Byte Magazine Vol.5 n°1 january 1980

p.3 In the Queue (table of contents)

Foreground

p.28 COMPUTERIZE A HOME

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

[author : Steve Ciarcia]

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

You can use your computer in conjunction with programmable timers to easily control a light dimmer. Since programmable timers simplify both hardware and software in such applications, you may think of other applications.

[author : John H Gibson]

p.74 A FURNACE WATCHDOG

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

[author : Theron Wierenga]

p.122 TELEPHONE DIALING BY COMPUTER

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

[author : Edward Joyce]

p.130 (p.129) ANALYSIS OF POLYNOMIAL FUNCTIONS WITH The TI-59 CALCULATOR, PART 2

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

[author : Pierre Chance]

p.156 ALPHA LOCK FOR YOUR ASCII KEYBOARD

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

[author : Terry Conboy]

p.180 RELOCATING 8080 SYSTEM SOFTWARE

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

[author : John Lipham]

p.212 EIGHTEEN WITH A DIE, A LEARNING GAME PLAYER

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

[author : Russell R Yost]

Background

p.20 MAKING COLOR SLIDES WITH AN INTECOLOR MICROCOMPUTER

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

[author : Alan W Grogono]

p.100 WHAT COMPUTERS CANNOT DO

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

[author : T C Lewis]

p.118 INDIRECT ADDRESSING FOR THE 6502

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

[author : Kenneth Skier]

p.138 (p.136) THE PLOT CONTINUES

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

[author : Leslie B Walter]

p.160 A COMPUTER-GENERATED REMINDER MESSAGE

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

[author : E M Pass]

Nucleus

p.6 Editorial

The Era of Off-the-Shell Computers Has Arrived

p.14 Letters

p.115 BYTE News

p.148, 151 Technical Forum

Aids to the Direct Reception of Weather Satellite Photographs

An Improved Maze Program

p.174, 206 Programming Quickies

A Pascal Checkbook Balancing Program

A French-English Dictionary

Z80 User Stack Emulation

p.176 Book Reviews

p.194 Clubs and Newsletters

p.195, 199 BYTE's Bugs

p.196, 150 BYTE's Bits

p.200 Event Queue

p.230 What's New?

p.271 Unclassified Ads

p.272 Reader Service, BOMB

p.28 ON THE COVER

The theme of this issue's cover illustration is "the domesticated computer." Robert Tinney has taken the idea of the remote controlled appliances suggested by Steve Ciarcia's article on page 28 and combined it with some imaginative cabinetry in a household setting. In the process, Robert used his artistic license to employ radio imagery with antennae and aetheric airbrushing as an alternative to ultrasonic techniques described by Steve. Either way, practical means of safely controlling 110V appliances from the computer with total electrical isolation now exist - both for the homebrewer and as practical products advertised in this issue.

Byte Magazine Vol.5 n°2 february 1980

p.3 In the Queue (table of contents)

Foreground

p.18 A FIRST LOOK AT GRAPH THEORY APPUCATIONS

If the use of graph theory raises a question, this article will supply an answer. The authors introduce the fundamental concepts of graph theory and two methods of directed-graph storage.

[author : Michael Ashbrook and Helmut Zinn]

p.32 A COMPUTER-CONTROLLED WOOD STOVE

Steve Garcia shows how he uses his computer to monitor and control a Hydrostove - a wood stove that heats water piped through it.

[author : Steve Ciarcia]

p.72 A COMPUTER-CONTROLLED LIGHT DIMMER, Part 2: Implementation

Part 2 of this article shows how to construct the design that was presented in the January 1980 BYTE, using the Heathkit ET-3400 microprocessor trainer.

[author : John H Gibson]

p.92 IMPLEMENTING DYNAMIC DATA STRUCTURES WITH BASIC FILES

Using linked lists to maintain sorted files is one way to deal with limited memory, large files, and additions and deletions to these files.

[author : Ted Carter]

p.106 A FAST, MULTIBYTE BINARY TO BINARY-CODED-DECIMAL CONVERSION ROUTINE

This general-purpose algorithm performs these conversions and assembler programs for the 8080 processor.

[author : Michael McQuade]

p.192 A FINANCIAL ANALYSES PROGRAM

Most investors will agree that financial stability and success require an organized systematic means of assessing investments. The program written by John Lehman can output the typical information required for such a financial report.

[author : John H Lehman]

p.202 ANOTHER PLOTTER TO TOY WITH, REVISITED: Design and Construction Details

Robert Newcomb tells how to construct and program the low-cost plotting system described by Peter Lucas in the February 1979 BYTE. Robert uses a KIM-I and various electromechanical parts.

[author : Robert K Newcomb]

Background

p.58 SOLVING PROBLEMS INVOLVING VARIABLE TERRAIN, Part 1: A General Algorithm

The method described by Scott Jones can be applied to a wide range of problems in business and industry as well as conflict simulations and games.

[author : Scott T Jones]

p.116 A QUAD TERMINAL INTERFACE

Building this interface solves the occasional problem of having one interface port and the need to use three or four peripherals.

[author : Stephen A Alpert]

p.128 COMPARISON OF SOME HIGH-LEVEL LANGUAGES

Some programming languages are more appropriate to a particular application than others. This comparison will help you choose the right language from the many possibilities.

[author : Robert A Morris]

p.176 BASIC FORMATTED OUTPUT

The feature provided here will give your BASIC package the control where a particular piece of information will appear on a line when you are performing input and output routines.

[author : William D Roch]

Nucleus

p.6 Editorial

The Seven Bridges of Königsberg

p.14 Letters

p.69 BYTE News

p.82, 86 Programming Quickies

Gasuse

String Comparator for Horizon

p.88 Clubs and Newsletters

p.140, 146, 172, 174 Technical Forum:

Some Example Plots

Introduction to Code Tightening

Mining the Skip Chain for Extra Bytes of Code

Audio Meter for Your TRS-80

Algebraic Identities Are Not Numerical Identities

p.154 Event Queue

p.162, 208 BYTE's Bits

p.168, 208 BYTE's Bugs

p.188 Book Reviews

p.212 What's New?

p.255 Unclassified Ads

p.256 Reader Service, BOMB

ON THE COVER

Topology is the theme of this month's cover painting, "The Seven Bridges of Königsberg" by Robert Tinney. It is a fanciful representation of a classical, topological problem made famous by the Swiss mathematician Euler, and it has a more than passing resemblance to the works of the Swiss artist M C Escher. The celebrated problem is discussed in detail by Carl Helmers in this month's editorial, and the Painting is also loosely inspired by the theme article, "A First Look at Graph Theory Applications," by Ashbrook and Zinn. Sharp-eyed readers might spot a visual reference to another famous mathematical problem hidden in the cover.

Byte Magazine Vol.5 n°3 march 1980

p.3 In the Queue (table of contents)

Foreground

p.17 EASE INTO 16-BIT COMPUTING: GET 16-BIT PERFORMANCE FROM AN 8-BIT COMPUTER

Steve tells you how the Intel 8088 is well-suited for building a minimum-configuration 16-bit computer.

[author : Steve Ciarcia]

p.34 ELECTRON BEHAVIOR IN A CHEMICAL BOND

Learn how to use a computer to explore the inner processes of a molecule by finding solutions to the Schrödinger wave equation.

[author : Michael Liebl]

p.74 SOLVING PROBLEMS INVOLVING VARIABLE TERRAIN, PART 2: SPECIAL CASES, INCLUDING HEXAGONAL GRIDS

After developing a general algorithm last month, Scott now explores several modifications that may be applied to typical conflict-simulation problems.

[author : Scott T Jones]

p.126 A POWER-LINE PROTECTION CIRCUIT

For hobby applications where an isolation transformer is too big and expensive, this relay-based circuit can provide some protection from power-line wiring errors.

[author : Neil Schneider and Bror Erickson]

p.130 LANDING MODULE SIMULATION WITH RANDOM SURFACE

This game uses the Motorola MEK6800 D2 kit. It can be interfaced to display the landing approach on an oscilloscope.

[author : S J Houng]

p.142 THE DIRT-CHEAP BOOTSTRAP, MORE NOTES ON BRINGING UP A MICROCOMPUTER

An inexpensive way to add front-panel functions to a minimal microcomputer system.

[author : Albert S Woodhull]

p.156 HYDROCARBON MOLECULE CONSTRUCTOR

The program presented here uses the high-resolution graphics ability of the Apple II to give a visual representation of molecular bonding.

[author : Randall S Matthews]

p.232 SUPER TIC

This is a three-dimensional, 4-by-4-by-4, tic-tac-toe game that can play against a human opponent. The program has ten levels of expertise, is written in BASIC, and can be modified to run in two dimensions.

[author : J Roebrig]

Background

p.60 HEWLETT-PACKARD'S NEW PERSONAL COMPUTER, THE HP-85

A first look at a personal computer from a company esteemed for its calculators and minicomputers.

[author : Christopher P Morgan]

p.84 TRS-80 PERFORMANCE, EVALUATION BY PROGRAM TIMING

James provides us with a direct comparison of the TRS-80 computer with an IBM System/370.

[author : James R Lewis]

p.114 ELECTRONIC PLANIMETRY

These authors describe a situation in which a specialized tool was replaced by a general-purpose minicomputer.

[author : Peter A Santi, John Fryhofer and Gregory Hansen]

p.194 OPERATION CODES FOR 8080, 8085, AND Z80 PROCESSORS

The need to convert an assembler mnemonic to the hexadecimal object code often occurs when programming the 8080 microprocessor family. Here is a helpful summary of related information.

[author : D Martin Harrell]

p.230 TO ERR IS HUMAN

Techniques to enable your computer to detect and correct typographical errors In assembly-language programs.

[author : Roger A McGregor]

Nucleus

p.6 Editorial

Hunting the Computerized Eclipse

p.14 Letters

p.68, 212, 240 Programming Quickies

Gear-Ratio Calculations for Bicycle Derailleurs

and many more

p.108 BYTE News

p.168 Book Reviews

p.174 BYTE's Bits

p.176 Clubs and Newsletters

p.180 BYTE's Bugs

p.184 Product Review: Lucidata P-6800 Pascal

p.186 Technical Forum

The Direct Impact of the Computer

Cutting the Gregorian Knot

p.208 Desktop Wonder

The Periodic Chart at Your Fingertips....

p.218 Event Queue

p.246 What's New?

p.287 Unclassified Ads

p.288 Reader Service, BOMB

ON THE COVER

This month's cover theme is "Computers in the Laboratory." Personal computers can be employed as a tool of analysis and control in scientific applications. We celebrate this theme with a fantasy suggestive of one area of scientific application: an advanced color-graphics-oriented personal computer is shown over a Bunsen burner on a beaker stand. On the terminal is a high-resolution image of some liquid boiling. This computer, without floppy-disk drives, certainly suggests a future direction: built-in, permanent mass storage with sufficient capacity to eliminate any need for removable media. We might even conjecture that a pattern is shown here being "boiled" into a bubble memory.

Byte Magazine Vol.5 n°4 april 1980

p.3 In the Queue (table of contents)

Foreground

p.96 COMPUTING THE I CHING WITH A TRS-80

If you cannot afford both a set of tortoise-shell casting wands and a personal computer, you should buy the computer and use the program in this article to peer into the Book of Changes.

[author : Dr Edwin Dethlefsen]

p.142 THE GREAT RACE AND MICRO DISK FILES, Horse Race Simulations

Here is a demonstration of some disk file management techniques used in a delightful game program.

[author : Joseph J Roehrig]

p.198 PROGRAM THOSE 2708s!

Programming this erasable programmable read-only memory for 8080-based microcomputers is easy with this author's hardware building and software usage methods.

[author : Robert Glaser]

p.212 APPLE AUDIO PROCESSING

Here is a simple interface you can add to an Apple II to allow audio input and output.

[author : Mark A Cross]

p.234 BUILD A LOW-COST EPROM ERASER

Do you need to change the programs in your erasable programmable read-only memory? Try building this ultraviolet EPROM eraser to do the job.

[author : L B Golter]

Background

p.18 USING THE COMPUTER AS A MUSICIAN'S AMANUENSIS, Part 1: Fundamental Problems

In the first of two parts, this author explores several musical concepts and poses some of the initial music-to-printed-score translation problems.

[author : Jef Raskin]

p.34 ADD A SIMPLE TEXT EDITOR TO YOUR BASIC PROGRAMS

Having a text formatting routine when you output large amounts of text is useful. Now you can see how easy It is to implement an editor in BASIC.

[author : Robert G A Goff]

p.40 EASE INTO 16-BIT COMPUTING, Part 2: Examining a Small Multi-User System

Last month, Steve told us about the 8088 processor's capabilities. Now he discusses a two-user system with Tiny BASIC that can be built using only five integrated circuits.

[author : Steve Ciarcia]

p.70 ADVANCED REAL-TIME MUSIC SYNTHESIS TECHNIQUES

This well-known computer music maker discusses the fine points of how he uses versatile digital-to-analog converters with a typical personal computer.

[author : Hal Chamberlin]

p.118 CALCULATING FILTER CAPACITOR VALUES FOR COMPUTER POWER SUPPLIES

Here is a homebrewer's explanation of how formulas and guidelines were developed for choosing a particular electronic component.

[author : John Thomas]

p.124 A GRAPHICS TEXT EDITOR FOR MUSIC, Part 1: Structure of the Editor

Now you can learn to enter musical scores into your computer by using a graphics tablet.

[author : Randolph Nelson]

Nucleus

p.6 Editorial: Bar Codes Revisited...

p.12 Letters

p.32, 240 BYTE's Bits

p.60, 68 Programming Quickies

An Animated Slot Machine in Color

A White Noise Generator for the Apple II

p.66, 220 BYTE's Bugs

p.104, 110 Technical Forum

MicroShakespeare

More GOTOXY

p.113 BYTE News

p.222 Clubs and Newsletters

p.226 Event Queue

p.242 What's New?

p.287 Unclassified Ads

p.288 Reader Service, BOMB

p.6 ON THE COVER

This month's cover features Hewlett-Packard's new bar code loader. The unit is described in detail in Carl Helmers' editorial on page 6. Bar codes, have been around for several years, in one form or another, but the HEDS-3000 Digital Wand is the first serious attempt to make bar codes a part of personal computing. Bar code readers will soon be used to enter recipe information into your microwave oven, read the bar codes on groceries, and enter programs into your computer. Also in this issue are several articles dealing with computer music. A lot has happened since our last special issue on music in September, 1977. Many of the new computers feature sound effects as a matter of course, such as the Atari and Texas Instruments models. This month Hal Chamberlin talks about recent developments in digital-to-analog (D/A) techniques for multiple-voice music generation; Jef Raskin describes a musical "amanuensis" or computerized music stenographer (the first of two parts); and Randolph Nelson reveals the details of how to enter and modify musical information into a computer quickly and efficiently.

Byte Magazine Vol.5 n°5 may 1980

p.3 In the Queue (table of contents)

Foreground

p.20 A DC-TO-DC CONVERTER

Here's a simple converter that uses a standard integrated circuit for producing a 25 mA bipolar source from a single-ended power supply.

[author : Michael Picco]

p.22 I/O EXPANSION FOR THE RADIO SHACK TRS-80, Part 1: Principles of Parallel Ports

This month Steve explains the operation of parallel input/output as a prelude to next month's design for an economical RS-232C interface.

[author : Steve Ciarcia]

p.44 KIMDOS, Using Your KIM-1 with a Percom Floppy-Disk Drive

Using the LFD-400 disk-controller board, the KIM-1 can access up to 87.5 K data bytes on several 5-inch hard-sectored floppy-disk drives.

[author : Joel Swank]

p.72 INTERFACE A FLOPPY-DISK DRIVE TO AN 8080A-BASED COMPUTER

Building a disk-controller board for a Shugart SA400 disk drive can be done easily and with commonly available parts.

[author : John Hoeppner]

p.196 GIVE YOUR COMPUTER AN EAR FOR NAMES

With the Soundex code, you can locate people's names in your data base by similar, but not exact, spellings.

[author : Tom Munnecke]

p.214 THE COSMAC DOODLER

An electronic sketchpad? Even a small system like the COSMAC ELF can draw designs using a video display.

[author : Jeff Duntemann]

p.250 ERROR CHECKING AND CORRECTING FOR YOUR COMPUTER

Storage devices can introduce data errors. The system presented here can increase reliability and speed of these peripherals.

[author : Gregory J Walker]

Background

p.12 THE CASSETTE LIVES ON, An Alternative to Floppy-Disk Mass Storage

Floppy disks may be the glamorous way to store programs and data, but the cassette is far from obsolete.

[author : Emory Cook]

p.104 A GRAPHICS TEXT EDITOR FOR MUSIC, Part 2: Algorithms

The conclusion of this article sets forth the routines to create and use the various arrays described in part 1.

[author : Randolph Nelson]

p.120 USING THE COMPUTER AS A MUSICIAN'S AMANUENSIS, Part 2: Going from Keyboard to Printed Score

Part 2 continues the examination of the subtle problems encountered when translating information from performance to written score.

[author : Jef Raskin]

p.130 COMPARING FLOPPY-DISK DRIVES BY SOFTWARE SIMULATION

Now you can get some idea of the relative performance of different units by simulating their mechanical functions in a BASIC program,

[author : Dennis Nendza]

p.202 THE CLUB COMPUTER NETWORK

If your club is considering to form a program- and data-exchange network, the telephone and amateur radio links described here will be a valuable source of ideas.

[author : Joe Kasser]

Nucleus

p.6 Editorial: Computer-Controlled Viewing of the 1980 Eclipse

p.8 Letters

p.144 BYTELINES (formerly BYTE News)

p.152 Technical Forum

Simplifying the Curve-Plotting Calculation by Geometric Means

Alpha Locking in Software

Maintaining a Single Exit Point

p.190 Programming Quickies

Decisions, Decisions

Formatted Program Output for the KIM-1

p.226 Book Reviews

p.230 Clubs and Newsletters

p.234 BYTE's Bits

p.236 BYTE's Bugs

p.238 Event Queue

p.280 NCC Information

p.286 What's New?

p.335 Unclassified Ads, BOMB Results

p.336 Reader Service, BOMB

ON THE COVER

On May's cover, Robert Tinney has formed an abstraction of the most important medium of mass storage in today's era of small computers, the floppy disk. Heightening its shimmering mystery, we find a disk wavering in the heat above some desert landscape. To enlighten you, this issue features several articles that present valuable information about floppy-disk technology. This technology is no mirage - it will even work well in a similar, hot environment of East Africa, as the editorial describes.

Byte Magazine Vol.5 n°6 june 1980

p.3 In the Queue (table of contents)

Foreground

p.24 AN ANSWER/ORIGINATE MODEM

Construction from precalibrated modules that eliminate the need for complicated adjustments makes this modem a practical project for the homebrewing hobbyist.

[author : Ronald G Parsons]

p.42 I/O EXPANSION FOR THE TRS-80, Part 2: Serial Ports

Along with a discussion of the theory of serial I/O ports, here's a design for an economical RS-232C interface that is compatible with standard TRS-80 software.

[author : Steve Ciarcia]

p.64 Z80 OP CODES FOR AN 8080 ASSEMBLER

Using predefined variable names, you can generate proper Z80 machine-language code.

[author : William T Powers]

p.96 COMMUNICATING IN TWO DIRECTIONS

With proper transmission lines, extra terminals can make your personal computer flexible and easy to access from many locations.

[author : Mark R Tichener]

p.122 A TIME-SHARING/MULTI-USER SUBSYSTEM FOR MICROPROCESSORS

This minimal hardware/software system shows that running multiple users on microcomputers is a simpler task to implement than most think.

[author : Don Kinzer]

p.140 A TELEPHONE-DIALING MICROCOMPUTER

Automatic telephone dialing can be done by two diverse methods.

[author : John Renbarger]

Background

p.88 MY TRS-80 TALKS TO MY CROMEMCO Z-2

Peripherals that were once dedicated to a single computer can now be shared by using this communications scheme.

[author : Rod Hallen]

p.108 UNDERSTANDING ISAM

Some microcomputers can use the indexed-sequential access method, known as ISAM, instead of random access or sequential access.

[author : Reginald D Gates]

p.214 INTERPERSONALIZED MEDIA: WHAT'S NEWS?

Decreasing costs and increasing availability of telecommunication facilities for microcomputers imply modes of communication vastly different from the ones we use today.

[author : James A Levin]

p.230 FIFTEEN: A GAME OF STRATEGY (OR TIC-TAC-TOE REVISITED)

This is a Nim-like game in which players try to pick numbers that will add up to 15.

[author : John Rheinstein]

Nucleus

p.6 Editorial: The Grass Roots Electronic Post Office...

p.12 Letters

p.84, 212, 228 BYTE's Bits

p.86 Ask BYTE

p.136 Book Reviews: The Network Nation: Human Communications via Computer

p.174 BYTELINES (formerly BYTE News)

p.182 BYTE's Bugs

p.186 BYTE's Bits: Bills Introduced in Congress

p.196 Technical Forum

A Race-Car Monitoring Program

Computing Time Between Dates

p.204 Event Queue

p.210 Clubs and Newsletters

p.238 Languages Forum: Comment and Correction for Mouse

p.242 What's New?

p.287 Unclassified Ads, BOMB Results

p.288 Reader Service, BOMB

ON THE COVER

On this month's cover, Robert Tinney has created a visual fantasy on a communications theme. Imagine a network of personal computers where each person's computer is a node. Each node can display some information about the network. The fantasy cover painting shows several such personal computers in a matrix of translucent network connections. A few message packets are in transit down gossamer conduits, and each computer shows a view of the network from that node's vantage point. As noted in this month's editorial, the real-world equivalent of this fantasy is the telephone network with low-speed modem equipment. While 300 bps is not the data communications equivalent of the bandwidth of a light beam, it is a good start which exists today. The nodes we know about via modems and telephones consist of our personalized directories of public access and private computer systems.

Byte Magazine Vol.5 n°7 july 1980

p.3 In the Queue (table of contents)

Foreground

p.22 HANDHELD REMOTE CONTROL FOR YOUR COMPUTERIZED HOME

Steve presents three schemes to conveniently send control data to the computer.

[author : Steve Ciarciq]

p.116 INTERACTIVE CONTROL OF A VIDEOCASSETTE RECORDER WITH A PERSONAL COMPUTER

Hardware and software link a Sony Betamax with an Apple II or TRS-80.

[author : Dr Richard C Hallgren]

p.154 PILOT/P: IMPLEMENTING A HIGH-LEVEL LANGUAGE IN A HURRY

Here's how to write a preprocessor in Pascal that translates the target language's source code into Pascal source code.

[author : David Mundie]

Background

p.46 THE 1980 WEST COAST COMPUTER FAIRE: A Watershed Year for Personal Computers

BYTE brings you pictures and comments about this record-breaking show!

[author : Chris Morgan]

p.56 SIMULATING HUMAN DECISION-MAKING ON A PERSONAL COMPUTER

The development of "intelligent" computer game programs, such as Othello, is traced from the early studies of human subjects to the final strategy.

[author : Peter W Frey]

p.74 EDUCATION FORUM: BOOKS AS AN ANTIDOTE TO THE CAI BLUES or Take a Publisher to Lunch

A successful author presents the case for publishing a new breed of personal computer books.

[author : Tom Dwyer]

p.86 EDUCATION FORUM: THE PERSONAL COMPUTER-Last Chance for CAI?

A brief history of computer-aided instruction is followed by speculation on its future.

[author : Lou Frenzel]

p.98 EDUCATION FORUM: COMPUTER ILLITERACY-A National Crisis and a Solution for It

More people need to know how to use computers.

[author : Arthur Luehrmann]

p.138 A PERSONAL COMPUTER ON A STUDENT'S BUDGET

Putting together a system by economical buying and building can be done.

[author : J C Johnson]

p.175 THE MICROCOMPUTER IN THE UNDERGRADUATE SCIENCE CURRICULUM

The current status of the microprocessor in colleges is assessed.

[author : W N Hubin]

p.198 THE USER'S COLUMN: OMIKRON TRS-80 BOARDS, NEWDOS+, and Sundry Other Matters

Science fiction writer Jerry Pournelle begins a semiregular column of hardware and software reviews.

[author : Jerry Pournelle]

p.210 CREATING A FANTASY WORLD ON THE 8080

Here are some valuable tips on designing your own Adventure game.

[author : Robert T Nicholson]

p.236 MICRO8: Using BASIC to Learn Assembly Language

The BASIC program presented here simulates a very simple stored-program digital computer with its own assembly language.

[author : Robert T Pickett III]

Nucleus

p.6 Guest Editorial

Computers in Learning Environments, An Imperative for the 1980s

[author : Dr Ludwig Braun]

p.14 Letters

p.20 BYTE'S Bits

p.20, 228 BYTE's Bugs

p.50 Product Description: The Apple III

p.104 Book Reviews

p.148 BYTELINES

p.216 Technical Forum: Some More On Performance Evaluation

p.220 Clubs and Newsletters

p.224 Event Queue

p.230 Ask BYTE

p.250 Whats New?

p.302, 303 Unclassified Ads

p.303 BOMB, BOMB Results

p.304 Reader Service

ON THE COVER

Our cover this month, Computers in Education, by Robert Tinney, is a fanciful version of a personal computer "playground." Computers are becoming fixtures in our schools, and this month's BYTE takes a look at some of the implications of this new wave in education. For more details about the education articles in this issue, see the guest editorial by Dr Ludwig Braun beginning.

Byte Magazine Vol.5 n°8 august 1980

p.3 In the Queue (table of contents)

Foreground

p.22 A BUILD-IT-YOURSELF MODEM FOR UNDER $50

This originate-only modem will allow you to get started in intercomputer communication with minimal expense.

[author : Steve Ciarcia]

p.58 THE HARD-DISK EXPLOSION: HIGH-POWERED MASS STORAGE FOR YOUR PERSONAL COMPUTER

Thanks to new hard-disk technology, personal computer users can add millions of bytes of mass storage to their systems at a reasonable cost.

[author : Tom Manuel]

p.100 WHAT IS FORTH? A TUTORIAL INTRODUCTION

Here is an overview of FORTH that lays the foundation for the other theme articles in this BYTE.

[author : John S James]

p.150 BREAKFORTH INTO FORTH

If you can't imagine any personal use for FORTH, can you imagine a 96-line program that plays a fast, animated game with sound on the TRS-80?

[author : A Richard Miller and Jill Miller]

p.164 FORTH EXTENSIBILITY: OR HOW TO WRITE A COMPILER IN TWENTY-FIVE WORDS OR LESS

This tutorial explains the capability for defining new families of FORTH words.

[author : Kim Harris]

p.210 CONSTRUCTION OF A FOURTH-GENERATION VIDEO TERMINAL, PART 1

Part 1 of this article presents a new design using the 8275 controller and a dedicated Z80 microprocessor.

[author : Theron Wierenga]

Background

p.76 THE EVOLUTION OF FORTH, AN UNUSUAL LANGUAGE

The inventor of the language recalls its design and how it evolved over a 10-year period.

[author : Charles H Moore]

p.198 KHACHIYAN'S ALGORITHM, PART 1: A NEW SOLUTION TO LINEAR PROGRAMMING PROBLEMS

Now you can study the algorithm that promised to revolutionize linear programming.

[author : G C Berresford, A M Rockett, and J C Stevenson]

Nucleus

p.6 Editorial: Threads of a FORTH Tapestry

p.14 Letters

p.40 Product Review: The Ohio Scientific CA-15 Universal Telephone Interface

p.46 Product Review: The Heath H-89 Computer

p.72 Programming Quickies: Self-Reproducing Programs

p.94 BYTEL1NES

p.98 Selected FORTH Vendors

p.196 A FORTH Glossary

p.226 Clubs and Newsletters

p.230 Event Queue

p.234 Ask BYTE

p.248 Whats New?

p.302 Unclassified Ads

p.303 BOMB, BOMB Results

p.304 Reader Service

ON THE COVER

This month's cover by Robert Tinney shows a rocket-like needle threading its way through granite cubes labeled: DOUBLE , DUPLICATE , and + . The threaded path of the needle is a representation of the process used in FORTH and other threaded languages to create a new word (here, DOUBLE ) with previously defined words (here, DUPLICATE and + ). Other aspects of this fascinating language are described in the editorial, "Threads of a FORTH Tapestry," and in the theme articles for this issue.

Byte Magazine Vol.5 n°9 september 1980

p.3 In the Queue (table of contents)

Foreground

p.26 BUILD A LOW-COST, REMOTE DATA-ENTRY TERMINAL

This terminal increases the flexibility of computer home-control systems.

[author : Steve Ciarcia]

p.46 AN 8088 PROCESSOR FOR THE S-100 BUS, Part 1

Part 1 covers the basic design considerations of an S-100 processor board based on Intel's 8088 microprocessor.

[author : Tom Cantrell]

p.86 PENNY PINCHER'S JOYSTICK INTERFACE

For about $6 and one night's work, you can add this interface to your system.

[author : Steven Wexler]

p.116 APL CHARACTER GENERATOR

This is a simple modification for any video display employing the MCM6571 character generator.

[author : John W Langer]

p.126 CONSTRUCTION OF A FOURTH-GENERATION VIDEO TERMINAL, Part 2

Part 2 helps you to complete the construction of the terminal and learn to use the built-in debugging features.

[author : Theron Wierenga]

p.242 KHACHIYAN'S ALGORITHM, Part 2: Problems with the Algorithm

A practical BASIC program can be used to explore the power and limitations of this new algorithm.

[author : G C Berresford, A M Rockett, and J C Stevenson]

p.270 EXPLORING BALLISTICS WITH YOUR COMPUTER

This BASIC program helps the target shooter to calculate the complex path of bullets.

[author : Robert W Jenks]

p.282 AN INTERRUPT-DRIVEN REAL-TIME CLOCK FOR THE TMS 9900

Three selectable interrupt rates make the Texas Instruments 16-bit processor count time.

[author : Thomas G Morris Jr]

p.328 A BASIC FLOPPY-DISK ACCOUNTING SYSTEM

Here's a complete six-program package keep your budget records in order.

[author : Joseph J Roehrig]

Background

p.76 DISSECTING THE TI SPEAK & SPELL

With these notes you can move toward the eventual goal of getting this toy to talk under personal computer control.

[author : Michael A Rigsby]

p.102 MACHINE PROBLEM SOLVING, Part 1: Trial-and Error Search, A Mechanical Plan to Save the Missionaries

Simple games help to express this method of solving problems with computers.

[author : Peter W Frey]

p.180 FCC REGULATION OF PERSONAL- AND HOME-COMPUTING DEVICES

New rulings by the FCC will affect the use and manufacture of personal computers.

[author : Terry C Mahn]

p.206 VARIETIES OF THREADED CODE FOR LANGUAGE IMPLEMENTATION

Some kinds of threaded code are position and system independent.

[author : Terry Ritter and Gregory Walker]

p.230 EDUCATION FORUM: NEW CULTURES FROM NEW TECHNOLOGIES

Children should learn to compute in the same way they learn to talk.

[author : Seymour Papert]

Nucleus

p.6 Editorial: Intellectual Ethics and Software

p.14 Letters

p.66, 322, 324 Programming Quickies

p.304, 308, 310 Book Reviews

p.94 Languages Forum

p.96, 194, 314, 316, 321, 326 Technical Forum

p.114, 312 BYTE's Bits

p.164 BYTELINES

p.172 Ask BYTE

p.256 Clubs and Newsletters

p.260 Event Queue

p.268, 313 BYTE's Bugs

p.336 What's New

p.398 Unclassified Ads

p.399 BOMB, BOMB Results

p.400 Reader Service

About This Issue

BYTE is five years old this month, and we're taking the opportunity to discuss one of our favorite subjects: homebrewing. Much of the personal computer hardware sold today is already assembled; even so, many of our readers like to build or modify their own equipment, and even "homebrew" it from scratch. The cover photograph by Raoul Hackel, Stock Boston, shows some colorful wiring harnesses inside a computer chassis, a familiar sight to the intrepid do-it-yourselfer.

Theme articles in this issue include a build-it-yourself, low-cost, remote data-entry terminal (from Steve Ciarcia); exploring the TI Speak & Spell; a pennypincher's joystick interface; and the beginning of a multipart article on building an 8088 processor for the S-100 bus. Along with these are features on threaded code; FCC regulations and your personal computer; machine problem-solving; some tax hints for personal computer owners; and much more.

You've probably noticed that this issue of BYTE is on the large side. In fact, it's the biggest issue we've ever printed. The extra space allows us to bring you even more articles and features in this issue and in the coming months. . . . CM

Byte Magazine Vol.5 n°10 october 1980

p.3 In the Queue (table of contents)

Foreground

p.62 AN 8088 PROCESSOR FOR THE S-100 BUS, Part 2

The second part of this article describes techniques for interfacing to the S-100 bus.

[author : Thomas Woodward Cantrell]

p.96 SORTING WITH BINARY TREES

This data-storage structure makes it easy to insert or delete items in the file.

[author : Bill Walker]

p.196 FLOPTRAN-IV: A TINY COMPILER

Commodore PET's BASIC interpreter is a handy foundation for a tiny compiler.

[author : Mark Zimmermann]

p.232 SYMBOLIC MATH USING BASIC

Here's an introduction to symbolic computer mathematics.

[author : David R Stoutemyer]

p.282 THE 6502 GETS MICROPROGRAMMABLE INSTRUCTIONS

A simple circuit and some clever programming make enhancing this processor's instruction set possible.

[author : Dennette A Harrod]

p.286 VECTOR GRAPHICS FOR RASTER DISPLAYS

When plotting a line on a raster display, there is more logic involved than moving from point A to point B.

[author : John Beetem]

Background

p.24 MAKE LIQUID-CRYSTAL DISPLAYS WORK FOR YOU

With appropriate interfaces, these displays are suitable for many applications.

[author : Steve Ciarcia]

p.114 AN INFORMATION-RETRIEVAL SYSTEM

This system is capable of maintaining a file of related records and printing a selective list based on given criteria.

[author : Robert W Elmore and Krishna K Agarwal]

p.154 ADD MACRO EXPANSION TO YOUR MICROCOMPUTER, Part 1

A macro assembler is often a valuable tool when developing large assembly-language programs.

[author : David C Brown]

p.266 MACHINE PROBLEM SOLVING, Part 2: Directed Search Using Cryptarithmetic

The best problem-solving programs often apply a combination of human and computer methods.

[author : Peter Frey]

p.274 THE FORTH STANDARDS TEAM

Using a standard dialect of the FORTH language keeps costs down in the long run.

[author : William Ragsdale]

Nucleus

p.6 Editorial: Who Reads BYTE?

p.16, 294 Letters

p.42 Product Review

p.50 Desk Top Wonders

p.90 Education Forum

p.172 Product Description

p.182 Technical Forum

p.186 BYTELINES

p.192 Languages Forum

p.273, 314, 332 Book Reviews

p.278 Programming Quickies

p.302, 332 BYTE's Bugs

p.306 Ask BYTE

p.325 BYTE's Bits

p.328 Software Received

p.329 Clubs and Newsletters

p.330 Books Received

p.334 Event Queue

p.338 What's New?

p.348 Tom Sloan Cartoon

p.398 Unclassified Ads

p.399 BOMB, BOMB Results

p.400 Reader Service

IN THIS ISSUE

Our main topic this month is Software - a perennial favorite among BYTE readers. This month's cover painting by Robert Tinney illustrates the colorful road that programmers often travel in search of bug-free code.

The software articles include: a tiny compiler that handles floating-point operations; machine problem-solving using crypt-arithmetic; sorting with binary trees; a macro assembler for your computer; adding to the 6502's instruction set; an easy-to-use information retrieval system; and symbolic math using BASIC.

Also this month: Steve Ciarcia's explanation of how to use liquid-crystal displays; a description of some vector graphics for raster-scan displays; a follow-up on FORTH; and the second part of a three-part discussion of an 8088 processor for the S-100 bus.

Byte Magazine Vol.5 n°11 november 1980

p.3 In the Queue (table of contents)

Foreground

p.32 HOME IN ON THE RANGE! AN ULTRASONIC RANGING SYSTEM

Combine automatic sonar ranging and infrared-light detection in a computer-controlled scanner.

[author : Steve Ciarcia]

p.64 MICROGRAPH, PART 1: DEVELOPING AN INSTRUCTION SET FOR A RASTER-SCAN DISPLAY

Micrograph is an intelligent, low-cost, color-graphics terminal that interfaces to any microcomputer and standard, unmodified color television receiver.

[author : E Grady Booch]

p.126 GRAPHIC COLOR SLIDES, PART 1

The first of this two-part article gives a series of useful subroutines for generating color images on a Compucolor II.

[author : Alan W Grogono]

p.148 THREE-DIMENSIONAL GRAPHICS FOR THE APPLE II

With this popular computer, use a two-color scheme to generate three-dimensional figure

[author : Dan Sokol and John Shepard]

p.296 A GENERAL INTERPOLATING GRAPHICS PACKAGE FOR THE TRS-80

Interpolate between points of a graphed function and three-dimensional figures.

[author : D K Cohen and Devon Crowe]

p.340 AN 8088 PROCESSOR FOR THE S-100 BUS, PART 3

This monitor program takes advantage of some powerful software and architectural aspects of the 8088 processor.

[author : Thomas Woodward Cantrell]

Background

p.22 THE FUTURE OF COMPUTER GRAPHICS

Take a look at the future of graphics hardware and applications.

[author : Bruce Eric Brown and Stephen Levine]

p.90 LANGUAGE CONTROL STRUCTURES FOR EASY ELECTRONIC VISUALIZATION

Zgrass, a hybrid of language and hardware, can be used to solve graphic-display problems.

[author : Dr Thomas DeFanti]

p.180 A SIMPLIFIED THEORY OF VIDEO GRAPHICS, PART 1

Part 1 covers the principles of television and computer-generated graphics.

[author : Allen Watson III]

p.206 GETTING TO KNOW YOUR MONITOR

Meet the most frequently used human/computer interface - the video terminal.

[author : Ron Dalpiaz]

p.220 DIGITAL STORAGE OF IMAGES

Theory and practice of digital-image capture and storage are explained in detail.

[author : Thomas Williams]

p.244 MACHINE PROBLEM SOLVING, PART 3: THE ALPHA-BETA PROCEDURE

In the conclusion of this series, we discover how searching for information stored in tree structures can be made more efficient.

[author : Peter Frey]

p.361 ADD MACRO EXPANSION TO YOUR MICROCOMPUTER, PART 2

Notes on implementation and options are presented in this final part.

[author : David C Brown]

Publisher's Note

As most readers will have observed, the September Fifth anniversary issue marked the beginning of a new phase for BYTE. The jump from a 300-page to a 400-page issue means a 33% increase in the material presented to our readers each month.

Because advertisements tend to be more visible than editorial content (especially in a technical journal), some readers may suspect that the larger issues mean merely more ads. But, in fact, the larger issues have approximately 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 editorial pages of BYTE to make the editorial content easier to find and use. We expect the new format to be implemented early in 1981.

We are confident that the increased editorial content and new format will make BYTE even more of a bargain as well as a more useful tool for our readers. And that, after all, is what it's all about.

Virginia Londoner

Publisher

Nucleus

p.6 Editorial

p.16 Letters

p.62, 86 Technical Forum

p.108 Book Reviews

p.112, 114, 292, 322 BYTE's Bugs

p.114 Books Received

p.116, 145 Programming Quickies

p.119 BYTE's Bits

p.147 Clubs and Newsletters

p.158, 190, 196 Product Reviews

p.172 SIGGRAPH Convention Report

p.240 BYTELINES

p.266 Ask BYTE

p.314 Event Queue

p.343 Tom Sloan Cartoon

p.372 What's New?

p.430 Unclassified Ads

p.431 BOMB Results

p.431 BOMB

p.432 Reader Service

In This Issue

p.172 The cover for this issue of BYTE is a still from a 90-minute computer-animated cartoon called The Works. The photo was provided by Dick Lundin and Lance Williams and is constructed from quadric surfaces and polygons, using texture-mapping and normal-perturbation techniques. The background was painted by Paul Xanter - programming credit also goes to 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.

p.6 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 interface program for simplifying man/machine communications, Ken is a senior software engineer whose long-term interests intermix art and computer graphics.

Byte Magazine Vol.5 n°12 december 1980

p.3 In the Queue (table of contents)

Foreground

p.24 MULTIMACHINE GAMES

The most exciting computer games are those with two machines and two or more players.

[author : Ken Wasserman and Tim Stryker]

p.44 COMPUTERIZED TESTING

A computer is useful for automating any process-even hardware testing.

[author : Steve Ciarcia]

p.96 GRAPHIC COLOR SLIDES, PART 2

This month we demonstrate the use of subroutines to generate equation plots, histograms, regression and monthly analysis graphs.

[author : Alan W Grogono]

p.120 MICROGRAPH, PART 2: VIDEO-DISPLAY PROCESSOR

Part 2 details more about this surprisingly simple high-resolution video display.

[author : E Grady Booch]

p.192 PIRATE'S ADVENTURE

The man who first brought Adventure games to microcomputers gives us an entire listing of one of his most enjoyable games.

[author : Scott Adams]

p.244 A POCKET COMPUTER? SIZING UP THE HP41C

This device comes close to being the world's first pocket-sized personal computer.

[author : Bruce Carbrey]

p.268 LOST DUTCHMAN'S GOLD

Applesoft BASIC is well suited to the writing of games, as this program shows.

[author : Bob Liddil and Ten Li]

Background

p.142 A SIMPLIFIED THEORY OF VIDEO GRAPHICS, PART 2

Explanations of color-video techniques and some of the quirks of microprocessor systems are provided.

[author : Allen Watson III]

p.158 ON THE ROAD TO ADVENTURE

Along with a survey of the major Adventure games, here's an explanation of how to play them.

[author : Bob Liddil]

p.172 ZORK AND THE FUTURE OF COMPUTERIZED FANTASY SIMULATIONS

One of the authors of Zork describes his game and how similar games may appear in the future.

[author : P David Lebling]

p.186 CHARACTER VARIATION IN ROLE-PLAYING GAMES

A variable set of character traits can be used to create a game of high adventure that is different every time you play it.

[author : Jon Freeman]

Product Reviews: Games

p.74 DUNGEON CAMPAIGN

p.78 A STELLAR TREK

p.84 MORLOC'S TOWER

p.90 ODYSSEY: THE COMPLEAT APVENTURE

p.114 SARGON II

p.264 MICROSOFT ADVENTURE

p.282 COMPUTER BISMARCK

Nucleus

p.6 Editorial: What's Wrong With Technical Writing Today?

p.14 Letters

p.94 Technical Forum: The Twelve Computerized Days of Christmas

p.214 BYTELINES

p.222 User's Column

p.288 Programming Quickies: Monster Combat

p.294 BYTE's Bugs

p.296, 325, 326 BYTE's Bits

p.306 Clubs and Newsletters

p.314 Event Queue

p.318 Ask BYTE

p.322 Books Received

p.324 Software Received

p.342 What's New?

p.398 Unclassified Ads

p.399 BOMB, BOMB Results

p.400 Reader Service

In This Issue

Although the mysteries and menaces lurking in the shadows of this issue's cover may exist only in the minds of an imaginative Adventure player or the cover artist, Robert Tinney, that doesn't make them any less real to the person playing the game. This issue explores the many aspects of Adventure and Adventure-like games. It includes two complete Adventures in BASIC, an excellent introductory article ("On the Road to Adventure," by Bob Liddil), two articles on the state of the art in Adventure games, and a handful of game reviews.

This issue also contains "Computer Testing," an article by Steve Ciarcia, as well as the second parts of several articles continued from the November graphics issue: "Micrograph," "Graphic Color Slides," and "A Simplified Theory of Video Graphics."