197712 Byte Magazine Vol 02 12 The Star Trek Computers

DECEMBER 1977 VOLUME 2, Number 12 EVIE the small systems Oe SPACEPORT GAMMA 6 HOLOGRAPHIC MUSEUM OF ANCIENT TECHNOLOGY MINIFLOPPY Sailr! Sisk evarem Sea CT-84 Scr Your computer system needn’t cost a fortune. Some computer kits include little more Ilhan a mother board and a front panel, and you pay extra for everything else you need to: make an operating computer. SWTPC doesn't do it that way, so you can get your Southwest Technical 6800 Computer up and running al a bargain cost compared with most other systems. !tcomes complete al $395 with features that cost you extra with many other systems. The Extras You Get These extras include 4K of random-access memory, a mini-operating system in read-only memory, and a serial control interface. They give you 1) a considerable amount of working memory for your programs, 2) capability through the mini- operating system to simply turn on power and enter programs without having to first load in a bootstrap loader, and 3) an interface for connecting a terminal and beginning to talk with your computer immediately. Low-Cost Add-Ons Now that you have a working computer, you'll probably want to add at least two features soon, more memory and interfaces for needed accessory equipment, Memory for our 6800 is another bargain. You can get 4K memory boards for just $100 and 8K boards for only $250. Our interfaces cost little compared with many other systems. $995 for the Dual Minifloppy $325 for the CT-64 Terminal $175 for the CT-VM Monitor Or BAC # _—— $250 for the PR-40 Line Panter $79.50 for AC-30 Cassette Inlerlace For just $35 you can add either a serial or parallel interface board. (And you won't have to buy several interfaces on a costly board to get just the one you want.) Peripheral Bargains Your computer is no good without at least a terminal for entering data and viewing computer output, and you will probably want a good method of storing programs and data. We offer you a line of high-quality peripherals at low prices. (You can prove this by just comparing prices.) Buy our CT-64 Video Terminal for only $325 and our CT-VM Monitor with matching cover for $175. Our MF-68 Dual Minilloppy costs just $995, complete with Disk BASIC and a disk operating system. For cassette storage our AC-30 Cassette Interface gives simple control for one or two cassette recorders. You can get inexpensive hard copy with our PR-40 Al- phanumeric Line Printer. We back up the 6800 system with low-cost software, including 4K and 8K BASIC. Compare the value you get with our computer and peripher- als before you buy. We think you'll find that SWTPC gives you more for your money in every way. au Tr Southwest Technical Products Corp. $395 for the 4K 6800 Computer OrMc # z S @ Address City State ee Daw. 19 W Rhapsody, San Antonio, Texas 78216 an Dee, London: Southwest Technical Products Co. Ltd. Tokyo: Southwest Technical Products Corp /Japan Zip. Circle 109 on inquiry card. BYTE December 19771 tines Hin SE port. ee re Serie mat protect you from lescence. FUTURE well as now the featu standard om early 1 1 3 . ine ac 20, 2 1 Gp) ee Tate tl 6) Cromemeco ‘Specialists in computers and peripherals 2400 CHARLESTON RD., MOUNTAIN VIEW, CA 94043 © (415) 964-7400 FORTRAN IV, and other programming power The easy way to get disk storage, 1 Can now finest mic Var you YOU CAN GET THAT ALL-IMPORTANT SOFTWARE, Too Loading your programs and files will take you only a few seconds with the new Cromemco Z-2D computer. You can load fast because the Z-2D comes equipped with a 5” floppy disk drive and controller. Each diskette will store up to 92 kilobytes. Diskettes will also store your pro- grams inexpensively—much more so than with ROMs. And ever so much more conveniently than with cas« settes or paper tape. The Z-2D itself Is our fast, rugged, professional-grade Z-2 computer equipped with disk drive and con- troller. You can get the Z-2D with either single or dual drives (dual shown in photo). CROMEMCO HAS THE SOFTWARE You can rely on this: Cromemco is committed to supplying quality software support. For example, here's what's now available for our Z-2D users: CROMEMCO FORTRAN IV COM- PILER: a well-developed and power- ful FORTRAN that's ideal for scien- tific use. Produces optimized, relo- catable Z-80 object code. CROMEMCO 16K DISK BASIC: a powerful pre-compiling interpreter with 14-digit precision and powerful 1/O handling capabilities. Particularly suited to business applications. CROMEMCO Z-80 ASSEMBLER: a macro-assembler that produces relo- catable object code. Uses standard Z-80 mnemonics. & 2 BYTE December 1977 C have the indus crocompt uter | oy I The professianal- grade microcomputer for professionals ADVANCED CONTROLLER CARD The new Z-2D is a professional system that gives you professional performance. In the Z-2D you get our well- known 4-MHz CPU card, the proven Z-2 chassis with 21-slot motherboard and 30-amp power supply that can handle 21 cards and dual floppy drives with ease. Then there’s our new disk con- troller card with special features: ® Capability to handle up to 4 disk drives © A disk bootstrap Monitor in a 1K 2708 PROM. © An RS-232 serial interface for interfacing your CRT terminal or teletype ® LSI disk controller circuitry Z-2 USERS: Your Z-2 was designed with the future in mind, It can be easily retrofitted with everything needed to convert to a Z-2D, Only $935 kit; or $1135 for assembled retrofit package. nemco oe or reat tpeaea Specialists In computers and peripherals 2400 CHARLESTON RD., MOUNTAIN VIEW, CA 94043 © (415) 964-7400 stry’s tn) dual Shown with optional bench cabinet We're able to put all of this in- cluding a UART for the CRT interface ‘on just one card because we've taken the forward step of using LSI con- troller circuitry, STORE/FACTORY Contact your computer store or Cromemco factory now about the Z-2D. It’s a real workhorse that you can put to professional or OEM use now. Kit: Z-2D with 1 disk drive (Model Z2D-K) .......-..0006 $1495, Assembled: Z-2D fully assembled and tested (Model Z2D-W}... .$2095. Additional disk drive (Model Z2D-FDD) ...........- $495. SOFTWARE (On standard IBM-format soft-sectored mini diskettes) 46K BASIC (Model FDB-S). fe FORTRAN IV (Madel FDF-5| -$95 Z-80 Assembler (Model FDA-S)....$95 Circle 34 on inquiry card. In the Queue 4 BUTE pecemser 1977 Volume 2 Number 12 ~~ — Fo und PUBLISHER re gro! Viiginis Pee EDITOR IN CHIEF 48 A $19 MUSIC INTERFACE Reet ANAC Music Systems—Struve twain they ne 76 ON A TEST EQUIPMENT DIET? TRY AN 8 CHANNEL DVM COCKTAIL! ees Test Equipment—Ciarcia CIRCULATION MANAGER 130 USING THE POLYMORPHICS VIDEO INTERFACE omy Sonesaiee Hardware—Wenzleft Uhristoner F Mongar 164 SAVE SOFTWARE: USE A UART FOR SERIAL 10. a LE ag ; HER Interfacing—McGahee lirabeth Alpauxh eerie Seott Mone Background raoucTion EDITORS 4 Gee Nan salon 12 THE COMPUTERS OF STAR TREK ADVERTISING Speculation—Schmucker-Tarr Pat Crk 24 A FLOPPY DISK TUTORIAL, EQIOR AE ASSISTANT F : iN Floppy Disks—Rampil PRODUCTION ASSISTANT 91 JACK AND THE MACHINE DEBUG EIRCU CA On ASS Software Techniques—Grappel-Hemenway factiwale 104 STRUCTURED PROGRAMMING WITH WARNIER-ORR DIAGRAMS: Part 1 eather ai Software—Higgins TRAFFIC MANAGER 112 SIMULATION OF MOTION: Part 2: An Automobile Suspension reel Modelling—Smith Wai Chiu Ui 118 A LITTLE BIT ON INTERRUPTS Doraiby Soameraky ico Shamonshy 446 ‘i Tutorial—Wier pope PUBLISHER ULTIPROGRAMMING SIMPLIFIED henere om CONVENTION SUPERVIS! Software—Lahasky Hhaban Atpaeth 154 WHERE TO GET BARGAINS IN USED COMPUTER EQUIPMENT ER EEUTIVE SECRETARIES c Ji Calihan Hardware—Libes Patricia Clark 156 A LOOK AT LISP RECEPTIONIST Jacqueline Earnshaw Software—McGath CLUBS AND NEWSLETTERS 162 RELATIVE ADDRESSING FOR THE 8080 hove ee RAFTING Software—Gaskell Douglas Glen 186 A USER'S REPORT ON THE INTERCEPT JR Stenhen Kruse aie Lynn Mal Applications~Lahore SiN Morello Doraihy, Shamonsky (RAPHY. Nucleus Custom Marketing Resources In. Goodway Graphics PHOTOGRAPHY 4 In This BYTE Ed rice 6 Is PASCAL the Next BASIC? Rumord Pres 10 Letters NEW PRODUCTS EDITOR 46 Technical Forum: Wheeler: ASSOCIATES Undocumented M6800 Instructions ate Bans 2 Technical Forum: Gordon: Dav yn The XF and X7 Instructions of the Beale as "a MOS Technology 6502 Flayd W Rebting PC77 Medellin Stephens. a4 Get Your System Together Rona Wise 143 Technical Forum: Gentry: Comments on Paging Schemes 146 Book Reviews 148 Programming Quickies ADVERTISING SALES: eblely out : 149 BYTE’s Bits Buhley forts Aswatates Ine 151 BYTE’s Bugs 313 Seu Bait 152 Clubs, Newsletters tos Araces CA 0019 168 Diddle 215) 826-1021 192 A Note to Novice Kit Builders. .. Ties msn ne 193, 196, 204,216 What's New? Hearst Building 97 Bit Statue Dipiay Sun tarwinu AMIS siti ds (isp 224 BOMB 224 Reader Service y BYTE December 1977 3 This month’s cover is based on Kurt | Schmucker and Robert M Tarr's article, The Computers Of Star Trek {page 12). It is an appropriate topic for computer people, many of whom are science fiction _ aficionados, Trekkies, and users of the Force. The theme, interpreted by artist Robert Tinney, is: What would happen if the crew of the Enterprise visited a holo- graphic museum of ancient technology that had an exhibit devoted to per- sonal computing, circa 1977? Robert used Willard Nico and his 8080 based computer system with dual floppy disk, video terminal and DECwriter as models for the diorama. The cassette recorder, made obsolete by the disk drives, is shown unused. The floppy disk can give your computer the extra storage power needed for many applications such as advanced music and voice synthesis, artificial intelligence and robotics. Find out more about the ubiquitous floppy in Ira Rampil’s A Floppy Disk Tutorial. Microprocessor operation code structure is sometimes incompletely documented, as is demonstrated in two articles: Gerry Wheeler's commen- tary on Undocumented M6800 In- structions and H T Gordon's commen- tary on The XF and X7 Instructions of the MOS Technology 6502. The effects of the undocumented op codes are interesting, even if you don’t want to use them as part of normal coding practices. In a neat combination of tutorial and practical information, Bill Struve’s article A $19 Music Interface (and Some Music Theory for Computer Nuts) provides a way to generate square wave musical tones for four channels as a result of an investigation of the theory of harmony. Transform your computer into a powerful 8 channel 3% digit voltmeter. Steve Ciarcia shows you how in the latest installment of Ciarcia’s Circuit Cellar. Let a BASIC program do all your calculations and get results that 4 BYTE December 1977 compare favorably with expensive digital voltmeters. Read On a Test Equipment Diet? Try an 8 Channel DVM Cocktail! Once upon a time, Jack and the Machine Talked; now Jack and his friendly 6800 have moved onto better things like debugging the programs issued by the assembler described in an earlier article. Turn to Jack and the Machine Debug by Grappel and Hemenway for a humorous (but tutorial) account of the development of a program called Tracer 6800 which uses software breakpoint techniques to provide an instruction by instruction machine code execution trace on a terminal or hard copy device. In This BUTE To write well conceived programs easily, you have to design them in a disciplined and structured fashion. David A Higgins begins describing one useful method in the article on Struc- tured Programming with Warnier-Orr Diagrams, Part 1: Design Methodo- logy. As a second installment in a series of articles, Stephen P Smith turns to the problems of motion in which effects of the motion’s current state feed back into the model. Turn to Simulation of Motion: An Automobile Suspension for a more detailed model which features damping (shock absor- bers) and bounce (springs) in response to external conditions (bumps in a road). The use of interrupts allows you to keep track of several devices at the same time. If you are not familiar with the use of interrupts read Robert Wier's article, A Little Bit on Interrupts. Constructing and interfacing a Poly- Morphics Video Interface is described by Wayne Wenzlaff. Wayne describes his experiences with his video interface and how he modified a television set for use as a monitor in Using the Poly- Morphics Video Interface. Multiprogramming allows — your computer to seemingly perform several tasks at the same time, It can save pro- cessor time by always having a pro- gram executing while another pro- gram waits for some type of input. Prof Irwin Lahasky’s article, Multipro- gramming Simplified, explains the basics of multiprogramming. Many experimenters, including the editors of this magazine, have dis- covered the real advantages of pur- chasing used but eminently usable gear. Sol Libes gives valuable pointers to frugal hackers in Where to Get Bargains in Used Computer Equip- ment. As personal computer users acquire more and more memory for their processors, thoughts can be turned to more powerful languages for the ex- pression of programs. Gary McGath feels that small computer users should have nonnumeric, symbolic data manipulation abilities in their lang- usages. In A Look at LISP, Gary de- scribes one of the candidates for such symbolic manipulations in the small computer, Relative addressing allows jumps within a program to be made indepen- dent of the location of the program in memory address space. But what about such position independent code in processors like the 8080 which have no relative branch addressing? Read James P Gaskell’s Relative Ad- dressing for the 8080 and learn how to simulate this feature for the 8080. Handshaking is the process of coor- dinating two asynchronous processes, such as serial communication opera- tions and a program. Ina short article, Thomas McGahee shows how to Save Software: Use a UART for Serial 10. What do you do if you're an ocean- ographer and want a microprocessor to help collect data at the bottom of the sea for eight weeks? One solution is to use a watertight titanium sphere and a battery powered processor. Henry Lahore shows how he did it in A User's Report on Intercept Jr. Meet The North Star Family THE NORTH STAR S-100 FAMILY—four high perform- ance products at attractive low prices. Our boards are designed for use in the North Star HORIZON computer and other S-100 bus computers using 8080 or Z80 proces- sors. Visit your computer store for a demonstration, or write for our free color catalog. 16K RAM BOARD No other S-100 bus memory can match the performance of the North Star 16K RAM at any price. This low-power board has been designed to work at full speed (no wait states), even at 4MHz with both Z80 and 8080 systems. Memory refresh is invisible to the processor, bank switch- ing is provided and addressability is switch selectable in two 8K sections, Best of all, a parity check option is avail- able. Kit: $399. Assembled: $459. Parity Option — kit: $39. Assembled: $59. MICRO DISK SYSTEM The North Star MDS is a complete floppy disk system with all hardware and software needed to add floppy disk memory and a powerful disk BASIC to 5-100 bus com- puters. The North Star MDS is widely considered one of the best designed and most complete S-100 bus products available. The MDS includes the S-100 interface board with on-board PROM for system startup, Shugart mini- floppy disk drive, cabling and connectors, and DOS and BASIC software on diskette. Kit: $699. Assembled: $799, Additional drive — Kit: $400. Assembled: $450. Single Drive Cabinet: $39. Optional Power Supply: $39. Z80A PROCESSOR BOARD The North Star ZPB brings the full speed, 4MHz Z80A microprocessor to the S-100 bus. Execution is more than twice the speed of an 8080, and the ZPB operates in sys- tems both with and without front panels. The ZPB in- cludes vectored interrupts, auto-jump startup, and space for 1K of on-board EPROM, Kit: $199. Assembled: $259. EPROM Option — kit: $49, Assembled: $69. HARDWARE FLOATING POINT BOARD \f you do number crunching, then this board is for you. The FPB performs high-speed floating point add, subtract, multiply and divide with selectable precision up to 14 decimal digits. Arithmetic is up to 50 times faster than 8080 software, and BASIC programs can execute up to 10 times faster. A version of North Star BASIC is included. Kit: $259. Assembled: $359. Prices subject to change. NORTH STAR = COMPUTERS 2547 Ninth Street - Berkeley, California 94710 - (415) 549-0858 Circle 83 on inquiry card. BYTE December 1977 5 Is PASCAL Editorial the Next BASIC? 6 BYTE December 1977 By Carl Helmers One of the most interesting phenomena in the academic world of computer science of late is the language PASCAL. This lang- uage is the subject of much intense activity, and is rapidly gaining acceptance as the lang- uage of choice for training and illustration of computer concepts to new students of the field. Characteristic of this phenomenon is the existence of on the order of 100 different implementations of the language for various computers and a very active “PASCAL User’s Group.” PASCAL began in the late 1960s as a tutorial experiment of Professor Niklaus Wirth: a method of teaching the concepts of programming in a systematic fashion using a consistent and highly structured program representation. Historically, PASCAL has antecedents in the ALGOL language but with the addition of con- cepts such as record and file structures which were missing in ALGOL's definition. The following passage by Professor Wirth gives the essence of PASCAL’s purposes. . . The development of the language PASCAL is based on two principal aims. The first is to make available a language suitable to teach programming as a system- atic discipline based on certain fundamental concepts clearly and naturally reflected by the language. The second is to develop implementations of this language which are both reliable and efficient on presently available computers. The desire for a new language for the purpose of teaching programming is due to my dissatisfaction with the presently used major languages whose features and con- structs too often cannot be explained logi- cally and convincingly and which too often defy systematic reasoning. Along with this dissatisfaction goes my conviction that the language in which the student is taught to express his ideas profoundly influences his habits of thought and invention, and that the disorder governing these languages directly imposes itself into the program- ming style of the students. There is of course plenty of reason to be cautious with the introduction of yet another programming language, and the objection against teaching programming in a language which is not widely used and accepted has undoubtedly some justifi- cation, at least based on short term com- mercial reasoning. However, the choice of a language for teaching based on its wide- Spread acceptance and availability, together with the fact that the language most widely taught is thereafter going to be the one most widely used, forms the safest recipe for stagnation in a subject of such profound pedagogical influence. { consider it therefore well worthwhile to make an effort to break this vicious circle. [Quoted from the second edition of the PASCAL User Manual and Report, by Kathleen Jensen and Niklaus Wirth, Springer Verlag, New York, 1974, page 133.| Since the time of PASCAL's creation by Professor Wirth, the language has become widespread, primarily because his tutorial purposes also happen to coincide with what one might want in a systems and appli- cations programming language used in software development. In fact acceptance has been sufficiently widespread that there now exist implementations for some of the more common microprocessors in the personal computing field (using the PASCAL User's Group Newsletter as a source for this information in a listing of implemen- tations in issue #8 recently published). What are the ramifications of PASCAL as it might affect personal computing users? At the present time, outside of low level assemblers, the personal computing field is dominated by one language, BASIC. It is the high level language of choice for users of the equipment and for manufacturers who sell to the users of the equipment. Any at- tempted personal computing system design these days must come up to the standards of a reasonable BASIC (such as the Micro- soft BASIC used by MITS, OSI, Commodore and others) or it will be at a relative dis- advantage in the marketplace. This domi- nance of BASIC as a language is a fact of life in this field. A decade and a half of language design evolution has occu’red since BASIC first came on the scene, yet it still dominates at the user level. Why? In a casual enumeration mode, | can list several fairly obvious and _ interrelated reasons why this has become the case; out of these reasons will come a similar scenario for development of PASCAL as a future option for personal computers. @ Everybody knows BASIC. ®@ BASIC has a manufacturer indepen- dent standard definition. @ Lots of implementations of BASIC are available. @ Much personal use applications soft- ware already exists in BASIC. ®@ BASIC is friendly. The most cost effective products for your microcomputer. RM64 64K bytes THE EXTENSYS RM64 MEMORY BOARD provides the most cost effective system memory found in the industry. The RM64 provides this because of our low cost per byte when compared to our competition plus the increased reliability of a single board over multiple boards containing less memory. The board is $-100 bus compatible making it usable in over a dozen different microcomputer systems including ALTAIR and IMSAI. The RM64 is available in four configurations: 16K, 32K, 48K, or 64K bytes of memory all on ONE board. The board is completely assembled, checked out and burned in for over 100 hours prior to shipment, This complete testing procedure allows Extensys to provide a one year warranty on parts, labor and materials {assuming no misuse of the board occurs). On board hardware is provided for: Individual memory bank address selection in 8K byte increments; Complete dynamic refresh logic without loss of processing efficiency while programs are running; Board select logic which allows more than one 64K byte board per system; S-100 bus compatibility including on-board voltage regulator; Memory overlap which allows memory sharing the same address space to coexist in the same system; ): Write protection in 16K blocks; and Fully socketed for 64K allowing 16K, 32K, and 48K versions to be upgraded at a later date. Delivery of the RM64 is 15 to 30 Days upon receipt of order. Prices for the RM64 include shipping and handling prepaid in the continental United States. Extensys Corporation is also announcing several other new, highly cost effective products. The FOS100 Floppy Disk System is based upon the Extensys File [/O Board and incorporates either one or two dual PerSci Model 277 floppy disk drives. The FOS100 System also includes the Extensys Multiprocessor Operating System, EMOS. EMOS provided many large system capabilities, such as multi-processor, multi-user operation and individual file privacy based on user supplied passwords. The MM16 Memory Manager interfaces to RM64 memory boards to create a megabyte or more of memory and adds full DMA capability to the FOS100 Floppy Disk System. Circle 52 on inquiry card. Extensys Fully Assembled and Tested Prices he “l PTAA Fosi00-2 $2880 Wl kathy RM64-16 $ 595 corporation RM64-32 $895 —- FOS100-4 $4680 35 Bernardo Avenue AMG4.48 = $1195 Mountain View, CA RM64-64 $1495 MMI6 $ 295 94040 16K Upgrade $ 375 (415) 969-6100 Articles Potiey AYIT os continually seeking euality pnanuscripts written by individuals whe are unpving personal computer systems, Uvstuniag MRR systems, Ur Whe fuse Anawiedde whieh will prave usetul 10 four readers. Hot w more tornut descrip: ign of provedares and eequicements, potential suthors auld send u sell wuidtessent, stamped envelope to BYTE Auinors’ Guide. 70 Main St, Peter burnaah NHL O34 58, Artiles which ure accepted are pur based with a tate ot up te $50 per maaarine paye, bused on iechnical nants wad suitabiity tor BY TE'S readesshit. Loh month, the authors ie twa Ieunting urticten on the ceader poll (BY TL'S Onuoing Monitur Bos oF “BOMB") uw presented with dorms shecks OF £100 unt $50, Uno ired material Showa be acvompanied by tull name und address, us well ac retura postoye. AY TL December 1977 At a superficial level, these reasons are part of a self-sustaining loop of circular reasoning: Since BASIC is friendly, every- body wants to know BASIC; since so many people learn BASIC, there tend to be lots of implementations. Much software for applications has been written in BASIC. Since a manufacturer independent standard for BASIC exists, conversion of programs from one machine to another is simplified, thus making widely available software useful to people, and so on... ad infinitum. . . This is Professor Wirth’s “vicious circle.” Like many similar conventions, BASIC has been bootstrapped into the public awareness over time, and has acquired a certain inertia of its own that will keep it going for years in the same way that FORTRAN seems to tive forever. Let's examine the reasons in this list, and in so doing compare BASIC to PASCAL, a lang- uage which is quite possibly in an earlier stage of a similar bootstrap cycle and may indeed become a much demanded “language of choice’ for the user community. Vicious circles can have positive aspects: it all depends on which circle one has established. A contention | make is that the same sort of “vicious circle” can be, and indeed is being established for the language PASCAL. Everybody Knows BASIC. BASIC historically was introduced at a time when “big” computers dominated the field, and there was a need to partition the activities of such computers into small individually oriented packages for purposes of making the “big” computer available to many people. This partitioning succeeded admirably: when professor X (or Y or Z) wanted to make real exercises in program- ming available to students, BASIC was frequently employed, due to its availability and interactive simplicity. Like any tech- nology, BASIC did not start out in an “everybody knows” state, but it got that way through its early availability and no small push from pedagogues of computer science. Today, the teachers of programming are tending to push PASCAL as the language of choice for teaching “good” programming concepts. The PASCAL User's Group is evidence of the number of academic people who support the ideas of Professor Wirth to the extent of implementing their own local PASCAL systems for educational purposes. (This is typically done using a number of techniques of machine independence con- ceived by carly implementors of PASCAL for purposes of spreading its implemen- tations.) One result of this availability is that PASCAL is becoming the tool of teaching programming concepts which Professor Wirth envisioned . .. and the beginnings of the ‘everybody knows” state for PASCAL are already evident, BASIC Has a Manufacturer Independent Standard Definition. This comment is nominally true of BASIC, Work is indeed in progress on an ANSI standard for BASIC, and there is of course the original Dartmouth College definition of BASIC. The fact that people are trying to define a standard form of BASIC, however, is a result of the fact that the implementations of BASIC have been somewhat subject to variations. In the personal computing world, there are numerous differences at a detail level between language extensions of various BASIC interpreters, some as basic as the variations in string and array handling in various forms of minicomputer BASIC. BASIC language implementors are no different from implementors of a number of languages, often succumbing to the “wouldn't it be neat if syndrome and throwing in features not part of the original definitions of the language. The hitch with such featurism is that if anyone uses the features, the programs written with the feature may no longer be portable. Of course PASCAL would be no more immune to featurism on the part of imple- mentors; at least thal would be an obvious contention since there is no fundamental difference between people who implement BASIC and people who implement PASCAL. But before making such a statement, an examination for the motives of implemen- tation featurism should be made, BASIC in its original definition is a very limited and parochial language, one which represents a viewpoint of quick implementation of programs with limited 10 formatting, standard floating point operations, and no intent to service large or complicated applications. Thus, many of the “feature” templations presented to BASIC imple- mentors are a result of attempts Lo correct the deficiencies of BASIC by adding omitted items (for example, strings, implemented differently in various BASIC interpreters). PASCAL, on the other hand, by having a definition which is more general in scope than BASIC (although by no means compli- cated to use in simple problems) helps cut down these ‘feature’ temptations on the part of its implementors. One basic example of this slightly more general definition is in PASCAL's inclusion of extensible data Continued on page 184 BS 2K/4% EPROM Board Kittens EF 84.93, Riteeim 97024 (1 ya) 10498 it with E-17028 (1 8) 144.95 SAT ma snes pera ate MET 16K Momory 8 wan an na Stor ps 285.00 ret TOK RAM 625.00 Baer Gos = 2095 And, we build just oord about any board you'll want for S-100 bus expansion. When you're thinking about expansion look to the Solid State Music “blue boards.’ You'll find quality and user versa- tility built into every one allowing you to ex- pand your system in whatever direction you choose . . . and, we've been doing It for years. Right from the start we design our boards with our customers in mind. Extra features are added that will aid in expansion, not hinder program design and devel- opment. All first class parts are used and they're checked Bt Video Intertace Board to make sure you have years of trouble free operation. Plus, Bure Pc. Bowe 29.98 every kit comes complete with assembly instructions and user information to make assembly a snap and operation a pleasure. Talk to your dealer today to get more facts about the “blue boards” or write direct. Compare prices, quality and features. You'll find out 3B) Music Synihorizer Bos: why more and more people are using Solid State Music "blue boards” RIUNSSATSCSUEER e100 08 for their S-100 bus expansion. SPECIAL BONUS OFFER An 8080 Monitor for 1/2 price!!! Kitiawe momory 108 sparen and 2-80 i : t aolenaiabaa Pe If you buy any of the Solid State Music kits or assembled boards you'll receive “Asvambies boards also available: a SSM8OC80 Monitor complete with ei- ene nooner prions. ther eight 1702's or two 2708's and over 50 pages of software information. A $49,965 retail vaiue. . . just $25.00, Hurry! @ o.bercom Solid State Music 2102A Walsh Avenue ° Santa Clara, CA 95050 Circle 106 on inquiry card, (408) 248-2707 We're the biue boards etters DON'T KNOCK HOMEBREW I just happened on Edgar Cohen's letter titled “Homebrew” (August 1977, page 12). He feels as | do, that we as readers should be looking at more homebrew computer articles in BYTE. My motive for writing was spurred by your follow-up comments, We in amateur radio have been home- brewing it for years, even before com- mercial equipment was available. And much of the present day homebrewing is for economic reasons. At age 13, | wouldn't have had my own amateur radio station had it not been for home built equipment, much of it coming from construction articles in publica- tions like BYTE. This same rule applies to test equipment I’ve built (frequency counter} and [ think it applies to com- puters as well. As a matter of fact, the only reason | don't have a computer yet is because practically everything on the market Is out of my price range. To top if off, there are very few good surplus buys available, another way we in amateur radio get by cheaply. I think you are wrong about the time invested in homebrew equipment. | and many other readers would gladly invest the time, if only the technology were there to give us a shove in the right direction. Certainly, the parts aren't ex- pensive at all and much can be saved by wire wrapping instead of using ready to go printed circuit boards made up and sold by someone else. Gary L Montgomery WB3GBQ Rockville MD. in reply, fet me reiterate the fact that } am a confirmed homebrewer, always trying to get the best system by my own viewpoints on the subject of design. But perhaps the reason | don't view the method as cost effective Is the remem- brance of money spent to get one of the first Motorola 6800 chips ($360 for an XC6800 in early 1975) and simitar purchase of 4 K static memory chips ahead of fater price reductions. I've built @ system with close to 800 TTL and MOS integrated circuits in the main processor modules, a system which, much to my homebrew surprise, works quite reliably. So} can certainly attest to the effectiveness of the approach. . .CH 10 BYTE December 1977 ANOTHER VIEW OF TECHNOLOGY'S: USEFULNESS Jam writing to BYTE in response to previous letters by Robert Garner {Ask BYTE, May 1977) and Nelson Ingersoll (Letters, September 1977) about the moral future and purpose of the com- puter. In response to Mr Garner's letter, the real hazard that results from computers being “plugged into applications right and left"’ arises not from intangible and poorly defined moral abuses that might result from their introduction, but rather from the standpoint of cost effective- ness. Computers are being considered for such purposes as maintaining home food recipe fites and keeping track of food inventory, where it is much simpler and cheaper to perform these tasks the old- fashioned way. | agree with Mr Garner that computers could be misused, but he seems to promote the same general hysteria that is currently plaguing the new science of genetic engineering. True, along with every new technological development comes a host of possibi- lities of misuse, but surely these can be minimized so that we could reap the maximum benefits fram i1? Sanctimo- nious morality does nothing but help the public to concentrate solely on the deficiencies of a technological develop: ment and destroy it before it has had a chance to prove itself. Mr Ingersoll's problem seems to lie in the fact that he sees the computer as a device that will replace all of our duties as human beings and turn us into nonthinking, passive entities. | primarily see the computer as a tool, as a device that will aid man and not replace him. The “automation of physical and mental drudgery" does not relieve man of any responsibility to be productive and to think, but rather it frees him from simpler tasks (drudgery) in order to be the most creative and achieve the greatest self-satisfaction; man is only utilizing the feature that distinguishes him from the rest of the animal king- dom; in this instance, a decided advan- tage. | argue that performing simple and thoughtless tasks /s drudgery. The “box” analogy is poor in that it presupposes it took no effort to design, build, and program the computer and robot to make the box. What Mr Ingersoll over- looks is that to accomplish this the man Continusd on page 19 im-pak AUTHORIZED DEALERS ALABAMA Mobile Lafayette Radia Electronics CALIFORNIA Berkeley At Lasher Electronics Montorey Zackil Palo Allo Zaok Etactronics Sacramento The Radio Place Sacramento Zackit ‘San Cartos aH Outat Store| Sen Francisco Zack Electronics| ‘Sunnyvaie Sunnyvale Electronics Vaitefo Zackit Walnut Creek Byte Shop Computer Store FLORIDA Tampa Microcomputer Systems} GEORGIA ‘Atianta ‘Atfenta Computer Mart HAWAII Aiea Delcoms Hawaii Honolulu Integrated Circuit Supply ILLINOIS Evansion ty Bitty Machine Co. INDIANA East Chicago Acro Electronics Corp. Hammond ‘Quantum Computer Works LOUISIANA Baion Rouge Davis Electronic Supply Co. MARYLAND Baltimore Computer Workshop of Baltimore Fockvils Computer Workshop MASSACHUSETTS Madtord Tults Electronics MICHIGAN Lansing Fulton Radio Supply Co. MINNESOTA Duluth Northwest Radio of Duluth Eagan Dacom Amateur Fadio Ctr MISSOURI Parkville Computer Workshop of Kansas City MONTANA Bitings Conley Radio Supply NEBRASKA Lincoln Altair Computer Center NEW JERSEY Hoboken Hoboken Computer Works NEW YORK Albany Fort Orange Electronics ‘New York Computer Mart of New York Now York The Computer Siore| Troy Trojan Electronics White Plains The Computer Corner HO Cincinnatt Digitat Design OKLAHOMA Oklahome City Bits, Bytes & Micros ‘OREGON Beaverton Altair Computer Center PENNSYLVANIA Murraysvite Computer Workshop of Pittsburgh RHODE ISLAND Cranston Jabbour Electronics City Pawtucket Jabbour Electronics City TENNESSEE Memphis: Ssre-Rose & Spencer Electronics Oak Ridge Computer Denn TEXAS Daitas Computer Shops ino. Houston Attgit Computer Contor Houston Interactive Computers VIRGINIA Alexandra Computer Hardware Store Springliaid Computer Workshop of Northern Virginla WASHINGTON Botevue Altair Computer Conter Longview Progress Electronics WEST VIRGINIA ‘Morgantown The Computer Corner Morgantown Electro Distributing Co, CANADA Alberta, Calgary The Computer Shop FORE! France, Paris Computer Boutique SAN CARLOS, CALIFORNIA 94070 yy, VISIT nmmvpal DEALER YOUR J TODAY! [electronic components} JIM-PAK, 1021 HOWARD AVENUE, Circle 67 on inquiry card, ATTENTION DEALERS: Announcing One- “Stop Component Center * Over 200 quality items in- cluding integrated circuits, resistors, diodes, transis- tors, capacitors, connect- ors, switches, sockets, LEDs and Data Books covering all JIM-PAK® items. «Immediate delivery on all orders *Store display racks avail- able *Stock rotation and return policy * Direct mail program avail- able from list of active electronic buyers indealers’ area, % National advertising cam- paign in teading electronics magazines to include fist of qualifying dealers *Nationally known manu- facturess' products at prices every dealer can afford * Guaranteed products *Standard industry part numbers 8 67 on Inquiry card. A component line of proven sellers developed for the independent dealer. Ideal for computer shops, scheol stores, electronic dealers, hobby shops, orany location where there is a potential market for electronic sales. A product line which sup- plies most of your needs from one distributor with a teputation for fast and efficient service. Attractive and compact display racks make initial instalation of the JIM-PAK® line easy. Your customers deserve the best. Now you can profitably retail name brand compon- ents at competitive prices. Be the first in your area to announce and sell the JIM- PAK® fine. Write or call today. FOR MORE INFORMATION AND PRICING SCHEDULE CONTACT: , adivision of James Electronics, 1021 Howard Avenue, San Carlos, California 94070, (415) 592- se | About the Authors Kurt { Schmucker has been employed as a mathematician at the Depart- ment of Defense in Washington DC since 1974, He received an MS in mathe- matics in 1974 from Michigan State Univerisity, and an MS in computer science from Johns Hopkins University in 1977. Mr Schmucker is also cur- rently an advanced special student in the computer science department of the University of Maryland. He is a member of Phi Beta Kappa, the Mathematical Association of America, and the ACM. Robert M Tarr has been employed as an electronics engineer at the Depart- ment of Defense in Washington DC since 1974. He received an MS in mater- ials science in 1972, an MS in electrical engineering in 1973, and an engineer degree in electrical engineering in 1975, all from the University of Southern California. He is currently pursuing a PhD in electrical engineering with a computers major at the University of Maryland, Mr Tarr is a member of Phi Beta Kappa, Eta Kappa Nu, and the 1EEE. 12 BYTE December 1977 Introduction The world of Star Trek represents many things to many people. To the majority it is an escape into a time when man is once again challenged by the vastness of his known universe and can assume the now lost role of the explorer of unknown ter- ritories with their inherent, but also un- known, dangers. To others it is the tale of man’s final triumph over his own inhuman- ity; a world where race (human, humanoid or other), color and background are not points of contention and disunity, but are rather different reference points from which the society can grow together in peace. In this case “infinite diversity in infinite combinations” yields a whole which is greater than the sum of its parts. To yet others it is a time when science and the mysteries of nature are more clearly under- stood, an understanding which brings forth a technology beyond one’s wildest imagination. Whatever view one takes of the Star Trek phenomenon, one can ask how closely our present culture approaches that ideal, be it in the area of science, human understanding, vr man’s view of himself in his world. This essay will try to measure one such gap between our own world and that of Star Trek: the state of computer technology. Star Trek, with its fantastic starship the Enterprise, presents a level of computer science and computer engineering predicted by many science fiction writers,!:? 3455 Problems like voice 10, automatic program- ming in a natural language and computer analysis of complex, ill-defined problems are handled routinely. How close is the present technology to solving these problems? How soon can the computers of the Enter- prise be constructed? Let us try to answer these questions. Very little, if any, technical information is available on the Enterprise computers. Only vague, nontechnical statements are ever made by the Captain or the Science Officer. “Deep in the heart of this ship are our computer banks, They operate the entire ship. They also contain the whole of human and humanoid knowledge. They are indisputably reliable. Our lives depend on them. ""6 “In a matter of a few seconds we can obtain an answer to any factual question, regardless of its complexity.'"7 No references are ever made to its physical configuration, Is it in fact one large central processor with terminals and perhaps ter- minal concentrators scattered throughout the ship, or a number of smaller optimized- for-special-functions processors —_ loosely coupled through a shipwide network? The portions of the Star Fleet Technical Manual which recently have been made available to other than Star Fleet personnel do not in- clude the “Ship's Computers Systems Schematics” section or the “Ship's Com- puters Maintenance Schematics” section.8 This essay will speculate on various hypotheses supported by the user level in- formation available, and will attempt to show the hardware and software possibilities. The Role of the Enterprise The world of Star Trek takes place in the late 22nd or early 23rd century.?*! In that era the United Starship Enterprise is perhaps the second largest scientific and technical have bonded together to form a union called the United Federation of Planets. It is a union more loose than the United States of America of the 19th, 20th and 21st cen- turies, yet stronger than the United Nations of the 20th century.'? These planets occupy a significant portion of the Milky Way called the Treaty Exploration Territory, roughly a sphere centered on Sol with a radius of 4750 parsecs (approximately 15,500 light years). The Articles of the Federation were the agreement which established this union. They authorized funds for the building of a Star Fleet to act as the armed, peace keeping force of the Federation. The Fleet would be designed and built using state of the art techniques. Included in this Star Fleet appropriation was an initial expenditure for 14 heavy cruiser starships, one to be named the Enterprise. These starships would be capable of extended duration patrol of the Treaty Exploration Territory and would be provided with weaponry and other capabilities enabling them to accomplish a myriad of possible tasks. A starship on patrol represented the Federation in all matters within its occupied quadrant of space. Its functions included military uses (defense of borders and moni- toring of intergalactic treaties with the Klingon and Romulan Empires, two other aserte ote 0000 achievement resulting from the combined technologies of a unified portion of the Milky Way.'! In the 22nd century a portion of the intelligent life forms of the galaxy “Computer, | want a complete rundown of afl references to the design of computer systems for Enterprise class ships in the first quarter century of BYTE magazine.” “Yes, sir, but are you prepared for recursion?” BYTE December 1977 13 14 RYTE Decemmer 1977 Federation-sized planetary unions, police actions (enforcement of Federation law, investigation of criminal actions), scientific missions (new explorations, data gathering assignments), diplomatic assignments, and missions of mercy. It may be of benefit to compare the star- ship Enterprise to its namesake of the 20th century, the United States aircraft carrier Enterprise, in order to get a grasp of the scope involved in the construction of such a vessel. The USS Enterprise, launched in 1960, was the largest warship of ils time and represented state of the art technology. It is still operational today and is powered by ten nuclear reactors. The USS Enterprise can sail on one set of reactor cores for about ten to 13 years or roughly 300,000 miles. It is provisioned every fow wecks, however. The total cost of the construction and outfitting was 451 million dollars. !n wartime, its complement is 5500 people consisting of 162 officers and approxi- mately 2940 ealisied men plus 2400 airmen attached to an air wing.!? The starship Enterprise, on the other hand, is powered by a controlled matter antimatter reaction.14+15 The totai cost of the Enterprise was 50 billion credits.'® On patrol, its complement consists entirely of 430 officers with 43 command (lieutenant and above) and 387 crew (ensign rank).?7 Traveling at the speed of light (ie: Warp Factor 1, approximately 1/200th of its flank speed) the Enterprise can travel for 18 years (as measured by a calendar traveling aboard the Lnterprise?) without refueling or taking on additional provisions,!® Computer Uses and Capabilities of the Enterprise An enterprise as complex as a starship requires a vast amount of computer sup- port. Many of the routine tasks, such as monitoring of life-support systems, food synthesis and turbolift control (a vertical and horizontal elevator used for intraship transportation) are automatically maintained and controlled by the ship's computers. These are manually controlled only during an emergency. Even more demanding and less well- defined tasks are routinely delegated to the ship’s computers. The computers can activate the ship’s alert systems and initiate the deflector shields (a set of very sophisticated defensive force shields which block matter and selective energy transmission) upon analysis from the ship’s sensors, It appears. that only a portion of the ship's vast amount of sensory data is routinely patched through the computer, since it is often instructed Jo “tie in to all ship's sensors” and provide the command staff with an analysis of unknown phenomena! 2:29?! If most of the fnterprise computing power resides in a central processing unit, this may point to a limitation in the com- puter's processing power. Perhaps if all data from all sensors were routinely processed there would be insufficient computing power to perform the remaining essential functions. If, on the other hand, there is a network of processors, then it may be that the results of sensor input are not routinely passed to the central compiex. Certain groups of sensors may be tied to local processors which perform the necessary functions, eg: activation of shields. The central processor complex does not routinely have need for these results unless correlation of the sensor data is required. Computer control of the weapons sys- tems (phasers and photon torpedoes) is also possible through analysis of sensor input, bul it is not as accurate as computer assisted human control coupled with visual contact with the desired target.?? This, too, may point to either a lack of sufficient com- puting power for timely analysis, or a lack of appropriate decision algorithms for this type of situation, Another major use of the computer, perhaps the one most apparent to the casual observer, is information storage. The need for an immense data base can be clearly seen when one considers the role a starship plays in its patrol area. A starship captain acts autonomously from Star Fleet Headquarters in almost all aspects of his command.?? As far as violations of Federation law are con- cerned, he is the judge and jury. In addition, the officers and crew often require instant access to the immense technical knowledge of the Federation in order ta cope with new phenomena encountered in their patrols. This requires the existence of an immense interactive data base on the Enterprise itself. Because of the intergalactic distances involved, there can be no link to the com- puters at Star Fleet Headquarters or on Memory Alpha.?4 Subspace communica- tions require time for transmission, too (often on the order of days).?° 926 The vast amount of information stored in this data base is best appreciated by relating two incidents that happened on the Enter prise. The first involved a small space cruiser traveling toward Ophiuchus VI without an identification beacon. Upon pursuit, the cruiser entered an asteroid belt. After Continued on page 172 HORIZON ™ — a complete, high-performance microprocessor system with integrated floppy disk memory, HORIZON is attractive, professionally engineered, and ideal for business, educational and personal applicaticns. To begin programming in extended BASIC, merely add a CRT or hardl-copy terminal. HORIZON-1 includes a Z80A processor, 16K RAM, minifloppy™ disk and 12-slot 5-100 motherboard with serial terminal interface — all standard equipment WHAT ABOUT PERFORMANCE? The Z80A processor operates at 4MHZ — double the power of the 8080. And our 16K RAM board lets the Z80A execute at full speed. HORIZON can load or save a 10K byte disk program in fess than 2 seconds. Each diskette can store 90K bytes. AND SOFTWARE, TOO HORIZON includes the North Star Disk Operating System and full extended BASIC on diskette ready at power-on. Our BASIC, now in widespread use, has everything desired in a BASIC, in- cluding sequential and random disk files, formatted output, a powerful line editor, strings, machine language CALL and more. Look To The North Star HORIZON Computer. EXPAND YOUR HORIZON Also available— Hardware floating point board {FPB); addi- tional 16K memory boards with parity option. Add a second disk drive and you have HORIZON-2. Economical serial and parallel [/O ports may be installed on the motherboard. Many widely available 5-100 bus peripheral boards can be added to HORIZON. QUALITY AT THE RIGHT PRICE HORIZON processor board, RAM, FPB and MICRO DISK SYS- TEM can be bought separately for either Z80 or 8080 S-100 bus systems. HORIZON-1 $1599 kit; $1899 assembled. HORIZON-2 $1999 kit; $2349 assembled 16K RAM—$399 kit; $459 assembled; Parity option $39 kit; $59 assembled. FPB $259 kit; $359 assembled. Z80 board $199 kit; $259 assembled. Prices subject to change. HORIZON offered in choice of wood or blue metal cover at no extra charge. Write for free color catalogue or visit your local computer store. NortH StarR *& ComPUTERS 2547 Ninth Street » Berkeley, California 94710 + (415) 549-0858 Circle 83 on inquiry card. BYTE December 1977 15, ing Apple II. Introduc The home computer thats ready to work, play and grow with you. Clear the kitchen table. Bring in the color T.Y. Plug in your new Apple II¥ and connect any standard cassette recorder/player. Now you're ready for an evening of discovery in the new world of personal computers. Only Apple I makes it that easy. It's a complete, ready to use computer—not a kit. At $1298, it includes features you won't find on other personal computers costing twice as much. Features such as video graphics in 15 colors. Anda built-in memory capacity of 8K bytes ROM and 4K bytes RAM —with room for lots more. But you don’t even need to know a RAM from a ROM to use and enjoy Apple II. It's the first personal computer with a fast version of BASIC—the English-like pro- gramming language— permanently built in. That means you can begin running your Apple ll the first evening, entering your own instructions and watching them work, even if you've had no previous computer experience. The familiar typewriter-style keyboard makes communication easy. And your pro- grams and data can be stored on (and re- trieved from) audio cassettes, using the built- in cassette interface, so you can swap with other Apple II users. This and other peri- pherals—optional equipment on most per- sonal computers, at hundreds of dollars extra cost—are built into Apple II. And it’s designed to keep up with changing technol- ogy, to expand easily whenever you need it to. Asan educational tool, Apple II is a sound investment. You can program it to tutor your children in most any subject, such as spelling, history or math. But the biggest benefit—no matter how you use Apple II—is that you and your family increase your familiarity with the computer itself. The more you experiment with it, the more you discover about its potential. Start by playing PONG. Then invent your own games using the input keyboard, game paddles and built-in speaker. As you experi- ment you'll acquire new programming skills which will open up new ways to use your Apple II. You'll learn to “paint” dazzling color displays using the unique color graphics com- mands in Apple BASIC, and write programs to create beautiful kaleidoscopic designs. As you master Apple BASIC, you'll be able to organize, index and store data on household fi- nances, income tax, recipes, and record col- fections. You can learn to chart your biorhythms, balance your checking ac- count, even control your home environment. Apple II will go as far as your imagination can take it. Best of all, Apple II is designed to grow with you. As your skill and experience with computing increase, you may want to add new Apple peripherals. For example, a re- fined, more sophisticated BASIC language is being developed for advanced scientific and mathematical applications, And in addi- tion to the built-in audio, video and game interfaces, there’s room for eight plug-in options such as a prototyping board for ex- perimenting with interfaces to other equip- ment; a serial board for connecting teletype, printer and other terminals; a parallel inter- face for communicating with a printer or another computer; an EPROM board for stor- ing programs permanently; and a modem board communications interface. A floppy disk interface with software and complete operating systems will be available at the end of 1977. And there are many more options to come, because Apple II was designed from the beginning to accommodate increased power and capability as your requirements change. If you'd like to see for yourself Apple II™ is a completely self-contained computer system with BASIC in ROM, color graphics, ASCII keyboard, light- weight, efficient switching power supply and molded case. It is supplied with BASIC in ROM, up to 48K bytes of RAM, and with cassette tape, video and game I/O interfaces built-in. Also in- cluded are two game paddles anda demonstration cassette. SPECIFICATIONS * Microprocessor: 6502 (1 MHz). * Video Display: Memory mapped, 5 modes—all Software-selectable: + Text—40 characters/line, 24 lines upper case. + Color graphics—40h x 48v, 15 colors + High-resolution graphics—280h x 192v; black, white, violet, green (16K RAM minimum required) + Both graphics modes can be selected to include 4 lines of text at the bottom of the display area. + Completely transparent memory access, All color generation done digitally. * Memory: up to 48K bytes on-board RAM (4K supplied) + Uses either 4K or new 16K dynamic memory chips - Up to 12K ROM (8K supplied) * Software + Fast extended Integer BASIC in ROM with color graphics commands + Extensive nionitor in ROM “Vo + 1500 bps cassette interface + 8-slot motherboard - Apple game 1/0 connector - ASCII keyboard port + Speaker Apple Dis also . available in board-only form for the do-it-yourself hobbyist. Has all of the features of the Apple II system, but does not include case, keyboard, power supply or game paddles. $798. PONG isa trademark of Atari Inc. ‘*Apple II plugs into any standard TV using an inexpensive modulator (not supplied). how easy it is to use and enjoy Apple II, visit your local dealer for a demonstration and a copy of our detailed brochure. Or write Apple Computer Inc., 20863 Stevens Creek Blvd.,Cupertino, California 95014. Circle 4 on inquiry card, q@goppic computer inc: Order your Appliell now. from any one of the following authorized dealers: ALABAMA gutarland ‘University Or, H.W, Humsvite $5080 The Computer Ce 303 B. Poplar Pi Birmingham» 942-8567 ALASKA Team Electonics 32 Shopping Center ARIZONA SIS Suda Road tame Hae CALIFORNIA rf r a Bia "e074 pele lo Computertand 6840 La Cionena Bivd, Inglewood 778-8086 Ba act Lane Shem lai, Szo68 Bae boning feat Baie 328 bdo Bye BS Se ive sadena Bu Stop 2626 Union Avenue San Jose 377-4685 Erle Ee Tere oe, Fe Nain Seet 288: ‘Walnut Creek 933-6252 ALVIDO Electronics 2210 Balfowe load Lona Beach 998-0444 Sea et ti Shore A 83 S651 Song eromng venue Wesinster "oe 8390 a Bees San eee 491-0840 unbow Computing, Inc. 23 White a Granade Hills 360-217 Stawbon Electonics Beinn 585.6201 ii 781-6232 Bee oe julder 447 Team Elciames Frets Colorado Sings 5965866 an Eleranice oles Fort Calling 484-7500 Tees ans Sopaing Cs let Aims Shopaing Comer Stan Sian “24-495 Etecenies ao, 18 BYTE December 1977 2 HA Fe Houston 77-0884 : 8438 Westhemer tin 5683 Ramm Gert alles 234-3412 Biante Son Antonio 826-0589 Sortie gn Ease 592-1777 anton Store vi cad apna beh ia Beach 466-1900 flectonics i cc 208.0926 WASHINGTON Teas Hecuoncs aH Wine “469.0918 WiscONsIN Ba lah oad ine 894-0328 ‘Team Blectromes $368, Clauusont Parkway tau 634-1208, ag Begunes inn et “saegaene Team Iau) ona on fg sot ite Elmwood Plare Sha Recine 554-050! ting Canter Figen sft — ‘389-3900 Beige ti ti ce ” 38 on SE iy, Team Electonics 3301-3500 $. 27th Steet om. a ese Tsheosn 255-7050 WYOMING wr Casner 235-8691 CANADA 2214 oes Montieal, Que, 731-4638 COLORADO {continued) pidaitahs (continued) MINNESOTA {continued} NORTH CAROLINA Team Et Teen Eo Bytn Shop 10 Main Street Bt Louisiana Steet ab Rice ‘Street ivi Yalshorou Ih St. Longmont 772-7800 Lawrence 841-3775 ‘SL Paul 227-7223 Raleigh 833-0210 ‘Team Electonics Tea Electro ‘Tear, Electronics, NORTH DAKOTA {azz Coecsation Read Heaton Soeaeae) schol is ba a Beetorice Pueblo 545-0703 Team Electronics, lismarck 223-41 Ht 3 ic Avenue, FLonios Ee ask FEI ESE a ome 2 Face HONE sam echo, ae Bbw aah a8 ate eee SOD" Mhaneapls 981185; Team Electonics Bus Shon Teun lecugics Ian flecoics Grand Forks 7404074 fn 1e East Square Me Mani 2503083 T5960 e Keitt oe Aye Jeam Elsctronics GEORGI Weenie 6838-8826 ye 200 Th aaa 54 Sate Matt, fn. arn eat Set Pate Sale ano Weta Bez Mankato a Team Elegie: Jaan Ccuanics Haws “Tha Walon Hayy Stet SiD Grom Avenue onIo Real Sh Wichta 632-7509 veleth 749-8140 hs Date Domain BEA wsr even tee Bie ” ito91 Javion b iLUNOIS. Parebug 2511070 he naling GRLAHOHA Hesonn in,Suc 4 Tomar rE Oe Tig Eerset Carpeniersvite “4286474” ———GI3'8 Lyndon tone a iano tn, ee cua Coreen i eo hs Shopoing Center ‘ Oren s77 778 ay cae Team Electonics fos ag sa eam Electonics. ington yoads Spec Sandburg The daa Oo 30) Stadium Bid klanone Sey Ge 3389 50 we ca Saath ‘Drive: 3028 Hunsinger Lane Columbia 445-4496 Team Electi med — Louisville 456-5242 Hictanle Compnacaes inti Penn a anae "Shonoina Ceater Feta Shon Center MARYLAND Eotunbe "ne Shes Oklahoma iy 848.5673 Mine Boe TaORS rede food Chea TBR Ht eae Nenu Rekvle 848-7 Tea lec Siitwater “397-2080 0 ck, Uniatiy Me snsaacnuserrs Gat Falls om Tepe Becunis aoe ese bee ES. & a e698 shgton 272-5 issoila 649-4119 Lay MICHIGAN Commuters Made Easy Asta ls a Team Elect Shei, Delo Plaza Sho a $08-3085 tha 362761 pon Escanaba” 786- NEBRASKA Team Hletroms certian Team Electronics Team Electronics Sueer Hie Schaumburg 882-5854 MBiM Plaza V4B Conestoga Malt Yokon 373-1996 pada Menominee 864-2213 Higheay 281 & 13th Street Bits, Bytes & Micros 2116 8, Mochtan Bit MINNESOTA oa ‘sland 361-0559 1186 W. asta Sea 4 ean and ret 2055 “O" Suet, SE Nene toss ete Mel thea "46-89 TRO PAR a. Aulington Heaghts 265-6488 4z003 Waveate Bhd Teun Earns Oklahoma City 842-1 Seapets ive Team Electonics Gedanel Ser fasta OREGON fins “abrtie a EG sue Bieth eer Company iar conics Bend S28 3 Recon eaten ary Bs Won Canby Ks 20 E08 geste ian reson Banh Figen oad WE. at Wan 4B 7611 ied Bovina be 3278 womb Be sour oan fndusapole 2613138 Hoth Piatte "6244545 TW Sear enue sown NEW HAMPSHIRE La Lia ans Computernart eam Hecton 2 Mam Steet : TOT Omane Set fos HNashue B88 %308 Aisa ti oes Beek Geet NEW JERSEY Ha cer Beiendet 385-7013 Sonoutateed 396-3730 Ta Fee Reve we Tean Electonics Mowistown $38-4077 Tere then verve me Viegmia 741-5919 Somowterrat ‘Western Mall Cedar Rapids 393-8956 ‘501 Route 27 ‘Sioux Falls 339-1421 Tean terres Ipocte fies Weta "269-0600 an cones Bo Kinet Bead iver Lake Road NEW YORK Sioux Empire Mal, Bevenon Jeb 7580 st eador I aad mh Bas ese Team Electronics Sere Nona Fate ae ay Rectan, 1755 §. Robert Steet Bulfalo 636-6511 eam econis 200, seni West $i Fal” 765 25 Mint Be Lae Team Electrics SE tte Hoag Seteown Fe Sate 16 Rinmeosols "377 3680 Geog Secon meee eat Glarence 8347199 ni See a “Bir If you would like to be an Apple dealer, call Gene Carter, Fasten saton Director of Dealer Marketing, 408-996-1010. ‘Sioux City 277-2019 ier | a computer inc: ‘atelog 238-8867 . wansas ee ee en 20863 Stevens Creek Boulevard, B3-C Garden City 276: tl Wee ae, Hutchinson 662-0632 Cupertino, California 95014 (408) 996-1010 Circle 4 on inquiry card. — a PERIEM the inside story = yeRMINVAL tare vie oN roca Circle 90 on inquiry card, jae =o a ° Record and playback at 120, 60 or 30 self-clocking bytes per second (extended Kansas City Standard) 1200, 600 or 300 baud data terminal interface Dual cassette operation Compatible with SWTPC cas- sette software Optional kit permits program control of cassettes Optional adaptor permits inter- facing with any computer Upgrade your SWTPC 6800 system to 1200 baud with PerCom’s CIS-30+dual-cassette/terminal interface The CIS-30+ ... four times as fast as SWTPC’s AC-30 with the same dual- cassette capability .. . plus a 1200-baud data terminal interface ... in a SWTPC color-compatible package that’s only 1/10 the size of the AC-30. Dependable? The simplicity of Harold Mauch PerCom Data designs says more than any well-chosen words. Simply put, for only $79.95 * you get the fastest, most dependable dual function interface you can buy for your SWTPC 6800. See your nearest dealer or order direct from PerCom. PerCom ‘peripherals for personal computing’ PERCOM DATA COMPANY, INC. DEPT. B +318 BARNES - GARLAND, TX 75082 (214) 276-1968 *kit price. Assembled and tested: $99.95 + shipping. Tex. res. add 5% tax. BAC & MC available. SRSA (feieern Continued from page 10 moment in my haste to try out the SR-SIA on the printer. Each ‘x’ value ee (1, 3, 5,7, 9, 11, 13) and each ‘y’ value x must have been extremely proficient at (2, 4, 6, 8, 10, 12, 14) is notated at the building boxes, for otherwise the pro- edge of the tape and the number of data ¥ cawrear (55 30°) foLan, gramming would have been impossible. points entered (7) are also shown. The x Te Rass, comm, (Anyone who programs computers shorter tape shows the printout of two - es would know this.) To illustrate my con- problems | copied from the owner's eS cept of the computer as a tool, | propose manual of the SR-SIA on pages 40 and . 0. that once the computer and robot have 42 respectively. The first is the conver- 4 ¥ (38 freed the man from the drudgery of sion of polar coordinates (5,30) to 5 “ U2 52K IY making simple boxes, he can really rectangular coordinates while the second € i Baa al irs think about what larger structure or is a conversion of spherical (5, 30°, 60°) % y scheme those boxes will be a part of. to rectangular coordinates. Q x Following these guidelines will make In addition to the SR-SIA I also Q the computer a safe and useful tool own the SR-50, SR-56 and the TI 4 y that benefits all society. Programmable 58 “Solidstate Software” ¢ x | ciprg nerarEd and of course the PC1OOA printer. As & gy | teeters 228, Mark Bizer 1am a newcomer to the hobby of home CLP ALL 43 Morgan Cir calculator and computer systems | would x ay Amherst MA 01002 appreciate hearing trom other readers ¥ cie who use these calculators | have men- “as CONFIRMATION OF THE SR-STA tioned, in order to exchange ideas and SubPe i PRINTER TRICK. ..AND SOME information with them. | would like to > sth GRAPEVINE JUICE know especially if anyone who practices INTC 69508 chemistry or biochemistry as a hobby or cur 62503~%. IY After reading Webb Simmons’ letter as a student has any programs for these y rm in the September 1977 BYTE regarding subjects that could be used or modified x the use of his SR-S! TI calculator on the for use on the TH58 or SR-56? sasin [Pc t0e-n PC-100A printer, | decided to try the Finally, | have heard that TI intends Subibble same with my SR-STA. Obviously this to release a “programmer” for the ; model tunctions on the PC-100A as well TI-58/59 which will allow users to tumors orice vou Rnewalf there: laiany, as the SR-51 as shown by the printout record their own library modules and . tapes { have included with my letter. The also is planning on video monitors and William A Faria longer tape is a line regression problem XY plotters to add on to their pro- 74 Division St which | “made up” on the spur of the grammable calculators. Are these idle New Bedford MA 02744 BYTE December 1977 19 NEED NEW PLAYER PIANOS? Since you didn't mention it in the September 1977 issue, let me be the first to tell you about Superscope’s latest entry: It's called the Pianocorder (a Super- scope trademark), and it is an electronic piayer piano. Built around an 8080 Processor, it's scheduled to come in two versions: a Vorsetzer, for grand pianos and such, and what seems to be a retrofit kit that can be put in an upright or spinet. This version is supposed to come out around $1500 or so. The control is ‘by means of a digital casette tape, which controls which keys are down, and also controls the dynamics (by controlling the pulses into the solenoids). There are two things that are really exciting about this: there's a record mode (casually invite Van Cliburn over and have him try ‘out your new piano); and the device will come with 100 cassettes, recorded from Mr Tuchinsky's collection. He’s presi- dent of Superscope, and an avid fan of player plano rolls from Welte; his collection includes most of the great pianists from the turn of the century, who cut rolls for Mr Welte. You can get more details from the source by contacting Tony Blazina, manager, Pfanocorder Division, Super- scope Inc, 20525 Nordhoff St, Chats- worth CA 91311. He says that basic descriptive literature should be available in a few weeks, and marketing early in 1978. | first read about it in a recent issue of Electronics magazine. A long list of possibilities come to mind. The output device is a piano. Given the data format, you could encode a score, make an arrangement for four hands (why not eight?), You could take the sheet music, encode it, fine tune the phrasing, pedalling, dynamics until you had the perfect performance. For learning and teaching, you could encode the right or left hand, or one part of a duet. 1 hope we'll see an article covering these bases not too long from now. Michael D Zorn 1833 S Peck Rd #8 Monrovia CA 91016 PRIMER REMOVER It was good to see so much attention to APL in the August 1977 issue. But you goofed when you recommended the APL Primer. The APL Primer may be easy to read, but its author missed the boat on two key attributes of APL. He neglected APL's treatment of arrays as wholes, and its treatment of programs as “user de- fined functions” that take arguments, return results, and behave just like primitives. The truth is, he didn’t realize at the time either how central those two topics are, or how easy to introduce they'd prove to be. Experience shows that they're not hard to get across. By shrinking from forthright treatment of these funda- mental aspects of APL (and thereby fostering dreadful programming habits), the APL Primer does the newcomer to APL a great disservice. You shouldn't recommend it. 1BM should withdraw it. Paul Berry 1 P Sharp Associates Inc Ste 110, 299 California Av Palo Alto CA 94306 PS: | know; I wrote it. page 40) this sequence (box below). 2. There are many serious errors in the APL references. For example, there are five errors in those on page 65 (August) alone. Perhaps you should consider publishing a carefully checked and annotated bibliography for APL. 3. In discussing APL, care should be taken to use appropriate terminolo- gy. For example, Mr Wimble's article confuses the important distinction between operators and functions (already commented upon in Mr Anthony's letter (August page 17)) and uses the term arity for valence. Perhaps the best reference for terminology and fundamental con- cepts is one not yet mentioned in your articles: APL Language Manual, available from IBM Corp APL COMMENTS | would like to offer a few comments on APL matters in your August and September 1977 issues: 1. The readabitity of APL expressions might be brought out more clearly by adding to your explanation (September BYTE, page 166) of my thought experiment (August BYTE, as Form #GC 26-3847, Kenneth Iverson 163 Great Oak Ln Pleasantville NY 10570 Mike Wimble concurs; the confusion over operators and functions is in part due to changes and revisions to APL. over the years. We regret the bibliographic errors, and will attempt to correct them in future APL articles. Ww Came. tae o=CiN)e. Le +/Q0=(1N Oo. LW 2=+/@0=(1N)e. |e C2=4/B0=(rN)e. LAN) /N All candidates for primes to WV. A remainder table. Divisibility table. Column J shows the divisors of I. ‘The number of divisors for each of WV . A sieve showing which numbers have ‘exactly two divisors {the primes). Selection of the primes by the sieve. 20 BYTE December 1977 Rated|G| Great Locations Computerland” Now Open: 3020 University Dive NW Huntsville, AL 35805, M074 Son Pablo Avenue Et Cemto. CA 94530 22634 Foothill Blvd Hayward, CA 94542 6840 La Cienega Biva Inglewood. CA 2 24001 Vio Fobicante *904 Mission Wey, CA 92630 4233 Convoy Steet San Diego. CA 9244 17 Fremont Street Son Francisco, CA 94405, ELCid Plaza AVE Thousand Oaks Bivd Thousand Oaks. CA 94360 104 W First Steet Tushn. CA 92680 2475 Block Rock Tumpike Fowtield, CT 06430 Astro Shopping Center Kirkwood Highway Newark, DE 49744 50 East Rand Road Arlington Heights 61004 95M No Milwaukee Avenue Niles, 60648 40935 S Cicero Avenue ‘ak Lown. tL 60453 813-B lyndon Lone Loursville, KY 40222 16065 Frederick Road [Pt 365) Rockville, MD 20855 419 Amherst Nashuo, NH 03060. 2 De Hort Street Morristown NJ 07960 4612 Niagara Falls Bivd Buffalo, NY 14150 226 Elmira Road Ithaco. NY 14850, 4304 SOM Center Road Moyhield Heights. OH 44124 Shoal Creek Piaza 3300 Anderson Lane Austin, TX 78757 6439 Westheimer Road Houston, 1X 77057 52-58 Clarence Street Sydney, NSW AUSTRALIA Opening Soon: 6743 Dublin Bivd Dublin, CA 94566 42-A2nd Avenue: Son Mateo. CA 94403 2927 28th Street Kentwood, MI 94508 Franchises Available: Computertand Corp. 4922 Republic Ave. Son Leandro, CA 94577 (415) 895-9363 (205) 539-1200 (415) 233-5010 i445) 538 8080 (243) 776-8080 7A) 770- 434 174d) S60 9912 1415) 546 1592 (805) 495.3554 71a) 5A4 1542 2113) 374-2227 2) 738-9656 (342) 285-6488 (312) 967-4714 312) 422-8080 1502] 425-8308 {309 948-7676 (603) 889-5238 (201) 539-4077 (716) 836-6511 607} 277-4888 1246) 461-4200 (542) 452-5704 (743) 977-0909/000 29-3753 Circle 30 on inquiry card. The Best Game in Town. Welcome to ComputerLand. An incredible adventure into the world of personal computers. A one-of-o-kind shopping experience. Each ComputerLand store presents everything you ever wanted fo know about computers. And then some. Take our Game Room, for starters. You'll find excitement for the whole family in our endless variety of challenging computer games. You can battle the Klingons in an out-of-this-world game of StarTrek. Create an elec- tronic work of art with a computer controlled TV. Test your skill in a game of computerized hangman. You can even plot your biorhythm. But we're more than just fun and games. ~ Each ComputerLand store offers a knowledgeable and person- oble stoff of professionals ear to serve you. Plus the greatest avail- able selection of micro components. Whether it’s a data processing system for your business or a computer controlled sprinkler system for your home, you'll find whatever you need at ComputerLand. Read on. Genuine Service. We want to supply you with the one system that’s right. Rather than a com- plete system that isn’t. Or a limited system that is. That's why, at Com- puterLand, you deal with real professionals who are also real people. People who speak your language in addition to BASIC, COBOL or FORTRAN. People, in short, who can offer both the novice and the old hand the same expert guidance in selecting the optimum system he or she needs. Yet, assisting in the purchase is only the beginning of ComputerLand’s service. If the kit you bought requires a little more do-it-yourself than you yourself can do, we provide assembly assistance. if that complex program proves to be just that, we provide programming assistance. Circle 30 on inquiry card. And if your system breaks down, our in-store service department will get you back up and running Right now! Great Selection. Your first stop at ComputerLand may well be your last stop. ComputerLand offers the finest quality and < iP a os x. largest selec- tion of all the major brand names. Like Apple Computer, Cromemeo, DEC, Diablo, Hazeitine, (COM, IMSAI, Lear Siegler, National Semiconductor, North Star, Texas Instruments, Vector Graphics and more. Pius o complete inventory of tools, books and accessories. What's more, at ComputerLand, we deal in product. Not promises. Our inventory is on our own shelves. Rather than the manufacturer's. So you can take delivery on tomorrow's com- ponents today. Which means, simply put, that at ComputerLand, you get exactly what you want. Exactly when you want it Be Our Guest. Begin with the grand tour of our exhibit areas, “Test- drive” any of our individual systems. Then tell us your needs. We'll sit down and talk about the system that's right for you. It’s as easy as that at ComputerLand. The great computer store. RATED G. Call or write forthe address of the ComputerLand store nearest you. Franchise opportunities available. 1922 Republic Avenue, San Leandro, CA 94577 (415) 895-9363 BYTE December 1977 217 Some people build personal computers for the love of building. And the systems they buy are usually more fun to build than to operate. ‘The Equinox System ™, on the olher hand, is designed for people who build for the love of computing. When you put it together, its really to- gether. Ready to work for, and with, you in the development of your own professional, intellectual, business and even social interests. The Equinox System ™ goes together easily with construction aids like parts legends and solder masks. The Equinox System ™ fits together perfectly, and will continue to be a perfect fit with future hardware and software. And it’s all S-100 compatible, so you'll be able to work together with the largest group of peripherals, software, suppliers and system users in personal computing. Mainframes, interfacing, memory, software—The Equinox System has itall together now. Really together. THE MAINFRAMES The Equinox System ™ offers an important choice in mainframes. The Equinox 100™ mainframe integrates the popular 8080A CPU into a powerful front panel programming center. For users! who prefer another CPU, however, we also offer the Equibox "a fully engineered cabinet, power supply and S-100 busboard system ready for installation of your choice of CPU. Ut would be diffcul to forego the speed and convenience of the Equinox 100™ front panel, however. It allows you to work in concise octal digils ona 12-key keyboard and digital LED display. It allows you to monitor and/or alter the contents of any CPU register 0 or register pair, V/O device or memory location. And the Equinox 100™ front panel will perform these operations while fully halted, single stepping, or Slow- Stepping ™ at a programmable rate! It is, quite simply, one of the most powerful, intelligent and wonder- fully convenient front panels in the world. And companisons of The Equinox System™ mainframes don't stop al the front panel. Both Equinox 100 ™ and Equibox ™ compare directly to feeae) and mini, computers in reliability of operation. Both Equinox 100™ Equibox ™ are equipped with massive 26-amp Constant Voltage fhe resonant) power supplies to protect your programs {rom in-home appli- WAL Devomber 177 ance loads, system loads, and even area-wide line voltage drops as | low as 90 VAC. And the exclusive Noisequard ™ system on our 20-slot busboard produces signals that are “textbook clean,” eliminating a major source of data errors and interfacing problems that plague most other personal computer systems, Plus, there are dozens of other features I to make your mainframe more convenient: carrying handle and tilt-up stand, key- operated power switch for system security, spare power regulators for your small peripherals, and more. It’s no wonder that Equinox ™ mainirames have been acclaimed asa major advance in per- sonal computers. Equinax 100™ or Equibox ™—each has the features you want all together in one elegant package. THE INTERFACING Inlerfacing your input/output devices to your mainframe can be a frustrating, expensive and time-consuming process. ‘That's why The Equinox System '™ offers all the interlacing you're likely to need in one low-cost kit, ‘The Equinox I/O Interface is a single board that plugs right into your Equinox 100™ bus. And you're ready to plug in 3 audio cassette units with individual motion control, a Teletype* or RS-232 terminal, and any 8-bit parallel device. . . including graphics display, line printer or Paper tape reader. The Equinox I/O Interface has 1K bytes of RAM and ROM on board, preprogrammed with powerful Cassette Operating Executive (COPE) software. COPE handles dozens of interfacing and data handling tasks to increase the efficiency of your software. Your programs can store and retrieve cassette data with a simple CALL COPE instruction. Data is formatted, checked and trans: ferred in blocks up to 64K bytes with a single READ or WRITE instruction. COPE can even bootstrap your programs. iL THER Ww! All Equinox software is designed to make full use of COPE capabili- ties. So loading your Equinox software is as simple as selecting an address and pressing RUN. Cassette data storage has never been more convenient. The Equinox I/O Interface is programmed for the highly-reliable 300 baud Kansas City Standard for cassette data transfers. . .but can be reprogrammed for faster rates in the future. Your TTY/ RS.232 channel also features vuser-programmable rates up to 4800 baud. And you have access to all COPE routines. There is no more cost- elfective way to handle your system mterfacing. And the Equinox V/O Interface is even more attractively priced when purchased with a complete system. THE MEMORY You can get your Equinox System ™ together with more low-cost memory. The Equinox Sysiem ™ is the first system to offer the ECONORAM Ill ™ 8K x8 memory board with the advanced SynchroFresh ™ natural-timing refreshing system. Configured as two ndivdually addressable 4K blocks, the ECONORAM III ™ comes as- sembled, tested and guaranteed to work perfectly in your Equinox System ™ for one full year. It is also available as a lower-cost kit For tight budgets, the K-Ration ™ 4K x8 stabc memory kit is also available for your Equinox System | This high-efficiency design is one of the most widely used, lowest power and lowest cost memories available for S-100 systems. ‘And the memory savings are even greater when you purchase your Equinox System ™ all together! ¥ Circle 88 on inquiry card THE SOFTWARE The Equinox System ™ now includes two primary software packages: EQU/ATE for text-oriented programming, editing and assembly , and BASIC-EQ language for number-onented programming. Both of these powerful programming languages have been greatly enhanced by full integration with our COPE interfacing software. EQU/ATE gives you the power of a fully programmable tex! language Using EQU/ATE, you can create programs to edit copy, keep inventory, manipulate your files of addresses or recipes, and more. EQUIATE is also one of the most powerlul editor/assemblers available. EQUIATE writes, assembles and executes your programs. It is fully symbolic, accepts global symbols and assembles programs larger than available memory. EQUIATE is also an extraordinary text editor which works interactively with you to edit by character, string or line. It also offers full number edit- ing of memory contents in octal, hex or decimal Yet, EQU/ATE is extremely compact, occupying only 4K of memory with 8K total memory required BASIC-EQ is a powerful, interactive, high-level programming lan- guage developed for math and science applications. Its primary use is in the manipulation of numbers, although it is capable of string oriented operation. Our version, BASIC-EQ, occupies 5K of memory. Both BASIC-EQ and EQU/ATE are supplied on cassette, ready to, load themselves into your Equinox System™. They are competitively priced. . .and are even more attractive when purchased together with your Equinox System GET IT TOGETHER! For more information and ordering: BY MAIL Send check or money order to Equinox Division, Parasitic Engineering, P.O. Box 6314, Albany, California 94706 BY PHONE = 800-648-5311. BankAmericard/Visa and Master Charge accepted. IN PERSON See The Equinox System™ at your local computer shop. *A trademark of Teletype Corporation. BY IE December 197 23 Iva Rampil 917 Engineering Research Bldg University of Wisconsin Madison WI 53706 Table 1: A comparison of several different mass stor- age techniques, 24 BYTE December 1977 A Floppy Disk Tutorial What peripheral device most often defines the home hacker’s ultimate system? It is, of course, the floppy disk. But what are these devices that seem to have the ability to transform the smallest microprocessor sys- tem into a full-fledged computer? How do they work, and are they worth the cost? | slowly uncovered the answers to these ques- tions as | sought to upgrade my system by adding floppies. Basically, the floppy disk is the little cousin of IBM and other manufacturers’ huge hard disk drives, As far as any com- puter is concerned, the floppy is a real disk drive. The differences between it and (for example} an IBM 3330 disk are mainly specifications of speed and storage capacity. Floppies, like other disks, are relatively fast random access memories. If the last three words sound familiar, it should be no sur- prise. Semiconductor random access mem- ories store {if programmable) and read data by address, with a unit quantity of data (typically one bit) at each address. The data at any address can be quickly and easily changed without disturbing the contents of any other address. So it is with floppy disks except that the access times are now measured in centi- seconds instead of nanoseconds, and the quantity of data at each point is now hundreds or thousands of bits instead of just one, Because the structure of disk storage is similar to that of main memory, it is often used to store programs and data, especially those programs and data which are fre- quently referenced or modified. In fact, during the early age of electronic digital computers, machines ‘ike the IBM 650 actually used a rotating drum similar to a disk as its only memory, which fetched new instructions for execution with each revolu- tion. It is widely believed that the Minute- man missile system still uses such a memory, All of the other mass storage techniques available to hackers, such as paper tape, audio, and even digital cassettes, are funda- mentally serial memories, That is, ali or most of the recorded data may have to be passed through in order to find a particular piece of data. Table 1 compares several different mass storage techniques, As you can see, floppy disks fall between hard surface cartridge 18M 2315 IBM 3740] Digital | Audio Technique Cartridge Disk | Floppy | Cassette | Cassette Units Data Capacity 48. 3.0 6.0 0.84 Million bits (unformatted) Average or Typical 035 5 20 120* | Seconds Access Time (* = manually controlled) Data Transfer Rate 2500 250 10. 0.3 k bps Price of Commercial $8000 $1500 | $1000** | $100 | **Note that Package: Drive + - Power + Controller than commercial drives System Cost per 32 6 10 33.3 [cents per bps Unit Oata Rate System Cost per 016 05 016 012 cents per bit Unit Storage stored Media Cost $100 $8, $4. $4. (unit quantity prices) Storage Cost V7 2.2 0.55 39 cents/kilobyte of media Typetronic: your source for complete computer management systems... now introduces New Jersey’s most complete computer store The new Typetronic Computer Store has all the professionalism and depth of the field-proven Type- tronic minicomputer management systems. In fact, the store is staffed by experienced professionals who have devoted years to the success en WW ee peUonic Seo store 806 Route 17, Ramsey, N.J. 07446 201-825-1300 Circle 122 on inquiry card. of the Typetronic systems... power- ful tools for management in such fields as retail chain stores and chemical distributor operations. The Typetronic Computer Store is New Jersey’s most complete and comprehensive store for hobby- ists, engineers, and business users. It offers a es wide range of I contact me. | Computer Store. If you are located in the N.J./N.Y./Pa. metropolitan area and desire additional details, return this coupon: We are considering the automation of our company operations. Please have a systems representative I (_ ) Please send me your brochure on the new Typetronic hardware and software packages, including microprocessor and NOVA* compatible minicomputer systems and peripherals...plus classroom courses, expert assis- tance, and many other services. Highlights include: ¢ Hands-on demonstrations of microprocessors and other equipment. A variety of microprocessor assembly kits...IMSAI, Pro- cessor Technology, Motorola, etc. Formal classes on both software and hardware topics. Library of publications, product literature, etc. Use of the Typetronic computer with micro-assembler. *NOVA is @ registered trademark of Data General Corp. Name Title | Company Div. ] Street i State Zip City Le ee ee ee BYTE December 1977-25 PLASTIC CARTRIDGE DISKETTE 7 COLOR KEY: BY PROTECTIVE WRAPPER BS MAGNETIC MEDIA CONCEALED MAGNETIC MEOIA VISIBLE THRU HOLES IN PROTECTIVE WRAPPER Figure 1; An X-ray view of a floppy disk. The floppy disk is encased in a protective plastic cartridge 8 inches square. Dotted line circles illustrate the portion of the disk where data Is stored. It is coated with an oxide layer similar to that used on magnetic tape. The combination read and write head contacts the oxide layer through the slot shown at the bottom of the cartridge, 26 BYTE December 1977 disks and cassette systems in terms of performance and cost, (We’re not even con- sidering the much more expensive 2311, 2314 and 3330 type disk drives of the big machines here.) Both floppies and digital cassette systems provide high per- formance at medium cost. Audio cassettes provide low performance at low cost. (Car- tridge disks are not likely to fall into the hands of a hacker; they are included for reference only.) The big tradeoff is speed versus price, of course. A floppy is very fast and more expensive, while the digital cas- sette is much slower but cheaper. The same holds true for the media. Diskettes cost more per kilobyte than do high quality audio cassettes like Memorex MRX-2 C30, when used for digital recording. If speed and random access are important, get a floppy. If flow cost and vast amounts of storage are important, get digital cassettes. My own system will eventually have a floppy disk for an operating system and a digital cassette transport for archival storage, Floppy disks were first developed at IBM laboratories in the middle 60s. They were first used as a means of storing micro- program code for programmable peripheral controllers in the 5/370 family, and were eventually used to store the microcoded diagnostics and emulator functions for the 370 computers. Then, in the beginning of 1973, IBM introduced the 3740 Data Entry System, Like a keypunch, except that data is recorded on a floppy instead of cards, one 3740 floppy disk holds the equivalent of 3000 cards. IBM then predicted that floppies would replace cards as the principle data entry medium. This of course has yet to happen completely, but is well under way. In the midst of all the commotion, someone discovered that floppy disks make excellent mini and microcomputer peripherals, and the floppy peripheral industry was born. Thus the 3740 is the device that started the floppy industry. As for the floppy disks (diskettes) them- selves, figure 1 provides a closeup view. An IBM diskette looks for all the world like a 45 rpm record in a plastic jacket. Actually, the diskette is defined to be a disk of heavy Mylar based magnetic tape material. It is 7.8 inches (19.8 cm) in diameter with a center spindle hole 1.5 inches (3.81 cm) in diam- eter. The 0.01 inch (0.025 cm) index hole is used to synchronize data as the disk rotates. Data is stored on the surface of the disk in the oxide coating, the same technique used in magnetic tape storage. And like magnetic tape, floppies are very susceptible to con- tamination by foreign particles (dirt, dust, fingerprints). Therefore, the diskette is en- closed in a thin semistiff low friction plastic jacket known as a cartridge. The standard cartridge has three openings in it to allow the spindle, read and write head, and index photosensor to have access to the disk. The inside surfaces of the cartridge have soft, low friction liners. The liners wipe the UP AND RUNNING TDL EQUIPMENT USED BY NEW JERSEY PUBLIC TELEVISION TO PROCESS NEW JERSEY GUBERNATORIAL PRIMARY ELECTION RETURNS John Montagna, computer engineer (above left), lead this successful network team in generating election results speedily, efficiently and reliably using predominantly TDL hardware and soft- ware. Montagna created three programs to get the job done. The text for a SWAPPER pro- gram was written and assembled using the TDL TEXT EDITOR and Z80 RELOCATING MACRO ASSEMBLER. The SWAPPER text and all debugging was run through TDL’s ZAPPLE MONITOR. The relocatable object code was punched onto paper tape. A MAIN USERS program updated votes and controlled air dis- play. An ALTERNATE USERS program got hard copy out and votes in. The latter two programs were written in BASIC. Montagna modified the ZAPPLE BASIC to permit time- sharing between the two USERS programs. TDL’s XITAN SYSTEMS have the capacity to do similar tasks for you. Write to us for XITAN information and the name of your nearest TDL dealer. Circle 117 on inquiry card. Four screens were incorporated, two terminals entered votes as they came in and were used to call back votes to check accuracy. Mon- tagna called on the power and flexibility offered by TDL’s ZPU board and three Z-16 Memory boards. Montagna’s setup worked constantly for over four hours updating and displaying state-wide and county-wide results without flaw. “| chose TDL because they have all the soft- ware to support their hardware, and it's good; it has the flexibility to do the job.” John Montagna We salute John Montagna and NEW JERSEY PUBLIC BROADCASTING for spearheading the micro-computer revolution. TECHNICAL DESIGN LABS RESEARCH PARK BLDG.H 1101 STATE ROAD PRINCETON, NEW JERSEY 08540 (609) 921-0321 BYTE December 1977-27 Figure 2a: A diagram of @ floppy disk showing a typical location of the wire protect (or file pro- tect) hole. When this hole is punched out, data cannot be erased from the disk. The write protect hole serves the same pur- pose as the plastic tabs on @ magnetic tape cassette, Figure 2b: A floppy disk with @ design modification to allow “hard sectoring.”” 32 0.10 inch (0,025 cm) hofes are punched in the disk in addition to the index hole. These holes en- able the hardware to detect the exact rotational position of the disk by means of a photosensor. The need for space wast- ing address fields is elim- inated with one hole per sector, and the number of data sectors can be typically increased from 26 to 32 per track. 28 BVT December 1977 WRITE PROTECT HOLE % 32 Olim SECTOR HOLES disk clean and eliminate static charge while reducing the necessary spindle torque. To protect the disk even further when the diskette is not in use, it is kept in a cardboard sleeve, in the same manner thal an LP record is kept in its album cover. The industry standard (IBM 3740} specifications for diskettes is fairly rigorous and widely accepted, although a number of variations have lately appeared on the scene. Two of these are shown in figure 2. The write protect hole is a small plastic knockout in the cartridge which serves the same purpose as the small knockout tabs in a tape cassette. A sensor detects whether the knockouts have been removed or not, and if so, disables the write electronics. Another variation is the presence of many small sector indexing holes punched in the disk. The advantage of this so-called hard sector- ing process is a higher data capacity per track. This will be discussed in more detail later. A third, relatively recent, innovation in the manufacture of diskettes is to coat both sides of the Mylar backing with magnetic oxide and ta put an additional head access slot on the opposite side of the cartridge, giving a two-sided floppy disk (see photo 2 and figure 6). Some manufacturers have gone so far as to develop a drive mechanism which simultaneously accesses both sides at once. IBM, Information Terminals, BASF and Wabash are some of the companies which sell floppy disks. The price of disk- ettes varies from $12 to $7 cach in boxes of ten to about $4 to $5 each in large quantities. Drive Hardware There is a commonly drawn analogy be- tween a disk drive and a phonograph. Both are mass storage devices in which the data is stored on a platter-shaped medium. The platter is seated on a spindle around which it revolves while the data pickup (needle or magnetic head) moves radially across the data. In the case of a phonograph record, the music, or data if you will, is recorded on spiral grooves or tracks which are cut into the record. To access a particular song, the tone arm is moved radially over the record and placed down in the starting groove of the song. In contrast, the data on a com- puter disk is stored in discrete concentric circles, not one continuous spiral. The con- centric circles are called tracks and are accessed by a magnetic head which is bumped mechanically from track to track under computer control. Data is stored by means of saturated magnetic recording at a maximum density of 3200 bits per inch (on the innermost track}, and 48 tracks per radial inch. Most floppy drives on the market today use either a synchronous AC or servo- controlled DC motor to drive the spindle at exactly 360 rpm. Speed control is very important to insure data reliability. The spindle motor runs continuously whether or not a diskette is loaded. When a diskette is loaded into a drive, it is inserted into a narrow slot and the cartridge is held in place between a spring and a small metal protrusion. The door over the slot is then closed, clamping the diskette to the rotating spindle. At the same time, in most drives, the read and write head is engaged. The type of read and write head used is one of the important differences between hard disks and floppies. Hard disks use a system known as flying heads in which the read and write heads are acrodynamically floated off the surface of the disk. They are held a very small and precisely controlled Continued on page 35 si Lower Case Numeric Pad A“ Tabbing ‘Dual Intensity A Rux. Port 24 Line x 80 Char. # Optional Printer Port & Block Mode ‘7 Protect Mode dy Ruto Repeat. 4715 Baud Rates wy Addr. Cursor t $QQO5 228 the ¥ SOROC IQ 120 is the most wanted terminal on the market. For information concerning the REWARD contact::: SsoRoCc 165 FREEDOM AVE., ANAHEIM, CA S280} x TECHNOLOGY, INC. 714:992-2860 / 800-854-0197 Circle 108 on inquiry card. BYTE December 1977 29 Ohio Scientific advances the state-of-the-art of small computers. From our inexpenalve 8K BASIC in ROM Challenger IIP to our powerful triple processor Challenger Ill, Ohio Scientific offers a full range of products that are technologically superior to anything available on the market today. Challenger IP Challenger IIP from Ohio Scientific is our unique personal computer with BASIC in ROM and 4K RAM for programs in BASIC. Complete with audio cassette interface and a full computer keyboard, Challenger IIP can be connected to a home TV via an RF converter and it's ready to go. Challenger IIP comes fully assembled and tested for only $598.00. —_ 11679 Hayden * Hiram, Ohio 44234 30 BYTE Decemner 1977 Challenger Il from Ohio Scien- Mis tific is a disk based computer capable of stor- _ _~ ing up to 500,000 *- bytes of informa- “tion on an Ohio . Scientific dual a ~ a +. me drive floppy disk. Challenger Il comes with 16K of RAM (the disk BASIC is automatically loaded into the computer so there is no need for ROM’s) and our powerful Disk Operating System (DOS) which allows the computer to perform big computer functions like random ac- cess, sequential and index sequential files in BASIC, and I/O distributors which support multiple terminals and industry standard line printers. And best of all a 16K Challenger Il with serial inter- face, single drive floppy disk, (250,000 bytes) BASIC and DOS costs only $1,964.00 fully assembled. Challenger II Challenger II Challenger Ill from Ohio Scientific is the revolutionary, new triple processor c