Byte Magazine Volume 03 Number 12 - Life

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Someday all terminals will be smart.

128 Functions-software controlled7x12 matrix, upper/lower case letters50 to 38400 baud -selectable

82 x 16 or 92 x 22 format—plus graphicsPrinter output port"CHERRY" keyboard

CT-82 Intelligent Terminal, assembled and tested $795.00 ppd in Cont. U.S.

SOUTHWEST TECHNICAL PRODUCTS CORPORATION

219 W. RHAPSODY

SAN ANTONIO, TEXAS 78216

Circle 350 on inquiry card.

ParallelI/O Port #3

RS-232 or

Current Loop

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LatchedOutputs

4 MHzCrystal Clock

On Card

Voltage

Regulation

8KROMCapacity

IK RAM

Standard Bus

for System

Expandability

ProgrammableBaud RateUART with

Interval Timers

4 MHz Z-80A

Completely BufferedBus Interface

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 S10Q-bus-compatib!e 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 Cromemco Model SCC is avail-able now at a low price of only $450factory assembled ($395 kit).

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

a CromemcoincorporatedSpecialists in computers and peripherals

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

Circle 80 on inquiry card.

BYTE December 1978

Model Z-2Up to 512K of RAM/ROM

Model Z-2D

One or two disks

Up to 512K of RAM/ROM

Up to 184K of disk

System Two

Dual disk

Up to 512K of RAM/ROM

Up to 184K of disk

Fill your computer needs

with the industry's

most professional microcomputers

#1 IN RELIABILITY

When you choose Cromemco youget not only the industry's finestmicrocomputers but also the indus-try's widest microcomputer selec-tion.

What's more, you get a computerfrom the manufacturer that compu-ter dealers rate #1 in product re-liability.*

Your range of choice includesour advanced System Three withup to four 8" disk drives. Or choosefrom the System Two and Z-2D with5" drives. Then for ROM-based workthere's the Z2. Each of these com-puters further offers up to Vz mega-byte of RAM (or ROM).

We say these are the industry'smost professional microcomputersbecause they have outstanding fea-tures like these:

• Z-80A microprocessor — oper-ates at 250 nanosecond cycletime — nearly twice the speed ofmost others.

Up to 512 kilobytes of RAM and1 megabyte of disk storage

* Rated in The 1977 Computer StoreSurvey by Image Resources, WestlakeVillage, CA.

System Three

Two to four disksUp to 512K of RAM/ROMUp to 1 megabyte of disk

30-amp power supply — morethan adequate for your mostdemanding application.

21 card slots to allow for un-paralleled system expansion us-ing industry-standard $-100cards.

S-100 bus — don't overlook howimportant this is. It has the in-dustry's widest support and Cro-memco has professionally imple-mented it in a fully-shieldeddesign.

• Cromemco card support of morethan a dozen circuit cards forprocess control, business sys-tems, and data acquisition in-cluding cards for A-D and D-Aconversion, for interfacing daisy-wheel or dot-matrix printers, evena card for programming PROMs,

• The industry's most professionalsoftware support, includingCOBOL, FORTRAN IV, 16K Disk-Extended BASIC, Z-80 MacroAssembler, Cromemco Multi-user Operating System, DataBase Management System, WordProcessing System — and morecoming.

• Rugged, professional all-metalconstruction for rack (or benchor floor cabinet) mounting. Cab-inets available.

FOR TODAY AND TOMORROW

Cromemco computers will meetyour needs now and in the futurebecause of their unquestioned tech-nical leadership, professionalismand enormous expandability.

See them today at your dealer.

There's no substitute for gettingthe best.

Q CromemcoincorporatedSpecialists in computers and peripherals

BYTE December 1978

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

Circle 80 on inquiry card.

In the Queue

Etll December 1978Volume 3 Number 12

14

26

32

94

100

128

140

168

45

54

68

84

108

124

186

194

46

10

43

76

92161,164166174176

184,202,192209246248

163

Foreground

FAST FOURIER TRANSFORMS ON YOUR HOME COMPUTER

Software-Stan ley-PetersonDESIGNING A UNIVERSAL TURING MACHINE: A Software Approach

Software—MunneckeBUILD AN OCTAL/HEXADECIMAL OUTPUT DISPLAY

Hardware—CiarciaINTERFACE YOUR COMPUTER TO A PRINTING CALCULATOR

Hardware—A s tmannZAPPER: A Computer Driven EROM Programmer

Hardware—GableCLOCKLESS MULTIPLICATION AND DIVISION CIRCUITS

Hardware—WeedCREATING A CHESS PLAYER, Part 3: Chess 0.5 (continued)

Computer Chess Software—Frey-A tk/'nPARTITIONED DATA SETS

Tu to rial—Halsema

Background

LIFE WITH YOUR COMPUTER

Applications: Life Games—Milliun-Reardon-SmartSOME FACTS OF LIFE

L ife—BuckinghamONE-DIMENSIONAL LIFE

Life Games—MillenCHESS 4.7 VERSUS DAVID LEVY

Computer Chess—DouglasAN EASY PROGRAMMING SYSTEM

Software—WeisbeckerTEACHING WITH A MICROCOMPUTER

Appfica tions—Gerh oldTHE MOTHER CHIP

Fiction-WillardFORTRAN AND ITS GENERALIZATIONS

Language Tutorial—Maurer

Nucleus

In This BYTE

New Wonders of the Computer AgeLetters

Book Reviews

Programming Quickies: LifeNybbles: Z-80 AssemblerBYTE's Bits, BYTE's BugsEvent QueueClubs, Newsletters

Programming Quickies: Tic-Tac-Toe in BASICLanguages Forum208 Technical Forum

Desk Top Wonders: A Game for the TI-58What's New?Unclassified AdsBOMB, Reader Service

BYTE is published monthly by BYTE Publications Ine, 70 Main St, Peterborough NH 03458. Address all mail except sub-scriptions to above address: phone (603) 924-7217. Address all editorial correspondence to the editor at the above address.Unacceptable manuscripts will be returned if accompanied by sufficient first class postage. Not responsible for lost manu-scripts or photos. Opinions expressed by the authors are not necessarily those of BYTE. Address all subscriptions, change ofaddress. Form 3579, and fulfillment complaints to BYTE Subscriptions, PO Box 590, Martinsville NJ 08836. Second classpostage paid at Peterborough NH 03458 and at additional mailing offices-USPS Publication No. 102410. Canadian secondclass registration No. 9321. Subscriptions are $15 for one year, $27 for two years, and $39 for three years in the USA and itspossessions. In Canada and Mexico, $17.50 for one year, $32 for two years, and $46.50 for three years. $25 for a one yearsubscription by surface mail worldwide. Air delivery to selected areas at additional rates available upon request. $25 for a oneyear subscription by air delivery to Europe. Single copy price is $2.00 in the USA and its possessions, $2.40 in Canada andMexico, $3.50 in Europe, and $4.00 elsewhere. Foreign subscriptions and sales should be remitted in United States funds.Printed in United States of America. Each separate contribution to this issue and the issue as a collective work copyright ©1978 by BYTE Publication Inc. All rights reserved.

Subscription WATS Line: (800) 258-5485

PUBLISHERS

Virginia Londoner

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DIRECTOR, EDITORIAL PLANNING

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TYPOGRAPHY

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December 1978©BYTE Publications Inc

The advent of the personal com-puter has made possible the calcula-tion of the fast Fourier transform(FFT) on the small system. Appli-cations of this powerful design toolinclude speech and music analysis aswell as circuit design and developmentRead Fast Fourier Transforms onYour Home Computer by William DStanley and Steven J Peterson.

page 14

Quite often a software approach toa problem is easier to implement thana hardware approach to the sameproblem. Tom Munnecke describes thesoftware used in Designing a UniversalTuring Machine and compares it to acomparable hardware approach.

page 26

Steve Garcia describes a simple butuseful addition to your computer inBuild an Octal/Hexadecimal OutputDisplay. This circuit can help you toconvert from octal to hexadecimal(and vice versa) or give you the statusof a byte during program execution.

page 32

Our cover theme this month(painted by Robert Tinney) is thegame of Life. In Life with YourComputer, Justin Milliun, JudyReardon and Peter Smart give astarting point for developing your ownversion of this exciting game, page 45

Researchers probing cellular auto-mata have used Conway's game of Lifeas a tool in creating a collection ofstrange and exciting patterns. In DavidBuckingham's article Some Facts ofLife we find a description of dis-coveries made since the original flurryof activity several years ago. page 54

One-Dimensional Life is an intrigu-ing variant on John Conway's famousgame. Out of this restricted formatcomes a surprising variety of familiarLife figures such as the flip flop andglider. Dr Jonathan K Millen leads usdown the Life line in One-DimensionalLife. page 68

The same folks who brought youChess 4.6 now bring you a new, im-

proved version, Chess 4.7. Read thestory of the epic battle of the mightycomputer and the tenacious, cleverhuman chess master in an article byJ R Douglas, Chess 4.7 versus DavidLevy. page 84

In many microcomputer applica-tions it is desirable to have a cheapmethod for printing numerical data.Robert H Astmann describes away to interface a Texas Instru-ments 5050M printing calculator toan 8080A based computer in Inter-face Your Computer to a PrintingCalculator. page 94

In This ElTl

When building a computer system itis frequently advisable to have yourmost often used basic routines storedin read only memory so that they willalways be readily available. To makethe best use of read only memory, theexperimenter should be able to pro-gram his own. G H Gable describesone system for programming read onlymemory in his article, Zapper: A Com-puter Driven EROM Programmer.

page 100

Are you having trouble affordingenough hardware to support a highlevel language such as BASIC? Are youfinding it difficult to program in yourmachine's assembler language? If youranswer to either of those questions is"yes," then what you're looking foris An Easy Programming System. Inthis article, Joe Weisbecker gives anintroduction to hexadecimal interpre-tive programming, an alternative tohigh level languages and assemblersalike. page 108

Computer aided instruction is anexcellent microcomputer application.To perform this function correctly,it helps to have a programming lan-guage designed for the purpose.Prof George A Gerhold describessome of the features such a language

should possess in Teaching with aMicrocomputer. page 124

If you have a need for multiplica-tion and division circuits and don'twant to worry about timing diagrams,read Mike Weed's discussion of someClockless Multiplication and DivisionCircuits you can work with, page 128

This month we present the secondhalf of Chess 0.5 in the series Creatinga Chess Player by Peter W Frey andLarry R Atkin. The program waswritten by Larry Atkin, who is co-author with David Slate of the worldchampionship computer chess pro-gram, Chess 4.6. The program iswritten in Pascal and is readily adapta-ble to personal computers havingPascal systems such as the UCSDPascal project software. page 140

To get the most out of your floppydisk units, you should know how tohandle the data that will be stored onthem efficiently. A I Halsema intro-duces us to the concept of PartitionedData Sets and briefly describes amethod for implementing them.

page 168

What is the world going to be likein twenty years? That's a difficultquestion to answer, but the chancesare that microcomputers will be partof it. Lawrence Willard takes a light-hearted look at one possible future inhis story, The Mother Chip. page 186

FORTRAN is one of the ante-cedents to a number of computerlanguages. The ever popular BASIC isin some respects a simplification ofFORTRAN. A number of later lan-guages build upon the computerscience learning experience which wasFORTRAN and its compilers in thelate 1950s and early 1960s. FOR-TRAN is even now becoming availablein floppy disk based systems at thehigh end of the personal computingperformance range. In this issue,W Douglas Maurer provides readerswith an article on FORTRAN and ItsGeneralizations, good backgroundreading on an important and still muchused language. page 194

4 December 1978 © BYTE Publications Inc

Specifications:

S-100 compatible. MFMencoding, 35 tracks with ten512-byte sectors per track.179,200 bytes on doubledensity SA-400 and North StarBASIC, DOS, and Monitorincluded.

For further information, writefor full color catalog or contactyour local computer store.

New from North Star

Double Density Performance at

Single Density Prices

The new HORIZON computer andMicro Disk System now record in dou-ble density! That means each newShugart SA-400 minifloppy disk driveaccesses 180K bytes of on-line infor-mation. All double density HORIZONcomputers and Micro Disk Systemshave a redesigned controller whichallows the use of quadruple capacitydisk drives as they become available inearly 1979. A three-drive North StarSystem with quadruple capacity diskdrives will access over a megabyte ofon-line information. But, best of allthere's no price increase for doubledensity models.

North Star BASIC and DOS have beenupgraded to accommodate the in-creased capacity and yet run existingprograms with little or no change. Thenew disk system also supports single

density, so existing single density disk-ettes can still be used. Single densitySA-400 drives previously purchasedwith North Star systems can also beused.

Pricing

HORIZON with one double densitySA-400 minifloppy (180K bytes), 16KRAM, Z80A processor and serial I/Oport: $1599 kit, $1899 assembled.

MICRO DISK SYSTEM with one doubledensity SA-400 minifloppy, controllerboard and power regulation: $699 kit,$799 assembled. (Cabinet and powersupply $39 extra each.)

* C

North Star2547 Ninth StreetBerkeley, California 94710(415) 549-0858

QMPUTERS

Circle 285 on inquiry card.

BYTE December 1978

Editorial

New Wonders of the Computer Age

Articles Policy

BYTE is continually seeking qualitymanuscripts written by Individuals whoare applying personal computer systems,designing such systems, or who haveknowledge which will prove useful toour readers. For a more formal de-scription of procedures and require-ments, potent/a/ authors should send alarge (9 by 12 inch, 30.5 by 22.8 cm),self-addressed envelope, with 28 centsUS postage affixed, to BYTE Author'sGuide, 70 Main St, Peterborough NH03458.

Articles which are accepted arepurchased with a rote of up to $50 permagazine page, based on technicalquality and suitability for BYTE'sreadership. Each month, the authorsof the two leading articles In the readerpoll (BYTE's Ongoing Monitor Box or"BOMB") are presented with bonuschecks of $100 and $50. Unsolicitedmaterials should be accompanied by fullname and address, as well as returnpostage*

by Carl Helmers

In recent months, trends in the develop-ment of integrated circuit technologyhave reached new highs of accomplish-ment, such that it is possible to note someexciting possibilities for design in the nextyear or so. These new highs are on a broadfront of semiconductor technology whichis required for the small computers ourreaders buy and use. The effects of thisnew technology may not be seen in theretail marketplace for another year or so,since there is a finite design delay timebetween the availability of a part's designspecification and its appearance in finishedproducts.

The first new high in semiconductortechnology is the announcement of severalnew 64 K bit dynamic memory parts (seethe Texas Instruments TMS 4164 describedon page 209 of this issue). What are theimplications of this technology for personalcomputers? Quite simply, they are newlows in prices for the same functions wesee now in the marketplace. Eventuallythe prices of the 64 K parts will fall to theunder $20 level now seen in 16 K chipspurchased in volume. Where it once took32 chips of 16 K bits per chip to saturatea personal computer's address space, it willnow take only eight chips (and perhaps adynamic memory controller chip) to dothe same thing. It is now possible to com-bine a current model microprocessor,a video controller chip, a dynamic memoryinterface chip, a floppy disk controller chip,and one or two parallel interface chipswith eight memory chips and obtain avery complete electronics module for asmall computer that uses only 13 or 14integrated circuits, yet has the performanceof a large scale minicomputer of severalyears ago. In short, the memory address

Continued on page 205

See Solat all these

fine

computer

centers

CA: Costa Mesa: Orange County ComputerCenter, (714) 646-0221. Modesto: ComputerMagic, (209) 527-5156. Mountain View:Digital Deli, (415) 961-2670. San Rafael: TheByte Shop, (415) 457-9311. Walnut Creek:The Byte Shop, (415) 933-6252. CO: Denver:The Byte Shop, (303) 399-8995. CT: Bethel:Technology Systems, (203) 748-6856. FL: Ft.Lauderdale: Byte Shop of Ft. Lauderdale,(305) 561-2983. Miami: Byte Shop of Miami,(305) 264-2983. Tampa: MicrocomputerSystems, (813) 879-4301. IL: Lombard: MidwestMicrocomputer, (312)495-9889. IA:Davenport: Memory Bank, (319) 386-3330. KY:Louisville: Martronix Associates, (502)459-0500. MD: Silver Springs: Computers Etc.,(301) 588-3748. Towson: Computers Etc.,(301) 296-0520. MO: Florissant: ComputerCountry, (314) 921-4434. NH: Nashua:Computerland of Nashua, (603) 889-5238. NJ:Cherry Hill: Computer Emporium, (609)667-7555. Iselin: Computer Mart of New Jersey,(201) 283-0600. NY: Endwell: The ComputerTree, (607) 748-1223. Syracuse: Computer Shopof Syracuse, (315) 637-6208. White Plains:The Computer Corner, (914) 949-3282. NC:Raleigh: ROM's N' RAM's, (919) 781-0003OH: Akron: The Basic Computer Shop,(216) 867-0808. OR: Beaverton: Byte ShopComputer Store, (503) 644-2686. Portland:Byte Shop Computer Store, (503) 223-3496.PA: King of Prussia: Computer Mart ofPennsylvania, (215) 265-2580. Rl: Warwick:Computer Power, Inc., (401) 738-4477.TN: Kingsport: Microproducts & Systems, (615)245-8081. TX: Arlington: Computer Port,(817) 469-1502. Arlington: Microstore, (817)461-6081. Houston: Interactive Computers,(713) 772-5257. Houston: Interactive Computers,(713) 486-0291. Lubbock: NeighborhoodComputer Store, (806) 797-1468. Richardson;Micro Store, (214) 231-1096. UT: Salt LakeCity: Home Computer Store, (801) 484-6502.WA: Bellevue: Byte Shop Computer Store, (206)746-0651. Seattle: Byte Shop of Seattle,(206) 622-7196. Wl: Madison: The MadisonComputer Store, (608) 255-5552. Milwaukee:The Milwaukee Computer Store, (414)445-4280.DC: Georgetown: Georgetown ComputerEmporium, (202) 337-6545. CANADA: London,Ontario: The Computer Circuit Ltd.. (519)672-9370. Toronto, Ontario: Computer Mart Ltd.,(416) 484-9708. Vancouver, B.C.: BasicComputer Group Ltd.. (604) 736-7474,ARGENTINA: Buenos Aires: Basis SistemasDigitales, 93-1988 or 57-7177 AUSTRALIA:Sydney: Automation Statham, (02) 709 4144.BELGIUM: Bruxelles: S.P.R.L. Finncontact,2/345-98-95. COLUMBIA: Bogota: VideoNational, 326650. MEXICO: Mexico City:Industrias Digitales, (905) 524-5132.PHILIPPINES: San Juan, Metro Manila: IntegratedComputer Systems, Inc., 78-40-71. SPAIN:Barcelona: Interface S.A., (93) 301 7851.SWEDEN: Stockholm: Wernor Eiektronik, (0)8717-62-88. UNITED KINGDOM: Huntingdon,England: Comart, Ltd., (O480) 74356.VENEZUELA: Los Ruices,Caracas:ComponentesYCircuitos ElectronicosTTLCA, 355591.

December 1978 ©8YTE Publications Inc

Circle 305 on inquiry card.

&r'''

Soli The small computer that won'tfence you in.

A lot of semantic nonsense isbeing tossed around by some of themakers of so-called "personal"computers. To hear them tell it, aninvestment of a few hundreddollars will give you a computerto run your small business, dofinancial planning, analyze data inthe engineering or scientificlab — and when day is done playgames by the hour.

Well, the game part is true.The rest of the claims should betaken with a grain of salt. Onlya few personal computers have thecapacity to grow and handlemeaningful work in a very realsense. And they don't comefor peanuts.

Remember, there's nofree lunch.

So before you buy any personalcomputer, consider Sol® Itcosts more at the start but less inthe end. It can grow with yourability to use it. Sol is not cheap.But it's not a delusion either.

Sol small computers are at thevery top of the microcomputer

spectrum. They stand up to thecapabilities of mini systemscosting four times as much.

No wonder we call it theserious solution to the smallcomputer question.

Sol is the small computersystem to do the general ledger andthe payroll. Solve engineeringand scientific problems. Use it forword processing. Program itfor computer aided instruction.Use it anywhere you wantversatile computer power!

Build computer powerwith our software.

At Processor Technology we'vetailored a group of high-levellanguages, an assembler and otherpackages to suit the widecapabilities of our hardware.

Our exclusive Extended BASICis a fine example. This BASICfeatures complete matrix functions.It comes on cassette or in adisk version which has random aswell as sequential files.

Processor Technology FORTRANis similar to FORTRAN IV and

has a full set of extensions designedfor the "stand alone" computerenvironment.

Our PILOT is an excellent textoriented language for teachers.

Sold and serviced only by thebest dealers.

Sol Systems are sold and servicedby an outstanding group ofconveniently located computerstores throughout the U.S.and Canada.

For more information contactyour nearest dealer in theadjacent list. Or write DepartmentB, Processor Technology,7100 Johnson Industrial Drive,Pleasanton, CA 94566. Phone(415) 829-2600.

In sum, all small computersare not created equaland Sol users know it to theireverlasting satisfaction.

ProcessorTechnotogy

hy Appleselling p

i

'hich personal computer will bemost enjoyable and rewarding for you?Since we delivered our first Apple® IIin April, 1977, more people have chosenour computer than all other personalcomputers combined. Here are thereasons Apple has become such anoverwhelming favorite.

Apple is a fully tested and assembledmainframe computer. You won't needto spend weeks and months in assembly.Just take an Apple home, plug it in,hook up your color TV* and any cassettetape deck—and the fun begins.

To ensure that the fun never stops,and to keep Apple working hard, we'vespent the last year expanding the Applesystem. There are new peripherals,new software, and the Apple II BasicProgramming Manual. And wait tillyou see the Apple magazine to keep

is the worlds" nal computer.

satisfaction a personal computer canbring, today and in the future.

& hi-resolutiongraphics, too.

Don't settle for a black andwhite display! Connect yotApple to a color TV andBASIC gives you instantcommand of three displaymodes: Text, 40h x 48vColor-graphics in 15 color:and a 280h x 192v HighResolutionarray thatlets you plographs andcompose3-D imagesApple give;you the addecapability of combinintext and graphics, too.

Back to basics, andassembly language too.

Apple speaks three languages: fa;integer BASIC, floating point BASICfor scientific and financial applications,and 6502 assembly language. That'smaximum programming flexibility. Andto preserve user's space, both integerBASIC and monitor are permanentlystored in 8K bytes of ROM, so youhave an easy-to-use, universal languageinstantly available. BASIC gives yougraphic commands: COLOR=, VLIN,HLIN, PLOT and SCRN. And directmemory access, with PEEK, POKEand CALL commands.

owners on top of what's new.

Apple is so powerful and easy to usethat you'll find dozens of applications.There are Apples in major universities,helping teach computer skills. Thereare Apples in the office, where they'rebeing programmed to control inven-tories, chart stocks and balance thebooks. And there are Apples at home,where they can help manage the familybudget, control your home's environ-ment, teach arithmetic and foreignlanguages and, of course, enable youto create hundreds of sound andaction video games.

When you buy an Apple II you'reinvesting in the leading edge of tech-nology. Apple was the first computerto come with BASIC in ROM, forexample. And the first computer withup to 48K bytes RAM on one board,using advanced, high density 16Kdevices. We're working to keep Applethe most up-to-date personal computermoney can buy. Apple II delivers thefeatures you need to enjoy the real

Software: Ours and yours*

There's a growing selection of pre-programmed software from the AppleSoftware Bank—BasicFinance, Checkbook, HighResolution Graphics andmore. Now there's a UserSection in our bank, to makeit easy for you to obtainprograms developed

other Apple owners. Our Softwareink is your link to Apple owners aller the world.

live withle soundf music.

Apple's ex-isive built-in>eaker deliverse added dimension of sound to yourograms. Sound to compose electronicusic. Sound to liven up games andlucational programs. Sound, so thatly program can "talk" back to you.hat's an example of Apple's "people)mpatible" design. Another is its light,irable injection-molded case, so youin take Apple with you. And therofessional quality, typewriter-style^yboard has n-key rollover, for fast,rror-free operator interaction.

kppleisthenroveii computer.

Apple is a state-of-the-art singleoard computer, with advanced LSIesign to keep component count to alinimum. That makes it more reliable,f glitches do occur, the fully socketed»oard and built-in diagnostics sim-»lify troubleshooting. In fact, on ourissembly line, we use Apples to&fct new Apples.

pple II plugs into any standard TV usingn inexpensive modulator (not included).

) California, call 408/996-1010.

Apple peripheralsare smart peripherals.

Watch the far right column of this adeach month for the latest in our grow-ing family of peripherals. We call them"intelligent interfaces." They're smartperipherals, so you can plug them inand run them from BASIC withouthaving to develop custom software.No other personal computer comesclose to Apple's expandability. In addi-tion to the built-in video interface, cas-sette I/O, and four A/D inputs with twocontinuously variable game paddles,Apple has eight peripheral slots, threeTTL inputs and four TTL outputs. Plusa powerful, state-of-the-art switchingpower supply that can drive all yourApple peripherals.

Available now.

Apple is in stock and ready fordelivery at a store near you. Call us forthe dealer nearest you. Or, for moredetails and a copy of our "Consumer'sGuide to Personal Computers" call

800/538-9696**or write AppleComputer, Inc.,10260 BandleyDrive, Cuper-

4

****

95014.

ty card.

^pjcippkz computer

Programming is a snap!I'm halfway through Apple's BASICnanual and already I've programmed

my own space wars game.

Those math programs I wrotelast week-1 just rewrote them usingApple's mini-assembler and got them

to run a hundred times faster.

New from Apple.

Valuable new series of softwarepackages for investors

Now private investors can generatetheir own stock market reports and per-form critical investment analysis instantlywith Apple II. Just log your Apple IIcomputer on to Dow Jones' central databank with powerful Apple software: theDow Jones Series. The first two of thesehighly practical programsare available now.

With Apple's StockQuote Reporterprogram, a local tele-phone calllinks you toDow Jones'continuouslyupdatedstock quotes formore than

6000 com-panies listedon six major U.S.exchanges. Currentactivity for stocks inthe investors portfolio is deliveredautomatically: ask/open, bid/close, high,low and last prices, and volume traded.Our Portfolio Evaluator enablesyou to analyze current value of yourportfolio, and short- and long-term gain/loss for each stock—or for your entireportfolio.

Cost of Apple's Dow Jones serviceis a one time contract fee of $25, whichincludes the Stock Quote Reporter pro-gram. An additional $3 charge is madefor the first three minutes of any transac-tion and 500 per minute thereafter.

To take advantage of Apple's newfinancial services, Apple II users needonly a communications card, a modemand an ordinary telephone. This equip-ment, the Dow Jones Series, and a broadselection of other Apple software arenow in stock at your local Apple dealer.

Circle 15 on inquiry card.

Apple's smart peripherals make

expansion easy. Just plug 'em in and

they're ready to run. I've already

added two disks, a printer and the

communications card.

r

Letters

PASCAL PRAISE

1 have just finished absorbing thePascal articles and editorial in the August1978 BYTE. If I were a crowd, I'd carryyou off on my shoulders, cheering.

The pressure of monthly deadlinesseems to have reduced most computeristperiodicals to compendia of "How I DidThis" and "How to Make That." Recentthemed issues of BYTE, though, showexceptional maturity and some solidplanning. Your reasoned advocacy of apowerful, common language, with sup-portive material gathered into onereference issue, ranks as the most impor-tant contribution yet.

Pascal appears satisfactory for all ourpurposes. The concept of p-code pro-vides the mechanism for bringing it tofruition.

Onward, computerists! The millingabout is over.

Paul F Doering

56 Elmore Rd

Rochester NY 14618

AUTOMATON TRUMPETER LIVES

On pages 105 and 106 of "AntiqueMechanical Computers, Part 2" inAugust 1978 BYTE there are referencesto automaton trumpeters and a state-ment that none survive.

I just returned from Europe and ob-served at the Deutsches Museum inMunich Germany a life-sized auto-maton trumpeter. One half (left side)is clothed and the other half is exposedso that the mechanism is visible. Pressedfor time, I was not able to find out if itstill operates, or who constructed it.

William Harmon2662 Grand SummitTorrance CA 90505

COMPUTERS AND ADVERTISING

I am working on both a book and amagazine piece about the use of com-puters in the field of advertising-parti-cularly in media control, includingproduction scheduling, space acquisitionand scheduling for print and broadcastmedia.

I would be grateful if any BYTEreaders with experience in this relativelyuntapped software area could send meany information they may have, includ-ing any programming information whichmight be helpful.

I am also interested in a programwhich not only includes production and

scheduling control, but carries the wholeprogram right through to a daily alertprintout, client billing, and acquisitionof advertising space and time.

Maybe I'm asking for too much—butI have a feeling that someone out theremay have already worked this out or isat work on it.

In any event, to anyone who wouldcare to send me information 1 can use inmy projected book and article, I wouldbe most grateful.

Larry Ashman

1624 Dole St #1004

Honolulu HI 96822

SIGNETICS 2650: A CORRECTION

I have just finished reading "How toChoose a Microprocessor" by LouFrenzel, page 124, in July 1978 BYTE. Ifeel that the advice he gives is excellent;however I also feel compelled to correctan inaccuracy in his section on theSignetics 2650, I own and constantly usea 2650 based microcomputer made bythe Central Data Corp. This is availablein a basic 1 board configuration com-plete with on board programmablememory, read only memory, cassetteand video input and outout (IO). It isexpandable to an S-100 system withfloppy disks, 8 K and 12 K BASICinterpreters, assembler/editor, and de-bugging program. Central Data alsopublishes a regular newsletter to com-municate with the already large numberof users of this system.

I have programmed PDP-11s, 8080s,the 2650, and a SC/MP. The 2650instruction set comes closest to thepower of the PDP-11, and I find it a realpleasure to use.

Gordon Brandly

RR2

Fort Sask

Alberta CANADA T8L 2N8

SOME REFERENCES ONNETWORKING AND PROTOCOLS

Concerning your editorial in July1978 BYTE, there are two pieces ofliterature which your readers may wantto review. Both concern the Octopuscomputer network in use at LawrenceLivermore Laboratory in LivermoreCA, which is one of the campuses of theUniversity of California.

The first article is in Datamation,April 19 1973, pages 58 thru 63. Thesecond article is in Computer Design,July 1978, pages 77 thru 86.

The most impressive points of theOctopus network design are simplicity ofboth software and hardware implemen-tation; suitability for use with standard,inexpensive, byte oriented, asyn-chronous modem hardware; and easy

Continued on page 158

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10

December 1978© BYTE Publications Inc

Circle 75 on inquiry card.

If the truth is that you want acomputer . . . then we want to be yourcomputer store.

We're ComputerLand, the #1computer store chain in the U.S. What'smeaningful about that fact is, thatComputerLand has been chosen by morepeople as having what they've beenlooking for. And, since you're looking, letus tell you what you'll find, when you visita ComputerLand store.

You'll find a product line that'scontinually evaluated to provide you withthe widest and best selection in quality,brand name microcomputers anywhere.You'll find an enthusiastic andknowledgeable staff able to interpret allthe equipment specifications, in terms ofhow they apply to you, and in a wayyou'll 'understand. You'll find demonstrationareas where you can get a firsthandexpedience of running a computer yourself.

You'll find educational materials to giveyou a total insight into the world ofmicrocomputers.

You'll find a fully equipped servicedepartment to provide whatever assistanceis required to keep your computer runningin top-notch condition. You'll find computeruser's clubs to join, where you can shareideas with people as enthusiastic asyourself. And, with each new visit, you'llfind excitement—from the people you dealwith, the equipment they offer, and fromyour own ever-growing personalinvolvement.

Enough about us. How about whatcomputers do.To attempt to describe allthe things your computer might do, wouldbe to describe your imagination. Soinstead, we'll briefly list some of the manythings for which small computers arealready being used.

In business, the advent of theversatile and compact microcomputer hasput the benefits of computing within reachof small companies. With systems startingat less than $6000, the businessman can

computerize things like accounting,inventory control, record keeping, wordprocessing and more. The net result is thereduction of administrative overhead andthe improvement of efficiency which allowsthe business to be managed moreeffectively.

In the home, a computer can be usedfor personal budgeting, tracking the stockmarket, evaluating investment opportunities,controlling heating to conserve energy,running security alarm systems, automatingthe garden's watering, storing recipes,designing challenging games, tutoring thechildren . . . and the list goes on.

In industry, the basic applications arein engineering development, processcontrol, and scientific and analytical work.Users of microcomputers in industryhave found them to be reliable, cost-effective tools which provide computingcapability to many who would otherwisehave to wait for time on a big computer,or work with no computer at all.

ComputerLand

WE KNOW SMALL COMPUTERS

14400 Catalina St., San Leandro, CA 94577 (415) 895-9363 • Franchise Opportunities Available

And now we come to you, which leadsus right back to where we started; If youwant a computer, then we want to beyour computer store.

Whether you want a computer for thehome, business or industry, come toComputerLand first. We'll make it easy foryou to own your first computer. Because,simply put, we really want your business.When you come right down to it, that'swhat makes us #1.

<§

BYTE December 1978

11

DYN ABYTE COMPUTERS

ARE ALL BUSINESS

INSIDE AND OUT.

J

When we designed our new smallbusiness computers, we meant busi-ness.

As basic as that seems, it is unique.Just about every other microcomputerbeing sold as a small business systemtoday was originally designed as a kitfor hobbyists.

Every design decision was madewith quality and reliability in mind. Theresult is dependable performance and asolid appearance for business, profes-sional and scientific applications.

FIRST SMALL SYSTEM WITHBIG SYSTEM STORAGE

Many applications handle largequantities of information, so the DB8/2uses two quad density 5-inch diskdrives with our exclusive Dual DensityDisk Controller for up to 1.2 megabytesof formatted storage. That's morecapacity than two single density 8-inchdrives.

If you need more storage, ourDB8/4 has two 8-inch drives with up to2 megabytes capacity, more than anyother dual floppy disk system on themarket.

OUR SOFTWARE ISBIG ON BUSINESS

Dynabyte helps you get down tobusiness immediately. The DB8/2 is thefirst microcomputer to offer enoughstorage capacity on 5-inch drives tofully utilize CP/M,* the most widelyaccepted disk operating system. Wealso supply and support BASIC, FOR-

* CP/M is a trademark of Digital Research.

TRAN and COBOL programming lan-guages. Our applications packages in-clude general ledger, accounts receiv-able, word processing and many otherCP/M compatible programs.

Reliability is a big consideration inbuying a business computer, so we builtit in. Our edge connectors meet militaryspecifications, the toughest electronicsmanufacturing standard. Our regulatedpower supply is designed to meet U.L.standards, which means the entire sys-tem runs cool and dependable. And ourcast aluminum enclosures are rugged aswell as attractive.

AND THE BIGGESTTHING OF ALL

Customer support. Our supportstarts at the factory with testing andbum-in programs that assure the entireintegrated system is reliable prior toshipment. Our completely modular de-sign allows continuing support in thefield. We maintain a bonded inventoryof all sub-system modules which meanswe can deliver replacement sub-assemblies overnight nearly anywherein the continental U.S.

Dynabyte built in little things, too.Like a fully-populated 12-slotbackplane, switched AC outlets for ac-cessories, an option for Europeanpower, quiet whisper fans with long-lifemetal construction, lighted indicatorswitches for Power On and Halt, ashielded enclosure to protect disk drivesfrom electro-mechanical interference,and a fully enclosed power supply for

operator safety.

Since we didn't cut corners in de-sign, the price/performance ratios ofour systems make good business sense.

THE INSIDE FACTS

The DB8/2 Computer System in-cludes two 5-inch disk drives eithersingle or double sided for up to 1.2megabytes of mass storage; a 4MHzZ-80 processing module with oneparallel and two serial ports, anEPROM programmer and up to 4kROM; 32k of RAM, a 12-slot fully-populated backplane; our exclusiveDual Density Disk Controller, andCP/M.

The DB8/1 Computer includes a4MHz Z-80 processor with one paralleland two serial I/O ports, an EPROMprogrammer and up to 4k of ROM; 32kRAM, and a 12-slot fully-populatedbackplane.

The DB8/4 Disk System, designedto be the mass storage companion to theDB8/1, includes two 8-inch floppy diskdrives in either single or double sidedconfiguration for up to 2 megabytes ofmass storage, our Dual Density DiskController, and CP/M.

All three units will be available inrack mount models.

For a descriptive brochure andprice list, call or write Dynabyte, 1005Elwell Court, Palo Alto, CA 94303.Phone (415) 965-1010.

Or better yet, see your local dealer.

YOU CAN DEPEND ON IT.

Circle 110 on inquiry card.

BYTE December 1978

13

(«)

(b)

Fast Fourier

Transforms

on Your

Home Computer

Figure 1: An arbitrary continuous signal x(t) expressed as a function of time (a) may aiso be described by its spectrum orFourier transform X(f), which is expressed as a function of frequency (b). The reiative strength of the spectrum at different fre-quencies is a measure of the frequency content that comprises the given signai. The concept of spectrum finds numerous appli-cations in many varied disciplines including music waveform analysis, communications signal analysis, mechanical vibrations,oceanography, statistics, and others. In signal analysis, the function x(t) is said to be a time domain representation, and X(f) issaid to be a frequency domain representation.

William D Stanley

Steven J Peterson

Dept of Electrical Engineering

Old Dominion University

Norfolk VA 23508

The advent of the home computer makespossible many new and varied applicationsboth of a general nature and of a scientificor mathematical nature. One of the latterapplications we have successfully imple-mented on a personal computer is the fastFourier transform, which we will subse-quently refer to as the FFT, according tostandard usage. Some of the most importantproperties of the FFT are described in thisarticle, and an FFT program written for theDigital Group Z-80 System using BASICis provided.

Continuous Fourier Transform

Before discussing the FFT in particular,it is desirable to briefly survey some of thegeneral concepts of the classical continuousFourier (pronounced "foor-yay") trans-form. The terminology used refers to timeand frequency since they are among themost common variables of interest in manyapplications, although the theory involvedapplies to a variety of different types ofphysical phenomena.

Consider the waveform x(t) shown infigure la which is displayed as a function oftime (denoted by t). The waveform can alsobe described by the frequencies present in

the signal. This description is called thespectrum of the time signal and, mathe-matically, it is the Fourier transform of thetime function. The process of Fourier trans-formation is represented by the mathemati-cal function

\

X(f) = /'

x(t)e

-j27Tft

dt

where X(f) is the Fourier transform of x(t).[The constant j is used in electrical engineer-ing to denote >>/—7, aiso called i. The num-ber e, 2.71828, is the base of the naturalalgorithms. . . .CM/ For all but fairly simplefunctions, this mathematical process repre-sented a formidable operation for manyyears. Prior to the development of the digitalcomputer, many analytical and experimentalmethods were investigated for determiningthe approximate spectra of functions thatarose in physical systems.

The magnitude of a typical spectrum isshown in figure 1b and is denoted by IX(f)l,where f represents the frequency in Hertz(Hz). For example, if x(t) were a music sig-nal, strong peaks of the spectrum at lowfrequencies would be characteristic of a sig-nificant amount of bass content such as

14

December 1978 ©BYTE Publications Inc

e miast ot tnetalk and the promises...

•'ill : . i-

1 }}}■* I 1 *■

!.'..»:.

»fi*

■

~~T\f

mm

«C5^**

x ■ w. )

PerSci delivers the Dual-Headed Diskette Drive that works andthe Double Density IBM Compatible Controller to back it up.

■

While everyone else was waiting andpromising—PerSci did it! Designed the industry'sfirst fully reliable, field proven, dual-headdesign—now available in a high technology dualdiskette drive, the PerSci Model 299. The 299 has atotal of four heads handling two double-sideddiskettes—providing up to 3.2 Mbytes ofdata in a drive the size of a standardfloppy. And because the Model 299 hasvoice coil positioning, this dual diskettedrive can seek data four to six timesfaster than possible on two independ-ent stepper motor drives. All offeredby PerSci at a highly competitiveOEM price.

To save time and money in systems

ircle 289 on inquiry card.

PerSci

Peripherals aGeneration Ahead

design, PerSci backs up the 299 with the first avail-able double density, dual-head flexible diskcontroller—the Model 1170—for all applicationsrequiring IBM 2D, IBM 3740 or S-100 bus compatibil-ity The PerSci 1170 is Z-80 based, the smallest, mostintelligent floppy disk controller on the market.The PerSci 299 and 1170 controller are de-signed with the same advancedtechnology that has made PerScinumber three in diskette product ship-ments (and moving up). Don't waitaround for more talk and more prom-ises. Call PerSci for full information.PerSci, Inc., 12210 Nebraska Avenue,West Los Angeles, California 90025.(213) 820-3764.

BYTE December 197S 15

drums or tubas. Conversely, many stringinstruments such as the violin displaystronger peaks at higher frequencies in theaudio spectrum. The frequency spectrum (orFourier transform) thus provides a plot ofthe relative weight of different frequenciesthat comprise or represent the given signal.If the Fourier transform or spectrum of asignal is known, the time function may bedetermined from the inverse transformationwhich is given by

x(t)

r

' \2nft

X(f)e df

Observe that the inverse transform has essen-tially the same general form as the directtransform except for the sign of the expo-nential argument.

The concept of the frequency spectrumhas long played a most important role innumerous scientific applications and hasbeen of interest to mathematicians, engi-neers and scientists of many different dis-ciplines. Among the areas where spectralanalysis has been employed are sound andmusic analysis, communications systemsdesign, analysis of mechanical vibrations,ocean wave analysis, statistics and manyothers.

x (n)

hi

POINT WHERE NEWPERIOD BEGINS

TIME INTEGER

(a)

[X (m)|

Ll±

\ !

_l L

, POINT WHERE NEWPERIOD BEGINS

M F K-

FREQUENCY INTEGER(HARMONIC NUMBER)

(b)

Figure 2: A sampled function of time (a) and its discrete Fourier transformspectrum (b)> The discrete Fourier transform (DFT) functions are used toapproximate the continuous transform functions whenever digital implemen-tation is to be used. The time function is sampled at N points separated by anincrement T over an interval tp = NT to create a discrete function x(n). Theresulting spectrum X(m) is periodic with a period fs ** J/T and contains Ncomponents within one period with spacing between components F= 7/tp. ifx(n) is a real function, only half or N/2 of the spectral components areunique. The integers n and m represent the time and frequency integers whichidentify the location in the sequence of the time sample (t = nT) and thefrequency component or harmonic number (f = mF).

Discrete Fourier Transform

The heart of the FFT is a mathematicaloperation known as the discrete Fouriertransform (DFT). In the DFT, a set of inte-gers n and m are defined to represent theequivalent in a sense of the time and fre-quency variables, respectively, of the con-tinuous Fourier transform. This correspond-ence is best seen by observing the sampledsignal x(n) shown in figure 2a. There areassumed to be N samples of the signalspaced T seconds apart. Thus, as n variesfrom 0 to N—1, the N samples of the timesignal are generated. The duration of thetime signal is tp = NT.

The DFT of x(n) is defined by the finitesummation

N-1

XM=^[ E *<n)wmn

n=0

where

W:

-J27T

N

The function X(m) represents a discretespectrum with m serving the same purposein frequency as n did in time. The frequencyincrement between successive components isF = 1/tp so that the spectral component at afrequency mF is X(m). For x(n) real and forN time points, a unique spectrum can becomputed only at N/2 frequency points.Actually, X(m) is periodic in m with Npoints in each period, but only N/2 areunique. X(m) is, in general, a complex func-tion consisting of a real and an imaginarypart at each frequency. For many applica-tions, the magnitude spectrum IX(m) I is thequantity of most significance. Some of thepreceding points are illustrated in figure 2b.As in the case of continuous signals, aninverse discrete Fourier transform (IDFT)can be defined. In this case, the inversetransformation is

16

December 1978© BYTE Publications Inc

It may be a hobby, or it may be an asset...It SHOULD be a Heathkit Computer System

/

No matter what your computer systemneeds may be, Heathkit computers makesense! Heathkit "total design" computersystems give you a wide selection ofperipherals, software programs to getyou up and running fast; pius the reliabil-ity, service and responsibility that comefrom being a leader in the electronicsindustry for some 50 years!

OUR 8-BIT COMPUTER

Every Heathkit Computer Product is designedto offer substantial benefits over competitiveproducts on the market. Our 8080A-basedH8 for example, is more than just a simple8-bit machine. With its "intelligent" frontpanel and keyboard entry and digital dis-play, it actually lets you compute and pro-gram without the addition of any peripherals.It's an ideal computer training system, andwhen you're ready to advance, its ready too.It's one of the most expandable computersaround, and now with its NEW floppy disksystem, it could be the only computer you'llever need.

OUR 16-BIT COMPUTER

If you need the power, speed and versatilityof a 16-bit machine, there's nothing betterthan our H11A. Based on the famous DEC LSI-11/2, the H11A provides complete DEC com-patibility and access to the thousands ofpractical software programs and applicationsthat entails. Along with our own completesystems software and our line of DEC-com-patible peripherals including the DEC Writer

II and our new floppy disk, you'll have state-of-the-art computing power at its very best!

OUR PERIPHERALS

The Heathkit Computer peripherals offer thesame competitive advantages of our twocomputers. Our H9 CRT terminal, H10 papertape reader/punch, ECP-3801 cassette stor-age recorder/player, and our new WH14 lineprinter, plus the new fJoppy disk storage sys-tems all give you the quality, performanceand value that Heath company is famousfor. And we sell the memory, I/O interfacesand accessories you need to custom designa system to your particular specifications!

ALL THIS,

PLUS HEATH DOCUMENTATION,

SERVICE AND SUPPORT

One of the most important parts of ANY com-puter system is documentation. And Heathdocumentation is quite simply, the bestaround. If you buy our computer products inkit form, you get a comprehensive step-by-step assembly manual that takes you everystep of the way from unpacking to final plug-in. The knowledge you gain in building yourHeathkit computer is invaluable-for serviceif it's ever needed, for quick troubleshootingand correction, and just for understandingthe workings of the machine. In both our kitand fully assembled products, our compre-hensive operating and instruction manualsare fully detailed, thorough and accurate.This documentation, plus Heathkit technicalconsultants and service nationwide, makeyour Heathkit computer system one you candepend on-to work right the first time, andto last for years!

SEND FOR YOURFREE CATALOG

Read all about these Heathkit computerproducts and peripherals in the new FREEHeathkit catalog. Write Heath Company,Dept. 334-482 for your FREE copy. Or visityour Heathkit Electronic Center (Units ofSchlumberger Products Corporation).

HEATHKITCOMPUTERS

Systems Engineeredfor Personal Computing

Heath Co. Dept. 334-482Benton Harbor, Ml 49022

CP-159

Circle 160 on inquiry card.

BYTE December 1978

17

x(0)

x(2)

x(3)

x(4)

x(5)

x(6)

x(7)

N-1x(n) = £ X(m)W-mnm=0

The resulting function is periodic in the vari-able n and has N points in one period. Thus,even if the original time signal were not

X(0)

X (4)

X(2)

X(6)

X(l)

X(5)

X(3)

X(7)

Figure 3: Flow diagram indicating the computations involved in an 8 pointfast Fourier transform (FFT) implementation of the discrete Fourier trans-form (OFT) function. Significant reductions in computation time areachieved with FFT realizations of large arrays. For example, the computa-tion time for a 1024 (2 ) sequence of samples using an FFT is approxi-mately 1 percent of the time required by direct application of the DFT.in the chart, two paths merging together in a given column represent acombination of two quantities in the preceding column. For example,the first quantity in the second column is obtained by forming x(0) +W°x(4). The first term is indicated by the dashed line and the second isindicated by the solid line. The integer in the circle is the power of W. (Seetext for definition of W.) The pattern continues until the spectrum appearsin the last column. This particular algorithm for the FFT results in a scram-bled order for the spectral coefficients as can be seen from the chart. Somevariations result in a natural order but require more internal memory.

periodic, the operation of the IDFT pro-duces a function capable of providing thedesired results in one cycle, but the patterncontinues to repeat itself if the interval isextended outside of the basic range.

Observation of the definition of the DFTreveals that there are approximately N com-plex multiplications and about the samenumber of complex additions required to

compute the spectrum at one particularvalue of m. Since there are N/2 uniquespectral components, the total number ofcomputations required to generate a com-plete spectrum is of the order of N2. TheCooley-Tukey algorithm, published in 1965,demonstrates one way to perform thistransformation with a number of computa-tions of the order of N log2(N), which turnsout to be an enormous savings in computa-tional time for long signal records. TheCooley-Tukey algorithm, along with subse-quent variations, is referred to as the fastFourier transform (FFT). Thus, the FFT isa high speed algorithm for computing thediscrete Fourier transform.

While the DFT is a finite summation andthe classical Fourier transform is an inte-gral transform, the DFT may be used toclosely approximate the continuous functionunder many circumstances. Some of the con-cepts involved with such an approximationare considered later in this article.

The various FFT algorithms work bestwhen the number of points in the samplerecord is an integer power of 2, ie: N = 2k,where k is an integer. The form of one ofthe basic algorithms is shown in figure 3for the case of N = 8. Obviously, N = 8 isfar too small for most applications, but theflow graph is of interest in understandingthe form of the general computationalalgorithm. This particular algorithm isreferred to as an in place algorithm sinceat each stage of the computation, the datamay be stored in the same memory loca-tions from which they were obtained.

Implementation of In Place Algorithm

The in place algorithm previously dis-cussed was implemented on the DigitalGroup Z-80 System using BASIC. The pro-gram is given in listing 1. The particularsystem used had 18 K bytes of memory,of which about 12 K bytes were requiredfor the BASIC software. It was determinedthat a 256 point transform could be com-puted with this system and the programlisted uses this capacity. It could be readilyexpanded or contracted as the availablememory size dictates. However, the sizeselected should be chosen as an integerpower of 2 as previously noted. Thus, thenext smaller size should be 128 and thenext larger size should be 51 2,

In order to reduce the memory require-ments, the trigonometric functions aregenerated as they are required in the pro-gram. This approach is not nearly as effi-cient from the standpoint of computationtime as would be the process of initiallygenerating and storing the functions in

18

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Listing 1: Fast Fourier transform routinedescribed in text. Lines 10 to 499 are avail-able for the user to describe the time func-tion that is to be studied.

2 DIM XK256) >X2<256)

4 N=2S6 : L=8 : PI=3.14157

6 REM — GENERATE TIME FUNCTIUN

10 REM

20 REM LINE NUMBERS 10-499 ARE USO TO

30 REM GENERATE OR INPUT THE TIME FUNCTION

40 REM

500 PRINT 'DO YOU WANT A LISTING OF THE GENERATED TIME FUNCTION

510 INPUT A$

520 IF A*-'NO' THEN 640

530 IF A$<>"YES" THEN 500

540 B=X1(0)

550 FOR Z-0 TO N-1

560 IF ABS<XKZ))>B THEN B^ABStXKZ))

580 NEXT Z

600 FOR Z=0 TO N-l

610 PRINT XKZWTABMl+ZOiXKZ^'B)?1*'

620 NEXT Z

630 REM - SCALE INPUT TIME FUNCTION -

640 FOR Z-0 TO N-l

650 X1(Z)=X1(Z)/N

660 NEXT Z

670 REM - - FFT IN-PLACE ALGORITHM - -

675 PRINT" - FFT CALCULATION IN PROGRESS -■

680 Il=N/2 : 12*1 I V^2*P1/N

690 FOR 1*1 TO L

700 13*0 t I4-I1

710 FOR K»l TO 12

720 X^INTC13/11)

730 GOSUB 1300

740 I5=Y

750 Z1=CQS<V*I5)

760 Z2=-SIN(V*IS>

770 FOR M*I3 TO 14-1

780 A1=X1(M) : A2*X2(M>

790 B1=Z1*XKM+I1)-Z2*X2<N+I1)

800 B2«Z2*XKH+I1)+Z1*X2(M+I1)

810 X1<M)=A1+B1 t* X2(M)-=A2 + B2

820 X1<H+X1)*A1-B1 : X2<M+I1)=A2-B2

830 NEXT M

840 13=13 + 2*11 I 14=^14 + 2*11

850 NEXT K

860 11=11/2 J 12=2*12

870 NEXT I

880 REM - OUTPUT RESULTS -

890 PRINT'IN UHAT FORM DO YOU WANT THE OUTPUT ?'

900 PRINT' MAGNITUDE SPECTRUM PLOT <1)'

910 PRINT' TABLE OF VALUES 12)'

920 INPUT A

930 IF A=*l THEN 970

940 IF A=*2 THEN 1130

950 PRINT'INCORRECT INPUT (1 OR 2)' t GOTO 890

960 REM - OUTPUT MAGNITUDE SPECTRUM PLOT -

970 B*=0

975 PRINT' - CALCULATIONS IN PROGRESS "

980 FOR 2*0 TO N/2

985 X--Z

990 GOSUB 1390

1000 IF X3>B THEN B=X3

1010 NEXT Z

1020 FOR Z=0 TO N/2

1025 X-=Z

1030 GOSUB 1390

1040 X4*-INT<56*X3/B>

1050 C=^0

1060 PRINT Z;TAB<5)» • I •'■!

1070 C«CU

1080 IF C<X4 THEN PRINT"*** I GOTO 1070

1090 PRINT '"

1100 NEXT Z

1110 GOTO 1240

1120 REM - OUTPUT TABLE OF VALUES

1130 U^O

1140 Z=0

1150 PRINT-HARMONIC»TAB<14)f"REAL"8TAB<30)»

1160 PRINT-IMAGINARY"*TAB<50)i'MAGNITUDE'

1165 X=U

1170 GOSUB 1390

1180 PRINT U?TAB<10>*XUYWTAB<30)fX2(Y>iTAB(50>*X3

1190 U=U+1 J Z=ZU

1200 IF Z>9 THEN 1140

1210 IF U>N/2 THEN 1240

1220 GOTO 1165

1230 REM - TERMINATE ? -

1240 PRINT'DO YOU WANT ANOTHER OUTPUT (YESr NO)-)

1250 INPUT A*

1260 IF A*=-YES" THEN 890

1270 IF AfO'NO" THEN 1240

1280 END

1290 REM - SCRAMBLER SUBROUTINE -

1300 Y=0 I N1=N

1310 FOR W=l TO L

1320 Nl=Nl/2

1330 IF X<N1 THEN 1360

1340 Y=Y+2"(W-1)

1350 X*X-N1

1360 NEXT W

1370 RETURN

1380 REM - MAGNITUDE <X3) SUBROUTINE

1390 GOSUB 1300

1400 X3*SQRT(X1<Y)~2 + X2(Y)"2)

1410 RETURN

1420 END

memory so that they can simply be calledas required. However, where speed is not amajor priority, this approach minimizesthe total memory required.

Statements 10 through 499 in the pro-gram represent the particular input signalfor which the transform is being computed.The time function may be generated byappropriate equations or an algorithm aswill be demonstrated for several case^. later.For experimental data, the values couldbe listed point by point if the functioncannot be readily described by an equation.

Applying the Program

In order to effectively utilize an FFTprogram for spectral analysis, it is neces-sary to understand some of the peculiaritiesof the DFT and its relationship to the con-\tinuous Fourier transform. Although the \time signal may or may not be periodic innature, the mathematical form of the DFTtreats the signal as if it were periodic. Thetotal duration of the time signal is the periodtp, and for the program being considered,this period contains 256 points. If T is thetime increment between samples, thentp = 256 T, The spectrum obtained from theDFT is also periodic and contains N (or256) spectral components. However, for atime function that is real (which incidentallyis the case for all signals considered in thisarticle), it can be shown that half of thecomponents are ambiguous; ie: they aresimilar to the other half and do not repre-sent any actual spectral information. Thus,there are N/2 (or 128) meaningful complexspectral components that are obtained withthe FFT. These components are spaced apartin frequency by F = 1/tp. The value form = 0 corresponds to the DC component,m = 1 is the fundamental, m = 2 is the sec-ond harmonic, etc. According to samplingtheory, a time signal must be sampled at arate at least equal to (practically speaking,greater than) twice the highest frequencycontained in the spectrum. Thus, if thehighest frequency contained in a spectrum

20 December 1978 © BYTE Publications Inc

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BYTE December 1978

21

10 REM GENERATE 25% PULSE

20 FOR Z=0 TO N/4

30 X1(Z)=-1

40 NEXT Z

50 FOR Z=N/4 TO N

60 XKZ>-0

70 NEXT Z

10 REM GENERATE 12.5X PULSE

20 FOR Z-0 TO N/8

30 X1(Z>*1

40 NEXT Z

50 FOR Z^N/8 TO N

60 X1(Z)=0

70 NEXT Z

10 REM - GENERATE 1000HZ SINE WAVE

20 T*0

30 FOR Z-0 TO N-l

40 X1(Z)-SIN(2*3.14159*1000*T)

50 T-T+i.*53123E-4

60 NEXT Z

10 REM - GENERATE 1010HZ SINE WAVE

20 T-0

30 FOR Z»0 TO N-l

40 XKZ)*SIN(2*3.14159*1010»r>

50 T=T+1.953125E-4

60 NEXT Z

Listing 2: Three different generating routines that can be used with listing 7as the time functions. The first routine generates a puise function that iasts25 percent of the time that is being analyzed, The second routine aiso gen-erates a puise but haif as iong as the first routine. The third and fourthroutines generate sine waves which are onty siightiy different.

x(n)

64POINTS

256 POINTS

Figure 4: Rectangular puise for which the FFT is partialiy displayed inphotos i and 2. The pulse is unity for 64 of the 256 points in the timerecord and zero for the remainder.

is known to be no greater than fh, the maxi-mum time between samples (T) should be

chosen to satisfy T < yf. If this condition

is not met, there will be a spectral overlapor aliasing effect which will distort thespectrum.

For a fixed number of points (such as256 for the program under discussion), thereis a trade-off between the high frequencycapability and the spectral resolution. Inorder to analyze higher frequencies, ashorter sampling time is required, but thisnecessitates a shorter overall period and alarger increment between successive fre-quencies. Specifically for 256 points, N/2 =128; and since N = 0 corresponds to DC, thehighest frequency that can be measured is127 times the spectral resolution. It is veryimportant that the sampling rate be chosento be greater than twice the highest fre-quency in the spectrum even if the higherfrequencies are not of interest. If the mini-mum sampling rate requirement is not met,erroneous spectral components may appearat various places in the spectrum.

There are various other properties of theDFT that may be important in applying anFFT program in various situations. Thereader is encouraged to consult one of thereferences listed at the end of this article orthe many other available sources for moreextensive details, since this article providesonly a brief overview of the theory alongwith the details of a workable program fora home computer.

Examples

Several examples that illustrate some ofthe properties of the FFT are now con-sidered. The various function programs forthese waveforms are shown in listing 2. Thefirst example is that of a single rectangularpulse whose duration is 25 percent of thetotal period corresponding to 256/4, or 64points as illustrated in figure 4. (Due to the

Figure 5: Rectangular pulse for which theFFT is partially displayed in photo 3. Thepulse is unity for 32 of the 256 points inthe time record and zero for the remainder.Since this pulse is shorter than the one offigure 4} the spectrum is broader. In gen-erai, there is an inverse relationship betweenthe width of a pulse-like time function andthe width of the frequency spectrum.This property is an important concept insignal transmission and results in the re-quirement of larger band widths for trans-mitting shorter pulse signals.

x(n)

32

POINTS

256 POINTS

22 December 1978 © BYTE Publications Inc

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large number of points, the function isshown as a continuous curve.) The videodisplay of the first 14 spectral componentsin tabular form is shown in photo 1, and thefirst 15 components of the magnitude spec-trum are displayed in photo 2. Henceforth,only the magnitude spectra will be shown.

When the pulse duration is changed to12.5 percent of the period or 32 points as

indicated in figure 5, the magnitude spec-trum changes to the form shown in photo 3.It should be pointed out that the band-width of a rectangular pulse is theoreticallyinfinite in extent and so there is some alias-ing error in each of these cases. However, theeffects of aliasing are not pronounced inthese two examples over the frequency rangeshown in the photos. At larger harmonic

HfWCWC RBflL

imm

mxnuE

Photo 1: The first 14 com-ponents (DC and har-monics up through the13th) of the FFT spec-trum corresponding to thepuise shown in figure 4.The program lists the realpart of X(m), the imagi-nary part of X(m) and themagnitude \X(m) I.

161188213 9BG457SE-03H5.18MSB7MZ

3 3744231E-82

3 986392E-83

-i.mrssM

1.99B9B78E-823 90G3336E-83-1.24Z?S8BE-ffi

e

81489184

-1S719375 mm

-1S912311 .15917186

-5.49818SZE-02 7.9B4H9E-§2

-2 9837BG3E-82- 05235B84-2 46337S-B2

"I

-l.fflSBBEE-K-.83167107-1 B333BGC-82

4.5844181-82

5389972GE-&

3.2193SZZE-82

8

2 98S9713E-82

3.1911861-82

2 85248K-82

-18185S0E-82 1.7387481E-82

Photo 2: Video graphics display of the magnitude spectrumcorresponding to the pulse shown in figure 4, The display isof course rotated 90° from the basic mathematical formillustrated in figure 2.

Photo 3: Video graphics display of the magnitude spectrumcorresponding to the pulse shown in figure 5.

24 December 1978 © BYTE Publications Inc

values for the given signals and at shorterpulse widths for the given frequency range,the aliasing errors would be more significant.

A sine wave representing an assumed fre-quency of 1000 Hz and an assumed samplingtime of T = 0.1953 ms was generated andanalyzed. The resulting spectrum is shownin photo 4. Note that the frequency resolu-tion is F = 1/(0.1953 x 10~3 x 256) = 20 Hzso that 1000 Hz corresponds to harmonicnumber 50. Observe that an ideal single lineappears as one might hope. On the otherhand, when the frequency is changed to1010 Hz while maintaining the same value ofT, the spectrum changes to the form shownin photo 5. The reasons for the strikingdifference are as follows: In the first case,the frequency corresponds exactly to one ofthe harmonic numbers (50th harmonic), anda property of the DFT is that no other linecomponents appear in this case. However, inthe second case, the component wouldtheoretically appear halfway between the50th and 51st harmonics so that the imper-fections of the finite time duration of theobserved sinusoid are now apparent. Thephenomenon observed is called leakage. Itcan also be readily verified that the first si-nusoid was observed over an exact integernumber of cycles, while in the second case,the sinusoid was truncated during a cycle.

This example illustrates the necessity ofunderstanding some of the limitations of the

truncation and sampling processes in orderto properly evaluate results. The phenomenajust noted can be reduced by smoothing thedata to be transformed with certain windowfunctions before computing the FFT. Win-dow functions smooth the beginning andend of a record length and reduce the effectsof leakage on the spectrum.

More Examples

Other applications include the use of ananalog to digital converter to sample speechand music waveforms or the waveforms en-countered in electronic systems. The samplepoints could be stored for later spectralanalysis using the FFT program. We hopereaders will be encouraged to experimentwith the program on their own computers."

REFERENCES

1. Bergland, G D, "A Guided Tour of the FastFourier Transform/' IEEE Spectrum, July1969, pages 41 thru 52.

2. Brig ham, E O, The Fast Fourier Transform,Prentice-Hall, Englewood Cliffs NJ, 1975.

3. Cooley, J W, and Tukey, J W, "An Algorithmfor the Machine Calculation of ComplexFourier Series," Math of Computation, volume19, April 1965, pages 297 thru 301.

4. Stanley, W D, Digital Signal Processing, RestonPublishing Co (a division of Prentice-Hall),Englewood Cliffs Nj, 1975.

Photo 4: Video graphics display of the magnitude spectrumcorresponding to a sine wave whose assumed frequency Is1000 Hz with a sampling interval T = 0.1953 ms. Thisassumption results in an integer number of cycles (50) in therecord duration tp, which corresponds to 50 ms. The fre-quency then corresponds exactly to the 50th harmonic andthe spectrum appears as a single line.

Photo 5: Video graphics display of the magnitude spectrumcorresponding to a sine wave whose assumed frequency is1010 Hz with a sampling interval T = 0.1953 ms. This fre-quency corresponds to the midpoint between the 50th and51st harmonics, and the imperfections of the DFT in repre-senting a continuous time signal now can be seen.

December 1978©BYTE Publications Inc

25

Designing a Universal Turing Machine

A Software Approach

Thomas MunneckeMetasy stems6199 Shaker DrRiverside CA 92506

Hardware or software; which is best? Thisquestion faces many designers when creatingnew systems. This article describes a soft-ware version of a hardware project detailedin December 1976 BYTE by Jonathan KMillen in his article "A Universal TuringMachine," page 114.

The universal Turing machine (UTM) iselegantly simple and capable of emulatingthe instruction set of any computer. TheTuring machine was invented by Alan Turing(1912-1954). It is an abstract computingdevice that contains all the fundamentalproperties a computer system must possessand is used to study computer concepts.Although difficult to program, its back-to-basics nature is alluring to anyone interestedin the fundamentals of computers.

The universal Turing machine designedby Jonathan Millen has two memories: onefor program storage and the other for themain storage or "tape." The tape is a sup-posedly infinite (but actually 1024 bits long)memory which is a series of Is and 0s. A biton the tape is pointed to by a counterknown as the head. A program counterpoints to a state in the program being exe-cuted. Each state consists of two instruc-tions: one to be used if the current bit underthe head of the tape is a 1, the other if it is a0. Each instruction contains fields describingwhether to write a 1 or a 0 on the tape,which direction to move the tape (left orright one position), and the address of thenext state to be executed.

Each instruction contains the followinginformation:

Bit 0: Write bit Write this bit on

the tape after the head is

adjusted.Bit I: Direction bit. If this is a 0,

move the tape to the left;

if it is a 1, move the tape

to the right.Bits 2 thru 7: Next state. These six bits

are the number of the next

state to be executed.

The reader is referred to Millen's articlefor a complete description of the universalTuring machine. His design implementsthis machine with about 15 integratedcircuits. The memories are 2102s, the headand program counter are counters, and thecontrol logic consists of various flip flops,shift registers, clocks and decoders. Thememories are loaded and examined withswitches and a 7 segment light emittingdiode (LED). The design is capable ofexecuting about 40,000 instructions persecond.

iA Software Approach

The program in listing 1 is the logicalequivalent of Millen's hardware versionfor the Motorola 6800 processor. The pro-gram storage, tape, program counter andhead are parts of the computer's memory setaside for those purposes. The memory organ-ization is shown in table 1. The rest of thelogic is programmed via the 6800's instruc-tion set. Table 2 is a comparison of thevarious functions and their implementationin the two approaches.

The program is a relatively straightfor-ward programming of the hardware version.The basic cycle of functions to be performedis:

• Test the bit on the tape under thehead.

• Write a 1 or 0 according to the writebit of the instruction indicated by theprogram counter and the tape bit.

• Move the tape (adjust the head)according to the instruction's direc-tion bit.

• Set the program counter equal to theaddress specified by the address bitsof the instruction.

• Go back to the first step.

Since the 6800 is a byte oriented machine,the head must keep track of both a byte inmemory and a bit within the byte. The

26 December 1978 © BYTE Publications Inc

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BYTE December 1978 27

Listing 1: 6800 assemblerversion of the universalTuring machine, which im-itates the hardware versionbuilt by Jonathan Milfen.This program is capableof executing 10,000 uni-versal Turing machine in-structions per second.

program uses variable HEAD to point tothe byte, and MASK to define the bit.MASK consists of seven Os and a single 1.The 1 corresponds to the bit under con-sideration. For example, suppose the headnow points to the third bit of byte 83(hexadecimal). HEAD and MASK wouldthen be:

HEAD yl 0 0 QA0 0 1 ]y (binary)

8 3 (hexadecimal)

MASK V0Q 1 0^0 0 0/ (binary)

2 0 (hexadecimal)

IB

Hexadecimal

Address

Code

Label

Op Code

ORG

Operand

$0100

Commentary

PC

EQU

$FB

TURING MACHINE PRO-GRAM COUNTER

MASK

EQU

$FD

SPECIFIES BIT IN HEADBYTE

HEAD

EQU

$FE

POINTS TO HEAD OF TAPE

0200

DE FE

BEGIN

LDX

HEAD

GET HEAD OF TAPE ADDR.

0202

D6 FD

LDAB

MASK

MASKS OUT BIT ON HEAD

0204

E5 00

BITB

o,x

IS BIT ON TAPE 0?

0206

27 03

BEQ

ZEROBIT

YES, DON'T INCREMENTPROGRAM COUNTER

0208

7C 00 FC

INC

PC+1

NO, INCREMENT PRO-GRAM COUNTER

020B

DE FB

ZEROBIT

LDX

PC

GET ADDRESS OF NEXTTURING INSTRUCTION

020D A6 00020F 0C

LDAA 0,X GET TURING INSTRUC-

TION IN REGISTER A

CLC CLEAR CARRY PRIOR TO

TESTHEAD GET HEAD BYTE AGAIN

0210 DE FE LDX

*SET HEAD BYTE/MASK UP OR DOWN ONE POSITION IF DIRECTION BIT IS 1OR00212 85 40 BIT A

0214 27 070216 56

0217 24 09

0219021A021 B

021 D

0856

20 0559

021 E 24 02

0220022102220224

0959DF

D7

FEFD

DEC

OK

BEQ

ROR B

BCC

INXROR BBRAROLB

BCC

DEX

ROLB

STX

STAB

*WRITE SPECIFIED BIT ON TAPE

0226 4D

02270229

022A022C

022E0230

2B 0553

E4 0020 02

EA 00E7 00

WRITE1BRANCH

TST A

BMlCOMB

AND BBRA

ORABSTAB

#$40

MASK OFF DIRECTION

BIT

DEC

DECREMENT IF IT IS

ZERO

ROTATE RIGHT IF IT'S A

ONE

OK

NO CARRY TO NEXT

BYTE

INCREMENT HEAD BYTE

SHIFT CARRY THROUGH

OK

ALL DONE

ROTATE MASK LEFT ONE

BIT

OK

NO CARRY TO NEXT

BYTE

DECREMENT HEAD BYTE

ROTATE THRU CARRY

HEAD

RESTORE HEAD POINTER

MASK

RESTORE MASK

CHECK LEFT BIT OF

INSTRUCTION

WRITE1

SKIP IF IT IS ON

COMPLEMENT MASK TO

WRITE A ZERO

o,x

'AND' IN A ZERO

BRANCH

SKIP AROUND THE

WRITE-A-ONE LOGIC

0,X

'OR' IN A ONE

o,x

PUT BYTE BACK TO TAPE

*SET TURING MACHINE PROGRAM COUNTER TO NEW ADDRESS

0232 84 3 F

02340235

4997

FC

0237 7E 02 00

AND A #$3F MASK OFF TWO LEFT

BITS

ROL A MULTIPLY BY TWO

STAA PC+1 STORE AS NEW PRO-

GRAM COUNTER

JMP BEGIN EXECUTE NEXT UTM

INSTRUCTION

The logic to test the current bit is:

TEST LDX HEAD Load head byte ad-dress.LDA B MASK Load bit mask within

byte.BITB 0,X Test corresponding bit

in memory.BEQ ITSONE Yes, it's a 1.

ITSNOT logic if bit was a 0.

ITSONE logic if bit was a 1.

The program increments the head position(moves tape to right) by rotating the maskto the right. If the bit is rotatei out andinto the carry, the HEAD address is incre-mented. The procedure is similar for movingthe tape left.

The universal Turing machine program isstored in the first 128 bytes of memory.Each state consists of two 1 byte instruc-tions, so that the instruction's address inmemory is the state number multiplied by2. The 6800 has no multiply instructions,but in this case the same effect may beaccomplished by the rotate left instruction:

Before shift 0 0 1 0 1.0 0 1 = decimal 41 state

number.

///////

After shift 0 10 10 0 10 = decimal 82 state

address.

Hardware versus Software

Although there is probably not a greatpractical need for Turing machines of thistype, the two designs provide some insightsinto the benefits and costs of each approach.

The most significant benefit of the hard-ware approach is speed. The program canonly process 10,000 universal Turing ma-chine instructions per second, or 25 percentof the circuit's capability.

The most significant benefit of the soft-ware approach is its flexibility. For example,suppose the address field of the instruction

HexadecimalAddresses

Use

0000 thru 007F0080 thru 00 FAO0FB thru 00FC

00FD

00FE thruOOFF

0200 thru 0237

Universal Turing machine pro-gram and state storage area.Universal Turing machine tapestorage area.

Universal Turing machine pro-gram counter address of nextstate.

Tape head mask.Tape head address.6800 interpreter program(listing 1).

Table 1: Memory allocation for the softwareimplementation of the universal Turingmachine.

28 December 1978 © BYTE Publications Inc

North Star SystemsGo To Work

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North Star BASIC and DOS have beenused to develop hundreds of com-mercial program packages. Thesepackages establish that North Starsoftware has the completeness andconvenience necessary for seriousprogram development. Because of themany independent vendors offeringsoftware using North Star BASIC andDOS, the HORIZON owner now hasthe widest selection of software in themicrocomputer industry! Softwareavailable includes: word processing,general ledger, accounts payable/receivable, mailing list processing,inventory and income tax prepar-ation. Program development systemssuch as assemblers, debuggers,editors, PILOT and FORTRAN arealso available.

EXPAND YOUR HORIZON

The basic HORIZON computer in-cludes a Z80 microprocessor, 16Kbytes of RAM memory, an I/O interfaceand one Shugart minifloppy disk drive.The HORIZON can be expanded to 60Kbytes or more of RAM, three diskdrives, and three I/O inter-faces. Performancecan be enhanced bythe addition of theNorth Star hardwarefloating point board.Also, S-100 bus pro-ducts from othermanufacturers maybe used to expandthe HORIZON.

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2547 Ninth StreetBerkeley, California 94710(415)549-0858Circle 285 on inquiry card, byte December T978 29

is to represent a signed displacement fromthe current program counter, as Millensuggests in his article. In hardware, thiswould require adding a 6 bit adder betweenthe address bus and the program counter,plus some temporary latches to hold theresults. In software, a store instruction mustbe changed to an add instruction. In hard-ware, the board must be modified to accom-modate the new circuitry, and the clock re-adjusted. In software, under MIKBUG, thechange can be made with seven keystrokes.

If this system were to be widely dis-tributed, complete documentation wouldhave to be written. The hardwired approachrequires a circuit board layout, a schematicdiagram, parts list and written commentary.In the software version, comments in theprogram serve to document the system,along with a written commentary.

The software approach allows a buildingblock technique. The program may be easilycombined with other programs. The externalprograms need to know only the addressesof the various blocks in the universal Turingmachine program's logic. The universalTuring machine circuit would have to bemodified to adapt it to other equipment.The software version uses MIKBUG's loadand dump routines to save the tape contents,but this would have to be a specially con-structed circuit for the hardwired design.

The design, implementation and testingtimes of the software version were two, oneand two hours, respectively. I don't knowthe exact times required for the hardwareapproach, but they should be at least severaltimes more than the software approach.

In order to build the hardwired circuit,the experimenter must obtain all the cir-cuitry, a circuit board, wire, power supply,etc, which may or may not be used in futureexperiments. However, once you have amicrocomputer to work with, no extra items

Function

Hardware Version

Software Version

Program storage

2102

Memory locations hexadecimal 00 thru 7F

Tape storage

2102

Memory locations hexadecimal 80 thru FF

Program counter

Two 74161s

Memory locations hexadecimal FB thru FC

Head

Three 74191s, 7474

Memory locations hexadecimal FD thru FF

Sequencing

7404,74161,74154

Conditional branching

Display

7 segment LED

MIKBUG print/punch command

Initializing tape

74157,7400,switch

MIKBUG load command

Saving tape

MIKBUG print/punch command

Debugging design

Logic probe andoscilloscope

MIKBUG break command

are needed and the computer is usable forany other projects without losing the abilityto reload the universal Turing machineprogram.

This example cannot be taken as a com-plete treatment of the trade-offs of the twoapproaches. Each designer must judge themerits of an approach according to theparticular needs of the problem to be solved.

If the universal Turing machine \mass-produced for time-critical cthe hardware approach would tikthe design is to be used for theafternoon project of a microcenthusiast who already has a systsoftware approach would be best.■

a to beations,est If

inday

puter

the

V;>;

Operating the Turing Machine

Table 2: Correspondence chart of the functions of the two approaches andthe means with which they are implemented.

1. Put your program in the state stoi •age area. Note that the address of eacrAstate is twice the state number. \

2. Initialize the tape storage area. You *,may put your tape anywhere in memory \as long as you set the tape head pointerto the proper initial address. Locationhexadecimal 0080 is convenient.

3. Initialize the program counter. Put

00 in location hexadecimal 00FB, and thefirst address in the Turing machine in lo-cation hexadecimal OOFC. This must bethe actual memory address (twice thestate number).

4. Initialize the mask. The mask se-lects which bit of the byte pointed to bythe head pointer to operate on. It mustbe composed of seven 0 bits and a single

1 bit. 01 is a reasonable starting value.

5. Initialize the head pointer. This is!the address of the byte in memory to bejconsidered as the head of the tape. It*must point to the tape storage area.

6. Set your MIKBUG start address tchexadecimal 0200, press G (for go), anqaway it goes.

REFERENCES

1. Millen, J, "A Universal Turing MaqDecember 1976 BYTE, page 114.

2. Ralston, A, and Meek, C (editors),pedia of Computer Science, PetrocellijNew York, 1976, pages 1432 thru 14

3. Shannon, C E, and McCarthy, JjAutomata Studies, Princeton UniveJPrinceton NJ, 1956.

30 December 1978 © BYTE Publications !nc

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That's right — even better reliability. Why? Because we didit the IBM way. IBM designed 2D formatting — so it has tobe reliable. Micromotion's innovative, state-of-the-art de-sign incorporates write precompensation electronics and aphase lock oscillator on a single, all digital, 5-100 circuitboard. So we guarantee the DOUBLER will be more de-pendable than your present single density controller — andwe warantee the DOUBLER for a full year.

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BYTE December 1978 31

Build an

Octal/Hexadecimal

Output Display

Steve CiarciaPOB 582Glastonbury CT 06033

"Steve, I think we have a little problem!"Ray charged into the basement and hoveredover me waiting for a response.

I slowly rotated in my swivel chair. Therate was barely sufficient to overcomestatic friction, but I finally made it. As Iraised my head to talk I was interrupted.

"Steve, I think we have a problem withthat EROM." Before he could finish, hisexpression abruptly changed and almostwithout a pause he ended the sentencewith, ". . .what happened to you? You looklike death warmed over!"

I could barely see the person standingbefore me with his hands on his hips. I alsoexperienced a strange sensation of either aveil covering my face or an advanced caseof furry eyeballs. Whatever the cause, Raywas still standing there awaiting a reply. Itwas a chore to speak. As the muscles con-tracted to produce the necessary air flow, Icould sense a sudden recurrence of physicalproblems which I had hoped were on thewane.

"Steve you look terrible! You should beraring to go after two weeks in Acapulco,basking in the sun."

Photo 1: Hewlett-Packard 5082-7340 hexa-decimal character display, which uses apseudo 7 segment dot matrix. On and offcontrol of the dots at the end of each seg-ment allows the circuit to display capitalBs and Ds. The display pictured is powered.

Cispcis'sGipcuif ■Oellap

\

Ray was referring to an engineeringconsulting job I had just completed inAcapulco for CBS. The Miss UniversePageant, which was broadcast live fnpmMexico, included a new twist this year.l Acomputerized judging system. It soundfedlike a fun consulting job as opposed to thteusual, "design me a computer for . . .Ttype. The final rationalization was, I needed\a vacation anyway. 1 wouldn't want anyoneto think that the 70 contestants had any-thing to do with my decision to go.

The other lucky members of our engi-neering party were Gus Calabrese (formerlywith Digital Group) and George Watson andDale Walker of CBS. Gus and I main-tained the hardware; Dale supported thesoftware; and, while George's official func-tion was the electrical scoring system, hisunofficial title was chief taco tester. He hadthis uncanny ability to sort through all thevarious smells emanating from a restaurantand evaluate palatability. If he didn't turngreen as he walked through the door, it wasAmercianized enough for us to eat there.

This smooth sailing trip was punctuatedby a succession of daily crises. For instance,George's wife, having thoughtfully packedhis suitcase without underwear, gave us thehoped for opportunity to take a crashcourse in Mexican capitalism and to ventureout to the market place. The cab driverwho "drove" us there (I use the wordloosely) was subject to suicidal fits. Fromthen on everything went downhill. The listgoes on and on. Reliving the past two weeksin my thoughts heightened the sense ofphysical malaise I was experiencing. Fortu-nately, Ray spoke again in time to bring meback to reality.

"What's wrong with you?"

32 December 1978 © BYTE Publications Inc

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G/2 Basics for SOL and SWTPC (created by MICROSOFT™) are far better than the interpreter you're now using. G/2 Stan-dard Basic lets your SWTPC 6800 execute programs faster, uses only 7K of memory, and offers string arrays, extensive stringrmctions, peek, poke, wait, continue, calculator execution, 10 nested subroutines, and much more. G/2 Extended Basic puts the kingi Basic interpreters in your SOL computer. It offers string arrays, 16-digit accuracy, fully descriptive error messages, automaticine numbering and renumbering, an amazing editing capability, trace function, and many additional features you thought were limitedto disk-based systems.

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G/2 Clinic helps you understand the effects of environment,heredity, personal habits, diet and even biorhythms on your health. Built-in prompts make these three programs easy for your family and friendsto use, even if they've never before touched a computer.

G/2 Contests for Apple Owners use the full power of Apple's colorgraphics to simulate the tense dangers of interplanetary war, thehair-trigger suspense of a shootout, and the challenges of several mathe-matical and pure logic puzzlers.

Start building your G/2 Program Library today. For the name ofthe G/2 dealer nearest you, call us toll-free at 800/538-1770. (InCalifornia, call 800/662-9810.) Then load one of these tapes and put thefull power of your computerto work for you. THE REASON

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"Let's just say it has something to dowith a guy called Montezuma."

"You're not supposed to drink. . . ."

"Yeah, I know! Don't drink the water!"

Ray looked at me and decided his prob-lem still needed attention, even thoughI was dying. "Steve, I was about to checkthe EROM contents against the listing yougave me when I noticed that it was in octal.We need to use that EROM tomorrow andwe had better find the error in it tonight. Imade a hexadecimal dump of the EROMcontents but I still can't check it againstyour listing."

The response was obvious. "Why don'tyou convert it by hand?"

"Sure," said Ray, "I can convert it, buta thousand conversions is more than I havetime for tonight. Can we assemble it inhexadecimal on your system?"

My temples were starting to throb. Ihadn't used my computer in three weeks.Nothing was hooked up and I was in nocondition to either attach and fire up myown programmer or write the simple algo-rithm to perform this minor calculation. Itwas hard enough for me to remember howto operate my own system without ex-plaining the intricacies to Ray.

"Look, Ray, any night but tonight. I'vegot it in octal, decimal, hexadecimal, binary,—anything you want, but not tonight. I justdon't think I can hack it You understand,don't you?"

He was disappointed, but being a goodfriend he understood. "Can I borrow yourTl programmer and some desk space? Athousand entries times five button pushes. . . shouldn't take more than an hour ortwo. Got your battery charger handy?"

It seemed a shame to make Ray go tosuch lengths. If my system were up it wouldtake only a matter of seconds to printout Ray's listing. It may have been a verypowerful Z-80 computer on any otheroccasion but tonight it wasn't processinganything.

As I reached for the calculator in mybriefcase I spied a relic that might providea solution to the problem. "Ray, see thatrectangular box with all the printed circuitboards plugged into the top of it?" I pointedto a bookcase that contained everything butbooks. "Bring it here and plug it in, andsearch through that pile of tapes over thereuntil you find one marked with the samename as your listing. I made a binary dumpon tape at the same time I made yourlisting." There are some advantages to beingill—letting others fetch and carry is one ofthem.

Relying mostly on Ray's high level ofhardware expertise, interspersed with what-ever limited verbal input I could manage, we

successfully fired up my Scelbi-8B 8008microcomputer. Even though I hadn'tused it for well over a year, the read onlymemory based operating system brought itto life immediately. The recognizablepattern on the light emitting diode (LED)display indicated it was ready to read inputdata, so I slapped in the cassette that Rayhad found. Fortunately the data was storedin a format acceptable by both machines,and totally independent of the processor. Icouldn't execute the Z-80 EROM listing Ihad loaded, but I could display it.

"OK, Ray. Now that we've loaded thedata we can step through it on single stepand look at it on this output port display,which I built a while back."

"How's that going to help?" Ray lookedat the 3 character display as he pressed thesingle step a few times. "The 8008 i is anoctal machine. Even the data on yourdisplay is coming out octal." he said.

It was hard to smile but I managed aslight variation on the theme as I said,"Flip the switch next to the display^"Instantaneously, the 257 previously dis-played changed to AF, its hexadecimalequivalent.

"Hey, that's not bad, a combinationoctal and hexadecimal display! All I haveto do is step through and copy down thehexadecimal equivalents, right?"

I nodded and Ray started to write.Barely ten entries had been made whenhis hardware curiosity got the best ofhim. "I was thinking of putting one ofthese on my system but it looked like toomany components. By the way, I only seetwo chips. Where are you hiding the rest?"

"Remind me to tell you when I recover."

Build a Combination Octal/HexadecimalDisplay

Some people may consider hexadecimaldisplays a trivial addition to an expensivecomputer system, but sometimes these littleadd-ons make program debugging easier. Ican't help but wonder whether other com-puter experimenters would have need forsuch a display. I don't expect it to replacethe video display; but often, when debugginga program, it's nice to be able to display abyte here and there to verify proper programexecution. It will never replace the stepperand breakpoint monitor I now use, butit's great to display keyboard or IO dataquickly with a single output instruction.

There are many methods to display hexa-decimal numbers on a 7 segment LED.Figure 1 and table 1 show an example of theusual brute force method using a read onlymemory as a hexadecimal decoder. Pro-gramming the 82S23 was described in the

34

December 1978 ©BYTE Publications Inc

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9 1 73 On inquiry Card. BYTE December 1978

35

November 1975 BYTE ("A Versatile ReadOnly Memory Programmer/' by Peter HHelmers, page 66). While this is a viableapproach, an excessive number of com-ponents is needed in this stand alone dis-play, and most people would rather not haveto program an EROM. The alternatives areto allow a computer to perform the de-coding and drive the 7 segment displaythrough the transistors from a latched 8 bitoutput port, or to put additional logicaround a standard 7 segment decoder driverfor the extra requirements. The former casenecessitates a computer program while thelatter can involve as many components asthose in figure 1.

InputCode

DCB A

0 0 0 00 0 0 10 0 100 0 1 10 10 00 1 0 10 1 10

0 1 1 1

1 0 0 01 0 0 1

I 0 1 010 11

II 0 01 1 0 11110

1111

82S23Program

d7d6d5d4d3 d2d1 dO

0 1110 111

0 10 0 0 0 0 1

0 110 1110

0 1 1 0 1 0 11

0 10 110 0 1

0 0 1 1 10 11

0 0 1 11 111

0 1 1 0 0 0 0 1

0 1 111 11 1

0 1 1 1 1 o 0 1

0 1 1 1 110 1

0 00111 1 1

0 0 1 10 1 1 0

0 10 0 1111

0 0 111110

0 0 11110 0

7 SegmentDisplay

Fortunately there are other products onthe market that can solve the problem. I'vebeen using the Hewlett-Packard HP7340hexadecimal display for a number of years.Those familiar with it can rightfully say howtrivial the solution was, while those who arenot may find it a revelation. Photo 1 illus-trates the physical size of the HP7340. Ahexadecimal A is displayed in a dot pattern.These hexadecimal displays depart fromstandard 7 segment format by being capableof displaying a capital B and D in hexa-decimal. This is accomplished by controllingthe corner dots which give the appearanceof "rounding." This ability discriminates aB from an 8 or a D from a 0. There are 16distinctly different characters.

An additional feature of the HP7340 isthat it contains a 4 bit latch and the decoder/driver as well. The result is a single 8 pinhexadecimal display which successfullyaccomplishes the function of all the circuitryin figure 1. The specification of the indi-vidual pins are in figure 4.

Figures 2 and 3 demonstrate how theHP7340 can be configured to function as a2 digit hexadecimal output port or a 3 digitoctal port. No 8 bit latch is required since it

Table J: Program for IC2 in figure 7.

D O

LATCH r—s^ENABLE '

IC37404

Figure I: Hexadecimal latch<, decoder anddriver using a standard 7seg-ment light emitting diode (LED). Line CS on IC2 can be used to per-form the blanking operation. This circuit can be replaced by a Hewlett-Packard HP 7340 or equivalent (see table 2).

36 December 1978 © BYTE Publications Inc

-"C/

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Circle 290 on inquiry card.

BYTE December 1978

37

Photo 2: Prototype boardof the circuit in figure 4.Two similar circuits werebuiit on the same board.When in the hexadecimaimode (shown at ieft in thepicture), the leading digitis blanked. The display atthe right shows the octalmode. Each Is wired as anindependent output port,but the computer sendsthe same data to both.

d6 O

d5 O-d4 O-

IC3

HP 7 340

DECODEDSTROBE

o-

d3 C>

d2 O

di O-

dO £>-

Hh

IC4

HP 7340

~7h

Figure 2: Hexadecimal latch, decoder anddriver display circuit.

PinNumber

12345678

Function

Input B

Input C

Input D

Blank Control {blank - +5 V)

Latch enable (latch - 0 V)

Ground

+5 V

Input A

Table 2; Pin functions for the Hewlett-Packard HP7340 binary coded decimal(BCD) to hexadecimai display. Similardisplays are made by Dialite and TexasInstruments.

DCBA

IC5

HP 7340

3

JF

it? I S '

a ( i jy

nr I—>» 8

4

a(j | >

rh

5

DCB

A

IC6

HP 7340

4

~7h

3

Hcl I ^» 2

00 i ,X

Id 1 S '

a 6 [ J>

5

DCB

A

IC7

HP 7340

4~?7

3

AT

An 1 >.

a c \ j>

rl 1 1 ^> '

do r~^» 8

au i ^

ED

e r^

<

5>

IS

*HP5082-7300 CAN BE SUBSTITUTEDFOR HP 5082-7340 IN OCTAL READOUTAPPLICATION. 7300 IS NUMERIC ONLY.

Figure 3: Octal latch, decoder and driverdisplay circuit.

38 December 1978 © BYTE Publications Inc

SELECT MODEMODE A OCTAL=0

HEXADECIMAL

FROM

COMPUTER {DATA BUS

dO O

DECODEDSTROBE Q>IS

MOST

SIGNIFICANT

DIGIT

LEAST

SIGNIFICANTDIGIT

Number

IC1

iC2

IC3

JC4

IC5

IC6

IC7

IC8

IC9

ICtO

IC11

IC12

Type

7475

82S23

HP7340

HP7340

HP7340

HP7340

HP7340

74157

74157

HP7340

HP7340

HP7340

+5V

516

7

7

7

7

71616

7

7

7

Gnd

123

Table 3: Power wiring table for figures I, 2,3 and 4,

already contains one. The 7340s can simplybe attached to the data bus at any otherparallel output port and strobed from achip select decoder.

Figure 4 is the circuit of the unit similarto the one Ray used. Two multiplexercircuits alternate the input connections tothe displays so that when switch 1 (SW1) isin the octal position, the circuit performs asfigure 2, and when in the hexadecimalposition, as figure 3. The leading characteris blanked when in the hexadecimal mode.Two of these circuits are combined in theprototype board of photo 2. The left displayis in the hexadecimal mode showing B7while the right is in the octal mode display-

ing an equivalent 267 octal. The samebinary information is being sent to eachport; only the switch setting differs.

Usually these or equivalent displays areadvertised only as hexadecimal displays.All strictly hexadecimal displays that I'veseen contain these same electronics. Whilealphanumeric displays will also work, theyrequire extensive scanning logic and are anoverkill for this application.

In Conclusion

I hope this simple circuit will eliminateany frustration you may have in the area ofhexadecimal displays.

If you have any comments about this orany other article I have written, please writeand include a stamped, self-addressedenvelope. The mail volume has risen to thepoint where I'm asked similar questions bymany experimenters. A few of these letterswill be included each month in BYTE's"Letters" column when appropriate.

One question I'm often asked is whethermy introductions are true. So far everythingI've written is based upon actual people orevents. While I take considerable poeticlicense in describing the situations, it is notnecessary to invent fiction when experienceis often so much more humorous."

Figure 4: Combinationhexadecimal and octal dis-play circuit.

December 1978 © BYTE Publications Inc 39

The Age

of Affordable

Personal

Computing

Has Finally Arrived

Ohio Scientific has made a majorbreakthrough in small computer technologywhich dramatically reduces the cost of per-sonal computers. By use of custom LSImicro circuits, we have managed to put acomplete ultra high performance computerand all necessary interfaces, including thekeyboard and power supply, on a singleprinted circuit board. This new computeractually has more features and higher per-formance than some home or personalcomputers that are selling today for up to$2000. It is more powerful than computersystems which cost over $20,000 in theearly 1970's.

This new machine can entertain yourwhole family with spectacular video gamesand cartoons, made possible by its ultra highresolution graphics and super fast BASIC. Itcan help you with your personal financesand budget planning, made possible by itsdecimal arithmetic ability and cassette datastorage capabilities. It can assist you inschool or industry as an ultra powerfulscientific calculator, made possible by itsadvanced scientific math functions and

40

BYTE December 1978

built-in "immediate" mode which allowscomplex problem solving without program-ming! This computer can actually entertainyour children while it educates them intopics ranging from naming the Presidentsof the United States to tutoring trigonometry— all possible by its fast extended BASIC,graphics and data storage ability.

The machine can be economically ex-panded to assist in your business, remotelycontrol your home, communicate with othercomputers and perform many other tasksvia the broadest line of expansion acces-sories in the microcomputer industry.

This machine is super easy to usebecause it communicates naturally inBASIC, an English-like programming lan-guage. So you can easily instruct it or pro-gram it to do whatever you want, but youdon't have to. You don't because it comeswith a complete software library on cassetteincluding programs for each applicationstated above. Ohio Scientific also offers youhundreds of inexpensive programs onready-to-run cassettes. Program it yourselfor just enjoy it; the choice is yours.

Circle 290 on inquiry card.

Ohio Scientific offers you this remarkable

■', y^-:: new computer two ways.

I4i>iil'4 i __,

i feElEIB BOIICCEGBI«czDB' IIIIC EECf IIIIIE Mil '>■■ 104

Superboard ] 1 $279 Challenger 1P $349

For electronic buffs. Fully assembledand tested. Requires + 5V at 3 Ampsand a video monitor or TV with RFconverter to be up and running.

-.Standard Features.

■ Uses the ultra powerful 6502 microprocessor

■ 8K Microsoft BASIC-in-ROM

Full feature BASIC runs faster than currently availablepersonal computers and all 8080-based business com-puters.

■ 4K static RAM on board expandable to 8K

■ Full 53-key keyboard with upper/lower case and userprogrammability

■ Kansas City standard audio cassette interface for highreliability

■ Full machine code monitor and I/O utilities in ROM

■ Direct access video display has 1K of dedicated memory(besides 4K user memory), features upper case, lowercase, graphics and gaming characters for an effectivescreen resolution of up to 256 by 256 points. Normal TV'swith overscan display about 24 rows of 24 characters;without overscan up to 30 X 30 characters.

Extras

■ Available expander board features 24K static RAM (addi-tional), dual mini-floppy interface, port adapter for printerand modem and an OS) 48 line expansion interface.

■ Assembler/editor and extended machine code monitoravailable.

Fully packaged with power supply.Just plug in a video monitor or TVthrough an RF converter to be up andrunning.

.ORDER FORM

Order direct or from your local Ohio Scientific dealer.

[] I'm interested. Send me information on your:

□ Personal Computers D Business SystemsD Send me a Superboard II $279 enclosedG Send me a Challenger 1P $349 enclosed[ J Include 4 more K of RAM (8K Total) $69 more enclosed

Name

AddressCity

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Payment by: BAC(VISA)Credit Card Account I __

Expires

.Master Charge

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Interbank #(Master Charge)

Ohio Residents add 4% Sales Tax

TOTALCHARGED OR ENCLOSED

All orders shipped insured UPS unless otherwise requested FOB Aurora, OH

i _ : j

Interested in a bigger system? Ohio Scientific offers 15other models of microcomputer systems ranging fromsingle board units to 74 million byte hard disk systems.

America's Largest Full Line Microcomputer Company1333 S. Chillicothe Road • Aurora, Ohio 44202 (216) 562-3101

Circle 290 on inquiry card.

BYTE December 1978

41

ALTOS presents a new standarcin quality and reliability

**..

1*N*

i /

,*

^iJU

WE'RE ALTOS COMPUTER SYSTEMS. Our SUN-SERIES ACS8000 business/scientificcomputer creates a new standard in quality and reliability in high technology computers.

HIGH TECHNOLOGY The ACS8000 is a single board,280®* disk-based computer. It utilizes the ultra-reliableShugart family of 8 inch, IBM compatible, disk drives. Achoice of drives is available: single or double density, single ordouble sided. Select the disk capacity you need, when youneed it: VM, 1M, 2M, or 4M bytes. The ACS8000 featuresthe ultimate in high technology hardware: a fast 4 MHz Z80CPU, 64 kilobytes of 16K dynamic RAM, 1 kilobyte of 2708EPROM, an AMD 9511 floating point processor, a WesternDigital floppy disk controller, a Z80 direct memory access,Z80 Parallel and Serial I/O (two serial RS232 ports, 1 parallelport), and a Z80 CTC Programmable Counter/Timer (real timelock). In essence, the best in integrated circuit technology.

ALTO*

COMPUTER SYSTEMS

BUILT-IN RELIABILITY The ACS8000 is a true singleboard computer. This makes it inherently reliable and main-tainable. The board and the two Shugart drives are easily ac-cessible and can be removed in less than five minutes. All elec-tronics are socketed for quick replacement. Altos providescomplete diagnostic utility software for drives and memory.

QUALITY SOFTWARE Unlimited versatility. The ACS8000 supports the widely accepted CP/M®** disk operatingsystem and FOUR high level languages: BASIC, COBOLPASCAL and FORTRAN IV. All available NOW.

PRICE $3,840. Standard ACS8000 system with 32 Kb RAMand Vz Mb disk. FPP, DMA and software optional. Dealer/OEMdiscounts available. Delivery: 3 weeks ARO.

*Z80 is a trademark of Zilog, Inc.

**CP/ Misa trademark of Digital Research, Inc.

Dealer/rep inquiries invited-

Circle 12 on inquiry

2378B WALSH AVENUE • SANTA CLARA • CA 95050 • (408) 244-576

/

Gook Reviews

The Pocket Calculator Game Book

by Edwin Schlossberg and John BrockmanWilliam Morrow and Company IncNew York 1975158 pages hardbound$6.95

For many of us, the introduction to themicrocomputer is the pocket calculator.However, after we learn its functions, itoften ends up in a drawer except for shop-ping and checkbook balancing. It shouldn't.There are many ways to use your calculatorfor enjoyment.

I like the competitive aspect of thiscomputer business, either against themachine or another player. Therefore I likethose books which show me new games toplay. In this collection of 50 games, theauthors present a variety which will appealto everyone. There are applications for the"four-banger" as well as the more complexscientific models. You can play with one ormore calculators, and one or more players.You may throw in dice or playing cards forvariety.

There are easy games and hard ones,offering a range for all ages. Several have twoversions, a simple method and complex onefor those of you with the costlier machines."1001 H is one of several games whose objectis to reach a particular number using thefewest moves. Use dice to determine yourmove, and hope for luck. There is "Calcu-lator Poker" with betting strategy to guideyou. For the business minded, there is"Economy" with all the trappings of highfinance. The student of political science willfind meat in "Cold War" or "Detente."There are puzzles, mazes and much more. Asa puzzle freak, I found my favorite amongthese pages. By multiplying and dividingin a judicious manner, one can deduce theproper path to follow. A game is a valuabletest to see whether your calculator canhandle certain operations. This would be anexcellent way to check out a calculator thatyou are considering buying.

Throughout the book, the authors offersamples of how each game should be played,as well as winning strategy. In the intro-duction are explanations for those conceptswhich may be new to some readers, such asrandom numbers, and a glossary of handcalculator terms. A handy index dividesthe games into like categories, such as num-ber of players, or games with dice, and soforth.

Many games are only the point of depar-ture for exploration by the hobbyist. Onecould extend many of these to any homebuilt computer. A lot of thought went intothis book and it shows. I think the bookdoes the best possible thing for a hobby: itmakes the hobby more fun.

Noel K Julkowski

Naval Environmental

Prediction Research Facility

Monterey CA 93940"

STATEMENT OF OWNERSHIP, MANAGEMENT ANO CIRCULATION

(Required by 39 U.S.C 368S)

I. TITLE OP fUlLICATION

BYTE The Small Systems Journal

]. FNCOUINCV OF ISSUE

Monthly

A PUBLICATION WO. 1, DATS Or FILING

1-| 0 I 2 | 4 |TyO~|Oct. 29, 1978

12

$15/year

4. LOCATION or KNOWN orrics or publication (Strut. City, County, Stat* and ZIP Codmf (Not prtnfrt)

70 Main Street, Peterborough, NH 03458

3. LOCATION Or THE HEADQUARTERS ON GENERAL BUSINESS OFFICES Of THE PUBLI1

70 Main Street, Peterborough, NH 03458

NAMES AND COMPLETE ADDRESSES OF PUBLISHER, EDITOR, AND MANAGING EDITOR

'UBLIBHER (Nam* and AddrtM)

Virginia Londoner, Grove Street, Peterborough, NH

03458

EDITOR (Noma and Addrtm)

Carl T Helmers, Jr., Noone Avenue, Peterborough, NH 03458

■ ANAGING EDITOR (Nam* and Addntmi

7. OWNER (If owned by a corporation, it* nam* and addrtu must a* nattd and alto immediately thtraundar th* nbolder* owning or Holding I percent or mora of total amount of *tock If not ownad by a corporation, iowner* mwl be given if ownad by ■ partnanhip or othmr unincorporated firm. It* nam* and addrambe Mtoan.t

j mnd mddramm* of the indtwtdmml! ae thmi of mc* t»dt«id~mi mm*

NAME

Virginia Londoner

Carl T Helmers, Jr.

Grove Street, Peterborough, NFT

Noone Avenue, Peterborough, NH

• KNOWN BONDHOLDERS. MORTGAGEES, AND OTHER SECURITY HOLDERS OWNING OR HOLDING 1 PERCENT OH MORI OP

TOTAL AMOUNT OF BONDS MORTGAGES OR OTHER SECURITIES at f*»re en nana, to ttmtmf

Nnnp

E. FOR COMPLETION BY NONPROFIT ORGANIZATIONS AUTHORIZED TO MAIL AT SPECIAL NATO IThe purpoM. function, mnd nonprofit xatui of tM» ofssnliMfon and tfts exempt rtetut tor Fa*

« 1*1 I ft, nut)

□

PRECEDING a MONTHS

□:

(If e**W#**\ MM

mat pspiM mMfmtmmttm mf 4

EXTENT AND NATURE OP CIRCULATION

, TOTAL NO. COPIES PRINTED (Nat From* JlttMj

• PAID CIRCULATION

t. SALES THROUGH DEALERS AND CVENDORS ANO COUNTER IALII

t. MAIL SUMC RIPTIONE

C. TOTAL PAID CIRCULATION (9mm of I OBI end lOmM,

m. TOTAL DISTRIBUTION (*mm of C and Df

1. RETURNS PROM NEWS AVERTS

133,765

21,469

103,484

124,953

3,423

128,376

3,710

1,679

ACTUAL MO. COP1M O* MIMU

PILING PATf

139,400

22,128

110,464

132,595

3,817

136,412

2,988

none as of today

139,400

It. FOR COMPLETION BY PUBLISHERS MAILING AT THE REGULAR R«7

39 U. S. C. 3*2*3 provide* In partlnam Part: "No paraon who would hew* boen amrttad «•hall mall euch matte* et the ratM provided uto mall matter at eweh rata*."

t to ISBRi 1 atmsap

SIONATUflS^AND ttTrnttfoW EDITOR. FUatflSHSR. BUM NEBS MANAalH, OR OWNER

Publisher

^73W//Vii

(See Initruct lorn on reverse)

December 1978 © BYTE Publications tnc 43

rA

$249 jgets the entire family intocreating video games, graphicsand control ^functions. I r

For starters.J A*9ul

M

^m^^

^"

COSMAC VIP, the completelyassembled, ready-to-operate RCAVideo Interface Processor, opens up awhole new world of computer excitement. Newchallenges in graphics, games and controlfunctions. Yet it's just $249.00.

Easy to buy. And easy to program, thanks toits unique, easy-to-use interpretive language.You get a complete how-to book includingprograms for 20 games: fun, challenging, andready to load and record on your cassette.

Simple but powerful.

Built around an RCA COSMAC micropro-cessor, the VIP is a complete computer systemthat can grow with you. It has 2K of RAM, ex-pandable on-board to 4K. Plus a ROM monitor,audio tone output to a built-in speaker, powersupply, and 8-bit input and output ports forcontrol of relays, sensors, or other peripherals.

Soon RCA will offeroptions for color graphics256 tone sound generation.Bh optional auxiliary keyboardwill dpnHpran exciting world of two-playergames.

Take the first step now.

Check your local computer store or elec-tronics distributor for the VIP. Or contact RCAVIP Marketing, New Holland Avenue, Lancaster,PA 17604. Phone (717) 291-5848.

'Suggested retail price. Does not include video monitor or cassette recorder.

The fun wayinto computers.

44

BYTE December 1978

ItCJI

Circle 322 on inquiry card.

Life With Your Computer

Ju«>tin MilliunJudy ReardonPeter Smart\N Ossipee Rd-Silver Lake NH 03875

/

/

What can you do with your computer?After hearing about the game of Life, youmay never ask the question again. Within thecapabilities of a very minimal system, Lifegives the computer the kind of job it doesbest: an enormous amount of repetitivelogical operations. [The authors' systemdemonstrates this point: it had 2 K memoryand a video terminai at the time of thiswriting.] This leaves you, the user, free toapply your creative energy on this fascin-ating game.

Developed by John Horton Conway, aBritish mathematician at the University ofCambridge, Life was first described in theOctober 1970 Scientific American byMartin Gardner in his "MathematicalGames" column. Its name comes from itsresemblance to changing societies of livingorganisms which can grow, move andoccasionally die out.

The Game of Life

An easy way to understand this game isto imagine an immense gridwork or checker-board. We call each square in the checker-board a cell, and the entire board a cellularspace. Each cell is identical and can performa number of specific functions. We won'tworry about the edge of the board: let'ssay the space is large enough so that wenever know there is an edge. In the game ofLife, each cell can sense its eight neighboringcells (as in figure 1). Each cell in our spaceis in one of two states: it is either alive, ornot alive (quiescent). The cellular spacechanges with time; time advances over the

entire space at once, in steps. Each of thesesteps is called a generation.

The rules which determine the state of agiven cell in the next generation are whatgive Life its delightful properties. They werechosen with great care by Conway, withreasons in mind that will be discussed later.[For mathematical background informationsee the book, Introduction to ArtificialIntelligence by Philip C Jackson, publishedin J974 by Petrocelit-Charter. A discussionof ceiluiar automata and pointers to severaldetailed references are found in chapter &/Let us say there is a pattern of cells in thecellular space, some living, some not. Therules tell which presently living cells survive,which living cells die, and which cells thatare not now alive will be living in the nextgeneration. The rules are as follows:

• Each cell presently alive which haseither two or three of its eight neigh-boring cells alive will be living in thenext generation.

• Each cell presently alive which hasother than exactly two or three liveneighbors will not be alive in the nextgeneration.

• If a cell is presently not alive, andexactly three of its eight neighboringcells are alive, it will be living in thenext generation.

The above rules are applied all at once inthe program for the game of Life. Every cellin the space is checked, as are its neighbors.The fate of that cell in the next generationis then determined. Note that this willamount to many thousands of checks ineach generation for a cellular space fillingeven a small video display screen.

When the program has been loaded intothe computer and you've entered thepattern, what can happen as the patternevolves? There are a number of possibilities.

f

2

5

4

o

9

6

7

8

Figure I: The center cell(0) has eight neighbors, asdoes every cell exceptthose bordering the edgesof the cellular space In anyfinite buffer in a computerprogram. Treating boun-dary conditions for a finiteLife buffer is a fine pointof Life program design.

•

•

•

•

2a

•

•

•

#

•

•

2b

Figure 2: Examples of stilllife cell patterns, the block(a) and the beehive (b).

December 1978 © BYTE Publications Inc 45

•

•

•

Generation 0

•

•

•

Generation 1

•

•

•

Generation 2

•

•

#

Generation 3

Figure 3: Four generationsof the blinker pattern.

Types of Patterns

The pattern may die, leaving you with anempty display as you search your imagi-nation for another possibility to try.

It may stop at what Conway calls a stilllife. A simple example (figure 2) is theblock, another the beehive. These patterns,when left undisturbed, remain the samegeneration to generation (a little more inter-esting than a blank screen, perhaps).

The pattern may develop a repeatingcycle. The simplest of these is the blinker,which returns to its original self every othergeneration (see figure 3). A more sophisti-cated periodically repeating pattern has beendescribed in the February 1971 ScientificAmerican. Discovered by G D Collins Jr,it is called the tumbler (figure 4). It has aperiod of 14 generations, but after seven itis an upside-down copy of the originalpattern; hence its name. Watching thetumbler change, you will notice that inevery generation there is a row of emptycells separating two mirror image patterns.Each half helps keep the other half undercontrol. If left to itself, half a tumbler willrun over 100 generations before settlingdown.

There are patterns which have mostintriguing properties of motion. The glidershown in figure 5 is one such pattern. It isso named because the way that it movesis called glide reflection, or reflection from adiagonal line. In four generations the gliderproduces a replica of itself, facing the samedirection but displaced one square dia-gonally. After only two generations, it is acopy of itself pointing 90° from its originalorientation. There are actually just twounique patterns in the life history of theglider, but it takes four generations for theorientation to match that of the originalpattern.

Another example of a moving pattern isthe lightweight spaceship shown in figure 6.This pattern also requires four generationsto move and to complete a full cycle; italso has only two unique patterns if wedisregard their orientation. Note that thispattern moves along a line of cells, as op-posed to the glider's diagonal motion.

Finally, patterns exist which continueindefinitely, forever evolving. (It was notcertain that such infinite patterns shouldexist for some time after Life was de-veloped.)

I

lukx:

•

i

•

•

•

i

•

•

•

i

•

•

•

•

ii

•

•

•I

i

i

••

i

Figure 4: An example of the tumbler, aperiodically repeating pattern.

Infinite Evolution a Possibility?

Conway selected the rules of'Life to meetthe following considerations:

• It should not be obvious that an initialpattern will grow without limit.(Conway specified that cells can diefrom overcrowding.)

• It should seem possible (but notobvious) that some patterns will growwithout limit.

• Some initial patterns should grow andchange for a considerable period oftime.

As reported in the original ScientificAmerican series of articles, Conway conjec-tured that there were no patterns whichwould actually grow without limit. At thattime he offered a $50 prize to the firstperson to prove or disprove his conjecture.A short time afterwards a group from MITdisproved it by their discovery of a glidergun. The glider gun produces a glider every30 generations. Since the glider moves awayfrom its birthplace, we may consider theglider gun to be a special type of repeatingpattern (see figure 7). The MIT group alsodiscovered other remarkable events in Lifeby observing such things as collisions be-tween numerous gliders.

Symmetry

A rather curious property in the evo-lution of many patterns is their tendency togain symmetry. As an example, let us beginwith a pattern with only partial symmetrycalled the snowflake, shown in figure 8a. In15 generations it becomes the pattern called

46 December 1978 © BYTE Publications Inc

•

•

■nnn

Generation 0

•

i

•

•

•

•

•

•

• I

•

Generation 1

•

•

•

•

•

•

•

•

•

•

[XXXJ

Generation 0

■nnnni

•

•

•

•

•

—

•i

fflffi

#

•

•

Generation I

M*

runni

•

•

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Generation 2

Generation 3

Generation 2

Generation 3

■

■

■

■

■

■

■

I

1

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1

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■

■

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Generation 4

Figure 5: Four generations of a glider pattern. Note thatin generation 2, the glider is reflected and rotated 90%moving down one space. In generation 4, the glider isagain reflected, but rotated 90° in the opposite direc-tion, as well as moved over one space.

Generation 4

Figure 6: This example of a lightweight spaceshippattern also has a 4 generation pattern cycle. Note thatgeneration 2 is a 90" rotation of generation 0 and ismoved over one space. In generation 4> the spaceshipreturns to the orientation of generation 0} but hasmoved over two spaces.

the honey farm, shown in figure 8b. (Thisinitial pattern used for producing a honeyfarm differs from the one discovered byConway and his collaborators.) Within thebrief history of this pattern, it gains newsymmetry it can never lose. Apparently,unless the pattern dies out completely,symmetry can only be gained, never lost.

Another example of a pattern increasingits symmetry is given in figure 9. Again,beginning with only partial symmetry,it evolves into another known pattern,a beautiful oscillating pattern called PulsarCP 48-56-72. It reaches this pattern in 26generations during which it gains itssymmetry. (The initial pattern given here

is again an alternative path to the knownpattern.) The oscillating period of the Pulsaris three generations, and it provides a veryinteresting display.

The "Garden of Eden"

Up to now, the evolution of patterns hasbeen considered, using some initial pattern.Can this initial pattern itself have unusualproperties? It has been proven that aso-called "Garden of Eden" pattern mustexist for the game of Life. A "Garden ofEden" pattern is one which cannot beproduced by any other pattern. In otherwords, no pattern ever becomes a "Garden

December 1978 © BYTE Publications Inc 47

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Figure 7: The glider gun isshown in mid-cycle withtwo generated gliders, thearrow indicating theirdirection of travel. A moredetailed description of thispattern is given in theFebruary 1977 ScientificAmerican column byMartin Gardner, page 114.

of Eden" pattern. Such a pattern can onlyexist, therefore, as an initial pattern speci-fied in generation zero.

It has been shown that a "Garden ofEden" pattern for Life can exist within asquare with 10 billion squares on each side,but possibly it could be much smaller.

Perhaps one way to find a "Garden ofEden" pattern is to apply some program-ming skill, and all your computer's sparetime. You start with a pattern you devisedor one your computer generated, randomlyor otherwise. The computer could thenattempt to find a pattern which generatesyour pattern by trying out all the patternspossible in a larger space than your patternuses. If it did not succeed in generatingyour pattern, you would have found a"Garden of Eden" pattern. A lucky appli-cation of this brute force technique maycome up with the answer, but the going willbe very slow. Perhaps some clever shortcutcould be developed.

A Warning

The game of Life is downright addictivebecause there is always another pattern thatyou'll want to try out in your search forattractive, unusual or unpredictable patterns.Examining properties of symmetry andmotion, and looking for "Garden of Eden"patterns and patterns like the glider gunwill test your ability to predict fate in thegame of Life.

The Program

A program for Life could be written inBASIC or some other high level language,but it would be grossly inefficient, both insize and speed. First of all, only a singlebit is required to store each cell, but thereis no simple way to manipulate individualbits in BASIC. You would therefore beforced to use one element of a floating pointarray for each cell, and since a floating pointnumber typically uses three bytes, youwould only make use of one out of every24 bits. That would mean for a 64 by 64cellular array you would need 12 K bytes.(Actually, you would need twice thisnumber since two copies of the cellulararray are needed in the simple Life programto be described.) The obvious way to reducethe size is to use every bit; a 64 by 64cellular array would then require only 512

48

December 1978©BYTE Publications tnc

I haven't stopped laughing since I read Steve Ciareia's new book,

'TAKE MY COMPUTER... PLEASE!" It's Steve's first full length book,

and It's the funniest to come along in years! It's even funnier

If you're into computers! Just one crazy misadventure after another,

based on Steve's true experiences, and his computer's inability to cooperate.

You'll roar when you read how he tries to win at Jai-Alai and gets beaten

at his own game. Or how he attempts a stock market killing that goes wrong

when he logs into his broker's computer circuit! Imagine what happens

when our hero sets up a computerized speed trap! And you'll fall on the floor

when our hero builds a foolproof computer burglar alarm,

and then locks himself out of the house with a souffle in the oven!

You can't beat this book for computerized belly laughs. It's got lots of

hilarious drawings that make Steve's easy writing style come to life even more.

And, you can't beat the low, low price of only *5.95 + S/H!

Order your copy of "TAKE MY COMPUTER...PLEASE!" Do it today.

It will tickle your fancy.

lake my computer

nloacA*

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by STEVEN CIARCIA

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BYTE December 1978 49

GD

ENTER THEINITIAL PATTERNINTO WORKSPACE

Figure 8: The snowflake(a) and the pattern itgenerates after 15 gener-ations, the honey farm (b).

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Figure 9: This seed pattern(a) generates pulsar CP48-56-72, One of the fourcycie phases of the pulsaris shown in (b).

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bytes. The most efficient way to manipulateindividual bits is to use assembly language.This will also be about ten times fasterthan a corresponding BASIC program, dueto direct execution.

A general flowchart for a Life programis shown in figure 10. The program requirestwo workspaces, each the full size of thedesired cellular array. The initial pattern isentered into workspace #1. The programthen creates the next generation in work-space #2, since the original generation mustnot be altered until the new one is com-pleted. After determining the new gener-ation in workspace #2, it is copied back into

DETERMINE THENUMBER OFNEIGHBORS FORA GIVEN CELL

CELL OIES

CLEAR THECORRESPONDINGCELL INWORKSPACE #2

COPY

WORKSPACE #2INTOWORKSPACE • I

DISPLAYWORKSPACE # I

SELECT FIRSTCELL INWORKSPACE • I

SET THECORRESPONDINGCELL INWORKSPACE #2

NEW CELL INWORKSPACE #2SAME ASCORRESPONDINGCELL INWORKSPACE ♦ I

Figure W: Flowchart of a Life program,/Authors' note: We have written a Lifeprogram for the SwTPC 6800 system fromthis flowchart Our version requires about7.5 K of memory for a 2000 cell array} andtakes only 6 seconds per generation. Ourprogram can be configured for any size arrayup to a maximum of 2016 cells. Our 6800Life program can be obtained from TheComputer Warehouse Store, 584 Com-monwealth Av, Boston MA 02215.J

workspace #1. The pattern is then displayed,and the procedure is repeated until theprogram is stopped.

As can easily be seen, Life can be a veryinteresting game. There are certainly movingpatterns other than those described herein,and the possibility exists that one of youreading this could find a previously un-known moving pattern. If you make anydiscoveries while running Life, we would beglad to hear from you. Enjoy Life!"

50 December 1978 © BYTE Publications Inc

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Some Facts of Life

David J BuckinghamComputer CommunicationsNetwork GroupE4, room 2369AUniversity of WaterlooWaterloo, OntarioCANADA IM2L3G1

Introduction

Life is a game that was developed byProf John H Conway at the Universityof Cambridge and first presented by MartinGardner in the October 1970 "MathematicalGames'* column in Scientific American.The game is derived from a field of mathe-matics known as automata theory (in thiscase cellular automata). In the February1971 "Mathematical Games" column thegame was described again along with agood introduction to automata theory.

The game is played on a uniform cellulargrid (in this case an area divided intosquares, such as graph paper) where everycell is surrounded by eight immediateneighbors (ie: cells touching the centercell under consideration). Each cell, orautomaton, can be in either a 1 or 0 state(on or off — alive or dead). The populationof cells is changed by a set of predeterminedrules. These changes proceed in intervalscaWed generations.

The rules are as follows:

• If a live cell is surrounded by two

or three live cells in the present

generation, it will remain on (orlive) in the next generation.

_o_ _o_ _oo_ _oo_

o_o_ _oo_ „o_o_ _o o

|Q _oo_ _opo_ _o_o

o o

Figure 1: Transformation of a Life pattern through three generations. Thisprocess is sometimes referred to as the automation of the pattern. Generation0 is the original pattern of five ceils. The succeeding generations proceedaccording to the rufes of birth, existence and death.

o

_oo_o oo_o oo

_oo_o oo o o

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Figure 2: Example of object contiguity. Group a Is considered to be twodistinct objects; groups b and c are considered to be single objects.

• If an empty cell is surrounded inthe present generation by exactlythree neighbors, the cell will be on(ie: born) in the next generation,

• If a cell has no neighboring live cells,or only one neighbor, it dies of lone-liness and will be turned off in thenext generation.

• If a cell has four or more live cellsneighboring it, it will die in the nextgeneration from overcrowding.

These rules are to be applied simultaneouslyto every cell in the pattern. The applicationof the rules to every bit in the field consti-tutes a generation. See figure 1 for anexample of rule applications.

Unresolved Questions

What is a unique object in this universeof cells? What is a collection of objects?How do we tell them apart? These are diffi-cult questions to answer conclusively.For the purposes of this article, an objectis a cluster of connected bits or cells, acollection of clusters which will causebirths by being near one another, or acollection of clusters that prevent somebirth that would otherwise occur. Figure 2gives some examples of patterns that wouldbe objects and some that would not.

A collection of distinct objects is re-ferred to as a constellation. Some con-stellations are so common that they arenamed as though they were a single object.Some of these are presented in figure 3.

Objects

Most people with access to some sortof computer have probably had a chanceto observe the variety of patterns thatexist within Life and to note some of thespecial properties particular to some of theseobjects. In order to be able to manipulatethese objects, they have been classified.

The major groupings of classificationare still lifes, oscillators, spaceships, uniformpropagators, and a catch-all group of randomobjects. A rough outline of this system isshown in table 1. I shall attempt to describe

54 December 1978 © BYTE Publications Inc

Subclass

Number

ofobjectsknown

Smallest object(s)

Class 1(still lifes)

subdivided bysymmetry

oo

block

Class II(oscillators)

(Hal) flip flops(Ila2) onK>ffs

oo

blinkerbeacon

(lib) billiard tableconfigurations

>100

MIT oscillator

(lie) inductors

4

tumbler

(lid) pulsators

8

mazing, peritadecathlon

(lie) shuttles

5

shuttle

(llf) eater bound

23

two eaters

Class III' (spaceships)

(Ilia) diagonal(1Mb) orthogonal

13

glider

lightweight spaceship(LWSS)

Class IV(uniformpropagators)

(IVa) stationary

2

glider gun

(IVb) moving(puffer trains)

4types

switch engine

Class V(random)

subdivided by typeof objects in census

oo

bit (single cell)

Number of

Number of

still life

live cells

patterns

1

0

2

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2

5

1

6

5

7

4

8

9

9

10

10

25

11

46

12

121

13

240

14

619

Table 1: Classes and subclasses of objects occurring In Life, along withsupplementary Information.

Table 2: The number of small still life patternswhich occur for each number of live cells up to 14.

a b c a

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Figure 3: Commonly occurring constellations. These are not a single object, but bear names for convenience, as follows: a,traffic light; b, honey farm; c, fleet; d, bakery.

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Figure 4: An assortment of still life objects. These remain stable from generation to generation when not disturbed by otherobjects. They bear names as follows: (top row} left to right) a, block; b} tub; c} boat; d, beehive; e} ship; f} barge; g, snake; h}aircraft carrier; (bottom row, left to right) i, burioaf; j} long boat; k} long snake; /, period 3 eater; m, pond; n, long barge; o}shillelagh; p, hat.

December 1978 © BYTE Publications Inc 55

Note:

A bibliography containingall Scientific American Lifearticles referred to in text isprovided at the end of thisarticle.

each class and some of the objects of par-ticular note within each class.

Class I: Still Lifes

Still lifes are objects in which there areno births or deaths and so remain the samefrom generation to generation. These par-ticular objects are fairly easy to enumerate.An associate of mine, Peter Raynham,wrote a program which found all still lifesof less than 15 bits. The statistics of theirdistribution are presented in table 2. Someof the smaller ones are shown in figure 4.

One of the most practical uses of a stilllife is as an eater. An eater is an objectcapable of destroying or modifying anotherobject and being able to return to its originalconfiguration. Still lifes are good for thissince they are able to attack any configura-tion at any phase (they are period 1 objectsand do not change).

At present we know of three differenteaters, each able to attack different typesof objects. By differing objects, I meanobjects that have different border config-urations. Since the eater attacks only theoutside surface of an object, this outersurface determines which type of eatermight be suitable for use. Each eater willbe described with an object that it can "eat"to show how that eater works.

The smallest member of the eater familyis the block, shown in figure 4a. The blockis effective in consuming objects that haveone connected bit in the row facing it(as in figure 5). Its other reason for utilityis the fact that it is very small. In oscil-lators and spaceship guns, where there maybe little room for the removal of spuriousdebris, there is usually enough room fora block.

The second object of this family is themost important and versatile. It is the 7bit still life referred to in figure 41 as theperiod 3 eater. This object attacks other

0

1

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3

o

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o

0

0

6

0

0

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6

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Figure 5: A block devours a beehive. This process requires seven generations,as shown here.

objects that exhibit a flat connected outerborder that is at least two bits long. Fig-ure 6 shows such an attack. Almost all ob-jects will develop this type of border ifthey expand. This property renders theperiod 3 eater invaluable. Although it isnot quite as small as the block, it is stillvery much smaller than any other of theeater family.

The third such object, the period 6eater, exhibits similarities to the period3 eater in the way it eats; however it re-quires six generations to dispose of itsprey and return to its initial state, where.asthe previous eater takes three generation;*.This increase in time is important for suc-cess if the object being eaten has left som^etransient debris near the eater. If the eatingmechanism were to reform itself quickly,this debris could kill the eater. In this case,the eater does not reform for an extra threegenerations, during which time this debrismay well vanish.

Most of the period 6 eater's prey are thesame as the period 3 eater's; but both areable to attack certain additional objects,complementing each other very nicely.Figure 7 shows the period 6 eater con-veniently disposing of a block.

Class II: Oscillators

Oscillators are nonmoving objects withperiods of two and greater. A blinker, shownin figure 8a, is a simple oscillator consistingof three cells alternating in subsequentgenerations between a vertical and hori-zontal row. At present, we know of roughly150 unique oscillators with a period greaterthan two.

There is a large undetermined numberof period 2 oscillators, since they are veryeasy to construct. The oscillators have beensubclassified by relating their mechanismsand their degree of naturalness. (Naturalobjects are those which may evolve fromrandom patterns of live cells without inter-vention by the experimenter.)

Since there are only two basic ways inwhich a period 2 oscillator can work, theseobjects are very well defined. Therefore,they are assigned to their own subclass(class I la). They must work as flip flops,on-offs or a combination of the two. In aflip flop, deaths occur because of under-population. In an on-off, any deaths thatoccur are due to overpopulation. (Thisis almost always true. Figure 9 is a period2 oscillator, which if traced, will revealthat it adheres to both definitions.) Avariety of small period 2 oscillators isshown in figure 8; the type of each oscil-lator is also given.

Next in the hierarchy are billiard table

56 December 1978 © BYTE Publications Inc

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BYTE December 1978 57

0

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Figure 6: The most ver-satile eater object, theperiod 3 eater, devoursthe precursor pattern tobeehive. Whiie in isoiatioia 7 ceii stiil life, this eateattacks other objects witta flat connected outeiborder at ieast two ceils inlength.

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Figure 7: A period 6 eaterattacks and eats a block.This new eater is notablymore symmetrical than theperiod 3 eater. Function-ally, each complementsthe capability of the other.

Figure 8: A variety of smallperiod 2 oscillators. These ob-jects alternate in succeedinggenerations between two pat-terns. Those on the top rowbear names as follows (left toright): a, blinker; b, beacon;c, clock; d, toad; e, bipole; f,tripole; those on the bottomrow are unnamed flip flops. Thebeacon is the only example hereof an on-off type oscillator.

a

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Figure 9: A period 2 oscillatorwhich functions both as a flipflop and as an on-off.

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58

December 1978 © BYTE Publications Inc

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• Client Information Management®

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• Fuel Dispensing and Accounting

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Figure 10: Billiard table configurations

These are artificial objects which have not occurred unless specifically constructed by the experimenter.They tend to be large; the smallest is composed of 18 live cells. Those illustrated bear names as follows: a,MIT oscillator (a period 3 object); b} burloaferimeter (period 7); c, an unnamed period 8 object; d, wave front(period 4); e, an unnamed period 5 oscillator; ff an unnamed period 9 object

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Figure 11: inductor and pulsator oscillators. These are natural objects which may appear from automation ofrandom patterns. Inductors possess an imaginary line of symmetry which pulsators lack. They are called bythe following names: a, pulsar (an inductor of period 3); b} tumbler (period 14 inductor); ct an unnamedperiod 8 inductor; d} pentadecathion (pulsator of period 15); e} mazing (period 4 pulsator); f} unix (period6 pulsator). The pentadecathion is of particular historical significance.

7M

60

December 1978©BYTE Publications Inc

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configurations (class lib). These oscillatorsare configurations that oscillate within anenclosed area, like balls on a billiard table.Billiard table configurations are consideredto be very artificial, since they have notturned up in the histories of any randomobjects. By this, I mean that if live cellsare placed randomly on the plane, the pat-terns which they generate probably willnever evolve into an artificial object, suchas a billiard table configuration.

They are quite large, as evidenced bythe examples in figure 10. The first exampleis the smallest such object, and it consistsof 18 bits. This subclass of oscillators con-tains the only known examples of oscillatorswith periods of 7, 10 and 11.

The next class, Inductors (class 11c),are natural oscillators that exist in two orfour pieces with an imaginary line of sym-

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Figure 12: Shuttle objects. Object a is the basic shuttle; object b is the twinbees shuttle. These move back and forth with a relatively long period. Eatersare used to remove debris from their path.

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Figure 13: Two eater bound oscillators. These differ In that they are stabi-lized by two different eaters. Oscillator a has a period of 6; oscillator b has aperiod of 5.

metry between them (exhibiting one-wayor two-way orthogonal symmetry). Pulsators(class lid) are also so far considered to benatural oscillators except that they do nothave this line of symmetry. One of theirproperties is that they require no externalstimulus to continue oscillating.

The aforementioned subclasses havegreatly similar characteristics, so I havegrouped them together. Most of the initialoscillators that were found were from thisgroup, since the methods for harnessingrandom objects into oscillators were notknown at the time.

Some of these oscillators are presentedin figure 11; the most important of theseis the pentadecathlon. This object throwsoff several sparks (small collections of dyingbits) that can be used to reflect a glider,reflect two gliders, turn a glider into a block,turn a block into a glider, etc. Some of theearly research into Life probably mightnot have occurred if this object had notbeen discovered.

Shuttles (class Me) are important for theexistence of much of the interesting re-search into Life. Shuttles are objects thatmove back and forth with a relativelylarge period. The two primary shuttles,the basic shuttle and the more complextwin bees, leave debris at their extremitieswhich would fatally wound the shuttlesif the debris were not removed before theyreturned (see figure 12). This is one of theuses of the eaters that was discussed in thesection on still lifes. In the examples I haveused blocks to remove the debris from theends, but just about any of the eaters wouldhave suited some phase of this debris. Thedebris left behind may at first seem to besomewhat of a bother, but without it therewould most likely not be any known gliderguns (defined later).

The very last class (class llg) containseater bound oscillators. These oscillatorsconsist of patterns which generally mustbe manipulated in order for the objectto return to its initial state. In figure 13a good example of two eater bound oscil-lators is given that also shows the differ-entiation between two eaters acting on thesame object (which is not often possible).A period 52 oscillator (figure 14) is shownto illustrate the unusual properties of ob-jects being eaten. The center object willbe attacked by one eater twice each timeit rotates (the object rotates 90° every 13generations). The example in figure 15is a period 6 oscillator using the period 6eater. The 7 bit eater is not suitable herebecause it would have returned to its originalstate too soon and would have attackedthe reforming object. (If the 7 bit eater

62 December 1978 © BYTE Publications Inc

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63

is used, the patterns results in two blinkers,six blocks, and one tub in 110 generations.)

Class III: Spaceships

Regrettably, there have been no newspaceships reported since the orthogonalspaceships presented in Scientific Americanin 1971. These are summarized in figure 16.The glider (figure 16a), which featuresdiagonal movement, has been used formany simulations and constructions.

Movement by an object of one spacein one generation is referred to as move-ment at the speed of light (c). There is nodistinction made between diagonal andorthogonal movement, even though alge-braically the distances are not the same.The glider travels at c/4 and the threeother spaceships travel at c/2. The interest-ing thing to note is that the three largerspaceships travel orthogonally. The ortho-gonal spaceships are most useful in severalof the types of puffer trains to be discussedin the next section.

Class IV: Pattern Producing Mechanisms

Class IV is divided into two sections: the

Figure 14: A long period eaterbound oscillator. This objecthas a period of 52; 13 gener-ations are required for 90* ofrotation. The central section isattacked twice by one eatereach time it rotates.

Figure 15: A period 6 oscil-lator which employs the period6 eater. This matching ofperiod frequencies prevents theeater from disrupting the re-forming central group.

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first contains static patterns that producemoving progeny, and the second containsmoving patterns that produce some typeof stationary or moving output.

Spaceship Guns

Class IVa consists of spaceship guns.These objects eject projectiles of class IIIobjects. The main two objects of class IVaare the glider guns of primary period 30 and46. There are no primary guns which pro-duce any of the other three spaceships.However, such a mechanism can be builtusing glider guns.

The period 30 glider gun (figure 17)works by having two shuttles of the typepresented earlier aimed at one another.The debris that would normally be removedby eaters collides and just happens to createa glider that escapes without harming theshuttles. The period 30 glider gun is ofparamount importance to simulations in Lifeand the possible existence of computingmechanisms. These implications will bediscussed in a later article.

The period 46 gun, known as a newgunyalso works by having two shuttles collide.It may be seen in figure 18. In this casethe shuttle consists of two B heptominos(described later) travelling opposite oneanother to produce debris at both ends oftravel. A glider is produced when these twoshuttles, which are of the twin bees type,collide at right angles. There are otherarrangements of this shuttle that producegliders in other ways, including an ambi-dextrous variety.

There is another interesting variation:if one of the debris removing blocks isremoved from the end of one of the twinbee shuttles, the gun will still work.

Puffer Trains

Puffer trains are patterns that move andleave debris in their wake. Because thesepatterns do move, as opposed to the sta-tionary spaceship guns, they are not onlyable to produce moving debris but alsotrails consisting of stationary objects. Leav-ing stable objects is useful when the inten-tion is to produce a train of puffers to buildsome sort of construction on the fly.

The three basic puffer trains all workby different means. The train which wasdiscovered first is presented in figure 19.The center object is a pre-B heptomino,which, if traced, will seem to move forwarduntil the debris in the back of it stops theuniform forward motion. In this case,the B heptomino is bounded by two light-weight spaceships able to control the object;the whole configuration puffs along at c/2.

64

December 1978 ©BYTE Publications Inc

This object reaches a stable period of 140after a startup time of over 1000 genera-tions. Additional spaceships may be addedto the end of the object to further adjustthe output from it in order to reduce thefinal period, the startup time necessaryto reach a stable period and to adjust theoutput to blocks, gliders, etc.

A type of puffer similar to the previousone is called a Schick ship (after its dis-coverer). This is an interesting object (con-sult figure 20) in that the "engine" is reallya tagalong, an object capable of beingpulled along behind another object (usuallya spaceship). Here, a heptomino followsa pair of mirrored spaceships. It is quiteremarkable that this configuration leavesa small trail of debris behind it and that,although this debris would die if left alone,additional spaceships following behind areable to trigger the debris into varying formsof static debris. The static debris can beleft behind and used later. It is relativelyuseful for building armadas because of therelative simplicity of creating this objectfrom gliders (producing a basic ship requires11 gliders).

The last type of puffer train is the small-est, a mere 11 bits at startup — the size issomewhat larger when the final repeatcycle is known, since there is transientdebris in the field. This particular traintravels very slowly, taking 96 generations totraverse eight spaces (speed c/12). It is alsovery unusual in that it is the only knownpuffer train that travels diagonally — thesame direction as the glider, but threetimes as slow.

Unlike the other puffer engines, thistrain does not require that any other space-ship exist to bound it. To stabilize the basicengine, a block must be placed somewherein the debris produced by the object toprevent the debris from destroying it. Ifthe engine is run without a stabilizing block,some rising debris finally catches the engineafter 11 full cycles and destroys it. Theremaining field settles down to a finalcensus only after 3911 generations!

Pertinent to the above paragraph is thefact that random patterns are quite oftenable to produce certain types of edge con-figurations, which enable them to surgeforward with a great burst of speed for shortperiods of time. In the case of the switchengine, when some random exhaust managesthis type of movement, this slow movingengine is easily caught.

The switch engine (presented in figure21) will produce, after its startup time,eight blocks every 288 generations. Otherdebris can be produced, including gliders.Since this train travels so slowly, there arepresently no real uses for it.

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Figure 7 7: This glider gun, which has a period of 30 generations, was thefirst object of class I Va to be discovered. It periodically emits a glider whichtravels away diagonally. The four block still iifes are used as eaters to disposeof debris. Glider guns are of great importance in simulations, where gliders aremade to collide, thus forming new objects.

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Figure 18: A period 46 glider gun which is called the newgun. Two twinbees shuttles collide at right angles to produce one glider every 46 gen-erations. As before, the block still Iifes are used to remove debris whichcould cause disruption of the formation.

December 1978 © BYTE Publications Inc

65

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Figure 19: A puffer train constructed from the precursor to aB heptomino and two lightweight spaceships, After a startupperiod of over 1000 generations, it stabilizes into a period of140 generations.

Figure 20: A Schick ship puf-fer train. The engine in thisobject is pulled along behindanother object in this exam-ple, a heptomino tags alongbehind a pair of mirroredspaceships. This object has aperiod of 12.

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Figure 22: Several com-mon nonterminal randomobjects. These are desig-nated as follows: a, Rpentomino; b, B hepto-mino; c, it heptomino; andd, acorn. The acorn is aMethuselah type object.Finding all the descend-ants of such an object is adifficult challenge.

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About the Author

David Buckingham is an undergraduate science student at the Univer-sity of Waterloo. He made a number of contributions to the now defunctpublication Lifeline, Most of these had to do with oscillators, which con-stitute his main field of interest in Life. He has at present found over TOOoscillators of periods greater than two.

Buckingham's most productive area of research has been the devisingof glider collisions to produce objects of classes I thru IV. As of August1978, he has managed to create collisions to produce all of the presentlyknown 1105 objects of less than 15 bits in size.

Class V: Random Objects

A random object is simply anythingthat does not fit in any of the above classes.It appears that all random objects eventuallybecome something from one of the aboveclasses. It has been assumed that thereare no objects that expand irregularlyforever (this is a common problem in othercellular spaces using other rules). Thereare some very popular nonterminals in life,which, due to their commonality, have beengiven names. In some cases these have beenrather heavily investigated. In figure 22 aresome of the more common nonterminals andtheir names.

The most common object of this classmust be the oft publicized R pentomino(figure 22a), which many people still believeruns forever. The result of this pattern was,however, published in Scientific American;it runs for 1103 generations, producingfour blinkers, eight blocks, one boat, fourbeehives, one ship, one burloaf, and sixgliders.

The B heptomino (figure 22b), with acensus of three blocks, one ship and twogliders in 148 generations, is one of the moreheavily investigated objects, as is evidencedby some of the material presented in thisarticle. It has the following interestingproperty: the front configuration of theobject moves along to reappear the sameevery other generation, but flipped over.

A close relative of the previous objectis the 7r heptomino (figure 22c) with acensus of five blinkers, six blocks and twoponds in 173 generations. Phase 1 of thisobject was called a blasting cap by theartificial intelligence researchers at Massa-chusetts Institute of Technology (MIT);we call phase 3 a house. If you trace thehouse for 30 generations, you will noticethat a house reappears at the front of thedebris ten spaces ahead of where it started.The house does not appear again after thisbecause the debris catches up with it andkills it. Many attempts have been madeto stabilize this object, with no successas yet.

A random object that consists of fewerthan ten bits and that has descendantsenduring for more than 50 generations isreferred to as a Methuselah. The acornpattern (figure 22d) is presently the recordholder for duration. This is presented as achallenge to anyone who would like a diffi-cult object to trace.

We hope that some of our investigationsinto the more exotic corners of Life willinspire readers to try their hands at thisfascinating pastime.■

66 December 1978 © BYTE Publications Inc

Early issues of BYTE carried a nevercompleted series by Carl Heimers inad-vertently entitled "LIFE Line," whichwas also the name used for RobertWainwright's newsletter. These Heimersarticles appeared as follows:

"LIFE Line 1," September 1975 BYTE,

volume 1, number 1, pages 72 thru 80;"LIFE Line 2," October 1975 BYTE,

volume 1, number 2, pages 34 thru 42;"LIFE Line 3," December 1975 BYTE,

volume 1, number 4, pages 48 thru 55;"LIFE Line 4," January 1976 BYTE,

volume 1, number 5, pages 32 thru 41.

article on the subject, including defi-nition of the several varieties ofspaceships.

January 1971: pages 105, 106 and 108.Continued progress on the Life frontincluding answers to several unsolvedquestions and results of a flurry ofcomputer Life activity.

February 1971: Special "MathematicalGames" article on "cellular automatatheory."

March 1971: pages 108 and 109. Shortnote about progress made by JohnConway and R William Gosper, plusillustration of a large scale flip floppattern which is delicately balancedand easily destroyed by minor disturb-ances such as impact of a glider.

April 1971: pages 116 and 117. Examplesof fuses, the 5 cell cross series, andannouncement of Robert T Wain right'sLifeline newsletter.

A bibliography of Scientific Americaninformation on LIFE (ail references areto Martin Gardners "MathematicalGames" column).

October 1970: page 120. This is the originalLife article, including the definition ofthe facts of Life, and illustration ofnumerous fundamental patterns.

November 1970: page 118. Answers toseveral questions posed in the first

November 1971: page 120. Short noteon continued progress at the MIT AILaboratory.

January 1972: page 107. The discoveryof the eater by Bill Gosper at MIT.

Hurry down to your public library ifyou wish to use these references, as dueto lack of space some local libraries maybe committing the unspeakable crime ofthrowing away Scientific American CH

The January 1979issue of BYTE will con-tain an article by MarkNiemiec which de-scribes several algo-rithms for Life. Readerswho wish to experi-ment with Life patternswill find these algo-rithms useful in writingefficient Life programsfor their computers.

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December 1978 © BYTE Publications Inc

67

One-Dimensional Life

Jonathan K Millen PhD

661 Main St

Concord MA 01742

Figure 1: The state of ace/f in the next generationis computed from its pre-sent state and the states ofthe four other ceiis in itsneighborhood. The neigh-borhood of a ceii consistsof ail ceiis within a dis-tance of two ceiis fromthe ceil in question.

The game of Life is known to many com-puter experimenters for its beautiful, sym-metrical two-dimensional displays and for itsimaginary population of blinkers, beehives,gliders, and other strange, pseudoliving or-ganisms. Invented by the British mathema-tician John Conway, the game was describedin the "Mathematical Games" section ofScientific American in October 1970 andFebruary 1971. A series of articles on howto program it for a home computer also

CELL X TO BE RECOMPUTED

NEIGHBORHOOD OF CELL X

appeared in three of the earliest issues ofBYTE ("LIFE Line 1, 2, and 3," BYTE Sep-tember 1975, page 72; October 1975, page34; December 1975, page 48). It is an attrac-tive home computer software project, butthe program requirements in memory capa-city, processor speed and display capabilitywere more than I possessed in my homebrewmachine. The programming effort alsolooked formidable. I developed One-Dimen-sional Life as a small scale substitute.

Conway's Two-Dimensional Life tracessuccessive generations of a pattern of cells inan infinite square array of cells like an un-colored checkerboard. The generation rulesdetermine the state of a cell in the next gen-eration based on its present state and thestates of its neighbors, the eight cells touch-ing it.

Each cell has two possible states: off and

(a)

1□

□

a

a

□

(b)

II I I I • 1 1 • !•!•! I !♦

i□

□

a

□

nnunn

a

Figure 2: The generation rules, illustrated here for a few representative cases. Each cell is marked with a dot if it is on, and leftas an empty square if it is off. The next generation of the middle cell in each neighborhood is shown below It. 2a Illustrates therule that a cell is "born " if and only If It has two or three on neighbors In Its neighborhood (in each example, the square beingexamined Is shown in color). 2b Illustrates that a cell survives If and only if it has two or four neighboring on cells. Note that acell dies If It has three on neighbors.

68 December 1978 © BYTE Publications Inc

on. A cell is "born" (ie: goes on when pre-viously off) if exactly three of its neighborsare on. A cell survives (ie: stays on) withtwo or three neighbors on. Otherwise it isoff in the next generation.

Generation Rules

In a one-dimensional version, patternshave to exist in a single row of cells. Eachcell in the row has two cells touching it. Itried all possible generation rules involving acell and its two neighbors, and I was disap-pointed in the results with all of them. Itfinally occurred to me to try a larger neigh-borhood including not only the adjacentcells but also the two adjacent to them (seefigure 1). It still took several tries to comeup with generation rules that seemed toyield a game approaching the richness of thetwo-dimensional game. The rules illustratedin figure 2 met my criteria for interest,which included the existence of oscillatingpatterns with long periods, patterns withlong lifespans that eventually vanish, andgliders. The rules can be summarized as fol-lows: Each cell is viewed with respect to a 5cell region including itself and two neighbor-ing sights on either side. Cells with two orthree neighbors on are born and those withtwo or four neighbors on survive. The restare off in the next generation.

The bare rules are rather plain withoutsome biological "facts of life" to dress themup. The following explanation is offered:

Rule 1: Birth. Cells that are off buthave either two or three neighbors on,go on.

Rule 2: Survival. Cells that are on andhave two or four neighbors on stay on.Those with zero or one neighbors ondie from loneliness; those with threeneighbors on die from overcrowding.What keeps a cell with four neighborson from dying is not clear. Maybethere is just not enough room to liedown.

Examples

Let us trace the life spans of a few pat-terns. The simplest oscillating pattern con-sists of two adjacent cells on. Its next gener-ation has two cells on with two cells off inbetween, and the third generation regener-ates the original pattern. Figure 3 showsthree generations of this pattern. Note thatthe successive generations of a one-dimen-sional pattern form a two-dimensionalpattern.

Another period 2 pattern is the flip flopin figure 4. A line of five adjacent cells on isalso periodic, but with period 6. Seven gen-erations of it are shown in figure 5.

A glider is shown in figure 6. It looks thesame in every generation, but in each genera-tion it moves one cell to the right. It is easilyproved, incidentally, that One-DimensionalLife, unlike Two-Dimensional Life, has nostable patterns that repeat in one generationin the same place.

GENERATION

• •

1

• •

I

• •

Figure 3: The simplest oscillating pattern, consisting of two adjacent cells on.Three generations are shown. Every second generation recreates the originalpattern, so this pattern is said to have period 2. Its alter ego, the pattern withtwo cells on separated by two ceils off, also has period 2. The three genera-tions are separated in order to emphasize that they are separate generationsrather than part of a Two-Dimensional Life configuration.

GENERATION

• ••

Figure 4: A pattern with period 2 that oscillates between the starting patternand its mirror image. These kinds of patterns are sometimes called flip flopsin conventional Life terminology. (Note that each line is the complete stateof the Life universe in one generation.)

GENERATION

« • • •_

A A A A A

Figure 5: A line of five cells that regenerates itself after six generations. In myexperience, this pattern has the longest period of any One-Dimensional Lifepattern.

GENERATION

• •••

Figure 6: A glider pattern, so called because it regenerates itself in a steadilymoving position. This glider has a period of 7.

December 1978©BYTE Publications tnc

69

We have seen a glider of period 1 and twostatic oscillating patterns of periods 2 and 6.Are there patterns with all possible periods?I generated the life spans of lines with up to15 cells and found one new oscillating pat-tern: a line of 12 cells that oscillates withperiod 4. This suggested that static oscillat-ing patterns could be found for even periods,though I have not yet found any with pe-riods longer than six. Of course if one startsa line of 12 (period 4) and a line of five (pe-riod 6) far enough apart to keep them from

GENERATION

• ••••••

Figure 7: A glider that moves right by one ceil every three generations. It haslength 8; there is another period 3 glider of length nine. The two intermediatepatterns of this glider are, of course, also gliders of period 3.

Pattern

Number

Fate(patterns referenced by hexadecimal)

Hexadecimal

Binary

1

1

Dies after generation 1.

3

11

Oscillates with period 2.

5

101

Dies after generation 2.

7

111

Becomes number 1F after generation 1.

9

1001

Oscillates, second form of number 3.

B

1011

Oscillates with period 2,

D

1101

Oscillates, second form of number B.

F

1111

Becomes number 33 after generation 1.

11

10001

Dies after generation 2.

13

10011

Oscillates with period 2.

15

10101

Oscillates, fourth form of number 1F.

17

10111

Glider with period 1.

19

11001

Oscillates, second form of number 13.

1B

11011

Oscillates, fifth form of number IF.

1D

11101

Glider with period 1.

1F

11111

Oscillates with period 6.

21

100001

Dies after generation 1.

23

100011

Becomes number 19 after generation 1.

25

100101

Becomes number D after generation 1.

27

100111

Becomes numbers 3F,DB,2B5,FF,37B,AQ5,201,0.

29

101001

Becomes number B after generation 1.

2B

101011

Becomes numbers 3D,31,13.

2D

101101

Becomes number F after generation 1.

2F

101111

Becomes numbers 23,19.

31

110001

Becomes number 13 after generation 1.

33

110011

Oscillates with period 2.

35

110101

Becomes numbers 2F,23,19.

37

110111

Becomes numbers C7,BF.(BF is glider with period 3.)

Table 7: Vital statistics of the first 28 One-Dimensional Life patterns. Theconvention used for identifying the patterns is to regard the pattern as a bi-nary number: on cells are represented by Js, and off cells by 0s. Only thecells between the leftmost and rightmost on cells, inclusive, are considered,and a binary (or hexadecimal) number can then be generated to representthe pattern.

interacting, the pattern as a whole will notrepeat until the twelfth generation, because12 is the least common multiple of 4 and 6.What about odd periods? Having found aglider of period 1, I tried a number of similarbut longer patterns and discovered the pe-riod 3 glider shown in figure 7. Readersmay enjoy discovering for themselves an-other period 3 glider that is one cell longerthan the one in figure 7. It is tempting toconjecture that gliders exist with all oddperiods. If anyone finds oscillating patternsor gliders of period 7 or greater, I would liketo hear about it

Tabulation

There is an obvious notation for specify-ing a pattern without drawing a picture. Aone-dimensional pattern, being just a se-quence of on and off cells, may be regardedas a binary number. By convention, we canconsider the pattern proper as just the cellsbetween the leftmost on cell and the right-most on cell, inclusive. Thus, the number fora pattern will always be odd, except for the"all off pattern, 0. Pattern numbers can bereported in decimal, octal or hexadecimal tosave space. For example, the first generationshown in figure 3 (two adjacent cells) can berepresented by binary 11 (or hexadecimal3). The second generation in figure 3 wouldthen be represented by binary 1001 (orhexadecimal 9). The pattern of binary 11111(hexadecimal 1 F) goes through the followingcycles, all noted in hexadecimal: 6B, 17D,49, 1 B, 55 and back to 1 F. (Note the 3-digithexadecimal number 17D, which is neededbecause the figure is nine cells wide at thatpoint in the cycle.)

This numbering system also provides ahandy way of enumerating patterns in asystematic sequence. This gives rise to theidea of constructing a dictionary of patternsin numerical order, listing for each patternits vital statistics: whether it oscillates,glides, dies or leads to a noninteracting col-lection of oscillating patterns and gliders. Byway of illustration, the first 28 entries insuch a table are shown in table 1.

Theoretically there is also the possibilitythat a pattern may grow in mass (ie: thetotal number of cells on) without bound,like the glider gun found for Two-Dimen-sional Life. No such infinitely growing pat-tern has yet been found for One-Dimen-sional Life.

Implementation

The discoveries of the period 4 patternand the large period 3 gliders were madeon my Turing machine computer. Imple-menting the One-Dimensional Life rules waseasy and would probably have been easier if

70 December 1978 © BYTE Publications tnc

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BYTE December T978 71

DIRECTION OF SCAN

NEW GENERATION <^=

=C> OLD GENERATION

CELL BEING RECOMPUTED

CELL ROW

N-2

N+2

r

1

1

OLDN-2

OLD

N- I

OLDN

T2

TO

NEIGHBORHOOD-CELLS USED TORECOMPUTE CELL N

Figure 8; Calculating the next generation in One-Dimensional Life. The algo-rithm uses a row of cells and three temporary ceil variables. Each cell has oneof two values: 0 for off and 7 for on. Each cell is a bit, a byte, or a word,whichever is most convenient in the programming language to compute thealgorithm. The states of the ceils are recomputed in a scan from left to right.Ceils behind the front of the scan have already been recomputed; those aheadof it still have their old states. As the algorithm scans from left to right, itmust temporarily remember the old states of each ceil long enough to com-pute the new values of its two neighbors to the right. (Similar temporaryvalue storage problems arise in conventional Life programs.)

I had had a more conventional computer towork with, instead of Turing machine (see"A Universal Turing Machine/' December1976 BYTE, page 114). The algorithm forproducing new generations according to therules is illustrated in figure 8, visualizing thememory requirements, and figure 9, a flow-chart. Note that, as in Two-DimensionalLife, there is one complication to bear inmind when computing the next generation:When you change the state of a cell, youmust remember the old state long enough touse it in computing the next state of itsneighbors. If the program scans the rowfrom left to right, changing cells as it goes,it needs a temporary memory of three cells.When the front of the scan is at cell N, theprogram is able to recompute cell N, aftersaving it, using its memory of the prior

states of cells N - 1 and N - 2, together withthe present states of cells N, N + 1 and N +2. The old state of N - 2 may then be for-gotten and the scan moved right one cell.

I will spare you the details of how thisalgorithm can be accomplished in Turingmachine language. A more universal problemis how to get the patterns displayed. Myonly output device, at first, was a single LED(light emitting diode) that could be steppedthrough memory, to display it one bit at atime. To improve on this I built a visibleshift register, a cascade of two 8 bit shift re-gisters with an LED on each output, givingme a movable 16 bit window on memory. Iwas considering extending the window to 32bits when I was lucky enough to get a longterm loan of a SwTPC CT-1024 video dis-play from a friend who had no present needof it.

There is a coincidental resemblance be-tween a Turing machine and a video display:both normally change memory addresses by± 1. It turned out to be easy and natural topatch in the CT-1024 memory in place ofthe Turing machine "tape" memory. Turingmachine computations were then directlyvisible as they progressed on the videoscreen. One more refinement was all thatwas needed to display successive generationsof a pattern below one another as in the

72 December 1978© BYTE Publications Inc

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BYTE December 1978 73

Figure 9: Flowchart forthe One-Dimensional Lifeaigorithm.

Photo 1: One-DimensionalLife display. On theauthor's system, Is arerepresented by excla-mation points and Os byblanks. Each line repre-sents one generation ofOne-Dimensional Life.

INITIALIZEN = lTl = 0T2-0

TO = CELL(N)

SUM=T2 + TI+CELHN + I)+CELUN + 2)

YES

BORN:CELL (N) = l

+ .

DISPLAYCELL ROW

DIES:CELLlN) = 0

SHIFT:T2 * Tl

Tl = TON = N+ I

II III II

1 If II

ill illill in

iiiiiiiiiii

III!!!!!!!!

! ! Ill ! !

■ nt mi r

III*!!! !!!

!!! I !!!

lltlll !!!!!!

II II Mill II II

• II I II I ■III! •• II llll*» t III I ••

figures: up and down cursor control. Out-puts were created by decoding the last threeinstruction address bits, effectively yieldingeight 1 bit output ports that were strobedevery time an instruction with the appro-priate address was executed. Two of theseoutputs became cursor control outputs.

After all this hardware activity and someprogram modifications, the result was thekind of display shown in photo 1. Thescreen has the first 16 generations of aline of seven cells. This pattern settles downafter 40 generations to a collection of non-interacting oscillating patterns, but beforethat happens it produces one of the mostintriguing displays of its kind, one that Iwould never have seen without the help ofa home computer. Of course, readers canverify these discoveries with any homecomputer and share in some of the excite-ment of exploration which I found."

74 December 1978 © BYTE Publications Inc

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Circle 301 on inquiry card.

The LFD-400 is ready to plug in and run

the moment you receive it.

Nothing else to buy! Not even extra memory!

YOU GET:

O The popular ShugartSA 400 minifloppy™ drive. Drive alignment

is double checked by PerCom before shipment.0 The drive power supply—fully assembled and tested.© LFD-400 Controller/Interface—plugs into the SS-50 bus •

accommodates three 2708 EPROMs • fully assembled and tested.O MINIDOS™ —the remarkable LFD-400 disk operating system on

a 2708 EPROM • plugs into the LFD-400 Controller card • no

extra memory required • no "booting" needed.0 Attractive metal enclosure.

O Interconnecting cable—fully assembled and tested.Q Two diskettes—one blank, the other containing numerous

software routines including patches for SWTP 8K BASIC and the

TSC Editor/Assembler.O 70-page instruction manual—includes operating instructions,

schematics, service procedures, and the complete listing of

MINIDOS™.® Technical Memo updates—helpful hints which supplement the

manual instructions.® 90-day limited warranty.

Minifloppy is a trademark of Shugart Associates.MINIDOS is a trademark of PERCOM Data Company, inc.

The LFD-400 is readily expanded to either two or three drives.Write for details. Send for our free brochure for more informa-tion about the LFD-400 Floppy Disk System and LFD-400software.

To save you money, the LFD-400 Floppy Disk System is availableonly from PerCom. Because of the special pricing, group anddealer discounts are not available.

MC and VISA welcome. COD orders require 30% deposit plus 5% handling charge. Allow threeextra weeks if payment is by personal check. The LFD-400 Floppy Disk System is availableimmediately. Allow three weeks for testing and transportation. Texas residents add 5%

PERCOM DATA COMPANY, INC.

Dept B 318 BARNES*GARLAND, TX. 75042(214) 272-3421

PERCOM™ "peripherals for personal computing'

BYTE December 1978

75

Programming Quickies

Life

William Englander

1966 Titus St

San Diego CA 92110

The game of Life was developed by JohnHorton Conway and was introduced in the"Mathematical Games'* section of theOctober 1970 Scientific American maga-zine. Life is played on a grid of squares (inthis case a 22 by 22 matrix). A given squareis either occupied or empty. The programuser specifies which squares are occupiedinitially.

The game of Life program produces newgenerations of the matrix by applying life's

laws for birth, survival and death to thepresent generation. These laws are:

Birth: An unoccupied square becomesoccupied if in the precedinggeneration exactly three of theeight neighboring squares wereoccupied (squares that touchhorizontally, vertically or diag-onally are said to be neighbor-ing squares).

Survival: An occupied square remainsoccupied if in the precedinggeneration two or three neigh-boring squares were occupied.

Death: An occupied square becomesunoccupied if in the precedinggeneration fewer than two ormore than three neighboringsquares were occupied.

Text continued on page 82

BASICE COMPILER VER 1.4

1 :

2J

4:

5 *617!

s:9i

10:11:12:13:

141

15:16;

17!

is:1?:20:21:22:23:

24 !25126!27128 t

29:

30:

3i:32:33:34:35:36:37:38;39:40:

41!42!43!44!45!46147!48!49150!51J52:53!54J551

56:

57!

0

30

■ERROR RE-ENTER': GOTO 10

DIM AC22,22> rB(22>22>

INPUT "ENTER INITIAL NUMBER OF ITERATIONS"fL

PRINT "ENTER INITIAL COORDINATES; 0»0 TO END"

INPUT X»Y

IF X + Y = 0 THEN GOTO 20

IF <X<1)0R<X>20)0R<Y<1>0R<X>20) THEN PRINT

X=X+1! Y^Y+1

A<XrY)=A(X»Y)+10

FOR XW-X-1 TO X + l! FOR YW=Y-1 TO Y+l

A(XUrYW) "A(XWfYW)+l

NEXT YW: NEXT XWGOTO 10

L*="+ .*- + "

INPUT "ENTER PAPER SIZE (IN LINES/PAGE)f SET UP PAPER & HIT ENTER"?PFOR I»l TO L STEP 2

PRINT L*

FOR Y=l TO 22! PRINT MMJ FOR X=l TO 22

IF MXrYXlO THEN PRINT ■ "» ELSE PRINT ■ Z1" t

B<X>Y>=0

NEXT X: PRINT '!"J NEXT YPRINT L*

for j-25 to p: print: NEXT J

FOR X=2 TO 21! FOR Y=2 TO 21AU=A(X»Y)

IF <AW<>3)AND(AW<>13)AND<AW<>14) THEN GOTO 30B<X>Y)=B(X»Y>+10FOR XU=X-1 TO X+II FOR YU=Y-1 TO Y+l

B(XWfYW)=B(XWrYW)+l

NEXT YW! NEXT XWNEXT Y! NEXT X

PRINT L$

FOR Y=l TO 22! PRINT "I"?! FOR X=l TO 22

IF B(X»YX10 THEN PRINT ■ "S ELSE PRINT "C3"»

A(X,Y>=0

NEXT X! PRINT "!"J NEXT YPRINT L*FOR J=25 TO P! PRINT! NEXT J

FOR Y=2 TO 21

>13)AND(BW<

14) THEN GOTO 40

FOR X=2 TO 21BU=B(XfY)IF (BU<>3>AND(BUA(X>Y)=ACX>Y>+10

FOR XU=X-1 TO X+l! FOR YW=Y-1 TO Y+lA(XWrYW)=A(XWfYW)+1NEXT YWI NEXT XUNEXT y: NEXT XNEXT I

INPUT "ENTER NUMBER OF ADDITIONAL ITERATIONS'pLIF L>0 THEN GOTO 20STOPENDERRORS DETECTED

Listing 1: BASIC E programand sample run of the game ofLife. A sequence of eight statesof Life demonstrates oper-ation of the program.

76

December 1978©BYTE Publications Inc

! MicroPro

MicroPro International Corporation

MicroProInternationalCorporation

TM

profession

giMtiiKi linSfS PET MtiiiiiKTil

proudly announces

SUPER-SORT

The ultimate in high performance

sort/merge

petrifications

JHigh Performance Tournament/Heapsort AlgorithmJMultiple Input Files Read in Parallel for True Merge

Operation. Up to 32 Sort and 32 Merge Input Files Handled.]Dynamically Invokable User Exit Routines]Record Selection via SELECT/EXCLUDE Statements] Handles Fixed and Variable Length Records1 Handles Fixed ancf Variable Length Fields]Handles up to 32 Sort Keys with Intermixed Sequence

Indicators, Data Types and Alternate Collating Sequences] Handles Multi-Volume Diskette FilesiCompatible with CP/M* and any Derivative Including

ADOS, IMDOS, CDOS, etc.D8080/8085/Z-80 Compatible

] Specialized Optimizations for Floppy Disk Environment]Keyword Command Input for Easy Operator EntryDBenchmarked at Over 560 Records per Minute!] Invokable as a Subroutine from FORTRAN, COBOL

and Assembler1 Furnished in Relocatable and Executable Form for

Easy Load-Address Definition^Optional TAGSORT OperationDData Types Include ASCII, EBCDIC, Binary, BCD

(COBOL Packed Decimal), etc.^Supports CP/M-compatible Diskette Files under

BASIC, FORTRAN, COBOL and Assembler.

'rice $250** includes manual and single densitydiskette.Manual only $15 refundable with purchase.

WORD-MASTER®

The last word in text editing

Specifications

□ Compatible with any "Dumb" CRT Possessing Ad-dressable Cursor and Backspace (Includes Hazeltine-All Models, SOROC, Lear Siegier, IMSAI-VIOC, ADDSRegent, Behive, etc.)

□ Bi-Directional Word Tab, Line Tab, Screen Tab

□ Bi-Directional Word Delete, Line Delete and CharacterDelete

□ Quad-Directional Cursor Movements

□ Mid-Line Insert and Delete

□ Automatic RAM/Diskette Buffering With No UserIntervention

□ Nested Command Looping with Conditional Execution

□ Global String Search, Global String Replace

□ Scratch-Pad Buffer for Text Movement, GlobalReplication, and String Command Storage

□ Multiple Input File Merging with User-ControlledInsertions for Easy Document Assembly

□ Multiple Output File Control by Section Under UserControl

□ Compatible with CP/M and Most of its DerivativesIncluding CDOS, IMDOS, etc.

□ Use TEX* for Print Formatting Functions

Price $150** includes manual and single density diskette.Manual only $9.00 refundable with purchase.

*CP/M and TEX are Trademarks of Digital Research.

** Prices and Specifications subject to change without notice.

© 1978, MicroPro International Corporation. All rights reserved.

ealer Inquiries Invited: Call (Northern California) (707) 544-2865, (415) 398-7062, (209) 445-0511, (408) 279-8980, (916) 485-i19 (Southern California) (213) 224-1619, (714) 634-2908. Outside California Call Collect (707) 544-2865. Principal officescated at 5810 Commerce Blvd., Rohnert Park, CA 94928

rcle 224 on Inquiry card.

Listing 1, continued:

About the Author

Wiiiiam Engiander is aseif-empioyed computerprogrammer as weii as aninstructor at San DiegoState University andNationai University.

RUN LIFEBASIC-E INTERPRETER

ENTER INITIAL NUMBER OF ITERATIONS'? 8

ENTER INITIAL COORDINATES? 0,0 TO END

? BrlO

? 9,10

? 10*10

? llflO

? 12,10

? 0,0

ENTER FAFER SIZE (IN LINES/PAGE), SET UP PAPER % HIT ENTER? 33

Ul€ KNOW

nnouT

COmPUTCR/

COULD/nvc

vou moNcv

• Finally, an objective look at the top24 micro systems sold throughout the world!

• Honest pros and cons of each system, plus astraightforward look at the micro computerindustry as it relates to you!

• Written in plain English for the layman. If you areconsidering the purchase of a personalcomputer, this book will save you money!

SAMPLE CONTENTS

• Don't Get Hung up on the Chips • Now, aboutthe hardware • What? No software! • Helpfulsuggestions before spending moneyREAD UP ON COMPUTERS BEFORE YOUPUT YOUR MONEY DOWN!ONLY $4,50 PER VOLUMETELEPHONE TOLL FREE:800-327-6543-or send this coupon! ^

+—

+

C3C 3C 3

+ -.-

—+

78 December 1978 © BYTE Publications Inc

Our Two Bits

Bit Pad Bit Pad ®m®Bit Pad Bit Pad ®mBit Pad Bit PadBit Pad Bit PadBit Pad Bit Pad

Bit PadBit Pad

Bit Pad™ is the low-cost digitizer for small computer systems. Better than a

joystick or keyboard for entering graphic information, it converts any

point on a page, any distance into its digital equivalents. It's also a menu for

data entry. You assign a value or an instruction to any location on the pad.

At the touch of a stylus, it's entered into your system.

Who can use it? Anyone from the educator and the engineer to the hobbyistand the computer games enthusiast. The data structure is byte oriented foreasy compatibility with small computers, so you can add a power supply,stand alone display, cross-hair cursor and many other options.

Bit Pad by Summagraphics. The leading manufacturer of data tablet digitizers.Bit Pad. The only words you need to say when considering digitizers.

$1,000 creativity prize. Just write an article on an original Bit Pad application

and submit it to any national small-computer periodical. If the editors publish

it—and the decision is solely theirs—Summagraphics will pay you $1,000.

■ Aunumdwyhicd*F * corporation35 Brentwood Ave., Box 781, Fairfield, CT 06430

Circle 356 on inquiry card.

Phone(203) 384-1344. TELEX 96-4348

Dealer inquiries invited

BYTE December 1978

79

Here comes another high-flyingBlue Board of Happiness from SSM.

The VB-2 Video Board...it saves programming time, memoryspace, and is built to U.S. videostandards.

Check out all our VB-2's great features, and

compare prices:

• It's an I/O controlledvideo interface thatturns a TV or commer-cial grade monitor intoa video terminal

• No need for anotherI/O board for key-board input and videodisplay

• Hardware controlledcursor for line feed,carriage return, andbackspace

• Reduced softwareoverhead frees upmore memory spacefor important data

Circuitry provided todrive a speaker forexternal "beep"tone

64 x 16 characterdisplay includes up-percase letters, num-bers and symbols

Characters can beswitch selected forwhite on black, orblack on white

Full interlace for com-plete compatibilitywith video stan-dardsS-100 compatible

Extra adjustments include adjustable characterwidth, horizontal margin and vertical position

All for only $149.95. Available at over'100 retail locations, or direct from SSM.

i, SSM manufactures a full line of S-100 boards. For complete details,^ just send for our new FREE catalog.

SStTf

2116 Walsh Avenue Santa Clara, CA 95050 (408) 246-2707

*We used to be Solid State Music. We stillmake the Blue Boards.

Listing 7, continued:

cd

CDCDCD

cdcd cdcdcdcdcd

CD

+

+

CDCDCDCD CDCD CDCD CD

CDCDCD

+

+

CD

CDCDCD

CD CD CD

CDCDCD CDCDCD

CD CD CD

CDCDCD

CD

December 1978 © BYTE Publications Inc

Circle 335 on inquiry card.

ITHACA AUDIO

THE OEM MARKETPLACE

IA ExpandsS-lOOLine

Video

Display

Board

Featuring a full 128 upper/lower case ASCIIcharacter set stored in a 1K buffer memory.Easy to read 16 line x 64 character format canbe displayed on an inexpensive video monitoror a modified TV set. Includes a TTY softwaredriver. Add our powerful K 2 FDOS to create aversatile operator console.

$25.00

Disk

Controller

Board

Controls up to 4 single or double sided drives.Data protect features include automaticdisable of write-gate during power-down fordata integrity. Supported by a reliablesoftware package, K 2 FDOS and completediagnostic documentation.

$35.00

K2

Operating

System

Power full disk software in the DEC tradition.Includes Text Editor (TED), File Package (PIP),Debugaer (HOT), Assembler (ASMBLt),HEXEfffl, 1 COPY, System Generator (SY&GEN).Command syntax follows Digitals OS-8. RT/11format. First in a family of high level software.Soon to be released, FORTRAN & PascalCompilers.

$75.00

Field-provenreliable engineering

Over 10,000 boards worldwide prove IthacaAudio provides the quality and reliability youdemand.

Ithaca Audio Boards are fully s-100compatible, featuring gold edge connectorsand blated-through holes. All boards (exceptthe Protoboard) have fully buffered data andaddress lines, DIP switch addressing, soldermask and parts legend.

Z-80 CPU Board Most powerful 8 bit centralprocessor available. Featurina power-on-jump, orovision for on-board 2708. Acceptsmost 8080 software. $35.00

8K Static RAM Board High speed static memoryat the lowest cost per bit. Includes memoryprotect/unprotect and selectable wait states.

$25.00

2708/2716 EPROM Board Indispensable for stor-ing dedicated programs ana often used soft-ware. Accepts up to 16K of 2708's or 32K of

27165 $25.00

Protoboard Universal wire-wrap board for de-veloping custom circuitry. Accepts any sizeDIP socket. $25.00

RAM!

32K for $359.

Ithaca Audio is now stocking the Mostek4115add-on RAM for S.D.'s Expandoram. Buy their

'Si

© 1978 ITHACA AUDIO

Mass Storage atIncomparable

Prices.

Ithaca AudioFloppy Disk

• Up to 250K bytes, single sided

• Up to 500K bytes, double sided

• Data protect

• Powerful software operatingsystem includes 8 utilityprograms, text editor.

Add the capacity of full size disk to your S-100microcomputer. Controller, Disk Drive, andSoftware available separately,

Memorex single sided

550 Flexible Disk Drive $456.

Memorex double sided

552 Flexible Disk Drive $830.

Disk Controller Board $35.

K2 FDOS Available on 8"

floppy disk w. manual $75.

Quality Components

ZILOG Z-80

$19.00

ZILOG Z-80A

23.00

INTEL 2708

11.00

FAIRCHILD 2102 LHPC

1.60

FAIRCHILD 2102 LIPC

1.35

IMSAI 8080 Kit with22Slot MB.$560.00

plus $10.00 shipping.

HOW TO ORDER

Send check or money order, include $2.00 shipping per order.N.Y.S. Residents include tax.

basic board, 32K of RAM from us and SAVE

S.D. SALES Expandoram board $ iv;

Ithaca Audio 32 4115s @ $5.00 ea.

32K Only

For technical assistance call or write to:

ITHACA3 AUDIO

WOT P.O. Box 91

Ithaca, New York 14850Phone: 607/273-3271

Circle 190 on inquiry card.

BYTE December 1978

81

w alpha

IT"

micro

See the exciting 16-bit world of AlphaMicro at your local Alpha Micro dealer.

HUNTSVILLEComputerland1205)539-1200

82

ANCHORAGEData ComSystems. Inc[907)344-4536

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Computer land of

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Byte Shop of

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(415) 459-1366

SANTA ANA

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The Computer Store

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SHERMAN OAKS

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Tech Mart

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VAN NUYS

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WESTMINSTER

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BOULDERByte Shop ot(303)444-8550DENVERByte Shop ot(303)399-8995Computer Hut(Prime Radix)(303) 573-4895Mitt MiniComputer CoENGLEWOODMiti MiniComputer Co(303)770-5005

December 1978©BYTE Publications Inc

CONNECTICUT

HAM DEN

JRV Computer Store

(203)281-1453

FLORIDACORAL GABLESSunny ComputerStores, Inc(305) 661-6042FORT LAUDERDALEComputer People(305) 792-4965HIALEAHMetronmComputers, Inc(305)885-4700MIAMI

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Australian Computer

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Products

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(604)684-5032

Personal Computer

WINNEPEG

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(215)647-8460

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LONDON

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TENNESSEE

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Byte Shops

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Computer Boutioue

HOUSTON

310-095-047

Computercraft. Inc

Euro Computer

(713) 977-0664

Shop Paris

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(713) 526-6934

GERMANY

Alpha Computer Solutions

HOLSTEIN

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Digitronic

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Computersystems 4103

Computer Mart ot

73-93/4103 68-69

West Texas

MUNICH

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Datameg KG

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The Micro Store(214) 231-1096

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SALT LAKE CITYByte Shop of(801) 355-1041Data World(801) 943-0033

HONG KONG

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VIRGINIA

ALEXANDRIA

JAPAN

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The ComputerHardware Store.

Nihon TerminatComputer

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(703) 548-8085

SPAIN

SPRINGFIELD

BARCELONA

The Computer

Infotecnos

Workshop Of North

(000) 235-7110

Virginia. Inc

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SWEDEN

VIRGINIA BEACH

BROMMA

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Mentor. AB

Center. Inc(804)340-1977

SWITZERLAND

ZURICH

Comicro, A G

(01) 242-2603

VENEZUELA

CARACAS

E D C MEGA. C A

33-79-90

Listing 7, continued:

+

+

CDCDCD

[][][]

CDCDCD

CDCDCD

CDCDCD

CDCDCD

CDCDCD

CDCDCD

+

+

Text continued from page 76

The Life program in listing 1 was writtenin BASIC E and run on an IMSAI 8080.Since it is necessary to reference the presentgeneration's matrix while developing thenext generation's matrix, two arrays, A andB, are used alternately. When an array ele-ment represents an occupied square, it isgiven a value of 10. 1 is added to it for eachoccupied neighboring square (including itselffor convenience). Consequently a square inthe next generation becomes occupied if itscorresponding element in the present genera-tion array is equal to 3, 13 or 14 (an emptysquare with three neighbors or an occupiedsquare with two or three neighbors).

Statements 1 through 13 establish thenumber of generations to be printed and theinitial occupied squares (in the A array).Statements 19 through 25 print the contentsof the A array and zero the B array. State-ments 27 through 34 generate the B arrayfrom the A array. Statements 36 through 42print the B array and set the A array to zero.Statements 44 through 52 generate the Aarray from the B array and then loop backto produce the next two generations."

Circle 4 on inquiry card.

Thinking of addingmemory to your S-

bu$?

Think twice!

You say you're ready for greater storage?Well now, with average access times of 28milliseconds, large, on-line direct access car-tridge disk files have become a reality inmicrocomputing. And, ALPHA MICROoffers you not one, but TWO ways to vastlyincrease your system capacity... and do itwithout overtaxing your budget.

First, there's the ALPHA MICRO AM-500™Hard Disk Subsystem. It uses the popularCDC 9427H (Hawk) cartridge disk drivewith a total of 10 megabyte capacity (5 fixed,5 removable). The AM-500 comes com-plete with interface formatter/controller,cabling, and disk drive. You can expandyour mass memory to meet your require-ments, in 10 megabyte increments, up to40 megabytes.

Circle 4 on inquiry card.

Thinking of even more mass memory?Check out the ALPHA MICRO AM-400™Hard Disk Subsystem. It features theCALCOMP TRIDENT Series Hard DiskDrive in a choice of models with 25, 50, 80,200, or 300 megabyte capacity. And, youcan daisy-chain up to four units, on-line, inany mix. How's that for capacity?

So, if you're thinking of adding massmemory to your S-100 bus, be sure to checkout the ALPHA MICRO AM-400 or AM -500Hard Disk Subsystem at your nearest ALPHAMICRO Dealer. And while you're there, askhim to show you the rest of the ALPHAMICRO hardware and software lines.

AM 40(F

AM 500™

^S alpha

micro

17881 Sky Park NorthIrvine, California 92714(714) 957-1404

BYTE December 1978

83

Chess 4.7 versus David Levy

The Computer Beats a Chess Master

J R Douglas

25 Cannon Dr

Elk River MN 55330

After 29 years, computer chess finallyachieved a victory in human competition atthe master class tournament level. Duringthe fourth game of a match held at theCanadian National Exhibition from Au-gust 26 to September 4 1978, InternationalMaster David Levy resigned to Chess 4.7/CYBER 176 after 56 moves, although he didwin the tournament, Vh to Vh.

David Levy was three years old in 1949,when the American mathematician andcomputer science pioneer Claude Shannonproduced the first paper describing themethodology for producing chess playingcomputer programs. Not until 1956 did anymachine win a game against a human op-ponent: MANIAC, a system developed at theLos Alamos Scientific Laboratory, won agreatly simplified chess game against anovice player in 23 moves.

12 years later, Levy, expert rated andScottish National Champion, attended theFourth Annual Machine Intelligence Work-shop. There he took exception to the viewsof John McCarthy of Stanford Universityand Prof Donald Michie of EdinburghUniversity, who agreed that within tenyears a computer system would be WorldChampion of chess. Levy countered that notonly would computers fall short of that goal,but they would be unable to defeat him in atournament style match within that 10 yearperiod. Neither side was able to shake theother's convictions and, as a result, Levywagered £1250 sterling that he could defendagainst the computer advances.

The machine intelligence community hadexpected Levy to be defeated by a large net-work of computers participating in thegame, until 1970, when a NorthwesternUniversity program called Chess 3.0, writtenby Larry Atkin, Keith Gorlen and DavidSlate, clearly emerged as the leading effortin the first US Computer Chess Champion-ship. David Levy was then 24.

The original feeling of confidence Levyheld must have been somewhat shaken as theyears 1973 and 1974 saw Chess 4.0 achieve aUnited States Chess Federation rating higherthan that of the average US tournamentchess player. [Note: the version number ofthe program increases aiong with its skill. ]Then, in 1976 and 1977, when Chess 4.5and 4.6 won the class B championship at thePaul Masson Open Chess Tournament andwon outright at the Minnesota Open, Levyconceded that he had begun to think that hismatch with Chess 4.7, "would not be a for-mality but could be just a bit of work."

The latter part of 1977 and early 1978saw a series of 2 game matches betweenLevy and Chess 4.6, the Duchess programfrom Duke, Greenblatt's MIT program, andKaissa from the USSR. Levy handily de-feated all the programs in the first game.

Chess 4.7, running on a Control DataCorp (CDC) CYBER 176, had compiled arating of 2030 after 31 tournament gamesand a speed chess performance rating of2450, when the last challenge was given. Theissue was to be resolved on the tenth an-niversary of the original wager, with play tobegin on Saturday, August 26.

Getting a computer to a chess match,which was the duty of this author and DrDave Cahlander, is a considerably moredifficult task than getting a human to amatch. Crossing the Canadian border withmicroprocessor controlled chessboards, andsetting up and testing telephone lines andmodems between Toronto and the CYBER176 in Arden Hills MN consumed most of aweek.

The glass box in which the match washeld, standing beside three bowling lanesand a fencing exhibition, faced a largedemonstration chessboard and seats for on-lookers. A square of chess tables used insimultaneous play filled the rest of theroom. Opposite the glass box was the stand

Photo I: International Master David N L Levy ponders his move while sitting In the glass enclosed booth at the Canadian Na-tional Exhibition. A crucial position in one of the match games appears on the electronic chessboard, which Is connected bytelephone lines to a Control Data Corp CYBER 176 computer.

84 December 1978 © BYTE Publications Inc

V

:

~-T* _

GAME I

POSITION AFTER 12. P-KR3

Figure 1: Position occurring in round 1after White's 12th move. The piayer ofBlack next unleashes an attack which winsmaterial and disrupts White's Kingside.

1.

P-KN3

P-Q4

33.

NxR

RxN

2.

B-N2

P-K4

34.

B-N4

R-KB6

3.

P-Q3

N-KB3

35.

R-Q8

P-KR3

4.

N-KB3

N-B3

36.

RxP

RxP

5.

0-0

B-Q2

37.

R-Q8

R-KB6

6.

P-N3

B-QB4

38.

R-R8

P-KN4

7.

B-N2

Q-K2

39.

P-Q5

P-KR4

8.

P-QR3

P-K5

40.

P-Q6

K-N2

9.

N-K1

0-0

41.

RxP

R-B2

10.

P-Q4

B-Q3

42.

R-R5

K-B3

11.

P-K3

N-KN5

43.

B-B3 check

K-N3

12.

P-R3

NxP/6

44.

R-K5

R-B6

13.

PxN

Q-N4

45.

B-N4

R-B5

14.

P-KN4

QxP/6 check

46.

R-K7

R-B2

15.

R-B2

B-N6

47.

RxP/4

R-Q2

16.

Q-K2

QxR check

48.

R-K7

P-R5

17.

QxQ

BxQ check

49.

K-N2

P-N5

18.

KxB

P-B4

50.

K-R2

P-N3

19.

PxP

N-K2

51.

K-N2

R-Ql

20.

P-B4

RxP check

52.

P-R4

N-Q2

21.

K-N1

P-B3

53.

P-R5

N-B3

22.

N-QB3

R-R4

54.

PxP

N-Q4

23.

K-R2

R-KB1

55.

P-N7

NxR

24.

N-Q1

N-N3

56.

PxN

R-KR1

25.

R-B1

BxP

57.

B-Q6

K-B3

26.

BxB

R-B8

58.

P-N8=Q

RxQ

27.

N-N2

R-B6

59.

BxR

KxP

28.

PxP

R/4XB check

60.

B-B4

K-B3

29.

K-N1

PxP

61.

B-Q2

K-N3

30.

R-B8 check

N-B1

62.

B-K1

K-N4

31.

B-B3

R-Q6

63.

B-B2

K-R4

32.

N/1-K3

R/RxN

Game agreed drawn.

Table 1: The score (record of moves) of game 1 of the match. The reader isasked to examine this game, and to form an opinion concerning which playerhad which color of pieces.

About the Author

/ R Douglas has 16 years of experience as a microprogrammed andmaintains an interest in artificial intelligence. His hobbies includephotography and amateur radio (callsign KAOACN).

of Josef Smolij, local speed chess king andguru of the all-night, outdoor Yonge StreetChess Association. Josef, we were to learn,would play a large part in the first win everfor a chess machine at the master level.

The relationship between the opponentsin the Levy match is difficult to describe.The two Davids, Levy and Slate, and theCDC folks stayed in the same hotel and atemeals, travelled and generally spent the en-tire time together as friends. Levy even con-sidered the machine to be sort of a friendlyfoe. Each night the entire group found itselfon the sidewalks of Yonge Street playingchess on overturned milk cartons with JoeSmolij until the small hours of the morning.Joe demonstrated his "Smash-Crash" Gam-bit (also known as the Greco Counter Gam-bit for those who have not yet met Josef)for 50 cents a lesson.

Levy's plan for the match was not diffi-cult to anticipate, since he had demonstratedthat, while tactical positions favored thecomputer, strategic positions favored him.He had used close, quiet games to defeat thecomputers in each defense of the wager,playing a strategic game until a weaknessdeveloped in the computer's position, thenwinning against that weakness.

The game score of round 1 is presentedin the form of a Turing experiment. Forthose not familiar with him, Alan Turingproposed a method for determining whethera machine should be called "intelligent." Inthis test, a human, linked via teletypewriterwith a machine, is told that he is communi-cating with either a machine or anotherhuman. If he is unable to determine withwhich of them he is communicating, themachine can be termed "intelligent." Thequestion: was Levy White or Black in game 1 ?Consult table 1 and form an opinion. Theanswer appears in the text box on page 90.

The first game was a draw. This createda great deal of speculation, as most of the

GAME I

m

.._

g

POSITION AFTER 63. ...K-R4

Figure 2; The final position reached ingame 1. The participants agreed to a draw.

86

December 1978©BYTE Publications Inc

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BYTE December 1978 87

GAME 4

POSITION AFTER 47. ...K-K2

POSITION AFTER 56. P-B6

Figure 3: Position reached in game 4 after Black has made his 47th move.The human chess masters present, including Canadian Master Bruce Amosand 14 year old US National Master Joel Benjamin, were of the opinion thatWhite must lose material. White did have a move they missed, and played it

Figure 4: The final position of game 4.White's pawns will march irresistibly to theeighth rank and become Queens. Black canfind no way to stop them, and resigns.

Photo 2: Josef Smoiij, theguru of the Yonge StreetChess Association, as hepresides over his midnightlessons in the Smash-CrashGambit.

Chess 4.7

Levy

Chess 4.7

Levy

1.2.3.4.5.6.7.8.9.

P-K4N-KB3PxPN-K5N-N4

NxN checkQ-R5 checkQxQ checkN-B3

P-K4

P-KB4

P-K5

N-KB3

P-Q4

QxN

Q-B2

KxQ

P-B3

At this point. Levy announced to the spec-tators that he was playing the "Smash-Crash"Gambit, attributed to Josef Smoiij of Toronto.

10. P-Q3

11. BxP

PxP

Possessing a one pawn advantage, the com-puter has forced Black's King to remain in thecenter of the board.

11.

N-Q2

12.

B-KB4

N-B4

13.

P-KN4

NxB check

14.

PxN

B-B4

15.

0-0

P-KR4

16.

N-R4

B-Q5

17.

B-K3

B-K4

18.

P-Q4

B-Q3

19.

P-KR3

P-QN3

20.

R/B-K1

B-Q2

21.

N-B3

PxP

22.

PxP

R-R5

23.

P-B3

R/1-R1

Levy has seized command of the King Rookfile. The defense is not at all obvious.

24. K-B1

25. R-K2

B-N6B-B1

The move 25. . . R-R8 with check failsbecause of the reply B-N1.

26.

K-N2

B-Q3

27.

B-N1

R-R6

28.

R/1-K1

R-N6 check

29.

K-B2

R/1-R6

30.31.

R-K3

N-K2

B-R3

Chess 4.7 forces the exchange of minorpieces, and thereby defangs Levy's attack.

31.

BxN

32.

R/1xB

P-B4

33.

P-B4

RxR

34.

RxR

R-R5

35.

K-N3

R-R8

36.

B-B2

R-Q8

37.

R-R3

PxP

38.

RxP check

K-B1

39.

R-Q7

R-Q6 check

40.

K-N2

B-B4

41.

RxP/5

R-Q7

42.

P-N4

BxP

43.

R-Q8 check

K-B2

44.

R-Q7 check

K-B1

45.

RxP/4

R-N7

46.

K-B3

This move avoids the pin of the Bishop tothe King — see why in the next move.

46.

B-B4

47.

R-Q8 check

K-K2

48.

B-R4! check

The human masters present did not see thismove. They thought the computer was certainto lose material.

48.

K-B2

49.

P-N5

P-N3

50.

R-Q7 check

K-B1

51.

PxP

RxP

52.

P-B5

R-R6 check

53.

K-N4

R-R5 check

54.

K-R5

R-Q5

55.

R-QB7

B-K2

56.

P-B6

Black has no way to prevent the steamrollerpawns from advancing to the eighth rank.

56.

Resigns.

Table 2: The score of the fourth round game. The computer had the White pieces and the firstmove. A fter Levy lost the game, Joe Smoiij complained that the Smash-Crash Gambit was foruse against people, not machines.

88

December 1978 © BYTE Publications Inc

Photo 3: In game 4,David Levy stolidly pon-ders the position after hismove 51 . .. , RxP. Thecomputer's material andpositional advantage Islarge, but tenaciously heseeks the best defense.

Photo 4: Levy forms hisplan, and reaches out overthe flickering electronicchessboard to put it intoeffect. He may persuadethe computer to tradeRooks. Getting rid ofChess 4.7's troublesomeRook would allow somefreedom of movement forLevy's beleaguered King.

Photo 5: The computerdecides not to tradeRooks. Levy pulls hisBishop back to act as ashield against the finalassault. He smiles as hesees that the steamrollerpawns will not stop.

December 1978 © BYTE Publications Inc 89

assembled experts had predicted a 3 gameconclusion to the 6 game match. The rulesrequired that Levy obtain only three pointsto win his wager. Now play would be forcedto at least four rounds. Levy's concentrationduring the opening phase of the second gamedid not falter as he quietly put away themachine without apparent trouble.

Round 3 was not scheduled for six days,so the glass booth, looking much like anabandoned bus stop enclosure, sat emptywhile various masters played simultane-ous exhibitions against spectators, amidstthe sounds of three bowling lanes and theclank of sabers from the adjacent fencingmatches.

Play resumed on September 2. The thirdround was another closed and quiet gamewhich Levy won without apparent effort.The score then stood Vi to 2M>, with Levyneeding only a draw to win the match.However, he chose to confront Chess 4.7directly in the fourth round by playing theGreco Counter Gambit. His decision wasmade only hours before, while sitting on amilk carton playing chess against Joe Smolij,the Smash-Crash Gambit expert.

Round 4 commenced with fireworks thatnever died out during the entire game. Themoves of that game are given in table 2.

Though Levy finished the match in thefifth round with another closed game andheld his 10 year wager, those on the com-puter chess side of the contest did demon-strate the ability to produce master levelgames. The most frequently heard commentafter the match was that there were no losersin Toronto.

What happens now? A new version of theprogram, Chess 5.0, waits in the wings, theCYBER 176 spends most of its waking hourshard at work aiding in the design of its suc-cessor, and Levy has offered a prize of$5000 to the developer of a system which isable to defeat him in match play within thenext five years. Here we go again.■

The answer to the Turing experimentquestion (page 86):

David Levy was playing White; Chess4.7 was playing the Black pieces.

The computer found a surprisingcombination in game 7. The diagram offigure 7 shows the position immediatelyfollowing Levy's move 12, P-R3. In theopinion of the computer operators,Chess 4.7 did not have any definite planwhen it moved its Knight to the fifthrank. But Levy took 510 seconds to ad-vance his Rook pawn. The program, cal-culating during all this time, exploredenough move trees to find the hiddenbenefit in the otherwise unlikely appear-ing move of Knight takes King pawn.

The key move in the combinationcame after Black played its Queen toKing Knight 4. Levy later said that if ahuman master had played the Knightsacrifice against him, he would haveresigned immediately. As it was, heplayed on, confident that he couldoutmaneuver the machine in the end-game. His confidence was justified,and he managed to salvage a draw.

Photo 6: David Slate(left), of NorthwesternUniversity, and David Cah-lander of Control DataCorp watch the computerterminal as it displays oneof Chess 4.7's moves ingame 4.

90 December 1978 © BYTE Publications Inc

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BYTE December 1978

91

Nybbles

Z-80 Assembler

Patrick A Crowe

22 Ringsbury Close

Purton

Swindon ENGLAND SN5 9DE

A Z-80 assembler that implements all of the Zllog defined mnemonics isavailable from BYTE. This assembler uses the conventions established byZilog in the Z-80 Assembly Language Programming Manual. It recognizesuppercase characters for labels, operators and operands. All defined pseudo-operations have been implemented except for macroinstructions and con-ditional assembly commands.

The assembler can be implemented in read only memory. It assumes that aconsole display and a paper tape reader and punch are available. However,since the user must supply the input and output routines for the program,this is not necessary, and the required functions can point to locations inmemory.

The Nybbles Library is an inexpensive means for BYTE readers to sharesome interesting but specialized forms of software. These programs arewritten by readers with small computers and printer facilities, and are there-fore designed for particular systems. The algorithms and programming tech-niques in these programs can be directly used by readers with similar equip-ment, or can serve as an inspiration for improvisation on computers ofdifferent characteristics.

Potential authors of such programs should send us a self-addressedstamped envelope, with a request for a copy of our "Guidelines for NybblesAuthors/' Payment for Nybbles items is based on safes and length of theitem. Rates are set at the time of acceptance.

Nybbles Library programs are sent in listing form, printed on 8.5 by 11inch paper on both sides. The Nybbles Library programs are 3 hole punchedfor collection in loose leaf binders, and come in an attractive folder whichserves as a cover.

This month 'The Z-80 Assembler" (# 107) has been added to the NybblesLibrary. To order your personal copy, at $4 postpaid, fill out the couponbelow.

Please send.

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BYTE Nybbles Library, 70 Main St, Peterborough NH 03458

You may photocopy this page if you wish to keep your BYTE intact.

92 December 1978©BYTE Publications Inc

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Computer Systems Design, Wichita, KSLouisiana

Microcomputers of New Orleans, LAMassachusettsCPU Shop, Charlestown, MAComputer Mart, Waltham, MAMichiganNewman Computer Exchange,

Ann Arbor, MIUnited Microsystems Corporation,

Ann Arbor, MIHobby Electronics, Flint, MIComputer Mart, Royal Oak, MINebraska

Omaha Computer Store, Omaha, NENew HampshireComputer Mart, Nashua, NHNew Jersey

Computer Mart, Iselin, NJNew York

Mini-Micro Mart, Syracuse, NYOhioCybershop Microcomputer Systems,

Columbus, OHDayton Computer Mart, Dayton, OH21st Century Shop

Cincinnati, OHOregonReal Oregon Computer Company,

Eugene, ORComputer Pathways Unlimited,

Salem, ORTexas

Micro Mike's, Amarillo, TXInteractive Computers,

Houston, TXByte Shop, Richardson, TXVirginia

Computers Plus, Alexandria, VAThe Computer Place, Roanoke, VAWashington, D.C.Georgetown Computers,

Washington, DC

Computerland

at most stores

Integral Data Systems, Inc.

14 Tech Circle, Natick, MA 01760{617)237-7610

Pay a little bit more

and get a printer that's

brighter than your computer.

The Brighter Writer.

sbcdef

a

warn

i::f:

ou

fof*ffcl'f

When a few dollars more buysfou a first-class impact printer,^hy settle for a toy? The Brighter-Writer gives you quality to startmih. And versatility that staysaven if you outgrow yourpresent personal computer.

Built smart like the big ones.

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Prints fat, skinny,tall, small.*

This printer canbe as creativeas your imag-ination. Stretchout your char-acters. Squeeze them closeMake them high. Low.Bold. Banner. You name it. *

Plugs into your computer.

Most popular personalcomputers interface to theBrighterWriter. Simply andquickly Hundreds ofBrighterWriters are working inApple, TRS-80, Heathkit, S-100and many other personal computer systems right now.

Pictures and fancysymbols/

The BrighterWriterdraws out your cre-ativity You can print ~* ^drawings, graphs, ■"*

diagrams, bold symbols, or justabout any graphic you canimagine.

*Some of these advantages require extra-costCircle 177 on inquiry card.

L/\

O

Picture your page as thou-sands of dots. The BrighterWritercan fill in the dots, plot them con-tiguously stack them, or scatterthem, And its special set of gra-^ . phic characterso ;:> H n simplifies the

process.

i • /-• -::: A

u- *... .v •..: Prints any char-

?::' f;% ET 4> acter a typewriterh.. v;: I ! can Faster

The BrighterWriter can printplain and simple. With 7x7 dotmatrix clarity You get all the let-ters, numbers, and standardsymbols of a

regular

typewriter At upto 80 cps throughput.

Ordinary paper.

Fancy or plain, the Brighter-Writer prints on ordinary paper.Better yet, it prints on manyshapes of paper. Single sheets.Roll. Fanfold.

Want more copies? TheBrighterWriter prints multiplecopies without extra adjustments.

Four easy buttons.

Operating the BrighterWritercouldn't be simpler. Up-front con-trols are easy to get to. A power

options.

button to turn it on. A test button toself-test your printer. A paper feedbutton to advance the sheets orforms. Aline feed button toadvance the paper a line ata time.

rrff:;-^ -*B*V Prints

any-which- way.

The BrighterWriter comes intwo models. The IP-225, at $949,gives you a BrighterWriter withtractor-feed drive for precisionforms control, This one canhandle everything from labels to8 W paper widths.

It has eight form lengths andgives you all the features of ourIP-125.

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Better yet, see the Brighter-Writer at the store nearest you.

Integral Data Systems, Inc.

BYTE December 1978 93

Interface Your Computer

to a Printing Calculator

Robert H Astmann58A Spring StRed Bank NJ 07701

Hexadecimal

Row

Vector (RWVCT)

Hexadecimal

Column

Vector 1CLVCT)

Key

08

01

"0"

04

01

"1"

04

02

"2"

04

04

"3"

02

01

"4"

02

02

"5"

02

04

"6"

01

01

"7"

01

02

"8"

01

04

"9"

OF

08

"T»

OF

04

Paper Advance

01

08

»#**

08

08

"+"

Table 1: Contents of the row vector and column vector tables (RWVCTandCL VCTy respectively) referenced by the program in listing 1.

OUTPUT FROMCALCULATOR CIRCUIT

COL I COL 2 COL 3 COL 4 COL 5

g g g g g

'1

H

n.

\

a

a

3.

1

1

I

"t"

1

1

'1

'1

-j ^> ROW

-( ^> ROW 2

-| ]> ROW 5

« ( ^> ROW 4

There are many microprocessor applica-tions in which it is desirable to produce ahard copy of numeric information beingmeasured or computed, yet even the cheapestof today's low cost printers could easilybe the most expensive component of such asystem. A solution to this problem is to useone of the thermal printing calculators nowavailable. By means of an interface to amicroprocessor, the calculator integratedcircuit can be given stimuli identical to thosereceived during the normal pushing of thecalculator keys. In this article I describesuch an interface which was implementedusing an Intel 8080A processor and a TexasInstruments 5050M printing electroniccalculator.

Basic Control Procedure

I first describe the method by whichdata is normally entered on a calculatorkeypad. Referring to figure 1, each buttonon the keypad provides a unique con-nection between a column output lineand a row input line. The calculator inte-grated circuit outputs a scan pulse to eachcolumn bus sequentially, and looks for aninput pulse from one of the rows. Theinterpretation given to a detected row signalis therefore dependent on which columnis being accessed during the given timeperiod.

The job for the microprocessor in thisapplication is to monitor the column signalsuntil the column containing the desiredcharacter key is active and then to drive thecorrect row bus to a high level so that thecalculator circuit senses the input while thegiven column signal is still active. Themicroprocessor software controls this proce-dure by using two stored lookup tables (seetable 1): a list of column vector bytes and alist of row vector bytes. The entries in thesetwo tables, together with the code for the

Figure 1: Keyboard arrangement of the Texas Instruments 5050M printing calculator. Calculator logic outputs a scan pulse toeach column bus sequentially and looks for an input pulse from one of the rows. This uniquely identifies the key pressed by theuser. Although there are only four row inputs to the calculator circuit, there are five rows of keys. Signals from the upper rowof keys appear simultaneously on ail four row inputs through the diode network.

94

December T978 © BYTE Publications Inc

Circle 293 on inquiry card. —*-

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For more information call or write Northeast Expositions, Box 678, Brookline Village, Massachusetts 02147. Phone (617) 522-4467

*-40^S

COL. I

COL 2

COL. 3

COL. 4

COL. 5

Figure 2: The sequence of column scan signals outputted by the calculatorcircuit

c

8080DATA BUS

PBlP82

IC28255

PROGRAMMABLE

PERIPHERAL

INTERFACE

PC2PC3

H li ii li

22i

K JLl7V

-<C] COL I-^""H COL 2-< | COL 3

14 -TL+5V

&

tCI7407

^

{^

1{>L

A.,:

li ii*

-j > ROW I

-j > ROW 2

-| > ROW 3

-j > ROW 4

I (FROMCALCULATOR)

POWER WIRING TABLE

NUMBER

TYRE

*5

GROUND

SCI

7407

14

7

)C2

6255

26

7

F/f7£/re 3: Circuitry for interfacing the 8255 programmable peripheral inter-face to the Texas Instruments 5050M printing calculator. The diodes preventthe inputs to the 8255 from going above 5.7 V when a column signal goes to17 V. The output lines from the interface are connected to open collectordrivers (ICI) which translate the 5 V signals to 17 V.

desired character, determine the mapping ofa column input into a row output.

Hardware Interface

The signalling between the Tl 5050Mcalculator integrated circuit and keypad isillustrated in figure 2. A 17 V pulse of40 /is nominal duration is outputted to eachcolumn bus with the entire sequence beingrepeated every 7.3 ms. This signalling con-tinues as long as no button is pushed. Whena button is pushed, the column signals areextended to about 150 jus to validate thebutton push. This pulse width is maintaineduntil the button is released, during whichtime any other button push is ignored. Itis immediately apparent that to interfacethis calculator to the 8080A processor,level translation circuitry in both directionsis required. The circuitry I used in thisapplication is shown in figure 3. An Intel8255 Programmable Peripheral Interfaceintegrated circuit was chosen because itwas already interfaced to the 8080A as akeyboard port. The diodes tied to +5 V in-sure that the inputs to the 8255 do not goabove +5.7 V when a column signal goes to+17 V. The output lines from the 8255 areconnected to open collector drivers whichtranslate a +5 V signal to +17 V.

The necessary connection points withinthe calculator case were easily accessedsince there were large metal strips connec-ting the printed circuit board to the keypad.A dual trace oscilloscope was used to deducethe identity of each connection. Once thecolumns were identified by noting the timedisplacement of the scan pulse on each busrelative to the others, the rows were identi-fied by pressing buttons and looking forresponses on the connections that normallydid not exhibit any signalling.

Software Interface

At the heart of the printer control soft-ware is the driver program, INTER. INTERis called when a single decimal digit or con-trol character is to be entered. A 4 bit BCDrepresentation of the digit must first beloaded into the C register of the 8080A.As shown in listing 1, this character code isused to select the correct column and rowvectors from the two lookup tables con-tained in table 1.

In my microcomputer system, which isbased on an Altair 8800 computer, thisprogram was executed out of programmablememory which utilizes a processor wait

96

December 1978©BYTE Publications Inc

•lt'pr

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Circle 255 on inquiry card.

control and buffering, drawing typically 2.6 amps.

Ask your local computer shop to order theSuperRam™1 32K kit for you. Or, if unavailable locallyorder direct from Thinker Toys™, 1201 10th St.,Berkeley, CA 94710. Or call (415) 524-2101, weekdays10-5 Pacific Time. Add $3 for handling. (Cal. res.add tax.) ^

t

Segmentof

MainProgram:

PR2DI

SKIP:LINE:

WAIT1:

Op

Code

LHLD

MOV

INX

MOV

INX

SHLD

CALL

MVI

CALL

CALL

Operand

POINT

C,M

H

B,M

H

POINT

OUTPR

C,OCH

LINE

SKIP

state on each memory access. This had theeffect of reducing program execution speedto the point where it was not possible todetermine when the desired column wasactive and thus to output the appropriaterow signal before the termination of thesame 40 /is column signal pulse. Instead,INTER actually scans the column inputsuntil the column to the immediate left ofthe desired column is sensed active. Thenthere is a software delay, after which thecorrect row output is activated. Next thereis a second software delay, after which all

Commentary

load HL with memory data pointer: load C from memory with 2 low order digits

: load B from memory with 2 high order digits

save memory data pointerenter the four digits

terminate the lineskip a line

MOV A,C ; get 2 low order decimal digits

STA SAVE + 1 ; save

MOV A,B ; get 2 high order decimal digits

MVI B,0 ; clear B reg for INTER

CALL PR2DI ; enter 2 high order digits

LDA SAVE+1 , retrieve 2 low order digits

JMP PR2DI ; enter 2 low order digits

STARRCRRCRRCRRC

ANI

MOV

CALL

LXI

CALL

LDA

ANI

MOV

CALL

LXI

JMP

SAVE

OFH

C,A

INTER

D,0F000H

DELAY

SAVE

OFH

C,A

INTER

D.0F000H

DELAY

; save low order digit

: BCD value for digit to be entered now

occupies right side of accumulator: clear left side of accumulator

; enter the high order digit

delay for calculator response timeretrieve low order digit

enter the low order digit

MVI

CALL

LXI

C,0BHINTERD,0

paper advance

JMP

DELAY

delay for thermal print head response and paper advance

INTER:

LXI

H,CLVCT

HL points to head of column vector table

DAD

B

HL points to correct column vector byte

MOV

D,M

load D reg. with column vector

LXI

H,RWVCT

HL points to head of row vector table

DAD

B

HL points to correct row vector byte

COL:

IN

PORTB

read status of column signals

ANA

D

is desired column active?

JZ

COL

No, keep looking

MOV

A,M

Yes, prepare to output row signal

MVI

C.OFCH

initialize first delay counter

INRJNZOUTMVIINRJNZXRAOUTRET

C

WAIT1

PORTC

COFOH

C

WAIT2

A

PORTC

time to output row signalsinitialize second delay counter

clear accumulatorreset row signals

INRJNZINRJNZRET

E

DELAYDDELAY

Listing 7: Assentbiy language program for interfacing an intei 8080A pro-cessor to a Texas instruments 5050M printing caicuiator using an 8255 pro-grammabie peripheral interface. Row vector andcoiumn vector (RWVCTandCL VCT) contents are iisted in tabie 1. The first section in the iist is the por-tion of the main program that caiis the routines.

row outputs are zeroed. The initial valuesfor the software delay counters were deter-mined experimentally (ie: they were ad-justed until the calculator consistentlyprinted a character each time INTER wascalled).

The entries in the column vector tableare set up so that a 01 vector will recognizecolumn 1, 02 will recognize column 2, etc.Since INTER looks for the column to theimmediate left of the column contain-ing the desired character, characters incolumn 1 (ie: C, %, x, etc), cannot beprinted unless INTER is modified to enable itto recognize when column 5 is active, then todelay for about 7,1 ms (ie: until column 1is active) before outputting a row signal.

Just above INTER in the software hier-archy is PR2DI, the routine which enterstwo decimal digits. The source listing showsthat INTER is called twice by PR2DI.Each call to INTER is followed by a soft-ware delay to allow the calculator chip tostore the entered digit and return to thescan mode. (The digits are not printed,since the complete line of digits has not yetbeen terminated.) The two desired digitsare passed to PR2DI in BCD form via theaccumulator.

In my application, the largest number tobe printed is four digits long. Hence theroutine OUTPR enters four decimal digitsby calling PR2DI twice. The BCD valuesfor the four digits are passed to OUTPRvia the BC register pair.

Finally, a segment of the main applica-tion program is shown. A series of 4-digitnumbers is printed as they are fetched frommemory. These numbers are already storedin BCD form in memory since they are theresult of arithmetic operations that werefollowed by the 8080's decimal adjustinstruction. First, the BC register pair isloaded with the codes for the four decimaldigits. The memory data pointer must thenbe saved in scratchpad programmablememory since the HL register pair will beused by INTER. Next, OUTPR is called totransfer the four digits to the calculator.Following this operation, the calculator iswaiting for either more digits or a linetermination. The 5050M can be made toterminate and print a line by means of anoperation keystroke or by using the #/Skey. (If this key is pressed after an operation,it is interpreted as a request to print a sub-total. If pressed after a series of digits havebeen entered, the numbers are printed andthe line is terminated with a "#". Thesenumbers are ignored by the calculator, butserve as an index for the benefit of the

98

December 1978©BYTE Publications Inc

user.) Hence, at this point in the applicationprogram the code for the #/S key is loadedinto the C register and the subroutine LINEis called. LINE proceeds to call INTERand then causes a delay of about 0.5 secondswhich enables the calculator to activate thethermal print heads and advance the paper.Finally, the subroutine SKIP is called inorder to skip a line before printing the nextnumber.

Conclusions

When using a microprocessor in a controlapplication, it is necessary to be able to"shake hands" with the device to be con-trolled. This is best accomplished by struc-turing the software so that a low-level driverroutine makes the handshaking transparentto the higher level software.

In this application, the signalling protocolof the printing calculator is utilized as acontrol mechanism by the processor. Theinterface between the two devices is easyto implement and the result is low costnumeric printing capability. Whenever thecalculator is disconnected from the pro-cessor interface, it will operate normallyagain."

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Mass. residents add 5% sales tax

CLIP *»° STRIP

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Circle 291 on inquiry card.

December 1978©BYTE Publications Inc

99

Zapper

A Computer Driven EROM Programmer

G H Gable

50 Cliftwood Dr

HalesiteNY 11743

One of the most fascinating and usefulproducts of recent technology is the readonly memory (often abbreviated as ROM)and especially useful for the experimentalsystems designer is the erasable and electri-cally programmable read only memory,variously abbreviated EROM or EPROM.

In designing my first microprocessorbased system, a read only memory was amust to contain the operating system andthe floating point arithmetic firmware. Idid extensive research into read only memorysystems and after a week or so I was readyto make a specification. I had previously

Photo 7: The prototype computer read only memory board with four EROMparts in the center. The eight sockets on the right hold the 7 K bytes of pro-grammable memory which is selected by a jumper on the pins in the lowercenter of the board (off pin 24 of the lowest EROM). The 8272s on the leftare the address bus drivers (lower pair). 8272s are abundantly used becausethey are the author's favorite all purpose medium scale integration chip.

chosen the processor for the system to bethe MOS Technology 6502 which requiresa memory access time of about 500 ns whenrunning with a 1 MHz clock. It was verydesirable to have the read only memorymeet this specification for two reasons. First,because of the dynamic nature of the 6502,it does not wait for slow memory veryreadily. Second, and by far most important,I wanted my arithmetic routines in read onlymemory to run as fast as possible since Iwould be using them very often. These con-siderations ruled out the older 1702 typememories as too slow.

The choice was obvious as soon as I readabout the Intel 2708. It had all the requisitefeatures: fast (450 ns) access time, largearray (1024 8 bit words) on a single chip,and easy straightforward programming. WhenI designed this programmer the going pricewas $100; currently the prices have droppedto about $10, making this chip even moredesirable.

The chip is also numbered 8708 to fitinto Intel's 8000 line which includes the8080. The 2708 and the 8708 are identicalas far as I know. They are definitely inter-changeable at a pin level. There is also avariation of the design called the 2704/8704which is arranged as an array of 512 8 bitwords. The 2704/8704 is electrically andlogically identical to the 2708/8708 but con-tains only half as much memory. The highorder address line is not defined for the2704/8704. (Rumor has it that 2704/8704parts are identical to 2708s but wired intothe package with the high order address bitunconnected.)

System Design

My design called for 4 K bytes of readonly memory resident firmware which couldbe built up over a period of time as theoperating system and arithmetic routineswere debugged. My approach to this was toprototype the eventual firmware in norma!

100

December 1978© BYTE Publications Inc

programmable memory and then transferit to read only memory after debugging. Idesigned a 4 K byte read only memory board(photo 1) which has four 2708 PROM chipsplus 1 K bytes of programmable memory.The programmable memory can be jumperselected to occupy any 1 K page on theboard. This allows for prototyping a routinein the actual address space that it will even-tually occupy. The system has worked outextremely well.

It was my original intention to have theread only memory programmed by profes-sionals offsite. My impression was that 2708programming was somewhat complex andthat a programmer board for a limitednumber of burns was not very practical. Afterlearning more about the 2708 my attitudechanged. A little thought convinced me thata computer driven programmer could besimply constructed at minimum cost. Itwould be very convenient to be able toprogram the chips in my own computer andto be able to make changes and correctionswith a short turnaround time.

Programming the EROM

When initially received, and after eacherasure, all the bits of the 2708 are in the"1" state (output high). The content ofthe 2708 is programmed by selectivelychanging state to "0" in the desired bitlocations. Programming a given byte requiresthe address of the byte on the address inputpins and the data byte on the data pins, allat TTL levels (+5 V) with the write enablepin held at +12 V, a program pulse of +26 Vat 20 mA is applied to the program pin. The2708 specifications require that the programpulse be between 100 jus and 1000 jus wide.A series of pulses are required to program aparticular address. Intel recommends thatone pulse be administered to each addresslocation in a loop. The number of timesthe loop must be repeated is a function ofthe pulse width. The final accumulated pro-gram current time to each address must begreater than 100 ms. Such a scheme is anatural for computer control.

The Zapper programming board shownin photo 2 and figure 1 is designed to havethe address and data multiplexed to itthrough a peripheral interface adapter (PIA)with at least eleven output lines. I use theperipheral interface adapter that is availableon my MOS Technology KIM-1 single boardcomputer to drive the Zapper. If you do nothave one of these PIAs I recommend eitherthe MOS Technology 6520 or the Motorola6820. The address and data are passed

through the lower eight lines (PA0-PA7)while three of the upper lines (PB0-PB2)control the multiplexing and programmingcurrent.

The driving computer is expected todirect the following sequence of eventswhich will program one address location inthe 2708:

• PB0 is brought high to enable theupper 8212 (IC1) eight bit latch.

• The lower eight bits of the addressare loaded on PA0-PA7 and thus intothe 8212.

• PB0 is brought low latching the lowaddress onto the outputs of IC1 whichare wired to the address inputs of the2708.

• PB1 is brought high to enable the lower8212 (IC2). The upper two bits of theaddress are loaded on PA0-PA1 andlatched when PB1 goes low.

• The data byte is loaded on PA0-PA7and latched by the PIA.

• PB2 is brought high for the pulse timegating the program current to theEROM.

This sequence is repeated the requirednumber of times to program the EROM.

A Note About UV Bulbs:

MSC Macalaster is locatedat Rte 111 and EverettTpk, Nashua NH 03060.

Photo 2: The Zapper board with the EROM in the upper ieft corner. Datafrom the Pi A as weii as iogic power and ground come in via the ribboncabie at the bottom which is connected directiy to the computer. Programpower comes in on the cabie in the upper right corner from an externaipower suppiy.

December 1978 © BYTE Publications Inc

101

PAO O

PAI O-

PA2 Q>-

PA3 £>-

PA4 O-

PA5 O

PA6 [[>-

PA7 O-

P80 | >-

o

3B2 O"

22

20

22

DIIDI2DI3DI4DI5DI6DI7DI8

DS2

STB

CLRDII

DI2

DI3

DI4

DI5

DI6

DI7

DI8

DS2STB

+ 5V

ICI6212

GND

m

+ 5V

4

1C28212

m

MDDOI

D02

D03

D04

D05

D06

D07

D08

DSI

DOID02

4.7K

19

*5V

24

21

-5V

23

01 02 03 04 05 06 07 08

A0AlA2A3A4A5A6A7

VDD

CS/WE

VCCVBB

IC32708

A8A9

PROGRAM

Figure 1: The address and data information for the Zapper is multiplexed through the PI A ports PAO-PA 7 while control signalsare presented on PB0-PB2. PBO is connected to the enable pin of the upper 8212 which latches the lower eight bits of theaddress. The high two bits of the address are loaded and latched on the lower 8212 by PB1. The data byte is latched by the PI A.When PB2 goes high, program power is gated to the program pin of the 2708 by the 3 transistor high current gate in the lowerright

102

December 1978 © BYTE Publications Inc

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Visit our new showroomWorking units on display

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Circle 355 on inquiry card.

BYTE December 1978

103

Software

J

1

;

PROGRAM ZAPPER

THIS

LISTING

WAS PREPARED

?

FROM

A HAND ASSEMBLED SOURCE

0200

A9

FF

ZAP

LDA

$FF

INITIALIZE CYCLE

0202

85

05

STA

CYR

COUNT TO 255

0204

8D

01

17

STA

PADD

SET PIA DIRECTION

020 7

A9

7F

LDA

S7F

REGISTERS FOR

0209

8D

03

17

STA

PBDD

OUTPUT PORTS

020C

A9

00

LDA

SOO

SET CONTROL PORTS

020E

8D

02

17

STA

PBD

TO "OFF"

0211

20

71

02

JSR

MSG

WAIT FOR PROG POWER

0214

A2

00

LDX

$00

SET INDIRECT INDEX

0216

AS

00

WXCY

LDA

BSL

TRANSFER STARTING

0218

85

10

STA

LRL

ADDRESS TO LOCATION

021A

A5

01

LDA

BSH

REGISTER

021C

85

11

STA

LRH

021E

20

3F

02

NXAD

JSR

BURN

BURN PULSE

0221

£6

10

INC

LRL

INCREMENT

0223

DO

02

BNE

Al

LOCATION REGISTER

0225

E6

11

INC

LRH

0227

A5

10

Al

LDA

LRL

0229

C5

02

CMP

BEL

COMPARE LOCATION

022B

DO

Fl

BNE

NXAD

REGISTER WITH END

022D

A5

11

LDA

LRH

ADDRESS TO CHECK

022 F

C5

03

CMP

BEH

FOR END OF BLOCK

0231

DO

EB

BNE

NXAD

0233

C6

05

DEC

CYR

DECREMENT CYCLE

0235

DO

D5

BNE

NXCY

COUNT

023 7

A9

07

LDA

S07

RING TTY BELL

0239

20

AO

IE

JSR

OUTCH

WHEN DONE AND

023C

4C

4F

1C

JMP

MONITOR

RETURN TO MONITOR

023F

Listing 1: The Tapper program programmable memory starting address(BSL,BSH) and ending address plus one (BEL}BEH) are set before execu-tion. The driving program sets up the PIA ports as outputs and insures thatthe control lines (PBD) are off (zeros) before programming power is applied.The loop through the addresses in the location register (LRL,LRH) suppliesa burn pulse for each location. The cycle is repeated so that each locationreceives 255 pulses. The end of the program is signaled by the Teletype bellor terminal signal.

023 F

A9

0 1

0241

8D

02

0244

A5

10

0246

8D

00

0249

A9

02

024B

8D

02

024E

A5

1 1

0250

8D

00

0253

A9

00

0255

8D

02

0258

Al

10

025A

8D

00

025D

E6

04

025F

A9

04

0261

8D

02

0264

AO

43

0266

E6

04

0268

88

0269

DO

FB

02 6B

A9

00

02 6D

8D

02

0270

60

0271

17

17

;I

PROGRAM ZAPPER/BURN

BURN

LDA

SOI

OPEN LOW ADDRESS

STA

PBD

BUFFER

LDA

LRL

GET LOW ADDRESS AND

STA

PAD

PUT IN BUFFER

LDA

S02

OPEN HIGH ADDRESS

STA

PBD

BUFFER

LDA

LRH

GET HIGH ADDRESS AND

STA

PAD

PUT IN BUFFER

LDA

SOO

LATCH ADDRESS

STA

PBD

BUFFERS

LDA

LRL(IX)

GET DATA AND

STA

PAD

LATCH

INC

m

WAIT FOR DATA TO SETTLE

LDA

S04

TURN ON PROGRAM

STA

PBD

PO WER

LDY

S43

WAIT 600US

AGN

INCDEY

WR

BNE

AGN

LDA

$00

TURN OFF PROGRAM

STA

PBD

POWER

RTS

RETURN

Listing 2: The burn subroutine multiplexes the address and data through thePIA port (PAD) controlled by the control lines (PBD). A 600 ys program-ming pulse is applied after the address and data have been latched. The INCWR instruction does nothing more than provide a 5 [is delay, ft is used firstto let the data lines to the EROM settle before the programming pulse isapplied. Later it Is used in the pulse timing loop simply to cut down thenumber of iterations.

The driving software, as shown in listings1 to 4, implements the above sequence ofevents in a double loop. The inside loop,listing 2, works its way through all theaddresses to be programmed and gives eachlocation a 600 jus programming pulse. Theouter loop, listing 1, repeats the process255 times giving a total program currenttime of 153 ms to each bit. This is sufficienttime to program the 2708. The start and endplus one addresses of the programmablememory block are loaded in BSL, BSH andBEL, BEH registers respectively beforeexecution is begun. Data is programmed intothe same relative addresses in the read onlymemory as they are found in the program-mable memory; ie: the low ten bits of theaddress are the same.

Notice that the 2708 can be partiallyprogrammed. If the memory block to becopied is less than 1024 bytes long, onlythe appropriate bytes are programmed. Theremaining locations are unchanged. Theblock to be programmed can start and endanywhere in the 1 K page. This is a veryuseful feature as it allows firmware to bedeveloped over a period of time. The partiallyprogrammed read only memory can be usedin the meantime. Incidentally, listings 2 and3 are subroutines only for the sake ofmodularity and the whim of the author.They are called at only one point each.

It is very important that the +26 V pro-gramming power be off at the power supplyuntil the computer has had a chance to latchPB2 low. After this initialization, a pause isbuilt in to allow the operator to turn on thepower supply before continuing. This pauseis implemented by waiting for input from aterminal in subroutine MSG, listing 3. Theapplication of program power before thecomputer has initialized the Zapper boardwill usually result in some random locationbeing burned with some random data.

Erasing the EROM

The 2708 is very easily erased using anultraviolet light source. Intel specificationsindicate that an integrated dose of 10 watt-sec/cm^ at a wavelength of 2537 angstromsis required to erase the 2708. A quick glanceat the CRC Handbook of Chemistry andPhysics shows that 2537 angstroms is themost persistent spectral line of mercury(Hg). This means that any mercury vaporlamp will do the trick. I use a nice packagedsource from MSC Macalaster (Catalog #3400)which slips over the top of the read onlymemory. (When using the unit, discard thefilters which come with it, and be sure youshield your eyes from the lamp.) The chip

104

December 1978 © BYTE Publications tnc

What do the S-100, the Heath H8,

the Radio Shack TRS-80, theApple, the Digital Group, and the

Intel/National 80/10 and 80/20machines have in common?

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I.

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Circle 150 on inquiry card.

TERMS: Allow 5% shipping, excess refunded. Cal res add tax.VISA®/Mastercharge® call (415) 562-0636, 24 hours. CODOK with street address for UPS. (85< COD charge applies).

BYTE December 1978 105

J1

;

MSG

PROGRAM ZAPPER/MSG

0871 AS

00

LDX

500 OUTPUT THE MESSSAGE

02 73 BD

BI

02

Ml

LDA

SMG+X FROM DATA BLOCK

0276 C9

00

CMP

$00 (SMG) UNTIL "NUL"

0278 F0

07

BEO

RET CHARACTER FOUND

027A 20

AO

IE

JSR

OUTCH

027D E8

I NX

027E 4C

73

02

JMP

Ml

0281 20

5A

IE

RET

JSR

GETCH WAIT FOR KEYSTROKE

0284 60

RTS

BEFORE RETURNING

0285 OD

OA

OA

SMG

DATA

CR/LF/LF

0288 54

55

52

"TURN ON 26V--

028B 4E

20

4F

PUSH ANY KEY"

028E 4E

20

32

CR/LF/LF/NUL

0292 36

56

20

0295 2D

2D

20

0298 50

55

53

029B 48

20

41

029E 4E

59

20

02A2 4B

45

59

02A5 OD

OA

OA

02A8 00

02A9

HEXADECIMAL

SYMBOL

COMMENTS

LOCATION

0000

BSL

STARTING ADDRESS OF

0001

BSH

PROGRAMMABLE MEMORY-

0002

BEL

ENDING ADDRESS PLUS ONE OF

0003

BEH

PROGRAMMABLE MEMORY-

0004

WR

WAIT REGISTER.

0005

CYR

CYCLE COUNT REGISTER.

0010

LRL

LOCATION REGISTER*

0011

LRH

1700

PAD

PA PORT DATA REGISTER.

1701

PADD

PA PORT DIRECTION REGISTER.

1702

PBD

PB PORT DATA REGISTER.

1703

PBDD

PB PORT DIRECTION REGISTER.

1EA0

OUTCH

TTY OUTPUT ROUTINE.

1F5A

GETCH

TTY INPUT ROUTINE.

Listing 4: External symbol table. The PI A registers (PAD, PADD, PBD, PBDD)are those assigned on the KIM-1 board. OUTCH and GETCH respectivelyoutput and input one character each to or from a terminal. They are part ofthe KIM-1 operating system.

Listing 3: The MSG routine effectivelycauses a pause so that programming powermay be turned on after the Zapper board hasbeen initialized. Execution is resumed whenany key on the Teletype is pressed.

should be stuck in a piece of conductingfoam while erasing. An exposure time of30 to 40 minutes will yield a fresh chipready to be programmed again. If you wantto make your own eraser, use the GE #G4S114 W mercury vapor lamp with a GE #89C504ballast. Both of these items are usually avail-able at commercial electrical supply houses.The exposure time is about 40 minutes withthe 2708 placed 1 cm from the bulb.

My experience shows that each successivetime a 2708 is erased the exposure time tocompletely erase it increases. As the totalenergy needed to erase it is cumulative,extra short exposures can be given as needed.A little program to check each byte for allones will assure that the memory is fullyerased.

It is also convenient to remember thatany 1 bit in the EROM can be changed to0. Sometimes a single byte needs to be modi-fied and this can occasionally be done with-out erasing the EROM and reprogramming it.This has been the case for me more oftenthen statistics would dictate. Someone elsemust not be nearly so lucky.■

REFERENCES

1. Intel Data Catalog, Intel Corp, 1975.

2. Memory Design Handbook, Intel Corp, 1975.

3. 8080 Microcomputer Systems User's Manual,Intel Corp, September 1975.

Intel CorporationLiterature Dept3065 Bowers AvSanta Clara CA 95051

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EDUCATIONAL AND CLUD DISCOUNTS AVAILABLEPERSONAL CONSULTANT AND DEALER INQUIRIES INVITED

106

December 1978©BYTE Publications Inc

Circle 303 on inquiry card.

We Start With A PriceThat's Hard To Beat.

But We Don't Stop There.

Central Data Corporation has combined the benefitsof new technology and high-volume company salesto bring you a RAM board with more features andproduct options for less money.

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To begin with, we've reduced the price of our 16KRAM board by $40 to $249. At $425—a pricereduction of $50—our 32K board costs less, too.Plus, we now offer a full 48K memory board for$599. These boards are expandable to 64K at aprice of $ 185 per 16K package. Or you can startright out with a full 64K board for $775.

Improved Board Design

We've also added improvements to the board designat no extra cost to you.

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Place orders prepaid or COD. Delivery is stock to 30days with shipping and handling prepaid in Con-tinental United States. Please include phone as wellas name and address.

Circle 45 on inquiry card.

BYTE December 1978

107

An Easy Programming System

Joseph Weisbecker1220 Wayne AvCherry Hill NJ 08002

This article describes a hexadecimal inter-pretive programming system which requiresless hardware than high level languages suchas BASIC, and which I feel is much easier touse than machine language. In my expe-rience, hexadecimal interpretive program-ming is ideally suited to real time control,video graphics, games or music synthesis.It can be used with inexpensive computersystems consisting of a hexadecimal key-board and only 1 K or 2 K of programmablememory. Expensive terminals and largememories aren't required. You can quicklyand easily write useful programs that re-quire five to ten times less memory thanconventional high level languages withoutresorting to the tedious complexities ofactual machine language.

Interpretive Programming

This programming approach isn't new,but surprisingly few people seem to beusing it. The technique consists of designinga high level pseudomachine language that ismore powerful for specific applications thanconventional machine language. An interpre-tive program is then written to execute thisnew set of pseudoinstructions. Each pseudo-instruction is really just a code that specifiesa machine language subroutine. This set ofsubroutines can be designed to perform anyfunctions you might need for your applica-tion. By staying with a machine languageformat, and not using labels or Englishwords for instruction codes, memory re-quirements are lower. By limiting the address-ing range and number of variables, you canlimit each pseudoinstruction code lengthto several bytes for further memory spacesavings. Interpretive programs for thesepowerful pseudomachine languages canrequire as few as 512 bytes of memory. Ithas seldom taken me more than a week toimplement a new hexadecimal interpretivelanguage, and I can then use it for years. The

approach can be thought of as verticalmicroprogramming with the microprocessormachine language used as the microcoderepresentation.

To illustrate the compactness of thesetypes of programs, I wrote a video tic-tac-toe program using the CHIP-8 languagedescribed below. Only 500 program byteswere required versus 3000 bytes for anequivalent version written in BASIC. Besidessaving memory, this also meant 2000 fewerkeystrokes for initial program entry. Inaddition, the CHIP-8 interpreter was abouteight times smaller than the BASIC inter-preter. The CHIP-8 program ran on a 1.5 Kmemory system with a hexadecimal key-board, while the BASIC program requiredan 8 K system with an ASCII keyboard andalphanumeric display. The CHIP-8 programtook about 12 hours to design, hand code,enter and debug. I suspect that the BASICversion took at least as long on a muchmore expensive system.

This hexadecimal interpretive program-ming approach is important for two reasons.First, it reduces the cost of the hardwareyou need to get started in home computing.Second, it drastically reduces the amount ofread only memory required in microproces-sor based products such as controllers andvideo games. Read only memory cost is asignificant factor in these types of products.

A detailed example will be used to il-lustrate the hexadecimal intepretive pro-gramming approach. The new RCACOSMAC VIP computer will be used forthis example (see August 1977 BYTE,page 30, for a description of this computer).It is a low cost, single card computer con-taining 2048 bytes of programmable memo-ry, a graphic video display, and a hexadeci-mal keyboard. I had this type of program-ming in mind when I incorporated featuressuch as multiple program counters inthe COSMAC (1802) microprocessorarchitecture.

The pseudomachine language used in myexample will be one called CHIP-8, designedfor use with the COSMAC VIP system. I will

108

December 1978 ©BYTE Publications Inc

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ACCEPTED, ADD 3%SERVICE CHARGE.

Circle 281 on inquiry card.

BYTE December 1978 109

discuss using this language rather than de-scribing the interpreter for it. Suffice it tosay that the interpreter only requires 512bytes and resides at memory locations 0000to 01FF (hexadecimal). Programs writtenin the CHIP-8 language must start at memo-ry location 0200 (hexadecimal). The sampleprogram described will run on a 1024 bytememory system. This includes the CHIP-8interpreter, the program, work area andvideo display refresh buffer. The programitself only requires 60 CHIP-8 instructions.

CHIP-8 Language

Table 1 describes the 31 CHIP-8 instruc-tions provided in this pseudomachine lan-guage. Each instruction requires only twobytes (four hexadecimal digits). Memoryaddressing is limited to 4096 bytes so thatonly three hexadecimal digits are needed tospecify a memory address. The number ofvariables has been limited to 16, labeledV0 to VF in this article. These are 1 bytevariables or registers that can be modifiedor examined by CHIP-8 instructions. Thereis also a 2 byte memory address registercalled I, which is used by certain instruc-tions. A real time clock or timer is pro-vided. This timer can be set to any hexa-decimal value between 00 and FF by the

(Hexadecimal)Instruction

1MMM

BMMM

2MMM

00EE

3XKK

4XKK

5XY0

9XY0

EX9E

EXA1

6XKK

CXKK

7XKK

8XY0

8XY1

8XY2

8XY4

8XY5

FX07

FX0A

FX15

FX18

AMMM

FX1E

FX29

FX33

FX55

FX65

00 EO

DXYN

0MMM

FX15 instruction. For example, if V2contained hexadecimal 0A, an F21 5 instruc-tion would set the timer to 0A. This timeris automatically decremented by one60 times per second until it reaches 00. Ifthe timer was set to 3C (decimal 60) itwould reach 00 exactly 1 second later. Thistimer can be used to provide delays ingame or control programs. A tone clock isalso provided which can be set to cause atone lasting from 1/60 to about 4 seconds.An important feature of this type of lan-guage is that all variables (registers) are con-tained in memory. This means thatdebugging is generally Imited to examiningmemory locations, not internal micro-processor hardware registers. Astute readerswill be wondering why I maintained a fixed2 byte instruction length when variableinstruction length was possible. Sinceabsolute memory addresses are used, fixed2 byte instructions avoid addressing con-fusion that increases programming errors.Also, any instruction can easily be replacedby a branch instruction of the same lengthfor debugging breakpoints or programpatching.

Graphic Display Approach

Before proceeding with a detailedprogramming example, readers will need tounderstand the video display system. Fig-ure 1 shows the graphic display format used.

Operation

Go toOMMM

Go to 0MMM + V0

Do subroutine at 0MMM (must end with 00EE)

Return from subroutine

Skip next instruction if VX = KK

Skip next instruction if VX ^ KK

Skip next instruction if VX = VY

Skip next instruction if VX # VY

Skip next instruction if VX ■ hexadecimal key (LSD)

Skip next instruction if VX # hexadecimal key (LSD)

Let VX = KK

Let VX - Random Byte (KK = Mask)

Let VX = VX + KK

Let VX - VY

Let VX - VX/VY (VF changed)

Let VX - VX & VY (VF changed)

Let VX - VX + VY (VF = 00 if VX + VY < FF, VF - 01 if VX + VY > FF)

Let VX = VX - VY (VF - 00 if VX < VY, VF = 01 if VX > VY)

Let VX ■ current timer value

Let VX = hexadecimal key digit (waits for any key pressed)

Set timer = VX (01 = 1 /60 second)

Set tone duration ■ VX (01 ■ 1/60 second)

Let I =0MMM

Let I = I + VX

Let I = 5 byte display pattern for LSD of VX

Let Ml = 3 decimal digit equivalent of VX (I unchanged)

Let Ml = V0 : VX (I = I + X + 1)

LetVO: VX = Ml (I = I + X + 1)

Erase display (all 0s)

Show n byte Ml pattern at VX-VY coordinates.

I unchanged. Ml pattern is combined with existing display via EXCLUSIVE-OR function.

VF = 01 if a 1 in Ml pattern matches 1 in existing display.

Do machine language subroutine at 0MMM (subroutine must end with D4 byte)

Table 1: CHIPS Instruction set. Note that Invalid hexadecimal characters In the hexadecimalinstructions listed are replaced by valid hexadecimal codes when a program is written. ThusBW00 might be a valid use of the BMMM instruction.

110 December 1978 © BYTE Publications Inc

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BYTE December 1978

111

Figure 1: A drawing of thevideo display. The innerdashed square is the play-ing area. The range of Xand Y is shown.

Memory

Address

Instruction

(Hexadecimal)

Code

0200

6200

0202

6300

0204

A20A

0206

D236

0208

1208

020A

2070}

020C

70F8>

020 E

D888J

The dotted line indicates the area of thescreen used for display. This display areaconsists of an array of spot positions 64wide by 32 high. These spot positions repre-sent bits in a 256 byte page of memory.When a memory bit is one, the spot position ison (white}. The CHIP-8 language specifiesspot positions on the screen by an XYcoordinate system as shown in figure 1. Thevalues of the X coordinate (horizontal spotposition) can run from 00 to 3F (0 to 63decimal). The values of the Y coordinate(vertical spot position) run from 00 to 1 F(0 to 31 decimal). Any two variables (V0to VF) can be used to specify the X and Ycoordinates of a spot position on the screen.

The display instruction (DXYN) lets youshow a pattern of spots on the screen. Thispattern of spots can form a picture, letter,number, etc. Patterns are represented inmemory by a list of one to 15 bytes. Sup-pose you want to display a rocket ship.You must first construct a rocket ship pat-tern on grid paper as illustrated in figure 2.The hexadecimal codes for this pattern canthen be derived directly from the bit pattern.

To show this rocket ship on the screenwith a DXYN instruction, you must first setI to the address of the rocket ship patternbyte list in memory. You must then set twovariables to the X and Y coordinates atwhich you want the rocket ship pattern toappear on the screen. The X and Y coordi-nates specify the position of bit 7 of the firstpattern byte on the screen. For example,the following short program would show therocket pattern of figure 2 at the top leftcorner of the screen:

Comments

Set V2 = rocket X coordinate = 00Set V3 = rocket Y coordinate • 00Set I = rocket pattern address ■ 020ADisplay 6 byte rocket patternEnd loop

The last hexadecimal digit of the displayinstruction (DXYN) must always specify thenumber of bytes in the pattern to be shownon the screen. The DXYN instruction com-pares each bit of the new pattern to be dis-played with whatever is already displayedon the screen at the same spot positions. Ifa 1 bit is already displayed at the same posi-tion as a 1 bit in the new pattern to bedisplayed, a 0 will be shown on the screenat this spot position, and VF will be set to01. In other words, the new pattern to beshown is combined with the pattern alreadyshowing on the screen via an EXCLUSIVEOR function. This means that after a pat-tern is shown on the screen it can be erasedby showing the same pattern again with thesame X and Y coordinates. Incrementingthe X or Y coordinate and showing thepattern a third time would cause the illu-sion of motion. If the value of VF is 01after showing the pattern on the screen, itmeans that the pattern touched or hit apreviously displayed pattern.

The DXYN instruction permits display-ing, erasing and moving individual patternson the video screen. The ability to detectwhen one pattern meets another permitsyou to program chase, paddle and targetgames.

Decimal Digits and Random Bytes

Several instructions are provided topermit displaying decimal numbers on thevideo screen. These are useful for gamescorekeeping, etc. An FX33 instructionconverts the value of any variable (VX) todecimal form. Suppose 1=0442 and V9=A7(hexadecimal). An F933 would cause 01 tobe stored in memory location 0422 (hexa-decimal), 06 in 0423, and 07 in location0424.

BYTE NO.

BIT POSITION

7 6

Rocket pattern byte list

HEX

2 0

7 0

7 0

F 8

D 8

8 8

Figure 2: The definition of the rocketpattern is shown. The dark squares areencoded as a J bit in the appropriate byte.The actual value of each byte of the patternis shown under the HEX column.

112

December 1978©BYTE Publications Inc

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BYTE December 1978 113

Photo 7: The actual video display of the game showing the rocket, UFO andscore.

Since A7 in hexadecimal equals 167 indecimal, we see that the three bytes ad-dressed by I represent the decimal equivalentof the value of V9. if 1=0422, an F265instruction could then be used to set V0, V1and V2 to the values of the three bytesaddressed by I above (01, 06 and 07). AnFX29 instruction can then be used to set Ito a 5 byte pattern representing any one ofthe three decimal digits. An F229 instruc-

tion would leave I addressing a 5 byte pat-tern for displaying the least significant deci-mal digit (7 in this example). A DXY5instruction can then be used to display thedecimal digit on the video screen at anydesired position.

The above example illustrates the use ofan FX65 instruction to transfer three memo-ry bytes to three variables (V0 to V2). TheFX55 instruction will store any number ofvariables in memory locations starting atthe I address. These two instructions can beused to increase the number of variables byswapping sets of variables and memorybytes. Just remember that variables arealways copied to or from memory in groupsstarting with V0 and ending with VX,inclusive.

It is often useful to generate random bytevalues. The CXKK instruction sets any vari-able (VX) to a random byte value. Thisrandom byte will have any bits matching 0bit positions in KK (a 2 digit hexadecimalnumber) set to 0. For example, a C407instruction would set V4 equal to a randombyte value between hexadecimal values 00and 07.

The remainder of theCHIP-8 instructionsshould be self-explanatory. The 2MMMinstruction will transfer control to a sub-routine which must be terminated by

INCREMENTUFO X

DECREMENTROCKET Y

A

ROCKET

<M-

SCORE

H

Figure 3: The range of rocket X values is from hexadecimal OF to 2E. Rocket Y is decremented from hexadecimal 7 A to 00.The UFO Y remains a constant hexadecimal 08, while the UFO X is incremented from hexadecimal 00 to 39.

114 December 1978 © BYTE Publications Inc

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BYTE December 1978 115

instruction OOEE to return control to theinstruction following the 2MMM. You cannest these subroutines. The OMMM instruc-tion permits a machine language subroutineto be inserted if required.

Designing a Video Game Program

A detailed example will illustrate howeasily the CHIP-8 language can be used toprogram a real time video game. The firststep always involves specifying the videodisplay and the functions to be pro-grammed. Figure 3 shows the display formatchosen for this game. An enemy UFO willbe constantly moving from left to rightacross the top of the screen. A single digitscore will be displayed at the lower right.A rocket ship will appear at a randomhorizontal position along the bottom edgeof the display area. You can launch thisrocket by pressing key F on the hexadecimalkeyboard. The rocket will then move ver-tically toward the top of the screen. When itreaches the top or hits the target UFO itwill be erased and a new rocket will appearat the bottom of the screen. After ninerockets have been launched the game endsand no new rockets will appear. If you hitthe UFO with a rocket the score is incre-mented by 1,

After specifying the positions of thevarious game patterns on the video screenas shown in figure 3, you must decide onhow the 16 variables will be used in theprogram. Table 2 illustrates how we willuse the variables in this example. Six vari-ables (V3, V4, V5, V6, V7, V8) are neededto specify the X and Y coordinates of thethree types of patterns involved (score,target UFO and rocket). We need two morevariables (V1, V2) to keep track of the cur-rent score and number of rockets launched.V9 will be used as a flag that shows whetheror not the current rocket has been launched.VA will be set to 01 if the rocket hits theUFO (ie: point scored) and V0 will be usedfor a working register in the program. VF isthe hit flag and is automatically set to 01when a hit occurs.

Flowcharting the Game

I believe you should always construct adetailed flowchart, such as the one shown infigure 4. Proper flowcharting will save hoursof debugging and will simplify making futurechanges to your program. A flowchart alsolets you see the major and minor loops inyour program, allowing you to avoid timingbugs that can occur in real time situationssuch as video games.

Step 1 involves initializing the score and

V0— Temporary variable

V1- Score (00 at start)

V2— Rocket counter (00 at start)

V3- Score X (38)

V4- Score Y(1B)

V5- UFO X (00 at start)

V6- UFO Y (08)

V7- Rocket X {random, OF to 2E)

V8- Rocket Y (1A at start)

V9- Rocket fired flag (00=no, 01=yes)

VA— Score increment (00 or 01)

VF- Hit flag (00 or 01)

Table 2: Rocket program variables. VB, VC}VD and VE are not used In this program.

rocket counters, as well as the X and Y co-ordinates for the target UFO and on screenscore digit. The UFO pattern is shown onthe screen so that it can subsequently bemoved. In step 2 the latest score is shownon the screen, and V2 is checked to see ifthe game should end because nine rocketshave been fired.

Step 4 performs the operations requiredto show a new rocket at the bottom of thescreen. The rocket count is incremented by1 for each new rocket. The rocket patternY coordinate is set to hexadecimal 1A sothat the rocket will appear at the bottom ofthe screen. The rocket X coordinate is setto a random value between hexadecimal OFand 2E so that it will appear at a randomhorizontal position without interfering withthe score digit. The flag V9 is set to 00 toindicate that the rocket has not yet beenfired. The rocket is then shown on thescreen and the program proceeds to theloop containing steps 5, 6 and 7.

This loop causes the target UFO to con-tinuously move across the top of the screenwhile waiting for key F to be pressed. TheUFO is randomly moved zero, one, two orthree spot positions to the right each timethe loop is executed. This gives it a ratherfast, randomly varying rate of motion, ma-king it harder to hit. The movement of theUFO merely involves incrementing its Xcoordinate (V5). When V5 is incrementedpast the right edge of the display area, wraparound automatically occurs so that theUFO reappears at the left edge of the displayarea. This wrap around automatically occurswhen any X or Y coordinate of any displaypattern is incremented or decremented pastany edge of the 64 by 32 bit display area.

When key F is pressed to launch therocket, step 6 causes V9 to be set to 01.Step 7 then causes step 8 to be included inthe loop. Step 8 checks the value of the sys-tem real time clock (or timer) to see if it hasreached 00 yet. When the timer reaches 00the rocket is moved up one spot position,and the timer is reset to a value of 03 (1/20

116

December 1978 © BYTE Publications Inc

TARBELL SOFTWARE

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• Number system 10 digits BCD integer or floating pointIncluded are commands unique to Tarbell BASIC whichprovide capabilities to:

• Chain to another program • Assign a physical device to

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A TARBELL Update Package for those now usingCP/M 1,3 is now available on diskette. The UpdatePackage adds new commands and the ability to accessfour disk drives, as well as 2 new CP/M manuals, TAR-BELL CP/M User's Guide and a new BIOS listing.Price: $50.00.

SPOOLER

This 8080 program will save many hours of computingtime. It intercepts all output to the list device, spools theoutput to a high-speed disk file, and directs the spooleddata to a low-speed printer during unused cycle time whilethe CPU waits for transfer of data to and from the console.System throughput is greatly increased with the aid ofSPOOLER. Output is never lost due to insufficient memoryallocation. Fully compatible with the CP/M file system,SPOOLER permits parallel processing without hardwareinterrupt, and with minima! impact on other processes.Price: $70.00 (Copyright KLH Systems.)

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Designed to work with CP/M Disk Operating Systemthis software requires a total of 20K bytes of memory.Included are 26 compiler error messages and 23 run-timeerror messages. Disk files may be read, written or up-dated by using both sequential and random access. In-cluded are blocked and unblocked files. Price for com-piler and run-time monitor on diskette is $10.00. Manualis available separately for $5.00. (Public domain soft-ware by Gordon E. Eubanks, Jr.).

CBASIC Programming System

Upward compatible from BASIC-E, CBASIC is simi-lar but expanded to include several business orientedfacilities, allowing decimal computations to 14 digits ofprecision, data formatting and PRINT USING state-ments. Statements allow access to disk files and diskfile maintenance. Strings of characters may be read fromthe console to permit correct input line format to bechecked before reading data. General programming fea-tures include variable names up to 31 characters, option-al line numbers, dynamic debugging tracers, and optionaldata output to printer. CBASIC on diskette and manualpriced at $100. (Copyright Software Systems.)

EMPLan 8080 APL

Especially suited to educational applications, EMPLis an adaptation of APL, using the ASCII character set.Only one-dimension arrays are allowed. This 8K versionoccupies the first 5376 bytes of memory and operates intwo modes. The Execution Mode permits all instructionsto be executed immediately. The Definition Mode per-mits the user to enter functions. EMPL on Tarbell Cas-sette with manual is $15. (Copyright 1977 Erik Mueller).

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Circle 360 on inquiry card.

950 DOVLEN PLACE • SUITE B • CARSON, CALIFORNIA 90746(213) 538-4251 • (213) 538-2254

BYTE December 1978 117

Figure 4: Flowchart for rocket game,

STEP i <

&

STEP 2 <

STEP 4 <

f START J

INITIALIZEVARIABLES

DISPLAY

UFO

PATTERN

\.

J

I

DISPLAYSCORE

STEP 5 <

STEPS (

STEP 8

STEP 9

STEP K) /

STEP II {

MOVE ROCKETUP ONESPOTPOSITION

G>

NO /ROCKET^, AT TOP OF^SCREEN

ERASE SCORE.ERASE ROCKET

ADD SCOREINCREMENTTO SCORE

I

SCORE

INCREMENT

•01

STEP 12 (

118 December 1978 © BYTE Publications Irtc

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Circle 95 on inquiry card.

BYTE December 1978

119

Address

(Hexadecimal)

Instruction

Pseudocode

Comments

0200

6100

V1=00

Step 1:

Score

0202

6200

V2-00

Rocket count

0204

6338

V3=38

Score X

0206

641 B

V4=1B

Score Y

0208

6500

V5=00

UFOX

020A

6608

V6=08

UFO Y

020C

A27E

t=027E

UFO pattern

020E

D563

SHOW3MI@V5V6

UFO

0210

226A

DO 026A

Step 2:

Show score

0212

4209

SKIP;V2 NE09

0214

1214

GO 0214

Step 3:

End loop

0216

7201

V2+01

Step 4:

0218

681A

V8=1A

Rocket Y

021A

6A00

VA=00

021C

C71F

V7=RND

021 E

770F

V7+0F

Rocket X

0220

6900

V9=00

0222

A278

1=0278

Rocket pattern

0224

D786

SHOW6MI@V7V8

0226

A27E

I-027E

Step 5:

UFO pattern

0228

D563

SHOW3MI@V5V6

Erase UFO

022A

C003

V0=RND

022C

8504

V5=V5+V0

Set VF

022 E

D563

SHOW3MI@V5V6

0230

3F00

SKIP;VF EQ00

0232

1262

GO 0262

Step 12 if hit

0234

600 F

V0=0F

Step 6:

0236

E0A1

SKIP;V0 NE KEY

0238

6901

V9=01

023A

3901

SKIP;V9 EQ01

Step 7:

023C

1226

GO 0226

Step 5

023 E

F007

V0=TIME

Step 8:

0240

3000

SKIP;V0 EQOO

0242

1226

GO 0226

Step 5

0244

A278

(=0278

Step 9:

Rocket pattern

0246

D786

SHOW6MI@V7V8

Erase rocket

0248

78FF

V8+FF

024A

D786

SHOW6MI@V7V8

024C

3F00

SKIP; VF EQOO

024 E

1262

GO 0262

Step 12

0250

6003

V0=03

Step 10:

0252

F015

TIME=V0

0254

3800

SKIP; V8 EQOO

0256

1226

GO 0226

Step 12

0258

226A

DO 026A

Step 11:

Erase score

025A

A278

1=0278

Rocket pattern

025C

D786

SHOW6MI@V7V8

Erase rocket

025E

81A4

V1=V1+VA

Score+VA

0260

1210

GO 0210

Step 2

0262

6A01

VA=01

Step 12:

0264

6003

V0=03

0266

F018

TONE=V0

0268

1258

GO 0258

Step 11

026A

A2A0

l=02A0

SSS:

3 byte work area

026C

F133

MI=V1 (3DD)

026E

A2A2

l=02A2

Least significant«

0270

F065

VO: V0=MI

0272

F029

l=V0 (LSDP)

0274

D345

SHOW5MI@V3V4

0276

00EE

RET

0278

2070

ROCK:

027A

70F8

Rocket pattern

027C

D888

027E

7CD6

UFO:

UFO Pattern

0280

7C00

Figure 5: The rocket program code in CHIPS hexadecimal interpretivelanguage instructions. The steps specified relate directly to the flowchartgiven for the game in figure 4.

second). This timer reset value determinesthe speed at which the rocket moves upward.The larger the timer value, the slower therocket moves. The loop comprising steps 5thru 10 keeps both the target UFO androcket moving on the screen until eitherthey touch each other (a hit), or the rocketreaches the top of the screen withouttouching the UFO.

If the rocket and UFO touch each other,step 12 is executed. This sets VA to 01 andsounds a short tone so the player knows(s)he scored. Step 11 is then executed toerase the rocket and the current score onscreen. Step 11 also increments the scorevariable (V1) by the 01 in VA. The programthen returns to step 2 where the updatedscore is shown on the screen. If less thannine rockets have been fired, a new rocketis shown on the screen in step 4, and thestep 5-6-7 loop is repeated as before.

If the rocket reaches the top of thescreen without touching the UFO, step 10will branch to step 11 causing the score androcket to be erased. In this case VA willcontain 00 (from step 4) so that the scorewill remain unchanged. Note that the entireprogram has now been designed. By double-checking the program in flowchart form,you can eliminate almost all program bugsbefore they occur. An extra hour spent onthe flowchart can eliminate many hours ofdebugging later. All that remains now is totranslate the flowchart into an appropriatesequence of CHIP-8 instructions.

Coding and Debugging the Final Program

The final program is shown in figure 5.To translate the flowchart into CHIP-8instructions, start by listing even numberedhexadecimal memory addresses in the firstcolumn, as shown in figure 5. Fill in thethird column with an abbreviated descrip-tion of the function to be performed byeach instruction. It is usually most con-venient to locate subroutines and patternbyte lists at the end of the program.Labeling the appropriate program addresseswith the flowchart step numbers will alsoprove helpful. The actual hexadecimalcodes for the CHIP-8 instructions can thenbe written in column 2 and entered into theCOSMAC VIP memory using the hexa-decimal keyboard.

To debug the program, replace the 4209instruction at memory location 0212 witha 1212 branch instruction. When the pro-gram runs, it will stop at location 0212since the 1212 branch loops on itself. Ifthe UFO and a 0 digit initial score show onthe video screen, you know execution wasproper up to location 0212. Replace the

120

December 1978 © BYTE Publications Inc

My Structured Systemsbusiness software has paidfor itself in labor hours

saved alone.

Mr. Ken Tunnah, Colloid-A-Tron Inc., Buffalo, New York

9*

Says Mr. Tunnah: "The program is designedfrom a CPA standpoint, for multiple corporations,which we have. It is flexible and gives me theability to change reporting by profit centerseasily. It is up and running quickly, and it justkeeps on running. I think it's the best businesssoftware available."

The best software available. That's what StructuredSystems Group set out to create.

Structured Systems offers three sophisticatedaccounting systems. Our General Ledger software isbig enough for multi-client write-up by the CPA, ormulti-corporate reporting for the business, but smallenough for the micro budget. The very comprehensiveAccounts Receivable and Accounts Payable packageswill operate independently, or they will coordinate withthe General Ledger.

Our systems record transactions easily and cor-rectly, and provide an audit trail from source documentto financial statements. And they will maintain monthlyand year-to-date information in dollars and inpercentages. And they are reliable.

The three systems interact with theuser to set up parameters such asformat and headings, accounttitles and numbering,automatic billing or remindernotices, credit limits, salesreports, a check register,and much more.

Circle 351 on inquiry card.

Ken Tunnah is oneof many innovatorsbringing the microrevolution to thesmall business. Asa programmer, heknows computersand their languages.As a businessman,he knows businessand its languages.And when Mr. Tunnahdecided to micro-computerize the ac-counting function atColloid-A-Tron, heturned to StructuredSystems software.

The software is designed to run on an 8080 or Z-80CPU with 48K of memory, dual disks with CP/M®,printer, keyboard, and CRT. To make it all work for you,we have provided the most extensive documentationand support in the industry.

We provide the capability to computerize complexaccounting functions on relatively inexpensive micro-computer equipment. Ken Tunnah has told us what thatmeans: "I've bucked some trends. I looked around,and decided that with the right software, I couldget a micro to outperform a $45,000 mini. I'msatisfied. It's simple economics."

We can refer you to a growing number of sophisti-cated retailers experienced in Structured SystemsGroup business systems. Or we can work directly withyou. We'd be happy to provide you with more informa-tion on our product line, which includes QSORT™ (asort/merge program), CBASIC (a business BASIC),NAD™ (a mailing and addressing system), and ourGeneral Ledger, Accounts Receivable, and AccountsPayable packages.

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Putting the Microcomputer in Business.

BYTE December 1978 121

Program faster,debug easier now

Flowchartrix™ a unique flowchart development tool from Stirling/Bekdorf,saves you time, space, and money, no matter what language you work with.Whether you program professionally or just for fun. The 78F2 Flowchartrix™helps your thoughts move in logical steps, and lets you retrace logic easilywhen debugging.

When you use "top-down" programming methods, you can use the 78F2to lay out your original logic concept blocks. Then by following the planyou lay out in words at the concept stage, you can write a finely detailedflowchart quite smoothly. Then it's easy to write actual code based on theflowchart.

54% more logic cells than other flowchart forms, so you get far moreof your program on each page. Each Flowchartrix has a full 77 logic cells,not just 50. This not only saves paper, but also makes your finished flow-charts easier to understand. By seeing up to 27 extra steps of your programon each page, you comprehend program flow more clearly. That's importantwhile writing the flowchart, more important when you write actual code.It's also extremely helpful when you debug, and indispensable when you comeback months or years later to modify your original work. 78F2's higher ma-trix count makes your flowcharts quicker to debug because there are fewerpages to search for errors, Fewer pages also save you money and storagespace.

Unique matrix can show your loops AS loops. The Flowchartrix 7x11matrix gives you plenty of room to write loops laid out as sort of a squaredcircle. This makes loops and subroutines easier to recognize, because theirform is readily apparent at a glance. Since they're easier to find, and mayeven be completed on a single page, they're also simpler to debug or modify.

Every matrix cell has a specific label to help you track branch points.Now it's far easier to follow your program from page to page, point to point.When you write program documentation, having a separate reference pointfor each cell makes your program much easier to describe clearly.

With Flowchartrix, you don't need a shape template to draw remarkablyregular logic symbols. Guides for the most-used logic symbols are right ineach matrix cell. They help you draw most standard flowchart symbols en-tirely free-hand. This saves all the time you'd otherwise spend hunting ashape template and positioning it to draw every symbol. Your tram of th-ought need no longer be interrupted by template tedium. With 78F2, yourpencil can fly as fast as you can write, without interruption. When a flashof insight strikes, now you can keep your pen on paper, flowing rapidly fromone step to the next without a break.

78F2 is surface-engineered to take both pen and pencil without blotching.The tough 22- base stock is the same brilliant white opaque material usedin our 78C1 Combination Coding/CRT Layout forms. Pure enough to usewith magnetic ink scanners, heavy enough to withstand vigorous erasure,every Flowchartrix gives you crisp, sharp, characters and symbols. It takesink without spreading, and accepts soft pencil lead with good contrast.

Order your supply today. Ask your local computer store for Stirling/Bekdorf™78F2 Flowchartrix™ To enjoy the world's most advanced programdevelopment aids most, use the entire Stirling/Bekdorf system: 78F2 Flow-chartrix (for concept planning and flowcharting), 78C1 Combination Coding/CRT Layout forms (for coding and display planning in BASIC, OPUS, andother line-number languages), and 78P4 Print-Out Design Sheets (to designreport printouts for easy coding). Our programming tools work togetheras a complete system to save time and reduce errors during every stage ofprogram development, from concept to completion. Try them for yourselftoday. If your store is out-of-stock, use the coupon below to get yourselfa supply on the way now.

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1212 branch with the original 4209 instruc-tion and put a similar idle loop branchfurther down in the program for the nexttest run. In this way you can identify whichprogram steps are causing a problem. If youneed to change any portion of the program,just insert a branch instruction to a patchadded at the end. Designing, coding anddebugging this simple game program re-quired about eight hours. Actual coding andloading the program into memory requiredless than an hour of this time.

The sample program was kept simple forease of understanding. Even in this simpli-fied form it is a challenging game to play.The speeds of the rocket and UFO can beeasily adjusted to make scoring more or lessdifficult. Adding multiple targets and2 digit scoring is possible. Multiple rocketlaunch angles or after-launch steering couldbe incorporated. Exploding UFO patternscould be shown when one is hit.

Conclusions

Hexadecimal interpretive programmingprovides an easy way to program smallcomputers. This approach requires fewerinstructions and is much easier than machinelanguage programming. On the other hand,hexadecimal interpretive programming re-quires much less hardware overhead costthan do high level languages such as BASIC.

A detailed example was provided toillustrate this interpretive approach for a realtime video game. The RCA COSMAC VIPand CHIP-8 language were used in thisexample, although other hexadecimal inter-pretive languages are possible, and a similarapproach can be used with othermicrocomputers. The steps required inprogramming with a language such asCHIP-8 are the same as required whenusing any language: you must specifythe functions required, decide on vari-able and memory utilization, prepare aflowchart, check the flowchart, do thedetailed coding, load the code, and debugto the extent required to get the programrunning properly. Only the last two stepsinvolve using the hardware. Skipping anyof the earlier steps will invariably lead toexcessive machine debugging time no mat-ter what language is used.

If you've never tried a language such asCHIP-8, you may be surprised at how easyit is to use. If you have a limited budgetyou will certainly appreciate the savings inhardware over conventional high level lan-guages. Last but not least, you might evendiscover that designing your own hexa-decimal interpretive language is also fun."

122 December 1978 © BYTE Publications Inc

Circle 352 on inquiry card.

6800 Debug Package

The TSC 6800 Debug Package provides a better way totrap program bugs. It is an extremely powerful andcomplete assembler language program debugging toolwhich is capable of simulating all functions of the 6800microprocessor, including interrupts and 1/0 operations.It is an ideal substitute for hardware logic analyzers or CPUemulators at only a fraction of the cost

Any number of breakpoints may be user defined. Eachbreakpoint may invoke any one or combination of eightdifferent actions. These actions may be dependent on auser defined condition such as register A=$FF or memorylocation $1B55=0. The actions may also be delayed orlimited by a pass count. Histogram breakpoints may beset to enable profiling of the executed program. Break-points may be set in RAM or ROM!

Complete simulation control allows trace mode to beenabled at anytime. During trace, registers and opcodemnemonics are displayed after each instruction is ex-ecuted. Single or multiple instruction stepping is per-mitted as well as simulation speed control. The trace backfeature allows the past 256 executed instructions to beviewed. Program execution may be halted at anytime byoperator command.

Memoiy protection and traps are another key feature. Anysection(s) of memory may be write, execute, memory, orsimulate protected. Execution traps allow program exiton general conditions such as interrupt instruction, trans-fer instruction, subroutine nest count, and instructioncount timeout

General features include a line at a time assembler,disassembler, memory interrogation commands, hexcalculator, machine states counter, stack protection, reg-ister modifier, and mode control. In all, there are over 50commands available. The manual includes detailedoperating instructions as well as the complete com-mented source listing. Requires 9K at $3C00.

SL68-30 Manual and source listing

SL68-30C with KCS Cassette

SL68-30D with mini FLEX™ diskette

SL68-30F with 8" FLEX™ diskette

$35.00$41.95$43.00$55.00

Send 25< for a complete catalog of TSCs assemblerlanguage software for the 6800, 8080, and 6502.

Technical SystemsConsultants, Inc.

S^-Va Box 2574 W. Lafayette, IN 47906Specialists in Software & Hardware for Industry & the Hobbyist

Circle 370 on inquiry card.

BETTER

BUG

TRAP

BYTE December 1978 123

Prof George A Gerhold

Dept of Chemistry

Western Washington University

Bellingham WA98225

Who doesn't want a tutor who is infi-nitely patient, expert on almost any subjectunder the sun, available at your beck andcall, adapted to your learning speed andstyle, and cheap? This has attracted theattention of a number of the manufacturersof personal computers, and several of themmake prominent reference to educationalapplications in their advertising. But thecustomer who uses educational applicationsto justify raiding the family budget for acomputer will have some explaining to do,for good teaching software on microcom-puters is not available, nor is it easy to write.Why?

If you examine the 20 years of develop-ment of computer assisted instruction (CAI)on mainframe computers, you'll see thatthe computer can be an effective teachingtool when used properly. Students taughtwith a computer perform as well or betterthan comparison groups; they may learntwo or three times faster. Their failurerate is lower and they express satisfactionwith the technique. Why then is the tech-nique not more widely used? There are threemain reasons.

TeachingWith a Microcomputer

First, teachers are conservative. In fair-ness we also must realize that teachers haveheard too many extravagant claims forthe miracle that this or that piece of edu-cational technology will produce; theircynicism is understandable. Proponents ofcomputer assisted instruction have notalways been conservative (nor have theyalways been accurate). The cost of hardwareis also seen to be prohibitive. Exceptions ex-ist, but the most visible (ie: highly funded)systems are costly to purchase or lease.Third, the creation of high quality softwareis a difficult and time consuming task whichto this point has provided little compen-sation beyond personal satisfaction.

The personal computer will eliminatetwo of the reasons. Teachers are discoveringcomputers through their own efforts andthrough stimulation provided by studentsand parents who have computers in theirhomes. The major price breaks in the costof hardware have resulted from the in-troduction of smaller machines. Mini-computer systems cost less than 10 per-cent of mainframe based systems, and

microcomputer systems will possibly costless than 10 percent of minicomputersystems (using in all cases initial capitaloutlay, the most relevant number for indi-viduals or small institutions). What remainsis to create appropriate software for teach-ing with a microcomputer.

Before we attempt to write good teachingsoftware, there are some rather fundamentalquestions to be answered. First, what do wemean by good teaching? A more usefulquestion might be, "What is good teachingnot?" One relevant answer for computerteaching is, "Good teaching is not justtesting."

Most programs described as teachingprograms are programmed tests; the formatis exclusively question, accept answer, onemessage for right, and a second for wrong.Random selection of messages from a listmay defer boredom a bit, but that featurealone does not change a test into teaching.

Good teaching is not repetitious to thepoint of boredom. That's an obvious state-ment, but it poses a dilemma for those whowould teach with the computer, becausethe efficient use of a computer usuallyinvolves repeated use of sections of code.The resolution of the dilemma is to writelong and varied course software whichcan be used by a large number of students.

Good teaching does not force eachstudent to proceed by the same path.Addition of hints or partial solutions forevery question on a programmed test doesnot make that program a good teachingprogram. If each wrong answer is diagnosed,and a hint or partial solution which buildson the correct portions of that particularwrong answer is given, then we may havea good teaching tool.

Good teaching does not consist of arandom collection of available bits andpieces. This implies that we should thinkin terms of sizable units which can becomesignificant components of a course orsubject.

Finally, we should not forget that goodteachers are most often experienced teachersand that any occasional lack of enthusiasmon their part about the teaching efforts ofwell-meaning parents is not invariablymisguided.

Another important question is, "What arewe trying to teach?" This question is espe-cially important for the personal computeruser because the output devices commonlyused cannot provide the notation which thestudents use elsewhere. Books are notwritten in uppercase only; exponents arenot usually written with arrows or double

124

December 1978 © BYTE Publications lot

asterisks; yes and 1 are not synonymous,nor are no and 0; the answer to every ques-tion is not a, or b, or c, or d - none of theabove, if we attempt to teach using deviceswhich impose notation limitations, we askourselves repeatedly, "Are we teachingwhat we want to teach, or are we teachinghow to use and cope with the limitations ofthe software?"

With these points in mind let us now con-sider computer languages for teaching.Some teaching languages are based on ateaching strategy; others are based onsoftware functions. Our experience is thatthe latter types are far superior to the for-mer, for they allow implementation of avariety of teaching strategies. Examinationof a large variety of good computer assistedinstruction materials shows that they arebuilt from a small number of operations.

For example, one must be able to sendtext to and accept text from the terminal.Call these functions type and accept (orT and A). (The notation herein is the PILOTnotation; for a more complete descriptionof the language see "Computer AssistedInstruction on a Microcomputer," November1978 BYTE, page 90.)

Having accepted text, one must be ableto analyze it. This is usually done with sometype of a match (M) algorithm. One alsoneeds some kind of jump (J) instruction,instructions for subroutine calls and returns(U and E), and some kind of compute (C)instruction so that one can use the fullrange of numerical and string operationsnormally associated with computers. Finallyone needs some way to make execution ofat least some of these instructions (at aminimum, the jump) dependent on thevalues of various variables or on the successor failure of certain matches.

The obvious question for the microcom-puter fan is, "Can I use BASIC?" Unfor-tunately, the answer is, "Only with extremedifficulty." Typing text is no problem, andaccepting input from the terminal can behandled. Accepting an input of two whenyou programmed INPUT X and expected theanswer 2 will take some extra code, butwe've already learned that these are going tobe long programs by usual computerstandards. The difficulties with acceptingdata pale in significance when compared tothe difficulties with match.

Consider an extremely simple case:a question that can be answered yes. WriteBASIC code which will match any of thefollowing:

yes, Yes, YES, O.K., OK, Of course,Sure, Always.

See the computer.See the computer run.Read The Computer Book.

This is it - a workbook that actually shows you howa computer is organized, programmed, and run. How?Because the book is a computer! The Computer Book.

Here's how it works: the top third of each page graph-ically represents a memory location (illustrated atright) which includes memory and address registersto be filled in by you, the reader-as-prog rammer. Theprogram steps are listed at the tops of the pages, andat each location you are giv-en your next instruction(s)to carry out. You play theswitch register and controlcircuits, a bookmark servesas the program counter,and your pencil is the lineprinter. Before you knowit, you'll be "jumping tosubroutine" and "clearingthe link" with the best ofthem! More importantly,you'll understand exactly why you're performing eachstep as you run through the programs. Not even step-ping a real computer through a program can provide acomparable learning experience - the reader is insidethe computer!

The text of The Computer Book is presented in sucha clear, down-to-earth style that it makes an ideal in-troductory reference for anyone, student and non-technician alike, who wishes to improve his/herunderstanding of the digital world. Contents include:

• Number Systems and Codes

• Memories

• Peripherals

• What Goes On In There?

• The Instruction Set

• Organization of the Computer

• Programming

• Thumbs-On Experience

• Our First Program Steps

• Practice Programs

• Assembly Language

• High Level Languages

• FORTRAN

• COBOL

• Microprogrammed Computers

• Microprocessors

• Microcomputers

ARTECH HOUSE BOOKS

610 Washington St. Dedham, MA 02026

(617) 326-8220

Please send me copies of The Computer

Book at $28.00 per copy.

I enclose check or m.o. for $

'v^SmjCS

m mc#

SBS Name

Exp. date

IgrSl Address

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X.' 9 d

State

Zip

Circle 11 on inquiry card.

December 1978 © BYTE Publications Inc 125

but which will not match any of these:

yesterday, yes and no, yes or no,Alyeska, eyes.

In a good teaching language it can be donein a single line. It could be done in BASIC,at least in a BASIC with a full range of stringoperators, but in practice no one bothersbecause it's so much easier to tell the studentto answer 1 for yes. One could program thematch algorithm of a good teaching languagein BASIC as a subroutine, but the resultingcode is too slow. It seems then that BASIC(and other computational languages, suchas FORTRAN and APL) are not suitablefor this purpose.

Fortunately one of the best teaching lan-guages, PILOT, is well suited for microcom-puters. The original form of PILOT is toolimited for production of top quality teachingmaterials. Several extended forms of PILOThave been developed, and the NationalLibrary of Medicine is supporting an effortto achieve a national standard for the ex-tended language. At Western WashingtonUniversity we have implemented whatpromises to be essentially this standard on aSwTPC 6800, and we are currently workingon 8080, Z-80 and Pascal implementations.

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By doing so we have shown that it is possibleto implement a language that includesall the operations necessary for teaching,including the full range of numeric andstring operators, full floating point, andnumeric and string arrays, all in a 20 K bytemicrocomputer. Moreover, the response timeis excellent. We maintain that there is noreason to settle for less in an instructionallanguage.

Now that you're convinced that you'llhave to get better systems software, whatabout hardware? It appears that any of thestandard microcomputers will be suitable forthis application if they can accept sufficientmemory (16 K to 20 K bytes). The length ofinstructional programs and the distance andcomplexity of branching within the programrequires the use of floppy disks or otherforms of mass storage.

A typical intructional dialogue programoccupies about 8 K bytes for every 5 minutesof instruction. Any individual student mightleapfrog an entire section in a few seconds ifthe program were written to move with awell-prepared student. Thus the system mustbe interpretative, with the programs storedon disks.

Good terminals for teaching should havegood graphics capabilities. At this time suchterminals are too expensive ($4000 to$6700), several times the cost of the rest ofthe system. What is needed is a video ter-minal with at least a 256 by 256 dot matrixthat can be superimposed on a 24 line by80 character display (upper and lowercase).Until such a unit is available, we must makedo with less. However, a 40 character line israther short for this purpose.

Finally, after all these cautions and dis-couragements, what can or should the ownerof a microcomputer who wants to use thething to teach do? One possibility is tosearch for or create games which providepractice in topics which your children havealready learned in school. An obvious exam-ple is a version of Spacewar that demandsfractional inputs as an exercise in fractions.A second possibility is the purchase ofsuitable systems software and course mate-rial. Such material is beginning to come ontothe market. The third and most excitingpossibility is to become involved in creatingteaching material. Get suitable systemssoftware and find an interested teacher. Theteacher provides the material and the ap-proach, and you provide the programming.If you take this route, remember that theteacher knows how to teach, that studentsare more varied than your imagination, andthat good materials require testing andediting and retesting and reediting."

126 December 1978 © BYTE Publications trie

Circle 184 on inquiry card.

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ANNUAL REPORT ANALYZER: With Annual Report in hand, you input revenue andincome figures for the previous five years aswell as basic Balance Sheet dataProgram computes Percentage year to yeargrowth in sales, profits, and earnings pershare; Average and compound EPS over fiveyears, PE ratio. Profit margin for previousfive years with graphic display that plotsrevenues against profit margins. Currentratio; Book value. Return on equity, Debtto equity ratio. Payout ratio; Oivident yield.Implied growth rate; Implied total return;Theoretical PE ratio. Theoretical value fotstock $2295

STOCK ANALYZER: (Use only with DataBase)

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OPTIONS: The National Corporate Sciencesversion of the Black Scholes equation, computes the theoretical valoe of an optionVafuE ol option is graphically depicted bymovement in stock price and days to expiration. $24.95

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10 BUILDER NUMBER SERIES: Developsa method of problem solving with practiceon problems ol increasing difficulty Highschool to adult S9.50

PRESCHOOL IQ BUILDER: Teaches tognttive skills Includes SAME AND DIFFERENTand LETTER BUILDER With ParentsGuide For ages 3 to 6 S9 50

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SPACETREK: Aversion of "Star

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GRAND PRIX GOLF Minefield

BRIDGE CHALLENGER: Playbridge against your PET

SUPER STARTREK Add some excitementto your Klmgon warfare* This version ineludes action, in addition to the "standard"Startrek features $14 95

SWARM: Huge Swarms ol killer bees arespreading at an alarming rate, causing thousands of casualties You must decide thetactics to be used to combat this deadlymenace $19.95

MICROCHESS: You play choice of 8 levelsof play against the computer, excellentgraphics. $19.95

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EDUCATION

BASIC BASIC A real tutorial program, introducing you to PET's BASIC. S14.9S

DIET PLANNER AND BIORHYTHM:

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BASIC MATH PACKAGE: Includes fourprograms Matrix Math Routines, VectorArithmetic, Trigonometry, and Calculus.

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10 BUILDER ANALOGIES: Teaches

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High school through adult. $9.50

IQ BUILDER VOCABULARY: Providespractice for vocabulary testing using synonyms and antonyms. 2 tapes. High schoolto adult. $12.50

RadioShack

The following program titles are now available for RAOI0 SHACK TRS-80 Com-putes. (See above for descriptions)

IQ BUILDER ANALOGIES

10 BUILDER VOCABULARY10 BUILDER NUMBER SERIESPRESCHOOL IQ BUILDER

STEP BY STEP

MICROCHESS

ANNUAL REPORT ANALYZER

STOCK ANALYZER

OPTIONS

STOCKSCREEN

ELECTRIC PENCIL

95095029 951995225034.9524 95299599 00

Role 206141 IIAH3Ii Exchange Commissifulness ol the above r>

4r

for ^^.

THE COMPUTER FACTORY . . . when software counts 485 Lexington Avenue 750 Third Avenue New York, N.Y. 10017](212)687-5001 (212) PET-2001 Foreign order desk - Telex 640055 Open Tu-Fr 10-6, Sat 104

BYTE December 1978 127

Mike Weed

Rt 2 Box 97A

Spring Valley MM 55975

Digital integrated circuits that multiplybinary numbers without the use of clockpulses have been available for several years.One such 4 bit by 4 bit multiplier is illus-trated in figure 1. The 8 bit product appearson the output lines about 40 ns (the propa-gation delay) after the input lines are set.Larger numbers may be multiplied by firstsectioning the inputs into 4 bit words, form-ing the products of each word of one inputwith every word of the other input, andsumming these products in the appropriatemanner. The propagation delay increasesapproximately linearly with the number ofinput bits. The number of integrated circuitsrequired increases roughly as the number of

bits in the multiplier times the number ofbits in the multiplicand.

Multipliers are readily constructed fromsimpler integrated circuits. A 4 by 4 multi-plier is illustrated in figure 2. The four bitsof the multiplicand are gated into the adderM places from the right if the VIth bit of themultiplier is 1. If this bit is 0, only 0 isadded in. The parts count is minimized bybringing the carry output of the last adderback to a previous adder input. This systemcosts less than the circuit in figure 1. Itsdisadvantages are a higher componentscount and a 60 percent increase in powerrequirements. The two systems have com-parable propagation delays.

Clockless Multiplication

and Division Grcuits

Figure 1: Commerciallyavailable 4 by 4 multiplier.

MULTIPLIER

A3 A2 Al AO

0000

m

MULTIPLICAND

t * \

B3 B2 Bl BO

0000

15 I 2 3 4 7 6

2D 2C 2B 2A ID IC IB IA

6ASB

ICI74284

Y7

Y6

Y5

Y4

IO

14

m

I3

15

2 3 4 7 6 5

2D 2C 2B 2A ID IC IB IA

GA

Qb

IC274285

Y3

Y2

YO

12

0 0 0 0

P7 P6 P5 P4

IO

12

0 0 0 0

P3 P2 PI PO

PRODUCT

128 December 1978 © BYTE Publications Inc

MULTIPLIER

MULTIPLICAND

A3 A2 Al AO

0 0

r

IC67408

n

B3 B2 Bl BO

3II

n0O0!!0ua,c,O!

i

"i ri3i i

12 13

■ill

8

B 7408

A4 B4

C4

24

B3 A2IC3 7483AZ3 22

B2

II

CO

Q,

1j

i

IG87408

0000 00G,c9GJ!

^

11

8

10 II

8 7408

A4 B4

C4

24

B3 A2IC4 7483A23 22

B2

21

16

8

10 II

Al

C4

A4 B4 A3 B3 A2 B2IC5 7483A24 23 22 21

CO

15

13

a

13

0,

ioooooo^

"J

P7

P6

P5

P2

PO

PRODUCT

Figure 2: Inexpensive 4 by 4 multiplier that has a higher number of inte-grated circuits and uses more power than the circuit in figure 7.

™mo©[^o)

6800 USERS

[and friends of same)

SWTPC - MSI - I5IMIX

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• U2708 EPROM—Containing driver software for B-08; compatible with all monitors

• L.S. Engineering EPROM Eraser$299.80 value for $274.80 — SAVE $25.0X1! Great gift idea!

The Micro Works 6800 series of computer accessories includes:

DS-68 — The Micro Works Digisector, a video digitizer for the 6800 with 256 X 256 picture element resolution,64 levels of grey scale. $169.95 S-100 users: Watch for our ad next month!

PSB-08 — PROM System Board with 1K on board RAM, space for 8 DIP-switch addressable 2708 EPROM s. Relocate the I/O portion of memory andexpand to 56K of contiguous RAM! $119.95

B-08 —2708 EPROM Programmer, all voltages generated on board with convenient extended board height. U2708 Utility in ROM tests, burns,verifies and copies EPROMs quickly and easily. B-08: $99.95; U2708: $29.95

UIO —Universal I/O board comes pre-wired for any Motorola 40 or 24 pin interface chips, maximizing available space for interface circuitry.$24.95

P.O. BOX ITIO DEL MAR, CA. 92Q14 714-756-2687

Circle 203 on inquiry card.

December 1978©BYTE Publications Inc

129

The circuit in figure 3 shows one of manypossible variations along these lines. This 4by 5 multiplier uses inverters and NOR gateson the inputs instead of the AND gates offigure 2. Desirable input buffering is thusprovided at about the same dollar cost, butrequires more packages and power.

Clockless division circuits are more com-plicated than multiplication circuits. One

way to obtain a 4 bit quotient from a 7 bitdividend and a left-adjusted 4 bit divisor isshown in figure 4. A subtraction is per-formed at each stage by complementing thedivisor and adding, while forcing a carryinput to the adder. If the difference is nega-tive, as indicated by a 0 carry output, a 4 bit1 out of 2 multiplexer is set to transmit theminuend to the next stage. If the difference

MULTIPLIER

MULTIPLICAND

fA3

A2

Ai

\

AO

r

B4

BO

g u g g

r

13

IC367404

Y Ye Y

u g g u g

f* ' v7 IC37a

-J t_

i—

IC37I 7404

Y Y Y Y Y

sir

■3r

"i r~"Pti

n r

J2| |

9~WS? UVW? -WVV «.?W?!!?W..9

n2i

L_

[ 7402

14

1*3J [740

8

T<3J l740

A4 B4 A3

C4

24

B3 A2ICIO 7483A23 22

B2 AI

Bl

CO

a

j?

16

8

Tl3 7402

16

10 13

1J L-

8

10 II

10 7402 13

C4

B4 A3 B3 A2

ICII 7483A24 23 22

B2 AI Bl

21

CO

15

ZJ

13

a

A4

B4 A3 B3 A2ICI2 7483A24 23

B2 AI

22

15

13

1

14

16

10

A4

B4 A3

B3 A2 B2

C4

ICt 3 7483A

24

23

22 2

i

P8

a

0 0 0 0 0 0 0

P6

P5

P3

Figure 3: 4 by 5 multiplierwith buffered inputs.

PRODUCT

130 December 1978 © BYTE Publications Inc

f) \ Osborne & Associates

BUSINESS SOFTWARE FORMICROCOMPUTERS

Osborne & Associates is publishing its business systems in book form.These systems represent five years of development and testing byO&A programmers, and the books include more than a year's worth ofextensive and detailed documentation.

What systems are we selling?

1) PAYROLL WITH COST ACCOUNTING —available now

2) ACCOUNTS PAYABLE AND ACCOUNTS RECEIVABLE —

available now

3) GENERAL LEDGER —orders now being accepted

Each book sells for $15.00, and includes source listings in Wang BASIC,program and system documentation, and user's manual. Each is acomplete package by itself, or all three may be implemented together to form a complete system with interdepen-dent files.

And if Wang BASIC won't work, or you don't know programming, or you'd rather not key in thousands of words ofsource code, take a look at the list of consultants who have adopted O&A programs, converted them to run onmany popular systems, and are waiting to hear from you.

CP/M CBASIC: GOOD NEWSfor CONSULTANTS, COMPUTER STORES AND SOFTWARE HOUSES

ne & Associates is converting its business software from Wang BASIC - as it was originally published - to CP/M CBASIC, which runs onmany floppy disk-based microcomputer systems. We will only sell the CP/M magnetic sun ace tc consultants, computer stores and softwarehouses. Osborne & Associates prefer to write and sell books, not customize the programs or answer the end user's questions. The disk for eachbook sells for $250.00. Once you buy the floppy disk you can copy it, resell it, change it or use it. We place no restriction on the magnetic sur-face; we copyright only the printed word in our books. CBASIC Payroll is available now. All three systems are scheduled to be available by theend of 1978; call or write for the exact availability of each system.

If you are an end user interested in

the CBASIC programs, write or call

us. We will put you in touch with your closest dealer.

DIGITAL GROUP:

MITS 4.1 BASIC:

MICROSOFT disk BASIC:

Wang BASIC on floppy disk:

John Musgrove

William K. Haines

Dan Kindred

Richard Armour

MUSGROVE ENGINEERING

ANACOM GENERAL CORPORATION

GNAT COMPUTERS, INC,

ATLANTIC COMPUTER & CONSULTING

9547 Kindletree Drive

1160 E. Ash Avenue

7895 Convoy Court

1104 Sparrow Road

Houston, TX 77040

Fullerton, CA 92631

San Diego, CA 92111

Chesapeake, VA 23325

(713)466-3486

(714)992-0223

(714) 560-0433

(804)764-3412

DIGITAL GROUP Z80. Oasis BASIC:

NORTH STAR:

CP/M CBASIC:

TRS 80:

Charles Finn

Alan P. Hald

OSBORNE & ASSOCIATES, INC

Jim Smith

THE SYSTEMS GROUP

BYTE SHOP OF ARIZONA

630 Bancroft Way

READY CORPORATION

2993 Boring Ridge Drive

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Berkeley, CA 94702

2502 Cade Madras

Decatur, GA 30034

Tempe, AZ 85281

(415)548-2805

Pleasanton. CA 94566

(404)289-8969

(602)967-1428

MICROPOLIS, PROCESSOR

(415)462-4381

IBM 6110:

TRS-80:

TECHr NORTHSTAR:

Mark Sherman

Don French

David Price

DATA WORKS

TANDY COMPUTERS

3901 Victoria Lane

35 E. Wacker Drive, Suite 1843

700 One Tandy Center

Midlothian, VA 23113

Chicago, IL 60601

Fort Worth, TX 76102

(312)726-2572

(817) 390-3011

""

ef*

Osborne & Associates, Inc.

P.O. Box 2036, dept. 115Berkeley, CA 94702 USA

(415)548-2805TWX 910-366-7277

ZIP Pr-

G } am a dealer interested tn purchasing CBASIC programs for resale Pleasesend description and order informationI for:

Q CBASIC Payroll \

D ! am an end user interested tn running CBASIC programs. Please notifyme of the closest dealer for:

ith Cost Accounting

O CBASIC Accounts Payable'ReceivableO CBASIC General Ledger

TITLE

09-8 Payroll with Cost Accounting

13-8 Accounts Payable/Receivable

20-9 General Ledger

PRICE

QUANTITY

$15.00

$15.00

$15.00

SHIPPING (Shipping for large orders to be arranged)

□ All foreign orders $3.00 per book for airmail

D $0.35 per book 4th class (allow 2-3 weeks in the U.S.)

D $0.75 per book UPS in the U.S. (allow 10 days)

D $1.50 per book special rush shipment by air in the U.S.

Please send the following information:

□ Becoming an O&A dealer

D School discounts

D List of foreign distributors

D Other O&A publications

Payment in advance must be enclosed for purchasesof up to $70.00. invoicing U.S. purchases over $70.00avatiable upon approval of your account AH foreignorders must be prepaid in U.S. dollars drawn on a U.S.bank.

California residents tax

TOTAL AMOUNTENCLOSED

Calif, residents aiid 6*>S.f. BART residents i

AMOUNT

■ f%

! on inquiry card.

6Y?tQK*r«&

131

DIVISOR (03= I)D2 Dl DO

v1 v1 0

DIVIDEND

QUOTIENT

A6 A5 A4 A3 A2 Al AO

y y v v ? ? t

REMAINDER

Figure 4: Simple but slow clockless division circuit.

132 December 1978© BYTE Publications Inc

The Microcomputer Bookstore AITC

25 Route 101 West Peterborough NH 03458 IBP I I H^P

Best Sellers

*

*

*

*

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—Getting Involved With Your Own Computer by Leslie Solomon and Stanley Veit answers thequestions: "What can small computers do? Which is best for my purposes?" Whether your interestis business applications, word processing, education, security, etc., this lucid text will bring you intouch with an exciting new world destined to affect us all. $5.95.

The Thinking Computer: Mind Inside Matter by Bertram Raphael. Artificial intelligence, or Al,

is the branch of computer science concerned with making computers "smarter." It is a growing,vital field that is, unfortunately, the subject of much popular misunderstanding. This book is alucid introduction to Al that does much to overcome this misunderstanding. With a minimum oftechnical jargon, it discusses the capabilities of modern digital computers and how they are beingused in contemporary Al research. It discusses the progress of Al, the goals, and the variety ofcurrent approaches to making the computer more intelligent. $6.95.

BASIC Computer Games: Microcomputer Edition edited by David H Ahl. Here are 102 classic

computer games, every one in standard microcomputer BASIC; every one complete with large,legible listing, sample run and descriptive notes. All the classics are here: Super Star Trek (oneof the most challenging versions anywhere), Football (two versions). Blackjack, Lunar Lander(three versions). Tic Tac Toe, Nim, Life and Horserace. This revision of 101 BASIC ComputerGames is a real must, even if you own the original. $7.50.

BASIC and the Personal Computer by Thomas A Dwyer and Margot Critchfield. A fascinating

book covering many areas of interest to the personal computer user. After giving an in-depthcourse in BASIC, which can be covered in 8 hours, the book discusses microcomputer hardware,graphics, word processing, sorting, simulation and data structures. This is an easy to read textthat is useful for the beginner and informative for the advanced user. 438 pp. $12.95.

—Scientific and Engineering Problem Solving With The Computer by William Ralph Bennett Jr isone of the most exciting books we've seen in years. Besides teaching BASIC, this lively, lucid bookpresents a wealth of imaginative and unusual applications programs taken from many disciplines (Asample exercise: "Using the algorithm in the text with the pair-correlation matrix from Hamlet,compute the most probable diagram path which starts with the letter T"). The exercises run thegamut from random processes to the dynamics of motion, from entropy in language to the Water-gate problem. You'll discover BASIC applications in lasers and in the Fourier series and the law(!). In its diversity and elegant style, it ranks with Donald Knuth's works as a milestone in the artof computing. Hardcover $19.95.

Computer Power and Human Reason by Joseph Weizenbaum. This book is one which should be

purchased or read for several reasons. If you're presently a programmer by trade or skill, you'll seea philosophy of computer use and abuse propounded. It's genuinely interesting, and definitelyprovocative if you reference the storm of letters, counter letters and counter counter letters whichthis book produced in the Association for Computing Machinery's SIGART newsletters during1976. If you're a novice to the field, the tutorial and explanatory chapters of this book, which areaimed at the layperson, will serve as an excellent background source which is also eminently read-able. This includes an excellent and low level explanation of what an algorithm is, and how com-puters go about executing effective algorithms. $5.95.

Praised by many critics as the best books in their field, The Art of Computer Programming,Volumes I, II and III, are part of a projected seven volume omnibus survey of computer sciencenow being completed by Donald E Knuth.

Volume I, Fundamental Algorithms, begins with a thorough discussion of the mathematics used

in computer programming, followed by a treatment of information structures, stacks, arrays,linked lists, dynamic storage allocation, and trees. 634 pp. $21.95.

Volume II, Seminumerical Algorithms, is concerned with random numbers, statistical tests,random sequences, as well as arithmetic (floating point and multiple precision), polynomials, andrational arithmetic. 624 pp. $21.95.

Volume III deals with Searching and Sorting, and as the name implies, the emphasis is on algo-rithms for sorting, including combinatorial properties of permutations, internal sorting, optimumsorting, and external sorting. Also included is a section on sequential searching, hashing, digitalsearching, and more. 722 pp. $21.95.

A hypothetical assembly language called MIX was developed by the author to illustrate pro-gramming examples throughout the series. MIX is easily convertible to other assembly languages.

Professor Knuth writes with style and wit. This classic work belongs on the reference shelf ofeveryone seriously interested in computer science.

*

yy^hltotifWMn

Computer

BasicComputer

******************

For your convenience in ordering, please use this page plus the order form on page 138. You may photocopy this page.DIAL YOUR CHARGE CARD ORDERS TOLL-FREE 1-800-258-5477.

Circle 35 on inquiry card.

BYTE December 1978 133

DIVISOR (D7=l)

f "\

D6 D5 D4 D3 D2 Dl DO

g g g g g

A4 B4 A3 B3 A2 B2 Al BlIC2I 7483A

24

23

22

21

IE

A4 B4 A3 B3 A2 B2 Al Bl

IC22 7483A

C4 24 23 22 21 C°

DIVIDENG

A7 A6 A5 A4 A3 A2 Al AO

g g g g g g

u

TE

13

16 3 4 8 7 10 II

A4C4

B4 A3 B3 A2 B2 Al BlICI9 7483A

24

23

22

21

CO

15 2 6

0

07

AOAlA2A3A4A5A6A7

B7 B6 B5 B4 B3 B2 Bl BO

8 BY 8 MULTIPLIER(SEE CAPTION)

PIS PI4 PI 3 PI2 PI I PIO P9 P8 P7

16 |3

io pT

A4

C4

B4 A3 B3 A2 B2 Al BlIC20 7483A

24

23

22

21

CO

0

15

Q6 Q5 Q4 Q3

0

02

n

0

Ql

QO

ROUND

QUOTIENT

134 December 1978 © BYTE Publications Inc

is positive, the multiplexer transmits thisdifference. The quotient bits are the samebits that set the multiplexers. This method isstraightforward and provides a remainder,but has the disadvantage of being relativelyslow.

A more elegant clockless divider makesuse of the relation 1/(1— r) * 1 + r, providedthe absolute value of r is much less than 1.The error in this estimate is r2, as can beseen by multiplying each side of the approxi-mate equality by (1—r). Suppose an 8 bitdividend (A = 3735353433323^) is to bedivided by an 8 bit left-adjusted divisor(D = dyd6d5d4d3d2dido) to yield an 8 bitinteger quotient Q. Let:

r=(23-d2d1d0)/[23(d7d6d5d4d3+l)].

This mesns thst:

D=(d7d6d5d4d3+1)(23)(1-r)

Q = 27(A)/[(d7d6d5d4d3+1)(23)(1-r)]f

Q~24(A)(1+r)/(d7d6d5d4d3+1).

Since d7 equals 1, r is less thsn 23/(23 x 24)or 2~4, 3nd r2 is less th3n 2~8. Q in this3pproxim3tion is accurate to at lesst eightbits. Let:

I =2l2/(d7d6d5d4d3+1)

3nd]=2l2/(d7d6d5d4d3+1)2

e3ch rounded to the nearest integer. ThenQ is approximstely equal to 2~8(A)[I+(23-d2d1d0)(2-3)(J)] and the divisionproblem has been reduced to addition andmultiplication once I, J and (23—d2d1d0)have been determined.

This last qusntity is easily derived fromfour simple gates, as illustrated in the com-plete divider of figure 5. The quantities I 3ndJ 3re listed in table 1 for all possible valuesof d7d6d5d4d3. These 3re found to 9 bitand 5 bit accurscy, respectively, to insure8 bit sccurscy in Q after the intermediate

Table 1: List of I and Jvalues for 8 bit dividercircuit of figure 5.

Figure 5: Faster 8 bit clockless divider. The4 by 5 multiplier is the circuit of figure 3.The I and J values are obtained from a set ofgates or a lookup table. The results beinglooked for are the values given in table 1.The 8 by 8 multiplier is the only device notpreviously discussed. The multiplier is com-posed of bit slices; the theory behind themultiplication circuits can be found in theTTL Data Book for Design Engineers, pub-lished by Texas instruments Inc. The devicenumber is SN54LS275, found on page 7-391of the 1976 edition.

Table 2: Power connec-tions for integrated cir-cuits used in figures 1 thru5.

Power Wiring Table

UPPER D

I

j

d7d6d5d4d3

l8i7iei5l4i3i2iilo

14J3J2HJ0

1 0 0

0

0

111100010

11100

1 0 0.

0

1

111000111

11001

1 0 0

1

0

110101111

10111

1 0 0

1

1

110011010

10100

1 0 1

0

0

11 0000 1 1 0

10011

10 1

0

1

101110100

10001

1 0 1

1

0

101 100100

01111

1 0 1

1

1

101010101

01110

1 1 0

0

0

10100 1000

01101

1 1 0

0

1

100111011

01100

110

1

0

100101111

01011

110

1

1

100100101

01010

1 1 1

0

0

100011010

01010

1 1 1

0

1

100010001

01001

1 1 1

1

0

100001000

01001

1 1 1

1

1

100000000

01000

Number

Type

+5 V

Gnd

IC1

74284

16

8

IC2

74285

16

8

IC3

7483A

5

12

IC4

7483A

5

12

IC5

7483A

5

12

IC6

7408

14

7

IC7

7408

14

7

!C8

7408

14

7

IC9

7408

14

7

JC10

7483A

5

12

IC11

7483 A

5

12

IC12

7483A

5

12

1C13

7483A

5

12

IC14-

7402

14

7

IC15

7402

14

7

IC16

7402

14

7

1C17

7402

14

7

iC18

7402

14

7

IC19

7483A

5

12

IC20

7483A

5

12

1C21

7483 A

5

12

IC22

7483A

5

12

JC23

7427

14

7

IC24

7432

14

7

IC25

7486

14

7

IC26

7483A

5

12

IC27

7483 A

5

12

IC28

7483A

5

12

IC29

7483 A

5

12

1C30

74157

16

8

IC31

74157

16

8

IC32

74157

16

8

IC33

74157

16

8

!C34

7432

14

7

JC35

7404

14

7

1C36

7404

14

7

IC37

7404

14

7

December 1978©BYTE Publications Inc

135

steps. I and J may be determined for a givendivisor by a lookup process or by a suitablearrangement of gates. Of course, the entiredivision may be performed by looking upthe inverse of the 8 bit divisor and then mul-tiplying, but the method described here usesone eighth the memory space and onlyslightly more circuitry.

This process uses the inverse of a smallnumber to find the inverse of a larger num-ber, and so suggests a procedure for handlingthe division of numbers of arbitrary size.Such multiple-precision calculations couldbe performed by expanding the kind ofhardware described here, or by an iterativesoftware routine. Remainders are notdirectly available from this circuit, and mustbe obtained by subtracting the product ofthe quotient and divisor from the dividend.

The requirement that the divisor be left-adjusted is something of a nuisance; dividersgenerally need a restriction of this sort tokeep the calculation in range of the hard-ware capability. Methods exist to make thisadjustment and the subsequent adjustmentrequired in the quotient without the use ofclock pulses. These cumbersome circuits willnot be described here.

Is any of this useful to the small systemsowner? Most microprocessors do not havemultiplication or division instructions. Prod-

ucts and quotients are obtained throughtime-consuming subroutines. Computergenerated music or animated video displaysmay not permit sufficient computation time.Such real time outputs would be feasible ifthe fast circuits described here were incor-porated into an external arithmetic unit andaccessed through the input/output (10)ports of the microcomputer. Then a divisionwould be performed by the following:

• Output the divisor to the externalarithmetic unit divider.

• Output the dividend to the externalarithmetic unit divider.

• Input the quotient from the externalarithmetic unit divider.

• Input the remainder (if desired) fromthe arithmetic unit divider.

Holding registers are required for the divi-sor and dividend. If 8 bit arithmetic is used,the entire calculation can be performedeasily in the time taken by the input andoutput instructions."

Editor's Note:

These circuits are theoretical. Theyhave been designed but not implementedby the author... ,RGAC,

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The Scelbi/BYTE Primer isdivided into four logical sec-tions, that take you from point"0" through building and pro-gramming your own computer...step-by-step-by-step.

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^

Periodical Guide for Computerists, January-December 1977,

by E. Berg Publications. This is a comprehensive index of all the ar-ticles, book reviews, editorials, letters, record reviews, and miscella-neous small inserts and notes from the top 25 magazines in the field.Several thousand articles are grouped into over 60 subject categoriesthat are listed alphabetically for easy reference. At the back is an au-thor index, including the major areas of their expertise. An indispen-sable guide for anyone in the fields of personal computing, amateurradio, and electronics. 72 pp. $5.00.

Robots on Your Doorstep by Nets Winkless and Iben

Browning. "This book will amaze you, frighten you, nauseate you,excite you...it will probably make you think about things you havenever contemplated before," states the introduction to this cleverand well-written account of robots: past, present, and future. Intelli-gence, artificial intelligence, brain structure and simulation, andcharacteristics of robots are only a few of the areas explored. Onechapter is devoted to the personal computer revolution and how ithas brought robots into the amateur's workshop. 1 79 pp. $6.95.

Programming in PASCAL by Peter Grogono. This book is an

excellent introduction to one of the fastest growing programminglanguages today. The text is arranged as a tutorial containing bothexamples and exercises to increase reader proficiency in PASCAL.Besides sections on procedures and files, there is a chapter on dy-namic data structures such as trees and linked lists. These conceptsare put to use in an example bus service simulation. Other examplesrange from the Tower of Hanoi problem to circumscribing a circleabout a triangle. Programming in PASCAL is sure to hold the read-er's interest. 359 pp. $9.95.

Z80 Programming for Logic Design by Adam Osborne, Jerry

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_8080A/8085 Assembly Language Programming by Lance A.

LeventhaL This book provides an introduction to assembly languageprogramming for the 8080A and the 8085 processors. Included aresections on the instruction sets for the two processors, assemblers,simple program examples, code conversion, tables and lists, subrou-tines, IO, interrupts, program design, and debugging. Many examplesand illustrations are included to cover critical points. 467 pp. $8.50.

How to Profit from your Personal Computer by Ted G. Lewis.

If you have wanted to use your personal computer in a profitablemanner, and you feel you need some help planning programmingtechniques for common business applications, this book is for you.Enjoyable and readable, it contains suggestions for accounting, pay-roll handling, inventory management, and sorting mailing lists. Manyterms and notations are explained. Sample programs in BASIC, theuse of blueprints to design program structure, and a full glossary ofterms are a few of this book's special features. 191 pp. $7.95.

SARGON by D. and K. Spracklen. A complete computer chess

program that won the 1978 West Coast Computer Faire ChessTournament. Highly praised in the 9/78 issue of Personal Com-puting. Available early November. 120 pp. $14.95. (No photo)

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Microcomputer Primer by Mitchell Waite and Michael Pardee.

Here's a microprocessor tutorial for readers having some electronicsbackground. Microcomputer Primer concentrates on the hardwareof microcomputers (although there are sections dealing with soft-ware) with chapters on basic computer concepts, hardware, pro-gramming, memories, and number systems. A full complement ofphotos and schematics accompanies the text. 224 pp. $7.95.

Programming a Microcomputer: 6502. This informal, well-writ-ten book may be just what you need to enter the world of micro-computers. Caxton C. Foster uses the 6502 as a basis for discussingthe techniques of writing programs. The chapters include simple,practical example programs for creating a Morse Code oscillator,combination lock, tune player, digital clock, and more. The empha-sis is on clarity, and the many illustrations and flowcharts help getthe author's points across. 231 pp. $9.95.

Programmable Calculators by Charles J. Sippl and Roger J.

Sippl. This large (526 pages) book is an exhaustive survey of theprogrammable calculator field covering its history and presentstatus. Chapters deal with the basic calculator, advanced hand-held products, RPN (Reverse Polish Notation) versus algebraicnotation, desktop calculators, and programming the program-mable calculator. Examples and illustrations abound in this use-ful reference work. $14.95.

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The First West Coast Computer Faire Conference Proceedings,

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Up your Own Organization! by Donald M, Dible. A great hand-book on how to start and finance a new business, this is the mostcomprehensive reference we've seen on the subject. For the pro-grammer-consultant or the basement homebrewer-turned-entrepre-neur, this is your book. It is recommended in the Bank of AmericaSmall Business Reporter and Changing Times magazines. 372 pp.Available for $14.95 in hardcover.

Fundamentals of Recordkeeping and Finance for the Small

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BYTE December 1978 139

Creating a Chess Player Part 3:CheSS 0.5 (continued)

Listing I: The second halfofChess 0.5, written in Pascal. This portion of theprogram covers evaluation of terminal nodes, the iook-ahead procedure anduser commands (fisting 7 continued on page 146).

Larry R Atkin

Health Information Services

542 Michigan Av

Evanston IL 60202

Peter W Frey

Dept of Psychology

Northwestern University

Evanston IL 60201

PROCEDURE EVALU8S

!•

EVALUATE CURRENT POSITION

VAR

INTV t tv;

<•

SCORE ')

FUNCTION EVKINGfAiRStBIRSMTV;

EVALUATE KING •>KING BIT BOARD *1FRIENDLY PAHN BIT BOARD •»

VAR

INTS 1 ts;inrs t rs;

INTV l TV1

1*

SCRATCH •»SCRATCH •!SCRATCH M

BEGIN

ANORS(INRS*A,C0RNRI ;IF NULRSCINRS) THEN

INTV t- 0ELSE

INTV ■■ fksanq;

KING NOT IN CORNER •»KING SAFELY IN CORNER ♦!

INRS 1- A(

IF HXTTSUNRS,INTS> THEN

BEGIN

ANQRS(INRS,ATKFRCINTS1,B)IINTV 1- INTV ♦ CNTRSUNRSH

end;

I*

•FKPSH01|R

FINO PANNS NEXT TO KINS •>CREDIT EACH CLOSE PAHN M

EVKING l* INTV;ENDS !• EVKING M

!•

RETURN KING SCORE •>

FUNCTION EVHOBLU,8lTP> itv:

EVALUATE HOBILITY MPIECE TYPES TO EVALUATE *1

VAR

inrs t rs;

INTS 1 ts;

intv i tv:

SCRATCH MSCRATCH •)SCRATCH •>

BEGIN

lORRSUNRS.TPLOCIAI.TPLOClBli: !• HERGE PIECE TYPES *)

INTV I* o; (• INITIALIZE COUNT •»

MHILE NXTTSIINRS,INTS1 00 <• COUNT ATTACKS •!

INTV t* INTV ♦ CNTRSCATKFRIINTS11 X

EVHOBL I* INTV; !• RETURN TOTAL ATTACKS •>

END; (• EVHOBL •!

FUNCTION EVPAHN

l»

EVALUATE PANNS •!

(ItftSt

!•

LOCATION OF PAHNS «t

BtTEt

(•

PAHN FORHARO DIRECTION •>

citrhtv;

f *

PANN HONE RANK •>

VAR

INRS I RSt

e»

SCRATCH •)

INRS t RSt

(•

SCRATCH •!

INTS I TS1

f

SCRATCH •!

INTV t TV?

!•

SCRATCH •}

BEGIN

SFTRSUNRS,

A.sn :

ANORSIINRS.

INRS.AIf

<•

BIT SET FOR SIDE BY SIDE •!

INTV !■ CNTRSUNRSI*FPFLNX;

«•

SCORE PHALANX •»

SFTRSUNRS,A,81) ;

ANORSIINRS,INRS.AI? I* BIT SET FOR PAHN DEFENSE •)

INTV I* INTV ♦ CNTRSIINRSI»FPC0NN; !• CREDIT CONNECTED PAHNS M

SFTRSUNRS,A,B2W

ANORSIINRS,INRS*Alt

INTV f* INTV * CNTRS(INRS>*FPC0NN1 (• AND OTHER CONNECTED PAHNS •!

SFTRSUNRS, A.BI tNOTRSIIHRS.TPLOCtNTll JANORStINRS.INRS.IHRSIt

intv i* intv - cntrsiinrs»»fpblok:

!• HOVE FORHARO •>

(• OCCUPIEO SQUARES »l

t* BLOCKED PAHNS •>

f PENALIZE BLOCKED PAHNS M

CPYRSUNRS.A) I

while NXTTSflNRS.INTSI 00 f* FOR EACH PAHN •}

INTV I* INTV *IABSIORO(Cl-0R0IXTSRHNTS|>ll«FPADCRIXTSFtINTSIM

(• CREDIT PAHN AOVANCEHENT M

EVPAHN i. I NTV{END; f* EVPAHN *>

f* RETURN PAHN SCORE *l

This month we conclude the listingand commentary of Chess 0.5 begunlast issue. The program was written byLarry A thin, who is coauthor with DavidSlate of the world championship chessprogram, Chess 4.6. The program isreadily adaptable to personal computershaving Pascal systems such as the UCSDPascal project software. Part 4 concludesthe series with a discussion of chessstrategy and tactics.

Evaluating Terminal Positions

Another important aspect of any chessprogram is the function which provides astatic evaluation of terminal positions in thelook-ahead tree. In the present program, thisroutine also doubles as a preliminary scoringfunction for sorting moves at the first ply, atthe beginning of the look-ahead search.Since the evaluation function is used repe-titively in the search, efficiency demandsthat it be carefully engineered. We have leftthis task as an exercise for the reader. Ourfunction presently includes only a few basicessentials.

The most important feature is material.We employ essentially the same function forthis that is used by Chess 4.5. A trade-downbonus is also incorporated, ie: trade piecesbut not pawns when ahead in material. Asecond feature which is considered is piecemobility. The mobility of Knights andBishops is weighted more heavily than thatfor Rooks and Queens. Special credit isgiven to a King which is located in one ofthe four corner squares in each corner ofthe board, ie: 16 squares total. This encour-ages early castling. Pawn structure is con-sidered by providing a bonus for advancingthe pawns in the four center files, for hav-ing a pawn near the King, and for having apawn adjacent to or defended by anotherpawn. This indirectly penalizes isolated orbackward pawns. There is a direct penalty

140

December 1978 © BYTE Publications !nc

if the square in front of a pawn is occupied.The position of the Rooks is considered byproviding a bonus for placing a Rook on theseventh rank and for attacking another Rookof the same color (ie: doubled Rooks). Theexecutive routine for these assessments isEVALU8.

The Look-Ahead Procedure

The look-ahead procedure is controlledby an executive routine called SEARCH.Several subprocedures are also definedwhich handle specific tasks. NEWBSTkeeps track of the move which is currentlythought to be best, and dynamically re-orders the moves at the first ply level eachtime a new best-move is selected. MINMAXdetermines whether the move under con-sideration will produce an a-0 cutoff.SCOREM is called into action when theprogram can find no legal moves at a node.It determines whether the position shouldbe scored as a checkmate or as a stalemate.SELECT is responsible for move ordering ateach node. It determines whether there areany more moves to be searched and if so,makes sure that they are generated in thecorrect order (ie: captures, killers, castlingmoves, and then the remaining moves).

SEARCH incorporates a number of im-portant features which make the look-aheadsearch more efficient. These include stagedmove generation, preliminary orderingscores, setting a narrow a-& window at thebeginning of the search, conducting thesearch in an iterative fashion, and dynami-cally recording moves at the first ply asthe search proceeds. Because of these fea-tures, the full-width search takes a long timeinstead of taking forever.

User Commands

For the user's convenience, the programshould be able to respond to a few simplecommands, inputs to the program are pro-cessed by a lengthy routine, READER,which has many component subprocedures.The translation of the input string is handledby a group of routines: RDRERR, RDRGNT,RDRSFT, RDRCMP, RDLINE, RDRMOVand RDRNUM. Each of the commands isexecuted by a separate routine.

When the human player wishes to termi-nate the game before it has reached its con-clusion (eg: when he is hopelessly lost anddoes not want to stay around to be crushed),he can simply type an END command andthe ENDCMD routine will terminate theprogram. If the user simply wishes to start anew game, he can type I NIT and theINICMD routine will set up for a new game.

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December 1978 © BYTE Publications Inc

141

Circle 353 on inquiry card.

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Users of computers and programmable calculatorsenjoy this magazine! The articles are ofinterest to hobbyists and professionals. Theprograms are accompanied by explanationswritten in clear, logical language. Ourauthors are people who own and use machineslike yours !

"The Recreational Programmer" is issued bi-monthly. It is available by subscription onlyfor twelve dollars per year (domestic), orfifteen dollars per year (foreign).

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If the user would like to set up a specificposition from the previous game or someother game, he can call the BO ACM D rou-tine, which will set up any position he de-sires. To use this instruction, the pieces aredesignated in the standard way (eg: K, Q,R, B, N and P) and the colors are designatedby L for light and D for dark. The board isdescribed by starting at the lower lefthandcorner and listing, row by row, the 64squares. Numbers are used to represent con-secutive empty squares. The command toset up the position after 1. P-K4, P-K4, 2.N-KB3, N-QB3 is: BOARD, LRNBQKB1RPPPP1PPP5N24P34DP33N4PPPP1PPPR1BQKBNR.

If the human player is lazy or simplywishes to test the program, he or she cantype GO and the machine will select amove. By repeatedly typing GO the usercan sit back and watch the machine playagainst itself. The routine that handlesthis is GONCMD. To specify a value forselected program parameter variables, theplayer can use LETCMD. For example, theamount of time the machine spends calcu-lating a move can be controlled by specify-ing a limit for the number of nodes to besearched. The command LET FNODEL =1000 will cause the machine to set a targetvalue of 1000 for the number of nodes tobe searched. In this case it will not start an-other iteration if it has already searched1000 nodes. If the user is confused aboutthe current board configuration, the com-mand PRINT will activate PRICMD whichcalls PRINTB for a representation (8 by 8array) of the board. For diagnostic purposesthe user can also ask for other information.The routine PAMCMD is activated by PBand provides an 8 by 8 attack map for eachof the 64 squares. The routine POPCMD isactivated by PO and gives information con-cerning the side to move (White or Black),the en passant status after the last move, thepresent castle status and the move number.If the user types PM, the routine PMVCMDwill provide a list of all moves which arelegal for the side to move in the current posi-tion. The command PL activates PLECMDwhich prints the value of a designated vari-able; for example, the user can determinethe present limit for the number of nodes tobe searched by typing PL FNODEL.

The user also has control over severalswitches. He can ask the machine to repeat(echo) each entry, to pause after 20 lines ofoutput, and to reply automatically eachtime the opponent enters a move. Theseswitches are set by the switch commands(eg: SW EC OFF), and are processed bySWICMD. If the user wishes to manuallyalter one or more of the status conditions

142 December 1978© BYTE Publications (nc

Circle 307 on inquiry card.

the electric pencil II

^^ © 1Q7R Michael Shraver

TM

The ELect

Word Procesentered asis man i puIeno rmous fhandling ofdeIi nea tedlines or paanywhere ishifts andview of theas well assince lines

ric PenciL II is a Character Orientedsing System,

a string ofated as suereedom and

text. Since

, any numbe

ragraphs may

n the text .

opens up or

user. The t

word hyphe

of text are

This means tcontinuous chh. This alioease in the

Ii ne endi ngr of charact

be i nse rted

The entiretycloses as neeyping of carrnation is no

formatted au

1978 Michael Shrayer

As text is typed in and the end of a screen

hat text is line is reached,, a partially completed word is

aracters and shifted to the beginning of the following line,

ws the user Whenever text is inserted or deleted, existing

movement and text is pushed down or pulled up in a wrap

s are never around fashion. Everything appears on the video

ers, words, display screen as it occurs which eliminates any

or deleted guesswork. Text may be reviewed at will by

of the text variable speed scrolling both in the forward and

ded in full reverse directions. By using the search or the

iage returns search and replace function, any string of

t required characters may be located and/or replaced with

tomatically. any other string of characters as desired.

When text is printed, The ELectric Pencil II automatically inserts carriage returns where theyare needed. Numerous combinations of line length, page Length, line spacing and page spacing allowfor any form to be handled. Character spacing, BOLD FACE, multicolumn as well as bidirectionalprinting are included in the Diablo versions. Right justification gives right-hand margins that areeven. Pages may be numbered as well as titled. This entire page (excepting the large titles andlogo) was printed by the Diablo version of The ELectric PenciL II in one pass.

Now on CP/M

The Electr

is also compI m s a i ' s IMDversions SSHnow ready. Thpac kage is noA utility prconverts PENto PENCIL fi L"CONVERT" is

ic PenciL II

atible withOS. HELIOS

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NEW FEATURES: * CP/M, IMDOS and HELIOS Compatible * SupportsFour Disk Drives * Dynamic Print Formatting * DIABLO as well as NECprinter packages * Multicolumn Printing * Print Value Chaining *Page-at-a-time Scrolling * New Bidirectional Multispeed ScrollingControls * New Subsystem with Print Value Scoreboard * Automatic Wordand Record Number Tally * Cassette backup for additional storage * FullMargin Control * End-of-Page Control * Non-Printing Text Commenting *Line and Paragraph Indentation * Centering * Under I i ning * BOLD FACE *

Available to Imsai VIO video users for a huge 80x24 character screen.These versions put almost twice as many characters on the screen !!!

HAVE WE GOT A VERSION FOR YOU ?

The ELectric PenciL II operates with any 8080/Z80 based microcomputer that supports a CP/M disksystem and uses a Imsai VIO, Processor Technology VDM-1, Polymorphic VTI, Solid State Music VB-1Bor any similar memory mapped video interface. REX versions now available. Specify when using CP/Mthat has been modified for MicropoLis or North Star disk systems as foLLows: For North Star addsuffix A to version number, for Micropolis add suffix B to version number, e.g. SS-IIA, DV-IIB.

Vers

VideoSOL

PrinterTTY or similar

Pr i ce$225.

SS-II

^^

SP-II

VTI

TTY or

similar

$225.

I

Tl

MICHAEL

SHRAYER SOFTWARE, INC.

SV-II

VDM

TTY or

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$225.

m

mm

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SR-II

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Electr

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rs:

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$275.

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UPGRADING POLICY:

Any version of

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$125.

The Electric

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DS

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Diablc

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CUTS

$150.

at any

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by simp

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DP

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original d i s

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DV

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difference between versions

DSN

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CUTS

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$175.

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to MSS

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Tarbell

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$175.

original media at time of pure

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DVN

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$175.

Demand a demo from your dealer!

Circle 319 on inquiry card.

BYTE December 1978 143

(eg: side to move, move number, en passant,castling), this can be done by activatingSTACMD.

Notes on Notation

The program also processes standardchess notation. This is not strictly necessary.Many programs use their own convention forentering and reporting moves. A commonprocedure is to denote the squares using anumber (1 through 8) for each row and aletter (A through H) for each column. Amove is defined by listing the present squareof the piece and then the destination square.For example, the common opening move,P-K4, would be E2E4. Moving the WhiteKnight on the kingside from its originalsquare to KB3 would be G1F3. This con-vention works nicely but it forces an ex-perienced chess player to learn a new sys-tem. Most would prefer standard chessnotation.

Because there are multiple ways to ex-press the same move in standard notation,the translation routine needs to be fairlysophisticated. Consider a position inwhich the White Queen's Rook is on itsoriginal square and the neighboring Knightand Bishop have been moved. A move which

LSI-11 TIME

It's TIME you brought your LSI-11 up to DATE. TIME and

DATE, two important parameters in the computer world, areavailable to your LSI-11 on one DUAL SIZE BOARD. Whenrequested, the TCU-50D will present you with the date (monthand day), time (hour and minutes), and seconds. Turn yourcomputer off and forget about the time — your battery sup-ported TCU-50D won't, not for 3 months anyway. The correctdate and time will be there when you power up.

The TCU-50D is shipped preset to your local time, but can be setto any time you want by a simple software routine.

AT $295YOU CANT AFFORD TO IGNORE TIME

Time is only one way we can help you upgrade your LSI-11 orPDP-11 system. We'd also like to tell you about the others. Socontact Digital Pathways if you're into -ll's. We are too.

DIGITAL P/4THWY1Y9 IMC.

4151 Middlefield Road • Palo Alto,California 94306 • Telephone (415) 493-5544

places the Rook on the Queen Bishop filecan be designated as R-B1, R-QB1, R/1-B1,R/1-QB1, R/R1-B1, or R/R1-QB1. It is im-portant that the program recognize that eachof these character strings represents the samemove. How is this done?

One way is to have the machine generatea list of all legal moves and then compareeach of these with the move entered by theplayer. If his move matches one on the list,that move is noted. The rest of the list isthen checked and if no more matches arefound, the noted move is assumed to be thecorrect one. If no match is found, the ma-chine prints "illegal move/' If a secondmatch is found (eg: P-B3 matches bothP-KB3 and P-QB3), the machine prints"ambiguous move." The process of trans-lating the opponent's move into machinecompatible form and checking its legalityor ambiguity is done by YRMOVE. Theprocess of translating the machine's moveinto standard notation is handled byMYMOVE. Both of these procedures callMINENG, which is responsible for con-structing the appropriating character strings.

Final Thoughts

This completes our listing of our dem-onstration chess program. Despite the pro-gram's length, there are many desirable fea-tures which have been omitted. The readerwith an interest in chess and programmingshould use this listing as a starting point fordeveloping a program. The time requiredfor move calculation can be reduced bywriting machine dependent code for someof the frequently used routines. There arealso features which can be added to improvethe level of play.

One useful addition would be an openinglibrary. An effective technique for this is de-scribed by Slate and Atkin in their chapterin Chess Ski// in Man and Machine (P WFrey, editor, Springer-Verlag, New York,1977). An opening library provides the userwith a challenging set of opening moves anddirects the game into situations which arefamiliar to the experienced chess player. Byincluding various options at the early choicepoints and using a random selection pro-cedure, the programmer can insure that themachine will not always select the samemove sequence. The programmer can alsogive the user the option of specifying aparticular opening against which he wouldlike to practice. For important matches, theprogrammer can prepare surprise openingsfor the machine in order to gain a psycho-logical edge on the opponent.

Text continued on page 157

144

December 1978 © BYTE Publications Inc

Circle 89 on inquiry card.

An advanced desktop data systemfor $1,995? QuitcherkiddinJANO.

We're not kiddin'.

Outpost 11 is exactly that. You get:

• A ruggedly designed unit,intended for heavy use

• Full ASCII keyboard

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• 32K bytes RAM

• M6800 CPUJust like this, for only

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BASIC software package

Over 20 applications packages

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User documentation

oi/rpesr//

COMPLETE

With Outpost 11 and the BASIC softwarepackage, you can:

Do full floating point BCD math # Pro-gram SAVE and LOAD with file names •

Program MERGE and CHAIN ION ERRORstatement • String variables and functions• Trig and math functions • GET, PUT andFIELD statements • Floppy file processor.■ ^" ^™ ^™ ^" Order Form ^™ ■■■ mm ^™ i

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Name

Company/Title

Shipping Address

Telephone

.Signature .

Charge my: D American Express; □ Visa; □ Master Charge: #_

Corporation

4521 W. Napoleon Avenue

Metairie, La. 70001

(504) 888-4884TWX 810-591-5229

Sales Offices: Los Angeles, CA —213/426-73/5 • Montreal, Canada—514/934-0000 • Boston, MA—61Z/969-4650 • Dallas, TX —214/358-130/ • Houston, TX—713/461-0038 • Denver, Col.-303/841-2788 • San Francisco, CA—408/37/-/001 • Chicago, IL—31 2/830-0060• Atlanta, GA —404/252-6609 • Washington. DC—301/589-2802 •

Circle 358 on inquiry card.

BYTE December 1978 145

Listing 7, continued from page 140:

FUNCTION EVftOOK

mirs;

RlRSMTVI

VAR

INTV I TVtINTI I Tit

ints i ts;inks i rs;

BEGIN

INTV t« c;

INRS I* A?

If NXTTSUNRS.INTSI THEN

BEGIN

ANORS(lNRS,A,ATKFRtXNTSHlir NOT NULRS(XNRS) THENINTV •■ INTV ♦ FROUBLtENOl

ANORS(lNRS,A,BI,INTI i> CNTRStlNRSIlEVROOK I* INTV ♦ INTI*INTI»FR«7TM: (* CREDIT ROOKS ON SEVENTH •!end; <• EVROOK •}

!• EVALUATE ROOKS MI* ROOK LOCATIONS •)<• SEVENTH RANK •>

(• SCRATCH •»

<• SCRATCH •!

\* SCRATCH •»

«• SCRATCH •)

!• INITIALIZE •>

(• LOCATE FIRST ROOK »)

1* ROOK ATTACKS FRIENDLY ROOK Ml« GIVE DOUBLED ROOK CREDIT •!

<♦ ROOKS ON SEVENTH •»

BEGIN

IF XTNVIJNTN)*N8VALUNTKI ♦ HAXPS «» BSTVLtJNTK-21 THEN

<• HOVE MILL PRUNE ANYWAY •!INTV I- XTHVIJNTH1 • NBVALIJNTKIELSEBEGIN

INTV t*l FMPAMNMEVPANN<TPIOCCLP1,S2,R2>-EVPAWNITPLOCCOPI.S*>,R7I)

1I

♦ FMHlNNMEVNOSLfLBtl.NI -EVHOOLCDB.OHI

♦ FNHAJHMEVNOBLILR.LQI -EVHOBLIOR,OQ>

♦ FNROOK*<EVR0OK<TPL0CtLRIvXRRSCR7|l

-EVROOK(TPLOCCOR1•XRRSIR21I

♦ FtfKINGMEVKING<TRLOC(LKl«TPLOC(LR]l

-EVKINGITPL0CC0K1.TPLOCCDP1II DIV 6*1HAXPS I* HAXtHAXPS,ABSUNTVI> |INTV I* XTHVIJNTHIMHBVALIJNTK]*INTVIIENOl

IF SNTR THENBEGIN

NRITEf- EVALU0**«JNTK.JNTMvlNOEX(JNTKl9tNTVltPRIHOVtHOVESfIMDEX(JHTKIl»t

eno:

value!index!jhtkii l« intv j i* return score •»eno? c evaluo •>

FUNCTION SEARCH

itn;

LABELlit12.13,16.IS,161

PROCEDURE NEWBSTCAtTKIf

I* SEARCH LOOK-AHEAD TREE MI* RETURNS THE BEST HOVE •!

I* START NEH PLY "I

I* TRY DIFFERENT FIRST NOVE

(• FLOAT VALUE BACK UP •>

<• FIND ANOTHER HOVE •!

!• BACK UP A PLY •>

I* EXIT SEARCH •!

(• SAVE BEST NOVE INFORMATION »1!• PLY OF BEST MOVE •!

VARINTHINRH

TH|

RHI

(• MOVES INDEX «|I* SCRATCH •»

1* SAVE BEST HOVE *>!» AT FIRST PLY "I

BEGIN

BSTHVIA] ■* INOEXCAtlll

IF A « AK THEN

BEGIN

INRM •• HOVESIBSTMVIAll, (• SAVE BEST NOVE •>

FOR INTM I* BSTNV(AI*1 OOMNTO AN*1 00

N0VESIINTN41I i. MOVES! INTM]? !• MOVE OTHER MOVES OONN •»HOVESIAMtll I* INRH! (• PUT BEST AT BEGINNING •>

BSTHVfAKI I* AN»H <• POINTS TO BEST HOVE •»

ENOELSE

IF NOT NOVESCBSTHVtAll.RHCA THEN

KILLRIJNTK1 1= N0VESCBSTHVCA1H (* SAVE KILLER NOVE •»END; !• NENBST •!

FUNCTION MINNAXUITKII TBI

I* PERFORM MINIM** OPERATION •!(• PLY TO MINIMA X AT •>I- TRUE IF REFUTATION •)

<• OEFAULT IS NO PRUNING •>

BEGIN

HINNAX l» FALSE!IF SNTR THEN

WRITE!* NINNAX-,A,-BSTVLlA-l],B$TVLlAl,-BSTVLIA»llMIF -BSTVLtA*il > BSTVLIA1 THENBEGIN

BSTVLtAl i« -BSTVLtA»lIt

NENBSTIAIt !• SAVE BEST HOVE •)

MINHAX I. OSTVLIAU) «• BSTVLfA-l||

I* RETURN TRUE IF REFUTATION •!IF SNTR THEN

WRITE!" NEN BEST, PRUNEt -,6STVLfA.il «- B$TVL{A-lll|EMOtIF SNTR THEN

HRITELNI «• PRINT TRACE LINE •!

ENOl I* MINHAX •}

PROCEDURE SCOREM|

(• SCORE HATE •>

BEGIN

HOVEStINDEXtJNTKU.RHHT I* TRUE J !• IHOICATE HATE •!IF HOVESt iHOEXtJNTKU.RHCH THEN I* CHECKMATE •>

VALUEIINOEXIJNTK11 ■> 66«JHTK - 2VELSE (• STALEMATE •>

VALUEIINOEXIJNTK11 l« ||IF SNTR THEN

NRITELNC* SCOREH-,JNTKcJNTNtXNOEX[JNTKJtVALUECXNOEX!JNTKI]lfEND: »• SCORER •!

FUNCTION SELECT■ TBI

LABEL21.ttl

VAR

INTB IXNTK •

INTM IINTH IINTV I

TBITKtTNI

TNITV |

PROCEDURE SELOONI

BEGIN

INTB l« FALSEl

IF SNTR THEN

HRITELNI" SELECT"

COTO 22|ENOl <• SELDOM •>

PROCEDURE SELNOV

(AlTHIf

!• SELECT NEXT HOVE TO SEARCH •!<• TRUE IF MOVE RETURMEO •»

I* HEM SEARCH MOOE •>!• EXIT SELECT •!

!• RETURN VALUE •>

I* SCRATCH ♦)

(• HOVE INDEX ••

<• SCRATCH •!

I* SCRATCH M

Is SELECT EXIT - DONE.

CALLED HHEN HO FURTHERHOVES ARE TO BE SEARCHEDFROH THIS POSITION,THE CURRENT POSITION HUSTHAVE BEEN EVALUATED. •>

!• RETURN NO MOVE SELECTED M

END.-It

!• EXIT SELECT •!

Is SELECT EXIT - SEARCH,CALLEO HHEN A HOVE TOBE SEARCHED HAS BEENFOUND, •)

!• INDEX TO SELECTEO HOVE •>

<• RETURH HOVE SELECTEO •!!• POXHT TO SELECTED HOVE •!!• FLAG HOVE AS SEARCHED *l

BEGIH

IHTB l« TRUE!INOEXtJHTK*ll I* At

HOVEStAl.RHSU •» TRUE I

IF SNTR THEN

BEGIN

NRITEf- SELECT-, JNTK,ORO(SRCHHt JNTKII.AIt

PRIMOVtHOVESfAlMEND*

SOTO 221 <• EXIT SELECT •!

ENOl f* SELNOV *l

PROCEDURE SELNXT

(AlTHlt

BEGIN

INDEXtJNTK»ll I* LIHDXIJNTK1-11

SRCHNCJNTK1 Is At

GOTO 21|END! <• SELNXT •!

PROCEOURE SELANV;

VAR

INTN | TM-,

BEGIN

FOR INTH is INDEX(JNTK*11*L TO JNTW-1 00IF NOT HOVEStIHTMl.RHSU THENSELHOVtlNTHIIENOl !• SELANY •!

BEGIN

211 <• NEN SEARCH MODE *lCASE SRCHMIJNTKI OF

HOI C INITIALIZE FOR NEN NOVE *lBEGIN

HVSELUNTK1 •• BtINTV Is BSTVLIJNTK-21tBSTVLIJNTK-ZI |« -ZV|HAXPS •• 01

<• SELECT EXIT - MEN MOOE.CALLEO HHEH A HEN SEARCHHOOE IS TO BE SELECTEO •)

I* HEN SEARCH MOOE •!

<♦ RESET HOVES POINTER M(• CHANGE SEARCH HOOE •!I* EXECUTE NEXT NOOE •>

I* SEARCH ALREAOY GENERATEDANO NOT ALREAOY SEARCHED •>

C HOVES INOEX •»

(• CLEAR HOVES SEARCHED *>

<• SAVE ALPHA «}

I* INHIBIT PRUNING IH EVA4.U6 •>

I* INITIALIZE NAXIHUH POSITIONAL

SCORE •!!• GEHERATE ALL MOVES •!

GENALL!

FOR INTH ■» AN»1 TO JNTM-i 00

BEGIN

IF UPDATEtHOVESIlHTHII THEH

BEGIN

INOEXIJHTKI la INTH| I* POINT TO CURRENT HOVE •!EVALUOt I* SCORE POSITION M

EHOt

DNDATEfHOVESClNTHII |END!

BSTVLIJHTK-2I I- INTVI I* RESTORE ALPHA •»SORT IT iVALUE,HOVES,JN T M-l I t

I* SORT PRELIMINARY SCORES •»FOR IHTK I- AK TO ZK 00

KlLLRtlHTK] I- NULNVt I* CLEAR KILLER TABLE •>

146 December 1978 © BYTE Publications Inc

..IT"

oooo

oooo

oooo

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oooo

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oooo

oooo

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00 20002D

002*>002O

CIS

$**«-****'■

SToc*i.s*c

..CIS COftOL V2-" 0IV1S10«. „,.

°o0o0oo*°o %»gg2U. SSS-

000120 RECORD K«00013° 01V1SI0H.000140 OKTK °ECTI0«. RECORD 3*'

000210 2 ^S1 EF^5^ M M ■■■LB ■■

000*00 °022 c.f-s;o«c 6, ^ ^^ B^ ^^ BHf

000310 02 FI^r00-DeS^m

000320 °02 S&U»*>C ">*&.•*"'

000310 Q2 fggjMJ* *»

000340 o2 CRT « JC x.

0003S0 02 rlUjS*

000360 pBOCE0ORE °lVT00003SOSR1-OISP^SP^F E

°o« »£*^S •

000430 0lSP^oOtS - -o ESD-I'

000480 rtQVE Cg0lT.SlZ6T STOCK C c0*rECT *

oSS «^giM •lSS? ■ pog^- ■ Fr°m Micr° F°CUS Ltd'

000550 DISP^ =El50 OF **<*

000560 DISP^.

ooo580 ^f CIS COBOL is the Compact, Interactive, Standard COBOL which offers

* El*° for the first time a cost-effective key to full commercial use of micro-

computers.

It can be used simply and naturally, offers facilities unavailable withother forms of COBOL, and produces efficient code without wastingspace. For example, a 32K byte sytem is sufficient to run the compileror a substantial application program.

CIS COBOL contains the most relevant parts of the ANSI 74 standardplus extra facilities to provide a powerful interactive business language.

The CIS COBOL Object Pack is available for shipment on IBM compatible diskette to users of avariety of 8080/Z80 based computers running the CP/M* or ISIS* Operating Systems.

Dealer and Appfication Vendor terms are availableEvaluation copy $500 in USA, 2 weeks delivery, payment by cheque, American Express or Visa.

Micro Focus offers a CIS COBOL licencing package to OEM's including access to internal docu-mentation and program source plus an interfacing Kit to enable CIS COBOL to be implementedquickly in the OEM's own hardware and software environment. The CIS COBOL compiler isitself written in COBOL making it self compiling and thereby extremely portable.

MICRO FOCUS LTD 58 Acacia Road, London NW 86AG, ENGLAND, UKTelephone 01-702-8843 TLX 28536

* CP/M is a trademark of Digital Research and ISIS is a trademark of Intel Corporation.Circle 216 on inquiry card. byte December 1978 147

oonooib

002F

0030

0036

00AO

004E

0065

006F

ooii

OOTD

0083

0089

009T

0G9&

009B

009F

00*3

00B4

Listing 7, continued:

H2t

IF SHTR OR SHPS THEM

FOR INTN %• AN*1 TO JNTW-1 DOBEGIN

WRITE I- PRELlH-,IMTW,VALUE(INTlin!

PRIHOVINOVESIINTW]*! (• PRIMT PRELIMINARY SCORES •>IF INTM/LPP ■ INTM OIV LPP THENPAUSERIENO!SELNXT(H6»| (• SEARCH ALL MOVES •)

END!

f* INITIALIZE AT NEH DEPTH «|BEGIN

HVSELIJNTK) l« BS (• CLEAR NOVES SEARCHEO •!

IF JNTK y JNTK THEN

BEGIN

EVALUA! (• EVALUATE CURRENT POSITION »1

INDEXIJNTK»1) I* AM;

BSTVLIJNTOIJ t- -VALUE! INOEXIJNTK ]] I

IF HINHAX(JNTK) OR (JNTK * ZKI THEN

SELOONfSRCHHIJNTKI I* HZ;ENOELSE

SRCHHIJNTK1 I- H3!GENCAP;

SELNXTfSRCHNt JNTK1MEND?

!• THIS HOVE PRUNES •»(• CAPTURE SEARCH •>

(• CAPTURES IN FULL SEARCH •»(• GENERATE CAPTURES •)(• CHANGE SEARCH HOOE M

(• CAPTURE SEARCH •>BEGIN

INTM i= am;INTV I* AVt

FOR IMTW I* LlNDXUNTKl TO JNTW-1 DONITH NOVES!IMTW] 00IF NOT RHSU THEN

IF ABStXTPVCRHCPJI > INTV THENBEGIN

INTV is ABSIXTPVtRHCPl)|

INTH I- INTM?

end;

IF INTH <> AM THEN

SELNOVtINTMlELSE

SELOONSEND!

(• BEST HOVE POINTER •>(• BEST VALUE •!

(• MOVE FOUND •!

f SELECT BIGGEST CAPTURE •!

«• QUIT •»

I* FULL MIDTH SEARCH • CAPTURES •)BEGIN

INTM I- AH| |* BEST MOVE POINTER •»

INTV t» AV; |» BEST VALUE M

FOR INTM I- LlNDXUNTKl TO JNTM-1 00MITH MOVES!INTM1 00IF NOT RHSU THEN

IF ABSUTPVIRHCPl) > INTV THENBEGIN

INTV t* ABStXTPVtRHCPJM

I* MOVE FOUNO •»

(• SELECT BIGGEST CAPTURE M

INTM i» INTN;

end:if inth <» am thenselmovuntmi

ELSE

IF NOT NULHVB(KlLLR(JNTK]> THENBEGIN

IMTW i* JNTW; !• SAVE CURRENT MOVES INDEX ♦►

GENFSLURSSIKlLLRtJNTKI.RHFRn 1

!• GENERATE MOVE BY KILLER •>SRCHHIJNTKI §■ H»t !• SET NEXT SEARCH NODE •»

FOR INTM l= INTM TO JNTM-1 00

(• LOOK AT MOVES BY KILLER •»IF KILLRIJHTKl.RHTO * MOVES!INTM).RHTO THENSELHOVilHTMK !• SELECT KILLER MOVE •!

end;

SELNXTfHfcll (• GO TO NEXT STATE •»

eno;

(• initialize scan of castle moves ano other movesby killer piece •>

BEGIN

GENCAS! I* GENERATE CASTLE MOVES •»

selnxtih5i! (• go to next state •!

end:

(• full midth search - castles ano other moves by killer

PIECE •»BEGIN

SELANY? (• SELECT ANY MOVE •>

GEMFSL(ALLOC!JHTK1If (• GENERATE REMAINING MOVES •»

SELNXTCH6I! (• NEXT SEARCH HOOE •!

end;

(• FULL NIOTH SEARCHBEGIN

SELAHYJ

if hvselijntk] = 0 thenscoreh:

SELOON;

eno:

(• research first ply M

BEGIN

JNTH 1= LINOX(AK»li;

REMAINING MOVES •>

SELECT ANYTHING ON LIST •!

(• SCORE HATE M(• EXIT SELECT •>

(* POINT TO ALREADY GENERATED

MOVES •>(• RESET MOVES SEARCHEO •)

end;

MVSELIAK] 1= 0;FOR INTM •■ AM*1 TO JNTM-1 00HOVESIIMTNl.RMSU is FALSE I

I* CLEAR SEARCHEO BIT •!IF SHTR THEN

MRITELN!- REDO ",JNTK.BSTVLIAK-2l,BSTVL(AK-1II|SELNXT(H611 (• SEARCH ALL MOVES *l

END;

22l (• SELECT EXIT •»

SELECT I* INTB1ENOI !• SELECT •)

BEGIN f SEARCH •»BSTMVIAK) I* AN!IN0EXCJNTK1 I- AM;MOVES!AN] |« LSTHVfEVALUBIBSTVLIAK-21 t* VALUE!AM]

MINO0N1

window!

<• RETURN VALUE •>

1* INITIALIZE MOVE •»(• INITIALIZE TREE •>(• INITIALIZE MOVE ♦»t* INITIAL GUESS AT SCORE •}(• INITIALIZE ALPHA-BETAMIN00M •>

BSTVLIAK-11 Is - VALUEfAMI

JNTK la JU»i;

MHILE (NODES < FNOOELI ANO (JHTK < MAXIZK OIV 2, ZK*BM 00

BEGIN

(• INITIALIZE ITERATION NUMBER •>

(• START NEN PLY •>BSTVLIJNTK] I* BSTVL! JNTK-2If

(* INITIALIZE ALPHA *>

(• DIFFERENT FIRST MOVE •»IF NOT SELECT THENBEGIN

BSTVLIJNTK] |a VALUE!INDEX!JNTK)1fNEMBST(JNTK)fENOELSEBEGIN

IF UPDATE (NOVES! INDEX! JNTOIIU THEN

GOTO 11 (• START NEN PLY •»

ELSEBEGIN

ONOATE(NOVESIINOEX!JNTK]]I I

goto 12t (* fino another move •!

eno;

(• FLOAT VALUE BACK MIF MINHAX(JMTKI THENGOTO 15;

(• PRUNE •)

M (• FINO ANOTHER MOVE AT THIS PLY »|IF SELECT THEN

IF UPDATE (MOVESIINOEXiJNTKUlH THEN

GOTO 11 (• START NEH PLV •!

ELSEBEGIN

ONOATECMOVESIINDEXIJNTK1 J»:

GOTO H»; (• FIND ANOTHER MOVE •)

ENOI

eno;

51 i* back up a ply •!if jntk » ak then

BEGIN (* NOT DONE MITH ITERATION •)

0N0ATE(M0VESIIN0EXIJNTK)1II !• RETRACT MOVE •)

GOTO 13t

end;

(• OONE MITH ITERATION •!IF (BSTVLIAK) <« BSTVLfAK-21) OR (BSTVLfAKl »- -BSTVLfAK-11I THENBEGIN I* NO MOVE FOUND •!IF NVSELIAK1 - 0 THENBEGIN (• NO LEGAL NOVES MGOTO 161

end;

BSTVLtAK-2) l> -ZV|

BSTVLIAK-1) l« -ZVt

SRCHMIAK) I* H7«

JNTM i* AK*lt

GOTO 111ENOI

BSTVLIAK-2] I- BSTVLfAK] - MINOON; (• SET ALPHA BETA MINOOH ♦»BSTVLCAK-11 I* - BSTVLfAKl - MINOON!

JMTK I- JNTK^l! (• ADVANCE ITERATION NUMBER •!

SRCHMIAK] is HZ IEND!

(• GIVE UP •»

(•SET ALPHA-BETA MINOON LARGE •)

(• TRY AGAIN •»

161 (• EXIT SEARCH »lSEARCH I* BSTNV(AK);END! (• SEARCH •!

PROCEDURE REAOER;

LABELHI

VAR

INRA | RA;INTJ I TJ!

PROCEDURE RORERR(AIRN);

VAR

INTJ I TJ!INTN t TN|

BEGIN

IF NOT SMEC THEN

BEGIN

WRITE(" -1;

FOR INTJ is AJ TO ZJ-1 00MRITE(ILINE(INTJ1M

mriteln;

EMO!

FOR INTJ is AJ TO JHTJ 00

WRITE!" -»!MRITELN( —JlFOR INTN is AN TO ZN 00

write(aiimtni»;mriteln;

GOTO 11|END! (• RDRERR M

(• RETURN BEST HOVE M

(• READ INPUT FROM USER *)(• COMMAND FINISHED EXIT M

(• SCRATCH TOKEN •!

(• ECHO COMMAND INDEX «l

(• PRINT DIAGNOSTIC ANO EXIT •»

<• STRING INDEX •»<• MESSAGE INDEX •)

(• ECHO LINE IF NOT ALREAOYOONE •!

(• WRITE INPUT LINE •)

(• LEADING BLAHKS BEFORE ARROW •)(• POINTER TO ERROR •!

(• WRITE OIAGMOSTIC •!(• COMHANO EXIT •>

148 December 1978© BYTE Publications Inc

f m$ \LmMR to ^a ®y®*mm *%

NEW!

MODEL CC-9

$200.00 (4800 Baud)

$220.00 (9600 Baud and 220V/50 Hz)

9600 BAUD CASSETTE RECORDER

An ASYNCHRONOUS NRZ type Recorder with remote motor start/stop. Error rate108 at 4800 BAUD. Can be used from 110 to 9600 BAUD into a UART - no clockingrequired. This is not an audio recorder. It takes RS232 or TTL signals from the terminal orcomputer and gives back the same signals. No audio interface is used. Motor start/stop ismanual or through TTL or RS232 signals.

Tape speeds are 1.6" / 3.0" and 6.0" per second. 110 volt, 60 Hz, 5 watts. (220 Volts onspecial order). Can use high quality audio cassettes (Philips Type) or certified data cassettes.

Recommended for DATA LOGGING, WORD PROCESSING, COMPUTER PROGRAMRELOADING and DATA STORAGE. Manual control except for motor start/stop. 6800,8080 or Z80 software for file or record searching available on request with order. Used bymajor computer manufacturers, Bell Telephone and U.S. Government for program reloadingand field servicing.

AVAILABILITY - Off the shelf.

PROVIDES MONITOR AND TAPE SOFTWARE in ROM. TERMINAL and TAPE PORTSon SAME BOARD. CONTROLS ONE or TWO TAPE UNITS (CC-8 or 3M3B).

This is a complete 8080, 8085, or Z80 system controller. It provides the terminal I/O(RS232, 20 mA or TTL) and the data cartridge I/O, plus the motor controlling parallel I/Olatches. Two kilobytes of on board ROM provide turn on and go control of your Altair orIMSAI. NO MORE BOOTSTRAPPING. Loads and Dumps memory in hex on the terminal,formats tape cartridge files, has word processing and paper tape routines. Best of all, it hasthe search routines to locate files and records by means of six, five, and four letter strings.Just type in the file name and the recorder and software do the rest. Can be used in theBiSync (IBM), BiPhase (Phase encoded) or NRZ modes with suitable recorders, interfacesand software.

This is Revision 8 of this controller. This version features 2708 type EPROM's so thatyou can write your own software or relocate it as desired. One 2708 preprogrammed issupplied with the board. A socket is available for the second ROM allowing up to a full 2Kof monitor programs.

Fits all SI00 bus computers using 8080 or Z80 MPU's. Requires 2 MHz clock from bus.Cannot be used with audio cassettes without an interface. Cassette or cartridge inputs areTTL or RS232 level.

AVAILABILITY - Off the shelf.

2SIO (R) CONTROLLER$190.00, Tested & Assmb.

ti

0

$

&

—► DOUBLE DENSITY FLOPPY DISK CONTROLLER

A new floppy controller for 5" and 8" drives utilizing the new 1791 chip to provide single or double density recording.Flip the switch to use one or the other mode. Can load memory from single density and re-record it double density on thesame drive so you can transfer or re-record your programs and files. Comes with new format program for double density ondisk to replace your old single density format program. (Soft Sector IBM format). $295. Assembled and tested.

SHIPPING STARTED OCTOBER '78,

—► PEGASUS DOUBLE DISK ENCLOSURE and POWER SUPPLY

Holds one or two drives, has two drive power supply. 110 or 220V. Comes empty or filled with Shugart drives. Varia-tions preclude listing prices. Call or write for full details.

SHIPPING STARTED OCTOBER '78.

Z 80 BOARD for SWTP COMPUTER

Now you can use the 8080/Z80 software programs in your SWTP 6800 machine. Re-places your MPU board with a Z80 and ROM so that you are up and running with yourpresent SWTP memory and MPS card. 1 K ROM on board replaces MIKBUG and enablesyou to use XITAN Z80 software which we can supply.

AVAILABILITY - Off the shelf.

_$190.00, Tested & Assmb.

For U.P.S. delivery, add $3.00. Overseas and air shipments charges collect, N.J. Residents add 5% Sales Tax. WRITE or CALL for furtherinformation. Phone Orders on Master Charge and BankAmericard accepted.

Naticiial Multiplex Ccrporaticn

> 3474 Rand Avenue, South Plainfield NJ 07080 Box 288 Phone (201) 561-3600 TWX 710-997-9530 t

Circle 279 on inquiry card.

BYTE December 1978

149

Listing 7. continued:

FUNCTION RORGNT(VAR flRAMTBt

var

INTJ I Tj|

I* SET MCXT TOKEN FROM COHHANORETURNS TOKEN IN A.RETURNS TRUE IF HOH-CHPTVTOKEN.

A TOKEN XS ANY CONSECUTIVECOLLECTION OF ALPHANUMERICCHARACTERS.

LEADING SPECIAL CHARACTERSIGNORED. *>

<• STRING INDEX »»

tEGIN

HHILE IJHTJ « ZJ} AND tORDI ILINEIJHTJII >* OW(N")i 00

JHTJ •■ JNTJ*ltA |. - -|

INTJ l« AA|

HHILE <JNTJ < 2 J) ANO IINTJ 4 ZAI ANO (ILINEIJNTJI IN I"A".."S"!! DOBEGIN

AIINTJ1 |« ILIHECJNTJlt <• CORY CHARACTER TO TOKEN •!

INTJ I* INTJtlt (• AOVAHCE POINTERS *)

JHTJ I* JHTJ*1IENOfRORGNT i» INTJ «» Ml (• RETURN TRUE IF ANYTHING

HOVEO •»HHILE (IHTJ * ZJ) ANO (ILINEUNTJI IN t"*".."9"H 00

JNTJ I* JNTJ*it (♦ SKIP REST OF TOKEN •)

ENO; f* RORGNT •»

PROCEDURE RORSFTt

VARINRAINT8

RA1

Tit

REGIN

JNTJ I* AJ|

I NT 8 I- RORGNT (INRAMEND? I* RDRSFT *}

PROCEOURE RORCHO

(• SKIP FIRST TOKEN IN CONNA NOLINE »|

(• SCRATCH •)!• SCRATCH •!

I* INITIALIZE SCAN •}

(• THRON ANAT FIRST TOKEN •»

I* TEST FOR AND EXECUTE CONHANOEXITS TO CONHANO EXIT IFCONHANO IS PROCESSED. •»

r

NEW SOFTWARE FORYOUR COMPUTALKER!

SOFTWARE PACKAGE IIavailable now

CTEDIT A new parameter editor

CSEDIT Editor for CSR1 input

CTEST CT-1 Hardware diagnostic

PLAYDATA To hear the data files

MEMVOICE A vocal memory dumper

KEYPLAY Subr. to play letters/dig its

PIANO A simple musical keyboard

8080 Assembly Language

*** Sources included *##

CPM 8"f North Star, Micropenis,

Tarbell, CUTS, MITS ACR,

paper tape

on any of the above media $30.00calif, res. add 6% sales tax

COMPUTALKER CONSULTANTS

1730 21st Street, ABSanta Monica, CA 90404

(213) 392-5230

(AtRAj

PROCEOURE XXXCHOM

BEGIN

IF INRA * A THENBEGIN

XXXCN01GOTO illENOtENOt 1* RORCHO •»

PROCEOURE roline;

<• POTENTIAL CONHANO KEYWORD •>C* PROCEOURE TO EXECUTECONHANO •>

I* EXECUTE COHHANO •>(• EXIT •>

<♦ GET NEXT INPUT LINE PROMUSER •»

VARINTCINTJ

TCJ

tj;

BEGINREAOLNtINTJ I* AJt

WHILE NOT EOlN ANO (INTJ < ZJI 00BEGIN

REA0(ICAR0(INTJ1MINTJ |a tNTJ»i;

end;

while not eoln 00reaountcm

while INTJ « ZJ 00BEGIN

ICAROCrNTJ] |a - "|

INTJ I* INTJ*1IENOt

ICAR0IZJ1 I* "I":JNTJ t« AJtENOt (• ROLINE •)

FUNCTION ropnovitbs

!♦ SCRATCH •!

(• STRING INDEX •)

(• ADVANCE TO NEXT LINE •}

(• COPT IHPUT LINE •»

•• SKIP REST OF INPUT LINE •!

(• BLANK REST OF LINE M

(• SET ENO OF CONHANO •»

(• RESET INPUT LINE POINTER •)

(• EXTRACT NEXT CONNANOFRON INPUT LINE.RETURNS TRUE IF NON-ENPTVCONNANO. •>

VAR

INTJ I Tjt

BEGIN

WHILE IJHTJ € ZJ> ANO UCAROIJHTJI

JNTJ I* JHTJ»i;IHTJ »s AJt

WHILE IJHTJ < ZJI ANO (ICAR0IJNTJ1BEGIN

ILINECIHTJI i* ICARO(JNTJ);

INTJ I* IHTj*:;

JNTJ i« jhtj*i;ENOtIF IICAROCJHTJ] = -;-) ANO (JNTJ <

JHTJ l« JHTj+ltRORNOV la INTJ <> Aj;HHILE IHTJ « ZJ 00BEGIN

ILINEIIHTJ1 |* - -;

INTJ l» IHTj*i;ENDt

ILINE(ZJI l» "ftJNTJ f> AJ|ENOt (• RORHOV •>

(• STORING POINTER •>

(' SKIP LEADING BLANKS *1

<> -t"l 00

ZJI THEN

(• SKIP SEHI-COLON M

(» RETURN TRUE IF NON-EHPTV •»

(• BLANK FILL LINE •!

(• STORE COHHAHO TERHINATOR MI* PRESET CONNANO SCAN *»

FUNCTION RORNUNI Tit

VAR

INTO t tb:INTI I Til

BEGIN

HHILE (JNTJ * ZJI ANO (ILINEUNTJI

JHTJ I- JHTJUtIF ILINEIJNTJI ■ --- THENBEGIN

INTO i« TRUEt

JHTJ I- JNTJ*itENOELSEBEGIN

INTB I* FALSE1

IF ILIHEIJHTJ1 ■ -♦- THENJNTJ M JNTJ*ltENOt

INTI t. At

NHILE ILINEIJNTJ] IN |"|-..-9-l 00BEGIN

IF INTI < HAXIHT/10 THEN

INTI l« 10»INTI»ORO(ILIN€(JNTJJI-OROI-O-I

ELSE

RDRERRC NUHBER TOO LARGE

JHTJ I* JNTjtltENOtIF ILINEUNTJI IN C"A-..-Z-| THEH

RORERR(" OIGIT EXPECTEDIF IHTB THEH

IHTI I* -INTItRORNUN I* INT ItENOt <* RORNUN •»

<• CRACK NUHBER FRON COHHAHOLIKE. RETURNS NUHBER IF HOERROR. EXITS TO COHHAHO EXITIF ERROR. •>

(• SIGH •!!• VALUE •»

« - -> 00

(• SKIP LEADING BLANKS •)

(• NUHBER IS NEGATIVE •»

(• ADVANCE CHARACTER POINTER •!

(* NUHBER IS POSITIVE «l

(• SKIP LEAOING ♦ M

-It

(• ADVANCE •!

*I1

(• CONPLEHENT IF NEGATIVE •!(• RETURN NUHBER •»

PROCEOURE BOACHOt

VAR

IHTH I THtINTS I ts;

(* COHHANO - SET UP POSITION *l

(• COLOR •!

(• POSITION ON BOARO M

150 December 1978 © BYTE Publications Inc

Circle 53 on inquiry card.

t« AO VANCE N FILES •»

!• STORE PIECE ON BOARD •!

Listing J, continued:

PROCEOURE BOAAOVCAiTII|

BEGIN

IF IMTS** « ZS THEN

INTS I* IMTS**ELSE

INTS I- 2S\ENOt C BOAADV *l

PROCEDURE BOASTOtAlTPIt

BEGIN

BOARD.RBISlINTSI I* AtIF INTS « ZS THENINTS I* ints»;:

END: !• BOASTO •>

BEGIN <• BOACHD MCLSTATt

ISTNV I* NULHVIFOR INTS I* AS TO ZS 00BOARD.RBISlINTS1 1= NT t

intn i« cite;

INTS t* It

REPEAT

I*F ILINE(JNTJ) IN (CASE ILINEIJNTJ] OF

"P"l BOASTOtXTUHPtEP.lNTHlIt"R'l BOASTOtXTUHPIER.INTNli;-N-i B0AST0(XTUHP(£N,INTH11;-B-l BOASTOtXTUHPCEB,tNTNIlt"Q"l BOASTOIXTUHPtEO.lNTHll%-<"i BOASTOIXTUHPtEK.INTNlIt*L"l IHTH l> LITE?"0-1 INTN l» DARK?-i-»"2".-3"t"*.-t-5-,-6-,-7-,"«-|

BOAADV tOROULlNEt JNTJ II-ORDI"0"I> tENDELSE

IF ILINEIJNTJI IN C-A-..-9"! THENBEGIN

FOR INTS t» AS TO ZS 00

BOARD.R6ISCINTSI i* NT XCLSTATJ «• CLEAR STATUS •>

RORERRt" ILLEGAL BOARD OPTION "It

end;

JNTJ l* JNTj»i;UNTIL JNTJ * ZJt

end; (• aoACNo •>

(• CLEAR STATUS FLAGS •><• CLEAR PREVIOUS HOVE *>

I* CLEAR BOARD •!

,-R-,-N-,-B-,-Q-

PROCEDURE ENOCHO;

BEGIN

GOTO 91END? !• ENDCHO •»

PROCEOJRE goncho:

BEGIN

GOING i= rornun;

IF GOING «« 0 THEN

GOING i= i;GOTO »ENOt (• GONCHO M

PROCEOURE INICHOI

BEGIN

GOTO 1|END! (* INICHO •»

PROCEOURE LETCMOt

LABEL

211

PROCEOURE LETONE

fAlRAl

VAR BITIM

BEGIN

IF A * INRA THEN

BEGIN

8 It RORNUHt

GOTO Zi;

ENOt

ENOt (• LETONE •!

BEGIN

IF RDRGNT(INRA) THEN

BEGIN

LETONEI-FKPSHO

"•FKPSHOI t

LETONEI-FXSANO

"•FKSANQtt

LETONEl-FNAXHT

-•FNAXNT1t

LETONEl-FNODEL

"•FHOOELIt

LETONEt-FPADQR

-.FPAOCRtFUIt

LETONEf-FPAOQN

-,FPA0CRIF21»;

LETONE("FPAOQB

-.FPA0CRIF3IM

LETONEf-FPAOQF

-,FPAOCRfF*Jlt

!• COMNANO - ENO PROGRAN »l

I* ENO PROGRAN M

I* COHNANO - GO N MOVES •>

I* CRACK NUNBER •»

I* EXECUTE MACHINES NOVE •»

COHNANO - INITIALIZE FOR A NCMGAME •»

(• INITIALIZE FOR A NEN CANE •»

t* COHNANO - CHANGE VARIABLE •)

I* LET COHNANO EXIT •)

(• TEST FOR ANO SET ONE

VARIABLE •»(• VARIABLE MANE •!(• VARIABLE •!

<• GET VALUE *)(• EXIT ♦!

LETONEC-FPAOKFLETONEt-FPADKBLETONEC-FPAOKNLETONE("FPAOKRLETONEt-FPBLOKLETONEI-FPCONNLETONE(-FPFLNXLETONEf"FROUBLLETONE(-FRKZTHLETONEl-FTRAOELETONEl-FTROSLLETONE("FTRPOKLETONE1-FTRPHNLETONEI-FHKINGLETONEC-FMHAJHLETONEI"FHHINNLETONEI-FNP*MNLETONEf-FHROOKLETONEl-HINOOH

-•FPAOCRIFSIM-.FPAOCRtFBHt-.FPAOCRtFTIlt-•FPAOCRIFBIM

-.FPBLOKlt-9FPC0NN)t"•FPFLNXI1-.FROUBL)t-•FRKFTHIt-•FTRADEIt-•FTROSLIt-.FTRPOKIt-•FTRPNNM-•FNKINGIt-,FNHAJHJ t"•FHNINHM-.FNPAHNIt-»F«ROOK>t• NlNOOMIt

RORERRt- ILLEGAL LET VARIABLE NAHEENOt21t I* LET COHNANO EXIT •>EHOt <• LETCND •)

PROCEOURE PLECHO:

LABEL

211

PROCEOURE PRIONS

(AiRAt

BITIM

BEGIN

IF INRA * A THEN

BEGIN

HRITELNtA.Blf

GOTO 2lt

ENOt

ENOt (• PRIONS •>

BEGIN *• PLECNO •!

WHILE RORGHT(IHRA)

00

BEGIN

PRIONEfFKPSHO

-.FKPSHOU

PRIONSl-FKSANO

-•FKSAMQIt

PRIONSf-FHAXHT

-•FNAXHTI1

PRIONS 1"FNODEL

-.FHOOELIt

PRIONSt-FPAOOR

-•FPAOCRIFIDI

PRIONEI-FPAOQN

-,FPA0CR(F2IH

PRIONE*-FPAOQB

-•FPAOCRCFSIIt

PRIONSl-FPAOQF

-,FPA0CR|F4|ll

PRIONSt-FPAORF

-.FPAOCRCFSIM

PRIONEI-FPAOKB

~,FPAQCR(Ftllt

PRIONEC-FPAOKN

-,FPA0CR(F7ll;

PRIONEC-FPAOKR

-•FPAOCRIFBHt

PRIONEl-FPBLOK

-•FPBLOKlt

PRIONE("FPCONN

"•FPCONNIt

PRIONEf-FPFLNX

"•FPFLNXIi

PRIONEl-FROUBL

-•FROUBLIt

PRIONEC-FRKZTH

-•FRKZTHIt

PRIONEt-FTRAOE

-.FTRAOEIt

PRIONEI-FTRDSL

-•FTROSLIt

PRIONEl-FTRPOK

-.FTRPOKi:

PRIONE1-FTRPHN

-.FTRPHNlt

PRIONE1-FNKING

-•FNKINGIt

PRIONEI-FNNAJN

-•FNHAJNIt

PRIONEl-FHHINN

-•FHHlNNIt

PRIONEl-FNPANN

-•FNPANNIt

PRIONE«-FNROOK

-•FHROOKIt

PRIONE("WINDOW

-.WINDOW)t

RORERRt" ILLEGAL

VARIABLE NAHE

I* COHNANO • PRINT VARIABLE •!

I* PRINT LET COHNANO EXIT *l

I* TEST FOR ANO PRINT VARIABLE •>

<• TEST VARIABLE NANS •!

I* VARIABLE •»

211 1* print let cchhano exit •>end;

ENOt <* PLECNO •!

PROCEOURE PRICHOI

BEGIN

IF RORGHTflHRAI THEN

PRINTSINBOROIELSE

PRlNTBtBOARO.RBISItENOt I* PRICHD •)

PROCEOURE PANCNOt

BEGIN

WHILE R0RGNT1INRAI 00IF INRACAA) * -T- THEN

PRIHAHCATKTOIELSE

IF INRACAA] * -F- THEN

PRINAHtATKFRIELSE

RORSRRC ATTACK HAP NOTENOt I* PAHCNO •)

(• COHNANO - PRINT BOARO •>

I* CONHANO - PRINT ATTACK NAP •>

PROCEOURE POPCHOt

WAR

INTO I TQt

TO* OR *FROH — lt

t* COHHANO - PRINT OTHER STUFF •>!• CASTLE TTPE INDEX •!

BEGIN

WITH BOARO 00BEGIN

NRXTELNIXTHA'RBTH),- TO HOVE.*!!

December 1978 © BYTE Publications Inc 151

Listing 1, continued:

WRITELNtRBTS," ENPASSANT.">JWRITELNI"HOVE NUHBER-.RBTI):FOR INTQ is IS TO OL DOIF INTQ IN RBSO THEN

WRITELN(XTQAUNTQ|,- SIDE CASTLE LEGAL.");

end;end; (• popchd m

PROCEDURE PHVCHO?VAR

inth t tw;

beginlsthov;for intm i* ah to jnth-1 ho

BEGIN

WRITE t INTWI*»," "I tPRIMOVIHOVESfINTM))IIF INTH/LPP * INTH DIV LPP THENPAUSERt

end;end; t* phvcho •)

PROCEDURE SNICHD?

I* CONHANO - PRINT HOVE LIST •»%• MOVES LIST INDEX •>I* LIST LEGAL NOVES •)

LABEL211

PROCEDURE SHIONE

(aira;

VAR 9ITB>;

VAR

INTJ I TJt

BEGIN

IF INRA ■ A THENBEGIN

IHTJ I* JNTj;

IF RDRGNTIINRA) THEN

BEGIN

IF INRA = "ON

B t= TRUEELSE

IF INRA * "OFF

B I* FALSEELSE

JNTJ 1= INTJ?PRISNKA.B) ;ENDELSE

PRISNU4.B) ;GOTO 21;

eno;end; (• smione *>

BEGIN (• SWICHtl *)

211 (• SWITCH OPTION EXIT M

WHILE RDRGNT(INFA) 00

BEGIN

SHIONEI"EC -,SWECi:

snionecpa -,swpa):

snionec-ps -*swpsi;

SHI ONE("RE ".SHREi;

SWIONEI"SU ",shsu»;

SWIONECTR ".SMTRi;

rorerrt" invalid smitch optioneno;end? !■• snicno •)

PROCEOURE STACMO;

LABEL211

VAR

INRA I ra:INTH I TM?

proceoure staepfiaira;bitfi;

BEGIN

IF A i INRA THENBEGIN

IF INTH * LITE THEN

B0AR0.R6TS I* XTRFSIR6.8IELSE

BOARD.RBTS I* XTRFSIR3»B1?GOTO 21?END?ENDl !• STAEPF ♦)

!• COHHANO - FLIP SNITCH •»

(• SMITCH OPTION EXIT •)

I* PROCESS ONE SNITCH •)(• SNITCH NAHE •)(• SWITCH *1

t» SAVE COMMAND INDEX •)

«• SAVE CURRENT POSITION •>

!• TURN SNITCH ON •»

(• TURN SNITCH OFF •)

(• RESTORE CURRENT POSITION •)I* PRINT SNITCH VALUE *)

(• SMITCH OPTION EXIT •)

(• COHHAND - STATUS CHANGES •>

(• STATUS COMHANO OPTION EXIT •)

!• CURRENT TOKEN •»

!• SIOE BEING PROCESSEO •»

!• PROCESS EP FILE •»

t» TEST TOKEN •!

!• EQUIVALENT FILE M

<• EXIT STATUS OPTION M

BOARD.RBSQ l« BOARO.RBSQ # (OS);ENOJ (• STACAK •)

PROCEDURE STACAKS

BEGIN

IF INTM = LITE THEN

BOARO.RBSQ I * BOARO.RBSQ ♦ (LSIELSE

C ALLOW CASTLE KING SIOE *)

PROCEOURE stacaq;

(• ALLOW CASTLE QUEEN SIDE •>

BEGIN

IF INTM * LITE THEN

BOARO.RBSQ t* BOARO.RBSQ • (LL)ELSE

BOARO.RBSQ i= BOARO.RBSQ ♦ (OLi;END? (• STACAQ •)

PROCEOURE STADRK;

BEGIN

INTH |a DARK;ENDt <• STADRK M

PROCEDURE STAENP;

(• SET BLACK OPTIONS •)

<» SET ENPASSANT FILE *»

BEGIN

IF NOT RORGNTtlNRA) THENBEGIN

CLSTAT; !• CLEAR STATUS •!

RDRERR(" ENPASSANT FILE OMITTED ");

eno;

STAEPF("QR ".Fill

STAEPF(«QN ",F2>?

STAEPFI-QB ",F3U

STAEPFI-Q "iF4)M

STAEPFCK "»F5>?

STAEPFCKB -,FG»?

STAEPFI-KN ".F7I?

STAEPFCKR ".FBI?

CLSTATj (• CLEAR STATUS •!

RORERRt" ILLEGAL ENPASSANT FILE "1 J

END; (• STAENP •)

PROCEDURE STAGOS?

BEGIN

BOARD.RBTM I* INTM*

JNTH !■ INTM?ENO? <• STAGOS •)

PROCEOURE STALIT;

BEGIN

INTH l= LITE;ENDS I* STALIT M

PROCEOURE STANUMt

BEGIN

BOARD.RBTI l= RORNUH;END; t» STANUM •>

PROCEOURE STAOPT

(air*;

procedure staxxx);

THEN

BEGIN

IF INRABEGIN

STAXXX?

GOTO 21;

eno;eno; (• staopt *>

(• STACMO •)

BEGIN

clstat;

INTM |a LITE?211 t* STATUS OPTION EXIT •)WHILE RORGNT(INRA) DOBEGIN

STAOPT("D

STAOPT("EP

STAOPT(-6

STAOPTf"L

STAOPTi"N

STAOPTC"00

STAOPT("000

clstat;

rorerrt" invalid status optionend;

END? !• STACHO •»

PROCEOURE WHACHO?

(• SET SIOE TO HOVE •!

(• SET WHITE OPTIONS •)

(• SET HOVE NUMBER »l

(♦ TEST STATUS OPTION •)(• TEST OPTION •)(• PROCEDURE TO EXECUTEEQUAL •)

(* EXECUTE PROCEOURE *)(• EXIT STATUS OPTION •

(• CLEAR STATUS •)

(• DEFAULT SIDE MHITE •)

-,STADRK)?".STAENP);"♦STAGOS);-.STALITI?-,STANUHIt-.STACAK)?".STACAQ1 ?

BEGIN

NRITELNIMOVHSKENO? (• WHACHO •)

BEGIN (• REAOER •)HI (• COHHAND EXIT MWHILE NOT RORMOV 00ROLINE?

<• COMMAND - WHAT? •)

(• PRINT LAST MESSAGE •!

152 December 1978 ©BYTE Publications tnc

Listing 1} continued:

IF SMEC THENBEGIN

NRITEI- -»|

FOR INTJ I* AJ TO ZJ-1 00MRITEIUINEIINTJII;

NRITELNt

eno:

IF ILINEIAJM1 IN t-A-..-N-f'"BEGIN

INRA I* " -|

INRAtAAl Is ILINElAJi;

INRA{AA*1) t* lLlN£[AJ*li;

RORSFTt

-,boacho>;-.endchoii

-,GOMCHD»t-•INICNO)J"tLETCNOII-.PAHCHO)J

-.popcno);

-.PLECNOIt-.PHVCNOIJ"•PRtCNOM

-,stachd>;-.snzcho);

MHACNDi;

RDRCNOCBORORCMOfENRORCNOI-GORORCNDCINRDRCNDCLERORCHOt-PBRORCNOI-PORORCNOI"PLRORCMOfPHRORCNOI-PRRORCHDI"STRORCHOfSNRORCNOftfMRDRERR1" IHVALIO COHHANO

end;

ENOI <• READER M

PROCEDURE HINENG

(AtRNfBlRAIf

VAR

INTN 1 TNT

PROCEDURE AOOCHR1AITCU

BEGIN

HOVHSdNTNl 1« At

IF INTN < ZN THEN

INTN is iNTN.i;

end; !• AODCHR •»

PROCEDURE AOOSQPlAtTSt

birdi;

BEGIN

NITH B 00BEGIN

IF ROPC THEN

AOOCHR ( XT UCtXTPUINBOROI All 111IF RDSL THEN

AOOCHRt"/"!;IF ROKQ THEN

IF XTSF[A1 IN (Fl..F«,J THEN

AODCHRI-Q-IELSE

AOOCHR|-K-||IF RDNB THEN

CASE XTSFtAl OF

FWFBI AOOCHRI-R-i;F2.F7I AOOCHRI-N-l;FIfF6l ADOCHRI-B-ltl AOOCMRI"Q"i;I AOOCHRfK'i;

!• ECHO LINE •!

(• EXTRACT KEYWORD •»

<• SKIP FIRST TOKEN •!

*l|

f» GENERATE NINIHUN

ENGLISH NOTATION •>(• HOVE TO MOTATE •>t* LEADING CONHENT •>

(• NESSAGE INDEX •>

<• ADO CHARACTER TO MESSAGE •!(« CHARACTER •»

(* ADD CHARACTER •)(• ADVANCE POINTER •»

(• ADO SQUARE TO MESSAGE •!(♦ SQUARE TO ADO *»(• SQUARE SYNTAX *t

F%F5

end;if rork then

IF JNTH s LITE THENCASE XTSRIA1 OFRll AODCHR(-l-|;R2I AD0CHR»-2-j;R3i AOOCHR(-3-I;Rkt ADDCHRf"%">tR5l AOOCHRI-5-);RBI AOOCHRI-B-);R7i A00CHR(-7">;

rbi adochri-b-i;

ENDELSE

CASE XTSRtAl OF

Rll ADOCHRI-A-l;

R2I AOOCHR("r-i;

R3i ADDCHR<-6-|;

Ri»l A00CHR("5"i;

R5l AD0CHRIwl»-> J

RBI A00CHR("J-»;

R7| A00CHRI-2-JJ

RBI A0OCHR("l-»;END;

eno;end? !• aodsqr ♦!

PROCEDURE AOOUROfAlRAtBITAM

VAR

INT*

i ta;

I* ADO MORO TO MESSAGE M!• TEXT OF MOftO •>I* LENGTH OF MORO *»

I* CHARACTER INDEX •)

BEGIN

FOR INTA is *« TO B 00AODCHR(A(INTA|ltEND; <* AOOMRO *1

FUNCTION OIFFER(A,BlRHl

i tit

VAR

INTB » tb;

!• COMPARE MOVES •!

(• MOVES TO COMPARE •>

!• TRUE IF MOVES ARE DIFFERENT •»

l» SCRATCH • >

BEGIN

INTB l« U.RMFR «» B.RHFRJ ORIA.RMTO «> B.RHTOI ORIA.RMCP «> B.RHCPMIF A.RMPR s B.RHPR THENIF A.RMPR THEN

OIFFER i> INTB OR IA.RHPP «» B.RMPP1ELSE

IF A.RHOO » B.RHOO THENIF A.RHOO THEN

DIFFER I* INTB OR (A.RMQS <> B.RMQS)ELSE

OIFFER l» INTBELSE

OIFFER l» TRUEELSE

DIFFER is TRUE;END'. !• OIFFER •>

PROCEDURE SETSQD

IAITS

Bird;

VAR

CISR

f

VAR

OlSFU

BEGIN

C is

IR1.

.R»);

0 is

1F1.

.fsi;

WITH

B 00

BEGIN

IF

ROKQ

ANO R0N8 THEN

0 I*

IXTSFlAli;

IF

INOT

ROKQI ANO RDNB THEN

CASE

XTSFIAJ OF

ru

FBI 0 I* CF1.F8);

fz.

F7| 0 t- IF2.F711

F3»

FBI 0 ■« [F3*F6)T

F*j

I D I» [FtI*

F5

i o i» ifsii

ENOt

IF

RORK

THEN

: 1*

IXTSRCAllt

eno;

ENO;

I* SETSQO •>

!• DEFINE SPECIFIC SQUARE

DESCRIPTOR •>I* SQUARE TO DESCRIBE •>!• SYNTAX TO USE ♦>!• SET OF POSSIBLE RANKS •>|« SET OF POSSIBLE FILES M

(• INITIALIZE TO DEFAULTS *1

PROCEDURE HINGEN

(AlRNt

BITI1

ClTIl {

LABEL

lit

tz%

VAR

INTG 1

TGt

INTI I

111

INTN |

tn;

INLR l

sr;

INRR I

sr;

INLF i

SF;

INRF I

sf;

«• PRODUCE MINIMUM

ENGLISH NOTATION FORMOVES ANO CAPTURES •»

«• MOVE OR CAPTURE •!

t* FIRST SYNTAX TABLE ENTRY •>

<• LAST SYNTAX TABLE ENTRY •!

I* EXIT AMBIGUOUS MOVE SCAN •!!• EXIT KINGEN • !

«• PROMOTION PIECE •>

<• SYNTAX TABLE INDEX M

(• MOVES INDEX M

(• RANKS DEFINEO ON LEFT •!

<• RANKS DEFINED ON RIGHT M

!• FILES DEFINED ON LEFT •»

I* FILES OEFIHEO ON RIGHT •>

BEGIN

FOR INTI Is 8 TO C 00WITH SYNTXIINTI1 DOBEGIN

IF A.RMPR THEN

INTG 1= A.RHPPELSE

INT& i= pb;

SETSQO(A.RHFR,RYLStINLR,lNLF>:SETSQD(A.RMTO*RYRS,INRR*lNRF);FOR INTN l« AN*1 TO JNTM-1 DOIF DIFFERIHOVEStINTM1.A) THEN

IF INBORO(A.RNFR) ■ NBORDIHOVEStINTM].RHFR]) ANO(A.RMCP ~ HOVESI INTHI.RHCP) THENWITH HOVESflNTN] DO

IF UTSRlRMFR] IN INLRIIXTSRIRMTO! IN INRRI<XTSF[RHFRI IN INLFI(XTSFIRHT01 IN INRF1

(IRHPR AND (INTGGOTO 21;

(• FOR EACH SYNTAX ENTRY •)

(• SET SQUARE SETS •!

ANOANOANDANO

RMPPI) OR (NOT RHPRH THEN

(• ANOTHER NOVE LOOKS THE SAME •>

:• NO OTHER HOVE LOOKS THE SAME •>

AOOSQR(A.RMFRfRYLS);ADOCHR(RVCH);AODSQR(A.RHTO,RYRSi;GOTO 22t

211 «• try next syntax •>end;

221 !• EXIT HINGEN »tENOt «' HINGEN •>

BEGIN f* HINENG •>M0VH5 i* -

INTN Is AN«lt

ADOWRO(B,ZA»tAOOMROC"-NITH A 00BEGIN

!• AOO FROM SQUARE •!

(• ADO MOVE OR CAPTURE •!

(• ADO TO SQUARE *l

(• EXIT HINGEN ♦!

I* CLEAR MESSAGE •)

I* INITIALIZE MESSAGE INDEX *t

!• ADO INITIAL COHHENT •!

.2»t

December 1978 ©BYTE Publications Inc

153

Listing 7, continued:

".3M

•tin

IF MOO THCNBEGIN

ADOMRO1-0-0

IF RHQS THCN

aoonroi--o

END

tiff

IF RNCA THEN

HINGEN<A,SYNCF,SVNCL>ELSE

HINGENIA.SVNHF.SYMHLIIIF RHPR THENBEGIN

AOOCMR|-«-|!A00CHR1XTGCCRHPP1)!CNOt

AOONROI".IF RHCN THENBEGIN

400NR0C-CHECKIF RHNT THEN

ADOMROI-MATEAOOCNRI-.-KENOELSE

IF RHNT THEN

ADDHRDt~STAL£HAT£ENOtENO; <• HINENG •!

.311

10);

PROCEDURE Mrmove;

rm;

VARINRN

BEGINCREATE!

INRN I* HOVESISEARCH!!IF INRH.RHIL THENBEGIN

GOING I* It

IF LSTHV.RMCH THEN

HRITCLMt*- CONGRATULATIONS."!ELSE

MRITELN1" ORANN. "1ENOELSEBEGIN

HIHENCIINRN,- NY HOVE "IIHRITELN(MOVNS!|TNEHOVIXNRM!IF SMSU THEN

MftITELMCBOARD.RBTI•*.-•MOOES•ENOIENO| (• HtHOVC •»

PROCEOURC VRHOVEI

LABEL

11. 12. 13, 1%,

1*.

17.

lit

VAR

INTB I tb;

INTC t TCI

INTH | Tj;

15,

INTPINCPIFCAIFPRIFOOIFQSINTOIFMV

IFLOIFLFIFROIFRF

tpi

TP|TBITBITBITBITGITBI

TBITBITBITBI

INLF I SF|

INLR I SRI

INRF | SF(

INRR I SR!

INRN I RN1

FUNCTION NCMIN

IAISC!

PROCEDURE YRNXXX)

• TBI

INTB t TB|

BEGIN

INTB l» NOT IINTC IN A!|

IF NOT INTB THEN

BEGIN

YRNXXX|

JNTJ •■ JNTJ*1!

MMILE ONTJ « ZJI

AMO IIILIHEIJNTJI -

!• CASTLE •!

I* NOT CASTLE •>!• CAPTURE *1

!• SIMPLE HOVE •)I* PROMOTION •!

«• CHECK •)

!• CHECKMATE •!

(• STALEMATE •!

I* MAKE MACHINES MOVE *»

!• THE MOVE •!

I* INITIALIZE DATA BASE •!

(• FIND THE BEST MOVE *!

!• NO HOVE FOUNO •!

!• CHECKMATE •!

!• STALEMATE •!

«• TRANSLATE MOVE TO CMCLISM •)!• TELL THE PLAYER •)I* MAKE THE MOVE *l

HOOES.-.BSTVLtAK));

I* MAKE PLAYERS MOVE •!

!• SYNTAX NODES •!t* SYNTAX ERROR *l<• AMBIGUOUS MOVE •»(• NORMAL EXIT •»

!• VALID MOVE FOUND •!(• CURRENT CHARACTER •)<• MOVES INOEX •!

f* MOVING PIECE •!

I* CAPTURED PIECE •!

!• CAPTURE •!

(• PROMOTION »1

%• CASTLE •!

(• QUEEN SIDE CASTLE •»

«• PROMOTION TYPE •>

I* MOVE FOUNO •!

I* R, N, OR B ON LEFT •!I* K OR Q ON LEFT •)!• R, N, OR B ON RIGHT •!I* K OR Q ON RIGHT •!

(• FILES ON LEFT •!

(• RANKS ON LEFT •!

I* FILES ON RIGHT •!

|« RANKS ON RIGHT •!

I* THE MOVE •!

I* OETERNINE IF NEXT INPUT

CHARACTER IS NOT IN A GIVEN

SET •»(• SET OF CHARACTERS TO CHECK •!(• SEHANTICS ROUTINE TO CALL

IF NEXT CHARACTER IS IN SET •!!• TRUE IF CHARACTER IS NOT IN

SET •>

!• SCRATCH •!

I* EXECUTE SEMANTICS ROUTINE •!»• ADVANCE PAST CHARACTER '!

-! OR lOROULlNEt JNTJ1I > OROIZCI1I DO

JNTJ i« JNTJ*1|INTC t- ILINEIJNTJIIIF IINTC ■ "."! OR IINTCGOTO 191ENOINCMIN I* INTB!

ENOI (• NCMIN •!

PROCEDURE VRMMITI

BEGIN

IF IFNV THEN GOTO 17|

IFNV i» TRUE!

INRN l> NOVESIINTN1|ENO! !• VRMHIT •)

PROCEDURE VRMCOHt

I* SKIP BLANKS •>!• NEXT CHARACTER •!THENI* EXIT SCAN •!

I* RETURN TRUE IF CHARACTER ISNOT IN STRING •!

I* FOUNO A MOVE. EXITS

TO AMBIGUOUS HOVE IF THISIS THE SECONO POSSIBLE HOVE.SAVES THE HOVE IN INRNOTHERWISE. »>

I* SECONO POSSIBLE MOVE •!I* FIRT POSSIBLE MOVE •!I* SAVE MOVE •!

(' COMPARE SQUARES. CALLS YRMHITIF NOVESIINTN1 NOVES THERIGHT TYPE OF PIECE. CAPTURESTHE RIGHT TYPE OF PIECE, ANOMOVES TO ANO FROM POSSIBLESQUARES •»

BEGIN

HITH NOVESIINTN1 00

IF (XTSRIRNFR1 IN INLR1 ANDtXTSFIRNFRI IN INLF) ANOIXTSR1RNT01 IN INRR) ANDtXTSFlRMTO) IN INRF! ANO(NOT RMIL) ANO

CBOARO.RBISIRNFRI * INTPI THENIF RNCA m IFCA THENIF RHCA THEN

IF RHCP * INCP THEN

YRMHITELSEELSE

YRNHITtENO! !• YRMCOM •)

PROCCOURE VRHCAP!

BEGIN

IFCA I* TRUE!ENOI I* YRHCAP •)

PROCEDURE VRNCAS!

BEGIN

IFOO »- TRUE!END! !• YRHCAS •!

PROCEOURE YRNCPCl

BEGIN

CASE INTC OF-P-| INCP I* XTUNPIEP.0THERIJNTNI1!-R-l INCP IN XTUMPIER.OTHERIJNTMlll"N"i INCP I* XTUHPIEN,0THCRCJNTM1)1-B-i INCP l« XTUNPIEB,OTHER! JNTH1)!-Q-l INCP 1* XTUMPIEQ.OTHER! JNTN))!ENOIEND| !• YRMCPC PI

!• SEMANTICS - CAPTURE •!

!• SEMANTICS - CASTLE •)

I* SEMANTICS • CAPTURED PIECE •)

PROCEOURE YRMCQS!

BEGIN

IFQS I* TRUE!ENO! !• YRMCQS ♦!

PROCEOURE VRMLKQt

I* SEMANTICS - CASTLE LONG *l

I* SEMANTICS - K OR Q ON LEFT •)

BEGIN

CASE INTC OF

-K-l INLF 19 IF5.

.FBI • INLF!

!• KING SIOE •!

-Q-l INLF i« |F1.

.f%i • inlf;

<• QUEEN SIOE •)

END!

IFLF t« TRUE!

END! 1* YRNLKQ •!

PROCEOURE VRHLRBI

BEGIN

CASE INTC OF-R-l INLF 1« IF1.F8)-N-l INLF l. IF2.F71-B-I INLF is (F3.FB1END;

IFLO I* TRUE!ENO! (• YRMLRB •)

PROCEOURE YRMLRK;

BEGIN

IF JNTH * LITE THEN

inlf;inlf;Inlf;

(• SEMANTICS - R. N, OR B ONLEFT •!

f ROOK FILE •!!• KNIGHT FILE •)!• BISHOP FILE •)

!• SEMANTICS - RANK ON LEFT •)

154 December T978 © BYTE Publications Inc

Computer Chess

CHESS SKILL IN MAN ANDMACHINE edited by Peter WFrey.

□ A game of endless varia-tions, chess has challengedour skill for centuries. Thisbook surveys our currentunderstanding of humanchess skill and covers thesubtleties of coaxing a ma-chine to play chess. The ini-tial chapter and appen-dix present a brief historyof the computer chess tour-naments. The next twochapters describe the essen-tials of how humans andcomputers play chess. Thefourth chapter provides adetailed description of theNorthwestern Chess Program,currently the national champion.The following three chapters discuss severalalternative approaches to chess program-ming. In the final chapter, a former cap-tain of the U.S. Olympic chess team asses-ses the present status of chess skill in humanand machine. 217 pp. $14.80 hardcover.

1975 U.S. COMPUTER CHESS CHAMPIONSHIP by David Levy.

□ The sixth annual U.S. Computer Chess Championship, heldin October 1975, was a tournament in which twelve computer pro-grams competed against each other. This book includes a detailedanalysis and description of all the games, presented by David Levy,the tournament director. 86 pp. $5.95.

CHESS AND COMPUTERS byDavid Levy.

□ If you enjoy playingchess, then you will thor-oughly enjoy this book,which is loaded with chessgames played by computers.The first chapter describesthe earliest chess "ma-chine," the famous Auto-maton chess player thattoured Europe and America.There is a detailed accountof Torres y Guevedo's in-vention that played theending of King and Rookagainst King. There is also adescription of how com-puters play chess, includingan account of early Sovietattempts at chess program-ming that contains muchinformation hitherto unpub-lished outside the Soviet Union.M £!#*" Many examples of computer playJf are given, which provide an excellent^jr insight into the problems facing chessF programmers. 145 pp. $8.95.

1976 U.S. COMPUTER CHESS CHAMPIONSHIP by

David Levy.

□ This book includes a detailed analysis and des-cription of all the tournament games played at theseventh annual U.S. Chess Championship held in Octo-ber 1976. 90 pp. $5.95.

AN EDITOR/ASSEMBLER SYSTEM FOR 8080/8085 BASED COMPUTERS by WJ Wellerand WT Powers. A Moil/ Rook 1

□ This 148-page book contains complete information for initializing and using a powerful new ** 11CW LJKJ\Jm\ l

editor/assembler and debugging monitor system, and the full SOURCE text of both. The assem-bler fully supports all Intel instruction mnemonics as well as the entire language used in PRAC-TICAL MICROCOMPUTER PROGRAMMING™: THE INTEL 8080. The editor/assembler isresident in less than 8K RAM and will run on any 8080; 8085 or Z80 based computer with peri-pherals which transfer on a character by character basis or can be made to do so by buffering.The user supplies his own I/O drivers. The text editor is extremely simple to use and does notrequire irrelevant line numbers. Also included is a program to convert Processor Technology™format tapes to a format useable by the editor/assembler.

This system is not the usual ''quickie" software, riddled with errors and limitations, but aprofessionally created, thoroughly tested and debugged system. At $14.95 it is the best soft-ware bargain you are ever likely to see.

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STANDARD DICTIONARY OF COMPUTERS AND INFORMATION PROCESSING 2nd Edition by MartinH Weik.

□ This is a very complete, fully cross-referenced dictionary. It goes a step farther in that itincludes full explanations, practical examples, many pertinent illustrations, and supplementaryinformation for over 12,500 hardware and software terms. It cross-references the terms to otherclosely related concepts, and appended to each definition, as the need arises, are explanations,tutorial information, examples, usage areas, and cross-references for further clarification of con-cepts and meanings. 390 pp. $16.95 hardcover. (No photo)

Circle 35 on inquiry card.

BYTE December 1978 155

Listing 7, continued:

CASE INTC OF

•4*1 INLR l"

irii;

"2"l INLR i*

IR2IS

"3-1 INLR la

IR3II

-%-| INLR I*

IRtlt

-*-t INLR l»

IR511

-6-1 INLR |a

IR6U

"f-l INLR l«

[R7M

-•"I INLR ■»

[Ran

ENO

ELSE

CASE INTC OF

-!-• INLR t»

CRAM

"2-1 INLR 1*

|R7j;

"3-1 INLR l«

[R6i;

-%"l INLR «•

IR911

"5-1 INLR •»

(R%1t

-6-1 INLR t-

CR3U

"7-1 INLR !«

[ R2 > t

-•-1 INLR 1*

IRUt

ENOt

ENOt <• VRMLRK •

PROCEOURE rRHNUL;

BEGIN

END; (* VRHNUL •)

PROCEOURE VRNPCNI

BEGIN

CASE INTC OF

-p-| INTP %U XTUNP(EP*JNTHU

-R-l INTP l» XTUNP(ER«JNTHi;

-N-| INTP |« XTUHPCEN.JNTHlt

"B"l INTP ■ ■ XTUHPtEB.JNTHlt

"Q"l INTP is XTUHPCEQ.JNTNi;

"K"l INTP l« XTUMPtEK,JNTHJ;END;

end; (• YRNPCN •}

PROCEDURE VRHPROt

BEGIN

CASE INTC OF"R-l INTG la PR;"N-l INTG l« PN;"B"l INT& tx P8}"Q"l INTG l» PQ;ENOt

IFPR I- TRUEtENOt (• TRMPRO •>

PROCEOURE YRHRKQ;

BEGIN

CASE INTC OF-K-l INRF l» IF5..F61 • INRFt"O-l INRF l» fFt..F%l • INRFJEND)

IFRF l« TRUE!ENOt !• YRNLKQ •»

!• SERANTICS - NULL M

<• SEMANTICS - PIECE HOVEO •»

(* PAWN •}

»• ROOK •!

1* KNIGNT •>

!• BISHOP •!

(• QUEEN •)

!• KING •>

I* SEMANTICS - PROMOTION •)

<• ROOK M

(• KNIGHT M

!• BISHOP •!

!• QUEEN M

l» SEMANTICS - K OR Q ON RIGHT •!

I* KING SIDE •!1* QUEEN SIOE •!

PROCEDURE VRNRRB;

BEGIN

CASE INTC OF"R-l INRF l« IF1.F81 • INRF;"N-l INRF |> IF2.F71 • INRF|-B-l INRF is IFJ.F61 • INRF:ENOt

IFRD l* TRUEtENOt (• YRHLRB •)

!• SEMANTICSRIGHT •>

R, N, OR B ON

PROCEDURE YRHRRKJ

(• ROOK FILE •>(• KNIGHT FILE •!!• BISHOP FILE M

(• SEMANTICS - RANK ON RIGHT ♦>

BEGIN

IF JNTN s LITE

CASE INTC OF

"l"l INRR I

"2

"J

THEN

-5"!-6-t-7-1

INRR lINRR lINRR lINRR lINRR |INRR IINRR I

-6'

ENOELSE

CASE INTC or

"1-1 INRR l

-2"l INRR i

-3-1 INRR I

"(."I INRR i

-5-1 INRR

-6-1 INRR

"7-1 INRR

"•-I INRR

ENOtENOt I* YRMLRK

(Rin

« IR2H

» tR3)t

s [Rt.il

* (R5lt

* [R61?

* (R7K= (R81?

(R8lttRfll

tRfci;IR5J;

* iR4i:

* IR3H» [R2lt> IRII;

•I

BEGIN (•

YRMOVE •!

INTB «=

false;

WHILE NOT INTB DO

BEGIN

REAOERt

LSTM0V1

IFCA

i* false;

IFPR

m false;

IFOO

is FALSE;

IFQS

i« false;

IFLO

i* false:

IFLF

I* FALSE;

IFRD

i* false;

IFRF

l« FALSE!

INTP

Is HT|

INCP

• « mt;

INLF

ts ifi#.F«n

INRF

is [F1..F8H

INLR

I" [R1..R8M

INRR

• ■ [R1..RS11

INTC

Is ILlNEIJNTJi;

IF

NCHINII-P-,

-R-.-N-**

IF

NCHINII-/-1

IF

NCHINt|-K-,

-Q-|

IF

NCHINI("R",

"N-,-B"I

IF

NCHIN<[-i".

,-B-l

I* REAO NEXT MOVE •>(• LIST LEGAL MOVES •»

ill <• LEFT SIDE OONE •!IF NOT NCHlNtt"-"]

IF NCHlN(t-»",-X-J

IF NCHIN(|-p-,-R-,-N-,"B",-Q

IF NCHINIC-/-1121 I* RIGHT SIOE SQUARE •»

IF NCMINIC-K-f-Q-|

IF NCHINIt-R-,-N-,-B-l

IF NCHINII-1-..-8-I131 I* PROMOTION •>

IF NCHINI|"■"!

IF NCHINI(-R-,-N-,"B-,-Q"l

GOTO 15;

111 (• CASTLING •!

IF NCHINIt"O","0"l

IF NCHINII"-"!

IF NCHINU-0-,-0-1

IF NCHINI!-•-!

IF NCHINI I-0","(Pi151 !• SYNTAX CORRECT M

IF IFRF AND NOT IFRO THENINRF Is INRF • {Flt.FSi;IF IFLF AND NOT IFLD THENINLF is IHLF • IF«i,F5i:IFNV I* false:INTM |s AH{WHILE INTH < JNTW 00MITH MOVES!INTM) 00BEGIN

IF RMPR « IFPR THENIF RMPR THEN

IF RNPP « INTG THEN

YRMCOMELSEELSE

IF RHOO ■ IFOO THENIF RHOO THEN

IF RHQS s IFQS THEN

YRHHITELSEELSE

yrmcom:

IHTN I* INTH»lt

end;

IF IFNV THENBEGIN

HINENG(INRM,-VOUR MOVE "I;

NRITELNIHOVHSM

THEHOVIINRM);

INTB l» TRUEtENDELSE

NRITELNI- ILLEGAL MOVE."MGOTO 18;

161 If SYNTAX ERROR •!

NRITELNI- SYNTAX ERROR.-)tGOTO IB;

171 I* AMBIGUOUS MOVE •!

MRITELNI" AMBIGUOUS M0VE,"1;181 !• EXIT •!

ENO;ENOt !♦ YRMOVE •!

BEGIN !• THE PROGRAM •>

NRITELNI" HI. THIS IS CHESS .5"»;

ihicoh;11 i* initialize for a nem gahe m

INITAL tBOAROUREPEATREPEAT

YRMOVE;UNTIL SHREt

2 1 I* EXECUTE HACHINES MOVE •!REPEAT

MYMOVEt

IF GOING > 0 THENGOING is GOING-l;UNTIL GOING * Ot

until false;91 !• eno of program •»

ENO.

"K"1.YRHPCMI THEN GOTO l*i;

.YRHNULI THEN GOTO lit

»YRNLKQ» THENf

•YRMLRBt THEN;

•YRMLRK) THEN;

•YRHNULI THEN GOTO 12t

•YRMCAPI THEN GOTO 16;

•YRMCPCI THEN GOTO 16;

fYRHNULI THEN GOTO 13;

•YRMRKQ) THEN;

•YRMRRB) THEN;

»YRMRRKJ THEN;

•YRHNULI THEN GOTO 15;

•YRMPR01 THEN GOTO 16;

•YRHHUL) THEN GOTO 16;

•YRHNULI THEN GOTO 16;

•YRHCASI THEN GOTO 16;

•YRHCQSI THEN GOTO 15t

•YRHNULI THEN GOTO 16;

(• SELECT K OR Q FILE *l

(• SELECT K OR Q FILE *l

I* NO HOVE FOUHO YET *l

(• INITIALIZE INDEX M

!• CORRECT PROHOTION TYPE •>

!• COHPARE SQUARES AHD PIECES M

!• NOT PROHOTION •!

!• CASTLING •!

I* CASTLING SAME HAY •»

I* NOT CASTLING 'I

!• COMPARE SQUARES AND PIECES M

(• ADVANCE MOVES INDEX •!

(* ONE NOVI FOUNO •)

I* CONVERT TO OUR STYLE •!!• PRINT MOVE •!(• MAKE THE MOVE •!I* EXIT YRMOVE •>

I* NO MOVES FOUNO *l

!• EXIT •!

I* INITIALIZE CONSTANTS *l

!• INITIALIZE FOR A HEN GAME •!

!• EXECUTE PLAYERS MOVE •!

156 December 1978 © BYTE Publications Inc

Circle 70 on inquiry card.

Text continued from page 144

A second and somewhat more challengingproject would be to develop a transpositiontable for the program. This requires theavailability of unused memory (at least 8 Kbytes and preferably 16 K or 32 K bytes),an efficient hashing scheme, and a set ofdecision rules to select among positionswhen a collision occurs (ie: two positionshash to the same address in the table).Another problem is that the use of a stagedevaluation process and the a-j3 algorithmoften provides an imprecise evaluation score(ie: the machine has determined that a posi-tion was not optimal but has not investedthe time to find out exactly how bad it was).If the programmer succeeds with the trans-position table, however, move calculationwill take 30 to 50 per cent less time in mostmiddle game positions and 60 to 90 per centless time in many end game positions.

A third area for improvement is the eval-uation function. Our program presently hasonly a rudimentary function. The readershould compare it with the one used byChess 4.5 which is described in detail bySlate and Atkin. Their evaluation functionprovides an excellent starting point for re-vising our present function. In part 4 we willdiscuss the advantages of using a conditionalevaluation function, ie: one that changes de-pending on the stage of the game and on thepresence of special features. One implemen-tation of this strategy is the special end gameprogram described by Monroe Newborn inChess Skill in Man and Machine.

It is appropriate for us to add two impor-tant disclaimers at this juncture. Althoughwe have carefully tested each of the rou-tines in the program and played several chessgames, it is still possible that there are a fewminor bugs in the program. If you find one,a letter to one of us or to BYTE would beappreciated. Secondly, our chess programwas written primarily for pedagogical pur-poses. For this reason it is not a productionprogram and does not run very efficiently.If you are the competitive type, our programshould provide many useful ideas, but youshould not expect it to compete successfullyin tournament play unless you make exten-sive modifications and additions.

A chess program has a tendency to growand change its personality as the program-mer becomes more familiar with each of itsmany limitations. It provides a constantchallenge for those of us who are too com-pulsive to tolerate obvious weaknesses. Infact one must be careful not to becometotally obsessed with this project. We do notwish any of you to lose your job or yourspouse because of a chess program."

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We offer classes with a hands-onapproach using various micro-

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Circle 65 on inquiry card.

December 1978 ©BYTE Publications Inc 157

Continued from page 10

recovery from transmission errors. Addto this the fact that the protocol hasbeen in service a number of years, andI am sure readers will find the literatureworth reviewing.

Carroll Perkins

POB 333

Pilot Mountain NC 27041

SIZING UPMODULAR PROGRAMMING

I enjoyed the 'Top-Down ModularProgramming" by Albert D Hearn inthe July 1978 BYTE, page 32. I thoughthe did a good job of explaining the sub-ject. While I realize that he was pur-posely trying to simplify matters, I dotake exception to his comment that amodule should be no more than 50 lineslong.

The concepts of structured pro-gramming are intended as guidelines,not as the dogma for a programmer'sreligion. All of the better known pro-ponents of the methodology stress thispoint, along with the idea that you mustapproach the study of structured pro-gramming with your eyes open, makingyour own evaluation. In this light let usexplore the 50 line limit.

One of the bases for breaking a pro-gram up into modules is so that a com-

plex problem can be handled with smalt,easy to understand pieces of code. Oneof the thoughts about module size is,therefore, that a module ought to beable to fit on one printed page. This is sothat all the information about themodule is in one place and the pro-grammer won't have to thumb throughseveral pages to read the code for a singlemodule. Having experienced "modules"running as long as 10 to 15 pages, Iheartily agree with this philosophy.

In professional programming instal-lations, this idea has frequently beentranslated into a local standard of about50 lines of code, since this is the numberof lines which are printed on an 8.5 by11 inch (21.59 by 27.94 cm) pagecoming out of a line printer (allowingfor headers, footers, etc). For thepersonal computer enthusiast, however,this limit might be more convenientlyset at 24, 32 or 40 lines—the size of thevideo display.

For many more complex problems,it is possible that a significant modulecannot be constructed in 24 lines. Thisis no problem—just make the moduleslonger. The point is to try to restrict themodule size to a length which enhancesthe programmer's ability to understandthe code.

James Fleming

2220 Sims Dr

Columbus IN 47201

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Name

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LIGHT SEEKING ROBOT

I enjoyed your "On Building a Light-Seeking Robot Mechanism" article(August 1978 BYTE, page 24). Thesonar description caught my eye, since Iam working on a similar problem, andthe approach in the article appears to bemore complex than necessary. Jq + T[_and Tq + Tr describe a unique point inthe plane. Only if human interactionwith this data were intended would it benecessary to translate this to 9 and Tq.An array in memory could map theplane, or decision points could be estab-lished and checked against currentvalues. We must be careful to avoid lim-iting the robot to human perceptions.

johnGledhill

678 Washington Av #4

Yuba City CA 95991

CIARCIA'S CIRCUIT CELLAR

I am not one for writing to a maga-zine, but your article "Let Your FingersDo the Talking0 (August 1978 BYTE,page 156, and September 1978 BYTE,page 94) was right on! I read magazinesand use the ideas and never let editorsknow. I sometimes write the authors.

Mr Ciarcia's article was just the bestidea for a teacher like me.

I have been trying to get such an ideaand equipment for my kids in my class-room.

This article has helped me take onemore step toward my idea! computerlearning system for my kids. The touchpanel is a great help for younger kids.Thanks!

I will be busy building the hardwareand developing the software. I can'twait for the next article. Tell Steve tokeep the software coming and tell himwhat a great contribution he has made.I can't wait to see my kids' reaction.

Harold R Whitlock

616 2nd St

White Bear Lake MN 55110

A QUESTION OF PATENTS

I read with interest the articles en-titled "Let Your Fingers Do theTalking," as they relate to a noncontacttouch scanner or panel. As you areaware, the University of Illinois has twopatents covering the touch panel de-scribed in the article. They are US patentnumbers 3,775,560 and 3,860,764. Mycompany represents the University ofIllinois Foundation in the licensing ofthese patents.

While we have no objection to yourdescription of how to build the touchpanel, I would appreciate your takingappropriate steps to notify BYTEreaders that, if they desire to build thetouch panels commercially, they willneed a license under our patents.

These patents have already beenlicensed to several companies in the USand their foreign counterparts licensedabroad. We are willing to provide licens-

158 December 1978 © BYTE Publications Inc

,Circle 328 on inquiry card.

ing terms and conditions to interestedcommercial entities.

Thank you for your consideration.

A Sidney Alpert

University Patents Inc

2777 Summer St

Stamford CT 06905

Steve Ciarcia replies:

While I am personally aware ofjournalistic freedoms with regard topatents, many readers may not be. Yourstatement is well taken. It should befurther noted that the University ofIllinois patents appear to cover thescanning principle and not the designcircuitry.

PLATO AND THE TOUCH PANEL

I lead a double life: during the nightI make up little things for my ownApple, but during the day I become arising young training executive of theCDC Plato terminal.

And that's why Steve Ciarcia's articleon touch input units brought me up witha start — because his touch panel isnearly identical to the touch panelsput on the first Plato terminals! I'mtaking about the original Magnavoxterminals that brought Plato out of thelab in Illinois and into the world. Thoseterminals, just like Steve's monitor,had a picture frame around them with32 LEDs and 32 phototransistors. Infact, there are only minor differencesbetween them and Steve's design exceptfor the aspect ratio - Plato terminalshave square screens. The Plato panelseven had a built-in circuit that triggeredthe 0.1 second beep Steve mentionedin his article.

One minor difference was that Platopanels had the LEDs on the top andthe phototransistors on the bottom.Steve's method is better — the old touchpanels would fail regularly whenever thesun shone on them at the wrong angle.

Those old panels are obsolete now.Both CDC and the other Plato terminalmaker are using different designs, underdirect control from an internal micro-processor. But there are still plenty ofthe old Magnavox boxes out there, inschools and colleges across the country.In fact, three microprocessor systemsthat I know of display output througha gutted and rewired Magnavox box,bought on the "orange and blackmarket." (named for the color of theold plasma screens, you know.)

Silas S Warner

8 Charles Plaza

Baltimore MD 21201

Steve Ciarcia replies:

Thank you for the vote of confi-dence, tt may interest you to know thatI worked for Control Data Corporationfor three years as a process controlengineering consultant. During that timeI became familiar with Plato, but neverhave, to this day, used the touch input

feature. I just liked to go in after workand play Star Trek or Empire againstother people on the system throughoutthe country.

The design illustrated in BYTE wasdone from scratch and any resemblanceto Plato is purely coincidental. I justgot an idea for it one Friday afternoonand brought the completed unit intothe office Monday morning.

VOICING AN OPINION

Congratulations to Bill Georgiou forhis excellent primer on speech recog-nition in June 1978 BYTE ("Give an Earto Your Computer," page 56). Thiswide-ranging and complex topic waspresented in a most understandableform, yet did not sacrifice excessivedetail.

As Mr Georgiou stated, voice recog-nition has a rather long history, and hasintrigued avid experimenters such asmyself for some time. Back in 1965, Idesigned and built a demonstration unitcapable of differentiating ten differentwords or short phrases, and activatingone of ten relays upon completion ofanalysis. The project was awarded a firstprize at the Canada-Wide Science Fairthat year.

The implementation was not unlikefigure 12 in the article, an automaticgain control stage followed by multiplebandpass filters, except that all pro-

cessing was done in analog. A degree ofdifferential comparison was incor-porated, to provide for the variablenessof fundamental pitch in each speaker.Template matching was used, with agreat deal of "cut-and-try" programmingeffort. And if Mr Georgiou thinks theBell Labs version of 1952 was "gro-tesque," he should have seen this one,built from old television sets and recordplayers.

Although the machine displayedabout a 90 percent recognition rate formy voice (it had obviously been pro-grammed that way), I was constantlysurprised during public demonstrationshow often it would react correctly to a"stranger's" voice. With a little practice,even a feminine voice could speak theword "open" and see my little solenoidlock snap back.

The article has rekindled my interestin the field, and I shall be looking for-ward to implementation with my micro-processor now.

F Wallace

Burroughs Business Machines Ltd

POB 861

Winnipeg, Manitoba

CANADA R3C 2P7

CALLING ALL COMPUTERS

I got quite a zing out of DonaldNewcomb's letter on the evils of radio

TURN YOUR COMPUTERINTO A TEACHING MACHINE

The staff at Program Design did not learnabout educational technology from a book—we wrote the book! We have been innovators insuch teaching materials as programmed instruc-tion and multimedia presentations. We also belongto that minority in education who actually test ma-terials to see that people can learn from them.

Now Program Design brings this experience to the personalcomputer field. PDI is developing a line of educational andgame programs for the whole family—from preschool child toadults.

Program Design educational software uses the compute rs full teachingpotential in exciting and effective ways. Programs are simple to use andmemory efficient, and most important . . . they teach!

TAPES NOW AVAILABLE FOR THE TRS-80, PET, APPLE II

SAMPLE OUR SOFTWARE FOR$2.00. Send us$2.00, your name, address, andtype of computer, and we'll send you a tape for your computer with actual samples ofour programs.

Or circle our number on the reply card for a printed catalog.

Department 200 PROGRAM DESIGN, INC. 11 IDAR COURT GREENWICH, CONN 06830

December 1978 © BYTE Publications Inc 159

AIM 65.Only $375.

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communications between computers,having just read the DOC's (the CanadianFCC) proposals on the "Packet RadioService." Welcome to the 19th century,Mr Newcomb!

The DOC is proposing not 1 MHz,but the entire amateur radio 220 MHzband and very likely will finalize at220-221 MHz, leaving room for acommunicator class or GRS (CB) servicein the remaining 4 MHz. Our FCC, whichworks very closely with the DOC, isthinking along the same lines.

Unquestionably, we'll have radiocommunications between computerswithin the next year or two. I, for one,am extremely excited by the fantasticpossibilities, and am already working onsuitable equipment. I'd appreciatehearing from others working along thesame lines.

Donad L Stoner W6TNS/7

John Hancock Bldg

Mercer Island WA 98040

IDEAS NEEDED FORPROJECT TO AID DISABLED

The Spain Rehabilitation Center atthe University of Alabama MedicalCenter has a project underway todemonstrate both the utility andeconomic feasibility of the new gener-ation of personal computers for use bythe severely disabled. The program-mability of the computer will allow it toserve as a general purpose appliance tobe used as an aid to communication andeducation as well as for environmentalcontrol and entertainment.

This system, as currently envisioned,will consist of a microcomputer; an online storage device for programs anddata; two television monitors for userfeedback and information display; aprinting device for typed output; aspeech recognition device for vocal inputof commands, data, and text; a powerline controller for environmental con-trol; and a telephone dialing andanswering device. We are attempting toselect components which are widelydistributed and serviced as well as beingplug compatible and economicallypriced.

Programs will be written or pur-chased to perform specific functions ineach of the four general areas mentionedabove. However, we would be very inter-ested in receiving ideas from yourreaders, particularly those who aredisabled, those who have disabled friendsor relatives, and those who have personalcomputers and would like to develophardware or software for the system ontheir own, regarding specific functionswhich they would like to see developedand which could be accommodated bythe proposed microcomputer system.

We are looking forward to receivinginput from anyone who may be inter-ested in this project.

Charles Healey

Spain Rehabilitation Center

UAB University Sta

Birmingham AL 35294"

160 December 1978 © BYTE Publications Inc

Circle 313 on inquiry card.

BYTE's Bits

Pascal for Computer Club Members

The UCSD Pascal Project has an-nounced a special offer for bona fidecomputer clubs. The UCSD Pascal soft-ware, which normally sells for $200,will be made available to club membersat a sustantial discount if the club assistsin the copying and production costs fordisseminating the software. For moreinformation, computer clubs shouldcontact Tracy Barrett, CO 21, UCSD,La JollaCA 92093."

Attention: HAL 9000 Owners

We have just received word - of animportant new book: ProgrammingInstructions for the HAL 9000 Com-puter, revised edition. The new editionof the HAL 9000 handbook has beenupdated to incorporate improvementssuggested by this versatile machine'ssurviving users. In particular, the manu-facturers suggest that priority be givento the retrofitting of small explosivecharges at strategic points in the centralmemory unit.

Authorized by

Arthur C Clarke

Chief Semantic Controls Engineer

Colombo SRI LANKA"

Some BOMB Reflections

Occasionally we like to share some ofthe unfettered comments, pro and con,that arrive monthly on the BOMB cards,our system for reader response through apostacard at the back of the magazine.

The following BOMB card came froman anonymous Pascal enthusiast:

E30(V1E3: •yte-iOnpfciMaxtor*>» *\n

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•OMB . Rating

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Other BOMB comments about theAugust issue include:

Best BYTE I have read in along time. Please devote more dis-cussion to Pascal. The language InIts beauty, compactness and read-ability is worth talking about.Would like to know more aboutthe extensions being discussed forthe language.

The article by Weems ("De-signing Structured Programs")was easy to comprehend andde five red a valuable message.

This was one of your bestissues. I like having related articlesin one issue.

To be fair, not all the comments wereas positive as the last three. The follow-ing BOMB card was also received for themonth of August:

BOMB: OYTE'i Onto** Monrtor Box 41SS

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We have been suitably chastened.This is the first time we have been ac-cused of not being subjective enough,and we will attempt to examine the pro-blem as subjectively as possible. . . .CM"

Incremental Motion Control SymposiumIssues a Call for Papers

The Eighth Annual Symposium onIncremental Motion Control Systemsand Devices will be held at the RamadaInn, Urbana IL, May 21 thru 24 1979.A call for papers has been issued byProf B C Kuo, director of the sym-posium, which is sponsored by theIncremental Motion Control SystemsSociety, in cooperation with the Univer-sity of Illinois, Dept of Electrical Engi-neering, and Warner Electric Brakeand Clutch Company of Beloit Wl.

The symposium will encompass abroad area with sessions devoted totutorial papers as well as original con-tributions, covering step motors,

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Circle 2 on inquiry card.

December 1978©BYTE Publications Inc

161

Circle 33 on inquiry card.

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We're Byte Industries. Incorporated™

and were offering individual

Byte Shop™ franchises, nationwide.

Here's your chance to share

in the expanding retail personal

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AS A BYTE SHOP YOU GET:

• The nationally recognized Byte Shoptrademark

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• Comprehensive technical and businessmanagement training, and on-goingadvisory services.

• Aid in local site selection, andprofessionally designed store interiors.

• Exclusive, protected territories.

To qualify, you should have an interestin computers, and a desire and abilityto operate your own business. Retailexperience and a sales background atmanagement level is a plus. A theoreti-cal or working knowledge of computertechnology is helpful. Investment isroughly $100,000 with an initial equitycontribution of at least $40,000,

If you've got what it takes, then you'reready for your own Byte Shop.™Write or call Dave Pava, our franchisedevelopment manager now.

408739*8000

#Byte

Incorporated - A LOGIC Company

I Yes. I'm interested in a Byte Shop^Franchise Please send me your FranchiseInformation packet today.

I Name

| Address

| City

I State

■ Phone„

_Zip_

■ Byte Industries, Incorporated

I 930 West MaudeSunnyvale. CA 94086(408) 739-8000

OB-1

You Are What You Eat

machine tool control systems, computercontrols, linear and AC/DC motors,clutch-brake devices and systems, andrelated incremental motion controlapplications. Exhibit space will be avail-able.

The call for papers, both theoreticaland practical, related to incrementalmotion control systems and devices,requests authors to submit a summary ofabout 500 words by January 1. Finalmanuscripts will be due around midMarch. Send all summaries and inquiriesto Dr B C Kuo, POB 2772, Station A,Champaign IL 61820, phone (217)333-4341."

A Call for Papers

The Instrument Society of Americahas issued a call for papers for its 1979conference and exhibit, ISA/79, Theconference will take place at the O'HareExposition Center in Chicago IL, fromOctober 22 through 25 1979. Theconference theme, Instrumentation forEnergy Alternatives, will emphasizecurrent practices in instrumentationdesign and implementation. Papers arebeing sought in the following areas:analysis, automatic control, chemicalsand petroleum, cryogenics, data handlingand computation, education and train-ing, food, glass and ceramics, main-tenance, management, marine sciences,

metals, mining and metallurgy, power,process measurement and control, stan-dards and practices, telemetry, testmeasurement, water and wastewater,pulp and paper, and biomedical instru-mentation. Paper topics should intro-duce or explain techniques or inno-vations in instrumentation and controlsystems design, testing, operation andmaintenance. The papers may be eithertheoretical in nature or applicationoriented. The deadline for unsolicitedabstracts is February 5 1979. The appro-priate forms should be requested from:ISA/79, Instrument Society of America,400 Stanwix St, Pittsburgh PA 15222."

American Management AssociationOffers Courses for EDP and NonEDPProfessionals

The American Management Asso-ciation's Information Systems and Tech-nology Division is offering courses forboth the electronic data processing(EDP) and nonEDP professionalmanagers. A sampling of the coursesoffered include: systems analysis anddesign computer security, minicom-puters, distributed data processing,fundamentals of EDP, office auto-mation, EDP applications to humanresources and much more. The coursesrun through March 1979. A brochure

162 December 1978 © BYTE Publications inc

describing these courses is available fromthe American Management Association,135 W 50th St, New York NY 10020"

Addendum

In the September 1978 BYTE wepublished a write-up in the "What'sNew?" section on an assembly languagedevelopment system for 8080 and Z-80microcomputers (page 198). We wouldlike to pass along some additionalinformation, which we have just re-ceived: the PDS development system isavailable for $99 and is operational onany Z-80, 8080, and 8085 computerusing the North Star or MicropolisModel II disk units. Contact AllenAshley, 395 Sierra Mad re Villa, PasadenaCA91107"

BYTEs Bugs

Chess Bug

Due to an oversight on our part, anumber of errors appeared in theOctober 1978 "In This BYTE" entry(page 4) for "Creating a Chessplayer"by Peter W Frey and Larry Atkin. Theintroduction implies that Peter Frey isone of the creators of Chess 4.6. This isnot true. The program was written byLarry Atkin and David Slate. Peter Freywas also erroneously referred to as"David" Frey, and Larry Atkin as Larry"Atkins." We sincerely apologize to allconcerned for these errors."

Address Change

In the "What's New?" section ofNovember 1978 BYTE we reported ona new product from TSA Software (page216). This company has notified us of achange of address, Their new addressis: 39 Williams Dr, Monroe CT 06468."

Tilt!

Some errors crept into the PinballWizard program that appeared in myarticle "The HP-67 and HP-97: Hewlett-Packard's Personal Computers" (June1978 BYTE, page 112). The code instep 69 of listing 1 (page 114) shouldread "35 00," not "36 00"; the keyentry is correct, however. Also, step 189(page 115) should read "RCL B 36 12,"not"RCL6 36 06," and step 139 shouldread LBL 0 21 00 instead of LBL 0 2116.

My apologies to any readers whomight have experienced difficulties inusing the program.

Craig A Pierce

2529 S Home Av

Brewyn IL 60402"

Shown with

optional 4k Memory

GUNT BOARD" I Kluge Board.

HOBBYISTS! ENGINEERS! TECHNICIANS! STUDENTS!

Write and run machine language programs at home, display videographics on your TV set and design microprocessor circuits—thevery first night—even if you ve never used a computer before!

II featuring RCA COSMACmicroprocessor/ COMPUTER *9995

as FORTRAN and BASIC must be translated into machinelanguage before a computer can understand them. With ELFII you build a solid foundation in computers so you'll reallyknow what you're doing, no matter how complicated thingsget.

Video output also makes ELF If unique among computersselling for such a low price. Attached to your TV set, ELF IIbecomes a fabulous home entertainment center. It's capable ofproviding endless hours of fun for both adults and children ofall ages! ELF N can create graphics, alphanumeric displaysand fantastic video games.

No additional hardware is required to connect ELF II toyour TV's video input. If you prefer to connect ELF II to yourantenna terminals instead, simply use a low cost RF modulator(to order one, see coupon below).

ELF Il's 5-card expansion bus (connectors not included)allows you to expand ELF II as your needs for power grows. Ifyou're an engineer or hobbiest, you can also use ELF II as acounter, alarm, lock, thermostat, timer or telephone dialer, orfor countless other applications.

ELF II Explodes Into A Giant!

Thanks to ongoing work by RCA and Netronics, ELF IIadd-ons are among the most advanced anywhere. Plug in theGIANT BOARDS and you can record and play back programs,edit and debug programs, communicate with remote devicesand make things happen in the outside world. Add Kluge Boardto get ELF II to solve special problems such as operating amore complex alarm system or controlling a printing press.Add 4k RAM board and you can write longer programs, storemore information and solve more sophisticated problems.

Expanded, ELF II is perfect for engineering, business,industrial, scientific and personal finance applications. Noother small computer anywhere near ELF Il's low price isbacked by such an extensive research and development pro-gram.

The ELF-BUG** Monitor is an extremely recent break-through that lets you debug programs with lightening speedbecause the key to debugging is to know what's inside theregisters of the microprocessor and, instead of single steppingthrough your program, the ELF-BDG£* Monitor, utilizingbreak points, lets you display the entire contents of the regis-ters on your TV screen at any point in your program. You findout immediately what's going on and can make any necessarychanges. Programming is further simplified by displaying 24bytes of RAM with full address, blinking cursor and autoscrolling. A must for serious programmers!

Netronics will soon be introducing the ELF II ColorGraphics & Music System—more breakthroughs that ELF IIowners will be the first to enjoy!

Now BASIC Makes Programming ELF II Even Easier!

Like all computers, ELF II understands only "machinelanguage"—the language computers use to talk to each other.But, to make life easier for you, we've developed an ELF IITiny BASIC. It talks to ELF II in machine language for you sothat you can program ELF 11 with simple words that can betyped out on a keyboard such as PRINT, RUN and LOAD.

"Ask Now What Your Computer Can Do...But What Can It Do For YOU!"

Don't be trapped into buying a dinosaur simply because youcan afford it and it's big. ELF II is more useful and more funthan "big name" computers that cost a lot more money.

With ELF II, you learn to write and run your own programs.You're never reduced to being a mere keypunch operator,working blindly with someone else's predeveloped software.

No matter what your specialty is, owning a computer whichyou really know how to use is sure to make you a leader. ELF11 is the fastest way there is to get into computers. Order fromthe coupon below!

Stop reading aboureomputers and get your hands on one! WithELF II and our new Short Course by Tom Pittman, you canmaster computers in no time at all! ELF 11 demonstrates all 91commands an RCA 1802 can execute and the Short Coursequickly teaches you how to use each of the 1802's capabilities.

ELF Il's video output lets you display an alphanumericreadout or graphics on any TV screen or video monitor plusenjoy the latest video games, including an exciting newtarget/missile gun game that was specifically developed forELF II.

But that's not all. Once you've mastered computer funda-mentals, ELF II can give you POWER with add-ons that areamong the most advanced found anywhere. No wonder IEEEchapters plus hundreds of universities and major corporationshave chosen the ELF II to introduce their students and per-sonnel to microprocessor computing!

Learn The Skill That May Soon Be FarMore Important Than Your College Degree!

The ability to use a computer may soon be more important toyour earning power than a college degree. Without a knowl-edge of computers, you are always at the mercy of others whenit comes to solving highly complex business, engineering, in-dustrial and scientific problems. People who understand com-puters can command MONEY and to get in on the action, youmust learn computers. Otherwise you'll be left behind.

ELF II Is The F-A-S-T Way To LearnComputer Fundamentals!

Regardless of how minimal your computer background is now,you can learn to program a computer in almost no time at all.That's because Netronics has developed a special ShortCourse on Microprocessor And Computer Programming innon-technical language that leads you through every one of theRCA COSMAC 1802's capabilities so you'll understandeverything ELF 11 can do.. .and how to get ELF II to do it!

All 91 commands that an 1802 can execute are explained toyou, step-by-step. The text, written for Netronics by TomPittman, is a tremendous advance over every other program-ming book in print.

Keyed specifically to the ELF II, it's loaded with "handson" illustrations. When you're finished, ELF II and the 1802will no longer hold any mysteries to you.

In fact, not only will you be able to use a personal computercreatively, you'll also be able to read magazines such asBYTE... INTERFACE AGE ...POPULAR ELEC-TRONICS and PERSONAL COMPUTING and under-stand the articles.

If you work with large computers, ELF II and our shortCourse will help you to understand what makes them tick.

A Dynamite Package For Just $99.95!

With ELF II, you learn to use machine language—the funda-mental language of all computers. Higher level languages such

f^NOW AVAILABLE FOR ELF II—

D Tom Pittman's Short Course On Mi-croprocessor & Computer Programm-ing teaches you just about everythingthere is to know about ELF II or anyRCA 1802 computer. Written in non-

SEND TODAY!

□ Deluxe metal cabinet for ASCIIKeyboard, $19.95 plus $2.50 p&h.D ELF II Tiny BASIC on cassettetape. Commands include SAVE,LOAD, ±,'x,-j-,( ),26variables A-Z,LET, IF/THEN, INPUT, PRINT,

technical language, it's a learning GO TO, GO SUB, RETURN, END,

breakthrough for engineers and laymen REM, CLEAR, LIST, RUN, PLOT,

alike. $5.00 postpaid! PEEK, POKE. Comes fully docu-

D Deluxe metal cabinet with plexiglas mented and includes alphanumeric

dust cover for ELF II, $29.95 plus generator required to display al-

$2.50 p&h. phanumeric characters directly on your

O ELF II connects to the video input TV screen without additional hard-

of your TV set. If you prefer to use ware. Also plays tick-tack-toe plus a

your antenna terminals, order RF drawing game that uses ELF Il's hex

Modulator, $8.95 postpaid. hey board as a joystick. 4k memory re-

□ GIANT BOARD® kit with cassette £lu,red- *14'95 Postpaid.

I/O, RS 232-C/TTY I/O, 8-bit P I/O,decoders for 14 separate I/O instruc-tions and a system monitor/editor,$39.95 plus $2 p&h.

□ Kluge (Prototype) Board accepts upto 36 IC's. $17.00 plus $1 p&h.

□ 4k Static RAM kit. Addressable toany 4k page to 64k. $89.95 plus $3 p&h.

□ Gold plated 86-pin connectors (onerequired for each plug-in board). $5.70postpaid.

D Professional ASCII Keyboard kitwith 128 ASCII upper/lower case set,96 printable characters, onboard regu-lator, parity, logic selection and choiceof 4 handshaking signals to mate withalmost any computer. $64,95 plus $2p&h.

□ Tom Pitt man's Short Course on TinyBASIC for ELF II, $5 postpaid.

□ Expansion Power Supply (requiredwhen adding 4k RAM). $34.95 plus $2p&h.

□ ELF-BUG5* Deluxe System Monitoron cassette tape. Allows displaying thecontents of all registers on your TV atany point in your program. Also dis-plays 24 bytes of memory with full ad-dresses, blinking cursor and auto scroll-ing. A must for the serious program-mer! $14.95 postpaid.

Coming Soon: A-D, D-A Converter,Light Pen, Controller Board, ColorGraphics & Music System...andmore!

Call or write for wired prices!

Netronics R&D Ltd., Dept. 0000 *

333 Litchfield Road, Phone I

New Miiford, CT 06776 (203) 354-9375 ,

Yes! I want to run programs at home andhave enclosed: D $99.95 plus $3 postage& handling for RCA COSMAC ELF II kit

$4.95 for power supply (required), I

D $5 for RCA 1802 User's Manual, D $5 I

for Short Course on Microprocessor & I

Computer Programming. '

D I want mine wired and tested with I

power supply, RCA 1802 User's Manual ■

and Short Course included for just $149.95 Iplus $3 p&h!

D I am also enclosing payment (including I

postage & handling) for the items checked [

at the left. {

Total Enclosed (Conn. res. add tax) J

$ □ Check here if I

you are enclosing Money Order or Cashier's J

Check to expedite shipment. f

USE YOUR □ VISA D Master Charge ■

(Interbank # ) j

Account # j

Signature Exp. Date !

PHONE ORDERS ACCEPTED (203) 354-93751

Print |

Name I

Address |

City j

State Zip

, _. DEALER INQUIRIES INVITED

Circle 280 on inquiry card.

December 1978 © BYTE Publications Inc 163

Event Queue

In order to gain op timum coverage ofyour organization's computer confer-ences, seminars, workshops, courses, etc,notice should reach our office at leastthree months in advance of the date ofthe event. Entries should be sent to:Event Queue, BYTE Publications, 70Main St, Peterborough NH 03458.

December 3-5, Ninth North AmericanComputer Chess Championship,Sheraton Park Hotel, Washington DC.The 1978 annual meeting of the Asso-ciation for Computing Machinery will bethe site of this chess championship. Thiswill be a 4 round Swiss style tournamentwith participants restricted to com-puters. Two rounds will be played onDecember 3 (1 PM and 7:30 PM), oneon Monday (7:30 PM) and the lastround on Tuesday (7:30 PM). Deadlinefor entries is October 20. ContactProf M M Newborn, School of ComputerScience, McGill University, MontrealQuebec H3A 2K6, CANADA.

December 4-6, 1978 Annual Conferenceof the Association for ComputingMachinery, Sheraton Park Hotel,Washington DC. Contact Dr RichardAusting, Dept of Computer Science,University of Maryland, College ParkMD 20742, (301)454-2004.

December 4-6, Minicomputers and Dis-tributed Processing, Atlanta GA. This3 day seminar will examine the uses,economics, programming and implemen-tation of minicomputers. Contact PhilipM Kowlen, director, Center for Con-tinuing Education, The University ofChicago, 1307 E 60th St, Chicago IL60637.

December 4-8, Microcomputer SoftwareDesign, Virginia Polytechnic Instituteand State University, Blacksburg VA.This workshop will develop assemblylanguage programming skill for 8080 and8085 based microcomputers. Topics to

Content-Addressable Memory

for the S-100 bus

Discussed and dreamed about bycomputer scientists for years, Con-tent-Addressable Memory (CAM)is now here at an affordable price.CAMs hqve been so costly to buildthat few have actually been pro-duced. Now Semionics has devel-oped a simplified design, loweringthe cost by two orders of magnitude.This new memory is called Recogni-tion Memory (REM), since (like thehuman brain) it can recognize words,patterns, etc.

Adding a REM board to an ordinarymicrocomputer converts it into a verypowerful machine known as a Con-tent-Addressable Parallel Processor(CAPP).Features:

ytes per boardStatic—no refresh neededCan be used as ordinary RAMor as CAM

RAM access time: 200 ns

CAM*Multiwrite—writing into multiple tlocations with one instructionMasking—for individual bit

Adds 17 associative memory func-tions to instruction set of Z-80 or 8080.Applications:

Pattern Recognition • InformationRetrieval • Compiling & Interpreting• Natural Language Processing •Code Compression • Artificial Intel-ligencePrice: $325

4K firmware package of REMroutines: $80

X SEMIONICS

41 Tunnel Road • Berkeley «CA 94705(415)548-2400

be discussed include floating pointmathematics, lookup tables, numberbase conversion, interrupt programming,searching and sorting. Contact Dr LindaLeffel, Donaldson Brown Center forContinuing Education, Virginia Poly-technic Institute and State University,Blacksburg VA 24061, (703) 951-5421.

December 6-8, Data Processing Oper-ations Management, Washington DC.This 3 day seminar will emphasize themanagement skill and techniques appli-cable to the data processing operationsfunction. Contact Phillip M Nowlen,director, Center for Continuing Edu-cation, The University of Chicago,1307 E 60th St, Chicago IL 60637.

December 12-14, Midcon/78, DallasConvention Center, High Technologyelectronics show and convention.Contact Electronic Conventions Inc,El Segundo CA, (800) 421-6816 (tollfree).

December 13, Computer NetworkingSymposium. Sponsored by the IEEEComputer Society's Technical Com-mittee on Computer Communicationsand the Institute for Computer Sciencesand Technology of the National Bureauof Standards. This symposium will high-light papers of practical and researchexperiences concerning both computerand communication networks. ContactDr George Cowan, Computer SciencesCorp, 6565 Arlington Blvd, Falls ChurchVA 22046.

December 13-15, Distributed Mini-computer Networks, Executive TowerInn, Denver CO. This seminar willaddress the minicomputer from theviewpoint of the distributed networkuser. The structure and management of alarge data base and software problemswith the trade-offs of languages utilized,hardware types, input and outputoptions, device controllers, systemfailure and recovery, sample applicationcase studies and the economics of mini-computer applications will be coveredin depth. Contact The Institute forProfessional Education, Suite 601, 1901N Fort Myer Dr, Arlington VA 22209,(703) 527-8700.

December 18-21, Microcomputer DataAcquisition, Instrumentation andMeasurement Systems, Virginia Poly-technic Institute and State University.Course to be given by the authors of theBug books. Contact Dr Linda Leffel,Donaldson Brown Center for ContinuingEducation, Virginia Polytechnic Instituteand State University, Blacksburg VA24061, (703)951-5421.

January 8-12, Structured Programmingand Software Engineering, GeorgeWashington University, Washington DC.This course is designed for experiencedprogram architects, designers andmanagers. It will provide up to datetechnical knowledge of logical expres-sion, analysis and invention for per-forming and managing software archi-

164 December 1978 © BYTE Publications Inc

Circle 323 on inquiry card.

PROGRAMS

GAMES

Eleven computer games, including Black- Ijack, Hangman, 23 Matches, Tlc-Tac-Toe,Silly Sentence Maker, Poem Writer, WordPuzzle, Backtalker, Math Quiz, Caricature |Printer, and Typing Speed Drill. (Stock No101.1, Cassette, Requires Ext. B.H. Basic,Issue 10.01 or 10.02, $10)

PERSONAL FINANCE

Includes two programs. Personal Budget

provides a personal accounting system andhelps reconcile your checkbook. Interestcalculates simple interest, compoundinterest, and mortgage amortizationschedules. (Stock No. 102.1, Cassette,Requires Ext. B H Basic, Issue 10.02, $10)

COOK'S HELPER

Two programs to help the cook Menu pro-duces nutritious, within-calorie-limits Imenus. Shopper makes your trip to the |grocery store more enjoyable by arrangingyour grocery list in the shelf order of yourfavorite store, prevents backtracking tolook for missed items (Stock No. 103.1,Cassette, Requires Ext. B.H. Basic, Issue10.01 or 10.02, $10)

MAILING LIST

Features programs for the creation, updat-ing, sorting, and printing of mailing lists Iand labels. Highly flexible, with provisionfor coding each entry, sorting on any desiredfield, printing selectively by code, printing |on various sizes and layouts of labels.(Stock No. 104.1, Cassette, Requires ExtB.H Basic, Issue 10.02. $20)

MAILING LIST-DISK

This disk-based package contains features Isimilar to those of the cassette version |above, plus the addition of a feature thatpermits computerized printing of formletters to persons on the mailing list. (StockNo. 114.1, Diskette, Requires HDOSBasic, $30)

IJ-fre Incorporated

6580 Buckhurst TrailAtlanta, GA 30349

Please send the following:

Amount Enclosed

GAMES @ $10PERSONAL FINANCE @ $10COOK'S HELPER @ $10MAILING LIST @ $20MAILING LIST-DISK @ $30

TOTALLess 10% Discount if OrderingTwo or More Items

AMOUNT ENCLOSED $_

Name __

Street Addr

City

State

tecture, design and production. Presen-tations will cover principles and appli-cations in structured programming andsoftware engineering. Design workshopswith analysis and review sessions willprovide actual practice in problemsolving. Contact George WashingtonUniversity, Continuing Engineering Edu-cation, Washington DC 20052.

January 15-17, Minicomputers and Dis-tributed Processing, San Francisco. Fordetails, see December 4-6, Atlanta.

January 17-19, Distributed Minicom-puter Networks, Ramada Inn, ArlingtonVA. For details, see December 13-15,Denver.

January 24-27, International Microcom-puters/Minicomputers Microprocessors'79/Japan, Harumi Exhibition Center,Tokyo. Contact ISCM, 222 W Adams St,Chicago IL 60606, (312) 263-4866.

January 30-February 1, CommunicationNetworks Conference and Exposition,Sheraton Park Hotel, Washington DC.Designed to bring together communi-cation network users, consultants, ven-dors and regulatory officials so thatissues can be discussed and analyzed.It is particularly aimed at executivesand managers who purchase communi-cation products and services. ContactThe Conference Company, 60 Austin St,Newton MA 02160.

February 1-3, Microprocessor Program-ming Workshop with a Take-HomeMicroprocessor, Jefferson Plaza Building.Arlington VA. Sponsored by the IEEE,this 3 day workshop is intended for thepracticing engineer, engineering managerand programmer. The course objectiveis to provide state of the art informationin order to acquire an understandingof the place of microprocessors asreplacements for wired logic and ascontrollers; to provide the capability ofunderstanding the design of systemsinvolving microprocessors; and theability to program the Motorola M6800microprocessor in machine language. AMstudents will have their own micro-processor and laboratory equipment.Contact IEEE Service Center, 2145Hoes Ln, Piscataway N] 08854.

February 13-15, The National OfficeExhibition and Conference, HarbourCastle Hilton Convention Center,Toronto Ontario. This 3 day exhibitionwill provide a showplace for approxi-mately 100 exhibitors in the areas ofword processing, office computers,office equipment and furniture. ContactCanadian Office magazine, 2 Bloor St W,Suite 2504, Toronto Ontario, CANADAM4W3E2, (416)967-6200.

February 14-16, The IEEE InternationalSolid-State Circuits Conference, Phila-delphia PA. Forum for the presentationof new advancements in all aspects ofsolid-state circuits. Contact LewisWinner, 301 Almeria Av, POB 343788,Coral Gables FL 33134"

SELECTOR II

• A QUERY LANGUAGE

• A REPORT WRITER

• AN ISAM FILE SYSTEM

What does SELECTORII do? Well just abouteverything . . .Simply define a filerecord with item namesand types (money fieldsor dates, etc.). Pick keyfields. Enter data.

At any time you canselect records by key forupdating or deletion. Oryou can select collect-ions of records by thedata they contain (likeall blue-eyed ladiesspeaking French whopurchased Gizmo 500'sin March). You can havethat information dis-played or summarizedon your screen or listedon your printer properlytitled, paginated, for-matted, totaled, aver-aged, max-ed or min-ed... as you desire.

SELECTOR II does all ofyour fielding, finding,formatting and fumingfor you. All you need dois issue orders.

SELECTOR II is avail-able for MicrosoftExtended Disk BASICand CBASIC, on diskette,with user's manual for$255 including 1 yearmaintenance. Dealer in-quiries gladly accepted.

Micro-Ap

8939 San Ramon Road

Dublin, CA 94566

Circle 113 on inquiry card.

Circle 218 on inquiry card.

December 1978 © BYTE Publications Inc 165

QlubsandNewsletters

Attention: Robot Enthusiasts

The Robotics Newsletter is a month-ly periodical for robot enthusiasts onboth the hobby and professional level.It presents timely articles on micro-computers, batteries, motors, automatatheory, sensory devices, manipulators,biophysical analogs, robot history, etc.Yearly subscriptions are $8. Contact theInternational Institute for Robotics,POB 615, Pelahatchie MS 39145.

Northern New England ComputerSociety

Albert Brunelli has written us that anew computer club has been formed "uphere in the north woods." It is locatedin Berlin NH and is called the NorthernNew England Computer Society. Theymeet the second Thursday of eachmonth at 7 PM at the New HampshireVocational Technical College, Milan Rd,Berlin. Their aim is to set up an areathat is accessible to local people wherethey can learn about and use small

computers. The membership fee is $10per year. For more information, writeto Albert Brunelli at POB 69, Berlin NH03570.

Denver Amateur Computer Society

The Denver Amateur ComputerSociety now has permanent club quar-ters and office at 1380 S Santa Fe Dr,Denver CO 80223. The club meets thethird Wednesday of every month at7:30 PM. For further information,write to the society's president, MikeDymtrasz, at the above address or call(303)979-6441.

The Okaloosa Computer Hobbyist Club

We have been notified that theOkaloosa Computer Hobbyist Club hasbeen formed in Ft Walton Beach FL.The meetings are held on the second andfourth Tuesday of each month and allinterested persons and newcomers arewelcomed. For more details, write toLoretta R Guske, #72, 32 Denton BlvdNW, Fort Walton Beach FL, (904)242-5938.

Computers in Mental Health Newsletter

Micro-Psych is a newsletter for pro-fessionals interested in the use of com-puters in mental health. Each bimonthly

S-100 BUS COMPATIBLE. The EMM 1104 single card plug-in memory hasbeen field tested and proven in a variety of systems including the Poly 88,IMSAI, MITS, COMPAL-80, TLD and CREMENCO. 16K BYTES ON A CARD.Convenient plug-in card, fully burned-in, tested and guaranteed by one ofthe industry's largest memory suppliers. NMOS STATIC RAM. The 4Kstatic RAMs have been proven in applications ranging from single chipmemories to IBM 370 add-on systems. They are fast,reliable, and no refresh cycle is required.See your dealer, or contact us for complete information.

S-100 Bus Compatible Memory

16K bytes on a card

NMOS static RAM

edition contains reviews of current workin the field, a forum for the exchange ofinformation, an ongoing bibliography,and news about pertinent hardware andsoftware. Membership and a subscriptionto Micro-Psych costs $10 per year. Formore information about this newsletter,contact Marc D Schwartz, MD, 26Trumbull St, New Haven CT 06511.

Connecticut Computer Club WelcomesAll Level Hobbyists

The Connecticut Computer Club,which is a few years old, consists of aninformal group of software and hardwarepeople who meet on a monthly basis toexchange ideas. Speakers and demon-strations are of general group interest.The club meets the first Thursday ofeach month at either the SuffieldLibrary or The Computer Store ofWindsor Locks. A newsletter is availableto members at a yearly cost of $5.Contact Leo Taylor, 18 Ridge Ct W,W Haven CT 06516, (203) 933-5918.

Quad City Computer Club

We have heard from John E Greve,president of the Quad City ComputerClub (QC3). The club, devoted to allphases of hobbyist computing, meets onthe first Sunday of each month at 7 PMat the Rock Island Arsenal classroom#5, Rock Island IL. The dues are $6per year, which includes a newsletter.For more information concerning thisclub, contact John E Greve, 4211 7thAv, Rock Island IL 61201.

Apple II Users Group in Portland OR

The Apple Portland Program LibraryExchange, or APPLE for short, has beenformed as a users group for owners ofthe Apple II. They are interested inexchanging programs and ideas withother clubs. Send a self-addressedstamped envelope for an applicationform to Ken Hoggatt, 9195 SW ElroseCt,Tigard OR 97223.

Canadian PET Owners Start Users Group

The Vancouver PET Users Grouprecently held their second meeting.Attendees included 40 owners and 15PETs. The club format includes a shortpresentation by a PET owner on pro-gramming, or PET hardware news fromCommodore and other sources. This isfollowed by PET patter and programswapping. For more information aboutthis club, write to Richard Leon,Vancouver PET Users Group, POB35353, Station E, Vancouver BritishColumbia, CANADA.

TRS-80 Computing

A complimentary copy of TRS-80Computing has been sent our way. This32 page first edition is packed withTRS-80 news including articles by aTRS-80 designer, a Radio Shack repair-man, and a couple of programmers; anarticle on how to install your own 16 K

166 December 1978 © BYTE Publications Inc

Circle 132 on inquiry card.

THE ENDOF YOURSYSTEM

The

Put this SOROC IQ 120 at theend of your system for fast andsilent input/output.

$"7QC00*

795

Put this T.I. 810 printer at theend of your system for fast andreliable hard-copy output.

$169500*

Put this TELETYPE 43 at theend of your system for reliablelow-cost input/output.

$

999

00*

[

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byte integrated circuits and save; a 10page schematic, and considerably more.The price for 12 issues is $10 and isavailable from Computer InformationExchange Inc, POB 158, San Luis ReyCA 92068.

Chicago Area Computer HobbyistExchange Forms User Groups

In keeping with the club's philo-sophy of dedication to investigatingthe roles and uses of microcomputersand related small size computing devicesin the hobbyist field, the Chicago AreaComputer Hobbyist Exchange (CACHE)has recently announced the formation ofuser groups. According to the club'snewsletter CACHE Register, the NorthStar, SOL and Digital Group user groupsare active and going strong. The CP/M,H-11/LSI-11 and computer aided in-struction user groups have formed butare not meeting regularly. There areother groups in the formative stages.CACHE members meet on the thirdSunday of each month at 1 PM in theNorthern Illinois Gas Building, Golfand Shermer Rds, Glenview IL. ContactBill Precht, president, POB 52, S HollandIL 60473.

Attention Minneapolis/St PaulApple II Users

We have been notified by DanBuchler, 13516 Grand Av S, BurnsvilleMN 55337, that an Apple II users grouphas been formed in the Minneapolisand St Paul area. The purpose of thegroup is to promote the exchange of userdeveloped programs and technical infor-mation among Apple II users. Help indocumenting programs will be offered.Contact Dan Buchler for further infor-mation.

Newsletter for Users of Digital GroupEquipment

BRIDGE (Bidirectional Reflectionsfor the Illumination of Digital GroupEnthusiasts) is an impressive newsletterdevoted to helping fellow Digital Groupowners over the voids. The cost ofmembership is $6, which entitles you tosix issues of the newsletter. The mostrecent newsletter contains a couple ofarticles, items for sale, random bits ofinformation of interest to Digital Groupequipment owners and much more,including a letter from BYTE's SteveCiarcia, an occasional contributer. Ifthis newsletter is of interest to you, itcan be obtained by writing to the DigitalGroup Independent Users Group, POB316,Woodmere NY 11598.

Rockwell's AIM 65 Users Group

An AIM 65 users group is beingformed for Rockwell's computer-on-a-board. A bimonthly newsletter will beavailable in January 1979 for $5 peryear. Article contributions are welcome.For more information about this group,contact Don Clem, RR #2, SpencervilleOH 45887."

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Circle 328 on inquiry card.

December 1978© BYTE Publications Inc 167

Partitioned Data Sets

A I Halsema

32014 GrenvilleCt

WestlakeCA 91361

Figure I: Information ar-rangement for a smallpartitioned data set.

VOLUME TABLEOF CONTENTSTRACK

VOLUMESERIALNUMBER

TRACKMAP

SECTORMAP

SYSTEMLIBRARYCONTROLBLOCK

EMPTY CONTROLBLOCKS

SEDITR

ASSM

LEDITR

SOURCEEDITOROBJECTCODE

ASSEMBLER

OBJECT

CODE

LINKAGEEDITOROBJECTCODE

FREESPACE

DIRECTORYENTRIES FORMEMBERS

MEMBER

DATA

RECORDS

About the Author

Mr Halsema is projectleader of a funds transfersystem for a subsidiary ofthe First National CityBank. At home he ownsa SwTPC 6800 with cas-sette storage and videoterminal,

If you have a floppy disk and are havingtrouble keeping track of where your pro-grams and data are written on it, this simplefile organization technique may provide theautomated management of disk space youneed.

A partitioned data set (PDS) is a filedivided (or partitioned) into areas, eacharea containing data not related to data inother areas. For example, a system librarymight contain a source editor, assemblerand linkage editor. Each of these programscould be stored in a separate partition in apartitioned data set. The partitioned areasin which these programs would be storedare called members of the data set, so thepartitioned data set just described wouldcontain three members, as in figure 1.

(W

Volume label

Number of table of contents sectors

T ra c ks pe r vo I u m e

Sectors per track

Bytes per sector

Track map

Sector map

Unused

Ob)

Data set name

Beginning address of data set

Ending address of data set

Length of logical records in data set

Length of directory in sectors

Unused

6 bytes1 byte1 byte

1 byte

2 bytes10 bytes97 bytes10 bytes

6 bytes2 bytes2 bytes1 byte1 byte4 bytes

Table 7; Possible arrangement for the label record (la) and data set controlblock (lb) for a partitioned data set.

Designing the Partitioned Data Set

Four things are required for definitionof a partitioned data set. First, a map fordefining those areas on the disk that are inuse (allocated). For this we create a trackmap that defines each track on the disk withone bit. If the bit is set to 1, the corres-ponding track is free. If the bit is set to 0,the track is in use. For a disk with 77 tracks,a 10 byte track map is sufficient. The posi-tion of each bit in the map defines theaddress of its associated track. The firstbit in the map defines track 0, the secondbit defines track 1, etc. The track map isreferenced whenever a data set is allocatedor scratched, so the smallest data set possiblewould be 1 track in length.

Second, we need a sector map to keeptrack of which sectors are in use and whichare free. As in the track map, we assign 1 bitin the map to each sector. If our disk has 10sectors per track, the sector map must be770 bits in length, so we assign 97 bytes toit. As in the track map, the position of eachbit defines the address of the associatedsector. The sector map, table 1, is used whena member is created in or deleted from adata set.

Third, a control block for defining thename and location of the partitioned datasets is needed. These blocks can immediatelyfollow the maps, and should contain spacefor the data set name, starting track addressof the data set, length of directory in tracks,and the ending track address of the data set.Following this control block are similar

168 December 1978 © BYTE Publications !nc

Member name

Start of data area address for member

End of data area address for member

Number of logical records in use

Data type of member

Unused

6 bytes2 bytes2 bytes

2 bytes1 byte

3 bytes

Table 2: Format for the directory entry information.

control blocks for other data sets andunused (free) control blocks. A free controlblock is indicated by the name field beingfilled with binary Os.

The maps and the control blocks can allfit on a single track. This track is called thevolume table of contents (VTOC) and beginswith the volume label, also known as thevolume serial number (VSN). If we want amultitrack volume table of contents, weneed to define how many tracks are in thetable for use by the access method software.A byte for a count of the tracks in thevolume itself should be included. If oursystem is to handle different formats anddensities it would be wise to include theformat information in the table of contents.The access method software could then readthe count of the number of tracks on thedisk and the number of sectors per trackdirectly from the table and be able tohandle several formats without modification.

In order to avoid wasting disk space, 16byte logical records can be blocked 8 to a128 byte sector. A single track volume tableof contents blocked in this way could handle136 partitioned data sets. The fourth itemrequired for a partitioned data set is a direc-tory for the members in the data set. Thedirectory, table 2, begins at the first sectorof the first track of the actual data storagearea. The directory entries are 16 bytes longand packed 8 to a 128 byte sector. Eachentry contains the name of the member, thestarting and ending track and sector addressesof the member, the count of the number ofsectors actually used by the member, andthe data type of the member. The data typemay be:

( diskinit J

COMMAND

OUTPUT READCOMMAND TEXT

CREATETRACK MAP

CREATESECTOR MAP

WRITE FIRSTVOLUME TABLE OFCONTENTS SECTOR

SEEK NEXTSECTOR

WRITE A ZEROFILLED SECTOR

MOVE TO FIRSTSECTOR OF DATASTORAGE AREA

1

\

WRITE ZEROFILLED SECTOR

SEEK NEXTSECTOR

/of C

slD\

ata\ no

AREA?

YES

( "T )

Figure 2: Disk initiaiiza-tion program.

0 : Source data.

1 : Core image object data.

2 : Relocatable object data.

Both source and BASIC programs may bestored in a member of data type 0, whiledata type 2 is used as input to a relocatingloader, linking loader or linkage editor.Data type 1 is used for storing nonrelocatableprograms.

Now that the design of the file structureis complete, we can design software that willcreate, manipulate and delete members anddata sets.

Implementation

The first program we need is a disk initial-ization routine such as the one in figure 2.The initialization routine creates and emptiesthe volume table of contents track and clearsthe data storage area by setting it to 0.The user is required to enter the volumeserial number and the beginning and endingtrack numbers of the data storage area. Thetrack and sector maps are created so that thebits corresponding to the data storage areaare set to 1 (free space) and all other bits

December 1978©BYTE Publications Inc

169

(allocate J

OUTPUT READCOMMAND TEXT

SEARCH ON LINEDRIVES FORPROPER DISK

(ERROR "\EXIT J

SEARCH TABLEOF CONTENTS FORDATA SET NAME

(ERROR A_EX'T J

Figure 3: The A LLOCA TEroutine, used to put a newfiie onto the disk andupdate ail pointers toindicate that the fiie ispresent

(ERROR "\."IT J

(ERROR \EXIT J

(ERROR *\EXIT J

SEARCH DIRECTORYFOR MEMBER NAME

SEARCH SECTORMAP FOR FREESPACE

SEARCH DIRECTORYFOR EMPTY ENTRY

SET SPACE INSECTOR MAP"IN USE "

REWRITE VOLUMETABLE OF CONTENTS

BUILD

DIRECTORY ENTRY

( EXIT )

SEARCH TRACKMAP FOR SPACE

SEARCH VOLUME TABLEOF CONTENTS FOREMPTY CONTROL BLOCK

SET SPACESTATUS "IN USE"IN TRACK MAP

BUILD CONTROLBLOCK

SET DIRECTORYSECTORS "IN USE"IN SECTOR MAP

REWRITE VOLUMETABLE OFCONTENTS

SET DATA STORAGEAREA TO ZERO

( EXIT )

(ERROR\

(ERROR %EXIT J

(ERROR AS2L J

170 December 1978 © BYTE Publications Inc

Circle 8 on inquiry card.

are set to 0 (space used). The volume label,a count of the tracks used by the volumetable of contents (permanently set to 1) andthe maps are then written on the first sectorof the first track of the disk. All othersectors of the table of contents track areset to binary 0. Every sector of the datastorage area is also set to 0. Initializationof the disk is now complete.

Once the disk has been initialized, we canallocate data sets on it by using the allocateroutine. The allocate routine shown in figure3 actually consists of two routines: one toallocate data sets, and one to allocate mem-bers in a data set. To allocate a data set, theuser enters the volume serial number of thedisk, the name of the data set to be allocated(six characters maximum), the number ofsectors to be used for directory, and thenumber of tracks to be devoted to the dataarea. Note that the space used for the direc-tory is included in the amount of spaceentered for the data area definition.

The allocator routine then reads thevolume table of contents track and verifiesthat the volume serial number on the diskmatches that entered by the operator andthat the data set name to be used does notalready exist. If neither test fails, the trackmap is scanned for contiguous free spaceequal to the amount requested by the user.If the free space is found, the necessarybits are reset to 0 in the track map. The dataset control block is now built by movingthe required data into an empty block in thetable of contents. The sector map is alsoupdated to reflect the sectors used by thedirectory and the updated volume tableof contents is rewritten on the disk, com-pleting the allocation of a data set

To allocate a member, the user must pro-vide the volume serial number of the diskas well as the name of the data set of whichthe member will be a part, the member'sname (six characters maximum), memberdata type, and the number of sectors to allo-cate to the member. The allocator programagain verifies that the proper disk is on lineand that the data set exists. Obtaining theaddress of the partitioned data set's direc-tory from the control block for the data set,the allocator verifies that a member with thesame name as that being allocated does notalready exist. If all is well, the sector map isscanned for contiguous free space in thedata set's data storage area sufficient tosatisfy the user's request. If space is available,an empty directory record is used to createa directory entry for the member. Thesector map is then updated and the directoryand table of contents are rewritten on thedisk.

We now have a partitioned data set with

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Sol is dependable. Each one comes with a full year's warranty.And when you do need service, just call us. We don't sell what wecan't keep running!

If you, along with hundreds of others, are sold on Sol, there'sonly one thing left to do. Talk to The Microcomputer People® atComputer Mart of New Jersey and Computer Mart of Pennsylvania.Write or call us today.

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Circle 73 on inquiry card.

December 1978 © BYTE Publications Inc

171

Circle 374 on inquiry card.

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a member allocated in it. To use this mem-ber, we need an access method to performthe input/output (10) operations involvedin opening the data set, finding the desiredmember, reading and writing the data inthe member, and finally closing the dataset. In addition, it is useful to have theaccess method open members sequentially.Given such an access method, we couldgraduate from doing physical 10 to a farsimpler logical 10 in which we need onlyspecify the volume serial number of a disk,a data set name and a member name inorder to read or write data. The accessmethod takes care of error processing,10 initialization and completion. Theaccess method would be used by the sourceeditor for saving source lines in members,and the assembler would use it for readingprogram source lines and writing programobject code. This means that two memberswould be open simultaneously, but theaccess method should be able to handlethat situation.

In order to free space on the floppy disk,deletion programs are required. Scratchinga data set would deallocate the space usedby the members in the data storage area(recorded in the sector map) and clear thetrack map bits used for the overall spaceallocation for the data set. The data setcontrol block is then filled with binary 0s,freeing all space previously allocated.

Scratching a member requires thatthe sector map be updated and the direc-tory entry for that member be rewritten asbinary 0s. The deletion programs should bewritten to be as forgiving as possible ofoperator errors. After the operator hasfinished giving the delete command, theprogram should echo the command andwait for operator verification. All this isneeded in order to avoid accidentally de-stroying irreplaceable data.

Another useful program is the volumetable of contents lister. The list programreads the data set control blocks fromdisk, formats and displays the informa-tion contained in them, and indicates howmuch space is allocated to each data set andhow much free space remains. As an addedfeature, the lister could be made smartenough to use the data in the data setcontrol blocks to find and display thecontents of the member's directory entries,thereby providing a powerful tool forcontrolling the data on the disk.

As with all good things, the free spaceon the disk will soon come to an end. Theobvious solution is to delete a few membersor data sets to make room for new things,but this has the disadvantage of destroying

172 December 1978 © BYTE Publications )nc

Circle 298 on inquiry card.

uircie 01 on inquiry caru.

programs and data that may be important.

A better solution would be to placethese programs into cheap archival storagein a format that simplifies their restorationonto the disk. Thus, the members or data setsto be saved would be written to magnetictape by an unload program and writtenback on the disk later with a load program.The unload program reads the data setcontrol block of the data set to be unloadedand writes it on tape. It then reads the direc-tory entries for the members of the dataset and writes the one selected to tape, fol-lowed by the data for the member from thedata storage area. It continues to write direc-tory entries followed by member data untilthe request entered by the user is completed.

The load program reads the data from thetape and if necessary allocates data sets andmembers before writing the data into themfrom the tape.

The partitioned data set file organizationtechnique has been used successfully onmany large systems and can be easily adaptedfor use by the hobbyist. In order to avoida situation similar to that encountered withaudio cassettes, standards should be formu-lated now so that disks can be interchangedfrom user to user."

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Circle 93 On inquiry Card. December 1978©BYTE Publications Inc 173

Programming Quickies

Tic-Tac-Toe in BASIC

Mike Stoddard16681 Lynn StHuntington Beach CA 92649

Figure 1: This is one ofthe patterns that can beused to always beat thecomputer. There are threeother winning strategiesthat wiil result in a win forthe human player.

Tic-Tac-Toe is a game that has beenturned into a computer program thousandsof times. Although it is fun to play with acomputer, the best a human opponent canhope for is a draw game. After a short timethe player loses interest because he or shenever has any chance of winning. My versionplays a regular game except that there are a

THfc CAMfc OF TIC-TAC-TOE. THERE ARE 4 POSSIBLE GAMESWHICH YOU CAN WIN. THE BOX SQUARES ARE NUMBERED!

I 2 3

4 b 67 8 9

I AM NOh READY TO PLAY. YOUR MOVE FIRST.

? 4 I WILL PUT AN X IN BOX 5 YOUR TURN.

? 2 LET'S PUT AN X IN BOX 9 YOUR TURN.

? I AN X IN BOX 3 WILL STOP YOU. YOUR TURN.

? 7 CONGRATULATIONS. YOU WIN THIS GAME.

n o x

o x -

o - x

I AM NOW READY TO PLAY. YOUR MOVE FIRST.?

few logic errors which put the player on amore even level with the computer. There isa fighting chance against the now imperfectopponent. The program logic that scans therows, columns and diagonals has beenaltered to produce countermoves much likethose of a person just learning the game.After playing dozens of games with themachine, if the player is lucky, the patternof moves that fool the machine will emergeand allow the player to beat the machineevery game. One such pattern is shown bythe sample game of figure 1.

To change the program logic back toplaying a perfect game every time, changethe value of Z at line 1140 from 1 to 2.This hint should allow any good hacker tofigure out how the program works inter-nally. You can have fun playing the com-puter and showing your friends you are,indeed, smarter than the computer!

What it means to you,

digM«kiHzer/dij*e'kit*izer/ n: (1): a high-value low-cost computer graphic input devicedesigned to be assembled by the user"(2): themost advanced graphics tablet in kit form (3):An instrument that, when assembled, allowsthe user innumerable methods of design andanalysis functions (4): Thelatest addition to the most k « # . ^

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174 December 1978 ©BYTE Publications tnc

No adjustments. No calibration.

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Circle 359 on inquiry card.

Listing 7: BASiC source code iisting forTic- Tac Toe game.

1000 REM "TV mmmm TIC-TAC-TOE WITH A TWIST

1010 REM 02-05-77 WRITTEN BY MIKE STODDARD

1020 REM

1030 DIM K(3,3). L<9),C*U2)

1040 PRINT "\21TATHE CAME OF TIC-TAC-TOE THERE ARE 4 POSSIBLE GAMES"

1050 PRINT "WHICH YOU CAN WIN THE BOX SQUARES ARE NUMBERED:"

1060 PRINT "\2irA 1 2 3\215\ 4 5 6\215\ ,76 9Y215V'

1070 FOR 1=1 TO 3

1080 FOR J<-1 10 3

1090 LKT K(I.J>«9

1100 LET L< (I-l>»3+J)«=0

1110 NEXl J

1120 NEXT I

1130 LET k:j 1

1140 LET 1*1

1150 PRINT "J AM NOW READY TO PLAY. YOUR MOVE FIRST. "

1160 60SUB 2900

1170 IF F«=l GO 10 1160

1180 LET L(l>^L1

1190 LET N2*1

1200 GOTO 2400

1210 IF K(2,2»<>9 GOTO 1250

1220 LET K(2. 2>< 4

1230 LET N^t>

1240 OOTO 1270

1250 LET Ml. 1 >' 4

1260 LET N-1

1270 LET LC'KN

1260 PRINT l Alf (7);"I WILL PUT AN X IN BOX

1290 GOSUB 2980

1300 IF F»l GOTO 1290

1310 LET L(3)=L1

1320 LET N2^2

1330 OOTO 1200

1340 LET H*f]

1350 LET NI»-1

1360 GOTO 1890

1370 ON Z GOTO 1420, 1380

1380 IF L(l>+L(3><>6 OOTO 1420

1390 LET N*l

1400 LET Ml, 1)' 4

1410 GOTO 1440

1420 LET M=22

1430 GOTO 1890

1440 LET L(4)=N

1450 PRINT TAB <7)i"LET'S PUT AN X IN BOX"

1460 GOSUB ,"9HO

1470 IF F=l GOTO 1460

1480 LET LI5)=L1

1490 ON Z GOTO 1570. 1500

YOUR TURN.

YOUR TURN

1500

IF Ll<>2 GOTO 1570

1510

IF Lt 11 H_<;h>013 GOTO 1570

1520

IF M1.3K>9 GOTO 1570

1530

LET H--:i

1540

LET MJ, 3)= 4

1550

LET Ml, 2)- 1

1560

GOTO 1760

1570

LET HP- 3

1580

GOTO 1200

1590

LET M=3

1600

LET Nl^-5

1610

GOTO 1870

1620

LET H-17

1630

LET Nl=2

1640

GOTO 1090

1650

LET M=1J

1660

LET Nl = 3

1670

GOTO 1890

1680

LET M-IT'

1690

LET N1M

1700

GOTO 1890

1710

LET L(6)-N

1720

GOTO 2960

1730

LET L(6)=N

1740

PRINT TAH (7);"AN X IN BOX";N;"WILL STOP

YOU. YOUR TURN

1750

GOTO 1020

1760

LET L<6)-N

1770

PRINT TAB (7); "I WILL PUT AN X IN BOX"iN,

" YOUR TURN, "

1780

GOTO 1820

1790

LET M=-27

1800

LET K3»5

1810

GOTO 1890

1820

GOSUB 2980

1830

IF F=l GOTO 1820

1840

LET H**3

1850

LET L(7)^l 1

1860

LET HP-A

1870

GOTO 1200

1880

REM COLUUMN ADD SUBROUTINE

1890

LET K2^1

1900

FOR 1*1 TO 3

1910

LET N4=0

1920

FOR J~\ TO 3

1930

Lfcl N4'N4+MI,U>

1940

IF N4-M GOTO 2230

1950

NEXT J

1960

NEXT 1

1970

LET K2-2

1980

FOR JM TO 3

1990

LET N4^0

2000

FOR 1= 1 10 3

2010

LET N4= N4+MI, J)

2020

IF N4^M OOTO 2230

2030

NEXT I

2040

NEXT J

2050

LET HP 3

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Listing 1 continued:

2060 LET N4=0

2070 FOR 1*1 TO 3

20B0 LET J=I

2090 LET N4=N4+K(I.I)

2100 IF N4^M GOTO 2230

2110 NEXT 1

2120 LET K2-4

2130 LET N4^0

2140 FOR 1^1 TO 3

2150 LET J-4 -1

2160 LET N4 = N4+K<X. J)

2170 IF N4-M GOTO 2230

2180 NEXT I

2190 IF K3=5 GOTO 2210

2200 ON Nl GOTO 1370. 1650. 16B0, 1790. 1620

2210 PRINT (AB (7); "THE GAME IS A DRAW. "

2220 GOTO 2700

2230 IF M=3 GOTO 2260

2240 IF K(I.J)-9 GOTO 2500

2250 ON K2 GOTO 2290, 2310. 2330. 2360

2260 PRINT TAB (7);"CONGRATULATIONS YOU WIN THIS GAME.

2270 GOTO 2700

2280 REM COEFFICIENT EVALUATION SUBROUTINE

2290 LET J^J -1

2300 GOTO 2240

2310 LET 1=^1 1

2320 GOTO 2240

2330 LET 1= ] -1

2340 LET J»--J 1

2350 GOTO 2240

2360 LET I=-I -1

2370 LET J^JH

2380 GOTO 2240

2390 REM CONVERT 1-9 SUBSCRIPT TO I-J VALUE

2400 LET N4= O

2410 FOR |*I TO 3

2420 FOR U^-l TO 3

2430 LET N4-- N4+1

2440 IF L1-N4 GOTO 2470

2450 NEXT J

2460 NEXT I

2470 LET K(), J)= 1

2480 ON N2 GOTO 1210. 1340, 1590, 1590, 2740

2490 REM CONVERT I-J VALUE TO 1-9 SUBSCRIPT

2500 IF N2<>4 GOTO 2550

2510 IF N1^2 GOTO 2540

2520 LET NJ^U

2530 GOTO 2550

2540 LET Nl: 6

2550 LET K( 1* J)= 4

2560 LET N^O

2570 FOR J|j 1 10 3

2580 LET N^ N + J m

On ExpressingMultiple Condition

LanguagesFopum

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176

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Circle 202 on inquiry card.

rat's nest of inserted problem bypassesand altogether impossible to read. I recentlyobtained a copy of a primer on Pascal inthe hopes that it would provide someknowledge and insight into providing a pro-per means of improving program structurethrough language format and syntax ratherthan relying on my own experience in thisarea. I can now see why this language hasbecome much more popular as a first lan-guage in many universities and I hope thatit will continue to grow in popularity andwide usage.

At various times in the past I have triedmy own hand at designing a source languagewhich would provide a much more meaning-ful approach to program structure whichmust be at least as important as function. Ihave no new language to propose in thecause of this interest, having never tried toimplement one of the languages I havedesigned, but I do have some commentswhich may be of interest to those who arealso involved in the search for the "perfectlanguage."

In various languages, to my knowledgeincluding BASIC, Pascal and COBOL, thereis at least one statement which tests a condi-tion and will or will not perform a specifiedfunction depending on the outcome of thetest. This is, of course, the IF statement in

the languages mentioned above. ELSE weforget, these languages also contain a state-ment which allows the testing of a variablestate and the optional performance of oneof several alternative functions dependingon the state encountered. In BASIC, this isthe "ON . . . GOTO ..." statement; inPascal it is the "case . . . of . . ." state-ment, and in COBOL it is the "GO TO . . .DEPENDING ON . , ." statement. FOR-TRAN also has this capability in a limitedway through the use of the numeric IFrather than the logical IF. In my humbleopinion, Pascal's implementation of thisfeature is far more meaningful not onlyto program structure but also to under-standing the condition which is actuallybeing tested. Many times when this struc-ture is used in BASIC or COBOL, it is thepowerful feature which justifies the useof that "hairy" computation to adjustthe conditions which are actually presentto be an integer between 1 and 10. Pascal'simplementation of this structure is stillnot perfect because it takes some extraeffort in defining data types to assurethat one of the alternatives will indeedbe picked. Correct me if I'm wrong, butthere is no explicit way to specify whatshould be done if none of the states forwhich there are alternatives is actually

Figure 7.

IF condition 1 statement 1condition 2 statement 2condition 3 statement 3

condition n statement nENDELSE statement

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December 1978 © BYTE Publications Inc 177

Figure 2.

IF x

<50 PRINT X;- 50 PRINT X;X*X>50 PRINT X

END

IF X =

1 SETY=

2 SET Y,

3 SETZ=

=X

z=x

X

END

ELSE

SETX=1

IF X=

0

LETY=Z

*z

AND Y=1

PRINT Z

AND Y=2

PRINT Z,

Y

END

ELSE PRINT X

found. I believe it would also be somewhattricky to use this single Pascal statementto perform one function if the variablebeing tested is less than 50, to performanother if the variable equals 50, or toperform a third if the value is greater than50, for example.

These are obviously closely related condi-tions and would ideally be resolved with asimple statement structure. Note that thesetypes of tests are possible in most anylanguage: however, my suggestion is thatthere should be an alternative to this some-times confusing structure.

Rather than having one statement to testa single condition and another to resolvemultiple conditions, why not make thesingle condition test a simple subset of themultiple condition test? A loosely definedstatement structure which would satisfythis requirement is shown in figure 1. As thisstatement is parsed, the statement becomesa multiple condition test when it containsmultiple conditions. When additional condi-tions are encountered, each is concatenatedto the first condition to form a new condi-tional expression which is then evaluated todetermine if the statement associated withthe new condition should be executed ornot. The one restriction I would like to seeon this type of a structure would entail

not evaluating the original condition 1 ifstatement 1 is omitted. This means thatonly the concatenated expressions whichare formed will actually be evaluated. Simpleexamples of possible forms of this type of astatement are shown in figure 2.

I believe that this statement structureprovides an excellent aid to properly or-ganizing program structure. It has thecapability of directly relating associatedstates in an easy to understand mannerand provides the flexibility which a multiplecondition test should have, without havingto go through any complex manipulationsto resolve the conditions present to anyparticular restrictive form.

I would welcome any and all commentson this proposal and am always interestedin finding more about the "perfect lan-guage" if you have any suggestions.

Perhaps a reader with language designexperience would care to comment on thevarious examples and suggestions proposed.Readers should note that none of theexamples of figure 2 follow the prototypeof figure J completely. But the examplesof figure 2 might provide interesting vari-ations on the multiple condition suggestionif they prove unambiguous to a languagetranslator or interpreter. . . ,CH"

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178 December 1978 © BYTE Publications Inc

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908 Salem Dr

Huron OH 44839

Pascal Critiqueand a Comment

I have just finished reading your August1978 issue and would like to comment. Iam more than a little disappointed with thevolume of coverage given to Pascal. Whateverthe relative merits of the language thatamount of discussion isn't merited in myopinion. There currently is no affordableimplementation of the language available tothe typical computer enthusiast. If and whenPascal is available I believe it will have a veryrough battle trying to compete with boththe pricing and heavy usage that BASIC en-joys today.

Another problem I think you have failedto address is the effect of the huge invest-ment in time and money many have made inBASIC. Just what is to become of that? Con-version? An unlikely prospect given thehistorical example of the COBOL and PL/Icontroversy. Use both languages? Again anunlikely prospect. Most people have all they

can handle without the demands a secondlanguage would require.

It should also be pointed out that Pascalhas little or no following outside the aca-demic community. It wouldn't be the firsttime that a language enjoying a great deal ofadmiration at the academic level has failedto gain acceptance as a viable tool in the realworld of data processing. Languages are usedand live only on the basis of perceived use-fulness, the availability of experiencedpractitioners, and widespread implementa-tion of the language. Pascal now has none ofthose attributes.

In my opinion the number of users ofany language speak many silent volumes thatby weight of numbers signal acceptance of alanguage more than any theoretical pro-posals or arguments about the relativeadvantages of competitive languages.

But there is an affordable implementationof Pascal — the UCSD system is availableseparately', or bundled with various manu-facturers' products. As a means of learning anew language, conversion of one or two pro-grams as tutorial experiments is just fine.Pascal should only be thought of as anavenue to more effective creation of newprograms.

As for "no following outside the academic

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December 1978 © BYTE Publications Inc

179

community," Pascal has a very strong fol-lowing as witnessed by the representativesof both industry and academia present atthe UCSD Pascal Workshop last summer.BASIC was once the only logical and effec-tive choice of languages to use.

The virtue of Pascal and similar languagesis the fact that the very expression of theprogram is so much closer to the way peoplethink. i} for example, think in terms of "Iwant to do thus and so"; in Pascal, I might

reference a procedure with the namethusandso. in BASIC I would have toreference it in the program with a numberartificially created for that purpose. Imight say GOSUB 10000, for example,when 1 really mean to call and execute athusandso procedure. Pascal can be used asany other programming language — for theunderlying computers are identical, it is amatter of making the expression of a pro-gram easier for the user. . . .CH ■

Timothy J Stryker477 Hope StProvidence Rl 02906

Continuing Comments on APL

John Howland's "Comments on APL'sCharacteristics" in the May 1978 BYTELanguages Forum, page 143, are for themost part well thought out. However, itseems to me that he is missing somethingwhen he states that an APL programmerwho composes programs on line is "similarto the person who opens his mouth andbegins to speak before engaging his brain."The whole point of having an interactivelanguage facility is based on the fact thatthe programmer does not always want to

have to map out in advance exactly what itis he will ask the machine to do.

At the root of the matter is the con-sideration that there is no clean distinctionbetween "implementing a program" andsimply "invoking a system utility." Suppose,for example, we wish to check on the valueof some variable, for example J, during anAPL terminal session. We simply type:

J

Now suppose that the value of J is lowerthan we expected, so that we become inter-ested in the first J elements of the array A.We type:

Ah J]

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Circle 220 on inquiry card.

But now perhaps we realize that J is actuallythe number of pairs of quantities in A and soin order to examine the set consisting ofthe first element of each pair we type:

A[-1+2Xt J]

I could go on, but I think the point is clear:at what level of complexity have we stoppedmerely using the facilities of the environ-ment and started writing a program?

My own view is that the above distinctionis immaterial and that what matters is simplythat the environment be structured tomaximize the programmer's capability toaccomplish the job at hand expediently.When the job at hand is large and compli-cated, there is no question but that atpresent hardware costs the most expedientrecourse involves writing out the bulk ofwhat is to be typed in beforehand. Likewisewhen the job at hand is trivial and trans-parent (eg: inspecting A[ i J], it is undeni-ably the case that writing it down beforetyping it in is a waste of time. In betweenthese two extremes, things are not so clear,and the point at which paper and pencilbecome necessary will depend both on theindividual programmer involved and on thesystem. However, what is clear is that themore complex the programmer finds himself

able to get, on line, while still maintainingcogency of thought, the more productivehe will be.

Mr Howland justly defends APL's right toleft order of evaluation from those whowould make it left to right: 3^-6 equals 2is not a pleasant prospect. However, avaluable property for any language/environ-ment to possess is one which allows short,transparent programs to be entered quicklyand easily, without any need for pencil andpaper in the process. My suggestion to theAPL terminal manufacturers, if they haven'tdone so already, is to implement an optionwhereby each line could be entered fromright to left (in much the way one fre-quently find oneself writing out lines of APLon paper, that is, starting at the righthandedge and working leftwards). In this way,the objective of simplified on line programcreation could be achieved at no cost in theway of incompatibility with existing APLprocessing precedence.

Reacting just slightiy to the fast para-graph of your fetter, a question comes tomind: is it the terminai manufacturer'sresponsibility or the APL interpreter-writer'sresponsibiiity to make the input sequencerun from right to ieft? With a fast enoughterminal, it is possible to rewrite the last

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line with the new input in a nearly unnotice-able blink of the eye. Fast enough meansa parallel memory mapped display, or aserial data terminal running at 9600 dps orhigher. . . ,CH"

Calling Attention to HPL

Gerald Robb

5158 E Dwight

Fresno CA 93727

In response to the discussions of highlevel languages I have been following inBYTE, I would like to call your attention toan existing language as implemented on theHewlett-Packard 9825A.

HPL, as Hewlett-Packard calls it, is imple-mented on the basic machine similarly toBASIC. Extensions are available by stagesin read only memory. String capabilities areenhanced by a string ROM. IO handling bythe general IO ROM is enhanced to besimilar to FORTRAN. The advanced pro-gramming ROM extends the capabilities tocover, in large part, the characteristics ofPIDGIN ALGOL as described in The Designand Analysis of Computer Algorithms byAho, Hopcroft and Ullman (AddisonWesley). A couple of features should benoted. An assignment operator is used,allowing the equal sign to be only a rela-tional operator. While the list of variablenames is limited to single letters, the flexi-bility of substrings, local variables in sub-programs and functions, and r variablesprovide for few problems in practical use.

I have been working with this system fora year and a half developing and implement-ing programs for an agricultural consultingfirm. While the firmware, fully implemented,is probably close to 70 K, this is an excellentexample of what can be done on a smallsystem, and might just be a good systemto emulate."

L anguages Forum is afeature which is intended as aninteractive dialog about thedesign and implementation oflanguages for personal com-puting. Statements andopinions submitted to thisforum can be on any subjectrelevant to its purpose offostering discussion and com-munication among BYTEreaders on the subject of lan-guages. We ask that all corres-pondents supply their fullnames and addresses to beprinted with their commen-taries.

182 December 1978 © BYTE Publications Inc

Circle 91 on inquiry card.

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BYTE December 1978

183

TechnicalFcrom

A Proposal for a Kitchen Inventory System, orDon't Byte the Wand That Feeds You

Richard ShufordEditor

Technical Forum is a fea-ture intended as an interactivedialog on the technology ofpersonal computing. The sub-ject matter is open-ended, andthe intent is to foster dis-cussion and communicationamong readers of BYTE. Weask that all correspondentssupply their full names andaddresses to be printed withtheir commentaries.

A practical and natural application foryour home computer is an inventory systemfor the kitchen. Such a system would relievehumans of the details involved in makingout a grocery list.

One convenient way of keeping track ofthe various items in the pantry is to usethe information that is now provided onmost food packages specifically for thatpurpose, namely, the Universal ProductCode, or UPC. This is, of course, put therefor use by food stores, but there is no reasonthat the UPC cannot be used in the home.

The Universal Product Code appearson a product label as a patch containingbar codes, with a line of human readablenumbers underneath. This distinctive designhas now become familiar to most NorthAmerican shoppers. Information containedin the bar codes can be read by an opticalsensing device connected to a computer.

At present many computer experimentersare equipping their computers with anoptical sensing device, a bar code readerthat has a scanning wand, for the purposeof scanning the new machine readablesoftware which uses similar bar codes. Agood example of such software is thePAPERBYTEtm series of books whichBYTE Publications produces. It is probablethat the same scanning wand used for read-

ing the software may be used to read theUniversal Product Code. The scanningwand provides a quick and easy methodto identify a given item without keystrokingany information into the computer. Itwill, unfortunately, be necessary to do somekeystroking to set up the system. Oneminimal implementation of an inventorysystem might be set up in the followingmanner. For each grocery item in stock,a data base would exist containing:

• a representation of the UniversalProduct Code for a given item,

• a human language description ofthe product including brand name,generic name, and size or quantity,

• the minimum quantity that shouldbe kept on hand,

• optional information on the item'sshelf life,

• any other information which isdeemed useful (for example, whichmembers of a household like a partic-ular item).

As the supply of an item becomes de-pleted, the container is thrown out. Immedi-ately before disposing of the container,though, the UPC bars are scanned. Thecomputer stores this code in a table of

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184

December 1978 ©BYTE Publications Inc

Circle 400 on inquiry card.

items which are depleted and should berestocked. Prior to setting off on a shoppingtrip, the user requests a display (preferablyon a hard copy device) of depleted products.The computer uses the depleted productstable to reference the master data base,and retrieves the human language descriptionof the product from the master data baseand displays it for the user, along with otherinformation. If the display is on a hard copydevice, the user simply tears off the paperand uses it as a grocery list.

Probably the best way to establish andmaintain the data base is with the use of aninteractive program. The user would buildthe data base from scratch by starting withthose items on hand at the time. For eachitem, the UPC bar codes are scanned, thenthe user types in the other informationabout the item. (Note that it is not necessaryfor the numeric product code to be key-stroked by the user.) After the initial datais stored, the interactive program may beexecuted to update the file with informationfor new or different products. It is notnecessary to start with a huge data basecontaining data for every possible product.Each household would keep informationtailored specifically to its needs in its database.

The size of the data base is dependenton the number of different products a givenhousehold buys. It should be noted thateach brand of a given generic item has itsown code. The data base may be kept smallif a single brand of a given item is usedconsistently. The procedure of reading theUPC bar codes just before consigning thecontainer to the garbage follows one of the

cardinal rules of computer use, which is:garbage in — garbage out.

Special arrangements would still benecessary to handle those products notmarked with the UPC in many stores, suchas fresh meat and local produce. It mightbe possible, with knowledge of the encodingmethod of the UPC, to make a custom UPCbar code symbol by hand. This could bemounted permanently near the garbage canscanning station and scanned instead of apackage symbol. The computer could thenat least note that the supply of a non-encoded item was depleted and call atten-tion to the fact.

An ingenious tinkerer could no doubtfind many ways to improve the system.For example, some means to indicateexactly which nonencoded item is depletedmight be devised. And it might prove usefulto scan a package as it is bought, to verifythat it is back in stock. Also, the additionof a modem for telephone communicationgives rise to many possibilities.

A computer equipped with a modemcould, with the proper programming, calla computer equipped food store and auto-matically order the necessary grocery items.And given the proper programming bothin the home and at the store, it could dialup several different stores, compare pricesand order from the store which providesthe lowest price for the entire list. Withelectronic transfer of funds, the computercould even automatically pay the grocerybill.

Automating the kitchen inventory shouldgive people the time to develop new recipesor new computer applications."

Circle 401 on inquiry card.

December 1978 ©BYTE Publications Inc

185

He did not want his

optional entertainment

chip tampered with; his

films, recordings, reading

and fantasy trips had all

been carefully selected,

carefully tested over the

years.

Lawrence F WillardPOB 202YalesvilleCT 06492

About the Author

Lawrence F Willard hasbeen a journalist and freelance writer for over 30years, contributing tomany magazines, includingNew Hampshire basedYankee Magazine. A hamradio operator, Larryteaches journalism andmedia courses at Man-chester Community Col-lege in Manchester CT.

The Mother Chip

Jonathon Witherspoon Twombly floatedup out of a warm and comfortable world ofdrifting, unconnected images to begin, un-fortunately, a new day. He stared at thecream colored ceiling, as he always did, toread the wedge of light that fanned fromthe top of the window shade to intersecta discolored area of the ceiling in a fairlysignificant manner. Nine o'clock, he guessed,disdaining for three and a half seconds theabsolute accuracy of his Minnie on thebedside table. He rolled over and lookedat it, stubbornly translating 24 hour timeto his own archaic measure. His guess wasa mere four minutes and ten seconds slow.Pretty close, he noted contentedly.

The mini-mini-micro-processor, his ownpersona! computer link to the vast andcomplex world of 1997, winked at himwith a softly glowing numeral 3. Not muchlarger than a deck of playing cards andhalf as thick, Minnie rested upright inher umbilical slot, absorbing power for herbatteries and sharing her thoughts with thehouse computer in its basement hideaway.A rather old microprocessor, Mike ran thehouse, but Minnie was boss as long she wasplugged into the table, or as long she was onTwombly's person and not more than a miledistant from the house. Beyond that rangeshe could integrate with Mike up to adistance of 40 miles using the high powercar facilities, and beyond the 40 mile radiusshe could use the worldwide network ofrelay stations. But that cost money and wasrarely necessary. Jonathon Twombly did nottravel very much or very far.

At the moment he was staring at theglowing figure 3 in disbelief. Three messagesfor him during the night? How unusual!Twombly was a nobody; no family, nofriends, no job. He didn't have to work,and so never would be allowed to. He livedon the regular income from his trust fund,and, with Minnie's help, he kept his outgoexactly equal to his income. It was a goodlife.

He removed Minnie from her niche andkeyed in a command. The four foot squarescreen built into the wall at the foot of hisbed lit up and the readout began:

MSG 1 BELLOGRAM 7.6.97 2207 66234621BP P12 TWOMBLY, JONATHON W 779 2888980 BMA

YOU ARE HEREBY CITED BY TRAFFICCONTROL OFFICER 229 BOSTON CITYPOLICE FOR MOVING TRAFFIC VIOLATION7.6.97 1201 HOURS PL 2395 SEC. 8. B. SECTORQUADRANT 9 FINE 25 DOLLARS REMITWITHIN 24 HOURS TO AVOID ARRESTPC JOHN KELLEY.

Twombly swore mildly (he was not anaggressive man). He'd had the car on manualfive minutes during the entire day and he'dmanaged to get a ticket. He might as wellpay now and get it over with. He didn't evenbother to call up the picture the cops hadsurely filed. He didn't want to see himselfon the screen making an ass of himself. Pay-ment of the fine would wipe the picture outof the police computer banks. He punchedup his bank balance, confining it to Minnie'ssmall screen. $207.81. Even with seven centsadded as interest during the night, it wasn'ta healthy balance. He swore again, mildly,and punched in the command, the amountand the police computer address, checked iton the screen and punched the executebutton. $182.66. The city had $25; thebank had its 15 cent service charge.Twombly called up the second message:

186

December 1978 ©BYTE Publications Inc

Circle 138 on inquiry card.

MSG 2 VIDEOPHONE CALL 0231 7.7.97CENTRAL HOTEL RM 63HI TWOMB OLD CHAP. REMEMBER ME?PUDDY, ROOMY, WESTERN U? IN TOWNFEW HOURS. HOW ABOUT A DRINK? NOW.LEAVING SUNUP. 766 26 0589 CHEERS.

Twombly shuddered, wiped the screenclear. He had set Minnie to store night calls,not wake him up; he wasn't sorry. He calledup the last message:

MSG 3 BELLOGRAM 7.7.97 0800 66091532FBCC BOSSOFF TWOMBLY, JONATHON W779 28 88980 BMAYOU ARE HEREBY REMINDEDAPPOINTMENT THIS OFFICE ANNUALCHECKUP AND FIVE YEARREPROGRAMMING 1400 HOURS THIS DATE.PREPARE FOR ROUTINE PHYSICAL,PSYCHOLOGICAL TESTS TO DETERMINEAGING FACTOR. ALL NEW PROGRAM CHIPSTO BE INSTALLED, INCLUDING OPTIONALS.YOU MAY RETAIN OR CHANGE OPTIONALS.NOTE: WHEN THE HELL ARE YOU GOINGTO LET US REPLACE YOUR ANTIQUATEDMINI FOR NEW ATOM POWERED MODEL?P. T. HARRIS BUCHIEF.

Twombly wiped the screen. Of course hehadn't forgotten. Minnie had already placedan order for a car. Good old Minnie. Likehell they would replace her. Not yet. He satfor a moment, thinking. They'd find himfive years older, reflexes a bit slower. Newprogramming would compensate. Obstacledetection devices would take over a littlesooner when he drove on manual, puttinghim a little less in control. His heart wouldbe monitored more carefully and his medi-save unit would probably get newer, morepowerful drugs. Minnie would probablycalm him down a little quicker when he gotoverexcited. Did he want his optionalentertainment chip tampered with? No.His films, his recordings, his reading, hisfantasy trips had all been carefully selected,carefully tested over many years. Theywould do without futher change.

Twombly got up, dressed (he wanted nohelp from the waldos, those mechanicalservants that Mike controlled), and dropped

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December 1978 ©BYTE Publications Inc 187

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Minnie into his inside jacket pocket fromwhich nobody but he could remove itwithout calling out the police emergencyvehicles and perhaps the National Guard;anyway, nobody had ever tried it. He wentinto his small but luxurious dining room toeat the late breakfast Minnie had summonedfor him. He was served by one of his twohousehold waldos, which glided across thecarpet on a cushion of air, delicately bearinga plate of scrambled eggs in hands thatcould bend a steel I beam into a pretzel.

Mike operated the waldos, using theirsensory substitutes for eyes, ears and senseof touch. Twombly had programmed Miketo speak through the waldos' vocodersystems in an almost human male voice,and he had also fixed it so that when Minniewanted to speak to him verbally throughMike, the waldos underwent a startlingchange of sex, answering in suitablefeminine tones. She spoke to him nowabove the plate of scrambled eggs.

"I have ordered you a car, a WhingerElectric, to be here at one o'clock. Veryfew of the agencies still have those in theirinventory. They are, as you know, obsolete.Next year we will have to pay the antiquecar premium to get one."

"I know, I know; we'll worry about thatnext year." Twombly ate his eggs, retired tohis study and programmed the next lesson inhis study course, "Late 19th Century andEarly Twentieth Century External BathroomArchitecture in Rural Areas." Fifteenminutes before the hour of one o'clock hewas standing on the sidewalk in front of histownhouse awaiting the Whinger Electric.He was not alone. Standing a few feet awayfrom him was the occupant of the neigh-boring townhouse, a Professor JohnCarmody, who taught English to first yearstudents at Radcliffe. Twombly wonderedwhether he should activate his noninter-course signal, but Minnie's low buzz indi-cated that the good professor had activatedhis own, thus solving the problem. It was,of course, the grossest kind of social blunderto speak to or take any notice of a personradiating a nonintercourse signal.

Just then the signal stopped, and beforeTwombly could activate his own signal, theprofessor spoke to him.

"Since your signal is off, sir, may I bepermitted conversation with you?"

It was now too late to emit a noninter-course signal, and the grossest kind of socialimpropriety not to answer.

"My dear Professor Carmody, you mayindeed converse with me," said Twombly."Nice day, isn't it?"

"Yes, I perceive you are waiting for acar?"

188

December 1978 © BYTE Publications Inc

Circle 348 on inquiry card.

"Indeed, yes. I am headed into the centerof the city, to government sector. Do youwish to share my car?"

"No, no, my dear Mr Twombly; my ownis on the way. Would you be interested in asmall wager, say five dollars, as to whichvehicle arrives first?"

'That would be most sporting," agreedTwombly. "Shall we say ten dollars?"

"Done," said Professor Carmody.

Although neither could now erect thenonintercourse barrier, by mutual unspokenagreement nothing more was said. At exactlyone o'clock both vehicles came into view,arriving from opposite directions.Twombly's arrived a fraction of a secondbefore the professor's. The professor noddedin token of defeat, and entered his car,Twombly's bank balance would shortly growby ten dollars. He felt very good about that.Entering the two seater electric, he tookMinnie from his inside jacket pocket andinserted it in the slot in the dashboard. Itwas now his car, for a daily rental fee, untilhe removed Minnie and gave the car a signalto return to its depot. He put the car onautomatic and keyed in the destination. Hecould not get a traffic ticket as long as thecar was under automatic control by thecity's own traffic computer which directedthe symbiotic duo of Minnie and the car'scomputer.

Twombly leaned back, completely re-laxed in the knowledge that he was in thesafest environment ever known to mankind.No matter what difficulties there were,through rain, fog, sleet or snow the carwould transport him without danger. If hehad a heart attack, his medisave implantwould go into action, administeringadrenalin, electric shock, or whatever elsewas needed for the few minutes it wouldtake for help to arrive. Minnie would workthrough the car computer and signal systemto coordinate the meeting of the car withthe nearest mobile medical unit, whichwould be receiving a flow of medical dataand electrocardiograms. It was exceedinglydifficult to die in an automobile, or on thestreet for that matter. Minnies could workdirectly into repeaters mounted on tele-phone poles no more than a mile apartthroughout the entire city.

At government center the car parkeditself to wait until Twombly's return, sincehe had not given it instructions to returnto the depot. He took Minnie out of thedashboard slot and returned it to his insidejacket pocket, stepped out of the car ontoa moving walkway, and was carried into thebuilding that housed the Boston office ofthe Federal Bureau of Computer Control.He took the elevator to the twelfth floor

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Office of Programming and Adjustment,where he underwent a battery of testswhich proved that he was five years older;His Minnie was sent to one of many labora-tories where highly skilled techniciansmade new program chips and inserted thechips in the Minnie to replace the oneswhich had served Twombly well for fiveyears. It was late afternoon when Twomblyleft; an hour after that, one of the techni-cians approached the lab chief with analmost microscopic program chip in thepalm of his hand.

"We have a condition red, 1 think," hetold the chief. (This is the alternate programentertainment chip from Twombly'sMinnie/'

"Carson," said the chief, "that simplycannot be. He couldn't get out of thebuilding without a full complement ofchips; the master computer wouldn't lethim through the door."

Carson, his face almost as red as the littledot on the chip which meant alternate pro-gram, said: "He had a full complementof chips. I got the wrong one in. He got anexperimental chip I was designing for mywife's Minnie."

"What kind of an experimental chip?"asked the chief in tones that made Carson'sflesh creep.

"You might call it a babysitting chip,"said the technician, "although it doesn'tjust sit. I can tell you that we're in a greatdeal of trouble if he activates that chip.We have to prevent that."

"Condition red," sighed the chief. "Wehave to key into his Minnie by way of thehouse computer, but we'll have to getauthorization from Washington. I'll notifyHarris; it's his problem. He won't like itmuch."

"I don't think we have time. He'll mostlikely activate the entertainment chip afterhe finishes dinner; Twombly is predictable."

"We have to take time. After that J ELewyt scandal, where the untouchabilityof our beloved director was found wanting,we've been under very rigid orders aboutinvading the privacy of private computers.We've got to get authorization."

They got it after a three hour delay, butas Carson feared, it was too late. When thespecial code got them access to theTwombly house computer, it reported thatTwombly had activated the alternate pro-gram entertainment chip. The chief sighedand requested a complete readout from thetime of activation.

CHIP ACTIVATED 2030 HOURS. SEQUENCECOMPLETED: UNDRESSING, BATHING,DRYING, POWDERING, DIAPERING. ASINSTRUCTED BABY HAS BEEN PUT TO BED

190 December 1978 © BYTE Publications Inc

Circle 140 on inquiry card.

Circle 75 on inquiry card.

WITH WARM BOTTLE. BURPING TO TAKEPLACE ON COMPLETION OF FEEDING.ESTIMATED TIME: THREE MINUTES FROMNOW.

"We can do without the burping/' yelledthe chief. "Carson, override the program atonce; switch off the alternate program. MyGod, I think we have a law suit on ourhands. You and I will end up in the coalmines."

"Program is off, chief. I'll see if I can getan informal but detailed report from hisMinnie. . . it's coming now."

Chief of Laboratory Q, George Justine,had chewed the nails down to the quick onone hand and had started on the other whenCarson leaned back in his chair and actuallysmiled.

'Twombly started to panic when thewaldos grabbed him and started to undresshim, but calmed down and gave in when hecouldn't stop them. He seemed to beactually enjoying the bath, and when he wasput to bed with the warm bottle he slurpedit down and actually cooed. He is now in adeep, peaceful sleep, and his Minnie reportsthat his blood pressure is normal for the firsttime in months."

"Well, we're not off the hook yet, but itlooks better."

"Chief, we'll call him in tomorrow andexplain the mistake, and apologize. We'llgive him back his entertainment chip and I'lltake back the babysitter chip."

"I doubt it. I mean, we can call him in,but something tells me he isn't going to giveup that chip. It fits in too well with his psy-chological profile. We'll have to give it tohim in addition to the entertainment chip.We'll gain one thing; I think we can gethim to take the newer model Minnie, be-cause the one he has doesn't have room forany more alternate programs. If he wants toplay baby, he'll have to exchange Minnies,and I think he will."

"I hate to lose that babysitter chip; I puta lot of work in on that."

"Carson, that's going to be the least ofyour worries. We're going to have to fillout lots of reports. . . you are. There'll belots of investigations and an awful lotof flack. There is one possible ray of light:there may be other people like Twombly,and this may prove to be some kind oflegitimate therapy. I don't know. That'sfor the psychologists to decide. Right nowwe have to get ready for the worst, chargesof invasion of Twombly's privacy. Wepanicked. We went to the top to getauthorization to enter the computer of aprivate citizen, citing clear and presentdanger. What did we achieve? We stoppeda man from getting burped.""

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December 1978 © BYTE Publications Inc 191

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Commanderin Chief

A Game for the TI-58

Programmable

Calculator

Larry Kollar

Room 225 W Wadsworth HallMichigan Technological UniversityHoughton Ml 49931

Commander in Chief is a TI-58 snowball

war game for one player (see listing 1).After entering the program, press E. Thisclears the memory and initializes the randomnumber generator (program 15 in the librarymodule). You are now ready to play. Enterthe number of snowballs you want up to100 and push A. If you try to enter morethan 100 snowballs, the program will placeonly 100 snowballs in your register. Noiceballs allowed.

After a few seconds, the calculator willcome back with a 1 or a flashing 1. If thedisplay flashes, you are at war. Next, youestimate how many snowballs the enemyhas and push B. The display will flash howmany snowballs the enemy actually has.Following this, it will display a 1, 0 or -1and then the year number; or the displaywill flash 9.9999999 99. If this occurs,there has been a holocaust and the enemyis rendered inoperative. If there is no holo-caust, the 1, 0 or —1 tells you whether youhave won, achieved a standoff, or lost; thenthe year number is displayed. You and yourenemy have lost half of your snowballs andeach of you will add more on the next year.

If there is no war at all during the year,you have the option of declaring war. Theprocedure is the same as that in which theenemy has declared war. If you can make itthrough ten years, you win the Snobel PeacePrize."

ACKNOWLEDGEMENTS

"Commander in Chief," The Pocket CalculatorGame Book, Schlossberg and Brockman, BantamBooks, 1976.

Thanks to David Nahakian for helping me withsome of the program sequences.

192

December 1978 © BYTE Publications Inc

Circle 179 on inquiry card.

Sample Game

Your Total

Total Enemy

Year

Snowballs

Snowballs (not seen)

1

100

68

(No war,

go on to the next year)

2

180

127

(No war)

3

260

209

(Enemy declares war.

Dlayer estimates 191 snc

wballs, an error of 18. This is multiplied

by the

actual enemy snowballs and the number

of his snowballs. The resulting holocaust

factor

is 978,120. The

holocaust factor needed to cause a holocaust is 1,500,000. There

has been no holocaust

, so each power loses ha

f his/her snowballs, discarding fractions.

Player

wins.)

4

130

104

(No war)

5

230

197

(No war)

6

330

224

(Player declares war and estimates 251 enemy

snowballs, an error of 27. The holocaust

factor

is 1,995,840. Th

ere has been a holocaust

and both sides are blitzed.

Loc.

Keys

Commentary

000 (*Lbl ) ( E ) (*CM's) (*Pgm ) ( 15 ) ( E ) Random number generator

006 (*Pgm)012 (x^t)

( 15 ) ( *E' ) ( R/S ) (*Lbl )

f — J 100 is maximum number of snowballsf 00 j added is one turn.

Lower limit

Upper limitQ 13 j Add enemy snowballs

War ?

CZ3

Enemy snowballs flash( X j Holocaust factor

079 (i )

086 Q

( 0 j Maximum holocaust factor

(RCT)

CZDC

( 15 ) (*x> t) ( Inx )InT

(RcT)CO C

C

c

)CZD

D CZD C^£D

092 ( 13 )

098 ( 13 )

104 ( *lnt )

110 02

111 ( »Op ) ( 10 )

113 ("Pause) (Pause ) ( RCL ) ( 21 ) (GTO)

119 (^LbP) (3) (CUT) fTl (33

127 ( ♦Lbl) (Lnx ) ( CLR ) ( 1/x ) (*CM's)

(RCL)(STO")(3D

CUD

Signum function (Who won ?)

r RCL J Flash year number

Listing 1: Commander inChief, a game for theTexas instruments Ti-58programmabie calculator.Note that some of theoperations of this Tl calcu-lator series aiiow multikeyentries into one location.This is indicated by anasterisk within the key.

R/S ) You are rendered inoperative!

December 1978 © BYTE Publications Inc 193

FORTRAN and Its Generalizations

It really is a necessary part of your knowledge, even if you're never going towrite FORTRAN programs.

W Douglas Maurer

Room 634

University Library Building

George Washington University

Washington DC 20052

The average small system user will not beable to use FORTRAN as a programminglanguage for his or her system. Some smallsystems have BASIC, and there is at leastone FORTRAN system for the 8080 (avail-able from Microsoft), but FORTRAN isstill chiefly a language for large computers(including minicomputers and mid-size com-puters). Nevertheless, there are many situ-ations in which a knowledge of FORTRANis important even to the small system user.The most important of these is in the de-scription of algorithms. It is of no use todescribe an algorithm in, say, INTEL 8080assembly language, since this would notmake sense to users of Motorola and othermicrocomputers; so algorithms are veryoften described either in FORTRAN, or insome other algebraic language. FORTRAN,though, seems to be the one that is usedmost often for this purpose, since morepeople know FORTRAN than any otheralgebraic language.

There are hundreds of books on FOR-TRAN today, all of which are written forthe large system user who is, presumably,actually going to use FORTRAN to solveproblems. It is very rare that one finds adescription of FORTRAN written for thosewho merely need to understand algorithmswritten in FORTRAN, but who are going torewrite those algorithms in some otherlanguage themselves. The present article iswritten to fill this need.

The basic function of an algebraic lan-guage, of course, is to allow one to writealgebraic expressions directly. Given aformula like

k = 'H+i

one has to write, in assembly language,something like "load i; multiply by j; sub-tract i; add j; divide by n; store in k" inorder to calculate the new value of k. Onmost small systems, the job is even harderthan this. We have to call subroutines formultiplication and division, and in an 8080based system, even addition and subtrac-tion of quantities in memory cannot bedone directly: the right addresses have to beloaded into H and L first. However, whenwe are describing an algorithm, rather thanwriting a program, the formula above iswhat interests us, and we would like towrite it directly. In FORTRAN, we wouldwrite

K = (l*J-l+J)/N

There are several differences between theFORTRAN version and the original formula.Some of them are due to the fact that wehave to be able to key the FORTRANformula into a system on a terminal or akeypunch. For instance, we have to useupper case letters instead of lower case andwe have to use the slash (/) to mean"divide." The parentheses are necessarybecause, if we did not use them, that is, ifwe wrote

K = l*J-l+J/N

the formula we would be expressing wouldactually be

k = ii-i+nL

since division takesaddition.

precedence over

194

December 1978 © BYTE Publications Inc

The last difference between the formulaand its FORTRAN version is in the use ofthe asterisk (*). This is necessary wheneverwe have a multiplication, since IJ, just as inassembly languages, would be the name of asingle variable. In FORTRAN, the name of avariable must start with a letter, can containonly letters and digits (although someversions of FORTRAN allow a few extracharacters, most do not), and has a maxi-mum length which depends on the systembeing used. Typical maximum lengths foridentifiers are eight characters (IBM 360 and370) and six characters (UNIVAC 1100series, DECsystem 10).

In addition to the use of formulas of thiskind, FORTRAN involves a number of otherstatements which express commonly en-countered sequences of instructions. Amongthese are:

(1) GO TO. Where the 8080 assembly lan-guage user writes J MP K, meaning "Jump toK,n and the 6800 user writes BRA K,meaning "Branch to K," the FORTRANuser writes GO TO 15, meaning "Go tostatement number 15." Statements in FOR-TRAN have numbers rather than names, andthe numbers have nothing to do with ad-dresses in the machine; they can be assignedarbitrarily and do not even have to be insequence (as they do in BASIC).

(2) IF. The keypunches used by manylarge system users do not have the charac-ters <, >, <, >, or I (although they do have=) and FORTRAN therefore uses .LT. (lessthan), .GT. (greater than), .LE. (less than orequal), .GE. (greater than or equal), and.NE. (unequal). Thus "If A is less than B,then go to statement number 15" would bewritten in FORTRAN as

IF(A.LT.B)GOTO 15

FORTRAN is distinguished from BASIC(and ALGOL, PL/I, and various other alge-braic languages) by requiring the parenthesesafter the keyword IF, and also by notmaking use of the word THEN. FORTRANalso uses .EQ. (equal) in comparing, and notthe character =, which is reserved for assign-ment statements involving formulas (suchas in K = (l*J-l+J)/N, discussed above).

(3) STOP. This signals the end of analgorithm, although a large system will notactually stop at this statement, but will goon to do the next job (assuming that thereare more jobs waiting to be done).

(4) END. This is simply the last state-ment in a program and has nothing to dowith stopping, which can happen at anytime. That is, we can have several STOP

statements in a program, but only one ENDstatement.

(5) READ. A READ statement inFORTRAN is largely self-explanatory; thusREAD (5, 91) N, A, B reads in three quan-tities and calls them N, A, and B. The 5 inthis statement is a FORTRAN convention:the standard input medium (as opposed toany special tapes or disk files which mightbe used) is referred to as unit number 5.The 91 is a reference to a FORMAT state-ment which describes, in this case, in whatformat N, A, and B are going to be given.This FORMAT statement can be ignoredby the person who is merely interested inwhat the algorithm does.

(6) WRITE. This is very much likeREAD, except for one peculiar convention:when one of the quantities to be written outis a constant string, then this string is foundin the associated FORMAT statement, ratherthan in the WRITE statement itself. Anexample should make this clear. Suppose wewant to write out the sentence THEREARE 7 ERRORS IN THE ABOVE PRO-GRAM. We have a count in our program

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called NERRS, which is, in this case, equalto 7. We would like to write a statementsomething like

WRITE 'THERE ARE ", NERRS,

" ERRORS IN THE ABOVE PROGRAM".

In FORTRAN, however, we have to writesomething like

WRITE (6, 92) NERRS

where statement number 92, the FORMAT

statement, is

92 FORMAT (' THERE ARE ', 13,

1 ERRORS IN THE ABOVE PROGRAM').

The 13 here is the format for NERRS (athree digit integer), while the 6 in theWRITE statement is like the 5 in the pre-ceding READ statement; that is, unit num-ber 6 is the standard output medium.Where constant strings are not present,WRITE is very much like READ. That is,we can have a statement WRITE (6, 93)N,A,B which will write out the quantitiesN, A, and B. In some versions of FORTRAN,we find PRINT 93,N,A,B with the unitnumber 6 left out; the only thing to remem-ber here is that we are not printing out thenumber 93, as this is the FORMAT state-ment number, just as before.

(7) DO. Suppose we want to repeat agroup of statements N times. Then, justbefore these statements, we can write

D025I = 1,N

where the last statement in the group to berepeated has statement number 25. This willnot only cause the statements to be repeated,but will set the index I to a different valueeach time: 1 the first time, 2 the secondtime, and so on up through N the last time.

(8) CALL. The FORTRAN programmercan write CALL SUB, just like the 8080programmer (the 6800 programmer wouldwrite JSR SUB, meaning "Jump to sub-routine SUB"); the difference arises whenthe subroutine SUB has parameters. Wherethe small system user has to figure out hisown way of passing parameters, FORTRANdoes this automatically. If the parametersare A, B, and C, for example, the FORTRANprogrammer simply writes CALL SUB(A,B,C).

(9) SUBROUTINE. At the beginning ofevery subroutine there is a statement likeSUBROUTINE SUB(X, Y, Z), which saysthat the name of this subroutine is SUB andthat its dummy parameters (sometimescalled formal parameters) are X, Y, and Z.This means that if SUB is now called asabove (that is, with the statement CALLSUB(A, B, C)), then X corresponds to A,

196

December T978 ©BYTE Publications Irtc

Circle 316 on inquiry card.

Y corresponds to B, and Z corresponds toC.

(10) RETURN. This is used in a sub-routine in place of STOP; it stops the sub-routine and returns to the program (whichcould possibly be another subroutine) whichcalled this subroutine. If we use STOP ina subroutine, the entire job will stop.

(11) FUNCTION. In FORTRAN thereare certain special functions: SQRT (squareroot), SIN (sine), COS (cosine), and thelike. Thus the FORTRAN statement Y =SQRT(A) sets Y equal to the square rootof A. But FORTRAN also allows the pro-grammer to make up his own functions.These are coded like subroutines, with twoexceptions. We start a function with astatement like FUNCTION F(X, Y, Z)which tells us that F is the name of thefunction and X, Y, and Z are the dummyparameters. At the end of the function(normally just before RETURN) we writeF = e, where e stands for whatever we wantthe value of the function to be. If we thenuse the function F by writing U = F(A, B,C), then, just as before, X corresponds toA, Y corresponds to B, Z corresponds toC, and e will now be computed and U willbe set equal to e.

(12) DIMENSION. This is used to definetables (arrays). DIMENSION A(50), forexample, defines a table of 50 variableswhich are called A(1), A(2), and so on upthrough A(50). We can also, of course, makereference to A(l), A(J+1), and the like.DIMENSION B(3, 3) defines a matrix ofnine variables, B(1, 1) through B(3, 3),and we can make reference to B(l, J) if Iand J have values 1, 2, or 3.

(13) REAL. Most large systems, of course,have floating point representations for realnumbers. FORTRAN assumes that everyvariable represents a real number unless itsname begins with I, J, K, L, M, or N, andeven this rule can be overridden by a REALstatement. Thus REAL LAMBDA specifiesLAMBDA to represent a real number, eventhough its name begins with L.

(14) INTEGER. The INTEGER statementallows us to define variables whose names donot begin with I, J, K, L, M, or N to be in-tegers rather than real numbers. An integeron a large system is typically 32, 36, 48, or60 bits long; an integer on a minicomputeror a midsize computer is typically 12, 16,18, or 24 bits long.

(15) COMMON. Normally, when we havea variable in a subroutine which is called(for example) J, and another variable inthe main program (or another subroutine)which is also called J, these are treated byFORTRAN as two different variables. The

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December 1978© BYTE Publications Inc Circle 383 OR inquiry card.

exception to this rule occurs when J appearsin COMMON statements in both programs.The rules for writing COMMON statementsproperly are complex; but in a publishedprogram, one may always assume that therules have been properly followed.

Every so often, one will be faced witha program written in some algebraic languageother than FORTRAN, such as ALGOL orPL/L The main differences between theselanguages are as follows:

(1) GO TO. Statements in FORTRAN andBASIC have numbers, but statements inALGOL and PL/I have names. When a nameis defined it is followed by a colon.

(2) IF, Most algebraic languages otherthan FORTRAN use the additional keywordTHEN, and many also allow the keywordELSE (meaning "otherwise"). Thus IF aTHEN P ELSE y means "If a is true, thendo the statement(s) 0; otherwise, do thestatement(s) 7."

(3) STOP. ALGOL does not have aSTOP statement; to stop in the middle ofa program, one writes GO TO a, where a isa label (followed by a colon) just beforeEND at the end of a program.

(4) END, In ALGOL and PL/I there aretwo kinds of END. One is used just as inFORTRAN, and the other is in the middleof a program paired with BEGIN. The state-ments between BEGIN and END are calleda block (or sometimes a compound state-ment), and may take the place of a singlestatement wherever one can legally occur inthe language. PL/I also requires an ENDpaired with each DO.

(5) READ, PL/I has two kinds of READ,one called READ and the other called GET.The GET variation is used when built-informat conversions are to be exercised.Some variations of GET involve no IO atall, causing conversions in memory. ALGOL,as it was originally defined, has no inputstatements at all, but many ALGOL pro-grammers assume that there is a subroutinecalled inreal(x), which inputs the real num-ber x, and similarly ininteger(x), which in-puts the integer x.

(6) WRITE. PL/I uses WRITE as well asanother form called PUT. WRITE corres-ponds to READ and PUT corresponds toGET. ALGOL has outreal(x) and outin-teger(x) to correspond to inreal(x) andininteger(x).

(7) DO. In PL/I, in order to repeatcertain statements from I = 1 to N, wewrite DO I = 1 TO N (note the word TO),followed by the statements to be executed,followed by END. In ALGOL, we write

Circle 102 on inquiry card.

for l:=1 step 1 until N do begin, followedby the statements, followed by end; if thereis only one statement to be repeated, thenbegin and end are not necessary (althoughthey may appear). In BASIC, we writeFOR 1=1 TO N, followed by the statements,followed by NEXT I.

(8) CALL. In BASIC we write GOSUB/7,meaning "Go to a subroutine at statementnumber /?"; subroutines in BASIC do nothave names as they do in FORTRAN,ALGOL, and PL/I. In ALGOL, we leave outthe word CALL; thus SUB(A, B, C) byitself is a statement which calls the sub-routine SUB.

(9) SUBROUTINE. Subroutines inALGOL and PL/I are called procedures,and where in FORTRAN one would writeSUBROUTINE SUB(X, Y, Z), in ALGOLone writes procedure SUB(X, Y, Z), and inPL/I one writes SUB: PROCEDURE(X,Y, Z). The situation in ALGOL is especiallyconfusing because a subroutine is writteninside the program of which it is a sub-routine, at the beginning of that programwith all the other declarations (real, integer,and the like). This makes it very difficult,in practice, to figure out where the firststatement of an ALGOL main program is,particularly if it has a lot of nested subrou-tines. You have to start at the beginning ofthe program and work your way throughall the subroutines, each of which is declaredby a procedure statement with a matchingend (which you have to find); then yousuddenly come, with no warning, upon asimple statement like i:=1 and, believe itor not, that is where you are supposed tostart executing.

(10) RETURN. In PL/I you writeRETURN(e) to correspond to ¥-e followedby RETURN in FORTRAN, where F isthe name of a function.

(11) FUNCTION. The terms correspond-ing to the FORTRAN FUNCTION forALGOL and PL/I are INTEGER PROCE-DURE, REAL PROCEDURE, and thelike; the adjective before PROCEDUREtells you whether the value of the functionis supposed to be an integer, a real number,or whatever.

(12) DIMENSION. In BASIC, one writesDIM instead of DIMENSION. In ALGOL,one writes integer array or real array; inPL/I, one writes DECLARE, which may beshortened to DCL (and usually is). DE-CLARE in PL/I is an all-purpose declarationhaving dozens of variations, but DECLAREA(100), sometimes followed by variousother keywords, is roughly like DIMENSIONA(100) in FORTRAN, as is real array

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December 1978 © BYTE Publications Inc 199

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A[1:100] in ALGOL (the 1 here is thelower bound on subscripts, which may bearbitrary in ALGOL, although it is always 1in FORTRAN).

(13) REAL. In ALGOL, the REALattribute refers to representation as a float-ing point number. [Note that the attributeFLOAT performs this function in PL//, andthat REAL in PL// is used on/y to distin-guish reai from comp/ex numbers. . .BLj

(14) INTEGER. BASIC assumes that allnumbers are real; integers will be treated asif they are real numbers, which usuallyworks the way we want it to, although someoperations like division must be watchedcarefully. In ALGOL, all integers must ap-pear in integer statements.

(15) COMMON. In PL/I, all mainroutine variables are common (called"global" in PL/I parlance) to internal sub-routines (ie: the subroutine is declared by aPROCEDURE statement within theboundaries of the calling PROCEDURE andits END) unless it is redefined in the sub-routine. The EXTERNAL attribute is usedto share variables between external pro-cedures. In ALGOL, any variable in a mainprogram may automatically be used in anyof its subroutines, unless there is anothervariable declared in the given subroutinethat has the same name.

(16) Assignment statements. In ALGOL,the symbol := is used where = is used inFORTRAN, BASIC, and PL/I. In addition,= is used where .EQ. is used in FORTRAN.Some versions of BASIC permit, and somerequire, the word LET at the beginning ofevery assignment statement.

(17) Semicolons. Every statement inALGOL ends with a semicolon unless it isfollowed by end. Every PL/I statement isfollowed by a semicolon.

There are hundreds of other differencesbetween the various algebraic languages, butthese are the basic ones which are requiredto be able to read published algorithms inFORTRAN, ALGOL, BASIC, and PL/I.Most such algorithms, with a few notoriousexceptions, are presented in such a way asto use only the rules described above. Thereader whose appetite has been stimulatedby the possibilities of algebraic languagesmight do well to supplement his smallsystem knowledge by renting a small amountof time (perhaps $100 worth) on a largesystem and trying out various features ofFORTRAN, PL/I, and the like. This is, ofcourse, in addition to the use of crossassemblers and cross compilers, which stillrequire large systems to produce smallsystem object code."

200

December 1978 © BYTE Publications Inc

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BYTE December 1978

201

TechnicalFcpum

Comments on the

RF Entry Method

for Video Monitors

Victor A Wiseman7960 Grand Oaks CtGurnee IL 60031

Photo 1: Author's systemwith Processor TechnologySOL-20 computer and rearview of RF entry videodispiay.

Jls —

mniutituMum

\ +**'

Ktf

mr*"'

' ,#*».;

^Jnl i i^Aw.

^ mx

■ " '■/ ■'■;':

|F/^

Photo 2: Typical display of the system.

This is a reply to a statement in MrFylstra's article "Convert Your TV Set toa Video Monitor," which appeared in theMay 1978 BYTE, page 22.

While I will not contest Mr Fylstra'sstatements and arguments that the directvideo entry method is definitely superiorto the radio frequency (RF) entry method,I must take a stand against his statementthat the radio frequency entry method<(. . .is enough to display at most about32 characters per line." Mr Fylstra hasaccurately identified and reported thepros and cons of the two methods, but anindividual reading his article and contem-plating a 64 or 80 character per line displaywould immediately discard the possibilityof the radio frequency entry method. Myexperiences should prove this to be unfair.

When considering the options I had foradding a video display to my SOL-20, Iconsidered buying a monitor for $180,converting my television for direct entry,and using the radio frequency entry method.Since I already had a portable televisionsuitable for the job, I decided against spend-ing $180 for a monitor. This left me withthe direct video and radio frequency entrymethods. I then armed myself with a SamsPhoto-Fact folder and performed someexploratory surgery on my television. Thisconvinced me that I could use the directentry method, but it would require somecare and time to do properly. I finallydecided that the most expedient methodwould be the radio frequency entry method;the cost was low enough so that, if it didn'twork out, I would not have lost much.As it turned out, the radio frequency entrymethod proved entirely satisfactory for myneeds and I have been using it for the pastyear and a half.

Photo 1 shows my system. The processoris a SOL-20 which incorporates everythingon a single printed circuit board, includingthe video display generator. The output ofthis generator is fed through the black cablecoming from the back of the SOL and acrossthe back of the television. This is part of asection of shielded coaxial cable suppliedwith the SOL-20 kit. It is connected to asmall aluminum box containing a Pixe-Verter, a battery pack of 4 AA cells, and anon/off switch (hidden). The radio frequencyoutput from the Pixe-Verter is fed througha twisted pair of solid conductor wires tothe small black connector on the back ofthe television set. This connector wassupplied with the set and is used for con-necting an external antenna. The upperbinding posts are for VHF and the lowerare for UHF, the switch in the center is fora local/distant setting (it is set for local).

202 December 1978 © BYTE Publications Irtc

1976/1977

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mn

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BYTE December 1978

203

The television itself is a Sony Model 9-51 UWwith a 9 inch (13.5 cm) diagonal screen.It is over 11 years old and well-used.

About the Photos

"mm1

«t

'^MFmmjmmmmmi

P/joto 3: Selected portion of the available character set.

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All photos were taken with a Leica M3with a 50 mm F/2 dual range Summicronlens, using Tri-X ASA 400 35 mm film. Thedelayed shutter release was used to dampenvibration effects. Photo 1 was taken withexisting light from a window on a sunnyday at 1/60 second at f/5.6. Photos 2 and 3were taken at a distance of 21 inches (53cm) at 1/30 second at f/4. The bright dia-gonal bands seen on the screen are due tothe discrepancy between the shutter speed,the scan rate of the television, and the focalplane shutter of the camera used to takethe photos. The darkening at the top of thescreen, the heightening of the charactersat the top, and the slight slanting of thecharacters is due to the poor vertical andhorizontal linearity of the set. The slightfuzziness of the display at the left of thepictures is due to depth of field restrictions.Overall, photos 2 and 3 accurately representwhat is seen by the human eye and brain(eye persistency eliminates the brightdiagonal bands).

Photo 2 is a common display of a portionof a program listing using all upper casecharacters. Photo 3 is a generated displayof a selected portion of the available charac-ter set. Control characters were eliminated,since they would cause unwanted displayfunctions like carriage returns and screenclearing. Photos 2 and 3 each show one ormore lines with 64 characters each.

Photo 3 is most indicative of the limita-tions of the radio frequency entry method.The lower case characters m and w show adefinite merging of the dot pattern. Theupper case versions also show this effectto a lesser degree. In normal use, however,the human eye and brain manage to fill ingaps in definition.

I hope this material will show that theradio frequency entry method is capableof producing a very satisfactory video dis-play of 64 characters per line."

Technical Forum is a fea-ture intended as an interactivedialog on the technology ofpersonal computing. The sub-ject matter Is open-ended} andthe Intent Is to foster dis-cussion and communicationamong readers of BYTE. Weask that all correspondentssupply their full names andaddresses to be printed withtheir commentaries.

204

December 1978 © BYTE Publications Inc

Circle 70 on inquiry card.

Continued from page 6

space potential of the current 8 bit micro-processors has effectively become saturated.

This saturation of memory address spacein the 8 bit 40 pin package microprocessorswith a mere eight parts leads to the nextnew high in semiconductor technology'scurrent innovations: the testing and sub-sequent approach to volume productionof three excellent large scale microprocessorswhich provide 23 and 24 bit address spacescapable of reaching 8 or 16 million bytes ofmemory (or peripheral hardware.) I referof course to the new crop of 16 bit tradi-tional microprocessors introduced by Intel,Zilog and Motorola. Perhaps the first suchpart was the Intel 8086 announced lastspring and most likely in production bythe time this is written. (From one contactI heard mention of an even newer 8087,but have not seen any written informationon such a part to date.) The second part,announced shortly after the 8086 lastspring, is the Zilog Z-8000. But what appealsto my mind, after hearing engineering intro-ductory talks on all three of these newproducts by representatives of the com-panies, is the Motorola 68000. It is my ownpersonal favorite, providing a 24 bit byteaddress space and a relatively simple systemdesign concept without elaborate memorypaging and address bus multiplexing require-ments. It is the kind of 16 bit micropro-cessor I like, namely one with a separate24 bit byte address bus, a 16 bit bidirec-tional data bus and simple power supplyrequirements. If I were to build a newsystem of the homebrew variety at thepresent time, it is the one I would mostlikely use. For the moment then, the threeprocessors from Intel, Zilog and Motorolaare the best possibilities for overcomingthe address limitation problems whichbecome very real as the 64 K dynamicmemory parts come to market.

The third major development of thecurrent crop of large scale integrationtechnology is that of new video displaycontroller chips. These parts are actuallyin production at the present time, and are,no doubt, quietly buried in the designsof many of the personal computing pro-ducts which have come to the marketfor the first time in late 1978 and thosewhich will arrive in early 1979. We'vealready received a number of articles onthis kind of device, articles which readerswill see in an upcoming special issue on thetheme of video graphic interfaces.

The final and most exciting developmentof recent months was relayed to me by KenBowles of the Pascal project at the Univer-

sity of California at San Diego (UCSD) in aphone conversation this past September 20.This is the development of a microcomputerchip set which directly executes the UCSDPascal compiler's p-code intermediate lan-guage. The firm responsible for this inno-vation is Western Digital, 3128 Red Hill Av,POB 2180, Newport Beach CA 92663. Inphone conversation with Dr Larry Lotitoof Western Digital I found out some moredetails about the processor, which he andKen jokingly call a "sand casting" of theUCSD p-code interpreter. This first highlevel language machine in microprocessorform will come to market in several formsin January of 1979.

As readers familiar with the developmentof minicomputer technology into micro-computer form will recall, Western Digitalwas the semiconductor manufacturer whichdesigned and first supplied the chip sets forthe Digital Equipment Corp (DEC) LSI-11product several years ago. These chip setsconsist of a microprogram controller and aset of read only memory programs whichemulate the desired computer's architecture.After the first LSI-11 parts had been createdand marketed, DEC began its own in housesemiconductor fabrication efforts andWestern Digital turned out to have less of a

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December 1978 © BYTE Publications Inc

205

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market for its microprocessors than mighthave been expected.

In the past two years or so, severalvariations of the basic 16 bit architecture ofthis chip set have been offered on a custombasis, and at least one such variation hasappeared in the form of an advanced S-100bus computer (MCP-1600). Of course,Western Digital has continued to supplystandard parts for the digital systemsmarkets, such as floppy disk controllerchips, and serial communications interfaces,among others. With the experience of pro-ducing more than one read only memorymicrocode definition for the MCP-1600microprocessor system design, it was nothard for the firm to write the microcodeneeded to emulate a new design, a "P-engine" that executes the intermediatelanguage codes produced by the Pascal com-piler developed by UCSD. Western Digitalcalls the resulting chip set the "PascalMicro Engine" and considers this name theirproprietary trademark. According to Larry,this product will be widely available inseveral forms in January of 1979. What issignificant is that the software developmentsystem for this chip set is the UCSD Pascalsystem without any modification: a com-

bination of Pascal compiler, editor anddisk operating system written in Pascal. Theassembler for this machine is the UCSDPascal compiler, and its "assembly language"is Pascal.

One of the most interesting forms inwhich the Western Digital Pascal MicroEngine will be made available is as an as-sembled black box computer which containsthe following hardware: the Pascal MicroEngine processor; 64 K bytes of program-mable memory; two RS-232 serial terminalports capable of operations at up to 19,200bps; two parallel ports for support of aprinter; a floppy disk controller with directmemory access which is capable of inter-facing four floppy disk drives of 8 or 5 inchsize, single or double density; and a powersupply for the processor. (Users will thushave to supply a terminal and the actualfloppy disk drives with their own powersupplies.) Given the special introductoryprice of $1995 for the first 500 systemsproduced, and the $2995 price after theintroductory period, this package is trulyamazing. It is intended as a developmentsystem for the MCP-1600 Pascal MicroEngine chip set, even though it will cer-tainly be available through the more pro-

PET PRINTER ADAPTER

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The CmC ADA 1200 drives anRS-232 printer from the PETIEEE-488 bus. Now, the PETowner can obtain hard copylistings and can type letters,manuscripts, mailing labels,tables of data, pictures, in-voices, graphs, checks, needle-point patterns, etc., using astandard RS-232 printer orterminal.

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21

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206

December 1978 ©BYTE Publications Inc

Circle 77 on inquiry card.

Circle 1 on inquiry card.

YOUR 6800 BASIC BOMBING? Q0

Try our guaranteed Basic with print using statements, renumbering with automatic revectoring, ^^ ■

random disc files and more. (Specify Smoke Signal Broadcasting or cassette) $ 50

Editor — Text Processor with mailing lists and labels, full disc handling capabilities.

(Specify Smoke Signal Broadcasting or Flex) .. $100

MSI version of Editor — Text Processor with custom DOS $125

Super Payroll includes initial loader, payroll, editor-text processor, 941 and unemployment compensationreports, departmental analysis, up to 10 states and 10 additional cities (or local governments), and more.

(Specify Smoke Signal Broadcasting, Flex, or MSI $400

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gressive local dealers to the personal com-puter trade.

Western Digital, however, considers itselfmainly a semiconductor manufacturer, soone of the reasons for the relatively lowprice on the development system's processorkernel is to promote sale of the chip sets foruse in new designs. We can expect to seemore than one personal computer manu-facturer taking advantage of this develop-ment, for the characteristics of the directlyexecuted p-code method allow programsto run from six to eight times faster thanwould be possible using the LSI-11 versionsof the software.

In the LSI-11 version of the UCSDsystem (or any other conventional pro-cessor's version) there are two levels ofemulation. At the first level is the hardwareneeded to execute the instruction set of theparticular microprocessor, be it 8080,LSI-11, 6800, 6502 or any other instructionset The second level comes in when theparticular microprocessor runs an interpreterwhich emulates the P-machine. With theWestern Digital innovation, the P-machineis directly executed by the hardware whichis seen by the system designer. This directexecution is the reason for the improvement

relative to the LSI-11 which uses very similarhardware. Designers who are interested increating dedicated microprocessor systemsthat use the most advanced and reliablesoftware development techniques will findthis chip set a natural one to use. Designersof personal computing products will alsofind it useful, for the extremely powerfulUCSD Pascal software system fits naturallyinto the machine.

This announcement of a high level lan-guage machine for Pascal is perhaps the highpoint of the current crop of wonders whichinclude the 64 K memories, large scalemicroprocessors and video controllers. Somepeople have disputed the relevance of highlevel languages like Pascal, on the groundthat they demand expensive systems, butthe arrival of the relatively inexpensiveWestern Digital machine next month isperhaps the last word on that argument fornow. The nature of the new levels of sophis-tication in the larger microprocessor chipssuch as the 8086, Z-8000 and 68000 com-plement the new heights of memory densityin the 64 K chips and further indicate boththe need for and practicality of high levellanguages like Pascal in future personalcomputers."

MONKCXSCC, MONK6XDO

JUST LIKE A MULLEN CONTROLLER

Thanks to 8 opto-isolatar inputs, the CB-1 Controller Board Kit ($68) can "see" a variety of condi-tions, and pass this information along to your computer; the computer then makes appropriate deci-sions, and tells the CB-1 what to "do." 8 on-board switches can either drive low power loads directly,or trigger Mullen 500 Watt control modules.

And what can a CB-1 do? Users report applications varying from environmental heating systems toautomatic cat feeders . . and we hear about more uses all the time. In fact, right now we're hear-ing about lots of applications thanks to our Controller Board Applications Contest. Stop by yourlocal computer store for details, an entry blank, and an in-person look at the CB-1.

If your computer would like to move up the evolutionary path and acquire appendages to go alongwith its intelligence, the CB-1 is the place to start.

Put your computer to work for you ... we make it easy.

MULLEN Computer Products

BOX 6214, HAYWARD, CA 94545

Circle 267 on inquiry card.

December 1978 ' BYTE Publications Inc

207

Circle 32 on inquiry card.

The Independent Newsletterof Heath Co. Computers

\m

The independence of Bus® is a cruits significance to users (and prosof Heath Co. computers. Informatioucts is presented to Buss readers aof Benton Harbor, not held back toof the manufacturer. This has beenfirst issue, which directed attentiand LSI-11 months before any adverton the H8 and Hll. Buss features cof owners' experiences with their cis far more valuable than an articl

cial factor inpective users)n on new prod-s it leaks outsuit the planstrue from itson to the 8080ising appearedandid accountsomputers--thise based on the

opinions of a single reviewer. It shares news ofcompatible hardware & software from other vendorsas well as reviews of books that can help you getthe most out of your computer system.

Every issue of Buss travels by first class mail(outside North America it goes by air for only $2extra). Your 12-issue subscription can be on itsway to you within a week. You have the choice ofstarting either with the latest issue or with allavailable back issues. Send $7.50 to Buss , 325-BPennsylvania Ave. SE, Washington, DC 20003.

TechnicalFonum

Resonating Modulators

Allen Watson III430 Lakeview WayRedwood City CA 94062

As a recent Apple II purchaser, I enjoyedyour review of the Apple II (March 1978BYTE, page 18). I was especially interestedto see that you encountered most of thesame problems I did, such as the inter-ference with the color receiver. I too amusing the M & R Enterprises modulator thatinstalls inside the Apple II along with a low

priced GE portable, and the interferencewith my first setup was pretty bad.

Something about the length of the leadto the TV set got me to thinking. I remem-ber making dipole antennas, and somehow

4 feet seemed like a familiar dimension.Channel 3's picture carrier frequency isabout 61 MHz, for a wavelength of about

5 meters. The cable from the modulatorto the color set is about 4 feet (1.2 meters)long or almost exactly a quarter wave. Thatmakes it a very good antenna for any har-monics (60 thru 65 MHz) of the Appleclock, character generator, etc. The cable islooped through a large ferrite toroid, whichhelps quite a bit, but a simple modificationmakes things even better. All you have to dois add an 18 inch extension cable, thusmistuning the channel 3 antenna, and 90percent of the interference will disappear.

We just got around the problem of radiofrequency interference with our Apple IIby use of the M & R Enterprises UHFmodulator recently acquired. Without evenputting a single toroidal balun core onthe coaxial cable, the same Panasoniccolor television runs without any inter-ference. . . XH"

ILLUSTRATING BASICA Simple Programming Language

DONALD ALCOCK

"Here's a book ... to introduce complete beginners to the

BASIC language in a charming way. Every page is illustrated

in pen and ink style; even the body of the text is

handlettered by the author. . . . Alcock's experience in

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lucid writing and dry humor. ... Of the many texts on

BASIC, this is one of the most engaging." - Computer

Dealer

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AN INTRODUCTION TO THE STUDYOF PROGRAMMING LANGUAGES

D. W. BARRON

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208

December 1978©BYTE Publications Inc

Circle 43 on inquiry card.

Texas Instruments Introduces 5 V 64 K Byte Programmable Memory

A New Color Graphics Computerfrom Chromatics

Texas Instruments has introduced theTMS 4164, a single 5 V 64 K bytedynamic programmable memory,organized as 64 K byte by 1. It comes ina 16 pin dual-in-line package, and allowsupward compatibility with the 16 Kbyte dynamic programmable memory.

The TMS 4164 single 5 V powersupply design is TTL compatible, offerslower power dissipation, and is moreimmune to system noise. Compactlayout, and an optimized design andprocess combination for 5 V onlyoperation result in improved perfor-mance.

Access times range from 100 to 150ns maximum, with minimum cycle timesof 200 to 250 ns. Power dissipation is200 mW maximum or 3 /iW maximumper bit. Comparing the 462 mW powerdissipation of the 16 K programmablememory at 375 ns cycle time, totalmaximum power dissipation of the newmemory is a reduction of 60 percent,

with improved cycle times, while bitdensity is quadrupled. As a result of thelower power dissipation, the TMS4164 features a 256 cycle refresh witha 4 ms maximum refresh period.

Due to TMS 4164 refresh com-patibility with the 16 K byte program-mable memory, the basic refresh con-troller timing does not require majorchanges. The only provision required isfor an 8 bit refresh counter and multi-plexer when upgrading to 64 K bytefrom a 16 K byte system. Also con-tributing to higher system operatingefficiency is a 1.3 to 1.6 percent refreshoverhead time, compared to 2.4 percenton the 16 K byte programmablememory.

The TMS 4164 is priced at $125.For further information write to TexasInstruments Inc, Inquiry AnsweringService, POB 1443, M/S 669, HoustonTX 77001,"

Circle 593 on inquiry card.

Chromatics Inc has introduced theCG series line of full 8 color graphic andalphanumeric readout computers. Theline consists of 13, 15 and 19 inch mod-els featuring noninterlaced screenrefresh, high resolution shadow tubes,and 512 by 512 or 512 by 256 individu-ally addressable and color selective dots.Each model employs a Z-80 processorwith full memory and input and output(IO) structure. The 13 inch modelstarts at $8995.

A bulletin describing the system maybe obtained from Chromatics Inc,3923 Oakcliff Industrial Ct, AtlantaGA 30340.*

Circle 594 on inquiry card.

New Keyboard for 64 and 80 Character Display Video Boards

This new MKB-2 keyboard is de-signed for use with the 64 and 80character display video boards. Standardfeatures on the MKB-2 include: a nu-meric key pad, upper and lower case,cursor control keys, 2 key rollover, andautomatic repeat on all keys. The MKB-2is assembled in a heavy duty steel casewith parallel interface, strobe or pulseand on board regulation (5 V, 12 V),and comes complete with standardDB25S connector and black double in-jection molded keys.

The price of the MKB-2 is $149. Forfurther information, write to MicroAge,1425 W 12th Pi #101, Tempe AZ85281."

Circle 595 on inquiry card.

December 1978 © BYTE Publications Inc 209

What's New?

PUBLICATIONS

6800 Programming Workbook

Expanded Book Catalog from BITS

„ m BITS

^(k$\v Books to erase the impossible

A new expanded BITS catalog is nowavailable, featuring books on micro-computing and other related subjects.There are new books on business andcalculators, Pascal, artificial intelligence,robotics, programming, hardware, gamesand much more.

BITS has a complete selection ofprofessionally reviewed microcomputerbooks (over 150 titles), including anumber of self-published works. Theirinventory has been expanded to includea greater number of posters and specialtyitems of interest to the computer enthu-siast. Request your free catalog fromBITS Inc, Dept 3, POB 428, Peter-borough NH03458.*

Circle 564 on inquiry card.

Software Handbook of StatisticaTechniques

This software handbook, entitledSIMPLE, comprises over 100 conver-sational computer programs written inBASIC for teaching statistics and exper-imental design to students from allengineering, science, business and socialscience disciplines. Course organizationaround the modular structure is consid-ered; and the manual contains a descrip-tion of each program, the program inputand format requirements, a sampleproblem, a copy of the terminal userdialogue and an explanation of what theresults mean in practice and the BASICprogram itself.

The price for this manual is $10.95.For further information contact SterlingSwift Publishing Company, POB 188,Manchaca TX 78652.»

Circle 565 on inquiry card.

This self-instruction workbook is aguide to the fundamentals of assemblylanguage and machine code programmingof the 6800 microprocessor and itsperipheral devices. Considerable coverageis given to programming of input andoutput devices. The asynchronous com-munications interface adapter and pe-ripheral interface adapter, each withits various modes of operations, areexplored in detail in both noninterruptand interrupt modes. Program design anddocumentation are emphasized alongwith programming hints and aids.Programming the 6800 Microprocessorby R W Southern is available fromSouthcroft Publications, POB 11703,Station H, Ottawa CANADA K2H 7T8,for $6.75. Submit US funds for USdelivery; Canadian funds for Canadiandelivery."

Circle 566 on inquiry card.

New Publication Devoted toTRS-80 User

Dump Publications has announcedthe release of a software publication forusers of the Radio Shack TRS-80 micro-computer system. Dump is a monthlyperiodical incorporating news, informa-tion, and running software ready to loadfrom a 33 1/3 revolution per minutedisk record. The Dump disk can beloaded into the TRS-80 system with theuse of an ordinary phonograph.

Each issue contains a wide variety ofprograms from finance and education togames and machine language. Programsare provided with complete documenta-tion and line editing information forLevel I and II BASICs.

A 1 year subscription costs $20. Formore information, contact Dump Pub-lications, POB 2454, Jacksonville FL32203.-

Circle 567 on inquiry card.210 December 1978 © BYTE Publications tnc

New Text on Basic Pulse Circuits

The basic building blocks of moderncomputers, radar, television and pulsecommunication circuits are presentedin this programmed text entitled AProgrammed Course in Basic Pufse Cir-cuits, by the New York Institute ofTechnology.

This 293 page programmed learningtext is organized in a logical sequenceof interrelated steps. Discussions onswitching devices such as unijunctiontransistors and silicon controlled rec-tifiers are included. All devices aresolid state, and some material on inte-grated circuits is presented. Each chapterbegins with a set of objectives andconcludes with a set of criteria tests tomeasure progress.

The price of this text is $9.95 and itcan be obtained from McGraw-Hill BookCompany, 1221 Av of the Americas,New York NY 10020."

Circle 568 on inquiry card.

THE BEST FOR BOTH WORLDS

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This month's specials.

16K MEMORY ADD-ON FOR APPLEORTRS-80

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NEW FROM SSM.THE CB-1 8080 CPU BOARD ATA

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$-100 WIRE WRAP BOARD

Over 3600 holes, for super versatility. Provisions for 4regulators. Double-sided, plate-through. All S-100 pinslabelled for number and signal. The PT-1. Hobby WorldPrice; Only $30.00

Hobby World Carries TAB Books! Affordable books forthe hobbyist. Hobby World helps out with a 10%discount. (Order by number, and don't forget the 10%discount)

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TELEPHONE ORDERSInside Calif: 243 886-9200Outside Calif: 800 423-5387

Computer Circuits and HowThey Work

Beginner's Guide toComputer Logic

Computer Technician'sHandbook

Build Your Own WorkingRobot

ProgrammingMicroprocessors

Beginner's Guide toComputer Programming

Digital Electronics:Principles and Practice

Microprocessor/Micro-programming Handbook

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California Residents add 6% Sales TaxCharge My MC #

VISASignature

Expiration.

Circle 170 on inquiry card.

BYTE December 1978 211

What's New?

MEMORY

High Speed EXORcisor Memory

:

16 Bit Microcomputer Module

The TM 990/100M series offers up to4 K words by 16 bits of erasable readonly memory and up to 2 K words by 16bits of static programmable memory onboard. The board also contains two serialinput and output (IO) ports; one is in-tended for remote usage with a terminalor modem, the other for local usage withTexas Instruments' 301 Microterminal,an EIA terminalor a Teletype,

The TM 990/101 M series offers threeprogrammable interval timers, up to 17interrupts and 16 lines of programmableparallel IO. The TM 990 series is sup-ported by Texas Instruments' AM PL

prototyping system. A user's manualdetailing the hardware and software ofthe TM 990 board will be supplied witheach unit. A wide line of accessories andperipherals also available.

Pricing on the fully assembled andtested TM 990/101M-1 including 1 Kword by 16 bit erasable read only mem-ory and 1 K word by 16 bit static pro-grammable memory is $625 in singlequantities. Inquiries should be forwardedto Texas Instruments Inc, Inquiry Ful-fillment, POB 1443, M/S 653 (Attn:TM990), Houston TX 77001.■

Circle 555 on inquiry card.

S-100 Compatible Single Card Plug-In NMOS Memory

This 16 K word by 8 bit program-mable NMOS memory system is S-100and card size compatible. The EMMModel 1104 is a single card plug-in

assembly which is fully burned-in andtested. The Model 1104 uses EMM 4 Kbyte static programmable memories,and no refresh circuitry is required.

Designed specifically for operationwith Motorola EXORcisor andMEC 6800 evaluation module isChrislinIndustries' new CI6800, 16 K by 8 bitsemiconductor memory system. The newmemory allows expansion to 32, 48 and64 K bytes by interchanging the 40274 K by 1 bit dynamic memory with the16 K equivalent. No further modifica-tion is required. The CI6800 memoryboard plugs directly into existing EXOR-cisor connectors.

It allows maximum processorthroughput with the use of hidden re-fresh control logic on board. Data accesstime is 300 ns and cycle time is 750 ns.

On board memory select is availablein 4 K byte increments up to 64 K wordsof memory. A write disable switch onboard makes the programmable memorya read only memory to the outsideworld.

Complete board power consumptionis under 5 W. The board size is 5.75 by9.75 inches (14.61 by 24.77 cm). Formore information, contact Chrislin In-dustries Inc, 31312 Via Colinas #102,Westlake Village CA 91361. ■

Circle 556 on inquiry card.

The system consists of the memoryarray with support electronics includingaddress and data buffering, timing andcontrol, and voltage regulation. Thememory array is divided into four 4 Kby 8 bit memory blocks, and each blockcan be assigned to a 4 K byte addressblock within a 0 to 64 K byte range.Operating modes are read, write anddeposit. The deposit mode is a phasememory cycle consisting of a writefollowed by a read.

For complete information contactElectronic Memories and MagneticsCorp, 12621 Chadron Av, HawthorneCA 90250.-

Circle 557 on inquiry card.

212

December 1978 ©BYTE Publications Inc

c

PLACE ORDERS TOLL FREE

800/421-5809 Continental U.S.800/262-1710 inside California

Computer Products

}

EPROM BOARD KITS

RAM'N'ROM

(16K any EPROM) $117.00

MR-8 (IK RAM, uses

2708) $99.50

MR-16 (IK RAM, uses

2716) $99.50

EPM-1 (uses up to 4 K

of 1702) $59.95

JG8/16 (uses 2 708 or

2716) $69.95

$10.95

$5.25-$8.25$5.25$5.95$9.00$900

MICROPROCESSORS

F8 $16.95

Z80 (2MHz) $20.00

Z80A <4MHz> $25.00

CDP1802CD $17.95

2650 $19.95

AM 2901 $20.00

6502 $11.95

6800 $16.95

6802 $25.00

8008-1 $12.95

8035 $20.00

8035-8 $21.00

8080 A $10.00

8085 $23.00

"TMS9900TL $49.958080A SUPPORT DEVICES

8212 $2.90

8214 $4.65

8216 $2.75

8224 (2MHz) $4.30

8224-4 (4MHz) $9.95

8226 $2.75

8228 $6.40

8238 $6.40

8243 $8.00

8251 $7.50

8253 $20.00

8255 $8.50

8257 $20.00

8259 $20.00

8275 $75.00

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2513 Upper (-12+5J2513 Lower (-12T5)2513 Upper (5v"olt>2513 Lower (5 volt)MCM6571 up scanMCM6571A down senPROMS

1k702A2708,

2716'(5+12> Tl2716 (5v> INTEL2758 (5v)DYNAMIC RAMS

416D/4116 (250ns>

2104/4096

2107B-4

TMS4027/4096 (300ns)

MM 52 70

MM5280

STATIC RAMS

21L02 (450ns)21L02 (250ns)2101-12111-12112-1

FLOPPY DISKCONTROLLERS1771B011781KEYBOARD CHIPS

AYS-2376AY5 3600MM5740MM5743

$10.00$4.95

$4.00

$6.60

$6.60

$11.25

$16.95

$8.65

$11.00

$9.25

$12.00

$28.75

$8.75

$2.50

$6.00

$8.00$11.95$10.00

$9.25$15.95$15.95$15.95$15.95$15.95$17.95

$6.75

$6.75

$9.75

$10.95

$10.95

$10.95

$8.00

$9.95

$25.00

$60.00

$23.40

$12.50$4.00$3.95$4.00$4.50$3.60

1-15 16-100

$1.50 $1.20

$1.75 $1.50

$2.95 $2.60

$3.25 $3.00

$2.95 $2.65

$39.95$69.95

$13.75$13.75$18.00$18.00

EXPANDOR'S BLACK BOX PRINTER

This 64-character ASCII impactprinter with 80-column capabilityis portable and uses standard8%" paper and regular typewriterribbon. Base, cover and parallelinterface are included. Assembledand complete with manual anddocumentation.

only $430.00

{90 day manufacturer's warranty)

TRS-80 Interface Cable for Black Box Printer

with mating connectors: $48,00

(must be used with expansion module, +8v/1 amp power

suppjy required)^

Power Supply for TRS-80/Black Box Printer

$49.00

*. STATIC RAMu,** SPECIALS **

2114'sflow power (1024x4)

1-15 16-99 100 +450ns 8.00 6.95 5.50

250ns 9.00 8.00 6.50

TMS4044/MM5257, low power

450ns 8.00 7.50 6.50

250ns 9.95 8.75 8.004200A (4Kx1, 200ns)

9.95 8.50 8.00

look).

DYNAMIC RAM BOARDSEXPANDABLE TO 64K

32K VERSION • KITS

Uses 4115 (8Kx1, 250ns)Dynamic RAM's, can beexpanded in 8K increments upto 32K.8K $199.00

16K $255.00

24K $310.00

32K $369.00

64K VERSION • KITS

Uses 4116 (16Kx1, 250ns)Dynamic RAM's, can beexpanded in 16K incrementsup to 64K.

16K $29Z00

32K $43Z00

48K $578.00

64K $721.00

xMJxxm PARALLEL/SERIALINTERFACE

S-10 0 compatible, 2 serial

I/O ports, 1 parallel I/O.

Kit JG-P/S $124.95

Ass. & Tested

JG-P/SA $179.95

Bare Board

with manual $30.00

FLOPPY DISK INTERFACE

JADE FLOPPY DISK (Tarbell

board)

Kit $175.00

Assm. & Tested $250.00

S.D. Computer Products

"Versa Floppy"

Kit $159.95

Assm. & Tested $189.95

STATIC RAM BOARDSJADE 8KKits: 450ns $125.95

250ns $149.75

Assembled & Tested:

450ns $139.75

250ns $169.75

Bare Board: $25.00

16K - Uses 2114's (low power)Assembled & Tested:

RAM 16 (250ns) $375.00RAM 16B(450ns) $325.00MEM-2 Kit:

250ns $285.00

16K with memory managementAssembled & Tested:

RAM 65 (250ns) $390.00RAM65B (450ns) $350.0032K StaticAssembled & Tested:

250ns $795.00

450ns $725.00

250ns Kit $575.00

ALL PRICES SUBJECT TO CHANGEWITHOUT NOTICE

TRS-80 #iPPtan

MEMORY EXPANSION KITS4116's

<16Kx1, 250ns) sjorjsaoq^

TRS-80 KIT

includes connectors andinstructions $98.00

8080A

with full documentation

Kit

Assm. & Tested

Bare Board

$100.00

$149.95

$30.00

Z80

with provisions for ONBOARD2708 and POWER ON JUMP

2 MHzKit $135.00

Assm. & Tested $185.00

4 MHzKit $149.95Assm. & Tested $199.95Bare Board $35.00

MD-690a CPU BOARD

S-100 Compatible 6800 MPUIK x 8 RAM, PROMexpandable to 10 K.

$199.95

OQ.ShugcytDISK DRIVES

SA 400 $295.00

Single-density SW', 3 5 trackdrive.

SA801R $495.00

Single-sided 8" floppy discdrive.

DM 2700-S

$750.00

Includes SA801 R disk drive,10M x 10" x 16" cabinet,power supply, data cable, fan,AC line filter.

Computer Products

THE PIGGYJSCQMING!

4901 W. ROSECRANS AVENUEDepartment "B"HAWTHORNE, CALIF. 90250

Cash, checks, money orders, and credit cards accepted.Add freight charge of $2.50 for orders under 10 lbs and$1.00 service charge for orders under $10.00. Add 6%sales tax on all parts delivered in California. Discountsavailable at OEM quantities.

WRITE FOR OUR FREE CATALOG

S-100 MOTHER BOARDS

JADE 6-SLOT

Kit $41.95

Assembled & Tested $56.95

Bare Board $24.95

9-SLOT "LITTLE MOTHER"

Kit $85.00

Assembled & Tested $99.00Bare Board $35.00

13-SLOT "QUIET MOTHER"Kit $95.00

Assm. & Tested $110.00

Bare Board $40.00

22-SLOT "STREAKER"Assm. & Tested $149.00

VIDEO INTERFACE

S-100 Compatible SerialInterface with Sockets Included.Kit $117.95

Assm. & Tested $159.95

Bare Board withmanual $35.00 a

Circle 195 on inquiry card.

BYTE December 1978 213

What's New?

Microprocessor Analog Interface Module

PERIPHERALS

24 Channel Digital Input System for Motorola Microcomputers

This single board microperipheral ac-cepts 24 digit inputs. MP710, with anon board power supply, operates withdry relay contacts and MP710-NS withvoltage input (wet relay contacts). Eachgroup of eight inputs is isolated fromother groups and from the computer busup to 600 VDC. In MP71 0-NS, isolationbetween inputs is 300 VDC.

MP710s are electrically and mechani-cally compatible with Micromodule andEXORciser microcomputers and operatefrom their +5 VDC supplies. They areprogrammed as memory locations andwith each input using one memory bit,any read command may be used. When

the board is read, logic 0 represents anopen contact (low voltage); logic 1, aclosed contact (high voltage). Each readcommand inputs the status of eightchannels. Address bits A0 and Al selectthe set of inputs to be read. The remain-der of the address lines are used to selectthe board itself. The address block occu-pied by each board is selectable and canbe located anywhere in memory.

The price of the MP710 is $355 inquantities of one to nine. For furtherinformation contact Burr-Brown, Inter-national Airport Industrial Park, Tuc-son AZ 85734.-

Circle 551 on inquiry card.

Process Control Output Module

The PCO-1A process control outputmodule provides two complete 4 to 20

mAor 10 to 50 mA process control cir-cuits on one Wyle microcomputer sys-tem output module. The 4 to 20 or 10to 50 ranges are independently select-able for each circuit, and both outputsare short circuit protected. The PCO-1Ais priced at $345 per module (2 outputcircuits). Contact Wyle Laboratories/Computer Products, 3200 MagruderBlvd, Hampton VA 23666."

Circle 552 on inquiry card.

The Wince Analog Interface Moduleenables laboratory and control engineersto interface thermocouples and othertransducers to a microprocessor andinterface the microprocessor to motors,servos, etc. Options include a 16 channelmultiplexer, an 8, 10 or 1 2 bit analog todigital converter and one or two 8 bitdigital to analog converters. The baseprice is $99. Write to Wintek Corp,902 N 9th St, Lafayette IN 47904 forfurther information."

Circle 553 on inquiry card.

Computer Video to UHFRF Interface Modulator

The Micro-Verter is designed to inter-face microcomputers to color or mono-chrome television receivers as an alterna-tive to the video monitor. The Micro-Verter operates in the UHF channelsabove channel 14, beyond the normalrange of switching harmonics, and is de-signed to interface directly with theApple II as well as with most othermicrocomputers. It comes complete withvideo cable and radio frequency (RF)output stub coupler and requires no di-rect connection to antenna terminalsexcept in special cases. The radio fre-quency signal is coupled directly intothe UHF tuner input via a 1 cm stubcoupler on the back of the modulator.The approximate size of the unit is 2by 3.5 by 4.5 inches (5.5 by 8.5 by 11.5cm) and it is priced at $35. For more in-formation contact ATV Research, 13thand Broadway, Dakota City NE 68731."

Circle 554 on inquiry card.

214 December 1978 © BYTE Publications Inc

Introducing

the simple

TRS-80 Up-grade

Fast, easy, guaranteedexpansion to 16Kat less than half theprice of Radio Shack.

Ithaca Audio makesit simple

No false starts and finding you needsome little item or special tool. Our'Kitcontains all the parts: 8 prime dynamicRAMs and a complete set of preprogrammedjumpers. No matter which model you have(even if you later purchase Level II software),you're covered.

Complete Instructions

Our easy-to-follow directions cut instal-lation time to just minutes. You can do ityourself—with no soldering! All you need isa household screwdriver.

100% Guarantee

Like our kit, simple: if a part ever fails, wereplace it, FREE.

Available now, only $140

Order from your favorite retailer. If bychance he hasn't stocked them yet we'll shiphim your Kit right away.

For technical assistance call or write to:

ITHACAAUDIO

Phone: 607/273-3271

P.O. Box 91 Ithaca, New York 14850

Available off-the-shelf at these fine computer dealers.

AL: Huntsville: Computerland, 3020 University Drive, N.W., (205) 539-1200. CA: Berkeley: Byte Shop, 1514 University Ave., (415) 845-6366, Marina DelRay: Base 2,13480 Beach Ave.,(213) 822-4490. Mt. View: Digital Deli, 80 W. El Camino, (415) 961-2670. DE: Newark: Computerland of Delaware, Astro Shopping Center, Kirkwood Highway, (303) 738-9656. FL:Tampa: Microcomputer Systems, 144 South Dale Mabry, (813) 879-4301. IL: Niles: Computerland, 9511 North Milwaukee Ave., (312) 967-1714. Oak I,awn: Computerland, 10935South Cicero Ave., (312) 422-8080. KS: Overland Park: Personal Computer Center, 3819 West 95th St., (913) 649-5942. Wichita: Computer Systems Design, 906 North Main St., (316)265-1120. KY: Louisville: Computerland, 813-B Lyndon Lane, (502) 425-8308. MA: Cambridge: Computer Shop, 288 Norfolk St., (617) 661 -2670. MD: Rockville: Computerland,16065 Frederick Rd., (301)948-7676. Ml: Royal Oak: Computer Mart, 1800W. 14 Mile Rd., (313) 576-0900. NJ: Budd Lake: Computer Lab of New Jersey, 141 Route 46, (201)691-1984Clark: S-100,7 White Place, (201) 382-1318. Iselin: Computer Mart of New Jersey, 501 Route 27, (201) 283-0600. Succasunna: Computer Hut, 15 Route 10, (201)584-4977. NY: Buffalo:Computerland, 1612 Niagara Falls Blvd., (716) 836-6511. Dewitt: Computer Enterprises, 3470 Erie Blvd. E., (315)637-6208. Ithaca: Computerland of Ithaca, 225 Elmira Road. (607) 277-4888. New York Qity: Computer Mart of NY, 118 Madison Ave., (212) 686-7923. Johnson City: Micro World, NYPENN Trade Center, RM 217, 435 Main Street, (607) 798-9800 OH:Cincinnati: Digital Design, 7694 Comargo Rd., (513) 561-6733. Dayton: Computer Solutions, 1932 Brown St., (513) 223-2348. OK: Oklahoma City: Micronics, 2834 N.W. 39th St.,(405) 942-8152. TX: Austin: Computerland, Shoal Creek Plaza, 3300 Anderson Lane, (512) 452-5701. Houston; Houston Computer Mart, 8029 Gulf Freeway, (713) 649-4188. UT:Orem: Johnson Computer Electronics, 699 N. 1060 W., (801) 224-5361. VA: Alexandria: Computers Plus, 678 So. Pickett St., (703) 751-5656. Arlington: Arlington ElectronicsWholesalers, 3636 Lee Highway, (703) 524-2412. VT: Essex Junction: Computer Mart of Vermont, 159 Pearl St., (802) 879-1683. CANADA: Ontario: Mississaugua: ArisiaMicrosystems, 1455 Gregwood Rd., (416) 274-6033. Toronto: Computer Mart Ltd. 1543 Bayview Ave., (416) 484-9708. WEST GERMANY: Munich: ABC. Computer Shop, Schelling-strasse 33, 8000 Munchen 40, Microcomputer Shop, Toelzerstr. 8, D-815 Holzkirchen. ISRAEL: Haifa: Microcomputer Eng. Ltd., Haifa 31-070.

BYTE December 1978

215

What's New?

Hard Copy Graphics Terminal

PERIPHERALS

Z-80 Arithmetic Processing Unit

Fully compatible with the ZilogZ-80 MCB, this high speed arithmeticprocessing unit board (HAPUB) pro-vides the hardware necessary to accom-plish arithmetic, trigonometric, inversetrigonometric, logarithmic, exponentialand square root functions. HAPUBsimplifies software and allows theZ-80 to perform other operations whileaccomplishing these functions. Alsofeatured are fixed point integer singleand double precision (16 and 32 bit),and floating point single precision(32 bit) operation with bidirectionalconversion capability. The board iscompatible with the Zilog Z-80 cardcage and 8 bit bidirectional data bus andcosts $749. Contact Signal LaboratoriesInc, 202 N State College Blvd, OrangeCA 92668,-

Circle 525 on inquiry card.

Triple Output DC Power Supply

Power-One has announced an addi-tion to their Hi-Vol series triple outputDC power supply line. The new model,designated HCAA-60W, is built in theindustry standard package size for a60 W triple output open frame powersupply. This model outputs 5 V at 6 Awith adequate overvoltage protection,+12 to 15 V at 1.0 A, and -12 to 15 Vat 1.0 A. The -12 to 15 V output maybe changed to -5 V at 0.4'A by jumper-ing two printed circuit board terminals.Targeted for use in systems requiringmultiple DC voltages, the HCAA-60Wwill power combinations of most semi-conductor devices including TTL, PMOS,NMOS, CMOS and linear devices. Total

isolation between the 5 V, ±12 V and±15 V outputs allows the user to arrangepolarities to suit specific applications.

Standard features include 115/230VAC ±10% AC input capabilities,±0.05% line and load regulation, andfull protection against short circuitand overload. Maximum output rippleis 3 mV peak to peak.

Each unit is tested and burned inand carries a 2 year warranty. The sizeis 9.0 by 4.87 by 3.2 inches (22.86 by12.37 by 8.13 cm) and it weighs 7.5pounds (3.36 kg). The price is $84.95from Power-One Inc, Power-One Dr,CamarilloCA 93010..

Circle 527 on inquiry card

This plotter system, calledPanographic-84, has a resolution of 100steps per inch in the X and Y directionsand a cumulative error of less than .020inches (.05 cm) in 10 inches (25.4 cm)of travel. The drives are stepping motoroperated for zero drift and no adjust-ments. Interfacing with a computer isvia eight wires from the plotter to aparallel port. When driving the plotterfrom BASIC language programs, com-plete handshaking is not required sincethe plotter response is considerablyfaster than the speed at which BASICcan drive it. If the user wishes to drivethe plotter from a machine languageroutine, full handshake capability isavailable. The polarity of handshakesignals is switch selectable.

Options available at present consistof a computer operated pen lifter anda vacuum formed plotter cover. Soft-ware provided with the system is writtenin BASIC and listings of these shortroutines are provided.

The price for the plotter kit withoutpen lifter and cover is $995. The penlifter kit sells for $85, as does themolded plotter cover. A factoryassembled plotter with pen lifter andcover sells for $1400. For more infor-mation, write to Pan Dynamics Inc,2950 Nebraska Av, Santa Monica CA90404.*

Circle 526 on inquiry card.

Where Do New Products ItemsCome From?

The information printed in thenew products pages of BYTE isobtained from "new product'* or"press release" copy sent by thepromoters of new products. Weopenly solicit releases and photosfrom manufacturers and suppliersto this marketplace. The infor-mation is printed more or less as afirst in first out queue, subject tooccasional priority modifications.While we would hoi knowinglyprint untrue or inaccurate data, ordata from unreliable companies,our capacity to evaluate the pro-ducts and companies appearingin the "What's New?" feature isnecessarily limited. We thereforecan no t be responsible for prpduc tquality or company performance.

4m

216

December 1978 © BYTE Publications Inc

CaIiFornia DiqiTAl

Post Office Box 3097 B • Torrance, California 90503

CLARE PENDAR |H1General Instrument Corp. LuJ

KEYBOARDASCII ENCODED

kV» $64.95

This is a one time purchase ofNEW Surplus keyboards, re-cently aquired from the Tele-communications Division of theSinger Corporation,The keyboard features 128ASCII characters in a 63 keyformat, MOS encoder circuitry"N" key rollover, lighted shiftlock, control, escape and re-pete functions.

Sloped pannel and positive feelswitches, makes this profes-sional quality keyboard an ex-cellent buy at only $64,95.Limited Quantities.

MS|7j>m.|,-lfT\!

fc»C4 I EMJMAKl KTI A IbUj \ I I US

pa

shift! j8

SOmTocT EOT ACK BEL

A 1 S D F G H

CAM|**X|SYNIsT*1 g I

X ! C | V B N

!„„„' TDf! I E T B }E NQbC 2 |t>C 4 I EM INAK I Ut I SI I bit I \ I

1 BEPE*T | Q I W [ E fR | T | Y 1 U | I | 0 | P I g> | I

|RS |FS, LbackIhereI|\ ■ jsmcq is |

*Tuke| re- j

feedIturn

TU

CONNECTORS

p3 ***> 1 : I

t* S* male

I 1 DB:

^ ...«^.3P

1 ai,.ii lJ

your choiceDB25Pplug&hoodor25S female

*3?5

Qty fe. male hd.10 3.45 2.45 1.1525 3.15 2.25 1.05100 2.85 1.90 .95500 2.25 1.60 .85IK 1.97 1.37 .73

EdgeConnectors

GOLD100 PIN

IMSAI/ALTAIR

Imsai solder .125*.250Imsai w/*.125eentersAltair soldertiil .140rowSPECIALS

22 44 Kim eyelet. 156"25/50 solder tab .156"36/72 wide post w/w.156

$4.95 3/S10.00$4.95 3/113.0015.95 3/(15.00

S1.95 3/S5.00

LSI Scotcli

Diskettes

StnchSoft(IBM)8 inch 32 sectorMini Soft sec.Mini 10 sectorMini 16 sector

Certified Digital

CASSETTES

Wont drop a BIT!

*5.50

CALIFORNIA

INDUSTRIAL

is an

Authorized

Dealer of

Scotch Brand

Dataproducts

MEMORY

DYNAMIC 1-7 8-32 32+

4115 8Kxl 11.95 11.50 *

4116 16Kxl 13.95 13.00 12.25(Apple II & TRS80)

4164 64Kxl * * *

* As you may be aware, publishersrequire advertisers to submit theirad copy 60 to 90 days prior to "press"date. That much lead time in a volatile market place,such as memory circuits, makes it extremely difficultto project future cost and availability.To obtain the best pricing on memory we have madevolume commitments to our suppliers, which in turnaffords us the opportunity to sell these circuits at themost competitive prices. Please contact us if youif you have a demand for volume state of the art mem-ory products.

100 Mother Board

18 slot

IMSAI

HEXADECIMAL KEYBOARD

Maxi-Switch hexadecimal keyboards are designed for a%^Sl^B| 95microcomputer systems that require 4-bst output ^ ^«3j" i1 f

In standard hex code.Each assembly consists of 16 hermeti-cally sealed reed switches and TTL "one^shot" debounce circuitry.Reliable tow friction acetal resinplungers are credited for the smoothoperation and long life of this premiumkeyboard.Requires single + 5 vol! supply.

•24.88

., , .wi v UlSffl/ACKEYBOARD

ie famous Sperry (jmvac 1710 Hollenlh keyboard assemblynow available trom California industrial tor only $24 6&6 ideal computer input device lor accountants andithf-maticians. The numeric keys are placed on the lower■ee rows to resemble a ten key adding machine This■mat allows one handed numeric daia entry.igmal cost was J385 Used but guaranteed in excellent

APPLE RS-232

Serial Interface *59.95

al printer.

ELECTRONICSYSTEMS

TELETYPE MODEL 43

Even if we have to give themaway, we're going to ship more43's in 1979 than the aggregateof all our competitors.

Model 43AAAEACH

875.

$925.

RS-232 Interface"!!" Add*75.oo

TEC

DISKETTES

Xi^rWim APPLE/TRS-80

verDaiim Mini - soft sect

sector

FROM ATARI

COLOR TELEVISIONR.E MODULATOR

tan R.F Modulatorcomputer data to bedisplayed directly upon yourexisting television system.This unit converts the sig-nal from the Apple II andOther video sources intotelevij

Operates from single 5

volt supply. Complete

metal case, mating

connector and 15

cable. Schematics

included.

SPECIAL

APPLE II

I6K MEMORY

COLOR ♦GRAPHICS'SOUND

$1024

PLUS SHIPPING ,

fcffg.Sug.Retail....

■^ LED .DIGITAL i

DarkroomTimer-Kit

As featured in the August 78 issueof POPULAR ELECTRONICS.T me 1 second to 10 hours

$9 A 95 Informationw"¥. ** upon request.

Extender Board

fllullen'3495

Facilitates design and trou-bleshooting of all S-100 mi-crosystems. Includes logicprobe along with high-lowand pulse LED display.Also available, the MullinCB-1 controller board $88.

IS-100 PROTOTYPE BOARD |* 19.98

STATIC

21L02 450nS.21L02 250nS.2114 1Kx4 4502114 1Kx4 3004044 4Kxl 450

4044 4Kxl 250

4045 1Kx4 4504045 !Kx4 2505257 low pow.

1-311.491. 696.958.958.959. 958.959.957.95

32-99 100-5C

I. 19

1.496.508.508.509.508. 509.507.50

1.051. 456.258.008.009. 008.009.007.05

1K+-.95 .89

6.00 5.75

SPECIAL CIRCUITS

Z80A 4 MHz. 24. 95

8080A CPU 9. 95

8085 22.50

8086 Intel 16 bits +

TMS 9900 16 bits 49.95

CRT TERMINAL

Sanders Associates

These used vidio display terminals werein working condition when we purchasedthem from the reservation division of amajor U. S. airline.

The terminals are RS-232 and should eas-ily interface to most micro-computers.To facilitate a quick liquidation of theseunits, we are offering them as-is>non-returnable for only $149.Please include $35. 00.for shipping,the balance will be refunded.

OPlOO-Maxtmum design ver-satility along with standardaddress decoding ortd buf-fering for S100 systemsBoom for 32 uncommitted 16pin ICs, 5 dus buffet & de-coolng chips, 1 DIP addressselect switch, o 5 vofl regu-lator and mote,WWIOO-Wlte wrap bread-boord. similar to the GP100.Allows wire wrop of oil sizesof sockets in any sizes ofsockets in any combination.An extra regulator positionfor multiple voltage applica-tions

Thijmbwheelswitch

r*S>.

oS

Ten position

SBCD10 50snsTsT

V

$.69

Conductor Ft.

RIBBON WIREJ

TWISTED PAIR

Transistors

ea. 10 50 100

AY5-1013A UART 4.95Floppy Disc ControllersWD 1771 single D. 39. 95WD 1781 Double D 65.00WD 1791 D/D3740 *

E PROMS 1-151702A 2K 4.952708 8K 9.95

2716 16K 19.952532 32K *

16-63 64+4.50 4.009.50 9.00

MJ30552N37722N3904

2N39Q6

2N2222A.20 .18 .16.152N3055 .69.e5 .59 .55.79 .75.69.65159 149 1.391?9.15 .11 .09.07.15 .11-09.07

Diodes

10 25 1001N4002 100* .08 06.051N4005 600*. 10.08,071N4148 signal .07.05.04jumbo red ea. M 25 100

LED's Hs.i3.ti .69

Power Adapter

6 vdc, 140mA $1.397vdc,l.4 A. 5.509vdc.200mA. 1J9l0vAc,300mA.

"M

*98

12v.ct. 175mA.

TRANSFORMER

TRIMMER

POTENTIOMETERS

2K 5K10K50H,

5fer*.98

20 50 100

(Tmastei charyej

16 14' 12<

(213)679-9001

SPECIAL SPECIAL SPECIALOnly 10,000 Available

NE555H

3i.,'SB

25»or*7 oo. 100*1950

CAPACITORS

ELECTROLYTICS

ea. 10 50

80,00 0/10 v. 395 349 2.954500 50v.M49 135 1J9

1000/15v $55 49 45

MUM

.1 disc $.12 .09 .07.01 disc .06 05 .04

MiniatureSwitches

■

your choice

coc 10 $° *00 lk*.3 0 $.88 .81.73.66 |SPOT Miniature Toggles

7101 C&K ON-NONE-ON

7107 jbt ON OFF(mnt.ON)

7108 CK ON(moment.ON)

Rocker JBT DPDT

Rotary 3P-4-Pos.

Rotary 3P-6-Pos.

PushSlN.0.) i.39ea 4 SI

DIP Switch

$149

DISCOUNT ' j

Wire WrapXenter

Heavy

dutfgroundedpower cord and matingchassis connectors.

Page Wire Wrap Kitsprecut & stripped

KITNo.1 *6.«

900 Assorted Lengths

KIT No.2 *19?5

2800 Assorted Lengths250' Bulk Wire

IC SOCKETS

pin

wire wrapea. 25 50

low profileea. 25 50

8

17< 16 15

14

37<36 35

18 17 16

16

38 37 36

19 18 17

24

99 93 85

36 35 34

40

169 155 139

63 60 58

£23.95BW630

50ft.

♦.98

KVNAR8.K

500 1,000 11,000*9. S15. $105.

What's New?

MASS STORAGE

Floppy Disk Systems SoftwareTransparent to RT-11

Mass Storage Unit Expands System 88 Filing Capabilities

PolyMorphic Systems has increasedthe storage capacities of its System 88microcomputers through the introduc-tion of a new option, the 88/MS, whichconsists of two drives for 8 inch floppydisks. One disk can hold 1.2 M bytes, ormore than 500 pages of text. A System88 microcomputer with one or two88/MS units can handle all the files andprocessing needs of most small busi-

nesses and professional offices.

Present owners of any System 88microcomputer can add the 88/MSmass storage unit with no changes intheir equipment's operating system.Ready to use packages are available fordoing tasks such as accounts receivable.

For more information on the 88/MS,contact PolyMorphic Systems, 460 WardDr, Santa Barbara CA 93111."

Short Length Cassettes Designed for Persona! Computers

Microsettes are short length, highquality cassettes designed for micro-computers. They feature a premiumquality Philips cassette and high energyaudio tape. Each cassette comes in ahard, 2 piece Norelco style box withtwo extra labels. The 50 foot length

of tape in the C-10 Microsette providesslightly more than five minutes ofrecording per side. For additional in-formation about the C-10 Microsettewrite to Microsette Co, 777 PalomarAv, Sunnyvale CA 94068."

Circle 596 on inquiry card.

The new Remex-11 floppy disk sys-tems are integrated hardware and soft-ware units that connect directly to thePDP-11 Unibus or LSI-11 Q bus. Thesystems are available with a utility func-tion that permits data interchange be-tween IBM 3740 diskettes and anyRT-11 supported device.

The new plug compatible versions ofthe Remex-11, the Remex 11/11 and11/12, are completely software transpar-ent to the RT-11 software on the LSI-11computers while offering added features.The Remex-11 provides read only mem-ory bootstrapping as a standard featureas well as individual write protectswitches to each drive, busy and errorstatus indicators, and an automatic re-initialize function.

For increased performance whilestill maintaining media compatibilitywith PDP-11 and LSI-11 systems, theRemex 11/21 and 11/22 are available.These systems will accept up to fourdiskette drives. Data can be transferredin 16 bit words, and up to 65 K wordscan be transferred in a single input/output (10) operation. For additions,the data buffer in the RT-11 controllercan be increased to two full sectors.

The Remex 11/31 and 11/32 employ16 sector and track soft sectoring for-mat. A contiguous file allocation struc-ture increases throughput by as much as50 percent.

Both media compatible and ex-panded capacity systems connect tothe PDP-11 by a bus extension cable;therefore no IO slot is required.

Remex-11 prices begin at $3195complete. For further information con-tact Marketing Manager, Remex Division,Ex-Cell-O Corp, 1733 E Alton St,Irvine CA 92713."

Circle 597 on inquiry card.

New Floppy Disks from OmniProducts Company

New floppy disks are available fromOmni Products Co, POB 223, MarltonNJ 08053. The disks include a full IBMcompatible, soft sectored version, as wellas Shugart compatible, hard sectored andMemorex compatible, hard sectored ver-sions. They are designed to meet or ex-ceed IBM and ANSI standards, and awritten guarantee is furnished. Prices are$4.95 in quantities of one through nineand $4 for orders of more than 50.Include $1.50 for shipping per order. NJresidents should include 5% sales tax."

Circle 598 on inquiry card.

*

218 December 1978©BYTE Publications Inc

'He*)!

KIT FEATURES:

16K E-PROM CARD

IMAGINE HAVING 16K OF SOFTWARE ON LINE AT ALL TIME!S-100 [Imsai/Altair] Buss Compatible!

1. Double sided PC board with soldermask and silk screen and gold ptatedcontact fingers.

2. Selectable wait states.

3. All address lines & data lines buf-fered!

4. All sockets included.5 On card regulators.

KIT INCLUDES ALL PARTS ANDSOCKETS (except 2708s) Add $25. forassembled and tested.

ijjjjjyj

ipp B™l>^jp™j !■

$59.95 kit

SPECIAL OFFER:

Our 2708's (450NS) arewhen purchased with above kit.

$8.95

NEW PRODUCTS FOR 1979

New Products are Scheduled for delivery during January 1979. Some may be available sooner. Call.

Z-80 CPU KIT$129

For S-100 Buss. Features Jumpon Reset capability. We feel thisboard has the most correctPSYNC signal for trouble freeoperation. Complete kit. Moredata on request, (for 4MHZ

ADD $10)

16K STATIC RAM KIT$295

For SS-50 (S.W. TECH. 6800)Buss. Fully static uses 2114RAM's. 450 N.S. At last, aqualityRAM board forthis popular Bussat an affordable price. Completekit. Additional Data on request.

DUAL DENSITY FLOPPY DISCCONTROLLER

For S-100 Buss. Reliability andQuality assured. Uses WD1791Controller Chip. For 5V* or 8 inchdrives. Full IBM and S-100compatible. Perfect for use withCP/M. Special P.L.L. design formaximum reliability. Assembled &

Tested - $219 Additional Data

~ on Request.

COMPUTER PARTS

Z-80 -$19.95 8080A-'$6.95Z-80A- 24.95 8212 - 2.25

CPM is a Trademark of Digital Research of California.

ALARM CLOCK CHIP

N.S MM5375AA. Six Digits.With full Data. New!

$2.49 each

MOTOROLA 7805R VOLTAGE REGULATOR

Same as standard 7805 except 750 MA output.TO-220. 5VDC output.

44c each or 10 for $3.95

FULL WAVE BRIDGE

4 AMP. 200 PIV.690 10 FOR $5.75

NOT ASSOCIATED WITH DIGITALRESEARCH OF CALIFORNIA, THESUPPLIERS OF CPM SOFTWARE.

450 MS! 2708EPROMS

Now full speed! Prime new units from a major U.S. Mfg. 450 N.S.Access time. 1 K. x 8. Equiv. to 4-1702 A's in one package.

$15.75 ea.

PRICE CUT

$g

95 4 FOR $50

iOfJ_

$29500

COMPLETE KIT

16K STATIC RAM KIT

ASSEMBLED & TESTEDADD $30

OUR LATEST COMPUTER KIT!

FULLY S-100 COMPATIBLE!

FULLY STATIC, AT DYNAMIC PRICES!

WHY THE 2114 RAM CHIP?

We feel the 2114 will be the next industrystandard RAM chip {like the 2102 was).This means price, availability, andquality will all be good! Next, the 2114 isFULLY STATIC! We feel this is the ONLYway to go on the S-100 Buss! We've allheard the HORROR stories about someDynamic Ram Boards having troublewith DMA and FLOPPY DISC DRIVES.Who needs these kinds of problems?And finally, even among other 4K StaticRAM's the 2114 stands out! Not all 4Kstatic Rams are created equal! Some ofthe other 4K s have clocked chip enablelines and various timing windows just ascritical as Dynamic RAM's. Some of ourcompetitor's 16K boards use these"tricky" devices. But not us! The 2114 isthe ONLY logical choice for a trouble-free, straightforward design.

:jl III 1.1,111,1.1111,1.1-

$33.00

(450 NS)

BLANK PC BOARD WITH DOCUMENTATIONSUPPORT IC'S + CAPS - $19.95LOW PROFILE SOCKET SET - $12.002114'S 4K RAM'S - 8 FOR $69.95SUPER SPECIAL: BUY 32 KITS (512 KILOBYTES) (8-64K BANKS) for '8,995

KIT FEATURES:

1 Addressable as four separate 4KBlocks

2 ON BOARD BANK SELECT circuitry{Cromemco Standard!) Allows up to512K on line!

3 Uses 2114 (450NS) 4K Static Rams.

4. ON BOARD SELECTABLE WAITSTATES

5. Double sided PC Board, with soldermask and silk screened layout. Goldplated contact fingers.

6. All address and data lines fullybuffered.

7. Kit includes ALL parts and sockets.

8. PHANTOM is jumpered to PIN 67.

9. LOW POWER: under 2 amps TYPICALfrom the +8 Volt Buss.

10. Blank PC Board can be populated asany multiple of 4K.

oo

NATIONAL SEMICONDUCTOR

JUMBO CLOCK MODULE

FEATURES

« FOUR JUMBO ft INCH LEO DISPLAYS

* 12 HR REAL TIME FORMAT

* 24 HR ALARM SIGNAL OUTPUT

* 50 OR 60 Hi OPERATION

* LED BRIGHTNESS CONTROL

* POWER FAILURE INDICATOR

* SLEEP & SNOOZE TIMERS

. DIRECT LED DRIVE (LOW RFI}

* COMES WITH FULL DATA

ASSEMBLED! NOT A KIT!

ZULU VERSION!

We nave a limited number or the 24 HR Reallime version of this module in stock#MA1008D - $9.95

PERFECT FOR USEWITH A TIMEBASE

(ACXFMR $1.95)

COMPARE AT UP TO TWICEOUR PRICE!

Digital Research Corporation

w (OF TEXAS! V

P. O. BOX 401247Y/GARLAND, TEXAS 75040/(214} 271-2461

SALE!

1N4148 DIODES. SILICON.

Same as 1N914. New,factory prime, Full Leads.

100 FOR $2- 1000 FOR $17.50

New! REAL TIMEComputer Clock Chip

N.S. MM5313. FeaturesBOTH 7 segment andBCD outputs. 28 PinDIP. $4.95 with Data

16K DYNAMIC RAM CHIP

16KX 1 Btts. 16 Ptn Package Same as Mostek 4116-4 250 NS access. 4 IONS cycletime Our best price yet for this state of the art RAM. 32K and 64K RAM boardsusing this chip are readily available These are new. fully guaranteed devices by a

$14.95 each

VERY LIMITED STOCK!

8 FOR $89.95

TERMS: Add 30<t postage, we pay balance. Orders under$15 add 75$ handling. No C.O.D. We accept Visa, Master-charge, and American Express cards. Tex. Res. add 5% Tax.Foreign orders (except Canada) add 20% P & H. 90 DayMoney Back Guarantee on all items.

••••i

•••••#

•••••i

What's New?

of INTEREST to DESIGNERS

S-100 Bus Prototyping Circuit BoardAccommodates up to70 Integrated Circuits

This new prototyping circuit board isbus and shape compatible with Altair.and IMSAI microcomputer boards. Itholds up to 70 14 or 16 pin dual-in-linepackages (DIP) or any combinationof DIP sockets with 0.3, 0.4, 0.6 or0.9 inch (0.76, 1.02, 1.52, 2.29 cm)lead spacing.

The 5.3 by 10 by 0.062 inch (13.46by 25.4 by 0.16 cm) Model 8804 cir-cuit board from Vector Electronicshas 100 (50 each side) card edge con-tacts on 0.125 inch (0.32 cm) centersto accommodate an S-100 bus organiza-tion. Two 100 hole rows of individual0.1 inch (0.25 cm) spaced pads acrossthe top of the board permit additionalinput/output (IO) via ribbon wire assem-blies. Wrap posts may be fabricated byinserting Vector's T46-5-9 wrapped wirepins into the holes.

For wiring convenience, power andground buses are in an offset ladder pat-tern on opposite board sides. One cornerof the 8804 may be used for a low pro-file heat sink with two regulators in theT0-220 packages. The leads of oneregulator position are prewired to powerinput, ground and regulated power. Theother regulator position is uncommitted.

The 8804 plug board is priced at$21.95 each in quantities of one to four.For further information, contact VectorElectronic Company, 12460 GladstoneAv,SylmarCA 91342."

Circle 606 on inquiry card.

Manual Details New Temperature Switch

An 8 page manual detailing the prop-erties and applications of Midwest Com-ponents Inc's temperature switch isavailable from the company. This switchutilizes a reed switch and temperatureactivated magnets for sensing. For thismanual, write to Midwest ComponentsInc, POB 787, 1981 Port City Blvd,Muskegon Ml 49443.■

Circle 607 on inquiry card.

Paper on S-100 Bus Standards

A reprint from Computer Magazineentitled "Proposed Standard for theS-100 Bus," Preliminary Specification,IEEE Task 696.1/D2 was presented atthe 1978 National Computer Confer-ence. This document is a specificationfor both timing and signal disciplines andwas prepared by two members of theIEEE Computer Society MicroprocessorStandards Committee. It is available bysending a self-ad dressed, stamped en-velope to Robert G Stewart, 1658Beivoir Dr, Los Altos CA 94022."

Intelligent Keyboard Has Capacitive Keyswitches

This new solid state keyboard uses asecond generation microprocessor andlow profile capacitive keyswitches. Thekeyboard uses an 8 bit single integratedcircuit processor with on chip readonly memory, programmable memoryand erasable read only memory. All keyfunctions are software controllable. Themicroprocessor permits automatic re-peats, multiple application programs ina single intelligent encoder, field pro-gram changes using new firmware,

serial and parallel input/output (IO),and n-key rollover (3 key rolloverbeing standard),

The switches have a life expectancyof 100 million operations. The legendsare selectable from a wide selection ofsymbols and letters in a host of lan-guages and disciplines.

For further information about thiskeyboard, contact C P Clare & Company,3101 W Pratt Av, Chicago IL 60645."

Circle 609 on inquiry card.

8080 Processor Board Offered

This S-100 bus 8 bit processor boarduses the 8080A processor. 74LS244 busdrivers are utilized to provide low powerwith higher drive capability. A switchselectable jump on reset circuit is pro-vided for use in systems without a frontpanel. Low profile sockets are provided

for all integrated circuits.

The 8080 board is $175 assembledand $120 in kit form. For more informa-tion write to Electronic Control Tech-nology, 763 Ramsey Av, Hillside N]07205."

Circle 610 on inquiry card.

*

*

220 December 1978 ©BYTE Publications Inc

COMPUTER INTERFACES & PERIPHERALS

For free catalog including parts lists and schematics, send a self-addressed stamped envelope.

APPLE II SERIAL I/OINTERFACE *

Part no. 2

Baud rate is continuously adjustablefrom 0 to 30,000 • Plugs into any periph-eral connector • Low current drain. RS-232 input and output • On board switchselectable 5 to 8 data bits, 1 or 2 stopbits, and parity or no parity either odd oreven • Jumper selectable address •SOFTWARE • Input and Output routinefrom monitor or BASIC to teletype or other serial printer.• Program for using an Apple II for a video or an intelli-gent terminal. Also can output in correspondence codeto interface with some selectrics. Board only — $15.00;with parts — $42.00; assembled and tested — $62.00.

MODEM

Part no. 109

• Type 103 • Full or halfduplex • Works up to 300baud • Originate or Ans-wer • No coils, only lowcost components • TTLinput and output-serial •Connect 8 ohm speakerand crystal mic. directly to board • Uses XR FSKdemodulator • Requires +5 volts • Board $7.60;with parts $27.50

DC POWER SUPPLY*

Part no. 6085

• Board supplies a regulated +5 voltsat 3 amps., +12, -12, and -5 volts at1 amp. • Power required is 8 volts ACat 3 amps., and 24 volts AC C.T. at 1.5amps. • Board only $12.50; withparts excluding transformers $42.50

TAPE INTERFACE *

Part no. 111

• Play and record KansasCity Standard tapes •Converts a low cost taperecorder to a digital re-corder • Works up to 1200baud • Digital in and outare TTL-serial • Output ofboard connects to mic. inof recorder • Earphone ofrecorder connects to input on board • No coils •Requires +5 volts, low power drain • Board $7.60;with parts $27.50

TV. TYPEWRITER

Part no. 106

• Stand alone TVT

• 32 char/line, 16lines, modificationsfor 64 char/line in-cluded • ParallelASCII (TTL) input •Video output • 1Kon board memory •Output for compu-ter controlled eur-ser • Auto scroll •Non-destructive curser • Curser inputs: up, down, left,right, home, EOL, EOS • Scroll up, down • Requires +5volts at 1.5 amps, and -12 volts at 30 mA • All 7400, TTLchips • Char. gen. 2513 • Upper case only • Board only$39.00; with parts $145.00

TIDMA

Part no. 112

• Tape interface Direct Memory Access • Recordand play programs without bootstrap loader (noprom) has FSK encoder/decoder for direct con-nections to low cost recorder at 1200 baud rate,and direct connections for inputs and outputs to adigital recorder at any baud rate. • S-100 bus com-patible • Board only $35.00; with parts $110.00

UART & BAUD RATEGENERATOR*

Part no. 101

• Converts serial to paralleland parallel to serial • Lowcost on board baud rategenerator • Baud rates: 110,150, 300, 600, 1200, and2400 • Low power drain +5volts and -12 volts required

• TTL compatible • All characters contain a start bit, 5 to8 data bits, 1 or 2 stop bits, and either odd or even parity.

• All connections go to a 44 pin gold plated edge connec-tor • Board only $12.00; with parts $35.00 with connectoradd $3.00

8K STATICRAM

Part no. 300

• 8K Altair bus memoryUses 2102 Static memory chips • Mem-ory protect * Gold contacts • Wait states •Onboard regulator • S-100 bus compatible • Vectorinput option • TRI state buffered • Board only$22.50; with parts $160.00

RF MODULATOR

Part no. 107

• Converts video to AM modu-lated RF, Channels 2 or 3. Sopowerful almost no tuning is re-quired. On board regulatedpower supply makes this ex-tremely stable, Rated veryhighly in Doctor Dobbs' Journal. Recommendedby Apple. • Power required is 12 volts AC C.T., or+5 volts DC • Board $7.60; with parts $13.50

RS232/TTY*INTERFACE

Part no. 600

• Converts RS-232 to 20mAcurrent loop, and 20mA currentloop to RS-232 • Two separatecircuits • Requires +12 and -12volts • Board only $4.50, withparts $7.00

RS 232/TTL*INTERFACE

Part no. 232

• Converts TTL to RS-232, Iand converts RS-232 to ITTL • Two separate circuits |

• Requires -12 and +12 volts

• All connections go to a 10 pin gold plated edgeconnector • Board only $4.50; with parts $7.00with connector add $2.00

ELECTRONIC SYSTEMS

Dept. B, R0. Box 21638, San Jose, CA. USA 95151

Mention part number and description. For parts kits add "A" to part number. In USA, shipping paid for orders accompanied by check, money order, orMaster Charge, BankAmericard, or VISA number, expiration date and signature. Shipping charges added to COD. orders. California residents add 6.5%for tax. Outside USA add 10% for air mail postage, no C.O.D.'s. Checks and money orders must be payable in US dollars. Parts kits include sockets for allICs, components, and circuit board. Documentation is included with all products. All items are in stock, and will be shipped the day order is received viafirst class mail. Prices are in US dollars. No open accounts. To eliminate tariff in Canada boxes are marked "Computer Parts." Dealer inquiries invited.24 Hour Order Line: (408) 226-4064 # Circuits designed by John Bell

To Order:

Circle 125 on inquiry card.

BYTE December T978

221

What's New?

SILICON

Single Chip ZSO-SIO for LSI Microcomputer System

A high speed, dual channel, multi-protocol serial data communicationscontroller circuit, the single chip ZSO-SIO, has been introduced by Zilog,10460 Bubb Road, Cupertino CA95014. The SIO is designed to work withZilog's Z-80 microcomputer family andalso interfaces with most other 8 bit and16 bit processors. The serial IO con-troller, an N/MOS 40 pin device, is aperipheral component that can controlcommunications peripherals and format

data in data communications networks.Each of the SIO's full duplex channelshas four control lines for most com-monly used modems. Applications in-clude fiber optics, microwave trans-mission and satellite communications.For systems with 2.5 MHz clock rate,the SIO's data rate goes up to 550K bits per second, while in a 4 MHzsystem, it's up to 880 K bits. Price is$49 in small quantities."

Circle 622 on inquiry card.

Complex Sound Generator Integrated Circuit

'o r

in

C4C, °typr

*'i

ly

"O^

The SN76477N, a complex soundgenerator integrated circuit, has beenannounced by Texas Instruments, POB84, M/S 812, Sherman TX 75090. ThisIC can be used to generate virtually anycomplex sound ie: siren, gunshot, jetengine, whistle, pinball sounds, etc.Since it is an integrated injection logic(|2l) linear integrated circuit with lowpower consumption, it is ideally suitedfor battery powered applications. TheSN76477N contains a voltage controlled

oscillator, super low frequency oscilla-tor, white noise generator, noise filter,oneshot, mixer, an attack and decayenvelope generator. The desired sound isexternally programmed by the userthrough logic and analog inputs. Newsounds can be implemented or modifiedquickly. The SN76477N is designedfor operation from -10 °C to 40 *C. It isoffered in a 28 pin package. Price is$1.65 in quantities of 100."

Circle 623 on inquiry card.

Single Channel DMAC fromWestern Digital

A low cost single channel directmemory access controller (DMAC) hasbeen introduced by Western DigitalCorp, 3128 Red Hill Av, POB 2180,Newport Beach CA 92663.

The DM 1883 is said to be fullycompatible with all popular microproc-essors built today. It includes the follow-ing features: control of all memoryhandshaking and device control; full 16bit memory address and block lengthcapability; block or word move; auto-matic end of block (EOB) shutoff andinterrupt on EOB or error detection; andthe option of auto load and bus timeoutinterrupt. The DM 1883 is powered by asingle +5 V supply."

Circle 624 on inquiry card.

Second Sourced TR 1953 USARTReplaces 8251

The second sourced TR 1953 uni-versal synchronous and asynchronousreceiver transmitter (USART) is said tobe the lowest priced replacement for the8251.

The TR 1953's complete compati-bility with the 8251 USART is furtherenhanced by synchronous and asynchro-nous operation, with 5 to 8 bit charac-ters on both modes. Internal or externalcharacter synchronization and automaticsync insertion is featured in the synchro-nous mode; 1, 16 or 64 times bps rate, 1,Vh or 2 stop bits and false start bitrejection on the asynchronous mode.

The TR 1953 comes in a 28 pinpackage, with TTL compatible IO, andoperates on a single +5 V supply. Writeto Western Digital Corp, 3128 Red HillAv, POB 2180, Newport Beach CA92663 for a sample."

Circle 625 on inquiry card.

222

December 1978©BYTE Publications Inc

■r'^W rw oaai A "Smart" VIDEO BOARDJ?* The EW-2001 KIT At A "Dumb" Price!

*$? A VIDEO BOARD + A MEMORY BOARD + AN I/O BOARD - ALL IN ONE!

■ STATE OF THE ART TECHNOLOGY USING DEDICATED MICROPROCESSOR I.C. <& ~| QQ O ^

■ NUMBER OF I.C.s REDUCED BY 50% FOR HIGHER RELIABILITY ■ MASTER PIECE *W ■*■ -? S* Zr *JOF ENGINEERING ■ FULLY SOFTWARE CONTROLLED Priced at ONLY Basic Software Included

SPECIAL FEATURES: ■ Programmable no. of scan lines OPTIONS:

■ S-100 bus compatible ■ Underline blinking cursor Sockets $10.00

■ Parallel keyboard port ■ Cursor controls: up, down, left, 2K Static Memory

■ On board 4K screen memory right, home, carriage return (with Sockets) $45.00

(optional)* relocatable to main ■ Composite video 4K Static Memory

computer memory *Min. 2K required for operation of this board. (with Sockets) $90.00

■ Text editing capabilities (soft- DISPLAY FEATURES: Complete unit, assembledware optional) —7Z7TT-—', . , . „' T , and tested with

.Seeing: up and down through ' %&2&i£5i±5& *'T' "i™ «

video memory numeric, controls) Basic software on ROM , S20.00

■ Blinking characters m 64 or 32' characters per line Text editor on R0M $75.00

■ Reversed video Gumper selectable)

■ Provision for on board ROM ■ 32 or 16 lines DEALER^^^ , ., , ^„ Gumper selectable)

■ CRT and video controls fully _ _ . „._ ^m

programmable (European TV) " Screen capacity 2048 or 512 INQUIRIES WELCOMED

■ Character generation:7x11 dot matrix

8080 SUPPORT

8212821482168228

82518255

$3.007.953.505.95

7.958.50

GROUNDEDA.C. CORDS

6 Ft. - $1.19

80&0*

CPU

$7.75

RAM-2114

1Kx4 450ns$8.00

WIRE WRAP WIREKYNAR 28 AWG

$2.95/100 FeetBlue, Red, White

Computer Grade

Capacitors

5000 mfd 60VDC

$1.50

EDGE CONNECTOR WIRE WRAP PINS

44 Pin $1.25 -72 Pin $1.75 - 100 Pin (S-100) $5.45

MISC. IC's

DM8810 3/$lDM8210 $2ea.N8TI5 $1 ea.9024 2/S1.5093L08 $1.50 ea.93L09 2/S1.5093L24 $1 ea.

CMOS

4011402240234071

6/S1.002/W.704/$1.005/S1.00

LINEARI.C.'s

LM320K-5

.99

LM320-12

.99

LM709N

11/$1

LM710H

6/$l

LM711H

6/$l

LM741M

7/$l

Transistors& Diodes

-L

2N3906

2N4400

2N4403

2N2222A

1N4003

1N4005

1N4148

SCR 400V

4A,TO220$.80

7/$l9/$l

4/$l12/S1

10/$114/$1

SHIPPING: Keyboard and Video Board: $3.50; orniRS 125

California residents add 6% sales tax-

ELECTRONICS WAREHOUSE Inc.

1603 AVIATION BLVD.REDONDO BEACH, CA. 90278

TEL. (213)376-8005WRITE FOR FREE CATALOG

Minimum Order: $10

ASCII KEYBOARD KIT $74.00

Additional Improvements: Double Size Return KeyControl Characters Molderd on Key Caps

Power: +5V 275mA

Upper and Lower Case

Full ASCII Set

7 or 8 Bits Parallel Data

Optional Serial Output

Selectable Positve orNegative Strobe, andStrobe Pulse Width

2 Key Roll-Over

3 User DEfineable Keys

P.C. Board Size:17-3/16" x 5"

OPTIONS:

■ Metal Enclosure PaintedBlue and White

■ 18 Pin Edge Con.

■ I.C. Sockets

■ Serial Output Provision(Shift Register)

■ Upper Case Lock Switch forCapital Letters and Nos. $

Assembled (on Sockets)

and Tested $90.00

$27.50$ 2.00$ 4.00

$ 2.00

2.00

APPLE II I/O BOARD KIT

Plugs Into Slot of Apple II Mother Board

18 Bit Parallel Output Port(Expandable to 3 Ports)

1 Input Port

15mA Output Current Sinkor Source

Can be used for peripheralequipment such as printers,floppy discs, cassettes,paper tapes, etc.

1 free software listing forSWTP PR40 or IBM selectric

PRICE:

1 Input and 1 OutputPort for $49.00

1 Input and 3 OutputPorts for $64.00Dealer Inquiries Invited

Whal's New?

SYSTEMS

A Single Board Microcomputer System

The SYM-1 is a complete micro-computer including keyboard, displayand operating software. Some of thefeatures of this stand-alone systeminclude a SY6502 microprocessor device;1 K bytes of user programmablememory, expandable to 4 K bytes inboard sockets; 28 key audio responsekeypad; RS-232 and current loopinterfaces allow operation of the systemwith video or Teletype facilities; 4 K

byte read only memory system monitor;25 general purpose input/output (IO)lines; SUPERMON software system;hardware compatible with KIM board;and more. Other hardware featuresinclude oscilloscope output display andfour general purpose tO buffers.

The SYM-1 is priced at $269. Con-tact Synertek, 3050 Coronado Dr, SantaClara CA 95051 .■

Circle 626 on inquiry card.

New Microcomputer Systemfrom OS I

Ohio Scientific has announced a new

microcomputer system, designated theC3-OEM. Its applications include use asa general purpose computer or controllerin large equipment such as medical diag-nostic equipment, scientific equipment,analytical equipment and industrial con-trol applications. It is also suited forsmall systems software since it will run

software for the 6502, 6800, 8080 orZ-80.

Its features include: single chassisconstruction, which can be either table-top mounted or rack mounted, includingdual 8 inch floppy disks for 500 K bytesof on line storage, 32 K bytes of staticprogrammable memory, one RS-232port, and Ohio Scientific's triple pro-cessor board which supports the 6502A,6800 and Z-80 processors. The systemcomes complete with a 6502 diskoperating system and BASIC for diskand multiple processor switching soft-ware. The unit features modular con-struction with an 8 slot mother board,of which only four slots are used in thebase machine. Additional options in-clude: additional memory, a 16 serialport input and output (IO) board anda 96 line parallel IO board.

Single unit price is $3590. ContactOhio Scientific, 1333 S Chillicothe Rd,Aurora OH 44202."

Circle 628 on inquiry card.

A System for Data Handling

The VP (video processor) seriesis a complete computer system withstandard interfaces for expandability.The basic ynit includes: video monitor,encoded keyboard, minifloppy diskdrive, 32 K bytes of programmablememory, serial RS-232 port, fourcounter timers, printer port, 16 program-mable IO lines, and a Z-80 processor.Interface electronics and card cage areavailable for use with S-100 boards.The main processor board allows ex-pansion to 48 K bytes of programmablememory, 8 K bytes of erasable readonly memory, four additional countertimers, and 48 programmable IO lines.The disk controller works with either 8inch (20.32 cm) or 5.25 inch (1 3.34 cm)floppy drives and supports three addi-tional drives.

All VP series units include a videodisplay offering programmable screenformats with up to 80 characters perline and 24 lines per frame. The videoprocessor has graphic capabilities andsupports an optional light pen. Reversevideo, blinking and highlight for singlecharacters or fields are included, as wellas an underline or block cursor.

The entire VP series includes theCP/M disk operating system. Alsoavailable are several BASIC interpretersand the C-BASIC compiler. Text editingand assembler are included with the soft-ware.

The smallest system, VP-80, includes32 K bytes of programmable memory.It is available to dealers and educationalfacilities for $3995. All units are as-sembled and tested. Contact Data WorldInc, 7541 Ravensridge Dr, St Louis MO63119."

Circle 627 on inquiry card.

Low Priced Microprocessor ComesCompletely Assembled

This complete ready to use micro-processor offers an economical solutionfor both scientific applications andindustrial usage. The MICRO-68 com-puter system is priced at $495 andcomes completely assembled. Builtaround the Motorola/AMI/Hitachi 6800processor, the MICRO-68 comes withits own integral power supply, 16 buttonkeyboard, 6 digit LED display, and128 words of programmable memory.The 512 MON-1 Bug programmableread only memory contains all the ser-vice necessary to load programs easily,inspect and edit them as necessary,insert break points for debugging, andexecute. Memory expansion to 64 Kbytes and full 16 bit input and outputcan be obtained via the edge connectors,which are provided for. All of the mem-ory lines of the MICRO-68 can be buf-fered on board. The MICRO-68 comesin a hardwood cabinet with a transparentsmoked Plexiglas lid. The unit measures9 by 16 by 2 inches (22.86 by 40.64by 5.08 cm). Contact EPA ElectronicProduct Associates Inc, 1157 Vega St,San Diego CA 92110"

Circle 629 on inquiry card.

224

December 1978© BYTE Publications Inc

DIODES/ZENERS

SOCKETS/BRIDGES

TRANSISTORS, LEDS, etc.

1N914

100v

10mA .05

8-pin pcb .20 ww

.35

2N2222 NPN (2N2222 Plastic .10)

2N2907 PNP

2N3906 PIMP (Plastic - Unmarked)

.15.15.10

1N4H05

600v

1A .08

14-pin pcb .20 ww

.40

1N4007

1000v

1A .15

16-pin pcb .20 ww

.40

2N3904 NPN (Plastic - Unmarked)

.10

1N4148

75v

10mA .05

18-pin pcb .25 ww

.75

2N3054 NPN

.35

1N47331N753A

5.1v6.2v

1 W Zener .25500 mW Zener .25

22-pin pcb .35 ww24-pin pcb .35 ww

.95.95

2N3055 NPN 15A 60vT1P125 PNP DarlingtonLED Green, Red, Clear, Yellow

.50

.95.15

1N758A

10v

.25

28-pin pcb .45 ww

1.25

D.L.747 7 seg 5/8" High corn-anode

1.95

1N759A

12v

.25

40-pin pcb .50 ww

1.25

MAN72 7 seg corn-anode (Red)

1.25

1N5243

13v

.25

Molexpins .01 To-3 Sockets .25

MAN3610 7 seg corn-anode (Orange)MAN82A 7 seg com-anode (Yellow)

1.251.25

1N5244B1N5245B

14v

15v

.25.25

2 Amp Bridge 100-prv25 Amp Bridge 200-prv

.951.95

MAN74A 7 seg corn-cathode (Red)FND359 7 seg corn-cathode (Red)

1.501.25

CMOS

- T

T L -

4000

.15

7400

.10

7473 .25

74176

.85

74H72 .35

74S133

.40

4001

.15

7401

.15

7474 .30

74180

.55

74H101 .75

74S140

.55

4002

.20

7402

.15

7475 .35

74181

2.25

74H103 .55

74S151

.30

4004 :

3.95

7403

.15

7476 .40

74182

.75

74H106 .95

74S153

.35

4006

.95

7404

.10

7480 .55

74190

1.25

74S157

.75

4007

.20

7405

.25

7481 .75

74191

.95

74L00 .25

74S158

.30

4008

.75

7406

.25

7483 .75

74192

.75

74L02 .20

74S194

1.05

4009

.35

7407

.55

7485 .55

74193

.85

74L03 .25

74S257(8123)

1.05

4010

.35

7408

.15

7486 .25

74194

.95

74L04 .30

4011

.20

7409

.15

7489 1.05

74195

.95

74L10 .20

74LS00

.20

4012

.20

7410

.15

7490 .45

74196

.95

74L20 .35

74LS01

.20

4013

.40

7411

.25

7491 .70

74197

.95

74L30 .45

74LS02

.20

4014

.75

7412

.25

7492 .45

74198

1.45

74L47 1.95

74LS04

.20

4015

.75

7413

.25

7493 .35

74221

1.00

74L51 .45

74LS05

.25

4016

.35

7414

.75

7494 .75

74367

.75

74L55 .65

74LS08

.25

4017

.75

7416

.25

7495 .60

74L72 .45

74LS09

.25

4018

.75

7417

.40

7496 .80

75108A

.35

74L73 .40

74LS10

.25

4019

.35

7420

.15

74100 1.15

75491

.50

74L74 .45

74LS11

.25

4020

.85

7426

.25

74107 .25

75492

.50

74L75 .55

74LS20

.20

4021

.75

7427

.25

74121 .35

74L93 .55

74LS21

.25

4022

.75

7430

.15

74122 .55

74L123 .85

74LS22

.25

4023

.20

7432

.20

74123 .35

74H00

.15

74LS32

.25

4024

.75

7437

.20

74125 -45

74H01

.20

74S00 .35

74LS37

.25

4025

.20

7438

.20

74126 .35

74H04

.20

74S02 .35

74LS38

.35

4026

1.95

7440

.20

74132 -75

74H05

.20

74S03 .25

74LS40

.30

4027

.35

7441

1.15

74141 -90

74H08

.35

74S04 .25

74LS42

.65

4028

.75

7442

.45

74150 .85

74H10

.35

74S05 .35

74LS51

.35

4030

.35

7443

.45

74151 .65

74H11

.25

74S08 .35

74LS74

.35

4033

1.50

7444

.45

74153 -75

74H15

.45

74S10 .35

74LS86

.35

4034

2.45

7445

.65

74154 .95

74H20

.25

74S11 .35

74LS90

.55

4035

.75

7446

.70

74156 .70

74H21

.25

74S20 .25

74LS93

.55

4040

.75

7447

.70

74157 .65

74H22

.40

74S40 .20

74LS107

.40

4041

.69

7448

.50

74161 .55

74H30

.20

74S50 .20

74LS123

1.00

4042

.65

7450

.25

74163 .85

74H40

.25

74S51 .25

74LS151

.75

4043

.50

7451

.25

74164 .60

74H50

.25

74S64 .15

74LS153

.75

4044

.65

7453

.20

74165 1.10

74H51

.25

74S74 .35

74LS157

.75

4046

1.25

7454

.25

74166 1-25

74H52

.15

74S112 .60

74LS164

1.00

4049

.45

7460

.40

74175 .80

74H53J

.25

74S114 .65

74LS193

.95

4050

.45

7470

.45

74H55

.20

74LS367

.75

40664069/74 C044071

.55.25.25

7472

.40

74LS368

.65

MCT2 .95 LINEARS

REGULATORS, etc.

4081

.30

8038 3.95

LM320T5

1.65

LM340K15 1.25

LM723

.40

4082

.30

LM201 .75

LM320T12

1.65

LM340K18 1.25

LM725N

2.50

MC 14409 14.50

LM301 ,45

LM320T15

1.65

LM340K24 1.25

LM739

1.50

MC 14419

4.85

LM308 (Mini) .95

LM324N

1.25

78L05 .75

LM741(8-14>.25

4511 ;

.95

LM309H .65

LM339

.75

78L12 .75

LM747

1.10

74C151

1.90

LM309K (340K-5J85

7805 (340T5)

.95

78L15 .75

LM1307

1.25

LM310 .85

LM340T12

.95

78M05 .75

LM1458

.65

9000 SEP

LM311D(Mini) .75

LM340T15

.95

LM373 2.95

LM3900

.50

9301 85

95H03

1.10

LM318<Minn 1.75

LM340T18

.95

LM380(8-14pin>.95

LM75451

.65

9309 35

9601

.20

LM320K5(7905)1.65

LM340T24

.95

LM709<8,i4RN).25

NE555

.35

9322 .65

9602

.45

LM320K12 1.65

LM340K12

1.25

LM711 .45

NE556NE565NE566NE567

.85

.95

1.25

.95

MICRO'S, RAE-PRC

74S188 3.001702A 4.50

MS, C

)MS82148224

PU'S,

8.953.25

INTEGRATED CIRCUI

ITS UNLIMITED

MM5314 3.00

8228

6.00

7889 Clairemont Mesa Boulevard, San Diego, California 9211

MM5316 3.502102-1 1.45

82518255

8.50

8.50

(714) 278-4394 (Calif. Res.) DISCOUNTS

2102L-1 1.75

8T13

1.50

All orders shipped prepaid

No minimum jotal Order

Deduct

2114 9.50

8T23

1.50

Open accounts invited

COD orders accepted $35. $99

10%

TR1602B 3.95TMS4044- 9.95

8T248T97

2.001.00

Discounts available at OEM Quantities California Residents add 6% Sales Tax **{J? " 3^™

15%20%

2107

B-4 4.95

All IC's Prime/Guaranteed. All orders

.hipped same day received.

8080 8.958212 2.95

2708Z80F

9.50MO 8.50

24 Hour Toll Free Phone 1 800 854 2211

American Express / Bank Americard / Visa / Master Charge

Circle 180 on ina

uirv ca

rd.

BYTE December 1978 225

f*WP

7400 TTL

SN74Q0NSN7401NSN7402NSN7403NSN7404NSN74Q5NSN7406NSN7407NSN7408NSN7409NSN7410NSN7411NSN74J2PJSN7413NSN74HfJSN7416NSN7417NSN7420NSN7421NSN7422NSN7423NSN7425NSN7426NSN7427MSN7429NSN7430NSN7432NSN7437NSN743BNSN7439NSN7440NSM7441NSN7442NSM7443MSN7444NSN7445MSN7448NSN7447I*SN7448NSN7450MSI* 7451NSl*7453*SN7454MSN/459ASN7460M

20%

SN7470NSN7472NSN7473NSN7474NSN7475NSN7476I*SN7479I*SN7480NSN7482NSN7483NSN7485NSN7486NSN7489NSN7490NSN7491NSN7492NSN7493NSN7494NSN7495NSM7496NSN7497NSN7410ONSN74107I*SN741[jgiMSN74116MSN74121NSM74I22NSN74T23NSN74125NSM74126NSN74132NS*/4)36NSM74141MSN74147NSN74143MSN74144NSW74M53ISN74147NSN74148I*SN74150*SI* 74151NSN741S2NSV74153NSN 741541*SN74155NSN74156^SN74157N

SN74160NSN74161NSN74162NSN74163NSN74164NSN74165NSN74166NSN74167NSN74170NSN74172NSN74173NSN74174NSN74175NSN74176NSN74177NSN74179NSN74180NSN74181NSN74182NSN74184NSN74185NSN74186NSN74188NSN74190NSN74191I*SN74192NSN74193NSN74594NSN74195NSN74196NSN74197NSM74198NSN74199NSN74S2Q0SN74251I*SN74279NSN74283NSN74284NSN74285NSN74365NSN74366NSN74367NSN74368NSN74390NSN74393I*

W Lj^igilite

Discount 100 pes combined order 25% -1000 pes combined order

CD40O0C04001CD4002CD4006CD4007C04009CD4010CQ4Q11CD4012C04013CD4014CO4015CO4016CO4017CO4018CD4019CD4020CD4021CD4022CD4023CD4024CD4025CD4026CM027

C/MOS

CD4028CD4029CD4030CO4035CD404C1CD4041C04042CD4043CD4044CM046GD4047CD4048CD4049CD4050CD4051CD4053CD4056CO40S9CD4060£04086CD4068

2 959 951 49

CD4070

CD4G71

CD4Q72

C04076

C04W1

CO4082

CD4093

CO4098

MC14409

MCI 4410

MC14411

MC14419

MCI 4433

MC14506

MCI 450?

MCI 4562

MC14583

C04508

C04510

CD4511

C04515

CD45J8

CD4520

CD4566

14 95(4 9514 95

74COO74C0274C0474C0674C1074C1474C2074C3074C4274C4874C7374C74

74C00

74C8574C9074C9374C9574C10774C15J74C15474C15774C16074C161

2903002 15

74C16374C16474C17374C19274C19374C19574C92274C92374C92574C92680C9580C97

2492492.60

5 95

6 258958 95150ISO

78MG

LM106H

LM300H

LM301CN/H

LM302H

LM304H

LM305H

LM307CN/H

LM308CN/H

LM309H

LM3Q9K

LM310CN

LM311N/H

LM312H

LM317K

LM318CN/H

LM319N

LM320K-5

LM32QK-5 2

LM320K-12

LM320K-15

LM320K-18

LM320K-24

LM320T-5

LM320T-5 2

LM320T-8

LM320T-12

LM320T-15

LM320T-JB

LM320T-24

LM323K-5

LM324I*

LM339N

LM340K-5

LM340K-6

IM340K-8

LM340K-12

LM340K-15

LINEAR

LM340K-18 1 35

LM340K-24 1.35

LM340T-5 1 25

LM340T-6 1 25

LM340T-8 1 25

LM340T 12 125

LM340T-15 125

LM340T-1B 125

LM340T-24 1.25LM358N

2 95

LM370N

LM373N

LM377N

LM380N

LM38XN

LM381N

LM382N

NE501N

NE510A

NE529A

NE531H/V

NE536T

NE540L

NE544N

NE550N

^fE555V

NE5S6N

NE560B

ME561B

NE562B

NE565N/H

NE566CN

NE567V/H

NE570N

LM703CN/H

LM709W.'H

1.953 25

3.936006004 95

5005005.00

LM710NLM711HLM723N/HLM733NLM739NLM741CN/HLM741-14NLM747N/HLM748N/HLM1310NLM1458CN/HMC14B8N 1.95MC1489N 1 95LM1496N 95

LM1556V 1 75MC1741SCP 3 00LM2111N 1.95LM2901N 2,95LM3053N 1 50LM3065N 1.49LM3900N(3401j.49LM3905N 89

LM3909N 1 25

MC5558V 59

803BB 4.95

LM75450N 49

75451CN

75452CN7545XN75454CN75491CN75492CN75493N75494CNRC4136RC4151RC4194RC4195

M

74LS0074LS0174LS0274LS0374LS0474LS0574LS0874LS0974LS1074LS1174LS1374LS1474LS1574LS2074LS2174LS2274LS2674LS2774LS2874LS3074LS3274LS3774LS40174LS42

74LS00HL

74LS4774LS5174LS5474LS5574LS73741S7474LS7574LS7674LS7874LS8374LS8574LS8674LS9074LS9274LS9374LS9574LS9674LS10774LS10974LS11274LS12374LS12574LS13274LS136

74LS13874LS13974LS15174LS15574LS15774LS16074LS16174LS16274LS16374LS16474LS17574LS18174LS19074LS19174LS19274LS19374IS19474LS19574LS25374LS25774LS25874LS26074LS27974LS36774LS36874LS670

Electronic HomeSecurity Timer

A mtoopFOCSBSor-based pre-programmod light control Itiat Ills into ahome wall socket, replacing tna standard on, otl Hghi 3witch Oscoufagesintruders and burglars by tumtng Sghts on and off m a -real-We pj^emwtiile you re away.

Unlike ofner etectiomecrianical terriers VtfltWe can simulale the hghtingpatterns ol hye drrtarent rooms as selected by the user VigiMe can alsocontrol over-head Ughts, «*iicri other timere cannot Three VigiSte units,simulating kitcnen bathroom, and bedroom lighting a>n give a homeuftmate protection, because the user chooses a Hghting pattern matdepicts his real lite pattern He then sets the VtgtHte ctock and roompattern accordingly. (See bar chart below J The house adualty looksoccupied, although no one is home

Easy to install, the VigjHte unit contains an accurate digital LED dock,plus pre-programmed independent Bghting. patterns for bedroom, bath-room, kitchen, living room, and outside porch lights AH-sokd-state com-ponents assure ine user long product hie and rehabHWy

Technical Specifications

3) Carmot be used to control Hb>

bteoadeeaeM tc Ml

Part Number

VCL1

$39.95 ea.

DISCRETE LEDS

.200' die.

XC556R redXC556G greenXC556Y yellowXC556C clear

.200" die.XC22R redXC22G greenXC22Y yellow

.170* dis.MV10B red 4

.085" dti.MV50 red 6tNFRA-RED LED1/4"x1/4"x1/16"flat 5/S1

S/$14/$14/$14/$1

5/$14/J14/S1

XC209RXC209GXC209Y

XC526R

XC526GXC526YXC528C

XC111RXC111GXC111YXC111C

.185" dis.

redgreenyellowclear

.190- dla.red

greenyellowclear

5/$14V?1

4/$1

5/J14/$14/$14/$1

5/$14/$14/$1

m

TIMEX T1001LIQUID CRYSTAL DISPLAY

FIELD E FFECT

4 OIGIT - .5" CHARACTERSTHREE ENUNCIATORS2.OCT X 1.20" PACKAGEINCLUDES CONNECTOR

TIDOI-Transmhitve J7.95

TIOOIAReflective 8.25

DISPLAY LEDS

TYPI

MAN 1MAN 2MAN 3MAN 4MAN7GMAN 7YMAN 72MAN 74MAN 82MAN 84MAN 3620MAN 3630MAN 3640MAN 4610MAN 4640MAN 4710MAN 4730MAN 4740MAN 4810MAN 4840MAN B310MAN 6630MAN 6640MAN 6650MAN 6660MAN 6680MAN 6710

POLARITY I

Common Anode-red5 x 7 Dot Matrix-redCommon Cathode-redCommon Cathode-redCommon Anooe -greenCommon Anode-yellowCommon A node-redCommon Cathode-redCommon Anode-yellowCommon Cathode-yellowCommon Anode-orangeCommon Anode-orange * 1Common Cathode-orangeCommon Anode-orangeCommon Cathode-orangeCommon Anode-redCommon Anode-red ± 1Common Cathode-redCommon Anode-yellowCommon Cathode-yellowCommon A node-orange-0 0Common Anode-orange i 1Common Cathode-orange-D DCommon Cathode-orange 1 ICommon Anode-orangeCommon Cathode-orangeCommon Anode-red-DO.

PRICE2 95

4.95

TYPE

MAN 6730

MAN 6740

MAN 6750

MAN 6760

MAN 6780

OL701

DL704

DL707

DL728

DL741

DL746

DL747

DL749

OL750

DL33B

FND70

FND358

fN0359

FND503

FND507

5082-7730

HDSP-3400

HOSP-3403

5082-7300

5082-7302

5082 7304

5082-7340

POLARITY

Common Anode-red * 1Common Cathode-red-D DCommon Cathode-red ± ICommon Anode-redCommon Cathode-redCommon Anode-red i 1Common Cathode-redCommon Anode-redCommon Cathode-redCommon Anode-redCommon Anode-red t 1Common Anode-redCommon Cathode-red ± tCommon Cattiode-redCommon Cathode-redCommon CathodeCommon Cathode * 1Common CathodeCommon Cathode] FND5O0)Common Anode (FND510)Common Anode-redCommon Anode-redCommon Cathode red4 x 7 sgl Digit- RHOP4 x 7 Sgl Oigrt-LHDPOverrange charade' ( • 1)4 x 7 Sgl Digit-Hexadecimal

1.302102.10

19.95199515 0022 50

RCA LINEAR

CA3013TCA2023TCA3035TCA3039TCA3046NCA3059NCA3060NCA3080TCA3081N

2 15 CA3082N

2 56 CA3083N

2 46 CA3086N1 35 CA3089N

1 30 CA3130T325 CA3140T

3 25 CA3160T.85 CA3401N

2 00 CA3600N

CALCULATORCHIPS/DRIVERS

MM5725 S2 95

MM5738 2 95

DM8864 200

1 Sfi

CLOCK CHIPS

MM5309 $4 95

MM5311 4.95

MM5312 4.95

MM5314 4 95

MM5316 6.95

MM5318 9.95

MM5369 2.95

MM5387/1998A 4.95

MM5841 9 95

MOTOROLA

MCI 40817 $4

MC1408L8 5

MC1439L 2

MC3022P 2

MC3061P 3

MC4016(74416) 7

MC4024P 3

MC4040P 6

MC4044P 4

8 pm LP14 pin LP16 pin LP

18 pin LP20 pin LP

14 pin ST16 pin ST18 pin ST24 pin ST

8 pin WW10 pin WW14 pin WW16 pin WW18 pin WW

IC SOLDERTAIL — LOW PROFILE (TIN> SOCKETS

25-49 50-100 1-24

■B i^^^m 22 pin LP S 37

19 is oH&i ■■ mm 24 pm LP 3a

mmwm 28Piplp 45

.28 .27 36 pin LP 60

32 30 SOLDERTAIL STANDARD (TIN) ^"LP *

28 pin ST S 99

36 pin ST 13940 pin ST 159

SOLDERTAIL STANDARD (GOLD)

24 pin SG S ?0

50-10035

25

32

WIRE WRAP SOCKETS(GOLD) LEVEL #3

28ptnSG MO

36 pin SG 1 65

40pinSG 175

22 pin WW | 95

24 pin WW 1.05

28 pin WW 1 40

36 pin WW 1.59

40 p.n WW 1.75

1/4 WATT RESISTOR ASSORTMENTS - 5%

ASST.ASST.

'0 OHM

OHM

1 Sea 2: OHM &0MM rdOMi I ■•'.'

68 OHM 8? OHM 100 OHM 1?0 OHM

2 Sea 180 OHM 2211 OHM 2 70 OHM 330 OHM

;::]OHM 560 OHM 680 OHM 8S6 0HM

3 5ea l,2K '.bK 1.8K 2 2K

3.3K <M i 7K 5.6k

4 5ea 6 ?n :ok I2K t^k

?70K680K

330K

820K

50 PCS

$1.75

50 PCS

1.75

50 PCS

1.75

50 PCS

1.75

50 PCS

1.75

50 PCS

1.75

ASST. 7

ASST. 8R

ii" item i.arvr i.nryi j./m

5M 2.7M 3.3M 3.9M 4.7M 5.6M 50 PCS 1.75

Includes Resistor Assortments 1-7(350 PCS.) $9.95 ea.

$5.00 Minimum Order - U.S. Funds OnlyCalifornia Residents - Add 6% Sales Tax

Spec Sheets- 25c

1979 Catalog Available—Send 41 c stamp

PHONE

ORDERS

WELCOME

(415)592-8097

ELECTRONICS

MAIL ORDER ELECTRONICS - WORLDWIDE1021 HOWARD AVENUE. SAN CARLOS. CA 94070

Advertised Prices Good Thru December

AY-5-9100

AY-5-9200

AY-5-9500

AY-5-2376

HD0165

74C922

TELEPHONE/KEYBOARD CHIPS ^>

Push Button Telephone Dialler $14.95

Repertory Dialler 14.95

CMOS Clock Generator 4 95

Keyboard Encoder (88 keys) 14,95

Keyboard Encoder (16 keys) 7.95

Keyboard Encoder (16 keys) 9.95

ICM7045ICM7205ICM7207ICM7208ICM7209

ICM CHIPS

CMOS Preasion TimerCMOS LED Stopwatch/TimerOscillator ControllerSeven Decade CounterClock Generator

24.9519.95

7.5019 956.95

NM0S READ ONLY MEMORIES

MCM6571 128 X 9 X 7 ASCII Shifted with Greek 13.50

MCM6574 128 X 9 X 7 Math Symbol & Pictures 13.50

MCM6575 128 X 9 X 7 Alphanumeric Control 13.50

Character Generator

MISCELLANEOUS

TL074CN Quad Low Noise bi-fet Op Amp 2.49

TL494CN Switching Regulator 4.49

TL496CP Single Switching Regulator 1.75

11C90 Divide 10/11 PrescaTer 19.95

95H90 Hi-Speed Divide 10/11 Prescaler 11.95

4N33 Photo-Darlington Opto-lsolator 3.95

MK5O240 Top Octave Freq Generator 17.50

DS0026CH 5Mhz 2-phase M0S clock driver 3.75

TIL308 .27" red num. display w/inieg logic chip 10.50

MM5320 TV Camera Sync. Generator 14.95

MM5330 4^ Digit DPM Logic Block 5 95

LD110/111 3v? Digit A/D Converter Set 25.00/set

LITR0NIX ISO-LIT 1

Photo Transistor Opto-isolator(Same as MCT 2 or 4N25)

2/990

SN 76477

SOUND GENERATORGenerates Complex SoundsLow Power - Programmable

3.95 each

TV GAME CHIP AND CRYSTAL

AY-3-8500-1 and 2.01 MHZ Crystal (Chip & Crystal _ n- . Jkincludes score display, 6 ganes and select angles, etc /.jjj/SCl

XR205 $3.40

XR210 4.40

XR215 4.40

XR320 1.55

XR-L555 1.50

XR555 .39

XR556 .99

XR567CP .99

XR567CT 1.25

XR1310P 130XR1468CN 3.85

XR1488 - 1.39

XR1489 1.39

EXAR

XR1800 3.20

XR2206 4 40

XR2207 3 85

XR2208 5.20

XR2209 1.75

XR2211 5.25

XR2212 4.35

XR2240 3.45

XR2242CP

XR2264

XR2556

XR2567

XR3403

XR4136

XR4151

XR4194

XR4202

XR4212

XR4558

XR4739

XR4741

TYPI

1N7461N7511N75ZIN 7531N7541N757TN7591N9591N9651N52321N52341NS2351N52361N52421N52151N4561N45S1N485A1N4001

DIODES

VOLTS W

400m40Om400m400m400m400m5O0m500m500m500m500m50Om

PRICE

4/100

m oo

4/1 004/1.00

TYPE

1N40021N40O31N40041N4005

11*40061N40071N36001l*4t481N41541N43051r447341N47351N47361N473811*47421N47441N11831M1841N11851N11861N1188

VOLTS W

100 PIV 1 AMP200 PIV 1 AMP400 PIV 1 AMP600 PIV 1 AMP800 PIV 1 AMP1000 PIV 1 AMP50 200m75 10m35 10m

12/1 0012 1 0012,1 0010'1 0010/1 0010/1006/1.0015/1 0012/1 0015/1 00

50 PIV 35 AMP100 PIV 35 AMP150 PIV 35 AMP200 PIV 35 AMP400 PIV 35 AMP

C360C38M2N2328MDA 980-1MOA 980-3

SCR AND FW BRIDGE RECTIFIERS

15A(a>400V35A fa) 600V1 6A @ tOOVl?A{a>50VB 200V

PN2907 Ptastic

C106B1

MPSA05

MPSA06

TIS97

TIS98

40409

40410

40673

2N918

2N2219A

2N2221A

2N2222A

2N2369

2N2369A

MPS2369

2N2484

2N2906

2N2907

21*2925

MJE2955

2N3053

2N3055

TftANSIsfbRS

FW BRIDGE RECFW BRIDGE REC

MJE3055

2N3392

2N3398

PN3567

PM3568

PN3569

MPS3638A

MPS3702

2N3704

MPS3704

2N3705

MPS3705

2N3706

MPS3706

2N3707

2N3711

2N3724A

2^3725A

2N3772

2N3823

2N3903

5/1 005/1 003/1.00

5/1 005/1005/1 00

^0_^,

2N39042N39052N39062N40132f*4123PN4249PN42502N44002N44012N44022W4032N44092N50862N50872N50882N50892N5129PN5134PN5t3821*51392N52102N5449

4/1.004/1 004/1.00

PAPAPITffcR M VOLT CERAMIC

UMI M 1/ I I Un DISC CAPACITORS

10 pf22 pf

47 pt100 pl220 pi470 pt

001ml00220W7mf.01 mf

1/35V15/35V22/35V33/35V.47'35V68/35V1 0/35V

47,'SOV1 O.'SOV3 3/50V4.7.'25V10/25V10/50V22/25V22/50V47/25V47/50V100/25V100/50V220/25V220/50V470/25V1000/16V:-'.-'0ii ihV

u» mm ifl2_

05 04 03 00VF

.05 04 03 O047uf

.05 04 03 01/iF.05 04 03 022MF05 04 03 047MF

.05 .04 .035 VF

100 VOLT MYLAR FILM CAPACITORS12 10 07 022mf047ml

Ifl

07

05 .04 035

22mf 33 2?

+ 20% DIPPED TANTALUMS (SOLIOl CAPACITORS

28 .23 .17 1 5/35V 30 .26

.28 23 .17 2.2/25V 31 27

28 .23 .17 3.3/25V 31 27

28 23 17 4.7/25V .32 28

28 23 17 68/25V 36 31

28 .23 17 10/25V 40 35

28 23 17 1525 V 63 50

MINIATURE ALUMINUM ELECTROLYTIC CAPACITORS

10

47,25V47/50V1 0/16V1 0,25V1 0/50V4 7/16V4.7/Z5V4 7/50V10,16V10/25V10/50V47/50V100.-16V100/25V1O0/50V220/16V470/25V

Radial Lead

15 13

28 j

y

226

BYTE December 1978

Circle 200 on inquiry card.

n

mci

[ELECTRONICS

Kits

Regulated Power Supply

* Uses LM 309K

* Heat sink provided

» P.C. board construction

* Provides a solid 1 amp (a5V

* Includes components,| hardware and instructions

* Sizes: 3-1/2" x 5" x 2" high

JE200 $14.95

Function Generator Kit

S£

\

* Provides 3 basic wave-forms: sine, triangle &square wave

* Frequency range from 1 Hzto 100K Hz

* Output amplitude from0-volts to over 6 volts(peak to peak)

* Uses a 12V supply or a ±*l 6V split supply

* Includes chip, P.C. board,components and instruc-tions.

JE2206B $19.95

Digital Stopwatch Kit

* Use Intersil 7205 Chip

* Plated thru doubte-sidedP.C. Board

* LED display (red)

* Times to 59 min. 59,59 sec. withauto reset

* Quartz crystal controlled

* Three stopwatches in one:single event, split (cum mutative)and taylor (sequential timing)

* Uses 3 penlite batteries

* Size: 4.5" x 2.15" x .90"

JE900 $39.95

4-Digit Clock Kit

* Bright .357" ht. red display- Sequential flashing colon

* 12 or 24 hour operation

* Extruded aluminum case (black)

* Pressure switches for hours, minutes and hold modes

* Includes all components, case and wall transformer

* Size: 3-1/4" x 1-3/4" x 1-1/4"

JE730

$14.95

6-DigitClockKit

Bright .300 ht. common cathode display

* Uses MM5314 clock chip

* Switches for hours, minutes and hold functions

* Hours easily viewable to 20 feet

* Simulated walnut case

* 115 VAC operation

* 12 or 24 hour operation

* Includes all components, case and wall transformer

* Size: 6-3/4" x 3-1/8" x 1-3/4"

JE701 $19.95

Jumbo

6-Digit

Clock

Kit

* Four .630" ht. and two .300" ht. common anode displays

* Uses MM5314 clock chip

* Switches for hours, minutes and hold functions

* Hours easily viewable to 30 feet

* Simulated walnut case

* 115 VAC operation

* 12 or 24 hour operation

* Includes all components, case and wall transformer.* Size: 6-3/4" x 3-1/8" x 1-3/4"

\ JE747 $29.95

MICROPROCESSOR COMPONENTS

821282148216822482268228823882518253825582578259

-8060A/W80A SUPPORT DEVICES-CPU

8-Bit Input/Output

Priority Interrupt Control

Bi-Oirectronal Bus Driver

Clock Generator/Driver

Bus Driver

System Controller/Bus Driver

System Controller

Prog. Comm 1/0 (USART)

Proo. Interval Timer

Prog. Periph. 1/0 (PPt)

Prog DMA Control

Prog. Interrupt Control—68M/68M SUPPORT DEVICES—

MPU

-MICROPROCESSOR MANUALS -

M-Z80 User Manual

M-CDP1802 User ManualM-2650 • User Manual

3.95

- ROMS

3.49

2513(2140)

Character Generatorfupper case)

$9 95

595

2513(3021)

Character Generator!lower case)

9.95

595

2516

Characte

Generator

10.95

7.95

MM5230N

2048-8it Read Only Memory

195

1495

19.95

1101

256X1

Static

$1.49

MC6800

MC6802CP MPU with Clock and Ram

MC681DAP1 128X8 Sialic Ram

MC6821 Periph Inter Adapt (MC6820)

MC6828 Priority Interrupt Controller

MC6830L8 1024X8 Bit ROM (MC68A30-8)

MC6850 Asynchronous Comm Adapter

MC6B52 Synchronous Serial Data Adapt.

MC6860 0-600 bps Digital MODEM

MC6862 2400 bps Modulator

MC6880A Quad 3-State Bus. Trans (MC8T26)

$149524,955.95

MICROPROCESSOR CHIPS—MISCELLANEOUS -

Z8CH780C) CPUZ8QA<780-1) CPUC0P1802 CPU2650

16-Bit MPU w/hardware, multiply& divide -SHIFT REGISTERS

9.9512.9514 95

2.25

$19.9524.9519.951995

MM500H

MM503H

MM504H

MM506H

MM510H

MM5016H

2504T

2518

2522

2524

2525

2527

2528

2529

2532

Dual 25 Bit DynamicDual 50 Bit DynamtcDual 16 Bit StaticDual 100 Bit StaticDual 64 8ft Accumulator500/512 Bit Dynamic1024 DynamicHex 32 Bit StaticDual 132 Bit Static512 Static1024 DynamtcDual 256 Bit StaticDual 250 StaticDual 240 Bit StaticQuad 80 Bit Static1024 Static

m

4X4 Register File (TriState) UART'S

1103

2101(8101)

2102

21L02

2111(8111)

2112

2114

2114L

2114-3

2114L-3

5101

5280/2107

7489

74S200

93421

UPD414

(MK4027)UPD416

(MK4116)TMS4044-

45NLTMS40452117

MM5262

1024X1256X41024X11024X1256X4256X41024X41024X41024X41024X4256X44096X116X4

Dynamtc

Sialic

Static

Static

Static

Static MOS

Static 450ns

Static 450ns low power

Static 300ns

Static 300ns low power

Static

Dynamic

Static

Static Tnstate

Static

Dynamic 16 pin

pin

Dynamic 1

Static

Static

Dynamic 350ns(house marked)Dynamic

14.9514,95

PROMS

1702A 2048 FAMOS

TMS2S16 16K' EPROM(intel 2716)

(2716) 'Requires single +5V power supply

TMS2532 4KX6 EPROM

2708 8K EPROM

2716 T.I 16K" EPROM

"Requires 3 voltages. —5V, *-5V, *12V5203 2048 FAMOS

A-Y-5-1013 30K BAUD

6301-1(7611) 10246330-1(7602) 25682S23 32X882S115 409682S123 32X874186 51274188 25674S287 1024

Tristate Bipolar

Open C Bipolar

Open Collector

Bipolar

Tristate

TTL Open Collector

TTL Open Collector

Static

The Sinclair PDM35.

\ A personal digital

multimeter for only S 59 M

Now everyone ci

DCVblti(4nn««)Ran?* ImViolOOOVAccuracy of Hiding 10% ± I couiio own a dlgi Ul S'o« 10 M11 input impedincc,« \c.li.i«M»-5kHziRinRt I V to 500 V

The Stoctaii PDM.>> i> nipplW c«m-k'l> .iswnihloti with icsi leads jnd punts,ilcctHi1 wallet and Op<>ruttir'>; ManualThe Sindau PI>M-^ i, Uil-.r-madc l<»»

a nifgtti but lighl pockr l-*

XMAS SPECIAL - Get your PDM-35PLUS the 117 volt AC Adapter andPadded carrying case for only(Retail valueS73.85)

$64.50

Model 2800$99.95

Ccmes witfi lest

leads. operating manual

and spare tuse

3Vi-Diflit Portable DMM

• Overload Protected

• 3 high LEO Display

• Battery or AC operation

• Auto Zerotng

■ 1rnv.1Va.Gl ohm resolution

• Overange reading

• 10 meg input impendence

• DC Accuracy 1"= typicalRanges: DC Voltage ■ 0-1000VAC Voltage Q-tOOOV

Freq Response 50-400 HZDC/AC Current. 0-100mAResistance 0-10 meg ohmSize 6 4x44x2

Accessories:AC Adapter BC-28 $9.00Rechargeable

Batteries BP-26 20.00Carrying Case LC-28 7.50

■ m I'icwm eoe

100 MHz8-Digit

Counter

• 20 Mz-100 MHz Range

• 6" LED Display . Four power souces. re

• Crystal-controlled timeOase batteries. 110 or 220V with

• Fully Automatic charger 12V with auto

• Portable - completely lighter adapter and externalself-contained 7.2-10V power supply

•^,,s::z-mx-m ..$134.95

ACCESSORIES FOR MAX 100:Mobiis Chirgtr Eliminator

use power from car batteryCharger/Eliminatoruse 110 VAC

Model 100 - CLA $3 95Model 100 - CAI $9.95

The IncrediblePennywhistle 103'

tjMaa.yO Kit Only

The Pennywhlslle 103 is capable of recording data to and from audio tape withoutcritical speed requirements for the recorder and it is abfe to communicate directly withanother modern and terminal tor telephone "hamming" and communications, inaddition, it is free of critical adjustments and is built with non-precision, readily availableparts.

.Frequency-Shift Keying, full-duplex (hall-duplex

selectable)

.300 Baud

Data Formal Asynchronous Serial (return to mark level required

between each character).Receive Channel Frequencies .. .2025 Hz for space 2225 Hz for mark.Traiumit Channel Frequencies . .Switch selectable: Low (normal) - 1070 space,1270 mark: High - 025 space, 2225 mark

Receive Sensitivity - 46 dbm accousticafty coupled

Transmit Level -15 dbm nominal. Adjustable Irom -6 dbm

to -20 dbm.

.Frequency reference automatically adjusts toallow for operation between 1800 Hz and 2400 Hz,EIA RS-232C or 20 mA current loop (receiver isoptoisolateO and non-polar)120 VAC. single phase, 10 WattsAll components mount on a single 5" by 9"printed circuit board All components includedRequires a VOM, Audio Oscillator, Frequency Counter and/or Oscilloscope to align.

TRS'80 16K Conversion Kit

Expand your 4K TRS-80 System to 16K. Kitcomes complete with:

* 8 each UPD416 (16K Dynamic Rams)

* Documentation for conversion

TRS-16K

$115.00

Special Offer - Order both your TRS-16K and theSup'R' MOD II Interface kit together (retail value$144.95) for only $139.95

COMPUTER CASSETTES

SB Mikli-MaX 6 Digit 50MHz Frequency Counter

• Guaranteed frequency range of 100 Hz to 50 MHz

• Full 6 digit display with antiglare window

• Fully automatic-range, polarity, slope, trigger, input level switching not required.

• Lead-zero blanking—All zeros to the left of the first non-zero digit are Wanked. Kiio Hertzand Mfjga Hertz decimal points automatically light up when the unit is turned on.

• Built in input overvoltage protection.

• Use 9V Battery or 110/220V power.

: sg^m0y8rna mim-max $89.95

Accessories For Mini-Max

Part No. Description Price

MM-A4 Antenna $ 3.95

MM-C5 Carrying case 5.95

MM-IPC Input cable with clip leads 3.95

MM-AC2 110V adapter 9.95

MM-AC3 220V adapter 9 95

$5.00 Minimum Order - U.S. Funds OnlyCalifornia Residents - Add 6% Sales Tax

Spec Sheets - 25*

1979 Catalog Available—Send 41 c stamp

PHONE

ORDERS

WELCOME

(415) 592-8097

MAIL ORDER ELECTRONICS - WORLDWIDE1021 HOWARD AVENUE, SAN CARLOS, CA 94070

Advertised Prices Good Thru December

1

• 6 EACH 15 MINUTE HIGHQUALITY C-15 CASSETTES

. PLASTIC CASE INCLUDED12 CASSETTE CAPACITY

. ADDITIONAL CASSETTESAVAILABLE #C-15-S2.50 ea

~v, CAS-6

$14.95

(Case and 6 Cassettes)

SUP R' MOD II

UHF Channel 33 TV Interface Unit Kit

*Wide Band B/W or Color System

* Converts TV to Video Display fnrhome computers. CCTV camera,Apple II. works with Cromeco Daz-zler, SOL-20, IRS-80, Challenger,etc.

* MOD IS is pretuned to Channel 33(UHF).

* Includes coaxial cable and antennatransformer.

MOD II

$29.95 Kit

Custom Cables & Jumpers

Part No.

DB25P-4-PDB25P-4-SDB25S-4-S

DJ14-1

DJ16-1

DJ24-1

DJ14-M4

DJ16-1-16

DJ24-M6

DB 25 Series CablesCable Length Connectors Price

4 Ft. 2-DP25P S15.95ea.

4 Ft 1-DP25P/1-25S $16.95 ea

4 ft. 2-DP25S

Dip Jumpers

1 ft.

1 ft.

1 ft.

t ft.

1 ft.

1 ft.

1 14 Pin1-16 Pin1-24 Pin2-14 Pin2-16 Pin2-24 Pin

S17.95ea.

S1 59 ea,1.79 ea.2.79 ea.2.79 ea.3.19 ea.4.95 ea.

For Custom Cables & Jumpers, See JAMECO 1979 Catalog for Pricing

^ CONNECTORS

25 Pin-D Subminiatiire

DB25P(as pictured) PLUG S2.95

DB25S SOCKET 3.50

DB51226-1 Cable Cover for DB25 P or S 1.75

63-Key Unencoded Keyboard

This is a 63-key, terminal keyboard newly manufactured by alarge computer manufacturer. It is unencoded with SPST keys,unattached to any kind of PC board. A very solid molded plastic 13x 4" base suits most application. IN STOCK ggg gg/gggjj

Hexadecimal

Unencoded

Keypad

19-key pad includes 1-10 keys,ABCDEF and 2 optional keys and ashift key. $1u\95/each

m

Circle 200 on inquiry card.

BYTE December 1978 227

What's New?

Thick Film Crystal Clock Oscillator

Get Your Feet Wet with a Solderless Breadboard Without Wringing Your Wallet Dry

derless bus strips, four 5 way bindingposts, a metal ground base plate, non-marring feet and all required hardware.When complete, its 630 tie points permitflexible configurations of as many as six14 pin dual-in-line package integratedcircuits. Of the four binding posts, oneis grounded to the ground base plate per-mitting high distributed capacitance andlow distributed inductance for enhancedhigh speed circuit operation. The threeremaining 5 way binding posts can beused to interconnect the circuit on thePB-6 to power and signal lines and theoutside world. Kit is priced at $15.95from Continental Specialties Corp, 70Fulton Ter, New Haven CT 06509."

Circle 545 on inquiry card.

The PB-6 Pronto-Board Kit comescomplete with a preassembled bread-boarding socket, two preassembled sol-

Compucruise Reduces Fuel and Repair Expenses

Compucruise is an automotive micro-computer combining a 20 button back-lighted keyboard, 5 digit blue fluores-cent display, and appropriate sensors toprovide a fuel management system, tripcomputer, clock and digitally displayedcruise control. Compucruise monitorsspeed, distance, fuel flow, time, batteryvoltage and choice of three tempera-

tures, inside, outside or coolant. Itsfuel management system indicates aver-age fuel consumption, fuel used andremaining, plus distance and time toempty. The precision quartz crystaltime computer features time, elapsedtime, trip time, stopwatch and alarm.The trip computer displays distance,time and fuel to arrival. A total of 44functions can be commanded by thetouch of a button. Compucruise fea-tures cruise control that will accelerateyour vehicle to any preselected roadspeed, can be instructed to adjust totraffic flow and has a resume feature.Either metric or English units can bedisplayed. With a command module nolarger than a hand held calculator,Compucruise can be flush or bracketmounted, and complete hardware andinstallation instructions are included.The price is $189.95 from Zemco Inc,1136 Saranap Av, Walnut Creek CA94595."

Circle 546 on inquiry card.

Master System Clock for LSI-11

A master system clock for use withDigital Equipment Corporation (DEC)LSI-11, LSI-11/2, and PDP-11/03 com-puter families has been announced byNortek Inc, 2432 NW Johnson St,Portland OR 97210. The dual widthmodule combines the features of aKW-11L real time clock, a KW-11Pprogrammable clock, and adds anRT-11 compatible date and timeclock.

-An independently powered micro-processor helps insure that date, timeand programmable count are maintainedwhen the processor is not running.Simple operating system modificationseliminate the need for manually settingthese values on power up.

13 programmable time rates from1 MHz to once per hour are available.The programmable clock may also

Low Cost Erasable

Read Only Memory Eraser

The Information Central E-PROMEraser is a 2 part unit consisting of a

2537 A ultraviolet lamp and a base thatholds up to two erasable read only mem-ories. It operates from 115 VAC, Theprice is $45; Illinois residents shouldadd 5% state tax. For more informationcontact Information Central Inc, 5521 .N Broadway, Chicago IL 60640.*

Circle 547 on inquiry card.

be used as an external event counter.

The basic unit with standard powersupply and installation instructions ispriced at $600. An optional batterybackup power supply is available toprovide protection against power failuresfor up to 24 hours."

Circle 548 on inquiry card.

LOCO II is a thick film crystal clockoscillator in dual-in-line (DIP) packageform. Six discrete frequencies are avail-able: 19.6608 MHz, 18.432 MHz, and16.000MHz.

This miniature oscillator is .820 by.520 by .250 inches (2.08 by 1.32 by.64 cm), operates from 5 VDC anddrives 10 TTL gates.

The LOCO II provides master clockfrequencies that can be divided todiscrete universal asynchronous receivertransmitter (UART) frequencies forvarious data transmission rates, or theycan be divided to provide multiple out-puts which can drive combinations oftransmission rate generators, micro-processors and LSI circuits in the samecomputer system.

The LOCO II is priced below $5. Forfurther information, contact MotorolaComponent Products, 2553 N Edington,Franklin Park IL 60131."

Circle 549 on inquiry card.

Attention Builders: Cases to HousePrototype Electronic Circuits

These Design Mate cases are designedto house prototype electronic circuits.They are made of high impact one-pieceinsulated plastic and feature a slopefront panel, a metal bottom and includemounting screws.

There are two models of the DesignMate case: the DMC-1 measures 6,75 by7.5 inches (16.15 by 19.05 cm) with aheight that slopes from 1.5 to 3.25inches (3.81 to 8.26 cm); the DMC-2measures 5.63 by 6.0 inches (14.30 by15.24 cm) with a height that slopesfrom 1.5 to 3 inches (3.81 to 7.62 cm).

The DMC-1 is $6.95 and the DMC-2is $5.95. For further information contactContinental Specialties Corp, 70 FultonTer, New Haven CT 06509,"

Circle 550 on inquiry card.

228

December 1978 © BYTE Publications Inc

BUY FROM THE BIGGEST

NCE/CompuMart

LJ3k P€T

kO*

1250 North Main Street, Department KBC8P.O. Box 8610 Ann Arbor, Michigan 48107

*i|",V' \r~\

\*

&0<

$795

THE PETCONNECTION

PET with 8K usermemory $795.00

Second Cassette drive $99.95RS-232 Printer Adapter —assembled board »„_ 5fl

With power supply, case &0625 $169.00

Beeper — PET controlledbeep $1995

Video Butter — add a

conventional monitor $19.95

BETSI — PET to St 00 10

Motherboard

Kit $105.00

Assembled $160.00

EXPANDAPET « Economical 16K

memory expansion for the PET (in-

Hams! Add aPET to your rig.

Computerize your station withMicrosomes M-65 Ham interfaceand included software You simply •plug the unit into your PET andyou're ready to display, transmitand receive either CW or RTTY atrates up to 100 WPM

ASSEMBLED KITS$99.95

SECOND CASSETTEFOR PET $99

This peripheral (ram Commodore

KIM-1

Hazeltine1400

5179

with pow«r aupply

$209

EXPAND YOUR KIM SYSTEMKIMSI

Assembled

MICRO TECH POWER SUPPLY

KIM ENCLOSURE

Give your KIM a professional appear-ance No alterations required, sturdyKydex 100 Black **«

$749.00

CASHAVAILABLECall Today: (313) 994-3200

16 Ln x 64 chr display 126 printablecharacters, software UART (ASCIIor Baudot) 3 serial interfaces •cassette I O true composite videoASCII keyboard (parallel input) TTLcompatible easy power con-

Assembled* tested NOW $1 87

Corripucolorll

TC-71 SELECT* C TERMINALS

Top-quality printing terminalwith RS-232. PTTC code In-cludes desk. 130 char.hneASCII version employs 6802for code conversion See ourcatalog lor details.ASCII M7<

Refurbished J695

Working J4S5

As-ls $339

Acoustic Coupler 1159

-AlE ASCII INTERFACE FOR TC-71

30 (Jay delivery Normally $199 NOW J}) I /yAcoustic Coupler tor use *#) ASCII TC- 71 $159

Introductory Sale Price —

Immediate Delivery

24 x 80 displayRS-232C interface110 to 9600 Baud12" CRT MonitorRemote screen controlUses 8048 microprocessorState-of-the-art design

A full capability terminal completelyassembled with a 90 day warrantyfor less than you'd pay for a kit.

SYM-1 -KB '

From Synertek $269.00

e

SANYOMONITOR

New Acoustic Coupler

<W Tl

PROGRAMMER

calculator converter

Reg. $59.95 NOW $53.95

P1XE-VERTER

$9.95

The original video to R.F conver-ter Converts any good T V to avideo monitor

HI PLOT1

Rutocomputer

AIM65

Hadsts F««l €••!* -

• la mi Mm * ■ * *

90 day limited warrantyNewest, most exciting products in per-sonal computingOutstanding valuesAll items fully assembled and testedunless otherwise stated.Send for our catalog for more detailedproduct information.

1-800

521

1534

|MATROX VIDEORAMS S-100

ALT-2480 24LN x 80CHdisplay $295

ALT-256 256 x 256 dotdisplay S395

The AUTOCOMP mounts in or onyour dash, and by pushbutton con-trol provides LED readouts of thefollowing driving functions Instan-taneous MPG Average MPF. FuelUsed Distance Traveled and Cor-rect Time

■AUTOCOMP can be installed onmost American and Japanese makeautos and vans except those withfuel iniection and is NOT recom-mended tor European imports

• Michigan residents add 4% sales tax. • Foreign ordersadd 10% additional handling (U.S. funds only). • P.O.'saccepted from D&B rated companies. * Toll FREEphones open from 9:00 AM — 7:00 PM EST. • Opend — call for credit application. • All or-day shipment

on prepaid and credit card orders, except as noted.

• Sorry — NO C.O.D.s. • AM prices subject to changewithout notice. • Write for giant FREE catalog.

• In the Ann Arbor area? Retail store open 11 ;00 AM —7:00 PM Monday-Friday 10:00 AM — 5:00 PM Satur-days.

Circle 283 on inquiry card.

BYTE December 1978 229

Circle 115 on inquiry card.

,—Electrolabs-

)|C Tl Sockets 1 cent per pin. All low profile solder tail 8 pin - 40 pin.

The "Pro" fully encoded ASCII KEYBOARD by Cherry. Auto RE-PEAT feature, 5 special function keys. 300mA/5V. (Shown asmounted in 'The Case', Below) $119.00, 3/99.00,10+/89.00

USED SYLVAN I A12" MONITORSWorking: $69.95Cold Chassis, 25lbs.With P39 (Green)Tube 109

The Dumb Terminal for Smart People

80X24 with full 128 char. ASCII UC+LCfont with all control characters displayed.300-19,200 baud RS232. 2nd font addressablefrom keyboard in you-prog ram-it 2708 forAPL, Graphics sets, etc. Plug in monitorI/O connector, 110VAC and you are ready.INCLUDES: 'The Case', Cherry Kbd. A usedmonitor, ESAT 200A, all options exceptvector addressable cursor and modem.Bulletproof design and construction.Normally $675.00 What you alwayswanted your ADM3 to be:SYSTENTA" $649.00 10/$599.00

4>Q Box 6721 Stanford*

NEW P4 (White)

Tube 99 "The Case" Beautiful and sturdy

anodized aluminum case in deep black designed to contain theESAT 200A, and with a bezel cut out for the Cherry 'Pro' keyboard,(installed as shown above) Choose deep brown, light yellow, or crim-son to accent or color code your installation. The only choice forhard-use institutional and educational applications. $69.00, 10/ 59.00

THE FANTASTIC!

MEMOREX FIVE-FIFTY

<a. 94309415-321-5601

TLX 345567^► '•'—<

* Hard and Soft Sectoring

* Single and Dual Density

* Double side configurationas a retrofit at any time.*U0/220V,50/60Hz

*Pin for pin compa table withShugart 800,801,850,851(50 pin edge connector)

* PRICE BREAKTHROUGH!$425 EACH

MERRY CHRISTMAS

Double Sided Retrofit$300

LATEST REVISION: ESAT 200B (BILINGUAL)

Stand Alone Single Board Communicating Terminal

80X24 Standard Format

Split Speed 110 to 19,200 Baud

Two Fonts, 128 Char. ea. in 2708 EPROM

Full Feature Cursor, Page Xmit., Scrolling

5V@3A, 8"X14" Board. Requires only a

keyboard and almost any monitor for the

best terminal for the money anywhere!

Supplied with U&LC ASCII in one font.

$329.00

■ NEW! 32 K, S 100 Universal Static Store. Accepts 2114 RAMs or' 70 ns, 3625 PROMs paging up to 8 Mby. Board only with manualand paging software $69.00. 32 Kby RAM 450 ns $679.00, 250 ns$789.00. We have software application notes for multi-task multi-user applications utilizing paging feature.

Shipping and Handling: Surface: $o.40/ib. Air: $0;CaL Tax: 6.5% Insurance: $0.50 per $100.00

;75/lb., 1.00 minimum

SSiV

FORMERLY CYBERCOM/SOLIO STATE MUSIC.

CB-1 8080 Processor Board. 2K of PROM 256 BYTERAM power on/rest Vector Jump Parallel port with

status. Kit .125.95

MB-6A Basic 8KX8 ram uses 2102 type rams, S-100

buss. Kit 450 NSEC $123.95. PCBD $24.95

MB-7 16KX8, Static RAM uses jliP410 Protection,

fully buffered KIT... $299.95

MB-8A 2708 EROM Board, S-100, 8K8X or 16KX8

kit without PROMS $75.00

MB-9 4KX8 RAM/PROM Board uses 2112 RAMS or82S129 PROM kit without RAMS or PROMS $72.00IO-2 S-100 8 bit parallel /IO port, 2h of boards is for

kludging. Kit $46.00 PCBD $25.95

IO-4 Two serial I/O ports with full handshaking20/60 ma current loop: Two parallel I/O ports.

Kit $130.00 PCBD $25.95

VB-1B 64 x 16 video board, upper lower case Greek,composite and parallel -video with software, S-100.

Kit $125.00 PCBD $25.95

Altair Compatible Mother Board, 11 x HY2 x 1/s".

Board only .$39.95. With 15 connectors $94.95

Extended Board full size. Board only $ 8.95

With connector $12.95

SP-1 Synthesizer Board S-100PCBD $39.95

KIT $135.95

82S23 $1.50

82S123 1.50

82S126 1.95

825129 1.95

825130 3.95

825131 3.95

MMI6330 1.50

IM5600 1.50

IM5603 1.95

IM5604 3.95

IM5610 1.50

IM5623 1.95

IM5624 3.95

PRIME SUPPORT

8080A $ 9.95

8212 3.25

8214 6.50

8224 3.49

L2114 (450 NSEC) 7.25L2114 {250 NSEC) 7.99

2102AL-2 1.70

2102AL-4 1.30

21L02 (450) 1.25

2708Q (National).. 8.954116 (Apple Ram) 14.99

wmc/j

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 (not included).DEC. & JAN. ONLY SPECIAL PCBD $23.95

FPB-1 Front Panel. (Finnally) IMSAI size hex dis-plays. Byte or instruction single step. PCBD special,DEC. & JAN. $39.95

MEM-1 8KX8 fully buffered, S-100, uses 2102 type

rams PCBD $24.95

QM-12 MOTHER BOARD, 13 slot, terminated, S-100

board only $34.95

CPU-1 8080A Processor board S-100 with 8 level

vector interrupt PCBD $25.95

RTC-1 Realtime clock board. Two independent in-terrupts. Software programmable. PCBD $25.95

EPM-1 1702A 4K Eprom card PCBD $25.95

EPM-2 2708/2716 16K/32K

EPROM CARD PCBD $24.95

QM-9 MOTHER BOARD, Short Version of QM-12.

9 Slots PCBD ........$30.95

MEM-2 16Kx8 Fully Buffered

2114 Board PCBD $25.95

16K RAM BOARD by HWE fully buffered, bank se-lect standard to IEE buss gold fingers, solder mask,

plated thru holes, silk screened PCBD $25.95

KLUDGE BOARD by HWE for S-100 glass epoxyover 2600 plated through holes, 4 regulators withCAPS all S-100 functions labeled, gold fingers.PCBD ...- $29.95

mm

419 Portofino DriveSan Carlos, California 94070

Please send for IC, Xistorand Computer parts list.

CHRISTMAS SALE (Dec. only)

5% OFF ON ALL KITS AND

PCBD ON PREPAID ORDERS ONLY

(charge cards & C.O.D. are not included on this offer)

MIKOS PARTS ASSORTMENTWITH WAMECO AND CYBERCOM PCBDS

MEM-2 with MIKOS #7 16K ram

with L2114 450 NSEC $249.95

MEM-2 with MIKOS #13 16K ram

with L2114 250 NSEC $269.95

MEM-1 with MIKOS #1 450 NSEC 8K

RAM $123.95

CPU-1 with MIKOS #2 8080A CPU 89.95

MEM-1 with MIKOS #3 250 NSEC 8K

RAM - 144.95

QM-12 with MIKOS #4 13 slot mother

board 89.95

RTC-1 with MIKOS #5 real time clock 60.95

VB-1B with MIKOS #6 video board less

molex connectors 99.95

EMP-1 with MIKOS #10 4K 1702 less

EPROMS - 49.95

EPM-2 with MIKOS #11 16-32K EPROMS

less EPROMS - 48.95

QM-9 with MIKOS #12 9 slot mother

board 67.95

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 account number, interbanknumber, expiration date and sign your order. Approx. postagewill be added. Check or money order will be sent post paid inU.S. It you are not a regular customer, please use charge,cashiers check or postal money order. Otherwise there willbe a two-week delay tor checks to clear. Calif, residents add6% tax. Money back 30 day guarantee. We cannot acceftt re-turned IC's that have been soldered to. Prices subject tochange without notice. $10 minimum order. $1.50 service chargeon orders leas than $10.00.

230 BYTE December 1978

Circle 229 on inquiry card.

ntS n

^f^^° H0 t,e <$*> **

*•* v Tko Io** $** soaS «**

>**

<***•

rfi

OWE I I ONE

our new retail locatio

LM3A 3 dig 1% DC $134.00

LM3.5A 3% dig .5% DC ... $ 158.50

LM40A 4dlg .1% DC $209.00

LM4A 4 dig .03% DC $250.00

I * Rechargeable batteries and charger in

] eluded

| • Measures DC Volts, AC Volts, Ohms and

Current| • Automatic polarity, decimal and overload

indicationI * Rechargeable batteries and charger| • Measures DC Volts, AC Volts, Ohms and

Current

I ♦ Automatic polarity, decimal and overloadindication» No zero adjustment and no full-scale ohms

adjust» Battery-operated — NiCad batteries; also AC

line operation.• Large LED display tor easy reading withoutinterpolation

i Size: 1.9"H x 2,7"Wx 4'DParts & labor guaranteed 1 yearTilt staod option * 3-SO

Purchase any of the LM series

Meters and buy the LEA THER CASE

for iC

$318,

l-*r:

it "

1

1 * 1

W | '*

1*

V '/) 0

#

•:J

MS-15 MtNISCOPE

Wilti Rechargeable Butteries A Charger Unit

• 15 megahertz bandwidth.

• External and internal trigger. PROBE 1C

• Time base — .1 microsec. to 0.5 Sec/div_- 21 PROBE it with thesettings .-* 3% /iS,^ purchase of SCOPEBattery or line operatfon. 'iplEl and iheMENTiONof

IU3J thiS MAGAZINE

• CatWtjr'MjMWi T 50. 3 pounds.

■ ,0.D1 lOmfproB. |«.

■ L«(h« carrying cm * 45.

• MS-215 Dual Trace Version of MS-15 » 435.

r line operation.Automatic & line sync modesPower consumption < 15 watts

S100WWG 50 lOOCont 1253 LEVEL WIRE WRAP 025 so ,on 350 spaced rows GOLD pla

14 59 10 24

9400 S3 75 S3 50

RG81G 50 ICSOLDER TAIL oiALTAIR mothert

S10OSTG 50 100 ComDIP SOLDER TAIL on 250 Irows lor VECTOR andmotherboards GOLD plated14 5 9 10-24

S4 00 S3 75 S3 50

R681-3 50 100 Com 125PIERCED SOLDER EYELETGOLD

Other Popular Edge Connectors

R644-G 22 44 Com 156

PIERCED SOLDER EYELESGOLD piaied

1-4 59 1024

S3 DO S2 75 S2S0

ATTN OEMS a

I Dealsi

3 LEVEL

GOLD WIRE WRAPSOCKETS

Sockets purchased in multiples of 50 per type may be combined for best price

1-24 25-49 50-99 100-249 250-999 1K5K

Spin* 41 38 35 31 27 23

14 pin* 39 .38 36 32 29 27

16 pin* 43 .42 .39 35 32 30

L$?i

18 pin .6320 pin .8022 pm* 90

587585

24 pin 90 .8428 pin 110 10040 pin 150 140

5470.80

78

90

i 30

4763

70

68

.84

1 20

425861

6376

1 04

.365357

587189

All sockets are GOLD 3 level closed entry ' End and side stacable 2 levet. Solder Tail LowProfile. Tm Sockets and Dip Plugs available CALL FOR QUOTATION '

LIQUID CRYSTAL DIGITALCLOCK-CALENDAR

• For Auto, Home, Office

• Small in size (2x2UxY*>

• Push button for seconds release tor date.

• Clocks mount my-where with either 3M double-sided (ape or VELCRO. included

• 2 MODELS AVAILABLE.

LCD-101. portable model runs on self-contained

batteries for better than a year

LCD-102. runs on 12 Volt system and is back

lighted

• LCD 101 Of LCO 102 fiA QRyour crtoic* #U*t ,3Uh

W$2.00

8803

I

MOTHERBOARDS100 BUSMICRO-COMPUTERS

L pectffi

Plugboards

n

n i»o Tsj-uciionste aplionol

.Price$29.50

8800V

Universal Microcomputer /processorplugboard use with S-100 uus Com-plete with heat sink & hardware 5 3"*10 x 1/16

1-4 5-9 10-24

$19.95 $17.95 ti.i.M

8801-1

Same as 8800V except plainbuses & heat sink

less power

10-24$11 96

3682 9.6x4.5"

$10.97

3682-2 6.5" x 4.5"

$9.81

Hi-Oensitv Dual-ln-LmePlugboard for Wire Wrapwith Power & Grd. BusEpoxy Glass 1/16" 44pm con. spaced ,156

3677 9 6"x4.5"

$10.90

3677-2 6.5" x 4.5"

$9.74

Gen. Purpose D.I.P.Boards with Bus Patternfor Solder or Wire Wrap.Epoxy Glass 1/16" 44pin con. spaced 156

3662 6.5" x4.5"

$7.65

3662-2 9.6" x 4.5"

$11.45

P pattern plugboards forIC s Epoxy Glass 1/16"44 pin con. spaced 156

o

0 ;:V:M

3690-12CARD EXTENDERCard Extender has 100

contacts-50 per side on .125centers-Attached connector-iscompatible with S-100 Bus

Systems $25.00

3690 6.5" 22/44 pin .158ctrs. Extenders SI 2.00

1/16 /feSf BOARD

.042 dia holes on0.1 spacing for IC's

Phenolic PR'CE

PART NO. SIZE 1-9 10-19

64P44XXXP 4.5x6.5' $1.49 134

169P44XXXP 4.5x17" $3.51 3.16

Epoxy Glass

64P4484P44169P44169P84

ELLV-#lHJL-LLl> «r -bo

Wraps tnsulatw) wire on 025 sctuara posts W*Jf *1,n ,w0

FOUR TIMES FASTER

9$24.50

2708

8K 450 ns

EPROM

FACTORY PRIME

$ 9.00 EA.

25 + Call ForPrice

14 & 16 PIN

^GOLD 3 LEVEL

\WIRE WRAP

SOCKETS

h4 - G3 100 for$30.0016-G3 100 for$30.00"50 of each for $32.00

Sockets are End & Side stackable,closed entry

FM-7With

RechargeableBatteries &Charger

unit $215

SC-5

WithRechargeable

Batteries A ceatu^es include • By using the new MS SC-5 Prescaler the range ol

Ch.rnor lfle FM? frequency Meter, wnich is 10 Hz to 60 MH;. may be extended

ii it j! ,0 512 MHi (,t)e UDper VHF & UHF ,reclufint:y baf,(,s! • The FM-7 uH-

S Q8 l,;es an LED reaaoul P'oviding 7-digil resolution • The FM-7 can tie

calibrated to an accuracy of 0 00001 % • Tne SC-5 is accurate to one

pari per million • Each unit has 30 millivolls sensitivity, is battery

powered and has a charger unil included • Dimensions at each ate 1 9

H»!?"W«3 9"0 • The units may be obtained separately or as a

' Frequency Quo ' • Parts & Labor guaranteed 1 year

Tilt Stand o pi ion ........ I 3.50

Leather case $20.00

M750

MA1003CAR CLOCK

Bright Green Fluorescent Display Crys-tal Time Base Assembled, just addswitches and 12VDC.

SPECIAL

r- ^14CS2100for*140016CS2 100fort1600

I Jj 14 pin CS2 10 lor •ST

18DlnCS2 S lor '2"

These low cost DIP sockets will acceptboth standard width plugs and chips.For use with chips, the sockets offer a iowprofile height oi only .125" above the board.These sockets are end stackable.

WRAP POST

for .042 dia. holes(all boards on this page)T-44pkg. 100 ...| 2.28T-44 pi

1000 $14.00

A-13 hand installingtool S 2.80

ELECTRONICS

Seputveda, CA 91343

Terms VISA, MC, BAC. check, Money Order, COD , U.S. Funds Only. CA residents add 6% sales tax Mini-mum order $10.00. Orders less than $75.00 include 10% shipping and handling, excess refunded. Just in caseplease inc'ude your phone no C000 ™RU "78

Send tor our latest brochure

phone orders welcome (213) 893-8202

OEM and Institutional inquiries invited

our new retail loc

24 PIN DIP PLUGS

WITH COVERS

pi 16/44 6lfor APPIE,

l6K RamTRS-8QJ,

3/$1.0040/j_

s 8 for

BRANDNEW

«gA., AK

COMPUTER POWER SUPP

^±22j93-8202

Output Specifications

under continuous current loads

+ 5 Volts @ 17 Amps ± 2%, 50 mv ripple& noise maximum*

-5 Volts 0 1.25 Amps as 5%, 50 mv ripple & noise maximum

* 12 Volts @ 3 Amps ± 3%. 150 mv rippie &

noise maximum

12 Volts <a 275 Amps ± 3%. 150 mv ripple & noise maximum

+ 24 VoISs 91 3,5 Amps ± 5%, 150 mv ripple &

noise maximum

* + 5 Volt supply has remote sensing and overvoitage

protection

ONLYS12995*

'price includes UPS delivery in the continental US.

Perfect for Computer Systems with Discs.Great for a Bench Supply.

I l.iVAC or 230 VAC. 48 63 Hz3 wire line cord.

We made a fantastic buyon these BRAND NEWTele Dynamic power sup-plies They are shipped toyou in the original factorycartons. Take advantage

Input

■omplete i

ith standard 115VAC

of this great offer and payonly a fraction of a largecomputer manufacturer'sacquisition cost. Supply islimited, we suggest youphone your order in.

' Logic Probes and Digital Pulsers

LOGIC PROBES

CSC logic probes are the ultimate tool for breadboard design and testingThese hand held units provide an instant overview of circuit conditions. Simpleto use; just clip power leads to circuit's power supply, set logic family switch toTTL/DTL or CMOS/HTL, Touch probe to test node. Trace logic levels andpulses through digital circuits, Even stretch and latch for easy pulse detection.Instant recognition of high, low or invalid levels, open circuits and nodes. Sim-ple, dual-level detector LEDs tell it quickly, correctly. HI (Logic "l"l; LO (Logic"0*"l. Also incorporates blinking pulse detector, e.g.. HI and LO LEDs blink onor off, tracking "1" or "0" states at square wave frequencies up to 1.5 MHz,Pulse LED blinks on for Vi second during pulse transition. Choice of threemodels to meet individual requirements; budget, project and speed of iogic cir

MODEL LP1

Hand held logic probe provides instant reading of logic levels for TTL, DTL,HTL or CMOS. Input Impedance; 100,000 ohms Minimum Detectable Putae: 50ns. Maximum Input Signal (FrequencyI: 10 MHz, Pul»e Detector (LED): Highspeed train or single event. Pulae Memory: Pulse or level transition detectedand stored.CSC Model I PI Logic Probe - Net Each $44.95

^K

MODEL LP-2

Economy version of Model LP 1. Safer than a voltmeter. More accurate than a

scope. Input Impedance: 300,000 ohms Minimum Detectable Pulse: 300 ns.

Maximum Input Signal (Frequency): 1.5 MHz. Pulse Detector (LED): High

speed train or single event. Pulae Memory: None.

CSC Model LP-2 Logic Probe - Net Each 124.95

MODEL LP 3

High speed logic probe. Captures pulses as short as 10 ns. Input Impedance:

500,000 ohms. Minimum Detectable Pulae: 10 ns Maximum Input Signal (Fre

quencyl: 50 MHz. Pulse Detector (LED): High speed train or single event.

Pulse Memory: Pulse or level transition detected and stored.

CSC Model LP 3 Logic Probe - Net Each 169.95

DIGITAL PLLSER

The ultimate in speed and ease of operation. Simply connect clip leads topositive and negative power, then touch DPl's probe to a circuit node;automatic polarity sensor detects circuit's high or low condition. Depress thepushbutton and trigger an opposite polarity pulse into the circuit. Fasttroubleshooting includes injecting signals at key points in TTL. DTL, CMOS orother popular circuits. Test with single pulse or 100 pulses per second via built-in dual control push-button; button selects single shot or continuous modes.LED indicator monitors operating modes by flashing once for single pulse orcontinuously for a pulse train. Completely automatic, pencil size lab/field pulsegenerator for any family of digital circuits. Output: Tri slate. Polarity: Pulse-sensing auto-polarity. Sync and Source: 100 m*. Pulae Train: 100 pps. LED In-dicator: Flashes for single pulse; stays tit for pulse train.(SI Model DPI DigiUl Pulacr - Net Each 174.95

^

/m?**

Digital IC Testers and

COUNTER

i^lddtiUU

clips over any DIP IC upiingle bit level detector thatactivated when the appliedirns LED on; logic'0'-keepsilly locales supply leads and

LOGIC MONITOR 1

Trace signals through all types of digital

to 16 pins. Each of its 16 conts

drives a high intensity, numbered LED readout

voltage exceeds a fixed 2 V threshold. Logic "1" t

LED off. A power seeking gale network automatic

feeds them to the LM-t's internal circuitry. Saves I

design, troubleshooting, debugging of equipment. Voltage Threshold: 2 V t.

0.2 V. Input Impedance: 100.000 ohms. Input Voltage Range: 4 15 V max. across

any two or more inputs. Current Drain: 200 mA at 10 V. Size: 4" I. x 2" w. x

1.75" d, when open. Weight: 3 ozs.

CSC Model LM1 Logic Monitor -Complete.

$59.95LOGIC MONITOR 2

Provides greater versatility and p-ecjsion in testing all types of digital circuits.The fully isolated power supply and selectable trigger threshold let you matchthe precise charactenstici of the logic family under test, permitting more ac-curate measurements. The connector'display unit clips over any DIP IC up to16 pins. The power supply module contains the precision reference power supply and logic family selector switch. Operation is simple. Set the thresholdswitch to the proper logic family, Connect back clip lead to circuit ground. ForCMOS circuitry, the red clip is connected to circuit positive or Vcc. The clipmodule is then clipped over the IC and the LED display instantly gives thelogic states of all pins. Logic Thresholda: CMOS. 70% of circuit Vcc; HTL., 7.5V; TTL, 2.4 V: DTL, 1.6 V; RTL. 1.2 V. Maximum Visible Input Frequency: 30KHz at 50% duly cycle. Size: Test Clip. 4" 1. x 2" w. x 1.75" d. when open;Power Module, 6" w. x 5.63" d. x 3" h. max. Total Weight: 20 ozs. Power Re-quired: 117 VAC, 50(60 Hz. 10 W; also available for 220 VAC, 50. 60 Hz at slightly higher price.CSC Model LM-2 Logic Monitor - Complete.

1129.95

| ACE •CircuitEvaluator

Ail- for fast, solderless,plug-in circuit buildingand testing

MAX 100 PORTABLE FREQUENCY COUNTER

MAX 100 is a portable, high precision frequency counter that sets new standards in performance and value. In a compact, portable case, it gives you continuous readings from 20 Hz to a guaranteed 100 MHz. with 8-digit accuracy.Fast readings with 1/6-sec. update and 1 sec. sampling rate. Precise readings,derived from a crystal-controlled lime base with 3 ppm accuracy. Highsensitivity readings from signals as low as 30 mV. with diode overload prolection up to 200 V peaks. Input signals over 100 MHz automatically flash the mostsignificant digit, and to indicate low battery condition and extend battery life,the entire display flashes at 1 kHz.

SPECIFICATIONS

Frequency Range: 2fi Hz to 100 MHz guaranteed: 110 MHz typical. Gate Time:1 sec. Resolution: 1 Hz. Accuracy: * 1 count + time base error Input Im-pedance: 1 megohm shunted by 56 pF. Coupling; AC. Sine Wave Sensitivity: 30mV RMS at 50 MHz. Internal Time Base Frequency: 3.579545 MHz crystaloscillator.Stability: ± 3 ppm at 25° C. Temperature Stability: Better than 0.2 ppm °C,

0 50° C, Max. Aging: 10 ppm year. Display: Eight 0,6" LED digits. Lead-ZeroBlanking: Decimal point appears between 6th and 7th digit when input exceeds

1 MHz. Overflow: With signals over 99,999.999 Hz. most significant (left handldigit flashes, allowing readings in excess of 100 MHz. Display Update: D6-sec.plus I pa*, gate time. Low Battery Indicator: When battery supply falls helow6.6 VDC, all digits flash at 1 Hz. Power Required: Internal, 6 "A A" cells; exter-nal. 110 or 220 VAC charger eliminator, auto cigarette lighter adapter or 7.2 10VDC external supply. Battery Charging: 1214 hrs. Size: 1,75" h. x 5.63" w. x7.75" d. Weight: Less than 1.5 lbs. with batteries.

CSC Model MAX-100 Frequency Counter-Net Each 1134.95

MAX 100 ACCESSORIES

Model 100-CLA - Mobile charger eliminator. Net Each * 3.95

Model 100-CA1-110 VAC charger eliminator. Net Each 9.95

Model 100-CA2-220 VAC charger eliminator. Net Each 9.95

Model 100 IPC - Input cable with clip leads. Net Each 5.95

Model 100-LLC- Low loss tap^ff 14.95

Model 100-MWA- Mini whip antenna 3.95

Model 100-CC-Carrv case 9.95

DIP JUMPERS &

FLAT RIBBON CABLEASSEMBLIES WITH DIP CONNECTORSAvailable with 14.16.24 and 40 contacts.Mate with standard IC sockets.Fully assembled and tested.Integral molded on strain relief.Llne-by-lineprobeability. - <a

o!

^

+tMi^ v y

vxo*

\:

IC TEST CLIPS|TC-14 3in. $4.50TC-16 3in. $4.75

TC-16fits

14 & 16

Pin Dips,

in Dipj^A

ft

SALE

PRIORITY

16723B Roscoe Blvd.

%v*N

MATERIALS

DIELECTRIC: UL rscogniied glass-filled polytatof.

CONTACTS: Nan corrosive copper alloy 770.

CABLE: All cable conductors ate #28AWG

stranded 7/36 tin-coated copper with vinyt insula-

tion. AH cable is grooved top and bottom for easy ^

tear down

A P DIP Jumpers are the low-cost, high-quality solution for jumpering within a PCboard; interconnecting between PC boards,backplanes and motherboards; interfacing In-put/Output signals; and more.

All assemblies use rainbow cable. Stan-dard lengths are 6,12,18,24 and 36 inches.

^*r„,»D.no,„PinNo i. SINGLE-ENDED

A wstsmi DIP JUMPERS

i

\

\

DOUBLE ENDED

UP JUMPERS

No.Contact*

Length6"

Langth12"

Langth18"

Longth24'

Lent

36

,h

14

9241066R$2.41 '

924106-52 R$261

924106 18-R$282

92410624-R

$3,02

924106-36-R$343

16

924116 6 R$2.65

924118-12-fl$2 88

924116-18-R$3.11

924116- 24-R$334

924116 36-R

*3.ao

24

9241266-R$415

924126 12 fl

$4.50

924126 18-R$4 85

92412624-R$5 20

924126-36- R$5.90

40

9241366 R

$6.93

924136 12 R$7 52

93

4136-16-R•8.11

92413624 R♦8 73

924i

3698

36 R8

ELECTRONICS

pulvecta, CA 91343

Terms VISA. MC. BAG chexk. Money Order C0D.US Funds Only CA residents add 6% sales tax Mini-mum order $10 00 Orders less than $75 00 include 10% shipping and handling, excess refunded Just in case

No.Contact!

Length36

14

924)02 36 R$233

16

924112 36-R$259

24

924122 36 RS4.00

40

924132 36 R$671

- fine

please include your pnone no

Send lor our latest brochui

phone orders welcome (213) 893-8202

Good thru 1978

OEM and Institutional inquiries

..Fflsw"

A'and"

th'^dE'516'

8 £°*

Circle 306 on inquiry ca

^.crdVisit our new retail loc

TElS-80' -^^

$98.0

Circle 296 on inquiry card.

\bu can get your Electric Selectric here

GTE/IS Novar Selectric Terminals

MOO ELS AND PRICES:

MODEL 5541 (IBM 2741 Type Terminal, EBCD or Corres.

Code).

.$695

MODEL 5550 (w/built-in cassette drive for offline data storageor use as memory typewriter, EBCD or Corres. Code). . . $1195

MODEL 5560 (ASCII code w/cassatte drive). . $1295

I/O TYPEWRITER ONLY SPECIAL:

MODEL 725 IBM Selectric includes keyboard pickup switches,out-put solenoids, and magnet driver PCS to coordinate input/output signals. Requires +24V and +5V.

MECHANISM ONLY, cleaned and adjusted $375

CASE from terminal, with POWER SUPPLY. ........$ 75

A standard IBM model 725 Selectric Typewriter (or your own 15" carriage Selectric I or Selectric II)

is the heart of this off-lease batch-processing hard-copy I/O terminal. (Thousands were made for Sears

and other major companies). Printing speed is 15 characters per second. Data transfer rate between

terminal and CPU can be as fast as 280 cps (over 2400 baud) by means of the 350 character line buffer

and built-in digital cassette tape drive which stores data from the keyboard as typed or as transmitted

from a computer or another terminal,

FEATURES:* Available in EBCDic or IBM correspondence code versions with ASCII translation and

I/O driver program in 8080 assembly language • Microcomputer hardware interface is 10 wire EIA

RS232 connector cable between terminal and standard serial I/O cardelncludes complete documentation:

Operator and Service Manuals, schematics, interface instructions for microcomputer and software

listing of I/O driver and ASCII translation program* Optional Built-in 103 or 202 Modem available*

Typewriter can be serviced by any IBM technician (solenoids, switches and wires have been attached

to the bottom of the typewriter without physical alteration of the factory mechanism).

•See. PERSONAL COMPUTING, September 1978, "Techno Turkey and his Electric Selectric/' by Lloyd Prentice and

Peter Henry. Reference in this advertisement to PERSONAL COMPUTING or to Messrs Prentice or Henry does not imply

their endorsement of PACIFIC OFFICE SYSTEMS or its products.

ii i i ik I I ■

c5^ Y-VVV"

Call or write for details, quantity prices, catalog. 15 dayreturn privilege PLUS 90 day no charge replacement ofdefective parts. AH orders shipped from stock. No backorders, no substitutions. M/C & VISA accepted.

PACIFIC OFFICE SYSTEMS, INC.

2600 El Camino Real, Suite 502

Palo Alto, Calif. 94306

(415) 321-3866

Full documentation included PLUS interface instructionswhere indicated. All equipment is shipped insured FOBPalo Alto within 14 days after check clears or COCorder is received. Prices may change without notice.

POWER OP AMP

250mA oufput current capability. Operates on aslow as 3V, Input parameters are programmable forsystem optimizing. Electronic shut down allowsoutput to float. Packaged in 8 pin mini-dip.

LM13080N $1.94

Specs and applications 60

16K DYNAMIC RAM

Replace your 4K dynamics for memory expansion.

Super buy on this exact replacement for the 4116.

uPD416 (200nS). $20, 8/$144.00

uPD416 (300nS) $18, 8/$128.00

21L02-4 (450nS)

Special buy from major producer allows superpricing on these brand new prime memories!MM2102AN-4L $1.44, 64/$73.60

6502 uProcessor $10.95

CONNEpTiON DIAGRAMSTO-3 PACKAGE

'TOP VIEWt

10 AMP REGULATORJUST RELEASED78P05 is a 3 terminal, 5V, 10 amp regu-lator as easy to u»e as the 78H05 and otherTO-3 regulators. All the self protectionfeatures of me famous 78H05: thermal limit,current limit, low drop out voltage, inTO-3 steel package.78P05SC $12.95

Specs.

60c

1

mi-minc

7808 North 27th AvenuePhoenix, Arizona 85021

r

Cluroa card taiaphom onton (S2G mm.) will c*«cc*pt*d 9-6 30 P.M. MC*pi wMiund*.Td.phon. (602> 995-9352 No colltci clli plw.

D

GOLD

CHARACTERISTICS

ELECTRICAL

Curfrm rUiaif i*mp> 3

Intubtnn fit tituik r

Contact RrtwwKF

Dtrlrtlnt * ithtunin*VoiUffiRMSiCptmanif p> nferxbMECHANICAL FOR 1*2" (IS;BLADE

(0.56 S'pf«ut»n mar I

MATERIALS

tody Pw4*.ireGlut Urd irwrmnj4j>u f»(v*iirrCote Mac*

C*:Z5...pi*'r mrkrliinjli*Gcfctifey(hrr nwi. 000100 fi J

.125" x .250"

WRWnppotuMlhrtmiver** '

EDGEBOARD

n AulO.OWWirm)

CONNECTORS

Texoi lntrrum»nfi, world \*odw in m*tullurgfcaltecHnology, ii introducing itV rww improved H43conrwctor and TR1-TEK it proud to oftV it for tK«firit Hmo to our curfonwn. Th* H43 roprMontitho bmi value in ttto industry on *i» popularcontactor ftyla,

Pin grid t aatignad to fl» matt of rh« S-I00 bwmaohtnat met) a» Imtai, Vactor, Cromamco.Will not PitAltalrn

Haovy gold inlay givos you up to tovwt times tH*gold in ttu cirticol contact oraa at reduced cart.T.I. hot tHe technology and TRI-TEK hat T.I.Soldartail H435121-50 $3.59 lfV$32.00Wire wrap H435II1-50 $3.» 1(^132.00

Quantity pricing available

Z80CPU

Famous single chip uprocessor with all the powerof the 8080A plus 80 additional operations. Single+5V supply and single phase clock. Directly in-terfaces with standard static and dynamic RAMS.

280 CPU $20

Z80ACPU $28

Specs $1

Z80CTC

Programmable four channel device that provices

counting and timing functions for the Z80 CPU.

Z80CTC... ..$11.00

Z80ACTC $16.00

Specs $1

Z80 PIO

Parallel interface controller is a two port TTL com-patible interface with the CPU.

Z80PIO ... $n.oo

Z80APIO $16.00

Specs $1

25 Pin Data Connectors

DBC-25P (male) $2.19, 10/19.80

DBC-25S (Female) $3.19, 10/30.50

DB-51226 ..Hood $1.39

D20418 Screwlock assembly $1.19

PRECISION VOLTAGE REFERENCE.AD584 is a precision monolithic IC which has pro-grammable outputs of 10V, 7^5Vt 5V and 2.5V @.3% maximum errorl Full ~55 to +150°operation.

AD584JH (in 8 pin TO-5 can) $6.95

Spec sheets... 60

l£«f

mium ih,oping (

rttuidid

*"*"•'

*.«»..«,.

P1..W ,

.« ■«•« addf

«.

tor OPS t

nipping *n»

COD

ups

NOp.rcil dOCOD Add

HCOD■ M io of o*t

Any c

arrcipondanc* n

™*Z™

Ct.d Hit

MSASE

«*,'

wh

Cl»tm«

fot inoriasa*0 d*v> of MM

z

dam* pad m«t*ri»i

mu

•t t»

Any rifundi wii M by chaxfc, not cradit vouch**!,if w* thoutd o* temporarily out of *tock «n «n* .1

CI.im.fo. (MOCT.v«

crt rK.>m ot MfcM. Oal

0*1. A oXactlv* partt

US. Md CANADA ADO 5KOthor countriot »dd 15%

Irourwm ! w» <• not r«*onabla for )Mil .50 )

234

BYTE December 1978

Circle 376 on inquiry card.

<*JtAJU*StOJ2s

Incredible! but True w Precutwireis Cheaper than cutting your own!

Fast

Reliable

Economical

Catalog available on request.

■ No more cutting & stripping by hand• Good, clean, uniform strip

■ Cheaper than using bulk wire

PRECUT WIRE BULK WIRE

100 pes of 3" at $.82^31/4^/11. 50 ft. roll at $1.99 = 4$/ft.100 pes of 6" at $1.06 - 2*/H. 100 ft. roll at $2.95 - 3$/ft.Wire Kit #1 at $6.95 = 21/3«/ft.

# 30 Kynar stripped 1" on each end. Lengths are overallColors: Red.Blue.Green.Yellow.Black.Orange.WhiteWire packaged in plastic bags. Add 25C/length for tubes.

2% in.

3 in.

3'v in,

4 in.

4V? in.

5 in.5% in,

6 in

61/? in

7 in.

7 in

8 in.

m in.

9 in.9'^ in

10 in.

Add I. in.

100 500 1000 5000

.78 2.40 4.30/K 3.89/K

82 2.60 4.71/K 4.22/K

.86 2.80 5.12/K 4.55/K

90 300 5 52/K 4.88/K

94 3.21 593/K 5.21/K

.98 3.42 6.34/K 5.52/K

1.02 3 65 6 75/K 5 86/K

106 3 85 7,16/K 6.19/K

115 4 05 7.57/K 6.52/K

120 4.25 7.98/K 6.85/K

1.25 4 45 8 39/K 7.18/K

1.29 4 65 8 80/K 7.53/K

1.321.361.40

1.45

.10

4.855055 25551

.41

9,21/K9 62/K10.03/K10.44/K

82/K

7.84/K8.17/K8.50/K8.83/K

66/K

WIRE WRAP TOOLSIts ijLp

getting it for pJ.Cf^^

HOBBY WRAPModel BW 630 with

rw%rr W,RE K,T#1

tKct ($6.95 Value)

Batteries & Charger

WSU 30 Hand Wrap - Unwrap Strip Tool

WSU 30 M, for Modified Wrap

BT 30 Extra Bit

2.2" x 6.5"

SK 10

$16.50

SOLDERLESS

BREADBOARDS

INCLUDING

Over 100 pteces of precut wirem assorted lengths — FREE'

INTERCONNECT CABLES

Ribbon cable connectors for connectingboards to front panels, or board to board.

SINGLE ENDED DOUBLE ENDED

14 pin 16 pm 24 pin 14 pin 16 pin 24 pin

6 1 24 1 34 2 05 2 24 2 45 3 37

12 1 33 1 44 2 24 2 33 2 55 3 92

24 1 52 1 65 2 63 2 52 2 76 4 31

48 1 91 2 06 3 40 2 91 3 17 5 08

WIRE KITS

n r

#1 $6.95(2.2 */«.)

#2 $19.95(1.9 0/ft.)

250

3"

100 41/2"

250 2V2" 250 5"

250

3Y2"

100 5"

500 3" 100 %W

100

4"

100 6"

500 31/2" 250 6"500 4" 100 SW250 4Y2" 100 7"1-250 ft. Roll

#3 $23.95(1.7C/fL)

#4 $42.95(1.5 (/ft.)

500

21/2"

500

41/2"

1000

21/2"

1000

AW

500

3"

500

5"

1000

3"

1000

5"

500

3V2"

500

51/2"

1000

3W

1000

51/2"

500

4"

500

6"

1000

4"

1000

6"

Choose One Color or Assortment

WIRE WRAP SOCKETS

1-9 10-24 25-99 100-249 250-999 1K-5K

%

Spin"

14 pin '16pin '

18pm'20pin22pm"

.3535.37

.60

8490

24 pin 91

25pmstnp 1.25

28 pin .95

40 pin 150

333335

55

.78,85

84

105

89

1 40

313133

78

.95

84

1 30

2929.31

43.63

78

68

80.801 20

,252830

,40.59

70

64

70

76

1 05

.232729

375460

5965

.74.90

Gold 3-Level Closed Entry DesignEnd & Side Stackable All prices include gold

2-Level Sockets Available J

EDGE CARD

CONNECTOR

SALE!

44 Pin Solder Tail $1.75 $15/10100 Pin Solder Tail $3.50 $30/10100 Pin Wire Wrap $3.50 $30/10

ALL connectors include Gold.

100 pin connectors are on IMSAl. spacing.

J V

ME

La

IE

Lb

h

135 E. Chestnut St. #5 Monrovia, CA 91016 (213)357-5005

ORDERING INFORMATION

• Orders under $25 and COD s. add %2

• All others, shipped Ppd in U S via UPS

• For Blue Label (Air) or 1st Class, add $1

• We accept Visa & Mastercharge

• Most orders shipped same day

Dealer Inquiries Invited

Circle 297 on inquiry card.

BYTE December 1978

235

HEATHKIT

SOFTWARE DOCUMENTATION

WRITER

At Heath Company quality documentation is anintegral pari of tha final product. Sinca Haathit expanding in tha computar products araa,writart ara naadad to continua tha Haathtraditions in tha sof twara documantation araas.

We are seeking applicants with:

• An enthusiasm for personal computing

• A desire and ability to communicatesoftware concepts

• Approximately four semesters ofprogramming experience, includingBASIC, one other high level language(preferably PASCAL), and the equivalentof one semester of assembly language

• A degree is preferred, but does not haveto be in computer science

Haath offers a competitive salary with excellentfringe benefit*, challenging opportunity and apleasant work environment.

Send resume and salary requirementsOr phone collect to: „ _ _

H. T. CartonHEATH COMPANYnton Harbor, Michigan 49022(616) 982 3201

An Equal Opportunity Employer M/F

Circle 161 on inquiry card.

TRS-80 SOFTWARE

Moving Signboard

9.95

File Handling (16K RAM req.)

9.95

Loan Payment/Amortization

5.95

Prime Numbers

5.95

Buzzword

5.95

Day of the Week

5.95 i

Hamurabi

5.95

j Pollution (16K RAM req.)

5.95

Tic-Tac-Toe

5.95

Slot Machine (with graphics)

5.95

Petals Around the Rose

5.95 !

20% off on order of three or more

One each of all of the above

49.95

Advanced Amway Distributor

Business System

119.95

Streamlined Amway Distributor

Business System

49.95 l

Amway SA-1/SA-2R Verification

Program

9.95

Circle Enterprises

P. O. Box 546

Groton, CT 06340

DEALER INQUIRIES WELCOMED!

Circle 48 on inquiry card

.

TRS-SO OWNERS

IIIIIIIIIIIIUIIIIIIIIIIIIIIIIIIIIIIIIIIIIUIIIIIIIIIIIIIHII

STATISTICAL PACKAGE ON CASSETTE- ONLY $8,951! USER ORIENTED YET MORESOPHISTICATED THAN STATISTICAL PROGRAMS COSTING 3X AS MUCH! FULL EXPLANATIONS AND TABLES INCLUDED.

-ANALYSIS OF VARIANCE- 3, 4, 5, or 6 groups!-CORRELATION- (also provides N, means, & van.)-T TESTS— 3 types - each gives t, F, Ns, DFs

Means, & Variances!-ANALYSIS OF COVARIANCE-2 oroup design-MEAN, VARIANCE, STANDARD DEVIATIONEACH PROGRAM RUNS IN 4K!

-SPECIFY LEVEL I OR II

IllllllllllllltlllllllllllllUIIIIIIIIIIIIIIIIIIIIIUIIIIIIII

NEW!! THE FOLLOWING PROGRAMSREQUIRE 16 K Level II:

DISASSEMBLER - Shows machine code StS.BRIDGE GAME - Play bridge/Si5.GAMEOFLIFE- Dazzling displays $5.

Programs & Systemi developed on request.

M, M, &S SOFTWARE16 MARILYN LANEWESTBURY, NEW YORK 11590

NY Stete residents add 7% sales tax

TRS-80 Z-80 8080

Professionally written softwarefor the serious user.

Subroutines and interactiveprograms from $5 in the fol-lowing areas:

MathFinanceStatisticsNavigationReal EstateMusic Analysis

ScienceAstronomyElectronicsInvestmentsAmateur RadioDigital Design

Music Synthesis Utility Functions

Performance Guaranteed,Write for free catalog.

BENCHMARKCOMPUTING SERVICES

P. O. Box 385-B1Providence, Utah 84332

Circle 31 on inquiry card.

RS232C Computer CompatiblePaper Tape Transmitter/Model 612

Stops and starts on character at all speeds,uses manual control or X-on, X-off 90-260volt, 50-60 Hz power. 50-9600 baud, upto 150 char/sec synchronous or asyn-chronous; gated internal or external clock,RS232C current loop or parallel output,reads 5-8 level tape, 7-11 frames percharacter, even or odd parity. Desk top orrack mount.

Addmaster Corporation

416 Junipero Serra Drive

San Gabriel, CA 91776

(213)285-1121

Telex 674770 Addmaster SGAB

Circle 6 on inquiry card.

Get your "computer nut'the perfect gift. Theoriginal single boardcomputer (an abacus)comes in a display casewith "Break Glass inEmergency"printed onthe front.

♦♦♦♦♦—h-

♦♦—»»»u

-♦♦

Send $14.95plus $2.50postage and handling to:

Intelligent Design

2535 Hayward Drive

Santa Clara CA 95051

TRS-80

16K MEMORY EXPANSIONKIT.. $ 79.95

DISK DRIVES $ 399.00

CENTRONICS 779 TRACTORPRINTERS $1179.00

TRS-80 & PET SOFTWARE.SEND FOR FREE CATALOG.

A

PPARAT, INC.

6000 E. Evans Ave. Bldg. 2Denver, CO 80222303-758-7275

Circle 9 on inquiry card.

TH€

COMPUTERHARDWARESTORE INC.

K1M-I.OAECYBERNEX. JIM PAK

WithALPHA-1 CASSETTE SYSTEM

16 BitsALPHA MICROTECHNICO STARTER SYSTEM

Catalog Available

3 FRANKLIN ST .ALEX , VA,

Circle 71 on inquiry card.

New S-44E Bus Microprocessor Modulas-Compatible with allAtwood and S-44 modules but feature 16 addran lines.On board address decoding. All bare board* $22.50.

• 8K RAM Board (2114i) • Hi Resolute Video (6845)•CPU Board (6502/6802) •Color Video (6847)

• Real-Time Clock

S-44 Microprocessor Card Price List

free

S-44 Microprocessor Card Manual

$3.70

Ohio Scientific Challenger H, 111 Manual

9.00

PET Technical Manual (Our Own) with Schematics

11.00

KIM 1 User Manual

695

KIM Katalog (Our Own)

free

KIM Komputer Enclosure

59.95

PAL Computer Technical Manual

7.25

Technical Book Discount Price Lilt

free

Computer Surplus Items Price List

free

Universal 16-bit Memory Brochure

free

2-Way Radio Price List

frea

6500, 6800, and memory tC Price Lilt

fnta

Repairs KIM, SWTP, or PET Repaired for

52.50

Ohio Scientific Special

New Challenger IP with BASIC in ROM

329,95

Ohio Scientific Price List

free

Wanted: 6800 and 6502 Software

Computer Class (Ohio Scientific)

Fri nita

Wind Generators and Solar Celts Catalog

2.00

SILVER SPUR .(714)627 9366

Electronic Communications Co • visa

P. O. Box 366, Chmo. CA 91710 • Mastercherge

or Visit Retail Store • Calif Residents Add13562 Central Avenue 6% Sales Tax

iimiuuiiiiiiiiiur

Circle 212 on inquiry card.

Circle 181 on inquiry card.

Circle 327 on inquiry card.

VISIBLE

OR

INFRA RED

USED FOR CHARACTER

RECOGNITION FOR

COMPUTERS WITH

EXTERNAL CIRCUITS

MAY BE USED IN

A VACUUM,UNDERWATER,HIGH ALTITUDE

IN MAGNETIC ENVIRONMENTBECAUSE THERE IS NO

HIGH VOLTAGE ORMAGNETIC DEFLECTION

MINATURE SOLID STATE

202 VIDEO CAMERA KIT

FEATURING A. .100 x 100 BIT SELF SCANNING CHARGED COUPLED DEVICE

THIS UNIQUE UPDATED CAMERA KIT

FEATURES THE FAIRCHILD CCD 202C IMAGE SENSOR

ADVANTAGES

• IN THE FUTUREWE WILL SUPPLY A

COMPUTER VIDEO INTERFACE CARD

• All clock voltages operate at 6Vreguiring no adjustments

• Higher video output signal

• We supply the power board, so onlya 5V 1 Amp power source is needed

• The circuitry has been simplified foreasier assembly

• Two level TTL output is supplied forinterfacing

FEATURES

• Sensitive to infra redas well as visible lightMay be used for IR surveillancewith an IR light sourceExcellent for standardsurveillance work, becauseof light weight and small sizeAll components mounted onparallel 33/4"x61/2" singlesided boardsTotal weight under 1 lb.

We supply all semiconductors, boards, data sheets,diagrams, resistors and capacitors, and 8MM lens.Sorry we do not supply the case, batteries and 5V supply.

$34900 kit

Add $75.00 to assemble and testAdd $2.00 Postage and Handling

UNIVERSAL 4Kx8 MEMORY BOARD KIT

$69.95

32-2102-1 fully buffered. 16 address lines, onboard decoding for any 4 of 64 pages, standard44 pin buss, may be used with F-8 & KIM

EXPANDABLE F8 CPU BOARD KIT$99.00

featuring Fairbuij PSU 1 Kot static ram, RS 232interface, documentation, 64 BYTE reqis.er

4001400240064007400940104011401240134014401540164017

C/MOS (DIODE CLAMPED)

18 4019

18 4020

96 4021

18 4022

3 7 4023

3 7 4024

.18 4025

18 4027

29 402B

75 4029

75 4030

39 4035

90 404 2

.90 4046

404990 405090 405390 4055

37 4b?0

.80 74CO0-

.95 74C02-

33 74C04-

9 7 74C08-

65 74C10

_ 1 3S 74C42

35 74C73

35 74C74

1 10 74C83-

1 25 74C86

70 74C93 -

18 74C151

97 74C160

fO 74C161

22 74C174

22 74C175

24 74C193

22 74C901

27 74C9028574C914 '

MVUKPHOM83SJ3

PRINTED CIRCUIT BOARD

7 WATT LD 65 LASER DIODE IR SR95

2N382QPFET $ 45

2N 5457 NFET $ 45

2N2646 UJT $ 45

ER 900 TRIGGER DIODES 4 S1 00

.-..-- . ' ■■■ t,-;

MINIATURF MULTI-TURN TRIM POTS100, IK, 2K, 5K, 10K, 20K, 50K, 100K,200K, 500K, IMeg, 2Meg, $.75 each 3/$2.00

CHARGED COUPLE DEVICES

CCD 201C 100x100 Image Sensor $95.00

CCD 202C 100x100 Image Sensor . . , . .$145.00

VEBIPAX PC BOARD $4.00

This board is a 1/16"single sided paper epoxyboard, 4VJ"x6y." DRILLED and ETCHED whichwill hold up to 21 single 14 pin IC's or 8.16 or LSIDIP IC's with busses for power supply connector.

rRANS . S 50

RED, YELLOW, GREEN or AMBER

LARGE LED's.2" 6/$1.Q0

TIL-11SOPTO-ISOLATOR $ .75

MOLEX PINS 100/Sl.OO

10OO/S8 00

1WATTZENERS 3 3,4.7,5.6,9 1,10,

12, 15. 18. or 22V 6/$1.00

MC6860 MODEM CHIP $9 95

MCM 6571A 7 x 9 character gen ... $10.75

Silicon Power Rectifiers

C«VS i a i '. %i

4 000MH/5DOOMH/6 000 MM/8 0OU MIV- 10 OOP MM/

RIBBON CABLElAT (COLOR CODED)

#30WIRE26 cond. - .50/per foot40 cond. - ,75/per fool50 cond. - .90/per foot

CTS 206-8 Piqlii position dip switch . . . . S1.60C PS 206 4 four position dip switch . . .$1.45

LIGHT ACTIVATED SCH j

TO 18 ?00V 1 A $ 70

SILICON SOLAR CELLS2V*" diameter .4V at 500 ma $4.00

FND 359 C.C. A" $ .50 LED READOUTS

FCS8024 4 diqn DL-704 C.A. .3" $ .

C.C 8" tl.splay $5 95 DL747CA 6" $1

FND 503 C C 5" $ 85 FND 803 C C 8" $1 I

FND 510 C.A 5" $ .85 FND 810 C A 8,r $1.!DL 704 3 ■ C.C $ 85

10 50 16.50

1000 20 45 1 10 7 75 12 50 2000SAD 1024 a REDICON 1024 stage analog ■•Bucket

IN 4148 UN914

RS232 DB 25P maiP

CONNECTORS OB 25S femaleHOODS

$2.25

$2.95

. $1 00

3G9K .

723 ...LM 376 .320T 12, 15Or 24V

REGULATORS

$ .95

340K 12,15

or 24V. .... $ 95340T-5. 6, 8, 12

15.18 oi 24VS 9578 MG ... .SI.35

TRANSISTOR SPECIALS

2N6233-NPN SWITCHING POWER $195MRF 8004 a CB RF Trans.stor NPN $ 75

2N3772 NPN Si TO 3 $ 100

2NT546PNPGE TO-3 $ .75

2N4908 PNP S. TO 3 S 1 00

2N6056 NPN S- TO 3 D.n l.mium S 1 707N5086 PNP Si TO 92 4 $ 1 00

2N3137 NPN Si RF $ .55

2N3919 NPN Si TO 3 RF S 1 50

2N1420 NPN Si TO 5 , . . . 3/S 1-00

2N3 76 7 NPN S. T O G(i S 70

2N2222 NPN Si TO 18 5S 1 00

2N3055 NPN Si TO 3 S .50

2N3904 NPN Si T0 9? 6/5 1.00

2N3906 PNP Si TO 92 6/S 1.00

2N5296 NPN S. TO 220 S 50

2N6109 PNPSi TO220 S .55

2N3j638 PNP S. TO 5 5 S 1 00

TTL IC SERIES7445„ 65 ]$)Vi- J

7400- 13 7446- 66 741&4- 94

7401- .13 7447- 58 74155- 5B

7402- .13 7448- 68 74157- 55

7403- .13 7450- 15 74161- 55

7404- .15 7472- 25 74162 - .79

7405- .13 7473- 28 74163- .55

7406- .16 7474- 28 74164- 85

7407- .20 7475- 45 74(65- 95

7408- IB 7476- .30 74170- 1 68

7409- 18 7480- 31 74173- 1 20

7410- 13 7483- 65 74174- 95

7411- .18 7485- 87 74175- 85

7412- .13 7486- 28 74176- 75

7413- .36 7489 1 25 74177- 75

7414- .60 7490- 42 74180- .65

7416- .22 749)- 58 74181- 190

7417- .25 7492- 43 74190- 1007420- .13 7493- 43 74191- 1.00

7425- 25 7494- 67 74192- 79

7426- 22 7495- .65 74193- 79

7427- .19 7496- 65 74194- 807430- .13 74107- .28 MM* 607432- .22 74121- .29 74196- 867437- .21 74122- .38 74279- 557438* .21 74123 .45 74367- 50

7440- .13 74125- 40 75325- 1.60

7441- .70 74126- 40 75491- 50

7442- -37 74150- 94 75492- 50

DATA CASSETTES 1/2 HR $.95

22/44 Pin Solder Tail .156" Conn. $1.95

MM 5387AA new clock chip which will directlydove LED's 12/24 hrs., 1 supply S< alarm $5.95.

NO. 30 WIRE WRAP WIRE SINGLESTRAND 100' $1.40

ALCO MINIATURE TOGGLE SWITCHtSMTA 106 SPOT S .95

MTA 206 DPDT S 1 70

MTA 206 P DPDT CENTER OFF $ 185MSD 206 P DPDT CENTER OFFLEVER SWITCH $ 1.85

Full Wave Bridges

DIP SOCKETS

8 PIN .17 :'4 PIN .3514 PIN .20 ?8 PIN 4fj16 PIN .22 40 PIN .60

SANKEN AUDIO POWER AMPS

Si 1010 G 10 WATTSSi 1020 G 20 WATTSSi 1050 G 50 WATTS

$ 7.8

$15.70

$28.50

TANTULUM CAPACITORS

22UF 35V 5 SI 004 7Uf 35V 5 SI 0068UF 35V 5 SI 001UF 35V 5 SI 002.2 uf 20V5 SI 003 3UF 20V 4 S1 004.7UF 15V 5*Si.00

74LSSERIES

6 8Uf 35V 4 SI 00

10UF 10V $ .25

22UF 25V S 40

V5UF 35V 3/S1.00

30UF GV 5/$1 00

4 7UF 20V S .35

68 UF 15V S .50

100 UF 10V S .40

• LSJ3 » )«IS?SJ

LINEAR CIRCUITS

LM 1Q1 T5

LM 301.748 2b

LM307 30

LM 308 75

LM3B?

LM 3H7

LM537

LMSS3

LM555

LM 556

NE540L

560

565

Terms: FOB C*

Send Check or Monty Order

include Poet

Order 15.00, C

SOLID STATE SALES

P.O.BOX 74B

SOMERVI LLE, MASS 02143 TEL. (617) 547

WE SHIP OVER 95%

OF OUR ORDERS THE

DAY WE RECEIVE THEM

Circle 340 on inquiry card.

BYTE December 1978

237

SURPLUS ELECTRONICS

ASCII

ASCII

IBM SELECTRIC

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 • ComponentsMany other items

Write for free catalogWORLDWIDE ELECT. INC.130 NORTHEASTERN BLVD.NASHUA, N.H. 03060Phone orders accepted using VISAor MC. Toll Free 1-800-258-1036In N.H. 603-889 7661

COMPUTER MARTof NEW HAMPSHIRE, Inc.

* SPECIALIZING IN BUSINESS &AND PERSONAL COMPUTERS ^*

DATA GENERAL microNOVA®XITAN GENERALAPPLE II

S-100 Bus ProductsSOFTWARE currently available:

AR, GL, AP, Inv., Payroll.

Word Processing, and Dental

Office Manager.

a

170 Main StreetNashua, NH 03060603/883-2386

rrncroNOVA* ,s a reguterediradema»k o< Oata Genial Corp

□

LIMITED OWHILE SU

ALL NEW!; Mini Discs $3.70 ea. in boxes of 10; North Star Check Balancing Pro-

[ gram $50.00

Two-tier walnut formica enclosurefor S. A. 400 Shugart $39.95

A Horizon — 2

R Centronic 779

C Hazeltine 1500

Dl Hazeltine 1400

A,B&D:$3,852

A,B&C:$4,150

I We also stock Imsai, Seals, Okidata,[ ADM-3A, Xitan and Cromemco.> Mail order only.

Circle 395 on inquiry card.

Circle 76 on inquiry card.

TORA SYSTEM29-02 23rd AvenueAstoria, NY 11105

(212) 932-3533

Circle 346 on inquiry card.

CATCHAPULSEII

^ 3 LOGIC PROBE^

circuit detection

Replaceable tin fi cord

• U.gh input impedance

10 Nsec SPEED AT 4 to^^v . Muhl.,.15VLEUELS 0Nlv$4495^^^

•etomt (Calit residents add

6% sales tan) to

ELECTRONICS

19299. San Diego CA92119 (714)447-1770

Circle 23 on inquiry card.

EPROM PROGRAMMER

, 4 ^

Software available far F-8,8085, 2-80, 6502, NIM-I, 1S02.

The EP 2A-79 wilt program the 2704. 2708,TMS 2708. 2758, 2716, TMS 2516, TMS 2716,TMS 2532, and 2732. PROM type is selected bya personality module which plugs into the frontof the programmer Power requirements are 11 5VAC, 50/60 HZ at 15 watts tt is supplied with a36-inch ribbon cable (14 pin plus) for connectingto microcomputer Requires 1 ''i I/O ports.Assembled and tested $145, Ptut $15-25 foreach personality module. Specify software.

OPTIMAL TECHNOLOGY, INC.

Blue Wood 127, iarlysville, Vo. 22*36Phone 804-973-5482

^p—«*4fr ■» ■ wtj/btm

n

TTY's, CRT's, Modem's,

mini-microcomputers -

whatever the need,

rely on usf < ►

TERMINAL SYSTEMS INC11300 Harland StreetN Hollywood, CA 91605(213) 769-6772(714) 738-4444(415)573-7723(800) 423-2449

Circle 377 on inquiry card.

Datapoint CRT Terminals

SS**r

Fully-Assembled — Guaranteed

#3360 $649.50

• Add $15 packing refurbished

• Guaranteed • Shipment FOB, no waiting

• Add $35 for scrolling mod, or do It yourselfNOW—Power your KIM-I or other smail processor

from these terminals. Up to 2 Amps at 5.14, 25 volts.

Model 3360 speeds from 300-4800 Baud, numerickeypad, cursor controls, Edit, Block-Transmit, searchmodes. ASCII Keyboard with codeable options.Green phosphor 24 82 Ch. lines, addressable cursor;RS-232 serial interface; other speeds availableManual $10, Cable kit $9.95. Datashare/IBM com-patible version $649.50. • Model 3000 $595.00

M-33 KSR Teletypes $495.00-

Cat! us for service on CRTs, micros, main-fraiies.

TELECOMMUNICATIONS SERVICES CO.

Box 4117, Alexandria, Va. 22303703-683-4019 / TLX 89-823

CITS SPECIALS

OF THE ■ M\MONTH ■ 1

• Floppy Kit ^^^

SA 801 floppy (8") & disk cont.

kit (S-100) $599

• Add On Floppy Drives

SA 8O0/1 (8") floppy $469

SA 400 mini floppy $285

• Centronics 779 printer $999

• Miscellaneous

CP/M Operating System/Manuals... $898" Memorex Diskettes

(IBM comp.) $3.50

8" Verbatim Diskettes

{IBM comp) $3.99

4" Diskettes $3.39

16k RAM chips $9.75

Pwr Supply cabinet (mini floppy)... $79Pwr Supply cabinet (floppy) $225

reOVIPLTER INTERMCE TECHNOLOGY

Peripheral Products Division2080 South Grand, Grand Centre Santa Ana, CA 92705 |

Circle 74 on inquiry card.

THE

ORIGINAL

LANCASTER

• PASCAL*

"Imported from England"For your micro-NOVA®, NOVA®or ECLIPSE® using RDOS or DOS

For sensationally low prices$70 binaries$140 binaries & sources

Contact Gamma Technology, Inc.

800 Welch Rd.r Palo Alto, CA

94304

I

lircle 284 on inquiry card.

Circle 373 oh inquiry card.

Circle448 on inquiry card.

QUEST 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, Tiny Basic, AscilKeyboards, video character generation, etc.The Super Ell includes a ROM monitor for pro-gram loading, editing and execution with SINGLESTEP (or program debugging which is not in-cluded in others at the same price. With SINGLESTEP you can see the microprocessor chipoperating with the unique Quest address anddata bus displays before, during and afterexecuting instructions. Also, CPU mode and in-struction cycle are shown on several LED indica-tor lamps.

An RCA 1861 video graphics chip allows you toconnect to your 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, input, memory protect,

memory select, monitor select and single step

Large, on board displays provide output and op-tional high and low address. There is a 44 pinstandard connector for PC cards and a 50 pinconnector for the Quest Super Expansion Board.Power supply and sockets for all IC's are in-cluded in the price plus a detailed 90 page instruc-tion manual.

Many schools and universities are using theSuper Elf as a course of study. OEM's 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 Hardwood Cabinet with drilledand labelled front panel $24.95. NICad BatteryBackup Kit $4.95. All kits and options also comecompletely assembled and tested.Questdata, a 12 page monthly software publica-tion for 1802 computer users is available by sub-scription for $12,00 per year.

Tiny Basic for ANY 1802 System

Cassette $10.00. On ROM Monitor $38.00.Super Elf owners, 30% off. Object code listing orpaper tape with manual $5.50.Original ELF Kit Board $14.95.

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 Elf. The board includes slotsfor up to 6K of EPROM (2708, 2758, 2716 or Tl2716) and is fully socketed ($12.00 value).EPROM can be used for the monitor and TinyBasic 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, (relocatable cassette file)another exclusive from Quest. It includes registersave and readout, video graphics driver withblinking cursor and block move capability. TheSuper Monitor is written with subroutines allow-ing users to take advantage of monitor functions

simply by calling them up. Improvements andrevisions are easily done with the monitor. If youhave the Super Expansion Board and SuperMonitor the monitor is up and running at the pushof a button.

Other on board options include Parallel Inputand Output Ports with full handshake Theyallow easy connection of an ASCII 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. A Godbout 8K RAMboard is available for$127.95. Parallel I/O Ports$9.85, RS 232 $4.50, TTY 20 ma l/F $1.95,S-100 $4.50. A 50 pin connector set with ribboncable is available at $12.50 for easy connectionbetween the Super Elf and the Super ExpansionBoard.

The Power Supply for the Super Expansion Boardis a 5 amp supply with + 8v ± 18v + 12v - 5v.Regulated voltages are +5v & +12v $29.95.Deluxe version includes the case at $39.95.

P.O. Box 4430X Santa Clara, CA 95054

*^^^^For will call only:(408) 988-1640Amu^^^mJk 2322 Walsh Ave.

Q

Hwror will call only:l*»woi soo-iotu■k 2322 Walsh Ave. ^

'ELECTRONICS

CLOCK MODULES Complete alarm clocks

ready to hook up with transformer and

switches Very compact with .50" and

74WTTL

LM340T-1B

1 10

CD4511

94

8212

2.90

84- digitsMA1002A, CorE SO" 8 95

7400N

.17

LM340T-24

1.10

C04515

2.52

8214

8.00

74<SN

.17

LM343H

450

C04516

1.10

8216

2.90

102P3 Trmrformer 2 25

7404N

19

LM370

1.15

C04518

102

8224

2.90

MA101BA. C or E 84 11.95

7409N

.23

LM377

4.50

CO4520

1.02

8226

5 35

102P2 Jrm^tmm 2 25

7410N

.17

LM379

50O

C04527

1.51

8251

8.50

Special transformer and Hi

w.moitiK 2.95IU10Q3 car moduli .3"

7414N

63

LM380N

1.00

CD452B

79

8253

10.00

7420N

.17

LM381

160

CD4553

5,75

8255

9.25

7422N

1.39

LM382

160

CD4566

2 25

8257

19.50

7430N

20

LM703H

.40

CD4583

4.50

8259

19.50

7442N

50

LM709H

.28

CD4585

1 10

COP1802CD

19.95

green flu or display 15.95

7445N

69

LM723H'N

50

CD40192

300

CDP18020

25 00

RESISTORS v< watt 5%

7447N7446N7450N7474N

60.69

.17.29

LM733NLM741CHLM741NLM747WN

67.352562

74CO074C0474C1074C14

2833

.282.10

CDP1861882068506502

12.969.9512.9512.50

10 per type 03 1000 pa/type 01225 per type .025 350 piece pack100 per type .015 5 per type 6.75

7475N

49

LM748N

35

74C20

jjj

KEYBOARDS

7485N

88

LM1303N

82

74C30

28

iC SOCKETS

56 key ASCII keyboard kit 162.50

7489N

2.00

LM1304

1.10

74C48

1 95

SoMwTto LM

Futty assembled 72.50

7490N

.43

LM1305

1 27

74C74

75

PIN 1UP PIN

1U?

53 key ASCII keyboard kit 55.00

7492N

.43

LM1307

2.00

74C76

1.40

8 .15 22

,30

Fully assembled 65.00 Enclosure 14.95

7493N

.43

LM1310

2.75

74C90

115

14 .18 24

.35

LEDS

Red T018 .15Green. Orange. Yellow T016 .20Jumbo Red .20Green, Orange, YeHow Jumbo 25Cllallte LED Mounting Clips 67$ 1.25(specify red, amber, green, yellow, dear)

7495N

.69

LM1458

.47

74C93

1.40

16 .20 28

.42

7410W74107N

.90.29

LM1800LU1812

1.75750

74C15474C160

3.00

1.44

18 .27 3620 .29 40

58.57

74121N74123N74125N74145N

.3459.39.69

LM1889LM2111LM2902

LM3900N

3001.751.5060

74C17574C19274C22174C90S

1.35

1.652.003.00

3 level win wrap goldUptn 25 16 pm 27' l*vtl 14 pin ww .20

741MK

95

LM3905

175

74C906

.75

WIDE WRAP LEVEL 3

CONTINENTAL SPECIALTIES la stock

741S1N

69

LM3909N

.61

74C914

1 95

PIN PIN

Complete knt ol breadboard test equipMAK-1M 1 *«rl Fteo. Ct. $121.15

74154N

1.00

MC145SV

.50

74C922

5.50

14 25 24

86

74157N74161N

69.87

NE540LNE550N

2.8965

74C92374C925

5,508.95

16 .27 28

18 57 40

1 001.23

OK WIRE WRAP TOOLS Hi atedt

74162N

•7

NE555V

43

74C926

6.95

Portable MuHmatar $18 00

74163N

.87

NE556A

79

74C927

695

UAflT'RFO

DIGITAL THERMOMETER $48 50

74174*1

.96

NE565A

1.00

AV5-1013

5.50

Ball oper General purpose or medtcal32°-230°F Disposable probe cover

74175N

90

NE566V

1.50

INTERFACE

AY5-1014

7,50

74190N

1.15

NE567V

1.20

8095

.85

3341

6.95

*.2° accuracy. Comp. Assy, in

741S2N

.87

NE570B

5 00

8096

.65

74133N

.85

NE5716

5.00

3097

.65

7422 IN

1,55

78L05

.60

B09B

65

1702A

3.95

COMPUTER WARD KITS

74298N

1.65

78L08

60

8T09

1.25

N82S23

2.95

8K RAM Board Kit $134.95

7438SN

.66

79L05

70

8T10

450

N82S123

3.50

4K EPROM Kit 114.95

74366N

66

mm

.85

8T13

3,00

NS2S126

3.75

1/0 Board Kit 44.50

74367N

.66

75108

1.75

8T20

5.50

N82S129

3.75

Extender Board w/connector 12.50

75491CN

.50

8T23

3.10

N82S131

3.75

Video Interlace board kit 125.00

T4LM0 T7L

75492CN

55

BT24

3.50

N82S136

8.75

16K EPROM board kit Wg PROMS 74.50

74LSD0N

25

75494CN

89

BT25

3.20

N82S137

8.75

16K Static RAM board kit 395.00

74LS02N

.25

8T26

1 69

2708

12.50

Narft Star Repay Uak Kit $665 00

Additional Drive Kit 415.00

74LS04N

25

AMD COHVERTEH

8T28

2.75

DM8577

2.90

74LS05N

.25

S03SB

4.50

8T97

1.69

8223

2.90

SPECIAL PRODUCTS

MM5865 Stopwatch Timer 9.00PC board 7 50SwttdMt Mom Pushbutton 273 pos slide .25Encoder HD0165-5 6.953 Digit Universal

74LS08N74LS10N

.25.25

8700CJ8701 CN

13.9522.00

8T98

1.69

2716T12716 Intel

22 5048 00

74LS13N

40

8750CJ

13.95

MOS'WFHORY

MM

74LS14N

.90

LO130

9.95

2101-1

395

CRYSTALS

74LS2DN

25

9400CJV/F

7.40

2102-1

.95

1 MHZ

4.50

74LS22N

.25

ICL7103

9.50

2102AL-4

1.60

2 MHz

4.50

74LS28N

ICL7107

14.25

21F02

1,25

4 MHz

425

74LS30N74LS33N74LS38M

.2539

.30

CO34001 Fair

50

2104A-4

2107B

2111-1

4954.953.75

5 MHz10 MHz18 MHz

4.254.25390

Operates 5-18 Volt DC to 5 MHztyp. 125' LED display 10.50Volet actuated twtek .50

74LS74N

.35

CD4000

.16

2112-2

3.95

20 MHz

3.90

74LS75N

.47

CO4O01

21

2114

8.50

32 MHz

3.90

Paratronics 100* Logic

74LS90N

.51

CD4002

.21

4116

17.95

32788 MHz

4.00

Aoatyzar Kit $22* 00

74LS93N

.51

C04006

1.10

25136

6.30

1 8432 MHz

4.50

Model 10 Trigger

74LS95N

1 89

CD4O07

.21

21L02-1

1 49

3.5795 MHz

1.20

Expander Kit $229 00

74LS107N

.35

CD40O8

.21

MM5262

.40

2.0100 MHz

1.95

Mode! 150 Bus

74LS112N

35

CD4009

39

MM52B0

3.00

2 097152 MHz

4.50

Grabber Kit $369 00

74LS113N

.35

C04010

39

MM5320

9.95

2.4576 MHz

4.50

TRANSFORMERS

74LS132N

.72

CD4011

21

MM5330

5.94

3 2768 MHz

4.50

6V 300 ma 3,25

74LS136N

.35

CD4012

21

PD411D-3

400

5 06S8 MH;

4.50

12 VoK 300 ma transformer 1,25

74LS151N

.67

CO4013

36

PD4110-4

5.00

5 185 MHz

4.50

12 6V CT 600 ma 3,75

74LS1S5N

67

CO4014

86

P510U

13.95

5.7143 MHz

4.50

12V 250 ma wall plug 2.9512V CT 250 ma wall plug 3 50

74LS157N

.67

C04015

86

4200A

9.95

6.5536 MHz

4.50

74LS162N

.91

CD4016

.36

82S25

2,90

14 31818 MHz

4.25

24V CT 400 ma 3 95

74LS163N

.91

CD40J7

.94

91L02A

1.75

18 432 MHz

4,50

10V 1.2 amp waN plug 4.85!8V 6 amp 1295

74LS174N

95

CO4018

.94

HO0165-5

6.95

22.1184 MHz

4.50

74IS190K

108

CD4019

,21

MM57100

4.50

74LS221H

1.95

CO4020

1 02

GIAY38500-1

995

CONNECTORS

44 pirtBdoe100 pin edge

DISPLAY LEDS

74LS258N

67

CD4021

1 02

MCW6571A

9.95

2.00

4.50

MAN1 CA 270 2 90

74LS367N

.89

C04022CD4023

.86

21

9368410D

35010 00

MAN3 CC 125 39MAN72/74 CA/CA .300 1.00

UKAft

CD4024

.75

416

16.00

100 pin edge WW 4.50

DL704 CC .300 1.25

CA3045

90

C04025

21

DL707/OL7O7R CA .300 1 00

CA3046

.67

CD4026

1.51

CLOCKS

KEYHAHD ENCODERS

DL727.728 CA/CC .500 1.90

CA3081

1 80

CD4027

36

MU5309

3.00

AY5-2376

$12 50

OL747/750 CA/CC 600 1 95

CA3082

1.90

CO4028

.79

MM5311

3.60

AY5-3600

1350

DL750 CC .600 1 95

CA3089

2.95

CD4029

1 02

MM5312

4.80

74C922

550

FR0359 CC .357 .70

LM301 AN/AH

.35

CD4030

.21

MM5.il 3

3.60

74C923

5.50

FND5O0/507 CC/CA .500 1 35

LM305H

87

C04035

1.02

MM5314

3.90

HD0165-5

8.95

FND5O3/510 CC/CA .500 90

LM307N

35

CD4040

1.02

MM5315

4.00

FND8OO/807 CC/CA 800 2 20

LM308N

89

CD4042

.71

MM5316

5.00

IC Te«t Cllpt

3 digit Bubbte 60

LM309H

115

CD4043

63

MM5318

3.60

1

11

4 digit bubble .80

LM309K

95

CD4044

63

MM5369

2.10

Red 56

.47

068 Fluorescent 1 75

LM311H/N

90

CD4046

1.67

MM5841

14.45

Black .55

.47

DG10 Fluorescent 1.75

LM317T/K

292

C04049

.36

MM5865

795

5 digit 14 pin display 1.00

LM318

1 35

C04050

36

CT7001

5.80

I«rtr8043

1450

NSN69 9 digit display 60

LM320K-5

1.20

C0405I

1.13

CT7002

8.95

comp w spec sock

7520 Oatrex ohotoceus .39

LM323K-5

895

C04060

1.42

CT7010

8,95

TIL311 Hex 9.50

LM320K-12

1.35

CD4066

.71

CT7015

7.25

TRANSISTORS

COMPUTER ORAM CAPS

LM320K-15

1.35

CD4068

.40

MM5375AA/N

3.90

2N1893

.40

1600 mtd 200V 4.50

LM320T-5

1.60

CO4069

40

MM5375AB/N

4.90

2N2222A

.18

2000 mtd 45V 2 50

LM320T-8

1.60

C04070

40

7205

16.50

2N2369

.30

3200 50V 2.50

LM320T-12

1.50

CO4071

,21

7207

7.50

2N2904A

.20

5500 25V 2 50

LM320M5

1.60

CD4072

.21

7208

15.95

2N2907A

.25

5800 40V 300

LM324N

1.15

CD4073

.21

7209

4.95

2N3053

.40

6100 40V 3.00

LM339N

1.55

CD4075

.21

DS0026CN

3.75

2N3638

.25

6100 50V 3.00

LM34QK-5

1.10

CO4076

1.75

OSOOSSCN

3.75

2N3643

.25

7700 50V 2.50

LM340K-8

1 10

C04078

40

MM53104

2.50

2N3904

.18

8000 55V 2.50

LM340K-12

LM340K-15LM340K-24

1.101.101.10

C04081CO4082

C04116

.21

.21.47

2N39062N30552N4400

.18

6925

9400 65V 3.0010000 20V 25012000 30V 3.50

6800

17.50

LM340T-5

1.10

CD4490

5.50

6802

24.95

2N4401

.75

35000 25V 5.00

LM340T-8

1.10

C04507

1.00

S080A with .lata

8.95

2N4402

.20

55000 25V 5.00

LM340T-12

1 10

CD4508

4 25

8085

27.00

TIP31

.60

82000 15V 6 00

LM340T-15

1.10

CD4510

1 02

280

29 95

TIP33A

1.00

160000 10V 6 00

Auto Clock Kit $15.95

DC dock with 4-.50" displays. Uses NationalMA-1012 module with alarm option Includeslight dimmer, crystal timebase PC boards. Fullyregulated, comp. instructs. Add $3.95 for beau-tiful dark gray case. Best value anywhere

RCA Cosmac VIP Kit 229.00

Video computer with games and graphics.

Not a Cheap Clock Kit $14.95

Includes everything except case. 2-PC boards.6-50" LEO Displays. 5314 clock chip, trans-former, ail components and full instrucs. Greenand orange displays also avail. Same kit w/,60"display!. Red only. $2195

60 Hz Crystal Time Base Kit $4.40

Converts digital clocks from AC line frequency tocrystal time base. Outstanding accuracy Kit in-cludes: PC board, MM5369, crystal, resistors,capacitors and trimmer.

Digital Temperature Meter Kit

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.Very accurate. $39.95

Beautiful hardwood case w/bezel $11.75

Sinclair 3V2 Digit Multimeter

Batt./AC oper. ImVand ,1NA resolution. Resis-tance to 20 meg. 1 % accuracy. Small, portable,completelyassem. incase. 1 yr. guarantee. Bestvalue ever! $59.95

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

Video Modulator Kit $8.95

Convert your TV set into a high quality monitorwithout affecting normal usage. Complete kitwith full instructions.

PROM Eraser

Ultraviolet, assembled

$49.95

2.5 MHz Frequency Counter Kit

Complete kit tess case $37.50

30 MHz Frequency Counter Kit

Complete kit less case $47.75

Prescaler kit to 350 MHz $19.95

Clock Calendar Kit $23.95

CT7015 direct drive chip displays date andtime on .6" LEDS with AM-PM indicator.Alarm/doze feature includes buzzer. Completewith all parts, power supply and instructions.

1978 IC Update Master Manual

1978 IC Update Master Manual $24.50. Com-plete IC data selector, 2175 pg. Master refer-ence guide. Over 42,000 cross references.Free update service through 1978. Domesticoostaae $3.50. Foreian $6.00.

Stopwatch Kit $26.95

Full six digit battery operated. 2-5 volts.3.2768 MHz crystal accuracy. Times to 59min., 59 sec., 991/100 sec. Times std., splitand Taylor. 7205 chip, all components minuscase. Full instructions.

D Connectors RS232

25 Pin Sub miniatures

DB25P 2.95

DE9P 1.50

DB25S 3.95

DE9S 1.95

Cover 1.50

DA15P 2.10

RS232 Complete Set 6,50

DA15S 3.10

S-100 Computer Boards

8K Static RAM Kit

$127.00

16K Static RAM Kit

265.00

24K Static RAM Kit

423.00

32K Dynamic RAM Kit

449.00

64K Dynamic RAM Kit

945.00

8K/16K Eprom Kit (less PROMS) $09.00

Video Interface Kit

$139.00

Motherboard $39. Extender Board $8.99

TERMS: $5.00 min. 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 1978QUEST CATALOG, include 28c stamp.

Circle 311 on inquiry card.

BYTE December 1978

239

What's New?

Low Voltage Miniature Soldering Iron

Compact Microcomputer Boards

A miniature printed circuit board forMotorola 6800 parts is now available.The single sided board measures 2 by 4inches (5 by 10 cm) and has circuitsetched for the 6802 processor, 6846read only memory, 6810 programmablememory and 6850 ACIA IO port.

Other addresses (for additional pro-grammable memory) may be enabledby painting the back of the card withphoto resistant paint, and etching awaythe unused metal cladding. The boardalone sells for $15.

Also available is a miniature, fullyoperational single board computer calledthe Ace, with 1 MHz clock, program-mable timer, and a 2 K byte read onlymemory monitor. This full scale 6802system provides for parallel data outputrates of up to 50 k bps interleavedwith serial output at rates of up to500 k bps and comes completely assem-bled and tested with female connectorfor RS-232 and 20 pin IO power connec-tor for $99.

For more information write LumbertComputer Company, 1220 W Alameda#104,Tempe AZ 85282."

Circle 576 on inquiry card.

Edge Connector Features WireWrapping Contacts

The Model Con-1 edge connector isa 44 pin connector for single or doublesided circuit boards 1/16 inch (.16 cm)thick. The connector features .025 inch(.06 cm) square 3 level wire wrappingcontacts on .156 inch (.40 cm) centers.The contacts are nickel silver overberyllium copper, and feature a bifur-cated bellows design that provides con-stant pressure while minimizing contactdistortion and stress. The connectorbody is molded of Underwriters' Labora-tories and military approved Valox, aninsulating material of dielectric, thermaland chemical characteristics. The Con-1is priced at $3.49 and it can be ob-tained from OK Machine and Tool Corp,3455 Conner St, Bronx NY 10475."

Circle 575 on inquiry card.

Automotive Computer Provides Driver Controlled Information Center

The Soldercraft Model 6A is a mini-ature low voltage production solderingiron designed for versatile microcircuitand fine instrument work. This solderingiron, when powered by a multitap 18 Wlow voltage transformer, will providecontrolled temperatures of 700° F at6 V, 625- F at 5.5 V, 555 * F at 5 V and480° F at 4.5 V from its 3/32 inch(0.25 cm) tip. The heat is generatedentirely within the tip, which providesmaximum efficiency and faster heatrecovery.

The Model 6A is priced at $6.90 andcan be obtained by writing to theMitchell-Hughes Co, 7534 Atoll Av,N Hollywood CA 91605.*

Circle 573 on inquiry card.

This self-contained driver-operatedautomotive computer instantly displayssuch data as miles to go, vehicle location,estimated time of arrival, miles pergallon, cost per mile and 19 otherfunctions. The Prince On-Board Com-puter, which is 101/2 by 2Vi by VA inches(26.67 by 6.35 by 3.18 cm) and weighsless than one pound (0.45 kg), is easilyinstalled in cars, trucks or vans byconnecting a speed transducer and fuelflow transducer, both supplied with thecomputer.

Function controls are color coded.

The main programming keyboard andmemory entry and recall bars are sizedand located for easy access. Large 0.3inch (0.76 cm) high intensity lightemitting diode displays are recessedand filtered for optimum legibilityday or night.

Other features of the unit includea memory scan and audio alarm whichis automatically activated one milebefore reaching a programmed location.

The unit costs $400. Contact thePrince Corp, POB 6, Holland Ml 49423.*

Circle 574 on inquiry card.

Wire Wrap Jumpers Save Time

American Data Cable wire wrapjumper cables provide a means for mak-ing temporary or permanent electricalconnections between 0.025 inch (0.0635cm) square terminal posts, such as thosecommonly used in integrated circuitsockets and printed circuit connectors.Small components such as diodes, resis-tors, and capacitors can also be tem-porarily connected using the jumpers.

These cables offer an alternative towire wrap or clip lead connectionsduring the development and testing ofelectronic equipment. They are fullyinsulated and can be installed in a fewseconds, generally without turning offequipment power.

These wire wrap jumpers are availablein lengths from 4 inches (10.16 cm) to6 feet (1.82 m) in five colors. Bothassortments and color code by lengthbulk packs are available. Contact sur-faces are gold, rated for 3 A continuous.The jumpers may be stacked up to threedeep on a standard wire wrap pin. Insu-lated sleeving helps protect againstshorts. Teflon wire and sleeving areavailable. Contact American Data CableInc, 903 San Antonio Rd, Los Altos CA94022.-

Circle 572 on inquiry card.

240 December 1978 © BYTE Publications Inc

CHRISTMAS GIFTS for YOUR

JS^SIOO PRODUCTS FROM WAMECO

FPB-1 FRONT PANEL BOARD

«fc DIRECT PLUG IN REPLACEMENTFOR IMSAI

•fc HEXADECIMAL READOUTS FOR DATA,ADDRESSES, AND PORT

•* USES LOW COST SEVEN SEGMENTDISPLAYS

#• CAN SINGLE STEP BY INSTRUCTIONOR BY BYTE

FDC-1 FLOPPY DISC CONTROLLER

•fc WILL CONTROLMINI OR FULL SIZEFLOPPY DISCS

«fc WILL CONTROL UP TO EIGHT FLOPPIESAS CONFIGURED, WITH SIMPLEMODIFICATION WILL CONTROL UPTO 64

■* USESCPM

$50 BARE

$45 BARE

OTHER WAMECO INC. S-100 PRODUCTS (bare board price)

* QMB-9 Nine Slot Mother Board $35.

* QMB-12 Thirteen SlotMother Board $40.

* MEM-1A 8 KBYTE 2102 Ram MemoryBoard $30.

* MEM-2 16 KBYTE 2114 Ram MemoryBoard $30.

* EPM-1 4 KBYTE 1702 EPROM Board $30.

* EPM-2 16 or 32 KBYTE 2708/2716 EPROMBoard $30.

* RTC-1 RealTime Clock Board $30.*CPU-1 8080 CPU Board $30.

WAMECO DEALERS AND DISTRIBUTORS:

AUSTRIA

Margreiter Data SystemA-1070 Wien GMBH

Schottenfelo Gasse 11Phone (02221 96 15 65

CANADAStephen FieldingHamilton Logic Systems62 Robing AvenueHamilton, Ontario L3H 4N4

F. Jackson Electronics Co.Box 20. Site 2. RR#3Aamdale, Halifax CountyNova Scotia B3L 4J3Phone 376-2920

* Orthon Computer*

12411 Stony Plain RoadEdmonton, Alberta T5N JNJPhone (403)488-2921

Robo-Tronics509 16 Avenue NWCalgary T2VROJ6Phone (403) 282-«468

The Computer Shop

3515 18th Street S. V.Calgary T2T 4T9

DENMARKPiezodan Aps.Bakkedraget 553480 FredensborgPhone 03-283744

ENGLANDLeenshire Ltd.13 Cathedral ViewWinchester SO?3 8PR

FRANCE

Euro Computer Shop

16. Rue Louis Pasteur

921O0 Boulogne

Paris

Phone Paris 825-82-52

GERMANY

ABC Computer-Shop GMBH

Scaellingstr. 333 000 Munchen 40Phone 089/282892

JAPAN

Onward Enterprise Corp.Suehirorocho Heim 31 dg. Rm 75-5, 3-Chome, Sokokanda,Chiyoda-Ku Tokyo, 101Phone (03) 255-9885

SCOTLAND

AIRAMCO Ltd.

30. Witches Linn. Ardrossa

Ayrshire. KA22-8BR

Phone 0294-65530

UNITED STATESARIZONA

* Computer Ware, Inc.214 West SouthernTempe, 85282Phone (602) 968-6312

CALIFORNIA

Adares Micro Computer Systems

239 Frances Street

Bakerstield. 93308

Phone (805) 393-1326

* Advanced Computer Products1310 "B" East EdingerSanta Ana. 92705Phone (714) 53b-6813

Dealer Inquiries Invited!University Discounts Available

Anchor Electronics2102 Walsh Ave.Santa CUraPhone (408) 246-3696

3yte Shop Computer Store3400 El Camino RearSanta Clara06 Phone (408) 249-4221

Byte Shop of Palo Alto2233 El Camino RealPalo Alto, 94306Phone (415) 327-8080

Com put rendBox 2541-KAnaheim, 92804Phone (714) 533-3572

D.C.I. Computer Systems

4670 N. El Capitan

Fresno

Phone (209) 266-9566

■ Electronics SystemsP.O. Box 9641San Jose. 95157Phone (408) 226-4064

Hobby World

5716 West Manchester ?5Los Angeles. 90045Phone (213) 641-4200

Hollywood Systems9100 Sunset Blvd.Suite 112Hollywood, 90069Phone (213) ?71-9726

* Jade Computer Products4901 West Roseerana BlvdHawthorne, 90250Phone (213) b79-3313

I. C. E. House, Inc.P.O. Box 336San BernardinoPhone (714) 888-3690

» Mikos419 Portofino Avenue

San Carlos, 9407 0

PCE Electronics4782 Dewey DriveFair Oaks. 95628Phone (916) 966.7033

Proko Electronics

San Luis Obisbo. 93401

Phone (805) 544-5441

COLORADO

Bits and Chips

718 9th Street

Greeley

Phone (303) 356-7554

PENNSYLVANIAMarketline Systems2337 Philmont Ave.Huntington ValleyPhone (215) 947-6670

Byte Shop of Colorado Springs Micro-Computer Products1845 N. Circle Drive 116 S. Pugh Street

Colorado Springs, 30909 State College, 16801

Phone (303) 633-7075 Phone (814) 238-77 11

TEXAS

Young Electronics Service

P.O. 3ox DD

College Station, 77840

Phone (713) 693-3462

WEST VIRGINIAThe Computer Corner22 Seechurst Ave.Morgantown. 26505Phone (304) 292-9700

The Comouter Broker12805 W. StanfordMorrison, 30465Phone (303)979-6441

Computer Technology3400 West 64th Ave.Denver, 30221

Miti Mini Computer Co.621 S. BroadwayDenver, 30209Phones (303) 778-6230.733-8681HAWAII

Mahalo Microsystems Limited355 Royal Hawaiian Ave.HonoluluPhone (808) 922-2152

NEW JERSEY

William Electronics Supply * DISTRIBUTOR

1863 Woodbridge Avenue

Edison, 08817

Phone (201)985-3700

MINNESOTA

P. 3. Inc.

1625 First Avenue North

Moorhead. 56560

Phone (218) 233-668?

wmc

inc. WAMECO Inc. 3107 LANEVIEW DRIVE, SAN JOSE, CALIF. 95132

Circle 388 on inquiry card.

BYTE December 1978

241

ASSEMBLYPROGRAMMERS

Our clients seek experienced mini/micro assembly programmers andsoftware/firmware engineers for avariety of positions in process con-trol, mini diagnostics, terminal sys-tems, scientific instrumentation andtelecommunications. Higher levelfluency or hardware ability a plus.Starting salaries 14-35K.

We invite inquiries from computerprofessionals seriously interested inadvancing their career. We can con-duct your job search on a continuous,confidential basis. For more informa-tion call collect. Dave Adams at (617)246-2815.

NEW ENGLAND RECRUITERS

6 Lakeside Office Park.

Wakefield, MA 01680

Fee Paid Management Consultants

Member Mass Professional Placement

Consultants

BASIC COMPUTERSHOP

i OS.I. i

NOW OPEN INAKRON

5 OHIO SCIENTIFIC !f * COMPUTERS * j

Easy Freeway access fromanywhere in Northeastern Ohio

\ SALES & SERVICE 1

Many systems on display withapplications software up andoperating.

« Business Home Hobby IJ Hardware & Software 5

OPEN MONDAY

» SEE0.lt. MOW! ■

THROUGH SATURDAY11 AM till 7 PM

The Basic Computer Shop

9 METRO DC. ARM &MMVIMD *

S The Math Box, Inc. £I (301)277-6828 *

2671 W. Market Street

Fairlawn Plaza

Akron, Ohio 44313

(216)867-0808

■ CENTRAL VIRGINIA AREA <»

■ H/B Computers,Inc. >* (804)295-1975 1

:i

Circle 282 on inquiry card.

Circle 28 on inquiry card.

Circle 213 on inquiry card.

CONVERT ANY TV

TO A HIGH QUALITY MONITOR

• Hot Chassis or Transformer sets

• 64-80 characters per line

• By-passes tuner & I.F.

• Normal viewing unaffected

• Safe—Easy installation

ACVM Hi-Resolution $24.95 ppd

RFVM Ch2-6 Modulator $9.95 ppd

VAMP INC. Box 29315

Los Angeles, Calif. 90029

Calif. Residents add 6% Sales Tax

CANADIANS

Announcing

HAMILTON LOGIC

SYSTEMS

Specializing in logicdevices, microprocessors,

memorys, TTL, Cmos ,etc.

Send for your catalogue

Box 7

STONEY CREEK

ONTARIO L8G 3X7

MICRO-VERTER

k SPECIAL COLOR MODULATOR FOR APPLE II USERS!!UHF Version, Operates above channel It. Eliminate* worms!I

Operates above the switching harmonics of the computer,thereby yielding a cleaner, worm-free picture. Tunableover a minimum of t channels. Interlaces directly withthe Apple II at well as most other micros, Comes withvideo cable and RF output stub coupler. Two-fone<J eowltype decorator cabinet. Size: 5.5cm i 8.5cm i II.gem.Power: +5V. Current approi. I ma. Self-powered with 4pencell batteries. Operating lite in eicess of 1000 hoursor near shelf-life of batteries. Excellent stability, Precisefrequency adjustment. No assembly required eicept torinstallation of batteries, not supplied. MODEL MVX-S00.

AVAILABLE FROM YOUR LOCAL COMPUTER DEALERor direct from ATV RESEARCH. COST including shipping |anywhere in USA and Canada— S35.00.

"PUE-PLEXER" An IC typo ytdeo-to-RF modulatorincludes FM sound sub-carrier, color subcarrier andseparate R-Y and B-Y inputs. Designed around theLM-1889 chip. A designers dream with full data sheets.Model PXP-J500. Kit form. 12*50 postpaid.

'PIXE-VERTER" The original computer videe-to-RFinterface module. Kit form: SB.50 Model PXV-2A

Circle 384 on inquiry card.

Circle 157 on'inquiry card.

Circle 22 on inquiry card.

WE SHIP FROM STOCK

TELETYPE MODEL 43

Only $985

withRS232 $1,085

INTERTUBE:

Smart CRT for intelligent shoppers.

Call or write for special low price.

HOLIDAY SALE

ON HAZELTINE TERMINALS

1500 Kit $885

1500 Assembled $995

To order: $10 shipping. 24 hr. shipping uponreceipt of certified check or money order. Personalchecks: allow 10 days. Credit cards: Add 4%. N.Y.residents add tax.

— We Also Export —

We have no reader inquiry number.Please call or write.

OWENS ASSOCIATES

147 NORWOOD AVENUESTATEN ISLAND, N.Y. 10304

Day, weekend, evening calls welcome.

(212) 448-6283 (212) 448-6298

SUPPLIES

■ FLOPPY DISKS, MINI ORSTAN0ARO MEM0REX OR 3M

• 3M DATA CARTRIDGESDC300A, DC100A

• 3M DIGITAL CASSETTES

• 3M OR MEM0REX AUDIOCASSETTES, C 60

• 3M DISK CARTRIDGES

WE OFFER:

• COMPETITIVE PRICING

• IMMEDIATE DELIVERIES(Any Quantity)

• UNCONDITIONAL GUARANTEE

BETA BUSINESS SYSTEMS

8369 VICKERS ST., #G

S.SAN DIEGO. CA 9211(714) 565-4505

Circle 34 on inquiry card.

AttractiveDurable Plastic

DISKETTE CASE

with each purchase of 10 Diskettes

at regular price of $3.65

DEALER INQUIRIES WELCOME

VR DATA CORP.

777 Henderson Blvd.

Folcroft, PA 19032

Call Collect: 215-583-5101

Circle 387 on inquiry card.

Circle 314 on inquiry card.

RONDURE COMPANY

2522 BUTLER ST.

DALLAS, TEXAS 75235

214-630-4621

the computer room

SPECIAL SALE$875.00

Used Workingand Clean

TESTED WITHNEWASCII

ELECTRONICS

Factory

Reconditioned

$1075.00

ASCII Selectric with ASCII parallel electronics.

Immediate Delivery—Shipped from inventory.

ASCII SELECTRIC

Printer Mechanism: Heavyduty input/output, Series745.

Weight: 120 lbs. Dimen-sions: 29"Hx35"Wx33"D-Print Speed: (14.8 charac-ters per second)Platen: 15" wide, pin feedor form feed device option-al (132 print positions).Parallel output only—15characters per second ac-cepts 7 bit ASCII parallelw/strobe & prints on Selec-tric. The unit still works asa typewriter in off-linemode.

DATEL SELECTRIC (IBM Selectric Mechanism)

Specifications:

• Size: 21"Wx21MDx8,,H.

• Power Input 115 VoltHz

• Inferface: RS232

• Weight: 54 lbs. (Shippingweight 65 lbs.)

• 15" Carriage

• 15 CPS

• Correspondence code

• Half Duplex

• 132 Print Positions, 10Pitch

"As Is" Complete

Working

Reconditioned

$395.00$495.00$695.00

Used

$395

NOVATION DC3102A

UsedWorking

$150.00

RS232 Connection300 Baud

Tl 990/4

Single Board 16 Bit Micro

Computer

NEW $250.00

USED MODEMS & COUPLERSNOVATION TC102 (Acoustic) $45.00

AJ 233 (Acoustic) $25.00

CF 318 (Hard Wire) $25.00

SHUGARTMINI-FLOPPY DRIVE

NEW PRICE$325.00 ea.

Model SA-400

FLAT PACK ACOUSTICAL

MODEM PICK-UPUseable with most modemchips/kitsUsed — $17.50 (w/prints)

ORDERING INFORMATION:

We ship the same day we receive a certified check or money order.Texas residents add 5% sales tax. Please call if you have a question.Write for our CATALOG of many parts, terminals, printers, etc.All items subject to availability. Your money returned if we are outof stock.

SHIPPING INFORMATION:

Modems: $2.00 each; 2 for $4.00 UPS.

Large Items & Parts: Specify Freight or Air Freight Collect

Foreign Orders: Add appropriate freight or postage.

We now take Master Charge and Visa orders, Specify full number,

bank number and expiration date.

ATTENTION TRS-80 & APPLE USERS

IN TIME FOR CHRISTMAS^= A PRINTER FOR YOUR COMPUTER ^=^=

TERMS: VISA, MASTERCHARGE,Cashier Check or Money Order.C.O.D. with 10% down.Shipping Via Air or Truck collect.

3 S SALES

P.O. BOX 45944TULSA, OK 74145918/622-1058

$99500

MODEL 3S-80 for TRS-80

Ready to plug into yourexpansion interface.

MODEL 3S-PP

for computers with 8 bit serialport.

MODEL 3S-SS

for computers with RS-232port.

•109500 for

MODEL 3S-AA

Includes RS-232 card for Applel ISpecify model number on order.

• Ready to plug into yourcomputer

• Very high quality print

• Completely refurbishedIBM 731 I/OSelectric terminal

in a new table

• Upper & lower caseremovable type ball

• Special I/O interface

• Heavy duty re-mfg. IBMpower supply

Circle 356 on inquiry card.

BYTE December 1978

243

The best choicein mainframes !

• S100 CARD FRAME • AXIAL SLOWER

• 14 MHz 12" CRT MONITOR • ASSEMBLED 8r TESTED

• 18 AMP POWER SUPPLY • HEADY FOR YOUR CARDS

• UPPER & LOWER CASE • $995,00 um. prk»

ASCH KEY BOARDS

W£ ALSO HAVE

POPULATED SYSTEMS, SI00 CARDS

LARGEST SELECTION OF 1802 SOFTWARE

••■■ INFINITE INCORPORATED

Celebrating Our 10th Year.1924 WAVERLY PL., MELBOURNE, FL 32901 - PHONE (305) 724-1588

Circle 171 on inquiry card.

At last. . the mechanical interface!

/TURN YOUR ELECTRIC TYPEWRITER\

INTO A LOW COST, HIGH QUALITY

HARD COPY PRINTER.

The all new I/O Pak from RochesterData, Inc. interfaces the keyboard ofany commercially available electrictypewriter with any computer. Theresult: low cost, high quality hard copy.

Write today for more information.Distributor inquiries invited.

USER LIST $395.00

Quantity and distributor

discounts available.

ROCHESTER DATA, INC.3100 MONROE AVENUEROCHESTER, NY 14618

LSM1/2®§&[La

KD11-HA® LSI-11/2 Microcomputers

Quantity

Price

1-910 up

$500.00$460.00

Building Automation That SavesTo order, call or write:

F. FerragonioCompuguard Corporation4709 Baum BoulevardPittsburgh, Pennsylvania 15213(412) 622-6200

® Registered trademark ofDigital Equipment Corp, May-nard, MA

HI

Circle 310 on inquiry card.

Circle 47 on inquiry card.

Thinking of changing jobs?

If you have a degree inengineering, chemistry,physics, geology or com-puter science, The CareerAdvertiser can make youaware of the job oppor-tunities you might other-wise miss. Nationwide inscope — Arranged to saveyour time.

The Career Advertiser

Department 4

P.O. Box 4067 Fort Hill Station

Lynchburg, VA 24502

Six months (12 issues) $5.00

Please send payment with order.

FREE SAMPLE COPY ON REQUEST

Your name kept confidential — Not an agency

couplers ^connect: alwa/s

The Datec 30 Originate Only and theDatec 32 Originate Answer acoustic couplersprovide reliable Bell System 103 113 compatibleDuplex or Half-Duplex, 300 bps data

communication over conventional telephones.

Datec acoustic couplers are the only couplerson the market wrth CRYSTAL CONTROLfor both the receiver and the transmitter

The Datec 30 and Datec 32 acousticcouplers connect, time ana time again

lufefe'

sm

PO Box 839

Chapel Hill, North Carolina 27514

phone: (919) 967-5605

^ TRS-80

SPFXIAL PROMOTION SALE

SAVE 10%, 15% or more on ALL |Computers, Peripherals, Software,and ALL other fine Radio Shack®products.

NO TAXES on out-of-state ship-ments.

FREE Surface delivery in U.S.

WARRANTIES will be honoredby your local Radio Shack* store.

Offered exclusively by

Radio Shack*

Authorized Sales Center

1117 Conway

Mission, Texas 78572

(512) 585-2766

^

Circle 83 on inquiry card.

Circle 85 on inquiry card.

Circle 304 on inquiry card.

NOW AVAILABLE .

Compucolor II

Personal Color Graphics Computer

at $1495.00

STANDARD FEATURES:

• 13" Color CRT

• Special Graphics Pkg.

• 16K Extended Disk Basic

• 8K RAM Memory

• 72 Key Keyboard

• Minidisk Drive

SADDLE BROOKSTEREO INC.

203 Market St.

Saddle Brook, N J. 07662

Phone:(201)843-7500

IDEA ASSEMBLERS P 0. BOX 1498 GALESBURG. IL 614151

INTRODUCES THOUGHTWARE!

Designed To Make The Operation Of YourPersonal Computer Easier And More Fun

THE TRS80 POKE GRAPHICS WORKSHEET

Supports quick, easy implementation of graphics m machine/assembly language or In fullest utilisation of Level II Basic.

1 pad of 25 sheets $3.95

2 pad! of 25 sheets S6.9S

THE TRS-80 GRAPHICS WORKSHEET

and RESET commands are urged to order.

2 pads of 25 sheets S3.9S

4 pads of 25 sheets S6.95

THE LINE MINDER

tat ion of up to 3848 for long penciled ptogrammers.

1 pad ot 25 sheers S3.95

2 pads of 25 sheets $6.95

AND OUR SELECTION OF NOTE PADS

thoughts Package of 6 pads (300 sheets, all same tulel S3.95

YOUR CHOICE OF TITLES BELOW. DONT WRITE IT OFF(II Bubble Babble, (21 Bus Lines, <3) Dandy Notes, (4)TRS-80 Owners Don t Baudot To Anyone. 15) Floppy Copy.(61 Padded Bits, (7} Under Disk ussion. 18) Tandy Say"Don't Make ASCII Of Self "

0

Q

DISKETTES

VERBATIM for Your DRIVE

Ea. inboxesof 10

Ea. inboxesof 10

II war $1 qnI 16 Sector U.uU

STANDARD $4 in

Soft or Hard Sector ■ ■ ■ V

CP/M1.4D0isKNrHho^o„$145

PLASTIC BOX SMS '3

HAZELTINE CRT 1500^1000

Complete 1*2«3 Computer

*5145

Visa, Master Charge, Cash, C.O.D.

System: Hazeltir.e 1500,Horizon-2, Centronic 779

Circle 337 on inquiry card.

-trcle 174 on inquiry card.

MANCHESTER EQUIPMENT CO., Inc.

30 Midland Ave. • Hicksville, N.Y. 11801Call Collect: (516) 433-0613

Circle 211 on inquiry card.

Circle 30 on inquiry card.

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BECKIAN ENTERPRISES

EDGE CARD COMNECTORS: GOLD PLATED.

BODY Non brittle, solvent resistant, high temp, G.E, Valox. The finest you can buy.CONTACTS; Bifurcated Phos./Bronze; Gold/Nickel.

ALTA1R S 100: Cont/Ctrs. .125 Row Spacing, .14050/100 Dip Sold. $3.95 ea.

50/100 Sold. Eye. 6.95 ea.

I MSA I S 100: Cont/Ctrs.50/100 Dip Sold.50/100 W/Wrap 31MSAI CARD GUIDES:

.125 Row Spacing, .250$4.20 ea.3.75 ea.0.19 ea.

5 pes.5 pes.

5 pes.5 pes.5 pes.

125 Row Spacing, .250

$6.50 ea. 5 pes.

CROMEMCOS 100: Cont/Ctrs50/100 Dip Sold.(Or short W/Wrap)

OTHER CONNECTORS AVAILABLE

■ 100" Contact Ctrs., .140" Row Spacing.

22/44 Dip Sold. $2.30 ea. 5 pes.

25/50 Sold. Eye. 2.95 ea. 5 pes.

40/80 Sold. Eye. 4.80 ea. 5 pes.

43/86 Dip Sold. 4.90 ea. 5 pes.

43/86 Sold. Eye. 4.90 ea. 5 pes.

.156 Contact Ctrs., .140 Row Spacing.

6/- Sgle. Row (PET) $1 00 ea.

22/44 Sold. Eye. (KIM) 1.90 ea.

22/44 Dip Sold. (KIM) 1.90 ea.

43/86 Dip Sold. 4.90 ea.

.156 Contact Ctrs.,

15/30 W/Wrap 322/44 W/Wrap 336/72 Sold Eye.36/72 W/Wrap 343/86 W/Wrap 3

.200 Row Spacing.

$1.05ea.2.30 ea.3.45 ea.3.85 ea.5.50 ea.

5 pes.5 pes.5 pes.5 pes.

5 pes.5 pes.5 pes.5 pes.5 pes.

$3.75 ea.6.50 ea.

$3.95 ea.3.50 ea.0.16 ea.

$6.00 ea

$2.10 ea

2.75 ea

4.50 ea

4.70 ea

4.70 ea

$0.90 ea

1.80 ea

1.80 ea

4.70 ea

$0.95 ea

2.10 ea

3.30 ea

3.70 ea

500 ea

POLARIZING KEYS FOR ALL OF THE ABOVE:

Specify: IN Contact or BETWEEN Contact:

1 to 49 pes. $0.10 ea. 50 pes./Up $0.08 ea.

SPECIAL

12/24 Pm 156" Cont/Ctrs. .200 " Row Spacing.

TIN PLATED CONTACTS.IDEAL FOR PET INTERFACE & PARALLEL USER PORT.$1.25ea. 5 pes. $1.10 ea.

All Prime Quality - - New Parts Only ■Satisfaction Guaranteed

SUBMINIATURE CONNECTORS: (DB 25 SERIES, RS 232.)

DB 25P Male Plug $2.50 ea. " 5 pes. $2.20 ea.

DB 25S Female Socket 3.60 ea. 5 pes. 3.40 ea.

DB 51212-1 Grey Hood 1.20 ea. 5 pes. 1.10 ea.

DB 51226-1A Black Hood 1.30 ea. 5 pes. 1.20 ea.

D 20418-2 Hardware Set 0.75 ea. 5 pes. 0.70 ea.

SAVE. BUY A SET: (1 DB25P, 1 DB25S, Any Hood.)

1 Set: $6.35 ea. 5 sets: $6.15 ea.

NOTE: For Hardware, (D20418-2) Add $.65/Set.

WHISPER FANS

Excellent for computer cabinet cooling. This is the most quiet fan you will find. Onlymeasures 4 3/4 square by \% deep. U. L. Listed.

$21.00ea. 5 pes. $19.00 ea.

I. C. SOCKETS. GOLD-WIRE WRAP 3 TURN.

14 pin $0.36 ea.16 pin 0.38 ea.

2708 EPROMS PRIME

$14.00 ea.

I. C. SOCKETS.Dip Solder. Tin.

14 pin $0.15 ea.16pin 0.17 ea.

8080 PRIME

$9.00 ea.

WRITE FOR LARGER QUANTITY DISCOUNTS. DEALER INQUIRIES AREWELCOME.

WE ARE CONNECTOR (EDGE CARD) SPECIALISTS. IF YOU DO NOT SEEWHAT YOU NEED IN THIS ADVERTISEMENT, PLEASE WRITE US. WE WILLREPL Y.

TERMS: Minimum Order $10.00: Add $1.25 for handling and shipping. All ordersover $25.00 in USA and Canada: WE PA Y THE SHIPPING.NOTE: CA residents please add 6% sales tax.

NO COD. SHIPMENTS OR ORDERS ACCEPTED.

ma,l ohders w £^.££0, EnterprisesP.O. Box3089Simi Valley, CA 93063

Discount Prices on

DEC* LSI-11 COMPONENTS

Manufactured and tested by Digital Equipment Corporation. Compatible with DEC PDP*-ll/03 and HeathkitH-ll. Or build your own computer using the card cage assembly. All cards 8.5 x 5 in.

KD11-HA LSI-11/2 Central Processor Unit. Includes power fail/auto restart,I/O DMA port, real time clock input, vector interrupt handling, firmware de-bugging and ASCII console routines, List $695 $ 599

MSVll-DA4kx 16-bit RAM, List $416 . $ 350

MSV11-DB 8k x 16-bit RAM, List $850 . . $ 675

MSV11-DC 16kx 16-bit RAM, List $1375.. $1095

MSVll-DD32kx 16-bit RAM, List $2400 $1925

H9281-BB 8-slot card cage and backplane.. , $ 155

Other components available, writefor catalog. Quantity discounts.Terms COD or prepaid.

^Trademark of Digital Equipment Corporation

MICROPROGRAMMING, INC.

1351 Larc Industrial Blvd.Burnsville, MN 55337Phone:(612)894-3510

Circle 221 on inquiry card.

BYTE December 1978 245

LJnclseeified Ads

WANTED: My 4 K PET needs more memory.Anyone with access to eight MOS 6550 pro-grammable memories please write Barry Swartz,3727 Tartan Ln, Houston TX 77025, (713) 663-6401.

FOR SALE: Altair factory assembled 2SIO board.Wired for TTY and RS232. Never used. Best offer.Write or call Robert Cardamone, 304 S Penn St,Punxsutawney PA 15767, (814) 938-4185.

FOR SALE: RS 232 interface for Diablo printerwith CDC interface advertised in May and June1978 BYTE. $250. H Stone, 64 Morgan Cir,Amherst MA 01002.

FOR SALE: Set of BYTE magazines September1975, number 1 to July 78, volume 3, number 7(complete, except November 1977, volume 2,number 11). 33 magazines total. Excellent con-dition. Best offer, (614) 389-3452,

WANTED: For MBT Inc (model 015) DiskMemory Unit: specifications, schematics andmaintenance manual. This company is now outof business: I have been unable to obtain tech-nical information through normal channels. BertRichardson, 13 Fern St, Natick MA 01760.

FOR SALE: Kfeinschmidt teletypewriter TT-117/FG with reperforator/transmitter, Baudot code.Used and working, $100. Tektronix type CA dualtrace plug-in unit for 585 or similar scope, $150.M H Research R100B plus and minus 300 V DCpower supply, $25. Locarte 3 A 120 V DC powersupply (not isolated from AC line), $20. LambdaLT 2095M 0 to 32 V, 0 to 2 A power supply,$75. SwTPC 143 0 to 35 V, 0 to 2 A powersupply, $20. All items plus shipping. S Lei, POB5312, Fargo ND 58102.

FOR SALE: BYTE number 1 to date, $25 year.SCELBI 8B users manual, machine language,assembler, monitor, editor, four issues SCBLBfComputer Digest for 8008 and similar computers,all for $50. Other manuals and books onelectronics and microcomputers. You pay postage.Davey B Moyers, 10743 Karen Gale Ln, Jackson-ville FL 32225, (904) 641-9485.

FOR SALE: Texas Instruments TI-59 program-mable calculator and PC-100A printer completewith extra paper rolls, magnetic cards and pro-gramming manuals. All for $300. Peter Ludwig,921 Fernwood Av, Plainfield NJ 07062, (201)263-0200 (ext 3576) days or (201) 753-9780evenings.

FOR SALE: Heathkit H-8 Computer System;expertly assembled and tested. Includes 24 K staticprogrammable memory, serial and cassette input/output, H-9 video terminal, cassette player, allstandard Heathkit software plus Extended BASIC,all documentation. I am graduating from collegeand must sell; asking $1725 and I will ship it. Callor write Dan Harrington, 927 J St, #49B, DavisCA 95616, (916) 756-7932.

NEW UNCLASSIFIED POLICY

Readers who have equipment, software or other itemsto buy, sell or swap should send in a clearly typed noticeto that effect. To be considered for publication, an adver-tisement must be clearly noncommercial, typed doublespaced on plain white paper, contain 75 words or less, andinclude complete name and address information.

These notices are free of charge and will be printed onetime only on a space available basis. Notices can be ac-cepted from individuals or bona fide computer users clubsonly. We can engage in no correspondence on these andyour confirmation of placement is appearance m an issue ofBYTE.

Please note that it may take three or four months for anad to appear in the magazine. •

FREE: Data cable with the sale of a Persci 1070intelligent disk controller $500 assembled andtested. TDL SMB board (dealer demonstrationmodel). Two serial input/outputs, one parallelcassette interface and TDL 2 K Zapple Monitorin read only memory and 2 K programmablememory. Fully assembled and tested, $220.TDL software package A with 12 K BASIC,Z 80 assembler, Z-TEL, text output processor,all to run under CP/M format. 8 inch diskette,manuals and notebook, $189. Call or write TedNakamura, 3421 Onyx St, Torrance CA 90503,(213)371-8138.

FOR SALE: Best prices. S-100 bus 16 by 64video interface (ASCII and block graphics),assembled $100. 8 K programmable memory,assembled $100. Prototyping board, includingbuffers and regulator on board $20. Full ASCIIkeyboard, including user defined keys $35. Callor write Philip Klein, 1524 Sacramento StBerkeley CA 94702, (415) 524-9711.

FOR SALE: HP-67 calculator for sale, program-mable, automemory stack and much more. Un-used, will accept reasonable bid. Call (913) 642-4663.

FOR SALE: MITS Altair 8800A, 8 K program-mable memory, serial input/output and audiocassette IO, all documentation, $450. Bright2610 magnetic tape drive, 800 bits per inch, 27.5inches per second with two controllers for DataGeneral line of minicomputers. Tape unit wasworking with one of the controllers when removedfrom system, condition of other controller un-known. Schematics and manuals included, $850.L D Stricklan, 21733 Alcazar, Monta Vista CA95014, (408) 257-4805.

FOR SALE: Dual trace oscilloscope, Heath IO-4510, 15 MHz, with calibrator, manuals. Likenew, $545. Digital Multimeter, Heath IM-2202with manual. Like new, $160. Swan 350 AmateurTransceiver, with 11 7cx power supply, transmittercontrol unit VFO, manuals. Good condition, $345.Robert Shostak, 1961 Camino de los Robles,Menlo Park CA 94025, (415) 326-0443.

WANTED: Any information that you may havepertaining to Radio Shack TRS-80 software andperipherals. I have a 16 K Level II system andwould like to add a printer and disk. Both mustbe capable of running off a 50 cycle power as I amstationed in Athens Greece. Robert Daniel, PSCBox 2088, APO, New York NY 09223.

FOR SALE: Teletype 3320 printer with 5JEpunch/reader, Carterphone DX 103A-7 and Dai-Data Dialer; $730 plus shipping. Steven Terharr,650 Beech, Moorhead MN 56560, (218) 236-8129.

FOR SALE: Centronics 101, 132 columns, 5 by 7,165 characters per second, 8 bit parallel interface,uses standard size pin feed paper. $950 on tradefor Diablo Hytype II. Frank Bennett, (408) 732-3800 ext 633 (work) or (714) 7350549 weekends.

OSI CASSETTE INTERFACE USERS: I havesome modules for 430 board to increase reliability.Also mods for 420C for standby power and modifi-cation of the OSI Audio Cassette Tape Generatorprogram to produce double speed tapes. I wouldlike to share information on these or similarsubjects. Phil Bryan, 529 West St, Park City IL60085.

FOR SALE: Tl 59 calculator with all standardaccesories and numerous games, in perfect con-dition, asking $220. Also for sale one slightlyused KIM 1, in very good condition with powersupply and all manuals. Philip Kaaret, 1113 E StateSt, Ithaca NY 14850, (607) 272-9119.

FOR SALE: SwTPC 40 printer; 40 columns, 75lines per minute. I've been using it for about oneyear and it works great!! $200 or best offer. DigitalGroup Phi-Deck mass storage with two drives,PHIMON, cabinet and cable. Complete docu-mentation included, $400 or best offer. HoldenCaine, 1 Windsor PI, Melville NY 11746, (516)692-9512.

FOR SALE: 8 K PET, Commodore. Too smallfor my needs. Two months old and completelyburned in. Some software and additional manuals.Will ship anywhere in USA, $750. Mike Avelis,108 Wynola Av, New Britain CT 06051, (203)224-7016 after 6 PM EST.

WANTED: Z-80 or 8080 system monitor andS-100 complete front panel with any availabledata. Steven Friedel, 33-44 149 St, Flushing NY11354, (212)358-8160.

FOR SALE: Sphere Boards: processor/2, cathoderay tube/1 A. Best offer. Richard Likwartz, 827West St, Rock Springs WY 82901, (307) 362-5316.

FOR SALE: 16 K Level II TRS^80, Diablo 1200Hy-Type (without keyboards), Regency HR-212,R-390 receiver. Will swap 212 for talkie withkeypad. Karl Schneider, 4423 W Broadway,Muskogee OK 74401, (918)683-6511.

FOR SALE: KSR 35 tabletop ASCII teleprinter.Uses either serial or parallel input/output, $550.Four SwTPC 4 K static memory boards, $75each. Heath IO 101 vectorscope/color bar gener-ator, $85. Gary Wachter, POB 18955, San AntonioTX 78218, (512)655-9314.

FOR SALE: E & L Instruments MMD-1. As-sembled and running, with Bugbooks. $250. Jim AChurch, 3570 Cortez Dr, Dallas TX 75220.

FOR SALE: 4 K Dynamic programmablememories, MK4096, MK4027, TMS4060, tinned,speed unknown (coded for Honeywell), $2 and $1each. Teletypes: 35KSR, 33ASR, $450 each. TwoDigitronics 3500 HS paper tape readers, lesselectronics, $75 each. Two MFE Digital cassettetransports and parts, $90 for lot. 14 pin DIPcables, $1 each. Will consider trades for ShugartFloppy disks for above. Carl D Cole, 1134 EGeneva Dr, Tempe AZ 85282.

FOR SALE: DEC PDP-8F Minicomputer system.16 K, two disk drives, video terminal, ASR 33and much software. Make offer. John Robinson,725 Berry Ln, Lexington KY 40502, (606) 266-1509.

FOR SALE: Kleinschmit ASCII print drum (76columns). Electronics/parts for 311-321 printer.Best offer takes it. Bill Vaughn, 2415 RichviewCt, Garland TX 75040, (214) 495-2371 evenings.

WANTED: Software for the VIM-1 on cassette orlistings. N Carr, 13709 Peyton Dr, Dallas TX75240.

BOWLERS NEED HELP: Hardware, software andinformation needed to operate a state bowlingtournament. Robert Woods, 220 Madison St,State College PA 16801, (814) 238-3816.

BYTE ISSUES: I have BYTE numbers 1 thru 15,except number 11. Best offer takes them. ThomasG McBride, 178 Mitchell- St, West Orange NJ07052

FOR SALE: Heath H8, H9, 16 K, cassette re-corder, assembled and running; $1200. David JMarcus, 430 Wolf Hill Rd, Dix Hills NY 11746,(516)427 1926.

FOR SALE: SwTPC 6800 mainframe; no cards,just mother board and power supply. Assembledand tested. $150. James VanProoyen, WeeksElectric Co Inc, 1057 Cottage Grove SE, GrandRapids Ml 49507, (616) 243-8866.

FOR SALE: AMI EVK-300 system M6800 1card computer. With 1 K programmable memory,2 K erasable read only memory and programmer,Proto monitor, Microassembter/Dlsas read onlymemory. Four parallel and one serial ports to19,200 bps, $700. 16 K board for the above,$390. Zvi Peshkess, (517) 355-3164.

246 December 1978 © BYTE Publications Inc

FOR SALE: KIM I and power supply; complete,working. First $200 takes it and I will ship it.Send SASE for return of late checks. Send certifiedcheck or money order to Judy Upchurch, 107-GTall Oaks Dr, Greensboro IMC 27408.

APPLE OWNERS: I am a collector of Apple soft-ware and have over 200 programs for the AppleII. Send me your programs on disk or cassette andI will trade them on a one-to-one basis. DaveGarson, 5163 Willow Wood Rd, Rolling HillsEstates CA 90274, (213) 378-3823.

FOR SALE: Digital Group Z-80 system, 34 K; fourdigital cassette drives (Phidecks); keyboard;monitor; all software (MaxiBASIC, BusinessBASIC, assembler, Star Trek, chess, etc). Totalprice as kit over $3300. Up and running for $3100.John Case, 6703 Timberhill, San Antonio TX78238, (512)681 7504.

FOR SALE: SwTPC 6800 Computer System; 16 Kprogrammable memory, serial IO, AC30 cassetteinterface and Smoke Signal Broadcasting BFD-68disk system. All documentation and software.$1400 or best offer. Craig Colvin, 817 CheyenneDr, Walnut Creek CA 94598, (415) 937-0778.

FOR SALE: What am I offered? BYTE magazines,September 1975 to December 1976 in BYTEbinder and full set of 1977 copies, unbound. Allperfect condition. Dick Neish, WOSIR, 904Marday, Sioux Falls SD 57103.

FOR SALE OR TRADE: BYTE volume 1. #1through # 10. All ten issues, top condition, $75or best offer. Don Erickson, 6059 Essex St, River-side CA 92504, (714) 738-3709 anytime.

WANTED: A Flexowriter with upper and lowercase characters suitable for computer generatedletters. Working or not. Don Erickson, 6059 EssexSt, Riverside CA 92504, (714) 738-3709 anytime.

FOR SALE: MOS technology KIM-1 microcomputer, manuals and power supply included,$150. KIM-3 8 K memory board, manual andpower supply included, $100. Martin Goldberger,15 West 72 St, New York NY 10023, (212) 874-3176 evenings after 6 PM and weekends.

HELP! I was too ambitious. I have 20 M6800chips in original factory packages. Will sell for $15each or trade all 20 for a minifloppy drive in goodcondition. Bill Ganoe, 1634 E Drachman, TucsonA2 85719.

GTE DIABLO FOR SALE: Commercial Hytype Iprinter/keyboard, fully equipped; RS232 interface.E Grossman, 410 Albany Post Rd, Croton NY10520.

FOR SALE: Complete Poly 88 system with a 41 Kprogrammable memory, 3 K erasable program-mable memory, 8080A processor, 16 by 64 video,graphics, hardware scroll, 300 and 2400 bpscassette, real time clock, serial port, four parallelports, single step hardware, 2708 erasable program-mable memory programmer, two DACs, 16channel ADC, 9 inch monitor, cassette deck, allhardware, documentation, and extensive softwaresupport. There is one S-100 slot left for a cardof your own. I will consider any offer over $2200.Michael Dunn, 45 Livingston Rd # 501, Scar-borough, Ontario CANADA M1E 1K8, (416) 266-1635.

INFORMATION WANTED: For G E TDM114A40 data set: I bought one and I need to testit, repair (if necessary), and use it. I would bewilling to trade printing or programming or pay forinformation, etc. Write Robert Heller, Box 51AStar Route, Wendell MA 01379 (no phone).

FOR SALE OR TRADE: Heathkit Digital Tech-niques Course and Trainer, Model 15 Teletypeparts including keyboards, type boxes, mainframes,and smaller parts. Will trade for Heathkit micro-processor trainer, George Kelm, POB 160, YapCaroline Is, GUAM 96943.

FOR SALE: Altair 8800 mainframe with processorboard, 1 K programmable memory, 2 K program-mable memory board. Ideal for hardware orientedbeginner. Asking $250. Randy Soderstrom, 4601Goldfinch, Madison Wl 53714, (608) 222-8056.

FOR SALE: Digital Group Z-80 4 board systemincluding processor, IO, video terminal cassetteand mother board assembled. Also two 8 Kmemory boards with ICs and sockets plus Maxi-BASlC, Editor, Super/Clock software plus ASCIIKeyboard and Encoder. Will take best offer.Asking $500. Oldrich Laznicka, 24 Payson Rd,Belmont MA 02178, or call (617) 484-4978 after6 PM weekdays or weekends.

WANTED TO BUY: Texas Instrument modelSR-52 programmable calculator in good condition.Dale Sebok, 127 Timothy Dr, Tallmadge OH44278, (216) 633-4297.

FOR SALE: Digital Group complete Z-80 PhiDecksystem with speech synthesizer. Major componentsinclude dual PhiDecks, monitor, keyboard, 32 Kstatic memory, finished cabinet, VOTRAX speechsynthesizer, and substantial software. Assembledand perfect working order. Best offer over $3000(price new $3750). John Theys, 24 Walnut Av,E Setauket NY 11733, (516) 473-4142.

FOR SWAP: Will swap BYTE issues May, Novem-ber or December 1977, for September 1976 orJanuary, February or April 1977. Bert Honroe,Schuermanslaan 65, 3070 Kortenberg BELGIUM.

IBM 3705 BSM: Did anyone ever try to connecta 3705-1 Bridge storage module (core). They areavailable now as most installed model 1s getconverted to model 3s having FET storage. Ifanyone did, please get in touch. I'm having pro-blem in the sense latch. Bert Honroe, Schuermans-laan 65, 3070 Kortenberg BELGIUM.

FOR SALE: Heathkit H9 video terminal, andHeathkit H10 paper reader/punch with parallelboard and connector cable. Fully assembled andrunning, checked out by factory. Best offer forboth or either. R Nicosia, 234 41st St, LindenhurstNY 11757.

FOR SALE: Two Innovex 200 double density 8inch disk drives, $200 each. Three Innovex 420double density 8 inch disk drives, $300 each. 4board Z-80 System (Z-80 4BD) largely factoryassembled with 10 A power supply, $900. CAS &CB2 Phi Deck Drive System (kit) with PHI-F,$300. Two blank 8 K memory boards. One 10-4kit. Robert Frieden, 359 Wilson Av, Kent OH44240. (216)673-7181.

FOR SALE: Complete set of BYTE from volume1, #1 to December 1977. Perfect condition. JimLarus, 27 Varick Hill Rd, Waban MA 02168.

FOR SALE: Digital Group TVC-64 board; operatesfine, with OP-System and documentation. AlsoRadio Shack keyboard video terminal added. $175for both. Bob Howarth Jr, RFD # 1, Box 36,Lisbon NH 03585.

SHERLOCK HOLMES FANS: You are invitedto correspond with Ben Fairbank, 307 Kent Av,El Paso Texas 79922 to consider together thepossibility of undertaking various computeranalyses of the "Sherlockian Canon" with theeventual goal of producing a concordance to the 60stories.

FOR SALE: Heathkit Computer System includesH8 computer, H9 video terminal, 16 K memory,IO board, cassette player, all manuals, schematics.Also includes many programs. Completely as-sembled and tested. Will pay shipping. $1500. T EAllen, MAG-11, H$MS-11, W/C 620, MCAS EltoroCA 92709.

FOR SALE: Altair 8800B System: full front panel,12 K static programmable memory, audio cassette,serial IO, Microterm act-1 keyboard with Sanyomonitor, cassette recorder, package II assemblerand 8 K BASIC plus many programs. Systemfully operational. Total price: $1850. Additionalequipment: Altair parallel IO 88-4PIO, $75;Cromemco dazzler, $200; Cromemco bytesaverwith 1 K erasable read only memory, $100. Com-plete documentation. Call Tom, (614) 369-3866nights.

FOR SALE: 20 back issues of BYTE (from Febru-ary 1976). Best offer takes all. Norman G Church,18310 Franklin Way, Gladstone OR 97027, (503)659-6763.

MUST SELL: SOL 20 with 24 K programmablememory; Panasonic monitor, cassette; North Starcontroller with Shugart SA400 disk drive; musicinterface board; 15 K extended cassette BASIC;12 K disk BASIC; game pack 1. Everything works-less than six months old. $3400 value for $2995.J Andrews, 6303 Kury, Houston TX 77008, (713)869-3985 evenings.

FOR SALE: 8 K byte, 250 nsec, S-100, staticmemories, $175. IBM Selectric type balls, $10.IBM Selectric tool kit, $25. IBM Selectric 10pitch to 12 pitch conversion kit, $35. AC/DCpower supply, 5 to 9 V, 20 A, overvoltage protect,overcurrent protect, $80. Sunny power supply,9 V 25 A, ± 18 V - 4 A; - 9 V - 4 A, $85. StanLevine, 1802 Melville St, Ocean NJ 07712, (201)531-8305.

FRIEDEN EQUIPMENT: 36 pieces, one ailoter,eight regens, (two brand new—still in crates), twocard punches, 13 2305 slave printers, one SPD,SPD stand, one Computyper with program blocksand desk, one Seiectadata transmitter, three trans-mitters, six power supplies, miscellaneous assort-ment of cables, spare parts, schematics, paper tapeand edge punch cards. Also three McGraw EdisonVoicewriters. No reasonable offer refused, plusshipping. Ron Komara, POB 267, Davidsville PA15928, (814)479-4674.

FOR SALE: SOL 20, two SOL 10s, Altair 8800Awith mother board, 24 K bytes of static program-mable memory, IO board, MITS vector interruptboard, real time clock board, ICOM dual floppydisks, ASR 33 Teletype, TDL Z-processor. Sendoffers and receive detailed list. Herbie Marsden,608 Kelly, Silver City NM 88061, (505) 538-5229.

FOR SALE: ASR 33 like new, with recent Inte-grated Circuit Touch Tone Modem. Includesall manuals, $750. You ship. Also SwTPC CT-1024with scroll, 16 lines, 64 characters, upper/lowercase, custom oak/formica cabinet, and lots ofspare parts. $225. Julian E Jetzer, 6400 HawthornRd, Sheboygan Wl 53081, (414) 457-3366.

FOR SALE: Poly 88 chassis with two Altair 4 Kstatic memory boards, WAMECO 8080 processorboard, Vector Graphic Reset-n-go programmableand read only memory board and National Multi-plex IO board with 4800 bps digital cassettedeck. All are in excellent working condition.Will include nonworking S D Sales Z-80 processorboard. Sell system for $500 or will sell separately.W R Giffen, POB 781, Richardson TX 75080.

FOR SALE: PDP 8L minicomputer with 4 K coreand teletype interfaces. I Ehrlich, 284 Hendrix St,Philadelphia PA 19116.

FOR SALE: Wintek M6800 processor with ASCIIkeyboard, ACIA, monitor, two PIAs, 5 K memory/power supplies, and cassette tape IO. $250 or bestoffer. Bob Watson, 2853 Pebble Beech Dr,Flagstaff AZ 86001, (602) 526-2312.

FOR SALE: AKI keyboard, matrix encoded,power supply and 5 level paper tape punch, $50. 5level paper tape reader, $50. Ron Rogers, POB17147, Baton Rouge LA 70893.

FOR SALE: MMD-1 8080-based system for inter-facing experimentation and software development.Assembled and tested, $275. Norm Levin, 4408Sherwood Rd, Philadelphia PA 19131.

WANTED: Cylindrical slide rule (such as Thatcheror Fuller) and pocket circular slide rule (such asCarpenter or Sperry) or any other unusual oldslide rule. Also need pocket mechanical calculator(Curta). Describe and price. Dr George Wentz,POB 626, San Marcos TX 78666, (512) 392-2872after 7 PM.

FOR SALE: Centronics Printer # 100; used, $750.Aaron Epstein, 5437 Laurel Canyon Blvd. Suite208, N Hollywood CA 91607, (213) 762-0020.

FOR SALE: Ithaca Audio Z-80 board, $35;Percom Data CI-812 cassette interface, $30; D CHayes board, $50. All bare boards with socketsinstalled. TDL Macroassembler, text outputprogram, Z-Tel, Zapple, text editor, $120 forall software. Kim, Calgary CANADA, 283-6863.

December 1978©BYTE Publications Inc

247

Fesdep Service

To get further information on the products advertised in BYTE, fiff out the reader service card with your name and address. Then circle theappropriate numbers for the advertisers you select from the list. Add a 15 cent stamp to the cord, then drop it in the mail. Not only do yougain information, but our advertisers are encouraged to use the marketplace provided by BYTE. This helps us bring you a bigger B YTE.

Inquiry No.

Page No.

1 AAA Chicago Computer Center 2076 Addmaster Corporation 236

2 Administrative Systems 161

3 AJA Software 201

4 Alpha Micro Systems 82, 8312 Altos 42

8 Ambico 171

9 Apparat Inc 236

14 Apple Computer 8

15 Apple Computer 9Art-by-Computer 173Artec Electronics 113Artec House 125ATV Research 242AVR Electronics 238Axiom 21Base 2 Inc 63Basic Computer Shop 242Beckian Enterprises 245Benchmark Computing Services 236Beta Business Systems 242BITS 133, 136, 138, 139, 155Byte Industries 162BYTE Back Issues 203BYTE Subscribers 203BYTE WATS Line 203Buss/Charles Floto 208California Digital 217Cambridge University Press 208Career Advertiser 244Central Data 107Chrislin Industries 188Circle Enterprises 236

47 Compugard Corp 24453 Compu talker 150Computer Corner 157Computer Enterprises 157, 204Computer Factory 127Computer Hardware Store 236Computer Interface Technology 238Computer Lab of NJ 183Computerland 10, 11. 87, 191Computer Mart of NH 238Computer Mart of NJ & PA 171Computer Plus 196CP Aids 187

CT Micro Computer 183, 206Control Data Corp 177Cromemco 1, 2Cyber-Score 178Data Discount Center 182Dataf acs 173Datasearch 173Datec Inc 244Digital Pathways 14495 Digital Research <CA) 119

100 Digital Research (TX) 219

102 Digital Research & Eng 199

110 Dynabyte 12, 13

113 Ed-Pro 165

115 Electrolabs 230

117 Electro Analytic Systems 192

120 Electronic Control Technology 205

125 Electronic Systems 221

130 Electronics Warehouse 223

132 EMM/CMP 166

101122232426283031343533

32394383454648

65

70

7174727576737879778280849181938589

Inqu

134

138

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148

150

153

156

217

157

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161

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212211213220218225219216222223201227221224202203226229255257265267279280281293282283285286287290291293284292

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296

iry No. Page No.

EMM/Semi 182Eicon 187

Forethought Products 190Gamma Technology 238Godbout 105

Graham Dorian Enterprises CHIGRT Corporation 33H & E Computronics 183Hamilton Logic Systems 242Heath Company 1 7Heath Company 236Hobby World 211Houston Instruments 35HUH Electronics 197Idea Assemblers 244Infinite 244

Integral Data Systems 92; 93Integrand 192

Integrated Circuits Unlimited 225Intelligent Design 236International Data Sciences 126Ithaca Audio 81Ithaca Audio 215Jade 213

Jameco Electronics 226, 227Leland Sheppard 1 73Lifeboat Associates 201M, M, & S Software 236Manchester Equipment 244The Math Box 242Meca 180Micro-Ap 165Micro Diversions 57MtcroDaSys 19Micro Focus LTD 147Micro Matt 167Micromation 31Micro Mike's 190Microproducts 200Microprogramming 245Micro Pro International 77Microtronics 176The Micro Works 129Micro World 51MikOS 230

Morrow/Thinker Toys 23, 97Motorola Semiconductor Products Inc 1 75mpi 200

Mullen Computer Boards 207National Multiplex Corp 149Netronics Research 163New England Electronics 109

New England Personal & Business Computer Show 95New England Recruiters 242Newman Computer Exchange 229North Star Computer 5, 29Northwest Microcomputing Systems 59Necleonic Products 111Ohio Scientific Instruments 37, 40, 41OK Machine & Tool 99Oliver Advanced Engineering 199Optimal Technology 238Osborne & Associates 131Owens Associates 242Pacific Digital 197Pacific Office Systems 234

Inquiry No.

Page No.

297 Page Digital 235

298 PAIA Electronics 172

288 PCE Electronics 206

301 PerCom Data 75

289 PerSci Inc 15

302 Personal Software 91

303 Personal Systems Consulting 106306 Priority I 231, 232, 233

305 Processor Technology 6, 7

Program Design Inc 159

PRS Corporation 71

Quest Electronics 239

Radio Shack Authorized Sales Center 244

RCA 44

Real World Simulations 201

The Recreational Programmer 142

Rochester Data Inc 244

Rockwell 160

Rondure Co 243328 Rothenberg Information System 167316 S-100 196

Saddle Brook Stereo Inc 244

Scientific Research 67, 73, 78

Scelbi 49, 52, 53, 61

Scelbi/BYTE Primer 137

Seattle Computer Products 115

Semionics 164

Michael Shrayer Software 143

Shugart CIV

Silver Spur 236

Small Business Computer Magazine 158320 Smoke Signal Broadcasting 27, 189, 191326 Softside141

Software 80 198

Solid State Sales 237

Southwest Technical Products Corp CM

SSM80

Stirling Bekdorf 122

Structured Systems Group 121

Structured Systems Group 142

Summagraphics 79

Sybex Inc 181

Synchro Sound 103

Talos 174

Tano 145

Tarbell Electronics 117370 Technical Systems Consultants 123373 Telecommunications Services 238

Terrapin 99

Terminal Systems 238

3 S Sales 243

Tora Systems Limited 238

Total Information Services 195

Trans Data Corp 183

Transition Enterprises 189

TransNet Corp 1 72

Tri Tek 234

University Microfilms International 203

US Robotics 198

Vamp 242

Vector Electronics 1 79

VR Data Corp 242388 Wemeco241395 Worldwide Electronics 238

400 Xitex 184

401 Xitex 185 ^Correspond directly with company.

309311304322

307310313314

337

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321340350355352351353356357355359358360

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erjMe-

DYTE's Oftfcing Mcoilcp 8cx

Article No.

12

3

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5

6

7

8

910T11213141516

ARTICLE

PAGE

Stanley-Peterson: Fast Fourier Transforms on Your Home Computer 14

Munnecke: Designing a Universal Turing Machine 26

Ciarcia: Build an Octal/Hexadecimal Output Display 32

Mifliun Reardon-Smart: Life With Your Computer 45

Buckingham: Some Facts of Life 54

Mi lien: One-Dimensional Life 68

Douglas: Chess 4.7 versus David Levy 84

Astmann: Interface Your Computer to a Printing Calculator 94

Gable: Zapper: A Computer Driven EROM Programmer 100

Weisbecker: An Easy Programming System 108

Gerhold: Teaching With a Microcomputer 124

Weed: Clock I ess Multiplication and Division Circuits 128

Frey-Atkin: Creating a Chess Player, Part 3 140

Hatsema: Partitioned Data Sets 168

Willard: The Mother Chip 186

Maurer: FORTRAN and its Generalizations 194

Pascal Blazes Into First Place

"A Tiny* Pascal Compiler, Part V' page58, by Chung and Yuen placed first in theSeptember BOMB. Second place went to"WADUZITDO," page 166, by LarryKheriaty. These articles placed 2.0 and 1.5standard deviations above the mean, respec-tively; first and second prizes of $100 and$50 will be sent to the authors. In thirdplace was "The Mathematics of ComputerGraphics," page 22, followed by "GraphicManipulations Using Matrices," page 156,in fourth.

The BOMB (BYTE's Ongoing MonitorBox) is our monthly forum in which readersrate the articles in BYTE. To participate,see the card at right."

248

December 1978©BYTE Publications Inc

program}

you can u^e in your bu^inc^yready to go noco!

if=

C J PACKAISt.

sr

8<?

**

Our programs will let you realize

We developed these programs because we needed themin our businesses, and, try as we might, could not purchasethem. They're on-line now, working for us and others aroundthe country.

As users ourselves we know the problems from yourperspective — not just as a manufacturer of software. Thebugs are out and they' re ready now to go to work helping makeyour life easier, keeping you in better control of your business.

Our first four program packages are: • ApartmentManagement • Cash Register • Inventory • PayrollHere's a typical program

To give you an idea of the thoroughness of these pro-grams, here's a summary of what the inventory package doesfor you. Gives a detailed listing of items in inventory anditemizes all goods sold from inventory, including which salesperson sold what, when it sold and for how much... recaps onone sheet this same inventory activity information ... investi-gates and changes any information in inventory, on request...prints list of items to be re-ordered ... provides profit analysiscomparing sales personnel and/or various products. And itcan be inter-connected with our cash register package as well,for total program management.

Each of our initial programs is conceived, proven andoffered with this same exacting thoroughness and attention todetail.

We stay with you after the sale #khh

We're in this for the long haul and our support ■ wj

program is dedicated to that objective. Registered !program owners receive:

Master Charge and Visa cards accepted

the full potential of your hardware.

• Periodic newsletters which include users' ideas andinformation exchange, plus tips to owners on further increas-ing benefits of the package through updated operational flexi-bility.

• Availability of software technicians to provide im-mediate answers to questions, via phone or mail.

• Customer rewrites and adaptations available on re-quest, at added cost.

CBASIC-2 free

It takes the world's most powerful commercial basic torun our programs and we deliver it to you free.

Each of our program packages contains a disk withCBASIC-2 Compiler, CBASIC-2 Run Command and yourGraham-Dorian software programs in INT and BAS file form.You also receive User's Manuals and Hard Copy Source List-ing. At a price which pays for itself!

CBASIC-2 was developed and written by Software Sys-tems, the people who wrote CBASIC, and includes manypowerful enhancementsTAll systems are compatible with anyZ-80 or 8080 CP/M® system. They are deliverable in standardeight-inch disk — either double or single density — or mini-floppy disk.

Give us a call or fill out the Reader Service Card in thisissue. We promise a response within 24 hours of receipt.That's the kind of information service we expect,andknowyou do too.

*CBASIC-2 may be purchased separately

from Graham-Dorian Software Systems for $89.95.

Graham-Dorian Software Systems

A Division of Graham-Dorian Enterprises

211 N. Broadway / Wichita, Ks. 67202 / (316) 265-8633

(k

ms

Circle 153 on inquiry card.

"My 8 to 5 minifloppy "nowworks nights and weekends!'

"I own a fast-growing business and before 1bought my computer system I put in a lot of latehours keeping up with my accounting andinventory control. Now the computer does mynumber crunching quickly, so I have time afterhours to have some fun with the system. My sonand I started out playing Star Trek on the system,and now we're learning to play chess.

"When ! was shopping around for my system,the guys in the computer stores demonstrated allthe unique features of the minifloppy. I've got toadmit that at first I didn't really understand all thetechnical details. But now that I use the systemevery day, 1 really appreciate the minifloppy's fastrandom access and data transfer. 1 like thereliability, too.

"I'm glad I went with Shugart drives. Look,when you lay out your own money for a system,you want dependable performance and goodvalue. Do what I did. Ask for the system with theminifloppy."

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

RL Shugart Associates

435 Oakmead Parkway, Sunnyvale, California 94086

For a list of manufacturers featuring Shugart's minifloppy in their systems, circle reader response number.

TM minifloppy is a registered trademark of Shugart Associates

Circle 312 on inquiry card.