1976 2.06 1978

Vol.2 n°6 june 1977

Vol.2 n°6 june 1977

(byte_1977_06.jpg)

[editor : Carl T. Helmers Jr.] [publisher : Virginia Peschke, Manfred Peschke] [art : Mary Jane Frohlich, Ellen Shamonsky] #Magazine

p.4 In This BYTE

p.4 In This BYTE

#Abstract

Some uses of a microprocessor involve the connection to the outside world through an analog interface. When fooling around with such projects from music generation to robotic control, however, it quickly becomes necessary to have a large number of inexpensive real world interfaces. To help point you in the right directions Douglas R Kraul supplied an article on Designing Multichannel Analog Interfaces.

In the past, readers have seen some interest expressed in the concepts of robotics, the use of small computers as the brains of mobile automated mechanisms. Robots have long been fancied in science fiction literature and cinema, but only rarely have people taken any practical steps towards a "real" robot as opposed to paper romanticisms or stage dummies. One of those rare cases is that provided by Ralph Hollis and his associate Dennis Toms, both of whom are physicists at the University of Colorado, Duane Physical Laboratory, Boulder CO. Ralph has been pursuing the design of practical robots as an avocation since 1957, and lately has progressed to the point of a working mobile computer system called Newt, whose picture provides the theme of this month's cover. Turn to Ralph's article, Newt: A Mobile, Cognitive Robot for essential background information on contemporary robot design philosophies.

Hard copy is a most useful output, but it tends to be somewhat expensive. Dan Fylstra shows one very attractive option in his article on Interfacing the IBM Selectric Keyboard Printer. Dan purchased a used print mechanism late in 1976, and since then has successfully interfaced the device to his KIM-1 system. Readers interested in using these printers (which are available in significant numbers on surplus markets) will find Dan's article an essential guide to the art.

How can hardware be used to accomplish the details of Interfacing With an Analog World? Turn to author Joseph Carr's second part of a two part series to find out some of the details of basic conversion circuits which use the outputs of sensors and preamplifiers discussed in last month's article.

Much of the software that is available on the market today is available on paper tape so as to be easily read into your microprocessor. The problem is that most common paper tape readers are so slow that it seems to take forever to read a large program into memory. In the article Come Fly With KIM, Rick Simpson introduces us to a solution to this speed problem: the Fly Reader, which he uses with MOS Technology's KIM-1.

Now that you've got the hardware built, how do you run it? Ken Welles answers this question in Software for the Economy Floppy Disk. His previous article (February 1977 BYTE, page 34) described how to construct an inexpensive floppy disk with minimal hardware. This month he provides a series of subroutines to run it, which could easily be expanded into a complete floppy disk operating system.

Last month in the first part of his article Artificial Intelligence, An Evolutionary Idea, Michael Wimble introduced us to the use of a simulated evolution technique by which it was possible for a program to alter itself and reshape its responses as a direct result of an outside stimulus. This month in Part 2: Implementation, Mr Wimble details how the computer experimenter can implement this type of program on any small computer system.

To many people the concept of assembly language is that of the fundamental language of the computer next to machine language. However, each particular assembly language command must be broken down into a series of simpler command sequences. These commands are known as microinstructions. In his article, An Introduction to Microprogramming, S M Quek describes how the concept of microinstructions is a great benefit to the user of a computer, allowing the easy change of basic instructions.

In previous issues Michael McNatt has shown us the availability of Baudot teleprinters and the ways in which they can be interfaced with your microprocessor. In his concluding article, A Guide to Baudot Machines: Part 3, A Teleprinter Test Circuit, he describes a test circuit that can be used for generating Baudot characters for alignment and adjustment purposes.

p.9 The Software Dilemma

p.9 The Software Dilemma

[author : Carl Helmers] #Edito

Extract : «  How is it possible to simultaneously make software widely available (and low priced), yet reward the producers of good software with adequate compensation for their efforts?

Conventional wisdom has it that proprietary software must come at extremely high prices, commensurate with concentrated work on the part of a small number of dedicated and thoughtful programmers. After all, this wisdom has it, we'll only sell a few copies of package X anyway, so why not keep a tight lid on it and charge as much as possible?

This conventional wisdom has worked well in the past, when the typical computer system might cost upwards of $10,000 or $100,000. But when the typical computer system comes in at a price on the order of $1000, paying prices which are of this same order of magnitude for software packages is not a very likely move on the part of the individual purchaser with his or her personal budget. [...]  »

TABLE OF CONTENTS

Foreground

Foreground

p.18 DESIGNING MULTICHANNEL ANALOG INTERFACES

p.18 DESIGNING MULTICHANNEL ANALOG INTERFACES

[theme : Hardware] [author : Kraul] #Electronic #Interface

Extract : «  Analog interfaces to and from the personal computer system can present a difficult dilemma to the small systems user: The analog interface usually is a very expensive proposition, especially if more than one input and one output are needed. Schemes like that suggested by Roger Frank [page 70 of the May 1976 issue of BYTE], can greatly reduce hardware complexity, and thus cost, since much of the interface burden is left to the software of the computing system. Direct extension of this principle to the case of multiple input voltages and multiple output voltages can, however, result in a hardware cost that at the least rises linearly with the number of needed outputs and inputs. One alternative scheme requires an additional bit of input to the computer and one additional voltage comparator for each additional analog to digital input up to a total of 8. On the output side each additional voltage output leads to an additional 8 bit output port and an additional 8 bit digital to analog converter. This results in a situation where a many input, many output analog interface requires an inordinate amount of hardware, which means money to the user. (We should not kid ourselves by saying that large numbers of analog channels are rarely needed. Many worthy applications, like control of analog music synthesis, automated test facilities or control of robots would easily push the number of channels needed beyond the point of no return for the previously suggested schemes of interface.) Thus one must turn to a modified philosophy of interface design in order to meet the necessary goal of a less expensive analog interface. [...]  »

p.46 INTERFACING THE IBM SELECTRIC KEYBOARD PRINTER

p.46 INTERFACING THE IBM SELECTRIC KEYBOARD PRINTER

[theme : Peripherals] [author : Fylstra] #Electronic #Interface #Keyboard #Printer

Extract : «  One of the most desirable forms of computer output is high quality typewritten text suitable for preparing letters, reports and other documentation. A word processing system which speeds up the process of writing and revising text would be a very useful and feasible application for a small microprocessor based system, provided that a suitable hard copy output device can be found at a reasonable price. [...]  »

p.76 COME FLY WITH KIM

p.76 COME FLY WITH KIM

[theme : Peripherals] [author : Simpson] #Interface #Storage #Listing #Assembly #Algorithm

Extract : «  Many computer hobbyists start with nothing more than a processor, a small amount of programmable memory, a small onboard monitor such as MIKBUG or KIM and some front panel switches. Those with more foresight, or cash, will have a keypad or even a full keyboard for data entry and processor control. But even with a good monitor and a full keyboard and display, loading programs is a tedious chore at best, and there is an awful feeling when you turn off power, knowing that twenty minutes of typing just evaporated.

The next step in expanding the system is usually an audio cassette interface or a Teletype with paper tape reader and punch for the wealthy or fortunate. Now the tedious retyping is eliminated and a program, once written and recorded or punched, can be reloaded in a matter of minutes. [...]  »

p.88 SOFTWARE FOR THE ECONOMY FLOPPY DISK

p.88 SOFTWARE FOR THE ECONOMY FLOPPY DISK

[theme : Systems Software] [author : Welles] #Listing #Assembly #Storage

Extract : «  As hobbyists are rapidly finding out, even the most sophisticated hardware is next to useless without the proper software to control it. My previous article on the floppy disk drive interface (see February 1977 BYTE, page 34) described a hardware device of the simplest and, consequently, most software dependent type. This month's article describes the operation and use of the routines needed for transferring data between the computer and a disk drive (one of up to eight) connected to the interface. [...]  »

p.100 ARTIFICIAL INTELLIGENCE: Part 2, Implementation

p.100 ARTIFICIAL INTELLIGENCE: Part 2, Implementation

[theme : Software] [author : Wimble] #ArtificialIntelligence #Algorithm

Extract : «  As described last month in part 1, there are five types of mutations that can be performed with the simulated evolution technique. A separate subroutine will be used for each mutation type. Four of the subroutines rely heavily on a subroutine which generates a random number between limits. (For those systems not already possessing random number generators, a box accompanying this article gives an algorithm to produce pseudorandom numbers by the power residue method.)

Figures 1 through 9 are flowcharts of the basic modules which were extracted from a fairly sophisticated system of FORTRAN programs. These are intended to serve as a starting point for the reader in implementing his/her own program. If there is sufficient reader interest, I would be happy to program and publish program listings of implementations for one or more small system processors, in any popular computer language. [...]  »

p.140 A 6800 SELECTRIC IO PRINTER PROGRAM

p.140 A 6800 SELECTRIC IO PRINTER PROGRAM

[theme : Software] [author : Guzzon] #Printer #Listing #Assembly

Extract : «  I understand there is some interest among your readers in using a Selectric typewriter for hard copy. As you can see I have tunneled an editor program (SWTPC) and an assembler program (SWTPC, too) through a Selectric typewriter. [The original of this note was typed on the Selectric] I bought the machine on the surplus market in Boston and it had some problems: It was stuck in upper case by a bolt screwed on the right side of the frame, it had some unrecoverable backlash in the head rotate mechanism, and many feedback and interlock contacts were missing or badly damaged. I had the machine serviced here in Rome (Italy) and at last, with a new carriage, a new motor (here we have 220 V 50 Hz power), and a new set of shift magnets, the printer was ready. I decided to use it only as a printer in order to reduce the hardware and software effort to a minimum. [...]  »

p.154 A GUIDE TO BAUDOT MACHINES: Part 3

p.154 A GUIDE TO BAUDOT MACHINES: Part 3

[theme : Construction] [author : McNatt] #Electronic #Interface #Keyboard #Printer

Extract : «  Now that you've found out what type of Baudot teleprinters are available on the surplus market, and where to go to get information on how to interface them to your microprocessor, it might be convenient to build a test box to check the working condition of your new acquisition. What follows is a circuit for just such a test box which can be used to provide the 60 mA current loop required by the Baudot machine. Circuits are also included in the box to generate signals which can verify correct machine function. Although not as handy as the test box, a Baudot keyboard may be used to test a page printer of the same speed. The test box has variable control of data rate for testing all Baudot teleprinters. The test box circuits supply the following functions: [...]  »

Background

Background

p.30 NEWT: A MOBILE, COGNITIVE ROBOT

p.30 NEWT: A MOBILE, COGNITIVE ROBOT

[theme : Robotics] [author : Hollis] #HowItWorks #Experience #Glossary #Robotics #Electronic

Extract : «  In the late 1930s, a young man named Rossum began manufacturing industrial robots in a small factory on the outskirts of Prague. This venture was immediately successful and would have virtually guaranteed a second industrial revolution had it not been for a singular tragic circumstance: The robot workers became irrational and revolted. They turned on their masters and burned the factory to the ground.

Fortunately, the preceding scenario is only a work of fiction by the Czechoslovakian writer K Capek. Since Capek's coinage of the word "robot" in his 1923 play R U R it has been the subject of a great many works of science fiction, including Isaac Asimov's I, Robot and the movies "Forbidden Planet," "Gog," "Silent Running," "Westworld" and others. [...]  »

p.54 INTERFACING TO AN ANALOG WORLD: Part 2

p.54 INTERFACING TO AN ANALOG WORLD: Part 2

[theme : Hardware] [author : Carr] #Electronic #Interface

Extract : «  Last month we discussed transducers and amplifiers. These are necessary portions of a signal processing system which result in scaled voltages of, for example, 0 to 10 V corresponding to the original physical parameter being measured. But how can we convert these voltages into numbers inside a computer for computation, and use numbers from computations to control external voltages? In this article we'll see how some of the more common conversions are accomplished. We'll start with digital to analog conversion, even though this may seem at first glance to be backwards. The reason for starting with the output process is that digital to analog conversion is simplest, and that many analog to digital input conversion techniques require a digital to analog conversion as part of the process. [...]  »

p.116 INTRODUCTION TO MICROPROGRAMMING

p.116 INTRODUCTION TO MICROPROGRAMMING

[theme : Software] [author : Quek] #HowItWorks #Microprocessor #Programming

Extract : «  What is Microprogramming?

When we consider the operation of a simple machine instruction, like add accumulator to register B on some computer, we often find that there is a sequence of even more elementary operations involved. For the example given, we may first have a transfer of data in register B to some temporary register in the arithmetic logic unit. Next, we may then perform an addition operation and finally, return the result of the operation to either the accumulator or register B. Figure 1 illustrates this sequence of operations.

Wilkes, an early pioneer in the field of computer design, called these elementary operations "microoperations." (See reference 1.) By this token, a single machine instruction, like the add described above, would consist of a microprogram of these microoperations. Microprogramming is, then, the implementing of control logic for a computer's instruction set through the ordered storage of processor control information. [...]  »

Nucleus

Nucleus

p.12 Letters

p.12 Letters

p.16 p.24 p.144 p.158 What's New?

p.16 p.24 p.144 p.158 What's New?

p.60 Ask BYTE

p.60 Ask BYTE

p.74 Technical Forum

p.74 Technical Forum

p.85 Classified Ads

p.85 Classified Ads

p.108 Clubs, Newsletters

p.108 Clubs, Newsletters

#Association

p.126 BYTE's Bits

p.126 BYTE's Bits

p.150 Desk Top Wonders: SR-52 Card BLACKJACK

p.150 Desk Top Wonders: SR-52 Card BLACKJACK

(byte_1977_06_p153.jpg)

p.160 BYTE's Bugs

p.160 BYTE's Bugs

p.180 BOMB

p.180 BOMB

p.180 Reader Service

p.180 Reader Service

ADS (content taken from the reader service p.180)

ADS (content taken from the reader service p.180)

p.164 Advanced Microcomputer

p.164 Advanced Microcomputer

p.165 Aldelco

p.165 Aldelco

p.151 Alpha Digital Systems

p.151 Alpha Digital Systems

p.14 p.15 p.17 Apple Computer

p.14 p.15 p.17 Apple Computer

(byte_1977_06_p014.jpg)

p.128 Artison Computer

p.128 Artison Computer

p.151 Beta Business Systems

p.151 Beta Business Systems

p.131 p.132 Bits Inc

p.131 p.132 Bits Inc

p.162 p.163 Bits Inc

p.162 p.163 Bits Inc

p.127 Byte Index

p.127 Byte Index

p.151 Byte Shop East

p.151 Byte Shop East

p.127 Byte Shop of Miami

p.127 Byte Shop of Miami

p.166 California Industrial

p.166 California Industrial

p.151 Camp Retupmoc

p.151 Camp Retupmoc

p.147 Comptek

p.147 Comptek

p.60 p.61 Compucolor

p.60 p.61 Compucolor

p.151 Computalker

p.151 Computalker

p.159 Computer Corner

p.159 Computer Corner

p.127 Computer Electronics

p.127 Computer Electronics

p.148 Computer Enterprises

p.148 Computer Enterprises

p.159 Computer Mart NH

p.159 Computer Mart NH

p.162 Computer Mart NY

p.162 Computer Mart NY

p.159 Computer Place

p.159 Computer Place

p.115 Computer Room

p.115 Computer Room

p.111 Computer Shack

p.111 Computer Shack

p.127 Computer Shop (Canada)

p.127 Computer Shop (Canada)

p.167 Computer Warehouse Store

p.167 Computer Warehouse Store

p.126 Continental Specialties

p.126 Continental Specialties

p.159 CRC Engineering

p.159 CRC Engineering

p.143 Creative Computing

p.143 Creative Computing

p.1 p.2 Cromemco

p.1 p.2 Cromemco

p.13 Cybercom

p.13 Cybercom

p.108 Data Search

p.108 Data Search

p.28 Digital Group

p.28 Digital Group

p.144 Digital Concepts

p.144 Digital Concepts

p.113 E&L Instruments

p.113 E&L Instruments

p.139 Economy Company

p.139 Economy Company

p.114 Edityper Systems Corp

p.114 Edityper Systems Corp

p.127 Electronic Control Tech

p.127 Electronic Control Tech

p.168 Electronic Warehouse

p.168 Electronic Warehouse

p.159 Electravalue

p.159 Electravalue

p.169 Eltron

p.169 Eltron

p.159 Fein-Marquart

p.159 Fein-Marquart

p.67 Franklin Electric

p.67 Franklin Electric

p.170 Godbout Electronics

p.170 Godbout Electronics

p.129 HAL Communications

p.129 HAL Communications

p.161 Hashizume Burt

p.161 Hashizume Burt

p.68 p.69 p.70 p.71 Heath Co

p.68 p.69 p.70 p.71 Heath Co

p.5 IMSAI

p.5 IMSAI

p.10 p.11 Intel

p.10 p.11 Intel

p.160 International Data Systems

p.160 International Data Systems

p.161 IOR

p.161 IOR

p.145 Ithaca Audio

p.145 Ithaca Audio

p.171 Jade Company

p.171 Jade Company

p.172 p.173 James

p.172 p.173 James

p.105 John Wiley & Sons

p.105 John Wiley & Sons

p.127 Logic Design

p.127 Logic Design

p.130 MACC

p.130 MACC

p.174 Meshna

p.174 Meshna

p.161 Micro Computers

p.161 Micro Computers

p.107 Micro-Term

p.107 Micro-Term

p.26 Micromation

p.26 Micromation

p.161 Micronics

p.161 Micronics

p.121 Midwestern Scientific Inst

p.121 Midwestern Scientific Inst

p.175 Mikos

p.175 Mikos

p.176 Mini Micro Mart

p.176 Mini Micro Mart

p.122 p.123 p.124 p.125 MiniTerm

p.122 p.123 p.124 p.125 MiniTerm

(p.CIV) MITS

(p.CIV) MITS

p.151 Mountain Hardware

p.151 Mountain Hardware

p.145 mpi

p.145 mpi

p.144 Mullen

p.144 Mullen

p.161 MVT Microcomputer Systems

p.161 MVT Microcomputer Systems

p.63 p.64 p.65 p.66 NCC

p.63 p.64 p.65 p.66 NCC

p.24 North Star Computers

p.24 North Star Computers

p.148 Northern Valley Systems

p.148 Northern Valley Systems

p.81 p.82 p.83 p.84 Noval

p.81 p.82 p.83 p.84 Noval

p.146 Objective Design Inc

p.146 Objective Design Inc

p.49 Ohio Scientific Instruments

p.49 Ohio Scientific Instruments

p.161 Oliver Audio Engineering

p.161 Oliver Audio Engineering

p.147 Omni

p.147 Omni

p.75 PC 77 Atlantic City

p.75 PC 77 Atlantic City

p.163 Page Digital Electronics

p.163 Page Digital Electronics

p.23 Paia Electronics Inc

p.23 Paia Electronics Inc

p.109 p.110 Parasitic

p.109 p.110 Parasitic

p.12 p.72 PerCom Data

p.12 p.72 PerCom Data

p.29 Peripheral Vision

p.29 Peripheral Vision

p.110 Perri-White

p.110 Perri-White

p.149 Personal Computing Expo

p.149 Personal Computing Expo

(p.CIII) PolyMorphic Systems

(p.CIII) PolyMorphic Systems

p.153 Prime Radix

p.153 Prime Radix

p.6 p.7 p.8 Processor Technology

p.6 p.7 p.8 Processor Technology

p.98 p.99 RHS Marketing

p.98 p.99 RHS Marketing

p.158 Riverside Electronic

p.158 Riverside Electronic

p.163 Rotundra Cybernetics

p.163 Rotundra Cybernetics

p.177 SD Sales

p.177 SD Sales

p.51 Sams Howard W

p.51 Sams Howard W

p.25 Scelbi

p.25 Scelbi

p.79 Scientific Research

p.79 Scientific Research

p.73 SEALS

p.73 SEALS

p.120 Smoke Signal Broadcasting

p.120 Smoke Signal Broadcasting

p.178 Solid State Sales

p.178 Solid State Sales

(p.CII) Southwest Technical Products

(p.CII) Southwest Technical Products

p.163 Sunny Computer Stores

p.163 Sunny Computer Stores

p.86 p.87 Synchro-Sound Enterprises

p.86 p.87 Synchro-Sound Enterprises

p.108 Szerlip Enterprises

p.108 Szerlip Enterprises

p.146 Tarbell Electronics

p.146 Tarbell Electronics

p.53 Technical Design Labs

p.53 Technical Design Labs

p.107 Technical Systems Consultants

p.107 Technical Systems Consultants

p.179 Tri-Tek Inc

p.179 Tri-Tek Inc

p.112 Urban Instruments

p.112 Urban Instruments

p.74 Vector Graphic Inc

p.74 Vector Graphic Inc

p.27 Ximedia

p.27 Ximedia

p.114 Xybek

p.114 Xybek