[editor : Carl T. Helmers Jr.] [publisher : Virginia Peschke, Manfred Peschke] [art : Bill Morello] [cover : Robert Tinney] #Magazine

#Abstract

Curiosity, experimentation and imagination are great aids to the user of a computer system. Charles A Crayne describes two in struction set variations he found while Programming the Implementation of an 8008 processor as a SCELBI 8H minicomputer.

Can a computer predict your state of mind? A better question would be: Is there a theory which can be computationally verified to predict your state of mind? Biorhythm for Computers is an article by Joy and Richard Fox on the use of a BASIC calculation to provide predictions based upon the pseudo science of a simple biorhythm hypothesis.

A key element of computing is the expression of ideas in the form of programs and algorithms. It takes the Magic of Languages to make such expressions in a form the computer can understand . Turn to Theodor Nelson's article for an introduction to some basic concepts of computer languages.

Ho hum, another memory article? Not quite. When Don Lancaster adds a twist of ingenuity, you find out How to Build a Memory With One Layer Printed Circuits, saving the trouble of using many wire jumpers or figuring out how to make double layer boards in the kitchen PC laboratory.

Aargh! (or, How to Automate PROM Burning Without EML) was Peter Helmers' reaction to a suggestion that relays be used to control a circuit. Study his figures for technical information and learn about the exciting new field of EML [sic] logic in the accompanying text.

It could not take long to find another contender in the marketplace for compact computer systems. In this issue, J Bradley Flippin discusses The SR-52: Another "World's Smallest Computer System."

Input is often done with a switch contact when simple on off states of electrom echanical systems are considered. But suppose you want to program stage lighting or drive a keyboard machine with so lenoids. Then you'll need information on Controlling External Devices with Hobbyist Computers. Robert J Bosen presents some ideas on the subject.

Computers require a large dose of that arcane ar t, interfacing. Jay A Cotton shows one example of that art in his discussion of how to Interface an ASCII Keyboard to a 60 mA TTY Loop.

Introspection is a prime technique for analyzing the human consciousness. Many parallels can be drawn between the design of camplicated computer networks and knowledge of human mental functions. While not purporting to be a complete or final model of human mental functions, Joe Murray's article on Frankenstein Emulation provides some good inputs on the ultimate hobby: modeling human behavior.

Minicomputers and microcomputers are really quite similar. The former are simply faster and more expensive than the current versions of the latter. Thus when you Design an On Line Debugger for a minicomputer, as Robert Wier and James Brown have done, the same general interactive design can be used as the control panel interface for any microcomputer as well. Add an on line debugger to your computer and you'll make it a much easier device to use.

What's better than an 8 bit processor in a 40 pin package? Why, a 16 bit processor in a 64 pin package, of course. In his Microprocessor Update: Texas Instruments TMS9900, Robert Baker provides readers with an overview of this exciting new computer which is sure to find its way into personal computing systems over the next year or so.

Ingenuity is an old American tradition. Roger W Thompson makes his contribution to that tradition in his description of how to Save Money Using Mini Wire Wrap, a socketless penny pinching way of wiring integrated circuit projects.

On the cover, at the suggestion of Tully Peschke, Robert Tinney created a fantasy on a theme of BYTE. First aid has already been applied and it is expected that the banner will be fixed in time for the May issue.

[author : Carl Helmers] #Edito

Extract : «  Each person who gets involved in this activity of acquiring and using a personal computer system will sooner or later appreciate the results of customization. Each computer system comes out differently according to the tastes and creativity of its owner (to say nothing of his or her pocketbook). The number "n" of choices available in creating a personal system is large, and is getting larger every day. [...]  »

TABLE OF CONTENTS

[theme : Application] [author : Fox-Fox] #Algorithm #Listing #BASIC

Extract : «  There is no doubt that all living things have biological rhythms. The study of three of these rhythms in humans has led to the development of a pseudo science, biorhythm, that, through the use of computers, is growing in popularity in the United States. This article describes a program, written in BASIC, which you can run in your own computer to plot biorhythm curves. [...]  »

[theme : Hardware] [author : Lancaster] #Electronic #Memory

Extract : «  The 2102 static programmable random access memory is a fairly obvious integrated circuit to use lor a memory. It is easy to interface to just about any microprocessor or minicomputer. It costs from 0.1 to 0.3 cents a bit, buying from ads in BYTE or from lots of other possible sources. [...]  »

[theme : Hardware] [author : P Helmers] #Electronic #Memory

Extract : «  I just received my copy of BYTE No. 3 and quickly looked to find my article on the design of a PROM programmer. There it was, prominently featured on page 66. Oh well, I figured, hardware is always given lower priority that software. But then, I noticed an italic section of extensions and modifications had been added to my final thoughts. What could be put after my final thoughts??? [...]  »

[theme : Hardware] [author : Bosen] #Electronic #Interface #Devices

Extract : «  There is an almost infinite variety of uses to which a hobbyist computer system may be applied besides calculating or data processing, and many of these can bring a great deal of satisfaction to the proud owner. For example, hobbyist microcomputers are invariably advertised with a long list of possible applications such as home security systems, light controllers, process controllers, or automated drink mixers. [...]  »

[theme : Hardware] [author : Cotton] #Electronic #Interface #Keyboard

Extract : «  I recently purchased a Sanders 720 electronic keyboard. This keyboard is identical to the Model 722-1 keyboard which was described in BYTE, September 1975, page 62, except for the key layout and the line feed code. My version of the keyboard had no line feed, but had a vertical tab key which produced an octal 013 code. In order to convert this to an octal 012 line feed code, some form of transformation logic was required. I also wanted to drive my Teletype's 60 mA current loop directly from the keyboard. By combining the special case code conversion, a UART for parallel to serial conversion, a clock and a current loop driver, I achieved the desired function of sending characters to my Teletype. Figure 1 shows the schematic of this conversion. [...]  »

[theme : Software] [author : Wier-Brown] #Algorithm #Programming

Extract : «  Machine or assembly language will most likely be used by many computer experimenters. While many professional programmers will swear by the use of assembly language, others, perhaps equal in number, will swear at it, preferring the use of high level languages. To those new to the field, these terms may seem confusing. It's really quite straightforward when one remembers that the language a machine uses differs considerably from the one used by the people. As one surveys a continuum from machine to human languages, the language most easily understood by the machine is a binary language; next on the continuum is assembly language with additional features that make it considerably easier to use, thus avoiding all night debug sessions, frazzled nerves, and 2 AM programming logic which hardly ever works, etc. For a good discussion on assemblers, see the October 1975 issue of BYTE. Easier yet for the programmer are languages such as BASIC, FORTRAN, PL/1, and ALGOL. These languages allow the problem to be stated and solved in terms better adapted to human understanding. Unfortunately, there are rather serious difficulties encountered when these high level languages are to be used on small systems. They require a compiler or interpreter to transform the problem from the high level language to machine language and more memory than is found in most small hobby systems. [...]  »

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

[theme : Hardware] [author : Thompson] #Electronic

Extract : «  For real economy in packaging integrated circuits in home built breadboard designs, consider this method which I call mini wire wrap. By using the actual pins of the dual inline package (DIP) as wire wrap posts, connectors are eliminated and very high circuit density can be obtained. This technique allows one of a kind projects to be quickly constructed with a minimum of material. The mini wire wrap method uses perforated phenolic or epoxy glass board. Integrated circuits can be mounted with the pins sticking up using mechanical fastening of the Vcc and ground pins soldered to bus wires on the opposite side of the board. (See figure 1.) A small amount of glue can also be used if a stronger mounting is desired. [...]  »

[theme : Software] [author : Crayne] #Software #Programming

Extract : «  When Scelbi Computer Consulting Inc designed their 8H minicomputer system around the Intel 8008 CPU chip, they implemented two instructions beyond those available on the Intel chip. It seems that these two instructions are a byproduct of the 8H design, and of potential interest to the hobbyist. [...]  »

[theme : Software] [author : Nelson] #Languages

Extract : «  A computer language is a system for casting spells. This is not a metaphor but an exactly true statement. Each language has a vocabulary of commands, that is, different orders you can give that are fundamental to the language, and a syntax, that is, rules about how to give the commands right, and how you may fit them together and entwine them. [...]  »

[theme : Systems] [author : Flippin] #Review #ComputerPortable

Extract : «  On September 16 1975 Texas Instruments announced the latest entry in their series of sophisticated pocket calculators, the SR-52, exactly 20 months after Hewlett- Packard announced their HP-65 fully programmable unit. Richard Nelson described the HP-65 in the December 1975 issue of BYTE. The purpose of this article is to provide some additional information on the new SR-52 and to provide a comparison to the HP-65. [...]  »

[theme : Speculations] [author : Murray] #Anticipation #ArtificialIntelligence

Extract : «  This is a let's get the ball rolling article. We now can analyze and build working models of at least portions of the human brain right in the home. Paper and pencil models of the brain develop naturally and almost without effort when we use real time digital design methods. The hardware and software mechanizations fall out naturally; then we just use the home computer lab to build what we have designed. [...]  »

[theme : Hardware] [author : Baker] #Review #Microprocessor

Extract : «  The TMS9900 microprocessor is a single chip, 16 bit central processing unit that requires power supplies of +5V, -5V and +12V, as well as a four phase, 3 MHz clock. Fast interrupt response and programming flexibility is provided by the implementation of a unique memory to memory architecture with multiple register files resident in memory. The instruction set includes hardware multiply and divide instructions making the TMS9900 comparable with many minicomputers. A compatible set of MOS and TTL memory and logic function support circuits together with separate data and address buses help simplify the system design. For industrial users, the TMS9900 system is fully supported by both software and a prototyping system. [...]  »

#Book

Extract : «  An Introduction to Microcomputers, Adam Osborne & Associates, Inc, 2950 7th St, Berkeley CA 94710, (415) 548-2805, $7.50. [...]  »

#Association