198011 Byte Magazine Vol 05 11 High Resolution Graphics

NOVEMBER 1980 Volume 5, Number 11 $2.50 in USA/$2.95 in Canada ® ~~ AMCGRAW-HILL PUBLICATION +. the small systems journal *. “peo AuNbU) UO ¥EE OID WHAT ARE YOU LOOKING FOR IN A SYSTEM? VERSATILITY — Data bus—motherboard design allows you to configure a system to the end users exact needs. EXPANDABLE — Minimum RAM capacity 56K Expandable to 768K. Two I/O ports — Expandable to seventeen. MASS STORAGE-— 3.0 M/bytes on 5%” flexible disks. (4 drives) 5.0 M/bytes on 8 inch flexible disks—(4 drives} 40 M/bytes on “Winchester” fixed disk. SOFTWARE — Operating System — Multitasking, multiuser with memory management. Languages — FORTRAN, Pascal, BASIC, PILOT Utilities — Debug, Sort-Merge, Diagnostics — over 40 others. Data Processing — General Ledger, Receivables, Payables, Payroll, Jobcost, Mail List, Inventory, Record Management System. Word Processing — Text Editor and Processor — device independent with proportional spacing bidirectional printing. COST EFFECTIVE—System consisting of 128K processor, terminal, and 2.4 M/byte dual eight-inch disk drives — less than $6,000.00 (O.E.M. 100 quantity) SOUTHWEST TECHNICAL PRODUCTS CORPORATION pay 219 W. Rhapsody ("San Antonio, Texas 78216 (512) 344-0241 Management information Display Ultrasonic heart sector scan High-resolution display with alphanumerics Get the professional color display that has BASIC/FORTRAN simplicity LOW-PRICED, TOO Here's a color display that has everything: professional-level resolution, enormous color range, easy software, NTSC conformance, and low price. Basically, this new Cromemco Model SDI* is a two-board interface that plugs into any Cromemco computer. The SDI then maps computer display memory content onto a convenient color monitor to give high-quality, high- resolution displays (756 H x 482 V pixels). When we say the SDI results in a high- quality professional display, we mean you can't get higher resolution than this system offers in an NTSC-conforming display. The resolution surpasses that of a color TV picture. BASIC/FORTRAN programming Besides its high resolution and low price, the new SDI lets you control with optional Cromemco software packages that use simple BASIC- and FORTRAN- like commands. Pick any of 16 colors (from a 4096-color palette) with instructions like DEFCLR (c, R, G, B). Or obtain a circle of specified size, location, and color with XCIRCE (x, y, , ©. "U.S, Pat. No. 4121283 Circle 1 on Inquiry card. Model SDI High-Resolution Color Graphics Interface HIGH RESOLUTION The SDI’s high resolution gives a professional-quality display that strictly meets NTSC requirements. You get 756 pixels on every visible line of the NTSC standard display of 482 image lines. Ver- tical line spacing is 1 pixel, To achieve the high-quality display, a separate output signal is produced for each of the three component colors (red, green, blue), This yields a sharper image than is possible using an NTSC-composite video signal and color TV set. Full image quality is readily realized with our high- quality RGB Monitor or any conventional red/green/blue monitor common in TV work, Model SDI plugs into Z-2H 11-megabyte hard disk computer or any Cromemco computer DISPLAY MEMORY Along with the SDI we also offer an optional fast and novel two-part memory that gives independent high-speed access ta the computer memory. The two-pert memory stores one full display, permit- ting fast computer operation even during display. CONTACT YOUR REP NOW The Model SDI has been used in scien- tific work, engineering, business, TV, color graphics, and other areas. It's a good example of how Cromemco keeps computers in the field up to date, since it turns any Cromemco computer into an up-to-date color display computer. The SDI has still more features that you should be informed about. So contact your Cromemco representative now and see ali that the SDI will do for you. Cromemeco 280 BERNARDO AVE., MOUNTAIN VIEW, CA 94040 © (415) 964-7400 Tomorrow's computers today BYTENovember 1980 1 Z-2H Computer dysten_- Here’s the state of the art in low-cost hard-disk computers 11 MEGABYTES OF FAST HARD-DISK STORAGE Yes, the Cromemco Model Z-2H is in a class by itself in the computer field. These Z-2H features tell you why: @ 11 megabytes of hard-disk storage ®@ 64 kilobytes of fast RAM @ Two dual-sided floppy disk drives @ Z-80A type processor @ Fast 4 MHz operation—150 nanosecond access time @ Fast hard-disk transfer rate of 5.6 megabits/second @ Low cost And that’s not alt you get. Not nearly, BROAD SOFTWARE SUPPORT You also get Cromemco software support—the broadest software sup- port in the microcomputer field. Soft- ware that Cromemca is known for. Like this: © Structured BASIC @ FORTRAN IV @ RATFOR (RATional FORtran) @ COBOL @ Z-80 Macro Assembler @ Word Processing System @ Data Base Management And more ail the time. FIELD PROVEN The Z-2H is clearly in a class by it- self. We introduced it last summer. It's field proven, It’s reliable. And it’s rugged. Housed in a sturdy, all-metal cabinet. EASILY EXPANDABLE As always with Cromemco, you get expandability. The fast 64K RAM in this Model Z-2H can be expanded to 512 kilobytes. That amount of RAM combined with 11 megabytes of hard- disk storage gives you enormous Cromemco computer power—the equal or even beyond what much larger computers sometimes offer. What’s more, this computer gives you a 12-slot card cage. That’s to plug in your special circuits as well as additional RAM and interface cards. This expandability is supported by still more Cromemco value — the Z-2H's heavy-duty power supply that gives you 30A at 8V and 15A at +18V to support plug-ins. LOW COST — SEE IT NOW The Z-2H is real. {t's been in the field for many months. It's proven itself. You should see the Z-2H now. Con- tact a Cromemco representative and arrange for a demo, Learn that Cro- memco is a survey-winner for reli- ability. And learn that the Z-2H is under $10K. In the long run it always pays to get the best. 280 BERNARDO AVE., MOUNTAIN VIEW, CA 94040 * (415) 964-7400 Tomorrow's computers today Circle 1 on Inquiry card. Page 22 FOR SIDEWAYS | BALLYOIO VIDEO | Page 172 BATE November 1980 Volume 5, Number 11 la The Queue Foreground 32 HOME IN ON THE RANGE! AN ULTRASONIC RANGING SYSTEM by Steve Ciarcia Combine automatic sonar ranging and infrared-light detection in a computer-controlled scanner. 64 MICROGRAPH, PART 1; DEVELOPING AN INSTRUCTION SET FOR A RASTER-SCAN DISPLAY by E Grady Booch Micrograph is an intelligent, low-cost, color-graphics terminal that interfaces to any microcomputer and standard, unmodified color television receiver. 126 GRAPHIC COLOR SLIDES, PART 1 by Alan W Grogono The first of this two-part article gives a series of useful subroutines for generating color images on a Compucolor II. 148 TEE ESA GRAPHICS FOR THE APPLE II by Dan Sokol and John hepar With this popular computer, use a two-color scheme to generate three-dimensional figures, 296 A GENERAL INTERPOLATING GRAPHICS PACKAGE FOR THE TRS-80 by D K Cohen and Devon Crowe Interpolate between points of a graphed function and three-dimensional figures. 340 AN 8088 PROCESSOR FOR THE $-100 BUS, PART 3 by Thomas Woodward Cantrell This monitor program takes advantage of some powerful software and architectural aspects of the 8088 processor. Background 22. THE FUTURE OF COMPUTER GRAPHICS by Bruce Eric Brown and Stephen Levine Take a look at the future of graphics hardware and applications. 90 LANGUAGE CONTROL STRUCTURES FOR EASY ELECTRONIC VISUALIZA- TION by Dr Thomas DeFanti Zgrass, a hybrid of language and hardware, can be used to solve graphic-display problems. 180 a SIMPLIFIED THEORY OF VIDEO GRAPHICS, PART 1 by Alien Watson III Part 1 covers the principles of television and computer-generated graphics. 206 GETTING TO KNOW YOUR MONITOR by Ron Dalyiaz Meet the most frequently used human/computer interface — the video terminal. 220 DIGITAL STORAGE OF IMAGES by Thomas Williams Theory and practice of digital-image capture and storage are explained in detail. 244 MACHINE PROBLEM SOLVING, PART 3: THE ALPHA-BETA PROCEDURE by Peter Frey In the conclusion of this series, we discover how searching for information stored in tree structures can be made more efficient. 361 ADD MACRO EXPANSION TO YOUR MICROCOMPUTER, PART 2 by David C Brown Notes on implementation and options are presented in this final part. Nucleus 6 Editorial 172 SIGGRAPH Convention Report 16 Letters 240 BYTELINES 62, 66 Technical Forum 266 Ask BYTE 108 Book Reviews 314 Event Queue 112, 114, 292, 322 BYTE’s Bugs 343 Tom Sloan Cartoon 114’ Books Received 372 What's New? 116, 145 Programming Quickies 430 Unclassified Ads 119’ BYTE's Bits 431 BOMB Results 147 Clubs and Newsletters 431 BOMB 158, 190, 196 Product Reviews 432 Reader Service November 1980 © BYTEPublicationsinc 3 Publishers Virginia Londoner Gordon R Williamson Associate Publishar John & Hayes As stant Chery! A Hurd Founding Editor Carl T Helmers Jr Editor-in-Chief Christopher P Morgan Editors Richard $ Shuford, Gregg Williams, Curtis P Feigel, Harold Nelson Stan Miastkowski Consuiting Editor Mark Dahmke Book Editor Bruce A Roberts Chief Copy Editor David W Hayward Copy Editors Faith Hanson, Warren Williamson, Robin M Moss, Anthony J Lockwood Assistant to the Editors Faith Ferry Assistants Debe Wheeler, Karen A Cilley New Products Editor Clubs, Newsletters Charles Freiberg Drafting Jon Swanson Production Director Panay Exte lant Production Director Christine Dixon Productlon/Advertising Coordinator Wal Chiu Li Production Art Holly Carmen LaBossiere, Deborah Porter Chie! Typographar Sherry McCarthy Typographers Debi Fredericks, Donna Sweeney Advertising Director Thomas Harvey Assistants Ruth M Walsh, Ms. Marion Gagnon Barbara J Greene, Rob Hannings Speclal Projects Coordinator Jill E Calihan Marketing Coordinator Laura A Hanson Circulation Manager Gregory Spitzfaden Assistants Agnes E Perry, Melanie Berton, Barbara Varnum, Loulse Menegus, Andrew Jackson Dealer Sales Thomas Yanni Controller Daniel Rodrigues Assistant Mary € Fluhr Accounts Recelvable Specialist Karen Burgess Accounts Recelvable Assistant Jeanne Gilley Receptionist Jacqueline Earnshaw Trattic Department Mark Sandagata In This Issue The cover for this issue of BYTE is'a still from a 90-minute computer-animated cartoon called T Works, The photo was provided by Dick Lundin and Lance Williams and is constricted from quadric surfaces and polygons, using texture-mapping and normal-perturbation techniques, The background was painted by Paul Xanter—programming credit also goes !o Tom Duff and Duane Palyka. A trailer of The Works was shown at SIGGRAPH '80 (page 172), although the film itself may not be finished for another two years. A number of the articles for this month's theme were solicited with the help of Jay Nickson and Ken Lodding: their editorial begins on page 6. Both are employed by DEC (Digital Equipment Corporation): Jay is the manager of the human in terface program for simplifying man/machine com- munications, Ken Is 2 senior software engineer whose long-term interests intermix art and computer graphics. Publisher's Note As most readers will haye observed, the September Fifth anniversary issue marked the beginning of a new phase for BYTE. The jump from a 300-page to 2 400-page issue means a 33% increase in the material presented to our readers each month, Because advertisements tend jo be more visible than editorial content (especially in a technica) journal), some readers may suspect that the larger issues mean merely more ads, But, in fact, the larger Kcsues have approxlinately one third’ more editorial content. The new size does create design and manufacturing problems, however. The solution to these problems includes.a redesign of the edito pages of BYTE to make the editorial content easier ta find and use. We expect the new format to be im- plemented early in 1981 We are confident that the increased editorial content and new format will make BYTE even more of a bargain as well asa more useful tool for our readers. And that, after all, is what it's all about Virginia Londoner Publisher Officers of McGraw-Hill Publications Company: Paul F McPherson, President; Executive Vice Presidents: James E Bodgort, Gene W Simpson; Group Vice President: Daniel A McMillan; Senior Vice President-Editorial: Ralph R Schulz; Vice Prasidents: Kemp Anderson, Business Systems Development; Stephen C Cro!l, Manufacturing, Robert B Doll, Circulation; James E Hackett, Controlier; William H Hammond, Communications; Erlc B Hert, Planning and Development; John W Patten, Sales, Edward E Schirmer, international, Officers of the Corporation: Harold W McGraw Jr, President, Chiet Executive Otticer and Chairman ot the Board; Robert F Landes, Senior Vice President and Secretary; Raiph J Webb, Treasurer. BYTE fs published monty by BYTE Publications Inc, 70 Main Si, Peterborough NH 03458, a wholly-owned subsidary of McGraw: Hill, Inc: Address all mai except subscriptions fo above address: phone (603} 9249281. Address subsctiptions, change of address, USPS Form 3579, and fullllment questions to BYTE Subscriptions, PO Box 590, Martinsvile Nu 08835. Controlled circulation postage paid at Waseca, Minnesota 56083 - USPS Publication No, 528890 (ISSN 0380-5280}. Canadian second class registration number 9321 Subscriptions are $18 for one year, $32 for two years, and $46 for tree years in the USAand lis possessions. in Canada and Mexco, $20 tor one year, $36 for lwo years, $52 for wee years. $32 for ane year air delivery to Europe, $32 surface delivery elsewhere, Air delivery to selecied areas at additional rates upon request. Single copy price is $2.50 in the USA and ts possessions, $295 in Canada and Mexico, $400 In Europe, and $4.50 elsewhere. Foreign subscriptions and sales should be remitted in United States funds drawn on 2 US bank. Printed in United Siates of America Address all editorial correspondence lo Ihe edilot at (he above address. Unacceptable manuscripts will be returned if accompanied by sufficient tirst class postage, Not responsible for ost manuscripts ar photos Opinions expressed by the authors are not necessary those of BYTE. Eniite contents copyright * 1980 by BYTE Publications inc. All nghis reserved Where necessary, permission is granted by the copytight owner for libraries and otnars registered with the Copyright Clearance Center (CCC) to photocopy any article hecein for the base lee of $100 per copy of the article oF item plus 25 cents per page. Payment shoud be sent directly to the COC, 21 Congress St,, Salem, MA 01970, Copying done for other than personal or inlernal reference use without the permission of McGraw hibited. Requests for special permission oF bulk orders should be addressed io the publisher BYTE® ic avatabla in microlorm from University Microfims International, 300 N Zeeb Rid, Dept PR, Ann Arbor Mi 48108 USA or 18 Bedlord Row, Dept PA, London WCIR 4EJ England ‘Aout Bernas Subscription WATS Line: (800) 258-5485 sec ree Office hours: Mon-Thur 8:30 AM - 4:30 PM, Friday 8:30 AM - Noon, Eastern Time NATIONAL ADVERTISING SALES REPRESENTATIVES: NORTHEAST (617) 444-3946 MIDWEST (312) 864-3467 EAST & SOUTH (212) 682-5844 SOUTHWEST (714) 540-3554 Hajar Associates Hajar Associates Hajar Associates NORTHWEST (415) 964-0706 280 Hillside Ave. 2405 Lawndale 521 Fifth Ave. Hajar Associates Needham Heights MA 02194 —_ Evanston IL 60201 New York NY 10017 1000 Elwell Ct, Suite 227 Palo Alto CA 94303 4 November 1980 © BYTE Publications Inc Circle 2 on inquiry card, —> RS-170 com- posite or direct drive output Local or extemal sync i generation i 4 or 5 Mhz Z80 micro- fe 0) processor 60 hertz real- time clock i 8 level interrupt tie-in IEEE S100 bus compatible Screenware™ Pak I A 4K byte operating system residentin PROM on MicroAngelo™ Pak I emulates an 85 char- acter by 40 line graphics terminal and provides over 40 graphics commands. Provisions exist for user-defined character sets and directly callable user extensions to Screenware Pak I. SCION Corporation 8455-D Tyco Road Vienna, ¥a. 22180 (703) 827-0888 MICROANGELO HIGH RESOLUTION GRAPHICS SINGLE BOARD COMPUTER by SCION CORPORATION Light pen interface i ee Time multi- \ y plexed refresh © ; ts 4K resident i Screenware™ Pak I operating mat | system % 32K RAM isolated from = host address Pe space High speed communica- tions over parallel bus ports Host Resident Terminal Software An interface software package that coordi- nates input/output from the MicroAngelo™ graphics board, the MicroAngelo™ keyboard, and your computer. The result is a flexible, yet sophisticated graphics terminal. European Distributor: Micro Diversions UK Ltd. 17/19 Mesnes Street Wigan, England WN1 1QP 09-423 4311 Circle 3 on Inquiry card. Have some oreal memories. 16K PROM boards. PROM card has 2708-type memory 1 Quality board construction Il 0-4 wait states Address any 4K group to any 4K boundary W Control up to 8 banks of memory W Fully assembled and tested ll PRICE—$300 {Calon esdenis 4d 6% soles tan) Expandable 5 MHz RAM boards. 8—32K expandable RAM board uses TI 4044 memory runs at SMHz I Fast 250 ns access time lM Bank select ll Address any 4K biock to any 4K boundary fl Quality board construction PRICE—8K—$175; 16K—$315; 24K—$475; 32K—$620; 8K add-on kits—$135 (Colifornia residents add 6% sales tax) Call or write Artec for details a al ta € ARTEC ELECTRONICS INC. 605 Old County Rd., San Carlos, CA 94070 Telephone (415) 592-2740 & November 1980 © BYTE Publications Inc The World of Computer Graphics Guest Editorial by Ken Lodding and Jay Nickson Man is a visual animal. He surrounds himself with graphic images. Images are employed to convey information, to explain concepts, and to com- municate feelings. The ability to draw is instinctive. It materializes in infants soon after the start of verbal development, perhaps to complement the slowly developing verbal skills. Although the ability to draw tends not to become as fully developed as verbal skills, images continue to provide much of the adult human communications ability. Pictures are a primary information-carrying channel: the histogram accompanying a financial article, the plot of a mathematical function, and the illustrations in BYTE are but a few examples, The importance of graphics for conveying information arises from the nature of man’s visual system, The eye provides an extremely high-bandwidth information channel for transferring the data to be processed by the brain's op- tic center. The importance of this channel can be seen from the redundancy built into the system and from the distribution of optic nerve fibers in the brain. It is believed that no less than six different brain sites are directly ser- viced by connecting optic nerve fibers. (See reference 4.) The fundamental im- portance of visual information is reflected in the old adage, “seeing is believ- ing,” and in the observation that understand is one of the synonyms of the word see. Text fails to use our native abilities to comprehend information fully because it presents data in a linear, sequential fashion. Contrast this with graphical images, which can be processed ina single viewing—a phenomenon called preattentive perception. (See reference 6.) The computer has become a primary source or conveyor of information, yet the main interface between man and machine has remained the serially oriented text display. The net result is that, as the volume of data available to be presented increases, the user's communication channel becomes swamped with an avalanche of text output. The volume of this avalanche far too often restricts the comprehension of the information. The information is obscured as effectively as if it had been encrypted. The spectacle of the computer user literally buried under reams of printed output has ceased to be an amusing car- toon and has become a nightmare for too many. To cope with the flood of in- formation, the computer user is turning to graphics. The information-transfer rate of a graph can be many orders of magnitude greater than an equivalent text presentation. Conceptually, a graph has greater information density than a table. Compare the plot of a sine curve with a table of sine values. Each value within the table corresponds to a specific point on the graph. However, the plot displays a far greater number of points than could the most extended table. A high information-transfer rate results from the greater data density and the faster operation of the human mind and visual system. Patterns, periodic functions, trends, and comparisons can often be ob- tained “by inspection” of a graph, while understanding a tabular display re- quires much more time and effort. This is not, however, accomplished without a cost. The only penalty paid for speed is the loss of precision: a graph cannot be read to the same number of significant digits as can be obtained from a table. This loss of precision is not a problem, as the specific data value of in- terest can be extracted from the function or table of data used to generate the plot initially. About the Authors Ken Lodding and Jay Nickson are employed by the Digital Equipment Corporation in Mer- rimack, New Hampshire. “For reliable data storage, I recommend systems with Shugart disk drives? (20:25... “The last thing you need when you put your personal computer or small business system to work is a disk drive that you can’t rely on. If the drive quits, your system is out of business.” ‘That$ why more and more manu- facturers and dealers depend on Shugart disk drives for reliable data storage. These professionals don’t want disk drive prob- lems any more than you do. Shugart has a TM—Minifloppy is a trademark of Shugart Associates, large family of drives, too—in all sizes and capacities to suit your system storage needs. For the smaller system, the original 5'%4-inch Minifloppy ™ stores 250 to 500 kilobytes (single or double-sided)—that’s about 50 to 100 pages of printed material. Our single and double-sided 8-inch floppys store 800 to 1600 kilobytes. And for systems that need a larger data base, our 8-inch or 14-inch fixed disk drives store from 5 to 58 megabytes. No other manufacturer offers such a wide variety of disk storage for personal computer and small business systems. Word processing, general business, accounting—big system or small, you can rely on Shugart drives. We're known as the Headstrong company for good reason. We're Headstrong about reliability, quality, and value. Ask your dealer, He knows us. Rely on the Headstrong Company. /.Shugart 475 Oakmead Parkway, Sunnyvale, California 94086 In addition to presenting data in a rapid, meaningful fashion, an important benefit of computer graphics is the ability to present images realistically. Plotting a topological surface, modeling DNA, creating an architec- tural rendering, and simulating a pilot's view from the cockpit of an aircraft are all enhanced by presenting the image in a manner which gives the viewer a sense that the picture is not an illusion. To achieve greater realism, a prime factor is to provide the illusion of depth. Perspec- tive, hidden-line removal, shading, and highlighting all provide depth cues to the viewer. This month’s com- puter-generated cover by Lance Williams of the New York Institute of Technology clearly illustrates the cur- rent state of the art as applied to an artistic endeavor. The same techniques are available and can be employed when graphically representing numeric data. Three-Dimensional Graphics To provide the illusion of depth, a three-dimensional model can be defined. Establishing the viewer's geometric relationship to the model and following the rules of perspective, the model image is mathematically projected onto a two-dimensional viewing plane. Although pro- viding good visual depth cues (eg: parallel lines appearing to meet at a point), there is no real illusion of depth; in other words, the model image is still “flat.” To correct this, the phenomenon of stereopsis (from the Greek, meaning “solid sight”) can be employed. You may be familiar with the 1847 Brewster stereoscope, Here, the approach taken to give the illusion of depth was to photograph the same scene twice, having moved the camera about 6 cm sideways between photos. The two images could then be viewed through a stereoscope that utilized a prism and lens system to alter the image paths to the eye, so that the two views seemed to originate from a common point. (The old-fashioned stereopticon and the modern View-Master are variations on this theme.) The observer's visual system fused the two images, giving the illusion of a three-dimensional image. Various computer-graphic techniques using the same principles have been developed. A common technique is to employ glasses with electro-optic shutter eyepieces to provide the image separation, With the electro-optic glasses, the cyclopic video display presents left- and right-perspective images in alternate frames, which are then synchronized with the electro-optic shutters. The left eye is presented with the left stereograph, while the right eye's view is blanked by the optical shutter; the im- age and shutter swap for the right eye. The viewer's inter- nal visual system fuses the image to give the appearance of depth. For an example of this, see “The Future of Com- puter Graphics,” page 22. A different approach to providing left and right images to the visual system uses color to separate the images. Using a device called an anaglyph, the left view is presented in one color, and the right in a different color. Color filters control which eye sees what view. A pro- gram for generating and viewing anaglyphs is presented in the article “Three-Dimensional Graphics for the Apple I.” (See page 148,) While the traditional colors employed are red and green, any two colors and corresponding filters could be used, because the illusion is based on the separation of the images, and has nothing to do with the particular colors. The phenomenon is as apparent to a 8 November 1980 © BYTE Publications Inc © PASCAL/Z*- Q.E.D. Ithaca Intersystems PASCALIZ is the most powerful CP/M™ compatible Z-80™ Pascal compiler ever... and here’s why: PASCAL/Z generates true Z-80 native code — ROMable and re-entrant — 5-10X faster than P-code interpreters; permits separate compilation; supports Direct File Access and variable length STRINGs; utilizes fast one-pass recursive descent organization; the macro-assembler generates relocatable object modules; and much, much more. Complete package includes compiler, macro-assembler, linker/loader and source for the full library on one disk; with free copy of Jensen/Wirth book and complete documenta- tion. Only $395.00. {T'S DEMONSTRABLE! Don’t just take our word for it. Ask for a demonstration of these features and more today at Computerland® and other full-service computer stores. Ithaca Intersystems Inc., 1650 Hanshaw Road P.O. Box 91, ithaca, N.Y. 14850. Phone (607) 257-0190 Computetiond is 4 renistered trademark of Computetland Corporation CPIM and 2-80 are trademarks of Digital Research Carp and Zilog. inc respectively PASCALIZ and lnierSystems ate trademarks of Ithaca Intersyscems Inc [looferssyesthennns” \thaca Intersystems Inc. Micros for bigger ideas. Outside of the garden you need a computer that can grow. For the average garden-variety home and hobby operation, a high quality personal computer is a real temptation. But let’s face it: in the world of business, engineering and ic applications you need a system that can keep up Bigger ideas today mean the power and flexibility to move the micro up to and beyond the level of yesterday's minis, More memory to hold bigger data bases. More flexibility to handle a variety of data entry devices. More programming and computing power for numbercrunching and applications development. And easy upgrade to 16 bit operation when you need it. Intersystems has that, and more. The power and flexibility of the versatile $-100 bus, with 20 slots of expandahility for up to 16 individually-addressable DMA devices and up to 1 Megabyte of memory, fully accessible to all users via our unique memory management system. Plus reliable Intersystems design and manufacture, and the support of our PASCAL/Z™...the most powerful Z-80™ compiler ever. For really serious computing, our front panel provides a powerful diagnostic tool for debugging or development. Combined with a scope, it allows you to look at any location in the circuitry, set breakpoints, trigger and view one-shot events, and many other activities usually possible only with expensive logic analyzers. No wonder it’s fast becoming the tool of choice for repair technicians and custom hardware designers. intersystems Series Il is the most complete line of fully IEEE 696 compatible S-100 boards...easily upgradeable to our MPU 8000™ or other 16 bit S-100 CPU’s as they become available...so you're never locked out of rapid expansion, or 10 obsolescence, by dependency on a proprietary product line. So if you’ve left those garden-variety applications behind, come to Intersystems and get a system that will grow as big as your next idea. Get it from the people who know small computers...your Computerland store...or other fine full service computer dealers. Ithaca Intersystems Inc., 1650 Hanshaw Road P.O. Box 91, Ithaca, N.¥. 14850, Phone (607) 257-0190 TWX: 510 255 4346, raderntres 0! Unzea inter asters Ine [looterSsyssfieennns™ vaca Intersystems Inc. Micros for bigger ideas. color-blind person as it is to a viewer with normal color vision, For those interested in further information, the book Seeing is an excellent reference on vision in general and stereopsis in particular. (See reference 4.) A more recent and unique approach to presenting three-dimensional images is SpaceGraph, developed by Dr Larry Sher. His technique uses a vibrating mirror and a video display. The technique is to generate on the display two-dimensional “slices” of the three-dimensional object to be viewed. The slices are rapidly generated in synchronization with the dynamic motion of the mirror, the front slice being generated when the mirror is extend- ed toward the viewer, the back slice when the mirror is concaved away from the viewer, and the intermediate slices as appropriate for the travel of the mirror between these extremes. The rapid sequence of images is fused by the viewer's visual system to give the illusion of a “space filling’ object. (See reference 7.) Those adventuresome souls who find three-dimensions insufficient for their purposes can use computer graphics as an aid for visualizing objects which, theoretically, exist in four or more dimensions. If you are interested in this area, Hypergraphics is a good introduction to the sub- ject. (See reference 3.) The book includes hyperstereograms of such objects as hypercubes or tesseracts, hypercones, and other denizens of higher dimensions. Animation is another technique that can assist in user comprehension of data. Often we are dealing with infor- mation gathered at discrete intervals over a period of time. Here, the problem of analyzing data is one of il LOPPY DISK FACTORY DIRECT FLOPPY DISK FACTO © Buy factory direct from the manufacturer of floppy disks sold exclusively under other well-known brand names. © Save distribution costs on reversible 5.25" floppy disks, which are 100% certified for 40 track, dual side, double density and all other standard applications. © 50% savings on 5.25" floppy disks with new factory- direct 2.2 megabyte capacity "Diskit". *Factory-direct "Diskit™, includes twelve floppy disks and accessories, plus a head cleaner disk and solution packaged in a bookcase binder for easy access, handling and Storage. "Diskit complete for the introductory price of only $49.50 plus $2.50 freight and handling Normal price $59.50. Order now and save $10.00 (CA residents add 62% sales tax). ® Availabe in hard and soft sector configurations; when ordering indicate number of sectors — 1, 10 or 16. © Send check or money order to: Factory Direct P.O. Box 60759 Sunnyvale, CA 94088 For VISA or MasterCard call toll-free (800) 824-7888 In Calif. (800) 852-7777 In Alaska & Hawaii (G00) 824-7919 Ask for Operator 98 V4 SIO AddO1d LOSIO AW t_ ACTORY OIRECT FLOPPY DISK FACTORY DIRECT FLOPPY DISK FACTOR 3410 AHOLOVS NSIO AddO14d LOAHIC AWD. 4 ASIC AddO14d LO35HIC AHOLOW ASIC AddO1d 19 10 November 1980 © BYTE Peblications toc Circle 4 on inquiry card, understanding what is occurring to the data elements over some length of time. Animation provides a looking glass into the time domain. Flowing, three-dimensional images can represent anything from an economic world model to a bridge under stress. Hidden Benefits There are times when animation provides the viewer with unexpected information—information which, in retrospect, was present but not readily discernible by any other method of examination. An interesting example of this situation involves the simulation of an internal com- bustion engine. The simulation, performed at a research laboratory, wrote out data in the conventional manner: stacks of numbers. At the same laboratory, some time after the engine simulation had been completed and used for experiments, a different group of researchers devel- oped a computer-animation system. The engine simula- tion was selected as a good demonstration of the new graphics software, and a computer-generated film was produced. During the screening of the film it was noticed that small rectangular elements, used to represent ideal- ized gas packets, displayed a strange, unexpected oscilla- tion at their endpoints. Review of the animation soft- ware provided no explanation for this erratic behavior. Close examination of output from the original simulation revealed that the oscillations were indeed present. This fact had not been previously noticed because the infor- mation had been obscured by a combination of the tremendous amount of data, the smallness of the oscilla- tion, and the extended period over which it occurred, What had in fact been found were acoustical-wave phenomena occurring within the cylinder of the engine, which could potentially be used for the development of more efficient engines. The events went unnoticed until a computer-generated movie was constructed. In the 30 years since its beginnings, computer- generated graphics has grown steadily, but not spec- tacularly, Previously the costs of both the display and the computer resources needed to support graphic displays have limited the impact. Rapidly falling memory prices and television technology have renewed the interest in computer graphics. The combination of a television raster display and a memory-intensive, bit-mapped ar- chitecture makes possible a graphic system capable of providing full-color, dynamic images with previously unheard of realism and economy. “Micrograph, Part 1: Developing an Instruction Set for a Raster-Scan Display,” describes the design and construction of a color-display processor that costs approximately $250 to build. (See page 64.) This is possible only because of the plummeting cost of hardware. This is a cost reduction of three orders of magnitude in 15 years, with color added for free! Graphics Software The advent of inexpensive graphics hardware has, not unexpectedly, spurred the development of graphics soft- ware. The traditional approach for supporting graphics has been to provide a collection of subroutines that per- form the graphic-display functions. These subroutines are called from languages whose orientation is toward the manipulation of text and numerical data. This approach is fine if you only want to accumulate data and make a Circle 5 on Inquiry card. —> — at ple ha : : sai ve have ey : n Apple and you want ojnterfaceit with ei gens about ts il the el and serial. [ we havea board ? / 4 © those and « 3 you that will do both, Tes the AIO™ | = S the AIO ha nd a few More here — ; res. The ial pore wire . ‘Serial Interface. D The para . The n nd STB. Paritllel por, ’ “The RS-232 standard assures maximum compat- ibility with a variety of serial devices. For ex- to a video terminal to get 80 characters per line instead of 40, a modem to use time-sharing services, or a printer for hard copy. The serial interface is software programmable, features three handshaking lines, and includes a rotary switch to select from: 7 standard baud rates. On-board firm- ware provides a powerful driver routine so you won't need to write any lel inte software to utilize the interface. a rhacey 4Vailable Parallel Interface. This interface can be used to connect your Apple® to a variety of parallel printers. The programmable I/O ports have enough lines to handle two printers simultaneously with handshaking control. The users manual includes a software listing for controlling parallel printers or, if you prefer, a par- allel driver routine is available in firm- ware as an option. And printing is only one application for this general purpose parallel interface. ; Two boards in one. The AIO is the only board on the market that can interface the Apple to both serial and parallel devices. It can even do both at the same time. That's the kind of innovative design and solid value that’s been POF, OF boy NOrder oup ot for era Cates ai Pi going into SSM products since the beginning of personal computing. ap tach The AIO comes complete with serial PROM’, serial and parallel mM the tser wae cable cables, and complete documentation including software listings. See the AIO at your local computer store or contact us for more information. ssi pA/// z 2190 Paragon Drive San Jose, California 95131 (408) 946-7400, ia IS there ing to meet it ng and the Apple. If you could talk to Orville Wright, he'd tell you the problems he faced as a turn- of-the-century engineer. You could tell him all about the technological solutions available to today's engineer and scientist... particularly a 20th century phenomenon thattests assumptions and defines models before a project gets off the ground. The Apple personal computer. Computation, calculation, analysis...the power to pilot your projects. With a highly-integrated system from the extensive Apple personal computer family, Orville and brother Wilbur would have increased their productivity. Perhaps even launched the Kitty Hawk Flyer well before 1903. An Apple in their hangar would have freed them from the time and tedium of crunching numbers by hand. An Apple in your lab or office will give you the problem-solving capabilities you demand from a big computer...without the time-consuming problems typical of remote processing. But the Apple system solution doesn't stop there. Itkeeps on soaring with proven performance, power and expandability Apples existing software library includes @ program that plots the sbape of an airfoil, given its parameters. that’s unparalleled for analyzing alterna- tive paths of design and modeling a wide variety of physical processes. Want more memory? Depending on your choice of system, Apple has memory expandable to 64K bytes or 128K bytes. Prefer wide displays? Choose 40 or 80 characters. Need to control instruments in the lab? Get on the IEEE 488 bus. Over Circle 6 on inquiry card. 100 companies also supply peripherals for Apple because Apple is the most popular personal computer with the least com- plicated interface, Want an efficient system of data storage and access? Apple's 54" disk drive not only offers you increased application versatility, but high density (143K bytes), high speed and low cost. You can even add up to four or more drives to your Apple system. With proven reliability, n0 wonder it's the most popular drive onthe market today. _ —— your own “© programs, the Apple also speaks in languages other than FORTRAN: Pascal, BASIC, PILOT and 6502 assembly language. Where to learn more about Apple, the small-yet- serious solution. Let your imagination soar with Apple. Discover the 20th century tool versatile enough to monitor quality controls and manufacturing sched- Wilbur determined that birds didn't have to constantly flap their wings to fly. With an Apple, he could've determined the Sixed-wing design of the Kitty Hawk Flyer much faster. ules, orchestrate tolerance tests and determine alternative FORTRAN that helped to design a 20th century flying machine. Fluent in the same language that helped to design the 747, Apple FORTRAN lets you tackle differential equations at the touch of a key. And since more than 170 companies also offer software for the Apple family, you can have one of the most impressive program libraries ever...including vast subroutine libraries for math, science, engineering and statistics. When you write parts selection. Learn why Apple emerges as the technological leader of reliable personal computer products that increase your productivity. Let the Apple dealer show you how, by putting the system of your choice through its paces. He'll tell you about our extended warranty, support and service. And he'll prove that a personal computer is not just a flight of fancy but a serious solution. Don't let history pass you by. Visit your nearest Apple dealer, or call 800-538-9696. In California, 800-662-9238. Sappic computer TS U-OiiOI6)y, intreduces two new and effective education packages. . Chem Lab Simulation #1 and#2. designed for use with the Apple I computer Developed by a chemistry professor at lahoma State University, both. programs listically anddynamically illustrate the laws asic chemistry, They provide virtually nited results and instant Feed back} Suitable for high school or college level introductory Chemistry students, the p valuable lecture aid, And for individual they provide first-hand student involvement as wellas help solve the ereninial teaching problems of limited time. space, and resources uses APPLE's™ high resolution sraphics to simulate: n acid-base titratiun periment *Determination of an anknown weak avid including 9 titratian exporimentand a pH meter experiment Determination of Avogadra’s Number including, a Hbration: t nent and a monomolecular film ‘AL written in machine language for fast response uses APPLE’s ™ colorful low. PeeaI Gun graphics to simulate eThe tdeal Gas Lan #The Kinetic Molyc Theor The Principh of Entropy > your nearest dealer today, or Contact 5 is ae Coins Fé | ES ae P.O. Box 14665 Iklahoma City, OK 73113 (405) 840-9900 APPLE™is a registered trademark of APPLE COMPUTER, INC. 14 November 1980 © BYTEPublications Inc Circle 7 on Inquiry card. picture from it. The subroutine approach excludes the possibility of treating graphical objects as variables within the language, or using them within statements and expressions. Some research work has been done which in- cludes the concept of graphical objects and operators within a language structure. To date, there have been a number of different approaches to the problem of han- dling graphical objects. Deeply intertwined in the prob- lem is our fundamental lack of understanding of how to provide graphics support. Viewed from the perspective of a language, what fundamental primitives must be pro- vided? What are the appropriate data types? How are ex- pressions constructed? What operators need to be pro- vided? The list of unknowns goes on and on. “Language Control Structures for Easy Electronic Visualization,” by Dr Tom DeFanti, addresses this area. (See page 90.) Some examples of other, experimental, graphics languages are given in references 2 and 5. SHAZAM (Smalltalk’s sHaded imAge Zippy Animated Moviemaker) is an in- teresting animated-movie language written in Smalltalk. (See reference 1.) In no way does this list exhaust the pro- gress that has been made in graphics languages, but rather it reflects a small sampling of recent work. All the aspects of graphics we have discussed allow us to construct windows into universes, real or imaginary. Computer graphics is exciting because with this tool we can witness the unraveling of a DNA molecule, or the collision of galaxies. We can watch the structure of the universe as it expands from the moment of the theoretical big bang, or, reversing entropy, see it collapse into the primordial particle. We can plot a mathematical func- tion, view an economic trend, or travel faster than light to where robotic insects populate metallic worlds. Best of all, we can make it all seem real, because we can see it! m@ References 1. Baecker, R. "A Conversational Extensible System for the Anima- tion of Shaded images.” Computer Graphics, Volume 10, Number 2, Summer 1976. 2. Bergman, S and A Kaufman. “BGRAF 2: A Real-Time Graphics Language With Modular Objects and Implicit Dynamics." Com puter Graphics, Volume 10, Number 2, Summer 1976. 3. Brisson, D (editor). Hypergraphics — Visualizing Complex Rela: tionships in Art, Science and Technology. Westview Press, 1978, 4, Frisby, J. Seeing. New York: Oxford University Press, 1980. 5. Gonzales, C and J Vial, “GRAL — A Graphic Computer Language for Intelligent Terminals." Proceedings of the Conference on conpuer Graphics, Pattern Recognition and Data Structures, y 6. Myers, W. “Computer Graphics: A Two Way Street." Computer, July 1980. 7. seenom H. "Realistic Spatial Display." Digital Design, June 1 8. Walters, T and W Harris. “Graphics in Depth.” BYTE, Volume 3, Number 5, May 1978, page 16. Articles Policy BYTE is continually seeking quality manuscripts written by indi- viduals who are applying personal computer systems, designing such systems, or who have knowledge which will prove useful to our readers. For a more formal description of procedures and requirements, potential authors should send a large (9 by 12 inch, 30,5 by 22.8 cm), self-addressed envelope. with 28 cents US postage affixed, to BYTE Author's Guide. 70 Main St. Peterborough NH 03458. Articles which are accepted are purchased with a rate of up to $50 ‘per magazine page, based on technical quality and suitability for BYTE’s readership. Each month, the authors of the two leading articles in the reader poll (BYTE’s Ongoing Monitor Box or “BOMB’) are presented with bonus checks of $100 and $50. Unso- licited materials should be accompanied by full name and address, as well as return postage. Circle 8 on inguiry card, ——> TRS-80* Model I Computer Owners. . . Double-density storage. It’s really here! Here at Percom. And your authorized Percom dealers. And double-density storage is here in a big way. Because now you can choose from three different levels of mini-disk systems — all double-density rated. And get the storage that precisely meets your applicatio needs. levels of Percom drives work equally well in single- density applications. You can operate these drives in ordinary single- density format using TRSDOS*, Percom OS-80™ or any other single-density operating system. Or, you can add a Percom DOUBLER™ to your Tandy Expansion Interface and store data and rograms in either single- or double-density format. Not to mention the service and quality that’s made Percom the industry leader. Although rated for double-density operation, all Under double-density operation, you can store as much as 350 Kbytes of formatted data — de- nding on the drive model.— on one side of a s That's four times the capacity of standard Model I mi capacity of the eight-inch IBM 3740 format! Available in 1-, 2- and 3-drive configurations in all three model lines, Percom bumed-in, fully- tested drives start at only $399. inch minidiskette. lisks, almost 100 Kbytes more than the TFD-40™ Drives } TFD-40 Drives store 180 Kbytes (double-density) or 102 Kbytes (single-density) of formatted data on one side of a 40-track minidiskette. Although economical- ly priced, TFD-40 drives receive the same full Percom Gualty control measures as TFD-100 and TFD-200 ives. TFD-100™ Drives || TFD-100 drives are ‘“‘flippy"’ drives. You store twice the data per minidiskette by using both sides of the | disk. TFD-100 drives store 180 Kbytes (double- density) or 102 Kbytes (single-density) per side. Under double-density operation, you can store a 70- page document on one minidiskette. TFD-200™ Drives TFD-200 drives store 350 Kbytes (double-density) or 197 Kbytes (single-density) on one side of a minidis- kette. By comparison, 3740-formatted eight-inch disks store only 256 Kbytes. Enormous on-line stor- age capacity in a 5” drive, plus proven Percom reliability. That's what you get in a TFD-200. the DOUBLER™ — This proprietary adapter for the TRS-80* — el | computer packs approximately twice balan il the data on a disk track. 2 z - Depending on the type of drive, you can store up to four times as much data — 350 Kbytes — on one side of a minidiskette as you can store using a Tandy standard Model | com- f puter drive. Easy to install, the DOUBLER merely plugs % = into the disk controller chip socket of your Expansion Interface. No rewiring. No trace .cutting. And because the DOUBLER reads, writes and formats either single- or double-density disks, you can con- tinue to run all of your single-density software, then switch to double-density operation at any convenient time. Included with the PC card adapter is a TRSDOS*-compatible double-density disk operating system, called DBLDOS™, plus a CONVERT utllity that converts files and programsfrom single- to double-density or double- to single-density format. Each DOUBLER also includes an on-card high-performance data separator circuit which ensures reliable disk read operation. The DOUBLER works with standard 35-. 40-, 77- and 80- trackdrives rated for double-density operation. Note. Opening the Expansion Interface to install the DOUBLER may void Tandy’s limited 90-day warranty. Drive enclosures, power supplies Percom drive enclosures are finished in compatible silver enamel. Three sizes accommo- date either 1, 2 or 3 drives. Drive power supplies are heavy duty, cool-running open-frame design. Three-wire ac power cords are safer, have lower noise pickup. Free software patch This software patch, called PATCH PAK™, upgrades TRSDOS* for operation with improved 40- and 7: track drives. For single-density operation only. Call toll free Quality Percom products are available at authorized dealers. 1-800-527-1592 for the address of your nearest dealer or to order directly from Percom. Prices and specications subject to change without notice ™ trademark of Percom Date Company, Inc. + wademark of Tendy Radio Shack Corporation which has ne relationship to PercomData Compary [PERCO PERCOM DATA COMPANY. INC. 211 N KIRBY > GARLAND Tx - 75043 (21a1272.342) ___ Letters —— Moore Praise Comes FORTH If FORTH is trickery, give me more trickery, In my view, FORTH is a common- sense approach to programming. Granted, there are also bits of pure genius thrown in. It makes sense to put all the routines used by the operating system, compiler, parser, editor, etc, in one dictionary conveniently accessible to the user at all times. That is, if they will fit. One of the bits of genius of FORTH is that they do indeed fit with room to spare for user-defined routines. The result is in- stant liberation from the "systems man” who tries but can’t please everyone, It is your computer, and with FORTH you have access to everything on it. It makes sense to use a stack to pass parameters between routines and to separate this stack from the return- address stack. You end up with a language that is designed to compute rather than to be read. Every step in FORTH is directed toward computing a result. FORTH is a sequence of com- mands rather than statements as found in BASIC or Pascal. The functions of computing and documentation are separated. Hence | strongly disagree with Gregg Williams’ advice (see August 1980 BYTE, page 130) that the user should introduce intermediate variables to improve readability, | concur with his objective, but | would encourage their use only in the commentary where they belong. There is no point to introducing unnecessary variables in the computing process. In the commentary, in- termediate variables can and should be used very effectively to help describe the computations that are occurring on the stack without interfering with the process, While FORTH takes away the ex- pository statement, it does give back an important documenting feature, namely relative ease in preparing precise common-language definitions of each routine. All FORTH routines have a describable goal, and most of the action takes place on the stack, Hence FORTH routines tend to be simpler to describe. | have never seen a glossary for a language or operating system that comes Thousands of “like new” products with money back guarantees. REI Sales Company (800) 227-8409 In Gahtornia (213) 993-7368, (415) 968-8845 or (714) 879-0861 16 November 1980 © BYTE Publications inc Circle 9 on inquiry caro. even close to the completeness and con- ciseness of the fig-FORTH glossary sup- plied by the FORTH Interest Group, It is a gem, a complete English-language description of FORTH. Every routine on the computer is concisely defined in English. You have to have faith that taking the sacred function of documenting out of the language and turning it over to the user to do as he sees fit will work. After awhile, you begin to wonder if Milton Friedman didn’t write FORTH for his television series Free to Choose. Finally, it makes sense to give the pro- grammer a shot at controlling the com- piler, especially when the compiler has access to all the routines of the system, CH Moore has shown with FORTH that compilers do not have to be large inflexible systems which try to take into account every eventuality and really can't do it. The result of this bit of FORTH trickery is a powerful compiler so tiny that it can be made interactive and used on line with no batch process- ing, linking loader, or other monstros- ity which we are accustomed to associate with a compiler. How small (or big) is tiny? The fig- FORTH system supplied by the FORTH Interest Group for the 6502 contains 220 primitive routines (not including the Editor or Assembler) that occupy a total of 6221 bytes. By my count, 34 of these routines are compiler functions, and they occupy a total of 982 bytes. My guess is that this is an order of magnitude smaller than other compilers of comparable power. That is trickery. If there ever is a contest for the all- time ingenious software development, [ would like to nominate C H Moore's best, the { CODE } routine and/or its logical extension { <BUILDS ... DOES> }. Edgar H Fey Jr Edgar H Fey Jewelers Inc 1156 Fox Valley Ctr Aurora IL 60505 Flash: Magic Exists! I was delighted to see an issue of BYTE devoted to FORTH. As a user of and tinkerer with STOIC for 5 years, | heartily agree with the various authors’ ravings about the extensibility, flexibili- ty, and increase in productivity provided by FORTH. | was, however, amused at the many ways in which postfix (reverse-Polish) notation was rational- ‘n late 1978, Intertec conceived the idea of the InterTube Video Display Terminal. Since that time, we've greatly enhanced its operation with the addition of many new exciting features. But perhaps the most sig- nificant announcement in the interTube line of video terminals is our new InterTube Ill The new $895* InterTube Ill obsoletes dumb terminals and out-performs the smart ones. Powerful standard features include: a full 24 line by 80 character display, 128 upper and lower case ASCII characters, feverse video, complete cursor addressing and control, an 18 key numeric pad, user- defined function keys, blinking, a self-test mode, protected and unprotected fields, below-the-line descenders, automatic key repeat, twin RS232 serial ports and character and line insert/delete. Incredible! “Quanity One - Orales nquries mvited InterTube Ill also boasts newly designed processor, video and power supply circuits. All in all, the InterTube Ill is what we believe to be the most powerful, reliable video termi- nal available today, And it costs less than its predecessor - our popular InterTube II InterTube Ill users will appreciate the many painstaking hours of human engineering which insure effortless operation without Operator fatigue. InterTube Ill's new high resolution, non-glare CRT provides the sharpest possible display image. And our newly designed keyboard has that expensive “feel” you normally find only on terminals Costing two to three times as much. But, Most importantly, the InterTube Ill features State-of-the art design with just three easily removable modules. So, with only a common screwdriver, servicing is a snap! Better yet, we've got a nationwide serv- ice network with outlets located in over 50 Cities to provide fast and efficient on-site or depot maintenance. Plus, an extended warranty program is also available. If you're an existing InterTube user, you no doubt have discovered the exceptional value the InterTube really is. And, if you're not, why Not call or write us today for the name and address of your nearest InterTube Ill dealer. Intertec video terminals are distributed world- wide and may be available in your area now. INTERTEC DATA 2 =A, 2300 Broad River Ad, Columbia, SC 29210 (803) 798-9100 TWX: 810-666-2115, Circle 10 on Inquiry card. ized as being a better or more efficient way to do things even though it renders programs “write only” or at best difficult to read, Since maintainability of programs becomes even more critical when pro- ductivity is increased tenfold or more, I feel that the requirement of postfix nota- tion by FORTH is a serious shortcom- ing. There is nothing mystical about postfix notation; all compilers and inter- preters must eventually reach this form because that is the order in which the computer must carry out its operations. Over the past two years Jeff Morris and | have added various superstructures. onto FORTH (one per application) that attempted to combine the better features of Pascal (eg: record structures, algebraic notation) with the power and flexibility of FORTH, The outcome of all of these experiments was a conceptual break- through which resulted in the invention of Magic. Magic has all the advantages of FORTH, plus, Magic programs are readable (thus maintainable). For example, the FORTH (or Magic) statement: B@ C@ + A@* AL can also be written in Magic as; A:=ANB+O) CT. 1-800-854-2003 ext. 815 Computer Technology Associates Technicians! Hobbyists! Engineers! Repairmen! NEW! 16 CHANNEL VARIABLE A-D BOARD! Now you Can digitally display, store, analyze and print your measurements! The NEW ADC-168 A-D Board can be used for: POSITION MEASUREMENTS PRESSURE MEASUREMENTS PHOTOELECTRIC MEASUREMENTS TEMPERATURE MEASUREMENTS A COMPUTERIZED VOLT-OHM METER YOU GET A COMPLETE SOFTWARE PACKAGE INCLUDING A TEST KIT, CALIBRATION METHOD AND VARIOUS APPLICATIONS! Only 17995 This is a variable Gain Board that allows increased measurements from 5 volts up to 100 volts. COMPUTER TECHNOLOGY ASSOCIATES ORDER TODAY! Credit Card Users Call TOLL FREE! In California Catt 800-522-1500 ext. 815 SE ee ee ] ‘5812 Cromo Drive, Suite 102, El Paso, Texas 79912 | [Meare rusn me NEW ADC-168 A-D Boards at the Introductory price of 179” each. I I (check enciosea = Mastercard = Co visa Liners club I Name. I I aaress ! I ry. State, Zip. l 1 texas restaents add 5% sates tax Please allow 4.6 weeks for delivery. | em ee ee ee 18 November 1980 © BYTE Publications Inc Cirele 11 on Inquiry card. and in fact compiles in three fewer words (since the @s are not needed), and the FORTH (or Magic) statement; A@ B@ = IF can also be written in Magic as: IF(A.EO.B) Magic is a major enhancement to the basic compilation structure of FORTH (a metaFORTH), not simply an add-on superstructure. Magic programs typically compile more slowly (due to the in- creased complexity of the compiler) but require less memory and run faster than equivalent FORTH programs. The concept of metaFORTH is discussed briefly in the article by Kim Harris. (See “FORTH Extensibility: or How to Write a Compiler in Twenty- five Words or Less,” August 1980 BYTE, page 164.) This is the direction of the future and will be the source of some super-powerful programming tools in the next decade, Magic is a first step in that direction. I hope and expect that new metaFORTH languages such as Magic will be developed so that FORTH users can have their cake and eat it too. The time has come to stop justifying the unreadability of postfix notation. Arnold Epstein PhD Director, Software Development Octek Inc 7 Corporate Pl S Bedford St Burlington MA 01803 Needs Tektronix Secrets Can a BYTE reader help me? I havea Tektronix 4051 computer which came with a BASIC interpreter. Some of my programs must run faster, and | would like to rewrite them in machine code. Tektronix states that machine code is unsupported on the 4051 and suggests spending another $10,500 for a faster Model 4052. Someone somewhere is pro- gramming the 4051 in machine code, as “Space Tag” on the demonstration tape is in machine code and runs incredibly faster than ordinary BASIC programs. Richard Daily 800 Charlesgate Dr St Louis MO 63122 Information Please Trecently acquired a Video Brain home computer built by A Umtech Company. The serial number is 003087 and the model number is 101A. It was built in either Santa Clara or Sunnyvale, Girele 12 on Inquiry card. ——> Mountain Computer can now EXPAND Your Apple II Peripheral Capacity EXPANSION CHASSIS Quality You Expect Eight more slots for your Apple! Now you can bank-select eight more peripheral slots with immediate or deferred software commands—like having up to 16 peripheral cards “on line"—or use the Select/Deselect switch mounted on the front panel. Expansion Chassis’ heavy-duty power supply is primarily for peripherals, without the heavy demand of motherboard support chips required in your Apple. This means much more power is available for peri- pherals than in your Apple itself! If you've run out of room in your Apple—Expansion Chassis is your answer. Drop by your Apple dealer for a demonstration, or contact Mountain Computer for the location of the dealer nearest you. ASA a Mountain Computer INCORPORATED Performance You Demand ® Eight mirror image I/O slots of the Apple Fully buffered, bi-directional data lines Apple |! compatible interface card Dual selection capability; hardware or software © Immediate or deferred selection in software mode ® From BASIC, a single POKE command turns the chassis ON or OFF ® Compatible with all software * Dedicated power supply with approved power transformer Mountain Computer INCORPORATED 300 Harvey West Blvd., Santa Cruz, CA 95060 (408) 429-8600 TWX 910 598-4504 California. 1 understand it has a Fair- child F-8 8-bit microprocessor. It has 1 K bytes of programmable memory and 4 K bytes of read-only memory. What I am looking for are cartridge programs, which have a 45-terminal bus, the expander sets, or anything that would be interchangeable. Also, any in- formation or leads would be gratefully appreciated by me and my friends. Richard L Rowland 7072 Kenwood Las Vegas NV 89117 An Overlooked FORTH Vendor The staff at Datricon Corporation was both delighted and disappointed with the August 1980 BYTE. Our delight stems from the extensive coverage of the language FORTH and Charles H Moore's interesting article, “The Evolu- tion of FORTH, an Unusual Language,” page 76. However, we were disappointed with BYTE's failure to mention Datricon’s ACS 12-PRO or Datricon’s 4 K D-FORTH. Datricon’s implementation of FORTH resides in 4 K bytes of EPROM (erasable programmable read-only memory), produces code that can be placed into ROM (read-only memory), and provides for interrupt handling and the automatic setting of the data-transfer rate. Our ACS 12-PRO, with D-FORTH and the STD BUS interface, is a very powerful 6800-based single-board com- puter. A development package is also available for generating application EPROMs. Jed W Heald, President Datricon Corporation 7911 NE 33rd Dr Suite 200 Portland OR 97211 We at BYTE were surprised to find additional FORTH vendors advertising in our August 1980 isswe. Other vendors include Rockwell International (for the AIM microcomputer, see page 67 of the August 1980 BYTE), Kenyon Microsystems (for 6809 systems, see page 104 of the same issue), Sirius Systems (for the Radio Shack TRS-80, see page 171), Quality Software (for the Exidy Sorcerer, see page 208), Eric Rehnke (for the KIM, SYM, and AIM computers, see page 290), the Software Farm (for the TRS-80, see page 292), and Professional Management Services (for the Alpha Micro, see page 294). FORTH vendors not listed in the August 1980 BYTE are invited to submit a two- paragraph product release, which will be published in a future BYTE "What's New?” column....GW 20 November 1980 © BYTE Publications Inc FORTH Is Better Than LISP, He Cs Unlike BYTE’s earlier issue on LISP, the August issue on FORTH did an ex- cellent job in making this intriguing language readily understood. The ar- ticles did not come right out and say that FORTH is so machine-efficient due to the user preprocessing his logic into postfix notation, but most readers should realize this. Although I can tolerate that sort of notation for a desk calculator, it is unbearable for computer data process- ing. Although the C language is philosophically different, it is a threaded language which is much preferable. Dick Sims 185 Freeman St, Apt 951 Brookline MA 02146 Check Out a Computer I always look forward to the new issue of BYTE and was especially eager to read the July 1980, Computers and Education issue. Arthur Luehrmann’s ar- ticle, “Computer Illiteracy—A National Crisis and a Solution for It,” page 88, struck home on a point with which I wholeheartedly agree: “this country’s general public is woefully ill-prepared to live and work in the Age of informa- tion.” I was, however, disturbed by the fact that the role of public libraries was never mentioned. Public libraries are in a unique position to help solve the prob- lem: they serve people of all ages, regardless of educational background; they are generally open more hours than schools; they are, perhaps more than any other institution, vitally interested in an information-aware public; they specialize in providing access to informa- tion, and they are free. Many public libraries have microcom- puters available for public use and pro- vide a complement of interactive pro- grams for individuals to learn with, Libraries that have done this report ex- tensive and enthusiastic use of the equip- ment. It's a sorry fact that most people have just never had the opportunity to even see a computer system. Until the oppor- tunity to see, touch, and use computers is afforded, computers will remain shrouded in mystery for the vast major- ity of people of all ages, The public library is one of the best hopes we have to alleviate this probiem. Carlton A Sears Adult Services Coordinator Asheville-Buncombe Library System 67 Haywood St Asheville NC 28801 Letters continued on page 122 Circle 13 on inguiry card. mp interval timers, plus flexible patcharea for external interface. Programmable interrupts, ‘on-board ROM, and much more. ‘7720A Parallel intertoce. Two bi-directional 8-bit 1/0 ports will connect your Apple toa variety of devices. Full featured, programmable inter. Tupts, supports DMA daisy chaining. 78118 Artmetic Processor. Interfaces with Applesoft, so you just plug in and run. Based ‘on the AM 9511 device, provides full 16/32-bit arithmetic, floating point, trigonometric, loga- rithmic, exponential functions. Programmed 1/0 data transfer, much, much more. 771A Asynchronous Serial Intertoce. Conform- ing to RS-232-C A thru E 1978 standard, this card will drive variety of serial devices such as CRT terminals, printers, paper tape devices, or cr erie dale US peat ll including other computers. Full hand-shaling, and fully compatible with Apple PASCAL! 7470A 3% BCD A/D Converter. Converts a DC voltage toa BCD number forcomputerized monitoring and analysis. Typical inputs include DC inputs from temperature or pressure ‘transducers. Single channel A/D, 400 ms per conversion. ‘7A90A GPIB IEEE 488 interface. A true imple- mentation of the IEEE 488 standard—the standard for instrumentation and test devices, Control and monitor test instruments such as digital voltmeters, plotters, function generators, or any other device using the IEEE 488. ‘71144 PROM Module. Permits the addition to or replacement of Apple {l firmware without removing the Apple [1 ROMs. Available with on-board enable/disable toggle switch. 7500 A Wire Wrap Board. For prototyping your own designs. ‘TSA Solder Boord. ‘TS90A Extender Boo'd. ‘OWA 16K Dynomic Memory Add-On. ‘Watch this space for new CCS products for the Apple. We've got some real surprises in the works, To find out more about the CCS product line, visit your local computer cetailer, The CCS Product line is available at over 250 locations nationally, including most that carry the Apple. Orcircle the reader service number on this ad. Apple Il, Apple Il Plus, and Aj Ps peli nd li ‘pplesoft are trademarks CCS makes the difference. We see the Apple a little differently. We see it as a good f f thi d high-speed math functions, and fast, high resolution graph- way 0 ge Ings one. ics. And tools to connect the Apple to lab test equipment like function generators or plotters. Apple has built a great computer. We at CCS have And we have tools toconnect the Apple to the outside built a great line of peripherals and components toexpand _ world, including A/D converters and interval timers with the Apple. To do almost anything you want to get done external interface. witha computer. We make components for the S-100 bus, the PET, and If you warit to do business with an Apple, we've got the TRS-80, too. We built our products to deliver hard- tools to connect the Apple to standard business printers and _ nosed value to the OEM, and tothe inventor who knows the terminals. Or to modems, for communications over tele- best, at prices that are unbeaten. phone lines, with other computers, even with other Apples. To find out how much computer your Apple II can be, Ifyou want toapply your Apple to engineering, scien- _ see things our way. Because for serious users with serious tific, or graphic projects, we've got tools for high-powered, —_uses for the Apple, we've got the tools. (Ee California Computer Systems F] 250 Caribbean Sunnyvale,CA94086 (408) 734-5811 The Future of Computer Graphics Bruce Eric Brown and Stephen Levine Lawrence Livermore National Laboratory University of California POB 808 Livermore CA 94550 Predicting the future can place one in a very precarious position. Although technology is moving for- ward at such a pace that it is almost impossible to look a long way down the road, we do have a good idea of what the near-future trends will be. So here I will discuss where the trends in computer-generated graphics are headed. Computer graphics is the fastest- growing segment of the computer in- dustry. Although many existing com- puters already have graphics capabilities, the future is even brighter. Since personal computer users will make up the largest percen- tage of the computer graphics market, the standard color television receiver will be the most common Editor’s note: Jt was only 5 years ago when the first annual computer graphics show was held. The Philadelphia show was sponsored by SIG- GRAPH (the Association for Computing Machinery's Special Interest Group on Com- puter Graphics). At that time, the show at- tracted ten vendors and a few hundred visitors. SIGGRAPH-80, which was held this surnmer in Seattle, brought to that city over 100 vendors, about 6000 visitors, and filled twenty-four times the space of SIGGRAPH-75. So you can surmise how the the computer graphics field will continue to grow....SM 22 November 1980 © BYTE Publications Ine display device, Research is continual- ly going on in video-generation techniques, and we can expect the quality of video images to improve dramatically. Also on the horizon is the use of networks. Best of all, the price of graphics systems should continue to fall, and as they do, the number of applications will increase drastically. Three Dimensions This is an exciting time for ex- perimentation with computer graphics. Looking into our crystal video display, we can see many changes coming within the next few years. True three-dimensional displays will become common. Researchers will finally be able to see their models in three dimensions without the need of special glasses, stereo pairs, or by viewing two- dimensional projections. Already in existence are integral hologram displays made from computer-generated images. (An ex- ample is shown in photo 9.) The holograms are made by photographing 1080 computer- generated images on 35mm film and transferring them to the hologram. In a few years it will be possible to generate these directly; we might even see a laser-driven, computer- controlled, holographic-image output device. There are currently several methods in use for displaying three- dimensional television images, but the most promising uses an interlaced television picture. The even scan lines display an image for viewing with the right eye and the odd scan lines have an image for the left eye. The screen is viewed through a pair of glasses whose lenses are made with PLZT (lead lanthanum zirconate titanate) ceramic. Voltage pulses synchronized with the display of the odd and even fields darken the left and right lenses alternately. As a result, the viewer sees a true three-dimensional image. Photo 10 is a composite view of a display showing the images for both the left and right eyes. Photo 1: A computer-generated com- posite view of a DNA molecule using both ball-and-stick and space-filling models, Using keyboard control, the configuration of the model can be changed and it can be rotated in any direction. Such models are already assisting scientists in their research and will have an even bigger role in the coming years. Photo courtesy of Nelson Max, Lawrence Livermore Na- tional Laboratory. Photo 2: Computer-generated art by Los Angeles artist David M. As you can see, computer graphics could revolutionize the world of art. Photo 3: A perspective view of a two- dimensional array of numbers. Photo courtesy of Melvin L Pruett, Los Alamos Scientific Laboratory. Photo 4: Census data plotted to show population changes. This is an example of the type of material which could be available on a computer network with wide-band capabilities, such as cable television. Courtesy of Edward Zimmer- man, White House. Photo S: A ground-level view of a computer-generated airport scene used in a real-time flight simulator. Photo courtesy of Marconi Radar Systems. Raster-Scan Displays Low-priced memory will also change the look of computer graphics. Up to the present, the market has been dominated by storage tubes and calligraphic (ie: stroke-writing) displays; however, raster-scan displays can be refreshed from a frame buffer of semiconductor memory, Therefore, in the coming years, we can expect the graphic- terminal market to be dominated by raster-scan devices. The standard display will be a color television receiver connected as a mirco- processor-controlled intelligent ter- minal. The cost of some of these graphics terminals will be at or near the cost of a modern color television receiver. Raster-scan color television will probably be the graphics standard for the following reasons: @ The US video standard is well established. @ It has a large industry supporting it. @ The cost of developing another standard is prohibitive. @ The great numbers of personal computer users will help determine the trend. Why buy a color output monitor when you already have one or several available at home? November 1960 © BYTE Publications Inc 23 Top-of-the-line video displays will include devices with 1000-line resolu- tion (already available) as well as a number with 2000-line resolution. The cost of these will be significantly higher than that of a modern color television receiver. On a raster-scan display, each dot on the screen is known as a picture element or pixel. Since each pixel is displayed 30 times a second, the im- age generator must either generate 30 Hz or store the pixel intensities in memory. Frame-buffer systems usual- ly use dual-ported memory which both stores the image and refreshes the display. To simplify things, let's assume a square picture with the standard 500 lines and each line containing 500 pix- els. To display a completely black- and-white line image with no shades of gray we would need 250,000 (500 by 500) bits or 32 K bytes of memory. In order to display gray levels, the number of bits used for each pixel must be increased. To display color, we either divide the number of bits available among the three primary colors (red, green, and blue) or use a color map. A color map takes each pixel value stored and out- puts the three intensities: the most common method is to use 1 byte in- put and 3 byte output. The number of colors which can be displayed is the product of the number of output in- tensities for each color, At a given time, only a subset, which is limited by the input values, can be displayed. If we use 8 bits in, 24 bits out, we can display any 256 colors of the 16,777,216 available, In the near future we should be see- ing 2000-line resolution systems with 24 bits per pixel (1 byte for each of the three primary colors and 12 bits per color in the map). 12 megabytes of memory would be needed for such a system. With memory prices ex- pected to continue to fall, in about 5 years the major cost element of such a system would be the monitor and elec- tronics. Vector Displays Although it ap- pears that raster- scan displays will 24 November 1980 © BYTE Publid have the major share of the graphics market, line-drawing (ie: vector- display) systems will continue to grow, though at a slower rate. There are basically two types of line- drawing systems: the storage tube and the refresh calligraphic writer. Storage tubes available today have higher resolution and greater image stability than most refresh systems. One disadvantage of the storage tube Photo 6 (above): An example of the computer-generated graphics used to train space-shuttle pilots at the Johnson Space Center in Houston, Texas. Photo 7 (below): The control panel for an experimental fusion reactor at Lawrence Livermore National Laboratory. Transparent touch panels mounted over the color video displays have eliminated most switches. To control the reactor, the operators need only to touch the screen over the desired control area shown on the screen. Photo courtesy of Glenn Spreckert. is the lack of selective erasure. In order to remove one line the entire screen must be erased and redrawn. With refresh displays the line is removed from the display list and the line is redrawn on the next refresh cycle, Calligraphic displays can display about 20,000 three-dimensional vec- tors or 100,000 two-dimensional vec- tors at 30 Hz. In the next few years we can also expect a doubling of these capacities. Raster-scan display buffers can also be used to display vector images and should begin to replace calligraphic displays as faster hardware becomes available, Many users will probably prefer the somewhat slower speed of the raster scan since they are able to display continuous-tone color im- ages, Input One tool which should see much use in the future is a transparent touch panel mounted over the face of a video screen. As shown in photo 7, an automated nuclear-reactor control room is one of the many possible ap- plications. (Note the lack of switches.) Hard Copy Currently, one of the major prob- lems of graphic terminal users is how to satisfactorily get hard-copy output. The most common method is to use a camera to take a picture of the video screen. A device is also available which records the video output directly on film. Both of these methods leave much to be desired. The final solution may not necessari- ly come from the manufacturers of graphic terminals. The goal of copy- ing machine companies is a dry method of putting a color image on a piece of paper (like the current, dry | black-and-white- image method). At present, the device with the highest-quality color output is the film recorder. For raster output devices, the reso- lution of current recorders is 4000 by 4000 pixels, each with a range of 256 intensities. These devices use Circle 14 on inquiry card. > Hard and Fast... ...Bulk Storage from Industrial Micro Systems THE NEW MODEL 16 The new Industrial Micro Systems Model 16 Hard Disk Subsystem is a “fixed-removable” high speed, bulk storage device providing from 32 megabytes (32 million characters) to 96 megabytes of on-line storage for the Industrial Micro Systems 8000 or Series 5000 microcomputer systems. The Model 16 includes a credenza enclosure that provides a quiet, strong and attractive package for office or industrial applications where large memory is required. The Model 16 also includes a fully buffered DMA S-100 bus controller for fast and easy interfacing WINCHESTER TECHNOLOGY WITH BUILT-IN BACKUP The Model 16 includes a 16 megabyte removable cartridge and a 16, 48, or 80 megabyte fixed media that employs Winchester 3340 technology. Files and programs may be copied between the fixed media and the removable cartridge for fast, easy backup and archival storage FAST ACCESS The interface between the Model 16 hard disk and the Industrial Micro Systems computer is provided by the Hard Disk Controller. The Hard Disk Controller utilizes Direct Memory Access (DMA) for fast data transfer with minimum processor interven- tion. The maximum data transfer rate is 1.2 megabytes per second and the controller fully buffers the data, a sector at a time, to and from the disk. Available in 220 V, 50 HZ Versions Now you don’t have to look hard for fast computing power. Contact your Industrial Micro Systems Dealer today. INDUSTRIAL MICRO SYSTEMS Marketing 628 N. Eckhoff, Orange, CA 92668 (714) 978-6966 Manufacturing 2800 Lockheed Way, Carson City, NV 89701 (702) 883-7611 See us at Comdex '80 Nov. 18-21, 1980 Las Vegas Convention Center. as many as seven filters and multiple passes are made on the film to create full-color images. Additive-color red, Photo 8: A problem in hydrodynamics illustrated through the use of computer graphics. The photo is part of a series illustrating a steel rod impacting a steel plate. Color changes represent areas of varying stress, In the future, such graphics will be widely used in education. Photo courtesy of Lawrence Livermore National Laboratory. Photo 9: Integral hologram of a molecule created by photographing 1080 computer- generated images on 35mm film and then transferring them to a hologram. In the future computers will be able to generate holograms directly, Photo courtesy of Donald L Vickers, Lawrence Livermore National Laboratory. 26 November 1980 © BYTE Publications Inc green, and blue filters or subtractive- color yellow, cyan, and magenta filters are used. In both systems, the seventh color is neutral for plotting black-and-white images. We can ex- pect to see more of these recorders available in the near future, and some of the stripped-down models should be available at lower prices. Another group of devices which fit into this category of film output are COM = (computer-output-on-micro- film) devices. Many of those current- ly available have graphic capability as well as variable intensity. At the present time, COM devices are main- ly used for alphanumeric-fiche out- put. Currently only black-and-white machines are available, although color-fiche machines are expected to be produced in the future. The most important consideration is the need for high-quality, large-format color images. The resolution of current COMs is about 32,000 by 32,000 pix- els, Although higher resolution is theoretically possible, such devices will not be produced until a need for them is demonstrated, Laser recorders may soon capture a portion of the expanding graphics market. Since a laser beam has much more energy to deposit on film than a CRT {ie: video display) image, laser recorders will be much faster than ex- isting methods. On a modern film recorder, one full-intensity pass at 4000 by 4000 pixels takes about 1 minute. To record the same amount of data, the laser requires 1 second or less. The energy of a laser beam is great enough that a split beam could record up to five copies at the same time. A current weak link in laser systems is the deflection systems. Although solid-state methods are be- ing developed, rotating mirrors are used today. Another drawback with any system that uses film is that unless users have their own process- ing facilities, film development takes at least 24 hours and sometimes much longer. The Xerox 6500 color copier can be interfaced to a number of terminals for image-recording, or it can be con- nected to computers for direct out- put. Ink-jet plotters, printers with color rihbons, and flat hed-drum plotters with color pens are included in this class of output devices. Con- tinued improvements in speed and color reproduction can be expected, The brightest future is for the video disk. Today, these devices can hold 50 minutes (180,000 frames) of video per disk, Although the initial cost is high, the great number of frames available makes this device the ideal output and storage medium. Computers — The Future Although so far I've concentrated on graphics hardware, what about the future of the beast behind the display — the computer? It seems likely that within a few years the home computer user will have a choice of several 32-bit virtual machines with at least a million words of expandable, central mem- ory, and 100 million words of disk space. This type of system will be ideal for a color-frame buffer system. Applications Since pictures are a very efficient means of communication, the future applications of computer graphics are virtually unlimited. Photo 6 is a photograph of computer-generated graphics used to train space-shuttle pilots. Within the next few years, games and simulations with graphics of nearly the same quality will be available to the personal computer user, The PLZT glasses described earlier will be used to provide three- dimensional images for the would-be space-shuttle or 747 pilot. You can also expect the technology to be put to use in amusement parks. The Disneyland people have already used computer-generated graphics in some of their attractions and are continuing to develop them for future use. Networks There are a number of advantages to having your own, isolated per- sonal computer, but connecting it toa network opens up a vast new world, Networks designed specifically for personal computer users, such as The Source, are already in existence. Un- fortunately, the narrow bandwidth of conventional voice-grade telephone lines severely limits graphic capabilities. One future possibility is the use of cable television for networks with graphic capabilities. Cable is increas- ingly available in all but the most rural areas and has wide bandwidth, portions of which are not used. Per- sonal computer users could tap into this resource and use the extra band- width for local communication nets. Another possibility is to have the Circle 15 on Inquiry card. ——> ATARI PERSONAL COMPUTER SYSTEMS THAT GROW WITH YOU Start with a better computer. Atari computers have built-in capa- bilities you can’t even add onto many other personal computers. Three programming formats (ROM cartridge, disk and cassette). A 57 key upper/lower case ASCII keyboard with 29 keystroke graphics symbols, 128 colors and hues. Four separate sound channels and a built-in speaker. Four controller ports. A built-in RF ©1980, Atari inc. @ A Wamer Communications Company Atats reserves Ine fight to make changes to products OF progtams without notice. modulator and FCC approval for connection to any TV. Plus, nationwide Atari Authorized Service Centers. And more. Add memory. The ATARI 800™ is supplied with g 16K of memory. You can expand up to a full 48K of RAM with 8K or 16K Memory Modules™ you install yourself. In less than a minute. The ATARI 4o0's™ 8K of RAM may be expanded to 16K at Authorized Ser- vice Centers. Both may be expanded to 26K of ROM with slip-in ROM cartridge programs. Add peripherals. The ATARI 410™ audio-digital program recorder, Sin- gle or dual density* disk drives. The ATARI 800 individually addresses up to four drives. Add the ATARI 850” RS232 Interface Module, Add high speed 4o or 80-column printers. Add an acoustic modem for remote data access, Adda light pen* And there are more Atari peripherals on the way. ATARI PERSONAL COMPUTERS Add programs. Choose among doz- ens of programs in Atari’s rapidly expanding software library. Programs categories include: * Personal Finance & Record Keeping * Personal interest & Development * Professional Applications + Education * Information & Communication + Entertainment * Programming Languages * Small Business Accounting Add ft up. With Atari, you start with more, And you can build to more, Because Atari offers you per- sonal computer systems that grow with you. Ask your Atari retailer to give you a full demonstration of Atari computers, peripherals and programs. Complete systems, Because when other people were thinking hardware and software, Atari was thinking systems. “Available Fal, 1980 1265 Borregas Avenue, Sunnyvale, CA 94086 Call toll free (foo) 538-547 (Except Alaska and Hawati) (ln Cali ornta: 00} 6722404) for the name of your nearest Atari retailer ATARI) GABSS BSSUT BASIC ee vatilels A Circle 16 on Inquiry card. 2 The System X8000 MICRO-MINI™ based on * the 16-bit Zilog 28000 processor is available for immediate delivery. FEATURES (partial ist) * Zilog 28000 CPU * Intel Multibus compatible © Unique memory management system allows up to 16 megabytes of memory * Optional 9511 arithmetic processor Jevel vectored + nor-maskable interrupts * Two programable timers * On-board monitor ROM option * Full “Multimaster” capabilities allow multiple processors and/or DMA devices on the same bus ® Flexible and/or hard disk controller » Powerful disk-based operating system ‘+ Memory boards: 16K, 32K, 48K, 64K, 96K, 128K * 15-slol backplane * Heavy-duty switching power supply * Industrial quality throughout Prices start trom $998. System discounts. Call for prices on complete custom systems. SYSTEM X9020 {CPU Manual $19.95) $4195 * csronn” SYSTEM FEATURES (parte Het) sl MICROENGINE™ X3000 ‘ot P-coge CPU. bytes RAM Flt DMA 1 Floppy gisk controler (SS 0¢ DS) joaieng pows narsware (IEEE stangara) tem soltware win enhancements ial 2 paraliei ports al compet tent editors, We manages CPU &mamoryoragnostcs symbohc Pascal debsaper. linker utlties and mare MODEL X-920 DISPLAY/EDIT TERMINAL “LIMITED TIMF cash price. 10% DOWN guaraniees: Drionty. Master Charge & VISA cards accepled ‘System discounts ADM3A+ plus RG graphics (512x256)...$1995 NEC Spinwriter 5510 or 5530 w/tvac.... Anadex DP-9500 printer (60dp))..... X-912 CAT (less 16 function keys) .. P-€ $50 CRT (‘Bantam’)......... Siemens standard 6" drive (ss/sd-dd) .. $900* with CPU 312 684-3183 « COMPUTEX Microcomputer Systeme 5710 Dreeel, Chicago, k 60837 November 1980 © BYTE Publications Inc Photo 10: Interlaced left-eye and right-eye view of a computer-generated image of an aircraft carrier. The image is viewed in three dimensions when the user wears glasses with lenses made of PLZT (lead lanthanum zirconate titanate) ceramic. The lenses by the right and left are darkened alternately by voltage pulses synchronized to the display. Photo courtesy of John A Roese and Larry E McCleary, the Naval Ocean Systems Center. cable-television company provide a main computer to control the net- work and act as a data base. The range of services which could be pro- vided is virtually limitless. An exam- ple is shown in photo 4, where census data has been plotted to show population changes. Exploring the Future Computer graphics have exciting possibilities as an artistic medium, It's been said that computer-generated color graphics will revolutionize art in the same way that acrylics changed the world of artists who once worked with oil paints. Photo 2 shows computer-generated art by Los Angeles artist David M. The simulators discussed earlier will also be widely used by film- makers. Special effects, instead of being animated one frame at a time, could be programmed and filmed in real time. For instance, a director could ask for an airport scene on a clear day, as in photo 5. By changing a parameter, the same scene could be created on a foggy day. The motion picture industry is in the forefront of developing and using sophisticated systems for computer- generated graphics. Increasingly higher levels of realism will be created in the future and the time-consuming, tasks of creating special effects and editing will be performed using laser scanner/recorders and video disks. In terms of dollars, the movies will be one of the largest users of computer graphics for the near future. Applications, as we've seen, are limited only by our present imagina- tions. Photo 1 shows a computer- generated composite view of a DNA (deoxyribonucleic acid) molecule using both ball-and-stick and space- filling models. Such displays will speed up the rate of research. The molecule model can be rotated, changed in configuration, and taken home for the scientist to use on his personal computer. Classroom displays will greatly surpass the audio-visual methods commonly used today. Photo 8 shows a hydrodynamic problem with impact calculations displayed through color changes. A computer display of this sort could be created and updated in the midst of a lecture. In the wide world of computer- graphic applications, we have only scratched the surface. @ THE UNBEATABLE S-100 MEMORY That’s the MEASUREMENT systems & con- trols DMB Series of S-100 bus memory modules, fully compatible with ALPHA MICRO, CROMEMCO, NORTH STAR, MP/M, and most other S-100 systems. Definitely a winner, the DMB Series is avail- able with Bank Select (OM86400) or without (DM8400) and utilizes industrial quality con- struction, provides outstanding reliability, and is backed by dedicated customer service and a one year guarantee. The DMB6400 uses I/O port addressing for the bank select feature. A switch provides the ability to select any one of the 256 I/O ports for addressing the memory banks. The mem- ory is configured as four totally independent 16K software selectable banks, with each bank addressable on any 16K boundary. ADivisionof MEASUREMENT systems & controls incorporated . TVA Outstanding features such as those listed below make the DMB series the UNBEATABLE S-100 Memory. * Four independent 16K software select- able banks. © Each bank is independently addressable on any 16K boundary. ¢ Switch selectable bank sizes — from 16K to 64K in 16K increments. ¢ Eight banks (512K) per I/O port for each of the 256 ports. * 2-80 4MHz operation with no wait states using transparent refresh. On-board diagnostic LED’s. Low power — 8 watts maximum. Reliable, tested and burned-in memory. IEEE S-100 compatible timing. One year guarantee. Attractive Dealer & OEM Prices. See your nearest computer dealer, or contact us for the complete story on the UNBEAT- ABLE S-100 Memory. 867 North Main St./ Orange, Calif. 92668 / (714) 633-4460 TWX/TELEX: 678 401 TAB IRIN 8-Bit Champion In price-performance, look to Intel’s powerful iAPX 88 microprocessor to leave the pack behind. Both now and down the road. In price-performance races, the iAPX 88 istheone to beat. It’s two times faster than the Z-80A and the 6809. And recent bench- mark tests show that the iAPX 88, with its 8088 CPU, consistently outperforms its closest competi- tors in memory efficiency, ease of programming and throughput—by as much as 4 to I. This is especially important in high-performance tasks such as block moves, charac- ter searches, word shifts, and 16-bit multiplies. All critical for applications like word processing, terminal control, scientific instrumentation and industrial control. And because it’s the only 8-bit microprocessor that addresses up to 1 million bytes of memory, the 8088 can take on large programs. Without having to slow down due to over- lays or memory bank switching, like other 8-bit processors. Tough price competitor In price competition with other 8-bit microprocessors, the iAPX 88 has become the front runner. You save dramatically on e080 «URS = «ONS rs £ cz 1982 | 8-Bit Microprocessor Price Trends memory chips, too. The iAPX 88 takes—on the average— 30% less memory than competitors for the same programs. Then too, it allows you to use lower cost memory to get the same throughput as competitors. With a 5SMHz 8088, you can use our 450ns memories and still outper- forma 4MHz Z-80 requiring 250ns chips. Depending on Cirle 17 on Inquiry card. the application, your cost savings here can be substantial. No contest now with new Intel software To unleash the new power that the iAPX 88 puts in your hands, it takes more powerful software — the kind only Intel delivers today. Software that produces object code directly and gives you important ex- tensions that allow you to fine-tune the software to your application. Software such as PASCAL-88, the block-structured application language rapidly becoming the one most widely used. With our PASCAL-88, you can do direct port I/Oand interrupt handling, as well as independent program module compilation. And produce code that runs faster than other, P-code interpreter versions. Along with PASCAL-88, you get PL/M-88, our systems imple- mentation language, our ANSI- compatible FORTRAN, and our ASM-88 macroassembler. So with more software capability than you've ever had before, now you can choose the right language tool for each application—whatever it calls for. Get out in front with complete development support All the development support tools you need are ready to go today from Intel. Start with the Intellec® Microcomputer Devel- opment System. Add to that our ICE-88™ in-circuit emulator. Together they give you CPU emula- tion in real time, plus features like symbolic debugging, diagnostic commands and program trace capability. With these tools you'll get your products to market faster than by any other route, Looking down the road Best of all, with the iAPX 88, your investment in today’s solution is protected. Since the 8088 is 100% object-code compatible with the 16-bit 8086— plus its future generations, the iAPX 186 and iAPX 286—you have the industry's only guaranteed headstart on the path to the future. Regardless of which language you're writing in. So if you want to outdistance the pack, choose the iAPX 88— available today from your local Intel distributor. To get your copy of benchmark results, contact your local Intel sales office or distributor. For more information write Intel Corporation, 3065 Bowers Avenue, Santa Clara, C