned computer architecture, upper and lowercasevideo terminal, printer, and high-level languages such asthat provided by the UCSD Pascal software system. Thisis the state of the art in small computing as it stands todate.

January I960 © BYTE Publications Inc 93

New for theAPPLE II &TRS-80*

OIL r-63 oit T-JK» FUCl-24 TACH-M"

subLOGIC FS1

Simulator!

Experience the excitement of a new era incomputer simulation as you make your landingapproach after a practice flight in your FS1.Then return to the skies where enemy fightersare waiting to intercept you.

The FS1 is a visual flight simulator that givesyou realistically stable aircraft control. And itsbeautifully accurate graphics are produced bya high-performance driver capable of drawing150 lines per second.

Please DO NOT confuse the FS1 with othersoftware claiming to offer flight simulation.The FS1 s sophistication, speed, and beautyare way beyond the ordinary.

See the FS1 package demonstrated at yourdealer's, or order directly from subLOGIC.Either way, it's only $25 plus 75<? for UPS or$1.50 for first class mail. VISA and Master-charge accepted.

"16K required. Specify your system: Apple IIor TRS-80 Level I or Level II.

(217)359-8482

LOGIC

BoxV, Savoy, IL 61874

The engineering and graphics expertsopening a new era in computer simulation.

A Particular System

The previous discussion of the glowing generalities ofour entry into the 1980s with personal computingtechnologies is only part of the information you needwhen contemplating a purchase. To provide a concreteexample of a particular case, I shall describe the newcomputer I just bought. First, why did I need a new one?The computer I have been using until recently (a North-west Microcomputer Systems Model 85/P) executes theUCSD Pascal system, meets all the minimum re-quirements, and had served me well for nearly a year.

But no computer, however competently engineered, isimmune to dumb users like yours truly. As an attempt toget around a relatively minor hardware problem, Imanaged to plug a terminal into the wrong socket and frya power supply, possibly worse. After a month ofwithdrawal symptoms, my frustration level reached sucha peak that I had to get another computer. . . . NOW!. . . INSTANTLY! Thus the genesis of this month'seditorial celebrating the existence of off-the-shelf per-sonal computers — when I had the need to get one, acomputer was available from a local retailer, and pur-chased with cash over the counter.

To be sure, I had been contemplating a new computerfor some time. I had also been looking into a possiblesmall UCSD Pascal facility for a good friend of mine whodesires a computer to handle his local political campaigndata processing activities. Thus I had actually priced outa system that was available off the shelf at BobMcGuffie's Computerland store in Nashua, New Hamp-shire. The system was an Apple II with UCSD Pascal andassorted peripherals. Then, the frustration level rose toexceed my threshold of action during the weekend of thePhiladelphia Personal Computing '79 show. On Saturdayof that week, I called Bob at his store in New Hampshireto firm up an order for a slightly expanded system.

The order for the system was placed on October 6. Ipicked up the system on October 11, with all items exceptan extra set of read-only memories for a second pair offloppy disk drives. Here is what I am now using to writeeditorials, write various memos involved with my every-day work, explore miscellaneous uses of personal com-puting, etc:

Apple II Plus Computer with . . .

UCSD Pascal Option (64 K total memory),

Serial Communications Interface,

Four 5-inch floppy disk drives (2 controllers,

520 K bytes on line),Parallel Printer Interface,D C Hayes Micromodem II, and extra phone

line.

To this list of equipment should be added an IntegralData Systems Model 440 "Paper Tiger" printer which Ihad ordered a month earlier with the intention of using asa scratch printer. Also added to this list is a COPS-10 ter-minal which was manufactured by the ComputerPeripheral Corp, of which several were already ownedby BYTE. This set of equipment (including the printer butomitting the cost of the COPS-10 terminal) cost only$6000 and, except for two read-only memory parts whicharrived ten days later, was delivered off the shelf.As the Apple Pascal comes delivered, it is oriented

94 January 1980 © BYTE Publications Inc

Circle 58 on inquiry card.

The ORIGINAL Computer People Who KNOW computersand offer EVERYTHING you need in Small Computer Systems

,

Compare PRICE, QUALITY, DELIVERY, SERVICE andyou'll see why you don't have to look anyplace else!

SUPERSPECIAL!

Circle 59 on inquiry card.

BYTE January 1980 95

toward use of the Apple II video display, a 24-line by40-character display built into the computer. Because ofthe short line width and uppercase only characteristics ofthe built-in Apple II display, I do not prefer to use it as aprimary UCSD Pascal terminal. This is no great problembecause the clever hardware design of the Apple Pascaloption and the documentation which comes with thesystem make it fairly trivial to reconfigure the UCSDPascal system for operation via any typical terminal. Atbootstrap time, the Apple II Pascal system simply checksto see if a Serial Comunications card is plugged into slotnumber 3 of the Apple peripheral bus. If so, it uses thatcard as the system terminal instead of the built-in Appledisplay. It of course makes default assumptions about theterminal, but these proved to be adequate to check somemajor points about the interface. The major technicalproblem was discovering that my terminal generated adefault bit in the wrong state when parity was suppress-ed, and that its cursor addressing feature did not seem towork. The parity default problem was solved by chang-ing a jumper option in the terminal. The cursor address-ing problem was solved by a GOTOXY kludge.

Using the Apple II built-in display as a bootstrappingtool, I was able to run the UCSD system's SETUP pro-gram to create a SYSTEM.MISCINFO file for theCOPS-10 terminal. This mode of operation also enabledme to write a custom Pascal "GOTOXY" procedurewhich is used by the UCSD Pascal system to do cursoraddressing with the particular terminal involved. It turn-

^\

DP-8000LINE PRINTER

LOGON offers you this excellent small reliable printer at alow introductory price. Every DP-8000 is complete with thelatest features: - Adjustable tractors and IK input buffer.Standard features include:

• RS232C, current loop and Centronics parallel

• 80 columns -112 char/sec

• 96 char set - 9 x 7 font — Bidirectional printing

• Top of form, skip over pert, out of paper, eightvertical tabs, etc.

Only

$795

Plus S20.00 shipping and

handling.

Terms - check with order -

Allow 3 weeks lor delivery

Logon Inc.

2460LemoineAve.

Fort Lee, N J. 07024201-224-6911212-594-8202

ed out that, as a kludge, I had to do cursor addressingwith a "home" followed by a sequence of "cursor down"and "cursor right" operations — a technical point I havenot yet resolved. The problem that keeps me from usingdirect cursor addressing is either the inability of the ter-minal to understand its documented addressing se-quences, or the inability of the compiled GOTOXY pro-cedure to emit the cursor escape character. The kludgegets around the problem temporarily at the price of somecursor movement delays. Listing 1 shows the Pascal codewhich resulted. Since the program was edited and com-piled before I had the terminal attached, it uses uppercaseonly. As I write these notes the cursor addressing kludgeremains in the system, slowing down operation of theUCSD system's screen editor during deletions and cursorpositioning.

After getting the terminal to work with defaultparameters I was able to write a Pascal procedure whichis compiled and saved as SYSTEM.STARTUP. When

Listing 1: This GOTOXY procedure meets the requirements ofcursor control for the UCSD Pascal system, given an Apple IIdriving a COPS-10 terminal. It uses an inelegant kludge for cur-sor positioning, one which requires a total of 105 charactertimes to reach the worst case position. Sooner or later it will bereplaced when direct cursor control's subtleties are masteredusing my terminal. This listing (and listing 2) was produced onthe Integral Data Systems Model 440 "Paper Tiger" printerthat is attached to the Apple via a parallel printer port. Acustom Pascal print utility program is used to transfer files to theprinter in formatted form instead of using the system's Filer pro-gram.

PROGRAM GOXY!

PROCEDURE FGOTOXY(X»Y: INTEGER))

(* COPS 10 - GOTOXY *)

CONSTHOME = 25?

DOWN = io;

ACROSS = 12?

VARSEND! PACKED ARRAYCO..O!l of 0..255;

j»i : integer;

BEGIN

SENDC03 := home;

UNITURITE(2fSEND»l>;IF X>79 THEN Xt=79ELSE IF X<0 THEN X!=0»IF Y>23 THEN Y!=23ELSE IF Y<0 THEN Yt=0;IF YOO THENBEGIN

send:0 3 := down;

FOR I t= 0 TO Y-l DOUNITURITE(2,SENDfl )

end;

if xoo then

BEGIN

sendco] := across;

FOR I := 0 TO X-l DOUNITURITE(2,SEND,1 )END

end;

BEGIN (* DUMMY MAIN *>END.

96 January 1980 © BYTE Publicalions Inc

Circle 60 on inquiry card.

...with new, low-priced printers for small businesses

Now small businesses can have the advantageof Centronics performance. We have newmodels to meet the needs of small businesses —a selection that covers the court. And we'vefollowed-through by pricing them lower thanother printers that can't match Centronics'features and reliability.

TOP-RANKED TEAM We understand yoursmall business needs—that's why Centronicshas sold more printers to the small businessmarket than anyone else. We have new, fully-featured models designed for small businessapplications. High throughput for inventorycontrol. Full 132-column width for accountsreceivable. Versatile forms handling capability

for invoicing, payroll, and statements. Plusexcellent print quality for labels and listings.The bottom line: with Centronics, small busi-nesses can have mainframe performance atmicro prices.

READY FOR ANY TOUR These printers aredesigned to deliver maximum in-service time,a key consideration for a small business. And wehave the largest worldwide service organizationof any independent printer company.

DON'T WRITE — phone Bob Cascarino todayat (603) 883-0111, extension 4032, or contactany of our 15 U.S.A. or 9 international salesoffices. Centronics Data Computer Corporation,Hudson, New Hampshire 03051.

■1

CERTRDRIC5 PRIRTER5

...the advantage

rcle 61 on inquiry card.

BYTE January 1980 97

Listing 2: This is a first cut at the program SYSTEM.STARTUP,which is executed every time UCSD Pascal wakes up on theApple II with the COPS-10 terminal. It uses direct addressing ofmemory through a standard Pascal variant record techniqueisolated in the procedure "set memory." The memory loca-tions directly addressed from procedure "set up cops" are the

addresses described for various parameters of the Apple II SerialCommunications Interface card.

PROCEDURE sel_up_cops»CONST

slot=3r

data_r3te_3ddress=1144 istop_bits_3ddress=1272;parity_address=1400!1inewidth_address=1784 Jdata_bits_address=1912;op_modes_3ddress=2040;

All constants for setting up the Apple-II serialterminal port are determined from information onpases 21 to 24 of the Serial Interface C3rd manual*♦UP-A2L0008/030-0012 ... 3/79-10K RP. Reference isalso made to the manual for the COPS-10 terminal}

C 19200 BPS =13

set—iiemory( 1»d3ta_r3te_3ddress )»

C COPS can use 2 stop bits 3set memory( 3»stop_bits_3ddress )»

C no parityr no checKsum 3set_memory( 6»P3rity_3ddress)}

C COPS has 80 character lines 3set_nemory( 80»linewidth_address )>

C COPS generates 8 data + 1 start bits 3set_memory( 9idat3_bits_3ddress)i

PROCEDURE set_memory ( valuer3ddress!INTEGER ) i

TYPE

Ptr = tCHAR!

memory_3ccess=( pointerinumber >;memory =RECORD

CASE memory_access OF

pointer ! (a_pointertptr )inumber ! ( 3-number '. INTEGER )

end;

VAR

anybyte J memory;

BEGIN Cset_memory3

anybyte.3_number != address+slot;anybyte.3_pointert 1= CHR( value)

end;

BEGIN Cset_UP_cops3

C

i no linefeed?lower caserno delay>no television 3C 0 + 32 + 64 + 128 3

set_»e»iory( 224»op_modes_sddress )

END Cset_up_coPs3;

BEGIN

set_up_coPSf

URITELN< " );

WRITELNC " );

URITELN< " )r

URITELNt

URITELN<

URITELN(

URITELN<

URITELN(

URITELN<

URITELN<

URITELN(

URITELNC

COPS-10 terminsl setup completed')!' );' >;' >;' >;

APPLE-2 Pascsl System 3t BYTE' )i' )!' )r

' );

WRITELNC'Remember to set the d3te usins the Filer' >iURITELN( " )END.

executed, this procedure manipulates the Apple II serialcommunications port through absolute memoryaddresses. SYSTEM.STARTUP changes defaults so thatthe terminal will run at 19,200 bps, its maximum rate. In

listing 2, the procedure "set memory" is used to place

arbitrary information in arbitrary memory locations; the

procedure "set up cops" references "set memory" in

order to set up the hardware specific control locations ofthe serial port in slot number 3 of the Apple. Reading andlearning about these system configuration details tookabout a weekend of work.

As my deadline for this editorial approaches, I have yetto try out the D C Hayes Micromodem with the system,although I expect it will be quite controllable from Pascalprograms — perhaps with a link to a short 6502assembly-language program if I use the read-onlymemory routines of the modem card.

The printer quite obviously works, as seen by the sam-ple listings. One of my first application tasks was typingin my 1025-line Pascal print utility program as I had usedit on my previous UCSD-based system. Only twolanguage related points worked differently on the UCSDversion II.0 Apple as compared to the UCSD version 1.5booted through CP/M. First, I found that the intrinsicprocedure PAGE(OUTPUT) did not work on my Apple,possibly due to some problem in my use of the SETUPutility to configure the system for my terminal. Second, I

received a syntax error for a statement which had compil-ed just fine in UCSD Pascal version 1.5 and which the ver-sion II.0 documentation of Apple implies should work:READ(KEYBOARD, anychar) where "anychar" is avariable declared CHAR. I got around both these pro-blems by using the UCSD-specific intrinsic procedureUNITWRITE and UNITREAD, respectively.

This Apple II system with UCSD Pascal demonstratesthat the state of the art in small computers is powerfulindeed. I was able to walk into a computer store and pur-chase a full-fledged machine with mass storage, lots ofmemory, a good high-level language, operating system,and printer. At $6000 this fits the bill of being personallyaffordable yet possessed of those features which make fora complete computer system. Of course there are othercomputers which are functionally equivalent to thisApple II system. I use its purchase as an example of whatthe state of the art is at present — a concrete example ofmy "ideal" abstraction of a personal computer cast into aspecific and eminently useful form as a mass-producedproduct. ■

Note:

You may have noticed that the familiar "In This BYTE" page ismissing from this issue. We have integrated the information fromthat page into tile "In The Queue" page so that readers do not haveto repeatedly flip between these corresponding pages.

98 January 1980 © BYTE Publicaiions Inc

Circle 62 on inquiry card.

BYTE January 1980 99

What Computers Cannot Do

T G Lewis

Computer Science Department

Oregon State University

Corvallis OR 97331

c

R

Figure 1: The game of Look is used to illustrate the concept ofcomputability. A piece of cheese (C) is placed in any one of thesquares, and a mechanical mouse robot (R) is placed in anyother square. The object of the game is for R to find C.

Rapid advances in computing, resulting from themicrocomputer revolution, are surprising even experi-enced computer professionals. A single integrated circuitmicroprocessor can perform the same number of compu-tations per second as the expensive, large-scale computerof ten years ago. Yet, in a technical sense, both the typeof computer and the things that computers are used forseem to have changed very little in the last ten years.

Ten years ago, BASIC was used in a manner similar tothat of today, except that more people are now using it.Ten years ago computers had registers and memories toperform calculations; today register and memory costshave decreased fantastically. The cost of computing hasdeclined, making it available to almost everyone. But hascomputing itself changed?

Can computers do any more today than they could tenyears ago? Has there actually been any progress made incomputing since Babbage's Analytic Engine, one hundredyears ago?

What is meant by progress, and what is meant by com-puting? If progress is measured by the number of com-puters sold, the impact on society, or the size of the com-puter industry, then something has certainly increasedand something else has decreased. What effect computershave had on our society is a moot question indeed, butone that I leave for another philosopher.

If computing is measured in terms of the number ofmachine cycles executed this year as compared to lastyear, or in terms of the number of programs written, thensomething has again increased and perhaps somethingelse has decreased (like size or cost). But this kind ofreasoning misses the point.

The essence of computing centers on two fundamentalquestions: (1) what exactly is computable, and (2) is itpossible to compute more today than ten years ago? Ifthese two questions can be answered, I believe that wecan determine if progress has been made, whether thisprogress is due to microcomputers or their dinosaurancestors, the maxicomputers.

Back to Games

Suppose a simple game called Look is played. Look isso trivial that it is easily played by any low intelligenceanimal. In fact, Look may be played by a simplemachine.

A 4 by 4 grid of squares is arranged as shown in figure1. A piece of cheese is placed in one of the squares and amechanical mouse is placed in any other square. Themouse is a robot designated by "R"; the cheese isrepresented by "C." The objective is for robot R to findcheese C. The game immediately poses a problem forrobot designers, for they must program R to find Cwithout outside help. How is R instructed to locate C?

The first area of concern is the simplest program for R.If it is impossible to solve the robot programming pro-blem in a simple manner, a sophisticated solution willprobably fail.

Suppose R is designed to move one step in any of direc-tions North, South, East and West. This is called a stepaction, and the direction is designated by writing STEPW for a single step in the western direction, for example.

Clearly, the robot must know when it has encountereda barrier (wall) and when it has found the cheese. Hence,mouse R is also empowered with a sensor that sets a con-dition code. Codes Barrier and Found are set by sensorson board R.

The STEP and condition code designs are a starttoward a working mouse. They allow the robot to move

About the Author

Dr Lewis is an Associate Professor of Computer Science at OregonState University, where he lectures on software engineering and per-sonal computer systems. He is the author of How to Profit from YourPersonal Computer and The Mind Appliance: Home Computer Appli-cations.

100 January 1980 © BYTE Publications Inc

TRS-80 MODEL II FORMAT NOW AVAILABLE

MM /

DIGITAL RESEARCH itoSS/SK?1

D CP/M* FLOPPY DISKETTE OPERATING SYS-

u TEM — Packages supplied on diskette complete with9080 assembler, text editor, 8080 debugger and variousutilities plus full documentation. CP/M available con-figured lor most popular computer/disk systems includ-ing; North Star Single. Double or Quad density. Altacr 8"disks. Helios II. Exidy Sorcerer. Vector MZ. Heath H17torH89t, TRS-BOt. ICOM 3712 and iCOM Micro Diskplus many other configurations available oft (he shell.

$145 $25

CP.'M version 2 (not all formats available immediately)

5170/S25

□ MP/M* S300/S5O

Ifitty**1-

4

D MAC — 8080 Macro Assembler. Full Intel macro defini-tions. Pseudo Ops include RPC, IRP. REPT. TITLE.PAGE, and MACLIB. Z-80 library included. ProducesIntel absolute hex output plus symbols lile for use by SID{see below) $85 $ 15

Q SID — 8080 symbolic debugger. Full trace, pass countand brsak-poml program lesting syslem with back-trace. and histogram ulilities. When used with MAC. providesI full symbolic display of memory labels and equated val-

, ues S70/S15

-.^v ZSID- As above lor Z-80 Requires Z-80 CPU $95 $ 15

D TEX — Text lormatter to create paginated, page-num-bered and justilied copy from source text files, directahleio disk or pnnler 570 S15

D DESPOOL — Program Io permit simultaneous printingof data from disk while user executes another programfrom Ihe console S45/S5

MICROSOFT '

BASIC-80 — Disk Extended BASIC, ANSI compaliblewith long variable names. WHILE/WEND, chaining, vari-able length file records $300/$25

BASIC COMPILER — Language compatible withBASIC-60 and 3-10 limes faster execution. Producesstandard Microsoft relocatable binary outpul. IncludesMacro-80. Also linkable to FORTRAN-80 or COBOL-80

code modules $350/$25

FORTRAN-80 — ANSI '66 (except for COMPLEX)plus many extensions. Includes relocalable objecl com-piler, linking loader, library with manager. Also includes

MACRO-80 (see below) $400/525

COBOL-80 — ANSI 74 Relocatable objecl output.Format same as FORTRAN-80 and MACRO-80 mod-ules. Complete ISAM, interactive ACCEPT/DISPLAY.

COPY. EXTEND $625/525

MACRO-80 — 8080/ZBO Macro Assembler. Inlel andZilog mnemonics supported. Relocatable linkable output.Loader. Library Manager and Cross Reference Listutilities included $149/51S

D XMACRO86 — 8086 cross assembler. All Macro and

ft) utility features ol MACRO-80 package. Mnemonics

slightly modilied from Intel ASM86. Compatibility data

sheet available. V* — ■ $275/525

D EDIT-80 — Very lasl random access texl editor lor lext(i) with or without line numbers. Global and inlra-line com-mands supported File compare utility included $89/515

MICRO FOCUS

D STANDARD CIS COBOL - ANSI 74 COBOL© standard compiler fully validated by U.S. Navy tesls IoANSI level 1. Supports many features to level 2 includingdynamic loading ol COBOL modules and a full ISAM filefacility. Also, program segmentation, interactive debugand powerlul inleraclive extensions to support protectedand unprotected CRT screen formatting from COBOLprograms used with any dumb terminal $850/550

D FORMS 2 — CRT screen editor. Output is COBOL data(I) descriptions for copying into CIS COBOL programs.Automatically creates a query and update program of in-dexed files using CRT protected and unprotected screenlormals. No programming experience needed. Outputprogram directly compiled by CIS COBOL (standard) $200/520

EIDOS SYSTEMS

D KISS — Keyed Index Sequential Search. Offers com-(u plele Mulli-Keyed Index Sequential and Direct Access lilemanagement. Includes built-in utility functions lor 16 or32 bit arithmetic, string/integer conversion and stringcompare. Delivered as a relocatable linkable module inMicrosoft formal for use with FORTRAN-80 or COBOL-80. etc $335 $23

D KBASIC — Microsoft Disk Extended BASIC with all

© KISS facilities, integrated by implementation ol nine

additional commands in language. Package includes

KISS.REL as described above, and a sample mail list

program $585/545

Io licensed users of "Microsofl BASIC-80 (MBASIC) $435/$45

Sortwiit /

MICROPRO wSumm

□ SUPER-SORT I — Sort, merge, extract ulilily as abso-© lute executable program or linkable module in Microsofl

formal. Sorts fixed or variable records with data in binary,BCD, Packed Decimal. EBCDIC. ASCII. Ifoating, fixedpoint, exponential, field justified, etc. etc. Even variablenumber ol lields per record! $225 $25

D SUPER-SORT II — Above available as absolule pro-© gram only $175 $25

D SUPER-SORT III — As II wilhout SELECT/EXCLUDE© $125/525

CI WORD-STAR — Menu driven visual word processing© syslem lor use with standard terminals. Text formattingperformed on screen. Facilities for text paginate, pagenumber, justify, center and underscore. User can printone document while simultaneously editing a second.Edil facilities include global search and replace, read/write Io other text files, block move. etc. Requires CRTterminal with addressable cursor positioning $445/525

D WORD-MASTER Texl Edilor — In one mode has

© superset of CP/M's ED commands including globalsearching and replacing, forward and backwards in Tile. Invideo mode, provides full screen editor for users wilhserial addressable-cursor terminal $125/525

SOFTWARE SYSTEMS

LJ CBASIC-2 Disk Extended BASIC — Non-tnteractive® BASIC with pseudo-code compiler and runlime interpre-ter. Supports lull file conlrol, chaining, integer and ex-tended precision variables, elc $109/$15

D PASCAUZ — Z-80 native code PASCAL compiler.Produces optimized, ROMable re-entrant code. All inter-lacing to CP/M is through Iha support library. The pack-age includes compiler, companion macro-assembler andsource lor the library. Requires 56K and Z-80 CPU.Version 2 Includes all of Jensen/Wirth excepl variant re-cords 7 $275/525

Version 3 Upgrade wilh vanant records and strings ex-pected 2/80 $395/$25

□ PASCAUMT — Subset of standard PASCAL. Gen-® erales ROMable 8080 machine code. Symbolic debugger

included. Supports interrupt procedures and BCD arith-metic lor real variables. CP/M file I/O and assembly lan-guage interface supported Lacks Sets, Enumeration andRecord data lyp*s. Manual explains BASIC Io PASCAL

conversion. Requires 32K $95/530

Source for PASCAL/MT run lime package. RequiresMAC. (See under Digtlal Research.) $50

STRUCTURED SYSTEMS GROUP

D GENERAL LEDGER — Interactive and flexible sys-lem providing proof and report outputs. Customization olCOA created inleraclively. Multiple branch accountingcenters. Extensive checking performed at data entry for

Eroof. COA correctness, etc. Journal entries may beatched prior to poslmg. Closing procedure aulomatieallybacks up input files. All reports can be tailored as neces-sary. Requires CBASIC-2 $899/525

D ACCOUNTS RECEIVABLE - Open Hem systemwith oufpul lor internal aged reports and customer-ori-ented slatemenl and billing purposes. On-Line Enquirypermils informalion lor Customer Service and Credit de-partments. Interface Io General Ledger provided il bothsystems used. Requires CBASIC-2 $699,525

D ACCOUNTS PAYABLE - Provides aged state-ments of accounts by vendor with check wriling lorselected invoices. Can be used alone or with GeneralLedger and/or wilh NAD. Requires CBASIC-2$899/525

D ANALYST — Customized data entry and reporting sys-tem. User specifies up Io 75 dota items per record. Inler-aclive data entry, retrieval, and update facility makesinformation management easy. Sophislicated reportgenerator provides customized reports using selectedrecords with multiple level break-points for summariza-tion. Requires CBASIC-2. 24 x 8 CRT, printer and 48Ksystem. $225/$15

□ LETTERIGHT — Program to create, edit and lype let-ters or other documents. Has facililies to enler, display,delete and move lext, wilh good video screen presenta-tion. Designed Io integrate wilh NAD lor form letter mail-ings. Requires CBASIC-2 $179,525

D NAD Name and Address selection syslem — interactivemail lisl creation and maintenance program wilh outputas full reports wilh relerence data or reslricted informa-tion for mail labels. Transfer system for extraction andtransfer of selecled records to creale new liles. RequiresCBASIC-2 $79 520

D QSORT — Fast sort/merge program lor liles with lixedrecord length, variable field length information. Up to fiveascending or descending keys. Full back-up of input filescrealed 595 $20

GRAHAM-DORIAN •*■« u

SOFTWARE SYSTEMS iA ZZ'

□ GENERAL LEDGER — An on-line system; no batch-© ing is required. Entries to other GRAHAM-DORIAN ac-® counting packages are automatically posted. User estab-lishes cuslomized COA. Provides transaction register,record of journal ontnss. trial balances and monthly clos-ings. Keeps 14 month history and provides comparison ofcurrenl year wilh previous year. Requires CBASIC-2.Supplier/in source $495 $35

□ ACCOUNTS PAYABLE — Maintains vendor lisl and© check register. Performs cash How analysis. Flexible —@ wriles checks to specific vendor for certain invoices or

can make partial payments. Automatically posts loGRAHAM-DORIAN general ledger or runs as stand alonesystem. Requires CBASIC-2. Supplied in source. $495/535

□ ACCOUNTS RECEIVABLE - Creates trial balance© reports, prepares statements, ages accounts and records® invoices. Provides complete informalion describing cus-tomer payment activity. Receipts can be posled lo differ-ent ledger accounts. Entries automatically updateGRAHAM-DORIAN general ledger or runs as stand alonesyslem. Requires CBASIC-2. Supplied in source. $495. $35

□ PAYROLL SYSTEM — Maintains employee masler© file. Computes payroll withholding for FICA, Federal and!g) State taxes. Prinls payroll register, checks, quarterly re-ports and W-2 forms. Can generate ad hoc reports andemployee form letters wilh mail labels. RequiresCBASIC. Supplied in source code $495/535

D INVENTORY SYSTEM - Captures stock levels.

© costs, sources, sales, ages, turnover, markup, etc.

(g> Transaction information may be entered for reporting bysalesman, type of sale, date of sale, etc. Reports avail-able both lor accounting and decision making. RequiresCBASIC. Supplied in source code 5495 $35

D JOB COSTING — Designed for general contractors.

© To be used interactively with olher GRAHAM-DORIAN

fgj accounting packages for tracking and analysing ex-penses. User establishes customized cost categoriesand job phases. Permits comparison of actual versusestimated costs. Automatically updates GRAHAM-DORIAN general ledger or runs as stand alone system.Requires CBASIC-2. Supplied in source. .. $495 $35

□ APARTMENT MANAGEMENT SYSTEM - Fi© nancial management system for receipts and security■m deposits of apartment projects. Captures data on vacan-cies, revenues, etc. (orannual trend analysis. Daily reportshows lale rents, vacancy notices, vacancies, incomelost through vacancies, elc. Requires CBASIC. Suppliedin source code $495/$35

D CASH REGISTER — Maintains files on daily sales.

© Files dala by sales person and ilem. Tracks sales, over-

iG) rings, refunds, payouts and tola! net deposits. Requires

" CBASIC. Supplied in source code $495/535

U tiny C — Interactive interpretive system lor leachingstructured programming techniques. Manual includes fuil

source listings $75/540

D BDS C COMPILER — Supports most major features% of language, including Structures, Arrays, Pointers,recursive funclion evaluation, linkable wilh library lo 8080binary outpul. Lacks dala initialization, long & float typeand static & register class specifiers. Documentation in-cludes "C" Programming Language book by Kernighan &Ritchie $110/515

□ WHITESMITHS' C COMPILER - The ultimate in© systems software lools. Produces laster code than Pas-cal wilh more extensive facilities. Conforms to Ihe lullUNIX'" Version 7 C language, described by Kernighanand Ritchie, and makes available over 75 functions forperforming I/O, string manipulation and storage alloca-tion. Linkable to Microsoll REL files. Requires 60K CP/M

$630 530

D POLYVUE/80 — Full screen edilor lor any CRT with(S) XY cursor positioning. Includes vertical and horizontalscrolling, interactive search and replace, automalic textwrap around for word processing, operations for manipu-lating blocks ol lext, and comprehensive 70 page manual. $135:515

□ POLYTEXT/80 — Texl formatter for word processing@ applications. Justifies and paginates source text files. Will

generate form letters with custom fields and conditionalprocessing. Support lor Daisy Wheel primers includesvariable pitch justification and motion oplimizalion. S05/S15

D ALGOL-60 — Powerlul block-structured languagecompiler featuring economical run lime dynamic alloca-tion of memory. Very compact (24K lotal RAM) syslemimplementing almost all Algol GO report features plusmany powerful extensions including string handling direeldisk address I/O etc. Requires Z80 CPU ... S199$20

Prices and specifications subject lo change without notice

] Z80 DEVELOPMENT PACKAGE - Consists ol;

*) (1) disk file line editor, wilh global inter and inlra-line facili-lies; (2) Z80 relocating assembler. Zilog.Mostek mne-monics, condilional assembly and cross relerence tablecapabilities: (3) linking loader producing absolute Intelhex disk lile $95/$20

J ZDT — Z80 Debugger lo Irace, break and examine reg-i> isters with standard Zilog Moslek mnemonic disassem-bly displays. $35 when ordered with ZBO DevelopmentPackage S5051O

] D1STEL — Disk based disassembler lo Inlel 8080 orTDL'Xilan Z80 source code, listing and cress relerencefiles. Intel or TDL'Xilan pseudo ops optional Runs on8080 565 $10

] DISILOG — As DISTEL lo Zilog Mostek mnemonicD files. Runs on Z80 only $65/$10

] TEXTWRITER III — Texl formatter lo justify and pagi-& nate letters and olher documenls. Special fealures in-clude insertion of lext during execution from olher diskliles or console, permitting recipe documents to becrealed from linked fragments on olher files. Has facilitieslor scried index, table ol contents and loolnole insertions.

Ideal lor contracts, manuals, elc $125 $20

] POSTMASTER — A comprehensive package lor mailD list maintenance. Fealures include keyed record extrac-lion and label production. A form letter program is in-cluded which provides neat letters on single sheel or con-tinuous forms. Requires CBASIC-2 $150 $25

j WHATSIT?*™* Inleraclive daia-base syslem usingassoc alive tags lo retrieve information by subject. Hash-ing and random access used for last response. RequiresCBASIC-2 $1 25, $25

] XYBASIC Inleraclive Process Conlrol BASIC — Fulldisk BASIC features plus unique commands lo handlebyles, rotate and shift, and lo test and set bits. Availablein Integer, Extended and ROMable versions.

Integer Disk or Integer ROMable $295/525

Extended Disk or Extended ROMable $395/525

J SMAL/80 Structured Macro Assembled Language —Package of powerlul general purpose texl macro proc-essor and SMAL structured language compiler. SMAL isan assembler language wilh IF-THEN-ELSE. LOOP-REPEAT-WHILE. DO-END. BEGIN-END constructs

$75/$15

] SELECTOR III-C2 — Dala Base Processor to create) and maintain multi Key dala bases. Prints formatted,sorted reports wilh numerical summaries or mailinglabels. Comes with sample applications including SalesActivity. Inventory, Payables, Receivables, Check Regis-ter, and Client/Patient Appoinlments. etc. RequiresCBASIC Version 2. Supplied in source code. $295/520

I CPM/374X — Has full range of functions to create orre-name an IBM 3741 volume, display directory infor-mation and edit Ihe dala set contents. Provides lull dietransler facilities between 3741 volume dala sets and

CP/M files S195 510

) BASIC UTILITY DISK — Consists of: (1) CRUNCH-) 14 - Compacting ulilily Io reduce Ihe size and increasethe speed ol programs in Microsofl Basic and TRS-80Basic. (2) DPFUN - Double precision subrojlmes lorcomputing mneleen transcendental functions includingsquare rool. natural log, log base 10, sin, arc sm, hyper-bolic sin, hyperbolic arc sin, etc. Furnished in source on

diskette and documentation 550/535

I THE STRING BIT — Fortran character siring han-1 dhng. Routines to find, fill, pack, move, separate, con-catenate and compare character strings. This packagecompletely eliminates the problems associated wilhcharacter string handling in FORTRAN. Supplied withsource $45/515

I BSTAM — Utility to link one computer lo another also1 equipped wilh BSTAM. Allows file transfers al full dataspeed (no c^nversic#M/nex), witb-CRC block controlcheck for very/raiarilis error detedhen and automalic re-try. We use ii< ttVgreatf FJL-wttdcarn expansions losend * .COM, et€ft^6jo^*fiiij*i«, 300 baud withphone connection/Efoth-ends riem-one. Standard and Mversions can talk/to one aroHwTCompalibte TRSDOS

version also available .. XZ. $150 $5

I Flippy Disk Kit— Templale and instructions lo modilysingle sided 5'/4" diskettes lor use ol second sioe in sin-gled sided drives $12.50

FLOPPY SAVER Protection for center holes of 5Ut*floppy disks. Only 1 needed pv%li5kelle. Kit containscentering post, pressufe tool, roughs-mil mylar reinforc-ing rings. Installation tools imd rings lor 25 diskeltes.

AH** *14-9S

Re-orders ol rings Bray $7.95

*CP/M is a HademarK ol Digilal Research'"Z80 is a trademark ol Zilog. inc"UNIX is a trademark ol Bell Laboratones■'WHATSIT'' is a trademark ot Computer Heaoware

tCP'M lor Heath. TRS-80 Model I and PolyMorphic 8813 aremodified and must use specially compiled versions Ol systemand applications soilwaret) Modified veision available tor use wilh CPM as impiemeniedon Heath and TRS-80 Model I computers

ShoppingList No.8

Software for most popular 8080/Z80 computer disk systems includingNORTH STAR, iCOM, MICROPOLIS, DYNABYTE DB8I2 & DB8I4, EXIDYSORCERER, SD SYSTEMS, ALTAIR, VECTOR MZ, MECCA, 8" IBM,HEATH H17& H89, HELIOS, IMSAI VDP42 & 44, REX, NYLAC,INTERTEC, VISTA V80 and V200, TRS-80 MODEL I and MODEL II,ALTOS, OHIO SCIENTIFIC and IMS 5000 formats.

Orders must specify disksystems and formats:e.g. North Star single,double or quad density,IBM single or 2D/256.Allair, Helios II.Micropolis Mod I or li.5'/i" soft sector (MicroiCOM/SD SystemsDynabyte). etc.

Prices F.O.B. New York.Shipping, handling andC O.D. charges extra.

Manual cosi applicableagainst price ofsubsequent softwarepurchase

The sale of eachpropriety softwarepackage conveys alicense for use on onesystem only.

TM^

"The Software Supermarket is a trademark ot Lifeboat Associates

Lifeboat Associates, 2248 Broadway. N.Y., N.Y. 10024(212) 580-0082 Telmt:2Z0Sml^4fU,/uem^Ci,/J

one square in any compass direction, detect a barrier, orlocate the cheese. Surely radar or any other sophisticatedtool is not needed to solve the Look problem.

Sit back and watch R move one square at a time aftereach command it is given. Recall, however, that Look is agame played only by a mechanical mouse without humanintervention; R is a robot. A robot can be defined asfollows:

Robot: Any device that operates without directhuman control.

By this definition, a wall clock is a robot because itkeeps time independently of direct human instruction.An automobile, however, must have direct contact witha human in order to operate.

The Look mouse must be given a brain with enoughintelligence to find its own way from one square toanother. This is where the concept of computing arises.

The Concept of Computing

A robot that acts without direct human guidance mustpossess two types of control: (1) basic actions and (2) in-trinsic control for sequencing basic actions. The follow-ing two sets are chosen in keeping with the simplest possi-ble design:

ACTIONS: STEP X, set condition code, BARRIER,FOUND, NOT FOUND, and START,STOP, where X is N, W, E, S.

CONTROL: simple sequence of a collection of ac-tions, looping of actions, decision(branch) capability.

These actions and control are programmed into Rthrough some yet to be determined mechanism. Apseudolanguage will be used to illustrate the programs inthis article, but it is important to remember that everyprogramming language for every computer known to theauthor has at least the three control constructs listedabove; that is, it is conjectured that the intelligence beinggiven R is no more than the intelligence of very simplecomputers. This leads to the following hypothesis:

Hypothesis 1: Any robot mouse with the actions andcontrol given to R can be programmed to solve theLook problem.

It is possible to go even further with this hypothesisand claim that the solution to the Look problem is indeedpossible. Possible means that a path from the startinglocation of R to the square occupied by C exists and iscomputable:

Hypothesis 2: Any path leading to C from R is a com-putation, and furthermore, any machine with the pro-perties of R is able to perform such a computation.

There is now a concept of computing. For the game ofLook, a computation involves finding a path. A functionis a set of operations that tries to calculate a computation

BATTERY-WRAP

WIRE WRAPPING TOOL

MODEL BW-2630

!8&Us«&£S

POSITIVE INDEXING

ANTI-OVERWRAPPING

BITS AVAILABLEFOR AWG 26, 28 & 30

BATTERY OPERATED

LIGHT WEIGHT

S5lj^

BATTERIES ANDBIT NOT INCLUDED

BW-2630

BATTERY-WRAP TOOL

$19.85

BT-30

BIT FOR AWG 30

$ 3.95

BT-2628

BIT FOR AWG 26 & 28

$ 7.95

RB-20

TWO NI-CAD BATTERIES

$10.75

I S25.00 / ADD SHIPPING CHARGE S2.00 / NEW YORK CITY f STATE RESIDENTS ADD APPLICABLE TAX

OK MACHINE & TOOL CORPORATION

3455 CONNER STREET, BRONX, N.Y. 10475, U.S.A.PHONE (212) 994-6600 • TELEX: 125091

102 January 1980 © BYTE Publications Inc

Circle 64 on inquiry card.

IMicraHIET

It's off and running. And delivering

as promised.

What is MicroNET?

It is the personal computingservice of CompuServe,Incorporated. CompuServe is anationwide commercial timesharing computer network withlarge-scale mainframes.MicroNET allows the personalcomputer user access toCompuServe's large computers,software and disc storageduring off-peak hours (from6 PM to 5 AM weekdays, all dayon Saturdays, Sundays andmost holidays).

What do I get?

You can use our powerfulprocessors with X-Basic,Fortran, Pascal, Macro-10, AIDor APL. You get 128K bytes ofstorage free (just access it atleast once a month). Softwareincludes games—includingnetworking multi-player games—personal, business andeducational programs.

In addition, there is theMicroNET National BulletinBoard for community affairs,

for sale and wanted notices andthe MicroNET Electronic MailSystem for personal messagesto other MicroNET users. Youcan even sell software viaMicroNET.

NEWIMicroQUOTE, asecurity informationsystem for corporatestocks and public debt.NEW! MicroNET Soft-ware Exchange withdozens of newprograms available fordownloading to yourpersonal computer at aspecified charge.NEW! Executive pro-gramsforTRS-80, AppleII and CP/M systems (soyour machine and ourscan talk to each othererror-free). You canswitch between terminaland local mode whileon line.

What do I have to have touse MicroNET?

The standard 300 baud modem.MicroNET has local phone

service in most major cities (seebelow) and a reduced phonecharge in over a hundred others.

What is the cost?

We've saved the best for last.There is aone-time hook-upcharge of only $9.00! Operatingtime—billed in minutes to yourVISA or MasterCharge card—isonly $5.00 an hour.

Want more information?

Good. Write to us at the addressbelow. We'll send you afullpacket of information aboutMicroNET.

CompuServe

Personal Computing DivisionDept. B

5000 Arlington Centre Blvd.Columbus, Ohio 43220

MicroNET is available via local phone callsin the following cities: Akron, Atlanta,Boston, Canton, Chicago, Cincinnati,Cleveland. Columbus, Dallas. Dayton,Denver, Detroit, Houston, Indianapolis,Los Angeles, Louisville, Memphis, WestCaldwell (NJ), New York, Philadelphia,Pittsburgh, San Francisco, Stamford (CT),St. Louis, Toledo, Tucson andWashington, D.C.

Access to the MicroNET service is avail-able in 153 other cities for an additionalcharge of $4.00 per hour.

". .. but the really impressive stuff is in the back room."

Circle 65 on inquiry card.

BYTE January I960 103

(ie: a path from R to C). A function is computable if Rcan get to C, and a function is undecidable if there is apossibility that R will fail to reach C.

Programming a Function in Look

Now an attempt is made to build a robot R that findsits way to C. The first attempt is again a simple approachto the problem. Suppose R is instructed to go West untilreaching a barrier, then another direction is chosen and itcontinues to travel in that direction until reaching abarrier, and so on. Such a program might look like thepseudolanguage program shown in listing 1.

Of course, this program does not solve the Lookpuzzle. It may correctly locate the cheese C if C is in aboundary square (see figure 2). The problem is that Cmay or may not be in a square along the circular pathestablished by program CIRCLE. Hence, it is undecidablewhether or not CIRCLE computes a path leading to C.

The intelligence of R must be increased in order toguarantee a computable path (as opposed to an undecid-able path). Clearly, the problem with CIRCLE is that itfails to cover every possible square. How can no squarebe left uncovered?

A second simple program (see listing 2) is attemptedthat exhaustively scans every possible square until it lo-cates C. Lines 200 thru 220 move R to a left side square.The program must cover every square, but since R maybe initially placed anywhere within Look, a starting pointmust be established that guarantees an exhaustive scan ofthe sixteen squares. This is done in lines 230 thru 250.

ruiMGSArirr

KEYED FILEMANAGEMENT SYSTEM

Sophisticated applications made simple.

Put data at your fingertips.. .easily accessed, displayed, andupdated by key. MAGSAM'" allows your CBASIC programs tocreate and access sophisticated keyed file structures throughsimple CBASIC statements.Powerful, affordable, and easy to use.

MAGSAM'" is now available in three versions offering an array offeatures and capabilities. Standard MAGSAM" features includerandom by key. sequential by key, generic by key. randomly byrecord number, and physical sequential access techniques. EachMAGSAM'" Package incudes the MAGSAM'" file manager, tutorialprogram, file dump utility. User Guide. Reference Card, and oneyear update service.

• MAGSAM" — Most advanced version. Secondary Indexing withany number of keys, and Record and Key Deletion with automaticreuse of freed space S145f

• MAGSAM II" — Single Key support with full Record and KeyDelete capability $99t

• MAGSAM I™ — Entry level version. Single Key support withoutDelete functions $75f

• MAGSAM" User Guide only — comprehensive tutorial andreference manual $15

Available for 8" soft sector, Micropolis. and TRS-80 disk formats.

Requires CP/M- or derivative and CBASIC, Distributed as CBASIC

subroutines in source form.

Visa and Masterchagre welcome. Dealer and OEM inquiries

invited

OflMG

MICRO APPLICATIONS GROUP

7300CALDUS AVENUEVAN NUYS, CA 91406

' Trademark ot Digital Research t Single site license

CIRCLE:

10

START R;

20

REPEAT LOOP

30

STEP W ; IF FOUND THEN STOP

40

UNTIL W BARRIER ;

50

REPEAT LOOP

60

STEP N ; IF FOUND THEN STOP

70

UNTIL N BARRIER ;

80

REPEAT LOOP

90

STEP E ; IF FOUND THEN STOP

100

UNTIL E BARRIER ;

110

REPEAT LOOP

120

STEP S ; IF FOUND THEN STOP

130

UNTIL S BARRIER ;

140

REPEAT LOOP

150

STEP W ; IF FOUND THEN STOP

160

UNTIL W BARRIER ;

170

STOP CIRCLE

Listing 1: Pseudolanguage program that calculates circular pathson the Look game board.

i,

vc

f

A

\ ■« R ■*

Figure 2: Path computed by the CIRCLE program (listing 1).CIRCLE creates circular paths for R on the game board, whichmay or may not intersect with C. It is therefore undecidablewhether or not CIRCLE computes a path leading to C.

EXHAUST:

200

REPEAT LOOP

210

STEP W ; IF FOUND THEN STOP

220

UNTIL W BARRIER ;

230

REPEAT LOOP

240

STEP S ; IF FOUND THEN STOP

250

UNTIL S BARRIER ;

260

REPEAT LOOP

270

REPEAT LOOP

280

STEP E ; IF FOUND THEN STOP

290

UNTIL E BARRIER ;

300

STEP N ; IF FOUND THEN STOP ;

310

REPEAT LOOP

320

STEP W ; IF FOUND THEN STOP ;

330

UNTIL W BARRIER ;

340

STEP N ; IF FOUND THEN STOP ;

350

UNTIL N BARRIER ;

360

STOP

Listing 2: Pseudolanguage program that makes an exhaustivesweep through every square on the Look board.

104 January 1980 © BYTE Publications lnc

Circle 66 on inquiry card.

R is now in the proper lower left position to begin look-ing for C by systematically visiting every square. This isdone by moving N after every E or W BARRIER is foundas shown in figure 3.

This version of the program for R illustrates two con-ceptually important features. Indeed, this program iscalled an algorithm because (1) it will systematicallycarry out the basic actions in a deterministic (predictable)manner every time it is executed, and (2) it will reach aSTOP statement every time it is run. The question re-mains, however: will this program (algorithm) find Cevery time?

Looking for C

The program for exhaustive search lacks a certainelegance. For example, the sophistication of R could beincreased to add subroutine capability:

SUBROUTINE MOVE: (X,Y)1000 REPEAT LOOP

1010 STEP X; IF FOUND THEN STOP;

1020 UNTIL Y BARRIER;

1030 RETURN

This would reduce program size and complexity byusing pieces of the program iteratively. Such an improve-ment may benefit a programmer or reduce the cost ofbuilding robots, but does nothing to improve the conceptof computing.

The EXHAUST program becomes easier to understandand write when additional control is supplied. However,the addition of subroutines, interrupts, and other sophis-ticated features does nothing to increase the computa-tional power of robots. This is an important fundamentalconcept:

Hypothesis 3: Every function that can be computed,can be computed by a robot with only three controloperations: (1) sequence, (2) looping, (3) conditionalbranching.

If true, this means that every solution to the Look puz-zle is possible with the simple machine designed here.There is no path through Look that cannot be computedwith the power of robot R. Does this mean that everycomputation in Look is computable by R? In this specificgame, the answer is yes. We have not proven the abovehypotheses, but they can be supported by evidence.

What Are the Limits?

What is not computable, if such a simple machine (R) isable to compute every function in Look? (This corre-sponds to finding every path from R to C.) If internal bar-riers are added to Look as shown in figure 4, does R needmore power? The answer is no. A larger, more sophisti-cated program may be required, but it can be constructedfrom the same simple building blocks as before.

Suppose that an attempt is made to fool robot R by re-moving C entirely (see figure 5). What becomes ofalgorithm EXHAUST? Reexamination of the algorithmshows that the program eventually halts when everysquare has been searched by R at least once. The STOPaction executed when C is located is a different STOPthan the one executed when C is missing from the game

+■ c

i

k

Figure 3: The exhaustive sweep solution is an inelegant but effec-tive method that systematically visits every square on theboard, looking for C.

c

R

Figure 4: Adding an internal barrier to the Look game. R doesnot need any more computing power to solve such a layout, butthe program may have to be more sophisticated.

R

Figure 5: Removal of the target C from the game. Although Rcan no longer find C, the program will still halt, and throughsuitable adjustments, the program can tell whether or not C wasfound.

January 1980 © BYTE Publications lnc 105

Heuristics

SpeechLink™

2000

Talk To Your Computer. . .

• Voice data entry to the Apple®computer

• Voice control of your Apple®system

• User variable vocabulary(64 words and up)

• Applesoft & Integer Basiccompatible with or withoutdisk operating system

Useful For. . .

• Collecting inventory data

• Running the Apple® as a terminal

• Controlling production testequipment (say "test 2")

• Menu selection of programs(say "stocks")

• Entering stock market data

• Educational programsforthe kids(say "square")

See your computer dealer.Model 2000 suggested retail price$259, model 20A $189.

Heuristics

INC

1285 HAMMERWOOD AVENUESUNNYVALE, CALIFORNIA 94086408/734-8532

Apple® is a registered trademark of Apple Computer Corporation

ll

"

I

i

R

Figure 6: A heuristic technique for finding C. The programmerhas assumed that C is more likely to be found in the centersquares, and has thus accelerated the search at the expense of anoccasional failure.

board. Can it be known which stop is executed whenEXHAUST halts?

Suppose lines 210, 240, 280, 300, 320, 340, and 360 inlisting 2 are modified to display the condition code settingwhen a STOP is executed. Then when the robot halts, thecondition code can be examined to see if it says FOUNDor NOT FOUND.

Indeed, R can be built cleverly enough so that it stopsand informs you of its condition. This requires that Reventually stop. When it stops, it is asked whether or notit has found a path to C. This leads to another importantconcept in computing:

The Halting Problem: A robot that computes an algo-rithm must eventually halt. If a robot tries to computea function (ie: find a path) that does not guarantee thetermination of its search, the robot is computing anundecidable function.

Normally, undecidable functions are avoided in com-puting. Often, however, the risk of encountering a non-terminating search is not great, and thus the rules can berelaxed to speed up the robot. For example, suppose thatthe EXHAUST algorithm is replaced by a faster heuristic.That is, the search strategy is changed as follows: theexhaustive search procedure is too slow. Its speed can beincreased by increasing the robot's speed (technologicalimprovement in equipment), or by decreasing the searchspace (eliminating the number of squares considered).Perhaps the cheese is in the central squares most of thetime. If so, a nearly perfect batting average can be ob-tained by searching the middle four squares only. Figure6 suggests one possible heuristic for computing a path toC.

Perhaps the "four-square" heuristic will locate C,perhaps not. This approach may seem too casual, butinterestingly enough, much of the software in contem-porary systems is of this nature. That is, many programsare heuristic in nature rather than algorithmic, becausethey have reduced their search space to only the mostprobable paths. One way of defining a heuristic is as "aprocedure for finding the solution most of the time."

106 January 1980 © BYTE Publications Inc

Circle 67 on inquiry card.

,j ; --djfM

^*

I

r^ _ .cwiulhmc

iMiliii

lllll

lllll

^^^—» . If ' ** -,J|j ""01230 «■*—■

■ 1

■f I''''

J

1 1

r I1

B0

if'9'

II

7**"^1

?ISi

i

1

1

'otli'

1 1

Illlll'l ' L

7 n h :lll:'^l: •: : J 4 * , * »fii f - ►

I nil :' * ^ * 1; v

wffi

♦•J

Ifcll'ISilP w n\r.l

».■:-■

0. 0 C (>f|nW|

flSM'h

p

llc-11

1 oil*

oiioij

olli

olk^j,

ollfc"

-|w MWKHT-T-T-T- !T—T"f 'I i LI. J

rKra

I

1

1 -

1

gl &** -

liaL'IiCr**^1!!

a

- ffllf

f 17 .U.I 1 1 . |'f

; S|j

if

III1

ill

J.Lllo Jill.*oti i Vie

i h 'I

—^

^*1

1 t2kiT3arAsM?-a

iniiiiiiiiiiiiiiiiiiiiiiiiiiii

lllfl

32K Board Pictured Above

Why Not the Best?

From The Dynamic RAM Company.

2MHz

4MHz

16K—$249

$259

32K—$375

$395

4BK—$500

$530

64K—$625

$665

We have now been shippingour 2MHz dynamic RAM boardsfor over two years. Hundreds of4MHz boards have been goingout every month since early1979. Our reliability is proven inthe thousands of systems whichcontain our board. Many quality-minded systems houses acrossthe country and overseas areusing our boards for theirequipment.

Our prices still beat all.Despite rising 1 6K memory chipprices (at least from reputablesuppliers), Central Data continuesto give you the best buy inmemory today. Nobody offers aboard with a capacity of 64K,assembled, tested, and guaranteedfor a full year at the price we do.

Circle 68 on inquiry card.

Deselect around PROMs. Our

boards have the important deselectfeature which lets you overlap anyfixed memory in your system withno interference.

Our features make the boardeasily used and expanded. Youaddress our boards on 1 6Kboundaries with mini-jumps (smallshorting plugs that slide over wire-wrap pins) near the top of theboard for easy access. If you wantto expand your board after youhave purchased it, all that youneed to do is add memory. Wecan supply you with expansionpackages ($150-2MHz,$160-4MHz) which include eightRAMs that you can depend on aswell as two mini-jumps foraddressing. And of course, ourboard never generates wait states.

Low power consumption keepsyour computer running cool andreliable. The total powerconsumption of our 16K board istypically less than 4 watts ( + 8V @300ma, +1 6V @ 1 50ma and

-16V @ 20ma). Boards withadditional memory typicallyincrease power consumption only1 watt per 16K!

Standard S-100 Interface. Ourboard is designed to interface withany standard S-100 CPU. All ofthe timing of the board isindependent of the processor chip,and the board is set up fordifferent processors by changingtwo plugs on the board.

Call or write us today. That willguarantee a fast response withmore information on the board. Ormake an order — you'll probablyhave the board in two weeks! Ifyou're interested, also ask for acatalog on our Z8000 16-bitprocessor board designed for theMULTIBUS. All of these productsare available to your local dealer,also.

Central Data Corporation, 713Edgebrook Drive, PO Box 2530,Station A, Champaign, IL 61820.(217) 359-8010

Central Data

BYTE January 1980 107

Hypothesis 4: Many computer programs are heuristicin nature because they do not satisfy the halting pro-blem, or do not cover the search space of solutions.

More has been required of the little robot than is re-quired of real computer programs. Thus, R is a goodmodel of what machines can do. Still, there must besomething R cannot compute. In fact, there is: R cannottell if its program is an algorithm or merely a heuristic.This is one of the cornerstones of computing.

A More Powerful Robot: GR

Suppose a more powerful generalized robot, GR, isconstructed. GR is basically like R, except GR solves aproblem called DECIDE. This new game is played asfollows: the instructions for a program written in robotR's language (eg: the EXHAUST problem) are given GRas its inputs. Thus, GR plays the DECIDE game on a pro-gram instead of a checkerboard. GR is smart enough tointerpret the instructions directly and to determine thehalting condition of R.

Let us assume that the EXHAUST program is given toGR. GR interprets EXHAUST and, when it reaches aSTOP, announces that R has halted. Further, GRannounces HALT NOT FOUND or HALT FOUND,depending on the condition code setting of R. In fact, GRis a general robot because it can interpret programs forother robots. In a sense, GR can simulate R because it caninterpretively execute any program which can be writtenfor R:

Hypothesis 5: Any machine GR that can simulate arobot of the power of R is a universal robot. A univer-sal robot is limited in its power, being able to computeonly computable functions.

Can a problem be found that is too difficult for GR? Itwould be interesting to discover if such an uncomputablefunction exists. GR is quite similar to real computers. Forexample, an Intel 8080 could be simulated on a Motorola6800 to perform the functions of a universal robot. Thus,if problems too difficult for GR are discovered, they willalso be too difficult for the Intel 8080, Motorola 6809,IBM 370, CDC 7600, or Cray-1!

The Halting Problem Revisited

It was stated earlier that the GR machine can interpretany program and decide whether or not it halts. To bemore precise, however, a GR robot cannot in generaldecide whether an arbitrary program from R's library ofprograms will halt or run forever. Notice the emphasis onany arbitrary program. A specific program can be exa-mined and it can be determined that it will halt. This wasdone for the EXHAUST program. However, a decidealgorithm is being sought that can be written before anyprogram from R is tried. Thus, the DECIDE programmust be smart enough to handle any program it is given.This is where the problem appears. Suppose a program iswritten in the language suggested earlier for R. Thislanguage made R powerful enough to compute anythingthat robots can compute. Thus, the DECIDE algorithmcan be written in this language. The DECIDE algorithm isloaded into a mouse just like R, and it becomes super-

mouse GR. Now GR can decide whether or not a givenprogram halts and, if so, whether or not the arbitraryprogram being interpreted has found its solutions. If it isshown that at least one program exists for which GRfails, then the DECIDE algorithm is undecidable (ie: it isnot an algorithm). In fact, there is such a program.

If the DECIDE program itself is input into GR, aparadox is created for GR. If it executes to a STOP actionand announces a HALT FOUND termination, theDECIDE program has succeeded. If, on the other hand,GR reaches a STOP and announces HALT NOTFOUND, then GR must itself have reached a NOTFOUND condition. This, however, is impossible, becauseGR cannot reach a FOUND termination point within theloaded DECIDE algorithm at the same time it reaches aNOT FOUND termination point within the interpretedDECIDE algorithm. Therefore, the DECIDE problem isunsolvable and is, in short, a problem no computer cancompute:

Hypothesis 6: The general halting problem isundecidable. This is an example of a problem com-puters cannot solve.

After that mind twister, it may be argued that such aproblem is of no practical significance. Unfortunately,the halting problem is completely analogous to severalimportant practical problems in computing. Here are afew:

Hypothesis 7: A robot GR that can test any otherrobot R to determine if R is malfunctioning is impossi-ble to build.

Hypothesis 8: A robot GR that can examine any otherrobot and determine if R is secure (impenetrable by ateam of spies) is impossible to build.Hypothesis 9: A robot GR that can examine a pro-gramming language robot R and determine if it iswithout ambiguity is impossible to build.

In essence, it has been illustrated that computers havetheir limits regardless of their size, speed, number ofregisters, or sophisticated instruction sets. This notion issummarized in the next hypothesis:

Hypothesis 10: Progress in computing has led tomicrocomputers and circuits that still cannot solve thesame problems that earlier computers could not solve.

In other words, computing has advanced in a techno-logical sense only, and not in a conceptual sense. Thelimitations of computing remain the same: the power ofcomputing is the same.

All computers do essentially the same thing. Some areeasier to program because they have high-level instruc-tions. Some are faster because their organizations aremore efficient. However, the fundamental problems ofcomputing remain.

Difficult Problems

Fable: An old man was about to send his son intothe world to travel. He bent over and wheezed into hisproud son's face, "Hear me well, son. The world has

108 January 1980 © BYTE Publications Inc

MainframeOwners...

TRS-80 Model

■32Kor64KRAM

« Built-in 8" Floppy (SOOK

Bytes)' Supports 4 Floppies (Up to

2 Megabytes)1 DMA and Vectored

Interrupts for Faster

Throughput

1 Interpreter BASIC (Other

Languages Available 2nd

Quarter 1980)• Z-80A Processor at 4 MHz' Separate Keyboard

Processor> 2 RS-232C I/O Ports,

1 Centronics Parallel Port

the

/ Maybe TRS-80® Model II

Should be Your Next

Hardware Investment!

Designed for business. Radio Shack's designconcept for TRS-80 Model II was to build a busi-ness computer — not a hobby, "home" or per-sonal computer that could be used by the busi-nessman. Model II is compact, fast and powerful.It's ideal for asmall business, and also "just right"for many time-consuming small jobs withinlarger businesses. For firmswith large mainframe com-puters, Model II canhandle the jobs thatconstantly interruptdata processingschedule — or those too hotto wait for open time on themainframe. Use it either as astand-alone computer or anintelligent terminal.

Language. Model ll's in-terpretive BASIC language iseasy to use, and will soon besupplemented by othercompiler languages. Thebuilt-in half-meg disk stor-age can be expanded to twomegabytes. Vectored inter-rupts, direct memory accessand a separate keyboardprocessor add to the throughput.

Availability. TRS-80 Model II is on dis-play at 50 Radio Shack ComputerSales/Service Centers and 100 spe-cialized Computer Departments inmajor area Radio Shack stores. It'sbeing delivered through our 7300 retailoutlets on a first-come, first-servedbasis. Visit your nearest Radio Shackstore for details or write the addressbelow.

Radio /hack

The biggest name in little computers®

A Division of Tandy Corporation * Over 7000 Locations in 40 Countries

TRS-80 Model II 32K

1-Disk Systems from *3450

TRS-80 Model II 64K

4-Disk System (shown) ... 9 6599

Retail prices may vary at individual stores and dealers

Free 24-Page TRS-80 Catalog

Write: Radio Shack, Dept. CMA-413.1300 One Tandy Center,Fort Worth, Texas 76102

Circle 69 on inquiry card.

BYTE January 1980

109

many perplexities."

"Yes, father, I have heard," the young man replied.

"There are two kinds of difficulties that will befall you

as you find your way. There are problems that you

can solve, and problems that you cannot solve. Be

wise and spend your energies only on the problems

you can solve."

"I will remember, father."

The Look example can now be returned to, and energycan be applied to solving a problem that it is possible tosolve. EXHAUST is a blunt approach to computing apath from R to C. It may be, however,that EXHAUST isthe easiest way to compute the location of C.

An algorithm need be only as complex as the problemat hand. Therefore, if the complexity of the problem canbe determined, a program can be designed that is no morecomplex than the problem. Is this possible?

The EXHAUST problem is actually rather uncompli-cated. Suppose that initially the cheese is in any square. Ifthere are S squares, the cheese can be in any one of (S-l)squares with probability 1/(S-1). The average number ofsteps for R to compute along the EXHAUST trail is theaverage of 1+2 + 3 + ...+ (S-l):

S-lAVERAGE = V^

#STEPS t-4

STEPS - 1

STEPSS-l

S2

Hence, the average number of steps to find C is half thetotal number of squares in Look.

The problem can be more difficult if C is located at theworst possible location (eg: at (S-l) steps from robot R).This is called the worst case complexity of Look, orSWORST = (S-l). In either the average or worst casecondition, the EXHAUST algorithm will complete in anumber of steps proportional to S. The complexity ofLook is O(S). Since Sis a straight line when plotted ongraph paper, the Look puzzle is called linear:

Hypothesis 11: Linear problems are easy, polynominalproblems are more involved, and exponential pro-blems are difficult.

Suppose the Look problem is modified to a more rea-listic situation. Try to trace the roots of your family treeback to 1600 AD. A great-great . . . great-grandparent isgiven as a target (C). You must trace your father ormother first, then their father or mother, etc. If yourancestors never practiced incest, remarried, etc, you willhave to compare at least 2" ancestors to find the shortestpath back to your roots, where R = number of genera-tions.

The roots problem is difficult because of the exponen-tial growth in the computation. Thus, an exponentialproblem is hard.

Let us examine another version of Look that poses atest for the power of microcomputers and maxicomputers

64KBYTE EXPANDABLE RAM

DYNAMIC RAM WITH ON BOARD TRANSPARENTREFRESH GUARANTEED TO OPERATE INNORTHSTAR, CROMEMCO. VECTOR GRAPHICSSOL. AND OTHER 8080 OR Z-80 8ASED S100SYSTEMS * 4MHZ Z-80WITH NOWAITSTATES.

* SELECTABLE ANO DESELECTABLE IN 4KINCREMENTS ON 4K ADDRESS BOUNDARIES

* LOW P0WER-8 WATTS MAXIMUM.

* 200NSEC 4116 RAMS.

* FULL DOCUMENTATION.

* ASSEMBLED AND TESTED BOARDS AREGUARANTEED FOR ONE YEAR ANDPURCHASE PRICE IS FULLY REFUNDABLE IFBOARD IS RETURNED UNDAMAGED WITHIN14 DAYS.

ASSEMBLED/TESTED

64KRAM S595.00

48KRAM S529.00

32KRAM 5459.00

16KRAM S389 00

WITHOUT BAH CHIPS S3I9.00

SIOO MAINFRAMEANO CARD CAGE

W/ SOLID FRONT PANEL $239.00

W/ CUTOUTS FOR 2 MINI-FLOPPIES $239.00

30 AMP POWER SUPPLY S119.00

VISTA V-2D0 MINI-FLOPPY SYSTEMS100 DOUBLE DENSITY CONTROLLER204 KBYTE CAPACITY FLOPPY DISKDRIVE WITH CASE S POWER SUPPLYMODIFIED CPM OPERATING SYSTEMWITH EXTENDED BASIC$695.00EXTRA DRIVE. CASE & POWER SUPPLY$395.00

16K X 1 DYNAMIC RAM

THE MK4116-3 IS A 16.384 BIT HIGH SPEEDNMOS, DYNAMIC RAM. THEY ARE EQUIVALENTTO THE MOSTEK, TEXAS INSTRUMENTS. ORMOTOROLA 4116-3.

» 200 NSEC ACCESS TIME. 375 NSEC CYCLETIME.

* 16 PIN TTL COMPATIBLE.

* BURNED IN AND FULLY TESTED.

* PARTS REPLACEMENT GUARANTEED FORONE YEAR.

SB.50 EACH IN QUANTITIES OF B

BETA COMPUTER DEVICES

P.O. BOX 3465ORANGE, CALIFORNIA 9266S

(714) 633-7280

CALIF RESIDENTS PLEASE ADD 6% SALES TAX.MASTERCHARGE & VISA ACCEPTED. PLEASEALLOW 14 DAYS FOR CHECKSTO CLEAR BANK.PHONE ORDERS WELCOME.

KIM/SYM/AIM-65-32K EXPANDABLE RAMDYNAMIC RAM WITHONBOARDTRANSPARANTREFRESH THAT IS COMPATIBLE WITH KIM/SYM/AIM-65 AND OTHER 6502 BASEDMICROCOMPUTERS.

* PLUG COMPATIBLE WITH KIM/SYM/AIM-65MAYBECONNECTEDTOPETUSINGADAPTORCABLE. SS44-E BUS EDGE CONNECTOR.

* USES >5V ONLY (SUPPLIED FROM HOSTCOMPUTER BUS). 4 WATTS MAXIMUM.

* BOARD ADDRESSABLE IN 4K BYTE BLOCKSWHICH CAN BE INDEPENDENTLY PLACED ON4K BYTE BOUNDARIES ANYWHERE IN A 64KBYTE ADDRESS SPACE

* BUS BUFFERED WITH US TTL LOAD.

* 200NSEC4116RAMS.

* FULL DOCUMENTATION

* ASSEMBLED AND TESTED BOARDS AREGUARANTEED FOR ONE YEAR, ANOPURCHASE PRICE IS FULLY REFUNDABLE IFBOARD IS RETURNED UNDAMAGED WITHIN14 DAYS.

ASSEMBLED /

WITH32KRAM

WITH 16K RAM

WITHOUT RAM CHIPS

HARD TO GET PARTS ONLY (NO RAMSI .

HARE BOARD AND MANUAL

mi

110 January 1980 © BYTE Publications Inc

NEW FROMMOUNTAIN HARDWARE.

THE APPLE CLOCK.

NEW UTILITY FORYOUR COMPUTER.

Until now, there hasn'tbeen a Real-Time Clockfor the Apple II*. TheApple Clock from Moun-tain Hardware keeps timeand date in 1 mS incrementsfor over one year. On-boardbattery backup keeps the clockrunning in the event of poweroutage. Software controlled interrupts aregenerated by the clock. That means you cancall up schedules, time events, date printouts.. .all in real time on a programmed schedule.EASY TO USE.

The Apple Clock is easily accessed fromBASIC using routines carried in on-boardROM. With it, you can read time andprogram time-dependent functions forvirtually any interval. From milliseconds todays, months or a year.PLUG IN AND GO.

Plug the Apple Clock into a peripheral sloton your Apple II and you're ready to go.

FEATURES.

• Time and date in 1mSincrements for periodsas long as one year.• Software for calendarand clock routines, aswell as an event timerare contained on on-board ROM.• Program interrupts.• Crystal controlled accuracyof ±.001%.• On-board battery backup keeps your clockin operation even during power outage.

REAL TIME AT THE RIGHT PRICE.

At $199 assembled and tested, it's the clockyour Apple has been waiting for. And, it'savailable now through your Apple dealer.Drop in for a demonstration. Or return thecoupon below.

A COMPLETE LINE.

Mountain Hardware also offers a completeline of peripheral products for many finecomputers.

Mountain Hardware, Inc.

300 Harvey West Blvd., Santa Cruz, CA 95060(408) 429-8600Sounds great.

Send me everything I'll need to know about the Apple Clock.

I've got a computer. Send me information.

Address^

. State.

_Zip_

"Apple II is a trademark of Apple Computer, Inc.

Circle 70 on inquiry card.

BYTE January 1980 111

Figure 7: The traveling salesperson problem. A salesperson wishes to visit all six cities in a given district, once every month,problem is to compute the shortest path that goes through each city only once.

The

alike. Suppose a die is tossed to decide which direction totake: N, W, E, or S. A random number generator is usedto produce a random walk around the Look checker-board. Will such an approach add to the complexity ofcomputation? A random selection introduces chance intothe EXHAUST algorithm. This is called a nondeter-ministic procedure (similar to a heuristic), because theexact path may not be reproducible due to the ran-domness. Eventually the path would be discovered,because there is a nonzero probability that every squarewill be visited by the meandering robot R.

A nondeterministic procedure may be more complexthan a deterministic procedure, or surprisingly it may beless complex, because it reduces the search spacestatistically. For example, under certain constrainingrules, the random walk through Look can produce ananswer in 0(V~S) average steps. This is an improvementover the average for EXHAUST. (The maximum or worstcase analysis can be much greater, however.)

The most difficult problems faced by computers areknown as NP - complete problems. Their algorithms arenondeterministic in nature and perform in a time propor-tional to some power of the length of their input data.This class of problems can be illustrated by examining thetraveling salesperson game.

Traveling Computer Salesperson

Suppose a computer salesperson is given a district withsix cities. Each city must be visited once every month.The salesperson wants to compute the shortest path thatgoes through each city one time only.

A map is shown in figure 7 along with candidate pathsbetween any two cities in the district. Each connectingline is labeled with the distance between cities. What isthe shortest route that begins at A and returns to A afterpassing through every city? Does this problem have asolution? If one path exists, is it unique, or are thereothers of equal distance?

The complexity of this problem and others like it con-tinues to be a conceptually difficult computation for com-puters. The difficulty of a number of important problemsin computing is just being realized.

This raises some philosophical questions for the future.For example, is the functioning of brain cells a complexproblem? If so, is the path established by a thought pro-cess representable as a computable function? Even ifthought is a computable function, it might also belong tothe class of NP - complete problems, and thereby be dif-ficult for computers to handle.

Conclusion

In summary, we must be realistic about the power ofcomputers. There are functions that no computer cancompute, and there are functions that require impressiveperformance to manage. The current crop of microcom-puters is no more able to compute a solution to pro-blems than computers of a decade ago. Programmersmay, however, have learned new ways to apply com-puting power in the interim.

On the optimistic side, many practical problems re-main to be solved in our society. Computers can helpsolve them and, due to the microcomputer revolution,there is an opportunity to economically apply thistechnology to the real world. Along the way, do notforget the limits to computing. ■

BIBLIOGRAPHY

Appl, K and W Haken, "The Solution of the Four-Color-Map Pro-blem," Scientific American, volume 237, number 4, October 1977, page108.

Gardner, M, "Mathematical Games: In Which Joining Sets ofPoints by Lines Leads into Diverse (and Diverting) Paths," ScientificAmerican, volume 237, number 5, November 1977, page 18.Additional discussion of the four-color problem appears in MartinGardner's "Mathematical Games" column in the issues of ScientificAmerican for September 1960, April 1975, and April 1976.

112 January 1980 © BYTE Publications Inc

$3,995

Million-Character Computer SystemOne-Year Transferable Warranty

$3,995

JE^P^

SEE System 6684 Unique Standard Features

• CPU integrated into Diskette Cabinet with

peripheral ports in rear of cabinet

• 4 Full communications ports RS232 or 20

mA/60 mA CL; 75 to 19,200 bits/sec.

$4,995

SEE System 6784 Unique Standard Features

CPU integrated into video terminal cabinet

with peripheral ports in rearVideo has 16 programmable function keys,

128 high resolution characters withgraphics, numeric keypad, reversed video,full editing, 24 x 80 display

Standard Features on All Systems

• Central Processing Unit with 12 slots; 2 MHz (ex-pandable to 4MHz with pipelining architecture)

• 8 Free Slots for expansion; capacity for 442,368characters of memory within standard chassis

• 49,152 characters of 200 ns random access memory;150 ns memory optional

• 8 vectored interrupts; all input and output is interruptdriven

• 1.2 million characters, double sided, dual 8" diskettes.IBM 3740 compatible

• Printer controller; Centronics compatible

• Magnum BASIC. Extremely fast business BASIC withfull editing capabilities, print using, sequential and randomfiles, integer and floating point arithmetic with up to 16digits precision; N-dimensional matrices and much moreA superset of Microsoft 16K extended disk BASIC

• Interactive conversational macro assembler and editorfor 6800 family microprocessors

• One-year transferable limited warranty on parts andlabor for all SEE hardware

• Guaranteed 24-hour turn-around time on repairs

Optional Features on All Systems

• Up to 64 interconnected, intelligent terminals with nodegradation of response time. Each is a stand alone CPU.True distributed processing

• Expandable to 12 MB of 150 ns RAM for each terminal

• Up to 64 RS232 ports with full communications. Talks toany peripheral or CPU with RS232 interface

• Expandable to 4 MB of diskette storageUp to 660 MB hard disk storage with removable modulesANSI standard 10.5 inch tapes (1600 BPI)11 MB cartridge tape systemMatrix and word processing printers from 55 CPS to

1400 LPM

• Choice of 6809 and/or 6512 CPU board with speed of upto 4 MHZ with 150 ns memory

• Interactive relocatable macro assembler, developmentsystem and DOS for 6502 and 6512 microprocessors. Canassemble source programs up to 2 MB long

• PASCAL compiler

• FORTRAN compiler

• BASIC compiler

• COBOL compiler

• Powerful word processing software

• Comprehensive business software, incl. General Ledger,Accounts Receivable, Accounts Payable, Inventory, Payroll;Packages for Physicians, Publishers, Manufacturers, etc.

Quantity discounts to bona fide dealers, OEMS, and schoolsSpecial configurations and modular shipment availableA few distributorships available in the United States and other countries

SYSTEMS ENGINEERING ENTERPRISES

1749 Rockville Pike, Rockville, Maryland 20852(301)468-1822

Circle 78 on inquiry card.

BYTE January 1980 113

lake the mysteryout of programming

with the latest from BYTE Bookstm

You Just Boughta Personal What?

by Thomas Dwyer and Margot CritchfieldWhether you are a novice programmer oran experienced computer user, this book istilled with practical ideas for using a per-sonal computer at home or work. It willtake you through the steps necessary towrite your own computer programs, andthen show you how to use structured designtechniques to tackle a variety of larger pro-jects. The book contains over 60 ready-to-use programs written in Radio ShackTRS-80 Level II BASIC in the areas ofeducational games, financial record keeping,business transactions, disk-based data fileand word processing. $11.95 pp. 256ISBN 0-07-018492-5

The BYTEBook of Pascal

Edited by Blaise W. LiffickBased on the growing popularity of Pascalas a programming language, numerousarticles, language forums and letters frompast issues of BYTE magazine have beencompiled to provide this general introduc-tion to Pascal. In addition, this book con-tains several important pieces of softwareincluding two versions of a Pascal compiler

- one written in BASIC and the other in8080 assembly language; a p-code inter-preter written in both Pascal and 8080assembly languages; a chess playing pro-gram; and an APL interpreter written inPascal. $25.00 Hardcover pp. 342ISBN 0-07-037823-1

Beginners Manual for theUCSD Pascal System

by Kenneth Bowles

Written by the originator of the UCSD

Pascal System, this highly informative bookis designed as an orientation guide forlearning to use the UCSD Pascal System.Once familiar with the system, you willfind the guide an invaluable reference toolfor creating advanced applications. Thisbook features tutorial examples of program-ming tasks in the form of self-study quizprograms. $11.95 pp. 184ISBN 0-07-006745-7

HOOKS OF INTEREST TO COMPUTER PEOPLE"

Please send

D.

D.□ .

copies of You Just Bought a Personal What?. copies of Beginners' Guide for the UCSD Pascal System. copies of The BYTE Book of Pascal

Name

Title

Company

Street

City

State/Province

Code

LJ Check enclosed in the amount of $_□ Bill Visa □ Bill Master ChargeCard No.

Add 60i per book to cover postage and handling

Exp. Date.

BYTE BOOKS Division • 70 Main StreetPeterborough, New Hampshire 03458

ill

iiuiiiiiiiiiNiiiimimiiiimiiiiiiiiiiiiiimiiiiiiiiiiiiiiiiiiiiiim

BYTE News ....

Mlllllllllltllllf IfliltlMIlMMIflllllllMrillfllllllllllllflllllf irilflllllMldllllllllll f 111111 f 11111 (III III1111 f I f I f IIIIIIII11111II f IIII1II1M II If MIIII If III Mil II1111MI f 1111III tl It 11111IIIIII111 111 III

INTEL 32-BIT MICROPROCESSOR RUMORED: As reported in this column last April, Intel wasrumored to be working on a 32-bit microprocessor. The project is moving closer to reality as Intelhas assigned a part number to the device. It will be called the 8800 (not to be confused with theAltair 8800 computer). The instruction set will not be compatible with Intel's 8-bit or 16-bitmicroprocessors. The device will be housed in the new 64-pin QUIP (quad-in-line package, see"BYTE News," June 1979) which is cheaper, smaller, and easier to test than dual-in-line packages.The 8800 is reportedly being developed at Intel's facility in Aloha OR. The first test prototypes arereported to have been produced.

TI RF MODULATOR FCC WAIVER GRANTED: The Federal Communications Commission (FCC)has granted Texas Instruments a waiver which permits TI to connect its personal computers to homecolor television receivers using a radio frequency (RF) modulator. TI originally petitioned the FCCfor approval of the RF modulator system in February 1979. The petition was rejected since theregulations required that the complete system be submitted for approval: TI submitted only the RFmodulator for approval. Subsequently, Texas Instruments applied for a waiver, provided that themodulator unit met the standards.

The FCC asked other personal computer system manufacturers to comment on the TI request.Radio Shack, Apple Computer, Commodore, Mattel, and Atari responded negatively to the request.Apple, Atari, and Mattel went to great expense to comply with the FCC regulations. The RadioShack and Commodore systems, which contain integral displays and do not use RF modulators, donot come under the FCC regulations.

The FCC decision further waives testing by the FCC and merely requires that the manufacturerprovide the FCC with test results showing compliance. In a related action, the FCC relaxed thestandards on RF interference generated by commercial and personal computer systems.

Several personal computer manufacturers that compete with TI have already stated that this waiverwill give TI a competitive advantage. Furthermore, several firms publicly questioned the FCC's rule-making methods in making its decision. The likelihood now is that the other personal computermakers will offer systems with RF modulators. It will probably take these manufacturers at least ayear to bring out such competing systems.

ULTRA MINI-FLOPPY DRIVE INTRODUCED: Sanyko Seiki Manufacturing Co, Tokyo, Japan, hasbegun producing samples of an ultra-small floppy disk drive and controller. Called the FMC-100, ituses a 2-inch floppy disk that stores 8 K bytes on one track. It is intended for use in word-processing typewriters and personal computer systems.

THWARTING COMPUTER SOFTWARE PIRATING: A patent (number 4,168,396) has been issued toRobert M Best, Seattle WA, for a "microprocessor which prevents the piracy of computerprograms." The device reportedly uses cryptography to protect the software. It is called a crypto-microprocessor and stores software in cipher to prevent if from being copied, disassembled, oraltered by unauthorized processes. Authorized users can decipher the software with special encryp-tion keys. The patent states that the device is intended primarily for use in personal computersystems.

AC LINE TO TTL INTERFACE IC INTRODUCED: General Instrument Optoelectronics of Palo AltoCA has introduced a low-cost, 8-pin integrated circuit that can be used to directly monitor ACpower line circuits and provide transistor-transistor logic (TTL) outputs. The device, therefore, canbe used to interface your microprocessor inputs easily and directly to monitor AC power-line-operated devices such as motors, solenoids, relay contacts, and the like. It can also be used todetect power failure and other such applications.

FLAT PANEL TERMINAL DISPLAYS BECOMING AVAILABLE: Computer terminals using flat-screenvideo displays are getting close to the marketplace. The technology is based on the plasma paneldeveloped by Owens-Illinois, Toledo OH, in the late 1960s. Currently, Interstate Electronics ofAnahiem CA, IBM, and Fujitsu have these panels in production. Control Data and NCR are plan-ning large-scale production. IBM now makes approximately 100,000 plasma panels annually, which

January 1980 © BYTE Publications Inc 115

are all used in-house. Interstate Electronics currently sells a plasma display terminal that has a 512by 512 matrix of dots and can display alphanumeric characters and graphics.

Plasma panel makers are working on getting the cost down to the point where these displays cancompete with cathode-ray tube (CRT) displays. This is still expected to take several more years.

RANDOM RUMORS: IBM will soon unveil small business (Model 5105) and multiterminal (Model5130) computers in their 5100 line of microcomputers. The 5105 computer will begin at $4500 andthe 5130 will range from $21,500 to $37,500. The basic 5105 will include 16 K bytes of program-mable memory, a 960-character video display screen, a magnetic tape cartridge, and a thermal orelectrostatic printer. Increasing memory up to 96 K bytes, adding a 1920-character screen, floppydisks, and high-speed printer, and including software packages will raise the 5105 price up to$20,000. It is expected that the 5105 will penetrate the personal computer market to some extenteven though it is intended to be an entry-level business computer system .... IBM is also rumoredto have an intensive research and development effort trying to develop a low-cost alternative to thecathode-ray tube (CRT) screen display. Reportedly they are currently investigating 24 differentalternatives. At this time, the most promising is the multiplexed liquid-crystal display .... It isrumored that a Japanese electronics company will shortly introduce a $600 personal computersystem that is hardware and software compatible with the Radio Shack TRS-80 (Level-II BASIC,16 K version) .... By the end of 1979, over 2,500,000 floppy disk drives had been manufactured.

64 K EPROMS AVAILABLE BY MID-YEAR: Samples of 64 K bit erasable-programmable read-onlymemory (EPROM), organized as 8 K words by 8 bits, are currently being distributed to customers byMotorola, and production quantities are expected to be shipped by the end of the second quarter of1980. Motorola has put their 64 K EPROM in a 24-pin package by multiplexing the program supplyand chip-enable signals on the same pin. Intel and Texas Instruments, it is believed, will use 28-pinpackages for their 64 K EPROMS.

In the meantime, the supply of 2708 EPROMS (1 K words by 8 bits) has caught up to demand andprices are now in the $6 range. The demand for the 2716 EPROM (2 K words by 8 bits) is still verystrong, and hence the devices are selling in the $20 to $24 range.

Texas Instruments is currently the largest manufacturer of EPROMs with about 38% of sales. Intelis second with 29%. Fujitsu and Hitachi share third place with 8% each.

AT&T RUNS INTO TROUBLE WITH UNIX: The Association of Data Processing Service Organiza-tions (ADAPSO) has petitioned the US Department of Justice to take action against AT&T's sale ofsoftware products, particularly the UNIX operating system. UNIX is one of the most popular softwaresystems for larger Digital Equipment Corp (DEC) PDP-11 machines. Most users feel that UNIX isbetter than DEC's software.

ADAPSO maintains that AT&T is in violation of a 1956 consent decree. In 1978 the Justice Depart-ment authorized an investigation after a similar petition by the Computer and Communications In-dustry Association (CCIA).

Developed at Bell Laboratories in 1969, UNIX was offered to non-Bell organizations starting in1973, for $20,000 per computer. In the first half of 1978, Bell reported $580,000 revenues from about800 non-Bell users.

Whitesmiths Ltd, a New York software house, is currently working on an LSI-11 version of UNIX.

IBM and MCA TO MARKET VIDEO DISK: IBM and MCA Inc have formed a joint venture, calledDiscovision Associates, to develop, manufacture, and market video disks and players. Until now,MCA has been the sole manufacturer of optical video disks. It is hoped that this will broaden the useof video disk technology in the home entertainment, industrial education, and information fields.The optical disk technology, which uses a laser to record and play back the recorded material,shows promise for use in the computer field. It could be used to store large amounts of read-onlydigital data in much more compact form than presently is possible on magnetic disks. NorthAmerican Philips is also marketing a video disk player and RCA plans to introduce a system soon.

MAIL: I receive a large number of letters each month, as a result oi this column. H youwrite to me and wish a response, please include a stamped.seli-addressed envelope.

Sol Libes

Amateur Computer Group of New Jersey

(ACG-NJ)

1776 Raritan Rd

Scotch Plains NJ 07076

116 January 1980 © BYTE Publications Inc Circle 72 On inquiry Card..

IS READY ...

WITH SYSTEMS AND SOFTWARE!

. . Feel Free to mm end Match

SYSTEM 1

$1750.00

«£»*?

TwlnMlnluj/aaiSYSTEM?

L-J

1 - $139.00

Leedex monitor

$110.00

Keyboard

MULTIUSER CAPABLE

$1650.00

$775.00

32K s-ioo mainframe T/u 912 Terminal

Tl 810'

SYSTEM 3

mULTIUSER CAPABLE

$1950.00

$985

oak s-ioo mainframe T/u 920 Terminal

$34.50

Diablo 1620

SYSTEM A

mULTIUSER

lDbsr Enclosure

Software:

CPM 1.4 $115.00

CPM2.0 $150.00

MPM MULTIUSER . $350.00

32 megabyte disk

CBASIC . .MBASIC . .FORTRANCOBAL. . .PASCAL..

S115.00 WORDSTAR S495.00

$300.00 ACCTS. PAYA0LE. . . . S699.00

$395.00 ACCTS. RECEIVABLE . S699.00

$625.00 GENERAL LEDGER. . . $899.00

$265.00 SUPERSORT $225.00

Base 2

$499.00

.■:■&«> j

$1350.00

i megabyteDouble Density storage

sn

$1850.00

2 megabyteQuad Density storage

t (Dealers Only)

at&t model 300

DATABASE. . .INVENTORY . .

QSORT

NAD

LETTERRIGHT

$150.00$440.00$ 95.00S 79.00$180.00

West:

DELTA PRODUCTS

1653 E. 28th StreetLong Beach, Calif. 90806Tel: (213)595-7505

East:

DELTA PRODUCTS

1254 South Cedar RoadNew Lenox, Illinois 60451Tel: (815)485-9072

Telex: 182-126 DELTMAR SGHL

Indirect Addressingfor the 6502

Kenneth Skier

25 Myrtle Ave

Cambridge MA 02138

One of the most attractive featuresof the 6502 processor—in fact, of theentire 6500 series—is the flexibilityoffered by its thirteen addressingmodes. Unfortunately, these address-ing modes are not always availablewhen you want them. Indirect in-dexed addressing, for example, isavailable for load and store instruc-tions (and a few others), but not forjump to subroutine (JSR).

A structured approach to program-ming leads one to write many pro-grams as nested subroutines, and it isnot always desirable for the program-mer to specify the addresses of thosesubroutines in advance. For a givenapplication, you may want the userto choose the address of the nextsubroutine that the processor willexecute, or you may want software tocalculate or look up that adddress,perhaps in response to sampled inputconditions. In either case, you needindirect addressing for the jump tosubroutine instruction.

In the 6502, the jump to subroutineinstruction has only one addressingmode: absolute. So how can you getwhat the 6502 does not have?

One solution is to use the jump tosubroutine instruction (JSR, hexa-decimal 20) in your program, andfollow it with two reserved bytes (ie:when you write the program, you do

not care what is in those two bytes).The rest of your program followsthose two bytes. When your programruns, it will ask the user to specify theaddress of the next subroutine, or elseit will look up or calculate that ad-dress according to some algorithm. Itwill then store that address in the tworeserved bytes mentioned earlier (lowbyte first). When the 6502 processorexecutes the JSR instruction, it willuse the next two bytes for the addressof the subroutine it is supposed toexecute.

This technique will work, but Iavoid it for several reasons. First, itrequires writing a program that modi-fies itself, and a simple error in such aprogram can cause it to self-destructor subtly deface itself, not somethingI would look forward to debugging.Second, such a program may workfine in programmable memory, but itcannot work in read-only memory.The third reason is the clincher: thistechnique is unnecessary. You canhave a program execute a subroutineand calculate or look up its addresswithout requiring that it modify itself.

What is the solution? Use the zeropage.

Set aside four consecutive bytes inthe zero page of memory. The firstpart of your program, which pre-sumably initializes I/O (input/-

output) ports, variables, flags, tablepointers, etc, will write a hexadecimal20 (JSR) into the first of these zero-page bytes, and a hexadecimal 60(RTS) into the fourth of these zero-page bytes. (It need not do anythingto the second and third bytes.) Whenit is time for your program to selectthe address of a subroutine and thenperform a subroutine jump to that ad-dress, have your program calculate orlook up the subroutine's address andthen store it, low byte first, in thesecond and third zero-page bytesmentioned above.

Now your program can jump to afixed address: the address of the firstof these four zero-page bytes. Uponarrival at the zero page, the processorwill perform a subroutine jump to anew address: the address it previouslylooked up or calculated. When itfinishes executing that subroutine, itreturns to the fourth of the zero-pagebytes, which tells the processor toreturn to the program that called it.In practice your program jumps to asubroutine with a fixed address,whereupon it jumps to a subroutinewith a calculated address. In effect,however, you get indirect addressingfor the JSR instruction.

The effect can be impressive.

Using this technique, you can dis-play an address, then let the user

118 January 1980 © BYTE Publications Inc

AUND^LIKE OPERATING SYSTEMFOR Z-80 MICROPROCESSORS

1. Multi-user & multi-process

2. Input/output redirection using pipes, links, and forks

3. User accessible spooler & event queue manager

4. Powerful structured macro language for shell programming

5. WHENEVER, UNTIL, IF-ELSE, & WHILE shell commands

6. Mountable, hierarchical, password-protected file systems

7. Global, group, & individual file permissions

8. Memory support from 64k to 1M; disk support to 4000M

9. Installed on Industrial Microsystems & Cromemco CS-3

10. Compatible with software developed on CP/MR

11. Now available from Y)urdon

12. Single CPU license: $350, support: $75/year

Available now from:

UNIX is a trademark of Bell LaboratoriesCP/M " is a trademark of Digital Research Inc.

YOURDDN SOFTWAREPRODUCTS GROUP

1133 Avenue of the Americas/New York, N.Y 10036/(212) 730-5840

Circle 71 on inquiry card.

BYTE January 1980 119

change that address or execute it as asubroutine. It is an effective way togive a GO function to a read-onlymemory monitor. I have discoveredmany other applications for thistechnique in system software andapplications programs.

Using this technique, your programcan jump to the Xth subroutine in atable: the table would simply be a listof the addresses of eligible sub-routines. Assuming that the begin-ning of your program initialized thefirst and fourth of the zero-page bytes(to hexadecimal 20 and 60, respec-tively), your program might look likelisting 2.

This technique works quite nicely,but why go to all of that trouble eachtime you want to call a subroutine?Listing 3 shows a subroutine namedCALL SUBROUTINE (X). The pro-grammer need only load the Xregister with the number of thedesired subroutine, and call CALLSUBROUTINE (X). (See listing 4 for aprogram segment that does just that.)

In other words, you can call a sub-routine by a name that you've givenit, rather than by its explicit address.To relocate any such subroutine, youneed only change its address in thetable of subroutine addresses; theroutines that call it need not bechanged in any way.

Here is one last point. You do nothave to put the four bytes (20, XX,XX, 60) in the zero page; you can putthem anywhere in programmablememory. However, putting them inthe zero page lets your programoperate on the second and third ofthese bytes (that is, on the sub-routine's address), with the zero-pageaddressing mode available on manyother instructions. Thus, by puttingthose four bytes in the zero page, youcan make your overall programshorter (and probably faster) than itwould be if you put those byteselsewhere in programmable memory.

Incidentally, this technique may beused for any instruction, not just forJSR. To achieve such indirect ad-dressing for other instructions, do notwrite a hexadecimal 20 in the firstbyte; write the op code for theinstruction you want to execute. (Besure that your program follows thatop code with the appropriate one ortwo byte operand, and that your pro-gram writes a return [RTS, hex-adecimal 60] in the byte followingthat operand, or your program, like

Listing 1: A program to initialize the zero-page bytes.

LDA #$20

STA zero page byte #1

LDA #$60

STA zero page byte #4

remainder of initialize routines

Write JRSand

RTS intozero page

Listing 2: The indirect addressing method discussed can be usedto jump to one subroutine in a table of subroutines. If the startof the program initializes the first and fourth byte of the zero-page reference to a jump to subroutine (]SR) command and areturn (RTS) command, the coding for using the table mightlook as above. Note that "Zero Page Byte §3" does not meanaddress 0003; rather it means the address of the third of the zero-page bytes referred to in this article.

Look up addressof Xth subroutineand copy thataddress into thezero pageExecute thatsubroutine

LDA

TABLE, X

STA

zero page byte #2

INX

LDA

TABLE, X

STA

zero page byte #3

JSR

zero page byte #1

remainder of program

Listing 3: Routine to create subroutine call using zero-pageaddresses.

LDA

TABLE,X

Look up address

STA

zero page byte #2

of Xth subroutine

INX

and copy that

LDA

TABLE.X

address into the

STA

zero page byte #3

zero page.

JSR

zero page byte #1

Execute that subroutine

RTS

Return to caller.

Listing 4: Shorter program segment to simulate an indirectsubroutine jump.

LDX subroutine #

JSR CALL SUBROUTINE (X)

remainder of program

Charlie on the MTA [a legendarysubway passenger...RSS], may neverreturn.) In any case, the program thatcalls this function must do so by exe-

cuting a subroutine jump to the firstof these zero-page bytes, even if thosezero-page bytes do something otherthan call a subroutine. ■

120 January 1980 © BYTE Publications Inc

i NHHUI mdn

A CompleteLibrary of M6800System Software!

These books will help you code, assem-ble, link, load, relocate, and debug

your 6800 assembly language programs. Each book includes completesource code, object code in hexadecimal format, and machine readable(PAPERBYTE") bar code listings, to make entering and modifying theprograms as easy as possible.

Tracer: A 6800 Debugging Program is for the programmer looking forgood debugging software. Tracer features single step execution usingdynamic break points, register examination and modification, andmemory examination and modification. This book includes detailedTracer program notes and a reprint of "Jack and the Machine Debug"(from the December 1977 issue of BYTE magazine).ISBN 0-931718-02-3 Pages: 24 Price: $6Authors: Robert D. Grappel & Jack E. Hemenway

MONDEB: An Advanced M6800 Monitor-Debugger has all the

general features of Motorola's MIKBUG monitor as well as numerousother capabilities. Some of the command capabilities of MONDEB in-clude displaying and setting the contents of registers, setting interruptsfor debugging, testing a programmable memory range for badmemory locations, changing the display and input base of numbers,displaying the contents of memory, searching for a specified string,copying a range of bytes from one location in memory to another, anddefining the location to which control will transfer upon receipt of aninterrupt.ISBN 0-931718-06-6 Author: Don Peters Pages: 88 Price: $5

RA6800ML: An M6800 Relocatable Macro Assembler is a two passassembler for the Motorola 6800 microprocessor. The Assembler canproduce a program listing, a sorted SymbolTable listing and relocatable object code. The ob-ject code is loaded and linked with otherassembled modules using the Linking LoaderLINK68. There is a complete desciption of the6800 Assembly language and its components.Each major routine of the Assembler is describedin detail, complete with flow charts and a crossreference showing all calling and called-byroutines, pointers, flags, and temporaryvariables. In addition, details on interfacing andusing the Assembler and error messagesgenerated by the Assembler are included. Thisbook provides the necessary background forcoding programs in the 6800 assembly language,and for understanding innermost operations ofthe Assembler.ISBN 0-931718-10-4Author: Jack E. HemenwayPages: 184 Price: $25

LINK68: An M6800 Linking Loader is a one pass linking loader whichallows separately translated relocatable object modules to be loadedand linked together to form a single executable load module, and torelocate modules in memory. It produces a load map and a loadmodule in Motorola MIKBUG loader format. This book provideseverything necessary for the user to easily learn about the system, in-cluding a detailed description of the major routines of the LinkingLoader, including flow charts. While implementing the system, theuser has an opportunity to learn about the nature of linking loaderdesign as well as simply acquiring a useful software tool.ISBN 0-931718-09-0

Authors: Robert D. Grappel & Jack E. HemenwayPages: 72 Price: $8

Tiny Assembler 6800, Version 3.1 is a small (4 K) but sophisticatedand useful assembler for a large subset of the Motorola 6800 assemblylanguage. The book includes detailed notes on the design and im-plementation of Version 3.0 of the assembler, a complete descriptionof the enhancements upgrading the Tiny Assembler to Version 3.1, anupdated user's guide, and complete listings for both versions, makingthis book the most complete documentation possible for JackEmmerich's Tiny Assembler.ISBN 0-931718-08-2 Pages: 80 Price: $9Author: Jack Emmerichs

Pleas.

copies of RA6800ML: An M6800 Relocatable Macro Assembler

copies of LINK68: An M6800 Linking Loader

copies of Tracer: A 6800 Debugging Program

copies of MONDEB: An Advanced M6800 Monitor-Debugger

copies of Tiny Assembler 6800, Version 3.1

Name

Title

Company

Street

□□

City State/Province

Check enclosed in the amount of $

Bill Visa □ Bill Master ChargeCard No Exp. Date.

Code

Add 60c per book to cover postage and handling.

BUI

uririniS

70 Main Street Peterborough NH 03458

m

L ~^rZ-Z^r.

Telephone Dialing by Computer

Edward Joyce

4603 Lyceum Dr

San Antonio TX 78229

How would you like to have yourcomputer dial a seven-digit telephonenumber in about 3/4 of a second? Fora small investment in hardware com-ponents and construction time, yourpersonal computer can dial a tele-phone number faster than you cansay that number. This articledescribes the construction and opera-tion of a dual-tone multiple-frequen-cy (Touch Tone) dialing device thatinterfaces with an ASCII computerterminal and can be used for auto-matic telephone dialing.

Many practical applications can bedesigned around an automatic dialfeature, but the most obvious is a per-sonal telephone directory. In such asystem, a list of frequently dialedtelephone numbers and associatednames is displayed on the computerterminal. The user selects the numberto be dialed by entering a singlecorresponding character on the com-puter keyboard (see table 1). Afeature that could be incorporated isan option to redial the last numberdialed, which would be useful forreaching busy numbers.

Assuming that you have a micro-processor and an ASCII terminal, theadditional hardware that is requiredcan be constructed for less than $20.Furthermore, this Touch Tone inter-face does not require its own I/O (in-

About the Author

Ed Joyce attended the University of Pitts-burgh and Trinity University where he com-pleted a master's degree in Computing andInformation Sciences. Since 1973 he has work-ed as a professional programmer with interestsin multiprocessor microprocessor systems andspeech recognition. Currently he is employedat Small Systems Engineering Dept, Data PointCorp in San Antonio TX. His recreationalinterests are backpacking and motorcycletouring.

Photo 1: Dialing the telephone is done by selecting from a menu displayed by the com-puter on the screen of the video terminal.

put/output) port, the telephone canbe used both automatically andmanually, the programming is rela-tively simple, and either a TouchTone or rotary-dial telephone can beutilized. [Note that the telephoneexchange to which the line is con-nected must be capable of inter-preting Touch Tones. Some tele-phone systems (such as those inPeterborough NH) still cannot useTouch Tone dialing....RSS]

Touch Tone Interface

A block diagram of the hardware isshown in figure 1. Note that com-munication with the Touch Tone

device is established through the ter-minal. Specifically, the computergenerates tones by sending certaincharacters to the terminal. Since mostASCII codes have predesignatedmeanings (for example, hexadecimal30 is the digit 0, hexadecimal 41 is theletter A, etc), it is necessary to assignthe Touch Tone controls to ASCIIcodes not used by your terminal. Alogical choice for these assignments isamong the thirty-two ASCII controlcodes (hexadecimal 00 thru hexadeci-

Touch Tone is a registered trademark of theBell System for its dual-tone multiple-fre-quency signaling equipment.

122 January 1980 © BYTE Publications Inc

'Superbrain is a registered trademark of Intertec Data Systems.

System Specifications

Microprocessors

Word SizeExecution TimeMachine InstructionsInterrupt ModeFloppy Diak

Storage Capacity

Data Transfer RateAverage Access TimsMedia

Disk RotationInternal MemoryDynamic RAMStatic RAM

ROM Storage

Display SizeDisplay FormatCharacter FontLine Drawing Charat-Display PresentationBandwidth

Co

imunicationa

Screen Data Transfer

Auxiliary Interface

Parallel Interface

S-1 00 Bus

Transparent Mode

Parity

Transmission Mode

Addressable CursorSystem Utilities

Disk Operating System

DOS SoftwareOptional Soitware

FORTRAN

COBOL

BASIC

Application Packages

Twin ZSOA's with 4MHZ Clock Frequency One ZSOA (the host processor) performs all

processor and screen related functions The second ZSOA is "down-loaded" by the host to

execute disk I/O When not processing disk data, the second Z80 may be programmed by

the host for other processor related functions

8 bits

1 0 microseconds register to register

158

All interrupts are vectored

320K total bytes formatted on two double density drives Optional external 10-300

megabyte hard disk storage is available using optional S-100 bus adaptor

250K bits/second

250 milliseconds 35 milliseconds track-to-track

5"- inch mini-disk

300 RPM

64K bytes dynamic RAM

256 bytes of static RAM is provided in addition to the mam processor RAM This memory

is used for program and'or data storage for !he auxiliary processor

1 K bytes standard Allows ROM "bootstrapping" of system a! power-on ROM storage is

2708 compatible and may be reprog rammed by the user lor custom applications

1 2-mch. dynamically focused EM phosphor25 lines x 80 characters per line8x8 character matrix on a 8 x 12 character field. Eleven special graphics symbols used for form generationLight characters on a dark background Reversible through keyboard program selection.20 MHZReversed image (block cursor)

Memory-mapped al 38 kilobaud Serial transmission of data at rates up to 9600 bps

Universal RS-232 asynchronous Synchronous interface optional

Radio Shack TRS-80 compatible

Printed circuit edge connector provided for connection of optional S- 100 bus adaptor

Enables display of all incoming and outgoing control codes

Choice of even. odd. marking, oi spacinci

Half or Full Duplex One oi two slop bits

Direct positioning by either disciete or absolute addressing

CPM

An 8080 disk assembler, debugger

text editor and file handling utilities

Keyboard

Alphanumeric Charade;Special FeaturesNumeric PadSpecial Functions KeysCursor ControlInternal ConstructionCabinetryComponent Layout

Mounting

Environment

Weight

Physical Dimensions

Environment

Power Requirements

AN'Sl standard Relocatable, random and sequential disk access

ANSI standard Relocatable, sequential, relative and indexed disk access

Sequential and random disk access Full string manipulation, interpreter

Extensive software development tools are available including software for the following

applications Payroll, Accounts Receivable. Accounts Payable. Inventory Control. General

Ledger and Word Processing

■ Generates all 1 28 upper and lower case ASCII charactersN-Key Rollover. Automatic repeat (at 15 CPS). Keyboard lock/unlock0-9. decimal point, comma, minus and four user-programmable function keysUp to 64 user-defined two-key function sequencesUp. down, forward, backward, and home

Structural foam

Two board modular design All processor related functions and hardware are on a singleprinted circuit board All video and power related circuits on a separate single boardThese two boards are interconnected via a single 22-pin ribbon cableCRT and two circuit boards mounted to base CRT in a rigid steel frame Disk Drive assem-bly mounted into upper cover lor ease of servicing

Approximately 45 pounds14 7"" (H) x 21 1» (W) x 23 -/-• (D)

Operating 01 to 50 C Storage 0 to 85 C, 10to95%rel humidity - non condensing.I 1 5 VAC. 60 HZ, 1 AMP (optional 230VAC50HZ model available)

SUPERBRAIN™

The Honor Graduate

OEM's...End Users...Computer Dealers.

I

SuperBrain users get exceptionalperformance for just a fraction of whatthey'd expect to pay. Standard systemfeatures include: two double density mini-jfloppies with 320K bytes of disk storage,164K of RAM memory to handle even the^most sophisticated programs, a CP/M DiskOperating System with a high powered texteditor, assembler, debugger and a diskformator. And, with SuperBrain's S-100 busadaptor, you can add all the programmingpower you will ever need. . . even a 10megabyte disk!

SuperBrain's CP/M operating system boastsan overwhelming amount of availablesoftware in BASIC, FORTRAN, COBOL, andAPL. Whatever your application . . . GeneralLedger, Accounts Receivable, Payroll,Inventory or Word Processing . . . SuperBrainis tops in its class. But best of all, SuperBraintackles your toughest jobs for less than one-third the cost of other similar systems.

You'll appreciate the careful attention givento every engineering detail. StandardSuperBrain features include: a full ASCIIkeyboard with numeric pad and user-pro-grammable function keys. A non-glare,dynamically focused, 1 2-inch CRT for sharpimages everywhere on the screen. Twin Z80microprocessors to insure efficient datatransfer to auxiliary peripheral devices. Auniversal RS-232 communications port forserial data transmission. And, a single boarddesign to make servicing a snap!

Performance and packaging have neverbeen better matched. Your operators willappreciate SuperBrain's good looks. You'llappreciate SuperBrain's outstanding value.Twin Z80A processors, dual double densitydisk drives, and a high resolution CRTterminal. All in a single, smart looking, self-contained desktop unit. And, all for a pricethat's substantially less than the competition!

Make no mistake about it. The freshmanstudents in the small systems business can'tbegin to compete with this year's honorgraduate. The SuperBrain. The only systemat the top of its class in price and performance

DEALER/OEM QUANTITIES AND SPECIAL PRICING AVAILABLE VIA MICROAMERICA DISTRIBUTING

NEECO

679 Highland AveNeedham, MA02194

Mon-Fri 9:30-5:30

MasterCharge &

Visa Accepted

(617)449-1760

Microcomputer Systems Division

Telex: 951021

MICROAMERICA DISTRIBUTING

"Nationwide distributors of Computer Equipment"

21 Putnam Street

Needham, MA ,«„—» --« mr%*n

02194 (617)449-4310

Circle 83 on inquiry card.

Circle 74 on inquiry card.

BYTE January 1980 123

AccessCode

123

Number

381-9604

699-1626

1-614-353-7795

Description

ParentsOfficeSpouse's Parents

9ABCD

828-3384

Weather

828-0553

Computer Shop

227-8341

Fire Dept

227-7201

Police Dept

824-5222

Dial-A-Prayer

Last Number Dialect

Table 1: Typical information displayed on the computer terminal in an automatictelephone dialing system that can be set up using the dialing device described in thisarticle. The user types a single-character access code on the computer keyboard and thesystem dials the corresponding telephone number automatically.

TOUCH TONEDEVICE

Figure 1: Block diagram of connections in the system.

High Group

r

Column

1

1209 Hz

Column

2

1336 Hz

Column

3

1477 Hz

Column

4

1633 Hz

/- Row 1' 697 Hz

1

2

3

A

Row 21 770 Hz

4

5

6

B

Row 3852 Hz

7

8

9

C

V. Row 4

941 Hz

*

0

#

D

LowGroup

Table 2: Row and column input lines on the integrated tone dialer device, associatedtone frequencies, and corresponding digits or signaling codes derived from the combina-tion of two tones of different frequency.

mal 2F). Most terminals use ten ortwelve of these thirty-two codes forpredesignated functions (such as linefeed and carriage return). However,there are generally about twentycodes that can be used for other pur-poses. The Touch Tone device de-scribed here will use ten of these con-trol characters.

How are the ASCII control char-acters sent to the Touch Tone device?By utilizing the decoding logic of theterminal. In units such as theSouthwest Technical Products Com-pany CT-64, all thirty-two controlcharacters are decoded by the ter-minal. Some of the control charactersare acted upon by the terminal (eg:line feed); however, those which arenot used are brought out to labeledpads on the main circuit board forcustom use and user-defined func-tions. For tone generation, simplychoose ten of these user-defined con-trol characters and connect theappropriate pins to the correspondingpins of the Touch Tone device.

Terminals which do not decode theunused ASCII control characters ordo not present at least ten pins foruser-defined functions require con-struction of a control-characterdecoder. The control-characterdecoder runs in parallel with the ter-minal and requires only two inte-grated circuits.

Touch Tone Generating Circuit

Now that the method of interfacingthe terminal with the Touch Tone cir-cuit has been described, the actualoperation of the Touch Tone devicewill be discussed. Basically, it consistsof two medium-scale integration(MSI) quad S — R latches, a Mostekintegrated tone dialer, and a relay forswitching the Touch Tone device tothe telephone.

The integrated tone dialer requirestwo inputs (a row input and a columninput) to generate a tone. These inputsignals activate tones as shown intable 2. Activating row 1 and column1 generates the tones for the digit 1;activating row 3 and column 2 gen-erates the tones for the digit 8, etc.

124 January 1980 © BYTE Publications lnc

IDS Announces

S-100 Energy Management Module

The 100-EMM Energy Management Module provides temperature measurement at four separate locationsindoors or out; monitors eight (8) doors, windows, or fire sensors; controls six external devices via relay or op-toislator; and provides an intrusion alarm with battery backup (alarm operates even during primary power out-ages). Put the 100-EMM to use in your home or business and claim a 30% tax credit for the cost of your S-100computer system including the 100-EMM. (Purchasing the 100-EMM can actually save you several times itscost in tax credits. Full instructions for filing are included in the 100-EMM manual.)

BUY THIS S-100 BOARDAND GET A 30% TAXCREDIT BASED ON THECOST OF YOURCOMPUTER SYSTEM!

100-EMM Energy Management Module

Assembled and Tested $395.00Kit $345.00

Options for 100-EMM:

CP-52 Cable Panel - Terminates two 26-conductor flat cables in 26 screwlugs. Use it for convenient interconnection of the 100-EMMto the "outside world". $45.00

CABL-26-STD 26-Conductor Flat Ribbon Cable - Four feet in length with connectors for 100-EMM and CP-52 above. $35.00 Otherlengths available on special order. Add $1.00 per foot.

OTHER PRODUCTS FROM IDS. The most complete source of S-100 compatible modules for process con-trol, data acquisition, energy management, and data communications.

88-MODEM S-100 ORIGINATE/ANSWER MODEM WITH AUTO-DIALER. Software selectable baudrate provides any baudrate from 66-600 baud. Provides 1.5 stop bits when operated in 5-bit code mode.Auto-answer programs available for CROMEMCO CDOS, CP/M, NorthStar Horizon and MDS, and Alpha Micro.

Assembled and Tested $395.00 Kit $245.00

88-UFC UNIVERSAL FREQUENCY COUNTER

Four software selected inputs. Measure frequency from O-650MHz and period from .luS to 1 Second. Extensive software in-cluded.

Assembled and Tested $299.00 Kit $199.00 Temperature-Compensated Crystal Oscillator option $145.00

88-SAI SYNCHRONOUS/ASYNCHRONOUS INTERFACE

The most versatile serial interface on the market. Computer ac-cess/control of all data and handshake lines and provision formasked interrupts, inversion of any input or output signal, andonboard baudrate generation for 110, 134.5, 150, 300, 600,1200, 2400, 4800, 9600, and many other baud rates. Manymore features.

88-SPM TIME OF DAY CLOCK with battery backup. Set theclock with three out instructions: no delays! Programs includedin North Star BASIC, CBASIC, and 8080 assembly language.

Assembled and Tested with crystal option $199.00 Kit lesscrystal option $99.00 Crystal Option Kit $25.00

88-RCB RELAY CONTROL BOARD

16 Relays on one board. Control appliances, production equip-ment, or even musical instruments (See BYTE Magazine Sept1977 page 12)

Assembled and Tested $299.00 Kit $199.00

Assembled and Tested $299.00 Kit $199.00

INTERNATIONALDATA SYSTEMS, INC.

Mailing Address:

Post Office Box 17269Dulles International AirportWashington, DC 20041

Telephone (703)661-8442

Shipping Address:

400 West Service Road, Suite 130Dulles International AirportWashington, DC 20041 USA

TELEX 901112 IDS CTLY

Circle 75 on inquiry card.

BYTE January 1980 125

Figure 2: Schematic diagram of the dual-tone multiple-frequency (Touch Tone)telephone dialing circuit. Connections tothe terminal apply to the SouthwestTechnical Products Corp CT-64 unit. Ter-minals which do not decode the entireASCII character set may require addi-tional decoding circuitry for use with thetelephone interface. The isolatingtelephone coupler is required for connec-tion to the telephone line of devices whichhave not been given approval by theFederal Communications Commission.

The tone combinations for thecharacters A, B, C, and D (column 4of table 2) do not have correspondingkeys on a normal telephone TouchTone pad but are reserved for futureuse. Since you will be generating onlythe tones 0 thru 9, only inputs forcolumns 1 thru 3 and rows 1 thru 4will be needed. Hence, seven ASCIIcontrol characters will be needed toactivate the three columns and fourrows. Use of the other three ASCIIcontrol characters (for a total of ten)is discussed later.

The purpose of the latches (ICl andIC2) is to hold the output state of thelogic decoder of the terminal. Sincethe terminal processes only one char-acter at a time and the tone dialerrequires the simultaneous presence oftwo input signals, the latch holds thefirst input from the terminal while thesecond input is being transmitted.There is a latch for each column androw of the integrated tone dialer. Thelatch IC2 is also used to control arelay for attaching the tone device tothe telephone. A schematic of thecomplete Touch Tone generating cir-cuit is shown in figure 2.

The output of the integrated tonedialer goes into an isolating couplerconnected to a telephone. Thecoupler must be approved by theFederal Communications Commis-sion, and it is required for user con-

Number Type +5V GND +12V

IC1 74279 16 8

IC2 74279 16 8

IC3 5086N 6 1,7

IC4 LM380 7 14

Table 3: Power supply connections forintegrated circuits in figure 2.

il .A..A.A...A&.

<_> rr

hi u

13 O

O cr

A-AM--A.

126 January 1980 © BYTE Publications Inc

APPLE OWNERS -

EXPAND YOUR SYSTEM

WITH 8" FLOPPY DISK

FROM WIZARD!

WIZARD 2+2

Many software programs are restricted by the 116 K available on the 5"drives now on the market. Some business programs require 1 2 or more disk-ettes, which can be both confusing and error inducing.

WIZARD offers three solutions:

" WIZARD 1 +1" : single 8" drive system; 256K $1695.

"W/ZARD2 + 2" : two 8" drive system; 516K $2495.

"WIZARD PLUS" : two 8" drives, double sided; over 1 megabyte $3195.

All systems are ready to run, fully assembled and tested, and include:

SHUGART full size 8" floppy disk drive(s).

Controller Card for your Apple (48K RAM required)

All interface software, cables, connectors, cabinet and power supply.

ONE YEAR parts and labor warranty from defects in material and workmanship.

WATCH FOR NEW WIZARD PRODUCTS FROM D&T ELECTRONICS:we are currently developing a 10 Megabyte disc, and other hardware/software.

ALL SYSTEMS AVAILABLE NOW (stock to two weeks).SEE YOUR LOCAL APPLE DEALER, OR CONTACT THESE WIZARD DISTRIBUTORS:

MARCOMP COMPUTER DISTRIBUTORS, INC.

175 East Edgewood Drive PO BOX 9194

McMurray, PA 15317 Austin, TX 78766

(412)941-5936 (512)345-9729

DEALER INQUIRIES INVITED

SOFTWARE: We have software available to run on these expanded capacity systems; pleasesend for our list.

If you are a software writer and have programs currently on 5" that wouldbenefit from the expanded capacity of our 8" systems, we would like to hearfrom you.

WIZARD is a registered trademark of D&T Electronics, Inc.Apple is a registered trademark of Apple Computer, Inc.

Circle 76 on inquiry card. BYTE January 1980 127

structed devices which attach to thetelephone company's equipment.Approved couplers can be purchasedfor approximately $5 from electronicsupply houses, or they can be leasedfrom the telephone company for $2 to$4 a month.

As previously mentioned, there arethree more ASCII control charactersrequired by the Touch Tone device.These perform the reset, relay on,and relay off functions. The resetcontrol is used to turn a tone off afterit has been turned on (the tone com-bination is turned on by activating arow/column combination). (That is,once a row and column have beenturned on, they remain on until areset is issued.) Reset is also used toclear the latches after powering up thecircuit. Note that the control char-acter used for reset (pin 13 of the ter-minal 74154) is connected to the resetpin of the latch for each row andcolumn control (ICl and IC2). Asingle reset operation clears all of therow and column latches. This is moreconvenient than clearing the row andcolumn latches individually.

The relay on and relay off controlsare used to make connection to anddisconnect from the telephone. TheTouch Tone device is connected tothe telephone coupler immediatelybefore dialing and is disconnectedfrom the terminal immediately afterdialing. This prevents random signalsand noise (such as that generated atpower on) from entering the tele-phone line from the terminal.

In my system, the power supply forthe Touch Tone device was takenfrom the terminal's power supply.After the Touch Tone generating cir-cuit has been constructed, the volumeoutput from the integrated tone dialershould be adjusted with a VU meterso that it will be in the range of — 6 to0 dB. Output signals less than — 6 dBin level will not be recognized by thetelephone company equipment. Out-put levels greater than 0 dB causecross-modulation into other phonelines. The general operation of theTouch Tone device can be tested off-line by entering the various controlcharacters with the terminal in fullduplex mode.

Introducing...

MINI-FLEX

Designed Specificallyto Protect 5" Diskettes

A4

The NewestMember of TheAdvance Access

DisketteProtection Family

For Further Information

CALL TOLL FREE

800323-0254

ADVANCE ACCESS GROUP

10526 W. Cermak Westchester, IL 60153 312 562-5210"Manufacturers o/Information Processing Supplies"

Dialing

Once the hardware is functioningcorrectly, dialing is simple. Basically,it consists of the following steps:

• Turn the line connection relayon (send the control characterfor relay on to the terminal).

• Turn column on for Nth digit(send the control character forthe column of digit N to the ter-minal).

• Turn row on for Nth digit (sendthe control character for therow of digit N to the terminal).

• Wait 40 ms.

• Turn tone off (send the controlcharacter for reset to the ter-minal).

• Wait 40 ms.

The preceding steps are per-formed once for each digit ofthe telephone (for example,seven times for a local telephonenumber).

• Turn relay off (send the controlcharacter for relay off to the ter-minal).

Note that from the perspective ofthe microprocessor unit, generatingTouch Tones is accomplished in thesame manner as displaying characterson the terminal screen. The 40 msdelays are minimum times requiredby the telephone company equip-ment. A tone must stay on for at least40 ms, and there must be at least a 40ms delay between tones.

Summary

This Touch Tone interface, used inconjunction with a microprocessorand an ASCII terminal, is an exampleof a practical computer application incommunications. I advise personalcomputing enthusiasts who constructtheir own Touch Tone devices to bemost careful when debugging thesoftware. Sending random sequencesof digits through a Touch Tone inter-face can be a painful way to debugyour program (although the pain maynot be felt until the telephone billarrives a few weeks later). ■

Acknowledgements

/ am grateful to Dink Stockert, Dr DavidCrouch, and Carl Zettnerfor their assistance inthe design and construction of the hardware.Lynn Mason, of Cimarron Information Sys-tems Inc, was very generous in providing acomputer system for preparation of the text ofthis manuscript.

128 January 1980 © BYTE Publications Inc

Circle 77 on inquiry card.

Build your own microcomputer

as you learncomputer technology at home.

New from NRI! The Most Complete and Up-to-date Home Study Course Ever Offered

As the microprocessor revolutionizes thecomputer world and microcomputers appearalmost everywhere, NRI brings you a new,convenient, and effective way to keep up withthis expanding technology. It's NRI's ComputerTechnology Course, created and designed exclu-sively for learning at home in your spare time.

Featuring NRI's ExclusiveDual Language Microcomputer

NRI goes beyond book learning togive you practical, "hands-on" experience indesigning circuitry, interfacing components,programming, and troubleshooting. As youlearn, you actually assemble NRI's designed-for-learning microcomputer, incorporating the latestadvances in the state of the art. It looks andoperates like the finest of its kind, actually doesmore than many commercial units. But NRIengineers have designed components andplanned assembly so it demonstrates importantprinciples, gives you working experience in detect-ing and correcting problems. And it's yours tokeep, put to work in your own home or business.

You also build and keep your own testinstruments, including a transistorized volt-ohm meter and CMOS digital frequency counter.And NRI's Discovery Lab® broadens yourhorizons with specialized experiments andtheory demonstrations.

The Proven Wayto Learn at Home

You don't have to worry with travel,classes, or time lost from work when you learnthe NRI way. As they have for more than 60

years of teaching technical subjects, NRI bringsthe material to you. You study in your spare time,at your convenience, using "bite-size" lessonsthat program material into logical segments foreasier assimilation. You perform experimentsand build equipment using kits we supply. Andyour personal NRI instructor is always availablefor consultation should you have questions orproblems. Over a million students have alreadyshown the effectiveness of NRI training.

Choice of Courses

Several courses are available, dependingupon your needs and P" """ ™" """ ™" 'background. NRI's MasterCourse in ComputerTechnology starts withthe fundamentals, ex-plores basic electronicsand digital theory, thetotal computer world,and the microcomputer.The Advanced Course,for students alreadyversed in electronicsand general comput-ers, concentrates on themicroprocessor and mic-rocomputer. In bothcourses, you build allinstruments and yourown computer.

Send for Free Catalog...No Salesman Will Call

Get the details on these exciting newcourses in NRI's free, 100-page catalog. Showsall kits and equipment, lesson outlines, and fullinformation, including facts on other electronicscourses. Mail the coupon today and we'll rushyour catalog. No salesman will ever call. Keep upwith the latest technology as you learn on yourown computer. If coupon has been removed,write to NRI Schools, Computer Department,3939 Wisconsin Ave., Washington, D.C. 20016.

NRI

NRI Schools

McGraw-Hill Continuing

Education Center3939 Wisconsin AvenueWashington, D.C. 20016NO SALESMAN Will CALLPlease check for one free catalog only.

All career coursesapproved under GI BilD Check for details.

D Computer Electronics Including

MicrocomputersD TV/Audio/Video Systems Servicing

□ Complete Communications Electronicswith CB • FCC Licenses * Aircraft,Mobile, Marine Electronics

□ CB Specialists Course

□ Amateur Radio • Basic and Advanced

□ Digital Electronics • ElectronicTechnology • Basic Electronics

□ Small Engine Repair

□ Electrical Appliance ServicingD Automotive Mechanics

D Auto Air Conditioning

□ Air Conditioning, Refrigeration, & HeatingIncluding Solar Technology

(Please Print)

City/Slate/Zip

Accredited by the Accrediting Commission of the National Home Study Council

170-010

BYTE January 1980 129

Analysis of Polynomial

Functions with the

TI-59 Calculator

Part 2

Pierre Chance20 Rue de Longchamp75116 Paris FRANCE

Consider the following polynomial:

P(x) = x4 - 8x2 + 7

For P(x) = 0 it is essential to study the characteristicelements, derived polynomials P' (x) and P"(x), andautomatically plot the function curve. The procedure isas follows:

1. Read the magnetic card of the main program ingroups 1 and 2.

2. Initialize by depressing key A.

3. Enter each of the coefficients with the keys. Startwith the coefficient for x6 by depressing key B eachtime. A 0 is entered for any term not having apower of x. Thus, you can perform the sequence 0B, 0 B ,1 B, 0 B, —8 B, 0 B, 7 B.

4. Depress key C.

Depressing key C causes the processing of P(x) to its con-clusion with no other intervention.

When reading listing 1, the following are seen suc-cessively, separated by program spaces:

• the column of the seven given coefficients or the 0swhich replace them

• the group of the lower boundary a and upper boun-dary b

• the group of interval (b — a) and increment Ax

• the indication of the maximum error

After these appear the following results:

• the group of roots followed by the series 9. 999...?that indicates the end of determination of the roots

• the table of the thirty-nine values of x

• the table of the thirty-nine values of P(x)

If it is desired to retain the data for P(x) to plot the func-tion curve later, this is the time to record it in groups 3and 4.

The procedure for the first derived polynomial is evensimpler:

1. Depress key B' once; this causes all the coefficientsof P '(x) to be printed one after the other.

2. Depress key C.

The second derived polynomial is obtained in the samemanner. The same applies for the derivatives of order n,provided the polynomial remains derivable. Notice thatit is useless to reinitialize to change from one polynomialto the next.

Plotting the Function Curve

By convention, hereafter designate the data used inplotting the function curve as listing 2. It can be the tableof values of P(x) already recorded or any other that couldbe substituted for reasons that will be discussed. The plotitself will be designated figure 1.

Text continued on page 134

130 January 1980 © BYTE Publications Inc

m

*

* *

Hi :+:

Figure 1: The six segments of output from the 77-59 that define the function curve.

January 1980 © BYTE Publications Inc 131

^gSMINIMAX

C° "FULLY INTEGRATED COMPUTER SYSTEM"

MINIMAX SERIES COMPUTER

PRINTER NOTINCLUDED IN PRICE

THE MINIMAX SERIES WAS DESIGNED

TO OFFER THE MARKET MINICOMPUTER

CAPABILITIES AT MICROCOMPUTER PRICES.

COMPARE THE CAPABILITIES & PRICE!

CONTACT NEECO FOR FULL SPECS - FREE MINIMAX MANUAL.

MEET THE

THE MINIMAX SERIES COMPUTER WAS DESIGNED BY INDUSTRY PROFESSIONALS.

MINIMAX COMPUTER compare the price and features to any other computer in its classi

•THE MINIMAX SERIES COMPUTER IS AN INTEGRATED, COMPACT UNIT CONTAINING THE CPU, DUAL DENSITY DISK STORAGE. 12INCH CRT, AND FULL STYLE KEYBOARD, WITH SEPARATE NUMERIC ENTRY PAD, ALL KEYS (INCLUDING CURSOR) WITH FULLREPEAT • HYBRID 2 MEGAHERTZ 6502 CPU • 108K SYSTEM RAM (48K USER) • FASTEST FLOPPY DISK ACCESS (24K LOADS IN 4.2SECONDS) • 16K ROM CONTAINS COMPUTHINK BASIC (AN EXTENDED MICROSOFT BASIC) WITH EXTENDED PRECISION, DOSINCLUDES COMPLETE FILE I/O WITH FULL RANDOM ACCESS, COMPLETE MONITOR WITH DEBUG & TRACE. AND TINY 6502ASSEMBLER • COMPLETE HIGH RESOLUTION GRAPHICS WITH INDIVIDUAL DOT (240x512) POINTSCREEN ADDRESSABILITY •FULL SCREEN TEXT EDITING WITH OVERWRITE. INSERTION OR DELETION • SPLIT SCREEN/WINDOW MODES • INDIVIDUALFIELD EDITING WITH FIELD PROTECT AND AUTO SKIP TO NEXT FIELD • DISK STORAGE SYSTEM TRANSFERS 6K PER SECONDWITH AUTO VERIFY AND PARITY CHECK • 12 INCH CRT-64 CHARACTERS BY 30 LINES. UP TO THREE PROGRAMMABLECHARACTER FONTS FOR LANGUAGES OR SPECIAL CHARACTERS • • • SWITCHABLE 110 OR 220V OPERATION • • • • HYBRIDCPU IS MICROPROGRAMMABLE WITH 64 USER DEFINABLE OPCODES. CHOICE OF 800K OR 2.4 MEGABYTE DISK STORAGE • FULLSERIAL RS-232C PORT WITH PROGRAMMABLE BAUD RATES AND MODEM CONTROL SIGNAL • DEDICATED DISK PORT •PRINTER PORT SUPPORTS PARALLEL COMMERCIAL PRINTERS • 24 PIN I/O USER PORT • PAGEMATE DATABASEAVAILABLE • PLM COMPILER AVAILABLE • BUSINESS PACKAGES AVAILABLE • COMPLETE DIAGNOSTICS & SCHEMATICSINCLUDED • COMPLETE USER MANUAL INCLUDED

MINIMAX I

$4495

MINIMAX I - .8 MEGABYTEON LINE MINIFLOPPY STORAGE

MINIMAX II - $5995

MINIMAX II - 2.4 MEGABYTEON LINE 8" FLOPPY STORAGE

THE MINIMAX WAS DESIGNED AND IS MANUFACTURED BY COMPUTHINKCOMPUTER CORP. DISTRIBUTED IN EUROPE AND THE EASTERN U.S. BY NEECO.

COMPUTHINK A & .8 MEGABYTE DISKDRIVES FOR THE NEW 16/32K PETS!

DISK SYSTEMS INCLUDE DISKMON OPERATINGSYSTEM IN ROM AND INTERFACE TO 16/32 PETS!

> Dual Minifloppy Drives with 200K per diskette side lor total 400K 800K on linei 800K model accesses all 4 diskette sides via dual read and write arm syslem

■ Dual Density Hardware a-id DOS loads20K iwitn verification) in 4 2 seconds completei DISKMON (DOS) adds 17 commands lo BASIC including Random Access and printer support' Syslem comes complete with plug in internal board containing 8K RAM DOS. and Disk Controller

Hardware Board plugs directly onto internal memory expansion pins1 System does not Utilize IEEE or USER Porl system lunctions directly liom rnemo'y purli All DISKMON DOS commands reside interactively with BASIC disk directory command and

format command do not interfere with program m RAM -DOS command were designed lor

simplicity ol use System was manufactuied lor neavy commercial use1 System installs completely in less than ten minutes immediately ready tor use

M295 and '1595 prices include all hardware. DOS complete user manual and demo utility diskette

■ Available software includes PLM Compiler (»250), Relocatable Assembler ('70) Source-EditorProgram ('70) Autolmk Linking Loader ('70). and a complete Database i/siem (Pagemate '495)

■ Call or write lor complete product information and specifications -User manual MO

(PRODUCT AVAILABILITY IS AUG/SEPT-CALL FOR INFO)

ALL 16/32K MODELS INCLUDE AN 400K-16N s1295

INTERNAL PLU3-IN INTERFACE 400K-32N '1295

BOARD CONTAINING DOS. 8K OF 800K-16N '1695

RAM. AND CONTROLLER 800K-32N '1695

FOR 8K PETS

(small keyboards)'

.4 Megabytes of Disk

Storage for 8K PETS!

(Requires Expandamem)

400K-8S DISK SYSTEM INCLUDES RANDOM

ACCESS IN DOS-LOADS 20K IN 4 SECONDS!

24K Expandamem Memory s525 $1 OQR

32K Expandamem Memory s615 I fc»70

NEECO

NEW ENGLAND ELECTRONICS CO., INC.

679 HIGHLAND AVE., NEEDHAM, MA 02194

MON-FRI, 9:00-5:30, E.S.T.

(617) 449-1760

Mcrocomputer Systems Division

132 BYTE January 1980

Circle 79 on inquiry card.

NEECO

PROUDLY ANNOUNCES THE NEWEST

Microcomputer Systems Division

son

3C.IV

HARDWARE AND SOFTWARE FOR YOUR PET!

The PET is now a truly sophisticated

Business System with the announcement

of these peripherals and software packages.

►A>\*

*&

.<*".

o,S\

tar*.

PRODUCT DESCRIPTION PRICE AVAILABILITY

PET 2001—8KN'Large Keys) 8K RAM $795 IMMEDIATE

PET 2001—8K 8K RAM $ 795 IMMEDIATE

PET 2001 —16KN(LargeKeys)i6K RAM* $995 IMMEDIATE

PET 2001—32KN (Large Keys)32K RAM $1295 IMMEDIATE

PET 2023 PRINTER ROLL FEED $ 850 IMMEDIATE

PET 2022 PRINTER TRACTOR/ROLL $ 995 IMMEDIATE

ROMRETRO KIT UPDATED O/S $ 90 IMMEDIATE

PET 2040 DUAL FLOPPY* $1295 IMMEDIATE

PET C2N 2nd Cassette $ 100 IMMEDIATE

"The 16K/32K (large keyboard) units do not include a cassette drive. Order C2N Cassette.2040 Floppy Drive requires a 16K or 32K unit. 8K RAM Retrofit available July.

ALL PETS ARE FULLY TESTED BY NEECO BEFORE SHIPMENT. NEECO IS A FULLCUSTOMER-ORIENTED COMPANY. CALL FOR OUR FREE CATALOG. ALL ORDERSOVER $795 WILL RECEIVE A FREE NEECO PET DUST COVER AND $100 OF SOFT-WARE FROM OUR CATALOG IF YOU MENTION YOU SAW THIS AD.

PET-DISK BASED BUSINESS SOFTWARE

SOFTWARE/APPLICA TION

REQUIRES

AUTHOR

AVAILABILITY

PRIC

WORDPRO II / WORD PROCESSING

2040 + 16K PET

PRO/MICRO

IMMEDIATE

$100

WORDPRO III /WORD PROCESSING

2040 + 32K PET

"

JANUARY

$200

GENERAL LEDGER

CMS SOFTWARE

IMMEDIATE

$295

ACCOUNTS PAYABLE

"

JANUARY ■

$295

ACCOUNTS RECEIVABLE

"

JANUARY

$295

MAILING LIST

"

IMMEDIATE

$100

MICROLEDGER

COMPUMAX

"

$140

MICROPAY

"

"

$140

MICROREC

"

"

$140

MICROINV

ii

"

$140

MICROPERS

"

"

$140

*The CMS Software (G/L, A/R, A/P) are based on Osborne & Associates trial tested business basic software.Software is complete with full documentation and user instructions. All packages require a printer for output.Commodore recommends the NEC Spinwriter (available from NEECO) as the output printer for WORDPRO.

PRODUCTS ARE AVAILABLE TO DEALERS VIA MICROAMERICA DISTRIBUTING (617-449-4310)

FOR WORD PROCESSINGNEC IS BEST!

55 characters per second output speedChangeable thimble for different typestylesLess than 1% warranty malfunction rateIBM quality letter outputDealer inquiries invited

THE NEC SPINWRITERMODEL 5530-P ( SSSST^r)

$2995

"Price includes IEEE interfaceto PET. IEEE Port is availablefor use with 2040 Dual Disk.

'The NEC 5530-P is the output printer recommended by Commodore for their Word Processing System.

K lCCf*r\ Mon-Fri 9:30-5:30INCtV/U MasterCharge &679 Highland Ave. visa Accepted

(617)449-1760

Needham, MA02194

Telex: 951021

Circle 237 on inquiry card.

MICROAMERICA DISTRIBUTING

"Nationwide distributors of Computer Equipment"21 Putnam StreetNeedham, MA

02194 (617)449-4310

BYTE January 1980 133

Listing 1: A listing containing the data and error specificationfor a six-degree polynomial, P(x). Thirty-nine values of x arealso printed along with the corresponding values of P(x)calculated for each value of x.

°: t

1: 4

7 u'

3!828427125 -3.

3.

7. 656854249

.3828427125 6.

0. 3

0. 000001

0. 000001

-2.6457516 ^

1.' 0 0 0 0 0 0 2 3 2 .0 0 0 0 0 03 725

2. 645751297 2. 000000063

<kt ■jqqqqqq 99? 9, 9999999 99v

-3.637005769 21 -2.85

-3.445584412 22 -2.7

-3.254163056 23 -2.55

-3.0627417 24 -2;4

-2. 483477631 27 -1.95

-2.297056275 28 -1.8

-2. 105684919 29 -1. 65

-1.914213562 30 -1.5

-1.722792206 31 -1.35

-1.53137085 32 -1.2

-1.339949494 33 -1.05

-1. 148528137 34 -0.9

-.9571067812 35 -0.75

-. 7656854249 36 -0. 6

-. 57426406S7 37 -0. 45

-'. 1914213562 39 -0. 15

5. -13 40 -9. 2-12

.1914213562 41 0.15

.3328427125 42 0.3

. 5742640687 43 0. 45

. 7656854249 44 0. 6

.9571067812 45 0.75

1. 148528137 46 0. 9

1.339949494 47 1.05

1.53137085 48 1.2

1. 722792206 49 1. 351.914213562 50 1.5

2. 105634919 51 1. 652.297056275 52 1.82.483477631 53 1.952. 679898987 54 2. 12.871320344 55 2.25

3.0627417 56 2.4

3.254163056 57 2.55

3.445534412 58 2.7

3.637005769 59 2. 85

"6.15249512 21 -11.749125

34! 42252761 23 -6.381375

19.94856125 24 -4.224

9.015614845 25 -2.390625

1. 124224037 26 -0.861-4.192852014 27 0.385125

-8. 811905689 29 2. 107875

-7.935002802 31 2.939825

-6.261295001 32 3.072

-4.140023871 33 3.042375

-1.81286571 34 2.871

.5107266897 35 2.578125

2. 653524043 36 2. 1844.470520569 37 1.7088755.848933998 38 1. 1736.708205561 39 0.596625

7. 40 3.68-11

6.708205561 41 -0.596625

5.848933998 42 -1.173

4.470520569 43 -1.708875

2. 653524043 44 -2. 184

.5107266897 45 -2.578125

-1.81286571 46 -2.871

-4.140023871 47 -3.042375

-6.261295001 43 -3.072

■■?. 935002802 '49 -2. 939625

-8. 887247468 50 -2. 625

-3. 811905689 51 -2. 107875

-7.370630645 52 -1.363

-4.192852014 53 -.3851250001

1.124224037 54 .8609999993

9.015614845 55 2.390625

19.94856125 56 4.224

34.42252761 57 6.381375

52.96920178 58 8.883

76. 15249512 59 11. 749125

134 January 1980 © BYTE Publications Inc

4041

4243444546474349

-2. 1547005382.154700533

4. 3094010'

. 21547005:

4041

424):44

45

46474 34 95051

54

-1.1547005"1. :5470029!

■ 1. 616- 1 . 40

50431

:5404

-1. 135085296-1. 077 350269-. 9696152423-. 8618802154-. 7541451884-. 6464101615-. 5386751346-. 4 309401077

-. 2154700538-. 1077350269

'. 2154700538

.4309401077. 5386751346. 6464101615. 7541451884. 8618802153. 96961524231.077350269

i.40055535

i!6160254041.7237604311.881495458,.9392S048S2.046965511

i'. 427281539

2.0210422781. 633016639

. 94 16065276

. 6232219549

. 3380510543

.0710938257

-.1726497309

-. 893179615 3

-. 5904958277

-. 7645983681

■. 9154872864

-1. 043162433

-1.147623957

-l! 321726497

-l!321726497

-1.286905989

-1.228671809

-1.147623957

-1.043162432

-. 9154872364

-.7645983681

-.5904958277

-. 393 179615 J

•.1726497308

. 0710933257

. 338051054;:

.6282219549

.9416065276

1.6330166392.021042278

2!356784472

3134

40414243444546

404142434445464748495051

Text continued:

The procedure is as follows in practice:

1. In groups 3 and 4 read listing 2 mentioned above.

2. In groups 1 and 2 read the magnetic card of the pro-gram for the function curve.

3. Initialize by depressing key A.

4. With the keys enter the two extremes envisaged forthe curve starting with the lower and then each timedepressing key B.

5. Depress key C.

Depressing key C initiates the entire process with noother intervention. The six strips obtained are separatedby cutting with scissors, and are assembled with glue oradhesive tape. This is the standard automatic procedure,and nothing prevents the operator from applying it inevery case using the data collected in listing 1.

However, you may desire to center the reproduction ina smaller field. When examining the table of values ofP(;c) obtained, it is obvious that, for registers R2i thru R25and R55 thru R59, small variations in x cause considerablevariations in P(x). In other words, the curve ends withparabolic branches. In the same way a photographertakes a close-up of a subject, you can neglect the infiniterange and concentrate on useful details.

For this purpose, you must disconnect automatic oper-ation and gain control of the depth of field. This time, theprocedure will be as follows:

1. Reread the card of the main program in groups 1and 2.

2. Initialize by depressing key A.

3. Re-enter the initial coefficients of R16 to R10 by eachtime depressing key B as previously indicated.

4. Switch to programming mode LRN, and performthe few modifications required:

• Replace the neutral NOP instructions providedfor this purpose at statements 087, 096 and 119by R/S instructions.

• Replace the initial partition of the interval (a, b)at statements 120 thru 122 by as many NOP in-structions.

• Replace all occurrences of e with a deliberatelyexcessive number, for example 999...

5. Return to the calculating mode, and depress key C.The rest of the program will be executed but willstop whenever useful to permit the entry of a dataitem of your choice:

• Boundary a with the first stop: here, it will be 3in absolute value but the calculator will recog-nize it as negative 3.

• Boundary b with the second stop: it will again be3.

• Partition of the interval {a, b) at the third stop:keep it at 20 on seeing the value of the intervalthe machine has just printed out after the boun-daries.

Naturally, each data entry with the keys is followed byoperation of the R/S key to restart the calculation.

What happens now? Without getting involved in a rootcalculation that is no longer of interest at this point, the

Let your LSI-11 breakthe 28K hi

With our Bank-Switching family

In LOCAL mode our memory is functionally justlike DEC memory. But when you run out ofmemory space you're not lost. Add an inex-pensive Bank-Switch Controller (BSC-256) andyou can go to two megabytes. Add anotherand go to four megabytes.So don't get boxed in with other brands ofLSI-11 * memory. Break free. Join the family:

RMA-032

RMS-016

BSC-256

32K by 16 bit RAM.On-board refresh16K by 16 bit ROM.(Intel 2716)The Bank-SwitchController

$1200(Single qty.)$300

(Single qty.)$300(Single qty.)

Substantial quantity discounts are available. For a freecopy of our Bank-Switching manual, call or write on yourcompany letterhead.

Digital Pathways Inc.

4151 Middlefield Road

Palo Alto, CA 94306

(415) 493-5544

'Registered trademark of Digital Equipment Corporation

DIGITAL PATHWAYS

Circle 80 on inquiry card.

BYTE January 1980 135

Listing 2: Listing of a sample input of data used to plot thetion curve.

func-

o.o.

I.

o.

-0.9

34

-0. 75

35

_^

-0. 6

< 6

-0. 45

-4

25849375

-u. 1 5

39

-M

-2.446460449375

0.

40

1. 1761

0. 15

41

61640625

0. 3

42

0.45

43

c

421f'fiA25

0.6

44

6.2SSI

0. 75

45

6

32050625

0. 9

46

-?

1.05

47

6

82050625

1. 2

4y

6. 2881

1.35

4"?

s

42100625

1. 5

4. 2496

1. 65

51

g

SI 640625

i. a

52

1.95

5'J

-0

60449375

2. 1

54

-2. 4464

2. 25

55

-4

25S49375

2.4

56

-S.9375

2.55

5.''

-,

2.7

58

2.85

59

-8

96099375

500625

21

-7

87109375

1. 8241

22

-5. 9024

749375

23

-2

73749375

5. 9024

24

1. 8241

109375

£5

7

99500625

3. 3319

26

41.1

41424344454647

calculator simply indicates the lowest root in approxi-mate fashion and then rapidly prints out the tables of

values of x and P(x) at the assigned values of a and b (seelisting 2).

All that remains is to use these values contained in

H.JO./H.

/^

MAIL ORDER MEDIA

100% GUARANTEED FLOPPY DISKS:

—MINI DISKS BOX OF 10 $29.50

(SOFT, 10 AND 16 SECTOR) +TAX

—MAXI DISKS BOX OF 10 $35.00

(SOFT AND 32 SECTOR) + TAX

ALSO SPECIALIZING IN:

—FLOPPY DISK STORAGE SYSTEMS—FLOPPY DISK MAILING PACKAGES— DATA CASSETTES AND CARTRIDGESMASTER CHARGE & VISA WELCOME 10 DAY DELIVERY

DEAR H.« -H.

NAME_

PLEASE SEND MORE INFORMATION TO

ADDRESS

PHONE

MAILORDER MEDIA

473MACARA#706SUNNYVALE. CA 94086(408)739-5215

registers R2i to R5, for the plot by continuing with theknown steps as follows:

6. In groups 1 and 2 read the card of the program forthe function curve.

7. Initialize with key A.

8. With the keys punch in — 9 B then 8 B to enter theextremes which are obviously appropriate here.

9. Depress key C which delivers the six ideal stripsafter this mathematical "zooming" as can be seenfrom looking at the curve in detail (see figure 1).

Above all, the question is one of knowing if this plot istechnically satisfactory.

For verification purposes, see if the coordinates of theminimums found by the calculation (±2, —9) and thecoordinates measured on the plot are consistent. Moreprecisely, determine the abscissa of the minimums withan ordinate of —9. From the small median triangular signmarking the 0 abscissa on the base line, you can easilycount ±13 intervals each having a value of 0.15, theincrement of x. This gives ±13 X 0.15 = ±1.95. Thisabscissa is very close to the value calculated (±2), and itcan be said that the plot is extremely accurate.

As for the points of inflection, their ordinate is foundto be —1.888... for P(x) evaluated from the roots of P"(x)= 0, in other words abscissas of ±1.154700. The pointsof inflection whose abscissa is ±1.15 in accordance withthe calculation fall slightly before the eighth point on thebase line at the abscissa (8 X 0.15 = 1.20). This is alsovery close to the value calculated. These are the pointswhere the curve crosses its tangent.

The zero ordinate can easily be deduced from a simplerule. Given that the difference between minimum andmaximum is 9 + 8 = 17 in absolute value and there are 4X 20 + 17 = 97 elementary intervals between thesepoints, each has a value of 0.175. From this the axis of theabscissas is at 9/0.175 = 51 intervals from the minimumof the curve.

From the table of P(x) it can be seen that the curvecancels between registers R34 and R33, R46 and R47, andthat this effectively corresponds to the interval 6-7 of thebase line. Without providing the precision of a profes-sional plotter, the reproduction obtained is thus ofsuitable quality given the means employed.

Conclusion

When a procedure is used for a rather long calculationthat requires only three keyboard operations:

• initialization by key A

• data entry by key B or B'

• complete execution by key C

the drawbacks of the relative slowness of calculation areconsiderably reduced.

The TI-59 cannot execute its program with great speed.However, most users can tolerate a delay of a fewminutes with no hardship. Some will appreciate the op-tion of allowing users to disable automatic operation tofollow their own inspiration. ■

136 January 1980 © BYTE Publications Inc

Circle 81 on inquiry card.

•

'Security... for yourS-100 hard disk data'

"0

B»cH'

OP

The availability of fast, reliable, high capacity harddisk storage for the S-100 computer market hascreated a wave of excitement. It has also under-scored the somber necessity for a reliable means ofbackup. No serious application is practical withouta dependable, economical method for backup andarchiving of critical on-line data.

Now, CSSN breaks the barriers to hard disk ap-plications by offering the complete solution for datasecurity ... a cartridge tape drive (13.4 megabytecapacity), fully S-100 interfaced, and software tomake it work. - BACKUP IS NOW A REALITY!

Put your valuable data on-line with a hard disk . . .Save it off-line with our Back-Up Solution

Circle 82 on inquiry card.

COMPUTER SERVICE SYSTEMS NETWORK

120 0OYLS1ON STREET • FOURTH FLOOR- BOSTON, MASSACHUSETTS 02116 • (617) 482-2340 • TWX (710) 321-1913 INCORPORATED

The Plot Continues

Leslie B Walter

72 Central St

Farmington NH 03835

Figure 1: A sketch ofthe complete plottermechanism.

I had a dream the other night. A won-drous vision: I built an inexpensive, simpleplotter and it worked. I remember that justbefore retiring, I was reading the March1977 BYTE, specifically the article on build-ing a plotter using model aircraft servo-motors ("Give Your Micro Some Muscles,"page 9).

The servomotor idea sounded great atfirst, but is quite complicated to run. Forone thing, the plotting routine must con-stantly send out carefully timed pulses.Either that or you need a set of program-mable clocks. Second, you must have acircuit that indicates when the plotter isfinished with the current line segment oryou would be plotting the next line beforethe first line is finished (unless you want towait out the worst case every time). Third,there is that trigonometric routine. I don'teven want to think about that. Fourth,there is the problem of wobble. With armslong enough to give a decent sized plottingarea, the slightest bump or small snag onthe paper and your beautiful plot begins tolook like a Los Angeles seismograph record.Arms rigid enough to avoid this problemwould be extremely difficult to build.There is also the problem of play. At the endof 10-inch arms, a small amount of play atthe servomotors would be greatly magnified,possibly enough to miss the desired pointby a fair margin.

I propose the following alternative designapproach. The idea isn't perfect, but I thinkit will work.

SLIDE BAR

SHAFT SUPPORT

CABLEDRIVE BELT

Figure 2: Cutaway showing details of drive mechanism. The motor drives theshaft, turning the disk. The interrupter sends a pulse to the controller eachtime a hole passes through it. A cable wrapped around the shaft comes upthrough the plotting bed and pulls the crossbar along the slide. There shouldbe a cable at each end of the crossbar.

Mechanical Description

The basis for the plotter (and the hardestpart to build) is the crossbars (figures 1and 2). These are two sets of perpendicularbars that slide on long rails set at the edgeof the plotting bed. The pen mount withits solenoid sits on the intersection of thebars. It slides along in a fashion similar tothe crossbars and their rails. By movingthe crossbars to the proper X,Y coordinatesthe pen moves with the intersection to thedesired point.

The bars are moved by cables wrappedaround a drive shaft. Rotating the shaft inone direction moves the bar up (or down).The other bar is moved by a similar arrange-ment, right or left. In order to keep trackof where the bars are, each drive shaft hasa disk mounted on the end with holesevenly spaced around it. As the disk rotates

138 January 1980 © BYTE Publications Inc

The

I

SUPRBfiAjfeT

INTE3TEC

DATA

SYSTEMS

32K

ONLY

$2995

64K $3245

More than an intelligent terminal, the SuperBrain outperforms many othersystems costing three to five times as much. Endowed with a hetty amount ofavailable software (BASIC. FORTRAN, COBOL), the SuperBrain is ready totake on your toughest assignment. You name it! General Ledger. AccountsReceivabfe. Payroll, Inventory or Word Processing.. .the SuperBrain handlesall of ihem with ease.

Features Include:

• two dual-density minifloppies with 320K bytes of disk storage

• 32Kof RAW to handle even the most sophisticated programs

• a CP/M Disk Operating System with a high-powered text editor,assembler and debugger.

JS*

Superbrain &Centronics 704only $4595

Available Software

Accounts Receivable/Payable $ 125

General Ledger $ 125

Payroll with cost accounting $ 125

APPLE II PLUS ONLY$1195

A complete self-contained computer system with APPLESOFT floating pointBASIC in ROM, full ASC 11 keyboard in a light weight molded carrying case-

Features Include:

• auto-start ROM • Hi-Res graphics and 15 color video output.

• Expandable to 48K.

Supertalker $279

Disk 595

Add-on Disk 495

Pascal Card 495

Business Software 625

Monitor 159

Printer Card 180

Micromodem $ 379

Programmer's Aid 50

Speechlab 229

Lightpen 250

Communication Card 225

Modem 200

EPROM Programmer 100

n

i

• 16-bit microprocessor

• 16K RAM

• 13" color monitor(24 lines of 32 chrs.)

• 26K ROM operating system(includes 14K BASIC)

• Sound - 3 tones. 5 octaves

• 16 colors: 192 x 256 res.

• Large Tl library of ROMprograms available.

only$1150

_ Includes 13"Color Monitor!

FINALLY

TEXASINSTRUMENTSTI-99/4Home Computer

Many Peripherals. Coming soon!

TO ORDER CALL (212) 687-5000

il£XSIiJtf

Commodore Computer

NEW!

MINIMAX

The Minimax Series Computer is anintegrated, compact unit containing theCPU, Disk Storage, 12 inch CRT, andFull Style Keyboard.Features Include:

• 2 Megahertz 6502 CPU

• 108K System RAM

• High Res. Graphics (240x512)

• Switchable.110 or 220V Operation

• Choice of 800K or 2.4 Megabyte Disks

• Business Packages Available$395 ea

• Serial and Parallel l/oMINIMAX I - .8 Megabyte

on line minifloppy storage $4495

MINIMAX II - 2.4 Megabyte

on line 8" floppy storage $5995

These low cost Commodore PE1 BusinessComputers have virtually unlimited businesscapabilities: Accounts Receivable. InventoryRecords, Payroll, and §~"other accounting /functions. / Inffl

PET16N&32N/ * . «<

COMPUTERS / "*"

• Full size keyboard a•16 or 32.000

Bytes Memory

• Level IIIOperatingSystem

•Full ScreeEditor

NEW! $1895 List S2500CENTRONICS 704

Case

3 cps Bi-Direct

• Upper/Lower

• 9 x 9 Matrix

• Tractor Feed

• Up to 15"Paper Width

• RS-252 SerialInterface

PERIPHERALS FOR PET

CENTRONICS 753

• New Word Processing Dot Matrix Printer

• 130-150 cps • Proportional Spacing

• Tractor Feed • N x 9 Matrix

$2495

$ 1595 Complete! L j| :16K model |L '*"$ 1895 A

32K model$ 2195

Compueolorll

COMPUCOLOR II Disk-Based Model 3Advanced hardware and software technologygives you:

• 13" Color Display

• Advanced Color Graphics

• 51K Disk Built-in

• 16K ROM Operating System

• 8K RAM User Memory

• 4K RAM Refresh

• 8080A Microcomputer

• RS-232 I/O

» 24K Memory Expansion .» 16K Memory Expansion .» PET to RS232 Serial ....» 2 Way Serial/Communicai Modem Board for PET ..' Analog to Digital Board .

for 16 Devices

» Second Cassette Drive ..» Parallel Printer Interface

CENTRONICS 730Parallel^ 895Serial $945

F'lOOCPS - MICROPROCESSOR'CONTROLLED!

Tractor & Friction Feed • UsesSingle Sheets. Roll, Fanfold* Uppe& Lower Case • Light Weight

ANDERSONJACOBSON

.NOW

841 1/0 Terminal

Ideal lor word processing

ntna

• ASC 11 Code

• IScpsPnntoi

• High duality Selective Priminge Keyboard tor PET

'* Reliable heavy duty Mechanism

• Completely Refurbished by A.J.

• Service in IS Maior CitiesPlus $35 Freight-In Charge

S0CK

d small bun

INS'

Parallel -

$1095

10 MegabyteSystem $17,040

DATA GENERALmicro NOVA

iThe ultimate in small[Business ComputersIwhen matched with

FACTORY'S. Software:vable/Payable.Inventory Control/ Order Entry,Genreal Ledger, Payroll Systems. . . .from $12,140 for 64K computerwith cabinet, printer terminal, video! terminaldual disk and mutli-useri operating system!

RADIO SHACK • PET • SORCERER •APPLE • COMPUCOLOR • ETC.

PRINTERS • PRINTERS • PRINTERS

The COMPUTER FACTORY'S extensive CENTRONICS 779 ... .$ 945

inventory and wide selection of computer TRENDCOM 100 375

printers assures you of finding the printer TRENDCOM 200 595

best suited for your needs and PAPER TIGER 440 $995

specifications The following printers work XYMEX 10)00, 2495

well with all known personal computers- XEROX1740 28,10

$1195

FREE

$35 of Softwarewith purchaseof any computeron this page.

Min Credit CardOrder $75

OpenMon.-Fri.

10-6Sat. 10-4

N Y residents add 8% sales lax

• Same day shipment on prepaid and

credit card orders • Add S5 shipping

[or computers S3 for boards

$1 each cassette tape.

Qverl000 software tapes, books,diskson display. Come in and brouse.

TO ORDER CALL (212) 687-5000 (46lr }

TLA /"YMl/IDI ITCD CAPTHDV 485 Lexington Avenue 750 Third Avenue New York. N.Y. 10017I I It? VAJIVIrU I Cn rMV/ I \Jt\ I Foreign order desk Telex 6400b5 ,

with the shaft, the holes pass through anoptical interrupter (a U-shaped device witha light source on one side and a photo-transistor on the other). Each time a holepasses through the interrupter, a pulsepasses to the control circuit, driving acounter up or down depending on thedirection it's turning. By comparing thecounter, which contains the current posi-tion of the bar, with the desired desti-nation point, the control circuits can movethe bar in the proper direction.

One small problem lies in the hard-ware department. The motors which drivethe crossbars must be able to stop fairlyfast, at least before the next hole comesup on the disk. If not, the plotter wouldsignal the computer that it is finishedeven though the motors would have toreverse themselves to return to the origi-

nal point. If you are using motors that aregeared down (ie: the motors are spinningfast, but the shaft is turning slowly) thenthis problem tends to disappear. The dis-advantage to geared down motors is time,of course. The more gear reduction that isused, the longer it takes to draw a linesegment, and the longer your processoris sitting idle. The ideal motor is one thatturns the shaft as fast as the pen and papercan tolerate and which can stop quickly.

Controlling the Plotter

From here there are two ways in whichyou can control the plotter: software andhardware. My choice is hardware, althoughboth methods have their advantages.

The hardware controller I came up with(figure 3) is simple. Set up three input/

Figure 3: A block dia-gram of a hardware plottercontroller.

o^-r

140 January 1980 © BYTE Publications Inc

RADIO SHACK COMPUTER OWNERSTRS-80 MODEL I AND MODEL II

TRS80

MONTHLYNEWSLETTER

FRfct

PROGRAMS AND ARTICLES PUBLISHED IN OUR FIRST 12 ISSUESINCLUDE THE FOLLOWING:

A COMPLETE INCOME TAX PROGRAM (LONG AND SHORT FORM)

INVENTORY CONTROL

STOCK MARKET ANALYSIS

WORD PROCESSING PROGRAM (FOR DISK OR CASSETTE)

LOWER CASE MODIFICATION FOR YOUR VIDEO MONITOR OR PRINTER

PAYROLL (FEDERAL TAX WITHHOLDING PROGRAM)

EXTEND 16 DIGIT ACCURACY TO TRS-80 FUNCTIONS (SUCH AS

SQUARE ROOTS AND TRIGONOMETRIC FUNCTIONS)

NEW DISK DRIVES FOR YOUR TRS-80

PRINTER OPTIONS AVAILABLE FOR YOUR TRS-80

A HORSE SELECTION SYSTEM*"ARITHMET1C TEACHER

COMPLETE MAILING LIST PROGRAMS (BOTH FOR DISK OR CASSETTE

SEQUENTIAL AND RANDOM ACCESS)

RANDOM SAMPLING***BAR GRAPH

CHECKBOOK MAINTENANCE PROGRAM

LEVEL II UPDATES***LEVEL II INDEX

CREDIT CARD INFORMATION STORAGE FILE

BEGINNER'S GUIDE TO MACHINE LANGUAGE AND ASSEMBLY

LANGUAGE

LINE RENUMBERING

AND CASSETTE TIPS, PROGRAM HINTS, LATEST PRODUCTS

COMING SOON (GENERAL LEDGER, ACCOUNTS PAYABLE ANDRECEIVABLE, FORTRAN 80, FINANCIAL APPLICATIONS PACKAGE,PROGRAMS FOR HOMEOWNERS, MERGE TWO PROGRAMS,STATISTICAL AND MATHEMATICAL PROGRAMS (BOTHELEMENTARY AND ADVANCED) . . . AND

WORD PROCESSING PROGRAM (Cassette or Disk)

For writing letters, text, mailing lists, etc., with each new subscriptions or renewal.

LEVEL II RAM TEST -

Checks random access memory to ensure that all memory locations are working properly.

PRACTICAL APPLICATIONSBUSINESS

GAMBLING • GAMESEDUCATIONPERSONAL FINANCEBEGINNERS CORNERNEW PRODUCTSSOFTWARE EXCHANGEMARKET PLACEQUESTIONS AND ANSWERSPROGRAM PRINTOUTS AND MORE

SEND FOR OUR 36 PAGE SOFTWARE CATALOG (INCLUDING LISTINGS OF HUNDREDS OF TRS 80 PROGRAMS AVAILABLEON CASSETTE AND DISKETTE). $2.00 OR FREE WITH EACH SUBSCRIPTION OR SAMPLE ISSUE.

•CQmPJTRQNICS;

Box 149 New City, New York 10956

ONE YEAR SUBSCRIPTION $24

TWO YEAR SUBSCRIPTION $48

SAMPLE OF LATEST ISSUE $ 4

START MY SUBSCRIPTION WITH ISSUE

(#1 - July 1978 • #7 - January 1979 • #12 - June 1979)

NEW SUBSCRIPTION RENEWAI

CREDIT CARD NUMBER

HOUR24 ORDER

LINE(914) 425-1535

EXP. DATE .

SIGNATURE

NAME

ADDRESS

ADD $6, YEAR (CANADA, MEXICO) ADD S12/YEAR AIR MAIL OUTSIDE OF U.S.A., CANADA & MEXICO '

Circle 84 on inquiry card.

BYTE January 1980 141

Figure 4: A sketch of the 45° syndrome. The stepped lines indicate thetype of line drawn by a software driven plotter. The lines with the singleangle are the type drawn by the hardware controller. If the line segment tobe drawn is less than a few plotter steps long, the difference is negligible.

-H h»-ONE PLOTTER STEP

STARTING POINT

At Last!

HIGH RESOLUTIONS-100 GRAPHICS

$925

Complete interfaceAssembled and testedOnboard memoryStandard video outputMonitor extraFOB Cambridge

Unretouched photograph

• LIGHT PEN

• HIGH RESOLUTION

• 51 2X640 MATRIX

• S-100 PLUG-IN

• HIGH SPEED

• SOFTWARE

Send for brochure and data

CAMBRIDGE DEVELOPMENT LAB

44 Brattle Street. Cambridge. MA 021 38I Call (617| 547-3894

output (I/O) ports: one for commandsand one each for the X and Y coordinates.

The command port accepts four com-mands: pen up, pen down, signal and move.The two pen commands are self-explanatory;the signal command generates an audibletone. This is an option I included for sig-nalling the end of a plot or calling attentionto a particular point in the plotting process.

The move command starts the motorcircuits (otherwise they would start movingthe plotter before both coordinates werein) and also generates a hold signal for theprocessor until the line segment is finished.When the move command is received,the motors drive the crossbars until thecounters, which hold the current plottingposition, match up with the eight-bit latcheswhich contain the position that the plotteris to move to. When the coordinates match,the hold line is dropped, allowing thecomputer to output the next command.

The comparator circuits are also usedto determine whether the pulses comingfrom the interrupters are used to drivethe counters up or down.

The only other circuit needed is aninitialization circuit that drives the pen tolocation (0,0) and clears the counters.This is used to synchronize the countersand pen when the plotter is first turnedon.

As to the circuits which actually drive themotors and pen solenoid, these depend onthe components themselves. If you wish todrive the plotter directly by software, thetwo coordinate I/O ports are used to readthe current location of the pen. A softwareroutine then decides how to move the cross-bars, one step at a time, to get to the desiredpoint. However, this requires more com-mands for the plotter, such as X up, X down,Y up, Y down.

With this hardware method you run intowhat I call the 45° syndrome. Since themotors turn at about the same speed, thepen will tend to move at an angle whichis a multiple of 45°. For example, if thepen has farther to go in the X direction, thepen will reach the proper Y coordinate first,giving a line with two segments (figure 4).If the line you wish to draw is a multiple of45°, drawing axes and such, then thispresents no problem, but with lines at other

142 January 1980 © BYTE Publications Inc

Circle 85 on inquiry card.

Word Processors are here. Just thumbthrough the pages of this magazine.There are at least five different com-panies selling them. So, which one's foryou? How do you judge the differ-ences? And what about cost. Are youwilling to pay the 300 plus dollars thatsome of the companies are asking?

Well go ahead and compare! AU-TOTYPE comes out ahead in EVERYcategory!

Features? AUTOTYPE has more pow-erful features than ANY other WordProcessor on the market. But, don'ttake our word. Go ahead, compare!AUTOTYPE has an exclusive MACROprogramming capability. No other WordProcessor can make that claim. AU-TOTYPE also has a scratch HoldingBuffer. Again, no one else even comesclose.

Price? AUTOTYPE beats 'em all! Witha price tag of $195, AUTOTYPE is wellbelow the competition. But, again, don'tjust take our word. Go ahead, look foryourself. Then fill out the order formbelow to start processing words insteadof using a word processor!

CAN I MOVE PARAGRAPHSAROUND?

YES! AUTOTYPE has a Holding Bufferthat can be used to save any amount oftext and then Unhold it to the locationyou want. AUTOTYPE even allows youto do multiple Unholds!

CAN I MERGE CUSTOMERSNAMES INTO LETTERS?

YES! AUTOTYPE contains a "merge"character that may be placed any-where in text. Then, at the time text isprinted, a separate file may be mergedinto the letter and then printed! An-other feature that NO OTHER WORDPROCESSOR has!

CAN I ENTER TEXT IN SOME OTHERFORMAT THAN 64 CHARACTERS

WIDE?

YES! AUTOTYPE has a screen redi-mension command. The screen can beset from 16 characters wide to 120characters wide. There's even horizon-tal scrolling to view the text! Once more,we're far beyond the competition!

CAN IT HANDLE TEXT LARGERTHAN MY COMPUTERS MEMORY?

YES! Most other Word Processors de-mand that the entire text be inside thecomputer AUTOTYPE allows you to"spool" your text from the disk. Thismeans that you can have edit files thatare over 200 type written pages long!!

CAN IT UNDERLINE?CAN IT BOLDFACE?CAN IT INDENT?CAN IT HYPHENATE?

YES! YES! YES! YES! AUTOTYPEhas ALL the standard Word Processorfeatures including underlining text,boldface printing and paragraph in-dentation. AUTOTYPE also has softand hard hyphens. Soft hyphens areused at the end of lines and disappearif movedl

WHAT ABOUT INSERTING IN THEMIDDLE OF A WORD?

Certainly! AUTOTYPE allows insertinganything anywhere! You can movesingle letters or entire chapters rightinto the middle of any word. NowTHAT'S POWER!

CAN IT SEARCH AND REPLACE?

YES! But, there's more! AUTOTYPE al-lows simple searches or search and re-place. AUTOTYPE also allows wildcard characters in the search string forprobable matching! A very simple fea-ture that AUTOTYPE makes very pow-erful!

CAN IT DO AUTOMATIC PAGENUMBERING AND TITLING?

Of Course! Any length title up to thecurrent line length. Page numbers canstart anywhere. And if that's notenough, the number of blank linesbelow the title is adjustable!

DOES IT HAVE "DYNAMIC" PRINTFORMATTING?

OH YES! And with a flare! The pagesthat you see printed here were allprinted from the same file. Only the printMACRO was altered! What's more,they were all printed on a standard se-rial printer. Complete "dynamic" printformatting can be accomplished withNO alteration of text!! Let's see thecompetition make that claim!

CAN IT DO SUBSCRIPTS ANDSUPERSCRIPTS?

YES! Once again, AUTOTYPE has thefeatures to be called a true proces-sor of words and not just another wordprocessor.

CAN IT VERTICAL TAB?

YES! And dc negative vertical tabs tothe top of page also! This is invaluablefor two column printing.

CAN YOU ADJUST THE INDENT,LINE LENGTH ANDJUSTIFICATION?

COMPLETELY! Either in the text itself,by manual formatting commands orwith a print MACRO. Only AUTOTYPEgives you that kind of choice!

WILL IT EXECUTE A SERIES OFCOMMANDS AUTOMATICALLY?

YES! That's one of AUTOTYPE'S stan-dard features. No other Word Proces-sor has the ease of use or the powerfulcommands that AUTOTYPE has.

ARE THE TABS ADJUSTABLE?

All tab stops are displayed graphicallywith a simple command. Tab removaland setting are simple cursor move-ments and a single key command! Nomore "guessing" where your tabs areset. They're all laid out in front of you!

HOW MUCH DOES AUTOTYPECOST?

$195. This question is the easiest toanswer. It's simple. We want you to useyour computer to its fullest extent. Andwe want you to be able to do it at areasonable price. This is the one areawhere our competition is way aheadof us!! They simply charge more thanwe do!

HOW DO I ORDER?

We thought you'd never ask! Just fillout the order form below and mail toINFINITY MICRO. Or call us directlyand place your order. It'll be shippedthe same day.

WORD PROCESSINGPOWER IS HERE!With AUTOTYPE©

Mail To:

INFINITY MICRO

P.O. BOX 4627

SANTA CLARA, CA 95050

(408) 988-1867

VIDEO

□ Memory mapped Video at CC00hex. as 64 characters by 16 lines.Processor Tech or equivalent.

□ *Cursor addressable terminal.(ADM-3A)

□ *Cursor addressable terminal.(HAZELTINE1500)

DISK

□ CP/M on IBM standard 8"

□ CP/M on Micropolis MOD ID CP/M on Micropolis MOD IID CP/M on North Star

□ CP/M on Double Density 8"Please specify Manufacturer.

NAME

ADDRESS

CITY STATE ZIP

Please ship

AUTOTYPE disks

and manuals immediately! Please find

enclosed $ @ $195/each.

* Available Nov-Dfec of 1979Copyright© 1979 Infinity Micro

Circle 86 on inquiry card.

BYTE January 1980 143

angles it will become apparent, especiallyif the lines are very long.

If, as in most plotting, the increments arevery small, this problem is no more seriousthan the usual stepping phenomenon thatoccurs on most plotters. With the softwaredriven plotter, the routine can smooth along line out by adjusting the incrementsin the X and Y directions.

The decision of which method to use liesmostly in the use to which you will put theplotter. If you're drawing long straightlines, then by all means use the softwaredriven method. If you are like me and planto use it mostly for plotting functions, thehardware method is much simpler to usebecause the length of the line segments tendsto be short.

Design Details

In designing a plotter for your own use,there are three factors to keep in mind.They are the desired resolution, the size ofthe plotting area and the number of bitsused for the coordinates. Determiningany two of these factors automatically setsthe third.

For instance, in my design I used a reso-lution of 0.05 inches (0.13 cm) and an 8-bitcoordinate system. This gave me a plotting

area of 12.8 inches (33 cm) square. Thatwas big enough for me.

The drive shaft is what causes problems.In order to have an exactly evenly spacedset of holes on the disk, you have to havea shaft with a circumference that is a multi-ple of the resolution, in this case 0.05 inches(0.13 cm). This is not easy. Short of goingto a machine shop and having them turnout special drive shafts, I decided to searchfor a standard diameter that would comeclose. One half inch works out fairly well.

With 31 holes in the disk, the formula:

RES = (ttx DIAM)/H

gives the true resolution. Here, n is 3.1415,DIAM is the drive shaft diameter (0.5inches), H is the number of holes and RESis the true resolution, in this case 0.05067inches, which was close enough to 0.05 tosuit me.

What this formula means is that the holesdivide the circumference of the drive shaftinto 31 segments, each one 0.05067 incheslong. Thus as the cable comes off the shaft,driving it one hole means that the crossbarwill move 0.05067 inches.

The only other critical parts are the cross-bar slides since the crossbars must glidesmoothly."

Low Power 32K RAM for Heath®1H8 computers

only $479

DG-32D 32K RAM FEATURES:

1^ Plugs into Heath" H8Computer

*** Ready to use. Fully assembled, tested & burned in

\^ Operates with existing Heath memory

i^ Protected Memory Output Buffers in the event of Address error.

J^ Utilizes popular 4116 RAM devices

k* Memory Address DIP switch changeable

u* Arranged as 4 Independent 8K Blocks

V Low Power Consumption: Less than 6 watts, typical

u* Transparent Refresh

C1 One year guarantee

t^ Compatible with all current H8 peripherals.

Heath * and H8 are registered trademarks of the Heath Corporation, Benton Harbor, Michigan.

n«B

ELECTRONIC

DEVELOPMENTS CO.

D»G Electronic Developments Co. brings you a totallycompatible, fully assembled and tested 32K RAM forHeath18 H8 computers. The DG-32D has less than 6 wattspower consumption. This allows you to add a full 32Kbytes of Random Access Memory without taxing or re-placing your computer's power supply. Engineered toplug-in and run without any user modifications, the DQ-32D can be used with or without existing H8 RAM withoutmodification. Protection of the memory output buffers isprovided in the event of assigning two blocks to the sameaddress space. The DG-32D is the ideal answer to expan-sion of the Heath H8 computer... Low power consump-tion, low price, high capacity, total engineering and exact-ing production methods.

Ordering Information: DQ-32D RAM available only from DG ElectronicDevelopments Co., P.O. Box 1 124, 1827 South Armstrong, Denison, Texas75020. Check, money-order. VISA or Master Charge, Phone orders acceptedon charge orders. MO COD's. Foreign orders add 30$. Texas residents add5*. For VISA or Master Charge orders call 214 465-7805. 5479.00 freightprepaid.

••i

144 January 1980 © BYTE Publications Inc

Circle 87 on inquiry card.

Discover

the most organized (and inexpensive) way to keep up withwhat's new in computer techniques and management—

The Library of Computer and Information Sciences

(Publishers' Prices shown)

62620. MICROCOMPUTER HANDBOOK.

Charles J. Sippl. Detailed reference to the technologyand applications of microprocessors. $19.95

79155. SOFTWARE INTERPRETERS FOR MI-CROCOMPUTERS. Thomas C. Mclntire. How todesign a reliable software interpreter for any micro-computer system. $18.95

70093. PRIMER FOR SMALL SYSTEMS MAN-AGEMENT. Gradv M. Easley. Spells out the super-visory skills needed in the day-to-day administrationof a small computer complex. $18.95

53704. HOW TO DESIGN. BUILD AND PRO-GRAM YOUR OWN WORKING COMPUTERSYSTEM. Robert P Haviland. $12.95

49600. THE FUTURE WITH MICROELEC-TRONICS. Barron and Curnozc. Shows how futuredevelopments will transform every area of societyfrom the factory to the home. $17.50

42303. A DISCIPLINE OF PROGRAMMING.

Edsger W. Dijkstra. Impressive new programmingtools to solve problems that range from the everyday tothe complex. $20.95

55353. INFORMATION RETRIEVAL SYS-TEMS: Characteristics, Testing, and Evaluation.

F. Wilfred Lancaster. A comprehensive and practicalintroduction to information retrieval. $19.95

40071-2. COMPUTER SYSTEMS PERFOR-MANCE EVALUATION. Domenico Ferrari. Countsas 2 of your 3 books. $29.95

79167. SOFTWARE RELIABILITY GUIDE-BOOK. Robert L. Glass. Spells out all the technologi-cal and management techniques. $18.95

59920. MANAGEMENT: Tasks, Responsibilities,Practices. Peter F. Drucker. The skills, techniques andtools a good executive needs to stay effective inmodern management. $17.50

39890-2. COMPUTER DATA-BASE ORGANI-ZATION. James Martin. An invaluable planning toolhaving over 200 diagrams. Counts as 2 of vour 3books. '$26.50

50551. GRANTS: How to Find Out About Them

and What to Do Next. Virginia P. White. $19.50

Take any 3 books

(values to $64.85)for only $1.00 each

if you will join now for a trial period and

agree to take 3 more books—at handsome

discounts—over the next 12 months

62748. MINICOMPUTER SYSTEMS: Organi-zation, Programming, and Applications. Hckhouseand Morris. $21.95

41785. DEBUGGING SYSTEM 360/370 PRO-GRAMS USING OS AND VS STORAGEDUMPS. D. H. Rindflasch, A superior guide tostorage dump debugging. Illustrations, examples,sample dumps. $19.95

40010. COMPUTER POWER FOR THE SMALLBUSINESS. Sippl and Dahl. A complete and practi-cal guide to micro and mini computers that will meetthe needs of your small business. $15.95

87218. THE WIRED SOCIETY: A Challenge ForTomorrow. James Martin. How the modern revolu-tion in telecommunications portends vast changes inthe way we live and do business. $12.95

39858. COMPUTER ARITHMETIC: Principles,Architecture, and Design. Kai Hwatig. Coversalgorithmic flow charts, arithmetic and Boolean equa-tions, schematic logic circuit diagrams. 422 pages, withover 230 illustrations. $21.95

32268. ADVANCED ANS COBOL WITHSTRUCTURED PROGRAMMING. Gary D.Brown. $19.95

45380. THE ENTREPRENEUR'S MANUAL:Business Start-Ups, Spin-Offs, and InnovativeManagement. Richard M. White, Jr. $16.95

32485. ALGORITHMS + DATA STRUCTURES= PROGRAMS. Niklaus Wirth. $20.95

39737-2. COMPACT NUMERICAL METHODSFOR COMPUTERS./ C. Nash. Hundreds of waysto solve mathematical problems on small computers.Counts as 2 of your 3 books. $29.95

EXTRAORDINARY^VALUE!

44900-3. ENCYCLOPEDIA OF COMPUTERSCIENCE. Edited by A nthony Ralston and Chester L.Meek. More than 1550 outsize pages of information onevery aspect of computer science—from algebra toautomata theory, from basic terminology to string-processing languages. 470 articles by 208 experts.Over 700 charts, tables, graphs, and diagrams. Countsas 3 of your 3 books. $60.00

If the reply card has been removed, please write to

The Library of Computer and

Information Sciences

Dept. 7-AA9, Riverside, N.J. 08370

to obtain membership information and application.

Circle 88 on inquiry card.

BYTE January 1980 145

44 TRS-80 USERS!

Vbur Software

I w-.

99

GAMES

Warfare I 4-game anthology, Level II, 16K $7.95

Backgammon by Scott Adams.Level II, 16K

$7.95

X-WIng II by Chris Freund. Level II, 16K $9.95

Talpan by Art Canfll. Level II, 16K $9.95

Sargon Chaas by Dan and Kathe Spracklen.

Level II, 16K $19.95

Chaaa Companion by Michael Kelleher. Level II,

16K $7.95

Threa D Tic Tac Toe by Scott Adams. Level II,

16K $7.95

Concentration by Lance Mlcklus. Level II, 16K

$7.95

Amazln' Mazes by Robert Wallace. Level II, 16K

$7.95

Time Bomb by David Bohlke. Level II, 16K $4.95

Life Two by Leo Chrlstopherson. With sound

-Level II, 16K $14.95

Android Nlm by Leo Chrlstopherson. With

sound • Level II, 16K $14.95

Cubaa by Leo Chrlstopherson Level II, 16K $9.95

Mastermind II by Lance Mlcklus $7.95

Mastermind II - Source List $20.00

Robot/Breakaway Game duo by Lance Mlcklus.

Level II, 4K $7.95

Tycoon by David Bohlke. Level II, 16K $7.95

Slalom by Denslo Hamlin, level II, 16K $7.95

9 Games for Preschool Children by George

Blank. Level II, 16K $9.95

Ten Pin by Frank B. Rowlett, Jr. Level II, 16K

$7.95

Atlantic Balloon Crossing by Dean Powell. Level

II, 16KS9.95

Space Battles by Level IV, Level II, 16K Tape or

32K Disk, Tape -$14.95, Disk - $19.95

Star Trek III.3 by Lance Mlcklus Level II, 16K

$14.95

Dog Star Adventure by Lance Mlcklus. Level II,

16K $9.95

Safari by David Bohlke. Level II, 16K $7.95Treasure Hunt by Lance Mlcklus. Level II, 16K$7.95

'Round the Horn by George Blank. Level II, 16K$9.95

Pork Barrel by George Blank. Level II, 16K $7.95Kamikaze by Russell Starkey. Level II, 16K $7.95All Star Baseball by David Bohlke. Level II, 16K$7.95

Barricade by Small Systems Software. MachineLanguage -$14.95

Journey To The Center Of The Earth by GregHassett. Level II, 16K Tape $7.95Pentomlnoes by James Garon. Level II, 16K$7.95

Snake Eggs by Leo Chrlstopherson. With soundLevel II, 16K $14.95

NowIn Stock!

NEW!!!

Understandable! Indexed library with 200Assembly Language Routines.

SARGON was the BEST]SARGON II is MUCH |BETTER!

Z80 Software GourmetGuide And Cookbook

from Scelbl. $14.95 + $1 postage.

Seven levels of playfaster, better end game .randomized opening.

$29.95

t,\al Of/s^

SPECIALPURPOSE

®

BOOKS

Sargon Handbook by Don & KatheSpracklen. $14.95 plus $1.00 shippingand handling.

The Basic Handbook by Dr. David A.Lien. $14.95 plus $1Z80 Instruction Handbook by ScelblPublications. $4.95The Little Book Of BASIC Style byJohn Nevlson. $5.95 plus $1TRS-80 Assembly Language Pro-gramming by William Barden, Jr.$3.95 plus $1

Introduction to TRS-80 Graphics byDon Inman. $7.95 plus $1Learning Level II by David A. Lien.$15.95 plus $1

Calculator by R. W. Robitaille, Sr.

Level II, 4K $2.95Moving Signboard by Circle Enter-prises. Level II. 4K $9.95Hlstograph/Scattergram by Gary S.Breschlni. Level II, 16K $9.95.Simple Simon by George Blank. LevelII. Written in BASIC. $4.95Math Drill by K. L. Brown. Level II, 16K$4.95

RPN Calculator by Russell Starkey.Level II, 16K $9.95

Ham Radio by Michael Kelleher.Level II, 16K $9.95

Ham Radio ARS 1.1 (32K disk) $24.95Electronics Assistant by John Adam-son. Level II, 16K $9.95Pralllght by Stephen Hebbler. LevelII, 16K $20.00

Basic Statistics by Steve Reisser.Level II, 16K $20.00Drill Masters by Computer Graphics -specify title desired. Level II, 16K$7.95 each. German, Russian, Italian,Spanish, or Music TheoryKeyboard-80 by John Adamson. LevelII, 16K $9.95

SAMPLER$5.95

a

a

ADVENTURELAND

; MISSIONIMPOSSIBLE.

PIRATE'ICOVE

VOODOOCASTLE

»*£&*■

(b

THECOUNT

o*

oo«-

STRANGEODYSSEY

SCOTT^DAMS'ADVENTURES

H

FUNHOUSE

Cassettes SU.85

Combinations on disk:

2 for $24.95

3 tor $39.95

146 BYTE January 1980

Circle 89 on Inquiry card.

by Lance Micklus

The STANDARDin Smart TerminalPrograms for the TRS-80

(32K Disk)$79.95

IMPORTANT

No sales tax •

All C.O.D.'s or special •delivery orders are a mini-mum of $5 for specialhandling

When ordering Percom •

please add $5 each,

packaging and handling fee.

PRICES DO NOT •INCLUDE SHIPPING

UTILITIES

NEWDOS by Apparat $49.95NEWDOS + by Apparat $99.95Machine Language Monitor by Small SystemsSoftware. Level II, 16K $26.95Three Monitors for Disk by Small Systems Soft-ware. Disk for 16 through 48K (all In one) $29.95KVP Extender by Lance Micklus. Tape - $29.95;Disk ■ $34.95

KVP 232 by Lance Micklus - KVP adapted for theTRS-232. Tape - $29.95ST80 Smart Terminal Level II, 16K $49.95ST80D Smarter Terminal for disk systems.$79.95

Micro Text Editor by Don Coons. Level II, 4K or16K $9.95

Text-80 by Frank B. Rowlett, Jr. For 32K disk

systems $59.95

8080-Z80 Conversion Level II, 16K $15.00

Renumber by Lance Micklus. Level II, available

in 16 through 48K (specify when ordering) $7.95

Renumber source listing $20.00

Electric Pencil by Michael Shrayer. Powerful

machine language word processing system.

Level II, 16K tape ■ $100; Disk version - $150

Level III BASIC by Microsoft. $49.95

Level I In Level II by Apparat. Level II, 16K $15.00

Fortran by Microsoft. 32K ■ 2 Disks. New low

price $195.00

JHARDSIIX

BUSINESS

Inventory 11.2 by M. Kelleher and R. W. Robltallle,Sr. 16K disk systems $59.95Inventory System II.3 by M. Kelleher. Improvedversion, $79.95

Inventory'S' by Roger W. Robltallle, Sr. Level 11,

16K Tape-$24.95; 32K Disk-$39.95

Payroll by Stephen Hebbler. For disk systems.

32K $59.95

Accounts Receivable II by S. Hebbler. 32K disk

systems $79.95

Appointment Log by Michael Kelleher. Level II,

16K$9.95 Disk version, $19.95

General Ledger I by M. Kelleher, requires 32K

Disk, $79.95

Mall List II by R. W. Robltallle, Sr. 32K disk

systems $99.95

Small Business Bookkeeping by R. W.

Robltallle, Sr. Level II, 16K. With journal -$22.00;Without journal - $15.00

PERSONAL

Typing Tutor by Roger W. Robltallle, Sr. Level II,

16K $19.95

Secrets of the Tarot by John T. Phllllpp. Level II,

16K$9.95

Biorhythma by Frank B. Rowlett, Jr. Level II, 4K

$4.95

Personal Finance by Lance Micklus. Level II,

16K$9.95

Advanced Personal Finance by Lance Micklus

for 32K disk systems $24.95

Home Financial Management by Michael

Kelleher. Level II, 16K $9.95

HARDWARE ACCESSORIES

Cassettes boxes of ten each. C-10 - $6.50 plus

$1.00 shipping

C-20 - $7.50 plus $1.00 shipping

Diskettes Dysan, (premium quality) box of 5

-$24.95 plus $1.00 shipping; nationally known

brand, box of 10 - $34.95 plus $1

Diskette Storage Box $5.00

WANTED

Used TRS-80 equipment! We buy and sell usedequipment. Call or write for details.

SPECIAL

$669. TRS-8016K, LEVEL

SAVE $167.

TRS-80 expansion interface with our16K RAM, single PERCOM disk driveswith cable, and NEWDOS operatingsystem. $830.

Floppy Armour™ Protective envelope for ship-ping floppy disks, 5-pack - $4.95 plus $1.00 ship-ping and handling

NEWDOS

Eliminate 90% of the hassle of a disk system byreplacing your TPS-DOS with NEWDOS! faster,more reliable, many more features $49.95.

Add Superzap, Directory checks, other utilities.NEWDOS + $99.95

PACKAGE PRICE $150

SEPARATELY:

MACRO ASSEMBLER $80.

FORTRAN $8C.

* A trademark of Radio Shack and Tandy Corp.Circle 91 on inquiry card.

TRS 232 by Small Systems Hardware - $49.95

Percom Disk Drives Single or dual, forTRS-80's.Single drive $399.00; Dual drive - $795.00; Cablerequired - $29.95

ASK ABOUT OUR FREEHARDSIDE CATALOG

TO ORDER (9AM - 5:30 PM, EST)

TOLL-FREE 1-800-258-1790

Software Exchange

6 SouthStreet, Box 68,Milford,NH 03055 603-673-5144

BYTE January 1980 147

Circle 90 on inquiry card.

Q

®

NOW BETTER THAN EVER

• Control Program for Microcomputers.

• Includes Editor, Assembler, Debugger, Utilities

• Supports Floppy Disks and Hard Disks.

• For 8080, 8085, Z-80, MDS, Cromemco.

• $150-Diskette and Documentation

• $25-Documentation only

Q

NEW INDUSTRY STANDARD

• Multi-terminal access.

• Multi-programming.

• CP/M-compatible.

• Real-time features.

• $300-Diskette and Manual

• $25-Manual only

OPTIONAL SOFTWARE PACKAGES

MAC™ MACRO ASSEMBLER:

• Compatible with new Intel macro standard.

• Complete guide to macro applications.

• $90-Diskette and Manual.SID™ SYMBOLIC DEBUGGER:

• Symbolic memory reference.

• Built-in assembler/diassembler.

• $75-Diskette and Manual.TEX™ TEXT FORMATTER:

• Powerful text formatting capabilities

• Text prepared using CP/M Editor.

• $75-Diskette and Manual.DESPOOL™

• Background print utility.

• Use with CP/M

• $50-Diskette and Manual.

Dl DIGITAL RESEARCH*

P.O. Box 579* Pacific Grove, California 93950(408) 649-3896

Technical Forom

Aids to the DirectReception of WeatherSatellite Photographs

William D Johnston, 1808 Pomona Dr, Las Cruces NM 88001

A recent note in "BYTE's Bits" (June 1979 BYTE, page225) brought to the attention of BYTE readers the pro-spect of direct reception of weather satellite photographsby amateurs using home-built equipment. The purpose ofthis brief article is to expand on that note, and to directthe interested reader to a number of existing resources.

Applications of the home computer in this field aremany and varied. They include such projects as orbitalpredictions, antenna tracking calculations, signal erroranalysis, generation of map overlays, and weathersystem modeling, to name just a few. Most of the mathe-matical calculations involved are quite simple, requiringthe use of nothing more difficult than high school trigo-nometry. A computer enthusiast can derive a great dealof personal satisfaction from writing software to arrive atthe correct solutions. Those who are hardware orientedwill want to go a step further and use their computers todrive a tracking antenna in real time.

The 1968 report by Vermillion (NASA SP-5079) men-tioned in BYTE's Bits was not the first to appear on thesubject. A comprehensive article on building a homereceiving station appeared in QST magazine as far backas 1965. Vermillion himself put out a number of otherexcellent NASA reports since the 1968 document,including SP-5080 and TN D-7994. Scientific Americancarried a construction article based on a design similar tothe 1965 QST equipment.

The great majority of technical literature on the sub-ject, however, has appeared in the various American andBritish amateur radio magazines over the past five or sixyears. A review of the annual indices (usually appearingin the December issues) of Ham Radio, QST, RadioCommunication, and Wireless World will reveal awealth of information. These articles are indexed under"Satellites," "Weather Satellites," "OSCAR," and"Facsimile." The subject matter runs the gamut from con-struction details for homebrew state-of-the-art receiversand recorders, to surplus equipment conversions, to com-puter software for orbital calculations and antenna track-ing.

An excellent book on the subject has been written foramateurs by Ralph Taggart. Mr Taggart is the author of

148 January ]°80 © BYTE Publications Inc

IS YOUR

Don't settle for less than the totalperformance built into your Z80Computer. Wake up its entire potentialwith an OASIS Operating System —the high-powered, professional softwarepackage that takes full advantageof Z80 power.

Utilizing optimized Z80 code, OASISmakes the system run faster. More andbetter tools let you develop softwarefaster, too.

It's easy to use because all thetools you need are included: ISAM files,hard and floppy disk support, editor,user accounting with logon, passwordprivilege level, and file security.Options: BASIC Compiler, spooler,text editor and output processor,

development package, and more.

The BASIC Compiler is also aninterpreter, complete with debugger.It makes programs run faster, takes less'memory, and provides software security.A first for micros, it's an OASIS exclusive.

FEATURES: Single- 2. Multi-User/User Accounting/Mulli-Tasking/F,le & Record Security/Logon. Password A Privilege Protection/Keyed (ISAM). Direc! & Sequential Files/Hard & Floppy Disk Support/Extensive Documentation

OASIS PRODUCTS: Single-User Operating Syslem/Mulli-User OperatingSystem/Macro Re-localing Assemnler/Derjjgger/Linker/Edilor/Output Text Formalter/Spooler/Commurncations Packago/Sorl/Diagnostic & Maintenance Utilities/Interactive EXEC Language/Re-entrant BASIC Compiler

OASIS IS AVAILABLE FOR: Altos/Billings/Digilal Microsystems/Digital Group/Cromemco/Vector Graphic/Micromalion/Compucorp/Norm Slat/Onyx/Bell Controls/TRS-80 Moo ll/Vonmex and others

MAKES MICROS RUN LIKE MINIS.

Multi-User OASIS, available for mostcomputer configurations, gets evenmore performance out of your system.It has all the Single-User features,PLUS a re-entrant BASIC Compiler, fileand record locking, variable time-slicing,user-to-user communications, andextended memory addressing. All fullyupward compatible with Single-User.

Documentation?...complete andextensive. And, of course, there'splenty of application software.

OASIS operating systems,languages, development packages,system utilities —all fully integrated,all from one source.

Ask your dealer or manufacturer.Or send the coupon direct, today.

Order OASIS direct from:Phase One Systems, Inc.7700 Edgewater Drive, Suite 830Oakland, CA 94621

Telephone (415) 562-8085 TWX 910-366-7139

My computer configuration (specify make, disk system, etc.)

Name

Street Address (No Box £ )

City State _

PLEASESEND ME:

OASIS (Includes Manual)D Single-User System $150

D BASIC Compiler $100

D Multi-User System $250

D Re-entrant BASIC Compiler $145

SPECIAL WITH THIS COUPON:System AND BASIC Manual

Complete Information

.Zip.

□ Check Enclosed

□ UPS COD.

Card Number:

Expiration Date:

Signature:

□ VISA

□ Mastercharge

Manual Only□ $17.50

□ $15

□ $17.50

D $15

D $27.50

a $1

Shipping

$1 for COD.

Californiaresidents addsales tax

TOTAL

Amount

$2

BYTE January 1960 149

EQ CROSSING

AT

67 DEGS

TIME

AZ

EL

RNG

MINS

DG

DG

KM

i*

177

0

3t83

5

178

3

3093

6

180

7

2706

7

183

12

2327

8

186

18

1961

9

192

26

1618

10

202

37

1319

11

223

t9

1102

ia

262

55

1022

13

299

t8

1108

it

318

36

1328

15

327

26

1628

16

333

16

1971

17

336

12

2336

18

339

7

2715

19

3tl

3

3100

20

3t2

-1

3t88

EQ CROSSING

AT

68 DEGS

TIME

AZ

EL

RNG

MINS

DG

DG

KM

it

179

0

3t79

5

180

3

3092

6

182

7

2708

7

185

12

2333

8

190

18

1971

9

196

26

1636

10

207

35

13t7

11

228

t6

lltl

12

26t

51

1070

13

297

t5

1158

It

315

3t

1375

15

325

25

1670

16

331

18

2008

17

335

12

2370

18

338

7

27t5

19

3t0

3

3127

20

3t2

-1

3513

Listing 1: A small portion of a typical satellite tracking printoutgenerated on a home computer. The data can be calculated inreal time, or a perpetual-prediction printout (about fifty pageslong) can be prepared in advance. All calculations are based onthe exact location of the ground station that is to use the print-out.

many of the articles that have appeared in the amateurradio magazines, including a very good introductorytreatise for beginners.

BYTE has published material which is directlyapplicable to the subject. This was related to computergeneration of map overlays for satellite photos. It is avery handy capability to have on occasions when yourreceived pictures show nothing but cloud cover and youneed a system of reference (see my article series "Com-puter Generated Maps/' May 1979 BYTE, page 10; June1979 BYTE, page 100).

Those who are concerned about the cost and complex-ity of such a project need not worry. It is entirely possibleto assemble a station capable of receiving high-resolutionphotos (both visible light and infrared images) with anoutlay of less than $100. Excellent quality picturerecorders, capable of recording images up to 19 inches (48cm) square, are available on the surplus market for as lit-tle as $50. Recorders that produce pictures about 4 by 6inches (10 by 15 cm) can be found for as little as $10.Advertisements in the amateur radio magazines and visitsto ham radio swap meets provide the best leads to equip-ment buys. Many of the previously mentioned articleseven show you how to build a recorder from scratch,

STATEMENT OF OWNERSHIP, MANAGEMENT, AND CIRCULATION

STATEMENT OF OWNERSHIP, MANAGEMENT AND CIRCULATION

(Kcquucd by 39 U.S.C. 3685)

-BYTE The Small Systems Journal

A. PUBLICATION NO. |l. bate of filing

0 1 3 1 6l 0 Is 1 2 U 1 0 1 9/27/79

Monthly 1 ANNUALI-¥ i2 1 """* Slft/vear

*. LOCATION OF KNOWN OFFICE OF PUBLIC ATION IStnrrt. City. County. Slot* and ZIP Coda! (.Vol pnnlcri)

70 Main Street, Peterborough, NH 05158

1223 Avenue of the Americas New York, NY 10020

6. NAMES AND COMPLETE AQDHESSES OF PUBLISHER, EDITOR. ANQ MANAGING EDITOR

Virginia Londoner Vale Street Peterborough, NH 0 3458

EDITOR fWom-r anil Addmti

Carl T lielmers, Jr. Carriage Hill Road Hancock, NH 03449

Christopher P Morgan Hancock Road Dublin, NH 03444

J. OWNER (If owned by n corporation, its name mid address must be stated and alio immediately thcrcun.t.i the inntes cud addresses of slack-liulderi owning or holding I percent or more o) foul amount of nock. 1/ not mined hy a corptirjiion tin- n.:me: end addresses of the individualowners must be gum. It tinned by a parinrrship or other uitiiicorpiiratnl firm, in name and addicts, as well as that of each individual must bej.-M<Ur- If the publication is published by a nonprofit organization, its name and address must be staled,/

NAME .

•BOBEK

PLEASE SEE ATTACHED SHEET*

>■ KNOWN UONDHOLDERS. MOHTG ACE ES. AND OTHER SECURITY HOLDE RS OWNING OH HOLDING 1 PERCENT OB MORE OFTOTAL AMOUNT OF BONDS, MORTGAGES OR OTHE R SECURITI ES III thrrx art none, ta •tale)

NAME

ADDDCSS

NONE

NOT APPLICABLE

1 lHAVr NOT CHANCED DURING 1 1 HAVE CHANCED DURING til than/1 d. puolltTi.' ntll llitMl tiplanatlon of chanlc

1 1 PRECEDING It MONTHS | | PRECEDING t* MONTHS Willi Will UBttmtnl.)

ID. EXTENT ANO NATUHE OF CIRCULATION

ISSUE DURING PRECEDING

ISSUE PUBLISHEO NEAREST TO

A. TOTAL NO. COPIES PRINTED (Net I'rctt Kuril

157.817

VENDOHS ANO COUNTER SALES

21,426

23,655

127,135

130,239

C. TOTAL PAID CIRCULATION ISum Of tGll I and 10011

148,561

153.894

SAMPLES.COMPLIMENTARY. AND OMll.li FREE COPIES

3,323

3,463

E. TOTAL DISTRIBUTION (Sum atC and Dl

151,884

157,357

1. OFFICE USE. LEFT OVER, UNACCOUNTED. SPOILED

4,656

3 , 9 5 3

«, RETURNS FROM NEW! AGENTS

1,277

None as of this date

a. TOTAL ISum alE, ¥1 ind 2-jhauJd caul net j.reii run iliown

157,817

161,310

ii, 1 certify that (he statements made by me rfln^above are correct and complete. B^^

"^iL >,/.

12. FOR COMPLETION BY PUBLISHERS MAILING AT THE REGU LAR' RATES (SrcfJon 132.111, f oital .Sffl'irr Manual!39 U. S C. 3.G2G provld.i In D.nlrunt Dan "No |».inn who wauia hiva Burr •niltlad ta mill m.tur unjir larrr... taction 43S9 al ml! nil.

tmm nraiantlv author Had tw 3S U. S. C. 3G26.

SIGNATUHcXNi) T*Tte OF COITofa. PUBlURIll, BUSINESS MABAOER, OH OWNER

nH 3526 fl'age I) (Sec instructions on revcisc)

The owner is McGraw-Hill Inc., 1221 Avenue of the Americas, NewYork, New York 10020. Stockholders holding 1 % or more of slock are:Donald C. McGraw Jr.; Harold W. McGraw Jr.; John L. McGraw; WilliamH. McGraw; June M. McBroom; Elizabeth McGraw Webster; all of 1221Avenue of the Americas, New York, New York 10020; Occi and Company,c/o Occidental Life of California, P.O. Box 3635, Terminal Annex, LosAngeles, California 90054.

BYTEs Bits

Patents Awardedto Apple

The US Patent Office hasgranted Apple ComputerInc, 10260 Bandley Dr,Cupertino CA 95014, twopatents for the switchingpower supply and colorvideo-display designs used inthe Apple II personal com-puter.

The AM-2 power supplyis a 40 W, multiple-output

flyback switching devicewith a unique starting andrestarting circuitry schemeand a secondary windingmechanism which counteracttypical power supply pro-blems of power dissipationand breakdown.

The video display includesa special timing referencemechanism and a recir-culating shift register thatresolves the difficultiesinvolved in simultaneouslygenerating horizontal, ver-tical, and color frequencysignals. They also eliminatemany of the componentsnormally required in a videodisplay. ■

150 January 1980 © BYTE Publications lnc

Put the BYTE on the IRS with Aardvark

Inanerawhencomputersarean integral partof business and entertainment, and computersoftware is more and more sophisticated,Aardvark is yet another breed in advancedcomputer software. Aardvark's Micro Taxseries is a true user-oriented Federal I ncomeTax package. Specifically developed byqualified tax professionals for use on person-al home computers, this low-cost, time-savingAardvark Micro Tax package accurately andefficiently computes your federal income taxliability. Aardvark will display and fill infacsimile Form 1040 and related schedulesand, if connected to a Centronics printer,will print out these facsimile forms auto-

matically. Each program is designed to usethe appropriate tax table or rate schedule.The more advanced Micro Tax II and III alsocalculate Income Averaging, Maximum Taxon Earned Income, Minimum Tax and Alter-native Minimum Tax. The Aardvark packageis compatible with Apple II and TRS-80 usersand includes an indexed instruction manualand input forms for easy input of tax data. Tosee how Aardvark can be tax-deductible,check the instructions in the binder of themanual. You can also use the binder to storepertinent 1979 tax records. Cure your head-aches this tax season, order today...and putthe BYTE on the IRS with Aardvark!

MICRO TAX I $25

Form 1040Schedule ASchedule BSchedule TC

(will not calculate IncomeAveraging, Max Tax or Alter-native Minimum Tax)

When Ordering Specify:

TRS-80 16K Level II BasicApple 11 32 K with Applesoft BasicApple II16K Micro with ApplesoftROM Card

$35

MICRO TAX II

Form 1040

Schedule A

Schedule B

Schedule G (Inc. Avg.)

Schedule TC

Form 4625 (Minimum Tax)

Form 4726 (Max Tax)

Form 6251 (Alt. Min. Tax)

Software

MICRO TAX III $50

Program 2 plusSchedule CSchedule DSchedule ESchedule SEForm 2119- Sale ofPersonal Residence

Coming Soon - Micro TaxPackage for PETand TlSystems.

P.O. Box 26505 Milwaukee, Wl 53213

24hrs. Call TOLL FREE 1-800-558-8570. 7 days

In Wisconsin 1-414-289-9988

©Aardvark Software Inc. 1979

VISA

Circle 92 on inquiry card.

GROUND

STATION ATI NEW

HAMPSHIRE.

PETERBOROUGH

42

53N

71 57ft

SYhCHRONOU

SYNCHRONOUS

SYNCHRONOUS

SYNCHRONOUS

SATELLITE

SATELLITE

SATELLITE

SATELLITE

LONG

AZ

El

RANGt

LUNG.

AZ

EL

RANGE

LONG

A2

EL

RANGc.

LONG.

AZ

EL

RANGE

DEG

UES

DEG

KM

DEG

DEG

DEG

KM

DEL

OEG

DEG

KM

DEC

DEG

DEG

KM

0

»

103

»

mi9i

1

*

103

5

141112

46 W

144

34

38273

91

ft

207

37

38035

136

W

25?

10

40S76

2

A

1014

6

410J3

47 w

146

34

38234

92

ft

208

37

3306o

137

W

25?

9

40653

3

A

105

7

40955

48 w

147

35

38197

93

ft

209

3b

36097

138

w

253

9

40729

4

W

105

7

406/o

49 W

148

35

38161

94

ft

ill

3b

38130

139

w

254

6

40807

5

ft

lOf,

6

■10799

50 W

149

36

38127

95

A

ma

35

38165

140

w

255

7

40864

o

n

107

9

40'22

51 W

151

36

3B094

9b

ft

213

35

36201

141

w

255

7

40Q62

7

w

ioa

10

40b45

52 W

152

37

38063

97

ft

211

34

36236

142

w

256

b

41041

d

*

10(1

10

40bb9

b3 w

153

37

38032

98

A

21b

34

36277

143

w

257

5

41120

9

«r

10°

11

4049J

54 w

155

37

38004

99

ft

,217

34

3d317

144

ft"

258

4

41199

JO

ft

Uo

12

4041e

b5 W

156

38

37977

100

ft

tlB

33

36356

145

w

25"

4

41278

11

H

111

12

140313

56 w

157

38

37951

Ijl

ft

219

33

36401

146

w

25°

3

4 135S

12

M

111

13

40269

57 w

159

36

37927

lu2

ft

t20

32

3844b

147

w

260

2

41436

13

A

112

in

U019b

58 W

160

39

37904

103

ft

i2l

31

38491

148

w

260

1

41518

It

ft

113

It

■4012,:

b9 w

lbl

39

37a83

104

ft

223

31

38537

149

w

261

1

4 1598

lb

ft

116

15

■10050

60 W

163

39

37664

lub

ft

221

30

3d585

150

ft

26?

0

41679

lb

h

115

lo

399'9

bl W

164

39

37646

liJD

A

£25

30

38634

151

w

* » *

.....

17

ft

116

17

39906

62 ft

lb6

40

37d29

1U7

A

226

29

3be65

152

w

♦ » ♦

♦ *.» •

13

n

116

17

3963d

63 ri

lo7

40

37615

108

A

227

29

38736

153

w

»»•

.....

19

H

117

la

39769

64 w

168

40

37801

109

ft

i26

26

36789

154

w

M •

.....

20

A

lie

19

39/00

65 W

170

40

37789

UO

ft

£29

26

38843

155

w

...

»*»• .

21

A

119

19

39b3<:

66 W

171

40

37779

111

A

230

27

38896

156

w

...

.....

2£

A

120

20

39bb =

b7 w

173

40

37771

112

A

231

26

38954

157

w

• • »

... . .

23

ft

121

21

39499

66 w

174

40

37763

113

A

232

2o

39011

158

w

• * ♦

.....

24

A

122

21

39*Jil

69 W

176

40

37758

114

w

£33

25

39070

159

ft

...

.....

2b

w

122

22

39370

70 W

177

40

37754

115

ft

234

24

39129

lbO

ft

*• *

.....

2o

ft

123

2i

39307

71 W

179

41

37752

116

A

£jb

24

39189

161

ft

...

.....

27

ft

12b

2j

39£43

72 w

ISO

41

37751

117

A

236

23

39251

162

ft

• * •

.....

28

ft

125

21

391B3

73 w

162

41

37752

lid

A

£37

23

39313

163

w

»* *

.....

29

A

126

2b

39123

74 ft

163

40

37754

119

A

2->8

22

39377

164

w

...

.....

31)

"

127

2d

390b4

75 ft

164

40

37758

120

ft

239

21

39441

165

w

..*

*. M *

31

„

12H

2o

3900o

7b w

166

40

37764

121

A

£39

21

3950o

166

w

...

32

A

129

2o

3894a

77 w

167

40

37771

US

ft

240

20

3957c

167

w

...

.....

33

w

13c

27

3669£

7b *■

169

40

37 780

123

A

£41

19

39639

168

w

...

* ♦ .. .

34

A

131

2o

38637

79 w

190

40

37790

124

A

242

19

39707

169

ft

...

.....

3b

A

132

26

36 764

60 ft

192

40

37602

12b

A

243

lb

39775

170

ft

...

. . ♦ . .

3o

A

133

29

38731

81 W

193

40

37816

126

A

244

17

39645

171

w

...

.....

37

A

13u

29

38b79

82 u

195

39

37631

127

ft

24b

16

39915

172

w

...

.* *. .

36

A

135

30

38629

63 w

196

39

37648

128

A

245

lb

3996u

173

ft

...

*. ...

39

W

136

30

36580

84 K

197

39

37866

129

A

24b

15

40057

174

w

...

.. *• .

■40

ft

137

31

3db3£

85 w

199

39

37685

130

A

£47

14

4013o

175

ft

...

• *•*•

HI

A

139

3£

3846o

66 K

200

39

37907

131

A

248

14

40203

176

w

...

142

ft

l»Q

32

36441

87 *■

202

38

37929

132

A

249

13

4027o

177

w

...

.* * . .

I|3

ft

111

i3

38397

6b ft

203

38

37954

133

A

£49

12

4035u

178

w

...

»**• .

44

w

1112

33

363b4

89 w

204

38

37979

134

A

2b0

12

40425

179

w

...

... A .

45

ft

143

311

38313

90 w

206

37

38007

13b

*

2bl

11

4050O

180

w

...

. *. . *

..

♦ MEANS THAT A GEO

SYNCHRONOUS SATE

LLITt

at The given

POSITION IS

NOT

VISIBLE FROM THIS GROUND STATION.

Listing 2: Part of a geosynchronous satellite antenna-pointing chart created on a home computer. Knowing the station longitude of aparticular satellite, one simply refers to that entry in the chart to find the antenna-pointing angles. The illustrated example xoasprepared for a ground station located in Peterborough NH, site of the offices of BYTE Publications.

using simple materials (eg: a kitchen rolling pin for arecording drum!), if you cannot find or do not want tobuy a surplus recorder.

The necessary radio receiving equipment is also rea-sonably simple. If you already own a general coveragereceiver, a converter can be built for as little as four orfive dollars. In fact, many public-service band radios andscanners can receive the satellites directly (on 137.5MHz), and all you need to add is an outdoor antenna.

Satellite tracking should be a snap for the average com-puter enthusiast. The published literature includes manyarticles on satellite tracking software. The only addi-tional data you need is the time and longitude of theequator crossing of an occasional reference orbit (onceevery few weeks or so). Reference orbit information istransmitted daily via teletypewriter to most NationalWeather Service (NWS) offices on the TBUS circuit. TheNational Weather Service also carries the information ontheir high-frequency radio teletypwriter (RTTY) circuits.The American Radio Relay League station W1AW trans-mits the same information by both voice and radioteletypewriter. See any recent issue of QST for theWlAW transmission schedule. It is also possible to have

your name put on a mailing list maintained by theNational Environmental Satellite Service, and receivethis information by mail on a monthly basis.

Some weather satellites are in geosynchronous orbits;that is, their periods of revolution are the same as therotational period of the earth (ie: 24 hours). Consequent-ly, they remain stationary with respect to the earth's sur-face. This makes life really simple because you do nothave to track them. It is only necessary to compute theantenna pointing angles once for each satellite. A recentarticle about locating geosynchronous satellites in QSTgives the procedure for doing this on either a pocketcalculator or a home computer.

Listings 1 and 2 show portions of the output fromtypical home-computer programs for polar orbiting andgeosynchronous satellites, respectively. The programsthat produced them are based on articles that haveappeared in amateur radio magazines, and they requirejust a few seconds to execute.

As you can see, there are quite a few areas of oppor-tunity for home computer projects in this exciting field. Itis intriguing to receive real-time weather satellite photosright in your own home and to try to outguess the

152 January 1980 © BYTE Publications lnc

weatherman! You can even use your computer to main-tain weather records over long periods of time to aid inyour forecasting.

I do not personally have additional advice to offer onconstruction details or equipment recommendations,other than to refer the reader to the many excellentarticles already in print. I can, however, provide someassistance with tracking data. As an extension of a serviceI provide to amateur radio operators to assist in trackingthe OSCAR communications satellites, I also provideperpetual orbital-prediction printouts for the currentprimary polar orbiting weather satellite, TIROS-N. (Ihave discontinued the printouts for all of the earlierweather satellites, but the service will be extended toinclude NOAA-6, which was launched in June 1979.) Aprintout showing antenna pointing data to all geosyn-chronous satellite locations, in one-degree increments, isalso available.

All printouts are computed based on the exact stationlocation, and can be used directly for tracking or as acheck on the accuracy of programs you develop on yourown. There is a nominal charge for the printouts ($5.00for the TIROS-N printout, and $1.00 for the geosyn-chronous satellite printout) to help defray the cost ofpostage and materials. If you would like additional infor-mation about the printouts, be sure to enclose a self-addressed, stamped envelope with your letter. ■

REFERENCES

Anderson, Wendell G, "Amateur Reception of Weather Satellite

Picture Transmissions," QST, November 1965, page 11.

Johnston, William D, "Computer Generated Maps," BYTE, May

1979, page 10 and June 1979, page 100.

Johnston, William D, "Locating Geosynchronous Satellites," QST,

March 1978, page 23.

Ruperto, Eugene F, "Weather Satellite Pictures Are Picked Up in

the Home," Scientific American, January 1974, page 114.

Taggart, Ralph E, "Amateur Weather Satellite Reception," 73,

May 1976, page 52.

Taggart, Ralph E, Weather Satellite Handbook, 1976, 73 Inc.

An Improved MazeProgram

David Lyons, 77 Elizabeth St S, Brampton Ontario,CANADA L6Y 1R3

I enjoyed "My Computer Runs Mazes," by David EStanfield in the June 1979 BYTE, page 86. I agree that theform of the listing provided is easy to enter, but it couldbe difficult to modify the program for other systems.Therefore, I have compiled the following informationwhich might help.

The maze matrix will not print properly on terminalswith line lengths other than thirty-two characters or

Find out more. Send this coupon.

□ Please send UCSD Pascal description and orderform.

□ Please send distributor and volume licensein formation.

Name-Title

Company-Address

City/State/Zip-

Computer system-

Send to: SofTech Microsystems

9494 Black Mountain RoadSan Diego, CA 92126

Byte 1

January 1980 © BYTE Publications Inc 153

Listing 1: Adding carriage return and line feed to maze displayoutput.

Listing 2: Command table extension.

Hexadecimal

Hexadecimal

Label

Instruction

Operand

lexadecimal

Hexadecimal

Instruction

Operand

Address

Code

Mnemonic

Address

Code

Mnemonic

02B3

BD 07 85

JSR

PATCH

0283

26 EB

BNE

$0270

0785

81 58

PATCH

CMP A

fX

0285

BD 02 5F

JSR

CRLF

0787

26 08

BNE

NFOUND

0288

01

NOP

078A

BD 02 DD

ISR

BACKSPACE

0289

01

NOP

078D078F0791

86 58A7 0039

LDA ASTA ARTS

fX0,X

0792

7E 02 D3

NFOUND

JMP

RESTORECHAR

without screen wraparound, since screen wraparound isrelied upon for the carriage return and line feed after eachrow of alternating X and space characters. These missingcharacters can be added by a modification to theappropriate printing routine, as in listing 1,

Cursor-right and cursor-up characters do not alwaysseem to be standard. The locations in which they occurare listed in table 1, if you need to alter them. Contrary towhat is implied in the listing in the original article, themaze-running program is contained in two sections ofmemory, one from hexadecimal 003D to 0060, and theother from hexadecimal 0100 to 0784. Also, the displaymemory is located between hexadecimal 0800 and 09FF.

Now I shall suggest some possible enhancements.Provisions are made to open up corridors and set thegoal, but not to replace a wall or remove the food exceptby redrawing the entire maze. By adding the patch inlisting 2, the command table can be extended to allow thesetting of an X at the current cursor location by pressingthe X key.

If the goal is not accessible in the maze, the same bran-ches can be searched repeatedly before the search ends.This seems due to the search strategy of eliminating onlythe end location of a branch each time a dead-end isreached, even though the entire branch back to thenearest node could be eliminated when backtracking isnecessary. The strategy can be modified so that dead-endpaths are searched only once by changing four condi-tional branch (BEQ) instructions as shown in table 2.

Move-Right Character

031 B049805200686

Move-Up Character

03AD056F069C

Table 1: Hexadecimal addresses of instructions using cursor-control characters.

HexadecimalLocation

05C805FB06240643

HexadecimalBranch Value

42E927E9

Table 2: Search strategy modification. Deposit the indicatedbranch values into the corresponding memory locations.

This change also has the added advantage of allowing thesearch to terminate on its own. You do not have to resetthe computer if a loop is encountered in a maze. I hopethat these comments will help others to enjoy this pro-gram. ■

How to Start and Run

A Successful Business

Hands On Techniques for:

uncovering lucrative markets and products

using the basic components involved in a business plan (and some innovativewrinkles which will help your plan attract capital)approaching venture capital groupsmoney leveraging

implementing management-by-objective, management-by-exception, and manage-ment by-motivation systems which maximize growthaccomplishing market penetrationa list of the keys that venture capitalists look fora comprehensive list of venture capital groups that continually invest innew ideasuse of profit center controls

For the businessman who wants to make a dime do a dollar's work, whowants marketing and sales boiled down to a commonsense discipline, and whowants to be able to perceive the major frontiers of American business in thenext decade, there is no better book. This is the sort of instruction for whichbusinessmen commonly pay consultants $50 an hour. The first investment youshould make. THE ENTREPRENEUR'S MANUAt can be one of the most pro-fitable you'll make.

Satisfaction guaranteed

Send $24.95 now to: RabinincP.O. BOX 942, N.Y., N.Y. 10004

add $1.10 for C.O.D.

~i Ill illinium 11 ■ 111 ■ 11111 ■ ■ 11 ■ i in 1111 ■ i ■ 11 111 ■ i • i i ■ 1111 ■ t i iiiinii iniiiiii ii it ii 111111 ■ 11 mi i i nun;

154 January 1980 © BYTE Publications lnc

Circle 94 on inquiry card.

MICROSOFT CONSUMER PRODUCTS

CONTINUING THEMICROSOFT TRADITION

Microsoft set the standard in microcomputer system software. We know moreabout the structure and capabilities of today's microcomputers than anyone else.And now we're using that power in a whole new way!

Microsoft Typing Tutor. There's no easier way to mas-ter your keyboard! Faster and more efficient thanany other teaching method, Typing Tutor helps you ifyou're starting from scratch or simply buildingspeed. The secret lies in Typing Tutor's exclusive TRM '*or "Time Response Monitoring" software. TRM moni-tors your keyboard 20 times per second so the com-puter can evaluate your skill. Your speed. Your errors.Your weakest keys. Typing Tutor tells you where youstand then automatically adjusts itself to help youimprove. Written by Dick Ainsworth and Al Baker ofthe Image Producers, Inc. For the Apple II with 16Kand Apple BASIC or the TRS-80 with 16K and Level IIBASIC. Priced at $14.95.

Announcing Microsoft Consumer Products. Dis-tinctive software packages backed by the Microsoftname. Each is created by a top-notch programmerand comes to you fully documented, at a cost youcan afford.

Microsoft Editor/Assembler-Plus. Now get everyfeature of Radio Shack's Editor/Assembler andT-Bugall in one package. PLUS—many "big computer"features to simplify your programming, editing anddebugging. All in a low cost cassette package.Don't waste time creating both source and objecttapes—Assembler-Plus assembles directly into mem-ory. Supports macros and conditional assembly, too.Editor-Plus simplifies editing with extra commandslike Substitute, Move, Copy and Extend. AndZ-Bug,™ the most powerful debugger ever availablefor the TRS-80, has single step execution, directexecution in calculator mode and symbolic refer-ences. And, you can use up to 8 breakpoints at atime, with no need to remove a breakpoint beforeproceeding. For the 16K, Level II, cassette TRS-80.Priced at $29.95.

Microsoft Adventure. Only Microsoft offers Adven-ture complete, as originally written for the DECPDP-10, now implemented on personal computers.The ultimate fantasy/logic game, Adventure allowsyou to explore the depths of the "Colossal Cave!'collecting treasures and magic, solving puzzles,avoiding hazards and adversaries—including thedreaded killer dwarves. Don't be fooled by imita-tion or incomplete versions. Only Microsoft has it all.Adventure fills an entire disk with everything youneed for your exploration. Written by Gordon Letwin,of SOFTWIN, Associates. Adventure for the TRS-80 re-auires a single-disk, 32K system. For the Apple 11,** asingle-disk, 32K system with either the standard diskor language card system. For just $29.95.

Microsoft Level III BASIC. Upgrade your Level IITRS-80 and increase your programming efficiencywithout additional hardware. Microsoft Level IIIloads from cassette tape on top of the Level II ROM.It gives you every feature of Disk BASIC except diskfile commands. But that's not all—Level Ill's high-speed graphics turn your TRS-80* into a virtual elec-tronic drawing board. And there's program renum-bering, long error messages, quick shift-key entries,time-limit INPUT statements and many more fea-tures. System requirements: Level II BASIC and 16K.Occupies 5.2K RAM. Priced at $49.95.

Where To Buy. Microsoft Consumer Products aresold by computer retailers nationwide. If your localcomputer store doesn't have them, call us. Phone(206) 454-1315. Or write Microsoft Consumer Products,10800 Northeast Eighth, Suite 819, Bellevue, WA 98004.

'TRS-80 is a trademark of Radio Shack Corp. ' 'Apple II is a trade-mark of Apple Computer, Inc.,™ Editor/Assembler-Plus and Z-Bugare trademarks of Microsoft. TRM _is_ a trademark of The ImageProducers, Inc.

VHicftpsofr

V CONSUMER^ PRODUCTS^

Circle 95 on inquiry card.

BYTE January 19B0 155

Alpha Lock forYour ASCII Keyboard

There are times when you need tohold the output of your keyboard inthe uppercase mode for all alphabeticcharacters. A great deal of software isdesigned to accept only uppercasealphabetic American Standard Codefor Information Interchange (ASCII)characters. The circuit given here isdesigned to be placed between thetransistor-transistor logic (TTL)parallel output of the keyboard andthe parallel input port on the com-puter (or the input to the parallel-to-serial converter in a serial dataarrangement). The programmer willthen be able to reduce the beautifullydesigned 128-character set to a102-character set.

A quick glance at a table of ASCIIcharacters will show that thealphabetic characters are easy torecognize. (Such a table appeared in"Complete ASCII" by David MCiemiewicz in the February 1978BYTE, page 19.) They all have a 1 inbit 6 (the most significant data bit notconsidering the parity bit). Lowercasecharacters have bit 5 equal to 1, anduppercase characters have bit 5 equalto 0. If the problem was as simple asthis, the circuit shown in figure 1would do the trick. (I was inspired to

Terry Conboy1231 Crestview Dr

San Carlos CA 94070

ASCII BinaryCharacter 6543210

Bits 6,4,3Octal

@

[

\

]

A

1000000

10110111011100101110110111101011111

4777

77

{}Delete

11000001111011111110011111011111110

1111111

477777

Bits 2,1,0Octal

03

456

7

034567

Table 1: The 12 ASCII characters with a binary representation having bit 6 (the mostsignificant data bit, not considering the parity bit) equal to 1 that should not be shiftedby the uppercase alpha-lock function.

+ 5V

£

ALPHALOCK

IC I7400

Number

IC1IC2

Type +5V GND

74007408

14

14

NORMAL

B6L^

B5|Z>-B40^

IC 2

74083

-C>B6

-OB5'

-OB4

B30

-rz>B3

About the Author

Terry Conboy is employed as a staffengineer for microwave telecommunicationsdevelopment at GTE Lenkurt in San CarlosCA. Interested in computers and digital com-munication, he is an Extra class amateur radiooperator and has published articles in severalham radio magazines.

B2[>

-OB2

biLZ^

boE>-

-0>BI

Obo

Figure 1: A simple circuit to provide alphabetic uppercase lock. It causes the undesiredshift of 6 punctuation and control codes in addition to the alphabetic characters.

156 January 1980 © BYTE Publications Inc

J**

Ybu Just Boughta Personal What ?

fey Thomas Dwyer and Margot Critchfield

Whether you are a novice program-mer or an experienced computer user,this book is filled with practical ideasfor using a personal computer at homeor work. It will take you through thesteps necessary to write your owncomputer programs, and then showyou how to use structured designtechniques to tackle a variety of largerprojects. The book contains over60 ready-to-use programs written inRadio Shack TRS-80 Level II BASIC inthe areas of educational games, finan-cial record keeping, business trans-actions, disk-based data file and wordprocessing. $11.95 ISBN 0-07-018492-5

Please send □

copies of You Just Bought a Persona] What?

Name

Title

Company

Street City State/Province

□ Check enclosed in the amount of $

□ Bill Visa D Bill Master Charge

Card No Exp. Date _

Code

Add 60c per book to cover postage and handling.

GIWE

earns

70 Main Street

Peterborough, New Hampshire 03458

lm

Circle 35 on inquiry card.

BYTE January 1980 157

OB6

Number Type +5V GND

IC1 74LS138 16 8

IC2 74LS151 16 8

IC3 74LS10 14 7

Figure 2: An alphabetic uppercase lock circuit which shifts only the 26 alphabeticcharacters when enabled by the switch.

develop this circuit by an ideadescription "Recognize UppercaseLetters Only with a Simple 2-GateCircuit," in Electronic Design, July 191977, page 106, written by ChackoNeroth.)

Of course there is a catch. Thereare 64 binary combinations in whichbit 6 is 1, and only 52 of them areletters. The remaining combinationsare punctuation marks, with the ex-ception of the delete control code, asshown in table 1. If the keyboardomits these characters, the simple cir-cuit of figure 1 will force bit 5 lowwhen bit 6 is 1 and the circuit is en-abled. However, if the keyboard doeshave these codes (and it probably hasdelete), remembering to unshift whennecessary can be a headache.

To overcome this problem, it isnecessary to detect the 12 non-alphabetic characters and inhibit theshift automatically. My first thoughtwas to use a multitude of inverters

and 8-input NAND gates (such as thesystem described by Steve Ciarcia in"Build a Keyboard FunctionDecoder," July 1978 BYTE, page 98),but there had to be a better way. Useof a programmable read-onlymemory would be nice, but it seemedlike overkill and perhaps more expen-sive than necessary.

The solution turned out muchsimpler than I expected. By formingthe octal equivalent of the group ofbits 6, 4, and 3 and of the group ofbits 2, 1, and 0, as shown in the lastcolumns of the table, the user can seethat by detecting the coincidence ofthese combinations, the desired shiftenabling line can be obtained. Thelucky combination of octal numbersallows the use of a 3-to-8-line decoder(74LS138) to unscramble the 3 mostsignificant bits of interest and an8-line multiplexer/data selector(74LS151) driven by the 3 leastsignificant bits. By selecting the pro-

per outputs from the decoder anddata selector (those corresponding tothe codes we wish to recognize), therecan be case shifting at the propertimes. The new circuit is shown infigure 2.

When the high-order bits aredecoded, the corresponding outputgoes to 0. If the low-order bits select a0 output from the decoder, the shiftenable line will also go to 0. Thisallows bit 5 to pass through unchang-ed. If the alpha-lock function is notdesired, allowing the active-lowstrobe input on the data selector to bepulled up to a 1 will force the shiftenable line to 0 regardless of the databeing sent.

The use of low-power SchottkyTTL integrated circuits allows addingthe alpha-lock function while typical-ly increasing the load on the powersupply by only 14 mA. The cost ofthe three integrated circuits will beeasily under $2B

158 January 1980 © BYTE Publications lnc

Circle 97 on inquiry card.

BYTE January 1980 159

A Computer GeneratedReminder Message

E M Pass

President

Computer Systems Consultants Inc

1454 Latta Lane NW

Conyers GA 30207

",2*

Listing 1: The Tickler filing program written in MSI 14 K Disk BASIC.

0100 REM TICKLER MESSAGE SYSTEM

0200 STRIND= 68

0306 DIDITS= 0

0400 LINE= 0

0600 DIM FK255>

0700 Z=0

0300 A8=8

8900 R9=0

1000 PRINT "TICKLER MESSAGE SYSTEM"

1100 INPUT "INSERT DATA DISK AND HIT RETURN",Z*

1150 IF 2*="NEW" DOSUB 6460

1200 OPEN #10,"TICKLRX" FOR UPDATE

1300 FIELD #16,Nl=2,N2=3,N3=S,N4=6,M*=68

1400 BET #10

1420 IF LEFT$<M*,7>="TICKLER" GOTO 1500

1440 CLObE #10

1460 GOSUB 6460

1480 GOTO 1200

1500 R1=N3

1600 A2=N4

1620 PRINT "ENTER PRINT CONTROL AS FOLLOWS^"

1648 INPUT " S=SELECTIVE,A=ALL,N=NONE,U=UPDATE ONL\

1660 IF LEFTS-CZS.D'C'fl" GOTO 1620

1688 IF LEFT*<:ZSJi;<>"U" GOTO 1620

1700 INPUT "ENTER CURRENT DATE CVVMMDD>-*, E>9

1720 IF D90INTXD9) GOTO 1700

1746 M.= I NT < D9/10008;

1760 D.£=D3-Dl*10000

1780 D2= I NT < D3/100 >

1300 D3=D3-D2*±88

1860 IF ftBS<Dl-83»li GOTO 1708

1330 IF HBSCD2-6 5)>6 GOTO 1780

1388 IF RBS<D3-16»1.S GOTO 1768

1948 IF LEFT*(Z*..l;-"N" GOTO 2320

I960 PRINT • PRINT ■■ PRINT -PRINT

1380 IF fil<2 GOTO 260©

2688 i-OR 0=2 TO HI

2028 GET #16

2840 IF MK1 GOTO 2268

2368 IF LEFT*<Z*,l>="fl"

2038 IF N3>D9 GOTO 2268

2898 IF LEFTt<Z*,i:J = "U"

2180 IF Z;-U GOTO 2148

2128 PRINT "ENTRY TYPE

2148 Z=Z+1

2145 1=68

2158 1=1-8

2:154 IF I<28 GOTO 2160

2156 IF MIO*<M*,I,8>="

2160 PRINT " ";G;THB <3)

2138 IF LEFT:r'iZ*,i:>=-"A"

2198 IF Nl=l Nl=8

2288 GOSUB 6888

2218 IF N1>1 N4=D9

2228 REWRITE 1*18

2246 IF NIDI GOTO 2388

2268 IF fi3<255 A9=H9+1

2238 fl<F(3>=Q

2i88 NE!<! I 0.

2318 PRINT : PRINT 'PRINT -PRINT

2i28 PRINT "ENTER ENTR'

GOTO 2100GOTO 2198DATE UPDATE

" GOTO 2158N1;TAB<12)jN3; " "iGOTO 2380

MESSAGE"-PRINT

n4jtab<;

sLEFT*<M*,1+8

NUMBERS TO BE DELETED

Listing 1 continued on page 162

Most people and businesses sharethe common problem of beingrequired to perform some actions atdefinite future dates. These actionsmay be of a one-time-only nature, orthey may be periodic according tosome rule.

The penalty for forgetting an eventsuch as a birthday may be minor, butthe penalty for neglecting to file anincome-tax return may be moresevere.

Solutions to the problem are num-erous, and include the use of humanmemory alone, writing notes on awall or desk calendar, or maintainingan ordered stack of notes and forms.The solution that I suggest here, call-ed the Tickler filing system, involvesthe use of a computer to help performthis function. The program describedhere was written for a smallmaintenance service company whichhas, in addition to the normalrequirements of small businesses, thenecessity of keeping track of periodicpreventative maintenance calls for itsclient companies.

The Tickler system enables a clerkto input a series of messages, each ofwhich has a starting date and a codeindicating the type of repetitiondesired for the message. Each timethat the program is executed, it cancheck a file of messages and print andreschedule all messages for which thetime limit has expired since the lastprinting. The clerk can then deleteand add additional messages, asrequired. Since the program containsno features that are specific to themaintenance service company, it

160 January 1980 © BYTE Publications Inc

THERE'S NO NEED TO COMPROMISEWITH COMPUPRO .

We don't compromise on our designs so you don't have to compromise onperformance. Our expanded S-100 line is the answer to the needs of professionalcomputer users — just ask the dealers who specify our components when making upsystems for scientific, commercial, and industrial applications. Speaking of dealers,Godbout products (under the CompuPro'" name) are now available from more dealersthan ever before . . . which makes it even easier for you to experience Godbout qualityin person. Shop around, compare prices, and compare specs: we think we know whoseproducts will earn a space in your computer.

MORE NEWS FROM THE MEMORY LEADER.

This month, we spotlight Econoram XIIIA — an S-100 bank select board that'scompletely compatible with Alpha Micro, Cromemco, and similar systems (all 8bits of the data word are available for bank select). Addressable on 4K bound-aries. Available in 16K, 24K, or 32K configurations; see list below {which in-cludes our other popular memories) for prices.

All Econoram' memories are fully static, run with 5 MHz (or slower) systems,include a 1 year limited warranty, and generally come in three different con-figurations to suit your needs — unkit, assembled and tested, or qualified underour high-reliability Certified System Component program (200 hour burn-in, im-mediate replacement in event of failure within 1 year of invoice date).

Name

8K Econoram HA

Buss & Notes

S-100

Unkll

$149

Assm

$179

CSC

$239

16K Econoram IV

S-100

$269

$329

$429

/L' J ....... PlffW ■J»*W

16K Econoram VIIA-16

S-100S-100

$279$398

$339$485

$439$605

:: U'-^iS^BSssS

24K Econoram VIIA-24

16K Econoram IX-16

Dig Grp

$319

$379

n/a

i f i '-i 4 « ' .• : J M

32K Econoram IX-32

Dig Grp

$559

$639

n/a

**

32K Econoram X

S-100

$529

$649

$789

^i^Mu'WiV1;";; jl

32K Econoram XI

SBC/BLC

n/a

n/a

$1050

* l*^* '• * '' ' w

16K Econoram XIIIA-16

S-100 (1)

$329

$419

$519

tt» 1 1 1 1 i •' l' J

24K Econoram XIIIA-24

S-100 (1)

$429

$539

$649

32K Econoram XIIIA-32

S-100 (1)

$559

$699

$849

MlUHwiHWairaiw '

16K Econoram XIV

S-100 (2)

$299

$359

$459

WlilJiiJlioiywlll

16K Econoram XV-16

H8(3)

$329

$395

n/a

ijn .. f|-

32K Econoram XV-32

H8(3)XVI — coming

$599soon!

$729

n/a

16K x 16 or 32K x 8 Econoram

(1) Bank select board addressable on 4K boundaries.

(2) Extended addressing (24 address lines). Single block addressable on 4K bo

undaries.

(3) Bank select option for implementing memory systems greater than 64K.

THE GODBOUT COMPUTER BOX:$259 desk top, $299 rack mount (htmduo«> Pr,ce)

The ideal home for your computer. Includes dual AC outlets and fuseholder onrear, power switch, heavy-duty line filter, black anodized front panel (with tex-tured vinyl painted cover for desk top version); pre-drilled base accepts ourhigh-performance S-100 motherboards or types by Vector, California Digital,and others. Rack mount version includes slides for easy pull-out from rack formaintenance or board changing. You can even cut a hole in the front panel andput in a mini-floppy ... all in all, this is a functional, versatile, and handsomeenclosure that does justice to the finest computer systems.

LIMITED QUANTITY SPECIAL:

PASCAL//VT MEMORY!

PASCAL can give a microcomputer with CP/M more power than many minis!And for a limited time only, you can buy an assembled 32K Econoram X, plus ourtotally standard Wlrth PASCAL/M™ 8" diskette, for $799 (regular combined price,$999). Includes manual, plus Wirth's definitive book on PASCAL; specify Z80 or8080/8085 version. Hurry — this is an introductory special. Diskette only withoutmemory board; $350.

DO YOU SPEAK TRS-80**?

We've been expanding the memory of Model I TRS-80* * machines for over ayear now with our low power, high speed memory expansion chip set ($87.20).Now you can use the same chip to expand memory in Apple, newer PET, ExidySorcerer, and Heath H89 machines — as well as expand a 32K Model IITRS-80* * to 48K or even 64K. And if that isn't enough memory for you, watchthis space for news on our high-density, Model II compatible 64K board with

bank select! ' 'TRS-80 is a trademark of the Tandy Corporation.

HIGH-PERFORMANCE MOTHERBOARDS

19 slot: $174 unkit, $214 assm12 slot: $129 unkit, $169 assm6 slot: $ 89 unkit, $129 assm

Unkits have edge connectors and termination resistors pre-soldered in placefor easy assembly. These boards exceed the latest S-100 specs and will workwith 5 to 10 MHz CPUs. Includes true active termination, grounded Faradayshield between all buss signal lines, and edge connectors for all slots.

2708 EROM BOARD $85 unkit

4 independently addressable 4K blocks, with dipswitch selectable jump startbuilt right into the board. Includes all support chips and manual, but does notinclude EROMs.

ACTIVE TERMINATOR BOARD $34.50 kit

Plugs into any S-100 motherboard (although ours don't need it) to reduce ring-ing, crosstalk, noise, and other buss-related problems.

S-100 MEMORY MANAGER BOARD$59 kit, $85 assm, $100 CSC

Now you can add bank select and extended addressing to older S-100machines like the Altair, IMSAI, Sol, Polymorphic, etc. Either use this boardwith our new extended addressing boards, or retrofit our high densityEconorams (the ones with phantom or extra qualifier lines) for use with theMemory Manager to get up to V2 a megabyte of memory space for your com-puter.

2S "Interfacer" S-100 I/O Board$189 unkit, $249 assm, $324 CSC

Dual RS-232 ports with full handshake; EIA232C line drivers and receivers(1488, 1489) along with current loop (20 mA) and TTL signals on both ports. On-board crystal controlled timebase with independently selectable Baud rategenerators for each port (up to 19.2 KBaud). Hardware UARTs.

3P PLUS S "Interfacer II" S-100 I/O Board$189 unkit, $249 assm, $324 CSC

Incorporates 1 channel of serial I/O (with all the features of a port from the 2S"Interfacer"), along with 3 full duplex parallel ports. The parallel section usesLSTTL octal latches for latched input and output data with 24 mA drive current,attention/enable/and strobe bits for each parallel port (with selectable polarity),interrupts for each input port, and separate 25 pin connectors with power foreach channel along with a status port for interrupt mask and port status.

TERMS: Allow 5% for shippingexcess refunded. Cal res addtax. VISA'/Mastercharge1 : callour 24 hr. order desk at(415) 562-0636. COD OK withstreet address for UPS. Pricesgood through cover month ofmagazine.

CompuProM

from

[OJLBB

ELECTRONICS

SEND FOR OURFREE CATALOGUE

725 Wright St., Oakland Airport, CA 94614 415-56Z-0636

Circle 98 on inquiry card.

BYTE January 1980 161

Listing 1 continued:

should be of general use to otherbusinesses and individuals needing asimilar facility.

A sample series of executions of theprogram appears in this article. Theprogram provides prompts for theuser after the file has been establish-ed. The user must enter NEW toestablish the file. The ability to entermessages, message types, and startingdates should provide sufficient flex-ibility for virtually any simple ap-plication.

Program Details

The program in listing 1 was writ-ten using a SwTPC 6800 running theMSI 14K Disk BASIC interpreterlevel 1.3. The hardware includes32 K bytes of main memory, oneMSI floppy disk drive, and one low-speed (thirty character per second)printing terminal. The interpreter andthis program require about 24 Kbytes of memory. Since it uses ran-dom access techniques, adapting theprogram to a cassette tape systemwould be difficult. Implementing iton another disk system or on atimesharing system should not be dif-ficult.

A flowchart of the major portion ofthe system appears as figure 1.

Initialization

Line 200 of listing 1 sets the stringlength to 68 bytes. For those withSwTPC 8 K BASIC, this statementmay be replaced with POKE (62, 68).Line 300 sets up the output routine toprint numeric values with a floating,not fixed, decimal point. Line 400causes the output routine to ignoreright margin considerations on out-put.

Line 600 allocates an area of 255variables to point to those recordsthat have been deleted and may bereused. Line 1100 causes the com-puter to wait until the clerk indicatesthat the proper disk has beenmounted, since the data disk is keptapart from the program disk. Line1150 checks for the entry of the wordNEW, which indicates that the datafile does not yet exist and is to be con-structed.

Line 1200 opens the data file inupdate mode; the MSI BASICinterpreter allows opening data filesin Input, Output and Update modes.Line 1300 defines the format of the

2348 INPUT " FOLLOWED BV ZERO",Q

2330 IF FtBSiCeXMNTXQ) QOTO 2328

2480 IF Q3R1 GOTO 232C

£420 IF 8<1 GOTO 2608

2430 IF 0.-1 GOTO 2320

24 '10 SET #10=Q

2460 GET #18

2400 IF Nia GOTO 2320

2520 IF R93255 R9~fl9+1

2S40 FKfi9>=0

2568 REWRITE #10

2570 PRINT " ".. Q," DELETED"

2530 LiOTO 232a

2600 INPUT "ENTER TVPE FOR NEW MESSRGE <:.

2620 If- RBSCHlXMNT'Jttl} GOTO 2S0G

2S40 IF Ml-0 GOTO 3600

2668 IF M1C10 GOTO 3040

2700 PRINT

i ','PtS RRE RS FOLLOWS ■"

1-SPECIFIC DRTE ONLV

NQUIT,99=HEL

.. Mi

2=MEEKLV"3=BIWEEKLY"4=M0NTHLV"5=BIMONTHLV"6=QURRFERLY"7-SEMI-hnnURlLV8=fiNNUfiLLV"3-EVEkv N DflVS™

FOR NEW "ESSHGh4 0

• N3=i13 ■ W*=H*

1000.. 3480, 3526..

2720 PRINT "

2740 PPINl "

2760 PRINT "

2700 PRINT "

2S00 PRINT "

2S20 PRINT "

2S40 PRINT "

2U6G PKlNi "

2330 PRINT "

2900 PRI'JT "

2920 PRINT

3020 GOTO 2600

30'!0 INPUT "ENTER D

3050 IF M3<D9 M3=09

3060 IF M30-INT<M3> QGTC

3070 D4=INT<M2/10S80>

3030 06=453 -D4 *10000

3090 D5=INT< 06/100;

3188 D6=D6-3":lO0

3130 IP HSbi.D4-89:Oil GOTO 3040

3200 IF HBS<D5-6. 5)36 GuTu 3040

3220 IF RBS':.06-16> J15 GOTO 3040

3248 INPUT "ENTER MESSAGE",N*

3260 Ir LOKNtJC GOTO 3240

■3230 Ho-hS'-l

3 iUiJ 1 r H33FI9 GU ! 0 3368

~T-'S IF R731 GOTO 0390

3358 IP RlOl 01=1

3360 Rl=Hi+X

.-•_o0 ri7~f!l

3390 IF fil>-=R2 GOTO 3880

24 00 3ET -ttlO-R7

3420 GET #10

3448 N1=M1!N

3-130 N4-L'9

3 160 ON Ml GO

3300 GOTO 4000

- "I Uj GuTu 4880

;56o N2=i

3530 GOTO 4000

3620 GOTO 4080

3360 GOTO 4000

3630 r<2~6

3708 GOTO 4000

3720 N2=12

3740 GOTO 4088

3768 INPUT "ENTER NUMBER OF DRVS",N;

3730 IF RBS',N2.;OINT':.N2;' GOTO 3768

3308 IF ftt3SXN2-508»493 GOTO 3760

3320 GOTO 4000

4 000 REWRITE #104UG0 GuTu 26086000 IF NK2 RETURN6020 I = i NI ■.. rj.i/luOOO >6040 K=N3-I*108006060 J= I HT< K/18Q :>6000 K=K-J*108

6100 IP I ViyOQ 1 = 1 + 1900

6120 IF Nl>3 GOTO 6308

6140 DOSUB 7880

6160 D=D+N2

6x86 GGSuB 7200__

6200 N3= ■■ '•. I -19U0) *"180+J >*188+K

6.J1U IF_N33D9 GOTO 6128

6220 RETURN

6._;'j0 IF Ni=9 GOTO 6140

6328 J=.J+N2

6340 IF J313 GOTO 6480

6360 J=J -12

6230 _1=1+1

6488 uuTu 62u0

v",'MMDD:>",M3

6u., 3600.. 3640. 3688. .3720. 3760

Listing 1 continued on page 164

162 January 1980 © BYTE Publications Inc

Why Should I Help A Hospital In Memphis?

Because St. Jude Children's Research Hospital offers hopeto stricken children wherever they may be.

1. Si. Jude Children';) Research Hospital is theonly institution dedicated solely to conqueringcatastrophic diseases of childhood.

2. Since opening in 1962, St. Jude Children'sResearch Hospital has brought hope in some ofthese diseases where previously none existed.

3. St. Jude Children's Research Hospital's im-pressive studies of infantile malnutrition have be-come the basis for government programs to feed

poverty-level childiui.

4. Treatment procedures developed by St. JudeChildren's Research Hospital are freely dissemi-nated to doctois and hospitals all over the world andhave been manipulated into the standard pedi-atric literature.

5. St. Jude Children's Research Hospital de-pends on public contributions to continue its life-saving work.

St. Jude Children's Research Hospital is unique. Under one loof, its basic and clinical doctors and scientists lookfor the answers that will save children in every community icgardless of race, creed or religion. Children admitted toits research programs receive total medical care at no cost. Some live and some die, but from these patients comesthe knowledge that may some day eliminate these dreadful diseases, giving hope to now hopeless children every-where.

Why Help?

Why should you help? Because St. Jude Children's Research Hospital knows no boundaries. Its impactis everywhere. Because you care.

Danny Thomas, Founder

I ST< JUDE CHILDREN'SRESEARCH HOSPITAL

Listing 1 continued:

646>3 INPUT "ENTER NEW TO CLEAR .DISK".Z*

S4S8 IF Z*0**NEH" RETURN

6580 OPEN *10j"TICKLRX" FOR OUTPUT

6520 FIELD #±8JN±=2,N2=3.iN3=iS>N4=6JM*=!6S

6540 INPUT "ENTER NUMBER OF MESSAGES TO BE HELD IN FILE'\K

655U IF fiBSaOOINTOO GOTO 6540

6568 IF KCL88 K=±80

6570 K=INT<<K+2>/2>*3 .„__„

6588 Nl=Q^ri2=0-N3=l'-N4=K'M*="TICKLER MESSAGE SVSTEM"

6600 PUT #10

6620 N3-Q:N4=Q-M*=" "

6640 FOR 1=2 TO K

6650 PUT #10

6660 NE.X I I

6600 CLOSE SIS

6700 RETURN

7000 REM HSTRGNOPilCRL DRV CD) FROM 7EHR ( I) , MONTHC J> , DfiVCIO

7020 Ti- - INT •'. ',14 -J > .'12 J

7040 T2-INT':. (146±*< I+4SuO+Tl> )/4)

7060 T3=INT<<367*<J-2-Tl*12>)/12)

73S0 T4=INT":<3*INT<<I+49BS+Tl>/10a))/4)

7100 D=K -.i2075+T2+Ti -T4

7120 RETURN

7200 REM VEftRCI) ..MONTH CI), DRV <K> FROM ASTRONOMICAL DAV<£»

7220 L=D+-6S569

7240 N=INT< <4*L>/146897)

7260 I=INTX >:i46037*N+3) /4)

7238 L=L-I

7308 I = INT>: (4006*<L+l>>/±461001)

7320 J=INTXC146±*I>/4:>

7348 L=L-J+31

7:60 J=INT< <S0*L3/2447)

7338 K=L-INT<:C2447*J)/'30)

7400 L=INT<; J/ID

7420 J=J+2-12*L

7448 I=i80*<N-49>-t-I+L

7-460 RETURN

3S00 PRINT "FILE FULL OF MESSAGES NOW"

3908 _Rl-fl2

3000 SE1 #1U=1

9100 GET 810

3200 Nl-0 i N-i=Hl •■ N4-R2

3300 REWRITE #18

9-tOO CLOSE #10

9330 INPUT "INSERT PROGRAM DISK AND HIT RETURN",Z*

3333 END

data file record, shown in table 1.Since this defines an 85-byte recordand each sector on the MSI disk (GSI110) is 256 bytes in length, there willbe three records per sector.

Lines 1400 through 1480 check thefirst record in the data file. If themessage text is not TICKLER, theprogram assumes that the disk is notvalid and asks the clerk if the diskshould be cleared. Lines 1500 and1600 retrieve the current and max-imum end-of-file pointers from thefirst record in the file.

Control Options

Lines 1620 through 1680 requestprint-control for the current execu-tion of the program. Options are ex-plained in table 2. Lines 1700 through1900 obtain the current date from theclerk and validate it. Line 1940 checksfor run option of N (no printing) and,if it is N, skips the checking of thecurrent messages.

Message Display

Lines 2000 through 2300 succes-sively check every message in the file.Line 2020 reads the next record in the

(THE MM-103 DA TA MODEM,

AND COMMUNICA TIONS ADAPTER

r

S-100 bus compatible

FCC APPROVED

\ r

Both the modem and telephone system interface areFCC approved, accomplishing all the required protectivefunctions with a miniaturized, proprietary protectivecoupler.

WARRANTY

One year limited warranty. Ten-day unconditionalreturn privilege. Minimal cost, 24-hour exchange policyfor units not in warranty.

HIGH QUALITY

-50 dBm sensitivity. Autoanswer. Auto originate. Autodialer with computer-controlled dial rate. 61 to 300 baud(anywhere over the long-distance telephone network),rate selection under computer control. Flexible, soft-ware-controlled, maskable interrupt system.

ASSEMBLED & TESTED

Not a kit! (FCC registration prohibits kits)

LOW PRICE-S35995-£SdB5L

plus shipping& handling

Potomac Micro-Magic, Inc.

Write for brochure:First Lincolnia Bldg., Suite B14810 Beauregard St.Alexandria, Va. 22312

Call for further information:

VOICE: (703) 750-3727

MODEM: (703) 750-0930 (300 baud)

164 January 1980 © BYTE Publications In

Circle 99 on inquiry card.

•1*1 MJ ^L^: »

p

e

e

D

THE CONDUCTOR M

A versatile dual densityfloppy disk controller.Backed up with dual den-sity CP/M™ ($150) andavailable NOW!!!

$325 assembled

VIDEOCONTROLLER

Memory mapped 80 x 24with dual character sets(programmable!) user romspace and HARDWARESCROLLING. Firmwareavailable.

$349 assembled

DISK SYSTEMS

All the hardware you needfor a COMPLETE floppy disksystem. PLUS-FREEOsborne Accountingsoftware. Just add CP/Mand a computerSingle disk $1095-Dual 1649

All DATASPEED products are fullyassembled and tested and warranted.

DATASPEED, INC.,1302 NOE ST.SAN FRANCISCOCA. 94131(415) 282-5616

Circle 100 on inquiry card.

( START J

INITIALIZATION

IDENTIFY PROGRAMAND ASK CLERK TOMOUNT DATA DISK

YES

OPEN FILE ANDESTABLISHRECORD FIELDS

READ FIRST RECORDIN DATA FILE(HEADER RECORD)

FIRST RECORD |MESSAGE* I--

"TICKLER" I

SET FILE

LENGTH PARAMETERS

REQUESTRUN OPTIONS"S","A","N","U"AND VALIDATE

REQUEST RUN DATEAND VALIDATE

CLEAR

INITIALIZEFILE ONNEW DISK

CLEAR

INITIALIZEFILE ONNEW DISK

RUN OPTION "N"

ENTERED

f next-recV

I CURRENT RECORD I

, INDEX GREATER I

1 THAN LAST I

( DELETES J

DELETES

)

READ NEXTDISK RECORD

RECORDDELETED

I""RUN OPTION "A""'

ENTERED

I MESSAGE DATE I

GREATER THAN \—1 RUN DATE I

RUN OPTION ' UENTERED

(print-allV

YES

-/next-rec J

YES

-(print-all)

YES

-/ NEXT-RECJ

YES

-/ NO-PRINT j

PRINT HEADING(FIRST TIME ONLY)THEN PRINT MESSAGE

/next-rec J

COMPUTE NEXTACTIVATION DATE...IF ONE-TIME-ONLY,MARK DELETED

UPDATE CURRENTDISK RECORD

RECORD MARKED

DELETED

ADD RECORD INDEXTO LIST OF DELETEDRECORDS

f NEXT-RECJ

Figure 1: Flowchart of a portion of the Tickler program that initializes disk files, selects options, prints messages, and computes newtime intervals for the next activation of periodic messages.

Variable Description

N1 Message type

N2 Days

N3 Message date

N4 Date of last update

M$ Message text

External Len

gth

Type

2 bytes

Numeric

3 bytes

Numeric

6 bytes

Numeric

6 bytes

Numeric

68 bytes

Character

itionS

Description

Selectively print and update

A

NU

messages

List all messages without up-dating datesOnly enter messagesUpdate message dates withoutlisting

Table 1: Format of the data file record for opening data.

166 January 1980 © BYTE Publications Inc

Table 2: Options for updating messages.

AITS gives you Access to Tools

Tools are only as useful as theuser's skills.

Sharpen yourcomputing skills withthe latest

microcomputer booksfrom BITS.

BEGINNERS MANUAL FOR THE UCSD PASCAL SYSTEMby Kenneth L. Bowles

□ Here from the originator of UCSD PASCAL is a system orienta-tion guide and reference manual. It explains the use of the screeneditor, file manager, and compiler with quizzes for PASCAL selfstudy and guides to use of disk files and libraries of specializedroutines. Appendices with specific instructions for the Apple II,TRS-80, and Terak 851OA implementations are included. (Ifyou're just learning PASCAL, the book Microcomputer ProblemSolving Using PASCAL by Bowles is recommended as a compan-ion text.) This book will have you running your PASCAL programsquickly, even if you have no computer experience. 229pp.

#249 $11.95

Z80 SOFTWARE GOURMET GUIDE & COOKBOOKby Nat Wadsworth

[ iFrom Scelbi Publications we have an appetizing and longawaited addition to their Gourmet Guide series. They've served upthe Z80 instruction set with a buffet of useful assembly languageroutines par excellence! The menu: The Z80 instruction set, Utili-ty routines, Stack operations, Input/output processing, Conver-sion routines, Search and sort routines, Decimal arithmeticroutines, Floating point routines, Space capture, and Creative pro-gramming concepts. 322pp. #250 $14.95

NUMBERS IN THEORY AND PRACTICEBlaise W. Liffick, editor

DThis reference, Volume 3 in BYTE Books ™ ProgrammingTechniques series, is a mix of reprints of articles from BYTEMagazine and much new material. In an effort to equip themicrocomputer user with a background in numbers and computa-tional methods, it covers the number system, floating pointnumbers, numerical methods, random number generators, and themath behind computer graphics. Of value to both the novice andthe experienced microcomputer programmer. 1 84pp.

#246 $8.95

THE S-100 & OTHER MICRO BUSESby Elmer C. Poe and James C. Goodwin

DThis book is about microcomputer buses; the hardware pathsthrough which the microcomputer's processor communicateswith present and future system components. A general discussionof bus structure is followed by chapters on 1 1 of the most widelyused bus systems, including the S-100, TRS-80, Apple II, Pet,and Kim buses. Also included are chapters on bus to bus interfac-ing. A valuable collection of microcomputer data. 144pp.

#247 $5.95

AITS PROGRAMM6R PAD

Improve your assembly language programming skills with BITSPROGRAMMER PADS™. Available for the Z-80 8080A, 6502,6800 or 1 802 microprocessors. Punched for 3-ring notebooks,and printed on both sides (pictured above). 50 page pads, only$2.50 each. (Shipping and handling: USA-75* for 1 pad, $1 .25for 2 or more; Foreign- $ 1 per pad to a max. charge of $4.)

Vxw

BEST OF INTERFACE AGE: VOLUME I

SOFTWARE IN BASIC

Edited by Carl D. Warren

DThe first volume of this new series contains classic software;four microcomputer versions of BASIC: Lawrence LivermoreLabs'8080 BASIC, Dr. Wang's Palo Alto Tiny BASIC (8080), Na-tional's Tiny BASIC for SC/MP, and Robert Uiterwyk's 6800 4KBASIC. Each includes full assembly language listing and guides toaid in implementing and using the interpreters. More to come.314pp. #248 $12.95

6502 ASSEMBLY LANGUAGE PROGRAMMINGby Lance A. Leventhal

□ 6502 programmers Osborne and Associates have included the6502 in their Assembly Language Programming series! Theythoroughly cover the 6502 instruction set and include assemblerconventions, code conversions, arithmetic problems, and programdesign, debugging, testing, and documentation. Over 80 programexamples are included, the 6520 PIA and 6522 VIA are covered,and the 6502 interface system is explained. Comprehensivecoverage! 606pp. #226 $12.95

MICROCOMPUTER PROBLEM SOLVING USING PASCALby Kenneth L. Bowles

UThis book is designed both for introductory courses in computerproblem solving at the freshman and sophomore college level, andfor individual self-study. Graphics are stressed in this version ofthe book. A complete single-user software system based onPASCAL has been developed at the University of California at SanDiego, where the author is a professor in the Department of Ap-plied Physics and Information Science. This system embodies ex-tensions to the standard PASCAL which include the necessaryfunctions and procedures for handling graphics and strings.563pp. #077 $9.80

BASIC BASIC, 2nd EDITIONby James S. CoanUBasic BASIC gives you step-by-step instructions for using a ter-minal, writing programs, using loops and lists, solvingmathematical problems, understanding matrices and more. Thebook contains a wealth of illustrations and example programs, andis suitable for beginners on many different levels. It makes a finereference for the experienced programmer, too. 256pp.

#014 $8.95

POSTAL CHARGES

U.S.-$.75/book to a maximum of $3.00; Foreign-$1 .00/book to a maximum of$4.00 (surface ratel; UPS IU.S. onlyl-$1.75 1st book, $.75 each additional book to amaximum of $4.00; Foreign Air Mail- $7.00/book.

1B010

IS I I J inc Bocks to erase the impossible

25 Route lOl West, PO Box 428, Peterborough, NH 03458.

DIAL YOUR BANK CARD ORDERSTOLL FREE 800-258-5477 S

(a)

f DELETED J

(b)

f ADDS J

REQUESTRECORD INDEXTO BE DELETED(OR ZERO TO STOP)

REQUESTED I

INDEX EQUAL |

ZERO |

I INDEX WITHIN I

FILE INDEX I

1 RANGE I

READ REQUESTEDRECORD

RECORD ALREADY IDELETED

YES

ADD RECORD INDEXTO LIST OFDELETED RECORDS

UPDATE CURRENTDISK RECORD

REQUEST NEWMESSAGE TYPE(OR ZERO TO STOP)

TYPE EQUAL

ZERO

I

TYPE OUTOF RANGE

-(last-time)

YES

PRINT POSSIBLEMESSAGE TYPES

REQUEST ANDVALIDATE MESSAGESTART DATE

REQUEST ANDVALIDATE MESSAGETEXT

COMPLETEPARAMETERS FORCURRENT MESSAGE

ALLOCATE A RECORDINDEX FOR CURRENTNEW RECORD FROMDELETED LIST ORAT END OF FILE

READ AND UPDATEDISK RECORD

Figure 2: Flowchart of (2a) the routine that deletes messages and (2b) the routine that adds messages to the file.

file. Lines 2060 through 2090 checkthe print-control option and currentdate to determine if a given message isto be listed. Lines 2100 and 2120 printa heading before the first message.Lines 2145 through 2156 reduce thenumber of trailing blanks to beprinted.

Line 2160 formats and prints thecurrent message, along with entrynumber and type, expiration date,and date of last update. Line 2180checks the print-control option for A(print all), and if it is A, bypasses up-dating the message date. Lines 2190through 2220 update the message dateand type, as required, on disk. Lines2240 through 2280 add deleted recordnumbers to a table for later reuse.

Message Deletion

Lines 2320 through 2580 allow theclerk to delete additional lines fromthe file and add any deleted record

168 January 1980 © BYTE Publications Inc

numbers to the table described above.Deleted lines are recognized by hav-ing a message type of zero. Figure 2ashows the deletion procedure.

Entering New Messages

The message addition procedure isshown is figure 2b.

Lines 2600 through 4020 allow theclerk to enter new messages into thefile. Line 2600 requests that a messagetype be entered. Line 2620 ensuresthat an integer value was keyed. Line2640 checks this value for zero and, ifit is zero, prepares to exit the pro-gram. Line 2660 checks this value forvalidity and, if it is not valid, causesthe information on lines 2700 through2920 to be printed. These lines iden-tify the message types, shown in table3.

Line 3020 returns to request that anew message type be entered for aninvalid type entry. Lines 3040

through 3220 request that a date beentered to be used as an initialmessage date. Lines 3240 through3260 request the clerk to enter themessage text and ensure thatsomething was entered.

Lines 3280 through 3390 attempt toallocate a record number for the newentry from those just deleted or at the

Type

0

DescriptionDeleted

1234567

Specific date only

Weekly

Biweekly

Monthly

Bimonthly

Quarterly

Semi-annually

89

AnnuallyEvery N days

Table 3: Message types available in theTickler system. These values are con-tained in the Ml and Nl variables in theBASIC program.

Model DMB-6400 Series dynamic 64k byte RAMS incorporate thefeatures which are standard in the DM-6400 Series and addsbank select for multi-user-timesharing applications.

• Four (4) 16k byte, functionallyindependent memory banks.

• Eight (8) 64k byte banks of mem-

• ALPHA MICRO, CROMEMCO,and NORTH STAR output portbank select.

• Memory bank size can be meremented to 64k bytes in 16kincrements.

ory per output port for ex pansion to 512k bytes for eachoutput port.

Model DM-6400 Series dynamic 64k memory boards feature IEEES-100 compatible timing and on board transparent refresh.

• Memory selectable and deselec- • 25 MHz on board crystal oscillator

table in 4k byte increments. for independent timing.

DMB-6400 and DM-6400 Common Features:

• 4 MHz Z80 operation with no waitstates.

• Tested and burned-in.

ONE YEAR GUARANTEE

Low power- 8 watts maximum.Reliable, expandable memories.

THE FOLLOWING PRODUCTS ARE AVAILABLE

□ DMB-6400/64KRAM □ DMB-3200/32K RAM □ DM-6400/64K RAM

□ DMB-4800/48KRAM □ DM-4800/48K RAM

ATTRACTIVELY DISCOUNTED OEM AND DEALER QUANTITY PRICES AVAILABLE

□ DM-3200/32KRAM

I

U.K. & EUROPEAN REPRESENTATIVE:

ABACUS COMPUTERS LTD.62. NEW CAVENDISH STREETLONDON, W1M 7LD U.K.TEL: 01-580/8841 TELEX: 881-3085

AUSTRALIAN REPRESENTATIVE:

COMPUTERLAND OF MELBOURNE555 COLLINS STREETMELBOURNE. VIC3000TEL: 625581

MEASUREMENT

systems &. controls

incorporated

867 North Main Street • Orange, CA 92668Telephone: 714/633-4460

BYTE January 1980 169

end of the current file. Lines 3400through 3450 read the data at theallocated record number and overlaythe record with more current data.Lines 3460 through 3820 continue thisprocess by filling in parametersdepending upon message type. Lines3760 through 3800 request andvalidate the number of days formessage type 9 (repeat every N days).Line 4000 updates the record on disk.Line 4020 returns to request addi-tional message entries.

Message Repetition

Lines 6000 through 6400 computethe next message activation date for amessage whose current-activation in-terval has elapsed. It does this usingthe message type and old expirationdate. If the newly computed messagedate is still earlier in time than thecurrent date, the new message datebecomes the old date, and the newmessage date is recomputed.

Data File Initialization

Lines 6460 through 6700 prepare anew-disk data file for use by the pro-gram. Lines 6460 and 6480 validatethe format request. Lines 6500 and

6520 open the file for output, creatinga new file, and provide the format ofeach record, as described earlier.Lines 6540 through 6570 request andvalidate the maximum number ofrecords to be placed into the data file.Lines 6580 through 6660 format therecords in the file. Line 6680 closesthe file to complete the last sector anddirectory entry.

This disk-clearing subroutine isshown in flowchart form as figure 3.

Date Conversion

Lines 7000 through 7460 provideGregorian date to Julian day number(as used by astronomers, a systemthat counts consecutive days sinceJanuary 1, 4713 BC) conversions tohelp facilitate the process of recom-puting the message activation date formessage types 1, 2, 3, and 9. Tocalculate the Gregorian date N daysfrom another, the following steps areperformed:

1. Convert Gregorian date to Julianday number.

2. Add N to Julian day number.

3. Convert Julian day number toGregorian date.

t±< ■ ■ i < 1111 > 111111111 in i it i > 11 ■ i ii 1111111 ii 111 ■ 1111 ■ 11 11 ■■ i ii i ii 111 11111 ■ 1111 > 1111 »

TRS-BO* PERIPHERALS

DISK DRIVES

40 tracks, with powersupply Si case and cableVERBATIM DISKETTESDYSAN DISKETTES

S3.0D$4.60

16k MEMORY KITSfor TRS-BO, APPLE. SORCERERw/jumpers and instructionsONE YEAR GUARANTEE!!!!!

TRS-80 computers in stock!!

PRINTERS fromCENTRONICS, INTREGALDATA, NEC SPINWRITER,TEXAS INSTRUMENTS.ALL AT GREAT SAVINGS!!

We also cany APPLE, SORCERER, PET, SD SALES products. WE WILL NOT BE UNDERSOLD.

GAMES

TRS 80 SOFTWARE

UTILITIES

BUSINESS

ANDROID NIM $14.00

nim robots that wink and respond.Excellent graphics and sound.

STAR TREK III $14.00

Travel through the galaxy on theEnterprise and destroy kilingons.New updated version.

AIR RAID $14.00

Real time shooting gallery.

SARGON:CHESS $19.00

Best chess lor TRS-80

LIBRARY 100 $49.00

100 games, utilities, and businessprograms in one package.Great value!

ADVENTURE $14.00

disk $24.95

NEWD0S+ $00 00

Enhanced DOS. Contains manyimprovements over TRSD0S. 7useful utilities built in. Eor 40track use also.

NEWD0S $49.00

Same as above without utilities.SYSTEM INTEGRATION TEST

$29.00

tests memory, disk drives, and

printer $99.00

MICROSOFT FORTRANS325.00

CPM $150.00

RENUMBER $14.00

disk $17.00

G2 LEVEL III $49.00

FORTH by MMS ... $65.00GSF by RACET $24.00

GL, AR, AP, PAYROLL INTERACTIVE $350. reports includeunbilled invoices, open/closedaccounts, ageing. Trial balance,income statement, balance sheet.Handles 200 accounts, 1750transactions.

Stand alone of each $95

INVENTORY II $99.00

activity listing, complete listing,selected listing, minimum quantitysearch, 1000 items per diskALL ABOVE PROGRAMSBY SBSG

ELECTRIC PENCIL . $99.00by Michael Shrayer

disk $150.00

BEST word processor for theTRS-80

Z The above list is just a brief summary of some of our most popular software. We have a large selection of other —5 software for many uses and tur many computers. Documentation for any of our programs is available on re- ~| quest. II you have any questions, please call. We would like to bear from you. S

TO ORDER, CALL OR WRITE:

MIDWEST COMPUTER PERIPHERALS

PO BOX 437WILMETTE, IL 60091

(312) 251-5020

C.O.D.

* TRS-8C is a Registered Trademark of Tandy Corp.

NEW YEARS

SPECIAL

10% Discount on

all Software orders

over $ 100

"1 s

f CLEAR J

REQUEST VALIDATION

OF DISK

CLEAR REQUEST

VALIDATION

NO

N. RECEIVED y

[yes

OPEN FILE ANDESTABLISH RECORDFIELDS

REQUEST ANDVALIDATE MAXIMUMNUMBER OF MESSAGESIN FILE

INITIALIZE HEADERAND DATA RECORDSIN FILE

CLOSE DATA FILETO COMPLETE LASTSECTOR ANDDIRECTORY

'L

( RETURN J

Figure 3: Flowchart of the subroutine thatinitializes a new disk file.

M.AST-TIMEJ

READ AND UPDATEHEADER RECORD

CLOSE DATA FILETO COMPLETE LASTSECTOR ANDDIRECTORY

ASK CLERK TO MOUNTPROGRAM DISK

f END j

~lllllllllllllllllllllllllllllllllllllllllll Ill I Ill I Ill IIII | 111117

Figure 4: Flowchart of the routine that ter-minates execution of the Tickler system inan orderly manner.

Exit Procedures

A flowchart of the exit operationsis shown as figure 4.

Lines 9000 through 9300 update thefirst record in the file, which contains

170 January 1980 © BYTE Publications Inc

Circle 103 on inquiry card.

A BUSINESS PROPOSITION

from

INTE3TEC DATA SY5TEMS

Dear Computer Enthusiast:

As a result of the phenomenal growth our company hasexperienced during the past year, there are now manyexcellent opportunities in our national dealership program.And as a result of this expansion in our dealership network,there are new employment opportunities in the marketingand technical divisions of our company. We'd like to talkabout these opportunities for just a minute.

Our two major products, the InterTube II VideoTerminal and the SuperBrain Video Computer are, to saythe least, an overwhelming success. This widespreadacceptance and demand for our products naturally requiresthe establishment and maintenance of a comprehensivedealer/service network. Many retailers and othermicrocomputer resellers have already joined our team. Theyare now realizing the true advantages our unsurpassedprice/performance products can give them. How aboutyou? Isn't it time you breathed a little new life into youroperation? Dealership and OEM contracts are now beingestablished in many areas. Call us today and discuss yourrequirements. You'll find us to be quite responsive.

Of course, our ability to successfully penetrate andmaintain our position in this ever-increasingly competitivemarketplace is due to the support of our many marketing,technical and service personnel. As our marketshareincreases, so does our requirement for qualified personnel.We are presently recruiting marketing representatives towork closely with our dealers in the field. Asales/management background in this industry wouldqualify you for consideration for one of these positions.Also, we are in search of technical personnel to assist ushere in South Carolina in supporting the varied applicationsour customers have for our products. At present, we arerecruiting Basic, Fortran and Assembly language pro-grammers as well as lab and production technicians.

Whatever your interests may be, dealership oremployment, we urge you to carefully consider theadvantages of association with our company. Pause for justa moment and give us a call at 803/798-9100. And if youdon't believe us, ask the industry experts. They will tell youwe're on the way to the top! So, why not join us now andenjoy the ride.

Best Regards,

The Marketing Department

INTERTEC DATA SYSTEMS CORPORATION

Dear Intertec,

Yes, I'm interested! Please call me with moreinformation about the opportunities I've checked below.

□ Dealership Programs

□ OEM Arrangements

□ Marketing positions presently available in my area.

□ Technical Support positions available at the factory

□ Other (specify)

If you're interested in dealership or OEM arrangements,please send us some detailed information on the nature ofyour present business including: 1) type of business; 2)length of time in business; 3) number of employees in sales,service and administrative positions; 4) products presentlyrepresented and/or manufactured, and 5) your applicationfor our products.

If you're interested in employment, whether it be in a fieldmarketing position or a technical factory position, pleaseenclose a resume detailing your experience and salaryrequirements.

Don't delay! Give us your name and address below andreturn this advertisement to:

INTERTEC DATA SYSTEMS

The Marketing Department2300 Broad River RoadColumbia, South Carolina 29210

If you're in a big hurry to reap the benefits of associationwith Intertec, skip the form and call us direct at803-798-9100. Just ask for someone in the MarketingDepartment.

Your name .

Company-Street

City, State & Zip.Telephone (

Circle 104 on inquiry card.

BYTE January 1980 171

Listing 2: A sample series of executions of the Tickler program.

TICKLER MESSAGE SViINSERT DATA DISK fir.

-H

N

_ iT. RETURN?ENTER PS I NT CONTROL Ab FOLLOWS '

S=S£LECT I '.•'£.. h=RLl.. N-NONE, U=UPDATE ONLYENTER CURRENT DATE <V¥MMDDr? 798289

ENTER ENTRY NUMBERS TO BE DELETED, FOLLOWED BY ZERO? 6ENTER i'.'PE FOR NEW MESSAGE <0=QUIT,99=»MELP>? 99

types are p.s follow :

1=SP£CIFIC DATE ONLV

2a44EEKl-Yi

3=BIM££KLV

4=M0NIHLV

5=BIM0NTNLY

E=OUHPTEKLV7=S£MI -ANNUALLY3=ANNUALLY9=EV£RV N DAYS

ENTER TYPE FOR NEW MESSAGE C8=QUIT,99=HELP>? 2

ENTER ORTE FOP NEW MESSAGE C¥YMMDD>? 79x00210

ENTER MESSAGE? MESSAGE1

ENTER TYPE FOR NEW MESbAGE <0-QuI T.. 99=HELP; ? 3

Enter date for nek message <vymmdd>? 790220

Enter MESSAGE? MESSAGE 2

ENTER V -:-F FOP NEW MESSAGE <8=QUIT 99=HEL:->? 4

l£ri^Ef- DAI"fc i-OR NEW MESSAGE '. VYMMDD >'? 790381

enter message? message 2

enter ts'pe fop new message <:0=quit,99=help>? s

enter drte fop new message <vvmmdd>? 798213

enter message? message 4

enter rYPE for new message c8=quit,99=help>? e

ENTER DATE FOR NEW r£SSAG£ tWHMDD.)? 790385

ENTER MESSAGE? MESSAGE 5

ENTER TYPE FOP NEW MESSAGE '■ 8=QUIT, 99=HE'_R,> ? 7

enter c-RTt. ^op new message <.yymmdd>? 790101enter message? message s

enter type fop new message i0=G!UIT.99=helP>? aenter date for new message ,ch,vmmdd>-"' 790*01

ENTER MESSAGE ? MESSAGE 7

enter pvpe for new message c8=quit.99=helpj? s

Er;Tby DATE FOR NEW MESSAGE 'CVVMMDD>'"> 790209

enter message? mesabe s

ENTER NUMBER of DAYS? 10

Er-TER type fop NEW MESSAGE o=quit..99=rtELP>? 1

iS DM

c r Jr.

NEW MESSAGE

CVYMMDC

'98481

enter message ■■ message 9

EriTER J-.'PE FOR NEW MESSAGE (.8=QU£T. 99-RELP.)INSERT PROGRAM DISK RND HIT RETURN?

:kl.EP MESSAGE SYSTEMi>£RT DATA DISK RND H]T-£* PRINT CONTROL HE-=bbLbC t l'.'L < ri'-ALL, N=r

T£y current date - yv?

ONE,U=UPDfl:E OnLtiDD > ? 79O210

UPDATE

MESSAGE

790210

798289

-MESSfiOE

1

790220

798289

-MESSAGE

2

798301

798209

-MESSAGE

3

790215

798209

-MESSAGE

4

790 285

798289

-MESSAGE

5

79S401

798289

-MESSAGE

6

798681

798269

-MESSAGE

7

798209

798289

-MESAGE :

3

79O401

798209

-ritbERuE

•u

ENTER ENTRY NUMBERS TO BE DELETED,. FOLLOWED BY ZERO? 8ENTER TYRE FOR NEW NESSHGE >:0=0U[ T, 99=HELP>? 9

EriTER DATE FOR NEW MESSAGEENTER MESSAGE? NEEERGE 18ENTER NUMBER OF DAYS? 24EriTER TYPE FOR NEW MESSAGEINSERT PROGRAM DISK RND Hll

:vs'mmdd:

'90401

8=C0IT.. 99-hElh.jRETURN?

MSI READY

#RUN

TICKLER MESSAGE SYSTEM

INSERT DATA DISK RND HIT RETURN?ENTER PRINT CONTROL RS FOLLOWS'

S=SELECTIV£, H=HLL, N=NONE, U=UPDATE ONLYENTER CURRENT DRTE tVYMMDD>'? 790281

MESSAGE

90218

798209

-MESSAGE 1

98228

798289

-MESSAGE 2

98-301

7902O9

-MESSAGE 3

90215

798289

-MESSAGE 4

98209

798289

-MESAGE 8

EriTER ENTRY NUMBERS TO BE DELETED, FOLLOWED BY ZERO"

3 DELETtDEriTER ENTRY NUMBERS TO BE DELETED, FOLLOWED BY ZERO'ENTER TYPE FOR NEW MESSAGE <8=SUIT,99=HELP>? 0INSERT PRGGRfiH DISK AND HIT RETURN?

MS I READY

#PUN

TICKLER MESSAGE SYSTEM

INSERT C'RTh DISK RND HIT RETURN'.''

ENTER PRINT CONTROL RS FOLLOWS'

S=S£LECTIY£,fi=ALL>N=NONE..U=UPDATE ONLY ? SENTER OJRRENI DATE < VYrlnDD .> '■■ 798581

JPDATE

MESSAGE

2

2

798381

798301

-MESSAGE

J.

3

79038b

798301

-MESSAGE

5

4

4

798401

798281

-NESSHGE

*?

5

5

798415

798381

-MESSAGE

4

E

b

790505

790289

-MESSAGE

5

7

7

798481

798289

-MESERGE

6

ia

1

798401

798209

-MESSAGE

Q

ii

M

790481

798218

-MESSAGE

10

ENTER ENTRY NUMBERS T0_8£_DELETED, FOLLOWED BY 2EP0? 0ENTER TYPE FOR NEW MESSAGE <0=UUIT.99=HFLP>? 0INSERT PROGRAM DISK AND HIT RETURN?

MSI READY

#RU

T - ERROR # 0i

MSI READY

#RUN

TICKLER MESSAGE SYSTEM

INSERT DRTR DISK RND HIT RETURN?

ENTER PRINT CONTROL AS FOLLOWS1

S=SELECTIVE..H=HLL,N=NONE,U=UPDfiTE ONLY ? SENTER CURRENT DATE C VYMMDD >? ?98502

ENTRY TYPE CflTE

798501

798501

UPDATE

790581790501

MFSSRGE

-MESSAGE-MESSAGE

ENTER ENTRY NUMBERS TO BE DELETED, FOLLOWED BY ZERO? 8ENTER TS'PE FOR NEW MESSAGE <0=ijuiT, 99=HELP>? 8INSERT PROGRAM DISK AND HIT RETURN?

MSI READY

current and last record numbers. Line delimiters once again. Line 9990 re- iodic reminders, then this program

9400 closes the file to update the first quests the clerk to insert the program should be worth the effort it takes to

record and directory entry. disk and acknowledge this action. key it in (and convert it, if necessary).

Line 9500 restores the input routine If you or your business have the There are rewards for using it and

so that commas become string problem of needing one-time or per- penalties for not using it.■

172 January 1980 © BYTE Publications [tic

J*'«J«

Hium

c

««iS»-M

C

'*>'Kenneth r i>

Written by the originator of the UCSDPascal System, this highly informativebook is designed as an orientationguide for learning to use the UCSDPascal System. For the novice, thisbook steps through the Systembringing the user to a sophisticatedlevel of expertise. Once familiar withthe System, you will find the guide aninvaluable reference tool for creatingadvanced applications. This bookfeatures tutorial examples ofprogramming tasks in the form of self-

MASTERUCSD

Pascal

study quiz programs.The UCSD Pascal Software Systems,available from SofTech Microsystems Inc,is a complete general purpose software

m

Bill

BffllM

"HOOKS OF INTtlibST TO COMPUTER PEOPLE"

Please send □

70 Main Street, Peterborough, NH 03458

copies of Beginner's Guide for the UCSD Pascal System

Name

Title

Company

Street

City

State/Province

Code

package for users of microcomputers andminicomputers. The package offers severalinteresting features including:

• Programs which may be runwithout alteration on the GeneralAutomation or DEC PDP-11minicomputers, or on an 8080,8085, Z80, 6502, 6800, or 9900based microcomputers.

• Ease of use on a small, single-usercomputer with display screen andone or more floppy disk drives.$11.95 ISBN 0-07-006745-7

□ Check enclosed

in the amount of $

□ Bill Visa □ Bill Master Charge

Card No.

Exp. Date

Add 60c per book tocover postage and handling.

Circle 35 on inquiry card.

BYTE January 1980 173

Programming Quickies

A Pascal CheckbookBalancing Program

Carl T Helmers, Editorial Director, BYTE Publications

Probably the most hackneyed example of what one cando with a personal computer is the proverbial checkbookbalancing program. Well, here I have gone and done it: Isat down and profaned Pascal by writing a simple littleinteractive checkbook balance figuring program (listing1).

The interactive sequence at initialization reflects ahardware specific aspect of a system which has UCSDPascal bootstrapped through the CP/M operatingsystem's "BIOS" drivers. This is the use of the "< con-trol P" character from the keyboard to toggle a singlebit flag which determines whether or not the printer is on.We assume the program is off upon entry, so that one

Main/Frames „„m $200

Main/Frames *. $200

• 14 Basic Models Available

• Assembled & Tested

• Power Supply:8v@15A, ± 16v@3A

• 15 Slot Motherboard(connectors optional)

• Card cage & guides

• Fan, line cord, fuse, power& reset switches, EMI filter

• 8v@30A. ± 16v@10Aoption on some models

Rackmountedfrom S200

' 8" Floppy Main/Frame

i (includes power for drives

I and mainframe) from S365

Write or call for ourbrochure which includes our

application note:'Building Cheap Computers'

INTEGRAND

8474 Ave. 296 • Visalia, CA 93277 • (209) 733-9288We accept BankAmericard/Vlsa and MasterCharge

depression of the < control > P character will turn on theprinter through the "BIOS" keyboard driver's action.

The general outline of the program, found in the lasteight non-blank lines of listing 1, is fairly standard andapplicable to a host of specific uses. For nearly every useof a computer, we start with a procedure called initializa-tion which sets up the necessary initial conditions of pro-cessing. Then, we continue with a repeat until done loopconstruct which does the main logic of the process overand over again.

When the flag done becomes true during the mainlogic, the repeat loop discontinues and we fall through tothe standard procedure summarize which does any finalprocessing before the program is complete. Of course, inthis particular example, summarize is a null operation,since I have no particular need to provide any reportingor file operations other than those encountered in themain loop. I have left the dummy procedure summarizein the listing to document this need for a possible sum-mary procedure in a more elaborate version of the sameprogram.

This program is run in UCSD Pascal, version 1.5. Thissame program should run identically on any computerwith the UCSD Pascal software system. A sample runfollows the listing. I have used the program now forseveral months; the interactive sequence used for all thedetailed computations could be much improved, eventhough the present form has proved quite practical.

Listing 1: A Pascal listing of the checkbook balancing program.

PROGRAM checks;

{ A simple little program written March 25 1979 by Carl Helmers }( Time from inception to working program approximately 15 minutes }

done : BOOLEAN;detail,balance : REAL;anychar : CHAR;count : INTEGER;

PROCEDURE initialize;BEGIN

balance := 0;count := 0;

{The following sequence turns on my printer if I type <ctrl p> }

PAGE (OUTPUT) ;

WRITELN('Checkbook balancer program');

WRITELN('Set printer to top of form, press <ctrl P>, then any key.1);

READ(KEYBOARD,anychar) ;

{Premature end of program if I type <esc> now}IF anychar = CHR(27) THEN done := TRUEELSE done : = FALSE;

(A sequence to get the initial balance...}IF NOT done THENBEGIN

anychar := 'N';REPEAT

WRITELN (' ');

WRITELN('Enter Initial Balance');READLN(balance);

WRITELN('Balance Starts at '.balance:10:2);WRITELN('IS this correct?');READ(KEYBOARD,anychar) ;WRITELN (anychar)UNTIL ((anychar='y') OR (anychar='Y'))END;END (initialize};

PROCEDURE process_one_check;VAR

s : STRING [50];

174 January 1980 & BYTE Publications Inc

Circle 106 on inquiry card.

PROCEDURE get_charge;BEGIN

anychar := 'N';REPEAT

WRITELN('Enter amount of ',s,': ');

READLN(detail) ;

WRITELN ('Is ' ,detail:]0:2,' the correct value of the ',s,

'? ');READ (KEYBOARD,anychar)UNTIL ((anychar='y') OR (anychar='Y'))END fget_charge};

Enter Initial Balance

1000

Balance Starts at 1000.00

Is this correct?

y

C? D? I? or <esc>c

Enter amount of check:15

Is 15.00 the correct value of the check?

Current Balance = 985.00

PROCEDURE display_balance;3EGIN

WRITELNC Current Balance = ' ,balance:10:2)

END {display_balance};

C? D? I? or <esc>3

C? D? I? or <esc>2

C? D? I? or <esc>

BEGIN {process_one_check}WRITELN(" );

WRITELNCC? D? I? or <esc>');READ(KEYBCARD,anychar) ;WRITELN (anychar);IF anychar = CHR(27)THEN

done := TRUEELSE

CASE anychar OF

'C ,'c' :

BEGIN

s := 'check';

get^charge;

balance := balance - detail;

display_ balanceEND;

■D','d'-.BEGIN

s := 'deposit';get_charge;

balance := balance + detail;display_balanceEND;

'I' ,' i' :BEGIN

s := 'interest';

get_charge;

balance := balance -t- detail;

display_balanceEND

END (CASE);

END {process_one_checkJ ;

PROCEDURE summarize;BEGIN

(Remarkable... this procedure doesn't do anything!)END {summarize};

BEGIN (checks)

(isn't this simple... all we do is )

initialize;

REPEAT

process one checkUNTIL doneTsurmari ze

Listing 2: A sample run.

Checkbook balancer program

Set printer to top of form, press <ctrl P>, then any key.

Enter Initial Balance

3. 1415927

Balance Starts at 3.14

Is this correct?

Enter amount of check:32.98

Is 32.98 the correct value of the check?

Current Balance = 952.02

C? D? I? or <esc>

i

Enter amount of interest:2

Is 2.00 the correct value of the interest?Current Balance = 954.02

C? D? I? or <esc>d

Enter amount of deposit:1000

Is 1000.00 the correct value of the deposit?Current Balance = 1954.02

C? D? I? or <esc>c

Enter amount of check:270

Is 270.00 the correct value of the check?Current Balance = 1684.02

C? D? I? or <esc> ■

Double your memory... not the price!

COMPARE AT $695...

Remex RFD 4000/8"Floppy Disc DriveDouble the storage!Double sided ...Double density!!

Offers qualify and features found in drives costingmuch more! ■ Single or Double Density ■ Double-Sided Drive ■ DoorLock INCLUDED ■ Write-Protect INCLUDED ■ 180 Day Warranty■ Compatible with Shugart 850/851 ■ Low Power Operation ensuresLONGER LIFE!! ■ Model RFD 4001 offers Data and Sector Separator

AVAILABLE OPTIONS/ACCESSORIES

□ Dual Drive Power Supply □ Single Drive Power Supply and Cabinet, $119.95and Cabinet, $139.95 H Interlace Manual, $2.95

□ RFD 4000 Manual, $5.95 Q Drive Cabinet. $29.95

SIRIUS SYSTEMS, P 0 Box 9748. Knoxville. TN , 37920

Phone orders accepted 9 AM-7PM (EST ) 615/577-1072. please send the following

□ RFD 4000. S525 Q RFD 4001. 5539 / Q Check □ Money Order □ C 0 D □ MC □ VISA p AE

ADDRESS

CARD #EXPIRATION DATE

CITY STATE TIP"- CARDHOLDERS SIGNATURE

AddS7 00 per Drive for Shipping/Handling Tennessee residents add 6% sales tax Toreign orders

add 10°o (payment in U S currency only)

Circle 107 on inquiry card.

January 1980 © BYTE Publications Inc 175

Book Reviews

Illustrating BASIC

Donald AlcockCambridge UniversityPress, 1977

134 pages, softcover withring binding $4.95hardcover $14.95

If you are looking for agood introductory BASICtext containing informativeillustrations, short pro-grams, a fundamentalapproach to programming inBASIC, and if you enjoyreading a unique typesetformat, then Illustrating

BASIC by Donald Alcock,is for you.

In order to set the generalapproach used throughoutthis book, the authorpresents a line drawing ofthe famous program "bug."This is but one of the many"biff! baml powl" Batmanand Robin type inserts usedto reinforce specific concepts

Big savings from A Jon TTYs, couplers,and modems.

Off-lease equipment, refurbishedby AJ at the factory.

A CD 11 ^'7'>5 (f\t 1"> Or lease for as low as $49/monthASK JJ q> ILZi (l^iy. I) (36-month lease), including service.

k'*il? 11 <t^O^ (f\t 1\ Or lease for as low as $45/monthIViMV JO qO:0 {yjiy. 1) (36-month lease), including service.

• 30-day parts/labor warranty* • Pedestal mounted

• Send and receive

• Paper tape punch

AJ Couplers/Modems

• The Cadillacs of the industry

• Some models under $100

• 30-day parts/labor warranty*

• Variety of models—up to1200 bps

• Visa or Master Charge

• Fast delivery

• Nationwide AJ servicenetwork

• Visa or Master Charge

Quantities limited and first-come, first-served.So call toll-free now: (800) 538-9721.

California residents call (408) 263-8520.

Prices subject to change without notice.

'Details available on request.

as they develop. Thisapproach leads the readerthrough a convenient how-to-do-it explanation ofBASIC programming.

The first chapter intro-duces the reader to what theauthor calls "Components ofthe Language." Immediately,the reader gets a taste of theunique presentation offeredby this book; illustrations,short programs, and inter-esting problems abound.The fundamental conceptsof most BASICs are intro-duced via a short note, anillustration, and a few pro-gram lines which allow thereader to see how the pro-gram should appear.Numeric variables (integer,real, and exponent form)and text variables (strings)are presented in a short butthorough exposition.

Chapter 2, entitled "Inputand Output, Expressions andFunctions," covers thestatements: DATA; READ;RESTORE; INPUT; thefunctions SGN, ABS, SQR,INT, LOG, EXP, SIN, COS,TAN, and ATN; RND;DEF; PRINT; TAB; andPRINT USING. For each ofthese statements, a simple il-lustrative program is given.For example, an engineermay be interested in theshort routine that calculatesthe spring properties of adiving board; thebusinessman will find themonthly repayment on aloan useful; the game playercan use the die throwingroutine; the mathematicianhas a routine that plots thegraph of the cosine function;and everyone should enjoythe examples given for thePRINT USING statement.

After these concepts isChapter 3, "Control." As inevery chapter, the pertinentstatements such as GOTO,IF. . . THEN, STOP, ON. . .GOTO, FOR . . .NEXT, GOSUB, andRETURN are introduced, il-lustrated, and programmedinto short routines. Chapter

176 January 1980 © BYTE Publications Inc

Circle 108 on inquiry card.

Circle 109 on inquiry card.

ram ^

A specially designed SF TACTICAL BATTLE GAME foryour PET, TRS-80 or APPLE Computer.

The man called Sudden Smith watched the five blips onhis screen spread out to meet the enemy. Two freightersconverted into something like battiewagons, powerfulbut slow, and three real cruisers: the most powerful groupof warships ever seen near the Promethean system — exceptfor the Stellar Union fleet opposing them. Everyone wascalling it Starfleet Orion, though it existed for only thisday. It was life or death, and, after the object lesson onthe planet Spring, everyone knew it.

STARFLEET ORION is a complete 2 player game system

• rule book • battle manual • cassette

• ship control sheets • program listings

Includes 2 programs, 22 space ship types, and 12 playtestedscenarios. Game mechanics are extremely simple, but playis exciting, challenging, and rich in detail. Specify PET (8K),TRS-80 (Level II, 16K), or APPLE II (16K& 32K) $19.95.

Ask your local dealer or send your check to:

Automated SimulationsDepartment YP.O. Box 4232Mountain View, CA. 94040

California residents please add 6% sales tax

Circle 110 on inquiry card.

WE CARRY -

•CROMEMCO

• NORTH STAR

•VECTOR GRAPHICS

•THINKER TOYS

•NEC

•CENTRONICS

•INTERTUBE

•SERENDIPITY

•PERKIN ELMER

• TEXAS INSTRUMENTS

Professional A/R, A/P, Ledger, Payroll, Medical Billing soft-ware with customization available. Send for our catalog —Send for quote.

SARA-TECH

COMPUTERS

P. O. Box 692

Venice, FL

33595

(813) 485-3559

SPECIALIZING IN

QUALITY MICROCOMPUTER HARDWARE

INDUSTRIAL • EDUCATIONAL • SMALL BUSINESS • PERSONAL

BUILDING BLOCKS FOR MICROCOMPUTER SYSTEMS, CONTROL & TEST EQUIPMENT

R2 I/O

2K ROM

2K RAM

3 Serial Ports

1 Parallel Port

WIRED: $295.00

16 K RAM

FULLY STATICMEMORYKIT: $279.00WIRED: $310.00

ECT-100-F

RACKMOUNTCARD CAGESKIT: $200.00WIRED: $250.00

ECT-

a sw

"*»*>*+,

POWER SUPPLIES, CPU's, MEMORY, OEM VARIATIONS

TT-10

TABLE TOPMAINFRAMESKIT: $340.00WIRED: $395.00

763 RAMSEY AVE.HILLSIDE, N.J. 07205

ELECTRONIC CONTROL TECHNOLOGY oou ese-soso

Circle 111 on inquiry card.

BYTE January 1980 177

3 does just that with theGOTO. Some of the pro-grams include: solving a pairof simultaneous equationshaving any number of right-hand sides; area calculationsfor triangles, rectangles, andcircles; and the game ofMoo (quite similar to Bullsand Cows; ie: a number-based Mastermind).

A useful routine inChapter 3 introduces thereader to stacks and to theconcept of recursion via theGOSUB statement. This by-the-way approach of intro-

ducing and examining arelatively complex idea isdone rather subtly andpainlessly.

Arrays are covered quitewell in Chapter 4, andmatrix operations arepresented in Chapter 5. Theconcepts in Chapter 4 con-cerning arrays are enhancedwhen the reader finishesexamining the matrices inChapter 5. The author ex-plains and illustrates matrixfunctions, although not allBASIC systems have them.He then manipulates

matrices without the func-tions, using nested loops.Some of the more interestingmatrix operations include:arithmetic operations uponarrays; transposing a matrix;initializing an array to allzeros or all ones; inverting amatrix; and input and out-put statements performed onarrays.

The array manipulatingroutines deal primarily withmatrix algebra applicationsand could prove useful tothe engineer or themathematician.

ORTRAN

for the 8080 only $9995

• FORT//80 is a subset of Fortran IV with many powerful enhancements!FORT//80 is an advanced software development tool!

• FORT//80 is AFFORDABLE!!

FEATURES

• F0RT//80 directly addresses 8080 ports as • Fast; Runs up to 10 times as last as PLMFORTRAN variables • FORT//80 directives specily location ol code in

• I/O drivers accessed via FORTRAN read/write memory at run-timestatements • Interrupt and interrupt control

• FORT//80 accepts embedded in-line machine code • FORT//80 control of interrupts and interrupt

• 8080 condition codes are available as FORTRAN service lines

keywords and can be operated upon • All code runs on 8080.8085 and Z80 (upward

• Multiple assignment operators accepted compatibility)

• Interleaved listings and object code for quick • FORT//80 is a true resident compiler anddebugging generates directly executable object code. No run

• Symbolic names up to 31 char long simplify time package needed

documentation • FORT//80 is very fast. It compiles quickly and

• Constants expressable to base 2,8,10,16 or as produces dense highly optimized code

char strings • Single and double precision IBM format floating

• Compact: Needs only 25K for compiler and point arithmeticminimum workspace

™ "pricing"

FORT//80CPM version and manual on 8" diskette $99.95 I

FORT//80 Language manual separately 20.00

FORT//80 Implementation manual 20.00 I

Sample diskette validation program and data 5.00

Shipping charges to US and Canada postpaid, overseas add $5.00. Please addappropriate state sales tax. Master Charge and Visa accepted.

1. FORT//80 is supplied on a single use basis, subject to the signing of a non-disclo-sure agreement.

2. FORT//80 can be implemented with other disc operating systems using the |implementation manual or special versions available by quotation.

3. The purchase price of manuals and sample programs will be credited towardssubsequent purchase of FORT//80 .

rsmsaij ulssf renins

BOX 4072, ROCHESTER, NY 14610PHONE ORDERS CALL 716-271-6487

Distributors:

• Digital Research of Texas, Box 401565, Garland, TX 75040, (214) 271-2461

• Electrolabs Inc., Box 6721, Stanford, CA 94305, (415) 321-5601

• Arkansas Systems Inc., 8901 Kanis Rd., Little Rock, KS 72205, (501) 227-8471*Arkon Electronics Ltd., 409 Queen St. W., Toronto, ONT M5V 2A5, (416) 868-131'

Dealer inquiries invited.

™Akron Electronics Ltd.

Chapter 6, entitled "Com-plete Example Programs,"contains only two programs.The first is a routine whichconverts Roman numerals toHindu-Arabic (such as VIIto 7). The other program isa critical-path analysisroutine. Expecting a host ofprograms in this chapter, Iwas disappointed to findonly two. They are goodexample programs whichbring together most every-thing the reader has seen sofar. Perhaps they could havebeen included as wrap-upprograms in other chapters.

The remaining threechapters ("Commands andSigning On," "Files ofData," and "Syntax")explain how the typicalBASIC interpreter handlesthe RUN, SAVE, UNSAVE,OLD, NEW, andCATALOG commands (thereader is cautioned as to theparticulars of his or her per-sonal BASIC); a typicalsign-on session (see yourowner's manual for thisone); a short (unfortunately)discussion pertaining tosequential and direct-accessfiles; and a modified Backus-Naur notation used to sum-marize the syntax of BASIC.

I ran most of the examplespresented in the text on myLevel II TRS-80. Since theauthor does not use anymachine- or interpreter-dependent statements in hisexamples, there should beno problem in running theexamples on othermicrocomputers. Some cau-tion is expressed by theauthor, however, withregard to the lack of porta-bility of BASIC. The readershould examine his or herBASIC manual for any dif-ferences between what theauthor labels "minimalBASIC" and the BASIC usedin the reader's computer.

Overall, IllustratingBASIC is a good first bookfor the novice computerist.The author's Preface state-ment does ring true afterreading this book: "Youdon't have to be a computerscientist to read this book: Itis for students meeting com-puters for the first time; forthose in industry (parti-

178 January 1980 © BYTE Publications Inc

Circle 112 on inquiry card.

cularly engineers) who neverformally studied computingbut would like to write sim-ple computer programs; formanagers who do not wantto write programs but wouldlike to know more about afield in which they oftenhave to take decisions; andfor those who can alreadywrite in BASIC but seek abroader view of portableprogramming and an intro-duction to a few program-mers' techniques like statetables and list processing."

Len Gorney

Box 91 RD 5

Salisbury Rd

Clarks Summit PA 18411

Implementing Softwarefor Non-NumericApplications

William M WaitePrentice-Hall. 1973110 pages hardcover$21.00

Implementing Softwarefor Non-Numeric Applica-tions is a textbook on listand string processinglanguages. It covers thebasics of lists and strings,and how to implementlanguages in order to dealwith these data types. Thereare two major reasons whya computer hobbyist mightwant to read this book: tolearn how such languageswork and to learn how tor iplement them.

Most of the book is aboutlists. It begins with a discus-sion of what lists are, andthen presents an idealmachine for processing them(cf Pascal p-code), a fairlysimple list processinglanguage called HELP, andthen LISP. The discussion ofLISP focuses fairly heavilyon what LISP does inter-nally and why. After morediscussion of complex lists,the book proceeds to adiscussion of strings;SNOBOL4 is introduced butnot discussed in the detailthat LISP is treated. The

final section is on imple-mentation.

The author of the bookfavors implementation byabstract machine modeling;this is the way in whichPascal is implemented. It hasthe advantage that a com-piler or interpreter, oncewritten, can be implementedon new machines with muchless effort than would other-wise be the case. The discus-sion of implementation ismore than just theoretical;the appendices contain com-plete FORTRAN listings foran abstract machine model,

and for HELP language com-piler and interpreter.

HELP is a languagesimilar to LISP. The soft-ware may be directly imple-mented if you have aFORTRAN compiler; other-wise it has to be translatedinto assembler (or perhapsBASIC, if execution speed isnot important). I cannot sayhow successful this wouldbe; I already have LISP formy Z80 processor and sowas not tempted to imple-ment HELP.

In conclusion, this book isfairly heavy going. If you

want a thorough intro-duction to how listlanguages work, why theydo what they do, and howto implement them, this isan excellent book. If youwant an introduction toLISP, it would probably bebetter to first read an in-troductory text. Then readImplementing Software forNon-Numeric Applicationsto really understand the waythings work.

John A Lehman716 Hutchins #2Ann Arbor MI 48103 ■

Basic Cat

A Cat acoustic modem lets yourcomputer talk face to face withany other compatible computeror terminal within reach of yourphone. It takes the data you typeinto your terminal and sends itout over standard telephonelines. It's that simple.

Talk to your office computerfrom home. Send or receive datafrom anywhere. Swap programsin Basic, Pascal, Fortran, Cobolor whatever—it doesn't matter

to Cat. It's the accurate, reliable,affordable (under $199) modemthat talks your language.

Novation

Tie your computer into the world

Call for details

(800) 423-5410

In California (213) 996-5060

Available at Hamilton/Avnet, Kierulff Electronics, Byte Shops, Computerland,and your local computer store.

Novation. Inc., 18664 Oxnard Street, Tarzana, California 91356

Circle 113 on inquiry card.

January 1980 © BYTE Publications Inc 179

Relocating 8080System Software

John G Lipham

Dept of Physics

University of North Carolina

at Charlotte

Charlotte NC 28223

Owners of both large and smallcomputer systems often experiencesoftware problems when the timecomes to upgrade the system. All oldapplications programs will have to bemodified to run under the newsystem. However, the real problemoccurs when you want to use some orall of the old system software. Thiswas recently the situation at theUniversity of North Carolina atCharlotte (UNCC) Physics Depart-ment.

The original hardware consisted ofan IMSAI mainframe with 20 K bytesof memory interfaced with a Teletypeand audio cassette. We added afloppy disk and Tektronix 4006-2graphics terminal. To operate thedisk, we acquired the CP/M opera-ting system written by DigitalResearch and distributed by IMSAI.

The CP/M system has a disk-basedversion of BASIC called BASIC-E,which was written by GordonEubanks. This is an excellent versionthat allows up to 31 characters forvariable names, nearly form-freeentry of statements with line numbersrequired only for program transfer(eg: GOTO ..., GOSUB ..., etc), andnumerous built-in functions, as wellas file handling capabilities.However, it is unusual for BASIC

About the Author

John Lipham's first contact with program-ming was as a graduate student in physics atthe University of North Carolina at ChapelHill. There he discovered PL/1 and assemblylanguage for the IBM 360. Recently he has beenworking with a colleague on a project using anIMSAI microcomputer system. The goal of theproject is to develop software to aid in teachingphysics, and to interface the system to scientificinstruments for research purposes.

because programs are first createdusing an editor, compiled into anintermediate file (using BASIC-E),and finally run (using RUN-E). Oursystem is used primarily for instruc-tional purposes and some of our stu-dents have had no previous program-ming experience. Hence, we felt thatit was desirable to have an interactiveversion of BASIC for their use.

We already had an interactiveBASIC with our old system. How-ever, there was a catch. To run underthe CP/M system, it was necessary toshift the origin of BASIC to theaddress hexadecimal 0100 from itsoriginal starting address of 0000. (TheCP/M monitor uses the addresseshexadecimal 0000 thru 00FF.)

In principle, if you have anassembly-language listing and anassembler program, it is always possi-ble to reassemble the assembly-lan-guage code to machine code with anew starting address. However, withour old version of BASIC, this listingconsisted of 113 typed pages! Ig-noring the difficulty of just enteringthis amount of code, a moment's re-flection will show that the assemblerand the code would never fit in 20 Kbytes. (The machine code itself occu-pies about 9 K bytes.) Assembling thecode in pieces that fit is a possibility.But, even with a cross-reference tableof variable names, this would be anexcruciating process. Hence, we wereleft with the only practicable alter-native: relocating the machine codedirectly.

Thus it was with great interest thatI read Leor Zolman's article in theJuly 1977 BYTE entitled "A MachineCode Relocator for the 8080." I haveused the program written by Zolman

and have found that it works asadvertised.

However, I have oversimplified myinitial statement of the problemsfaced in modifying our old BASIC torun under CP/M. There were seg-ments of the old software that had tobe removed to be compatible withCP/M. Thus, to avoid a lot of NOPs,various relocations to lower-memoryaddresses had to be made. (Variousadditions and replacements also hadto be made.) As pointed out byZolman, his program works by mov-ing blocks of code tail-to-tail. Hence,"relocating backward into lowermemory fails if the difference be-tween the source and destination ad-dress is not greater than the blocklength." Also, his suggested solutionto this limitation of performing tworelocations was impracticable be-cause of our memory limitations.

I found that by making some modi-fications I could remove the limita-tion in Zolman's original program atthe cost of 36 additional bytes of pro-gram code. This modified relocatorprogram is presented in listing 1. Aswritten, the program is designed torun with the CP/M system's DynamicDebugging Tool (DDT), which is atype of monitor program formachine-code programs. I found thisto be a useful procedure, since theDynamic Debugging Tool allows themachine's memory to be reviewedand modified via a terminal key-board. I also found the disassemblerroutine of this program to be invalu-able. (The program can be modifiedto run without a monitor, or withanother monitor, by changingmemory location hexadecimal2DCC.)

180 January 1980 © BYTE Publications Inc

Circle 114 on inquiry card.

Circle 115 on inquiry card.

JIMAifo

68

announces

North Star Horizon Timesharing

with

Hard Disk Interface

In excess of 120 megabytes bulk storage capacitynow possible. Several different hard disk units areavailable, interfaced to North Star DOS andBASIC.

Two to seven-user timesharing North Star Horizonintegrated computer systems with: Dual density orquad capacity eight inch drives and/or hard diskunits with your choice of a variety of printers.

A complete selection of innovative business appli-cation software is available for North Star*systems.

Foreign orders are our specialty.Dealerships are available. Call or write for descrip-tive literature, hard disk availability and/or dealerinformation package.

Micro Mike's, Incorporated

905 South Buchanan • Amarillo, Texas 79101 * USATelephone: 806-372-3633

making technology uncomplicated — for People

TRS:§P

.«QSS8f"

The world's most popular microcomputer, with 16K ofmemory and Level 11 basic for only $750, complete withfull 90 day Radio Shack warranty. We accept check,money order orphoneorders with VisaorMasterCharge.(Shipping costs added to charge orders).Disk drives, printers,peripherals, softwareand games . . . youname it, we've got it(Both Radio Shack &other brands). Writeor call for ourcomplete price list. //■■ WSt Y

Shown Is Level I.Level II IncludesAlphanumeric keypad.

C&S

ELECTRONICS MART

Ltd.

AUTHORIZEDDEALERSHIP

Radio /hack

32E.MainStreet«MilanMichigan48160«(313)439-1400

CP/M 2.0 FOR THE MOD-II

The Latest CP/M Operating System up and running now

on the TRS-80 MOD-II

THE PROBLEM...

Yes, theTRS-80 Mod-ll is the most powerful computeryou can buy for the money today. And yes, it is asgood as computers selling for up to three (or more)times the price.

But just like the IBM 5110 Radio Shack compares itwith, the new TRS-80 Mod-ll suffers from a familiarproblem... not enough systems software, not enoughapplications software.

SOLVED...

We've done it.Taken the world's most popular micro-operating system and matched it to the world'snewest micro business computer. It's up and runningtoday, and you can have it in your Mod-ll this week.And we mean STANDARD CP/M Version 2.0.The latestand best.With all of its features. And some of ourown.

Make no mistake.This is not just a promise, it's a powerful workingsystem. Order C.O.D. Send $25 down, pay $225 + $2.50 Shipping &Handling, or save C.O.D. and shipping by sending $250 with yourorder. Master Charge and Visa also accepted. Air Shipment add$2.00. California residents add 6% sales tax.

IN STOCK NOW. MANY APPLICATIONS PROGRAMSAVAILABLE NOW. BASIC, FORTRAN, COBOL, APPLICA-TIONS PACKAGES AVAILABLE FOR BUSINESS & PRO-FESSIONS! FOR INFORMATION CALL (415) 592-6633.

STANDARD CP/M 2.0 FEATURES

•Microprocessor Control Program

•Includes Editor, Assembler, Debugger, Utilities

• Supports Floppy and Hard Disks

PLUS SOMEOF OUR OWN

•Reads single and double density diskettes•Single drive copy and backup routines•All routines optimized for TRS-80 Mod-ll

WHAT YOU GET

•The complete CP/M diskette from Digital ResearchCorp.

•The MPU diskette with our additions and patches to

make it work on theTRS-80 Mod-ll•Seven manuals from Digital Research Corp.•One manual from MPU to explain our additions

SEND FOR OUR

CATALOGS OF

TRS-80 MOD-I AND MOD-II

APPLICATIONS SOFTWARE

MPU

POST OFFICE BOX BOBSAN CARLOS, CALIF 34070

CP/M is a trademark of Digital Research Corp. TRS-80 is a trademark of Tandy Corp.

Circle 116 on inquiry card.

BYTE January 1980 181

While there are some differences indetail as to the operation of themodified relocator, this program isrun in the same manner as Zolman'soriginal program. For ease of refer-ence I have retained Zolman's nomen-clature, (nb: Using this nomenclature,you view the memory as though youwere looking down into a barrel.Numerically smaller addresses are atthe top and numerically larger onesare at the bottom.) The same pieces ofinformation are required for a reloca-tion and reference fix, as in Zolman'sprogram. This required informationis outlined in table 1, which, exceptfor memory addresses, is the same asZolman's.

The LXI Problem

As pointed out by Zolman, theload immediate (LXI) instruction is apotential source of problems in relo-cating machine-code programs. Themain difficulty is that this instructionis frequently used for two differentjobs: to load a constant into a registerpair, and to load an address into aregister pair. The relocator programcannot distinguish between these twouses. Hence, if a program constanthappens to be equal to an addresswithin the program block beingmoved, an erroneous reference fixwill be made.

Unfortunately there seem to be nowidely accepted conventions for theuse of this instruction that produceeasily relocatable machine code.Adoption of the following conven-tions is suggested for all those de-siring to write relocatable code:

(1) The LXI instruction shall be usedonly to load addresses into aregister pair (eg: LXI H,3101H).

(2) All program constants shall beloaded into a register pair using 2move immediate instructions (eg:MVI H,31H MVI L,01H).

The cost of adopting these conven-tions is relatively modest in that itwill take 4 bytes to load a 2-byte con-stant into a register pair, instead ofthe 3 bytes required using the LXI in-struction. Furthermore, if you onlywant to zero out a register pair, thefollowing sequence of instructionsachieves the same result at no addi-tional cost, without using the LXI in-struction:

182 January 1980 © BYTE Publications Inc

Listing 1: A relocator program for use on 8080 systems. This is a modified version of therelocator program written by Leor Zolman in the ]uly 1977 BYTE. This relocator willmove a source program to any location in memory and fix address references. Reloca-tions of a source-program block to any address outside the source are performedwithout overwriting. The program is designed to run with the Dynamic DebuggingTool (DDT) of the CP/M software system. If need be, the program can be modified torun without a monitor or with another monitor by changing the contents of hexa-decimal memory location 2DCC. While differing in some details with Zolman'srelocator program, it requires the same information and is run in the same manner.

2D00

ORG

2D00H

;SET ORIGIN

2D00

31162E

BEGIN:

LXI

SPjSTACK+8

;INTIALIZE STACK

2D03

2A032E

LHLD

SBOT

."BOTTOM OF SOURCE

2D06

EB

XCHG

;d,e»sbot=cb>

2D07

2A012E

LHLD

SSTRT

;h,l=sstrt=ca>

2D0A

4D

MOV

CL

2D0B

44

MOV

B..H

;SAVE IN B,C

2D0C

CDCD2D

CALL

COMPH

;compliment<a) * add i

2D0F

19

DAD

D

;h, l=cb>-ca)=blocksize

2D10

E5

PUSH

H

jsave on stack

2D11

2A052E

LHLD

DTOP

;top of destination

2014

EB

XCHG

;d..e=dtop=(C>

2D15

69

MOV

L,C

2D16

60

MOV

H, B

;H,L=SSTRT

2D17

CDCD2D

CALL

COMPH

2D1A

19

DAD

D

;h,l=(C>-<a)=displ

2D1B

220C2E

SHLD

DISPL

;save displacement

2D1E

F5

PUSH

PSW

;has sign of displ

2D1F

3A0B2E

LDA

FUNC

;check for move

2D22

B7

ORA

A

2D23

CA602D

JZ

STEP2

;IF 0 FIX REF. ONLY

2D26

Fl

POP

PSW

2D27

DA3E2D

JC

DOWN

; <o> ca) if carry set

;if COME

HERE DESTINATION IS ABOVE SOURCE

;so MOVE

IS DONE HEAD-

•TO-HEAD

2D2A

EB

UP:

XCHG

;h,l=d,e=dtop

2D2B

Dl

POP

D

;d,e=blksize

2D2C

0A

X:

LDAX

B

;b,c=sstrt=source ptr.

2D2D

77

MOV

M#A

;move to new loc.

2D2E

7A

MOV

A,D

2D2F

B7

ORA

A

2D30

C2382D

JNZ

Y

jCHECK IF THRU

2D33

7B

MOV

A,E

2D34

B7

ORA

A

2D35

CA582D

JZ

TEST

;IF D,E=0 THEN MOVE DONE

2D38

23

Y:

INX

H

;incr DEST. ptr- to next

2D39

03

INX

B

;INCR SOURCE PTR.

2D3A

IB

DCX

D

;count down blksize

2D3B

C32C2D

JMP

X

CONTINUE

;if COME

HERE DESTINATION IS BELOW SOURCE

;so MOVE

IS DONE TAIL'

-TO-TAIL

2D3E

EB

DOWN:

XCHG

;h, l=d,e=dtop

2D3F

Dl

POP

D

;d,e=blksize

2D43

D5

PUSH

D

;save ON STACK

2D.11

19

DAD

D

; H> L = DB0T = DT0 P + 3LKS I ZE

2042

EB

XCHG

;D,E = D30T: H,L=BLKSIZE

2D43

09

DAD

B

;H,L=SSTRT+BLKSIZE=SB0 T

2D44

EB

XCHG

;D,E=SB0T:H>L=D30T

2D45

CI

POP

B

;b,c=blksize

2D46

1A

XXI

LDAX

D

;D*E= SOURCE PTR.

2D47

77

MOV

M,A

;move to new loc.

2D48

78

MOV

A,B

2D49

B7

ORA

A

2D4A

C2522D

JNZ

YY

;CHECK IF THRU

2D4D

79

MOV

A,C

2D4E

B7

ORA

A

2D4F

CA582D

JZ

TEST

;B,C = 0,MOVE DONE

2D52

2B

YY!

DCX

H

;PT. TO NEXT DEST.

2D53

IB

DCX

D

;PT. TO NEXT SOURCE

2D54

0B

DCX

B

/•COUNT DOWN BLKSIZE

2D55

C3462D

JMP

XX

."CONTINUE

2D58

3A0B2E

TEST:

LDA

FUNC

; = 02 IF MOVE ONLY

2D5B

FE02

CPI

02H

2D5D

CACC2D

JZ

DONE

iCOME HERE TO DO REFERENCE FIXING.

;necessary ONLY FOR 3

BYTE OP CODES

2D60

01E72D

STEP2:

LXI

B..TABL3

;8,C= TABLE PTR

2D63

2A032E

LHLD

SBOT

JNEED TO ADD 1 TO SBOT

2D66

23

INX

H

2D67

22032E

SHLD

SBOT

2D6A

2A072E

LHLD

START

ID, E=MEM0RY PTR.

2D6D

EB

XCHG

2D6E

2A092E

CHEKF:

LHLD

SSTP

JCHECK FOR END OF FILE

2D71

CDCD2D

CALL

COMPH

;d,e=mem. ptr.

Listing 1 continued on page 184

Circle 117 on inquiry card.

For Business Systems Software

Programmers Only!!

Machine Language

ISAM

FOR

TRS-80* Models I and II

ACCESS TIME % SECOND!"

This machine language ISAM ROUTINE provides file accesssophistication required to implement complex business software,and is completely compatible with TRS-80* BASIC.

Specifications: based on 1000 record file, key length of 6, datalength of 64

Access time of V2 second

Best add/delete time oi 1 second

Average add/delete time of 2 seconds

Worst case add/delete time of 5 seconds

Keys up to 25 characters

Data up to 255

Provides next highest key upon each file access.

Preset range of allowable key values, set upon file creation up to 4 files

held open concurrently.

No special utilities needed to "Reclaim" used record space.

Model I Routine occupies 5 K of user space (loads at top of user memory)

Model II Routine occupies 6 K of user space (loads at top of user memory)

EOF, file full, empty, key not found, INVALID key value and all

TRS DOS* error codes supported.

TRS-80 Model I (32 K + 48 K only) $160.00TRS-80 Model II (64 K only) $170.00

Includes: All necessary documentation, file creation program, fileinspection program, machine language ISAM routine and loader.

SYSTEMS SPECIALISTS

415 MILLBURY STREET

WORCESTER, MA 01607

(617) 755-8134

INCTX

' TRS-80 and THS DOS are trademark of Tandy Corporation, which has no relationshipto HCH Inc.

Circle 118 on inquiry card.

Zs - SYSTEMS

siI * 11 MM

■'■"'-. ™,.™iP. m III

64K RAM BOARD

The Zs-SYSTEMS 64K RAMboard is designed to operatein any Z80 based microcom-puter having S-100 bus. Ituses 16K dynamic RAM chips,& features:

—Board select

—Bank select

—Transparent on-boardrefresh

—2 or 4MHz operation(w/ no wait state)

—Memory disable

FLOPPY DISKCONTROLLER

Handles with no modification

up to:' 4 standard 8" drives

(Shugart or compatible) or* 3 minidrives 5"Run with 2 or 4 MHz CPU

Compatible with Cromemcoand M/PM multiuser. Fully

assembled, burned in, &

tested. Available from stock

to 60 days

As low as $500.00 in

guantities of 100

Price of one.

.$695.00

With 16K RAM $359.00

Plus shipping charges

Use CP/M Disk Operating SystemUsing the 1771 LSI controller

Price of one $245.00

PC board only $35.00

SEND FOR FREE INFORMATION

6 months warranty on our boards with normal use

Zs-SYSTEMS

PO Box 1847, San Diego, CA 92112(714) 447-3997

TRS MOD I and MOD II PROGRAMS FROM |-RACET computes-f

co BASIC for Level II and Disk Systems $49.95

Full MATRIX Functions - 30 BASIC commands!!Mathematical and common matrix functions. Change arrays inmid-program. Complete array handling. Tape array read and write,including strings. Common subroutine calls.

Over 50 more STRING Functions as BASIC commands!! Stringmanipulation, translation, compression, copying, search, screencontrol, pointer manipulation and utility functions. Includesmultikey multivariable machine language sorts. Load only machinelanguage functions that you want! Where you want in memory!Relocating linking loader! Morethan you ever expected!!

co BUSINESS (Requires Infinite BASIC) $29.95

20 Business oriented functions including:Printer Automatic Pagination with headers and footers!Packed Decimal Arithmetic ( + , -, *,/) 127 digits!Binary array searched and hash code generator!

COMPROC Command Processor for Disk Systems $19.95

Auto your disk to perform any sequence of DOS commands,machine language loads, BASIC, memory size, run program,respond to input statements, etc. Single BASIC command filedefines execution! Includes auto key-debounce, screen print andlower case software driver.New Products Jan/Feb! We answer reader response inquiries!!

ATTN/ System Houses - We license usage of our routines!

TRS Add-On OEM's - Direct BASIC commands tailoredfor your hardware.

REMODEL + PROLOAD Specify 16, 32, or 48K Memory $34.95

RENUMBER any portion or all of BASIC program. Line references

adjusted.

MOVE any portion of a BASIC program from one location to

another.

DELETE lines or ranges of lines while using the utility.

MERGE all or any portion of a program from tape. (Load lines

300-500 from your tape to existing program at line 1000 with

renumbering on the way in!)

SAVE combined/merged programs, or any portion to tape with

VERIFY.

COPSYS Copy Systems Tapes (Editor/Assembler Format) $14.95

GSF (16, 32, or 48K) $24.95

18 Machine language routines using 'USR' calls. Includes RACETsorts, array handling, and fast lines and scrolls.

DOSORT (Specify 32 or 48K ■ 2 disk minimum) $34.95

Sort/Merge multi-diskette sequential files. Multiple keys andvariables. Includes GSF - machine language sorts, comparatorsand string handling.

MOD II SUPPORT

RACET is supporting the MOD II!!

Call or write for current information! We have a MOD II Superzap

and other assembly language tools!

Ask your dealer if he carries our products!

DEALERS! We will work with you directly or through our

distributors.

CHECK, VISA, M/C, CO.D. • Calif. Residents add 6% • Telephone Orders Accepted (714) 637-5016

WHEN ORDERING PLEASE ADVISE PUBLICATION SOURCE

£- RACET COMPUTES "^702 Palmdaie, Orange CA 92665

Circle 119 on inquiry card.

BYTE January 1980

183

Listing 1 continued.

2D74

19

DAD

D

;d..e-h,l=diff.

2D75

DACC2D

JC

DONE

JDIFF.>=0,CARRY SET

2D78

1A

NEXT:

LDAX

D

;load mem. using d#e

2D 79

67

MOV

H,A

;SAVE IN H

2D7A

AF

XRA

A

;ZER0 ACCUM.

2D7B

6F

MOV

L,A

;SET UP CNTR.

2D7C

2C

C0MP3:

INR

L

;bump CNTR

2D7D

7D

MOV

A*L

2D7E

FE1B

CPI

27D

;CHECK FOR END OF TABLE

2D80

CA8C2D

JZ

AGAIN

;IF THRU, LOOK • 2 BYT OPS

2D83

0A

LDAX

B

;LOAD TABLE ENTRY

2D84

94

SUB

H

JCOMP- WITH CURR. MEM.

2D85

CAA12D

JZ

MTCH3

;JMP IF MATCH

2D88

03

INX

B

;ELSE BUMP TABLE PTR.

2D89

C37C2D

JMP

C0MP3

;look again

2D8C

01D52D

AGAIN:

LXI

B,TABL2

;nou,look at 2 byte ops

2D8F

AF

XRA

A

;ZERO ACCUM.

2D90

6F

MOV

L,A

J SET CTR.

2D91

2C

C0MP2:

INR

L

;bump CTR.

2D92

7D

MOV

A,L

2D93

FE13

CPI

19D

;CHECK FOR END TABLE

2D95

CAC52D

JZ

OUT1

;NO MATCH 2 OR 3 BYTE OPS

2D98

0A

LDAX

B

J LOAD TABLE ENTRY

2D99

94

SUB

H

;COMP. WITH CURRENT MEM.

2D9A

CAC42D

JZ

0UT2

;JMP IF MATCH

2D9D

03

INX

B

;else bump table ptr.

2D9E

C3912D

JMP

C0MP2

;look again

2DA1

2A032E

MTCH3:

LHLD

SBOT

;found 3 byte op code

2DA4

CDCD2D

CALL

COMPH

;is addr. in range?

2DA7

13

INX

D

;get lo addr. byte

2DA8

1A

LDAX

D

;load in acc

2DA9

4F

MOV

C.A

;STORE IN c

2DAA

13

INX

D

;GET HI ADDR. BYTE

2 DAB

1A

LDAX

D

;load acc.

2D AC

47

MOV

B,A

;put IN B

2DAD

09

DAD

B

;H\»L=MEM. ADDR. -SBOT

2DAE

DAC52D

JC

OUT1

;mem.addr.>=sbot+i*c set

2DB1

2A012E

LHLD

SSTRT

;less than caj?

2DB4

CDCD2D

CALL

COMPH

2DB7

09

DAD

B

;h.,l=mem. addr.-sstrt

2DB8

D2C52D

JNC

OUT1

;MEM.ADDR. < SSTRT>C=0

2DBB

2A0C2E

FIXR:

LHLD

DISPL

;IF COME HERE* IN RANGE.

2DBE

09

DAD

B

;H>L=MEM. ADDR. +DISPL

2DBF

7C

MOV

A,H

2DC0

12

STAX

D

; STORE NEW HI ADDR.

2DCI

IB

DCX

D

;PT. AT LO ADDR. BYTE

2DC2

7D

MOV

A,L

2DC3

12

STAX

D

; STORE NEW LO ADDR. BYTE

2DC4

13

0UT2:

INX

D

2DC5

13

0UT1:

INX

D

;ADV. PTR. TO NEXT OP

2DC6

01E72D

LXI

B..TABL3

;RESET TABLE PTR.

2DC9

C36E2D

JMP

CHEKF

;continue

2DCC

FF

DONE:

RST

07

;finis/Return to ddt

;•****

SUBROUTINE

*****

2DCD

7C

COMPH:

MOV

A,H

;subroutine used to

2DCE

2F

CMA

;find 2'S compliment

2DCF

67

MOV

H,A

;representation of

2DD0

7D

MOV

AjL

;h,l register pair

2DD1

2F

CMA

2DD2

6F

MOV

L,A

2DD3

23

INX

H

2DD4

C9

RET

******

TABLES AND

2DD5

060E16

TABL2:

DB 0 6H,

0EH, 16H

;table of 2 byte

2DD8

1E262E

DB 1EH,

26H,2EH

;op CODES

2DDB

363EC6

DB 36H,

3EH,0C6H

2DDE

CEDED6

DB 0CEH

,0DEH,0D6H

2DE1

DBDEE6

DB 0D8H

>0DEH»0E6H

2DE4

EEF6FE

DB 0EEH

,0F6H,0FEH

2DE7

011121

TABL3:

DB 01H,

11 H, 2 1 H

;table of 3 byte

2DEA

222A31

DB 22Hj

2AH.I 31H

;op CODES

2DED

323AC2

DB 32H,

3AH,0C2H

2DF0

C3C4CA

DB 0C3H

^0C4H*0CAH

2DF3

CCCDD2

DB 0CCH

v0CDH, 0D2H

2DF6

D4DADC

DB 0D4H

,0DAH, 0DCH

2DF9

E2E4EA

DB 0E2H

, 0E4H, 0EAH

2DFC

ECF2F4

DB 0ECH

^0F2H,0F4H

2DFF

FAFC

DB 0FAH

,0FCH

2E01

SSTRT:

DS 02H

; SOURCE TOPCA)

2E03

SBOT:

DS 02H

..•SOURCE BOTTOM(B)

2E05

DTOP:

DS 02H

DESTINATION TOP(C)

2E07

START:

DS 02H

; START OF REF. FIXING CD)

2E09

SSTP;

DS 02H

;END OF REF. FIXINGCE)

2E0B

FUNC:

DS 01 H

;00 = REF. FIX ONLY CF);02=MOVE ONLY;01=MOVE 4 FIX

2E0C

DISPL:

DS 02H

; DISPLACEMENT

2E0E

STACK:

DS 08H

;MEM. SPACE FOR STACK

Hexadecimal

Code Operator

AF676F

XRAMOVMOV

Operand

AH,A

L,A

Meanwhile, back in the real world,the LXI problem will usually be en-countered by anyone relocating soft-ware. Going through a massiveassembly listing and manually fixingreferences would be a tedious andtime-consuming chore. Fortunately,the computer can be used to do the"grit" work.

A program that enables the com-puter to look through the machinecode for LXI operation codes is pre-sented in listing 2. I have called itFIXLXI, though corrections must stillbe made manually. However, thecomputer does the tedious job of find-ing LXI operation codes. Upon find-ing an LXI operation code, the com-puter outputs the address where theinstruction is located, followed by theoperation code (eg: 01 for LXI B), andfinally the 2-byte hexadecimal con-stant that is loaded into the registerpair. For compatibility with the ter-minal, all output is in the form ofASCII code. (The conversion frombinary to ASCII is done by a simpletable look-up procedure.)

For example, upon finding themachine code equivalent of LXID,21AEH at hexadecimal address24AB, the program will cause outputof the following:

24AB 11 21AE.

Afterward, control passes to themonitor and the operator consults thelisting to verify that the code is cor-rect. If not, a manual fix must be per-formed. (Using CP/M's Dynamic De-bugging Tool program as a monitormakes this an easy task. Simply typ-ing in S24AB to the terminal invokesa routine that displays both thememory address (24AB) and thememory contents (01) of the desig-nated location. It then waits for achange to be entered, a command tolook at the next memory location, ora command to quit.) When the pro-gram is reentered, the search for LXIoperation codes resumes at the nextoperation code following the pre-viously found LXI operation code.To operate FIXLXI you need only

184 January 1980 © BYTE Publications Inc

Circle 121 on inquiry card.

BYTE

BACK ISSUES

FOR SALE

The following issues are available:

1976: July, November

1977: March, May thru December

1978: February thru October, December

1979: January thru December except March

Cover price for each issue through August 1977 is $1.75 Domestic;

$2.75 Canada and Mexico; $3.75 Foreign. September 1977 through

October 1979 issues are $2.50 Domestic; $3.25 Canada and Mexico;

$4.00 Foreign. November 1979 to current is $3.00 Domestic; $3.75

Canada and Mexico; $4.50 Foreign.

Send requests with payment to:

BYTE Magazine

70 Main St, Peterborough NH 03458

Attn: Back Issues

F-

Use x, y Genesis

Applesoft: Subroutines for

jcippkz computer

Graphs.

-

+

yssflH+K 't

Y»BH*BKta*CXt3+K'

aflK + BtitE+K

DEGREE

1 3 3

S3, b -5. 56 -It 4

. 2533 B. 121 6. 815

— -. BEB -. Ill

— sriflu

11 BR. 464. 3 11R. 5

APPLICATIONS IN:

Engineering Physics MathematicsBusiness Education Stock Market

For more information:

Department E312514 UNIVERSITY DR.DURHAM, NC 27707[313] 489-7486

DATA TERMINAL EQUIPMENT — FROM MICROMAIL

SOROC IQ 120 $795.°°

• RS 232C, upper/lower case, fullASCII

• Numeric keypad, protected fields

• Cursor keys plus addressable cur-sor

• Auxiliary extension port

LA34 DECwriter IV

$1,199.°°

Upper/lower case, 9x7 dot matrix

10, 12, 13.2, 16.5 characters/inch

2, 3, 4, 6, 8 or 12 lines/inch

22"W x 7"H x 15V4"D, 25 lbs.

110 or 300 baud, RS 232C serial

ASCII

Friction feed, paper width to 15"

SOROC IQ 140 $1P250.00

• RS 232C and 20mA current loop

• Extensive editing features

• 25th line terminal status display

• 16 function keys (32 with shift)

Newfrom DIABLO

DIABL01640 $2,690.°°Receive-only $2,331.°°

High-quality daisywheel printing at45 cps.

DIABLO 1650 $ 2,779.°°Receive-only $2,419.°°

Metal daisywheel printing at 40 cps.

T.I. 810 printer $1,695.°°

• Includes upper/lower case

• 150 characters per second

• RS 232C serial interface

• Adjustable forms tractor

NEC Spinwriter

Call or write for prices

To Order: Send certified check (personal or company checks requiretwo weeks to clear) including handling* and 6% sales tax if deliveredwithin California.

"Handling: Less than $2,000, add 2%; over $2,000, add 1%. Everythingshipped freight collect in factory cartons with manufacturer's warranty.

clUJCRClMfiJL

MICROMAIL • BOX 3297 • SANTA ANA, CA 92703(714) 731-4338

Circle 122 on inquiry card.

BYTE January 1980

185

specify the starting address (SSTAR)and the ending address (SSTP) of thecode to be examined. In listing 2 thisinformation is entered at hexadecimaladdresses 2E42 and 2E44.

Employing the FIXLXI programwith a terminal operating at a datarate of 1200 bits per second (bps), Ifound that I could get through ourBASIC listing in less than two hours.Similar results were obtained when Irelocated another old assembler pro-gram.

Data Block Problems

It is not good programming prac-tice to place program constants in themidst of executable code. Unfortu-nately, this and other kludges are fre-quently found. However, you willfind in most cases that the programconstants are at least huddledtogether in a contiguous block. If thisis true, the data block can be moved,but no fixing of references should beperformed within the data block. Asindicated by Zolman, the procedurein this case is to perform the fixing ofreferences in two stages. First, pro-gram references are fixed in the pro-gram block up to, but not including,

Table 1: These six pieces of information must be entered into the locations shown(beginning at hexadecimal location 2E01 for listing 1) before a relocation can be per-formed with the modified relocator program.

Label

Numberof Bytes

Address

Comments

a

2

2E01,2E02

First address of block to be relocated

b

2

2E03,2E04

Last address of block to be relocated

c

2

2E05,2E06

Destination address

d

2

2E07,2E08

First address to have references fixed

e

f

2

1

2E09.2E0A

2E0B

Last address to have references fixed

00 = fix references onlyFunction select: 01 = move block and fix references02 = move block only

the data block. Then, skipping overthe data block, program referencesafter the data block are fixed for theremaining portion of the programblock.

In addition to the usual data blockproblems that have been mentioned,there is another difficulty en-countered when systems software isrelocated. The data blocks in anapplications program will normally

contain constants that are indepen-dent of the location of the program.In a systems software program likeBASIC this is not true for all con-stants. This is so because of the designlogic of an interpreter program.Essentially the interpreter works bycomparing an input command orfunction to a table of legal commandsor functions. If a match is found, con-

Text continued on page 190

New from Osborne 7 McGraw-Hill

Adam Osborne

foretells the Next Industrial Revolution

A revolution based on microelectronics. Will it prove tobe a dream or a nightmare? In his new book, Dr. Osbornetakes an honest look at the microelectronics boom; hescrutinizes what is happening today and predicts what wicertainly be happening tomorrow.

Running Wild—The Next Industrial Revolution

by Adam Osborne#28-4. $3.95

Running.

win)

PET®

Personal ComputerGuide

by C. Donahue & J. EngerNEW this Winter

Everything you always wanted to know about PET butCommodore didn't tell you. A practical guide to PET program-ming techniques, graphics, operation, and how to cope with those*&$! PET peculiarities. #30-6. S15.00

PET and the

IEEE 488

(GPIB) Bus

by E. Fisher and C. W. Jensen

NEW this Winter

'~^x This is the only complete guide available on interfacing PET to"\?)-yGPIB. Learn how to program the PET interface to control power7y supplies, signal sources, signal analyzers and other instruments.The book's full of practical information, as one of its authorsassisted in the original design of the PET GPIB interlace.

'PET is a registered Irademark of Commodore Business Machines #31-4. $1 >.00

m

<^

OSBORNE/McGraw Hill

630 Bancroft Way, Dept. B1, Berkeley, CA 94710

For credit card or phone order, call (415)548-2805

186 January 1980 © BYTE Publications In

S 10 7 <Circle 123 on inquiry card.

Circle 124 on inquiry card.

ANNOUNCING:

NEW!

Circle 125 on inquiry card.

MICROSTAT

A complete statistics package for business, scientific,education and research work. No other package hasthe features of MICROSTAT. For example:

• File oriented with COMPLETE editing

• A Data Management Subsystem for editing, sort-ing, ranking, lagging, data file transfers PLUS 11 datatransformations (e.g., linear, reciprocal, exponential,etc.) • Frequency distributions * Simple and multipleregression • Time series (including exponential smooth-ing) »11 Non-parametric tests • Crosstabs/Chi-square

• Factorials (up to 1,000,000!), permutations, combinations

• 8 Probability distributions • Scatterplots

• Hypothesis test (Mean, proportion) • ANOVA(one and two-way) • Correlation • Plus manyother unique features

Users manual: $10.00 (credited towards purchase)and includes sample data and printouts. UsesNORTH STAR BASIC 32K of memory, one or two diskdrives (2 recommended). Printer optional. Price: $200.00

1ECOSOFT „

master charge]

P.O. Box 68602Indianapolis, IN 46268

Phone orders:(317)253-6828

CP/M 2.0

Expand the horizons of your TRS-80model II with the industry standard oper-ating system, CP/M version 2.0, and getthese advantages overTRSDOS:

• compatible with hundreds of existingsoftware packages

• wide choice of programminglanguages: BASIC, PASCAL, FORTRAN,COBOL, C, ASSEMBLER, and others

• faster disk access

• more storage per diskette

• assembler, editor, file handler, anddynamic debugger included withthe operating system

Introductory price: $175 including manuals

H

X

</>

I

oo

o

OD

For full details about how CP/M 2.0 canimprove the performance of yourTRS-80model II, contact:

fgj^ PICKLES & TROUT

P.O. BOX 1206. GOLETA, CA 93017. (805) 967-9563CP/M is a trademark of Digital Research Inc. TRS-80 is a trademark of Tandy Corp.

Z-80/TRS-80 ™ Users

BOOK YOU'VE WANTED NOW CAN BE YOURS

THE Z-80: HOW IT WORKS

(THE PROGRAMMERS PERSPECTIVE)

By Monte Corum

Best Most Complete Reference Yet

cpu Operation Explained

Addressing Modes Demystified

Register Functions Described

Instructions Defined

Interrupts Diagrammed

Cycles Outlined Formats Described

Execution Described in Text,

Notation and Diagrams

Meaningful Analysis of 698 Commands

in Formatted, Usable Tables

Simple, Consistent Notation and Formats

A Programmer's Book, Beginner or Experienced

Ideal Text for Class Instruction

Pricse: $17.95 Plus Tax and Shipping

VISA & MSTRCHRG-NUMBER AND EXP. DATE

PREPAID WE SHIP

MICROWARE ASSOCIATES, INCORPORATED

9301 N. 58th St. DPT. AAA

SCOTTSDALE, AZ. 85253

DEALER INQUIRIES INVITED

'" TRS-80 IS A TRADEMARK OF TANDY CORP.

S-100, 6-PORT COMMUNICATIONS

nrmrm MM jPi -\

UtMlMI

If!) if

• INTERFACES MULTI TERMINALS, COMPUTERS,PRINTERS, MODEMS, ETC.

• 2,4, OR 6 CHANNELS;2 OPTIONAL RTC'S

• SELECTABLE 1/0 ADDRESS

• PROGRAMMABLE SYNC. CHARACTERS

• SYNC AND ASYNC

• HARDWABE ERROR CHECKING (CRC-16, CCITT)

• COMPLIES WITH: EIA RS-232C STANDARD; IEEEPROPOSED S-100 BUS STANDARD

FULL 6-PORT CONFIGURATION (ASSEMBLED ANDTESTED) $895.00

For information, contact: Dianne Polk (703) 893-4330 x 100

Inco, Inc.

7916 Westpark Drive D McLean, Virginia 22102

Circle 120 on inquiry card.

Circle 102 on inquiry card.

BYTE January 1980 187

Circle 127 on inquiry card.

SENSATION!

You have been reading about our astoundinghigh performance microcomputer products.Our X-9000 Pascal MICROENGINE"" CPU thatexecutes Pascal 13 x faster than an LSI-11and 3 x faster than a PDP11 -34. Our X-920CRT matches the features of the SOROC IQ140.Our X-800016-bit CPU addresses 8M bytesof memory directly and is coming soon!

'Trademark Western Digital Corporation

DISPLAY/EDIT TERMINALModel X-920

$920

$820 (Without 18 (unction keys)

STANDARD FEATURES (partial list)

• Microprocessor controlled

• Serial RS232C and 20 ma current loop

• 10 baud rates—75 to 19,200

• 24 lines x 80 characters

• 96 ASCII displayable characters

• Upper and lower case

• 12 x 10 character resolution

• Dual intensity display

• Clear full intensity data only

• Programmable reverse video

• Programmable underline

• 105 keys with alpha lock

• 14 key numeric pad with decimal

• 16 special function keys

• 8 edit function keys

• 2 block transmission keys« Self test mode

• Protect mode

• Block mode

• 80 storable tabbing

• Insert/delete character and line

• Scrolling

• Addressable cursor

• A host of other features, including cursor controlsand remote commands such as clear to nulls.spaces, end of line, end of screen; set hi,lo.zerointensity; set blink; etc.

• Optional screen print Si 2nd page memory

For our system or for yours, in commercial,technical, educational or personal applications,the Computex X-920 is unmatched in its class.

All features of the Hazeltine 1400 and ADM-3A

Plus: 128 ASCII characters...

7x10 matrix... Reverse

video... Print key...

Shiftlock ... Transparent

mode... Backspace...

Tabbing... Integrated

numeric pad.

$799

List price $9 5 6PERKIN-ELMER (Model 550)

Off the shelf delivery now on the Model X-920and P-E Model 550. Add 40 lb. shipping.Customer satisfaction is guaranteed.

Full refund with the return of any productwithin 10 days. X-9000 CPU $2995. PascalMICROENGINE" owners manual $19.95; X-920operators manual $10, postpaid. Cash prices.10% down guarantees priority. IL residents add5% sales tax. Master Charge and Visaaccepted.

Computex stands for competence. We servicewhat we sell. Written hardware warranty.Nationwide service contracts. Custom software.We provide expert technical support.

(312)684-3183

COMPUTEX

Microcomputer Systems ^

"The Computer Experts"5710 Drexel AvenueChicago, IL 60637

Listing 2: An 8080 program to facilitate the examination and correction of load X im-mediate (LXI) instructions. (Because of the multiple uses of the LXI instruction, therelocator program of listing 1 can, in certain circumstances, mishandle the 2 bytes of in-formation following the LXI code.) The program is designed to run with the DynamicDebugging Tool (DDT) of the CP/M software. Given the starting and ending addressesof a source program block, this program finds LXI operation codes. It then displays thefollowing information on the user's terminal: the memory address where the LXI in-struction is located; the operation code; the 2 bytes following the operation code. Con-trol is then passed to the monitor to allow the operator to make any needed corrections.Upon reentry the search for LXI operation codes is resumed at the next operation codefollowing the LXI operation code previously found.

2D00

ORG

2D00H

;SET ORIGIN

2D00

01182E

START:

LXI

B,TABL3

;B/C=table ptr

2D03

2A422E

LHLD

SSTAR

;D/E=memory ptr.

2D06

EB

XCHG

2D07

314E2E

LXI

SP/STACK+8

;intialize stack

2D0A

CDEB2D

CALL

BUSY

..•CHECK CRT STATUS

2D0D

3E0A

MVI

A/BAH

JUNE FEED

2D0F

D304

OUT

CRT

;to CRT

2D11

CDEB2D

CALL

BUSY

/CHECK STATUS

2D14

3E0D

MVI

A, 0DH

; CARR. RET

2D16

D304

OUT

CRT

;to CRT

2D1S

3A452E

CHEKF:

LDA

SSTP+1

;CHECK FOR END OF FILE

2D1B

92

SUB

D

2D1C

C2262D

JN2

NEXT

.-CONTINUE IF NOT

2D1F

3A442E

LDA

SSTP

2D22

93

SUB

E

2D23

CA9D2D

JZ

ENDF

;ouit IF END

2D26

1A

N EXT:

LDAX

D

;load MEM.contents using ptr

2D27

67

MOV

H/A

/•SAVE IN H

2D28

AF

XRA

A

;ZER0 ACCUM.

2D29

6F

MOV

L/A

;SET UP CNTR.

2D2A

2C

CO MP3:

INR

L

;bump CNTR

2D2B

7D

MOV

A/L

2D2C

FE1B

CPI

27D

iCHECK FOR END OF TABLE

2D2E

CA3A2D

JZ

AGAIN

;JMP IF THRU

2D31

0A

LDAX

B

J LOAD TABLE ENTRY

2D32

94

SUB

H

;C0MP. WITH CURR. MEM.

2D33

CA4F2D

JZ

MTCH3

;JMP IF MATCH

2D36

03

INX

B

;ELSE BUMP TABLE PTR.

2D37

C32A2D

JMP

C0MP3

J LOOK AGAIN

2D3A

01062E

AGAIN:

LXI

B,TABL2

JPTR HAS ADDR 2 BYTE OPS

2D3D

AF

XRA

A

;ZER0 ACCUM.

2D3E

6F

MOV

L/A

;SET CTR.

2D3F

2C

C0MP2:

INR

L

;bump CTR.

2D40

7D

MOV

A/L

2D41

FE13

CPI

19D

; CHECK FOR END TABLE

2D43

CA572D

JZ

NO MAT

;JMP IF THRU

2D46

0A

LDAX

B

/•LOAD TABLE ENTRY

2D47

94

SUB

H

;C0MP. WITH CURRENT MEM.

2 DA 8

CA562D

JZ

MTCH2

;JMP IF MATCH

2D4B

03

INX

B

JELSE BUMP TABLE PTR.

2D4C

C33F2D

JMP

C0MP2

;look again

2D4F

7D

MTCH3:

MOV

A/L

JFOUND 3 BYTE OP CODE

2D50

FE05

CPI

05D

;LXI'S FIRST FOUR IN TABL3

2D52

DA5E2D

JC

FDLXI

JIF L<«4 OP IS LXI

2D55

13

NO LXI:

INX

D

;N0T LXI IF HERE* SO

2D56

13

MTCH2:

INX

D

;M0V MEM. PTR. TO NEXT LOC.

2D57

13

NO MAT:

INX

D

2D58

011S2E

LXI

B/TABL3

;RESET TABLE PTR.

2D5B

C3182D

JMP

CHEKF

;C0NTINUE SEARCH

2D5E

7A

FDLXI:

MOV

A/D

/•FOUND LXI*PREP FOR OUT

2D5F

CDAD2D

AODR:

CALL

BYTE1

;0UTPUT 1ST DIQITlHI ADDR

2D62

7A

MOV

A/D

2D63

CDB52D

CALL

BYTE2

/•OUTPUT 2ND DIGIT:HI ADDR

2D66

7B

MOV

A/E

2D67

CDAD2D

CALL

BYTE1

/•OUTPUT 1ST DIGIT:L0 ADDR

2D6A

7B

MOV

A>E

2D6B

CDB52D

CALL

BYTE2

/OUTPUT 2ND DIGIT:L0 ADDR

2D6E

CDDC2D

CALL

SPACE

1 INSERT TWO SPACES

2D71

1A

0PC0D:

LDAX

D

2D72

CDAD2D

CALL

BYT El

;0UTPUT OPCODE BYTES

2D75

1A

LDAX

D

10 F LXI INSTRUCTION

2D76

CDB52D

CALL

BYTE2

2D79

CDDC2D

CALL

SPACE

1 INSERT TWO SPACES

2D7C

13

CONST:

INX

D

;D/E POINTS TO 16 BIT

2D7D

13

INX

D

/CONSTANT FOLLOWING LXI OP

2D7E

1A

LDAX

D

/'LOAD IT IN ACCUM.

2D7F

CDAD2D

CALL

BYTE1

/OUTPUT 1ST DIGIT OF CONSTAN-

2D82

1A

LDAX

D

/LOAD AGAIN (BYTE1 CLOBBERS)

2083

CDB52D

CALL

BYTE2

iOUTPUT 2ND DIGITCASCII CODE

2D86

IB

DCX

D

/•POINT TO 3RDJS4TH DIGITS

2D87

1A

LDAX

D

/'LOAD IN ACCUM.

2D88

CDAD2D

CALL

BYTE1

/■OUTPUT 3RD DIGIT

2D8B

1A

LDAX

D

;L0AD AGAIN

2D8C

CDB52D

CALL

BYTE2

/•OUTPUT 4TH DIGIT

Listing 2 continued on page 190

188 January 1980 © BYTE Publications Inc

Circle 128 on inquiry card.

Circle 129 on inquiry card.

VULCAN = DBMS

THE PROFESSIONAL DATABASEMANAGEMENT SYSTEM

For 8080/Z80 systems under CP/M or PTDOS

' VULCAN is a complete database management system that has38 powerful, easy to learn, English-like commands tomanipulate files, records, fields, and scratch-pad variables.

' VULCAN has a command repertoire which includes such com-mands as: SORT, REPORT, APPEND, INSERT, EDIT,COPY, REPLACE, LOCATE, DISPLAY, DO, LIST, andLOOP.

K VULCAN structured data records can be selectively chosen forprocessing using complex Boolean, string, or mathematical ex-pressions.

' VULCAN can be used in interactive or program mode. Theprogram mode uses modern structured command programs tocombine powerful DBMS operations.

' VULCAN is written in assembly language for efficient infor-mation processing and requires 36K bytes CP/M system andone or more disk drives.

1 VULCAN can accept or store data in standard ASCII files tobe compatible with BASIC, FORTRAN, etc.

*VULCAN (CP/M or PTDOS) $490

Manual only $ 25

SCDP

Software Consultation Designand Production

6542 Greeley St.Tujunga, CA 91042 (213) 352-7701

California residents add 6% sales tax.

Disc/3

MART, INC.

DO IT YOURSELF

LOW-LOW PRICES

ANADEX Printer, DP 8000 $ 845.00

CENTRONIX 730 Matrix Printer 825.00

(with 4 free zip pack ribbons)

HAZELTINE 1520 1319.00

IMS 16K RAM Memory Board 350.00

SOROC IQ 120 TERMINAL Assembled . . 795.00Tl "SILENT 700" PORTABLE PRINTERS

TI743(RO) 1095.00

TI743(KSR) 1250.00

Tl 994 Personal Computer 1150.00

CARTRIDGES • DISKETTES • MAG TAPEACCESSORIES

ADDS, CENTRONICS, HAZELTINE, IMSAI, LEAR

SIEGLER, TECHTRAN, Tl, VECTOR GRAPHICS

AND OTHERS

STORE HOURS: 9 A.M.-5:30 P.M. Mon. through Fri.

Call or write for quotes or information.

Disc/3

MART, INC.

1840 LINCOLN BLVD.,

SANTA MONICA, CA 90404

(213) 450-5911

•COLOR • GRAPHICS • SOUND•APPLE II ACCESSORIES-

APPLE SOFT BASIC CARD »155

OC HAYES MICROMOOEM '335

ALF MUSIC SYNTHISIZER »240

CORVUS 10 MEGABYTE DRIVE »4,650

APPLE OISK II '440

WITH CONTROLLER CARD .... "495PASCAL LANQUAQE SYSTEM. .'450INTEGER BASIC CARD '155

.

SD EXPANDORAM

•64K S-1 00 DYNAMIC RAM BOARD•WORKS WITH Z-80. 8080 S 8085•POWER CONSUMPTION 5 WATTS•BANK SELECT -PHANTOM REFRESH•NO WAIT STATES REQUIRED

WITHOUT MEMORY

_S149 00

.1?K KIT

4RKKIT

349 00

R4KKIT

409 00

ADD $50 FOR ASSEMBLED 8. TESTED

Ex 801 MicroPrinter $495Ex 820 MicroPlotter $795

WORKS DIRECTLY WITH APPLE, TRS-80 PET

'SILENT NON-IMPACT OPERA TION•160 CHARACTERS PER SECOND•80, 40 OR 20 COLUMNS PER LINE•RS232C/20MA OR PARALLEL ASC I I e«?

. TO ORDER .

Phone: orders if

J". (»<0 Mmnumj Wi hBn1l.-q ihipang Mr i>"Jict sic1insurance or equipment w4) be shipped ' i

Califomii'i residents add fA. safes tax: All equipment is: intit i'ii. ' 4ttnt><s with t i

r:: nubjeot iOi:iii:;it chtnm 'ind ai/yiisbiliiy: without <KrtwMm^/

master charge

OMPUTER SPECIALTIES

»I63 II CA JON Ol¥»., SUIT! MS.

Circle 130 on inquiry card.

BYTE January 1980 189

Listing 2 continued:

2D8F

CDDC2D

CALL

SPACE

;INSERT TWO SPACES

2D92

13

THRU:

tNX

D

;ADVANCE MEM PTR

2D93

13

INX

D

;TO NEXT OP CODE

2D94

01422E

LXI

B,SSTAR

;SAVE MEM PTR

2D97

7B

MOV

A,E

;to next loc.

2D98

02

STAX

B

;so can look for

2D99

7A

MOV

A,D

;next op code

2D9A

03

INX

B

;upon reentry

209B

02

STAX

B

;to prog.

2D9C

FF

RST

07

J GO manual control

2D9D

01 Ft 2D

ENDF:

LXI

B,MESGE-1

;FIND EOF MESSAGE

2DA0

03

LOOPO:

INX

B

;LOAD IT/BYTE AT A TIME

2DA1

CDEB2D

CALL

BUSY

;CHECK STAT OF CRT

2DA4

0A

LDAX

B

2DA5

D304

OUT

CRT

;put IT OUT

2DA7

FE4 8

CPI

*H*

-TILL END

2DA9

C2A02D

JNZ

LOOPO

-go to manual

2DAC

FF

RST

07

;CONTROL WHEN FINIS

OUTPUT SUBROUTINES •«•»•

2DAD

E6F0

BYTE1:

ANI

0F0H

.-MASK LEAST SIG. BITS

2DAF

47

MOV

B,A

;save IT

2DB0

AF

XRA

A

J SET FLAG-0

2DB1

CDBE2D

CALL

OUTT

;OUTPUT TO CRT

2DB4

C9

RET

.•RETURN FOR NEXT

2DB5

E60F

BYTE2:

ANI

0FH

;MASK MOST SIG. BITS

2DB7

47

MOV

B,A

;save

2DBS

AF

XRA

A

;a=0

2DB9

3C

INR

A

;SET FLAG-l

2 DBA

CDBE2D

CALL

OUTT

;OUTPUT TO CRT

2DBD

C9

RET

; MO RE7

2DBE

FE00

OUTT:

CPI

00H

;CHECK FLAG

2DC0

C2CB2D

JMZ

RESTR

J IF 01 BR AROUND

2DC3

78

MOV

A,B

iGET OUT BYTE

2DC4

IF

RAR

; SHI FT INTO

2DC5

IF

RAR

-LOWEST 4 BITS

2DC6

IF

RAR

;PREP FOR CONV

2DC7

IF

RAR

;to ascii

2DC8

C3CC2D

JMP

TYPOT

;CONVERT 4. OUTPUT

2DCB

78

RESTR:

MOV

A-B

iGET OUT BYTE

2DCC

6F

TYPOTi

MOV

LjA

;SET UP FOR CONV

2DCD

AF

XRA

A

2DCE

67

MOV

H,A

;0 IN TOP 8 BITS

2DCF

01322E

LXI

B.ASCTB

;LOAD ADDR TABLE IN B-C

2DD2

09

DAD

B

;get pos in table

2DD3

EB

XCHG

;SAVE D-E

2DD4

CDEB2D

CALL

BUSY

;CHECK STAT OF CRT

2DD7

1A

LDAX

D

/•LOAD CONV. VALUE

2DD8

D304

OUT

CRT

;put IT OUT

2DDA

EB

XCHG

J GET D-E BACK

2DDB

C9

RET

J RETURN FOR NEXT BYTE

2DDC

CDEB2D

SPACE:

CALL

BUSY

;CHECK CRT STAT

2DDF

3E20

MVI

A* * '

- SPACE

2DE1

D304

OUT

CRT

;to CRT

2DE3

CDEB2D

CALL

BUSY

;CHECK STAT

2DE6

3E20

MVI

A* ' '

;ANOTHER SPACE

2DE8

D304

OUT

CRT

;to CRT

2DEA

C9

RET

;•*•**

STATUS CHECK OF OUTPUT PORT «•»**

2DEB

DB05

BUSY:

IN

CRTS

;CHECK IF READY

2DED

IF

RAR

2DEE

D2EB2D

JNC

BUSY

2DF1

C9

RET

-•RETURN IF READY

2DF2

0A0D

MESGE:

DB 0AH,0DH

2DF4

454E44204F

DB 'END OF FILE SEARCH'

TABLES AND CONSTANTS *»*»*

2E06

060E16

TABL2:

DB 06H,0EH, 16H

; TABLE OF 2 BYTE

2E09

1E262E

DB 1EH,26H,2EH

;op CODES

2E0C

363EC6

DB 36H, 3EH..0C6H

2E0F

CEDED6

DB 0CEH..0DEH..0D6H

2E12

DBDEE6

DB 0DBH, 0DEH..0E6H

2E15

EEF6FE

DB 0EEH,0F6H,0FEH

2E18

011121

TABL3:

DB 01 H, 1 1 11*2111

J TABLE OF 3 BYTE

2E1B

312A22

DB 31H..2AH, 22H

;OP CODES.

2E1E

323AC2

DB 32H,3AH, 0C2H

-LXI INSTR. ARE FIRST

2E21

C3C4CA

DB 0C3H,0C4H,0CAH

2E24

CCCDD2

DB 0CCH..0CDH..0D2H

2E27

D4DADC

DB 0D4H, 0DAH* 0DCH

2E2A

E2E4EA

DB 0E2H,0E4H,0EAH

2E2D

ECF2F4

DB 0ECH..0F2H, 0F4H

2E30

FAFC

DB 0FAH, 0FCH

2E32

30313233

ASCTB:

DB 30H,31H,32H,33H ; TABLE OF ASCII

2E36

34353637

DB 34H,35H,36H,37H -EQUIVALENTS OF

2E3A

38394142

DB 38H,39H,41H,42H -NOS. 1-F HEX

2E3E

43444546

DB 43H*44H*45H*46H

2E42

SSTAR:

DS 02H

; START OF SOURCE

2E44

SSTP:

DS 02H

;end of source

2E46

STACK:

DS 08H

; SPACE FOR STACK

0004

=

CRT EQU 04

;CRT PORT

0005

=

CRTS

EQU 05

;CRT STATUS PORT

Text continued:

trol is passed to that routine withinthe BASIC code. This procedure isfrequently implemented by storingthe address of the desired routineimmediately adjacent to the com-mand (function). (Actually, sincecommands (functions) are not all thesame length (RESTORE is larger thanFOR), it is common practice to placea delimiter, such as 0, immediatelyafter the command (function). Theaddress of the proper routine thenfollows.)

Thus, after the system software hasbeen relocated and program refer-ences fixed, the command and func-tion table addresses must also befixed. These areas will usually beclearly indicated in the programlisting. Also, since the data that mustbe changed is reasonably small, amanual fix can be readily performed.The success of this process is depen-dent upon your knowing the new ad-dresses of the command (function)routines. Consequently, if a numberof shifts and/or additions must bemade, I would strongly suggest thatchanges and fixes be made one at atime. While this procedure requiresmore work, it is preferable to makingall changes at once, since it is easy tolose track of where everything islocated.

Caveat Emptor

After carefully implementing theprograms and following the proce-dures that have been outlined, youmay still find that your relocated soft-ware has glitches. Excluding piloterror, the source of any problems canlogically be only an improper refer-ence fix. While there may be manyways for this to happen, I have foundonly two species of software bugsthat create this problem.

The first, and potentially leasttroublesome, bug occurs when anisolated byte or two of data is buriedin the middle of executable code.With this particular gem I also founda call to a subroutine whose sole func-tion was to implement a jump overthe data! (I'm not making this up. Ireally did find this super kludge.)

If you are extremely lucky, the iso-lated byte(s) will not just happen tobe the same as one of the 2- or 3-byteoperation codes. In this case the relo-cator program will assume incorrect-ly that it is a 1-byte operation andcorrectly continue to search for3-byte operation codes. In the more

190 January 1980 © BYTE Publications Inc

Circle 131 on inquiry card.

NO FRILLS! NO GIMMICKS! JUST GREAT

DISCOUNTS

MAIL ORDER ONLY

HAZELTINE

1400 I

1410

Call

1420

> For

1500

Prices

1500(Kit) .... J

CENTRONICS

779-2

995.00

700-2

1350 00

703 tractor

2195.00

Micro Printer ....

395.00

730

975.00

NORTHSTAR

Horizon I assembled.

1629.00

kit

1339.00

Horizon II assembled.

1999.00

kit

1599.00

TELETYPE

Mod 43

995.00

INTERTEC

Superbrain

2195.00

DIGITAL SYSTEMS

Computer $4345.00

Double DensityDual Drive 2433.00

TELEVIDEO

912 .... ] Call

920 „For

I PricesDEC

LA34 1149.00

CROMEMCO

System III $1000 ott . . 4990.00

TEXAS INSTRUMENTS

810 Printer 1595.00

ATARI 800 . 795.00

ADDS Regent 25 CALL

Optima Cabinets (New) .... 99.955" Scotch Diskette. . . Box/29.958" Scotch Diskette. .'. .Box/34.95

Most items in stock for immediate delivery. Factory-fresh, sealed cartons.

DATA DISCOUNT CENTER

Box 100 135-53 Northern Blvd., Flushing, New York 11354, 212/465-6609

N.Y.S. residents add appropriate Sales Tax. Shipping FOB N.Y.BankAmericard, Master Charge add 3%. COD orders require 25% deposit.

T.D.Q.TAPE DATA QUERY

THE IDEAL SOLUTION FOR PERSONAL ANDVERY-SMALL BUSINESS DATA MANAGEMENT

PET-8K

TRS-80-LVL II

* COMPLETE CASSETTE FILE MANAGEMENT SYSTEM

-ENGLISH-LIKE COMMAND LANGUAGE

-REPORT GENERATOR

-UTILITY PACKAGE

-NO PROGRAMMING KNOWLEDGE REQUIRED

-REQUIRES 2 CASSETTE RECORDERS

• T.D.Q. APPLICATION CASEBOOK

-COMPLETE DIRECTIONS TO MICRO-COMPUTERIZE:

CUSTOMER DIRECTORYAPPOINTMENT SCHEDULINGVENDOR MASTER FILEPAYROLL JOURNALCHECKBOOK JOURNALTELEPHONE BOOKRENT COLLECTION$100.00**

• INVENTORY CONTROL •

• ACCOUNTS RECEIVABLE •

• ACCOUNTS PAYABLE •

• ORDER PROCESSING •

• LABEL PRINTING •

• CHECK PRINTING •

• INVOICE PRINTING •

"SPECIAL YEAR-END SALE PRICE

INCLUDES:

CASEBOOK; 2 CASSETTES; 3 USER'S MANUALS & REF. CARDS

ORDERS MUST BE RECEIVED BY IAN. II, I980

SEND CHECK OR MONEY-ORDER TO:

H. GELLER COMPUTER SYSTEMS

P.O. BOX 350

NEW YORK, N.Y. 10040

[N.Y RESIDENTS ADD SALES TAX)

«mt& sum

Published by Dalasouth Computer Corporation, 62','-f 'Minuet Lane, Charlotte, NC 28210.

For LA36 Owners, 1200 Baud Breakthrough

charlotte A spokesman for Data-south Computer Corp. confirmedreports of LA36 DEC writers* print-ing at blazing speed. WithDatasouth's DS120 Terminal Con-troller, the LA36 prints bidirection-ally at speeds up to 165 cps withtrue 1200 baud throughput. AlOOOcharacter internal print buffereliminates the need for fillcharacters.

Well-Endowed WithFeatures

Versatile performance featuresinclude complete forms control anddata formatting capability program-mable from either the keyboard ordata stream; plus both an EIARS232-C and 20mA Current Loopinterface.

Easy Installation

This blazing speed is accom-plished by replacing the LA36 logiccard with the DS120 unit—which

is fully compatible with existingelectronics.

Results Are In

As BAUD NEWS went to press,DS120's were providing enhancedspeed and versatility for more than3000 LA36 owners. The micro-processor-based electronics haveproven very reliable, and service,when needed, has been prompt andefficient. Of course, the DS120comes with a 90-day warranty onmaterials and workmanship.

Delivered Nationwide

Datasouth reports a network ofstocking distributors in major citiesthroughout the U.S. for promptservice and delivery. The spokesmanadded that he welcomes inquiriesand willgladlygiveyou all the detailson the DS120. He can be called at704/523-8500 or addressed atDatasouth's office, 627-F MinuetLane, Charlotte, N.C. 28210.

DEC is a registered trademark of Digital Equipment Corporation.Installation of the DS-120 will void any DEC warranty or service contract.

Circle 132 on inquiry card.

Circle 133 on inquiry card.

BYTE January 1980 191

usual case, the isolated byte will beidentical to a 2- or 3-byte operationcode. Then the possibility exists notonly for an improper reference fix,but also for a mangling of the opera-tion code(s). Fortunately, this mang-ling process is generally not self-propagating, so the damage is usuallylocalized.

The second, and potentially mosttroublesome, bug involves thewriting of relocatable code. While itmay come as a surprise, yes there issuch a thing as nonrelocatable code.To see that this is so, recall that therelocator program fixes references byoperating only on the 2-byte hexa-decimal constant following 3-byteoperation codes. Implicit in this pro-cedure is the logical assumption thatall references to program addresseswill be made via 3-byte operationcodes. Certainly this is the easiest andmost natural way to handle ad-dresses. However, it is possible to usethe 1- and 2-byte operation codes tomanipulate addresses.

As a case study of this particular"buggy" (and bugging) practice, Isubmit the verbatim example from alisting of an assembler program inlisting 3.

In this example the programmerneeded to load the character fol-lowing an operation code into theDE register pair without disturbing

the HL register pair. Without adetailed knowledge of other programconstraints, it is difficult to specify afoolproof fix for this code. Assumingno stack problems, appropriate sub-stitutions are suggested in listing 4.

Those wishing to write relocatablecode will avoid use of the program-ming practice illustrated in listing 3.(This is not an onerous requirement,since code that violates this conven-tion tends to be tortured andunnatural.) Those who, for pro-prietary or other reasons, wish towrite nonrelocatable code will liberal-ly sprinkle their code with suchexamples.

What To Do

At this point it is reasonable to askwhat can be done if you encounterone of the exotic bugs I have dis-cussed. Unfortunately, there is noquick fix that is generally applicable.However, the following guidelinesand suggestions may be helpful.

First, the source of the bug needs tobe isolated to an area less than thesize of the whole program. To dothis, study the actual operation of theprogram. For which commands orfunctions does the program fail?After this bit of detective work, exa-mination of the command or functiontable of your listing will tell youwhere to begin looking for the bug(s).

If nothing turns up at this point,the bug may be in a subroutine calledby the command (function) routine.Even worse, it may be in a subroutinecalled by the subroutine, etc.

Finally, if all else fails, it will benecessary to perform a step-by-steptrace of the operation of the program.At best this is a tedious process. If,however, you have isolated the bug,it is possible to set up a breakpointthat is activated only upon entry tothe program segment that is suspect.(A breakpoint works by causing pro-gram control to pass to the monitorwhen the breakpoint is encountered.Before the breakpoint is activated,program execution is performed atnormal machine speed.) With theDynamic Debugging Tool program ofthe CP/M system distributed byIMSAI, a single breakpoint can be setby temporarily replacing a byte of thesuspect software with the RST 07instruction (FF in machine code).After the monitor has control, youcan use it to generate a detailed traceof the program's operation for thesuspect area.

After this recounting of the perilsof relocating systems software, I hopethat the reader is not totally dis-couraged. For well-designed soft-ware, relocation can be easily man-aged using the relocator and FIXLXIprograms. ■

Hexadecimal Instruction

Address Code Mnemonic Operand

BDC4 3E F0 MVI A.ABUFF and OFFH

BDC6 80 ADD B

BDC7 5F MOV E,A

BDC8 3E D4 MVI A,(ABUFF and 0FF00H)/256

BDCA CE 00 ACI 0

BDCC 57 MOV D,A

BDCD 1A LDAX D

Commentary

;LOAD LOW BUFFER ADDRESS;ADD LENGTH OF OP CODE

;GET HIGH ORDER ADDRESS

;FETCH CHARACTER AFTER OP CODE

Listing 3: An example of poor programming practice. In this example, the programmer has loaded theDE register pair without disturbing the HL register pair. However, because the reference to the addresshexadecimal D4F0 is done via 1 and 2-byte op code, this machine is not machine relocatable.

Hexadecimal Instruction

Address

Code

Mnemonic

Operan

BDC4

11 F0 D4

LXI

D.D4F0

BDC7

E5

PUSH

H

BDC8

68

MOV

L,B

BDC9

26 00

MVI

H,00

BDCB

19

DAD

D

BDCC

EB

XCHG

BDCD

E1

POP

H

BDCE

1A

LDAX

D

Commentary

;LOAD BUFFER ADDRESS

;SAVE H,L PAIR

;GET LENGTH OP CODE

;PAD WITH ZEROS

;ADD LENGTH TO BUFFER

;PUT RESULTS IN D,E

;GET H,L BACK

;FETCH CHARACTER AFTER OP CODE

Listing 4: Another method of performing the operation shown in listing 3. Here the reference to theaddress hexadecimal D4F0 is done using the LXI op code. This code is machine relocatable.

192 January 1980 © BYTE Publications Inc

Circle 134 on inquiry card.

j HEAVY DUTY COUPLER

Crystal control punches through rain-soaked,muddy lines to grab weakened signals.

Heavy duty rubber cups hold fast... knock outnoise.

Torture testing boosts reliability above 99%.

DATEC Heavy Duty couplers are guaranteed.

We're building our reputation on acousticcouplers. We've got to build them better.

1

Datec Incorporated300 E.Main StreetCarrboro;N.C. 27510(919)929-2135

DATEC 30 originateonly. DATEC 3? orig-inate and answer.Full or half duplexswttchable. 0-300BPS.

CP/M SOFTWARE

Word Processing For CP/M

FMT Text Formatter S75

Use FMT and your text editor to convert your CP/M system to apowerful word processor. FMT features include automatic pageheadings and footings, page numbering, centering, underscoring,external file merging, and in-line console input. FMT works with anyvideo, CRT, or hardcopy terminal and printer combination. Addedcapabilities for daisy-wheel printers: superscripting, subscripting, andhalf-line spacing.

Run Cromemco Software Under CP/M

ADAPT Software Interface S50

Now you can get Cromemco software to run on your CP/M system.ADAPT interfaces those powerful Cromemco packages (except forMulti-User BASIC] to any CP/M Version 1.4 system without patching.ADAPT works without changes for any memory size.

Fast RATFOR

RATFOR (RATional FORtran) 595

RATFOR lets you write structured code that translates to Microsoft orCromemco FORTRAN. TSW's RATFOR (RATional FORtran]precompiler runs at more than 1000 statements per minute.Documentation includes "Software Tools" book by Kernighan andl'lauger. |ADAPT and RATFOR packages combined S125)

THE SOFTWARE WORKS

8369 Vickers

San Diego, CA 92111

|714| 569-1721

rademark of Digital RettWh

WE ARE KNOWN FOR OUR PROMPT,COURTEOUS SERVICE

• HAZELTINE CRT's •• NEW, LOW PRICES •

1500 (assembled) $885.

1510 $980.

1520 $1,210.

50 Hz option available for all models $100.

German, French, Danish character sets $30.

TELETYPE MODEL 43

4320 AAA (TTL interface) $985.

4320 AAK(RS232 interface) $1,085.

with transformer to operate on 50 Hz., 220 v.

installed inside cabinet $75.

PAPER TIGER $950.

Graphics option, add $199.

198 cps. 8 software selectable character sizes, adjustabletractor, plain paper, Impact, dot matrix printer. Anoutstanding value!

DECwriter 35/36 upgrade sPecs availableINCREASE BAUD RATE TO 1200 $750.

IMS 5000 and IMS 8000 Complete Z80 systemsstarting at $2,050. 4 I/O ports, 1K EPROM bootstrap loader,double density drives, 51/4 or 8" disks. S-100 bus. 12 slotmainframe. A beautiful, high quality system. Runs CP/M.

INTERTEC SUPER BRAIN $2,885.

Dual Z80, dual double density floppies, 32K RAM(expandable) 4Mhz., CP/M, Contained in Intertube II.

INTERTUBE II $875.

SOROC IQ 120 $865.

IMS 16K Fully static memory, 250 ns $285.

MARINCHIP SYSTEMS 9900 16 BIT CPU

Price includes DOS, BASIC, word processor, text editor,

linking loader Assembled $700.

Kit $550.

Complete systems configured from $5,700.

DRIVES

SIEMENS 8"double density, Shugart compatible .... $450.

PER SCI 277 $1,200.

299B $1,700.

INNOTRONICS 2 drives with cabinet and power ... $1,565. Shugart compatible. Extremely reliable.

CONTROLLERS:

Tarbell single density $255.

double density $380.

Konan S-100, hard disk controller $1,550.

TEI Mainframes completely tested and assembled

12 slot $433.

22 slot $609.

MODEM: "THE CAT" from Novation $190.

Originate/answer, 300 baud. Incredibly compact!

CENTRONICS, TEXAS INSTRUMENTS,PRINTERS, DIABLO, NEC SPINWATER, DECLA 34, PET, TRS-80 ALSO AVAILABLE.

TO ORDER: We ship within 24 hours of receipt of certifiedcheck, bank check or money order. Credit cards add 4%.Personal checks: allow ten days.

COD'S ACCEPTED AT NO EXTRA CHARGE.Shipping charge: $13. for terminal, $4. for memory, modems.N.Y. residents add sales tax. Prices and availability subject tochange without notice. DEALER INQUIRIES INVITED.

WE EXPORT TO ALL COUNTRIESOVERSEAS CALLERS USE (212) 448-6298 ORTWX: 710 588 2844 CABLE: OWENS ASSOC.

We have no reader inquiry number.Please call or write. Product sheets available.

john d OWENS ASSOCIATES, inc.

12 SCHUBERT STREET

STATEN ISLAND, NEW YORK 10305

(212) 448-6283 (212) 448-6298

Circle 135 on inquiry card.

Circle 136 on inquiry card.

BYTE January 1980 193

U.S. ROBOTICS, INC.

Tabs

132 columns

10. 12, 13.2. 16.5

characters/inch

2. 3. 4. 6. 8 or 12 lines/inch

Optional tractor feed

LA34

DECwriter IV

$1199.00

110 or 300 baud

RS232C/ASCII

Friction feed/up to 15" wide

paper

9x7 dot matrix, impact

printing

Upper/lower case

Teletype

Model 43 KSR

$1049.00

• 110 or 300 baud

• RS232C/ASCII

• Pin feed/8 V-." H x 11" Wpaper is perfect for filingand copying.

132 columns

Upper/lower case, true

descenders

Dot matrix, impact printing

Shiftlock Key

Print Key

Integrated Numeric Pad

Editing Functions

Extremely Compact:

15" W x 19" D x 14" H

Silent fan-free operation

The 550 BANTAM

from Perkin-Elmer$799.00

All the features of theHazeltine 1400 &LSI ADM-3A plus

• Upper/Lower Case

• 7x10 Character Matrix

• White or Black Characters

• Transparent Mode

• Addresable Cursor

• Tab Function

• Backspace Key

PENRIL 300/1200MODEM

Originate/Auto-Answer$799.00

• RS232

• Full duplex over voicegrade phone lines

• 1 year warranty

• Stand alone

0-300 or 1200 baudBell 212A & 103/113compatible

FCC certified for directconnection to phone linesvia RJ11C voice jack(standard extensionphone jack)

USR-300 Series

USR-310 Originate

USR-330

Originate/

Auto-Answer

Acoustic Coupler$159.00

• 0-300 Baud

• Bell 103/113 compatible» Stand Alone

• RS232

• 1 Year Warranty

• Crystal Controlled

• State of the Art LSI circuitry

• 5 stage active filters

Modem$339.00

FCC certified for directconnection to phonelinesviastandard extension phonejack.

USR-320Auto-Answer Modem$319.00

U.S. ROBOTICS, INC.

Sales

General Offices

Service

1D35 w. LAKE ST.

CHICAGO, ILL. 6D6Q7

(312) 733-0497(312)733-0498(312)733-0499

Blubs and Newsletters

Hobby Computer Club ofHolland (HCC)

The HCC now has over3000 members in 12 localgroups which meet on amonthly basis. Theywelcome information on allaspects of microcomputingand currently are in need ofinformation on hardwareand software for the AppleII. Contact the HCC,Christinalaan 171, Eind-hoven, NETHERLANDS.

Home Software

Exchange's Program

of the Month Club

This club offers an oppor-tunity for persons who ownsmall computers to buy andsell cassette computer pro-grams. Upon joining, eachmember receives a yearlycatalog of all programslisted on the exchange andmonthly newsletter updates.A $2 royalty fee is giveneach time a member's pro-gram is purchased. Member-ship dues are $6 per year.To join send the member-ship dues and the programsyou wish to list on cassetteswith a listing of the programand a short description.

Contact the Home Soft-ware Exchange, 1716 DixieDr, Jackson MS 39209.

ComputerizedInvestments Club

The purpose of this clubis to trade ideas, data, andprograms related to thestock, option, and com-modity markets. Club pro-jects include the develop-ment of computerizedtrading and investmentsystems, and the develop-ment of a shared data base.

Write to Computerized In-vestments Club, R D 1 Box138, Sicklerville NJ 08081.

Videodisc News

This monthly newsletter isdesigned for readers in com-munications, education,television, audio and visualproduction, informationstorage and retrieval,microcomputers, and homevideo entertainment. Articleswill cover newdevelopments in softwareand hardware, competitivecomparisons, conferencesand services, and more.A special subscription rateof $95 per year is availableto BYTE readers.

Contact Subscriber Ser-vices, Videodisc News, POB5340, W BloomfieldMI 48033.

Medical ComputerJournal

MCJ is a newsletter that isdevoted to informationabout computers and theiruses in the daily practice ofprivate physicians. Issueswill cover the most commonillnesses and the use of com-puters in dealing with them,computer systems,laboratory test interpretationand analysis using com-puters, and ideas for theuses of computers in offices.

Subscriptions are $15 peryear. For information, con-tact Dr Aziz Ghaussy, editorof the MCJ, 42 E High St,E Hampton CT 06424.

Computer Newsletter forEngineers

Engineering ComputerApplications Newsletter(ECAN) is being publishedmonthly to inform and ad-vise engineers on how to useadvanced computertechnology and increase pro-ductivity and profits. ECANwill contain articles on small

194 January 1980 © BYTE Publications Inc

Circle 137 on inquiry card.

computers, peripheral equip-ment, engineering programs,combining large and smallcomputers, graphics inengineering design, andmany other topics. Subscrip-tions are $36 per year. Con-tact ECAN, 5 Denver TechCtr, POB 3109, EnglewoodCO 80111.

Crescent CityComputer Club

This club meets once amonth in a general meetingand they also have monthlymeetings for their specializedgroups. Their meetings areheld at 8 PM in room 2120of the University of NewOrleans Science Bldg, on themain campus. The club alsopublishes a newsletter thatcovers the events of themeetings.

Contact the Crescent CityComputer Club, POB 1097,University of New OrleansLA 70122.

Arcadian Newsletter

This newsletter has ar-ticles concerning variousaspects of computing. Pro-grams, schedules of events,corrections of programs, andgeneral information itemsappear. Ads are welcome,and the latest issue includedan item from the editorlooking for reviews of soft-ware programs.

Contact Arcadian, 3626Morrie Dr, San JoseCA 95127.

Apple Canada UsersGroup

This new group has beenmeeting on the first Wednes-day of every month at theComputerland/Torontostore, 2180 Yonge St,Toronto, Ontario Canada.The meetings begin at7:30 PM.

Contact Apple-Can, 2180Yonge St, Toronto, OntarioM4S 2B9 CANADA.

Heath Users Group(HUG) Newsletter

REMark is a HUGmembership magazinepublished quarterly formembers only. The news-letter contains articles onprogramming, expanding thecapabilities of Heath com-puters and items of generalinterest. Subscriptions are$14 a year and should besent to the Heath Users'Group, Hilltop Rd, StJoseph MI 49085.

Sphere Newsletter

The Sphere Microcom-puter Newsletter containshardware and softwarefeatures of interest to M6800microcomputer owners andmore specifically to Sphereowners. The newsletter ismailed 6 times a year. Thesubscription rate is $12 andshould be addressed toJeffrey Brownstein, 2 TorRd, Wappingers NY 12590.Material for publicationshould be sent to coeditorRoger J Spott, 13975 Con-necticut Ave, WheatonMD 20906. ■

BYTEs Bogs

Like All Modern Vehicles— The Cost Goes Up

George, the program-mable toy van fromBeneficial Marketing, waslisted in the November issueas costing $24.95. Thisshould read $39.95. ■

DYNACOMP

Quality software for:

Apple II PlusTRS-80 (Level II)North Star

All software is supplied with complete documentation which includes clear ex-planations and examples. Each program will run with standard terminals (32characters or wider) and within 16K program memory space. Except wherenoted, all software is available on North Star diskette (North Star BASIC orMicrosoft BASIC for those North Star systems running under CP/M), TRS-80cassette (Level II) and Apple cassette (Applesoft BASIC). These programs arealso available on PAPER TAPE (Microsoft BASIC).

FLIGHT SIMULATOR

(as described in SIMULATION, Volume II)

A realistic and extensive three-dimensional simulation of take-off, flight and landing.The program utilizes aerodynamic equations and the characteristics of a real airfoil.You can practice instrument approaches and navigation using radials and compassheadings. The more advanced flyer can also perform loops, half-rolls and similaraerobatic maneuvers.

Price: $17.95 postpaidSIMULATION, Volume I

(BYTE Publications): $6.00

VALDEZ

A simulation of supertanker navigation in the Prince William Sound and ValdezNarrows. The program uses an extensive 256X256 element radar map and employsphysical models of ship response and tidal patterns. Chart your own course throughship and iceberg traffic. Any standard terminal may be used for display.

Price $14.95 postpaid

BRIDGE 2.0

An all-inclusive version of this most popular of card games. This program both BIDSand PLAYS either contract or duplicate bridge. Depending on the contract, your com-puter opponents will either play the offense OR defense. If you bid too high the com-puter will double your contract! BRIDGE 2.0 provides challenging entertainment foradvanced players and is an excellent learning tool for the bridge novice.

Price: $17.95 postpaid

HEARTS 1.5

An exciting and entertaining computer version of this popular card game. Hearts is atrick-oriented game in which the purpose is not to take any hearts or the queen ofspades. Play against two computer opponents who are armed with hard-to-beat play-ing strategies.

Price: $14.95 postpaid

MAIL LIST I NEW

A many-featured mailing list program which sorts through your customer list by user-defined product code, customer name or Zip Code. Entries to the list can be con-veniently added or deleted and the printout format allows the use of standard sizeaddress labels. Each diskette can hold approximately 900 entries.

Price: $18.95 postpaid {available for North Star only)

TEXT EDITOR I (Letter Writer)

An easy to use, line-oriented text editor which provides variable line widths and simpleparagraph indexing. This text editor is ideally suited for composing letters and is quitecapable of handling much larger jobs.

Price: $14.95 postpaid

COMPRESS

Make your BASIC programs run faster and use less memory! In many cases you canreduce the size of your programs by 30% or more, while improving execution speed bya comparable amount. Save money by storing more programs on each diskette orcassette.

Price: $9.95 postpaid

GAMES PACK I NEW

Seven entertaining games for less than a dollar a kilobyte! Play CATAPULT, CRAPS,SWITCH, HORSERACE, SLOT MACHINE, BLACKJACK and LUNAR LANDER.This is an excellent way to introduce your children to computers.

Price: $10.95 postpaid

All orders are processed within 48 hours. Please enclose payment with order. If paying byMASTER CHARGE or VISA, include all numbers on card. Foreign orders add 10% forshipping and handling.

Write for detailed descriptions of these and other programs available from DYNACOMP.

master charge

DYNACOMP

P.O. Box 162

Webster, New York, 14580

New York State residents please add 7% NYS sales tax.

Circle 138 on inquiry card.

January 1980 © BYTE Publications Inc 195

SPRING 1980

10001010111O101OOOOOOO1OQOO1011111010001010101111

JAM€S MARTINS€MINAR

10001010111010100000001000010101111101000101011101

Future Strategy,Management,& Design for:

■ Distributed Processing

■ Data Base

■ Networks

■ Corporate Strategy

Atlanta

Feb. 25-29

San Francisco

March 17-21

New York

March 17-21

Chicago

March 24-28

CALL OR WRITE: (213)476-9747

P.O. BOX 49765, LOS ANGELES, CA.90049 (213)476-9747

BYTE's Bits

A New System forMedical Data Processing

The Computer Center Inc,433 Valley Ave, BirminghamAL 35209, is marketing theDoctors Office ComputerSystem (DOCS). DOCSorganizes precise methods tocontrol cash flow and hasthe capability to handle alldoctors' medical and finan-cial bookkeeping needs in asingle system. The presentpackage processes chargeand payment entry, patientstatements, insurance billing,Medicare and Medicaid sub-mittals, collection agencyreferrals, and the patientaccounting system identifiesunpaid charges by age,amount, and percentage ofpayment. Additionally, thepatient accounting systemhandles patient admissionupdates, records, andappointments.

DOCS is designed to runon an Alpha Micro 100,with a minimum of 64 Kmemory and is currentlybeing adapted for use onTexas Instruments andHewlett-Packard systems.To install DOCS, a medicalgroup can expect to investfrom $35,000 to $70,000 forhardware and software.

Call for Papers

On August 27-28, theIEEE Computer Society willsponsor the SecondWorkshop on Picture DataDescription and Manage-ment in Asilomar, Cali-fornia. This conference willaddress the problems ofstorage, retrieval andmanipulation of pictures ofgreat complexity and oflarge numbers of pictures.Papers on pictorial informa-tion systems, applications ofpictorial data bases, picturesyntax and semantics, com-binatorial problems in imagedata structures, data struc-tures for image data mange-ment, computer graphics of

complex images and anima-tion, irnge stores, computerarchitecture for picture pro-cessing, and other topics arebeing solicited. To submitpapers, please send fourcopies to Professor S KChang, Program Chairman,1980 PDDM Workshop,Dept of InformationEngineering, University ofIllinois at Chicago Circle,POB 4348, Chicago IL60680.

Word Processor Cuts

Hospital Paperwork

Costs

Due to annual hospitalcost increases and theescalating requirement forpaperwork of governmentagencies, insurance com-panies and other groups,hospital paperwork isexpanding constantly.

Burroughs Redactronword processing equipmenthas powerful text editing,formatting, file managementand arithmetic capabilities topartially or completelyautomate the completion ofMedicaid forms, patientrecords of all kinds,laboratory results andpatient correspondence, aswell as other hospital relateddocuments; so that paper-work is handled quickly,accurately and at a lowercost.

Tufts-New England andthe Presbyterian Hospital ofDallas, are using thesesystems to facilitate accurateand economic preparation ofpatient discharge summaries,for surgical reports, toupdate pharmaceutical in-ventories, controlling andprinting tests and testresults, and much more. Theuse of the system hasresulted in more efficientand economical use of timeand attention in hospitalsand laboratories. For moreinformation, contact Redac-tron Corp, 95 Horse BlockRd, Yaphank NY 11980.

196 January 1980 © BYTE Publications Inc Circle 139 on inquiry card.

Circle 140 on inquiry card.

TEXAS INSTRUMENT CUMF'

T I ?9 4 CIJHt-UTT H

♦ VvS.

TI BIO RAMC PRINTER

« r~j9 0.

11 B 2 0 b rt S I C PR IN 1 Eft

« 1 9 9 0 .

Tl SOFTUARE

♦ SAVE

CENTRONICS PRINTERS

? T1- 2 IROC. F ['

*949 .

? 7 ? - 1 F R I C . F Ii

«B90.

730-1 NEU PRNTR

»799.

730-3

i849 .

MICRO PI 1390. NICftI) Bl

• -47S.

COMHOI'OKE BUSINESS machines

pet :0 0 1 -B K

167S.

PET 2001 - 16N , P

«B59 .

F'ET 2001-32N.R

»IO'/0.

PET 2040 DUAL FLOPPY

«IO90

PEI 2022 TRAC.FD PRINTER

• B49.

PET 2023 FR1C.FH PRINTER

»749.

NORTH STAR COMPUTERS

BIG tl SAVINGS

INTERTEC SUPERI'KAIN

THE HONOR GRADUATE CUNIUIEK

129Y0

IiISf'LAT TERMINALS

INTERTUBE II

• 775

HAZELTINE 1400

♦ 490.

1410

♦ 783

1500

♦ 950.

1510

♦ 1 149.

MULTI-BUSINESS COMPUTER SYS

TEMS

29 MARLBOROUGH STREET

■■J" PORTLAND, CONN. 04460

MM

(2031 342-2747

FIELD ENGINEERS

Never sell yourself short!If you fix computers and theirperipherals, and it is time for a jobchange, let

FIELD SERVICE

SEARCH

locate the best opportunities foryou. Employer pays fees. Callcollect (312) 398-5535.Address:

FIELD SERVICESEARCH

925 E. Rand Road

Arlington Heights, IL 60004

Private Employment Agency

SURPLUS ELECTRONICS

Circle 141 on inquiry card.

Learn FORTH

FORTH is a structured high level language thatdramatieally cuts program development time. Youcan expand the FORTH language by defining newoperations and data types. FORTH programs arccompiled to reduce memory space and speed execu-tion.

tinyFORTH is a complete version of the powerfulFORTH language tailored to the TRS-80. ThetinyFORTH system includes FORTH, a text editor,an assembler, graphics, and cassette I/O.Learn FORTH on your own computer. ThetinyFORTH user's manual contains hundreds ofexamples to leach you FORTH in a hands-on style.tinyFORTH for 16k level II TRS-80:

Cassette and full documentation $29.95

Documentation only $ 9.95

All orders are fully guaranteed. And $1.50 forpostage and handling. Order with check, moneyorder. Visa, or Mastercharge.

Write for a FREE booklet describing FORTH.

The Software Farm

Dept. A14

Reston, VA 22090

ASCII

ASCII

IBMSELECTRIC

BASED I/O TERMINAL

WITH ASCII CONVERSION

INSTALLED $645.00

• Tape Drives • Cable

• Cassette Drives • Wire

• Power Supplies 12V15A, 12V25A.5V35A Others. • Displays

• Cabinets • XFMRS • HeatSinks • Printers • Components

Many other items, SEND $ 1.00 FOB CATALOGREFUNDABLE FIBST ORDERWORLDWIDE ELECT, INC.130 Northeastern Blvd.Nashua, NH 03060

Phone orders accepted using

VISA or MC

Call 603-889-7661

Circle 142 on inquiry card.

New fromVantage Data Products

550 West 200 South

Suites

•Provo,Utah 84601

(801)377-6687

Communications/Control CPU Card

•CPU-Z-801KRAM16 bit interval timer and interruptEPROM • 2708 standard (2716 optional)

•Serial CommunicationsRS-232 interface,UART Complete MODEM capability,programmable baud rates, etc.

• Parallel I/O -16 bits in (TTL), 16 bits Out (TTL)

•Power - on and external reset•EPROM not included

$195 assembled, tested, with warranty anddocumentation

Immediate delivery from stock!

All orders shipped prepaid

MC, VISA, phone orders welcome

Utah residents add 4Wsales tax

Circle 143 on inquiry card.

Circle 144 on inquiry card.

Circle 145 on inquiry card.

CROMEMCOSYSTEMS

DISCOUNTED

System 2 with 64k RAM—$3195

System 3 with 32k RAM—$4795

with 64k RAM—add $ 595

Discounts up to 20% on most Cromemcohardware. We carry the full Cromemco line.

TORREY PINES BUSINESS SYSTEMS

14260 Garden Rd„ Suite 8A

Poway, California 92064

(714) 486-3460

California residents add 6% sales tax

$ MINI FLOPPY AT $$ STORE DISCOUNT $

SINGLE SIDED-$225.00DOUBLE SIDED-$345.00

CABINETS-CABLES ANDPOWER SUPPLIES AREALSO AVAILABLE

INTERFACE,INC20932 CANTARA STCANOGA PARK.CA 91304

(213) 341-7914

16 K RAMS & RAM CONTROLLERS

16KX1 DYNAMIC RAMS mkiti6P3

• 200 NSEC ACCESS/375 NSEC CYCLE TIMES

• 16 PIN/TTL COMPATIBLE

• ALL CHIPS BURNED IN AND FULLY TESTED

• PRICE WITH DATA SHEET

S68.00 IN OTY OF 8/THAT'S S8.50 EACH

MAKE 64K BYTE MEMORY FOR YOUR 6800 OR 6502THIS SET INCLUDES

• 32 M5K 41163. 16< X 1. 200 NSEC RAMS

• 1 MC3480 MEMORY CONTROLLER

• 1 MC3242A MEMORY ADDRESS MULTIPLEXERAND COUNTER

• DATA S APPLICATION SHEETS PARTS TESTEDAND GUARANTEED

S295 00 PER SET

DYNAMIC MEMORY CONTROLLER Kami

• GENERATES RAS/CAS & REFRESH TIMING FOR16KT0 64K BYTE MEMORIES

. PRICE WITH DATE SHEET S13 95 EACH

TEMOR77DTHlsTMu77cOuNTERm?««r

• MUX ADDRESS & REFRESH COUNTER FOR 16K TO64K BYTE MEMORIES

• PRICE WITH DATA SHEET: S12 50 EACH

DUANTITY DISCOUNTS AVAILABLEftU ORDERS PUSIPAIIJ US FUNDS UN INTEHNATID.'IAIUHUEHS CHECK GR MONET ORDER VISA BA MC A1SU ACCEPIEU SENOACCT HO EXPIRATION UAIE R INTERBANKNO WITH SIGNED ORDER CAUF RES1DENFS PLEASE ADD6*t SALES TAX PRONE ORDERS <' 14i 633 4460

MEASUREMENT SYSTEMS & CONTROLS, INC

MEVDRi DEVICES DIVISIONSET N0R1H MAIN ST ORANGE CA 32668

Circle 146 on inquiry card.

Circle 147 on inquiry card.

Computer ChessCompetition

Chess 4.9, the programwritten by David Slate andLarry Atkin of North-western University, regainedthe title of North AmericanComputer Chess Championin the tournament heldduring the convention of theAssociation for ComputingMachinery (ACM) inDetroit, Michigan fromOctober 28 to October 31,1979.

Slate and Atkin's program(then called Chess 4.7) wasupset in the 1978 champion-ship by the program Belle,written by Ken Thompsonof Bell Laboratories. Bellewon the 1978 competitionwith a perfect score of fourwins in the 4-round SwissSystem tournament. (See"Computer Chess Report,"May 1979 BYTE, page 174.)

In the 1979 Tenth AnnualNorth American ComputerChess Championship,however, Belle suffered asetback in the third round of

o

■o•ao

3

3

3

Mil

Player

O

orCD

u>w

03B

5"

a

co

ITCD0)

en

o

0)

o

r

CDX

o

CD

J5'c<D

2-<o

CDWCA

2

en

CO

w

CD—iCQOTD

N>

in

o

—1

o'

=r

00

o

>

CDCO

a>

33

c

cw

Score

Chess 4.9

\

y2

1

1

1

3V*

Belie

Vi

\

Vi

1

1

3

Duchess

0

\

1

1

1

3

Chaos

Va

0

\

1

1

2Vz

L'excentrique

0

\

Vi

1

1

2Va

Mychess

*\

0

1

1

2V4

Blitz 6.9

0

0

V2

1

iy2

Sargon 2.5

0

0

1

Vz

1%

Ostrich 80

0

0

Vi

1

1V4

Awit

0

0

Vi

\

1

11/2

BS '66 '76

0

0

0

\

1

1

Rufus

0

0

0

0

\

0

Table 1: Cross-table of the results of games in the Tenth AnnualNorth American Computer Chess Championship, held October28 to October 31, 1979 in Detroit, Michigan. The table containsblank entries, since each program did not play every other pro-gram in the 4-round Swiss System event.

competition when the Chaosprogram (written by MikeAlexander, Fred Swartz,John O'Keefe, and Victor

Berman of the University ofMichigan) fought Belle to adraw. The hopes of Belle'sbackers were further dashed

TURN-ON!

Now have full computer control of up to 256 lights, appliances and even wallswitches without special wiring. The SciTronics REMOTE CONTROLLER permitsdirect control of the inexpensive BSR remote line-carrier switches sold by Sears,Radio Shack and many others.

HOW IT WORKS: Writing 3 control words to the controller board sends one of 6 in-structions over the a-c line to the desired switch. The instructions include anyremote on, off, all off, any light bright, dim, or all on. Reading the board tells ifbusy.

FEATURES:

FULL S-100 COMPATIBILTY—all lines fullybuffered, board address dip switch select-able to span 65K.

FULL TRS-80-1 COMPATIBILITY —boardhoused in attractive woodgrained case withpower supply and connector cable allowsdirect connection to TRS-80-I expansion port.COMPATIBLE WITH OTHER SYSTEMS—com-bination of on-board select switches and

complete connector wiring informationallows ease of use with Apple II, PET, KIM,SYM, HEATH H8, plus others.SYSTEM SELECT SWITCHES—chose activehigh or low inputs, addressed or I/O drive,parallel or serial entry, non S-100 inputs likeVMA, clocking on any transition.SIMPLE TO USE—sample software includedfor all systems listed, all IC's socketed.

APPLICATIONS:

* Make your entire home, business or apartment "computer controlled"-k Save energy by controlling lights and appliances*Ar Control lights and alarms tor security systems

REMOTE CONTROLLER BOARD

ENCASED SELF POWEREDCONTROLLER FOR TRS-80-1

remote switches not included

$159.$184.

Send check or money order to:SciTronics Inc.

523 S. Clewell St., P.O. Box 5344

Bethlehem, PA 18015

(215) 868-7220Please list system with which you plan to use controller.Master Charge and Visa accepted. PA residents add sales tax.

when Chess 4.9 also achiev-ed a draw with Belle in thefourth and final round.With this final half-point,Chess 4.9 wrested a clear-cutvictory in the tournamentwith a score of 3Vi out of 4possible points.

Three programs of thetwelve competing in theevent were run onmicrocomputer systems. Theprogram Mychess, written inZ80 assembler language byDavid Kittinger ofAnchorage, Alaska, ran ona Cromemco Z-2D systemwith 64 K bytes of memoryand gained a score of 2%points. Dan and KatheSpracklen entered version2.5 of Sargon, which ran ona 6502-based electronicchessboard processor; theprogram obtained a score ofIVi points. The programRufus, written by CharlesSullivan in 6502 assembler,did not fare so well. It lostall games and ended with ascore of zero. Rufus ran onan Apple II computer in 48K bytes of memory.

Besides these three pro-grams that used micro-processors to calculate whatmoves to make, two pro-grams that ran on largecomputers employedmicroprocessors to controlelectronic chessboards thatindicate moves with light-emitting diodes and transmitopponent's moves auto-matically. Both Chess 4.9and Blitz 6.9 (written byRobert Hyatt and AlbertGower of the University ofSourthern Mississippi) usedthese devices.

The tournament wasorganized by a committeecomprising MonroeNewborn, Ben Mittman, IraPurchis, and David Dahm.The tournament directorwas International MasterDavid Levy (who wasfeatured in "Chess 4.7 versusDavid Levy," by J RDouglas, December 1978BYTE, page 84). In atten-dance as observers wereone-time World ChampionMax Euwe (oy - vuh),president of the FederationInternationale des Echecs(FIDE), and GeorgeKoltanowski, former presi-

198 January 1980 © BYTE Publications Inc

Circle 150 on inquiry card.

dent of the United StatesChess Federation (USCF)and noted player of blind-fold chess.

Stanford University pro-fessor John McCarthypresented the tournamentawards and spoke at aceremonial luncheon held onthe final day of the ACMconvention.

A cross-table of gameresults achieved by thetwelve programs is repro-duced here in table 1. Ac-cording to Dr Newborn, thestrength of play of all theprograms in the 1979 com-petition was greater than inthe previous tournaments.

An interesting experimenttook place on the Saturdaypreceding the tournament.David Levy, with an abilityrating of about 2390, playeda single game against a teamconsisting of David Slate(USCF rating of about 2050)and his program, Chess 4.9(also rated at about 2050).The purpose was to find outif cooperation between manand machine could producebetter play than either manor machine playing alone.

According to ratingstatistics, a player rated2050 should, in a 20-gamematch, win perhaps twogames and draw perhapsfive. It was expected thatthe Slate-Chess 4.9 teamwould have an effectiverating of about 2150, withLevy favored to win.

True to expectation, Levyused his knowledge of thestrong and weak areas of theopposing team and won thegame. Nevertheless,development of the sym-biotic relationship betweenthe human player and acomputer may yet extendthe capabilities of both menand machines.

Microcomputers inEducation

A nonthreatening first ex-perience with microcom-puters for kindergarten to12th grade teachers has beendeveloped by Dan Isaacsonat the University of Oregon.He designed a self-instructional, laboratory-type course to help teachers

use computers without hav-ing to be programmers.The course consists ofprograms and text that showhow to turn on the com-puter, load programs, ex-plore materials at variouslevels in fine arts, business,English, foreign languages,consumer economics, andmore. The program will bereleased in the summer of1980 for use by publicschools and colleges ofEducation. For more infor-mation, contact Dan Isaac-son, Computer Center,University of Oregon,Eugene OR 97403.■

BYTE's Begs

ReformattingDollars and Cents

Mr J R Borden of LagunaHills CA, has pointed out anerror in my recent letter onformatting dollars and cents("Good Cents," September1979 BYTE, page 150). Intrying to compact the pro-cedure to one line, I erred inthe roundoff, the results notbeing correct for $1,995 andsimilar cases. A correct ver-

sion is given in line 30 of theadjacent listing.

20 IF X < 0 THEN X = ABS

(X): PRINT"—";30 X = X + 0.005: PRINT

"$"; INT (X);".";RIGHT$ (

STR$( INT (100 * (X +

D)),2)

Mr Borden also con-sidered the case of negativequantities. To handle theserequires an additional line,line 20 in the listing.

I apologize for any in-convenience this error mayhave caused.

James D Childress5108 Springlake WayBaltimore MD 21212 ■

The AJ 630data terminal.Low noise. Low price.High performance.

The AJ 630 thermal printing dataterminal. Now you can get a lot ofterminal for a little money.Just look at its features:

• Exceptionally quiet thermaloperation

• Desktop portability

• Proven reliability

• Selectable printing speeds upto 30 cps

• AJ-supplied thermal paper

• Standard ASCII and APLconfigurations

And look at its price:

• Just $53 a month on a 36-monthstandard lease, including main-tenance—and equally attractivepayout lease.

• Just $995 for outright purchase.

In short, you can have a full-fledged data terminal for about theprice of a high-quality electrictypewriter.

And to make it as easy as pos-sible for you to have the AJ 630,you can even use your Visa orMaster Charge cards.

The AJ 630 comes with ourstandard 30-day parts and laborlimited warranty. And is backed byAJ's nationwide service network.

Act now. Write AndersonJacobson, Inc., 521 Charcot Avenue,San Jose, California 95131. Or callyour nearest AJ regional office:San Jose, CA (408) 946-2900;Rosemont, IL (312) 671-7155;Hackensack, NJ (201) 488-2525.

NOW-a monthlease!

995 u tpurchase!

Prices subject to change without noiice.

ANDERSONJACOBSON

Circle 151 on inquiry card.

January 1980 © BYTE Publications lnc 199

Event Oueue

JANUARY 1980

Education Coordinators'Workshops 1980. Heldthroughout 1980, theseworkshops will covercosting, justifying costs,course design strategies,scheduling, record keepingand reporting to manage-ment. For information onwhen and where the-workshops will be held,write to Deltak Inc, 1220Kensington Rd, Oak BrookIL 60521, or call (312)920-0700.

January 3-4

Hawaii International Con-ference on System Sciences,

Honolulu HI. The con-ference will coverdevelopments in theory andpractice in software and

hardware, and advancedcomputer systems applica-tions in selected areas, withemphasis on medical infor-mation processing andcomputer-based decisionsupport-systems for upperlevel managers in organiza-tions. For more information,contact Perry G Patteson,Office of Management Pro-grams, University ofHawaii, 2404 Maile Way,Honolulu HI 96822.

January 5-8

International Winter Con-sumer Electronics Show, Las

Vegas Convention Center,Grand Ballroom of the LasVegas Hilton and the JockeyClub Hotel, Las Vegas NV.The show will have over 850exhibitors covering marketsincluding audio systems,software, television and

I *

xxxvvvvxvvvwxvxxwxvtvrvyvvy

*£M0 ^

APPLE KIM AIM65

INEXPENSIVE CONTROL SOLUTION FOR

HOME SECURITY • ENERGY CONSERVATION

GREENHOUSES ■ ENVIRONMENTAL CONTROL

INDUSTRIAL CONTROL ■ LABORATORIES

CmC's uDAC system now includes an interface to the BSR X-10 remotecontrol modules. These low-cost modules allow control over lamps,motors and appliances. With the CmC X-10 interface your computer cancontrol 256 separate devices. Lamps can be turned on or off, dimmed orbrightened. Alarms, kitchen appliances, hi-fis, TVs, motors, pumps,heaters and more can be put under your computer's control.

Direct plug-in and software for most computers.

Circle the reader service number, call or write for our latest catalog.

CONNECTICUT microCOMPUTER, Inc.

O1S0POCONO ROADBROOKFIELD, CONNECTICUT 06804

TEL: (203) 775-9659 TWX: 710-456-0052

^J^^^X XXyrX.X.XXX.XX-yrj-iy: v; vvr^v;-v^-K^

video tape and disk systems,home computers,calculators, and many more.Contact Consumer Elec-tronics Shows, 2 IllinoisCenter, Suite 1607, 233 NMichigan, Chicago IL 60601.

January 5 and 12

Introduction to Computingand Personal Computers,

Human ComputingResources, 10 St Mary St,Toronto Ontario M4Y 1P9CANADA. This course willcover introductions to com-puters, programming, soft-ware and hardware, usingcomputers in homes and of-fices, and buying and own-ing a personal computer.

January 8-24

Tuesdays and Thursdays,Introductory Programmingin BASIC, Human Com-puting Resources, 10 StMary St, Toronto OntarioM4Y 1P9 CANADA. Directexecution of commands, thewriting of simple BASICprograms, system dialects,error handling and debug-ging, and programmingmethods and style will becovered in this course.

January 15Invitational Computer Con-ference, Orange CountyCA. New developments incomputer and peripheraltechnology such as Pascalsystems, printers, andstreaming tape drives willbe featured in this con-ference directed to the quan-tity buyer. For more infor-mation, contact B J Johnsonand Associates, 2503Eastbluff Dr, Suite 203,Newport Beach CA 92660.

January 15-18TV-Microelectronics andMicroprocessing Exhibition,

National Exhibition Centre,Birmingham, England.Manufacturers and suppliersof microprocessors, elec-tronic and microcomputergames, video display units,

In order to gain optimumcoverage of your organi-zation's computer con-ferences, seminars, work-shops, courses, etc, noticeshould reach our office atleast three months in advanceof the date of the event. En-tries should be sent to: EventQueue, BYTE Publications,70 Main St, PeterboroughNH 03458. Each month wepublish the current contentsof the queue for the month ofthe cover date and the twofollowing calendar months.Thus a given event may ap-pear as many as three times inthis section if it is sent to usfar enough in advance.

video cameras and projec-tion systems and digital con-sumer electronics are invitedto participate. Over 9000retailers, wholesalers,distributors and governmentbuying authorities are ex-pected to attend this show.For more information, con-tact TMAC, 680 Beach,Suite 428, San FranciscoCA 94109.

January 17

Electronic Road Shows,

Proud Bird Restaurant, LosAngeles Airport, LosAngeles CA. This travelingexhibition of components,materials and instruments isbeing produced by the Elec-tronic RepresentativesAssociation (ERA). Over 80ERA member firms will par-ticipate, and products fromover 700 electronic com-panies will be displayed. Formore information, contactthe Southern California ERAoffice, 20969 Ventura Blvd,Suite 9, Woodland Hills CA91364.

January 21-24

American Association ofPhysics Teachers and theAmerican Physical Society,

Chicago Marriott Hotel,Chicago IL. An introductionto microprocessors, a Pascalprogramming workshop,and a course on the use ofpersonal computers in learn-ing physics, plus more ses-sions on microprocessorswill be presented.

Contact the AmericanAssociation of PhysicsTeachers, Graduate Physics

200 January 1980 © BYTE Publications Inc

Circle 152 on inquiry card.

MAXIMUM VALUEFOR YOUR DOLLAR

NORTH STAR COMPUTER PRODUCTS

DOUBLE DENSITY

KIT ASM

$1590. $1850.

1910. 2200.

550. 640.

330.

KIT ASM

$1750. S2040.

2230. 2560.

720. 800.

480.

come standard

HRZ-1-32K-DHRZ-2-32K-DMDS-A-DEXTRA DRIVEQUAD DENSITYHRZ-1-32K-QHRZ-2-32K-QMDS-A-QEXTRA DRIVEAll HORIZONS nowwith 3 ports and all edge connectorsand minimum 32K memory.BOARDS-DISCS KIT ASM

RAM-16K W/PARITY $300. $345.

RAM-32K W/PARITY 475. 520.

FPB-A 205. 270.

VERBATIM DISCS, BOX OF 10 . . $29. PPWe will try to beat any deal. Call:

A.E.I.

3851 HACKETT AVE.

LONG BEACH, CALIF. 90808

(213)421-4815

5VOLT 1 AMPREGULATED POWER SUPPLY

\ Hi. 5VDC (•ctlon It i.flulaled ind compatible' with TTL and DTL decoder drlvara and tuocUtedlogic clrcullt, Ttia 200VDC •action li unragulatad•nd makai an Idaaliupply aourca lor all gaadlichirga typa numerical raadouta.

• DC Output: (1) 200V si 0-Sil mA (unragulatad)

io (215V fl 0-1A Ragutalad. FACTORY

• AC Input .Currant Limit: CLOSEOUTI17V.60HI 1.2AAutomallc S19.*°8ach

UmiladOllar

ALCOS.P.D.T.MINI TOGGLE

ipa 3

22/44 EDGEBOARD CONNECTORTIN SOLDERTAIL .156" x .200"

LARGE QUANTITIES AVAILABLES1.35aach 10forS12.50

'"' HOUSE MARKEDfSSSte) DARLINGTON p TRANSISTOR

_ „ IBAmpaSOVolta

51.50 isowatta

each Similar lo:Mj*030PNP

Similar lo:MJ4033NPNSpnclly NPN or PNP

ALL CLECTROfllCS CORP.

905 S. Vermont Ave.DEPT. BV-1

> Lor Angeles, Calif. 90006(213)3808000 TERMS

• QuinlltUlLlmlt.d

STORE & WAREHOUSE HOURS . un on., no on

Mon.Frl. Saturday -Afld 11.50

9 AM -5 PM 10 AM-3 PM .SRSSm

SEND FOR OUR FREE CATALOG .P,„,„p,s,„p„„,0

SHORT 50 ft.CASSETTES

Al'

Qty. Price

:;:; hi warn 0 »

1 $1.00

10 $0.75

Circle 153 on inquiry card.

Circle 154 on inquiry card.

50 $0.65

Premium tape and cassettes acclaimedby thousands of repeat order microcom-puter users. Price includes labels, cas-sette box and shipping in U.S.A. VISAand M/C orders accepted. Californiaresidents add sales tax. Phone (415)968-1604.

MICROSETTE CO.

475 Ellis StreetMt. View, CA 94043

Circle 155 on inquiry card.

FLOPPY DISKREPAIR

• PerSci and Shugart

• Quick turnaround

• Eight inch andminis

National Computer Service

1023 N. LaBrea

Hollywood, CA. 90038

213-851-2226

MODEL 1200 RS 232 DATA SPLITTER

available in kit form

Model 1 200K gives the terminal or micro-processor user a second interface for a printer,plotter, cassette or tape drive. It operates at anyspeed & isolates the two output devices fromeach other, while providing 2 RS-232 interfacesfrom the terminal or microprocessor.

The kit consists of 3 RS-232 connectors,printed circuit board, all necessary components,enclosure, mounting hardware & assembly in-structions $59

write or call

TERMINAL DATA CORP.

1187B Coakley Cir.

Rockville, MD 20852

(301) B81-7655

8" DISK CONTROLLER

APPLE DOS COMPATIBLE

• DOUBLES APPLE If"STORAGE

• SHUGART 800/801 COMPATIBLE

• STANDARD IBM"" 3740 FORMAT

• CP/M""',UCSD PASCAL'™ CAPABILITY

Available at your local APPLE Dealer: $400.

2r*>

SORRENTO VALLEY ASSOCIATES11722 SORRENTO VALLEY RD.SAN DIEGO. CA 92121

Circle 156 on inquiry card.

Circle 157 on inquiry card.

Circle 158 on inquiry card.

CASSETTES

withAgfa Premium Grade Tape

C-lOs

)rrrrrj(

50 ft

)

5-screw type

24 pack — $2l.OO

Illinois Residents add 6% sales tax

includes Norelco-sty'e boxes withindex cards, 48 labels, shipping.

Call or write today

*^*** ^r^. 312/298-5300

1233 Rand Rd. Des Plaines, IL 60016

TRS-80 Model I and II quality software

DATA BASE MANAGER IDM-IV SB9

Von can use it to maintain a data base & produce reports without anyprogramming Define tile parameters & report formats on-line Featuies keyrandom access fast multi-key sort field arilh label generator audit lot]MOD-II version with more than 50 enhancements S199

ACCOUNTS RECEIVABLE ACCT-lll S69

One of more drives Order entry calculates sales tax shipping amount (ormultiple items Credil checking, aging sales analysis invoices statementsand reports As opposed lo most other A/R curs ran he used by doctors slore

managers etc MOD-II version S149

WORD PROCESSOR 16K $39 32K $49 MOD-II $49

First word processor specifically designed far the TRS-80 thai uses diskstorage for text Written in BASIC No special hardware and text limit Use forletters manuals & reports 32K version lealnres upper/lower case withouthardware change and multiple input texl files

MAILING LIST advanced MAIL-V $59

Fast sort by any field Multiple labels and reports 4-digil selection code new/id code ext screen input live keyboard powerful report writer MOO-II $99INVENTORY INV-V $99

9-digit alphanumeric key for fas! key random access Reports include orderinfo performance summary e!c Calculate E 0 Q Powerful report writer MOD-II $149

All progiams are on-line interactive, random access, virtually bug freedocumented and delivered on disks MOD-I requires 32K. DOS We challenge allsoftware vendors to offer low cost manuals so you can compare and avoidthose high-priced undocumented an-memorv programs Send S5fof a MOD-Imanual and $10 for MOD-II

MOD-II programs are extensively modified guaranteed to run with 1 yearnewsletter & updates Iff- off for ordering more Irian 1 MOD-II progiams

MICRO ARCHITECT

96 Dothan St., Arlington. MA 02174

SALEIRS SALE

ALL BRAND NEW 16K LEVEL 2

FULL WARRANTY $699.°

ALSO:

16K MEMORY UPGRADE S59.

TRS80 3SPEED KIT UPGRADESTRS80 TO FAST, SLOW ANDNORMAL SPEEDS $19.

5V-EPROM 2716 $35.

2708 EPROMS $7.

MICROTEK PRINTERS $725.

SOFTWARE AND INTEGRATEDC I RCUITS(TTL'S MOS.CMOS)SEND FOR FREE'CATALOG

DES-MAR ELECTRONICSPOST OFFICE BOX 4482AGNEW STATIONSANTA CLARA, CA. 95054

oCALIF. ADD 6.5% TAX

T« nciy Corporation

Circle 159 on inquiry card.

Circle 160 on inquiry card.

SAVE

ON ADD-ONPRODUCTS FOR

TRS-80

The largest familyof disk drives fromthe largest supplier,

drives come

complete with

power supply and

cabinet.

TF-Pertec FD200. 40 track, use both sides $382

TF-3 Shugart SA400, 35 track, same as tandy $389

TF-5 MPI B51. 40 track , $379

TF-70 Micropolis. 77 track with 195K of storage $639

TDH-1 Dual sided drive. 35 track $499

mviaxTdisk^-"

Max, Disk 1:10 Megabyte Hard Disk With 5 fixed. ^OO

5 removable with controller

Maxi Disk 2: 10 Megabyte (fixed) $5349

Winchester Technology

77 tracks of Storage includesnewDO^

PRINTERS

DP800 Anadex. 80 column. 112cps $950

LP779 Centronics 779 $1099

LP730 Centronics 730 $950

LP700 Centronics 700-1 $1495

LP701 Centronics 701-1 $1759

LP702 Centra ics 702-2 $1995

SPW-1 Spinwriter-NEC $2495

^ewTlineprinter

BASE 2

S-fi.*."*1 $599

* DRIVES FOR ANY MICROCOMPUTER*

Does not include power supply & caPinet.MOD II DISK DRIVES NOW AVAILABLE

Perfec FD200 $282

Perfec FD250 (dual head) $399

Shugart SA400 (unused) $286

Shugart SA800 $479

MPI B51 $279

MPI B52 $349

SOFTWARE

New DOS* with over 200 modifications and

corrections to TP.S-DOS $99

New DOS* 40 track $110

AJA Word Processor $75

AJA Business Program $250

Racet Infinite Basic $49.95

Disk Drive Alignment Program $109

Radix Data Base Program $99.95

Electric Pencil $150

ALL PRICES CASH DISCOUNTED. FREIGHT FOB/FACTORYCircle 239 on inquiry card. /M\

L|J /MICROCOMPUTER JM\

ELSll&^o c£—ipporat, Inc.

2080 South Grand Ave. 7310 E. Princeton Ave.

Santa Ana, CA 92705 Denver, CO 80222

(714) 979-9923 (303) 758-7275

Building, State University ofNew York at Stony Brook,Stony Brook NY 11794.

January 22-24Designing, Installing andManaging An InternationalTelecommunications PrivateUser Network, Dallas TX.This course is intended forcommunication professionalsinterested in understandingand developing communica-tion systems, services, andtechniques. For more infor-mation, contact TelecomSystems Group, 579 Pomp-ton Ave, Cedar Grove NJ07009.

January 23-26International Microcom-puters MinicomputersMicroprocessors (IMMM),Harumi Exhibition Centre,Tokyo Japan. This is a showfor manufacturers, commer-cial and financialestablishments, service in-dustries and institutions, anddesign engineers interested inbuying computer systems,components and services.For more information, con-tact Industrial and ScientificConference ManagementInc, 222 W Adams St,Chicago IL 60606.

January 28-30

Communication Networks

'80, Sheraton WashingtonHotel, Washington DC. Theprogram will offer 50 con-ference sessions in areassuch as fiber optics, satellitecommunications, systemsnetworks, and innovationsin electronic mail and officeadministrative networks.

For further information onregistration, speaking oppor-tunities or exhibit space,contact William Leitch, TheConference Company, 60Austin St, Newton MA02160.

January 28-30Principles of ProgrammingLanguages, Las Vegas NV.This symposium concernspractical and theoreticalaspects of principles and in-novations in the design,definition, and implementa-tion of programminglanguages. Some topics are

algorithms and complexitybounds for language pro-cessing tasks, specificationlanguages, error detectionand recovery, and unusualor special-purpose languagesthat raise issues of principle.Contact Professor JohnWerth, Dept ofMathematical Sciences,University of Nevada, LasVegas NV 89154.

January 30-February 1MIMI'80 Asilomar,Asilomar ConferenceGrounds, Pacific Grove CA.This symposium covers allaspects of mini andmicrocomputers includingtechnology, hardware, soft-ware engineering, languages,education and more. Con-tact The Secretary, MIMI'80 Asilomar, POB 2481,Anaheim CA 92804.

FEBRUARY 1980

February 6

Invitational Computer Con-ference, Ft Lauderdale FL.This conference is directedto the quantity buyer andwill feature the newestdevelopments in computerand peripheral technology.Contact B J Johnson andAssociates, 2503 EastbluffDr, Suite 203, NewportBeach CA 92660.

February 12-14

Data Communications Con-ference and Exhibition, Har-bour Castle Hilton, TorontoOntario, Canada. Panel ses-sions, presentations,workshops, and technicalsessions related to the fieldof data communications willbe featured. Network con-trol, management, perfor-mance and architecture;communications hardwareand software; fiber optics;distributed data processing;and international com-munications policies aresome of the subject areasthat will be discussed.

The exhibition at the con-vention center will featureover 100 exhibitors.

For more information,contact Whitsed Publishing

202 January 1980 © BYTE Publications Inc

Circle 162 on inquiry card.

Ltd, Suite 2504, 2 Bloor StW, Toronto Ontario M4W3E2 CANADA.

February 13-15

The IEEE International SolidState Circuits Conference,

San Francisco CA. This con-ference is a forum for thepresentation of ad-vancements in all aspects ofsolid state circuits. It willcover design, performance,fabrication, testing, and ap-plications in digital, analog,microwave, and other areasof new solid state circuits,device structures,phenomena and systems.For more information, con-tact Lewis Winner, 301Almeria Ave, POB 343788,Coral Gables FL 33134.

February 18-21

European InformationManagement Exhibition andConference, Wembley Con-ference Centre, LondonEngland. This show willexhibit microcomputersystems and peripheral itemswith demonstrations and ap-plications focused on pro-blem solving for themanagement executive. Con-tact, Expoconsul, 420 Lex-ington Ave, New York NY10017.

February 22-23

Louisiana Computer Exposi-tion, University ofSouthwestern Louisiana,Lafayette LA. This con-ference is entitled"Distributed Systems Basedon Mini and Micro Com-puters." It will cover pro-gramming languages,operating systems, evalua-tion of distributed systems,design criteria for distributedsystems, and other relatedtopics. There will be exhibi-tions of equipment andpapers will be read anddiscussed. For more infor-mation, contact the Com-puter Science Dept, Univer-sity of Southwestern Loui-siana, POB 44330, LafayetteLA 70504.

February 25-27

Communication Networks'80, Shoreham AmericanaHotel, Washington DC. This

conference and expositionwill cover business com-munications. For programinformation, contact theDirector of ProgramDevelopment, The Con-ference Company, 60 AustinSt, Newton MA 02160. Forexhibit information, contactthe national sales manager,Communications Networks'80, POB 96, HaddonHeights NJ 08035.

February 25-28

Compcon 80, Jack TarHotel, San Francisco CA.The conference theme is"VLSI: New ArchitectureHorizons." It will bedevoted to developingadvanced technologies forcomputers. Contact Comp-con Spring '80, POB 639,Silver Spring MD 20901.

February 26-28Nepcon West '80, AnaheimConvention Center,Anaheim CA. The con-ference and exhibit will dealwith the latest advances inelectronics by covering suchtopics as wave soldering,etching, automatedassembly, die attaching,hybrid circuit packaging,photo lithography, preciousmetal recovery, laser anneal-ing, and much more. Forfurther information, contactISCM Inc, 222 W Adams St,Chicago IL 60606.

February 26-29

Office/Korea/80, KoreaExhibition Center, SeoulKorea. Exhibits at thisexposition will include therange of products needed inoffices from computers,word processing equipmentand software to stationary,supplies, furniture and ser-vices. Information about theshow may be obtained fromExpoconsul, a division ofClapp and Poliak, 420 Lex-ington Ave, New York NY10017.

MARCH 1980

March 3-5Office Automation Con-ference, Georgia World

Guaranteed software from Data Access Corporation. . .

TRS-80 ISDMS

INDEXED SEQUENTIALDATA MANAGEMENT SYSTEM

Interactive Data Base Definition

Random Key Access To Any Record

Sequential Key Access To Any Record

Fast Assembler Sorting On Any Field

Complete Interactive File Maintenance

Fast In-Memory Directory Of All Records

Automatic Blocking & Unblocking Of Records

Loads It's Assembler Program from BASIC

BASIC & Assembler Source Included

Sample Data & Programs Included

Includes Assembler Disk Sort

INKEY$ Data Entry Routine

Runs On 2, 3 or 4 Drives

IF YOU'VE GOT A TRS-80* DISK SYSTEM, WE'VEGOT A FAST, FEATURE PACKED SOFTWARESYSTEM THAT'S READY TO GO TO WORK FOR YOUNOW! INTERACTIVELY DEFINE A DATA BASE ANDBEGIN USING IT IN HOURS! BUILD YOUR APPLICA-TION WITH ISDMS, ITS A SOLID FOUNDATION!

PRICE: $175.

ISDMS WITH REPORT GENERATOR

The complete ISDMS Package combined with areport definition and generation program. WithISDMS and the Report Generator you can create acomplete file and report system without writing aline of code!

PRICE: $225

TRS-80 BUSINESS PROGRAMSTRS-80 Model II conversions available soon

Accounts Receivable, up to 1200 Accounts... .$500

On-Line Inventory, up to 1800 Items $600

Point Of Sale Inventory, up to 3000 Items $750

General Ledger w/Check Writer $500

Payroll, All Fed., State Taxes, Tips & EIC $500

Mailing List, up to 1800 names on 4 Disks $200

Licensed copies of Data Access 'TRS-80 programsare guaranteed to load and run on operationalsystems, and to be free from programming defects.

DEALER INQUIRIES INVITED

Data Access Corporation

4221 Ponce De Leon Blvd.

Coral Gables, FL 33146

Phone: (305) 446-0669

•TRS-80 is a registered trademark of Radio Shack

Circle 163 on inquiry card.

January 1980 © BYTE Publications Inc 203

Congress Center, AtlantaGA. A combination con-ference and exhibition ofoffice computer systems hasbeen developed to helpmanagement understand thegrowing technology ofbusiness computer systems.For more information, con-tact H A Bruno andAssociates Inc, 78 E 56th St,New York NY 10022.

March 10-12

1980 National Office Exhibi-tion and Conference,

Automotive Building,Exhibition PI, TorontoCanada. Subject areas of theconference will includeenergy conservation, smallbusiness computers,micrographics, word pro-cessing, telecommunications,copiers, office landscaping,and many others. There willbe approximately 100exhibitors presenting theirproducts and givingdemonstrations.

For more information,contact Whitsed PublishingLtd, Suite 2504, 2 Bloor StW, Toronto Ontario M4W

3E2 CANADA.

March 14-16

West Coast Computer Faire,

Civic Auditorium andBrooks Hall, San FranciscoCA. An expected 15,000 at-tendees, over 340 exhibits,and more than 100 con-ference speakers willhighlight this year's pro-gram. Exhibitor and speakerinformation may berequested from the Com-puter Faire, 333 Swett Rd,Woodside CA 94062.

March 17-20

Interface '80, Miami BeachConvention Center, MiamiBeach FL. This conferenceand exposition is devoted todata communications,distributed data processing,and networking. Approx-imately 1000 exhibitors areexpected and attendance isexpected to exceed 12,000.For information, contactInterface '80, 160 Speen St,Framingham MA 01701.

March 17-21Applied Time SeriesAnalysis, University of

California at Los AngelesCA. This course is designedfor engineers, scientists, pro-grammers, economists andother users of digital timeseries who require modernmethods of data analysisusing the fast Fouriertransform, digital filtering,power spectral densities andcorrelation functions. Thelectures cover topics relatingto the Fourier transform,sampling linear systems,convolution, covariance,digital filtering, power andcross-spectral density func-tions, and introductions tonew methods in spectralanalysis and rotatingmachinery analysis. Formore information, contactUCLA Extension, 10995 LeConte Ave, Los Angeles CA90024.

March 20Electronic Road Shows,

Castaways Restaurant, Bur-bank CA. See January 17for details.

March 24-28Fourth European Conference

on Electrotechnics, Stutt-gart. This conference willreview recent developmenttrends and applications inthe field of microelectronics.Microprocessors, computercommunication, industrialelectronics applications ofmicroelectronics in theautomobile and in medicine,and other topics will becovered. The conferencelanguage will be English.Contact Professor Dr W EProebster, IBM DeutschlandGmbH, Postfach 80 08 80,D-7000 Stuttgart 80 GER-MANY (BRD).

March 26-28Viewdata '80, WembleyConference Centre, LondonEngland. Viewdata 80 is aninternational exhibition andconference on video-basedsystems and microcomputerindustries. The British PostOffice is presenting thePrestel Show, about elec-tronic mail services.

Contact TMAC, 680Beach St, Suite 428, SanFrancisco CA 94109. ■

name:

address:city:

««%>ce»*»

state:

.zip:

ELECTRONICS, Dept.1 B 1020 W. Wilshire. Oklahoma City. OK 73116 J

MICAU

OSBORNEBUSINESS SOFTWARE

in CBASIC2 or CROMEMCO 16K BASIC

* features *

Four Complete Packages—

• General Ledger

• Accounts Receivable

• Accounts Payable

• Payroll with Cost AccountingStrong support from Osborne ManualsCBASIC2 runs under CP/M or under COOSversion 1.07 on Cromemco computers16K BASIC runs on Cromemco computersCursor addressing routines for Hazelline,Lear Siegler and Cromemco (Beehive)Terminals

Source Codes and Installation Instructions

provided along with disks

Automatic Command Start-up

Easy to apply to all of your business and

syslems needs

hardware required *

One or more 8" or 5" Floppy

Drives

CRT with cursor addressing

132-Column Printer

$95 p

package

tO ORDER

Add S J tor -hippin

Calif add ft-I'M s

CREDIT CARDS Al

• DEALER INQUIRIES INVITED.

MtCAH'S PRODUCTS 01 DISTINCTION

• OSflOKN! BUSINESS

• DUP/1 (Disk Utilities

• EXPAND |Run Cromem-

SOI TWAKE (in CBASIC2 lor CP'M and CDOS|

co Sofrware on CP/M)

& U.Ki

• UUP/2 [Disk Utilities foi

• BLACKJACK (Tutorial

• ("BIOS (CfVM tor

Cromemco]

Casino Action)

Cromemco Compute

i] .dup/j (DDP/2 Expanded!

• drive [Customized

• Mil ROI'LOt (VcfiJtil

• SPOOL (Cromemco

Printer Drivers]

Prinlei Graphics]

formal Ulilily)

■ DBMS Conversion lu NAD

• Call or Write for Free Catalogue and More Information •* We will Customize any of our programs at our Standard Consulting Rates

Ah! MIEAIH

.Satisfyin' Software

That turns your system on!

MICro Applications and Hardware

. CONSULTANTS and SOFTWARE DEVELOPERS .

. MICAH Box 22212 San Francisco, California 94122 USA phone: 415/664-0778 ■

204 January 1980 © byte Publications Inc Circle 164 on inquiry card.

Circle 165 on inquiry card.

TRS-80, PET,APPLE,

SORCERER

Hardware/SoftwareSystems

Available now:

■ HAM INTERFACE-including themost sophisticated RTTY systemsmoney can buy.

■ Baudot and ASCI I printerinterfaces.

■ Electra Sketch- .ANIMATIONGRAPHICS Compiler

H rile or call for free catalog

AMCROTRONICSJnc..

P.O. Box 518(A) Keyes, CA 95328(209) 634-8888 / 667-2888 (R) (S)We are experiencing telephone difficulties,please keep trying.

DISCOUNT PRICES

NORTH STAR

APPLE II

POLYMORPHIC

INTERACT

HAZELTINE

SOROC

CENTRONICS

MICROTEK

INTERTUBE

& Others

Call for Prices(301) 694-8884

FREDERICK COMPUTERPRODUCTS

Municipal AirportFrederick, MD. 21701

CASSETTEDUPLICATION

TRS-80 (I & II), PET, APPLE, KIM, ATARI

Quality software duplication is morethan copying cassettes. Microsette du-plication uses a proprietary high speedduplicator designed specifically forcomputer program duplication. The fin-ished products are of consistent quality,guaranteed to load. Minimum order is100 with discounts for higher quanti-ties. Call (415) 968-1604 for details.

Circle 166 on inquiry card.

Circle 167 on inquiry card.

MICROSETTE CO.

475 Ellis StreetMt. View, CA 94043

Circle 168 on inquiry card.

SEARCHING THROUGHYOUR ENTIRE

NORTH STAR

BASIC PROGRAM LISTINGS.

WITH OUR MEW "SCAN" COMMAND YOU CANINSTANTLY DISPLAY OR PRINT -

ALL LINES THAT CONTAIN A SELECTED VARIABLE.

• ALL REFERENCES TO ANY LINE NUMBER

• ALL OCCURRENCES OF ANY CHARACTER. NUMBER,LINE NUMBER. GROUP OF CHARACTERS OR ANYTHINGTHAT IS CONTAINED IN ANY BASIC LINE.

This il nol one of Won "lijiiiiy program; ivntlcn in BASIC." Il il amaehtrw language addition in BASIC that (esiacs completely withinNORTH STAR BASIC It will nut effect normal BASIC or DOS It isMil loading and can he loaded separately to operate with BASICor mod along whh BASIC ji d cony ol BASIC with lha "Scan" commarnl Does nol change memory available to BASIC Easy to under

■ Available lor version 6 as well as 14 digit basic

• State your version when ordering

• Dealer inquiries invited

PHONE ORDERSACCEORDER TODAY

use your visa on M

ONLY $27§Q *>**

ELECTRONIC TECHNICIANS

SOFTWARE SERVICES

107! CASITAS PASS RO

CARPINTERIA. CA 93013

8056846049

Circle 169 on inquiry card.

aTRS-80 basic

renumbering program

that does more

Renumber a program in any desired manner in onepass • renumbers even ihe longest programs inseconds • changes all line number references •rearranges program order • easily repealed usebecause commands are BASIC remarks • returnsoriginal BASIC program on errors • called fromBASIC, returns lo BASIC • specify 4 or 16K Level IIor 32 or 48K DOS

Tested casseite'program bolh S'des S20

TRS-80 acting up7 • check your RAM with our ver-satile RAM check • runs until interrupted • lindspermanent and intermittent bad memory* memorysize independent

Tested cassette program Dotn sides SI 0

MICROBIOTIC COMPUTING, INC.j* 6515 ROSS AVENUE S.E. 3JALBUQUERQUE. NEW MEXICO 87108

•

(•APPLET)

APPLE II or

APPLE II PLUS $995.00

•

DC HAYES MODEMS 339.95

•

FLOPPY DISK W/CONT. 529.95

•

APPLE SOFT CARD 159.95

•

PASCAL CARD 459.95

•

ALF MUSIC

SYNTHESIZER 249.95

•

10 MEGA-BYTE DISK DRIVE

({or APPLE) 4695.00

UCATAN

COMPUTER STORE

across from Rwanda Inn

PO Box 1000

Destin, Florida 32541

(904) 837-2022 or (904) 243-8565

Circle 170 on inquiry card.

The AE-35 is a one-board microcomputer utilizingthe 8035 geared toward stand-alone applicationswith:

• an 8-bit input, output, and bi-directional port

• fully programmable hand shake lines oneach port

• crystal based timer

• 64 bytes RAM. expandable onboard to 1 Kbytes

• provisions for program memory to 4 K bytes

• single supply capability [ + 5 V]

• small size [5 inches x 3v* inches]

• low cost [99.95 - singles plus shipping]

Contact factory for availabilitymoney order, check, or C.O.D.

Adroit Electronics, Inc.

5 East Long Street, Suite 1012

Columbus, Ohio 43215

614-221-3060

MemorexFloppy Discs

Lowest prices. WE WILL NOTBE UNDERSOLD!! Buy any

quantity 1-1000. Visa Masterchargeaccepted. Call free (800)235-4137for prices and information. Allorders sent postage paid.

PACIFICEXCHANGES

100 Foothill Blvd.San Luis Obispo. CA93401. (In Catcall(805) 543-1037.)

Circle 171 on inquiry card.

H9 OWNERS!

Now you too can have graphic capa-bilities similar to those of the TRS-80with GRAFIX. No modification to ex-isting circuit boards is required.GRAFIX simply plugs into existing ICsockets.

Comes with complete instructions.Full G month warranty.

Kit $59.95

Assembled and tested $69.95

Northwest Computer

Services, Inc.8503 N.E. 30th AvenueVancouver, WA 98665

Circle 172 on inquiry card.

Circle 173 on inquiry card.

Circle 174 on inquiry card.

Circle 175 on inquiry card.

CATCH THE

S-100INC.

BUS!

/I V^ \ v \ W

LIST

PRICE

OUR

SPECIAL

CASH

PRICE

Ithaca Audio Z-80 Processor,Assembled & Tested 2 MHZ

Godbout Econoram MA, 4 MHZ 8K"Unkit"

Mullen TB-2 Extender Board withProbe-Kit

Morrow's Micro Stuff/Thinker ToysSwitchboard Kit

North Star Horizon 2-32K-DAssembled & Tested

S.D. Systems Z-80 Starter Kitw/PIO

175.00 140.00

149.00 125.00

49.00 39.00

199.00 165.00

2765.00 2299.00

249.00 210.00

Subject to Available Quantities • Prices Quoted Include Cash Discounts.

Shipping & Insurance Extra.

We carry all major lines such as

S.D. Systems. Cromemco, IMSAI. Vector Graphics, North Star, Sanyo, ECT,

TEI, Godbout, Thinker Toys, Hazeltine, IMC

For a special cash price telephone us.

bus...SHOD,inc.

Address 7 White Place

Clark, N.J. 07066Interface 201-382-1318

Pascal / MT

from

/Aieto Te&\

soso / ZBO

' COMPILER S SYMBOLIC DEBUG!' RUNS UNDER CP/M [S. Derivatives]' Generates Romable Machine Code1 Needs only 32K bytes

Output is 10X faster than P-code' Efficently compiles a subset of

Standard Pascal

Available for ALL CP/M Systems

S99.95

Options include: real/business arithmeticmulti tasking, interrupt procedures, etc.

Call/Write Meta Tech

330B Midway DriveSuite 2BS

Dealer Inquiries San Diego, CA 9211 O

Invited ["714] 223-556B X2BS

Programming duckies

A French-English/

English-French

Dictionary

Dr Fred Levit, 251 E Chicago Ave, Chicago IL 60611

The program FRENGLSH turns a microcomputer intoa foreign language dictionary. As written here, it willlook up the French or English word entered and thenprint the translation. It does not translate phrases orsentences, but serves as a replacement for a paper dic-tionary.

FRENGLSH is written in CBASIC and uses two fileswhich are stored on a disk. The first file, called DIC-TION, is a random access file each record of which con-tains pairs of words with the pairs separated by slashes.Each pair of words consists of a French word followed bya dollar sign and then the corresponding English word, oran English word followed by a colon and then the cor-responding French word. As you can see in table 1, theword pairs are arranged in the record alphabetically bythe left-hand word of each pair.

The second file used by FRENGLSH is called FRINDEXand is an index to the diction file. It contains a list of thefirst words in each record of the DICTION file, arrangedalphabetically, with the corresponding line number in theDICTION file where that word is found. This file is readinto an array in memory so that it can be searched rapid-ly when the program is running.

When a word is entered, FRENGLSH first searches theindex to find the line number in DICTION where thewanted word pair will be found (lines 70 to 97 of listing1). It then goes to that line in the file and searches therecord for the wanted word plus the correct separator.Searching for the word with the separator appendedavoids problems caused by similarly spelled words withdifferent meanings which may be shared by French andEnglish. When the correct left-hand member of the wordpair has been found then the right-hand member of thepair is extracted (lines 99 thru 108, listing 1) and theentered word and its translation are printed.(See listing2.)

The DICTION file contains about 1100 French words,which includes those most commonly used and needed bysomeone studying the language. Naturally not everyword one might seek can be found, but, before giving up,FRENGLSH does one more thing. The infinitive form ofmost French verbs ends in -er or -oir, and that is the waythe verbs are listed in a dictionary. But many verbs aremost frequently encountered in the second person form,

206 January 1980 © BYTE Publications Inc

Circle 176 on inquiry card.

Circle 177 on inquiry card.

Table 1: A portion of the file DICTION. Each record of 240characters or less occupies about two and a half lines. Note thatthe words are in pairs, either French$English or English:French.The list is alphabetized by the left-hand word in each pair.

'7A$TO/ABORD$APPROACH/ABOVE:AU-DESSUS(V)/ABOVE

ALL:SURTOUT/ABSENCE:ABSENCE(LA)/ABSENCE$ABSENCE/

ABSENT:ABSENT/ABSENT$ABSENT/ABSOLUMENT$ABSOLUTELY/

ABSOLUTELY:ABSOLUMENT/ACCEPT:ACCEPTER/"

"/ACCEPTER$ACCEPT(TO)/ACCIDENT$ACCIDENT/ACCIDENT:

ACCIDENT(LE)/ACCORD$AGREEMENT/ACCOUNT:COMPTE(LE)/

ACE:AS(LE)/ACHAT$PURCHASE/ACHETER$BUY(TO)/ACHEVER$

FINISH(TO)/ACIER$STEEL/ACQUAINTANCE:CONNAISSANCE(LA)/"

"/ACQUERIRSACQUIRE/ACQUIRE.ACQUERIR/ACROSS:

TRAVERS/ACT:AGIR/ACTIF$ACTIVE/ACTION$ACTION OR

STOCK/ACTION :ACTION/ACTIVE:ACTIF/ACTUEL$PRESENT

TIME/ADD:AJOUTER/ADDITION$CHECK(RESTAURANT)/"

"/ADDITIONAL: ADD ITIONN EL/ADDITION NELSADDITIONAL/

ADDRESSER$ADDRESS(TO)/ADIEU$GOODBYE/ADMETTRE$

ADMIT(TO)/ADMIT:ADMETTRE/ADRESS:ADRESSE(LA)/ADRESSE$

ADRESS/ADULT:ADULTE(LE)/ADULTE$ADULT/"

'7ADVANCE(TO):AVANCE R/AD VANTAGE: AVANTAGE(LE)/

ADVENIR$HAPPEN(TO)/ADVENTURE:AVENTURE(LA)/

ADVERTISEMENT:ANNONCE(LA)/AFFAIRE$BUSINESS/AFIN$SO

THAT/AFRICA:AFRIQUE(LA)/AFFIQUE$AFRICA/AFTER:APRES/"

''/AFTERNOON :APRES-M I DI(LE)/AFTERWARDS: ENS UITE/

AGAINST:CONTRE/AGIR$ACT(TO)/AGREEMENT:ACCORD(LE)/

AIDE$HELP/AIDER$HELP(TO)/AILLEURS$ELSEWHERE/AIMABLE$

AMIABLE/AIMERSLIKE OR LOVE/AINSI$SO/AIR$AIR/"

"/AIR:A

B>

Listing 1: A listing of FRENGLSH. The program is written inCBASIC so that the line numbers at the left are not referencedby GOTO statements. Instead statement numbers are added bythe programmer for statements which must be returned to. Forexample, line 61: GOTO 75 sends the program to line 48, whichis statement 75.

It

PEN

PRDGPftfl FPENGLSH IS COPYRIGHTED C1978> BY

St

PEH

THE AUTHQPp FRED LEVIT H.D.. RHD RLL RIGHTS

3:

PEH

RPE RESERVED.

4i

'.:

DIM UDPD$<188'>»LIME.MUM«198>

6i

PRINT "V 1.0"

7!

PPIMT "JUL 78"

8:

9:

PPINTiPPIMTlPPIMT

10:

11:

15:

PPIHT THB'3fi> ! "PRDGRfiM FPEMGLSH"

13:

PPIHT

14:

PPIHT THB'22>!"ft FREHCH-EH'5L I SH-FPEHCH DICTIDHflPY"

15:

16:

17:

PPIHTtPPINT

19:

PPIHT "ITfiPTIHG MDDE IS "EHCH-EHGLISH. TD REVERSE HDDE

19i

PPIHT "EHTEP R I INSTEAD DF R WDRD"

£0:

PPIHT

Stl

FPINT"TD END THE PPDGPRH EHTEP R 9 INSTEAD DF fi IJDPD"

22:

FPIHT:PRINT

25:

PPIHT "PLEfi^E UftJT 40 SECONDS WHILE WE LORD"

24:

25:

PPIHT:PPINT

26:

27:

2&:

DPEH "DICTIOH" PECL 204 Hi 2

2?:

HDDE'$=,'F"

30:

3H

PEM

PERD INDEX INTO MEMDPY

32:

□PEN "FPINIiEX" PECL 25 R- I

33:

IF EHD ::1 THEH 50

34:

.',:

N=I

3*:

MHILE -1

37:

REhD ::l . h: UlQPDt I N) • LI HE . NUH <H'

33:

H=H+ 1

40141:

MEND

50

•:ld:e i

42:

4 3:

PRINT "EHTEP FRENCH WORD RFTEP FP= DP ENGLISH RFTER EH

44:

PRINT:PPIHT

451

4*:

47:4:3:

REM

ENTER MDPD TO BE SOUGHT

75

PRINT:PRINT

491

IF MODES""F" THEH I EPRRRTQR$="i" ELSE :EPRRRTDP4=": "

50:

IF f1DDE1="F" THEH PPIHT "FP= "1 ELSE PRINT "EH= "J

511

52:

INPUT ENTERED.UDPD*

53:^■4:

85

i.«DPD. i.DUGHT$aENTE»ED,WOffM

IF WORD.SDUSHT*»"9" THEN STDP

561

IF WORD. SOUGHT**"I" l™*1 MDDE*="F" THEH'-.

57:

HDDEt ="E":\

5S1

GO TD 75

»i

IF i.irjRIi. :aiJGHTl="l" RHD NDDE*="E" THE^

60:

HDDE1="F":--

61:

6Q TO 75

62:

63:

64:

*En

PAD UCRD.SOUGHTS TO 15 CHARACTERS

WHILE LEH'UORD.iDUGHTt>-l5

Listing 1 continued on page 208

THE BEST

MICRO COMPUTER

— Exporter —

That's Right'

Sigma

>^"*^/ IMTCDMATIHMAI

INTERNATIONALINC.

Fast + Efficient

Our Foreign Customers Receive:

• Purchasing Agent's Service

• Wholesale Discounts

• 220 V/50 Hz Power

Products

NORTH STAR

TEXAS INSTRUMENTS

SOROC

INDUSTRIAL MICRO

HAZELTINE

EXIDY SORCERER

MICRO PERIPHERALS

TELEVIDEO

BASE 2

KONAN CORPORATION

CENTRONICS

INTEGRAL DATA

VERBATIM

+ More

P.O. Box 1118 Scottsdale, Arizona 85252 U.S.A.Tel: 602-994-3435 TELEX: 165745

DECLSM1Components

Dependable serviceat discount prices

Domesticand Export

mini

t

Computer Suppliers, Inc.

25 Chatham Rd., Summit, N.J. 07901Since 1973

(201) 277-6150 Telex 13-6476

©Mini Computer Suppliers, Inc.1979

Circle 178 on inquiry card. January 1980 © BYTE Publications Inc 207

Listing 1

continued:

*~i

WORD. JQU8HT5*=UaRD. SOUGHTS*" "UEHD

70!

PEN

BEGIN ZEftPCH DF INDEX

74:

75:

TOP.LIME = 1

BOTTOM.LIME = N-l

100

HI ALINE = INT- -BOTTOM.LINE-TOP.LINE)-'

£.»+TDP.LlNE

s?j

IF WORD,S0USHT4 = WDRMClItH-INEVSTHEN LINE.SOUGHTaMDLINEl -

SO TD 5 0 0

S4J

IF biaRD.SOUSHTl LT wrjPM.-nlIiLINE' -THEM BOTTOM. LINE=Mir.iL INF

IF I.IOPT'. SOUSHTS ST UDRDStrilfiLItONTHEN TOP.LlNE=MniLINE

1G4:105:10s:

1 IS:119:IS01

isit

128:

1^9:130>

IF BOTTOM.LIME-TOP.LIME ME 1 THEM"-GO TD 100

IF UaRD.SQUGHTS LT WDPDi . EiQTTOM. LIMEi ^THEN LIME.SDUSHT»TDP.LIME:VGO TD 500

IF UQRD.SDU6HT* -3E i.lOPDi <E:OTTOM.LINE>^THEM LIME. iOUC.HT = &0TTO'1.LINE: >*0 TD 500

MATCH FOP UOPD HEEDED

PEHD »£»LlNE.SaUGHTiRS

L0C1 = riRTCHvEMTEPED.Liapri'J+;EPRPHTDPl.Fi*. t)IF LDC 1 ■ 0 THEM SD TD 1000LQC£»tlMTCH(" '"'■HItLDCI*LDC3= MATCH-lEPHPHTDPt.H*.LDC1>

TPHM:LHTEDt=MItii<H*.LDC?+l.LDCe-'LDC3+l>>

PPIMT TPHN;LHTED l.'OPD

PPIMT ENTERED.WORDS!" = " 1 TRANSLATED*

50 TD 75

I.IDPD MDT FDUMD. CHECK FDP VEPD ENDING

PPIMT ENTERED.WORDS*" MDT FDUMD. ":IF RI6HT$(ENTERED.UDRDttS) «"*E2" THEN*

ENTEPED.UOPD*=LEFTt'ENTEPED.WDPD*.LEM'ENTERED. IJOPD*>-i>+"EP":

CO TO S5

IF PISHT*'EMTEPED.!.iaPDl'£.'="EP" THEN-

ENTEPED.UDFD*=LEFTV ENTERED. liiOPD*.LEN'ENTERED. UDPD*>-£>+"0 IP"iSD TD 85

Listing 2: In this run of FRENGLSH the first prompt FR = ? wasanswered by typing "bonjour," and FRENGLSH found the cor-responding English word "hello." In the third example, the word"voulez" is not the dictionary form of the verb. The -ez endingsignifies it is second-person present tense. FRENGLSH did nottherefore find "voulez," so it looked for the stem of the wordwith common infinitive endings, -er or -oir. "Vouloir," the cor-rect infinitive form of the verb, was found and the correspon-ding English was printed.

PROGRAM FPENGLSHH FRENCH-ENGLISH-FRENCH DICTIONftPY

STARTING MODE IS FRENCH-ENGLISH. TD REVERSE MODEENTER ft 1 INSTEAD DF ft WORD

TD END THE PRDGRRM ENTER ft 9 INSTEAD OF ft WDRD

PHEftSE l.lRIT 40 SECONDS WHILE ME LORD

ENTER FRENCH WORD HFTEP FR= DP ENGLISH AFTER EN=

FP= T BONJDURBONJOUR = HELLD

FP= 7 FITTER IP

ATTEPIR = TD LAND (.AIRPLANE-'

PPIMT60 TD

VOUP WORD SPELLED CDFPECTLY

FP= ? VOULEZ

VOULEZ MDT FOUND. VDULER NOT FOUND.

VOULDIP = TO WANT

ending in -ez. For example, vouloir means "to want"while voulez means "you want." Parler means "to talk"and parlez means "you talk." If the word you give toFRENGLSH ends in -ez and is not found in the DICTIONfile, FRENGLSH will search for the root of the word withan -er ending, and, if that fails, for an -oir ending (lines116 thru 128 in listing 1). Only if those additional twosearches are unsuccessful does FRENGLSH report failure.As can be seen, at 130 lines, including comments andblank lines, FRENGLSH is not a very long program. Ofcourse, the real problem is in creating the DICTION filewith its thousands of words. This was done by usingseveral other programs. One program permitted theentry of word pairs, assigning the correct separator, andwriting the list to a file which was then corrected usingthe system editor. These lists were concatenated as they

were created, and the completed list was split intotwenty-six separate lists, each beginning with a differentletter of the alphabet. These individual lists were thenproofread, corrected, concatenated, and alphabetized tomake a single long file. The final file was then read by aprogram which created the DICTION file by insertingslashes between the word pairs and assembling the pairsinto records of 204 or less characters. Finally a small pro-gram was used to read the first word in each record in theDICTION file, together with its record number, to createFRINDEX, the index file.

FRENGLSH is quite fast. Most of the time it is con-siderably faster than thumbing the pages of a paper dic-tionary, especially for people like me who have neverreally learned which letters follow which in thealphabet. ■

Z80 User StackEmulation

Allen Gelder, Box 11721 Main Post Office,San Francisco CA 94101

Passing arguments to subroutines via the Z80 hard-ware stack is complicated by the presence of thesubroutine return address at the top of the stack. Thisartifact of the CALL instruction makes a cork-in-the-bottle effect that precludes just PUSHing the argumentsonto the stack and later POPing them into the subroutineafter the CALL. The problem is solved on the newMotorola 6809 by the addition of a user stack which does

208 January 1980 © BYTE Publications Ire

not participate in the CALL housekeeping. Such a struc-ture is easily emulated and can be integrated verynaturally into the Z80 instruction set by the use of therestart instruction group.

Recall that the restart (RST) instructions are 1-bytecalls to selected page 0 locations. For example, hexa-decimal op code D7 is RST 10. When program flow en-counters this instruction, the program counter (registerPC) will be pushed onto the stack and control will betransferred to location 0010. Often this location containsa vector to the actual routine, which will typically beconcluded by a return (RET). This is the arrangementhere (see listing 2, page 210). It is easy to link this emula-tion; just initialize UPSTOR with a 2-byte user pointer tothe desired top of the user stack, and then vector therestarts as indicated. (See listing 1, page 210.)

When program flow encounters a D7 op code (RST10), the result will be a POPU DE, that is, the top of theuser stack will be popped into DE, and the user pointer(UP) will be updated. Similarly, a DF op code (RST 18)will result in a PSHU DE onto the top of the user stack,etc (see table 1). This action is perfectly consistent withcurrent hardware stack usage, right down to the nearcongruence of the POPU and PSHU instruction bytes.

The difference is that this stack is totally controlled bythe user, at very little programming expense. In the con-figuration of table 1, the user stack access covers theprimary register pairs BC, DE, HL and AF. An alter-native assignment (see listing 3, page 210, and table 2) ofrestarts can include registers IX and IY. This is at the ex-pense of register pairs DE and AF, but saves one byte overthe corresponding PUSH or POP IX (or IY) instruction.

Interpretation of the restart group of instructions isvaried. In the literature, the restart instructions aredescribed as saving space, useful for interrupts, or as left-over 8080 instructions. In practice they are often usurpedby the input/output (I/O) software, or perhaps page 0 issubmerged in read-only memory. If this is the case inyour Z80-based system, it is worth looking for a vectortable in programmable memory or in some other waygaining access to the restart instructions. Because they arean embedded group of 1-byte, user-programmableinstructions, they bestow a kind of microprogrammabi-lity on the Z80.

User Stack Instruct

on

Hardware Stack Instruction

POPU BC

C7

(RST00)

POP BC

C1

PSHU BC

CF

(RST08)

PUSH BC

C5

POPU DE

D7

(RST10)

POP DE

D1

PSHU DE

DF

(RST18)

PUSH DE

D5

POPU HL

E7

(RST20)

POP HL

E1

PSHU HL

EF

(RST28)

PUSH HL

E5

POPU AF

F7

(RST30)

POP AF

F1

PSHU AF

FF

(RST38)

PUSH AF

F5

User-Stack Instruction

Hardware-Stack Instruction

POPU IX

PSHU IX

POPU IY

PSHU IY

D7 (RST10)

DF (RST18)

F7 (RST30)

FF (RST38)

POP IXPUSH IXPOP IY

PUSH IY

DDE1DDE5FDE1FDE5

Table 2: Restart (RST) instruction assignments made bymodified user-stack emulation in listing 2.

In this user stack setup, the restart instructions areexploited as 1-byte PSHU and POPU instructions in ser-vice of an emulated processor architectural feature. Theycould as easily call an emulated addressing mode notavailable on the Z80. The point is that an appropriateuse of the restart group is in calling instruction-likesubroutines that represent the primitives serving theuser's own fanciful structure. Thus you can design yourown corner of the Z80. Let your curiosity PSHU into try-ing it.

Table 1: Restart (RST) instructions assigned to user stack inlisting 1.

new ANALOG PERIPHERAL FUNCTIONS

kits! ... in touch with reality!

QK-100 Triple A ■ D Converter $36.95

QK-101 Dual Air Temperature Sensors 26.95

QK-102 Dual Ground Moisture Sensors 29.95

QK-103 Power Supply with Dual Sockets 29.95

QK-104 Dual Liquid Temperature Sensors 32.95

QK-105 Dual Photo Sensors 27.95

QK-106 Dual Water Level Sensors 34.95

QK-108 Dual Surface Temperature Sensors 30.95

QK-109 Dual Hall-Effect DC Magnetic Sensors 54.95

QK-110 Multiplier and Voltage-Controlled Amp 43.95

QK-112 Peak Sense and Hold/Sample and Hold 28.95

QK-115 8/16 Input Analog Multiplexer 38.95

QK-122 Dual Instrumentation Amplifier 24.95

QK-124 Log and Anti-Logarithmic Functions 40.95

QK-133 Multiple Audible Alarm 25.95

QK-134 Multiple Analog Comparators 39.95

QK-138 Dual "People" Sensors 34.95

QK-900 Socket and Mounting Board 8.95

Si

c

AVAILABLE IN ASSEMBLED MODULES

(602) 299-9831 CALL Q-KIT

P O BOX 35879 WITH YOUR CUSTOM

TUCSON SYSTEM REQUIREMENTS!

ARIZONA 85740 a division of j.r. conwell corporation

Circle 179 on inquiry card.

January 1980 © BYTE Publications Inc 209

Circle 180 on inquiry card.

SOFTWAREBREAKTHROUGH!

A true breakthrough in 8080development software has beenachieved ...

R-A-l-D

RAID stands for "Real-time In-teractive Assembler Debug," butRAID is much more.

SIMULATOR ■ RAID is a true simulator and real-timedebug in one! Simulation mode provides TOTAL CONTROL oflest program. It's crash proof! Segments of memory may bewrite-prolected. limits specified for stack, program counter,etc. Simulation mode is transparent and both modes may beused together for high speed simulations.

SYMBOLIC DEBUG ■ RAID is a fully symbolicdebug, including labels and operands! Also included are multi-ple radix, multiple breakpoints, memory search, 9 display for-mats, single-step, multi-step, display/alter registers or memory,programmable output, etc. Over 70 commands in all!

Memory

ASSEMBLY/DISASSEMBLY

may be displayed or altered in instruction mnemonic lorm com-plete wilh symbolic labels and operands. Exclusive feature per-mits "following" subroutines during dis-assembly.

I KAOIIMCa ■ Elaborate trace facilities have been includ-ed. Trace each instruction as executed, trace subroutines asentered and exiled, trace by breakpoint dumps with user pro-grammable dump data

FULL DISK ACCESS ■ In addition lo loading/"-saving named files. RAID permits reading/writing on aspecified track & sector basis.

FLOATING POINT OPTION - Permits

direct display or alteration of FPP (see below) numbers. 12 digitmantissa, exponent to ± 127,BCD format.

CP/M COMPATIBLE - RAID will run on any

CP/M system ol 24K or more Works wilh both ASM and MACassemblers fully symbolically.

TO ORDER: Specify softwaredesired and enclose check ormoney order (COD ok).

A) RAID without floating point

option $150.00

B)RAID with floating point option,

and FPP source code $250.00C) FPP Floating Point Processor

only $125.00

D)RAID Documentation

Only $25.00

E) ISIS to CPM Conversion Utilities

$125.00

All software supplied onCP/M compatible8" diskette.ISIS versions also available.

SOUTHERNSYSTEMS

OF BIRMINGHAM

Post Office Box 3373ABirmingham, AL 35205(205) 933-1659

Listing 1: Vectoring RST10.

0010 C310 50 00099 RST1C

JP FROMK

Now D7 calls FROM 10

Listing 2: Assembled program for Z80 user-stack emulationusing restart (RST) instructions.

5000

00100

0RO

500011

5000

00

00101

SPSTOR

HOP

, SP raved here.

5001

00

00102

NOP

5002

00

00103

UPST0R

NOP

, UP saved here.

5003

00

0010'.

NOP

500^

E5

00105

FhOM00

PUSH

HL

, Vector C? here.

5005

21C100

00106

w

HL,00ClhT

5006

1826

00107

JR

USRSTK

500A

E5

00 108

FROM08

PUSH

HL

, Vector CF here.

500B

21C500

00109

LD

1IL,00C5H

500E

1822

00110

JR

USRSTK

5010

E5

1)0111

FROM10

PUSH

HL

, Vector D7 here.

5011

21D100

00112

LD

HL,00D1H

501 It

181C

00113

JR

USRSTK

5016

E5

001 ll4

FROM 18

PUSH

11L

, Vector PF here.

50 IT

21D500

00115

LD

HL,00D5H

501A

I8l6

00116

JR

USRSTK

501C

E5

00117

FROM20

PUSH

HL

, Vector E7 lie re.

501D

21E100

00118

LD

HL.00E1H

5020

1810

on 119

JR

USRSTK

5022

E5

no 120

FR0M28

PUSH

HL

, Vector EF here.

502 3

21E500

00121

LD

I1L,0OE5H

5026

180 A

00122

JR

USRSTK

5028

E5

00123

FROM30

PUSH

HL

, Vector F7 here.

5029

21F100

0012t,

LD

HL,00F1H

502C

180;.

00125

JR

USRSTK

502E

E5

00126

FROM38

PUSH

HL

, Vector FF here.

502F

21F500

00127

LD

HL,00F5H

5032

223E50

00128

USRSTK

LD

(0PST0R),

HI.

, Place in 0PSTOR.

50 35

El

00129

POP

HL

5036

ED730050

00130

LD

(SPSTOR)

SP

, Save the SP.

50 3 A

ED7B0250

1101 31

LD

SP,(UPST0R)

, Ini ti alize "ser St

ark

503E

00

001 32

0PSTOR

NOP

, Event happens here

503F

00

00133

NOP

501)0

ED730250

001 3'i

LD

( UPST0R ) ,

SP

, Save the UP.

50Mi

ED7B0050

00135

LD

SP,(SPSTOR)

, Restore the SP.

50'i8

C9

00136

RET

, Back to program.

Listing 3: Alternate assembled listing to include index registersIX and IY. These two sections of code are directly substitutedfor the code in listing 2.

5010

E5

00111

FROM10

PUSH

HL

5011

21DDE1

00112

LD

HL,E1DDH

501)1

181C

001 1 3

JR

USRSTK

5016

E5

001 111

FROM 18

PUSH

HL

5017

21DDE5

00115

LD

HL,E5DDH

501A

1816

00116

JR

USRSTK

5028

E5

00123

FROM 30

PUSH

5029

21FDE1

0012)i

LD

502C

180!4

00125

JR

502E

E5

00126

FROM 38

PUSH

502F

21FDE5

00127

LP

5032

223E50

00128

USRSTK

LD

Vector D7 here.

Vector DF here.

HL ; Vector FT here.

HL.E1FDH

USRSTK

HL ; Vector FF here.

HL,E5FDH

(OPSTOR).HL ; Place in OPSTOR.

210 January 1980 © BYTE Publications Inc

16K STATIC MEMORY (RAM)

250 nsec Access Time, Assembled,tested, and Guaranteed. $300.00

Fully Static - TMS 4044

S-100 Bus - Buffered lines. Dip Sw address in

2, 8K blocks 4K incr., Write Protect, Phantom

disable, Battery backup, fully Socketed.

Bank Select - Port 40H (Cromemco Software

Comp.). 80H or COH.

Guarantee - One full year. To order, call for

Visa, M.C., or C.O.D. ($4 fee.) Personal check

o.k. M.O. speeds shipping. Stock to 72 hour

delivery. Illinois residents add 5!4% tax.

S. C. DIGITAL

P.O. Box 906, Aurora, IL 60507Phone: (312) 897-7749

H-8 OWNERSAD-8/4 H

Analog/Digital Subsystem

• 8 Analog Input Channels

• 100 us A/D Conversion Time

• 4 Analog Output Channels—

Each with Sample and Hold

• Full 8 Bit Resolution

• Uses Single Card Slot

• Fully Assembled and Tested

• Full Documentation Provided

• VISA and M.C. Accepted

$125.00

CCM, Inc.

P.O. Box 2308

Reston, VA 22091

THE AMSAT-GOLEM 80PROJECT

Front Panel Hardware

Boards $45.00

Kits $245.00

Assembled and Tested $349.00

AMS80 Software

Documentation (178 pages) $15.00

Source code 8" CP/M* disc $30.00

Source code 5" Northstar* (CP/M*)$30.00Object Code 5" Northstar* $10.00

Write for information on other S-100 cardsand software optimized for Amateur Radiocommunications, control and logging.

SNOW MICRO SYSTEMS INC.

P.O. Box 1704Silver Spring, MD 20902

' CP/M and Northstar are registered trademarks.

Circle 181 on inquiry card.

Circle 182 on inquiry card.

Circle 183 on inquiry card.

BYTE's New

yToll-free\ "SubscriberW.A.T.S. Line

(800) 258-5485

To further improve service toour customers we have installed

a toll-free WATS line in our

Peterborough, New Hampshire

office. If you would like to order

a subscription to BYTE, or if ypu

have a question related to a BYTE

subscription, you are invited to

call (800) 258-5485 between

8:30 AM and 4:30 PM Eastern /

Time. This applies to calls from

within the continental US ortlyi

We thank you and lookforward to serving you

1 JUJLSUULOJLflJLflJLSJU

STATISTICAL DATA

DATABANK programs contain 10years of monthly statistical data onten related subjects. Information isthe most current available. Eachcassette is date stamped. Includesgraphs, tables, trends, comparisons,update routine, and external input.

Programs available for TRS-80 LS, 16K

' General Economy

* Manufacturing & Trade

* Industrial Production

* Money & Credit

* Money Rates & Yields

* Commodity Spot Prices

* Mortgage Terms & Yields■ Foreign Exchange Rates

* Energy Production

* Petroleum Production

$29.95 each 3 for $84.95

Cassette storage album included withorder for six or more programs.

till* DATABANK POB 9283HIP Ft Lauderdale, FL 33310

Radio /haett

D1ALEB

COMPUTER CENTER

M.CRQ MANAGEMENTSYSTEMS

Up To 15% Discount

on

TRS-80's

WE HAVE THE HIGHLY

RELIABLE LOBO DISK DRIVE

INSTOCK!

MINI MALL—DOWNTOWN SHOPPING CENTER

CAIRO, GEORGIA31728

912-377-7120

Circle 184 on inquiry card.

Circle 185 on inquiry card.

GAME DESIGN

Leading Coin-op AmusementGame company will consider useof YOUR pinball, video or othergame idea on a royalty, commis-sion or other basis. WRITE FORDISCLOSURE FORM BEFORESUBMITTING GAME IDEA.

Department BMA

P.O. Box 236

Bensenville, IL 60106

$19992399276527993215

80001149

Save More Than 20%

North Star—Intertube

Thinker Toys—Microtek

The Smartest Computers at the Smartest Price

Quad * Double Density

ListHorizon-l-32K-D KitHorizon-2-32K-D Kit

Assembled & TestedHorizon-2-32K Kit Quad

Assembled & TestedPascal for North Star on DiskPowerful North Star BASICZTEI PT 212 Computer 5 mHzThinker Toys Discus/2D A&TDuscus/2 + 21.2 Megabytes A&T 1549Measurement system memoryA&T 4mHz 64 KGodbout Memory Call for price

Intertube II Smart Terminal 995 745

Microtek Printer 750 675

Anadex Printer 995 875

Florida Data Printer 600 CPS 4300 Call for priceMaryellen Word Processor Your Best Buy 38Textwriter III

EZ-80 Tutorial Learn Machine LanguagePDS For North Star Better Than CP/MCompiler for Horizon Secret Superfast Code10% Off Software Prices With ComputersVerbatim the Best Diskettes Box of 10Which Computers Are Best? Brochure.North Star Documentation RefundableW/HRZ

American Square ComputersKivett Dr ' Jamestown NC 27£8C (9191-883-1108

Only

S158!

1905

319!

222!

255!

49

FREE

6250

949

1299

640

1252599

100

99

FREE20

RS 232C Computer CompatiblePaper Tape ReadersAvailable from Stock

Addmaster Corporation announces that theModel 612 Stand Alone Paper Tape Readers isnow available from stock and is shipped in 1 to 3workinq days after receipt of order. The Model612 has greater capacity than earlier models. Theability to read 5 to 8-level tape and to transmit 7 to11 frames per character at 50 to 9600 baud areamong the new features. Others include startingand stopping on character at all speeds, choice ofmanual control or X-on, X-oif, 90 to 260 volt, 50 to60 Hz power and even, odd or no parity.RS 232, current loop or parallel outputs are avail-able as is choice of desk top or rack mounting.Single unit price of the new Model 612 is $656.00to $779.00

Addmaster Corporation

416 Junipero Serra DriveSan Gabriel CA 91776 (213) 285-1121

Circle 186 on inquiry card.

Circle 187 on inquiry card.

Circle 188 on inquiry card.

Eighteen with a Die

A Learning Game Player

Russell R Yost Jr

1825 E Palo Verde Dr

Phoenix AZ 85016

The simulation of human intellectby a machine of human invention hasfascinated mankind for centuries. Un-fortunately, the attainment of such agoal still seems to be distant. The ad-vances in machines that mightachieve such a goal seem to be con-tinually offset by additions to ourknowledge of the complexity of thehuman intellectual process. Simplegame-playing machines, however,are feasible, and their popularity pro-bably stems from the above mention-ed human yearning, even thoughthese games represent only a narrowslice of human intellect.

Game-playing programs are ofgreat value to the personal computerowner, since results of great interestto spouse and neighbors can be pro-duced with only a small investment inmemory and software. Rarely dosuch programs involve more thanlogic plus simple integer arithmetic,and they are so short that handassembly of machine-language pro-grams is entirely feasible.

Many games are well adapted tointeraction with the human playerthrough the same I/O (input/output)channel used for programming. I amsure that the first program tried bymost buyers of the Southwest Tech-nical Products Corp 6800 computersystem (after some memory checkprograms) is the Tic-Tac-Toe pro-gram whose listing is supplied withthe computer kit.

Although such beginner gamessoon become boring, game-playingprograms of real and continuingchallenge are now becoming feasiblefor all amateur computer owners.Meanwhile, simple game players suchas the one described here continue tointrigue computer enthusiasts.

Game Categories

Thus far I have been using the term"game player" loosely, and indeed theterm is loosely used in many articles.Three distinct categories are easy todefine: puzzles, gambling machines,and man versus machine gameplayers.

It seems to me that a game likeShooting Stars (by Willard I Nico,May 1976 BYTE, page 42) is really apuzzle that the human tries to solve inas few moves as possible. Star Trek-type games might be considered ex-amples of a gambling program.Through the use of random numbergenerators, the human's moves pro-duce random results following pre-scribed odds; luck is involved in theresult.

Tic-Tac-Toe is an example of aman versus machine game. Themachine plays the role of an adver-sary, playing by the same rules thatapply to the human.

This last category comes the closestto the simulation of human intellect,which is why I feel it is of great inter-est to the computer owner. However,

all three types of games are inter-esting to players, and many gamescombine elements of all three in theirarchitecture.

Game Learning Program

A natural extension of the thirdcategory is the game learning andplaying program. In this type, themachine is given the rules of thegame, but initially does not possessany strategy for selecting its moves.Through playing a series of gameswith the human, it learns a strategyfor increasing its chances of winning.This type comes even closer to thesimulation of human intellect.

The design of such machines hasbeen one of my hobbies for overthirty-five years. I recently purchaseda computer because my ambitionsoutgrew what could be built usingrelays and stepping switches, or even

About the Author

Russell Yost studied physics at the CaliforniaInstitute of Technology before World War IIdiverted him into working on defense elec-tronic systems. Since 1952 he has worked forMotorola; he is now the chief engineer forradar systems in the Government ElectronicsDivision. When he saw the rising tide ofmicroprocessor electronics, he bought aSouthwest Technical Products 6800 computersystem to gain experience in the new field. Heuses the 6800 system to design logic circuits athome; at work he writes FORTRAN programsfor simulation on a Sigma 5 computer. He isactive in amateur radio and photography.

212 January 1980 © BYTE Publications Inc

small-scale integration logic elements.Software generation for suchmachines is now my current hobby.

The learning process can be imple-mented in various ways. One way isthe "reward or punishment" ap-proach exemplified by the gameHexapawn, which was described byMartin Gardner and based on a learn-ing machine developed by DonaldMichie. (See "Mathematical Games,"Scientific American, volume 206,number 3, March 1962, page 138.)

The computer's response to eachgame situation is selected at randomfrom a set of legal moves whose indi-vidual selection probabilities are theresult of a previous experience. Aftereach game in which the computerwins, the moves that it used areenhanced in probability. After eachgame it loses, the moves that it usedare reduced in probability.

Gardner presented a simple modelof such a game in which eachresponse was the label of a box con-taining a certain number of beads.Losing moves were penalized by theremoval of beads; winning moveshad beads added to their boxes. Theprobability of selecting a given movein future games was related to thenumber of beads contained by itsbox. Robert Weir described a simplerprocess in which the various responseprobabilities were either 0 or 1 ("Hex-pawn: A Beginning Project in Arti-ficial Intelligence," November 1975BYTE, page 36).

Win Table

Another learning process is theconstruction of a table of winningmoves for each position or situationof the game. Many games are charac-terized by the existence of such atable. Each player tries to move toprevent the other player from gettingto a winning situation in the table.Such a table is sometimes referred toas a game tree because of the multiplebranches that lead to a single finalwinning position represented by thetrunk of the tree.

For learning, the machine can ini-tially be given the table of all possiblemoves for each game situation, withwinning moves unidentified. For eachsituation the machine plays from, itfills in the winning moves by deter-mining which of its permitted movesprevent the player from reaching awinning situation. Furthermore, aftermaking its move, the machine may

In a game-learning pro-gram, the machine isgiven the rules of thegame, but initiallypossesses no strategy for

selecting its moves,iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiuiiiiiiiiiiiiii

again analyze the new situation,before allowing the player to take hisor her turn.

For the early games in a sequenceof games, when most of the winningmoves are unidentified, this processproduces many errors. However,when the end of the game can bereached from the situation beinganalyzed, this process correctly iden-tifies winning moves.

In subsequent games of a series, thecorrect entries appearing close to theend of the game permit the correctionof earlier errors. To do this, the com-puter designates as losing movesthose resulting in a situation from

which the player can, with a legalmove, attain a winning situation.

The net result is that during a seriesof games, the win table, which origi-nally identified none of the winningmoves, is gradually improved until itcontains no significant errors and asufficient number of winning movesto enable the machine to play fault-lessly. Thereafter, one of the twoplayers has no chance to win unlessthe other errs. Naturally, the gamemust be arranged so that the losingplayer is the human player; otherwisethe learning process would not be ap-parent.

The above process of computerlearning is quite similar to the way ahuman would learn to play such agame. At the start of the early games,play would be more or less random.Near the end of each game the begin-ning player would consider the oppo-nent's legal responses to each of thepermitted moves, and would try toselect one that prevented a win by theopponent. In subsequent games theplayer would remember the situationsfrom which he or she was able to win,

flftD DISC SVST€M

SUPERPRICE/PERFORMANCE

■ Complete Sub-System; DRIVE, CONTROLLER, and CABLES for S100computers ■ Uses the most popular drive for small business systems

■ 10 Megabyte formatted capacity ■ 5MB fixed platter plus ■ 5MB 5440removable cartridge for FAST BACK-UP and UNLIMITED off line STORAGE

■ Look Ahead buffer for maximum performance ■ expandable to 40 MB

■ Supported by CP/M 2.0, MP/M, Oasis, Famos, Fordos, Tempos OperatingSystems ■ Beautiful teak finish table top (shown) enhances any office decorRack mount also available ■ Dealers/OEMs contact John Costello.

XCOMP

XCOMP, INC., 9915-A Businesspark Ave., San Diego, CA 92131 • (714) 271-8730

Circle 190 on inquiry card.

January 1980 © BYTE Publications Inc 213

Circle 191 on inquiry card.

CP/M® SOFTWARE TOOLS

NEW ED-80 YEXT EDITOR

ED-80 offers a refreshing new approach for the creation and editing of program and datafiles conversationally-and it saves you money. Its powerful editing capabilities will satisfythe most demanding professional-yet it can still be used by the inexperienced beginner.Look at These Outstanding Features:

■ FULL SCREEN window displays with forward and backward scrolling for edit-ing your data a page-at-a-time, rather than line-by-line.

■ Provides you with all the features found on the large mainframe and minicom-puter editors, such as IBM, UNIVAC, CDC. and DEC.

■ Commands include forward or backward LOCATE, CHANGE, and FIND; andINSERT, DELETE, REPLACE, APPEND, SAVE, PRINT, WINDOW, MACRO,TABSET, SCALE, DUMP, and others.

■ Compatible with existing CP/M edit and text formatted files, with CBASIC, andwith Microsoft's MBASIC, FORTRAN, COBOL, and ASSEMBLER.

■ CHANGE commands allow you to make conditional changes and to use vari-able length strings.

■ Designed for CP/M and derivative operating systems, including LIFEBOAT.CDOS, IMDOS, DOS-A, ADOS, etc.

■ GET and PUT commands for concatenating, moving, duplicating, and mergingyour edit files on the same or different diskettes.

■ Provides you with fast memory-to-memory COPY commands, and an inter-mediate buffer for copying lines over-and-over.

■ Saves your last LOCATE, CHANGE, FIND, and APPEND command for easyre-execution.

■ Simple line-oriented commands for character string editing.

■ Safeguards to prevent catastrophic user errors that result in the loss of youredit file.

■ INLINE command for your character-oriented editing.

■ Designed for today's CRT's, video monitors, and teletypewriter terminals.

■ Thoroughly field tested and documented with a comprehensive User's Manualand self-instructional tutorial.

And remember — in today's interactive programming environment — your most impor-tant software tool is your text editor. ED-80 is already working in industry, government,universities, and in personal computing to significantly cut program development timeand to reduce high tabor costs. Why not let ED-80 begin solving your text editing prob-lems today? ED-80 is protected by copyright and furnished under a paid-up license foruse on a single computer system. Single Density Diskette and Manual: $99.00, or theManual alone: $20.00 (credited with purchase of the Diskette). Specify Disk make/model,5" or 8", hard or soft sectored. ORDER NOW and well pay the postage!

SOFTWARE DEVELOPMENT & TRAINING, INC.Post Office Box 4511 Huntsvilte, Alabama 35802

■■■f Dealer Inquiries Welcomed

■mb ® CP/M is a trademark of Digital Research

General Ledger

PAYROLL

Accounts Receivable & Payable

Flexible and sophisticated business software that isamong the highest quality on the market. Originallydeveloped by OSBORNE & ASSOCIATES and rapidly becom-ing a standard. Our service is support. We will send youthese programs with the proper I/O and CRT specificsubroutines for your hardware configuration. Get back tobusiness and leave the programming to us. Include hard-ware description with order.

• Accounts Receivable and Payable 145.00

• Payroll (California) 145.00

• Non California state tax calculations

(please inquire) 15-250.00

• General Ledger 145.00

• Multiple profit center option for G/L 25.00

• Manuals (each) 15.00

All programs in CBASIC under CP/M (includes source)UTILITIES

• DOS MOVER for NORTH STAR. Moves DOS and BASICanywhere you want it. (i.e., from 2A00 to 0000) 35.00

• ALS-8 MOVER on North Star Disk 35.00

Synergetic Computer Products

3885 Magnolia Drive • Palo Alto, CA 94306

(415)856-6049

Visa • Mastercharge • COD • Certified Check

CP/M is a trademark of Digital Research

and would attempt to attain thosepositions earlier in the game.

There is another interesting parallelto human behavior in a machine thatlearns by this scheme. The machine'srate of learning (ie: the rate at whichit corrects errors in the win table) isdependent on the skill of the humanopponent. Since the human cannotwin when the win table is error-free,the only way the new player can winearly in a series of games is to takeadvantage of the errors, by playing toreach those situations for which thewin table is erroneous. If this is done,the machine has an opportunity toanalyze the results of moves from,and correct the errors for, that situa-tion. On the other hand, if the humanplays poorly and does not take ad-vantage of the machine's errors, themachine does not correct the errorsfor early game situations, but wins inthe end game.

A final, and most provocativeparallel to the learning process ofliving systems is the need for randomtrials to discover winning moves thathave been erroneously erased ornever discovered. In analyzing agiven situation, the machine some-times cannot find a winning movebecause of an error in a situationcloser to the end of the game. I foundthat no fixed preprogrammed movestrategy would guarantee that themachine would correct such an error.

It was absolutely essential for themachine to try moves at random eachtime it analyzed that situation until it"accidently" made the correct move,played to the erroneous situation,and then corrected the error residingthere. This is a striking analogy to therandom attempts of the smallest in-sect (or for that matter, a humanbaby) to manipulate its environment.

A Suitable Game

As implied above, it is essential tofind a simple game to demonstratelearning by filling in the win table. Atthe same time, the game must be chal-lenging enough to maintain the in-terest of its human player. Eighteenwith a Die is such a game.

I discovered a variant of the gamein a book by Geoffrey Mott-Smith anumber of years ago (Geoffrey Mott-Smith, Mathematical Puzzles forBeginners and Enthusiasts, TheBlakistone Co, Philadelphia PA,1946). As described, the game was

214 January 1980 © BYTE Publications Inc

Circle 192 on inquiry card.

played with a die (half of a pair ofdice). One player makes a randomroll for his first play. Thereafter eachplayer, in turn, turns one of the fourvertical faces of the die upward byrotating it 90 degrees in a direction ofthe player's choice. A running total ofall the plays is kept, and the object isto make the total hit a given targetvalue on the move. Mott-Smith usedthe goal number of thirty-one.

I have shortened the game to thegoal number of eighteen, and haveallowed the first player a free choicefor the first move, rather than makingit random. Mott-Smith described analgorithm by which, given the currenttotal and the last player's move, awinning play could be derived.However, it was not infallible, parti-cularly near the end of the game.Thus the idea of the win table evolvedas the approach to a learningmachine.

Since the opposite faces of a diesum to seven, the rules for Eighteenwith a Die become the following:

The machine's rate oflearning is dependent onthe skill of the human op-ponent.■iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiiiiiii

after the first play, each player mayplay a number from one to six inclu-sive, but it may not be the numberjust played by his opponent nor itscomplement with respect to seven.Thus, if the total is seventeen, one is awinning play if the opponent has notjust played one or six. Sixteen isalways a winning situation for theplayer whose turn it is. The playercan win by playing two, or if that isnot legal, by playing one, whichprevents the opponent from hittingeighteen exactly on his turn.

Electromechanical Game Player

In 1959 I designed and constructeda relay and stepping-switch machinethat demonstrated this learning game.

I called it GLIM, for Game LearningIntelligent Machine. Photo 1 showsGLIM and the author (quite a bityounger then). Each memory bit wasimplemented as a pair of neon lampssharing a common dropping resistor.

One of the lamps of each pair wasused internally as part of the memoryreadout system. The other was in-cluded in a random display on thefront panel which was shaped some-what like a human brain. Thoughrandomly arranged (to preventutilization by the human player), thelamps that would be lit when the wintable was error-free were located inthe upper part of the brain display.Thus the degree to which the machinehad become "highly" educated couldbe estimated.

The memory was read out by amotor-driven scanner containing sixphotocells, one for each of the sixplays that the machine might make.A servo-mechanism positioned thescanner over a 6 by 18 array of neonlamps so that the photocells could

Photo 1: The author with Game Learning Intelligent Machine (GLIM) in 1959. GLIM was a machine built with hard-wired logic in theform of relays and stepping switches that played the game Eighteen with a Die. It was a forerunner of the general-purpose computerof today that uses software to play the same game. GLIM contained eighteen 6-bit words of memory consisting of pairs of neonlamps, one pair for each bit. Each lamp pair had a common, current-controlling dropping resistor.

L,

-v

E323 °

118]

''■ i. • ■ •

( START J

INITLZ

SET UP MSKTBLAND WINTBL

PRINT INSTRUCTIONS"READY TO START?"

INPUT"Y"OR "N"

Figure 1: A flowchart of the main routinefor the game-learning program. Most ofthe details that distinguish the game beinglearned and played are contained in thesubroutines.

LSTPLA — HPLAYHTURN— 1SCNFLG - 1

ADVANCE ONE MOVEAND ANALYZE GAME

PRINTYOUR PLAY"

DETERMINE MACHINESMOVE (MPLAY)

LSTPLA —MPLAYHTURN —0SCNFLG—0

PRINT "MYPLAY IS"

PRINT MACHINE SMOVE

scan ahead in the memory, lookingfor lighted memory cells through a"legal play" mask mounted on thescanner. Plexiglas light collectorsformed an optical OR function, whilethe mask formed an AND with eachneon cell.

For example, the photocell thatlooked at the row of memory corres-ponding to the current total plus amove of one was masked so that itcould see only the neon lamps in col-umns 2, 3, 4, and 5 of the memory ar-ray. These are the human's legalresponses to a play of one. The nextphotocell could see only columns 1,3, 4 and 6. Similar logic is embodiedin the program described in this arti-cle.

As described above, the machinewould play faultlessly after its wintable was error-free. With the goalnumber of eighteen, the first player(the human) has no winning play andis doomed to lose every game afterthe machine has learned the game. Tomake the game more interesting, thelogic was designed to cause themachine to "goof" occasionally. Itskipped the procedure of picking outa winning move and merely selected arandom legal play. In the programgiven here this is available as a soft-ware option. If selected, the goofsoccur at random (controlled by apseudo-random number generator)about once every eight machineplays.

Software Game Player

Figure 1 shows the flowchart of themain program for Eighteen with aDie. As can be seen, it is quitegeneral. Most of the details thatcharacterize it for this particularlearning game are contained in thesubroutines which are describedbelow. The storing of human play(HPLAY) and machine play(MPLAY) in lastplay (LSTPLA) is anexception. Another exception is thesetting of scan flag (SCNFLG) toallow the win table (WINTBL) to beupdated both before and after themachine's play is added to the total.

The initialization subroutine(INITLZ) is flowcharted in figure 2.Mask table (MSKTBL) is initializedwith a pattern of ones that corres-pond to legal responses to playsrepresented by the row indices. Theleast significant bit (LSB) represents aresponse of one.

Next, win table (WINTBL) is ini-

216 January 1980 © BYTE Publications Inc

( INI1

o

LOAD

MSKTBL

r oouiiii

[CO — 3F

ci: — ie

| 00011110

[21— 2D

1 00101101

C33 — 33

| 00110011

[41 — 33

00110011

[5] —2D

| 00101101

[63-

■IE

1 00011110

1_

LOAD W

INTBL

til —00

[18: —00

[191 — 03

[24]-

-03

RANUM

L— 03

LTSTINH-00

SCOREH— 00

SCOREM —00

SF — 1

( RET

URN J

.J

Figure 2: Flowchart of the initializationsubroutine (IN1TLZ). The bit pattern setinto mask table (MSKTBL) signifies legalresponses to plays denoted by the rownumbers. Win table (WINTBL) is loadedwith blanks until the six rows after thegame end. These rows are loaded to causecorrect winning plays to be found duringgame playing.

tialized. Rows 1 through 18 arecleared, signifying no winningmoves. However, rows 19 through 24(those reachable by attempted playsfrom 18) are loaded with ones in boththe 1 and 2 columns. One or both willrepresent a legal, winning humanresponse, and will cause correct winor lose move information to berecorded in one or more of the col-umns of win table rows 13 through18, when individual games have pro-gressed that far. RANUM must be in-itialized to any nonzero value for thepseudorandom number generator.

LTSTIN is a 2-byte variable that isthe operand for the legal test(LGLTST) subroutine. The low-orderbyte could be loaded and utilizedbefore a double-precision load andtest is made, so the high-order byte

InputCharacter

HexadecimalASCII

CT1024 TerminalResponse

SwTPC PeripheralResponse

Control-P

10

Cursor home up

Same

Control-U

15

Erase to end of line

Same

Control-V

16

Erase to end of page

Same

Table 1: Use of cursor and cassette tape control characters assumed in this program,compared with uses recommended by Southwest Technical Products Corp.

must be initialized to zero. SCOREHand SCOREM are used to accumulatethe human's and machine's scores,and must start from zero for eachseries of games.

After initialization, the main pro-gram prints the game instructions,ending with the question, "READYTO PLAY?" All such messages andformats are stored as strings of ASCIIcharacters, terminated by hexa-decimal 04 (Control-D, or EOT).

After loading the microprocessor'sX register with the starting address ofthe string, the string is output by asubroutine starting at hexadecimalE07E in the MIKBUG monitor. It tests

for hexadecimal 04, outputs the char-acter to the terminal, increments theX register, and recycles. Detection ofa hexadecimal 04 causes a return tothe user program. If you do not haveMIKBUG or a similar monitor, youcan easily write this subroutine.

Next, a human response to thequestion at the end of the instructionsis sought, a Y, or N, signifying yes orno. Again, a MIKBUG subroutine IN-EEE (location E1AC) is used for thisprocess. The ASCII characterrepresenting the human's responseends up in the A accumulator. Afterthe human's response to this ques-tion, one of two messages is printed.

FIDELITYCHALLENGER*

computerized gamesthat challenge YOU!

our prices are LOWERthan Sears Roebuck catalog!

__ -B^k *Wish Book for the 1979 Holiday Season Cpage B5B-BB1]

PUIS.... WE PAY POSTAGE!

Price subiecl lo change withoul notice. Relunds guaranteed.Circle 193 on inquiry card.

SATISFACTION GUARANTEEDOR YOUR MONEY BACK!

Quality Mam in U.S.A. Copyright ©1979 Factory Direct Sales

January 1980 © BYTE Publications Inc 217

Both begin by erasing the instruc-tions.

For a Y response, the message thencomprises the new game header,while the "thanks for playing"message occurs for any otherresponse. Instruction erasure is per-formed by ASCII control charactersat the start of each of these twomessages that activate cursor-homeand erase-to-end-of-page (EOF). TheASCII codes I have used for such ter-minal controls are shown in table 1.The codes are compatible with thoserecommended by SwTPC.

f gtvlhp J

GET ASCII CHARACTERIN A ACCUMULATOR

CONVEHT CHARACTERTO NUMBER IN A

YES

PRINT

"invalid"

LGLTST

SET

LEGAL FLAG

PRINT

"illegal"

HPLAY — A

( RETURN J

Figure 3: Flowchart of subroutine to get avalid, legal human's play (GTVLHP). AMIKBUG subroutine (INEEE) is used toinput a move. After verifying that theplay is in the valid range 1 through 6,LGLTST is called to see if the move islegal.

The "goof" feature causes

the computer to make an

occasional mistake.iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii

Figure 3 shows the flowchart forthe subroutine get valid legal humanplay (GTVLHP). This begins by look-ing for an ASCII character from thekeyboard to be loaded into accu-mulator A, which is accomplished byusing the MIKBUG INEEE sub-routine. Subtracting hexadecimal 30converts the ASCII code to a binarynumber, which is tested to determineif it is in the range 0 through 6. If thenumber is not in this range, an "in-valid" message is printed. It is thensubjected to the legal test (LGLTST)subroutine, figure 4, where it is com-pared with last play (LSTPLA) accor-ding to the rules governing legalplays. Legal plays are then loaded in-to HPLAY. Illegal plays are denotedby setting the zero flag bit in theM6800's condition register to one.

Figure 5 shows the flowchart forthe subroutine advance and analyzetotal (AVAZTO). Two totals are ac-tually calculated. One is TOTBCD, abinary-coded-decimal version of thetotal that is output to the terminal.Each time it is augmented by addingLSTPLA to it, the 6800 decimal adjustinstruction (DAA) is employed torestore the number to binary-coded-decimal form. TOTAL is the total inhexadecimal notation and is used inthe program for detecting the end ofthe game, advancing the win table in-dex, etc. If the total equals or exceedshexadecimal 12 (decimal 18), the flag,ENDGAM, is set, and the win or loselogic decides who won and in-crements the scores acccordingly. Thescores are used only for display, andare stored in binary-coded-decimalform.

The next subroutine used is revisewin table (RVSTBW), shown infigure 6. This process is accomplishedin two steps. First, the rows of thewin table corresponding to trialmachine plays of 1 through 6 areANDed with corresponding rows ofmask table, which contain the legalresponses to those plays. The resultsare stored in a 6-byte table of winninghuman response flags (WHRF).

Next, machine trial play pattern

(MPTPAT) is initialized to hex-adecimal 20, which sets bit 5 to 1. Theindex register, X, is initialized to acorresponding value of six. Startingwith six and decrementing facilitatessubsequent use of the 6800's stackpointer.

In the second phase of this sub-routine, each row of the WHRF tableis tested to see if any winning humanresponses were found in the firstphase for the play held in the Xregister. If no winning humanresponse was found, MPTPAT isORed into the win table row cor-

f LGLTST J

FLAG—0

A —MOVE TO TEST

YES

YES

YES

A —A+LSTPLA

YES

FLAG —1

!flag=i is~~] error return j

f RETURN J

Figure 4: Flowchart of the legality testingsubroutine (LGLTST). The legal-moveflag is first cleared to indicate an accep-table move. The computer-generated ran-dom plays of 0 and 7 are rejected. A trialplay is then compared with the last play(LSTPLA) and with a value of7+LSTPLA to implement the rules. If theflag returns from this routine with a valueof 1, the move is not legal.

218 January 1980 © BYTE Publications Inc

Figure 5: Flowchart of the subroutine forgame analysis (AVAZTO). LSTPLA is ad-ded to two totals, a binary-coded-decimalversion for display and a hexadecimal ver-sion for internal program use. If the gameis over, the binary-coded-decimal score ofthe winning player is incremented.

YES

I DOES

TOTAL EQUAL

HEXADECIMAL \"I 12 I

I I

f AVAZTO J

ENDGAM — 0

jTOTAL

! LESS THAN

\ HEXADECIMAL '

I 12 I

I I

ENDGAM —1

YES

PRINT"I WIN"

YES

PRINT"YOU WIN"

INCREMENTMACHINE'SSCORE

INCREMENT

HUMAN'S

SCORE

( RETURN J

responding to the current total, toadd an apparent winning move to therow. If any winning human responsewas found, the Xth column of the wintable row corresponding to the cur-rent total is zeroed, by being ANDedwith the one's complement ofMPTPAT, thus deleting any er-roneous winning play indication.In the first case, X represents an

apparent winning play for themachine, so it is tested to determine ifit is a legal play. If so, it is stored inmachine play, winning (MPLAW). Xis then decremented and MPTPAT isshifted right by one place, to corres-pond to a play of five, and the secondphase is repeated. At the conclusion,MPLAW holds the smallest winningplay discovered, and the win table

NEW,'

Circle 194 on inquiry card.

.WANT TO BE KINGvl OF THE HILL?

Treat Yourself Royally with GIMIX

Unique and Incomparable Boards

and Systems... DIP-switch Versatility

for use with both SS50 (6800) and

SS50C (6809) Systems (SWTP. etc.)

32K STATIC RAM BOARD

• SS50C Extended Addressing (can be disabled)

• 4 separate 8K blocks

• Low Power 2114L RAMS (2 AMP TYP. for 32K)

• Write Protect

• Fully Socketed for 32K

• Gold Bus Connectors

16K. $328.1224K..$438.1432K. $548.15

16 & 24K Versions are socketed for 32K and requireonly additional 2114S for expansion.All GIMIX Memory Boards are assembled, burned-in,and tested at 2MHz.

FACTORY PRIME STATIC RAMS2114L 450 ns . . . $5.90 200 ns.... $6.904044 450 ns $5.90 250 ns.... $6.90

Add $5.00 Handling on Orders Under $200.00

THE UNIQUE GIMIX80 x 24 VIDEO BOARD

• Upper and Lower Case with Descenders

• Contiguous 8x10 Character Cells

• Hardware Scrolling

• X-Y Addressable Hardware Cursor

It is the ONLY Video Board thatgives you Software Control of:

• A programmable RAM Character Generator plus2 EPROM Character Generators (128 char. ea.).

• Selecting 256 Displayable Characters from 384available.

• Normal or inverse video, full or reduced intensity,or combinations of these by both ASCII Code andBit 8.

• GHOSTability — multiple boards at the same ad-dress.

Fully decoded occupies only 2K of address spaceFully socketed — Gold bus connectors.Assembled, Burned-in, and Tested at 2MHz.

Deluxe Version $458.76

Without RAM Character Generator.. $398.24Other Video Boards from $198.71

THE^CLASSYCHASSIS

• Ferro-resonant Power Supply

• Heavyweight Aluminum Cabinet with fan and pro-visions for two 5" disk drives.

• 6800/6809 Mother Board, fifteen 50 pin and 8 DIP-switch addressable 30 pin slots — Gold PlatedPins. Fully decoded $798 19

With Baud Rate Generator on Mother Board ... $828.19

32K SYSTEM Incomparable Features,at a Comparable Price! $1,594.59

Includes: Chassis, 6800 CPU, 32K RAM Board,Choice of I/O Card.

16K Version of above $1,374.49

Phone, write, or see your dealer for details and prices on ourbroad range of Boards and Systems for the SS50/SS50C busand our AC Power Control Products for all computers.

Gimix <s

1337 W. 37th Place • Chicago, IL 60609(312)927-5510 • TWX 910-221-4055

The Company that delivers.

Quality Electronic products since 1975.

GIMIX* and GHOST" are Registered Trademarks

of GIMIX Inc.

January 1960 © BYTE Publications Inc 219

f RVSTBW J

MACHINE'S WINNINGPLAY —0X — 1

,"

WHRF(X) —W(TOTAL + X)-M(X)

X —X + l

N0/y,

7 ^>

( RETURN )

Figure 6: Flowchart of the subroutine that revises the win table (RVSTBW). The wintable row corresponding to the total before and after the computer's play is revised bytrying all possible computer plays, and by selecting those plays that block the humanfrom a legal winning response. The smallest apparent winning computer play is saved inMPLAW. The following logical notation is used: "■" is logical AND, "+ " is logical OR.

row for the current total has been up-dated, based on examining the nextsix rows of the win table.

Making the Machine Fallible

The subroutine select machineplay (SELMPL) shown in figure 7 isneeded because sometimes nomachine winning plays are found, inwhich case the machine must choosea legal play at random. If the "goof"feature is desired, the program's cur-rent winning move (MPLAW) will beignored, and a random play will beselected.

The generate random play(GNRNPL) subroutine actuallygenerates numbers from 0 thru 7. Theoccurrence of a zero causes the com-puter to make a random move if the"goof" option is active. Next,MPLAW is tested to determine if ithas changed from its initial value ofzero. If it is no longer zero, its value isloaded into MPLAY as the machine'splay. If MPLAW is zero, another ran-dom number from 0 thru 7 isgenerated and tested for legality.Numbers are generated again andagain until a legal one is found for useas MPLAY, the machine's move.

The GNRNPL subroutine (figure 8,page 229) uses logic feedback arounda shift register to generate a pseudo-random sequence. Two bytes plus thecarry bit comprise a 17-stage register.Since seventeen is a prime number,coding theory assures us that everyunique feedback arrangement willgenerate a sequence that will notrepeat until after 217 -1 (or 131,071)shifts. The three least significant bitsare masked off to generate numbersfrom 0 thru 7.

Three shifts are used to generateeach play, to assure that all three bitsare randomly changed. I could haveused a shorter shift register, but Ifound that with a shorter register, agiven play was followed by only afew of the theoretically possiblevalues. A few additional instructionsare required to implement the17-stage register, in which any givenplay will be followed with nearlyequal probability by all of the values0 thru 7.

The feedback comprises the Exclu-sive-OR of the zero and third orderbits. This is accomplished by ANDingthe low-order byte with hexadecimal09. The carry bit is set to one if theresult is one or eight and to zero if theresult is zero or nine. The carry bit is

220 January 1980 © BYTE Publications Inc

f RETURN J

Figure 7: Flowchart of the subroutine that determines the machine's play (SELMPL). Ifthe goof option is selected, the odds are one in eight that the computer will make a ran-dom legal play, instead of playing the apparent winning play discovered while revisingthe win table. If no winning play is found, a random play is made.

then shifted into the most significantbit of the high-order byte. The leastsignificant bit is shifted into the carryand then into the most significant bitof the low-order byte. The latter'sleast significant bit is discarded.

During initialization, at least one ofthe shift register bits must be set toone, otherwise only zeros wouldcirculate endlessly. The full 17-bitword cannot take the value zero, butthe three least significant bits can takethis value.

Other Random Methods

The above scheme has the disad-vantage that the sequence is fixed by

the initialization constant, so thateach new series of games set up byloading the program start out withthe same sequence of random plays.If the human should play the identicalsequence of moves for a whole seriesof games, the machine's responses tothose moves would not vary.

I have employed a way around thisin other machines using the player'sresponse time, measured in sufficient-ly small units, to generate randomnumbers. For example, three asyn-chronous free-running flip-flops atfrequencies of 100, 141, and 173 Hzcan be allowed to run during the timethe computer is waiting for the

human to respond. When stopped bythe response, they will represent arandom binary number from 0 thru 7that depends on the human's responsetime measured in hundredths ofseconds, modulo 7. Using frequenciesrelated by ratios close to s/2 and \J3assures that the flip-flops willgenerate a relatively long sequence(of order 100) before repeating.

This approach was not feasible,however, when using a MIKBUGsubroutine to get the human'sresponse.

Listing 1 is the program listing inassembler format for the SwTPC6800. MIKBUG subroutines werefreely used for input and output. Allconstants and variables are stored onpage one of memory, starting at hexa-decimal address 0020. The initializa-tion subroutine is also stored here.The main program begins at hexa-decimal 0100. Messages start at hexa-decimal 02D0 and extend to hexa-decimal 057F. About 1380 (decimal)bytes are needed. Addresses from0000 to 001F were not used, in com-pliance with SwTPC's suggestion thatthese be reserved for a disk operatingsystem.

You may wish to revise messageformats. Revisions of starting ad-dresses will require revisions of theload index register (LDX #) instruc-tions in the main programs andsubroutines wherever the messagesare printed.

How to Play Against the Machine

The human player has several op-tions for competing with themachine. With the goof feature dis-abled, try to see how many gamesyou can win, starting with the wintable empty, before the machine iswinning every game. Your strategyshould be to induce the machine toload as many errors as possible intothe win table, then play to inhibit themachine from correcting those errors.

When you have memorized all ofthe winning plays for each total, youwill do better. This knowledge can beacquired through experience, or byexamining the win table after themachine has thoroughly learned thegame. Unless the goof feature is used,some winning moves may not befound by the machine, but it will findenough that one or more will be legal

Text continued on page 229

January 1980 © BYTE Publications Inc 221

How to Use the Program Listing

The program in listing 1 wasassembled using Jack Emmerichs'sTiny Assembler for the 6800 pro-cessor. Since this assembler oper-ates using only one pass throughthe source code, it must handle for-ward references in a special way.

A forward reference occurs dur-ing assembly when some instruc-tion in the program references asymbol that appears after it in thesource code. (A symbol is a labelfor an instruction or for data.)Since the assembler has not yetcome to the referenced symbol anddoes not know what its address is,the assembler cannot initiallygenerate the proper object code.

If you have your own assembler,you will face no difficulty in usingEighteen with a Die (since you willprobably wish to reassemble it onyour own system). If you do nothave an assembler in your 6800system and want to enter the ob-ject code directly from listing 1,you must be aware of the behavior

of the Tiny Assembler in its treat-ment of forward references.

As the Tiny Assembler scans thesource code, it maintains aforward-reference table inmemory. When it comes to a for-ward reference, such as:

JSR TXTOUT

(which appears at hexadecimallocation 0109 in listing 1) that hasnot been encountered and is there-fore not yet defined in the symboltable, the Tiny Assembler gen-erates "dummy" code (consistingof zeros) in the locations where theaddress of TXTOUT should be.Data identifying TXTOUT andkeeping track of where the dummycode was generated is placed in theforward-reference table.

When the Tiny Assembler getsto the definition of TXTOUT in thesource listing, it resolves allprevious forward references toTXTOUT at once. At the placein listing 1 where the symbol

S-100 INTELLIGENT

COLOR GRAPHICS BOARD

CGS-808

graphics board for the S-100 bus The

GGS-808 is simple to use. just plug it

in and run, It requires no memory

space and little software overhead.

■ •;.., ■ _ _ ■ ^ ■ '- ■■ ■■■

Features:

• MC6847 video display generator, on-board 8085 microprocessor.

• Eight colors—green, yellow, blue, red, buff, cyan, magenta, orange.

• IT programmable modes ranging from 64x64 to 256x192 in 4 and 1 colors.

• I/O mapped for true S-100 compatibility.

Software:

• Firmware Pack Mclear screen, change mode, plot point, draw line, alphanum-eric/semigraphic, read/write screen.

• Firmware Pack II—relative and absolute modes, ellipses, alphanumerics (two sizes),3D hidden dot.

• Firmware Pack 111—shaped ellipses, shaded polygons, chain lines, move point, moveline, bar graph, expansion port driver.

CGS-808B (Bare "Kit") $125.00

(Includes PC board, documentation, MC6847, MC1372, 8085 and 2708

with Firmware Pack I)

CGS-808A (Assembled and Tested) $399.00

Firmware Pack II $ 60.00

Firmware Pack III $ 99.00

SubLogic 2D Graphics Driver $ 35.00

SubLogic 3D Graphics Driver $ 30.00

Phone Orders Welcome — Visa/Mastercharge — Add $3.00 for Shipping & Handling

• California Residents Add 6% Sales Tax — Call or write for your free brochure.BIOTECH ELECTRONICSP.O. Box 485, Ben Lomond, CA 95005(408) 338-2686

TXTOUT appears, we see thesource code:

TXTOUT JMP PDA TA1

At this point the following ob-ject code is generated:

7E

OWE

7E

E0

010A

01

8E

0117

76

0126

67

0137

56

018B

02

015D

30

017F

0E

The resolution of hexadecimallocation 010A uses the extendedaddressing mode; other resolutionsshown use the relative addressingmode. After the address of thesymbol TXTOUT is found, thereference to TXTOUT is deletedfrom the forward-reference table.

When the output of the assem-bler is loaded into memory by theloader program, the forward-reference resolution data is writtenover the dummy values (zeros)that were originally generated. Ifloading the object code by hand,they should be written over thedummy values in the same way.

You can, if you wish, look at thesymbol table shown at the end ofthe listing at any time to find outwhat values were obtained for allsymbols during the assembly. TheTiny Assembler uses only fourcharacters (the first three and thelast one) of a symbol, and the sym-bol table uses these condensedsymbols, not the full spellingsfound in the program.

Complete documentation aboutthe Tiny Assembler appeared inthe following BYTE articles byJack Emmerichs: "Designing theTiny Assembler: Defining the Pro-blem," April 1977, page 60;"Implementing the TinyAssembler," May 1977, page 84;"Expanding the Tiny Assembler,"September 1977, page 44.

Reprints of these magazine ar-ticles plus PAPERBYTE® barcodes for optical scanning areavailable in book form under thetitle Tiny Assembler 6800, Version3.1, by Jack Emmerichs. You mayobtain this book for $9.60 (in-cluding postage) from BYTEBooks, 70 Main St, PeterboroughNH 03458.

222 January 1980 © BYTE Publications Inc

Circle 195 on inquiry card.

Ul

UJ

or

O

1-

o

rr

3

uj

z:

Ul

,»

o

i-

or

a

o

z z t

>H UJ |

X. z :

O .

>- X

e: Ul

u. o

I- C3

D Ul —i E —i ->«H X O _J X >

3H

X Ul

5S x

UJ CQ

xo

cj cj

e:O <x

*•* #cc >-

h- o < fe:

mUJUJE.Z UJ -J ID

JU. .

w *

Ul

hoiuC

o —

X Z

Kl

M

■Ka

t-H

-J

CQ

Hz

Kl »-.

tfc 3

CA**CM

± z K S

=1 H a: x

z in o o<r H o o

X JU1W

<r <c <t

<£CX<XX

i- _j o m z= a.

ui <n < x x

z: O (- 5- a.

UJ

z

■a <r < <z <r<r x <: <i <: co

HJHHhh

inu JtnM

O CO

Jw

t—1

o fflw o w w tn k

s

s

23

oo

5

m

o

ox

CD

:*:

<t

*-t z

1— O UJ

„

E:

(-

=3 UJ f-

Ul

B

ae

O

x >-ui

z:

1-

tn

i— a z »Ul<; O >-z uj a. ■

<x

X

1—

UJ

H

5

—f=g3i-.

*

X

Ul

H OC O

1—

a

zx z

z.

o

-HUll-

PH

ff:

x

oc <t UJ u.

Dr

<:

x

x cd_

IX

i—

H

»-

H

^

■<r

— :=> uj

u-\

3

or

S E

t-

m OUJEd 1— UJ >-

E3

O H-

s <r

,—1

1-

5?

—. tfl

BE

£ X = "

CM

e;

X

o

*rt =*fc

•"•

>tfc I-1 i-t *t

iZ

^

t—

o

to co x

xx xx

a

XKQ.

x o

Ul

DWUlE

UJ

O

co

e:

o jt j-j-jom

-J CD I

UJ >-

_j <r

CO JU.

<t a. »-h

f->

c^ • •

ZQCDm

.-. <r -JUJ

•

s u. cr

>■

o

<c

UJ • o

• _J

H ^uj a,

>-x

0<£

i

<r

z: J < •

c~

_j t—

uj a. cd o

>-

x ui

O _J

<I

<x

-a <t

_J

• _j

o e; z o

0,

X

• I— UJ

D

CD UJ O

t—

_J z:

<t *cc: 1— SS

Ul

< <c

_J CD O UJ <t

CD

»■ <c ^- Ul

UJ >.

_] ut •z; Gu op • t-

or

_1<C

ZD

-J

CC Ul —•

o

c a.

=5 ^ =- _J

>-

M X

f—• <r o <c a

c

_]

O-hH

ff ^

• Ul Ul o _J

H

> 1-1

X MHfl

z

en :> h-

•—t

I— 1—

H7UJOO

1 3 or) o oIt- o: x ui

Ul U] c/)X DC

OJ >-J t\J (

=> Ul S ii-X

O ^ O %(-

o_ cd a.

1—0- <t

nx) 1

- a.

u] <z or i— H

°^uiej3

XH

r- d- Ul —

CD x -J =»fc

or »• i

h o :

X Ul •

UJ •

or cd

<x <c <x <t <c

<<c<iXQrxorxor xor or <i <r <r <r <c or

HHhCH/iDmDt/lCtncnD'-'CHHwUlUlUl-)CO-J-D-J-3-JcOr)_Jul_JulUl"-3

UJ t/i UJ i/} !—■

or x o: x -t => uj

O 00 O CM Ul CD UJ

o H o t— uJ h- uj :

i in D U) D E x z •: % O % O % H M =

t-GfXDTXDTXQrQTCUOiUJCyiO iVjC UlUlEl-CO-J-3-J-3_JCD-DO

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA— iO C7\ «^C=it2ISCD Sf^

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

S SCO S*S W Sl1*-"^ '•T^r^"

f^u.bJr-coc)Wi3p-coowr-li.r-»>r^^

UJDUJDD-r-

co co o m m co w

G)St*J ^T<r'«TtSlSSUJCSUJQG|Jsi'c'"'*''S'*'''*:'"G)

ujouj u-oor-r-t-uiouioujoujoocor-^r-r-oooo^- <T5icM7imocoocooo]ucoiii<7iCACo^aim

sissssscas-^u]

SSStlJstjJSISl'jJ'"T

OMJOUIOUJOO-^■COOCDOCDOCOCOCO

^w^cuClBW^^^<owt«^olnwwwBBwW(71cJU.-K5K)WaImaJ^lOU)|ac^]l/^^' <Qqio^ com qu-- ■O'AcocottcDDS'ow oiuw-k)r-r*r^r^r-i^ooooooeococDtccoencnc^aio^c^<7^ssGSisicsiS

oS

lu

85

JPI

■u

ft)

c

0

Q

"^-

6

ts a

"0

0

9§

boUj

9

be

"a

u

sa

Ul

a.

tv

-a

F

=

QJ

-as c

o °

f i ui

\J ui

cu

.. u

-1 S c

M ^ S

I-S o

2 S £

* » # **

**

*#*

*

*

**#»»***

CD

<r

C3

Ul

5.

u:

■

I

'Or

t^

P£

UJ

CJ

>~

*

<r

< m

<t

a.

"

Ul

u.

o

zr

+

o

e:

i—i

CC

Ul

UJ

UJ

•

_J

M

CC

or

CO

<:

x m

•■

3:o

f—

o

t^S

»—t

i—(

(3

1—

z:

HH

o

X

5

«_

u

a.

OC

Ul

CJ

Cu

<r

0=

t—

H

CD

G

UJ

z;

(—

Z:

or

_-i

z:

i—<

CD

Or

.—i

or

•

a.

CC

t—

z

a.

CO

or

o

.,

W

e:

*.

>.

or

or

or

Cfl

CD

Ul

Ul

CO

n

3

m co

CD

CD

CD

K

:*r

m oi

CD

x.

g

:*:

e: £.

e:

E.

£3 o

N3

<t CO

UJ

h. <:

UJ

o

(0

r-

<t —

s.

t£

cs

s>

=D UJ UJ

Ul Ul

UJ

UJ

feR

m

3

ZJ

3

=3

o

a

©oo

Ul UI UJ Ul UJ

J

Ul

„

Ul

fs

x or

<£

UJ

CO

E

t-

Ul

^i

H

<r

SB

o

3

3

cu

# »-«

CD

o

O

CL

r-'ul

19

Ul

a

or

f-or

—. uj

CO it

orco >- ■« zic:<Ett:tiiLn _j ul UJ<I 0u UJ H cc

e: e; i- o

cd <r <c o

to z: co a. ui

UJ l-H

en z: o >.o

?Z2<0O i-. UJ _1 CD0-3 CU

ui , or •

UJU.O J£

or o u. <£i-. a

JUJUlccZ

S-J CD t— <tCO <cuj <r o_ • •_ii- & e: x

cd a. ui

rJUll*-

t— en <o o i

x o I

«H ■

U1.-J

• U-

cq x <r<r o uit- u. e:

: 3 CD

[ J§

J <r ui

. I— _] • z

O CD <t

iHcclUE

o cc n:u_ u. x

«-H x

UJ CD

i— _J uj z:uj co H >-t •ui <r <r z uii-t Q z: >_

• X CD i-t <tU<E3 J<C > O CLl-J O Ul

UT i— 0 ui e:

n cocui cl o _Jz ui (- <I

mUIlomX

[-. (_ (_ u.

<C X

_J Ui • (

o, e _j ac

CO H te: o <r tn ■

. 3 UlO CO

>->.UJH Jh

i-t —i <r x • oco o > o x ui

OECD-J

z e: mo,

UJ 3 co < H t

cd e» <r o

i3UIH<ti— 3 or

3 z:

X •

Ul Ul ui

_J H H*

C0 H l-H

<r <r m

H x

SC UJ CD

CO Ul i-i

e: o

B.H

UJ 01 Ul

MUl<i

CD CQ X

mmxmmmcamcae:e:e:e:e:e:e:e:e:

m

x e: e:

E.

e:

o ct x

X

xxxxxxxxx

X

_J -J

i- t e: o <r co

«IUJU1_JCD>--J3:-J

e:

pa x

s

i- t-

xxx<Eca<rxprU-

Ul •-<

xooooclco^-cj

z

e: 3

elow^hx JIW #

* ui

Ui _H —

—

—

CM CO CM

EC

m

PI

:-

3£

E

3C

it:

X

X

or

XX

X

9

X

>

<r

o

_J 3

-J _J

t->

m

SB

X

X

(0

^

<T

E.

e: # ui

.=«

X

CQ

h- X UJ C ro

QaeKjX— XXCMXXrOX

WE4S*-W*W^*K1at

<c<i<r<E<i:<t<t<E<t<:

CcDOHQHf-QHHQH

o_j_jLn-Juiui-Juiui-Jui

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

SICM

(SU-isUJ — ^DOcMir>K>Kl

ujyji^wi^r^UJNr-wr'occ<cco<r<i:co<x<i:co<:

SSSSSQSSSSSSO^<mWsssSQ^^S-N^^^^hCOi^^CA<OOWWK)^^Wco<C<OCSN^^tC<IOl«lQN

ssQscssssisc.ac£™ssESQSsssssKscasssKcaKQcsoessscaesics;Ke£sc3G-s

January 1980 © BYTE Publications Inc 223

a:

*******

<: <t

CC CD

-J ^z <r ouj cd *-.

in o

OrQ-UJ ECO O

— en — in ^

ui o a

ffiomcocc

cc

H

(')

CD

o

s:

<c

Ul

>-

uj

E

2

t

CD CC

O

CC

<c

S

CD en

in

>- C CO

[-•

a.

—^

►—i

2

a-:

<r

Q.

H- -J

CO

z t-

s

_j

-J =-

_j

UJ o

<t

cl re o

cu

J«H

z

H

5 z

_] O

V

(-«

D

o

*-> b- <x

h-

t-«

t—

UJ _)

2:

(-*

*

O

o

_1

in <t

I

<r x"

<r

x

I-"

Q >-

<t

-J <c

_j

<ca:

N

»-

C3-

M

<c

o

Ul 1-

.-h t-i UJ<2D

UJ Q—. 2tfl UJ

CD CC

CC _J

5 o

CD JZ

in o a. ccui h- t- 3

^ i- _j x

<t CO

o o

O COCO H

i- o

o \-

D.2 ►-<

1

tn <c E

re -J -J -J <r

co a. <z <c cd

i— h- h- t— co c;

DW00-.W~

^ l-H C

as g

ro e x —■ u<r =»t t- =*t in

<t<c <r <c <c <c <r m <c <x <r

D<c<c><cc<cQ<rcot--,of^C3i--'C2fXCC<i:C=i<i:<rcn

D<tl-iDmDClH5j2WliJWUJDU]DQ<lHH<DWJTJ<r(ficnCQHhCQHcQJTJ<lDv)Q;

O Ul

>-cc

»-i occ =

5 5

h- O O

x — o a

H =*fc en in

<t <c <zcc <c Q <r <r co

l/)QD<rhH

-a _j <c a in cc

p

AAAAAAAA

* t*.*.-**.-*-**.-* * <AAAAAAAAAAAAAAA

AAAAAAAAAAAAAAAAAAAAAAAAAAA

C3 *t <Z &> S3 W

Q "V O *f S3 CO

CQ0OCa,*~KvC:)Gl^C>r^

w ~ r~ — r- -* i— co—•cacjco-c

CnSl CM CO CO CnCMCnCOrOSlCaSl

S BS S3 **> W f*

Gi l*J G <I T «r

u.«uja wwf- ca o co cr.cn

<TE,U|-^,^<T-^oC2

ca s: ea —• -*• co

S3 S S Q C2 "T

CQ^r-UJQWCQ^sDuCl^Dr-UJOWCQ 0»t- CTi^J£n — Cn O CO criChChCOCNJ^'^COiACOOCQ co oi —' Ch »0 —

A A A A A A

UlUJOWCOCTi^CTiO S3 CO CC <?% — OifO

cocou~*<3:oUJSQJ<:rVJcocoCi-fOt7i<7) c?tC7>c2^iZ>c2^c^c2iC^c7ic2^Kis,^'KiWco<;ooCiJu—■<rr^^mOU.«^lr>r^co<c2i^c^^'^^catococT1CQUjQcOroir\

OOCOOOOODClOOOODClO OOOOOaODCOUJliJ^UUJU]U)LiJU]liJUl^U.U.llElutQSS|SSBS^«««rt^««|a-«WWN^— — — — —«——<—— — — — —« — -' «-------«««««««-«-«««--^-«««(\iwcOWWNNNCJWWWNWWWWWWWCOW

03

i -J

E3

£

CC _J *f- CQ CC

c<r »J

- Ul >- Q_

= o ■

Hm a. e

3 CD

UJJIU

tn en **< ujz ^, i- _j

o>zxwcu uj <i uj enwcru2UJ en -

CC C I- UJ3: U. UJ en

C?S

xcr,

Ul =^

cc inUJ uJ

> _J

' >-h * CC

CD

as <cUJ ccCQ CO

■ >--J

- <x. a.

o <* ui a. m

^~ CC 1

: <r <r t

)Dh,

I- crocen w enHim_Jtou enen-J

cc <c cc <cen en en ccen J "3 co

CC <I

tn cc

CO CO

H a.

UJ

cc

= x

ts UJ

S

KS

O _J

<r ui

—. ■&.

*fc CD qfc CD

e:

xh-

W »-4

^t

H«tD

<c <r

CD cc

en uj a. u:

CC <t

o^ en

5 _) E _J

o

en cc

o -^

en co o co

_j

CO CO

h-

a.

=3

T

O

1

f- >

!-■

f-- CD

a:

<x

en cc

CO

cu

AAAAAAAAAAAAAAAAAAA

A A A /A

A A A A A A

A A A A A A A

A A A A A

5

UJ -<r

<r co

os

is ta ta c\j *£>

S S B lA "^

co t- ea ca co s: uj*r -<t cj es «r\ uj co

ea ca <cta sj <e

ca uj

uj t«

— ta ea ta W ea

W < fO Q S B

Q UJ UJ

E QUJ

co ca ca ea s- ca

"*T S 5 S D w

CQ u"\

00

^-C3

CO CSJ

o <r

CO —

f*- CO CO CTt 0\ "V

r^- r- uj d w o 5)

Oi CA o CO en CO CM

ui co ca Q)

O — CO CO

ui-Hwr-wcoQU1

a _ s u. _ u.

CD Sj CO CO CO CO

o S CO CO

r^ r- o w uj o caoi ca co cm o co co

en si en k>

r- i- o

VD CD -V

<c«:«ou.c\i,<rtD

r-

r~ cr)CQUjQCou-\t^r-(^UJ<:oUiUJ<rr-ccir-cocriU.—.—.—.^r^r-F-r- cocococococo'^ cocococoe:— co'ocoir.r- &, <?, a\<z

S3 C7i*OiOr^- CTtCQCD'^UJiscOCO*!'*'"'^ (7iU Ws s tfl N ^ iTi iA in

<cro<c<c<:<r<t<r<r<rcoccco<toncQcococooocQCJ)oooo

*-j

ts Si

ca

SI s.

SGfSSISSGS.

QEHSGSSSS

ea ea

ca ea s ia

S G. G Q S. O t IS G G C. S G

SB E BQ EB

ea s: s> ta

ea

eaeacacacacaeaeasieaeaeaeasica

224 January 1980 © BYTE Publications Inc

Ld >-■J<E

f- I—

Ul £

t- O>-H ClCD UlLdLd CC0= cc

JO

o cc

F— < H (—

CO CC UJ UJHQ.Z

>-

tn

CL

3

O

H

V-

O

=>

ac

CL

S Ld

o

C3

cr.

<t

_J

S

l-«

<r

o

Cc

UJ

cn

t—\

Cl

UJ

-J

cc

C0

H

CO

Ld

t—

UJ

(—

<c oc

CC

<

(-<

o

Ld

CC

Q_

H»

:>

O

tn

o

o

U.

3 Ld

£

*-*

cc

— — CC

CC Q_ Ld

£ m*

S • H CL

CC O 3

UJ t-i ^ UJ

co in tn

e: »-h • id

Z LOO •

o o u.

EI CD Lt_

O U_ O

O O -

z: O Q C

U- i-h f—

i-h <C CD2= CC Ld

UJ >.CD <c

Ld f-

CC in

g

Ul

cn

s

UJ

o

f5

<r

CD

cc

Ld

>■

CC

UJ

0=

f-

s

>-

<x

_)

_j

cc

CL

a «!

3

- Ld >.

: c-t~ ccH — >- oc

co <r

> II o

3

5 I _J UJ

O (— CO t— o

<T DL

CC :sC

O en

x <c iuj ,— ■

: i-h CC

] CO hO >-1—

1 I _J

i-iCL CO

CO <t ul

>-

CI

cc cc

CQ UJ

w m

uj en

IXi <c

a x z: x

2yiOUCCLOC

cr> ocOJ ==

CDCC

o

ccen

"3

ii

t-H

f-

H

<

CO K)

CC

in

_j

CO

w

_)

CL Cl

*z

H<

CD

CL

H

CL

cn cn

o

_J

CO

<

<

G» <c

cc

<c cc

Gf

«e

<t

UJ cc

w

f-«

cn

Ld

D H

DJ CQ

~J

in

-d

CO

-J in

S£

CO

rO

;=-

2

_

^

<

—

CC CQ

CC

<

<r

6

<E

r-

cc

^

CD sfc.

ID

CC

cc

CC

%

CQ

CQ

CQ

<r

<c

O

Cl o Cl o

UJ o

CL

DC

2

UJ

<c

(3

cn

!E

EI

LJ£_J^UJ

O

o

ZFt D

z

(-.

<£

o

CO CD O

CQ CO

CC

cc

o

CO

j

<c

or

AAAAAAAAAAA

A A A A A

A A A A A

A A A A A A A

AAAAAAAAAA

AAAAAAAA

S S S)

in

O C3Si (7»

cn ro t~- s — <s f-

CM

uj ai

CTi^O

CQ SI

Si SIS> Si

CQ —' ^ i

OiSlCOCO C0SlC7lCQC\jaiCnSl»O

Si El E

Si CQ CO

UJ CO 00

OBS

cr. —• st co

f\ Sl Si C3DOOOOSCOSSl^S.f^SlCs] C^CO^Q

VIp; > VJi — Ol ' l.\J Wl^J U-J Vil t\J W) Ol W W u-l liJ Ul IU t\| Kl UHil nj u cj ^ ^j ■—' v-< i.\j >—; >c* I.NJ <^i. o* ' Q*. ' tii I.NJ 1/) U.1 *"J

oj-TiAccr^ci ctiU oUJUJts—«— — cssiSifOto»AiAiri'*:'''^"crtCQC0 cnUJQpo m[^-<tcr><r<:<3:siS: s-Qkhoia^^ (7iCQQUJts<: — f*« ^[^kxuuiU.t^r-r^t^^o^or-r^r^i^r^corocococnc7>r^cncnaicn(7icr,c^

WWCOWWWWWWWWWWNWWN^WCOWWWWWWWCJWCONCOWNWQGS&QSGlElQQISlSSISlQSSISSISiaQiaiSlQSGISISGISQSISlSSiaSSISSISSSQSSGG

OCC

<I

UJ UJ <t

i- o tnh- - •

tn i2

• E. a

^ X

l-H O -

CC UJ o

c^ < cn Hz s -J<t < uj ZL

Q> <r

ui ccCQ co

Ld 5 •CC i-h UJ

n: in •

>- ^J DC

5e • uj

J£CSH

Cl f— Z

O. UJ kh

CD CD O

zuj <n cl

hJO.^ CO SC

I-H • C <t (

tnfh- cc uj

Ul <i (— Ld I

in uj >- r> .

Ld _J CQ <T «

cc o cn ■

3 cc

<£ -J_J CQ

M _J M

Ul — c

C UJ:cli

3 ^ [O UJ iOC H '

Go

O DCH

UJCC _JH COCL <X

i H •I cn 3

h- h-

) UJ UJ

> —■ cn *D

+

a. a.) cc o:: —i -J

■ CO CO

1 h- M

. 3 3

<r <c <z <z <r <r <c

ucc <c<i tn>c <o<tu] J

CC—I f— f— MO OOh-D=)

Oo mm m—] _J <r cn —i cl

3 _j

o <e __)

CC H rf

a ^ cd

UJ H- • UJre 5--3

(-< f— <::

^ Jtm uj cl H

hCC i-h

CC UJ 3

m =• ^

hOhK

x x cn

P-* uj o <zx <i £:

CO cc <c

• F- h- _J S:

cl <r: z e: o

ItH H m

<r =)

HH COCC UJH CC

m uj

co i-h uj m

UJ CC Cl UJ

cn H uj tn

OH O

CL X »CL

ui^^a

CC V cc

X uj U. ~cCD _

<t X XUJ

f— ZO.Z

cn i-h o cq

UJ I

_J UJ I

CQ *= =2:

<r i-h hh

Oh>.H Z „J

UJ I-H

Ld CC O> CC UI

o =3 cn

CQ O CC

<r o

Ld o

O X =

^ P I-H

ZD •

O O >- 3

cn ccW tD rz>

>ZOUJChmE_J D > <cCL ^ Ul tn

o cc

£ cl CL UJ

CD UJ >- H

^ CC Z

HOKCE

■z. o o

33U

o _im

Q CC UJ >-

O Cl <c

<r uj _J

X -Cl*H« UJ

3 m cd

O 2: M Z

•■UJ

>-

C3 3-X

<c

_]

l-H _J

a.

Z^-0.0 •

^ >- F— U)

cc

h<CDZ J

Ld

H

3 _J =£ ^h CQ

CD

in

Cl i-h <C

•

q:

UJ

>- ^ =: F-

.6

<r

_j

•^EZCC

z: _J

j

uj <r i-h uj •

SS

f-H

<r

_J J3H3

cn

H

CQ H <r H

l-H l-H

>- CD

• cn

<C O i-h <t <c UJ

_J o

<r. o

^o ^->

H UJ cc CL X

s0-

_J .-H

t- •

H P tO ^_'

Cu >

ttliJ3H

• UJ i-t (—

UJ ic

UJ

O CD «x E

3 a o Hu.

Jo

-J oc

—I UJ

H >- CQ O

<c

<r cl

>- *CL CC

U. z: <

OC h-

<I ^ E CC

O <c m _J _] 3O UJ CL <t o

p [/}

cc >-

_j y- =3

u.

F— s:

a, o ^ o

^ cn cn i-h cc

CD

<C

D l-H

uj ^z: cc

>_2

UJ

_J o

f- to o H _J

<C l-H

oc cc

<C CD >.!-.

>-rD a. -J <r

-1 CC

O UJ

-H = <C

CO o m <X Ld (—'

CL O

I- ■>

DC i-h _J CC

w _ UJ hh x o

F-h

m o

H (— Cl l—

~> CC CC i-1 H

<r uJ

^ Cl

3 UJ I-h

m »

e: ^D CD

O cc X * H

l-H cc

_j 3

02K

CC CL *CC ^

DC

<r <C

t— O i-h H

JH OU!

F- CC

CD J

o K m

_J O <r O - CC

U)

UJ cs-

UJ >- rt

<hCDZ cc

F-h t-

_i e;

JCQhH

F-i Cl UJ 03

CQ U.

Ul <c

UJ w 3 UJ

O _] u, ^ 0

U-

m f— x i-h

co >-HuJ >

F— t-t —

i-h m i-h 3

HOH h- <r

to (-• —' m —J

F-1 m CD «T (— CL -T

_j m -Jcc -J e: cc

<t <i

<C <X X

<c <c

3<r <<rXXyjuL.^i--^.^^L

ciuJito 2:rzlccln'~,,—imUJOf-'ccJDh mO.OD.t/1-]~ncQ-JtncQ

AAAAAAAAAA

CC -X- + *

* * # *

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

m —•

CO CO

Sl *3 w

m IT\ iTi

u. co f- f*"

■*» si cn a,

U, Ld

W3 Ki r- <JP

co *? m la

u? co r- uj coco cr> cn a> fO

coo^

IS CO CO

CO <7i O

ujto vJcoorioU-ujor^^or-E! lorocootto m co^ooi'ncricncQcocTicnco r-_iro

^U3^r^r^o^CQCQCQCQCOQS)K)^ro^in^<I<EOUJ|SC\l^^iOr0^iAr^r^cOm

C\]C\JSCNJC^WWCS]CvJWC\]^K)^K3r0rOr0iOrOrOi^'O^^^^^^^^^

OJWO0C0O0C\]C\]C0C0C\JWCvJC\]~CJO0CXJC0CNJCv]W

QBGQQSBSiSSQSSIS(SSiS<3SBSQSISISSSS^SQQSSEll2SiaSSISSQQSQS:iSSISSl3Q(2Q

January 1980 © BYTE Publications Inc 225

UJ

y

UJ

B

u.

U-

B

o

K)

en

>-

a.

>•5

a.en

u.

E

_1

M

cc

(71

O CO

en

O

p

U-

K

PC

o

C_> CO

CD O

_J n

CQ O

a

O -J rO

CQ CD O

£££

K S

a uiu- e:

„

k> 3:

tA 0

IA

S CM

CD 00

0 u.

CQ 0

££

u. r- ■Tscacj'^csi'^

■^"K)U"vcOC0*T|ACOT\

caoir»cac7>cosQ■ t ir\ m »n *r 00 co

tA G 0>

tA ia ia

r<\'OJ"*r'om-<rcjooco

t iAiAiAc\j^r*rco*r'A^r ^roiAcoco^r|Aco'A co^iaiaja^coco tA ia ia ^rww^io^^www

m T tt\ Ol *T G,iTiW*T*3'*TC>lU~i'T*T*? eaiAC0C0tA-*TTc0'l3"'**'*''Gl*r*'''<''C0<3'C0iA»O*''E'^'C0'"T Q <TiA-*TiAiACOtAiAiAC0

U]WE'A*INC;<t<ro^QN'^^^^Cl^ClUJt\]<rDinK)^-CU.«sWDrOff>-k-DtnwUl*]DCW^^''OWGaiK'*-^S^

moomw — *rmr^<rQs.fOW£7ioCi-coiri«?cocG'jO—•■^•r-<iQis)foint^<t05)fot^cAOLl—n^woioQ^s'o^'oiU^w^tflmw^KisGjap'OW^^<r^^inin^^ifi<nC5W«iwc5t5^r^c^i^Ft^tococo»Mmc^c^^fflt7i<<<«ic<mDmcQmm[0 0ooouo"CODDQwllJcdu-u-wb-u-

rOK)rtiOrtrti0^iOtOiOiOi0^iOtOtOrOrtiOKlfOi0^^iOiOiOiOtOrt^'OrtfOh0^iOKliO«iOiOrtfOrOiOi')»OiOtOiOK)rtrO'OiOiOFOiOiOfO'0«iOiOSSGSQGGQSQGGGGQBSSSSISGCSIQ<SSCSllSSSlBSQGC\GGSSGSGGSlSQGtSEiGSSS'SSEQGIStSSQGSGQ

AAAAAA AA

SICO

<o s s s

—1 «• tSj CO

e; 10 cs <s

ca s co

# *

* *

* *

*

*

* C2 *

# < #

♦ CO #

*

*

+

****

****

*

**

***

en

UJCD

CO

#

**

**

**

***

:**

^ UJ scUJUJmUJ U. ECC

O UJ CCW ZOwU.Ul _1CO _J

CC :

A A A A A A A

:CQ

-J CC

o

a. c^j 3

o cc cc

a

WDqHUJ2 UJ

u~ Ul •£. oc

UJ cc _»t- in

Ul UJ UlEttDZ

0 E!: O O

1 bJ UJ X UJ Ul O fc UJCD UJZHu. O

m <c cd cc b- >-h <r

O ,_, E O JUJUJ m

wccMcnUJ in en ccr3<ti-^>i-i^cccc<c

UOUJU-JI-'UJUJcj

— <e <r

G. E K S U^ W)

—• D —< <C <t -h -h Q

GJCZrC2(C3C2fGfGJGJGfUIUJUJUIUJUJUJUJUJ

Of- (n

UlU.(/]£QQ (-■

s-JdnrU-u—i u. uu

-cczmzzooa:

OUUJOJJUlUJoAAAAAAAAA

3

CO

t

>-

3

a,

in

i—i ty=f o S Q K3O

3 cd ca mao

cc ceo a o p

I— O U, U. G. U.

s

1

8

o

Io

o

la*

cc —

CQ O

££

UJ

en

ES

>-3

a.

CQ O

£££

CQ O

— miooQ cocntsi^rcjoj-rm-TooKj^oo^tM

04 «? oiU, oi^ticjcs:

UJ SJ —• "T tST CM T U~\ CO

in^oo^^oo^OJ u^u^u^"^"^CMu»ir\"MOJ mK)T^'i4ir\",>j^j(\] ^t\j^u»cd

^ocsjtS) cACjr^iscri«i~~cosim <rU.iv>Cjts;U.mujuJcoo «iWQQ'''uin»OG<iiA<«,iuGnr\

SCOIS (S IXIQTE —■COtS^T—•Oi—« O cnC;—*CQt30K)-^tSC3oJ—*Q"*TiAUJlSiG:CQ OiU^^C^^Q OiCO^SliS5lSl^CMu^CM^CvJCM^^^CMCau^W^K)^iJ^<rc\]^U^rO

^^Sl^WincM^CvJCv]vA^^CMCau^W^K)^iJ^<rc\]^u^rOQ^u^W

bo

= U.U.U.U.U.U.U.U.U.U,W<r<TQ<£<CinWDU,U.U.isSi*-5J <ri/\ mmUJ-^■<rr^<rDs^O■*T,^ <7>pU_(^u-»f1ocQUJ--.<Tif\f--<Clts;fotO C^Ou-C0"^"'^' o^o1'- 00

'C UUOOUOOOOU-SS«QS--QUUOQcS^ODQDDWUlUIUlWU,li.U.li.UUU.Qi3s

.2 WC\]C\JWCvJC\JWCs)CvJWSOiSKQ<tQSSC0W

>-J laiSQQSSQSElS-QISliaiSJSGlBSQQQQSlSQSSQQSSQSQISiaSQESQSSISQiaSiaS

226 January 1980 © BYTE Publications Inc

I>-

3

CJ lub9 O

O CQ

o u.

CO O

f£f£

UJ JE

g££

m m cjo a pu. u_ u.

8

K

CD O

COUJ

m

00

gy

£

CO

UJ

UJ

5

a asg£

A A A A A A

C7i <T Q U, u~\ S]

—I IS (7^ UJ CO UJ<T CO m *T <T CO

O -» CO — *T CO *r

■<r co u~\ -«r m m q

A A A A A A

<£> en cs a> ts cms co «"*•

tA-^TiAirviriiACOiri'O'O

<£ CJ WoS-iS-'-CiOQG

ts)<r t-tco'^co-T'O-'Tcoco

Q^Q CTi —""TO—' O tS "^ m UJ CS "^

CStSQ*TT<3"-<Tc0'<;''O0mmc0C0CS

'TIS IS

u~» CM OJ

ui <c<Il on

o ta s ^T^

—' Q tti G lA ■'T -T 13

a

A A A A A A

<7) CS UJ

13 in (TiS DCO lA "T CO CD

UJ U_ r- — *T -«T

co «T m co cs cs

A A A A A A

A A A A A A

Gl CS UJ

co co -^r

CO CO "W co w

uj en»"- —« ^r <rco "J" m co cs cs

<e -q* o

cs cs ts

•<t co u~\ -«r m m ts QQQ-T-TT'Cco^cMiniricMWGi — cs cs cs m <r -<t cs co "3" m co

U-^ino3CQtjJ^cocooJWC>]0^inK)m^J^^r^<r^csto^inininUJUJ^Moic^e?^cnc7><c<<<<i:<]:<x<<<<<rmcacxicQraoooooooc^

SBSQI3GQHSQiaSQI3QQQGSC3C.:SSI3SSIScaGI31SQSS

a

o

>-

>-3

a

or co

fc9 o

Ul

CO-J•» en

DTCDU

£f££

en u

CO D3EC p

CQ —1 C3 CQ

Cu § O U.

UJ

CQ O

CS P* «> CS W — <7>

CO *** ^ CO IH T ^"

ts Ch *V UJ en CS *^"

CO *T m *T "T CO "<T

tStSCS{SCSCSr~U~»r~CO CO CO CO CO CO —

tSCSQCiCSCSCS^D

cococococococo-^'q'

■*T Q CS IjJ IS CS CSm CO CO CO CO CO CO

A A A A A A

CSG:CSC*CStStsQtSUJ<3:(SCSCSCSCSCStSC7>CS <E^OfOGQQGQ

CNJCOWCOCOWCO^CO^CSCOCOCOCOCOCOCOinCO CS'T^irv'OCOCOCOCO

A A A A A A

cocjiT\m'<rm,^'»o

<£ m gjcscs'A^'Ocsc^cs*^ oocjoju^^u^inir*

O-T<rtSCSCSl5-CSlC0CS--S^r

tscscsoococo^cou^cxi^cocs

<t co cs o r- cs

Q CO CS * ""3" CO

a «t cs en m o

CiintOirM*-COS'AQ<EGGGQaQG-fOt1-OQSGGQGGQminQ-T-^SGSQG'^

co^^^in<rco^cstswcococJcocow^u^^cscsjcocv)C\]cocococ\]un^s^

r^ < o ts ro ^> en o o u, E ki w cnoi*-cou-\cocnQU-c\jin ooca^-^'^^'CmQts^^ aio^co^u^^^inu^^r^tom^ — ^^<QG«—cv]<^3c^Jc^](^J<:'*'"^:, <7iuk^^QMQGcaQQ^-««- — cviwc\JWWNrtr^iorort^^<r^^'TLniAininininwwwwiow

CititSCStSCSCSCSGlOtSCStSCSlSCStSCSCitSCStacSCSCiQ

January 1980 © BYTE Publications Inc 227

Listing 1 continue

i:

0554 41

54

45

G4F9 15

>

FCB

EOL

0557 52

21

0 4FA 4E

45

57

>

FCC

23, NEW GAME? ("Y" OR " N")

0 5 59 0 4

>

FCB

ENDST

04FD 20

47

41

055A

>

aca ad

45

3F

0 55A

>* MY

PLAY

IS - M

0 503 20

2S

22

055A

>

0 50S 59

22

20

0 55A

>

ORG

S55A

0 509 4F

52

20

0 55A 0A

>MES6

FCB

LNFD

B50C 22

4E

22

0 1 7C 05

5A

0 50 F 29

20

055B 0D

OA

>

FDB

CRLF

0511 04

>

FCB

ENDST

055D IS

>

FCB

EOF

0512

>

055E 00

00

>

FDB

0

0512

>*

THANKS

, ETC. - MES5

0 5S0 00

00

>

FDB

0

0 512

>

0 5S2 4D

59

20

>

FCC

11, MY PLA

0 512

>

ORG

$512

05S5 50

4C

41

0512 0D

>MES5

FCB

CRET

0 56S 59

20

49

0114 05

12

0 5 SB 53

20

0513 54

48

41

>

FCC

28,THANKS FOR PLAYING. HOPE YOU

05SD 04

>

FCB

ENDST

051S 4E

4E

53

05SE

>

0519 20

46

4F

056E

>* YOUR PLAY?

051C 52

20

50

05SE

>

0 5 1 F 4C

41

59

05GE

>

ORG

S5SE

0 522 49

4E

47

05SE 2E

>MES7

FCC

1..

0525 2E

20

43

0 138 05

SE

0 528 4F

50

45

0 5SF 0A

0A

>

FDB

LHFDS

0 52E 20

59

4F

0571 20

20

59

>

FCC

13, YOUR

0 52E 55

0574 4F

55

52

0 52F 0D

0A

>

FDB

CRLF

0577 20

50

4C

0 531 45

4E

4A

>

FCC

24,ENJOYED IT AS MUCH AS I.

0 5 7A 41

59

3F

0534 4F

59

45

057D 20

0 53 7 44

20

49

057E 04

>

FC3

ENDST

053A 54

20

41

057F

>

0 53D 53

20

4D

057F

>

0 5 40 55

43

48

057F

>

END

0 543 20

41

53

054S 20

49

2E

0 5 49 0D

0A

>

FDB

CRLF

<:« UNRESOLVED ITEMS

>>>

054B 53

45

45

>

FCC

14,SEE YOU LATER!

054E 20

59

4F

0551 55

20

4C

IS

K2S7

PLAY?

THE HSSENCEof output quality

Any IBM SELECTRIC®can be con-verted to produce high quality out-put at an affordable price!

Interfaces directly to SI00, Parallel,RS-232 or IEEE-488.

Compatible with TRS-80, Sorcerer,Pet, Apple, Horizon, etc.

Why be printer bound? Prices from

$496 to $575.

n

Backspace and TabAvailable NOW!

m

Escon Products, Inc.

171 Mayhew Way, Suite 204

Pleasant Hill, Ca., 94523

(415) 935-4590

(t

At last...the mechanical interface

Turn your electric typewriter into a lowcost, high quality hard copy printer.

%

30 Day Delivery

User list$469°°

Dealer InquiriesInvited.

Now available withinterfaces for mostpersonal computers:TRS-80, Apple, GPIB, etc

The all new

I/O Pak from

Rochester Data,

Inc. interfaces the keyboard

of any commercially available

electric typewriter with any

computer. The result: low cost, high

quality hard copy.

Write today for more information.

V

Incorporated3100 Monroe Avenue, Rochester, New York 14618^y

228 January 1980 © BYTE Publications Inc

Circle 196 on inquiry card.

Circle 197 on inquiry card.

<<< SYMBOLS >>>

Al

020A

A2

0217

A3

0218

A4

022 6

AUAO

01E0

CHMF

1016

CONL

E0E3

CRET

000D

CRHM

0010

CRLF

0D0A

ENDM

00 49

ENDT

0004

EOF

001S

EOL

0015

Gl

P1AB

G2

01B2

G3

01C0

GNRL

02B0

GR1

02B3

GR2

02C0

GR3

02C1

GTVP

01A0

HPLY

0045

HTUN

00 4 7

I 1

00 7A

12

0084

I NEE

E1AC

INIZ

005D

LI

01D8

LGLT

01CS

LNFD

000A

LMFS

0A0A

LSTA

0046

LTSN

004A

Ml

0113

M2

01 IB

M3

0133

M4

0145

M5

0167

MS

0187

MES1

02 D0

MES2

03 F"0

MES3

0 4 65

MES4

04 F6

MES5

0512

MESS

055A

MES7

05SE

MESS

04A2

MES9

0482

MESA

04CE

MESB

04EA

MESC

04DD

MPLW

0053

MPLY

00 52

MPTT

0040

MSKL

0020

OUTR

E0SB

OUTS

E0CA

PDA1

E07E

Rl

02 42

R2

0254

R3

026E

R4

02 7S

RANM

00 58

RVSW

0230

SCNG

00 48

SCOH

0041

SCOM

0042

SELL

0290

SP1

0295

SP2

029 B

SP3

02A7

SSTO

0054

TOTD

0044

TOTL

0043

TXTT

018E

WHRF

00 4C

WINL

002 7

WTBP

0056

C

Table 2: Symbols for the Eighteen with a Die learning program(written for the Motorola M6800 processor) shown in listing 1.

Text continued from page 221:

for every total having winningmoves. (Some totals, including zero,have none.)

Using the goof feature, and if thehuman does not err and seizes everyopportunity to win, the gamebecomes a game of luck. The randomplays made by the machine may bewinning plays, and a sequence ofwinning plays found at random is notimpossible. With the goof featureactivated, the machine willsometimes surprise you by playingthe very first game of a seriesfaultlessly.

The game can readily be extendedto a goal total greater than eighteen.Multiples of nine assure that no win-ning play is available to the firstplayer. Longer games will slow thelearning process; not only will eachgame be longer, but the propagationof "good" information from the endof the win table to its beginning willrequire many more games. Anotherelaboration could be a "brain"display similar to the one that I imple-mented in my mechanical machine,GLIM.B

REFERENCES

1. Gardner, Martin, "Mathematical Games,"Scientific American, Volume 206, Number3, March 1962, page 138.

2. Gardner, Martin, 77ie Unexpected Han-ging, Simon and Schuster, New York,1969.

3. Mott-Smith, Geoffrey, MathematicalPuzzles for Beginners and EnthusiastsThe Blakistone Co, Philadelphia, 1946.

4. Nico, Willard I, "Shooting Stars," BYTE,Volume 1, Number 9, May 1976, page 42.

5. Wier, Robert R, "Hexpawn: A BeginningProject in Artificial Intelligence," BYTE,Volume 1, Number 3, November 1975,page 36.

f GNRNPL J

I «-« I

„'

'

| B —00001001 |

B— B-RANUML

Figure 8: Flowchart of the subroutine togenerate random play (GNRNPL). Aseventeen-stage shift register with feed-back generates a random sequence ofnumbers from 0 through 7 that will notrepeat before 131,071 digits have beencalculated. Subscripts H and L indicatehigh-order and low-order bytes of a 16-bitquantity.

YES

ROTATERANUMHRIGHT THRUCARRY

1

ROTATERANUML

RIGHT THRUCARRY

ri

FEEDBACK SHIFT REGISTER

ii

i

cc

7

• • •

0

i_

( RETURN J

January 1980 © BYTE Publications Inc 229

WttsftNsw?

Apple Writer — A Low-Cost Text Editor forApple II Users

Using the Apple Writer, a documentneeds to be typed into the computeronly once; corrections, text additionsand the rearrangement of text can beaccomplished easily and quickly.Automatic search and replacement forspecified words or phrases, justificationof text, and uppercase and lowercasetype are some of the other features ofApple Writer. The 48 K byte storagecapacity of the Apple II permits storageof at least 12 pages of text in each on-line file.

The package consists of two master5-inch floppy disks and an operatingmanual. The floppy disks include aninteractive tutorial which the user cancall to the screen for quick learning orreview of the Apple Writer system. Thecost for the system is $75. ContactApple Computer Inc, 10260 Bandley Dr,Cupertino CA 95014.

Circle 562 on inquiry card.

Program SimulatesSolar Home

The Sunsim-1 program calculates thesun's energy in hourly intervals at anyspecified location on earth, anddemonstrates its use for domestic spaceheating, cooling, and hot water heating.

Cumulative energy and temperaturevalues are displayed, including solarenergy collected and used, backupenergy used, thermal and hot waterstorage temperatures, and more. Userscan input their requirements for size ofhome, volume of thermal storage, andarea and angle of solar collector. Writ-ten in Level II BASIC for TRS-80 thisprogram requires 16 K bytes of storage.Sunsim 1 is available on cassette for $49from Solartek, POB 298, GuilderlandNY 12084.

Circle 563 on inquiry card.

SOFTWARE

Pascal Compilerfor the 6800

Dynasoft Pascal is a subset of stan-dard Pascal intended for cassette-basedmicrocomputers that cannot supportfull-scale implementations such as UCSDPascal. It includes the control structuresof standard Pascal and supports most ofthe data types. Language extensionsinclude EXTERN, PROCEDURES andFUNCTIONS, LINK to other Pascal pro-grams, an optional OTHERWISE clauseon the CASE statement and absolutememory addressing.

The one-pass compiler producespseudo-code which requires only a 1.3 Kbyte interpreter to execute, making itpossible to run programs in as little as2 K bytes. The system, including thecompiler, interpreter, a line-oriented

C Compiler for 8080 andZ80 Microprocessors

The BDS C Compiler is the implemen-tation of a subset of the C ProgrammingLanguage. It is designed for 8080 andZ80 microcomputer systems runningunder the CP/M 1 operating system.The practical minimum memory sizenecessary to run BDS C is 32 K bytes,although many modestly sized programsmay compile in as little as a 24 K bytesystem. A larger memory size allows forlarger sized source files, since BDS Cloads the entire source file into memoryat one time. Separately compiled func-tions can always be linked together, so aC source file which is too lengthy forcompilation in one group may bebroken up into pieces, compiledseparately, and then linked together forexecution.

The C Compiler and a copy of The CProgramming Language, by Ritchie andKernighan, are available from LifeboatAssociates, 2248 Broadway, New YorkNY 10024, for $110. The manual is $15.Circle 565 on inquiry card.

Dental Office ManagementPackage

Dental System I performs patientregistration and inquiry, managesaccounts receivable, including aging,and provides delinquency reports.Itemized statements and insurance formscan be printed, finance charges on pastdue amounts can be included for anypatient, or the entire practice. Thesystem produces a daily journal ofcharges, receipts and adjustments, apayment journal summarized by pay-ment method, a report summarizingcharges generated by each doctor or

hygienist, recall and reminder lists, andmore.

Minimum hardware requirements area 64 K byte computer, two double-density 8-inch floppy disk drives, avideo terminal and a 132-columnprinter. This system can support a prac-tice with up to 4000 patients and theaddition of a hard disk would make itpossible to handle a larger number ofpatients.

The price for the Dental System I is$1995. For further information, contactSTR Corp, 5455 Buford Hwy, SuiteB-123, Atlanta GA 30340.

Circle 567 on inquiry card.

editor, and system supervisor, occupieslittle more than 7 K bytes of memoryand compiles a 2000-character sourceprogram in 12 K bytes of memory.

Price for the basic cassette version,with manual, is $35, from DynasoftSystems, POB 51, Windsor Junction,North Saskatchewan BON 2V0CANADA.

Circle 564 on inquiry card.

LISP Interpreter forApple II

This new LISP system features a built-in prettyprinter and LISP editor, bothwritten in LISP, along with prompts thatmake it clear that LISP is taking in anexpression and returning its value.Errors are trapped by the interpreter,and a full trace-back can be printed.Owl LISP has eliminated the PROGpseudofunction, yet defines localvariables by using an extended syntaxwhich allows for optional and localvariables with default values. Owl LISPalso provides a LOOP, WHILE, andUNTIL construction to allow foriterative programming. PEEK, POKEand CALL are provided to access Applegraphics and other functions. String pro-cessing can be carried out using IM-PLODE and EXPLODE which convertbetween character strings and lists.

The system consists of about 6 Kbytes of code, 300 bytes of garbage col-lector work space and 4 K bytes ofpredefined LISP work space. LISP costs£40 from Owl Computers, 41 StortfordHall Park, Bishops Stortford, Hert-fordshire, CM23 5A] ENGLAND.Circle 566 on inquiry card.

Where Do New Products ItemsCome From?

The information printed in the newproducts pages of BYTE is obtained from"new product" or "press release" copysent by the promoters of new products. Ifin our judgement the information mightbe of interest to the personal computingexperimenters and homebrewers whoread BYTE, we print it in some form. Weopenly solicit releases and photos frommanufacturers and suppliers to thismarketplace. The information is printedmore or less as a first in first out queue,subject to occasional priority modifica-tions. While we would not knowinglyprint untrue or inaccurate data, or datafrom unreliable companies, our capacityto evaluate the products and companiesappearing in the "What's New?" feature isnecessarily limited. We therefore cannotbe responsible for product quality or com-pany performance.

230 January 1980 © BYTE Publications Inc

North

Star

Horizon

HeathH89

CromencoC3

TRS-80 V*Model I

TRS-80Model II

YourComputer

"BSTAM"

The missing link betweenany CP/M or TRSDOS computers!

A commercially oriented telecommunications

facility for transmitting and receiving

CP/M* and TRSDOS** files, BSTAM has BIG

computer features for your micro:

links computers directly at 9600 baud with

UARTS, or via phone lines using modems~ full speed data transfer without hex

conversion overhead

full wildcard expansions to send

* .COM, etc.■ reliable error detection

and automatic retry with

console messages for

status and errors

It's Terrific!

We use it ourselves!

s150c^

COMPUTER

SC MANUALO ALONE

lifeboat Associates

\ THE

SOFTWARESUPER-MARKET

"CP/M is a trademark of Digital Research

"TRSDOS is a trademark of TandyCorporation

Lifeboat Associates

2248Broadway NewYork,N.Y.10024 (212)580-0082 Telex:220501

Circle 199 on inquiry card.

TRS-80® BUSINESS SOFTWAREfor Model I & Model II

CP/M® and CBASIC® based softwareoriented toward business applications.

FEATURING

Model l CP/M (sel. 1.5) $ 150.00

Model II CP/M (rel. 2.0) 250.00

APH (Automated Patient History) 175.00

DOWNLOAD program 95.00

RESIDENTIAL PROPERTY ANALYSISsystem 300.00

The Genuine Article:Osborne & Assoc. CBASIC source programs—

O&A Payroll w/Cost Accounting $250.00

O&A Accts. Rec./Accts. Payable . . . 250.00O&A General Ledger w/Cash Journal. 250.00O&A CBASIC books for above (each).... 15.00

Send 3(X SASE for CP/M Users Group softwarelist & free "CP/M Primer".

■' TRS-80 is a registered trademark of Radio Shack, a Tandy company" CP/M is a registered trademark of Digital Research' CBASIC is a registered trademark of Software Systems

(714) 848-1922

8041 NEWMAN AVENUE • SUITE 208 • HUNTI NGTON BEACH CALI FORNI A 92647

OTB586668TO8S68W

on computers, peripherals, software and other Radio Shack® products.Offered Exclusively By

Pan American . Radio/haeH

EleCtrOniCS, InC. M Authorized Sales Center

1117 CONWAY MISSION,TEXAS 78572

Toll Free 800/531-7466

In Texas 512/581-2765

NO TAXES on out-of-state shipments.FREE delivery available on minimum orders.WARRANTIES honored by Radio Shack®.

VISA'

Circle 200 on inquiry card.

BYTE January 1960 231

WbsftNew?

SOFTWARE

Music System forApple II

Micro Music Inc, University Plaza,Suite 8, 309 W Beaufort, Normal IL61761, has released Micro Composer, anApple II compatible music-system thatallows the user to enter, display, edit,and play music with up to four voices ina 4-octave range. The program allowsthe user to see all four voices as music isplayed; enter music by a coding systemwhich keeps track of rhythmic dura-tions, program pitch, rhythm andtimbre; choose from seven tone colorsfor each voice or create tone colors; andhas seven preset timbres. Micro Com-poser comes with a manual, software,and a music card for the Apple II exten-sion slot and is connected to an 8 ohmspeaker. Memory requirements are 32 Kbytes for the cassette-based system and48 K bytes for the disk-based system.The price for the package is $220.Circle 568 on inquiry card.

MMSForth for the TRS-80

Forth is a structured language similarto Pascal except that, in Forth, the pro-grammer defines additional commandsas they are needed. The MMSForthSystem Diskette supplies reliable diskI/O, virtual memory, double precisioninteger math, in-line editing, stringhandling and arrays, and user calleddisk and tape I/O. MMSForth includesfull source code for the majority ofMMSForth which is written in Forth.Speed is approximately half that ofassembler code, while development isusually much less than half.

This system costs $64.95 from MillerMicrocomputer Services, 61 Lake ShoreRd, Natick MA 01760.

Circle 569 on inquiry card.

Radio Shack HasVariety of Softwarefor TRS-80 Systems

Radio Shack's programs come oncassette and 5-inch floppy disks for theTRS-80 systems. Among the new pro-grams available are a General Ledger I,an Inventory Control System, StatisticalAnalysis, Real Estate, a Level-I BASICcourse that teaches the user how to pro-gram, and several advanced program-ming aids. Radio Shack also has anumber of computer games and noveltyprograms for the TRS-80. For further in-formation on Radio Shack TRS-80 soft-ware or products, contact the RadioShack Computer Customer Service, 205NW 7th St, Ft Worth TX 76106.Circle 570 on inquiry card.

Hard Copy Graphics Pro-gram for the PET,Apple II, and TRS-80

West Coast Consultants software pro-vides users with full graphics capabilityfor Houston Instrument's Hiplot plotter.Programs that drive the plotter throughan RS-232 interface are currentlyavailable on tape cassette for the PET,Apple II, and TRS-80. The programs arewritten in BASIC and require aminimum of 16 K bytes of memory. Forfurther information, contact West CoastConsultants, 1775 Lincoln Blvd, TracyCA 95376. The prices are $50 and $75for the programs.

Circle 571 on inquiry card.

Adaptable OperatingSystem for 6809Microprocessor

Percom Data Company has developeda 6809 operating system for the com-pany's new SS-50 bus-compatible 6809control computer and other 6809microprocessing systems. The 1 K byteoperating system, called PSYMON, in-cludes eight monitor-type commandsand fifteen callable utilities. Hardwareadaptability is easy because interfacingis accomplished with simple, specificdevice driver routines that reference atable of parameters called a Device Con-trol Block (DCB) which is independentof the operating system. Command ex-pansion or modification is facilitated bya feature that allows user-writtenroutines in read-only memory to alterPSYMON pointers and enhance ormodify the basic PSYMON commandrepertoire.

The erasable-programmable read-onlymemory version for the Percom SBC/9sells for $39.95 and the versions for theother systems sell for $69.95 including ausers manual. For information, contactPercom Data Company, 211 N Kirby,Garland TX 75042.

Circle 572 on inquiry card.

Pascal SoftwareCompiler for the1802 Microprocessor

The new GR-Pascal compiler runswith a minimum of 20 K bytes of pro-grammable memory plus a floppy disksystem and utilities. Minimum targetsystems can be from 2 K bytes upwardsof program code, including full 16-bitarithmetic package for signed integervariables. The compiler is written inPascal and features a provision forassembler code, hexadecimal numbers,byte variables, interrupt procedures and

disk input/output (I/O) facilities. Atypical 200-line Pascal program willcompile into 3 K bytes of programmablememory, and processing speed is in-creased by a factor of 3 to 4 by restric-ting variables to signed integers with16-bit accuracy.

The compiler comes on an 1802 circuitin 2 K bytes of read-only memory on-board with 64 K bytes of programmablememory and sells for £40. For moreinformation, contact The Golden RiverCo Ltd, Telford Rd, Bicester, Oxford-shire, OX6 0UL ENGLAND.

Circle 573 on inquiry card.

Data Base ManagementSystem forMicrocomputers

This data base management system(DBMS) runs on 8 to 16 K bytes ofread-only memory for Z80, 8080, and6502 systems. This system provides afull network capability and generalizessome features of the CODASYLapproach. The Data Definition LanguageAnalyzer/Editor and Data ManipulationLanguage permit many-to-many-setrelationships. Full data base security ismaintained by providing read and writeaccess levels for all record types, items,

and set relationships. A common database is maintained in order that no dataneed be duplicated in different files, anddifferent applications can be supportedin the one data base. Routines arecallable from host languages and haveinput/output (I/O) and host languageinterface routines isolated for adaptionto North Star, CP/M, and TRS-80operating systems.

The user's manual and sample applica-tion programs are included in thepackage which costs about $800. Formore information, contact Micro DataBase Systems Inc, POB 248, LafayetteIN 47902.

Circle 574 on inquiry card.

232 January 1980 © BYTE Publications Inc

circle sm on inquiry card.

EPROM PROGRAMMERS

EP-2A SERIES

PROGRAMS 2708 and 2716

EPROM5

Price $59.95 Assembled and

Tested

Kit price $49.95

Includes Connector

; ■ :: ■ ■

EP-2A-78 SERIES

PROGRAMS 270B, 2716,

2758, TMS 2716 and TMS

2532 EPROMS

TEXTOOL ZERO FORCE

SOCKET

Price $79.95 Assembled and

Tested

Includes Connector

Software available for the Rockwell AIM-65, MOS TechnologyKIM-1, Synertek SYM-1, Motorola D2, RCA VIP and many othersingle board computers that use the 6502, 6800, 8080/85, Z-80, 1802,F-8 and 2650 CPU's. Stock. Specify one set of software.

Optimal Technology Inc.

Blue Wood 127

Earlysville, VA 22936 U.S.A.

Phone (804) 973-5482

WhatyoiTCis whatyou get!

C Compiler for CP/M

New, and available now! An easily affordable compilerincorporating most of the features of the full C language.

BD SOFTWARE

System requirements: CP/M and at least 24K of RAMVariable Types: char, int, unsignedComposite Types: arrays, structures, unionsPointers: to variables, structures, unions and functionsFeatures: is a structured language, all functions (Programs)recursive; more powerful expression operators than anyother von Neumann type language; allows free-formattedsource; close enough to UNIX**C to make conversionsfeasible.

Speed: On 2 MHz 8080, the statementfor (1 = 1; i<30000;i++)x = 5;takes about 4 seconds to execute.

Package contains: compiler, linker, library manager; standardfunction library; sample source files include games, aterminal emulator with disk I/O plus the source formany standard library functions; BDS C User's Guide;Book—The C Programming Language by Dennis Ritchieand Brian Kernighan of Bell Labs. ~ Price: $110

Recipient of the Computer Lib Seal of Approval

'CP/M is a trademark of Digital Research Corp." UNIX is a trademark of Bell Laboratories

Lifeboat Associates

2248 Broadway, New York, N.Y. 10024 (212) 580-0082 Telex 668585

AIM 65

AIM 65 is fully assembled, tested and warranted. With the addition of a low cost, readily available powersupply, it's ready to start working for you. It has an addressing capability up to 65K bytes, and comeswith a user-dedicated 1K or 4K RAM.

• Thermal Printer

• Full-Size Alphanumeric Keyboard

• True Alphanumeric Display

• Proven R6500 Microcomputer System Devices

• Built-in Expansion Capability

• TTY and Audio Cassette Interfaces

• ROM Resident Advanced interactive Monitor

• Advanced Interactive Monitor Commands

PRICE: $375.00

'(1K RAM)

Plus $4.00 UPS (shipped in U.S. must give street address), $10 parcel post to APO's, FPO's, Alaska,Hawaii,Canada, $25 air mail to all other countries

We manufacture a complete line of high quality expansion boards. Use reader service card to be addedto our mailing list, or U.S. residents send $1.00 (International send $3.00 U.S.) for airmail delivery of ourcomplete catalog.

VAK-4 DUAL 8K-RAM $379.00VAK-2 8K-RAM (1/2 populated) $239.00

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 servicecard to be added to our mailing list, or U.S. residents send $1.00 (International send $3.00U.S.) for airmail delivery of our complete catalog.'Product of MOS Technology

ENTERPRISES

INCORPORATED?9R7 W. Fairmount Avenue • Phoenix, AZ 85017 • (602) 265-7564

Circle 204 on inquiry card.

BYTE January 1980 233

What's New?

SYSTEMS

AMD Delivers theAmZ8000 System

jmm

The AmSYS 8/8 floppy disk-basedsystem, designed to support theAmZ8000 processor in both hardware

and software, supports the 8080, 8085and Z80 microprocessors also. Its basicconfiguration contains 32 K bytes ofmemory, two floppy disk drives, andmultiple serial and parallel input/output(I/O) ports. Software support includes adisk operating system; macroassemblerfor the AmZ8000; translators from 8080,8085 and Z80 code to AmZ8000 code;Pascal compiler for the AmZ8000 and avariety of software packages. Pricesstart at $7450. AMD also has the AMC96/4016 Evaluation Board, which incor-porates the AmZ8002, 8 K bytes of pro-grammable memory, twenty-fourparallel I/O lines, two RS-232 serial I/Oports, 12 K bytes of erasable-programmable read-only memorysockets, system clock and residentmonitor for $975.

Contact Advanced Micro Devices Inc,901 Thompson PI, Sunnyvale CA 94086.Circle 591 on inquiry card.

Multiprocessor S-100CP/M CompatibleComputer

ft**

•

The Discovery Computer System MPSeries A, from Action Computer Enter-prise Inc, 75 W Green St, Pasadena CA91105, features an 8080 microprocessorwith 32 K bytes of programmablememory (expandable to 64 K bytes),two serial and two parallel input/output

(I/O) ports per processor, a separateS-100 bus for each processor, dual8-inch floppy disk drives, a video ter-minal with 24 lines by 80 columnsdisplay, 128 upper and lowercase ASCIIcharacters, and an optional printer. Upto 4-user processors can be configuredwithin a single chassis with the ability toexpand through auxiliary mainframesand processors.

The Distributed Processing OperatingSystem (DPOS) contains CP/M andsupervises reading and updating of files,provides write protection on a diskbasis, and prevents incorrect interleavingof file updates. CBASIC-II is providedas the standard user language.

Single-user systems, expandable tomultiuser capabilities, start at $3000. Acomplete four-user computer can be pur-chased for $11,000. Kits are alsoavailable.

Circle 592 on inquiry card.

Inexpensive WordProcessor Capable ofPowerful Formatting andText Editing

The SDS 420 consists of a videodisplay, keyboard, floppy disk storagethat will store 1.2 M bytes of memory,computer, and printer. In addition tostandard formatting, the SDS 420 wordprocessor has instructions for rightjustification, underline, bold text, in-clude a file, indent, exdent, columns,decimal alignment, headings, footings,subscripts and superscripts. The 12-inchscreen will display 25 lines of 80characters per line with variable speedscrolling. The printer will print up to 96standard characters at 45 characters persecond.

The system retails for under $12,000from Scientific Data Systems, 12640Beatrice St, Los Angeles CA 90066.Circle 590 on inquiry card.

Separate BASICComputer for S-100Systems

-JtCTj

The DLX-10 is a single-board com-puter that executes BASIC directly inhigh-speed hardware from 5 to 10 timesfaster than 8080 systems or 2 to 5 timesfaster than Z80 systems. It does notreplace the microprocessor but functionsas a separate BASIC computer. It canboost an S-100 bus microcomputersystem into the performance range of aminicomputer.

The DLX-10 runs independently of themain processor and accesses memory asa direct memory access (DMA) device.It runs in parallel to the existing pro-cessor, has a stack architecture, andutilizes on-board programmabe memoryto hold intermediate computations.

BASIC source language programs aretranslated by software to relocatableBASIC stack-machine object code andare then executed by the DLX-10.

The DLX-10 comes with software torun Northstar BASIC or CBASIC for$1250 from Alasda Computer Systems,12759 Poway Rd, Poway CA 92064.Circle 593 on inquiry card.

234 January 1980 © BYTE Publications Inc

What's New?

SYSTEMS

Microcomputer Kit with8086 Processor

The Intel SDK-86 is a complete 8086microcomputer system on a board withmemory and I/O (input/output) systemsin kit form. This stand-alone 16-bitmicrocomputer allows designers to ob-tain hands-on experience with Intel's8086 16-bit HMOS microprocessor,which offers ten times the processingpower of the 8080 processor.

Included in the kit is an 8086 pro-cessor; 8 K bytes of 2316 or 2716-typeread-only memory; 2 K bytes (expand-able to 4 K bytes) of 2142-type program-mable memory; 48 parallel I/O lines(implemented through two 8255A pro-grammable peripheral interface devices);an RS-232 or current loop serial I/Ostructure (implemented via an 8251Auniversal synchronous/asynchronousreceiver-transmitter); selectable data ratefrom 110 to 4800 bits per second (bps);TTL-compatible bus signals and parallelI/O signals; 24-key hexadecimal dataand control keyboard; 8-digit hexa-decimal display and control (using an8279 programmable keyboard anddisplay controller); and 256 vectoredinterrupts.

The 2 K bytes of 2142-type program-mable memory can be doubled byimplementing additional devices in thepositions provided. There is room for8 K bytes of program instructions usingeither or both of the keyboard and ter-minal software monitors included in thekit. There is a fully buffered system bus.Programs and data may be entered threeways: from the built-in keyboard;through a built-in serial communicationsinterface; or via cable (SDK-C86) from

any Intellec Microcomputer Develop-ment System.

A complete design library is providedwith the kit. This library includes boththe assembly and user manual, plus anMCS-86 user manual and 8086 assemblylanguage reference manual. The SDK-86microcomputer kit is priced at $780. Forfurther information, contact Intel Corp,3065 Bowers Ave, Santa Clara CA95051.

Circle 594 on inquiry card.

Personal ComputerIntroduced by TexasInstruments

Texas Instruments has introduced apersonal computer featuring easy-to-usecomputing power for personal finance,home management, family entertainment

and education. Designated the ModelTI-99/4, the system consists of a consolewith 16 K bytes of programmablememory, a wide range of sound effects,sixteen colors for graphic display, apowerful extended BASIC programminglanguage, and a 13-inch color videomonitor.

At the heart of the TI-99/4 is a libraryof Texas Instruments Solid State Soft-ware command modules. These com-mand modules allow users instant pro-gram accessibility. Solid State Softwarecommand module titles include:Demonstration, Diagnostic, Early Learn-ing Fun, Beginning Grammar, NumberMagic, Video Graphs, Home FinancialDecisions, Household Budget Manage-ment, Video Chess, Football, PhysicalFitness, Speech Construction, InvestmentAnalysis, Personal Record Keeping,Statistics, Early Reading, and Tax andInvestment Record Keeping.

Among peripheral accessories offeredis a Solid State Speech synthesizer witha price of $150. By building a basicvocabulary into the language system,home programmers can place audiblemessages in their programs. The speechsynthesizer module has a 200-wordvocabulary and plugs into the console.Speech can be written into programsusing BASIC programming language.Future command modules will call up

spoken words automatically.

TI BASIC is a full floating point,13-digit expanded version of BASIC thatis fully compatible with ASCII and theBASIC specification of the AmericanNational Standards Institute. TI BASICincludes a full complement of 24 BASICstatements, 14 commands, colorgraphics, and sound and music overfour full octaves. A Beginner's BASICGuide for self-teaching comes with theTI-99/4. For users knowledgeable aboutprogramming, McGraw-Hill has pub-lished Programming BASIC With the TIHome Computer, a book by HerbertPeckham.

Remote controls are offered as acces-sories to the TI-99/4. Two of these con-trols may be connected to the computerat the same time. Each includes amultiposition (360°) rotary lever with aside-mounted pushbutton. Other acces-sories offered by Texas Instruments in-clude: a printer, disk storage, and anRS-232 interface device for connectingthe computer to other electronic devices.

The price for the TI-99/4 system is$1150. Solid State Software commandmodules carry prices ranging from$19.95 to $69.95 each. For further infor-mation, contact Texas Instruments Inc,Consumer Relations, Attn TI-99/4, POB53, Lubbock TX 79408.

Circle 595 on inquiry card.

J

January 1980 © BYTE Publications Inc 235

Whal'sftew?

PERIPHERALS

New Motherboard for theKIM-1, SYM-1, andAIM-65

The Little Buffered Mother mother-board incorporates 4 K bytes of pro-grammable memory on the motherboarditself, which, when used with either theSYM-1 or AIM-65, gives the user a totalof 8 K bytes of contiguous program-mable memory (5 K contiguous on theKIM-1). The motherboard also hasregulators for the on-board logic andhas the power required for all threemicroprocessor boards, except the+ 24 V for the AIM printer.

The unit is available for $139 withoutprogrammable memory or for $189 with4 K bytes of programmable memory.Optional boards for the Little BufferedMother include programmable memoryand a programmer, parallel input/out-put (I/O), and disk controller.

For more information, contact SeawellMarketing, 315 NW 85th St, Seattle WA98117.

Circle 596 on inquiry card.

High-Capacity Hard DiskDrive for S-100 Systems

MicroAge has introduced the FujitsuM2201 Drive with S-100 bus controllerfor North Star Horizon systems. Thissystem allows accessing up to 40 Mbytes of disk storage per drive with thecapability of adding up to 4 drives persystem. The M2201 was developed withthe advent of a new type of directmemory access (DMA) disk controllerboard capable of very high-speed datatransfer. A 2400 RPM rotation combin-ed with a quick seek time and relativelylow latency time give the M2201 anaverage access time of 30 ms.

The system is available for $9995. Formore information, contact MicroAgeWholesale, 1425 W 12th PI, Tempe AZ85281.

Circle 597 on inquiry card.

Low-Cost PeripheralAccepts Hand-PrintedCharacters

With the PrestoDigitizer tablet, userscan communicate with their computersthrough ordinary hand-printedcharacters. Stroke direction andsequence are the parameters which aretransmitted to the computer that allow itto recognize the user's style of hand-printed characters. The learning andrecognition algorithms fit in approx-imately 2 K bytes of memory. Versionsof the tablet are available for severalpopular computers. The tablets canrecognize the entire uppercase alphabet,numerals, and many punctuation marks.The PrestoDigitizer retails for $48.50, in-cluding software, from Innovision, POB1317, Los Altos CA 94022.

Circle 598 on inquiry card.

8-Inch Fixed Disk DriveSeries Offers Low Cost PerMegabyte

An 8-inch Winchester fixed disk driveseries that offers 5 and 10 M bytes at alow cost has been introduced byShugart, 435 Oakmead Pky, SunnyvaleCA 94086. Specifications include acapacity of 5.33 M bytes per drive forthe SA1002 and 10.67 M bytes for theSA1004; formatted capacity is 4.2 and8.4 bytes, respectively. Transfer rate foreach type is 4.34 M bits per second.Average access time is 70 ms. The Win-chester drives offer the sameenvironmental specifications as the stan-dard 8-inch floppy disk drive. Meantime between failure (MTBF) is 8000power-on hours of typical usage.Optional data separator and controllerprinted circuit boards are available.

Price for the SA1002 in single quan-tities is $1600 and $1980 for the SA1004.Circle 599 on inquiry card.

MCD ConsultingIntroduces the BionicVoice

Designed around a ComputalkerConsultants CT-1 Speech Synthesizer,the Bionic Voice uses English languagedesign. Knowledge of phonemes orphonetic alphabet is not required.Predefined dictionaries are provided,and custom dictionary entries may beadded. Rapid conversations are possible,because of the English language design.The Bionic Voice can be operated like aconventional language or spelling board.All numerals, letters of the alphabet,and any words or phrases defined on thekeyboard may be vocalized instantly asthe keys are depressed. There are nocommands or codes to memorize nor isknowledge of computers necessary.

To upgrade to a version of the BionicVoice that has more capability, a simplechange of keyboard and computerprogram can be made.

The Bionic Voice may be used as avoice response for nonvocal or non-verbal individuals; for educational andinstructional applications in speechpathology and linguistics; and as aforeign language translator. The BionicVoice is not limited to voice synthesis. Itmay be applied to other computerfunctions. The price ranges between$2700 and $3500 depending on necessarymodifications.

For further information about theBionic Voice, contact MCD Consulting,8306 Selleck, 600 N 15th St, Lincoln NE68508.

Circle 600 on inquiry card.

236 January 1980 © BYTE Publications lnc

New?

PERIPHERALS

Video Digitizer AllowsDisplay and Storage ofComputer GeneratedImages

This fast-scan video digitizer can beutilized in consumer environments andin medical, security and other special-

purpose applications requiring imagestorage and analysis.

This device, for S-100 bus computers,converts output from the video camera(or other source of composite video) in-to 8-bit gray scale digital information.Maximum horizontal resolution isapproximately 700 points per line andvertical resolution is 480 lines per image.Data can be transferred via software toeither a memory mapped high-resolutionvideo board or to main memory. Adriver program, implementing sixteenshades of gray, is included for control-ling the board, displaying images on ahigh-resolution video board, storingimages on disk and printing images on amatrix printer.

The price for the video digitizer isS175, and it is available from VectorGraphic Inc, 31364 Via Colinas,Westlake Village CA 91361.

Circle 601 on inquiry card.

Digital Controller forTouch Screen Digitizer

MttHikl

1

The TSD Touch Screen Digitizerenables untrained personnel to gainaccess to a data base by simply touching

the screen with a finger. The controllerprovides an interface between the touchscreen and other computer equipment.The controller provides all timing signalsrequired by the screen; measures thetime delay between the transmittedsignal and the reflected signal from anobject touching the glass, which allowsthe resulting data to be adjusted tooverlay the display behind the touchscreen; processes and filters the echotimes to produce clean X,Y positiondata; and formats the X,Y data intoeither parallel or serial form.

It is available from TSD Display Pro-ducts Inc, 35 Orville Dr, Bohemia NY11716, for $2000.

Circle 602 on inquiry card.

The Microtek MT-80Printer

The MT-80 series printer supports thefull uppercase and lowercase96-character ASCII set in three softwareselectable fonts on original plus threecopies. The printer contains a

240-character buffer, with optional databuffers to 4 K available in 1 K in-crements. A self-diagnostic program isautomatically run on power up. Lifeexpectancy of the print head is 100million characters and mean time be-tween failures (MTBF) is 1 million lines.

The pin feed system can accept fan-fold forms from 4.5 inches (11.5 cm) to9.5 inches (24 cm) wide. The unitfeatures top of form control and up to10 vertical tab settings. Form length issoftware programmable in one-lineincrements.

The unit weighs 22 pounds andmeasures 7.3 by 17.7 by 14.8 inches (18by 45 by 37 cm). The Centronics-compatible parallel interface version ispriced at $750 and the serial (RS-232)version is priced at $835. The MT-80G,with an IEEE-488 interface, is alsoavailable. Contact Microtek Inc, 7844Convoy Ct, San Diego CA 92111.Circle 603 on inquiry card.

Versatile Printer fromMalibu Design Group

The Model 165 printer can beoperated as a high-speed dot matrixprinter at 165 characters per second(cps); a reduced speed, letter-quality dotmatrix printer at 90 cps; or a fullgraphics matrix printer. The 165 printercan do computer portraits, customcharacter sets such as Japanese, musicsymbols, high-density characters forword processing, and more.

Underlining, expanded characters,programmable horizontal and verticaltabs, selectable left margin, useradjustable platen and a feature thatshuts off the fan when the printer is idle(which reduces noise and power con-sumption) are some of the features ofthis printer.

Price for the basic Model 165 is $2395from Malibu Design Group Inc, 8900Eton Ave, Suite G, Canoga Park CA91304.

Circle 604 on inquiry card.

Pocket Computer forGeneral-Purpose Use

NtKDORF

LK-3COOM 1

atatatatmamiau

EDS 1

M 13 19 IU Ul l!l 1J kl U

cats!

m a m ta va a a m

sal

Using easily loaded electronic applica-tions modules, the Nixdorf LK-3000 per-sonal computer can be freely program-med to be used as a personal date bookor telephone directory, or it can func-tion as a data collection system capableof communication with other data pro-cessing systems. The unit also functionsas a hand-held language dictionary totranslate German, English, French,Greek, Italian, Spanish, Polish andSwedish words and idioms. The unit isproduced by Nixdorf Computer Corp,168 Middlesex Tpke, Burlington MA01803, and is priced at $140.

Circle 605 on inquiry card.

January 1980 © BYTE Publications Inc 237

WbatsNew?

PERIPHERALS

Inexpensive andCompact Printer

The low-profile DIP-80 features 7 by 7or 14 by 14 dot matrix printing, upperand lowercase character set, 100

character per second (cps) bidirectionalprintout, roll or fanfold paper, a full96-character ASCII set, upper andlowercase printing at either 80 or 96characters per line on 8.5 inch widepaper, and a 2-line buffer. Paper feed, atthe rate of 1 line per second, isaccomplished through a friction roller.Interface options include Centronics-compatible parallel, RS-232C serial or 20mA current loop. The printer measures15.75 by 9 by 3.5 inches (40 by 23 by8.8 cm) and is available from DIP Inc,210 Lincoln St, Boston MA 02111, for$625.

Circle 606 on inquiry card.

TelecommunicationsFacility for Transmittingand Receiving CP/M

The Byrom Software Telecommunica-tions Access Method (BSTAM) allowstransmission of program or data filesbetween any two computers and is com-patible with all 8080/Z80 systems usingCP/M operating systems or a derivative,including Heath and TRS-80 adapta-tions. Transmissions are made over anormal voice-grade telephone line at 300bits per second (bps) and over directwire interconnections at 9600 bps. Errorchecking, cyclic redundancy check(CRC) error checking, protocol informa-

tion, and group file transmission arefeatured but no data expansion is per-formed, resulting in fast transfers.BSTAM can precisely transfer data overpoor circuits, with retry provisions andperfect reporting in the event of harderrors. The user interface allows a longsequence of files to be sent, with the filenames automatically announced to thereceiving computer. Sample drivers for8250, 8251, 6850 and other UniversalAsynchronous Receiver Transmitters(UARTs) are provided.

BSTAM comes on floppy disk for$150. Documentation is $5. ContactLifeboat Associates, 2248 Broadway,New York NY 10024.

Circle 607 on inquiry card.

Apple Serial and ParallelInterface

The A10 interface allows maximumflexibility for interfacing an Apple IIwith peripherals such as printers, plot-ters, terminals, modems and other com-puters. The software-programmble serialinterface uses the RS-232 standard andincludes three handshaking lines. Aswitch selects nine standard datatransmission rates. On-board firmwareprovides a powerful driver routine thateliminates the need to write any soft-ware to utilize the interface. The AlO'sparallel interface features software pro-grammable I/O ports with enough linesto handle two printers simultaneouslywith handshaking control.

The A10 comes with serial interfacefirmware, two cable assemblies and amanual with easy to follow applicationnotes. It is priced at $175 assembled,and $135 in the kit form, from SSM(Solid State Music), 2116 Walsh Ave,Santa Clara CA 95050.

Circle 608 on inquiry card.

Single Chip Real-TimeSignal Processor

Intel Corp has developed a single chipreal-time analog input/output (I/O)microcomputer, the 2920 Signal Pro-

cessor, and the SP20 hardware and soft-ware support package. The 2920 con-verts analog input signals to digitalinformation, processes this informationin its computer, and produces analogoutputs in a real-time mode. The SP20support package, a 2920 softwaresimulator assembler and 2920 erasable-programmable read-only memory(EPROM) board, run on the IntellecMicrocomputer Development System.The 2920 interfaces directly with analogsignals using the on-chip circuitry andcan handle multiple signals using I/Omultiplexers, enabling thousands ofcomplex analog systems to be for-mulated from one standard integratedcircuit. The device can implement func-tions such as filters, limiters, oscillators,modulators and demodulators, nonlinearconversions, and perform logical opera-tions all under program control.

The 2920 can be used in phase lockloops, complex filters, test andinstrumentation circuits, speech process-ing, medical electronics, and many otherapplications. The 2920 device costsabout $300 and the support packagecosts $3400. Contact Intel Corp, 3065Bowers Ave, Santa Clara CA 95051.Circle 609 on inquiry card.

238 January 1980 © BYTE Publications lnc

PUBLICATIONS

Bubble Memory DesignHandbook

1^5*

A 64-page catalog presenting thefeatures, descriptions and functionalcharacteristics of the 7110 1 M bit bub-ble memory and its support device fami-ly is now available from Intel MagneticsInc. Included in the handbook arespecifications, diagrams, and tables forthe 7110 magnetic bubble memory, the7220 controller, 7230 current pulsegenerator, 7242 dual formatter/senseamplifier, 7250 coil predriver, 7254 quadVMOS drive transistors, and IMB-100development board.

Contact Intel Literature Dept, 3065Bowers Ave, Santa Clara CA 95051, forfree copies of the guide.

Circle 610 on inquiry card.

Quarterly Review of Soft-ware for TRS-80

80 Software Critique is a collection ofreviews of TRS-80 cassette software.Program reviews are included only ifthey have been run several times; weakpoints and bugs in programs aredocumented. Program reviews includegames, simulations, educational pro-grams, music programs, and others.Business software is not included.Names and addresses of software ven-dors are provided and software pricesare included. A one year (4 issues)subscription is $24 and the price of asingle issue is $7. Write to 80 SoftwareCritique, POB 134 Waukegan IL 60085.Circle 611 on inquiry card.

New Heathkit CatalogAvailable Free

A new 96-page catalog describingnearly 400 electronic kits designed forthe hobbyist is available from HeathCo, Dept 350-880, Benton Harbor MI49022. New products in this cataloginclude the H89 computer, a 3.5 digitauto ranging multimeter, a low-pricedDC to 5 MHz single-trace oscilloscope,and more.

Circle 612 on inquiry card.

Wall Chart and Book onthe Z80

The Working Programmer Press, 5080Shady Ave, San Jose CA 95129, has theZ80 processor pins and elements on awall-chart poster and work-sheet thatmeasures 18 by 24 inches (46 by 60 cm).It retails for $7.95 by mail.

The drawings are from the book TheZ80, How It Works, A ProgrammersPerspective, published by MicrowareAssociates Inc, Scottsdale AZ. The bookdescribes the working and program-mable elements for the Z80. Sections oninstruction cycles with detailed registerinteractions are included.

Circle 613 on inquiry card.

New Language for the6502 User

XPLO is a simplified Pascal-typelanguage available for 6502 systems withless than 32 K bytes of memory. It is afast, structured compiler, so users cantalk to their computers in their ownlanguage. Versions for 20 K Apple II,KIM, TIM, and SYM systems areavailable for under $70. For furtherinformation on XPLO and otherlanguages, assemblers, and games, plusa free catalog, write to The 6502 Pro-gram Exchange, 2920 Moana, Reno NV89509.

Circle 614 on inquiry card.

Educational SoftwareCatalog for PersonalComputers

A new mail order catalog devotedexclusively to educational software isbeing published by Queue, 5 Chapel HillDr, Fairfield CT 06432. The catalog willcontain listings from numerouspublishers. Software listings will beseparated by educational level and field,and by computer. Listings for allpopular personal computers will beincluded, and all software can beordered directly from Queue.

Circle 615 on inquiry card.

Bugbook IV, Microcom-puter Interfacing with the8255 PPI Chip

This new book details microcomputerinput/output (I/O) techniques and theirimplementation with the 8255 Program-mable Peripheral Interface (PPI)integrated circuit. Techniques andexperiments are presented in such a waythat the principles can be applied toother PPI chips by students, scientistsand engineers. All of the modes ofoperation are detailed, and a clear ex-planation of data transfer processes, flagsensing, bit testing, and similar topicsare included. The price is $8.50. Formore information, contact E and L In-struments Inc, 61 First St, Derby CT06418.

Circle 616 on inquiry card.

Analog Dialogue

sample/hold amplifier, CMOS switches,

three power supplies, and several data

converters. The booklet is available for

free from Analog Devices, Rt 1

Industrial Park, POB 280, Norwood MA

02062.

Circle 617 on inquiry card.

■...;.'■/>■■

□■■■

This publication includes applicationarticles on very high-speed data acquisi-tion, statistics methods using RMS toDC, checking converter linearity, a 300kHz continuous 12-bit conversionsystem, and more. Product descriptionsinclude voltage to current (V/I) con-verters for process control, a 14-bit

Connecticutmicrocomputer Catalog

This catalog presents the DataAcquisition Modules Systems (DAM),including the AIM 16 analog to digital(A/D) converter. The publication alsoincludes program reviews and a list ofdealers for the company's products.Contact Connecticut microcomputerInc, 150 Pocono Rd, Brookfield CT06804.

Circle 618 on inquiry card.

January 1980 © BYTE Publications Inc 239

MISCELLANEOUS

Parallel Input/Output andTimer Board

A parallel input and output (I/O)board has been developed by TecmarInc, 23414 Greenlawn Ave, ClevelandOH 44122, for interprocessor com-munications. It has two 16-bit parallelinput ports and two 16-bit parallel out-put ports, status word for polled opera-tion, interrupts for vectored interruptoperation, and is individually maskablefrom software.

Tecmar also has a 16-bit timer with8-bit prescaler, intervals up to 8.4seconds with resolution of 128microseconds, status byte for polledoperation, interrupt for vectored inter-rupt operation, and is compatible withconventional S-100 8080 and Z80systems.

The cost for the entire board is $350.Circle 619 on inquiry card.

A Single Board ComputerSystem

The VP Single Board ComputerSystem provides the functions neededfor business, process control or softwaredevelopment systems. No other boardsof any type are required. Incorporatingon-board voltage regulators, it will evenoperate from a 12 V battery. The multi-ple serial and parallel input and output(I/O) ports allow the VP to interfacewith transducers, modems, couplers, ter-minals, printers, plotters, digitizers,temperature, pressure, voltage monitorsand many other devices with an elec-trical output. The typical configurationincludes a Z80 processor, Centronicsprinter port, 8-bit parallel input port,RS-232C serial port, disk controller foreight drives, and 32 K bytes of pro-grammable memory. The softwarelibrary includes operating systems,

BASIC, CBASIC, FORTRAN, COBOL,and business accounting, payroll, andword processing packages. The board isavailable from Data World Inc, 7541Ravensridge Dr, St Louis MO 63119, for

Circle 620 on inquiry card.

Computer GamesTelephone Network

GameMaster is a computer gaminginformation network that is available forPET, Apple II, TRS-80, and any otherpersonal computer that is outfitted witha modem. The system offers games,information, educational programs andother items of interest for computerusers in the Midwest. For more informa-tion, contact GameMaster, 205 WWacker Dr, Suite 1517, Chicago IL60606.

Circle 621 on inquiry card.

Smoke Signal's New 6809Chieftain Computer

Smoke Signal Broadcasting hasdeveloped a new integrated computersystem utilizing the Motorola 6809 pro-cessor, and configured around the new

Chieftain microcomputer with program-mable read-only memory (PROM) orerasable-programmable read-onlymemory (EPROM) storage, and aminimum of 32 K bytes of program-mable memory.The system also includes expansion

capability to at least 256 K bytes — andperhaps up to 1 megabyte — requiringlarger memory cards than the current16 K byte board. In addition, the newmotherboard will handle as many as six-teen serial or parallel ports in its 30-pininput/output (I/O) section. Nearlyunlimited I/O capability is possible ifthe user wishes to use any of the 50-pinpositions.

Smoke Signal has also developed anew disk controller allowing eithersingle- or double-density recordingtechniques to be employed. Along withthe ability to handle double-sided disks,users can store up to 1 megabyte oneach 8-inch floppy disk (320 K bytes ona 5-inch floppy disk). Current users ofany SS-50 bus disk system compatiblewith the Smoke Signal system canpurchase the controller board separatelyor as part of the new Chieftain.

The new controller allows instantaccess and immediate response to aninterruption request at any time duringdisk operation or other multiuserapplications. The unit can be expandedfor multiuser operation.

The Smoke Signal disk operatingsystem has been converted to run on the6809, as well as the text editor and textword processor. All higher-levellanguages are available for the 6809including UCSD Pascal.

A hard disk capability on the order of15 megabytes of fixed storage and 15megabytes of removable storage isavailable, expandable to 80 megabytesof fixed storage.

For more information, contact SmokeSignal Broadcasting, 31336 Via Colinas,Westlake Village CA 91361, or call (213)889-9340.

Circle 622 on inquiry card.

240 January 1980 © BYTE Publications Inc

SAVE 10%*

ON ANY PREPAID ORDER

OVER $10000

FROM OUR 52 PAGE DETACHABLE

1980

ENGINEERING

SELECTION GUIDE

BEGINNING ON PAGE 80

STOP

GO BACK

TO PAGE 80

JUST ATTACH THIS COUPON TO YOUR ORDER ORMENTION WHEN PLACING YOUR ORDER BY PHONE

PRIORITY

ELECTRONICS

©

16723 Roscoe Blvd. Sepulveda, CA 91343

10°/c

FROM OUR 1980

ENGINEERING

Circle 248 on inquiry card.

OSELECTION GUIDE

DISCOUNT COUPON

VALID ON PREPAID ORDERSRECEIVED BEFORE FEBRUARY 15, 1980

*Sorry Discount Not Valid On

ROCKWELL, AIM, MICROPOLIS,

SHUGART, SIEMANS,

AND SHIPPING CHARGES

BYTE January 1980 241

WtelsNew?

MISCELLANEOUS

Fiber Optic EvaluationKit for SystemsEngineers

Motorola has introduced a fiber opticevaluation kit, developed to givedesigners experience with the latest fiberoptic components. The kit is called TheLink, and refers to the optical link be-tween the transmitter and receiver ofany system with all of the optical por-tions needed. The kit includes anMFOE103FB fiber optic infrared light-emitting diode (LED) source, anMFOD402FB integrated detec-tor/preamplifer, a 1 meter length offiber optic glass cable with matchingAMP connectors, design considerations,applications and circuit ideas.

Price for the kit is $99. Additional fer-rule semiconductors and components areavailable. Contact Motorola, POB20912, Phoenix AZ 85036.

Circle 629 on inquiry card.

The BASIC Programmer'sToolkit

The Toolkit is a collection of machinelanguage firmware aids designed toenhance the writing, debugging andpolishing of BASIC programs for thePET. This 2 K byte read-only memorychip offers additional read-only memorystorage, avoiding any need to load tapesor give up valuable programmable

storage. The Toolkit contains 10 power-ful commands to help programmers withtheir PET. The board attaches to thememory expansion port of any 8 K bytePET. The Toolkit costs $79.95 and theversion for the 16 K or 32 K byte PETretails for $49.95. For more information,contact Palo Alto ICs, 430 ShermanAve, Palo Alto CA 94306.

Circle 630 on inquiry card.

Low-Cost Transmitter/Receiver IntegratedCircuit Pair forRadio Control

National Semiconductor Corp hasdeveloped a low-cost transmit-ter/receiver pair of integrated circuitsthat allow for the design of lightweightand compact remote control systems.The LM1871 and 1872 make use of anunusual pulse code modulation tech-nique that allows the chip set to handleanalog and digital control signal infor-mation. The chip set is adaptable for usein toys, such as model cars, airplanesand trucks with simple on/off digitalcontrol to sophisticated units withseveral channels of proportional analogcontrol.

The LM1871 and 1872 feature twodigital and two analog channels for con-trol, operation in the 27 MHz and49 MHz unlicensed bands or in the72 MHz licensed band, 50 meter out-door control range, and an internalvoltage regulator which keeps radiatedpower constant even if the supplyvoltage changes. The chips have built-inflip-flops which eliminate the need forbulky timing components.

The devices come in 18-pin dual in-line packages and operate on 9 V orless. They are priced at approximately$12 for the set. For more information,contact National Semiconductor Corp,2900 Semiconductor Dr, Santa Clara CA95051.

Circle 631 on inquiry card.

Joystick for Apple II

ISC Inc, 2224-C Old Middlefield Way,Mountain View CA 94043, has introduc-ed the Model VS20/APL Videostick X/Ycontroller for the Apple II. The unitfeatures a large push (firing) button anda linear joystick designed specifically forapplications such as plotting graphics orplaying games. The controller plugsdirectly into the Apple II and can behand-held or table positioned.

The Videostick is priced at $39.95,and is available from Computer PlusInc, 1324 S Mary, Sunnyvale CA 94087.Circle 632 on inquiry card.

Floppy Disk Mailer

Inmac, 2465 Augustine Dr, POB 4780,Santa Clara CA 95051, has designed afloppy disk mailer that protects up tofive standard floppy disks or five 5-inchfloppy disks against bending, curling orcupping in transit. The disks are placedin the center of the new Inmac mailer,then the mailer is folded according tothe instructions printed on the maileritself, assuring safety in mailing. Con-sisting of 10 mailers, a package costs$10. When purchased simultaneously,three or more packages cost $8.50 perpackage.

Circle 633 on inquiry card.

242 January 1980 © BYTE Publications Inc

MATCHMAKER TECHNOLOGY

TURNKEY DISK SUBSYSTEMS

DISK

IS

For those who wish to avoid theaggravation, fussing, irritation, an-noyance etc., of assembling yourown subsystem, plug in and GO!!!

^SORCERERi^TRS-80DAPPLEsHPIBi^PET

APPLE

SORCERER

FEATURES:

— 2 8" Floppy DISK DRIVES (Single Sided)

— Color Coordinated Cabinet with Power Supply

— Expanded version of APPLE-DOS

— Single Density Disk Controller

— Full Cabling, Connectors + Documentation

— Assembled and Tested

-Plug In and GO!!! $1695.00

OPTIONS:

— 2 8" Double Sided Drives (In place of Single Sided)

$2395.00

— 16K Internal Memory Expansion Kit 69.00

PET

Prices and specifications same as for APPLE exceptPET Operates via PET-DOS

TRS-80

Prices and specifications same as for SORCERER withfollowing exceptions:

— Expansion Interface necessary

— Space for up to 48K plug-in dynamic memory onController Card

— Software package as above $ 995.00

FEATURES:

— 2 8" Single Sided Floppy Disk Drives

— Single and/or Double Density

— Color Coordinated Cabinet with Power Supply

— Full RS-232 Interface

— OS-1 Disk Operating System (Fully CP/M

Compatible) CP/M is a registered trademark of Digital Research

— Full Cabling, Connectors + Documentation

— Assembled and Tested

— One S-100 Slot available for Memory Expansion-Plug In and GO!!! $2195.00

OPTIONS:

— 2 8" Double Sided Drives (In place of Single Sided)

$2845.00

— 32K Dynamic RAM Memory Board, Assembledand Tested $ 299.00

— 16K Dynamic RAM Internal Memory Expansion Kit

$ 69.00

— Deluxe Business Software package includes:C BASIC

WORD PROCESSING SOFTWAREINTERACTIVE "Big 4":

General Ledger, Accts. Payable, Accts. Rec.

and Payroll $ 695.00

— 10 MBY Removeable Hard Disk - Call for Details

ANOTHER Fine Product brought to you exclusively by the folks at:

In California: 415-321-5601Outside Cal: 800-227-8266

Electrolabs

Worldwide:

TLX: 345567 Electrolabs PLA

POB 6721, Stanford, Ca.94305

Circle 207 on inquiry card.

BYTE January 1980 243

Whal's New?

MISCELLANEOUS

Scotchflex BrandBreadboard System from3M

3M has developed a breadboardsystem that eliminates stripping, solder-ing and crimping of wires. Connectionsare made with continuous, 30 AWG

solid insulated wire which is easilyinserted into the "U"-contact with ahand-tool supplied by 3M, saving timeand labor. Multiple bussing is simplifiedby putting 2 wires into each contactwhich provides 4 connections. The con-tacts are only about one-third the heightof wrap posts so prototype circuitboards can be mounted in the samespace occupied by production boards.Wires can be removed without unwrap-ping or cutting, and dual sockets andplug strips can be removed with an inex-pensive hand-tool, simplifying reuse ofthe board and components.

Kits with 8 contact solder strips, plugstrips, 16 position dual sockets andScotchflex "U"-contacts cost $97.50.Separate components are also available.Contact 3M Co, POB 33600, St PaulMN 55133, Dept EP9-9.

Circle 638 on Inquiry card.

Microcomputer UsersProvided Access toCommodity Futures DataBase

A commodity futures data base, usedby professionals in the field, is beingmade available to personal computerowners. The MJK data base providesdaily information on 38 major com-modities including interest rate futuresand foreign currencies, as well asagricultural commodities with cash andprice information on many. The databecomes available at 2:15 PM (PST)each trading day. In addition to pro-viding daily price, volume and open in-

terest data, MJK makes available a seriesof programs for calculating movingaverages, spread charts, bar graphs, etc.POISE is a special program for testingtrading systems in the history of thedata base.

A minimum of $25 per month ischarged after a subscriber set-up fee of$25. Additional charges for the serviceare $16 per hour for connect time and14c a second for processor usage. In-cluded is the cost of TYMNET, pro-viding telephone connection at localmessage-unit rates from most USpopulation centers. For further informa-tion, contact Krause and Co, CentralTower Building, San Francisco CA94103. circle 639 on inquiry card.

Heathkit H8 E> fenderBoard Kit

The H8 Extender Board allowsHeathkit owners to troubleshoot theirmachine easily because each board is upabove the computer for access to all cir-cuits and components. Jumper links inpower lines make power measurementsimple. The links can be replaced withfine copper wire, which protects thetraces or the motherboard from damagedue to excessive current during testing.

The kit features a double-sided printedcircuit board, with plated through holes,and a Molex, 25-pin edge connector,with formed leads.

The kit is available from Mullen Com-puter Products inc, POB 6214, HaywardCA 94545, for $39.

Circle 640 on inquiry card.

Talking LanguageTranslator Is Introducedby Texas Instruments

A talking Language Translator, utiliz-ing speech synthesis and offering solidstate electronic modules for English,French, German and Spanish, has beenintroduced by Texas Instruments Inc,

POB 53, Lubbock TX 79408. Designedfor world travelers as an aid in com-municating in a foreign country and forlanguage students in learning to pro-nounce a foreign language, the hand-held device is programmed with avocabulary of words and phrasesselected for everyday use, and can beused as a basic vocabulary for learning alanguage.

The Language Translator has the abili-ty to form thousands of spoken phrasesby linking together its spokenvocabulary words. Each module con-tains about 1000 words of which halfwill be spoken and displayed, while halfwill be displayed only. Components in-clude a speech synthesizer integrated cir-cuit, a controller, and four read-onlymemories. An earplug is provided forquiet use.

There are five basic functions forusers:

• Common phrases - allows user to key-

in a numerical code to access one of 25preprogrammed phrases.

• Partial phrases - users may formthousands of their own phrases bylinking preprogrammed partialphrases with words from the wordmemory.

• Translate mode - translates 1000words from input language to outputlanguage.

• Memory learn mode - drills user onpronunciation and translation of user-selected words.

• In the learn mode - a programmed drillassists the user to learn.

The Language Translator is priced atapproximately $250.

English, Spanish, French and Germanmodules are available. Japanese andChinese will be ready in the first quarteiof 1980. The approximate price of eachis $50.

Circle 641 on inquiry card.

244 January 1980 © BYTE Publications Inc

SAVE THE WHALE

The Fin Whale is the world's greatest long-distance communicator.

Scientists believe that loud, deep-tone, low-frequencysounds made by Fin Whales (frequencies around 20hertz, or cycles per second) actually travel -J&

underwater for distances of at least 500 , &■&■?

miles, and under optimum conditions . 4

might carry for a radius of over ydljh f

4,000 miles, potentially reaching an area greater than theentire Atlantic Ocean. ■**

Don Sintlt

for wh

if Fin Whales,^/r' creatures ever to

earth, grow up to 24 meters in length (

ceeded only by the 30-meter Blue Whale)

ihabit all the oceans of the world. Tens of th

Whales have been "harvested" in recent years,

nternational Whaling Commission, for the sal

ich substitutes are readily available

ex-

andousands ofby agreemente of products

The CONNECTICUT CETACEAN SOCIETY is a small, totally volunteer, non-profit edu-cation and conservation organization dedicated to seeking the abolition of all whale killing. Anyconcerned citizen can help our efforts by sending name and address and a $1 5 or more contributionto: CCS, P. O. Box 145, Wethersfield CT 06109.

UP TO 25% OFF^

YOUR OWN TRS-80 SYSTEM AT TREMENDOUS SAVINGS

QTRS-80 Complete System

Includes: CPU/Keyboard, Power Supply,Video Monitor, Cassette Recorder, Manual,and Game Cassette.

£)Line Printer©Mini Disk SystemOC-10 Cassettes©Verbatim Diskettes

DISK DRIVES IN STOCK!

a

REG.

OUR

ITEM

PRICE

PRICE

Level II—4k

$619.00

$575.70

Level II—16k

$849.00

$789.60

Expansion Interface

$299.00

$278.10

Mini Disk Drive

$ 495 00

$ 385 00

Centronics 730 Printer

$ 995.00

$ 850.00

Centronics 101 Printer

$1595 00

$1400.00

Anadex DP-8000 Printer

$ 895.00

$ 99500

Memory K1M16K) FR££ installation

$ 149 00

$ 98.00

Verbatim Diskettes ea

$ 5 95

$ 4 95

3

$ 17 89

$ 1200

10

$ 5900

$ 37 00

C-10 Cassettes 5

$ 4 95

S 450

25

$ 24 75

S 1875

Paper (9' ? x 11 lanfold.

3500 sneets)

$ 35.00

S 29.95

SALE

Centronics 779

$995.00

Same as Line Printer I (Tractor)

TRS—80 MODEL II

$3626.00

• 64K RAM

• V2 MEG DISK

ADDITIONAL DISK DRIVE (1ST)

$1069,50

ADDITIONAL DISK DRIVE (2ND + 3RD)

$ 558.00

MINI DISK DRIVES NOW $385

Over $100 less than Radio Shack's !

There are new developments every day—write or call for the latest information.

W/Sada

777 Henderson Boulevard N-6Folcroft Industrial ParkFolcroft PA 19032(215) 461 5300

VISA

TOLL FREE1-(800) 345-8102

Orders only!

FOREIGN and DOMESTIC DISTRIBUTORSHIPS AVAILABLE

Till tlH.TTTTTTIYII.IIIIITTMTTITM

Circle 206 on inquiry card.

BYTE January 1980 245

cloppv systems

1 8" Siemens FDD120-8D

All Siemens options in-cluded in this drivemay be configured hardor soft and single ordouble density. We findthis to be an extremelyreliable drive. $430.00Fully Shugart compatible.SYt" BASF Magical Miniature Minidrive only 2/3 the size of othersis reliable and durable and quicklygaining in popularity with ourcustomers. Single or dual densityfast access times $259.00

Tarbell Controller may be re-configured to control 5V drivesand includes short cable for onedrive. KIT S179.00, ASM $265,but only$219 with purch. of 2 drives.

Cable Kits For 8" Drives with10' 50 cond. cable and conn3 y ectors. Also power cable andW connectors. Flat cable assemif you wish. For one drive27.50, two 33.95, three 38.95

Cable Kits for S'/i" Drives as above, but 34cond. For one drive 24.95, two 29.95.

SOFT-WARE:SUPERDOS I (Z-80)Single User, UNIX- LikeFile System, AND TotallyUpward Compatable From "XX/X"(What did you say, Digital Research??)

PS: SUPERDOS -I runs on the TRS-80,and can transform it from a toy computerto a real business machine !!!

10MByDRIVE$3300

S-100

DMA

CONTROL

POWER

UNIT

$395.00

For the first time in something like 10 years,a new STANDARD in removable media hasevolved. Selected by Datapoint, and otherswho have not yet announced, this drive isbeautifully simple and easy, if not trivial tomaintain. 920kBy/sec. transfer rate, 3600 RPM39 lbs and only 125 Watts.

1

^JSfc. "Power One" Model CP206„""i, Power Supply adequate forHfl ' at least two drives. 2.8A/24V

2.5A/5V, 0.5A/-5V beautiful™' quality. $99.00

CABINETS forFDD120and801 R drives, or CP206 supply.Matte finish in mar resistantblack epoxy paint and stack-ing design 29.95

DISKETTES

(3M, MRX, BASF,Georgia Magnetics,& Victor Borge)8" $39.95/10S%" $29.95/10$290.00

32K-$490.00 16K

NEW!! - CHRISLIN 64K Dynamic RAM $750.00(Showing Amazing Similarity to Tarbell's unit)(16K Shown in photo)

32K-$549.00 16K - $349.00

"BACK TO SCHOOL"KEYBOARD SPECIAL

CHERRY "PRO" Keyboard $119.00Streamlined Custom Enclosure $34.95BOTH ONLY $124.95 !!!!!!!!

246 BYTE January 1980

Electrolabs

POB 6721, Stanford, CA 94305

415-321-5601 800-227-8266

Telex: 345567 (Electrolab Pla)Visa MC Am. Exp.

Daisy Wheel Printers^0 Qume Sprint: 3\45

PRINTER (factory warr.) $1199.00POWER SUPPLY (Boschert) $349.00(shown mounted on rear of printer)

COMBINATION SPECIAL $1699.00

DATA DISPLAY MONITORS

Used 12" Sylvania mon-itors. Composite Video,15 MHz, 120VAC. Re-built with NEW P39anti-glare tube $119.00New P4, 109.00, usedP4 79.00.U-fix model, 10/$300.00

ESAT 200B

BI-LINGUAL 80x24

COMMUNICATING

TERMINAL

Scrolling, full cursor, bell,8x8 matrix, 110- 19,200baud. Dual Font Appli-cations. Arabic & Hebrew,Multilingual Data EntryForms Drawing, Music, &Switchyards. $349.00

"OEM STYLE" as above,will fit any case. (Bothversions serviced by quali-fied tech). Identical toabove but subtract $12.00

Doppler Motion Sensorl\lew I Intrusion Detector

Extremely effective microwavemotion detector for detecting%::\:^\$>Mff?'-\^'W+:M unwanted visitors. Ignores mice

and other non-larcenous creatures,, Operates on 12VDC or from smalltransformer supplied. Output isayi % relay closure for alarm control

interface, or to switch on lightsannunciators. Will operate THROUGH\, door of closet or thin wall. Best

■«;*. application seems to be to turn

on outside lights to help invited- guests, and to intimidate un-wanted ones. $159.00Water Repellent Cover S24.95

SOCKET SPECIAL

8 14 16

"Won't Let Go"

Low ProfileSolder Tail1 CENT/Pin!! (0.75/1000's)

18 20 22 24 28 40

Circle 207 on inquiry card.

CP/M* Source Code -FREE! when you purchase "OS-1"Electrolabs' new operating system for the Z-80 designed to have exactlythe appearance of UNIX**, including virtual I/O, "set TTY", a tree and ashell, filters and pipes PLUS total compatibility with CP/M software]

^^% ^^^ M© (Because OS-1 is truly a comprehensive

I ^^ "OS", and not merely a file handling

I H^\ ^m I rr atiidcc "DOS",we have changed the name

\J \J I PCAIUMta from "Superdos" to "OS-1")

VIRTUAL I/O - copy with a single command between floppy and hard

disk, or from TTY to printer to tape to disk... etc., etc.

No messy I/O routines to write, & no awkward transfers.SECURITY - 9 modes of file protection, user and login protection.MULTI-USER - up to 256 passwords, (non-simultaneous users)16MBy FILE SIZE - but no limit to no. of directories per device, thus

allowing EASY implementation of gigantic storage devices."SET TTY" - for printer or crt: tabs, page width, buffer, cursor, UC/LC,

fonts, formfeed, arbitrary control characters etc., etc."LOGIN" - automatically executes user selected programs and "set TTY",OCCUPIES 12KBy - only 50% larger than CP/M, but 500% more features.CP/M & CDOS COMPATABLE - your library is guaranteed to run!

*(Naturaliy, we are not giving away the version of CP/M written byDigital Research, Please pardon our pun, but they might object.What we ARE giving you is a greatly enhanced version of CP/Mwhich resides on OS-1, and allows the user of OS-1 to run any andall of his programs, packages or system utilities which are alreadyrunning on CP/M. We give you the source code at no charge sothat you may modify any part of the CP/M to suit your own sys-tem requirements. At no charge, you also receive the enhancementallowing 4MBy files instead of 256K.)

OS-1 (with debugger, linker and screen oriented editor $199.00

Update service, per year 29.00

Symbolic Debugger 150.00

MACRO-Assembler (Creates relocatable code) 150.00

"C" Compiler 660.00

FORTRAN Compiler 100.00

BASIC Compiler (very fast) 350.00

PAPER TIGER

IDS MODEL 440

— 8 Software Selectable CharacterSizes

— Parallel & Serial Interface

— 98 ASCII Character set, upper& Lower case

— Forms length control

— Tractor Feed $995.00Graphics option with 2K CRT

screen buffer add $199.00

DYNAMIC DEVICES MODEM

— Acoustically coupled modemassembly set

— Asynchrous 0-300 Baud

— Switchable originate or answermodes

— Operates full or half duplexmode

— 15 minute assembly $149.95

NEW YEAR'S IC(While Supply Lasts)

MEMORY &EPR0M

2114- $ 3.00

2114-2 6.99

Pd411 2.50

2107 (pull outs) 2.00

SPECTACULAR

7001 (pull outs) 2.00

4116 (set of 8,

16K)

69.00

5204

4.95

2708

8.95

2516

35.00

2716

35.00

ELECTROLABSPOB6721 Stanford, CA 94305415-321-5601 800-227-8266Telex: 345567 (Electrolab Pla)

TMS2716

19.00

2732

95.00

CPU

1802CD

$19.95

6502

6.25

Z-80

9.95

Z-80A

12.95

8080A

8.99

8085

2Z00

8741

79.00

FLOPPY CONTROLLERS

1771 $26.95

1791 37.95

Pd372 39.00

MISCELLANEOUS

(CALLUS!!)

Graphics

High Resolution ' 480x512

for B&W and Color Imaging and Graphics

ght pen, A-D, D-A, TV synchro (needs no time baseirrection or adjustment with anything between ran-dom interface Si NTSC commercial standard). T.V.single frame grabber ("snapshot"). Up to 1 Byte of at-tributions per pixel.

LSI-100&S-100 applied to:

Graphic Presentation — such as computer generated animation Si othergraphic displays up to 256 colors Si up to 256 bSiw gray scales. ImageAnalysis — using built-in FRAME GRABBER, for medical image en-hancement, contour analysis, Si pattern recognition. Commercial TV

Tilting & Advertising — using synchronization capability. Interactive

graphics — using light pen accessory.

BASIC CONFIGURATION -

LSI-11 $1995. S-100$1265.For TRS-80/Exidy Add $595.00Includes: Data Board - 32K (480x 512 x 1 pixel) D-A 16 level videogenerator. Video SynchronizationCircuitry. Address Control Si Tim-ing Board,

FEATURES — High speed. DMAor 2KBy window memory mapped interface.Full NTSC commercial color capability. Lowpower consumption. Excellent Software

Options - Accessories - Software

Options include: light pen, auxiliary outputs,text mode, memory and much more. Acces-sories include: b&w and color cameras andmonitors. Software: "Plot" 2D or 3D,"Tilting", "Contour", "Image Enhance-ment", "Vector Curve Generation".

Call for price and details

•CPM and "UNIX

trademarks of Digital Research and Western Electric respectively

BYTE January 1980 247

COMPUCRUISE

Put a computer inyour car, which givesyou the most effec-tive and functionalcruise control everdesigned, plus com-plete trip computing,fuel management sys-tems, and a remark-able accurate quartzcrystal time system.So simple a child canoperate, the newCompuCruise com-bines latest computertechnology with

state-of-the-art re-liability in a packagewhich will not likely beavailable on new carsfor years to come •Cruise Control • Time.E.T.. Lap Timer. Alarm

• Time. Distance, Fuelto Arrival • Time, Dis-tance, Fuel to Empty •Time, Distance andFuel on Trip • Currentor Average MPG,GPH •Fuel Used, Dis-tance since Fillup •Current and Aver-age-Vehicle Speed •Inside, Outside orCoolant Temperature

• Battery Voltage •English or MetricDisplay. $169.95 .without cruise con-trol $129.95.

FLOPPY DISKSTORAGE BINDER

This black vinylthree-ring bindercomes with tentransparent plasticsleeves which ac-commodate eithertwenty, five-inch orten, eight-inch floppydisks. The plasticsleeves may be or-dered separately andadded as needed. Acontents file is in-cluded with eachsleeve for easy iden-tification and organiz-ing. Binder S 10 hol-ders $14.95 Part No.BBQD; Extra holders95* each. Part No.800

OPTO-ISOLATED

PARALLEL INPUT

BOARD FOR

APPLE II

There are 8 in-puts that can be dri-ven from TTL logic orany 5 volt source.Thecircuit board can beplugged into any ofthe 8 sockets of yourApple II. It has a 16 pinsocket for standarddip ribbon cable con-nection.

Board only $15.00.Part No. 120, withparts $69.95. PartNo. 120A.

TIDMA

• Tape Interface DirectMemory Access • Re-cord and play programswithout bootstrap load-er (no prom) has FSKencoder/decoder fordirect connections tolow cost recorder at1 200 baud rate, anddirect connections forinputs and outputs toa digital recorder atany baud rate • S-100bus compatible • Boardonly $35.00 Part No.112. with parts $110Part No. 112A

SYSTEMMONITOR

8080, 8085. or Z-BOSystem monitor for usewith the TIDMA board.There is no need for thefront panel. Completewith documentation$15.95.

16KEPROM

Uses 2708 EPROMS,memory speed selec-tion provided, ad-dressable anywhere inB5K of memory, canbe shadowed in 4K in-crements. Board only$24.95 part no.7902, with parts lessEPROMs$49.95partno. 7902A.

ASCII KEYBOARD

TTL & DTL compatible • Full 67 key array

• Full 128 character ASCII output • Positivelogic with outputs resting low • Data Strobe

• Five user-definable spare keys ■ Standard22 pin dual card edge connector • Requires+ 5VDC, 325 mA. Assembled S. Tested.Cherry Pro Part No. P70-05AB. $1:19.95.

ASCII KEYBOARD

53 Keys popular ASR-33 format • RuggedG-10 PC. Board • Tri-mode MOS encoding•Two-Key Rollover-MOS/DTL/TTL Compat-ible • Upper Case lockout • Data and Strobeinversion option • Three User DefinableKeys • Low contact bounce • Selectable Par-ity • Custom Keycaps • George Risk Model753. Requires +5, -12 volts. $59.95 Kit.

ASCII TO CORRESPONDENCECODE CONVERTER

This bidirectional board is a direct replace-ment for the board inside the Trendata 1000terminal. The on board connector providesRS-232 serial in and out. Sold only as anassembled and tested unit for $229.95.Part No. TA1000C

DISK JACKET™

Made from heavy duty.0095 matte plasticwith reinforced

grommets. The mini-diskette version holdstwo 5-1/4 inch disk-ettes and will fit anystandard three ringbinder. The pockets tothe left of the disk-ette can be used forlisting the contents ofthe disk. Please orderonly in multitudes often. $9.95/10 Pack.

f

ATARI 800

Computer with 8K$995.00, disk drive$549.00. printer$599.99

VIDEO TERMINAL

16 lines, 64 columns •Upper and lower case

• 5x7 dot matrix • Se-rial RS-232 in and outwith TTL parallelkeyboard input • Onboard baud rategenerator 75, 110,150, 300, 600, &1200 jumper select-able • Memory 1024characters (7-21L02)

• Video processor chipSFF96364 by Necu-lonic « Control char-acters (CR, LF, ->, •-.\ i, non destructivecursor. CS, home, CL

• White characters onblack background orvice-versa • With theaddition of a key-board, video monitoror TV set with TVinterface (part no.107A) and powersupply this is a com-plete stand aloneterminal • also S-100compatible • requires+ 16, & -16 VDC at100mA, and 8VDC at1A. Part No. 1000A$199.95 kit.

ftmmmmmm

■W" :* ■■■«

RS-232/20mAINTERFACE

This board has twopassive, opto-isola-ted circuits. One con-verts RS-232 to20mA, the other con-verts 20mA to RS-232. All connectionsgo to a 10 pin edgeconnector. Requires+12 and -12 volts.Board only $9.95,part no. 7901, withparts $14.95 PartNo. 7901A.

COMPUCOLORII

Model 3, 8K $13 95,Model 4, 16K $15 95,Model 5, 32K$18 95.Prices include colormonitor. computer,and one disk drive.

PET COMPUTER

With 32K S. monitor-$1195. Dual DiskDrive-$1195.

^cippkz ii

or

APPLE II PLUS

16K - $995, 32K -$1059, 48K - $1123.Disk &cont. $589

\

CASSETTE TAPEERASER

REMOVES RECORD-INGS IN ONE SEC-OND! The processeliminates static pos-itive / negative ionsand maintains originaltone quality with min-imal tape hiss • To im-prove tone quality • Toreduce hissing • Forquick and easy toerase • No battery orliquid required • Pow-erful and effective ac-tion • Unconditional 2year guarantee.

ERASER-8 $19.95.

16KRAMS

For the Apple.TRS-80 or Pet $8each Part No. 4116/2117.

APPLE II HOBBY/

PROTOTYPING

CARD

$14.95 Part No.7907

T.V. INTERFACE

• Converts video toAM modulated RF.Channels 2 or 3. Sopowerful almost notuning is required. Onboard regulated powersupply makes this ex-tremely stable. Ratedvery highly in DoctorDobbs' Journal. Recom-mended by Apple •Power required is 12volts AC C.T., or +5volts DC • Board only$7.60 part No. 107.with parts $13.50 PartNo. 107A

PARALLELTRIAC

OUTPUT BOARD

FOR APPLE II

This board has 8 tnacs capable ofswitching 110 volt 6 amp loads (660 wattsper channel) or a total of 5280 watts. Boardonly $15.00 Part No, 210, with parts$119.95 Part No. 210A.

Trj (Vfjpr ■ Mention part no. description, and price. In USA shipping paid by us for orders accompanied by check or money order.'We accept C.O.D. orders in the U. S. only, or a VISA or Master Charge no., expiration date, signature, phone no.,shipping charges will be added. CA residents add 6.5% for tax. Outside USA add 10% for air mail postage and han-dling. Payment must be in U. S. dollars. Dealer inquiries invited. 24 hour order line (408) 448-0800

Send for FREE Catalog ... a big self-addressed envelope with 41* postage gets it fastest!

ELECTRONIC SYSTEM S Dept .B, P. 0. Box 21638. San Jose, CAUSA 95151

248 BYTE January 1980

TRS-80ESSERIAL I/O

• Can input into basic

• Can use LUST andLPRINT to output, oroutput continuously •RS-232 compatible ■Can be used with orwithout the expansionbus • On board switchselectable baud ratesof 110,150,300, 600,1200, 2400, parity orno parity odd or even,5 to B data bits, and 1or 2 stop bits. D.T.R.line • Requires +5.-12 VDC • Board only$19.95 Part No. B010,with parts S59.95 PartNo. 801OA, assembledS79.95 Part No. 8010C. No connectors pro-vided, see below.

MODEM

• Type 103 • Full orhalf duplex • Works upto 300 baud • Origi-nate or Answer • Nocoils, only low costcomponents • TTL in-put and output-serial

• Connect 8 n speak-er and crystal mic.directly to board •Uses XR FSK demod-ulator • Requires +5volts • Board only$7.60 Part No. 109,with parts $27.50 PartNo. 109A

EIA/RS-232 con-nector Part NoDB35PS6DO, with9'. B conductorcable S10.95PartNo 0835P9

3' nbbon cablewith attached con-nectors to litTRS-90 and our serialboard SI 9 95 PartNo 3CAB4D

RS-232/ TTLINTERFACE

• Converts TTL to RS-232, and converts RS-232 to TTL • Two sep-arate circuits • Re-quires -12 and +12volts • All connectionsgo to a 10 pin goldplated edge connector,kit $ 9.95 Part No!232A 10 Pin edgeconnector $3.00 PartNo. 10P,

***°*iVin^fi*"*

^

DISKETTES

Vferbaiim

Box of 10, 5" $29.95,8" $39.95.

Plastic box, holds 10diskettes, 5" - $4.50,8"-$6.50.

RS-232/TTYINTERFACE

This board has twoactive circuits, oneconverts RS-232 to20mA. and the otherconverts 20mA toRS-232. Requires+12 and -12 volts.$9.9 5 Part No. 600AKit.

past WP soa

S-100 BUSACTIVE TERMINATOR

Board only $14.95 Part No. 900, with parts$24.95 Part No. 900A

..■■■■■.■■.:.,'.■■ i

apple ii-::-

SERIAL I/OINTERFACE

Baud rate is continuously adjustable from 0to 30,000 • Plugs into any peripheralconnector • Low current drain. RS-232 inputand output • On board switch selectable 5 to8 data bits, 1 or 2 stop bits, and parity or noparity either odd or even • Jumper selectableaddress • SOFTWARE • Input and Outputroutine from monitor or BASIC to teletype orother serial printer • Program for using anApple II for a video or an intelligent terminal.Also can output in correspondence code tointerface with some selectrics. • Alsowatches DTR • Board only $15.00 Part No.2, with parts $42.00 Part No. 2A, assembled$62.00 Part No. 2C

8K EPROM piiceon

Saves programs on PROM permanently (untilerased via U V light) up to 8K bytes. Programsmay be directly run from the program saversuch as fixed routines or assemblers. • S-100 bus compatible • Room for 8K bytes ofEPROM non-volatile memory (2708's). • On-board PROM programming • Addressrelocation of each 4K of memory to any 4Kboundary within 64K • Power on jump andreset |ump option for "turnkey" systems andcomputers without a front panel • Programsaver software available • Solder mask bothsides • Full silkscreen for easy assembly.Program saver software in 1 2708 EPROM$25. Bare board $35 including custom coil,board with parts but no EPROMS $1 39, with4 EPROMS $179, with 8 EPROMS $219.

WAMECO PRODUCTS

WITH

ELECTRONIC SYSTEMS PARTS

FDC-1 FLOPPY CONTROLLER BOARD willdrive shugart, pertek. remex 5" & 8" drivesup to 8 drives, on board PROM with powerboot up, will operate with CPM (notincluded). PCBD $42.95

FPB-1 Front Panel. (Finally) IMSAI size hexdisplays. Byte or instruction single step.PCBD $42.95

MEM-1A 8Kx8 fully buffered, S-100, uses2102 type RAMS.PCBD $24.95, $1 68 Kit

QMB-12 MOTHER BOARD, 13 slot, termi-nated, S-100 board only $34.95

$89.95 Kit

CPU-1 8080A Processor board S-100 with

8 level vector interrupt PCBD .. $25.95

$89.95 Kit

P.TC-1 Realtime clock board. Two independ-ent interrupts. Software programmable.PCBD $25.95, $60.95 Kit

EPM-1 1702A 4K EPROM

card PCBD $25.95

$49.95 with parts less EPROMS

EPM-2 2708/2718 1BK/32K

EPROM card PCBD $24.95

$49.95 with parts less EPROMS

QMB-9 MOTHER BOARD. Short Version of

QMB-12. 9 Slots PCBD $30.95

$67.95 Kit

MEM-2 16Kx8 Fully Buffered 21 14 BoardPCBD $25.95, $269.95 Kit

T.V.TYPEWRITER

• Stand alone TVT

• 32 char/line, 16lines, modifications for64 char/line included

• Parallel ASCII (TTL)input • Video output

• 1K on board memory

• Output for computercontrolled cursor •Auto scroll • Non-destructive curser •Curser inputs: up, down,left, right, home, EOL,EDS • Scroll up, down

• Requires +5 voltsat 1.5 amps, and -12volts at 30 mA • All7400, TTL chips •Char. gen. 2513 •Upper case only •Board only $39.00Part No. 106, withparts $145.00 PartNo. 10BA

UART &BAUD RATEGENERATOR

• Converts serial toparallel and parallel toserial • Low cost onboard baud rate gener-ator • Baud rates:110, 150, 300, 600,1200, and 2400 •Low power drain +5volts and -12 voltsrequired • TTL com-patible • All characterscontain a start bit, 5to 8 data bits, 1 or 2stop bits, and eitherodd or even parity. • Allconnections go to a 44pin gold plated edgeconnector • Board only$12.00 Part No. 101,with parts $35.00 PartNo. 101 A, 44 pin edgeconnector $4.00 PartNo. 44P

TAPEINTERFACE

• Play and record Kan-sas City Standard tapes

• Converts a low costtape recorder to adigital recorder • Worksup to 1200baud» Dig-ital in and out are TTL-serial • Output ofboard connects to mic.in of recorder • Ear-phone of recorder con-nects to input on board

• No coils * Requires+5 volts, low powerdrain • Board only$7.60 Part No. 111,with parts $27.50 PartNo. 111A

HEX ENCODEDKEYBOARD

E.S.This HEX keyboardhas 19 keys, 16 encod-ed with 3 user defin-able. The encoded TTLoutputs, 8-4-2-1 andSTROBE are debouncedand available in trueand complement form.Four onboard LEDsindicate the HEX codegenerated for eachkey depression. Theboard requires a single+5 volt supply. Boardonly $15.00 Part No.HEX-3, with parts$49.95 Part No. HEX-3A. 44 pin edge con-nector $4.00 Part No.44P.

DC POWER SUPPLY

• Board supplies a regulated +5volts at 3 amps., +1 2, -1 2, and -5volts at 1 amp. • Power required is8 volts AC at 3 amps., and 24 voltsAC C.T. at 1.5 amps. • Board only$12.50 Part No. 6085, with partsexcluding transformers $42.50Part No. 6085A

TX OrHpr ■ Mention part no. description, and price. In USA shipping paid by us for orders accompanied by check or money order.1 We accept C.O.D. orders in the U. S. only, or a VISA or Master Charge no., expiration date, signature, phone no.,shipping charges will be added. CA residents add 6.5% for tax. Outside USA add 10% for air mail postage and han-dling. Payment must be in U. S. dollars. Dealer inquiries invited. 24 hour order line [408] 448-0800

Send for FREE Catalog ... a big self-addressed envelope with 41* postage gets it fastest!

ELECTRONIC SYSTEMS » »

P. 0. Box 21638, San Jose, CA USA 95151

Circle 208 on inquiry card.

BYTE January 1980 249

Computer Products

cH\pS ^J/o °FF ' MEMORY PRICES REDUCED !!! ° SyST£/l/fs

$*(.£

S D SYSTEMS

EXPANDORAM

EXPANDABLE TO 64K USING 4116 RAMS

Interfaces with most popular S-100 boards

Bank selectable; PHANTOM provision

Draws only 5 watts fully populated

Designed to work with Z-80, 8080,and 8085 systems

No wait states required

16K boundaries & protect via dip switches

Kits come with sockets for full 64K

Invisible refresh

MEM-16130K (16K KIT) $199.00

MEM-16130A (16K A&T) $249.00

MEM-32131K (32K KIT) $265.00

MEM-32131A (32K A&T) $315.00

MEM-48132K (48K KIT) $339.00

MEM-48132A (48K A&T) $389.00

MEM-64133K (64K KIT) $394.00

MEM-64133A (64K A&T) $444.00

S D SYSTEMS

PROM-100

VERSATILE EPROM PROGRAMMER

S-100 bus compatible (note: board height 7")Dip switch selects 2708, 2716, 2732, 2758, or 2516's25 VDC programming pulse generated on boardProgramming time only 100 seconds for 16K bitsSupport-software listing provided in manualProgram and erasure verificationSoftware provides for reading of object file fromCP/M and programming into EPROM

MEM-99520K (KIT) $145.00

MEM-99520A (A&T) $215.00

S D SYSTEMS

EXPANDOPROM

lEXPANDABLE TO 32K USING 2716 EPROMS

rrffirlfflr

S-100 bus compatible, uses 2708 or 2716 EPROMsDip switches allow selection of: each EPROM, 16Kor 32K boundary, wait states

MEM-32220K (KIT) $135.00

kMEM-32220A (A&T) $199.00

GET THE INSIDE TRACK

JADE DOUBLE-D

DOUBLE DENSITY DISK CONTROLLER

Read/write single or double density, 8"or 5%"drives

On board Z-80 insures reliable operation

CP/M compatible in either single or double density

Density is software selectable

Up to 4 single or double sided, single or double

density drives may be mixed on the same system

EIA level serial printer interface on board-up to 9600

baud (perfect for despooling operations)

All the hard work of disk access is done by the on

board Z-80A and 2K memory, leaving your host

CPU free for its normal duties

Uses IBM standard formats for proven reliability

THIS BOARD REALLY WORKS !!!!!!

IOD-1200K (DOUBLE-D KIT) $285.00

IOD-1200A (DOUBLE-D A&T) $349.00

IOD-1200D (MANUAL ONLY) $15.00

S D SYSTEMS

VERSAFLOPPY II

DOUBLE DENSITY DISK CONTROLLER

7**

Single or double density floppy disk controller

985600 bytes on 8" double sided diskettes

259840 bytes on double sided 5'/4" diskettes

S-100 bus (IEEE) standard compatible

IBM 3740 format in single density

8" and 5%" drives controlled simultaneously

Operates with Z-80, 8080, and 8085 CPU's

Controls up to 4 drives

Vectored interrupt operation optional

IOD-1160K (KIT) $305.00

IOD-1169A (A&T) $399.00

S D SYSTEMS

VERSAFLOPPY

VERSATILE FLOPPY DISK CONTROLLER

IBM 3740 soft sectored format

S-100 Z-80 or 8080 compatible

Controls up to 4 single or double sided drives

Compatible with all popular disk drives

CP/M compatible

Listings for control software included

IOD-1150K (KIT) $139.00

IOD-1150A (A&T) $229.00

NEW 2 OR 4 MHz REV. C BOARD

THE JADE BIG Z

Z-80 CPU BOARD WITH SERIAL I/O PORT2 or A MHzswitchable, on-board 2708,2716, or 2732EPROM useable in SHADOW mode (full 64K RAM)Automatic MWRITE generation if no front panelOn-board USART for sync or async RS232

CPU-30201K (KIT) $159.00

CPU-30201A (A&T) $209.00

S D SYSTEMS

EXPANDORAM H

4 MHz RAM BOARD EXPANDABLE TO 256K

m

S-100 bus compatible, up to 4 MHz operationExpandable memory from 16K to 256KDip switch selectable boundariesPage-mode allows up to 8 boards on the same busInvisible refresh; PHANTOM output disableDesigned to operate in Z-80 based systems

MEM-16631K (16K KIT) $275.00

MEM-16631A (16K A&T) $325.00

MEM-32632K (32K KIT) $359.00

MEM-32632A (32K A&T) $410.00

MEM-48632K (48K KIT) $445.00

MEM-48632A (48K A&T) $495.00

MEM-64632K (64K KIT) $529.00

MEM-64632A (64K A&T) $579.00

S D SYSTEMS

VDB-8024

80 X 24 I/O MAPPED VIDEO BOARD

80 character by 24 line display, 7X10 dot matrixComposite or seperate TTL video outputsOn-board keyboard interface with powerOn-board Z-80 and 2K RAMBlink, underline, reverse, protect, up/down scrollUpper/lower case characters, 32 special charactersOptional 128 user-programmable characters

IOV-1020K (KIT) $295.00

IOV-1020A (A&T) $459.00

S D SYSTEMS

SBC-100/200

2 OR 4 MHz SINGLE BOARD COMPUTER

WE

iinrffnfiniTniiiiiiHTriiiiiimiirrtnniiiiTr

S-100 bus compatible Z-80 CPU

1K of on-board RAM

4 EPROM sockets accomodates 2708. 2716. or 2732

One parallel and one serial I/O port

4-channel counter timer chip (Z-80 CTC)

Software programmable serial baud rates

CPC-30100K (2 MHz KIT) $215.00

CPC-30100A (2 MHz A&T) $345.00

CPC-30200K (4 MHz KIT) $255.00

CPC-30200A (4 MHz A&T) $365.00 1

PRICES SLASHED FOR JANUARY !!!!

CALL TOLL-FREE AND SAVE

800-421-5809 CONTINENTAL U.S. 800-262-1710 INSIDE CALIFORNIA

S D SYSTEMS

iZ-80 STARTER KIT

COMPLETE Z-80 MICROCOMPUTER

On-board keyboard, display, EPROM programmer,

and cassette interface

On-board S-1Q0 interface

Wire-wrap area and room for 2 S-100 connectors

Two 8-bit parallel I/O ports, 4-channel CTC, 5

programmable breakpoints

Examine and change memory, I/O ports, or register

CPS-30010K (KIT) $219.00

CPS-30010A (A&T) $365.00

CP/M 2.0

Digital Research has done it again! This new release of their

industry standard disk operating system is bound to be aneven bigger hit than the original version. All of thefundamental file-size restrictions of release 1 have beeneliminated, while maintaining full compatibility with theearlier versions. This new release can be field-configured bythe user for a single mini-disk up through a multiple drivehard-disk system with 128 megabyte capacity. Fieldconfiguration can be accomplished easily through use of theMacro Library (DISKDEF) provided with CP/M 2.0.

A powerful operating system for only ... $150.00

JADE'S NEW MOTHERBOARDS

THE ISO-BUS

WERE PROUD OF OUR MOTHER !

6-SLOT

BARE BOARD $24.95

KIT $49.95

ASSEMBLED & TESTED $59.95

12-SLOT

BARE BOARD $39.95

KIT $89.95

ASSEMBLED & TESTED $99.95

18-SLOT

BARE BOARD $59.95

KIT $129.95

ASSEMBLED & TESTED $149.95

SPECIAL PACKAGE PRICE

ROCKWELL AIM-65

THE HEAD-START IN MICROCOMPUTERS

KIM-1 compatibleOn-board printerFull ACSII keyboard jfcpjT<3

AIM-65 w/1K RAM..$375.00 ^BpSB?

AIM-65 w/4K RAM..$450.00J)S&-J^1

8K BASIC ROM..$100.00 k\.< Wfitts££*F-

POWER SUPPLY..$59.95<^

CASE for AIM-65..$49.95_"

4K Assembler/Editor..$80.0'O

Special Package Price $599.00

4K AIM-65. 8K BASIC ROM, Power Supply, and Case.

JADEMEMORY EXPANSION KITS

FOR

TRS-80 APPLE EXIDY

Everything you need to add 16K ol memory to yourcomputer. Your kit comes neatly packaged witheasy to follow instructions. In just minutes yourcomputer is ready to tackle more advancedsoftware.

$75.00

AVAILABLE IN FEBRUARY

NEW JADE P/S I/O

PARALLEL/SERIAL/INTERRUPT BOARDZ-80 SIO/PIO, 2 CTCs, expands to 2 SIOs, 4 CTCs4 serial ports (async, sync, bisync, SDLC/HDLC)2 parallel ports with full handshakeSoftware baud rate generators, interval timers,counters, and generates 32 vectored interruptsDesigned especially for MP/M multi-user multi-tasking operating systems. For use with Z-80 only

IOI-1045B (BARE BOARD) $45.00

IOI-1045K (KIT) $169.95

IOI-1045A (A&T) $224.95

MICROPROCESSORS

F8 $16.95

Z80 (2MHz) $10.95

Z80A(4MHz) $14.95

CDP1802CD S24.95

6502 $11.95

6800 $12.50

6602 $20.00

8008-1 $15.95

8035 $24.00

8035-8 $24.00

8080-A S10.00

8085 $23.00

TMS9900TL $49.95

8080A SUPPORT DEVICES

8212 $5.00

8214 $4.65

8216 $2.95

8224 (2MHz) $4.30

8226 $2.75

8228 $6.40

8238 $6.40

8243 $8.00

8251 $7.50

9253 $20.00

8255 $6.40

8257 $19.95

8259 $19.95

B275 $69.95

8279 $17.70

USRT

S2350 $10.95

UARTS

AY5-1013A $5.25

AY5-1014A $8.25

TR1602B $5.25

TMS6011 $5.95

IM6403 $9.00

BAUD RATE GENERATORSMC14411 $10.00

6800 PRODUCT

6821P $5.25

6828P $12.00

6834P $16.95

6850P S4.80

6852P $7.50

6860P $9.25

6862P $12.00

6875L $7.30

6880P $2.50

CHARACTER GENERATORS

2513 Upper $7.95

2513 Lower $6.75

2513 Upper (5 volt) .... 9.752513 Lower (5 volt) .. $13.00MCM6571 up scan ..$13.00MCM6571A down scnnS10.95PROMS

1702A $5.00

270B $8.95

2716 $39.95

2716 (5v) 539.95

2758 (5v) $30.00

DYNAMIC RAMS4116/416D 6 lor $74.95

2104/4096 $4.75

2107B-4 $3.95

TMS4027/4096 S4.75

STATIC RAMS

21L02 (450ns) $1.50

21L02 (250ns) $1.75

2101-1 $2.95

2111-1 $3.25

2112-1 $2.95

2114L (450ns) $5.75

2114L (300ns) $5.95

TMS4044 (450ns) $8.00

TMS4044 (300ns) $9.95

410D (200ns) $9.95

4200A (200ns) $9.95

Computer Products

4901 W ROSECRANS, HAWTHORNE, CA 90250213-679-3313

PLACE ORDERS TOLL FREE

800-262-1710 800-421-5809

INSIDE CALIFORNIA CONTINENTAL U.S.

WRITE FOR OUR FREE 1979 CATALOGFOR CUSTOMER SERVICE OR TECHNICAL INQUIRIES

CALL 213-679-3317TERMS OF SALE: Cash, checks, money orders, and creditcards accepted. Minimum order $10.00. California residentsadd 6% sales tax. Minimum shipping and handling charge$2.50. Prices are for U.S. and Canadian delivery only and aresubject to change without notice. For export prices andinformation send for a JADE INTERNATIONAL CATALOG.

INTEGRAL DATA SYSTEMS

THE PAPER TIGER

132 COLUMN DOT MATRIX PRINTER

Up to 198 CPS

1.75 to 9.5 inch adjustable

tractor and friction feed.

Parallel and serial

interface.

98 character ASCII set.

80 to 132 columns.

6 or 8 lines per inch.

Eight software selectable |

character sizes.

110, 300, 600, or 1200 baud.

PRM-33440 $995.00

PRM-33441(with graphics & 2K buffer).. $1195.00

DISKETTE SPECIAL

5.25" SOFT, 10, OR 16 SECTOR

10 for $29.95' SOFT SECTOR IBM COMPATIBLE10 for $34.95

S-100 CONNECTOR SALE

100 PIN IMSAI TYPE SOLDER-TAIL CONNECTOR

6 for $17.50 12 for $30.00\

SPST DIP SWITCHES

jL ]Sjk

PART NUMBER

SWD-103

SWD-104

SWD-105

SWD-106

SWD-107

SWD-108

SWD-109

SWD-110

9^

&

) I ■

4

OF SWITCHES

PRICE

3 $1.00

$1.18

4 $1.05

$1.20

5 $1.10

$1.24

6 $1.15

$1.28

7 $1.20

$1.30

8 $1.25

$1.34

9 $1.30

$1.36

10 $1.35

$1.38

TEXTOOL

ZIP* DIP II SOCKETS

TTITTT

16 PIN ZIP* DIP II $5.50

24 PIN ZIP* DIP II $7.50

40 PIN ZIP* DIP II 10.25

* ZERO INSERTION PRESSURE

SPECIAL HOLIDAY PRICE !

NOVATION CAT

ACOUSTIC COUPLER/MODEM

$175.00

Let your computertalk to other computers IBell Systems 103 compatible^300 baud, answer or orginateIOM-5200A (SALE PRICED)

Circle 209 on inquiry card.

Circle 210 on inquiry card.

3'/2 Digit)

IHICKOK

[Mini-Multimeter

|MOD6LLX303 5gg_gg

x-

Sinclair «*«"«PDM35 $49.95digital MultlMeter

'31/2-Digjt(Portable DMM

wrat.on* 3'- high LED D»lD Zero.ng Mode| 3300

15 MHz MiniOscilloscope

/Model MS 15

15 MHz Dual Trace

■ Triggers in excess

of 25 MHz

$795

inciugmg probes

Weller Controlled OutputSoldering %

Station ■fir' 4.

$49.95 uZS&T

irz.so ^iK'**li.

SENCORE

TV-VTR-MATVand Video Analyzer

CONTINENTAL SPECIALTIES100 MHz 8-0igit Counter$i27.50

I l30Hj 100 MM.- II..i«ii-«U" LED Display* Fully Automatic Reg. $150.00

I„«,av.u^PSSOO 500MHZ Prescaler $59.95

ModelVA48

$945.75 sm9b0D

Weller'-Xcelite'

Beg. S313 00

S269.95

NOW AVAILABLE

• 15MHz Dual Trace ■ ModelMS 215Reg. S435.00. $369.95

• 30 MHz Dual Trace ■ Model MS 230

Rea. S55a $479.95

BSSMMI Digital |~,Capacitance Meter,

95^

'Accessories

AnsweringDevices

Model 14O0S199.95

I $29.95

Model^BSR ■ 129

Logic Monitor

WAHL

0-TIPCharge'

$29.95

I Service Master AttachejjtyjeI Tool Kit Tool Cases

Model 99SM MODEL TC 100'ST —-

$47.50 $279.95 8ff |?8 K

Reg SE9-9& Reg £449.00 J) | J. J J

™«"f"»^m *... rC ^J

i Sti •WotkiwnJi DTL. V I

TIL JticlCMDS* 16 LEndisplrty \l!

ml pawenttt dmgn Reg SG9.95

i $59.95 c°mp|e,e

Logic Probe$44.95

T«BOnS«c completeblltly DTUTTL/MTL/CMOS

30MHz Dual Trace with

DelaiLine HI.!

Reg. SI 100 00

$892.50

' probes

-'■.■

MiniatureHigh FidelityStereoSpeaker System.

Reg. $139.00 $69.50

_ mm mm

RemoTe Control for Lights& Appliances

4 Pihco Stnrtef K

'Reg. $87.96

$79.50

Two (21 LainiiMoiJu0".'HI Appl'.iwM

Magnifierlamp rj

Model MG IDA \ S

$49.50

\RHWWWIfM

SUPER

SPECIAL

-700 Series

i ijiound ;ind pohshud Iration lens. Uses3 Circling fluorescent. |RC Circuit Bnx/RCAVlZl

ii 10 megohms) I

Function Generator Chess Challenger W,B

It I 11 m ~ T.I I 'Se.eo LxelsolPlay ,,„,, „, ,„ g 22 oil

OlZ/.bU fj Bj Mod.lBCC Jj^tk. Model WC4I2A

. r— — B^^^^ . _ _ -<tatyZZ. Flcq S49.9S

!SE S,n. sou,.,. i.iinglKiidupa'in (fl/I QC •SSSijli^ - « O

mzooi mi - 3>/4.^3 \-ftiV^ i fr/lv ,.

Model1B27

30MHzPorta

FrequencvCounter

Reg SI 3D 00

$65.00

ww^irMicroflarne

60I Torch Kitmodel I Model 4400» ,80° I Reg. $39.95I $29.95

In Dash

AM/FMlTrack^Stereo |

C-777

$52-5D AM/FMCassette]cassoa Stereo$57.50

Bearcat Scaj.asi

Model 250 I

$299.9ffl

Touch K100 Scanner

Stereo Power Booster

nnlll Jin THE BIG SHOT

P0W-4U 40 WATTS STEREO

Ann nc 20 WMTSPERCHA"

$24.9'J BASS BOOST

■--■0

..FREE^^"^ 1979

.eefenoj.!

IQ channel,

cumputer

controlled

Catalc

check our puces

TJallTOLL FREEL(800)645-9518 5T«wS5»

.,,| MastefCharge • Bank Amer.card fjfcaj.

-»-"^—*SS • COD • Check • MonevO.de. C3

S 199 95 Ad"S3G0lo'sh'pp,n9and,nsurj"c'j _

"We Will Beat AnyAdvertised Price"

C.O.D.'s Extra New York Staleresidents add approp. sates tax

| 855R Conklin Si. Farmingdale. N Y 11735

HOBBY WORLDELECTRONICS

America's Largest Mail-Order Computer Store

Inml

74LS

Order by Cat No.

TYPE

NO.74L$ 0074LS 0174LS 0274LJ 0374 LS 0474LJ 0574LS 0874L$ 0974LJ 1074LS 1174LS 1274LS 1374LS 1474L$ 1574LJ 2074 LS 2174 LS 2274L$ 2674LS 2774L| 2874LS 3074LS 3274L$ 3374LS 3774LS 3874LS 4074LS 4274LS 4774LS 48

.591.25

999 and typeTYPENO.74LS15774LS15874LSI6074LS16174LS16274LSI6374LSI6474LSI6574LSI 6874LS16974LSI 7074LS17374LS17474LS17574LS18174LS19074LSI 9174LS19274LS19374LS19474LS19574LS19674LS19774LS22174LS24074LS24174LS24274LS24374LS244

PRICE1.45

1.10

1.25

1.691.29

2.251.101.101.101.101.101.10

1.651.254.502.401.502.502.60

74LS 5174L$ 5474LS 5574L$ 7374 LS 7474LS 7574L$ 7674L$ 8374LS 8574 L$ 8674LS 9074LS 9274 L$ 9374 LS 9574LS 9674LS10774LSI0974LS11274LS11374LS11474LS12274LS12374LSI2474LS12574LS12674LS13274LS13874LS13974LS14574LS15174LS15374LSI5474LS15574LS156

74LS24774LS24874LS25174LS25374LS25774LS25874LS25974LS26074LS26174LS26674LS27374LS27574LS27974LJ28374LS29374LS29574LS29874LS36574LJ36674LS36774LS36874LS37374LJ37474LS37774LS37874LS38674LS39374LS39574LS39974LS42474LS66874LS67081LS 9681L$ 97

1.101.101.99

1.504.50

3.051.953.901,25.651.951.452.951.951.252.491.451.55 l

CMOS

Cat No.

PRICE

I Order by

TYPE

NO.I CD 4000I CD 4001I CD 4002I CD 4006I CD 4007I CD 4008I CD 4009I CD 4010I CD 4011I CD 4012I CD 4013I CD 4014ICD 4015I CD 4016I CD 4017ICD 4018I CD 4019I CD 4020I CD 4021I CD 4022I CD 4023I CD 4024I CD 4025I CD 4026LCD 41127

[MICROPROCESSORS!

I Order by Cat No. 999 and type

1.101.251.10

OS ^

999 and type

NO PR,CE

CD 4028

.85

CD 4030

.45

CD 4035

.99

CD 4040

1.10

CD 4044

.79

CD 4045

.89

CD 4046

1.19

CD 4049

.45

CD 4050

.45

CD 4051

LIS

CD 4052

.69

CD 4053

1.19

CD 4066

.85

CD 4069

.49

CD 4071

.26

CD 4081

.29

CD 4082

.29

CD 4510

.99

CD 4516

.79

CD 4519

.59

CD 4522

1.25

CD 4526

1.25

CD 4520

.99

CD 4529

.49

CALL TOLL FREE:(800) 423-5387 USA ^IN CALIF: (bbb !

(800) 382-3651 ^^

LOCAL & OUTSIDE USA(213) 886-9200

ATARI

THE AFFORDABLE COMPUTER

The perfect computer iorSo phis I idled, vel simple. De-signed by the expcrl in homecomputer b.ised accessories. Hwon'l become obsolete, becauseit has an expandable memory,advanced peripheral compo-nents, and comprehensive arrayof software modules. Whelheryou've had programming experi-ence or nol, you'll find yourselfOperating your Atari in no timeat all! Features of the Model 400include: 57 key keyboard, high-resolution color graphics, built-in TV modulator for direct con-nection with any standard colorTV, 8K RAM, 8K BASIC ROM.

both home and businessplus more and more! The model800 has all the features of Hie400 plus two channel digital re-corder, BK RAM, (expandable to48K) and 16K ROM, (expandablelo 32KJ.

Cat No. Description Price

2172 Atari 400 Per- $550.00sonal ComputerDigital Recorder 40.00for 400

Atari 800 Per- 995.00sonal ComputerMinidisk Drive 750.00for 800

Line Printer for 600,00800

2176

2173

HAZELTINE TERMINALS

Standard interlacing to most systems.'

C«il No. Model Description Price

2167" 1400 53 key, 80 x 24 display, dumb $840

2168* 1500 Intelligent, 74 key, 80 x 24 S1195

2169' 1520 Intelligent, 81 key, 95 char. $1588

TYPE NO.Z80 A18026502680080358080 A8085TMS 9400

PRICE12.7516.5014.50

6.5011.75

6.6015.9549.00

HOW TO ORDER

Pay by check, Maslercharge,Visa, or COD. Charge ordersplease include expiration date.Foreign pay in U.S. funds. Orderby phone or mail, or at our retail.MINIMUM ORDER $10. pleaseinclude phone number and mag-a/inelissue you are orderingfrom. Prices valid thru last day ofcover date. SHIPPING: USA-add $2.00 for the first 2 lbs. Forground add 35< for addf I lb. Forair add 75C (or addt'l lb. FOR-EIGN: surface: add $3.00 for first2 lbs, 60C per addt'l lb. Air: add$11.00 for first 2 lbs, $5 lor each

addt'l lb. CODsSI addt'l. Guar-anteed satisfaction for 121) daysor your money back! Nol re-sponsible (or typographicalerrors. Some items subject toprior sale. We reserve the rightto limit quantities.

SEND FOR FREE CATALOGFEATURING:Computers and accessories, diskdrives, printers, integrated cir-cuits, LEDs, semiconductors.books, software, connectors,plus more and more! The widestselection at the lowest prices!Circle our reader service numberor phone/write today for yourcopy!

19511 Business Center Dr. Dept. Bl Northridge, Ca. 91324

252 BYTE January 1980

\M Radio Hut

201 L0CHW00D MALL • DALLAS, TEXAS 75218

ORDER BY PHONE—214-324-5509

PLEASE WRITE FOR CATALOG OR

WHILE IN DALLAS, VISIT OUR RETAIL

STORE AT 201 LOCHWOOD MALL,

DALLAS, TEXAS 75218

(GARLAND ROAD AT JUPITER).

ORDERING INFORMATION & TERMS: Orders under $15.00add 75e handling. No C.O.D. We accept Visa, MasterCharge,and American Express cards. Tex. Res. add 5% tax. Foreignorders (except Canada) add 20% P&H. 90 Day Money BackGuarantee on all items. Add 5% P&H, maximum $5.00.ORDER BY PHONE — (214) 324-5509

• Complete kit includes all Sockets for 64K

• Memory access time: 375ns, Cycle time:500ns.

• No wait states required

• 16K boundaries and Protection, via Dip|Switches

• Designed to work with Z-80, 8080, 80851CPU's

EXPANDORAM 64K Kit (16K Ram)

WITHOUT MEMORY $139.001

16K 209.001

32K 275.001

48K 340.001

64K 405.00|

SD'S VERSAFLOPPY II

• IBM 3740 Compatible Soft Sectored Format for Single Den-sity Drives • Operates with Single and Dual Sided Drives.Single or Double Density Drives and 5" & 8" Drives — in any Icombination of four simultaneously • Drive Select and Side ISelect Circuitry • S-100 Bus Compatible • Vectored Interrupt |Operation Optional • Phase Locked Loop Data Recovery Cir-cuit • Operates with Z80 CPUs • Uses FD1791-1 Controller |Chip • ther Versatloppy II incorporates all the possible fea-tures of a flexible disk drive controller into one board. Capable Iof handling four drives simultaneously, combinations of any Ivariety are possible, such as 5" single sided. 8 dual density Idual sided, 5' dual density single sided. Most popular drivesare controlled directly with the Versatloppy II. The operatingsystem for the Versatloppy II is the extremely powerful SDOS Iavailable for SD Systems. Diagnostic and control software |available to complete your disk system.

$290 KIT, $385.00 ASSEMBLED & TESTED

SD'SSBC-100SINGLE BOARDCOMPUTER

The SBC-100 provides a|complete micro-computer Ion a single board! The Z80 microprocessor is used as the heart Iof the SBC-100. The SBC-100 meets all the requirements of a IZ80 CPU board with the added features of I/O ports, counter/1limer channels, on board RAM, provisions for PROM/ROM Iand a software programmable baud rate generator. S-100 Bus Icompatible, the SBC-100 features are: 8K bytes ol available IPROM, 1024 bytes on-board RAM, Serial I/O with both syn-chronous and asynchronous operation. Parallel I/O ports, IOperational Vectored Interrupts, and Four Counter/Timer |Channels. SD Monitor available for RS-232 and Video Ter-minals. Disk based system software also available.SBC-100 KIT $209.00

I The EXPANDORAM is available in versionsI from 16K up to 64K, so for a minimum invest-I ment you can have a memory system that willI grow with your needs. This is a dynamic mem-lory with the invisible on-board refresh, and ITI WORKS!]• Bank Selectable|» Phantom!• Power 8VDC, +16VDC, 5 Watts

1 Lowest Cost Per BitI • Uses Major Brand 16K RAMS|» PC Board is doubled solder masked and has

silk-screened parts layout!• Extensive documentation clearly written

SD EXPANDORAM

SD'S PROM 100 PROM Programmer Board

I The PHOM-100 Programmer is a development tool forS-100 Bus computer systems. The Zero InsertionForce Programming Socket extends above the cardcage height for easy access to PROM devices. Soft-ware verifies PROM erasure, verifies program loadingand provides for reading of object file from Disk orPROM and programming into PROM/EPROM. Fea-tures include: On-board generated 25vdc Program-ming pulse, TTL compatible, maximum programmingtime for 16,389 bits is 100 seconds. Programs: 2708,Intel 2758, 2716, 2732 and Tl 2516. DIP SelectableEPROM type.PROM-100 Board Kit $149.95

SD'S MPB-100Z80 CPUBOARD KIT

The MPB-100 provides,a Z80 microprocessorbased CPU for S-100 Bus systems. Front panel us-age is optional, making the MPB-100 suitable forupgrading existing systems to Z80 level. A PROMsocket is provided on-board which makes the MPB-100 adaptable to process control applications. Fea-tures include: Power-on Jump to 4K boundaries, 2Megahertz or 4 Megahertz operation, optional waitstates, on-board PROM socket.MPB-100 KIT $199.00

SD'S VDB-8024VIDEO DISPLAYBOARD

The VDB-8024 featuresits own on-board Z80

I microprocessor. This gives the capability of using soft-ware (included in ROM) to control functions and en-hancements without interference with the computer's

I CPU. Included in the special features: 80 charactersby 24 lines display, keyboard power and interface,composite and separate video output, 2K on-boardRAM, a total of 256 available characters, full cursorcontrol, forward and reverse scrolling, underlining,field reverse, field protect enhancements, program-mable characters. VDB-8024 KIT S289.00

SD'S

"VERSAFLOPPY I"

KIT

FEATURES: IBM 3740 soft sectoredcompatible, S-100 BNS Compatible for Z-80or 8080. Controls up to 4 drives (single ordouble sided). Directly controls the followingdrives: Sugart SA400/450 Mini Floppy • Shu-gart SA800/850 Standard Floppy • PERSCI70 and 277 • MFE 700/750 • CDC 9404/9406$135.00

TARBELL FLOPPY DISK INTERFACE

Compatible with Z80 & 8080. S-100 Bus. UsesCPM operating system. Plugs directly into yourIMSAI or ALTAIR • Fastest transfer rateKIT $190.00 Assembled & Tested $260.00

TARBELL CASSETTE INTERFACE

Plugs directly into your IMSAI or ALTAIR •

Fastest transfer rate • Extremely reliable •

Phase encoded • 4 extra status & control lines

KIT $99.95

COMPUTER CORNER

CPU'S

Z80 $10.99

RELATED CHIPS

2114 (300ns) $5.99

Z80 PIO $9.95

2708 $7.99

4115 8/534.95

4116 8/$80.00

DISC CONTROLLER

1771 $29.95

1791 $37.95

IC SOCKETS

SOLDER TIN

LOW PROFILE

PIN

PIN

8 .12

16 .17

14 .15

18 .24

24 .32

40 .54

28 .39

20 .26

Z80 STARTER KITKit: $219.95 Assembled & Tested $369.95

SD Systems Z80 Starter Kit enables the novice to build a

I complete microcomputer on a single board. Featuring thepowerful Z80 microproces-sor, the Z80 Starter Kit fea-

| tures • Keyboard and Dis-play • Audio Interface •PROM Programmer • Ex-

i pansion and Wire WrapArea • On Board RAM • 4Channel Counter/Timer •

| Z-BUG Monitor in PROM •I/O Ports.

DIP

SWIT

3Pos.

$1.10

4POS.

$1.12

5Pos.

$1.16

6 Pos.

$1.20

7Pos.

$1.22

8 Pos.

$1.26

9 Pos.

$1.36

10 Pos.

$1.30

LEDS AND READOUT

Jumbo Red LED's 8/1.00Jumbo Green LED's 4Z.95Jumbo Yellow LED's 4/,95Jumbo Amber LED's 4/.95MVRed 10/1.00

FND 70CC

DL707

DL 747CA

DL728CC

FND 800CC

Red Filter 4 Bezel

Green Filter 4" Bezel

Amber Filter 4" Bezel

4N25

4N26

4N27

4N28

4N31

.50

.95

.65

1.19

1.50

2.50

2.50

2.50

1.60

1.25

1.10

.95

1.20

S-100 CONNECTORS

High-Quality Gold Pins

$2.99 EACH

FLOPPY DISK SPECIAL

5.25" SOFT, 10 OR 16 SECTOR

10 FOR $29.95

8" SOFT SECTORED IBM COMPATIBLE

10 FOR $34.95

| • S-100 Bus Compatible

Up to 4Mhz Operation

Expandable Memory from 16K to 256KI • DIP Switch Selectable Boundaries

Uses 16K (4116) or 64K (4164) Memory

Devices| • Page Mode Operation Allows up to 8 Memory

Boards on BusI • Operates with Z80 CPU'sI • Phantom Output Disable[• Invisible Refresh (Synchronized with Wait

States)

Circle 212 on inquiry card.

SD'S EXPANDORAM IIThe Randem Access Memory

SD Systems' ExpandoRAM II is a dynamic RAMIboard with capacities from 16K bytes (4116) tol256K bytes (4164). It operates on the industry!S-100 Bus. The design allows 8 boards to op-rerate from the same S-100 Bus. The Expando-IRAM II is compatible with most S-100 CPU's|based on the Z80 microprocessor.EXPANDORAM II KIT

W/O $195,001

16K 285.001

32K 375.001

48K 465.001

64K 555.001

Circle 213 on inquiry card.

rnrri Up to $170 in merchandise with purchasernCC! of one of following PET-CBM items! ! !

Axiom EX-801 PETPrinter(withgraphics)$ 475.00

Axiom EX-820 PET Plotter $ 749.00

Anderson Jacobson 841 Selectric ... $1015.00

Leedex Video 100 12" Monitor $ 119.00

HeathWH19Terminal(factoryasm.) ...$ 770.00Heath WH14 Printer (factory asm.) ... $ 735.00IEEE-RS232PrinterAdaptorforPET ... $ 88.00

KIM-1 $159 (add $30 for power supply) SYM-1 $209

BAS-1 Microsoft ROM Basic for SYM $ 85

Memory Plus (KIM, SYM, AIM) $195

SYM Assembler in ROM $ 85

SEA-16 New 16K Static RAM $325

Seawell Motherboard - 4K RAM Space ... $139

KTM-2/80 Synertek Video Board $349

S-100 16K Static RAM Kit SALE $219

2716 EPROM (5 volt) $ 39

6550 RAM (for 8K PET) $ 12.70

6502 $9.75 6522 $9.00 6520 $5.50

2114 L 450 ns $5.35 24 @ $4.95 100 @ $4.45

TIS PET Workbooks - set of 6 $ 21.50

Dust Cover for PET $ 8.90

ProgrammersToolkit-PETROM Utilities.$ 44.90

Sargon II (TRS-80 or Apple) NEW! $ 24.90

Microchess for PET (Peter Jennings) $ 17.90

PET 4 Voice Music System $ 29.90

4 Voice Music Monitor for PET $ 15.90

CmCWordProcessorprogramforPET... $ 25.00Adventures by Scott Adams 15% Off

BETSI PET to S-100 Interface $ 119.00

PET Connectors-Parallel or IEEE $ 1.95

Cassette Port $ 1.45

Hands on Basic with a PET $ 9.45

Programming the 6502 (Zaks) $ 9.45

6502 Applications Book (Zaks) $ 10.45

6500 Manuals (MOS Technology) .... $ 6.50

Programming a Microcomputer: 6502 . $ 8.456502 Assembly Language

(Osborne) NEW! $ 8.10

All Books and Software 15% Off

CBM Word Processor for PET- Machine LanguageAuto Scroll, insert, delete, form letter append, etc.8K Version $24.00 16K or 32K with disk $89.00

Cassettes (all tapes guaranteed) AGFA PE611Premium quality, high out put lownoise in 5 screwhousing with labels:C-10 10/5.65 50/25.00 100/48.00C-30 10/6.90 50/30.00 100/57.00

SALE

3M "Scotch" 8" Disks 10/$31.00

3M "Scotch" 5" diskettes ... 10/S31.50

Verbatim 5" diskettes 10/$26.50

Diskette Storage Pages 10/$ 3.95

Disk Storage Boxes 8" $2.85 5%"$ 1.95(Write for quantity prices)

115 E. Stump RoadMontgomeryville, PA 18936

(215)699-8386699-5826

A B Computers

PET SPECIALS *FREE

PET 16N 16K full size graphics keyboard $995 $130

PET 16B 16K full size business keyboard $995 $130

PET 32N 32K full size graphics keyboard $1295 $170

PET 32B32K full size business keyboard $1295 $170

PET 8N 8K full size graphics keyboard $ 795 $100

PET 2040 DUAL DISK DRIVE-343,000 bytes $1295 $170

PET 2022 Tractor Feed Printer $ 995 $130

PET 2023 Pressure Feed Printer $ 849 $110

PET C2N External Cassette Deck $ 95 S 12

Used 8K PETs (limited quantities) $ 495

*Amount of Free Merchandise with Purchaseof PET-CBM Item.

ATARI — INTRODUCTORY SPECIAL

ATARI 400, Atari 800, and all Atari Modules 20% OFF.

MINIMAX

by COMPU/THINK

MINIMAX I I.8 Msgabyte Disks) $4495MINIMAX II (2.4 Mtgibyte Disks) $5995

SPECIAL—Ml NIMAX prices include Compu/Think PAGEMATE Database and Report Writer at no charge.

The most advanced complete microcomputer system available.

Includes CPU, 12" CRT, Full Keyboard, 2 Quad-Density DiskDrives, 2 Megahertz 6502 Hybrid Processor (double speed), 108K System Memory, High Resolution (512 x 240) Graphics,Programmable Character Fonts, Microsoft Extended BASIC,DOS with Random Access I/O, Full Complement of I/O Ports,Monitor with Debug, Trace, and Tiny Assembler, Fifth (PL/M andForth combination) Interpreter, Complete editing and entry withsplit screen capability, 64 Microprogrammable Opcodes, Bus-iness software (with Database) available.

WRITE FOR COMPLETE CATALOG

Add $1.00 per order for shipping.

We pay balance of UPS surface charges on all prepaid orders.

C/MOS (DIODE CLAMPEDI

4001

??22

■1034

22

25? -

20

4ot j ;

27

35

4Q[)'J

45

4038

SO

40H1 -

.22

4010

.05

4620 -

1.00

4011

73

4030 -

35

74C00 -

401?

97

74C02 -

27

4013

40

4042 -

85

74C08 -

.30

4014

1 20

BS

.27

4015

1 00

4045 -

74C14 -

1 20

45

74C20 -

4017

1.05

75

90

401 a

.90

4050

45

74C73 -

75

4019

45

■1051

1 10

74CJ4 -

.50

4020

1 10

4053

1 10

74C83 -

1.30

PRINTED CIRCUIT BOARD

4" x 6" DOUBLE SIDED EPOXY

BOARD 1/16" thick

$.60 Ba 5/S2.GO

EPOXY glass vector board

1/16" thick with 1/10" spacing SI.95

VERIPAX PC BOARD $12.95

Our now Prototyphnj board is a hi density4V? x 6V(" single sideo 1/16*" G-10 board. It willhold 40, 24, 16 (31 units), 14 + 8 Pin IC'S.There are three busses, *5V, ground and afloating buss. There is a pad for a TO-220 reg-ulator. There is a 22 pin edge connector with156" spacing.

7 WATT LD-65 LASER DIODE IR $R95

TTL REED RELAY - 5PST5V 20ma SI.00

- 235 BB30 2 95

25 watt Infra Red Pulse I SG 2006 equ.v. ILaser Diode (Spec sheet included) S24.95

MINIATURE MULTI-TURN TRIM POTS100. IK, 2K, 5K, 10K. 20K, 50K,200K. IMcg, 2Mcr), $.75 each 3/S2.0Q2N 3820 P TET S 45

2N 5457 N FET S 45

2N2646 UJT S .45

ER 900 TRIGGER DIODES 4 SI 00

?N 6038 PROG UJT S r.f.

FP 100 PHOTO TRANS S .50

RED, YELLOW, GREEN

LARGE LED's. 2" 6/S1.00

RED/GREEN BIPOLAR LED's .2" . ..95

TIL-118 0PTO-ISOLATOR $.75

MCT-6 OPTO ISOLATOR $ .80

1 WATT ZENERS: 3.3, 4.7, 5.1. 5.6,9.1.10. 12, 15, 18, or 22V 6/S1.00

TRANSISTOR SPECIALS

2N6233-NPN SWITCHING POWER S 1.95MRF-8004 a CB RF Transistor NPN $ 75

2N:(/72 NPN Si TO 3 . S 1.00

2N1546PNP GE TO-3 $ ,75

2M4908 Pf*JP Si TO 3 SI 00

ZN5086 PNP St TO-92 <* S 1.00

2N3137 NPN Si RF S .55

2N3919 NPN Si TO 3 HI S 1.50

2N1420 NPN Si TO 5 3/S 100

2N3767 NPN S. TO 66 S 70

2N2222 NPN St TO-18 5'S 1.00

2N3Q55 MPN Si TO 3 S 60

2N39Q4 NPN S* TO 92 6/S 1.00

2N3906 PNH Si T092 6/S 1.00

2N5296 NPN Si TO 220 S 50

2NIJ103 PNPSi TO 220 S 55

2M363S PNP S. TO 3 0 S ' 00

MPSA 13 NPN Si 4/S 1.00

TTL IC SERIES

Silicon Power Rectifiers

8" DISKETTES - HARD SECTOR$1.75, 10/S16.00

CRYSTALS £3.45 ea.

2.000 MH* 6.144 MHi4,000 MH* 8.000 MH*3.57 MHi 10.000 MHi5.000 MHi 20.000 MH;6.000 MHz

RIBBON CABLETLAT (COLOR CODED)#3QWIRE

UNIVERSAL 4Kx8 MEMORY BOARD KIT

S69.95

322102 1 fully buffered, 16 address linos, o..

board decoding for any 4 of 64 pages, standard

44 pin buss, may be used with F-8 & KIM

SILICON SOLAR CELLS

V diameter .4V at 1 AMP $10.00

LED READOUTS

PCS 8024 4 diqn DL-707C.A. .3" $ .75

C.C 8'r display $5.95 OL 747 C A 6" $1 50

FND503CC 5" S 85 HP3400 8" CA S1.95

FND510C.A. 5"S .85 Hp34nc p.. rr Si .95DL 704 .3" C.C. S .85 Mrji,us ° LL

PRV100

SAD 1024 a HEDICON 1024 stage an

»8 IIN9141 15/S1.00

1 uf 25V ceramic disc caps. 16/Sl.00, S5.00/100

RS232 OB 25P n

CONNECTORS DB 25S f

HOODS

SI.50

REGULATORS

323K - 5V 3A . .S 5.75 340K - 12. 15

309K S 1.60 or 24 V .... S 1.50

723 $ .50 340T-5, 6,8, 12

320T- 16.18 or 24VS 1-30

5, 12, or 15 V 79MG SI.35

■ ■ ■ $ 1.30 78M05 $ .75

MM5387AAM7001 . . . .MM5311 . . .

CLOCK CHIPS

NO. 30 WIRE WRAP WIRE SINGLESTRAND 100' SI .50

„ MINIATURE TOGGLE SWITCHESMTA 106 SPDT S 1.05

MTA 206 DPDT S 1.70

MTA 206 PDPDT CENTER OFF * ■) 85

MSD 206 PDPDT CENTER OFF

LEVER SWITCH ... $ 1.86

I, C.O.D Purcha■■ ieS20.00.

SOLID STATE SALES

P.O.BOX 74B

SOMERVILLE, MASS. 02143 TEL. (617) 547-7053

Full Wave Bridges

1.90

4.40

DIP SOCKETS

8 PIN .17 24 PIN .3514 PIN .20 ^8 PIN 4016 PIN .22 40 PIN .6018 PIN .25

SANKEN AUDIO POWER AMPS

Si 1010 G 10 WATTS S 7.80

Si 1020 G 20 WATTS SI 5.70

Si 1050 G 50 WATTS . S28.5Q

TANTULUM CAPACITORS

.22UF 35V5/S1.00.47UF 35V5/S1.00.68UF 35V5/S1.001UF 35V 5/S1.002.2UF 20V 5/S1.003.3UF 20V 4/S1.004.7UF 15V 5/S1.00

74LS SERIES

6.8UF10UF22UF15UF30UF100UF150UF6BUF -

35V 4/S1.0010V S.2525V $ .4035V 3/S 1-006 V 5/S1 0015V S.7015V $.95

74LS04 - .3-

74LS05 - .3!

74L508 .3!

74LS09 - .3:

74USI0 - ,3(

74L5I1 - .4!

74LS13 - .0!

74LS14 1.9!

74L.SI5 - .3!

74LS20 - .3(

74LS21 - .5!

74LS22 - .3!

74LS26 - M

74US27 - .41

74LS28 - .41

74LS30 - .3!

74LS32 - ,4(

74LS37 - .41

74LS3B - .!.:

74LS40 - .4t

74LS42 - 1.01

74LS51 - .3!

74LSS4 - .31

74LS73 - .4-

■4LS163 - 1.24L5164 - 1.2JLS168- 1.2.LS169 - 1.2L5170- 1.7

'4LS259'4LS265 -L.SZ6G

4LS290

i.S298

TRIAC

s

PRV

1A

IDA

25A

100

45

80

1.55

200

'60

1 30

2 10

400

1.30

1.90

3.10

600

2 00

2 75

4.30

WE SHI

■ OVER 95%

OFODAYW

UK UERE(

RDERSTHEJElVE THEM

■jV

S 50

LM 324 -.95

LM 3B?

- 1 35

LM386

- .80

LM 3H7

1 3b

LM 18UO

2.20

lm lean

1 75

CA30RI1

LM537

-2 50

LM 553

-2 50

14583900B03BCC

.80 | 3.60

254 BYTE January 1980

By Netronics

ASCII/BAUDOT,STAND ALONE

Computer $U995Terminal 1W

The Netronics ASCII/BAUDOT Computer Terminal Kit is amicroprocessor-controlled, stand alone keyboard/terminalrcquring no computer memory or software. It allows the use ofeither a 64. or 32 character by 16 line professional display for-mat with selectable baud rate, RS232-C or 20 ma. output, fullcursor control and 75 ohm composite video output.

The keyboard follows the standard typewriter configurationand generates the entire 128 character ASCII upper/lower caseset with 96 printable characters. Features include onboardregulators, selectable parity, shift lock key, alpha lock jumper,a drive capability of one TTY load, and the ability to matedirectly with almost any computer, including the new Ex-plorer/85 and ELF products by Netronics.

The Computer Terminal requires no I/O mapping andincludes Ik of memory, character generator, 2 key rollover,processor controlled cursor control, parallel ASCII/BAUDOTto serial conversion and serial to video processing—fullycrystal controlled for superb accuracy. PC boards are thehighest quality glass epoxy for the ultimate in reliability andlong life.

VIDEO DISPLAY SPECIFICATIONS

The heart of the Netronics Computer Terminal is the micro-processor-controlled Netronics Video Display Board (VID)which allows the terminal to utilize either a parallel ASCII orBAUDOT signal source. The VID converts the parallel data toserial data which is then formatted to either RS232-C or 20 ma.current loop output, which can be connected to the serial I/Oon your computer or other interface, i.e., Modem.

When connected to a computer, the computer must echo thecharacter received. This data is received by the VID whichprocesses the information, converting to data to video suitableto be displayed on a TV se't (using an RF modulator) or on avideo monitor. The VID generates the cursor, horizontal andvertical sync pulses and performs the housekeeping relative towhich character and where it is to be displayed on the screen.Video Oulpul: 1.5 P/P into 75 ohm (EM RS-170J • Baud Rate:110 and 300 ASCII • Outputs: RS232-C or20 ma. current loop• ASCII Character Set: 128 printable characters—

!,mt,()*+,-./01234K789: ;<=>?WBC0EFWI3KUICP«STUUyXVZC\]A.Nabcdef9hijklftnowstuvvxyr(>}*l

bauuu i L.naraeier sei: a tsi^ut.tutiiJt\ l. m NO P QRSTUVWXYZ-?:*3$H().t9014!57;2/68*Cursor Modes: Home. Backspace, Horizontal Tab, Line Feed,Vertical Tab, Carriage Return. Two special cursor sequencesare provided for absolute and relative X- Y cursor addressing •Cursor Control: Erase, End of Line, Erase of Screen, FormFeed, Delete • Monitor Operation: 50 or 60Hz (jumperselectable.

Continental U.S.A. Credit Card Buyers Outside Connecticut

CALL TOLL FREE 800-243-7428

To Order From Connecticut Or For Technical ^m mmr Assistance. Etc. Call (203) 354-9375 ■

I Netronics R&D Ltd., Dept. PE-9 I

333 Litchfield Road, New Milford, CT 06776

I Please send the items checked below—

ID Netronics Stand Alone ASCII Keyboard/Computer mTerminal Kit, $149.95 plus $3.00 postage & handling. IID Deluxe Steel Cabinet for Netronics Keyboard/Termi- ■nal In Blue/Black Finish, $19.95 plus $2.50 postage II and handling.D Video Display Board Kit alone (less keyboard), $89.95

I plus $3 postage & handling.D 12" Video Monitor (10 MHz bandwidth) fully assem-Ibled and tested, $139.95 plus $5 postage and handling.□ RF Modulator Kit (to use your TV set for a monitor),

I $8.95 postpaid.D 5 amp Power Supply Kit In Deluxe Steel CabinetI(±8VDC @ 5 amps, plus 6-8 VAC), $39.95 plus $2postage & handling.I Total Enclosed (Conn. res. add sales tax) S By-

ID Personal Check D Cashiers Check/Money Order□ Visa □ Master Charge (Bank #__ )

I Acct. #

_ Signature Exp. Date

I Print

■ Name

i City.

L__

I

D Send Me More Information mm hm J

_zip

Start Computing For Just $129.95 With An8085-Based Professional Computer Kit—

Explorer/85

100% compatible with alt 8080A and8085 software & development tools!

No matter what your future computing plans maybe, Level "A "—at $129.95—is your starting point.

Starting at just $129.95 for a Level "A" operating system,you can now build the exact computer you want. Explorer/85can be your beginner's system, OEM controller, or IBM-formatted 8" disk small business system.. .yet you're neverforced to spend a penny for a component or feature you don 7want and you can expand in small, affordable steps!

Now, for just $129.95, you can own the first level of a fullyexpandable computer with professional capabilities—a com-puter which features the advanced Intel 8085 cpu, therebygiving you immediate access to all software and developmenttools that exist for both the 8085 and its 8080A predecessor(they are 100% software compatible)—a computer whichfeatures onboard S-100 bus expansion—plus instant conver-sion to mass storage disk memory with either 5-1/4" diskettesor standard IBM-formatted 8" disks.

For just $129.95 (plus the cost of a power supply, keyboard/terminal and RF modulator, if you don't have them already),Explorer/85 lets you begin computing on a significant level...applying the principles discussed in leading computer maga-zines. . .developing "slate of the art" computer solutions forboth the industrial and leisure environment.

Level "A" Specifications

Explorer/85's Level "A" system features the advanced Intel8085 cpu, an 8355 ROM with 2k deluxe monitor/operatingsystem, and an 8155 ROM-I/O—all on a single motherboardwith room for RAM/ROM/PROM/EPROM and S-100 ex-pansion, plus generous prototyping space.

(Level "A" makes a perfect OEM controller for industrialapplications and is available in a special Hex Version whichcan be programmed usingthe Netronics Hex Keypad/Display.)

PC Board: glass epoxy, platedthrough holes with solder mask• I/O: provisions for 25-pin(DB25) connector for terminalserial I/O, which can also sup-port a paper tape reader...provision for 24-pin DIPsocket for hex keyboard/dis-play ... cassette tape recorder in-put.. .cassette tape recorder output.. .cassette tape controloutput.. .speaker output... LED output indicator on SOD{serial output) line.. .printer interface (less drivers).. .total offour 8-bit plus one 6-bit I/O ports»Crystal Frequency: 6.144MHz • Control Switches: reset and user (RST 7.5)interrupt. . .additional provisions for RST 5.5, 6.5 and TRAPinterrupts onboard • Counter/Timer: programmable, 14-bitbinary • System RAM: 256 bytes located at F800, ideal forsmaller systems and for use as an isolated stack area inexpanded systems... RAM expandable to 64k via S-100 bus or4K on motherboard.

System Monitor (Terminal Version): 2k bytes of deluxesystem monitor ROM located at F000 leaving 0000 free for userRAM/ROM. Features include tape load with labeling .. .tapedump with labeling.. .examine/change contents of memory.. .insert data.. .warm start.. .examine and change allregisters... 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.. .fillblocks of memory with a constant.. .display blocks of memory... automatic baud rate selection ... variable display line lengthcontrol (1-255 characters/line).. .channelized I/O monitorroutine with 8-bit parallel oulpul for high speed printer...serial console in and console out channel so that monilor cancommunicate with I/O ports.

System Monitor (Hex Version): Tape load with labeling...tape dump with labeling.. .examine/change contents of mem-ory ... insert data... warm start... examine and change all

By Netronics

Level "A" at $129.95 is acomplete operating system,perfect for beginners, hob-biests, or industrial con-troller use.

Explorer/85 with"C" card cage.

^Ne7ronlcsR&D"L7cT, RpTKRff"I 333 Litchfield Road. New Milford, C

Please send the items checked belo

□ Explorer/85 Level "A" Kit (ASCIIVersion), $129.95 plus $3 p&h.

D Explorer/85 Level "A" Kit (Hex

Version), $129.95 plus $3 p&h.

D 8k Microsoft BASIC on cassette

tape, $64.95 postpaid.

D 8k Microsoft BASIC in ROM Kit

(requires Levels "B," "D," and "E"),

$99.95 plus $2 p&h.

D Level "B" (S-100) Kit, $49.95 plus

$2 p&h.

□ Level "C" (S-100 6-card expander)Kit, $39.95 plus $2 p&h.

□ Level "D" (4k RAM) Kit, $69.95plus S2 p&h.

□ Level "E" (EPROM/ROM) Kit,$5.95 plus 50C p&h.

D Deluxe Steel Cabinet for Explorer/85, $49.95 plus $3 p&h.

□ ASCII Keyboard/Computer Ter-minal Kit (features a full 128 characterset, upper & lower case, full cursor con-trol, 75 ohm video output convertibleto baudot output, selectable baud rate,RS232-C or 20 ma. I/O, 32 or 64 char-acter by 16 line formats, and can beused with either a CRT monitor or a TVset (if you have an RF modulator),$149.95 plus $2.50 p&h

CT 06676

plus $2 p&h.

D Deluxe Steel Cabinet for ASCII

Keyboard/Terminal, $19.95 plus $2.50

p&h.

□ Power Supply Kit (± 8V @ 5 amps)in deluxe steel cabinet, $39.95 plus $2p&h.

O Gold Plated S-100 Bus Connectors,$4.85 each, postpaid.D RF Modulator Kit (allows you touse your TV set as a monitor), $8.95postpaid.

D 16k RAM Kit (S-100 Board expandsto 64k), $199.95 plus $2 p&h.

□ 32k RAM Kit, $329.95 plus $2 p&h.D 48K RAM Kit, $459.95 plus $2 p&h.G 64kRAMKilr*589.95plus$2p&h.D 16k RAM Expansion Kit (to expandany of the above up to 64k), $139.95plus $2 p&h each.

O Intel 8085 cpu User's Manual, $7.50postpaid.

D Special Computer Grade CassetteTapes, $1.90 each or 3 for $5, postpaid.D 12" Video Monitor (10 MHz band-width), $139.95 plus $5 p&h.D North Star Double Density FloppyDisk Kit (One Drive) for Explorer/85 (includes 3 drive S-100 controller,

registers.. .single step with register display at each break point...go to execution address. Level "A" in the Hex Versionmakes a perfect controller for industrial applications and canbe programmed using the Netronics Hex Keypad/Display.

Hex Keypad/DisplaySpecifications

Calculator type keypad with 24system defined and 16 userdefined keys. 6 digit calculatortype display which displays fullm&Ja^H- address plus data as well as

Hex Keypad/Display. register and status information.

Level "B" Specifications

Level"B" provides the S-100 signals plus buffers/drivers tosupport up to six S-100 bus boards and includes: addressdecoding for onboard 4k RAM expansion select-able in4k blocks.. .address decoding for onboard 8k EPROM expan-sion selectable in 8k blocks... address and data bus drivers foronboard expansion... wait state generator (jumper selectable),to allow the use of slower memories.. .two separate 5 voltregulators.

Level "C" Specifications

Level "C" expands Explorer'smotherboard with a card cage,allowing you to plug up to sixS-100 cards directly into themotherboard. Both cage and« cards are neatly contained insideExplorer's deluxe steel cabinet.Level "C" includes a sheet metal superstructure, a 5-card goldplated S-100 extension PC board which plugs into the mother-board. Just add required number of S-100 connectors

Level "D" Specifications

Level "D" provides 4k or RAM, power supply regulation,filtering decoupling components and sockets to expand yourExplorer/85 memory to 4k (plus the original 256 bytes locatedin the 8155A). The static RAM can be located anywhere from0000 to EFFF in 4k blocks.

Level "E" Specifications

Level "E" adds sockets for 8k of EPROM to use the popularIntel 2716 or the Tl 2516. It includes all sockets, power supplyregulator, heat sink, filtering and decoupling components.Sockets may also be used for soon to be available RAM IC's(allowing for up to 12k of onboard RAM).

Order A CoordinatedExplorer/85 Applications Pak!

Experimenter's Pak (SAVE $12.50)—Buy Level "A" and HexKeypad/Display for $199.90 and get FREE Intel 8085 user'smanual plus FREE postage & handling!Student Pak (SAVE $24.45)-Buy Level "A," ASCII Keyboard/Computer Terminal, and Power Supply for $319.85 andget FREE RF Modulator plus FREE Intel 8085 user's manualplus FREE postage & handling!

Engineering Pak (SAVE $41.00)—Buy Levels "A," "B,""C," "D," and "E" with Power Supply, ASCII Keyboard/Computer Terminal, and six S-100 Bus Connectors for $514.75and get 10 FREE computer grade cassette tapes plus FREE8085 user's manual plus FREE postage & handling!Business Pak (SAVE $89.95)—Buy Explorer/85 Levels "A,""B," and "C" (with cabinet), Power Supply, ASCII Key-board/Computer Terminal (with cabinet), 16k RAM, 12"Video Monitor, North Star 5-1/4" Disk Drive (includes NorthStar BASIC) with power supply and cabinet, all for just$1599.40 and get 10 FREE 5-1/4" minidiskettes ($49.95 value)plus FREE 8085 user's manual plus FREE postage & handling!

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 "1

sonalized disk operating system—just ■plug it in and you're up and running!),!$699.95 plus $5 p&h.

□ Power Supply Kit for North Star IDisk Drive, $39.95 plus $2 p&h.

□ Deluxe Case for North Star Disk IDrive, $39.95 plus $2 p&h.

□ Experimenter's Pak (see above), I$199.90 postpaid.

O Student Pak (see above), $319.851postpaid.

D Engineering Pak (sec above), I$514.75 postpaid.

D Business Pak (see above), $1599.401postpaid.

Total Enclosed $ I

(Conn. res. add sales tax) By— |

D Personal Check D M.O./Cashier's |Check D Visa □ Master Charge |

(Bank*.

Acct. # _Signature _PrintName

_Exp. Date _

AddressCity

□ Hex Keypad/Display Kit, $69.95 DOS, and extended BASIC with per- State

_Zip_

D Send Me Information

Circle 215 on inquiry card.

Circle 238 on inquiry card.

BYTE January 1980 255

page

Precut Wire Wrap Wire

PRECUT WIRE SAVES TIME AND COSTS LESS THAN WIRE ON SPOOLS

Kynar precut wire. All lengths are overall, in-cluding 1" strip on each end. Colors andlengths cannot be mixed for quantitypricing. All sizes listed are in stock forimmediate shipment. Other lengthsavailable. Choose from colors: Red, Blue,Yellow, Orange, Black, White, Green andViolet. One inch tubes are available at 50C.State second choice on colors when pos-sible.

Length

100

500

1,000

Length

100

500

1,000

2.5 inches

1.04

2.98

5.16

6.5 inches

1.60

5.37

9.84

3

1.08

3.22

5.65

7

1.66

5.63

10.37

3.5

1.13

3.46

6.14

7.5

1.73

5.89

10.91

4

1.18

3.70

6.62

8

1.78

6.15

11,44

4.5

1.23

3.95

7.12

8.5

1.82

6.41

11.97

5

1.28

4.20

7.61

9

1.87

6.76

12.51

5.5

1.32

4.48

8.10

9.5

1.92

6.93

13.04

6

1.37

4.72

8.59

10

1.99

7.26

13.57

Kit #1 $7.95Less than 2.7C/ft. (#30)

Kit #2Less than

S19.952C/ft. (#30)

KIT #3Less than

$24.951.7C/ft. (#30)

Kit #4 $44.95Less than 1.6C/M. (#30)

#30 Spools1-4

5-9 10+

250 3" 100 4"250 3" 100 5"100 4" 100 6"

250 2V4"500 3"500 3V4"

500 4"250 AW

250 5"100 5'/2"250 6"100 6V2"100 7"

500 2V2"500 3"500 3W500 4"

500 4'/2"500 5"500 5'/2"500 6"

1000 2'/2" 1000 AW1000 3" 1000 5"1000 3'/2" 1000 5"1000 4" 1000 6"

50 ft. 1.75

100 ft. 3.00

250 ft. 4.75

500 ft. 8.50

1000 ft. 14.50

1.60 1.402.75 2.504.50 4.258.00 7.5012.50 10.50

Wire Wrap Tool

BATTERY HOBBY TOOL*

• Auto Indexing

• Anti-Overwrapping

• Modified Wrap

BW2630 Tool $19.85

BT30 #30 Bit 2.95

BT2628 #26 Bit 7.95

BC1 Batteries & Charger... 11.00

" Requires 2 "C" Nicad Batteries

JANUARY SALES!

SolderlessBreadboarding

skio 2/S25.00 _&i£*e-

The SK10's unique matrix config-uration is embedded in a high temp-erature plastic molding. It gives you 64pairs of 5 common spring contacts forprinciple circuit construction and aseries of common buss strips (8) of 25connections each.Dimensions: 33"h x 2.2"w x 6.5"l

ICSockets

RN HIGH RELIABILITY eliminatestrouble. "Side-wipe" contacts make100% greater surface contact with thewide, flat sides of your IC leads torpositive electrical connections.

AVAILABLE AT SELECTED LOCAL DISTRIBUTORS

Tl Edge CardConnectors

44 pin ST (.156" centers)100 pin ST (.125" centers)100 pin WW (.125" centers)

All connectors gold plated.

WIRE WRAP

Size

Quant./Tube

Price Ea.

Price/Tube

SOCKETS

08 pin

WW 52

.31

$16.12

3-level Gold

14 pin

60

.32

$19.20

Closed Entry Design

16 pin

52

.34

$17.68

All prices include Gold

18 pin

23

.50

$11.50

20 pin

21

.65

$13.65

2-level Sockets

22 pin

19

.70

$13.30

Also Available

24 pin

10

.70

$7.00

Sockets sold at these

28 pin

10

.95

$9.50

prices by the tube only.

40 pin

7

1.20

$8.40

ORDERING INFORMATION

• Orders under $25, add $2 handling

• Blue Label or First Class, add $1 (up to 3 lbs.)

• CODs, VISA & MC orders will be charged shipping

• Most orders shipped next day

page

135 E. Chestnut Street 5A, Monrovia, California 91016 Phone (213) 357-5005

256 BYTE January 1980

Circle 216 on inquiry card.

CaIIFornia DIgitaI

Post Office Box 3097 B • Torrance, California 90503

With Purchase of TheINTEGRAL DATA 440

Paper Tiger

Your Choice, $200 Value1) Graphics Option Package2}Interface for APPLE II3) TRS-80 Printer Interface

California Digital has resently

researched the complete lowcost printer market. It is ouropinion that the IDS 440 PaperTiger is, without doubt, the-most versatile and offers thebest value of any primer cost-ing under SI,000.

This quality dot matrix printerincorporates such features assoftware selectable character size to allow print densities upto 132characters per line. Full forms handling capabilities and tractorfeud mechansim adjustable to 9.5". The Paper Tiger is engineeredlo accept cither parallel or RS232 serial ASCII. UO/22QV,50/6GHz.■;;**** $995^00 plus shipping *****

CONNECTORS

your choice

DB25P

. male plug & hood

orI DB25S female

*325

Qty. fe. male hd.

10 3.0S 1.95 1.15

25 2.95 1.79 1.05

100 2.65 1.67 .95

500 2.25 1.60 .85

IK 1.97 1.37 .73

EdgeConnectors

GOLD100 PIN

IMSAI/ALTAIR

Imsai solder.125x.250Imsai ww.l25centersAltair soldertail .140rowSPECIALS22/44 Kim eyelet.156"25/50 solder tab .156"36/72 wide post w/w.156

(2.95 3 ■* 7.50$4.95 3/$13.00(5.95 3 S15.00

11.95 3/15.0011.09 3/$2.00*1.95 3/15.00

Authorized Distributor

Scotch

Data Products

H

740-9 IBM soft format.740/2 Double side soft

7-11-0 Double density743-0 D ou bio /Double7-10-32 8" Hard sector7 44-(0)(10)(16) 5 l/4"miniLibrary case for any abov831 A Data CassetteDC 100 MinicartridgeDC 300 Data Cartridge920( ) Disk Cartridge

501- I$3. 50 |

10 PalsS3!). 0005. 0093. 00 I. 970. 00 S. 630.00 J. 339.00 3.5■; Add S3. 005. 5016.0020.00

as), oo

S-100 Mother BoardQuiet

18 slotIMSAI

Minidisk Drive for TRS-80

your choice <J» |

f#° IncludesUlSta Interface Cable

TELETYPE MODEL 43

4320 KEYBOARD

TTL AAA $1050

RS232....AAK 1150

Friction ... AAE

103 Modem AAB 1575

1100 shipping

TET

rnrr PLASTIC LIBRARY CASE

I 1* rr withpurchaseofeachbojiot ..

Verbatim mini-diskettes. $5 value.

DISKETTES

i Digital <

the distrili

t we havi- reaently come aci unique that wo lust had 10iroauci tme. Litis la the System X-10 manufaetuI i in l jt■ l-—- company, v his apace age system will•r tpaUsnce in viiiir home or office. Command s;lai command console over your existing wiring,hair you can control up to 16 different electrical d,-uur home. Use the System X-10 to control yourliiilii fixture on the premises.

dlable in the following components:

add i

■ol Console

alle

$34.

SPECIAL

APPLE [(

I6K MEMORY

COLOR • GRAPHICS* SOUND

$988

PLUS SHIPPING

Mte.Swg.

Retail....

•1195

Nj.Shugarf Associates

SA800-R Floppy Disk Drive

Thi' most cast effective way lo store data proc-essing Information, when random recall is aprime factor. The SA800 is fully compatiblewith the IBM 3740 format. Write protect cir-cuitry, low maintenance & Sougarl Quality.

$44950

*85

KEYBOARD

ASCII ENCODED

KEYTRONIC

ASCII & ASCIIcomplement.*Ten key data pad I^Cursor controls*Six user switches* Alpha Lock*AutO repeal'Single 5 volt.*Glass reed.

NEW

MEMORY

TRS-80 $|APPLE II

16k memory (8)4116's

Installation is simple. Anyone who has I .1ever changed a spark plug should be able C^to up-grade his microcomputer.How can California Digital offer thesememory up-grade sets al 25% below our competition?Simple, we buy in volume, wholesale to dealers andsell the balance directly lo owners of personal micro-systems. These 16K dynamic memory circuits arefactory prime and unconditionally guaranteed for onefull year. NOW, before you change your mind, pickup the telephone and order your up-grade memory

from California Digital.

STATIC

21L02 450nS.21L02 250llS.2114 lKx-l -1502114 Hsx4 300

4044 4K.\1 4504041 IKxl 250

4045 1K.\4 4501045 11-0:4 250

1-311. 191. 495.958. 955.959.958. 959.955. 95

Add S3 for TKS80 jumpers.32-99 100-5C -999 1K+

.991. 395.50

8. 505. 50

9. 50

8. 50

9. 50

.951. 255. 25

8. 005. 25

9. 008. 009.005. 00

4. 80 4. 60

SPECIAL CIRCUITS

Z80A 4 MHz. 24.95

11080A CPU 0. 95

8085 22.50

8086 Intel 16 hits 85. 00[■MS9900 16 bits 48.95

AV5-1013A UAI1T 4.95

I'loppv Disc ControllersWD 1771 single D. 39. 95

WD 1781 Double D 65. 00WD 1791 D/D3740 *

E PROMS l-li1702A 2K 4.95

2708 8K 9.95 9.50

2716 5V16K 39.95 35.00

2716 Tl 24.88 20.00

2532 85. 00 t

1.50 4.00

8U

it

legem

& from

APPLIED DIGITALDATA SYSTEMS

Buying a CRT Terminal ?

Hazeltine* Soroc • Lear Siegler

ell if you really insist upon purchasing one of the aboverminals, sure, we'll sell it to you. Bui. when the key-lard starts to double bounce, the screen fades and thepower supply just craps out don't call us, complain tothe manufacturer.

Che alternative, lake a serious look at the ADDS Regent25, we have, and concluded that this terminal offers, thebest value in todays market. Through years of researchthe ADDS Company has evolved alow maintenance, ex-tremely durable CRT terminal capable of withstandingan allusive 24. hour duty cycle. The Regent 25 featuresIntel 8085 microprocessor controlled circuitry along withI he Cherry Switch long-life capacitance keyboard.18 key cursor and numeric pad doubles to allow for userdefinable special functions. True descending lower casecharacters along with a fully addressable cursor makesthe Regent 25 the ideal word processing terminal.High-resolution screen is capable of displaying 96 upperand lower case ASCII characters and 32 control codes.

["his unique feature assist in the debugging of programs.

The Regent 25 is switch selectable to display six Euro-pean languages along with Kafakana.Clearly tiie Regent 25 is not your adverage terminal,but than, ADDS is not your adverage terminal company.

\$

Miniature /Switches A

w

your choicetf qo " 50 100 Ik*.30 S.88 .81.73.66SPDT Miniature Toggles

7101C&K 0N-N0NE-0N

7107 jbt ON-OFF(mnt.ON) I

7108 CK 0N(mornent ON)7103 CK ON OFF ONRotary 3P-4-Pos.Rotary 3P-6-Pds.PushB (N.0.) V39ea.4/Jl

DIP Switch

SJ29

25 100 IB

PORTABLE DATA ENTRY SYSTEM

Tfeese used data terminals were originally designed for chain store Inventory con-trol ami order entry systems. The operator rasters the inventory control numbsr,merchandise on hand ana the mill pric^. After all pertinent data tins been entered Inthe recorder, the main warehouse is telephoned, the handset Lb placed in the acoustncoupler and ail the recorded information is transmitted back to the master computer.With a tittle imagination and one of these portable entry systems, you should be able10 exchange programs and computer Information with associates across the country.Ail units were removed from service in working condition. Orinin.il coat S2.5uo.Each system comes complete with:■Portable Cassette Drive Unit -Five Gould "U" NiCads »Dfl25 Cable

Llile !.:.!

1.1.1

Ills,

I Ke\

■Ba;;..:

I Chii

I Couple;

■lull I

irp

DISCOUNT ' |

Wire Wrap Renter

IC SOCKETS

wire wrapea. 25 50

low profileea. 25 50

17' 16 15

37' 36 35

18 17 16

38 37 36

19 18 17

99 93 85

36 35 34

169 155 139

63 60 58

5011.

198

S29.95,

500 1,000 11,000S9. S15. S105.

VISA

(213)679-9001

Circle 216 on inquiry card.

7400 TTL

8N74QDN

SN7401NSN7402NSN7403NSN7404N

SN7405NSN7406NSN74Q7NSN740BNSN7409NSN7410NSK7411NSN7412NSN7413NSN7414NSN7416NSN7417NSN7420NSN7421NSN7422NSN7423NSN7425NSN7426NSN7427NSN7429NSN7430NSN7432NSN7437NSN7438NSN7439NSN7440NSN7441NSN7442NSN7J43NSN7444NSN7445NSN7446NSN7447NSN7448NSN745QNSPJ7451NSN7453NSN7454NSN7459A5N7460N

CD4000CD-1O0ICD4002COJ006CD4007CD4Q09CDJ010CD-tOIICO4012CD4013CD4014CD4015CDJ016CDJ0I7CD4Q18CO4019CD4020CD4021CD4022CD4023CD4024CD4025CD4026CD4027

74CO074C0274C0474 COB74C1074C1474C2074C3074C4274C4874C7374C74

78MG

LM106H

LM3Q0H

LM301CN/H

LM302H

LM304H

LM305H

LM307CN/H

LM30BCN/H

LM309H

LM309K

LM310CN

LM311N/H

LM312H

LM3I7K

LM31BCN/H

LM319N

LM320K-5

LM320K-5.2

LM320K-12

LM320K-15

LM320K-18

LM320K-24

LM320T-5

LM320T-52

LM32DT-B

LM320T-12

LM320I-15

LM320MB

LM320T-24

LM323K-5

LM324N

LM339N

LM340K-5

LM340K-6

LM3JQK-B

LM340K-12

LM340K-15

7-1LSQ074LSOI74LS0274LS0374LS0474LS0574LS0B74LSC974LS1074LS1!74LS1374LS1474LS1574L52074LS2174LS2274LS2674LS2774LS2874LS3074LS3274LS3774LS4074LS42

SN7470NSN7472NSN7473NSN7474NSN747SNSN7476NSN7479NSN74B0NSN7JB2NSN7483NSN7485NSN7486NSN74G9N5N749QNSN7491NSN7492NSN7493NSN 749-1NSN7495NSN7496NSN7437NSH74VXHSN74107NSN74109MSN74116NSN74121NSN74122NSN74I23NSN74125NSN7412GNSN74132NSN74136NSN74141NSN74142NSN74143NSN74144NSN74145NSN74147NSN7414BNSN74150NSN74151NSM74152NSN74153NSN74154NSM7J155NSN74156NSN74157N

C/MOS

CD4Q2BCD4029CO4030CD4Q3SCD4040CD4041CD4042CD4043CD4044CD4Q4GCD4047CD404BC04049CD4050CD4051CD4053CD4056CD4059CDJ060CD4066CD4068CD4Q69

74C00

74CB574C9074C9374C9S74C10774CI5174TJ15474C15774C16074C161

LINEAR

LM340K-IS 1,36

LM340K-24 1.35

LM340T-5 1.25

LM3407-6 1.25

LM340T-B 1.25

LM3J0T-12 1.25

LM340I-15 1.25

LM340T-18 1.25

LM340T-24 1.25

LM3S8N 1.00

LM370N

LM373N

LM377N

LM38QN

LM3B0CN

LM381N

LM3B2N

NE501N

NE510A

NE529A

NE531H/V

NE53GT

NE540L

NE544N

NE550N

NE555V

NE556N

NE560B

NE561B

NE562B

NE565N/H

NE566CH

NE567V/H

NE570N

LM7Q3CN/H

LM708N/H

74LS00nL

74LS4774LS5174LS5474LS5574LS7374LS7474LS7574LS7674LS7B74LS8374LS8574LS8674LS9074LS927JLS9374LS9574LS9B74LS10774LSI0974LS11274LS123741S12574LS13274LS136

SN74 ICONSN741G1NSN74162NSN7-1163NSN74I64NSN74165NSN7416GNSN74167NSN74170NSN74172NSN74I73NSN74174NSN74175NSN74176NSW74177NSN74179NSN741B0NSN74181NSN74182NSN741B4NSN74185NSN7418GNSN7418BNSN74190MSN74191NSN74192NSN74193NSN74I94NSN74195NSN74196NSN74197NSN7419BNSN74I99NSN74S200SH74251NSN74279NSN74283NSN742B4NSN74285NSN74365NSN?4366NSN74367NSN74368NSN74390NSN74393N

CO4070

CD4071

CO4072

CO4076

CD40B1

CD40B2

CD4093

CD4098

MCM409

MCI 4410

MC14411

MC14419

MC14433

MCI 4506

MC14507

MCM562

UCHSSS

CD450B

CD4510

CD45J1

CD4515

CD4518

CD4520

B04S6E

74C16374C16474C17374C19274C19374C19574C92274C92374C92574C92680C95B0C97

LM710N .79

LM711N .39

LM723N/H .55

LM733N 1.00

LM739N 1,19

LM741CN/H .35

LM74M4N .39

LM747N/H .79

LM748WH .39

LM1310N 1 95

LM145BCN/H .59

MC14B8N 1.95

MC1489N 1 95

LM1496N .95

LH1556V 1.75

MC1741SCP 3.Q0

LM2111N 1.95

LM2901N 2.95

LM3D53N 1.50

LM3065N 1.49LM3900N{3401] 59

LM3905N 1 49

LM3909N 1.25

MC5558V .59

LM75450N

75451 CfJ

75452CN

75453CN

75454CN

75491CN

75492CN

75493N

75494CN

RC413G

RC415I

RC4194

RC4195

4.95

4.49

74LS138 .89

74 LSI 39 89

74LS151 .89

74LS155 .89

74LS157 .89

74LS1G0 1.15

74LS161 1.15

74LS162 1.25

74LS163 1 15

74LS164 1 25

74LS175 .99

74LS181 2.49

74LS190 1.15

74LS191 1.15

74LS192 1.15

74LS193 115

74LS194 1 15

74LS195 1 15

74LS253 ,89

74LS257 .69

74LS25B 1.75

74LS260 69

74LS279 .75

74LS3G7 .75

74LS36B 75

74LS670 2.49

QCromemcoI n c orporat e d

TU-ARTDigital

Interface

>CQ's TU-ARTdigital Interface Is aconucnlenl interfacefor CRT terminals, linentors. modems, andother devices. Has 2_ I/O porls, 2 8-bitparallel I/O ports, and It) Independent pro-grammable interval timers. Baud rates aresoftwaro-soiectable from 110-76,800 baud.Has vectorod prioritized Interrupts so It Isable to support the powerful vectored in-terrupt structure of a Z-80mlcroprocessor.10 interval timers w/real-limc capability.

Hig> 1 10.9600 luu

mam Baa-re.aoon.

TRT-W

(Assembled) .

$295.00

DISCRETE LEDS

XC5S6RXC556GXC556VXC556C

XC22RXC22GXC22Y

greenyellowclear

2DQ dla.redgreenyellow

.170- dla.

5/S14/S11/S14/S1

5/$14;S1

4/S1

INFRA-RED LED

Wx1rt"x1/16" Hat

5/S1

.125" dla.

XC209R redXC2096 greenXC209V yellow

.185" dla.XC526R redXC526G greenXC526Y yellowXC526C clear

.190" dla.XC111R redXC111G greenXC111V yellowXC111C clear

5/11

4/$l4/S1

5/SI4/S14/S1

TtMEX T1001

LIQUID CRYSTAL DISPLAY

CLASS II

FIELD EFFECT

' PN % ZZZ V

O Q * Q Q E

A DIGIT .0" CHAFiACTERSTHREE ENUNCIATORS2.0O1" X 1.20" PACKAGEINCLUDES CONNECTOR

TIOOITransmissiue S7.95

TIOOIA-Peflective 6.25

DISPLAY LEDS

TYPE

MAN 1MAN 2MAN 3MAN 4MAN7GMAN7YMAN 72MAN 74MAN 82MAN 84MAN 3620MAN 3630MAN 3640MAN 4610MAN 4640MAN 4710MAN 4730MAN 4740MAN 4810MAN 4840MAN 6610MAN C,fi:j0MAN 6640Mm 6650MAN 6660MAN 6GB0MAN 6710

POLAfllTY I

CommDii Aimdc-red

5 x 7 Doi Matrix-red

Common Cathoilc-rei)Common Cnlliodc-iedCommon Anode -fjreenCommon Anode-yeHowCommon Anodc-iedCommon C^lliotle-reiJCommon Anodn -yellowCommon Callioile-yellowCommon Anode-orangeCommon Anode-oiantje s 1Common Cathode-orangeCommon Anode-orangeCommon Caihodc-orangeCommon Anode-fedCommon Anode-ied * 1Common Caihodc-redCommon A node-yellowCommon C3lliode-yellowCommon Anode-arangc-O.DCommon Anode-Drange • 1Common Caihode-orangc-D.D.Common Cathode -oranga - 1CommonAnodc-orangeCommon Ciiiliode-orantieCommon Anoile-rcd-O.D.

TYPE

MAN 6730

MAN 6740

MAN 6750

MAN 6760

MAN 6780

DL701

0L7D4

DL707

DL728

DL741

0L746

DL747

DL749

DL750

DL33B

FN070

fND358

FN0359

FND5D3

FNO507

5082-7730

HDSP-340Q

HDSP-3403

5082-7300

5082-7302

5082-730-1

5082-7340

POURITTf

Common Anode'fed t 1Common Catnode-rcd-D.D.Common Cathode-red 1 1Common Anode -redCommon Cathode-redCommon Anode-red : 1Common Cathode-redCommon Anode-redCommon Cathode-redCommon Anode-redCommon Anode-ied i 1Common Anode-redCommon Cathode-ied s 1Common Cathode-redCommon Cathode-redCommon CalhodeCommon Cathode * ICommon CathodeCommon Cathode(FND500)Common Anode (FND510)Common Anode-redCommon Anode-redCommon Calhode red4 > 7 sgl Digtl-RHDP■1 « 7 Sgl Digit-LHDPOverranrjecharaclor,(: 1)4x7 Sgl. DiQil-Hcxadocimnl

199519.95HUM

22.50

RCA LINEAR

CA3013TCA2023FCA3035TCA3039ICA3Q46NCA3I159NCA3060NCA3060ICA3081N

2 15 CA3082N

2.56 CA3083N

2.48 CA30B6N

135 CA30B9N

1.30 CA3130T

3.25 CA3140T

3.25 CA31607

-85 CA3401N

2.00 CA3600N

CALCULATOR

CHIPS/DRIVERS

MM5725 S2.9

MM5738 29:

DMB86-1 2.0i

MM5309 S4.95

MM5311 4.95

MM5312 4.95

MM5314 4.95

MM531G 6.95

MM5318 9.95

MM53G9 2.95

MM5387/1998A 4.95

CT7001 6.95

IC SOLDERTAIL — LOW PROFILE (TIN) SOCKETS

MC1408L7 S4 95

MC1408L8 5.75

MC1439L 2.95

MC3022P 2.95

MC3061P 3.50MC4016(74416)MC4024P

MC4O40P 6.95

MC4044P 4.50

25-49 50-100

1-24

14 pin ST S.27

8 pin SG14 ptn SG16 pin SG18 pin SG

8 pm WW10 pin WW14 pin WW16 pin WW18 pin WW20 pin WW

22 pin LP S -37

24 pin LP -38

28 pin LP .45

27 36 pin LP .60

30 SOLDERTAIL STANDARD (TIN) « Pin LP 63

2B pin ST S .99

36 pin ST 139

40 pin ST 159SOLDERTAIL STANDARD (GOLO)

" n SG S -70

25-49 50-100

.29

WIRE WRAP SOCKETS(GOLD) LEVEL *3

28 pinSG 1 TO

36 pinSG 1.6S

40 pin SG 175

22 pin WW S 95

24 pin WW t.05

28 pin WW 1 40

35 pin WW 1,59

40 pin WW 1.75

1/4 WATT RESISTOR ASSORTMENTS -5%

ASST. 1ASST. 2ASST. 3ASST. AASST. 5ASST. 6ASST. 7

1M

OHM

B Ohm /.' DHM

?? OHM 33 OHM 19 OHM 47 OHM 56 DHM

68 OHM &? OHM 100 DHM I2fl OHM I5Q OHM

180 OHM ZZOOHM .TO OHM 330 OHM 390 OHM

170 OHM 560 OHM 680 OHM 820 OHM IK

'.?* 1.5* 1.8K 7.2K 2.7n

UKB.2K

l,9KIQK

!>.6*

S1.75

1.75

1.75

1.75

1.75

1.75

so pcs 1.75ASST. BR Includes Resistor Assortments 1 -7 (350 PCS.) S9.95 ea.

so PCSso PCS

50 PCS50 PCS50 PCS50 PCS

S10.00 Min. Order - U.S. Funds Only Spec Stieets - 25^

Calif. Residents Add 6% Sales Tax 1980 Catalog Available —Send 41 istamp

Postage — Add 5% plus$1 Insuranco (if desired)

■ 3«=tHl;HKIM.1

PHONE

ORDERS

WELCOME

(415)592-8097

MAIL ORDER ELECTRONICS - WORLDWIDE

1355 SHOREWAY ROAD, BELMONT, CA 94002ADVERTISED PRICES GOOD THRU JANUARY

TELEPHONE/KEYBOARD CHIPS

AY-5-9J00 Push Button Telephone Dialler

AY*S42D0 Repertory Dialler

AV-5-9500 CMOS Clock Generator

AY-5-2376 Keyboard EncoOer (8fl key*)

HD016S Keyboard Encoder 16 keys

74C922 Keyboard Encoder (JO key*

/4C923 Keyboard Encoder (20 keys)

$14.%14.954.9514.95/.957.95C.25

ICM7W5ICM7205I CM 7207ICM720BICM7209

ICM CHIPS

CMOS Precision TimerCMOS LED Stopwatch/TimerOscillator ControllerSeven Decade CounlerClock Generator

24.95

19.957.50

19.956.95

NMOS READ ONLY MEMORIES

MCM6571

128 xg X 7 ASCII Shifted Willi Greek

13 50

MCM6574

128 X 9 X 7 Math Symbol & Pictures

13.50

MCM6575

128 X 9 X 7 Aloha Conlrol Char Gen

13.50

TL07-ICII

TL494CN

TL496CP

1IC90

95H90

4M33

MK50240

DS0026CH

TIL308

MM5320

MM5330

LD110/111

MCI4433P

MISCELLANEOUS

Quart Low Noise bi-lel Op Amp

Switching Regulator

Single Switching Regulator

Divide 10/11 Prescaler

Hi-Speed Divide 10/11 Prescaler

Photo-Darlington Oplo-lsolalor

Top Octave Freq. Generator

5Mhz 2-phase MOS clock driver

.27" red num. display w/integ logic chip

TV Camera Sync. Generator

4Vi Digit DPM Logic Block (Special)

3'/i Digit A/D Converter Set

3'/i Digit A/D Converter

2.494.491.7519.9511.953.9517.503.7510.9514.953.9525.00/sel13.95

LITRONIX ISO-LIT 1

Photo Transistor Oplo-lsolalor(Same as MCT 2 or 4N25)

49^ each

SN 76477

SOUND GENERATORGenerates Complex SoundsLow Power - Programmable

S3.95 each

TV GAME CHIP AND CRYSTAL

AY-3-8500-1 and 2.01 MHZ Crystal (Chip & Crystal _ _ _ .

Includes score display. G games and select angles, etc 7 . j5/Se\

4.404.401.551.50.39

XR205XR210XR215XR320XR-L555XR555XR556XR567CP .98XR567CT 1.25XR1310P 1.95XR1468CN 3.85XRI488 1.95XR1489 1.95

EXAR

XR2208 5-20

XR2209 1.75

XR2211 5.25

XR2212 4.35

XR2240 3.45

XR2556XR2567XR3403XR4136XR4151XR4194XR4202XR4212XR4558XR4739XR4741

3.202991.251.253.954.953.602.05

DIODES

TYPE

IN7461N751IN 752IN 753IN 7541N7571N759IN959IN9G51N52321N52341N52351N52361N52421N52451N456IN4581N485A1N4001

400m400m400m400m400m400m500m500m500m500m500m500m

PRICE4/1 004/1.004/1.004/1.004/1.00

TYPE1N40021N4003IN40041N4005KJ40061N40071N36001N41481N4154IN4 7331N47341N47351N47361N47381N47421N4744INI 1831NUB4INI IBS1N118G1N1188

VOLTS W PRICE

100PIV1 AMP 12/1 00

200 PIV 1 AMP 12/1 00

400PIV1AMP 12;1,

600 PIV) AMP 10'1

800 PIV 1 AMP 10/1

I000PIV1 AMP 10/1 00

50 200m 675 10m 15/1.0035 10m 12/1.00

51 lv 2856 1w 28

50 PIV 35 AMP 1 60

100 PIV 35 AMP 1 70

150 PIV 35 AMP I 70

200 PIV 35 AMP 1 BO

400 PIV 35 AMP 3 00

C360C36M2N232BMDA 980-1MDA 980-3

SCR AND FW BRIDGE RECTIFIERS

r 400Vr 600Vr 300V

C106B1

MPSA05

MPSA06

TIS97

TIS98

40409

40410

40673

2NS1B

2N2219A

2N2221A

2N2222A

PN2222 Plastic

2N2369A

MPS2369

2N24S4

2N2906

2N2907

PN2907 Plastic

2N2925

MJH2955

2N3053

7/1 005/1 00

TRANSISTORS

2N3055 39

MJE3055 1.00

2N3392 5/1.00

2N3398 5/1.00

PN3567 3/1.00

PN3S68 4/1.00

PN3569 4/1 OD

MPS3638A 5/1.00

MPS3702 5/1 00

2N3704 5'1 00

MPS3704 5/1 00

2N3705 5/1 00

MPS3705 5/1.00

2N3706 5/1.00

MPS3706 5/1.00

2N3707 5/1.00

2N3711 5/1 00

2N3724A 65

2N3725A I 00

2N3772 2 25

2N3823 1.00

2N3903 5/1.00

2N39042N39052N39062N40132N4123PN4249PN42502N44002fJ44012N44022N44032N44092N50B62N50872N50B82N50892N5129PN5I34PN51382N51392N52102N5449.:n;.h:ii

4/1.004/1 004/1.004/1.00

CAPACITOR

CORNER

22 pt47 pi100 pf220 pi470 Dl

001ml.0022,0047m(,01ml

1/35V15/35V

22/35V.33/35V. 47/35 V

68/35V1 0/35V

.47/50V

I.0/50V

3.3/50V

4.7/25V

10/25V

10/50V

22/25V

22/50V

47/25V

47/50V

100/25V

100/50V

220/25V

220/50V

470/25V

1000/16V

2200/16V

05 .04 .035

OOI^F,0047/iF01,iF.022*1 F,047^FApt

.12

1B0 VOLT MYLAR FILM CAPACITORS-022m!047ml

.10 .07

,1mt

.28

.22ml

+ 20°,, DIPPED TANTALUMS IS0LI01 CAPACITORS

15-35V 30

2.2/35V .35

3.3/25V .35

4.7/25V .33

.28 .23 .17 6.8/25V .49

.28 .23 .17 15/25V -75

.28 .23 .17 22/6V >»

MINIATURE ALUMINUM ELECTROLYTIC CAPACITORS

.15

.13

.10

47/25V.47/50V1.0/16V1.0/25V1 0/SDV4 7/16V4 7/25V4.7/50V10/16V10/25V10/50V47/50V100/16V1O0/25V100/SOV220/16V470/25V

Radial Lead

28

y

258 BYTE January 1980

Circle 218 on inquiry card.

;t°H Continuity Tester and Flashlight

Convenient versatile tool for quicklychecking continuity of dead circuits,switches, appliances, cords, fuses,motors, control equipment, coilsand panel boards. Also tests cir-cuits for low-resistance shorts andhelps identify wires in multi-wirecables. Dozens of other uses. Plusthe added convenience of a handy,durable flashlight. Uses two AA sizepenlight batteries (not furnished).Insulated clip prevents accidentalshorting to case. Alligator clip has48" lead with plug.

RT300 *7.95

Custom Cables & Jumpers

DB 25 Series Cables

Part No. Cable Length Connectors PriceDB25=-4-P 4 Ft 2-DP25P S15.95 ea

OB25P-4-S 4 Ft. 1-DP25P/1-25S S16.95 ea

DB25S-4-S 4 It. 2-DP25S S17.95ea.

Dip Jumpers

DJ14-I 1 tt. 1-14 Pin S1.59 ea.

DJ16-1 1 It. 1-16 Pin 1,79 ea.

DJ24-I 1ft. 1-24 Pin 2.79 ea.

DJ14-1-14 1 It. 2-14 Pin 2.79 ea.

DJ16-1-16 1 ft 2-16 Pin 3.19 ea.

DJ24-1-24 111. 2-24 Pin 4,95 ea.

For Cuslom Cables a Jumpers, See JAMECO 1980 Catalog lor Pricing.. U.UU1UU 25 PIN-D SUBMIHIATUHE

CONNECTORS

(Meets RS232)

PART WO. DESCRIPTION PRICE

DB25P PLUG (as pictured) $2.95

DB25S SOCKET 3.50

DB51226-1 CABLE COVER lor DB25P or DB25S... 1.75

DB25P-S31 PLUG - Right Angle - P.C. Mount 4.95

DB25S-831 SOCKET -Right Angle -P.C. Mount . . 5.25

Printed

Circuit

Connectors

15(3 Spacing-Tin-Double Read-Out

Bifurcated Contacts

Fits .054 to .070 P.C. Boards

PART NO. DESCRIPTION PRICE

15/30SE 15/30 Contacts-solder eyelet SI.95

18/36SE 18/36 Contacts-solder eyelet 2.49

22/44 SE 22/44 Contacts - solder eyelet 2.95

22/44 WW 22/44 Contacts - wire wrap 3.95

50/100 WW 50/100 Contacts-wire wrap (R681-1K

(.125 Spacing) 6.95

Jumbo 6-Digit Clock Kit

* Four ,630"ht. and two .300'*M.

common anode displays

* Uses MMS314 clock chip

* Switches tor hours, minutes and hold functions

* Hours easily viewable to 30 feet

* Simulated walnut case

* 115VAC operation

* 12 or 2* hour operation

* includes all components, case and wall transformer

* Size: 6V* x iVa x 1%

JE747 $29.95

20 ft

JE701

• Bright .300 ht. comm. code display

• Uses MM5314 clock chip

• Switches for hours, minand hold modes

• Mrs. easily viewable

• Simulated walnut case

• 115 VAC oporatlon

• 12 or 24 hr. operation

• Incl. all comDononts, casewall transformer

• Size: 634" x 3-1/8" x IK"

6-Digit Clock Kit $19.95

Regulated Power Supply

Uses LM309K. Heat sink ^*C^ ;\provided. PC board con- "*j

struction. Provides a solid1 amp 8> 5 volts. Can supply upto ±5V, ±9V and i12V withJE205 Adapter. Includes compo-nents, hardware and instructions.Size: Z%" x 5" x 2"H

JE200 $14.95

ADAPTER BOARD-Adapts to JE200-+5V, ±9V and ±12V

DC/DC converter with +5V input. Toriodal hi-speed switching XMFR. Short circuit protection.PC board construction. Piggy-back to JE 200board. Size: 3'A" x 2" x 9/16"H

\JE205

$12.95

MICROPROCESSOR COMPONENTS

821282148216822482268228823882518253825582578259

-8M0A/8OBQA SUPPORT DEVICES

CPU $

8-BiI Input/Oulput

Priority Interrupt Control

Bi-Direclional Bus Driver

Clock Gen era! or/Driver

Bls Driver

System Controller/Bus Driver

System Controller

Prog Comm. 1/0 (USART)

Prog, Interval Timer 1

Prog. Penph. 1/0 (PPI)

Prog. DMA Control 1

Prog. Interrupt Control 1

6800/6800 SUPPORT DEVICES

MFU S1

MFu with Clock and Ram 3

128X8 Static flamPeiiph. Inler. Adapt (MC6B20)Priority Interrupt Controller 1

1024X8 BitROW (MC6I3A3G-8) 1

Asynchronous Comm AdapterSynchronous Serial Data Adapt.0-600 Ops Digital MODEM 1

2400 bps Modulator 1

Quid 3-State Bus Trans. IMC8T26)- MICROPROCESSOR CHIPS— MISCELLANEOUS -

-MICROPROCESSOR MANUALS-

M-ZB0 User Manual

M-CDP1802 User ManualM-2650 User Manual

-ROM'S-

2513(2140) Character Generator! up per case)

£513(3021) Character Generator!, lower case)

2516 Character Generator

MM5230N 2048-Bit Read Only Memory

280(780C)

280A(780-1) CPJ

CDP1802

2650

6502

8035

P8085

TMS9900JL

MPU

Eit MPU *.clock. RAM. 10 lines

MM500H

MM503H

MM504H

MM506H

MM510H

MM5016H

2504T

2518

2522

2524

2525

2527

2528

2529

2532

3341

74LS670

16-Bil MPU w/hardware, multiply& CivirJe

SHIFT REGISTERS

Dual 25 Bit Dynamic

Qua 50 Bit Dynamic

Dua 16 Bit Static

Dua too Bit Static

Dual 64 Bit Accumulator

500/512 Bit Dynamic

1024 Dynamic

Hex 32 Bit Sialic

Dual 132 Bit Static

512 Static

1024 Dynamic

Dual 256 Bit Sialic

Dual 250 Static

Dual 240 Bit Static

Quad 80 811 Static

Filo

4X4 Register File (TnStaie)

not

256X1

1103

1024X1

2101(8101)

256X4

2102

1024X1

21L02

1024X1

2111(B111)

256X4

2112

250X4

2114

1024X4

2114L

1024X4

2114-3

1024X4

2114L-3

1024X4

5101

256X4

5280/2107

4096X1

7489

16X4

74S200

256X1

93421

256X1

UPD4T4

4K

(MK4027]

UPD416

16K

(MK4116]

TMS4044-

4K

45NL

TMS4045

1024X4

2117

16.3Q4X

S 50 MM5262

- RAM'S -Sialic

Static

Static

Static

Static MOS

Static 450ns

Static 450ns low power

Static 300ns

Static 300ns low power

Static

Dynamic

Static

Static Trislato

Static

Dynamic 16 pin

Dynamic 16 pin 250ns

Static

Static

Dynamic 350ns(house market!)Dynamic

3.954.952.95

2.954.004.00

2716INTELTMS2516(2716)TMS2532

82S2382S11582S123

PROMS

2048 FAMOS

16K- EPROM

1BK* EPROM

•Requires single t 5V power supply

4KX8 EPROM

BK EPROM

16K" EPROM

Requires 3 voltages.

SS.9559.9549,95

12V

2048) 1024) 25632X8409632X8

A-Y-5-1013 30KBAUD

FAMOS

Tristate Bipolar

Open C Bipolar

Open Collector

Bipolar

Tristate

TTL Open Collector

TTL Open Collector

Sialic

3.492.953.9S

JE600 HEXADECIMALENCODER KIT

It 10 V'

FEATURES:

• Full 8 Pit latched output lor micro-processor use

• 3 Use' Define keys wuh one Being bi-stable operation

• Denounce circuit provided lot all 19keys

■ LED re

• Easy interlacing witn standard 16 pinlC CDnnectui

• Only -5V0C rerjuned lor ooeialionaFULL 8 BIT LATCHED OUTPUT—19 KEYBOARD

The JE600 Encoder Keyboard provides two separate tie>adeamaldigits produced Iron seguential key entries to allow direct prog-ramming.tor 8 bit m cfopmcessot or 8 04 memory circuits Three(3) additional keys are provided tor user operations wiin one havinga bistable output avaiiaole The outputs are latcned and monitoredwith LED readouts Also included is a key entry strobe

JE600 $59.95

Hexadecimal Keypad only SI 4.9 5

DIGITALTHERMOMETER KIT

■ Dual sensors—switching control for in-door/outdoor or dual monitoring

■Continuous LED ,8" ht, display

• Range: ■40°F to 199°F / -40°C to 100°C

■Accuracy: ±1° nominal

•Set for Fahrenheit or Celsius reading

■Sim. walnut case - AC wall adapter incl.

■ Size: 3-1/4"Hx6-5/8"Wxl-3/8"D

JE300 $39.95

62-Key ASCII Encoder Keyboard Kit

-. i > > > . « . i •

BMH

The JE610 62-Key ASCII Encoder KeyboardKit can he interfaced into most any com-puter system. The JE610 Kit comes com-plete with an industrial grade keyboardswitch assembly (62 keys), IC's, sockots,connector, electronic components and adouble-sided printed wiring board. Thekeyboard assembly requires +5V @ 150mAand —12V @ 10mA for operation.

FEATURES:

•60 Keys generate the full 128 char-acters, upper and lower case ASCII

set• Fully buffered•2 user-define keys provided for

custom applications*Caps lock for upper 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-pin dip

or 18-pin edge connector

JE6TO $79.95

62-Key Keyboard only. . $34.95

HICKOK

LX303 Portable LCD Digital Multimeter

Ulav iimi 600 u»,30Mn,.il^l

Digital Multimeter $74.95

115V AC ADAPTER 7.50

PADDED CARRYING CASE 7.50

X10 OC PROSE ADAPTER (Up lo IOK) 14.85

■lOkV DC PROBE .-- 35.00

io Amu DC Currant Stiuni 14.95

$10.00 Min. Order - U.S. Funds Only Spec Sheets - 25c'

Calif. Residents Add 6% Sales Tax 1980 Catalog Available — Send 41 istamp

Postage —Add 5% plus$1 Insurance (if desired)

PHONE

ORDERS

WELCOME

(415) 592-8097

ELECTRONICS

MAIL ORDER ELECTRONICS - WORLDWIDE

1355 SHOREWAY ROAD, BELMONT, CA 94002ADVERTISED PRICES GOOD THRU JANUARY

The Incredible"Pennywhistle 103

J|>1 Ua.SJO Kit Only

The Pennywhltlle 103 is capaDle ol recording data to and Irom audio tape wiliaut

critical speed requirements lor the recorder and it is able to communicate directly witn

another modern and terminal for telephone "hamming/' and communications In

addition, it is free ol critical adjustment and is built wilh non-precision, readily available

parts.

Oala Transmuslon Method Frequency-ShiM Keying, lull-duplex (half-duplex

selectable} .

Maximum Data Hals 300 Baud.

Dala Format Asynchronous Serial (return id mark level required

between each character).Receive Channel Frequencies .. .2025 Hz for space; 2225 Hz for markTransmit Channel Frequencies ..Switch selectable: Low (normal) = 1070 space.

1270 mark; High - 025 space. 2225 mark.

Receive Senslllvlty - 46 dbm accoustically coupled

Transmit Level -15 dDm nominal Adjustable Irom -6 dbm

Id - 20 dom.Receive Frequency Tolerance ...Frequency reference automatically adjusts lo

allow for operation between 1800 Hz and 2400 HrDigital Data Interface EIA RS-232C or 20 mA current loop (receiver is

oploisolated and non-polar).

Power Requirements 120 VAC, Single phase. 10 Watts.

Physical All components mount on a single 5" by 9"

printed circuit board. All components includedRequires a V0M. Audio Oscillatcr. Frequency Counter and/or Oscilloscope to align.

TRS-8016K Conversion Kit

Expand your 4K TRS-80 System to 16K.Kit comes complete with:

* 8 each UPD416-1 (16K Dynamic Rams ) 250NS

* Documentation for conversion

TRS-16K $75.00

'30 AWG wire ".025" square posts'Daisy chain or 'Built-in cut offpoint-to-point .Includes 50 ft. wire•No stripping or slitting required-just wrap

Pin No.JW-1-BJW-1-WJW-l-VJW-1-R

BlueWhiteYellowRed

Price

$14.9514.9514.9514.95

JUST WRAP' Replacement Wire

Part No.R-JW-BR-JW-W

R-JW-YR-JW-R

Color

Blue 50 ft. roll .

White 50 ft. roll .

Yellow 50 ft. roll .

Prle»

S2.982.982.98

Red .

. 50 ft. roll 2.J

JUST WRAP' Unwrap Tool $3.49

JUST VJURAP' Kit •v°J0^i™ue'"■'''"'•""'■

• JUST WRAP Tool "Unwrapping Tool

JWK-6 $24.95

VV-1 $3.49

EPROMErasingLamp

•Erases 2708, 2716, 1702A, 5203Q, 5204Q, etc.■Erases up to 4 chips within 20 minutes.•Maintains constant exposure distance of one 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 $69.95

Micro-MiniatureJoystick

•2 each TOOK pots (LinearTaper)9 •Printed Circuit Board. I Mount

Jfj »Size: 1" x 1-3/16" x 1-3/16"

Micro-Miniature Joystick

$4.95y

Circle 218 on inquiry card.

BYTE January 1980 259

Circle 219 on inquiry card.

■^■0 CALIFORNIA COMPUTER SYSTEMS

16K BAM BOARD Fully buflererj addressable in 4Kblocks IEEE standard (or bank addressing 2114s

PCBD $26.95

Kit 450 NSEC $259.95

PT-1 PROTO BOARD Over 2.600 holes 4" regu-lators All S-100 buss functions labeled, gold lingers

PCBD S25.95

PT-2 PROTO BOARD Similar to PT-1 except set-up lo handle solder tail socketsPCBD S25.95

ssm

FORMERLY CYBEHCOM.'SOLID STATE MUSICPB-1 2708& 2716 Programming Board with provisionslor 4K or 8K EPROM No external supplies require

texiool sockets Kit .$124.95

CB-1A 8080 Processor Board. 2K of PROM 256 BYTERAM power on/rest Vector Jump Parallel port with

status. Kit TBD PCBD . $30.95

MB-6B Basic 8KX8 ram uses 2102 type rams. S-100buss Kit 450 NSEC .S139 95 PCBD $26 95

MB-7 16KX8. Sialic RAM uses UP410 Protection

lully bullered Kit $299.95

MB-BA 2708 EROM Board S-100, 8K8X or 16Kx8

kit without PROMS $75 00 PCBD S28 95

VB-3 80x55 VIDEO BOARD

Graphic included ... . .. TBD

IO-2 S-100 8 bit parallel /IO port. **, ol boards is forkludging. Kit $46.00 PCBD S26 95

IO-4 Two serial I/O ports with lull handshaking20/60 ma current loop: Two parallel I/O ports.Kit $130.00 PCBD $2695

VB-1B 64 x 16 video board, upper lower case Greek,composite and parallel video with software. S-100.Kit $12500 PCBD $26.95

Allair Compatible Mother Board. 11 x 11 Vi x Ve".Board only $39 95. With 15 connectors $94.95

Exlended Board full size. Board only $ 9.49

With connector $13.45

SB-1 Synthesizer Board S-100

PCBD $42 95 KIT $135.95

W7T7C

inc. WAMECO INC.

FDC-1 FLOPPY CONTROLLER BOARD will driveshugart pertek, remic 5" & 8" drives up to 8 drives,on board PROM with power boot up will operatewith CPM'M inot included)

PCBD . $42.95

FPB-1 Front Panel IMSAI size hex displays Byte,or instruction single step

PCBD $47.50

MEM-1A 8KX8 fully buffered, S-100, uses 2102 type

rams. PCBD - $25.95

OM-12 MOTHER BOARD. 13 slot, terminated. S-100board only $38.75

CPU-1 8080A Processor board S-100 with 8 levelvector interrupt PCBD $26 95

RTC-1 Reallime clock board. Two independent in-terrupts. Software programmable PCBD $23.95EPM-1 1702A 4K Eprom card PCBD $25.95EPM-2 2708/2716 16K/32K

EPROM CARD PCBD $25.95

OM-9 MOTHER BOARD. Short Version of QM-12.9 Slots PCBD $30.95

MEM-2 16K x 8 Fully Bullered

2114 Board PCBD $26.95

PTB-1 FOWER SUPPLY AND TERMINATOR BOARDPCBD $25.95

2708 $8.99

2114 (450 NS) low pwr 5.99

2114 {250 NS) low pwr 6.99

2102A-4L 1.20

8080A

$995

8212 ... .

2 49

B214 ...

. ... 4.49

8224

3.49

W\

(415) 592-1800P. O. Box 424 • San Carlos, California 94070

Please send for IC. Xislorand Computer parts list

JAN. SPECIAL SALEON PREPAID ORDERS

i.Oarge cards nol included on ihis ollan

FPB-1 with MIKOS #14

Front Panel Kit $119.95

8Kx8 Ram 450 NSEC fully buffered, 2.5amps typical $99.99

MIKOS PARTS ASSORTMENTWITH WAMECO AND CYBERCOM PCBDS

MEM-2 wilh MIKOS "7 16K ram

wilh 12114 450 NSEC $249 95

MEM-2 with MIKOS "13 16K ram

with L2114 250 NSEC S279 95

MEM-1 with MIKOS *1 450 NSEC 8K

RAM $119 95

CPU-1 with MIKOS *2 8080A CPU $94.95

MEM-1 with MIKOS *3 250 NSEC 8K

RAM S14495

OM-12 with MIKOS #4 13 slot molher

board . $89.95

RTC-1 with MIKOS #5 real time clock $54.95

EMP-1 wilh MIKOS "10 4K 1702 less

EPROMS $49 95

EPM-2 with MIKOS oil 16-32K EPROMS

less EPROMS $59 95

QM-9 with MIKOS #12 9 slot mother

board $79 95

FPB-1 wilh MIKOS «14 all parts

lor front panel $134.95

MIKOS PARTS ASSORTMENTS- ARE ALL FACTORY PRIMEPARTS KITS INCLUDE ALL PARTS LISTED AS REQUIREDFOR THE COMPLETE KIT LESS PARTS LISTED ALL SOCKETSINCLUDED.

VISA or MASTERCHARGE Send acconumber, expir

I be added

nlerbanx

eck or money order wU S l( you are nol a regular custom,cashier's check or postal money ordebe a Iwo-week delay for checks

be sent posl paidplease use charge.Otherwise Ihore will.„ clear Call! residents addMoney back 30 day guarantee We cannol accept re-turned IC s lhal have been soldered lo Prices subiecl tochange without notice S10 minimum order. $1.50 service chargeon orders less than $10.00.

WAMECO

THE COMPLETE PC BOARD HOUSEEVERYTHING FOR THE S-100 BUSS

■* FPB-1 FRONT PANEL BOARD. Hex Displays,

IMSAI Replaceable. PCBD $54.95

* FDC-1 FLOPPY DISC CONTROLLER BOARDControls up to 8 Discs. PCBD $45.00

* MEM-1 A 8K BYTE 2102 RAM BOARD

PCBD $31.95

KIT 450 NSEC $141.95

* MEM-2 16K BYTE 2114 RAM BOARD

PCBD $31.95

KIT 450 NSEC $299.95

* CPU-1 8080A CPU BOARD with Vector Interrupt.

PCBD $31.95

KIT $124.95

* EPM-1 4K BYTE 1702A EPROM

PCBD $29.95

KIT LESS PROMS $59.95

* EPM-2 16K or 32K BYTE EPROM 2708 or 2176Interchangeable.

PCBD $30.00

KIT LESS PROMS $74.95

* QMB-9 9 SLOT MOTHER BOARD

Terminated. PCBD $35.00

KIT $89.95

* QMB-12 12 SLOT MOTHER BOARD

Terminated. PCBD $45.00

KIT $115.95

* RTC-1 REALTIME CLOCK

Programmable Interrups $27.95

KIT $79.95

* PTB-1 POWER SUPPLY BOARD

PCBD $30.95

KIT LESS REGULATORS $55.95

FUTURE PRODUCTS: 80 CHARACTER VIDEO BOARD,

IO BOARD WITH CASSETTE INTERFACE.

DEALER INQUIRIES INVITED, UNIVERSITY DISCOUNTS AVAILABLE

AT YOUR LOCAL DEALER

wmc

260 BYTE January 1980

inc.

WAMECO INC. 111 GLENN WAY "8, BELMONT, CA 94002 (415) 592-6141

Circle 220 on inquiry card.

DIGITAL RESEARCH COMPUTERS

(214) 494-1505

16K EPROM CARD-S 100 BUSS

10

FIRST TIME OFFERED!BLANK PC BOARD - $28

USES 2708s!

Thousands of personal and business systems around the worlduse this board with complete satisfaction. Puts 16K of softwareon line at ALL TIMES! Kit features a top quality soldermasked andsilk-screened PC board and first run parts and sockets. Anynumber of EPROM locations may be disabled to avoid anymemory conflicts. Fully buffered and has WAIT STATEcapabilities.

OUR 450 NS 2708'SARE S8.95 EA. WITHPURCHASE OF KIT

ASSEMBLED

AND FULLY TESTED

ADD $25

16K STATIC RAM KIT-S 100 BUSS

PRICE CUT!

$259

KIT

fill El III! BUI III111 II[IIIllllllII

KIT FEATURES:

1. Addressable as four separate 4K Blocks.

2. ON BOARD BANK SELECT circuitry. (Cro-memco Standard1) Allows up to 512K on linel

3 Uses 2114 (450NS) 4K Static Rams.4. ON BOARD SELECTABLE WAIT STATES.5 Double sided PC Board, with solder mask andsilk screened layout Gold plated contact fingers6. All address and data lines fully buffered7 Kit includes ALL parts and sockets8. PHANTOM is jumpered to PIN 67.9 LOW POWER: under 1.5 amps TYPICAL fromthe+8 Volt Buss

10 Blank PC Board can be populated as anymultiple of 4K.

BLANK PC BOARD W/DATA-S33LOW PROFILE SOCKET SET-S12

SUPPORT IC'S & CAPS-S19.95ASSEMBLED & TESTED-ADD S30

OUR #1 SELLINGRAM BOARD!

8K LOW POWER RAM KIT-S 100 BUSS

SALE paice

$11050

1 ■ w KIT

21L02(450 NS RAMS!)Thousands of computer systems rely on this rugged, work horse.RAM board. Designed for error-free, NO HASSLE, systems use.

Blank PC Board w/Documenlation

S29.95

Low Profile Socket Set .13.50

Support IC's (TTL & Regulators)S9.75

Bypass CAP'S (Disc & Tantalums)S4.50

ASSEMBLED AND FULLYBURNED IN ADD $30

ALL ASSEMBLED BOARDSARE TESTED AT 4MHZ.

16K STATIC RAM SS-50 BUSS

PRICE CUT!

*249k,t

IIII11II11 Hi III 1

,.'r~?~ ***■.--.» ..*■-*.-*->* ^fn

Jil I i 11 i i i i 1B11 III

FULLY STATIC

AT DYNAMIC

PRICES

;SuJfcilEa*»5fc"=

FOR SWTPC6800 BUSS!

ASSEMBLED ANDTESTED - $30

KIT FEATURES'

1 Addressable on 16K Boundaries

2 Uses 2114 Static Ram

3 Runs at Full Speed

4 Double sided PC Board Solder maskand silk screened layout Guld fingers

5 A'l Parts and Sockets included

6 Low Power Under 15 Amps Typical

BLANK PC BOARD—$26 COMPLETE SOCKET SET-SUPPORT IC'S AND CAPS—$19.95

-S12

PROC. TECH. QUITS THE MICROPROCESSOR BUSINESS!

FACTORY CLOSE OUT - SPECIAL PURCHASE!

#16KRA

16K S-100 Dynamic Ram Board$149.95

We purchased the remaining inventory of PT's popular 16K RamBoard when they recently closed their plant. Don't miss the boat!These are brand new, fully tested, ASSEMBLED and ready to go.All are sold with our standard 90 day limited warranty!!Orig. S429 each! 72 Page Full Manual, Included Free!

Perfect fori S-100 Z80 CPU CARD

OEM's I

$159

95

WIRED!NOT A KIT!

4 MHZ

Z-80 PROGRAMMING MANUAL

By MOSTEK, or ZILOG. The most detailed explanation ever on theworking of the Z-80 CPU CHIPS. At least one full page on each of the 158Z-80 instructions. A must reference manual for any user of the Z-80. 300Pa9es $12.95

ASSEMBLED AND TESTED! READY TO USE! Over 3 years of designefforts were required to produce a TRUE S-100 Z80 CPU at a genuinelybargain price! BRAND NEW!

FEATURES'

* 2 or 4 MHZ Operation. * Generates MWRITE, so no front panel required.• Jump on reset capability * 8080 Signals emulated for S-100 co-npatability* Top Quality PCB Silk Screened Solder Masked Gold Plated Contact Fingers

c, LOW POWER - 250NS 8 FOR

SAA-fc- 2114 RAM SALE! $55

4K STATIC RAM'S. MAJOR BRAND, NEW PARTS.These are the most sought after 2114's, LOW POWER and 250NS FAST.SPECIAL SALE: $75° ea. or 8 For $55

NEW! G.I. COMPUTER SOUND CHIP

AY3-8910. As featured in July, 1979 BYTE! A fantastically powerful Sound& Music Generator. Perfect for use with any 8 Bit MicroprocessorContains: 3 Tone Channels, Noise Generator. 3 Channels of AmplitudeControl. 16 Bit Envelope Period Control, 2-8 But Parallel 70. 3 D lo AConverters, plus much more! All in one 40 Pin DIP. Super easy to interfaceto the S-100 or other busses.SPECIAL OFFER: S14.95 each Add S3 for 64 page Dats Manual

Digital Research Computers

9 (OF TEXAS) '

P.O. BOX 401565 • GARLAND, TEXAS 75040 « (214) 494-1505

TERMS: Add SI.00 poslage. we pay balance. Oideis under S15 add 75Chandling. No COD. We accept Visa and MaslerCharge. Te> Res. add 5%Tax Foreign orders (except Canada) add 20% P & H. 90 Dav Money BackGuarantee on all items.

NOT ASSOCIATED WITH DIGITAL RESEARCH OF CALIFORNIA, THE SUPPLIERS OF CPM SOFTWARE.

Circle 221 on inquiry card.

BYTE January 1980 261

MICRO

BUSINESS WORLD

Immediate response to your orders (verbal or written). Phone (213) 371-1660

r

Apple IIpersonalcomputer.

16KRegularor Plus

$920.

Disk II with controller $495.

Disk II without controller $425.PASCAL Language Card $399.

ALL Apple made boards

25% off list priceEuropean Apple models available

commodore pet

A truly professional

computer system

isk$849. 32K$1095.

Dual Floppy Disk

Model 2040 $1095.

Single Disk Drive $795.

Tractor Feed Printer

Model 2022* $849.

Friction Feed Printer

...~r,. r> nLM/MK. cv-uuv Model 2023* $749.

WORLD FAMOUS SONY Trinitron"

Sharpest picture color television H5"Diag,*nee5^^//^°P^ca*te tt'°°

now comes with direct input video. Get

your 'COLOR MONITOR" for the Apple II

or Atari for only $495.00

HEATHDATA SYSTEMS

Smart Video TerminalWH-19HasaZ80micro processornumeric keypad

$795.00

or an IEEE to IEEE cable 35.00

DYSAN DISKETTES

THE CADILLAC OF THE

FLOPPY DISKSAT LOW LOW PRICES8" (BOX OF 10)3740/1 sgl side/

sgl density 4.00 ea3740/1D sgl side/

dbl density 6.50 ea

5" (BOX OF 5 )104/1 sott sector 4.00 ea107/1 10 sectors 4.00 ea

105/1 16 sectors 4.00 ea

For each 2 boxes ol 8" or 4boxes ol 5" you get one plasticstorage case, but hurry —. supply is limited.

EPSON (A SEIKO COMPANY)

TX-80 Printer with GraphicsCapabilities. 7x6 dotmatrix.Parallel (Centronics) standard 80cols. Tractor Feed Model $695.Friction Feed Model $595.Popular Computer Interfacesavailable for only $79.(including cables)

ATARI 800 Computer System

Packed with: Computer Console,Basic Language Card, EducationSystem Master Cartridge. CassetteRecorder, TV Modulator, 8K Memory(expandable to 48K), Power Supply& all Books and Manuals $849.99

ATADE A nfl Personal ComputerAlttnl *HJU System for lessPacked with: Computer Console.Basic Language Cartridge, PowerSupply. TV Modulator, and all

Books and Manuals $469.99ATARI Program Recorder $69.99

ATARI Software. Roms.Cassettes

25% off list priceATARI Expansion Memory:

8K Module $99.9916K Module $199.99

CZf£AIG3.Mioo

Electronic Language Translator$179.95

FRENCH

SPANISHITALIAN

GERMANJAPANESE

Language Modules $22.95

Plastic FloppyDisk Holder

(up to 10)8" $3.95

Plastic FloppyDisk Holder

(up to 10) 5" $3.25

16K RAMselof84116s 200 ns or betler $65.00

Prices subject to change without notice.VISA and MASTER CHARGE WELCOME. Allow2 weeks for cashiers check to clear, 4 weeks forpersonal checks.Add 2% for shipping andhandling. Calif, residents add 6% sales tax.U.S. and International dealer inquiries invited.

APPLESTICK »MORE FUN

AND GAMES! 2 in 1: a Joystick andGame Paddles all in one box $49.50

/MICRO

BUSINESS WORLD

15818 Hawthorne BoulevardLawndale. California 90260(213)371-1660Circle 222 on inquiry card.

computerproducts,

inc.

11542-1 KNOTT ST.

GARDEN GROVE,

CA 92641

(800) 854-6411

(714)891-2663

4116's

(250NS)

ADD-ON MEMORYFOR APPLE, TRS 80, HEATH

8 for $64.0016 for $120.00

FULLY GUARANTEED

2708s

450NS.

8.00 each

OR

8 for $60.00

ORDERING INFO

NAME, ADDRESS, PHONESHIP BY: UPS OR MAILSHIPPING CHRG: ADD$2.50 UP TO (5) LBS.

IMSAI CONNECTORS

100 PIN 'SOLDERTAIL

$3.00 each

OR

10 for $2.75 each

WRITE TO US FOROUR NEW CATALOG

SPECIAL

.1 @ 12 VOLTS

CERAMICCAPS

10$ each

OR100/$9.00

TERMS

WE ACCEPT CASH,CHECK, MONEY ORDERVISA & MASTER CHRG(U.S. FUNDS ONLY) TAX:6% CALIF. ONLY

LO-PRO SOCKETS

14PIN16PIN18PIN20PIN24PIN28PIN40PIN

1-24

.15.16.19.27.35.40.50

25-99.14.15.17

.25.31.33.46

100 Up

.13.14.15.23.27.29.41

REGULATORS

320T-5... . (.80)320T-12...(.80)340T-5... . (.75)340T-12...(.75)78H05... (5.00)78L12.... (.35)

MICROBYTE16K RAM BOARD

•FULLY S-100

COMPATIBLE•USESLOW-PWR4KX1

MM 5257 STATIC RAM•2MHZOR4MHZ•4KBANK

ADDRESSABLE•EXTENDED MEMORY

MANAGEMENT

•NO DMA RESTRICTIONS

•ASSEMBLED & TESTED

2MHZ $250.00

4MHZ $265.00

MICROBYTE32K RAM BOARD

•FULLY S-100

COMPATIBLE•USESLO-PWR4KX1

MM5257 STATIC RAM•2MHZOR4MHZ•BANKADDRESSABLE•EXTENDED MEMORY

MANAGEMENT•8—BIT OUTPUT PORT•NO DMA RESTRICTIONS2MHZ $525.004MHZ $540.00

SA800

DISKDRIVE

INSTALLED IN DUAL

CABINET W/PWR SUPPLY

ASSEMBLED & TESTED

(1) DRIVE INSTALLED

$695.00

(2) DRIVES INSTALLED

$1125.00

MISC. COMPONENTS

LM324

.75

LM348

1.05

LM377

1.25

LM380

.75

LM556

.75

LM3900

.50

21044108

1.503.00

MCM 6574

CHARACTERGENERATOR

$7.00.,

2716's

5 VOLT ONLY450NS.

$35.00 ea.

8/$250.00

8251

4MHZ/U-ART

$5.00 ea.

2732's

(4K) E-PROM

5 VOLTS

$95.00 ea.

262 BYTE January 1980

Circle 223 on inquiry card.

• iil'j; iSllli -

When the people

behind the products count!

(Formerly the CPU Shop)

As the CPU Shop, we have been dedicated to meet-ing the needs of the microcomputer user. The suc-cess of the CPG Shop has led to ComputerCity—the merging of our manufacturing, wholesale andmail order divisions with our rapidly expanding re-tail outlets to provide the increased products andservices the microcomputer consumers of todayand tomorrow want—and need. We remain dedi-cated to providing the same service, technical assis-tance and fair pricing you've come to expect fromthe CPG Shop.

David C. Lourie, President

ComputerCity SamplerDisk Drives

When you're ready to add disk storage to your TRS-80*, we're here to help.Our CCI-100'" and -200™ drives offer more capacity than Radio Shack 35-Track (85K Bytes) drives. These drivesare fully assembled, tested and ready to plug-in the moment you receive them. They can be intermixed with eachother and Radio Shack drives on the same cable. 90 day warranty.CCI-100'" 40 Track (102K Bytes) $399.00 CC1-200'" 77 Track (197K Bytes) $675.00

Printers

Letter Quality High Speed Printer

NEC Spinwriter: In-cludes TRS-80* inter-face software, quickchange print fonts, 55GPS, bidirectional,high resolution plot-ting, graphing, pro-portional spacing and

tractor feed assembly. 90 day warranty $2979.00Also: Centronics, Paper Tiger, HI Plot Digital Plotter16K Memory Up-grade Kits

Fast and ultrareliable $99.00

DISK OPERATING SYSTEMSNEWDOSbyApparat+ $49.95

NEWDOS "PLUS" by Apparat+ $99.95

DOS 3.0 by the original author of 2.1 $49.95

DISKETTE TRS-80*

BUSINESS SOFTWARE BY SBSG

Free enhancements and upgrades to registeredowners for the cost of media and mailing. 30 day freetelephone support. User reference on request.Fully Interactive Accounting Package: General Ledger,

Accounts Payable, Accounts Receivable and Payroll.

Report generating.

Complete Package (requires 3 or 4 drives) $475.00

Individual Modules (requires 2 or 3 drives) $125.00

Inventory 11: (requires 2 or 3 drives)Mailing List Name & Address II

(requires 2 drives)Intelligent Terminal System ST-80 III:The Electric Pencil from Michael ShrayerFile Management System:Budget Control Program 11 by CSACash Register System II by CSA

$ 99.00

$129.00$150.00$150.00$ 49.00$ 49.95$ 99.00

(ComputerCity

A division of CPU Industries, Inc.

U75 Main Street, Dept B-l Charlestown, MA 02129 ,

Hours: 10AM - 6PM (EST) Monday - SaturdayFor detailed information, call 617/242-3350Massachusetts residents add 5% Sales Tax

'"CCI-100 and -200 are ComputerCity Inc. trademarks

* Tandy Corporation Trademark + Requires Radio Shack TRSDOS*

TO ORDER CALL TOLL FREE 1-800-343-6522

Massachusetts residents call 617/242-3350

Retail Store Locations:

175 Main Street, Charlestown, MA

K Mart Plaza, Manchester, NH

50 Worcester Road(Rt.9), Framingham, MA

165 Angell Street, Providence, RI

Visa and Master Charge accepted

Franchise and dealer inquiries invited

Circle 224 on inquiry card.

BYTE January 1980 263

Circle 225 on inquiry card.

BECKIAN ENTERPRISES

ALL PRIME QUALITY - NEW PARTS ONLYSATISFACTION GUARANTEED.

EDGE CARD CONNECTORS: GOLD PLATED:

Abbreviations: S/E Solder Eye . S/E Sold Tail: W/W Wire Wrap.

PART # DESCRIPTION.

BRAND: TEXAS INST.

4070 501100 ImsailCrom.

4090 SOU 00 Imsai WfW

BRAND: SDLLINS: U.L Rog.

129805 001100 Solder Eyu501100 SIT Imsai501100 WlWImiai501100 Srr Altair501100 SrT Cromom

Row Sp. 1-9pc. 10 24pcs. 25pci. Up.

«3.55sa. »3.15aa.3.05ea. 3.45sa.

123870129875129B85129990

.250.250

.140.250.250.140.250

»3.95aa.4.30ea.

B.BOaa.

4.50ea.

5.25

4.95

4.75

OTHER .125" CONTACT CTR CONNECTORS:12305 22144 S/E No Ears .140 4.15

12759 36172 SIT .140 5.40

12790 40IB0WIW .250 8.30

100" CONTACT CTR CONNECTORS10048 13126

1028010175101801019010485104901050010535105401055010585106051059510615

2515020140201402014036172361723617240IB04018040180431864318643IBB43186

SIE No EariSIE TRS 80SIE TRS 80WfW TRS 80SIT TRS B0SIE VectorWIE VectorSIT VectorSIE PETWIWPETSIT PETSIE COSIELFS/T COSIELFWIW COSIELFSIT COSIELF

140.140.140.200.140.140.200.140.140.200.140.140.140.200.200

3.404.505.853.303.205.505.805.705.856.005.806.956.606.906.80

B.IOea.4.1 Oea.4.754.454.25

3.754.B55.65

3.054.055.353.002.904.905.254.205.355.405.256.255.956.206.10

5.45aa.

3.70

4.20

3.95

3.80

3.354.355.00

2.153.604.752.152.554.404.654.604.754.804.655.555.305.955.40

.156" CONTACT CENTER CONNECTORS.

PART tt DESCRIPTION. Row Sp.

15105 6112 SIE PETINSC .140

15110 BI12 SIT PETINSC .140

15137 6112 SIT PETINSC .200

15175 01- SIE Sgla Row

15270 10120 SIE .140

15275 10120 SIT .140

15435 12124 SIE PET .140

15440 12124 SIT PET .140

15445 12(24 SIT PET .200

15505 16130 SIE GRI Key .140

15510 15130 SIT GRI Key .140

15515 15130 WIW GRI Key .200

15600 18138 SIE .140

15610 18136 SIT .140

15615 18136 W|W .200

15700 22144 SIE KIMIVEC .140

15705 22144 SIT KIMIVEC .140

15710 22I44 WIW KIMIVEC .200

15875 25150 SIE .140

15880 25150 SIT .140

15885 25150 WIW .288

16115 36172 SIE .140

16120 36172 Sfr .140

16125 36172 WIW .200

16145 36172 SIT .200

16235 43186 SIT Mot 6800 .140

16240 43166 WIW Mot 6880 .200

16260 43186 SIT Mot 6800 .200

16725 43IBB SIE Mot 8800 .140

1-9nc.

11.801.851.801.702.152.002.602.B52.752.502.402.603.353.003.602.983.9B3.494.654.554.858.506.556.756.506.607.B06.507.20

10-24pca.»1.65

1.65

1.54

1.50

1.95

1.85

2.35

2.40

2.50

2.25

2.15

2.35

3.05

2.70

3.20

2.90

3.30

3.20

4.20

4.10

4.35

5.85

5.90

6.10

5.B5

5.95

7.05

5.85

6.50

25pcs. Up.$1.45

1.50

1.45

1.30

1.70

1.60

2.10

2.15

2.20

2.00

2.95

2.10

2.70

2.40

2.90

2.75

3.00

2.85

3.75

3.65

3.90

5.20

5.25

5.40

5.20

5.30

6.25

5.20

5.75

D' TYPE SUBMINIATUAE CONNECTORS.

PART NUMBER DESCRIPTION.

DE 9P

DE 9S

DE 110963-1

DA 15P

DA 15S

DA 512111

DA 512261

DA 1109632

DR

25P

DB

25S

DB

512121

DR

512261

DB

1109833

DC 37P

DC 37S

DC 1109634

DD 50P

DD 50S

DD 512161

DD 1109635

D 20419-2

Male

Female

2 pc. Grey Hood.

Mala

Female

1. pc. Grey Hood

2 pc. Black Hood

2 pc. Grey Hood

MaleFemale

1 pc. Grey Hood

2 pc. Black Hood2 pc. Grey Hood

Male

Female

2 pc. Grey Hood

MalaFemale

1 pc. Grey Hood

2 pc. Grey Hood

Hardware Set11 Hood Set)

1 -9pcs.

M.GOoa.2.25ea.1.50aa.

2.3 5ea.3.25oa.1.40ea.2.50ea.1.60ea.

2.80Ba.

3.60ea.1.50ea.I.SOea.

1.75ea.

4.20o».6.00ea.

2.25oo.

5.50oa.9.40aa.2.40eo.2.60ea.

.9088.

OUANTITV

10-24pcs.

«1.40ea.

2.0088.

1.35aa.

2.1 568.

3.10ea.1.206a.2.25e».

1.3588.

2.60ea.

3.40oa.

1.3068.

1.65ea.

1.50oa.

4.00aa.5.75ea.2.00ea.

5.10aa.8.60ea.2.20oa.2.40ea.

2599pcs.

«I.SOea.

1.9000.

1.2068.

2.00oa.2.9068.

1.1508.

7.00a>.1.30ea.

2.40ea.

3.2068.I.IOoo.1.45oa.1.3508.

3.70aa.5.50ee.

1.75oa.

4.7 5ea.S.OOaa.2. OOaa.

2.1068.

.70eo.

14 pin16 pin

I.C. SOCKETS GOLD.WIWRAP 3 TURN

$0.40 aa.0.44 ee.

8080A PRIME.$6.00 ea.

EIA 8 CONDUCTOR CABLES 8ft. Long.CLASS #\ Typo Cables.

1. to 4 pes. $23.00

5 to 9 pes. 20..00

I.C. SOCKETS TIN.

14 pin16 pin

$0.15 ee.0.17 ea.

CONNECTORS FOR CENTRONICS 700 SERIES.Amphenol 57-30360

1 to 4 pes. $9.00 aa.

5 to 9 pes. 7.00 aa.

COOLING FANS.Extra Ouiet.

1 to 45 to 9

$18.00 ea.17.00 ea.

MAIL ORDERS TO:

TERMS: MINIMUM ORDER: $15.00 ADD $1.35 ForHandling & Shipping. Orders over $30.00 in the U.S.A.We Pay the Shipping. CALIF. RESIDENTS: Please Add6% Sales Tax.

NOTE: NO C.O.D. OR CREDIT CARD ORDERS WILL BEACCEPTED.

BECKIAN ENTERPRIES

P.O. BOX #3089SIMI VALLEY, CA 93063

BUILD YOUR OWN LOW COSTMICRO-COMPUTER

POWER SUPPLIES

FOR S-100 BUS, FLOPPY DISCS, ETC.

POWER TRANSFORMERS (with mounting brackets)

ITEMNO.

USED INKIT NO.

PRI. WINDINGTAPS

SECONDARY WINDING OUTPUTS2x8 Vac 2x14 Vac 2x24 Vac

SIZEW x D x H

UNITPRICE

T1T4

OV, 110V, 120VOV, 110V, 120VOV, 110V, 120VOV, 110V, 120V

2x7.5A

2X12.5A

2x9A

2x4A

2x2.5A2x3.5A2x2.5A

2x2.5A2x3A

3%"x35/b"x31/8"3%"x4%"x31/8"33/4"x4%"x31/8"3%"x35/a"x31/8"

21.9527.9529.9521.95

POWER SUPPLY KITS (open frame with base plate, 3 hrs. assy, time)

ITEM USED FOR @+8Vdc (5)-8 Vdc @ + 16Vdc (3-16 Vdc @ + 28 Vdc

SIZEWxDxH UNIT PRICE

KIT1 15 CARDS SOURCE 15A

KIT 2 SYSTEM SOURCE 25A

KIT 3 DISC SYSTEM 15A

KIT 4 DISC SOURCE 8A

1A1A

2.5A3A2A

2.5A3A2A

4A5A

12"x6"x4%"12"x6"x4%"14"x6"x4%"10"x6"x4%"

51.9558.9566.9549.95

EACH KIT INCLUDES: TRANSFORMER, CAPACITORS, RESIS., BRIDGE RECTIFIERS, FUSE & HOLDER, TERMINAL BLOCK BASEPLATE, MOUNTING PARTS AND INSTRUCTIONS.

DISC DRIVE POWER SUPPLY "R3" assy. & tested, open frame, size: 9" (W) x 5" (D) x 5" (H) 59.95

SPECS: +5V @ 5A REGULATED, -5V @ 1A REG., +24V @ 5A REG., SHORTS PROTECT.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.

MAIL ORDER:

P.O. BOX 4296

TORRANCE, CA 90510

SUNNY INTERNATIONAL

(TRANSFORMERS MANUFACTURER)Telephone: (213) 633-8327

STORE:

7245 E. ALONDRA BLVD.

PARAMOUNT, CA 90723

STORE HOURS: 9 AM-6 PM

264 BYTE January 1980

Circle 226 on inquiry card.

NEW PRODUCTS!Super ColorS-100 Video Kit$99.95 Elf II Adapter Kit $24.50

Expandable to 256 x 192 high resolution color -graphics. 6847 with all display modes computercontrolled. Memory mapped. 1K RAM expanda-ble to 6K. S-100 bus 1802, 8080, 8085, Z80 etc.

Gremlin Color Video Kit $59.95

32 x 16 alpha/numerics and graphics; up to 8colors with 6847 chip; 1K RAM at E000. Plugsinto Super Elf 44 pin bus. Not expandable to highresolution Graphics.

Plugs into Elf II providing Super Elf 44 and 50 pinbus plus S-100 bus expansion (With Super Ex-pansion). High and low address displays, stateand mode LED's optional S1B.00.

1802 16K Dynamic RAM Kit $149.00

1802/S-100 expandable to 32K, Hidden refreshw/clocksupto4 MHz w/no wait states Addl. 16KRAM $79.00.

Quest Super Basic

Quest, the leader in inexpensive 1802 systemsannounces another first. Quest is the first com-pany worldwide to ship a lull size Basic for 1802systems. A complete function Super Basic byRon Cenker including floating point capabilitywith scientific notation (number range ±.17E"),32 bit integer ±2 billion; Multi dim arrays; Stringarrays; String manipulation; Cassette I/O, Saveand load, Basic, Data and machine language pro-grams; and over 75 Statements, Functions andOperators.

Easily adaptable on most 1802 systems. Re-quires 12K RAM minimum for Basic and user

programs. Cassette version in stock now. ROMversions coming soon with exchange privilegeallowing some credit for cassette version.Super Basic on Cassette S40.00

Tom Pittman's 1802 Thy Basic Source listingnow available. Find out how Tom Pittman wroteTiny Basic and how to get the most out of It.Never offered before. $19.00

S-100 4-Slot Expansion $ 9.95

Super Monitor VI.I Source Listing S15.00Coming Soon: Assembler, Editor, Disassem-bler, DA/AD, Super Sound/Music, EPROM pro-grammer.

RCA Cosmac Super Elf Computer $106.95

Compare features before you decide to buy anyother computer. There is no other computer onthe market today that has all the desirable bene-fits of the Super Ell for so little money. The SuperElf is a small single board computer that doesmany big things, it is an excellent computer fortraining and for learning programming with itsmachine language and yet it is easily expandedwith additional memory, Full Basic, ASCIIKeyboards, video character generation, etc.Before you buy another small computer, see if itincludes Ihe following features: ROM monitor;State and Mode displays; Single step; Optionaladdress displays; Power Supply; Audio Amplifierand Speaker; Fully socketed for all IC's; Real costof in warranty repairs; Full documentation.The Super Elf includes a ROM monitor for pro-gram loading, editing and execution with SINGLESTEP for program debugging which is not in-cluded in others at the same price. With SINGLESTEP you can see the microprocessor chip opera-ting with the unique Quest address and data busdisplays before, during and after executing in-structions. Also, CPU mode and instruction cycleare decoded and displayed on 8 LED indicators.An RCA 1861 video graphics chip allows you toconnect toyour own TV with an inexpensive videomodulator to do graphics and games. There is aspeaker system included for writing your ownmusic or using many music programs alreadywritten. The speaker amplifier may also be usedto drive relays for control purposes.

A 24 key HEX keyboard includes 16 HEX keysplus load, reset, run, wait, Input, memory pro-tect, monitor select and single step. Large, onboard displays provide output and optional highand low address. There is a 44 pin standardconnector slot for PC cards and a 50 pin connec-tor slot for the Quest Super Expansion Board.Power supply and sockets for all IC's are in-cluded in the price plus a detailed 127 pg. instruc-tion manual which now includes over 40 pgs. ofsoftware info, including a series of lessons tohelp get you started and a music program andgraphics target game.

Many schools and universities are using theSuper Elf as a course of study. OEMs use it fortraining and research and development.Remember, other computers only offer Super Elffeatures at additional cost or not at all. Comparebefore you buy. Super Elf Kit $106.95, Highaddress option $8.95, Low address option$9.95. Custom Cabinet with drilled and labelledplexiglass front panel $24.95. Expansion Cabinetwith room for 4 S-100 boards $41.00. NiCadBattery Memory Saver Kit $6.95. All kits andoptions also completely assembled and tested.Questdata, a 12 page monthly software publica-tion for 1 802 computer users is available by sub-scription for $12.00 per year.Tiny Basic Cassette $10.00, on ROM $38.00,original Elf kit board $14.95. 1802 software;Moews Video Graphics $3.50. Games and MusicS3.00, Chip 8 Interpreter $5.50.

Super Expansion Board with Cassette Interface $89.95

This is truly an astounding value! This board hasbeen designed to allow you to decide how youwant it optioned. The Super Expansion Boardcomes with 4K of low power RAM fully address-able anywhere in 64K with built-in memory pro-tect and a cassette Interface. Provisions havebeen made for all other options on the sameboard and it fits neatly into the hardwood cabinetalongside the Super Ell. The board includes slotsfor up to 6K of EPROM (2708, 2758, 2716 or Tl2716) and is fully socketed. EPROM can be usedfor the monitor and Tiny Basic or other purposes.A IK Super ROM Monitor $19.95 is available asan on board option in 2708 EPROM which hasbeen preprogrammed with a program loader/editor and error checking multi file cassetteread/write software, (relocatible cassette file)another exclusive from Quest. It includes registersave and readout, block move capability andvideo graphics driver with blinking cursor. Breakpoints can be used with the register save featureto isolate program bugs quickly, then follow withsingle step. The Super Monitor is written with

subroutines allowing users to take advantage ofmonitor functions simply by calling them up.Improvements and revisions are easily done withthe monitor. If you have the Super ExpansionBoard and Super Monitor the monitor is up andrunning at the push of a button.Other on board options include Parallel Inputand Output Ports with lull handshake. Theyallow easy connection of an ASCI I keyboard to theinput port. RS 232 and 20 ma Current Loop forteletype or other device are on board and if youneed more memory there are two S-100 slots forstatic RAM or video boards. Also a 1K SuperMonitor version 2 with video driver for full capa-bility display with Tiny Basic and a video interlaceboard. Parallel I/O Ports $9.85, RS 232 $4.50,TTY 20 ma l/F $1.95, S-100 $4.50. A 50 pinconnector set with ribbon cable is available at$15.50 for easy connection between the SuperElf and the Super Expansion Board.Power Supply Kit for the complete system (seeMulti-volt Power Supply).

Same day shipment. First line parts onlyFactory tested. Guaranteed money back.Quality IC's and other components at fac-tory prices.

INTEGRATED CIRCUITS

740011174MN

7402N7404N7409N7410N74 UN7420N7422N7430117442N7445N744?N744BN745QN7474N747SN74B5N

LM323K-5 5.95

LM3ZQK-12 1,50

LM320K-15 1.50

LM320T-5 1.60

LM32QT-B 1.6D

LM320T-I2 1.50

LM320T-15 1.60

LM324N 1.15

LM339N 1.55

LM340K-5 1,35

LM340K-B 1.35

LM340K-12 1.35

LM340K-15 1.35

LM340K-24 1.35

LM340T-5 1.25

LM340T-8 1.25

LM340T-12 1.25

LM340T-15 1.25

LM340T-18 1.25

LM340T-24 125

LM343H 4.50

LM350

7.50

LM370

1.15

LM380N

1.00

LM381

1 60

LM3B2

1.60

LM703H

40

LM709H

.28

!.M7?:lM.N

.50

LM/.'nN

67

LM741CM

35

LM741N

LM747H'N

LM74BN

35

LM1303N

1.75

LMI304

1,10

LM1305

LM1307

2.00

LM1310

2.75

LM145B

47

LM2902

1.50

LM3900N

.60

LM3G05

NE550N

Ni5bcA

NE565A

NE566V

781.05

75491CN

.50

75492CN

MIS93N

71)

75494CN

7JLS95N

1 11)

7 ■; L S U) 7 N

AH

A 10 D CONVERT! •;

74LS112N

4>>

6038B

4,50

74LS1UU

as

B700CJ

13.95

7-1LS132N

RS

8701CN

22.00

74LS13GN

4,h

8750CJ

13.95

741.S151N

as

LD130

995

74LS1iJ5N

rift

!Vl!!'JCJV.T

7.40

74LS15/N

(ft

ICL7103

9.50

74l.Slb2N

1 I1!

ICL7107

14.25

74LS163N

1 1h

74LS174N

J ill!

CMOS

74LSI90N

1 llfi

CD34001 Fair. .50

741S221N

1 4S

CD4000

.16

74LS258N

H7

CD4001

.28

?4iS3ii7K

1.35

CD4002

.28

LINEAR

CA3045 .90

CA3046 1.10

CA3C81 1,80

CA30B2 1.90

CA3C89 2.95LM301AN/AH 35

LM305H .87

LM307N .35

LM308N B9

LM3D9K 1,50

LM311H/N .90

LM317T/K 3.75

LM3I8

1.35

LM320K-5 1.50

CD400GCD40O7CD4008CD4009CD4010CD4011CD4012CD4013CD4014CD4015CD4016CD4017CD4018CD4019CD4020

Box 4430X Santa Clara, CA 95054i^For will call only:(408) 988-1640km 2322 Walsh Ave. ^

ELECTRONICS

RESISTORS '. wall 5%10 per type 03 1000 per type .01225 pel type .025 350 piece pack100 per lype .015 5 per type 6.75

V? watt 5% per type .05KEYBOARDS

56 key ASCII keyboard kit S67.50Fully assembled 77.50

53 key ASCII keyboard kit 60.00

Fully assembled 70.00 Enclosure 14.95LESS

RedTOIB .15

Green, Yellow T018 .20

Jumbo Red .20

Green, Orange, Yellow Jumbo .25CllplllB LED Mounllnrj Clips B7$1.25(specify red. amber, green, yellow, clear)

CONTINENTAL SPECIALTIES In slockComplete line of breadboard lest equip.MAX-100 B digit Freq. Ctr. $128.95

S1B.0

SPECIAL PRODUCTS

MM5BG5 Stopwatcfi Timer 9.00PC board 7.50

Switches Mom. Pushbutton .27

3 pos slide 25

Encoder HD0165-5 6 95

3 Olgll UniversalCounlei Board KitOperates 5-18 Volt DC to 5 MHztyp. .125" LED display 10.50Paralrontci 1D0A LogicAnalyzer Kit 1224.00

Model 10 Trigger

Expander Kit $229.00

Mode! 150 Bus

Grabber KilSinclair 3V, Digit

Multimeter »on.sa

Clock Calendar KM S23.95

2.5 MHi Frequency Counter

Kll S37.50

30 MR: Frequency Counter

Kll (47.75

TRANSFORMERS6V 300 ma 3.25

12 Vol! 300 ma transformer 1,2512GVCI GOO ma 3 75

12V 250 ma wall plug 2.95

12V CT 250 ma wall plug 3.5024V CT 400 ma 3.95

10V 1.2 amp wall plug12V 6 amp12V 500 ma wall plug

S3G9 0

1295

I plug1 plug

G.5D8.50

12V 1 amp *12V 3 amp w

DISPLAY LEDS

MAN1 CA .270 290

MAN3 CC .125 .39

MAN72/74 CA'CA 300 1 00

01704 CC 300 1.25

DL707/OL707R CA 300 1.00

DL727/728 CA'CC 500 1.90

CA/CC .600 1.95

CC .600 1.95

CC 357 .70

CC/CA .500 1 35

CC'CA 500 .90

CC/CA .800 2.20

DL747/750

DL750

FND359

FND500..'507

FNO503/51O

FND800/8D7

3 digit Bubble

4 digit BubbleDGB FluorescemDG10 Fluorescent

5 digil 14 pin displayNSN69 9 digil display7520 Clairei photocellsTIL31I Hei

MAN3E40MAN461DMAN4640MAN4710MAN4740MAN6640HAN6710

MAN 6740

MA1O02AMA1012A102P3 l ran simmer

CC .30 1.10CA 40 1.20CC .40 1 20

ROCKWELL AIM 65 Computer

6502 based single board with full ASCII keyboardand 20 column thermal printer. 20 char, al-phanumeric display, ROM monitor, fully expand-able. $375.00. 4K version $450.00. 4K Assem-bler $85.00, 8K Basic Interpreter $100.00.

Special small power supply for AIM 65 assem. inframe $49.00. Complete AIM 65 in thin briefcasewith power supply $485.00. Molded plasticenclosure to fit AIM 65 plus power supply $47.50.

AIM 65/KIM/VIM/Super Elf 44 pin expansionboard; 3 female and 1 male bus. Board plus 3connectors $22.95.

AIM 65/KIM/VIM I/O Expansion Kit; 4 paralleland 2 serial ports plus 2 internal timers $39.00.PROM programmer for 2716 $150.00.

Multi-volt Computer Power Supply

8v5amp, ±18v .5 amp, 5v 1.5 amp, -5v.5 amp, 12v .5 amp, -12 option. ±5v, ±12vare regulated. Kit$29.95. Kit with punched frame$37.45, $4.00 shipping. Woodgrain case$10.00, $1.50 shipping.

PROM Eraser

Will erase 25 PROMs in 15 minutes. Ultra-violet, assembled $37.50

60 Hz Crystal Time Base Kit $4.40

Converts digital clocks from AC line frequencyto crystal time base. Outstanding accuracy.

79IC Update Master Manual $35.00

Complete IC data selector, 2500 pg. master refer-ence guide. Over 50,000 cross references. Freeupdate service through 1979. Domestic postage$3.50. No foreign orders.

Not a Cheap Clock Kit $14.95

Includes everything except case. 2-PC boards.6-.50" LED Displays. 5314 clock chip, trans-former, all components and full instructions.Orange displays also avail. Same kit w/.80"displays. Red only. $21.95. Case $11.75

NiCad Battery Fixer/Charger Kit

Opens shorted cells that won't hold a chargeand then charges them up, all in one kit w/fullparts and instructions. $7.25

S-100 Computer Boards

8K Static RAM Kit $135.00

16K Static RAM Kit 265.00

24K Static RAM Kit 423.00

32K Static RAM Kit 475.00

16K Dynamic RAM Kit 199.00

32K Dynamic RAM Kit 310.00

64K Dynamic RAM Kit 470.00

8K/16KEprom Kit (less PROMS) $89.00

Video Interface Kit $129.00Motherboard $39. Extender Board $8.99

Video Modulator Kit $8.95

Convert your TV set into a high quality monitorwithout affecting normal usage. Complete kitwith full instructions.

Digital Temp. Meter Kit $34.00

Indoor and outdoor. Switches back and forth.Beautiful. 50" LED readouts. Nothing like itavailable. Needs no additional parts for com-plete, full operation. Will measure -100° to+ 200°F, tenths of a degree, air or liquid.Beautiful woodgrain case w/bezel $11.75

TERMS: SS.OOmin. order U.S. Funds. Calif residents add 6%tax.BankAmericard and Master Charge accepted.Shipping charges will be added on charge cards.

FREE: Send for your copy of our NEW 1979QUEST CATALOG. Include 28c stamp.

Circle 227 on inquiry card.

BYTE January 1980 265

Circle 228 on inquiry card.

The IMEVTRANS1000

A completely refurbishedIBM Selectric Terminal with

built-in ASCII Interface. **

-1|

Features:

$1495

300 Baud

14.9 characters per second

printout

Reliable heavy duty Selectric

mechanism

RS-232C Interface

Documentation included

60 day warranty-parts and

labor

High quality Selectric printing

Off-line use as typewriter

Optional tractor feed available

15 inch carriage width

HOW TO ORDER f

DATA-TRANS 1000

1. We accept Visa, Master »Charge. Make cashiers checks orpersonal check payable to:

DATA-TRANS

2. All orders are shippedF.O.B. San Jose, CA

3. Deliveries are immediate

For orders and information

DATA-TRANS

2154 OToole St.

UnitE

San Jose, CA 95131

Phone: (408) 263-9246

SERIAL I/O

Four Serial I/O RS-232 ports, S-1Q0Bus. Software orjumper selectablebaud rates (110, 300,600, 1200, 2400,4800, 9600. 19.2K).on board Xtal baudrate generator, Ad-dressing, switchselectable, Parity orno parity [odd or even]switch selectable. 1 or2 stop bits, 5 to 8bits/character Boardonly $29,95. Part No.7908. With parts (kit)$199.95, Part No.7908A.

MICRO-PROCESSORINTERFACINGTECHNIQUES

Microprocessor in-terfacing is no longeran art. It is a set oftechniques, and insome cases just a setof components. Thiscomprehensive bookintroduces the basicinterfacing conceptsand techniques, thenpresents in detail theimplementation de-tails, from hardwareto software. It coversall the essential per-ipherals, from key-board to floppy disk,as well as the stan-dard buses (S100 toIEEE 488) and intro-duces the basic trou-bleshooting tech-niques. [2nd Ex-panded Edition], ByAustin Lesea and R.Zaks. Ref. C207SYBEX. $11.95

PROGRAMMINGTHE 6502

PROGRAMMINGTHEZ80

PROGRAMMINGTHE 8080*It covers all essentialaspects of program-ming, as well as theadvantages and dis-advantages of the6502 and shouldbring the reader tothe point where hecan start writingcomplete applicationsprograms. For thereader who wishesmore, a companionvolume is available:The 6502 Applica-tions Book. By R.Zaks. 6502: Ref.C202; Z80: Ref.C280; 8080: Ref.C208. SYBEX. Each$10.95

44 BUS MOTHERBOARD

Has provisions for ten44 pin (.156) connec-tors, spaced 3/4 of aninch apart. Pin 20 isconnected to X, and22 is connected to Zfor power and ground.All the other pins areconnected in parallel.This board also hasprovisions for bypasscapacitors. Boardcost $15.00 Part No.102. Connectors

$3.00 each Part No.44WP.

■#

V

GAME PADDLES

& SOUNDFor Your TRS 80(Level II or Disk)

Includes: 2 game pad-dles, interface, soft-ware, speaker, powersupply, full documen-tation including: sche-matics, theory ofoperation, and userguide: plus 2 games oncassette (Pong andStarshipWar). $79.95Complete Part No.7922C

LEEDEXMONITOR

^Ji

12" Black and White-12 MHz Bandwidth• Handsome PlasticCase-$139.00

DIGITALCASSETTE

5 min. each side. Boxof 10 $9.95.

Tq OrHpr ■ Mention part no. description, and price. In USA shipping paid by us for orders accompanied by check or money order.We accept C.O.D. orders in the U. S. only, or a VISA or Master Charge no., expiration date, signature, phone no.,shipping charges will be added. CA residents add 6.5% for tax. Outside USA add 10% for air mail postage and han-dling. Payment must be in U. S. dollars. Dealer inquiries invited. 24 hour order line (408] 448-0800

Send for FREE Catalog ... a big self-addressed envelope with 41* postage gets it fastest!

ELECTRONIC SYSTEMS Dept B P °- Box 21638,San Jose. CAUSA 95151

266 BYTE January 1980

Circle 208 on inquiry card.

10-DAY FREE TRIAL

Send for ourFREE Catalog

$100 FREE ACCESSORIESWITH 16K or 32K PET

FREE

8K-Keyboard N $795

16K-Keyboard B $995

16K-Keyboard N $995

32K-Keyb>oard C 1,295

32K-Keyboard B $1,295

32K-Keyboard N $1,295

C —calculator keyboard (only version with tape deck)B— large keyboard (graphics not on keys)N — large keyboard with graphics symbols

When you buy a 16K or 32K PET, apply $100 toward PETaccessories, FREE. Just indicate on your order that you haveeduced the cost of your accessories by $100.

Terminal Package with 8K PETs

See Special Below

PET ACCESSORIES

Commodore Dual Floppy Disk Drive $1.100

Computhink BOOK Disk Drive SI.295

Commodore Printer (tractor feed) $849

Commodore Printer (friction feed) $995.00

Second Cassette- from Commodore $95.00

Commodore PET Service Kit $30.00

Beeper-Tells when tape is loaded $24,95

Petunia-Play music from PET $29.95

Video Buffer-Attach another CRT $29 95

Combo-Petunia and Video Buffer $49 95

New Serial Printer Interface for PET $79.95

KIM 1 (A Single Board Computer

from Commodore) $179.00

Hazeltine140(

Immediate Delivery —\2-Year Factory Warranty

Sti95 COMMODORE** DISK DRIVES

Reg. $1,295 Sale $1,100

apple II

1 ■ p/vs

1200 FR€€ flCC€SSORI€S

I The new Apple II with Applesoft BASIC built-in! Elimi-I nates the need for a $200 Firmware Card and includes II new Autostart ROM for easy operation. This combined I

with the FREE accessories from NCE could save you up I

to $400 on a 48K Apple II system!

PET OWNERS ...

REMOTETERMINAL

for

onlyS&ftl

A self-containedmodule and programcassette enables yourPET to function as a300 baud terminal,Supports Upper/Lowercase, Rubout, Escape& all control functions.Output is TTL,

SHI

16KApplellPlus-32KApplellPlus-48K Apple II Plus-

Si 195 (take S100 in free accessories)$1345 (take $150 in free accessories)■ $1495 (take $200 in free accessories)

Hfc\N

I Apple II Accessories

I General Business $625

I PASCAL $495

llnteger BASIC ROM Card $200

IviSI-Calc $99

(Centronics Printer Interface $225

iDisk and Controller $595

■ Parallel Printer Card $180

ICommunications Card $225

|Hi-Speed Serial Card $195

iFirmware Card $200.

IN STOCK NOW!

EVERY ITEM IN THIS ADVERTISEMENT IS IN STOCKAND READY TO SHIP, EXCEPT WHERE NOTED.

PAPER TIGER 440SPE

The Graphics Printerfor Appie //

Now you can print illustrations, block letters, charts,graphs, and more—all under software control. Andwith the expanded buffer, the Paper Tiger can hold thetext from an entire 24-line-by-80-column CRT screen.

$1194.00

NCE/CompuMarts^

DEPT. BY10,

270 THIRD ST.. CAMBRIDGE. MA 02142To Order: 1(800)343-5504

In Mass: 1(617)491-2700

3 Member:

Computer DealersAssociation

from Heath Data SystemsThe All-ln-One Computer

Dual Z-80 Processors- Built-in 102K Floppy Disk- 16Kto 48K RAM • 25 x 80 Character Display • Upper/LowerCase and Line Graphics * 80 Character Keyboard withKeypad • 8 User-definable Keys • Two BASIC'S andAuto-Scribe Word Processing available • Can supportCP/M

Heath's third generation of computers is a compact,hi-style desktop unit which includes a complete termi-nal, a computer and a disk All-ln-One! System includesBootstrap in ROM, other programs available separately,HDOS operating system includes Heath's BASIC, an as-sembler and text editor along with important diskutilities. Microsoft language requires HDOS.

WH89 with 16K RAM $2,295

WH89 with 32K RAM $2,445

WH89 with 48K RAM $2,595

WH17 Second Disk Drive $550

Dual-port Serial Interface $85

HDOS Operating System $100

Microsoft BASIC $100

Word Processing $395

SINCE1971

LIST

SALE

$649

Hazeltine 1410 — $835Hazeltine 1500 — $1069

Hazeltine 1510-Hazeltlne 1520-

$1195$1499

New 300 baudOriginate/AnswerAcoustic CouplerLooks good, worksgreat <£-t ft Q

priced at S» IO«»

Lear Siegler's ADM-3A

Back Again at Our Lowest Price Ever

The ADM-3A is industry's favorite dumb terminal forsome very smart reasons:

• 12 in. diagonal screen

• Full or half duplex operation at 11 selectable datarates

• 1920 easy-to-read characters in 24 rows of 80 letters

• Typewriter-style keyboard

• RS-232 C interface extension port

• Direct cursor addressing

Our Low Sale Price $795

£$> ZENITH COLORVIDEO MONITOR.

Zenith's first color video displaydesigned specifically for computers.

This 13-inch monitor is Zenith's first color video display]designed specifically for computers. Features includeautomatic color level, color processing and degaussing Icircuits.

Zenith Color Monitor $499.001

<**

&

Just Released

Compumart's NewFall/Winter 1979 Catalog.

We've just published our catalog and its packed withnew products and money saving specials. Ourillustrated 32-page book features microcomputers andmicrocomputer systems from Apple. Commodore PET.Heath, and Exidy Sorcerer. Also covered are theCommodore's KIM and Rockwell's AIM A broadselection of terminals, books, software and peripheralsare presented in detail. The text is thorough andprovides a wealth of technical information. To get yourFREE copy write to our address below. Please includethe dept. number to speed handling.

CENTRONICS 779-2 PRINTER

SALE PRICE $1095Form thickness control |Horizontal and verticalform positioningUsed with controller(Apple generalbusiness software)

TRACTOR FEED

Parallel interfaceContinuous variableprinting density 80-132characters per line5x7 dot matrix

SANYO MONITOR$169 $279

9-Inch -ftHQ_ 15-Inch frtgO,

e

IMPORTANT ORDERING INFORMATION

All orders must Include 4% shipping and handling. Mass. residents add 5% sales tax; Mich.

residents 4%, for sales tax.

VISA

Phones open from 8:30 a.m. to 5:30 p.m. EST Mon.-Frl. • P.O.'s accepted from D&B ratedcompanies — shipment contingent upon receipt of signed purchase order • Sorry no C.O.D.s •All prices are subject to change without notice • Most Items In stock lor Immediate shipment —call tor delivery quotation • In the Ann Arbor area? Our retail store Is open 11:00 a.m. to 7:00 p.Tues.-Fri., 10:00 a.m. to 5:00 pm. Saturdays (closed Sun. and Mon.)

If not satisfied, return your purchase with-in 10 days for fullrefund of purchase price!

Circle 230 on inquiry card.

BYTE January 1980 267

APPLE II PLUS**

(limited offer) ^.__ _ __16Konly $990.00

Disk I 475.00

Disk II w/Controller 575.00

Pascal Card 475.00

Parallel Printer Card .... 165.00Communications Card.. .210.00Business Software Pkg.... 625.0010 Megabyte Hard Disk... 695.00D.C. Hayes Modem 349.95

Firmware Card 175.00

Proto Card 22.00

M & R Modulator 29.95

Sanyo Cassette 54.96

16K Upgrade Kit 74.95

Apple Radio Car 159.00

8" Floppy Controller.... 350.00Heurislics Speechlab... 179.95

TRS-80/APPLE

MEMORY EXPANSION KITS

4116's

16K (200/250 ns.)

8 pes. for $74.95w/instructions & jumpers.

HICKOKLX303

$74.95

Z80StarterKit$249

A CompleteMicrocomputeron a Board

• Z80 Central Processing Unit with 158Instructions.

• On-Board Keyboard and Display.

• Kansas City Standard Cassette Interface.

• PROM Programmer Built on-board.*■ Expansion provision for two S-100

Connectors.+ Wire Wrap area for custom circuitry.

VDB-8024

Video Display Board

$319 KIT

With On-Board Z80 Microprocessor

* Full 80 Characters by 24 lines display.

* Characters displayed by High Resolution7x10 Matrix.

* Keyboard Power and Interface.*■ Composite Video Output.

* Separate TTL Level Synchronization and VideoOutputs.

* 2K Bytes Independent On-Board Memory.

* On-Board Z80 Microprocessor.

* Glich Free Display.

.5%, 31/z digit 19

Range DVM, W LCD displays

runs 200 hrs on 1 battery. 10 Meg

Ohm Input. 1 yr. guarantee,, made in

U.S.A., test leads included.

Available Accessories

RC-3 115V AC Adapter $7.50

CC-3 Deluxe Padded Vinyl Carrying Case .... $7.50VP-10 X10 DCV Probe Adapter/

Protector 10 Kv $14.95

VP-40 40 Kv DC Probe $35.00

CS-1 10 Amp Current Shunt $14.95

SOL-20

WITHCP/M

We are proud to offerthe SOL-20 with a dualfloppy subsystem all operating underCP/M. Now you can use the SOL-20 and takeadvantage of the unlimited CP/M based soft-ware that is available.

A. MINI-DISKSYSTEM

INCLUDES:

• SOL-20 W/32K

• VISTA V-200 controller

• (2) double density drives

• CP/M w/documentation

• Assembled & tested

$2995.00

B. STANDARD

FLOPPY SYSTEM

INCLUOES:

• SOL-20 W/24K

• VISTA controller

• (2) 8" disk drives

• CP/M w/documentation

• Assembled & tested

$3295.00

SOL nKRA (expandable to 65K) RAMboards. Assembled and socketed w/omemory, data delay and proms.Only S139.95

Sol-20 Keyboards Only $139.95

ADVANCED

COMPUTERPRODUCTS

FLOPPY DISK DRIVES

PERSCI Model 277 Dual.... 1195.001

MPI B51-5V." 40tracks 279.00 WANGO/SIEMENS 5'V Drire. 290.001

Shugarl SA400-5V.35 Iracks.295.00 MPI B52 5V<" Dual 395.001

Siemens/GSI FDD120-8 8".. .375.00 WANG07SIEMENS 282 Dual 5V."Shugart 800/801 R 8" 495.00 395.001

KIM-1Now only$179.00

irk Power Supply

Add $59.95

** Cassette Recorder

Add $44.95

*• Sanyo 9" Monitor

Add $169.00

Add enclosure $29.95.

AIM 65

$375.00

* On Board 20 columnalphanumeric printer

w/IK RAM $375.00

w/4K RAM $450.00

Assembler ROM ... Add $85.00BASIC IN ROM...Add $100.00

Power Supply Add $69.95

Enclosure Add $49.95

SYM-1 IN STOCK

Reg. $269.00

Now$219.00

* KIM-1 Compatible

* 4K ROM Monitor

* lKflyles2114 RAM'

* 65K Memory Exoarision

* User EPROM 2716

* * Power Supply Add S59-95

* * Cassette Recorder Add S44.95

** Sanyo 9M Monitor Add SI69.95

SYM Enclosure $39.95

School i gioup discounts available.

Buy now and receive 5100.00 worth ol

* SRM-1 IKStat*: RAM e«p..

reg. S-J2.00 disc 132.00

* PEX-1 I/O Port.

reg. 16*00 disc. $50.00

* SYM BAS-1 Basic ROM (Microsoltl,reg. $159.00 disc. $109.00

* KTM-2 CRT/TV Keyboard,

reg. $34800 disc.$319.00

EXIDY SORCERER only $799.00

$799 w/8K$1099 w/16K$1249 w/32K$1449 w/48K

User programmable or use cartridges.Combines the desirable leaturesonhePET. APPLE and TRS-80 into a com-plete expandable computer system.

*# I/O expansion kit 5149.00

* # Vista V-200 add-on mini-floppy for Exidy. (requires exp.module) w/CPM S699.00

#*■ New Word Processing Pac

S99.00

* INCLUDES:Keyboard & enclosure90 day WarrantyMICROSOFT BASICVideo & Casseite CableComplete Documentation** S100 Expansion

Module AddS299.00

** Casseite recorder

AddS-44.95

** Sanyo 9" Monilor

Add $169.95

-i -*i M. M SALE $100.00 OFF.. . and it's COLOR

"The Compucolor II"

... a personal cotorgraphics system for the modern computer man ...

* Color Graphics 13" Color CRT

* Proven 8080A CPU System

* 16K Extended Disk Basic

* Up to 117* Key Keyboard

* Upto32K- RAM

* Minidisk Drive 51.2K Bytes/Side

Model 3 w/8K, 72 Key Keyboard, RS232 . TAKE ■■■|$1495.00Model 4 w/16K. 72 Key Keyboard, RS232 sioonn ...{$1695.00Model 5 W/32K, 72 Key Keyboard, RS232 VJSe ..($2295.00

Options: 101 Key Keyboard Add S 150.00

117 Key Keyboard Add $225.00

Formatted Diskettes 2/S19.95

Programmed Diskettes S19.95

Diskette Library Inc. Hangman, Othello, Math, Chess, Stamek.Blackjack, Cubic Tic Tac Toe, Finance Vol. I, Finance Vol. II, Bonds andSecurities, Assembler. Text Editor, Personal Data Base.

Tl 99/4

Finally! We've heard so much about it and we areproud to offer:

• Color • Up to 72K • 16 Color Graphics • Music •Sound • Solid State Software

LIMITED QTY

$1150.00

SBC-100

2-80 based singleboardcomputer by SD Systems

* 1K RAM

* RS232 port

* 4 channel counter/timer

Kit S239.00

Assembled $369.00

TK80A

8080A

* Monilor ROM

* DMA Display

* 25 Key Keyboard

* Cassette I/O

$299.00

RCACOSMACVIP

NEW LOW PRICE $249.00

Assembled. Regular price S299.95

w/Sanyo 9" Monitor S169.95

268 BYTE January 1980

Circle 231 on inquiry card.

^-/Iadwvnced^^> z>-computer

THE FIRST TO OFFER PRIME PRODUCTS TO THE HOBBYISTAT FAIR PRICES NOW LOWERS PRICES EVEN FURTHER!

1. Pl"OV©n QUdilty Factory tested products only, no re-testsor fallouts. Guaranteed money back. We stand behind our products.

1979 CATALOG NOW AVAILABLE.

Send $1.00 for your copy of the most complete catalog of computer products. A must

STATICX /RAM BOARDS.

1W>-..

tfwif*

S-10O 32K (uses 2114)ASSEMBLED Kit " \'h

450ns. 599.00 450ns. 539.95

250ns. 699.95 250ns. 599.95

Bare Board 49.95Bare Board w/a!l parts less mem. 99.95

jm

RAM 65 (16K Static w/Memory

Management)

2 MHz $379.00 4 MHz $399.00

RM 16 (16K Static w/Bank Select)

2 MHz $299.00 4 MHz $329.00

(16K Assembled & Tested Using Low Power

2114's)

fm . jttjw

LOGOS I8K

ASSEMBLED

450 ns. 149.95 KIT 450ns. 125.95

250ns. 169.95 250ns. 149.95

Bare PC Board w/Data $21.95

■'Special Offer" Buy (4) 8K 450ns. Kits $11 7.00

TRS-80 ADD-ON DISK

• VISTA V-80 MINIDISK

* 23% More StorageCapacity-40Tracks

* 40 track patch nowavail.

* Up to 8 Times Faster2 Drive Cable Add $29:954 Drive Cable Add $39.95

(395.00)

S-100 ADD-ON MINI-DISK

* VISTA V-200 MinifloppySystem

* 204K Byte Capacity

* Double Density Drive

* CP/M & Basic "E"

* Double Density Controller

* Case and Power Supply

* Assembled & Tested Ready to Plug In

* EXIDY, HORIZON, SOL, etc. Compatible

S-100 ADD-ON DISKSUBSYSTEM /v-iooo\

* VISTA V-1000 Floppy Disk (1 699.00)Subsystem \~ ~y

* (2)Shugart8"DiskDrives ^—"^•k Case with Fan & Power Supply

* VISTA Floppy Disk Controller Card

* CP/M Disk Operating System

* Fully Factory Assembled & Tested

LOW-COST ADD-ON DISKSUBSYSTEM KIT

* (2) Siemens 8" Drives

* VISTA Floppy ControllerCard

* Power Supply and Inter-

* CP/M Disk Operating System

* Box of 10 Diskettes

IMS STATIC RAM BOARDS #&

* Memory Mapping * Low Power ft*

* Phantom * Assembled & testedRecommended by Alphamicrosystems

250 ns_ 450 ns.

8K Sialic $209.00 $189.00

16K Static S449.00 S399.00

32K Static $799.00 $699.00

ANADEX PRINTER

Model DP-8000 compact, impact, parallel or/^HMyM serial. Sprocket feed. 80 cols,LJ9^M^^b 84 lmes/min., bi-directional.^^^^^T New only $895.00

FLOPPY DISKETTES Q>jJ

• 5'A" Minidiskettes * o9^oSoftsector, 10 Sector, 16 Sector rwrf|$4.25 Each. 10/39.95 riO^&V

* 8" Standard Floppy Disks • jfeffcSoft Sector, Hard Sector vw$4.50 Eachi 10/41.85

•Add 4.95 for 10 Pack in Deluxe Disk Holdei

MOTOROLA EXORCISER COMPATIBLE

9600 MPU Module w/6802 CPU S495.00

9601 16 Slot Mother Board 175.00

9602 Card Cagefl9" Retma Rack Mount) ... 75.00

9603 8 Slot Mother Board 100.00

9604 Switchmode System PowerSupply.... 250.00

9610 Utility Prototyping Board 36.00

9616 Quad 8K Eprom Module '"

9620 16 Channel Parallet I/O Module.... 295.009622 Serial/Parallel I/O Combo ***

9626 8K Static RAM Module 295.00

9627 16K Sialic 450ns 495.00

9630 Card Extender 68.00

9640 Multiple Programmable Timer

(24 Timers) 395.00

9650 8 Channel Duplex Serial I/O 395.00

96103 32/32 I/O Module 275.00

96702 32 Point Reed Relay Module 350.00

0800 BARE BOARDS

9620-0 S45.00 9603-0 27.00

9626-0 45.00 9600 55.00

9650-0 45.00 96103 55.00

9601 -0 50.00 96702 55.00

Also AMI EVK System in Stock

APPLE/EXIDY/EXPANDOTRS 80 16K-UPGRADE KIT

* 16K with Jumpers & Instructions

for either Level I or Level II $74.95

+ 16K for Apple II Upgrade $74.95

* Special: TRS80 Schematic $ 4.95

* Expansion Interface Schematic .. $ 4.95-*- Expansion Interface Connector... 7.95

* Bank Selectable • Uses 4116 200 ns.

* Write Protect * Power 8VDC. ± 16VDC

* Phantom * Lowest Cost/BitExpando64Kit(411b)

16K $248.95 48K S469.0032K $369.00 64K $565.00

FROM INTEGRAL DATA SYSTEMS

MODEL 440 "THE PAPER

9.5" adjustable tractor TIGER1

feed, parallel & serial I/O,

132 columns, software

selectable character size,

110,300, 600,1200 baud, to 1 98 cps.. $995.00

Graphics option w/2K buffer add $199.00

TASA touch activated solidstate KEYBOARD

• Full 128 position 8-bitASCII

3 color code, 55positionsImmune to static charge

• Low power

Only.. 89.05 Optional stand 15.00

UV "Eprom" Eraser

Model UV3-11E $69.95

Holds 4 Eprom's at a time.

Backed by 45 years

experience.

Model S-52T... $265.00

Professional Industrial Model

TARBELL FLOPPY INTERFACE

* Z8078080 S 100 Compatible * Uses ukm

Assembled for Shugarl SALE S25Q.95

Assembled Other Drives $269.95

Kit S179.95

Bare Board S36.95(Doc. Add $10.00)

Note: For CPM Add (70.00. Documentation Add S20 00

Vista Double Density5".."Controller Assem S299.00

SD Versa Floppy Kit 5159.95

SD Versa Floppy Assembled $1 89.95

Tarbel Cassette I/O Kit S115.00

Sale * 1771-01 Floppy Chip S27.95

ViSTA Floppy Controller 8" (Shugart Comp.)... 5259.95

NEW CENTRONICS 730 PRINTER

^rr^-x Uses any paper roll, fanfold,s WOW >. Singie sheets, 96 characterl$945.0CV ASCII, 7 x 7 dot matrix, 50\_____^' CPS, RS232 or parallel I/O

Z-80/Z-80A/8080 CPU BOARD

+ On board 2708 * 2708 included (450ns.)-*■ Power on jump # completely socketed

• Z-80 Assembled and Tested S185.00

• Z-80 Kit S1 29.95

• Z-80 Bare PC Board S 34.95

• For 4MHz Speed Add S15.00

8080AKit S 99.95

8080A Assembled S149.95

S-100 MOTHERBOARD SPECIAL

8 slot expandable w/9 conn.

reg S69.95 . NOW $52.95

SIEMEN'S FLOPPY SALE^

• Special buy whilesupply lasts.

• 8" Drive with Double-Density

• 90 Day Warranty $350.00

ACOUSTIC MODEM

NOVATION CAT™

0-300 Baud

Bell 103

Answer, Originate $189.00

ACOUSTIC COUPLER SPECIAL

AJ MODEL A30SPECIAL PURCHASEOF SURPLUS UNITSAVAILABILITY LIMITED $29.95

DATA BOOKS • COMPUTER BOOKS

1979 ICMaslor 49 95 Intel MCS 60 Manual. . .7.95

NSCTTL Dat.i 3.95 Intel MCS 40 Manual 4.95

NSC Linear 4 95 AMD 8080A Manual 5.95

NSC Linear ":-.[> Notes I 3.95 AMD Schottky Databook . 4.95

NSCCMOS 3.95 AMI MOS/LSI Data.. 3.95

NSCMemo-Y 395 Gl MOS/LSI Data 4.95

Intel Dalabih> 4.95 Harris Analog Databook 4 95

Intel MCS 85 ManuB' 7.50 Tl Linear Control Data.. .3.95SALE • OSBORNE BOOKS ■ SALE

s Vol C

FU«. Sal*■ftfiO 7.75ffSQ 7.759-SO 7 75(3*50, 7.758""SQ 7.753T*00 27.50.5050

BOBOA Programmer]

6800 Programming

Z80 Programming

Vol. II Some Real M::: coprocessors w/9 n.

Vol. Ill Same Real Support Dc

Intro to Micros Vol Mi

SALE • DIUTHIUM COMPUTER BOOKS

Understanding Computers

8080Microcompuler E«De»n-en!s

Beginning BASIC ....

Beginners Glossary & Guide

Peanut Butler a Jelly G. JC toCcmOuivrs

8080 Machine Language Programming

Home Compulers Vol I MaiO*srt> T-9* f

Home Compulers Vol M Software '-S^i I

Stars! "

■ SALE

■»**.

1^96. I^-96.(Mi.

T-9*.

your copyfor the serious computer u;MICROPROCESSORS

Z8000

Z-80

z-aoA

F-B I3B50I

2650

CD 1802

B080A

B060A-4MHZ

SALE 8085

8003-1

2901

169516 951895

12.95

2901 A

TMS 9900JL

CP1600

6502

6502A

IM610O

6800

6802P803587558748

6809 SCALL

8086 SCALL

SUPPORT DEVICES

19.9529.9513.95

24.9519.95

A 951 1-1 300 n.

3881 IZ80 PIO)3881-4 i4MH;l

3882 [Z-BO CTCl3882-4 (4MHzi

3883 SIO

3884 DMA 49.95

820S74S13B Decode' 2 95

821!

it I/O

8216 Bus Driver322-1 CHx* Gen6224-4 i4MHt)

B226 Bus Drivei

BT26 BuS Dnver .. .822B Sys Control

823(1 Sy, Conl

8251 Prog I/O

8253 Ini Timer

8255 Prog I/O

6257 I-i;x( DMA

B259 Prog Int

8275 CRT Conlroller

8279 Prog Keyboard

6810-1 128 >8 RAM

6820 PIA

6B21 PIA

G828 Pr.nnly Ini

6834-1 512 i 8 Eprom

6850 ACIA

6852 Si.."i;il Adapter

6845.'HD46505CRTC->"!'

6860 Mortem

6962 Modulator

6871 A 1 CMHi OSC

6875

6860 Bur. Driver

MC68488

1821 SCD IK RAM

1822 SOD 256' 4 RAM1324 CD 32 « 8 RAM1852 CD 8 tin I/O

1854 Uart

1856 CD I/O

1857 CD I/O6520 PIA6522 Mult6530-002ii53D-0'.),i6530-0046530-005

DYNAMIC RAMS

416/4116 16K (16 Pin).. .." Df 8 41"

2 50

2 959 75

3 952 395.956.256.95

19.505.95

12.955.955.95

39.95

239. 19.9525 0016 959 9510.95.. 10.95

9.2515 5015.5015 50

4115 8KI

6 Pin)..

.6.95

1 118 Pi

1 (22 Pi

4060 1K.

)

.4.95

4096 4 K ,

1 (16 Pr

2104 4Ki

1 116 Pi

)

..4.75

1 (16 Pi1.95

5261

1103...

..1.95

5262

1.95

4008L .

.4.95

5270

5260 495

5290_... 12.45

PROMS

3 (5V, 1

■1612 if

14V)

AY51014

AY51015A/18G3I5V1 6 95

-MS 601 1 [5V, 12Vt 5 50

IM64Q2 7.95

IM6403 8.95

2350 USFi! 9.95

167 IB Astros 24 95

SALETR1472B S.S5

BAUD RATE GEN

4702 14 95

WD 1941 9 95

KEYBOARD ENCODERS

AY5-2376 13 75

AY5-3600 13 75

HD0165 9.95

74C922 9.95

74C923. 9.95

A/D CONVERTERS

6700 8 b.l Binary8701 lOuil Binary.8703 8 till TS'MOO Vdll lnRcq. Conv8750 3-1/2 Diflll BCD1408L6 6bil140BLBBIHIDACOI A/0

. 135022.0C. 13.507 2513 953955.955.95

puter products.;STATIC RAM HEADQUARTERS SOCKETS

21L02 450n;21L02 250n =2102

2114L-250ns

211.

.-300n<

3 752 952.9012 95

2114L-430ni. 7 50

4044/4041 300ns. 9.954044/4041 430ns. 7.50EMM4200A 9 75

EMM4402 7 95

EMM4804 12.50

5101C-E 7 95

up:J4IO[4200> '095

AMD9M0.M1 1095

AMD9130/J1 1295

FSC 460.46*116K CCDGnl, •1131 195

P2125/93426 145 ns l 7 956508 IK > I CMOS 7 956518 IK « 1 CMOS 7 9574S189 64 oil flam 3 958155 l/Ow/Ram 21.952147LowPower4KStaln: 14

7.956.758.756.75

1.103.552652.559.956.454.73

CHARGE COUPLED DEVICES

I6KCCD -First time offered Fairchild460CCD16K Memory (now you can cxperimenl with CCD

lion note suiiplu.-tl wKM i.Mfii ."dor Quantity limned

$18.95 each (reg. 43.00)

CRYSTALS

Microprocessor Timobases TV Cam*

Frequency Price Frequency Pr

4 0MH*

■l I943Q4MI

J'HSIIMH.

43MH,

5 95

5 95

DISPLAYS/OPTO/LED'S

* 7 SEGMENT * CALC * CLOCKS *

DL 704 (CC), DL 707 iCA) 300 HpiI 99

FND 357 (CC) .357 Run 99

FND 500/503 (CC] 500" Red 99

FND507/510(CA 503 Red 99

FND BOG/803 (CO SCO- Red... .1.75

FND8O7/810(C-V i.'CORed.. I 75

XAN 3062 .500" Greer : 15

HP50B2-7731 (CA) .• 30" Red 19

9 Dio.il Bubble M -i Cilu Display 39

9Digil Panaplen Dim-;iy 400" 99

9 Digit Fluorescent 300" 99

MAI003 1 2V Auro Clock Moc. e 13.95

Bezel for MA1003 w Rod Fi'ior 4 T5

MA 10-32A LED i?f, Clock Module 1095

* HEX DISPLAYS * ENCODED DISPLAYS *

HP 5082-7340 Red Hoioocimal . .1595

HP 5082-7300 Rftd Mymerlc 14 95

TIL305 695

TIL 306 Numeric w.'lorjc . ....TIL 308 Number w/logleTIL 309 Number w/LogiC

22 Pin ST 35

TEXTOOL ZEROINSERTION FORCESOCKETS

CONNECTORS

;!.',-.1.1 WAV. S/T. KIM ..■13/86 WAV, S/T. MOT50/100 S-100 Cdnnector50/100 S-100 Connector

S650

... 2 95

. .6 50

4 25

CTS DIPSWITCHES

CTS206-4 SI 75 CTS206-8 SI £

cisixiiv::. si /:■ crs206-;i n ■cii^ce-o si /*j cih?06-'ii •■■

CTS206-7 SI 75

NAKED PC BOARDSALE

Z-80 CPU (Ithaca) S34 95

8060ACPU ..34 95

8K Sialic RAM (Logos) 21 95

16K Static RAM (2114). .32K Sialic RAM (2114).Floppy I/O (Tarbelll .Casselle I/O (Tarbelll8K epiom(270BI1702 Eprom Board2708/2716 Eprom lllhaeal270B/2716Epiom(WMC|Renllime Clock .ACPProtoBd.OM Conn)Vector 8800ProloVector 8B03 11 slot MBACPE.lender w/ConnVideo Interlace (SSM|Parallel tnieitanc iSSMi13SlotMotherBoard(WM'9SIOIMo!her8oardiWMC|SSIol Mother (e.pandoble)

29 95

29 <•<:>

30 OC34 9530 0034 9527 9522.2029 9515 9527 9527 95

WAVEFORMGENERATORS

8038 Funcl.cn Gen

MC4024 VCO

LM566VCO

XR2206 Function Generator

FLOPPY DISK I/O

1771-01 8"S Minifloppy '.

uPd372 Nee Floppy '■

1781 Dual Floppy ;

1791 Dual Floppy I

TV INTERFACES

.. 8.95

..ass

.8.9512 95

8 95 MSR Modular

2716-5V 12V 29.95

2758 SV 29.95

5203AG 1 I 95

5204AO 995

6834-1 12 95

IMS61Q 2 95

SALE 0223 32 xB 2.89

H2S115 512 iBfSi 16.95

02S12332 x8. 2.50

B2S126 256 x 4 3.50

B2S129 256x4 fSi 3.50

82S130 512> 4 :OC: 6.50

- NSC DM7578 32 » 8 2.95

8ZS23 6.95

8ZS131 14.95

BZSia7 , ,, 14.95

CHARACTER GEN

2513-001 (5V)L:::::i" 9.50

2513-005 (8V)L0wei 1095

2513-ADM3(5V) Lower..

MCM6571

MCM6S71A

MCM6574

MCM6575

UARTS/USRTS

TR1602B

SPECIAL PURCHASE(while supply lasts)

21L01-4 (450 ns.). ...9921L01-2 (250 ns.)...1.15TMS 4060 (pullouts)

1 95

MC 14411....! ^9^90

P8251 Intel 4.95

FCM 7001 Clock... 5.50MM 5311 Clock... 4.50MM5314Clock...3.95

MM 2114N 4.49

MK 3870 (programmed)

1.50

AM 9060 (4K RAM)

3 9527S08(32 x8) ...1.95

75492 75

8T97 1.35

2513-001 (U.C.)... 7.958085 17.95

NOTICE: WE DO CUSTOM PROM PROGRAMMING

COMPUTER SPECIALS

0.750754.50

LIST

SALE

Apple II Plus W/16K 1195.

990.

IPSI 1620Diable R0 329: .

2695.

PET 20O1-16N 995.

895.

Anadex DP 8000

995.

895.

Exidy Sorcerer w/8K 895.

795.

Centronics Micro P-'

595.

395.

Compucolor II w/8K 1495.

1395.

Centronics Micro S-'

595.

525.

CrcmemcoSys Ml 5990.

4990.

Soroc IO 1 20

995.

850.

Horizon 1 W/16K 1599.

1349.

Teletype Model 43

1349.

1150.

TEIPI20B W/32K

HiPjot Plotter

1085.

899.

dual floppy & CRT

HiPlot Digitizer

795.

735.

(1 avail) 4995.

2995.

Intedube II

895.

784.

Pascal Mlcroengine 2995.

2395.

SOL 20

1095.

* LED'. * OPTOISOLATERS *

LEDSRed, Yellow. Green .185 5/1.00

MCT2PhotO XSTR HFE 250,30V 99

4N25 PtiotoXSTR HFE 250.30V 1.29

4N33 Photo Darlingion 1.75

FPT110B Pholo XSTR Flat Lense... SALE 4/1.00

MONTHLY IC SPECIALS

LF 13508 JFET Anloq Mulli 8 bit O 95

ICM723B Sfv..cn Ducade Counler 17 95

ICM72D7 rj'.ciijuoi Conlroller 6 95

ICM7045 Pmcision Sto/Wnu 'i Timer 22 95

ICL7107 3') Diijil A/D (LED) 14 9b

ICL8211 Voltage Reference i 95

LM39C Baltarj OP Audio Amp . 3 1 00

LM 1850 Ground Faull IC J I 00

LM1SC0 Pliase Lock Looo FM Stereo 3 l 00

LM1820 AM Radio 3'1 00

7520 .75 1496L 75

7524 75 DS3625 2.25

75LS 75 75322 75

140BL6 4/19.95 10147 ECL Flam... 9.95

148B/1489 2/1.99 LF356HBiFet .3/1.99

22 Pin S/T Sockel 10/1.00 MCM14505 8.95

8223 Prom... 2.95 74S89 3/1.99

MK5014Calc 2/1.99 74107N 6/1.99

74141 N 3/1.99 75452N 8/1.99

8T26/flT2a 2.39 741N-14 10/1.99

96H90 9-95 555CN 5/1.99

8281 50 556CN 3/1 99

TV CHIPS/SOUND

AY3850C-1 6 Games B/W .. . S

AY385I5 Color Convener

AY38603-1 Roadrace Game ...

AY38605-1 Warfare Game

AY38606-1 Wipeoui Game

AY38607-1 Shooling Gallery. .AY38910Gimini Cnckei Sound

Generator i

SN76477 Tl Sound GeneratorMM5320/21 TV Synch Gen.

MM5369 Prescaler

LM1889 RFModulalOr

MM571000 NSC Color TV

All Shinmenls FCM or UPS. Ordiunder S100.00 add 5% handling apostage. Orders over Si0000 a2.5% handling & postage. M:ist

prime factory tested guaranteedAdd .35 cents for Data.Retail pricing may very from MnilOrder Pricing. All pricing subiucl to

P. 0. BOX 17329 Irvine, California 92713 Phone (714) 558-8813

TWX: 910-595-1565

Retail Store Open Mon. - Sat.Located at 1310 "B" E. EdingerSanta Ana, CA 92705

Widen the ability of yourTRS-80

The Vista V80:$395

The Vista V80 MiniDisk System is the perfectway to widen the capabilitiesof yourTRS-80* Micro-computer. Quickly andinexpensively. Our $395price tag is about $100 lessthan the Radio Shackequivalent. Our delivery timeis immediate (24 hourturn-around from our Santa Ana,Ca. factory). And our system isfully interchangeable. That'sjust the start.

It will give you 23%more storage capacity byincreasing useable storagefrom 55,000 to 65,000 bytesper drive with our newsoftware patch.

It can work 8 timesfaster than the TRS-80 Mini-Disk system, because track-to-track access is 5ms versus40ms for the TRS-80. Youcan realize this added speed

•TRS-80 ©Tandy Corp.270 BYTE January 1980

once the new double diskexpansion interface isavailable without expensivemodification of the existingunit.

It has a betterwarranty than any comparableunit warranty available - a full120 days on all parts andservice. When you considerhow much more goes into theVista V80, that shows a lot offaith in our product.

A full 3 amp powersupply means you have 21/2times the power necessary tooperate the V80, and fullventilation insures that therewill be no problems due tooverheating.

The Vista V80 MiniDisk System requires Level IIBasic with 16KRAMExpansion interface (itoperates from the RadioShack interface system. It

comes complete with adependable MPI Minifloppydisk drive, power supply,regulator board and ventedcase. It's shipped to youready to run-simply take itout of the box and plug it in.You're in business. From thecompany that meansbusiness-Vista ComputerCompany.

The Vista Computer Company.

Manufacturers of Quality

Computer Systems

and Software.

714/953-0523

1401 Borchard

Santa Ana. Ca. 92705

Circle 232 on inquiry card.

Unclassified Ads

FOR SALE: The first sixteen issues of BYTE in mint con-dition. Best offer over $100. Pat Gerstle, 1460 Oak Cir,Boulder CO 80302.

FOR SALE: SwTPC 6800 computer with 12 K memory,SWTBUG, serial and parallel input/output (I/O); CT-1024terminal with scrolling mod in Enclosure Dynamicscase; AC-30 cassette interface; GT6144 graphics boardwith joystick, each housed in separate cases; all inter-connecting cables, full documentation, and large varietyof software (SwTPC 4 K and 8 K BASIC, MicrosoftBASIC, Assembler, games); $650. R Maryanski, 424Grant Av, Eatontown NJ 07724, (201) 542-4735.

FOR SALE: PERTEC iCOM FDOS-II dual drive/singledensity floppy disk drive with Intel interface card.Almost new. Paid $3300, will take best offer received onemonth after offer appears. Gary Miner, POB 1177, SantaCruz CA 95061, (408) 429-1331.

FOR SALE: An S-100 bus system comprised of thefollowing: TDL Z80 processor board. TDL systemmonitor board with two serial ports and one parallelport, cassette interface, and read-only memory monitor.TDL video display board with 1920 characters andgraphics. Keyboard. Morrow 16 K memory board. Allhoused in Vector Graphics box with 18 A power supply.Best offer. Richard Blum, 3 Mohawk Dr, Westboro MA01581, (617)366-9734.

FOR SALE: IMSAI 8080 with Micropolis double densityfloppy disk, 32 K bytes static programmable memory(250 ns), 8 K Bytesaver board with 16 K read-onlymemories, additional 16 K programmable-memory boardwithout chips, SIO-2, PIO-4, Tarbell cassette board,Mountain Hardware clock board, OAE paper-tapereader, Hazeltine 1500, 80-column printer, modem, andultraviolet read-only memory eraser. All boards fullysocketed, up and running. All brand new. Write for moredetails, give phone number. Jim Bartkus, 6519 S KostnerAv, Chicago IL 60629.

FOR SALE: Monroe 326 scientific calculator withcassette drive model 392, programmable 120 steps andIwelve data registers, with nicads and charger, softwareincluded for financial analysis. Asking $600 or bestoffer. Stanley Katz, 208 Hamden #305, Marshall MN56258, (507)537-1136.

FOR SALE: BYTE and Kilobaud magazines in good condi-tion. Complete sets, volume 1 number 1 thru presentdate. Make offer for either or both sets. Mel Hart, 936Dontaos Dr, St Louis MO 63131, (314) 966-4263.

FOR SALE: TRS-80, Level 2 BASIC, 16 K complete withvideo monitor, power supply, keyboard, cassette unit.Level 1 and 2 manuals, game software, all in perfect con-dition, I pay shipping; $750. Robert E Stahl, 18273 GumTree Ln, Huntington Beach CA 92646, (714) 842-5832.

FOR SALE: Computer Automation Alpha/LSI-2 computerwith 8 K 16-bit words of core memory, front panel, and8-port serial input/output (I/O) board. $1000. Phil Hughes,POB 2847, Olympia WA 98507, (206) 357-4415 days or(206) 352-9637 evenings.

FOR SALE: S-100 boards, Processor Technologycassette user tapes system interface with CUTER,Extended Cassette BASIC and ALS-8, $160; VDM-1, $150;BASE 2 16 K fast static programmable memory, $325;Digital Micro System 16 K static programmable memory,$290; IMSAI 8080 processor board, $80; Advanced Com-puter Products LOGO I 8 K static programmablememory, $180. All assembled and tested. Teletypewriterpaper, Canary, $3. T Tai, POB 142, Eagleville PA 19408.

FOR SALE: First two volumes of BYTE, excellent condi-tion, complete. Please submit bids for both completesets or individual issues. Magazines will go to highestbidder(s). K Watson, 600 Arapahoe #7, Boulder CO80302.

FOR SALE: Solid State Music IO-4, 2P + 2S, input/ out-put (I/O) board, S-100, documentation. Best offer. StuartSheedy, 1 Schoolhouse Ln, Syosset NY 11791, (516)921-4321.

FOR SALE: Terminet 300 keyboard printer. Excellentcondition. Friction-feed Model B, RS-232, 10/15/30 cps(switch selectable), upper/lower case, 118 column, ASCIIterminal. Full set of documentation included. Best rea-sonable offer. F P Godici, Rd #2 POB 135, Oswego NY13126, (315) 343-3314.

FOR SALE OR TRADE: SwTPC 6800/2 with 24 K totalmemory; CT-64 terminal; AC-30 cassette interface; NP-Ncalculator interface. All equipment unassembled. Inoriginal cartons with all manuals and documentation.Sell for cash, or trade for TRS-80 expansion interfacewith memory, mini disk system, printer, etc. GaryBlanken, 1804 Ladd St. Silver Spring MD 20902.

FOR SALE: Teletype ASR33. Excellent condition. Wiredfor motor control, with pedestal, and one box of newpaper tape; $850. DSI paper-tape winder for Teletype 33;$50. United Data 20 mA to RS-232C converter; $125. RGroome, 1701 E 12th St Apt 9W West Tower, ClevelandOH 44114, (216)621-4129.

FOR SALE: Assembled Heathkit H8, H9, and cassetterecorder. Hardware includes 24 K memory and cassetteinterface. Software is Heath Extended BASIC,Assembler, Game Set 1, Biorhythm, and Space War.Included are reference manual and most ofREMarksfHUG magazine) to date. Would cost nearly$1800 as a kit. The first check or money order for $1440gets it. G Counsil, 1258 33 Av, San Francisco CA 94122,(415) 664-4508.

FOR SALE: Two IMSAI 4 K static programmable-memoryboards with individual 1 K write protect. $85 each. OnePolymorphics Video-Graphics board with 16 by 64 char-acter display and 48 by 128 graphics display. 1 K of onboard programmable memory and a parallel port forkeyboard. $150. All for S-100 bus. Everything assembled.Frederick Stark, 859 Standish, Pacifica CA 94044.

FOR SALE: TDL ZPU Z80 processor card and TDL Z16memory card with 8 K bytes. Includes TDL Z80 macro-assembler, TDL 8 K BASIC, TDL 1 K monitor, andmemory test software on paper tape. Documentationincluded: macroassembler user manual, Z80 processortechnical manual. Z16 manual, and 8 K BASIC user manual.All for $500 or best offer within thirty days. Art Wetzel,1123 Walnut St, Pittsburgh PA 15221, (412) 624-5208 or(412) 241-3578.

FOR TRADE: Are you interested in swapping software?If you send me an original game program in any versionof TDL BASIC or either version of CBASIC, I will sendyou a game program in the appropriate language. Alongwith the program include a SASE, and two extra copiesof your program, if possible. Your program must betyped or printed by computer. Michael Schiff, 184 FochAv, Lawrenceville NJ 08648.

FOR SALE: Tarbell tape interface board, assembled andworking, $80 or best offer. Also, Memorex model 650floppy disk drive, 8 inch, hard-sectored, with documenta-tion, $200 or best offer. Frank Tuccio, 80 N Railroad Av,Mahwah NJ 07430.

Unclassified Policy

Readers who are soliciting or giving ad-vice, or who have equipment to buy, sell orswap should send in a clearly typed noticeto that effect. To be considered for publi-cation, an advertisement must be clearlynoncommercial, typed double spaced onplain white paper, contain 75 words or less,and include complete name and addressinformation.

These notices are free of charge and willbe printed one time only on a spaceavailable basis. Notices can be acceptedfrom individuals or bona fide computerusers clubs only. We can engage in nocorrespondence on these and your confir-mation of placement is appearance in anissue of BYTE.

Please note that it may take three or fourmonths for an ad to appear in themagazine.

WANTED: CAI programs wanted. Teachers, do you haveany original TRS-80, PET, or Apple CAI programs fortrade with other teachers? Bob Purser, POB 466, ElDorado CA 95623.

FOR SALE: Complete set of BYTE magazine from firstissue to 1979. Make offer. Benjamin Clark, Rt 3 POB 800,Moncks Corner SC 29461.

FOR SALE: Static-memory boards assembled withoriginal documentation. Godbout 4 K, paid $130, asking$50; SD Sales 4 K lowpower, paid $95, asking $65; MITSAltair 8800 1 K, $25. All three boards for only $125 and Ipay insurance and postage. Also, I have an ASR33 tele-typewriter with built-in 101C data set and phone dialer.Asking $875 or best offer. Barry Woo, 949 Erica Dr,Sunnyvale CA 94086, (408) 737-2935.

FOR SALE: PDP-8/L computer; $1000. James Foy, (609)646-2132 after 6:00 PM.

BUY, SELL OR TRADE: Digital Group equipment. Haveinput/output (I/O), video display, Z80 processor, dual Phi-Deck system, keyboards, monitors, cabinets, etc. Needmemories and TVC 96, real-world interface, etc. JackBuster, POB 8062, Anchorage AK 99508, (907) 349-3324.

FOR SALE: Data General Nova 1220 minicomputer with32 K bytes programmable memory, Auto-Program-Load,paper-tape reader and Teletype interfaces, manuals,logic diagrams, and paper tapes. All in mint condition.$1500 plus shipping. R C Meyer, 618 13th St NE, Owa-tonna MN 55060, (507) 451-6911 evenings.

FOR SALE: Input/output (I/O) board, S-100, MorrowSpeakeasy, one parallel, one serial, cassette with con-trol for three machines, 512 bytes programmablememory, read-only memory with bootstrap and cassetteroutines on board. Assembled and tested, with cable.Best offer over $110. Rusty Bryttan, 78 Clinton PI, BronxNY 10453, (212) 367-0663.

FOR SALE: Altair computer, two 4 K dynamic memories,ACR, PIO. $500 or best offer. Also complete backlog ofBYTE, best offer. Dan Starr, 58 Spruce St, Princeton NJ08540.

FOR SALE: I am selling parts and spares from my oldcomputer to pay for my new computer. All parts made byIntel. 13 K bytes P2102A-4; $1.50 each, 4 K bytes C1702a;$4 each, 24 D8212; $2 each, 3 C8080A; $7 each, 3 D8224;$3 each, 8 P8226; $2 each, 2 P8214; $4 each, 20 unusedd3601 read-only memory like 82S126; $3 each. Pleaseadd $1 for UPS. Send cashier's check or money order.Frank Worrell, Lakeshore Dr RD4, Colchester VT 05446.

January 1980 © BYTE Publications Inc 271

Header Service

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 theadvertisers you select from the list. Add a 15-cent stamp to the card, then drop it in the mail. Not only do you gain information, but our advertisers are encouraged to usethe marketplace provided by BYTE. This helps us bring you a bigger BYTE. "Correspond directly with company.

Inquiry No.

Page No.

Inquiry No.

Page No.

Inquiry No.

Page No.

Inquiry No.

Page No.

92213

52188173

77231154

121B7108151162

31223

19140109153225

115

21685

182686137

23065

22476

50

33130

44156

82127

54152

161199163184131133100228134

72160

87

48

80

90

Aardvark Software 151

AB. Computers 254

Ackerman Digital Systems 86

Addmaster Corp. 211

Adroit Electronics 205

Advanced Access Group 128

Advanced Computer Prod 268, 269

All Electronics Corp 201

Altos 19

American Square Computers 211

Anderson Jacobson 176

Anderson Jacobson 199

Apparat 202

Apple Computer 55

ASAP Computer Products 262

Atari Personal Computers 31

ATV Research 197

Automated Simulations 177

Avionic Enterprises (A.E.I.) 201

Beckian 264

Beta Computer Devices 110

Biotech Electronics 222

Bits, Inc. 167

BYTE Back Issues 185

BYTE Books 114. 121, 157, 173

BYTE WATS 211

C & S Electronics Mart 181

California Digital 257

Cambridge Development Labs 142

CCM Inc. 211

Central Data 107

Centronics 97

Compucolor Corp 63

CompuMart 267

CompuServe (Micronet) 103

Computer City 263

Computer Distributors 127

The Computer Factory 139

Computer Furniture & Ace 84

Computer Headware 18

Computer Mart of NJ 58

Computer Specialties 189

Computer Room 76

Computer Service Center 201

Computer Serv Sys Ntwk (CSSN) 137

Computex 188

CTC88

CT Micro Computer 200

Corvus Systems 25

Cromemco 1, 2

Cybernetics Inc 231

Data Access Corp 203

DataBank 211

Data Discount Center 191

Data South Computer 191

Data Speed 165

Data Trans 266

Datec 193

Delta Products 117

DES-MAR Electronics 201

DG Electronics 144

Digital Marketing 82

Digital Pathways 135

Digital Research Corp (CA) 148

20

32

129

221

138

124

207

111

208

169

196

193

141

57

210

167

121

132

194

98

84

97

11

17

67

211

38

102

86

18

36

14

106

147

75

9

104

4

8

209

218

15

43

60

74

66

159

172

222

239

45

29

2

122

185

114

Digital Technology Inc 35

Digitus Corp 57

Disc 3 189

Digital Research: Computers 261

Dynacomp 195

Ecosoft 187

Electrolabs 243, 246, 247

Electronic Control Technology 177

Electronic Systems 248, 249, 266

Electronic Technicians 205

Escon 228

Factory Direct Sales 217

Field Service Search 197

Folio Books 92, 93

Fordham Radio Supply 252

Frederick Computer 205

Futureworld 185

H Geller 191

Gimix 219

Godbout Electronics 161

H & E Computronics 141

Hayden Book Co 159

Heath Company 17

Heath Company 26, 27

Heuristics 106

Hobby World 252

Houston Instruments 67

Inco Inc 187

Infinity Micro 143

Infosoft Systems Inc 29

Inmac 62

Integral Data 23

Integrand 174

Interface Inc 197

International Data Systems 125

Intertec Data Systems 15

Intertec Data Systems 171

Ithaca Intersystems 9

Ithaca Intersystems 14

Jade Co 250, 251

Jameco 258, 259

JJR Data Research 24

Konan Corp 75

Lifeboat Associates 101, 231, 233

Logon Inc (Technical Marketing) 96

MacMillan Book Club 145

Macrotronics 205

McGraw-Hill Book Company 64, 65

Measurement Sys & Cont 169. 197

Micro Appl & Hardware (MICAH)

204

Microamerica 123

Micro Applications Group 104

Micro Architect 201

Microbiotic Computing 205

Micro Business World 262

Microcomputer Technology Inc 202

MicroDaSys 77

Micro Data Base Systems 53

Micro Diversions 5

Micromail 185

Micro Management Systems 211

Micro Mikes 181

Micro Pro International 49

155 Microsette 201168 Microsette 205

56 Microsoft 91

95 Microsoft (Consumer Prod Div) 155

40 Microtek 71120 Microware 187

41 The Micro Works 723 Micro World 8

103 Midwest Computer Peripherals 170

219 Mikos260

81 MOM 136

178 Mini Computer Suppliers 20739 Morrow/Thinker Toys 69

10 Mountain Hardware 16

70 Mountain Hardware 111

51 MPI 85

116 MPU 181

176 MT Microsys (Formerly Metatech) 206

143 Multi Business Computer Sys 197

156 National Computer Service 20183 NEECO 123

79 NEECO 132

237 NEECO 133215 Netronics 255

238 Netronics 255

174 Northwest Computer Serv Inc 205

113 Novation 179

• NRI Schools 129

235 Ohio Scientific Instrument CIV

7 Ohio Scientific Instrument 12, 13

27 OK Machine and Tool 4764 OK Machine & Tool 102

28 Olivetti 51

" onComputing 33

202 Optimal Technology 233

49 Oregon Software 83

123 Osborne/McGraw-Hill 186

136 Owens Associates 193

171 Pacific Exchanges 205

217 Page Digital 256

164 PAIA 204

200 Pan Am Electronics (A Radio Shack

Auth. Sales Ctr.) 231

234 Per Com Data C III

25 Per Com Data 43

26 Per Com Data 44

241 Per Com Data 44

242 Per Com Data 44

243 Per Com Data 45

244 Per Com Data 45

245 Per Com Data 45

246 Per Com Data 45

46 Personal Software 79

47 Personal Software 81

' Phase One Systems 149

125 Pickles & Trout 187

99 Potomac Micro Magic 164

■ Polyline Corp 201

30 Power One 54

53 Prodigy 87

' Priority One (insert)

248 Priority One 241

179 The Q Kit (Div JR Conwell Corp) 209227 Quest Electronics 265

94119212

69112

20419717511018112815021

177107

22

63

183

5

191

91

144

24

135

214

158

180

233

6

58

226

34

240

59

192

78

42

55

139

157

13

146

170

13714523232206220

142

190

71

118

Rabininc 154

RACET Computes 183

Radio Hut 253

Radio Shack 109

Ramsey Electronics 178

Reliable Cash Register (Systems

Specialists) 183

RNB Enterprises 233

Rochester Data 228

S-100 206

Sara Tech 177

S C Digital 211

SCDP 189

SciTronics 198

Seattle Computer Products 37

Shugart 6, 7

Sigma International 207

Sirius Systems 175

Smoke Sig Broadcasting (Dealers) 39

Smoke Signal Broadcasting 39

Snow Micro Systems Inc 211

Softagon Inc 10

Softech Micro Systems 153

Softside 146

Software Dev & Training 214

The Software Exchange 147

The Software Farm 197

The Soft Warehouse 42

The Software Works 193

Solid State Sales 254

Sorrento Valley Associates 201

Southern Sys of Birmingham 210

Southwest Tech Products Corp Cll

SSM 11

SubLOGIC 94

Sunny International 264

Supersoft 59

Sybex 61

Synchro Sound 95

Synergetic Computer Products 214

System Engineering Enterprises 113

Tarbell Electronics 73

Technical Systems Cons (TSC) 89

Technology Transfer 196

Terminal Data Corp 201

3/M Company 21

Torry Pines 197

Ucatan Computer Store 205

University Micro Films 99

US Robotics 194

Vantage Data Products 197

Vector Electronics 40

Vista Computer Company 270

VR Data 245

Wameco 260

Whales 245

Worldwide Electronics 197

X-Comp 213

Yourdon Software Prod Group Inc 119

Zs Systems 183

BOMB — BYTE's Ongoing Monitor Box

Article No.

ARTICLE

1 Grogono: Making Color Slides with an Intecolor Microcomputer

2 Ciarcia: Computerize a Home

3 Gibson: A Computer-Controlled Light Dimmer

4 Wierenga: A Furnace Watchdog

5 Lewis: What Computers Cannot Do

6 Skier: Indirect Addressing for the 6502

7 Joyce: Telephone Dialing by Computer

8 Chance: Analysis of Polynomial Functions with the TI-59 Calculator, Part 2

9 Walter: The Plot Continues

10 Conboy: Alpha Lock for Your ASCII Keyboard

11 Pass: A Computer-Generated Reminder Message

12 Lipham: Relocating 8080 System Software

13 Yost: Eighteen with a Die, A Learning Game Player

Page

20

28

56

74

100

118

122

129

136

156

160

180

212

October BOMB

"Picking Up The Pieces" (page 76) byAlfred S Baker won first place in theOctober 1979 BOMB. Second placewas taken by Fred R Ruckdeschel's"Curve Fitting With Your Computer"(page 150). "Self-Refreshing LEDGraphics Display"(page 58), by SteveCiarcia, placed third. ■

272 January 19S0 © BYTE Publications Inc

from PEflSCM

One-Drive System:

$399. (40-track) & $675. (77-track)Two-Drive System:

$795. (40-track drives) & $1350. (77-track drives)Three-Drive System:

$1195. (40-track drives) & $2025. (77-track drives)Requires Expansion Interface, Level II BASIC & 16K RAM.

Low Cost Add-On Storage for Your TRS-80

In the Size You Want.

When you're ready for add-on disk storage, we're ready for you.Ready with six mini-disk storage systems — 102K bytes to 591K bytes of

additional on-line storage for your TRS-80*.

• Choose either 40-track TFD-100™ drivesor 77-track TFD-200™ drives.

• One-, two- and three-drive systems im-mediately available.

• Systems include Percom PATCH PAK#1™, on disk, at no extra charge. PATCHPAK #1™de-glitches and upgradesTRSDOS for 40- and 77-track operation.

• TFD-100™ drives accommodate "flippydisks." Store 205K bytes per mini-disk.

• Low prices. A single-drive TFD-100™costs just $399. Price includes PATCHPAK #1™ disk.

• Enclosures are finished in system-compatible "Tandy-silver" enamel.

Whether you need a single, 40-track TFD-100™ add-on or a three-driveadd-on with 77-track TFD-200™s, youget more data storage for less moneyfrom Percom.

Our TFD-100™ drive, for example,lets you store 102.4K bytes of data onone side of a disk — compared to 80Kbytes on a TRS-80* mini-disk drive —and 102.4K bytes on the other side, too.Something you can't do with a TRS-80*drive. That's almost 205K bytes permini-disk.

And the TFD-200™ drives provide197K bytes of on-line storage per drive

— 197K, 394K and 591K bytes for one-,two and three-drive systems.

PATCH PAK #1™, our upgradeprogram for your TRSDOS*, not onlyextends TRSDOS* to accommodate 40-and 77-track drives, it enhancesTRSDOS* in other ways as well. PATCHPAK #1™ is supplied with each drivesystem at no additional charge.

The reason you get more for lessfrom Percom is simple. Peripherals arenot a sideline at Percom. Selling disksystems and other peripherals is ourmain business — the reason you getmore engineering, more reliability andmore back up support for less money.

in the Product Development Queue ... a printer interface for using your TRS-80* with anyserial printer, and ... the Electric Crayon™ to map your computer memory onto your color TVscreen — for games, animated shows, business displays, graphs, etc. Coming PDQ!

™ TFD-100. TFD-200. PATCH PAK and Electric Crayon are trademarks of PERCOM DATA COMPANY.

•TRS-80 and TRSDOS are trademarks ol Tandy Corporalion and Radio Shack which have no relationship lo PERCOM DATA COMPANY

To order add-on mini-disk storage for your TRS-80*,or request additional literature, call Percom's toll-freenumber: 1-800-527-1592. For detailed Technical infor-mation call (214) 272-3421.

PERCOM DATA COMPANY, INC.211 N. KIRBY • GARLAND, TX. • 75042

Orders may be paid by check or money order, orcharged to Visa or Master Charge credit accounts. Texasresidents must add 5% sales tax.

Percom 'peripherals for personal computing'

Circle 234 on inquiry card.

Step up to yournext computer.

STEPUPT0AC4PFROM OHIO SCIENTIFIC

You know about computers. In fact,you probably own one now. One thatyou might be thinking of expanding. Wehave a better idea. Take a giant stepinto the personal computing future withan amazing, new C4P from Ohio >

Scientific.

SPEED SEPARATES THECOMPUTERS FROM THE TOYS

The C4P MF has execution speed thatis twice as fast as Apple 11 orCommodore PET and over THREEtimes as fast as TRS-80. They aremany times faster than the recentlyintroduced flock of video game typecomputers. And, as if that weren't fastenough, the C4P nearly doubles itsspeed when equipped with the GToption.

Just look at the backpanel of the C4P MR

SOUND

1—programmable tone generator

200 —20KHz1 —8 bit companding digital to analog

converter for music and voice

output.

HUMAN INPUT EXPANSION

2—8 axis joystick interfaces2—10 key pad interfaces

HOME INTERFACE

1 —AC-12 AC remote control interface

DISPLAY

32 x 64 with upper and lower case2048 Characters.256 x 512 effective Graphic Points16 Colors

SOFTWARE

Ohio Scientific offers a comprehensivelibrary of both systems andapplications software for the C4P.

i:-£:i\

The C4P is an outstanding premiumcomputer — years ahead of themarket. We know because there'snothing quite like it for the price,anywhere. And probably won't be for avery long time.

C4P*698

8K BASIC-in-ROM, 8K of static RAMand audio cassette interface. Can bedirectly expanded to 32K static RAMand two mini-floppy disks.

C4PMF*1695

All the features of the C4P plus realtime clock, home security systeminterface, modem interface, printerinterface, 16 parallel lines and anaccessory BUS. The C4P MF startswith 24K RAM and a single mini-floppyand can be directly expanded to 48Kand two mini-floppies. Over 45 diskettesnow available including games,personal, business, educational andhome control applications programs aswell as a real time operating system,word processor and a data basemanagement system.

Compulers come wilh keyboards and floppies where specified.Other equipment shown is optional.

For literature and the name of your localdealer, CALL 1-800-381-6850 TOLL FREE.

Apple II, Commodore PET, TRS-EComputer inc.. Commador*' Busini

. and Alan BOO are registered Irade names ol Appleb Machines Lid., Radio Shark Alan, respectively

umuwwnil

1333 SOUTH CHILLICOTHE ROADAURORA, OH 44202 • [21B] 562-3101

Circle 235 on inquiry card.