1980 6.03 1982

Vol.6 n°3 march 1981

Vol.6 n°3 march 1981

(byte_1981_03.jpg)

[editor : Christopher Morgan] [publisher : Virginia Londoner, Gordon R Williamson, John E Hayes] #Magazine

p.4 In This Issue

p.4 In This Issue

#Abstract

Do you have trouble making all the pieces fall in place when you are writing a new program? Robert Tinney's cover this month symbolizes the theme of programming methods. But the symbolism is only pictorial-the process of designing and putting a new program together is often much harder than assembling an intricate jigsaw puzzle. This issue includes several articles on different aspects of programming and design: "What Is Good Documentation?" by Jim Howard; "Structured Programming and Structured Flowcharts" and the editorial, "Is This Really Necessary?", both by Editor Gregg Williams; "A Coding Sheet for FORTH," by John O Bumgarner; and "A Simple Approach to Data Smoothing," by Fred Ruckdeschel and Janice A Krinsky.

p.6 Editorial: Is This Really Necessary?

p.6 Editorial: Is This Really Necessary?

[author : Gregg Williams] #Edito

Extract : «  [...] What Is Design?

Webster's New Collegiate Dictionary defines design, the verb, as "to conceive and plan." As a noun, a design is "a preliminary sketch showing the main features of something to be executed." In terms of programming, design becomes proportionately more important depending on the size of the problem: We speak of program design when we write a game program for ourselves, project design when we design and write an accounting system on an existing computer at work, and system design when we draft a proposal for a hardware/software combination that will implement a given set of requirements for a data base system. (Actually, "system design" is used in the literature to describe the design of anything larger than one program; but I wanted to make a distinction between project design and system design because of the widely varying amounts of work they require.)

In designing and writing programs, I've found that the point dividing system design from program design is the point at which I have specified the function of the program and its use of computer resources (eg: are records stored on disk in a random-access file and called as needed, or are they read into memory before any processing is done?). After this point, I am designing the program (usually a fairly straightforward — though nontrivial — process). Before this point, I'm making certain critical decisions that strongly influence the requirements and performance of the proposed implementation of the program. In this sense, such decisions will often need to be made even when I'm designing and writing a single program. I can then see that both system design and program design have enough in common so I can eliminate the modifier and speak simply of design. I can safely say then that design is concerned with making a set of performance-related decisions and specifying the program(s) that implement them. [...]  »

TABLE OF CONTENTS

Features

Features

p.20 Structured Programming and Structured Flowcharts

p.20 Structured Programming and Structured Flowcharts

A technique that makes programs easier to write, understand, fix, and change.

[author : Gregg Williams] #Algorithm #Listing #BASIC #Method #Programming #Book

Extract : «  Structured programming — that phrase, unfamiliar to me and, I assume, to most people several years ago — is now endowed with such magical powers that most books on programming include it somewhere in their titles.

But what is structured programming? Most of us feel that it is probably good for us, like getting regular exercise or brushing our teeth after each meal. You may also think it's too complicated (not true), that it slows down programming (wrong, it usually speeds it up), or that it cannot be done unless your computer runs a language like Pascal or ALGOL (wrong again).

Simply put, structured programming is a set of techniques that makes programs easier to write, easier to understand, easier to fix, and easier to change. These techniques are simple and general and can be adapted to any computer language that has a goto statement — that includes BASIC, assembly language, FORTRAN, and COBOL. The purpose of this article is to show you a new form of notation that will help you write structured programs. But first, let's review structured programming. [...]  »

p.36 Build the Disk-80: Memory Expansion and Floppy-Disk Control

p.36 Build the Disk-80: Memory Expansion and Floppy-Disk Control

Steve discusses how to use dynamic memory and floppy-disk-controller integrated circuits and presents a design that incorporates them.

[author : Steve Ciarcia] #Electronic #Memory #Storage #Book

Extract : «  The term "memory expansion" no longer causes the same pained expression among computer owners as it did a few years ago. Back in the "Model T" days of personal computing, it was a major undertaking, often the largest expense of setting up a personal computer system. At that time, volatile memory integrated circuits contained only a fraction of the capacity of those available today, and mass storage often consisted of slow audio cassettes.

Back in 1975, if you were adding 32 K bytes of memory to your computer you would probably have used 256 type-2102A 1 K by 1-bit static memory chips. These cost between $2 and $5 each, and you probably would have needed a power supply larger and heavier than the computer. Believe it or not, the 2102A was a major improvement over the previous type-1101 memories (256 by 1-bit static devices). It would have taken 1024 (1 K) of the type-1101 components to make 32 K bytes.

Since that time, memory technology has progressed by leaps and bounds, and the cost per bit has dropped considerably. Many computer manufacturers now use dynamic rather than static memory. The result is much higher density, lower system cost, and easier after-market memory expansion on most computers.

The 64 K-byte personal computer system is more common than you would imagine. Adding another 16 or 32 K bytes of memory these days simply means plugging a few (8 or 16) integrated circuits into a memory expansion unit or motherboard. Usually the standard power supply suffices. [...]  »

p.54 Three-Dimensional Computer Graphics, Part 1

p.54 Three-Dimensional Computer Graphics, Part 1

Ways to display solid objects with the removal of hidden lines and surfaces.

[author : Franklin C Crow] #Listing #Pascal #Graphics #Book

Extract : «  The process of generating computer representations of three-dimensional structures has been pretty thoroughly worked out over the past fifteen years. Several books on computer graphics describe the necessary steps and commercial graphic software has been available for some time. Recently, three-dimensional graphic software has been made available even to those using microcomputers for personal or recreational purposes.

The software necessary for producing representations of simple shapes is not terribly complicated. In this article, I will try to lay out a few fundamental algorithms that can form the core of a three-dimensional graphics package. However, in order to make sense of these algorithms, considerable explanation will be necessary.

To generate an image of a three-dimensional shape, we have to have a computer-readable representation of the shape. (I will describe a couple of ways to represent shapes.) Then the data for the shape must be transformed to conform to the view of the shape that would be seen from a given point. The data must then be further transformed to fit the shape to the limits of a display surface (video display or plotter). Finally, those parts of the shape that are hidden from view, either because they exceed the limits of the display or because they are hidden by other parts of the shape, must be eliminated. [...]  »

p.132 What Is Good Documentation?

p.132 What Is Good Documentation?

How to write clear and effective documentation.

[author : Jim Howard] #Method

Extract : «  As more and more people discover the joys of owning a microprocessor the need for good documentation will continue to grow. Information will be needed at all levels, from detailed hardware and software documentation to descriptions of which buttons to push to play your favorite game.

Who will provide this information? The simple answer is that those who know will tell those who don't know. It sounds simple, but it's not. Everywhere, complaints are made about documentation — "inadequate," "erroneous," "over my head," "bad or nonexistent," and so on. All too often, companies market excellent systems with poor or sketchy documentation, resulting in unhappy customers and unsatisfactory sales.

It's a common mistake to believe that because somebody is an expert in a subject, he can explain it to others. For example, it's assumed that a professor who knows a subject inside and out can pass on this information to students. However, whether he can or cannot depends on something else besides his knowledge of the subject. It depends on his ability to put himself in the place of the users, the students, to begin where they are, using their language and their knowledge level. (Of course, if there is a failure to communicate, it is the students who fail, not the professor!)

The microprocessor industry is a classic example of the communication problem. Aside from a few shining lights, microprocessor literature suffers from a bad case of "the jargons." The problem was not as serious while the technology was being pursued by only a few hobbyists, who like to work things out for themselves. Now that the public is becoming involved in large numbers, the information must adapt to the customer, not the other way around.

Many could undoubtedly do a better job of communicating if they followed a few principles. But doing this requires conscious dedication. And, of course, it requires principles. Those principles are what this article is about.

To translate the jargon of the expert into terms meaningful to the rest of the world, we need an interpreter. Such an interpreter is similar to the compiler or interpreter used in computers, which translates the source language into one the machine understands. In both cases, the source language is provided by the computer expert. The machine is the user in one case, the public in the other. [...]  »

p.166 A Beginner's Guide to Spectral Analysis, Part 2

p.166 A Beginner's Guide to Spectral Analysis, Part 2

Images can be transformed into holograms via Fourier transforms.

[author : Mark Zimmermann] #Electronic #Listing #BASIC #Assembly #Audio #Book

Extract : «  In Part 1 of this article, I introduced some of the ideas behind the Fourier transform in one dimension. Here, I will try to extend those ideas to two dimensional space. I will introduce a few of the many uses of two-dimensional spectral analysis, with particular emphasis on image processing. The main computer program that accompanies this article (see listing 1) is a 6502 assembly-language program that performs a two-dimensional transformation on a 25- by 40-pixel image. The program is specifically adapted to run on the Commodore PET microcomputer with 8 K bytes of programmable memory, but it should be a reasonably straightforward process to modify the code to work on other comparable machines. Several floating-point arithmetic routines are used from the PET's BASIC ROM (read-only memory); a table is included that describes what each routine does, so that it may be replaced by your own arithmetical procedures if necessary. [...]  »

p.262 A Simple Approach to Data Smoothing

p.262 A Simple Approach to Data Smoothing

The techniques described here can aid in the interpretation of data taken from real-world situations.

[author : Fred Ruckdeschel and Janice A Krinsky] #Listing #BASIC #Mathematics #Book

Extract : «  The storage and processing of data has become a major activity in modern society. Computers have created an increasing demand for data because of their highly organized storage and retrieval facilities. Computers have also provided a means for rapidly transforming data into a format that emphasizes particular aspects of the underlying information. Data and information as used in this context are not synonymous terms. The word data refers to sets of numbers. Information is the knowledge that may be derived from those numbers.

Data appears in many forms. For example, a person interested in stocks may have a history of daily quotations for a particular company. A businessman may have a weekly sales record for each item in his inventory. A hospital administrator may have a record of emergency admittances. A scientist may have a table of results from a series of experimental measurements. All these types of data, when plotted against time (or another independent variable), may contain information regarding trends. However, existing trends in the data may not be visible because they are masked by statistical fluctuations, which are often a component of any real-world measurement. [...]  »

p.300 The New Literacy: Programming Languages as Languages

p.300 The New Literacy: Programming Languages as Languages

BASIC, ALGOL, and APL are compared to the English language.

[author : Jon Handel] #Listing #BASIC #APL #ALGOL #Languages #Book

Extract : «  "To be a good programmer today is as much a privilege as it was to be a literate man in the sixteenth century." Andrei Ershov, USSR Academy of Sciences, Novosibirsk University

Many people would declare that Ershov is making an incongruous comparison: he compares the ability to read, a universally desirable trait, with the ability to program a computer, which fewer people deem to be a desirable trait. Stranger still, he compares reading, which is linked with the appreciation of literature and with the artistic use of language, to programming. Programming is the recording of arcane codes that make a computer perform some data manipulation. Such coding seems unconnected with art and language, yet he implies that it is. Consonant with this view, program-coding systems are called languages, but most people would find it difficult to specify any way in which a computer programming system merits the label language.

Some people are, in fact, hostile to the very idea that programming and programming languages have anything at all to do with creativity and language. Sometimes these people are confused between the computer and its human programmer, attributing programming to the computer rather than to human beings.

Programming languages are in fact languages in a meaningful sense of that word: they exhibit some of the complexity of form and function that natural languages do. Computer programming languages are much more than mere coding systems. [...]  »

p.317 Computer Music: A Design Tutorial

p.317 Computer Music: A Design Tutorial

A modest amount of theory provides the background for building a simple program-controlled digital tone generator.

[author : Thomas P Orlofsky] #Electronic #Algorithm #Listing #Assembly #Audio #Book

Extract : «  The computational power necessary to synthesize high-quality, polyphonic computer music in real time exceeds the resources of the currently available microprocessors. Despite this discouraging observation, I decided early in the fall of 1978 to design a microprocessor-based music synthesizer. My goal was to discover just how successful I would be with a minimum system constructed from readily available parts. My self-imposed design constraints included an avoidance of special-purpose hardwired logic and an intention to stick with a byte-oriented architecture.

I hesitate to call the results of my efforts a music synthesizer. A more honest description might be a program-controlled, digital tone generator. Specifically, the design generates a predetermined sequence of sinusoidal waveforms in the manner of a player piano. A binary musical score or command program specifies the pitch and duration of each note. Each instruction in the command program selects between approximately 30,000 possible pitches from 0.1 Hz to 3 kHz, and selects between 255 possible durations from 10 ms to 2.55 seconds. This relatively fine time and frequency resolution permits quite sophisticated melodic articulations such as the slur, glissando, and vibrato. While the design provides memory for 341 notes or rests, this limitation is by no means essential.

I will begin by discussing the frequency-synthesis method before diving into a more detailed description of the implementation in both hardware and software. Along the way, you will become familiar with the engineering trade-offs inherent in the design of a digital sound system. At the conclusion, some possible improvements and points of departure for your own experiments will be discussed. [...]  »

Reviews

Reviews

p.84 The Micro Matrix Photopoint Light Pen

p.84 The Micro Matrix Photopoint Light Pen

[author : Stephen B Gray] #Review #LightPen

Extract : «  Because it's called a light pen, and because of the way it seems to be used, many people have the incorrect impression that a light pen does something directly to the image on the video screen. In actuality, it's the other way around. A light pen contains a photodiode that detects the movement of a point of light on the video screen, determines the coordinates of that point, and branches to a specified action for that point.

For example, if you're playing tic-tac-toe, you only have to point the light pen at the square in which you want to place your X. With a scan limited to nine areas on the video screen, the photodiode detects which area you're pointing to and puts an X in that square.

Applications

As hinted above, one of the most popular applications for the light pen is games. Instead of pressing a key, you need only point the pen. This eliminates having to memorize which key does what.

Another popular application is the fast selection of items in a screen menu. Some advanced graphics programs use light pens and menus. A screen may present a selection of shapes along one side, for example. You touch one, then touch the point on the screen where you want the computer to place the shape. Using small menus along the bottom of the screen, you control the size and rotation of the shapes to create complex subjects. [...]  »

p.90 What's Inside Radio Shack's Color Computer?

p.90 What's Inside Radio Shack's Color Computer?

[author : Tim Ahrens. Jack Browne, and Hunter Scales] #ComputerDesktop #Electronic #Review #Algorithme

Extract : «  The only similarity between Tandy Corporation's new Color Computer and its older brother — the original TRS80 — is the name. Even the microprocessor has been changed. In an apparent breakaway from the Z80, the Color Computer uses the Motorola MC6809E microprocessor as the workhorse of the new silver box. In fact, when we opened the enclosure, we didn't see any semiconductors that weren't made by Motorola.

The Color Computer is totally self-contained — no bulky separate power transformers — and the only cord, the one to the wall socket, has a standard three-prong connector. It can work with any color or black-and-white television set and has provisions for joysticks, a 1500 bps (bits per second) cassette interface, and an expansion connector for preprogrammed game cartridges.

Our aim in this article is to expose the insides of the computer and show what makes it run. Using this information, you should be able to expand the Color Computer in a number of ways, with a minimum of expertise. We will also describe the graphics interface so that do-it-yourself graphics routines should be a piece of cake. [...]  »

Nucleus

Nucleus

p.12 Letters

p.12 Letters

p.152 p.333 Programming Quickies: Computing the Determinant of a Matrix; Constellation I: An Astronomy Program

p.152 p.333 Programming Quickies: Computing the Determinant of a Matrix; Constellation I: An Astronomy Program

p.155 Languages Forum: A Coding Sheet for FORTH

p.155 Languages Forum: A Coding Sheet for FORTH

p.164 p.314 p.316 BYTE's Bits

p.164 p.314 p.316 BYTE's Bits

p.216 p.224 p.234 Technical Forum: DATALINE; Addition and Subtraction: The 1802 Versus the Z80; Build a Simple Video Switch

p.216 p.224 p.234 Technical Forum: DATALINE; Addition and Subtraction: The 1802 Versus the Z80; Build a Simple Video Switch

p.230 Desk-Top Wonders: Hunt the Wumpus with Your HP-41C

p.230 Desk-Top Wonders: Hunt the Wumpus with Your HP-41C

#Listing #HP #GameAdventure

p.236 System Notes: Software Addressing Modes for the 8080

p.236 System Notes: Software Addressing Modes for the 8080

p.242 BYTELINES

p.242 BYTELINES

p.248 Software Received

p.248 Software Received

p.252 Books Received

p.252 Books Received

#Book

Basic Computer Programs for Business, Volume I, Charles D Sternberg. Rochelle Park NJ: Hayden Book Company Inc, 1980; 25 by 20 cm, 264 pages; softcover, ISBN 0-8104-5162-X, $9.95.

Basic FORTRAN, James S Coan. Rochelle Park NJ: Hayden Book Company Inc, 1980; 15.5 by 23 cm, 248 pages, softcover, ISBN 0-8104-5168-9, $8.95.

Communicating with Microcomputers, Ian H Witten. London, England: Academic Press Inc Ltd, 1980; 15.5 by 23 cm, 164 pages, hardcover, ISBN 0-12-760750-1, $18; softcover, ISBN 0-12-760752-8, $10.50.

Computers and Programming Guide for Scientists and Engineers, second edition, Donald D Spencer. Indianapolis IN: Howard W Sams & Company Inc, 1980; 14 by 22 cm, 463 pages, softcover, ISBN 0-672-21693-0, $15.95.

The Computer in the School: Tutor, Tool, Tutee, Robert Taylor, editor. New York: Teachers College Press, 1980; 15.5 by 23.5 cm, 274 pages, softcover, ISBN 0-8077-2611-7, $14.95.

Computer/Law Journal, Volume II, Number 2, Jay Becker, editor. Los Angeles CA: Center for Computer/Law, 1980; 17.5 by 25.5 cm, 469 pages, softcover, ISSN 0164-8756, $16.

Designs of VMOS Circuits with Experiments, Robert T Stone and Howard M Berlin. Indianapolis IN: Howard W Sams & Company Inc, 1980; 14 by 22 cm, 174 pages, softcover, ISBN 0-672-21686-8, $10.95.

A Guide to FCC Equipment Authorizations, Willmar K Roberts. New Smyrna Beach FL: Willmar K Roberts, 4637 Van Kleeck Dr, 1980; 21.5 by 27.5 cm, 142 pages, softcover, ISBN none, $24.50 in North America, $29.50 elsewhere.

Introduction to Pascal, Including UCSD Pascal, Rodney Zaks. Berkeley CA: Sybex, 1980; 18 by 23 cm, 421 pages, softcover, ISBN 0-89588-050-4, $12.95.

Introduction to TRS-80 Level II BASIC and Computer Programming, Michael P Zabinski, PhD. Englewood Cliffs NJ: PrenticeHall Inc, 1980; 22.5 by 29 cm, 186 pages, hardcover ISBN 0-13-499970-3, $14.95; softcover, ISBN 0-13-499962-2, $10.95.

Micromatics, Steven K Roberts. Elmwood CT: Scelbi Publications, 1980; 22 by 29 cm, 190 pages, hardcover, ISBN none, $19.95.

Modern Microprocessor System Design, Daniel R McGlynn. Somerset NJ: John Wiley & Sons, 1980; 22.5 by 29 cm, 295 pages, hardcover, ISBN 0471-06492-0, $21.95.

The Nature of Computation: An Introduction to Computer Science, Ira Pohl and Alan Shaw. Rockville MD: Computer Science Press Inc, 1981; 16 by 23.5 cm, 397 pages, hardcover, ISBN 0-914894-12-9, $16.95.

Owning Your Home Computer, Robert L Perry. New York: Everest House, 1980; 19 by 25.5 cm, 224 pages, softcover, ISBN 0-89696-093-5, $10.95.

Personal Computers Handbook, Walter H Buchsbaum, Sc D. Indianapolis IN: Howard W Sams & Company Inc, 1980; 14 by 22 cm, 286 pages, softcover, ISBN 0-672-21724-4, $11.95.

p.254 Ask BYTE

p.254 Ask BYTE

p.308 Event Queue

p.308 Event Queue

p.315 Clubs and Newsletters

p.315 Clubs and Newsletters

p.337 What's New?

p.337 What's New?

p.382 Unclassified Ads

p.382 Unclassified Ads

p.383 BOMB, BOMB Results

p.383 BOMB, BOMB Results

p.384 Reader Service

p.384 Reader Service

ADS (content taken from the reader service p.384)

ADS (content taken from the reader service p.384)

p.117 p.162 Aardvark Software Inc

p.117 p.162 Aardvark Software Inc

p.361 AB Computers

p.361 AB Computers

p.354 Abbott, Robert

p.354 Abbott, Robert

p.222 ABM Products

p.222 ABM Products

p.339 Ackerman Digital

p.339 Ackerman Digital

p.277 ACOM Electronics

p.277 ACOM Electronics

p.63 Action Computer

p.63 Action Computer

p.146 Adaptive Data & Energy Sys

p.146 Adaptive Data & Energy Sys

p.348 p.349 Advanced Comp Prod

p.348 p.349 Advanced Comp Prod

p.356 ALL Electronics

p.356 ALL Electronics

p.59 Alpha Byte Storage

p.59 Alpha Byte Storage

p.275 Alpha Omega Comp Sys

p.275 Alpha Omega Comp Sys

p.198 Am Micro Prod Inc

p.198 Am Micro Prod Inc

p.231 American Square Comp

p.231 American Square Comp

p.89 Anadex

p.89 Anadex

p.360 Ancrona

p.360 Ancrona

p.16 p.279 Anderson Jacobson

p.16 p.279 Anderson Jacobson

p.230 Andromeda Systems Inc

p.230 Andromeda Systems Inc

p.13 Apple Computer

p.13 Apple Computer

p.318 Applied Analytics

p.318 Applied Analytics

p.328 Artec Electronics

p.328 Artec Electronics

p.187 ASAP

p.187 ASAP

p.211 Ashton-Tate

p.211 Ashton-Tate

p.277 Atlantis Computerized Sery

p.277 Atlantis Computerized Sery

p.354 ATV Research

p.354 ATV Research

p.356 autocontrol Inc

p.356 autocontrol Inc

p.274 p.283 Automated Equip Inc

p.274 p.283 Automated Equip Inc

p.233 BASF Systems

p.233 BASF Systems

p.347 John Bell Engineering

p.347 John Bell Engineering

p.186 Beta Comp Devices

p.186 Beta Comp Devices

p.354 Bit Bucket, The

p.354 Bit Bucket, The

p.356 Blacksburg Grp Inc, The

p.356 Blacksburg Grp Inc, The

p.204 Bower-Stewart & Assoc

p.204 Bower-Stewart & Assoc

p.51 p.201 p.382 BYTE Books

p.51 p.201 p.382 BYTE Books

p.350 C & A Associates

p.350 C & A Associates

p.21 Calif Comp Systems

p.21 Calif Comp Systems

p.374 p.375 Calif Digital

p.374 p.375 Calif Digital

p.285 Cambridge Develop Labs

p.285 Cambridge Develop Labs

p.330 Cawthon Scientific Grp

p.330 Cawthon Scientific Grp

p.354 CBAS

p.354 CBAS

p.251 Central Data

p.251 Central Data

p.190 Cexec Inc

p.190 Cexec Inc

p.255 Chrislin Industries

p.255 Chrislin Industries

p.23 C. ITOH Electronics Inc

p.23 C. ITOH Electronics Inc

p.365 Clev Con Comp & Compnts

p.365 Clev Con Comp & Compnts

p.297 Cognitive Systems

p.297 Cognitive Systems

p.68 p.69 CompuMart

p.68 p.69 CompuMart

p.293 Computer Age Inc

p.293 Computer Age Inc

p.287 Computer Case Co

p.287 Computer Case Co

p.174 Computer Disc of Am

p.174 Computer Disc of Am

p.115 Computer Factory, The

p.115 Computer Factory, The

p.194 Computer Furn & Access

p.194 Computer Furn & Access

p.320 Computer Marketing Corp

p.320 Computer Marketing Corp

p.268 Computer Plus

p.268 Computer Plus

p.208 p.209 Comp Prof Book Club

p.208 p.209 Comp Prof Book Club

p.354 Computer Shopper

p.354 Computer Shopper

p.352 Computer Society

p.352 Computer Society

p.76 p.77 Computer Specialties

p.76 p.77 Computer Specialties

p.326 Computer Tech Inc

p.326 Computer Tech Inc

p.85 Computer Warehouse

p.85 Computer Warehouse

p.352 Computers Plus Inc

p.352 Computers Plus Inc

p.108 p.109 Computers R Us

p.108 p.109 Computers R Us

p.302 Computex

p.302 Computex

p.67 Compuview Products Inc

p.67 Compuview Products Inc

p.360 Concord Comp Components

p.360 Concord Comp Components

p.108 p.109 Consumer Computers

p.108 p.109 Consumer Computers

p.73 Corvus Systems

p.73 Corvus Systems

p.295 Cover Craft

p.295 Cover Craft

p.119 CPI

p.119 CPI

p.363 CPU Shop, The

p.363 CPU Shop, The

p.1 p.2 Cromemco

p.1 p.2 Cromemco

p.79 Crystal Computer

p.79 Crystal Computer

p.356 Custom Business Comp

p.356 Custom Business Comp

p.350 Custom Peripherals

p.350 Custom Peripherals

p.98 Cybernetics Inc

p.98 Cybernetics Inc

p.327 Data Discount Center

p.327 Data Discount Center

p.62 Datamax

p.62 Datamax

p.24 Data Safe Products

p.24 Data Safe Products

p.333 Datasouth Computer Corp

p.333 Datasouth Computer Corp

p.105 Decision Master

p.105 Decision Master

p.191 Delta Products

p.191 Delta Products

p.171 Denver Software Co, The

p.171 Denver Software Co, The

p.245 DG Electronics

p.245 DG Electronics

p.207 Diablo (Div of Xerox)

p.207 Diablo (Div of Xerox)

p.112 Digiac Corp

p.112 Digiac Corp

p.254 Digital Graphic Systems

p.254 Digital Graphic Systems

p.243 Digital Marketing

p.243 Digital Marketing

p.133 Digital Pathways

p.133 Digital Pathways

p.25 Digital Research

p.25 Digital Research

p.351 Digital Research Computers

p.351 Digital Research Computers

p.217 DIP Inc

p.217 DIP Inc

p.312 Discount Sftw Grp, The

p.312 Discount Sftw Grp, The

p.248 Disk Supply Co

p.248 Disk Supply Co

p.332 DMA

p.332 DMA

p.218 Dual System Control Corp

p.218 Dual System Control Corp

p.277 DWP

p.277 DWP

p.289 Dymarc Industries

p.289 Dymarc Industries

(p.CIII) Dynabyte

(p.CIII) Dynabyte

p.263 Dynacomp Inc

p.263 Dynacomp Inc

p.88 Ecosoft

p.88 Ecosoft

p.178 Edmund Scientific

p.178 Edmund Scientific

p.356 Electravalue Industrial

p.356 Electravalue Industrial

p.212 Electronic Control Tech

p.212 Electronic Control Tech

p.350 Electronic Equip Unitd

p.350 Electronic Equip Unitd

p.279 Electronic Specialists

p.279 Electronic Specialists

p.291 Ellis Computing

p.291 Ellis Computing

p.165 Epson America Inc

p.165 Epson America Inc

p.128 Escon

p.128 Escon

p.26 ESP Comp Resources Inc

p.26 ESP Comp Resources Inc

p.324 Essex Publishing Co

p.324 Essex Publishing Co

p.143 Exatron Inc

p.143 Exatron Inc

p.322 Faircom

p.322 Faircom

p.283 Farnsworth Comp Center

p.283 Farnsworth Comp Center

p.275 Feith Software

p.275 Feith Software

p.97 John Fluke Mfg Co

p.97 John Fluke Mfg Co

p.362 Fordham

p.362 Fordham

p.297 Frederick Comp Prod

p.297 Frederick Comp Prod

p.352 Game-A-Tron

p.352 Game-A-Tron

p.139 General DataComm Ind

p.139 General DataComm Ind

p.138 GNT Automatic Inc

p.138 GNT Automatic Inc

p.220 p.221 Godbout Electronics

p.220 p.221 Godbout Electronics

p.14 Mark Gordon Computers

p.14 Mark Gordon Computers

p.196 p.197 p.253 H & E Computronics

p.196 p.197 p.253 H & E Computronics

p.355 Hanley Engineering

p.355 Hanley Engineering

p.352 Harris Corp

p.352 Harris Corp

p.271 Hayden Book Co Inc

p.271 Hayden Book Co Inc

p.61 p.287 Hayes Microcomp Prod Inc

p.61 p.287 Hayes Microcomp Prod Inc

p.195 Hazeltine Corp

p.195 Hazeltine Corp

p.17 Heath Company

p.17 Heath Company

p.135 Hewlett-Packard

p.135 Hewlett-Packard

p.60 High Technology Inc

p.60 High Technology Inc

p.358 Hobby world Electronics

p.358 Hobby world Electronics

p.71 Houston Instruments

p.71 Houston Instruments

p.350 IDM

p.350 IDM

p.275 Illinois Comp Mart Inc

p.275 Illinois Comp Mart Inc

p.127 IMS International

p.127 IMS International

p.18 Info Unitd Software

p.18 Info Unitd Software

p.265 Innovative Sftw Appl

p.265 Innovative Sftw Appl

p.121 Integral Data Sys

p.121 Integral Data Sys

p.256 Integrand

p.256 Integrand

p.53 Intel

p.53 Intel

p.285 Intelligent Control Sys

p.285 Intelligent Control Sys

p.235 International Microsystems

p.235 International Microsystems

p.103 Intertec Data Systems

p.103 Intertec Data Systems

p.286 Ipex Intl Inc

p.286 Ipex Intl Inc

p.8 p.9 Ithaca Intersystems

p.8 p.9 Ithaca Intersystems

p.350 J & S Computers

p.350 J & S Computers

p.372 p.373 Jade Computer Prod

p.372 p.373 Jade Computer Prod

p.368 p.369 Jameco Electronics

p.368 p.369 Jameco Electronics

p.314 JDR MICRODEVICES

p.314 JDR MICRODEVICES

p.362 JR Inventory Control

p.362 JR Inventory Control

p.266 KeeSoft

p.266 KeeSoft

p.145 Konan Corp

p.145 Konan Corp

p.252 p.316 Lax Computer Products

p.252 p.316 Lax Computer Products

p.91 Leading Edge Products

p.91 Leading Edge Products

p.125 p.228 p.260 Lifeboat

p.125 p.228 p.260 Lifeboat

p.131 Lifelines

p.131 Lifelines

p.356 Lin mar

p.356 Lin mar

p.232 Livermore Data Sys Inc

p.232 Livermore Data Sys Inc

p.285 LNW Research

p.285 LNW Research

p.136 p.137 Lobo Drives Intl

p.136 p.137 Lobo Drives Intl

p.84 Lomas Data Prod

p.84 Lomas Data Prod

p.252 McClintock Corp

p.252 McClintock Corp

p.350 Macrotronics Inc

p.350 Macrotronics Inc

p.274 Mann, Charles & Assoc

p.274 Mann, Charles & Assoc

p.281 Marymac Industries Inc

p.281 Marymac Industries Inc

p.284 Mattel Inc

p.284 Mattel Inc

p.270 MBC Systems Inc

p.270 MBC Systems Inc

p.29 p.129 Meas Sys & Controls

p.29 p.129 Meas Sys & Controls

p.336 Meta Technologies Corp

p.336 Meta Technologies Corp

p.290 MFJ Enterprises Inc

p.290 MFJ Enterprises Inc

p.151 Micro Age Computer Store

p.151 Micro Age Computer Store

p.281 Micro Architect

p.281 Micro Architect

p.291 Micro Business World

p.291 Micro Business World

p.304 Micro Comp Discount Co

p.304 Micro Comp Discount Co

p.329 Micro Comp Store, The

p.329 Micro Comp Store, The

p.169 Micro Data Base Sys

p.169 Micro Data Base Sys

p.241 Micro Management Sys

p.241 Micro Management Sys

p.49 Micro Mikes

p.49 Micro Mikes

p.269 Micro Pro International

p.269 Micro Pro International

p.275 Micro Products Unitd

p.275 Micro Products Unitd

p.319 Micro Works, The

p.319 Micro Works, The

p.123 MicroAce

p.123 MicroAce

p.183 MicroByte

p.183 MicroByte

p.180 p.181 Microcomp Tech Inc

p.180 p.181 Microcomp Tech Inc

p.161 MicroDaSys

p.161 MicroDaSys

p.331 Microhouse

p.331 Microhouse

p.325 Micromail

p.325 Micromail

p.260 Micromate Elect

p.260 Micromate Elect

p.261 Micropolis Corp

p.261 Micropolis Corp

p.275 MicroTech Exports

p.275 MicroTech Exports

p.250 Microware Sys Corp

p.250 Microware Sys Corp

p.364 Mikos

p.364 Mikos

p.100 Miller Microcomputer Serv

p.100 Miller Microcomputer Serv

p.281 Mini Computer Suppliers

p.281 Mini Computer Suppliers

p.380 p.381 Mini Micro Mart

p.380 p.381 Mini Micro Mart

p.113 Morrow Designs

p.113 Morrow Designs

p.19 Mountain Computer Inc

p.19 Mountain Computer Inc

p.159 mpi

p.159 mpi

p.83 MT Micro Systems

p.83 MT Micro Systems

p.272 MTI Inc

p.272 MTI Inc

p.295 Mt. View Press

p.295 Mt. View Press

p.130 MUSYS

p.130 MUSYS

p.270 Multi Business Comp Sys

p.270 Multi Business Comp Sys

p.273 NCC '81

p.273 NCC '81

p.216 NCE Supply Corp

p.216 NCE Supply Corp

p.167 NEECO

p.167 NEECO

p.303 p.305 Netronics

p.303 p.305 Netronics

p.317 Noesis Computing Co

p.317 Noesis Computing Co

p.193 NRI Schools

p.193 NRI Schools

p.82 Ohio Data Products Corp

p.82 Ohio Data Products Corp

(p.CIV) Ohio Scientific Instr

(p.CIV) Ohio Scientific Instr

p.111 OK Machine & Tool

p.111 OK Machine & Tool

p.293 Olympic Sales Co

p.293 Olympic Sales Co

p.310 Omega Micro Computers

p.310 Omega Micro Computers

p.202 Omega Research

p.202 Omega Research

p.219 Omega Sales Co

p.219 Omega Sales Co

p.306 Omikron

p.306 Omikron

p.225 onComputing

p.225 onComputing

p.283 Optimal Technology

p.283 Optimal Technology

p.147 Orange Micro

p.147 Orange Micro

p.148 p.149 Osborne/McGraw-Hill

p.148 p.149 Osborne/McGraw-Hill

p.258 OSM Computer

p.258 OSM Computer

p.28 p.308 p.309 Owens Associates

p.28 p.308 p.309 Owens Associates

p.352 P & S Electronics

p.352 P & S Electronics

p.275 Pace Age Tech

p.275 Pace Age Tech

p.330 p.352 Pacific Exchanges

p.330 p.352 Pacific Exchanges

p.353 Page Digital

p.353 Page Digital

p.358 Pan American Elec

p.358 Pan American Elec

p.6 PCD Systems Inc

p.6 PCD Systems Inc

p.354 PC Newsletter, The

p.354 PC Newsletter, The

p.356 Pelican Programs

p.356 Pelican Programs

p.15 p.35 p.185 Percom Data

p.15 p.35 p.185 Percom Data

p.213 Personal Micro Computers

p.213 Personal Micro Computers

p.31 Personal Software

p.31 Personal Software

p.249 Phase One Systems

p.249 Phase One Systems

p.254 Pickles & Trout

p.254 Pickles & Trout

p.266 pk systems inc

p.266 pk systems inc

p.164 Potomac Micro Magic

p.164 Potomac Micro Magic

p.134 Power One Inc

p.134 Power One Inc

p.376 p.377 p.378 p.379 Priority One

p.376 p.377 p.378 p.379 Priority One

p.334 Professional Business Sftw

p.334 Professional Business Sftw

p.277 Professional Comp Store

p.277 Professional Comp Store

p.321 Prometheus Products Inc

p.321 Prometheus Products Inc

p.277 p.330 p.352 Purchasing Agent, The

p.277 p.330 p.352 Purchasing Agent, The

p.350 Q Systems

p.350 Q Systems

p.310 p.370 p.371 QT Computer Systems

p.310 p.370 p.371 QT Computer Systems

p.223 Qantex

p.223 Qantex

p.275 Quality Computer Parts

p.275 Quality Computer Parts

p.179 Quality Software

p.179 Quality Software

p.239 Quasar Data Products

p.239 Quasar Data Products

p.345 Quest

p.345 Quest

p.275 Quintrex Inc

p.275 Quintrex Inc

p.12 R & B Computer Systems

p.12 R & B Computer Systems

p.289 Racet Computes

p.289 Racet Computes

p.289 Radgo Sales Co

p.289 Radgo Sales Co

p.81 Radio Shack

p.81 Radio Shack

p.258 Rainbow Computing

p.258 Rainbow Computing

p.192 RCA Solid State

p.192 RCA Solid State

p.184 REI Sales Co

p.184 REI Sales Co

p.334 RNB Enterprises

p.334 RNB Enterprises

p.299 Rochester Data

p.299 Rochester Data

p.30 S & M Systems

p.30 S & M Systems

p.295 S-100 Inc

p.295 S-100 Inc

p.177 Howard W Sams Co

p.177 Howard W Sams Co

p.277 SC Digital

p.277 SC Digital

p.279 Scientific Eng Labs

p.279 Scientific Eng Labs

p.5 Scion Corp

p.5 Scion Corp

p.299 SciTronics Inc

p.299 SciTronics Inc

p.144 Scottsdale Systems

p.144 Scottsdale Systems

p.267 Seattle Computer Prod

p.267 Seattle Computer Prod

p.7 Shugart

p.7 Shugart

p.291 Silverman Assoc

p.291 Silverman Assoc

p.87 Sinclair Research

p.87 Sinclair Research

p.354 Skyles Electr Works

p.354 Skyles Electr Works

p.275 Sluder

p.275 Sluder

p.315 Small Business Appl

p.315 Small Business Appl

p.101 Snapp Inc

p.101 Snapp Inc

p.157 p.214 Softech Microsystems

p.157 p.214 Softech Microsystems

p.176 Software Toolworks, The

p.176 Software Toolworks, The

p.313 Solid State Sales

p.313 Solid State Sales

p.238 Sorcim

p.238 Sorcim

p.286 Sorrento Valley Assoc

p.286 Sorrento Valley Assoc

p.227 Southern Semiconductors

p.227 Southern Semiconductors

(p.CII) Southwest Tech Prod Corp

(p.CII) Southwest Tech Prod Corp

p.205 Spectrum Software

p.205 Spectrum Software

p.11 SSM

p.11 SSM

p.163 Standard & Poors

p.163 Standard & Poors

p.287 Street Electronics

p.287 Street Electronics

p.293 SubLOGIC

p.293 SubLOGIC

p.52 Summagraphics

p.52 Summagraphics

p.364 Sunny Intl

p.364 Sunny Intl

p.10 p.92 p.93 p.102 p.311 SuperSoft

p.10 p.92 p.93 p.102 p.311 SuperSoft

p.155 Super Star Intl Corp

p.155 Super Star Intl Corp

p.107 Sybex

p.107 Sybex

p.75 p.292 Synchro Sound

p.75 p.292 Synchro Sound

p.259 Systems Plus

p.259 Systems Plus

p.299 Tarbell Electronics

p.299 Tarbell Electronics

p.55 Tech Sys Consultants (TSC)

p.55 Tech Sys Consultants (TSC)

p.352 Technical Innovations

p.352 Technical Innovations

p.237 TecMar Inc

p.237 TecMar Inc

p.350 Terminal Data Sys

p.350 Terminal Data Sys

p.27 Texas Instruments

p.27 Texas Instruments

p.335 3G Company

p.335 3G Company

p.95 3M Company

p.95 3M Company

p.276 Thunderware

p.276 Thunderware

p.354 Mitchell E Tim in Eng Co

p.354 Mitchell E Tim in Eng Co

p.356 TPA

p.356 TPA

p.256 TNW Corp

p.256 TNW Corp

p.277 Toolsmith, The

p.277 Toolsmith, The

p.226 TransNET

p.226 TransNET

p.172 p.173 TSE/Hardside

p.172 p.173 TSE/Hardside

p.140 p.141 United Software of Am

p.140 p.141 United Software of Am

p.34 Urban Software Corp

p.34 Urban Software Corp

p.366 p.367 US Micro Sales

p.366 p.367 US Micro Sales

p.229 US Robotics

p.229 US Robotics

p.277 Vamp

p.277 Vamp

p.104 VANDATA

p.104 VANDATA

p.57 Vector Graphics

p.57 Vector Graphics

p.354 Vertical Data

p.354 Vertical Data

p.215 Victor Data

p.215 Victor Data

p.247 Videx

p.247 Videx

p.153 p.359 Vista Computer Co

p.153 p.359 Vista Computer Co

p.188 p.189 Westico Inc

p.188 p.189 Westico Inc

p.33 White Computer Sys

p.33 White Computer Sys

p.99 Whitesmith's Ltd

p.99 Whitesmith's Ltd

p.200 CJ Wigglesworth Software

p.200 CJ Wigglesworth Software

p.280 Wild Hare Comp Sys

p.280 Wild Hare Comp Sys

p.297 John Wiley & Sons

p.297 John Wiley & Sons

p.356 Wintek Corp

p.356 Wintek Corp

p.120 Winterhalter & Assoc

p.120 Winterhalter & Assoc

p.352 Winchendon Group, The

p.352 Winchendon Group, The

p.350 Worldwide Electronics

p.350 Worldwide Electronics

p.357 WW Component Supply Inc

p.357 WW Component Supply Inc

p.175 Xerox

p.175 Xerox

p.277 XPS Inc

p.277 XPS Inc

p.257 Zobex

p.257 Zobex