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

#Abstract

Richard Simpson describes his first Date With KIM, the new product from MOS Technology which comes assembled and ready to use. This product, wh ich is the basis of his system, marks the first direct entry of a semiconductor manufacturer into the personal systems field .

Are different microcomputers equivalent? In n Source, RD Boudinot presents some excellent background information on multiple sources of components and systems, the mixing of products from different manufacturers and methods of evaluating products for use in a personal computing system.

Of what use is a nice friendly permanent memory? Dale Eichbauer contributes some ideas on the use of Read Only Memories in Microcomputer Memory Address Space.

Previous articles have covered programming and uses of some of the simpler fusible link read only memories. But how about erasable ROMs? Roger L Smith provides some More Information on PROMs including a method of programming the widely available 1702 parts.

One way to get a hard copy terminal is to use a receive only Teletype unit. Using an inexpensive ASCII keyboard and a UART circuit, Dr George Haller shows how to Serialize the Bits From Your Mystery Keyboard and achieve the same function as a keyboard send receive Teletype for·about half the cost.

Dissatisfied with toggle switches? Usc An Octal Front Panel similar to Hemran DeMonstoy's design to replace toggle switches with an octal keyboard.

You'll be SHOOTING STARS in a fascinating logical game when you implement a version of Will ard Nico's program on your computer. On the cover is artist Robert Tinney's impression of a SHOOTING STARS addict.

A simple signal generator might suffice for a radio man, but testing of computers and data communications hardware can require more sophisticated equipment. One such item is a Serial ASCII Word Generator such as the design Ronald Finger·describes.

How do you take advantage of a decade of software experience? One way is to emulate anothcr computer's architecture as Intersil has done with its IM6100. Robert Nelson describes a "Chip" Off the Olde PDP-8E in this first part of a two part article.

Can a computcr measure voltages with out hundreds of dollars worth of hardware? Of course it can. The secret is to use Microprocessor Based Analog/Digital Conversion Techniques of the sort described in Roger Frank's article on a very basic interface.

One of the keys to creating an assembler is defining exactly what the input source language will look like. An appropriate choice which simplifies writing the assembler will greatly speed up the process of implementing the program. In his article on the subject, Gregory Jewell shows how to Simplify Your Homemade Assembler using techniques which are applicable to most microcomputers.

[author : Carl Helmers] #Edito

Extract : «  (This editorial is taken from the text of a talk presented at the recent "World Altair Convention" held by MITS Inc in Albuquerque NM.)

Where is the small computer field headed? In order to talk about the future of small computers and their applications, I have to take on the role of a prognosticator, a predictor of future trends and events. Prognostication is an art to which mystical or magical qualities are often attributed, but which in reality is nothing more than a combination of reasoning and imagination based upon observation. The injection of imagination about possible trends and developments makes prognostication a bit different from a narrow linear extrapolation of identified trends. The imagination component is heavily influenced by personal values and philosophies, and represents a feedback of oughts and shoulds into the course of events as they develop. Prognostication is thus a method of extrapolating observed current trends into the future coupled with the prognosticator's opinions of what should be happening. In the terms of the scientist or engineer, prognostication is like an operational amplifier system in which the input signal is the observed set of trends and the feedback network is the prognosticator's personal philosophy and imagination. For example, in predicting the fate of civilization, if one is a congenital pessimist like the members of the Club of Rome, then the predictions will come out claiming disaster and ruin. If one is an optimist about the expanding possibilities created by advancing technology, then a totally different character of prediction will result. When you listen to what I have to say, be warned that I have a definite personal point of view regarding computer technology and its proper uses, and that this shapes the nature of the imagination content and the trends I select to emphasize. [...]  »

TABLE OF CONTENTS

[theme : Hardware] [author : Smith] #Electronic #Memory #Algorithm #Listing #Assembly

Extract : «  Have you ever wanted to program your own read only memories automatically so that you could copy programs into a permanent storage device? This article concerns one kind of erasable read only memory, the Intel 1702A integrated circuit and its pin compatible equivalents the National MM5202AQ and MM5203Q. These memories store 256 eight bit bytes of data using a method which allows total erasure and reprogramming many times. The method of programming is complex while erasure can be accomplished simply by exposure to an ionizing radiation (such as ultraviolet light). When you need to store large tables of data or programs, use of such read only memories is a very attractive alternative to more elaborate types of memory provided a method of programming is available. These erasable read only memories are economical as well, since typical prices at the time of this article are in the $20 range. [...]  »

[theme : Hardware] [author : Haller] #Electronic #Interface #Keyboard #ComputerTerminal

Extract : «  Now that you have deciphered your mystery keyboard, (page 62, September 1975 BYTE) and have determined which terminals are for the power supply, data bits, and flag pulse, what are you going to do with it? Well, one good use is to make it part of a Teletype style terminal. The Teletype models 33KSR or ASR, which are complete with printer and mechanical keyboard, are still quite expensive, usually over $1000 new; but the model 33R0, which consists of the printer only, can be bought for less than one half of that price. Now, mate the model 33R0 Teletype with your electronic keyboard and you have the equivalent of the 33KSR for your computer terminal. The ASR is the same with the addition of paper tape punch and reader. The computer terminal is usually specified as a full duplex terminal which merely means that while both the printer and the keyboard operate with serial data, they are not connected together except through the computer. The following is a description of a small adapter which will convert your electronic keyboard from a parallel to a serial output device which will then be the keyboard half of your full duplex terminal. The cost of the parts for this adapter, exclusive of power supply, is less than $10. [...]  »

[theme : Hardware] [author : DeMonstoy] #Electronic #Keyboard #Display

Extract : «  A standard method of writing a program into a computer has been to use toggle switches. Being lazy and becoming very tired of toggling in data, I was sure there was a better way. Figure 1 is a block diagram of my "better way" to input front panel data. This is a keyboard control unit which eliminates most of the toggle switches, replacing them with an octal data entry keyboard and various function buttons. No program needs to be entered before using it. The computer sees the data just as if the original toggle switches were there, but one keystroke now [...]  »

[theme : Applications] [author : Nico] #Algorithm #Listing #Assembly #Game

Extract : «  There are probably as many reasons to have a computer in the home as there are computers in homes. For whatever reason you have one though, it's only human nature to want to show it off to other people.

Say you have a super program called "Investment Portfolio Analysis and Statistical Summary" (IPASS) up and running on your Scelbi 8H or whatever. It took months to write and debug the program and it involved several unique concepts of which you are justifiably proud. You can picture the furious activity going on inside the little heart of the computer and would dearly love to show off your skill to Mr and Mrs Nexdor and bask in their admiration. So you invite them over for cocktails. [...]  »

[theme : Hardware] [author : Finger] #Electronic #Encoding

Extract : «  A couple of months ago, I decided to design and build a hardware ASCII to Baudot code converter. The design of this unit was going along quite well when it suddenly dawned on me that there would be no way to test the converter without generating a serial ASCII test pattern. So the converter was put aside temporarily while I decided what to do about generating test patterns. [...]  »

[theme : Interface Techniques] [author : Frank] #Microprocessor #Listing #Assembly #Electronic

Extract : «  Analog input and output capabilities, when added to a microcomputer, can greatly expand the power of the home or hobby computer. Inherently, the microprocessor is a digital device, ideal for control of discrete (on or off) input and output levels. However, many analog signals can also be processed with only minimal additional hardware. With this addition, such devices as temperature sensors or photocells can be monitored, and output peripherals such as oscilloscopes and audio amplifiers can be added to the microprocessor. [...]  »

[theme : New Product] [author : Simpson] #Review #ComputerKit

Extract : «  Here it is! In the November 1975 BYTE, Dan Fylstra reviewed the capabilities of the MOS Technology 6501 microprocessor chip in an article titled "Son of Motorola" (page 56). The article stated that "it will be three to six months before you see (a 6501) designed into a kit..." Well, MOS Technology has gone one better and introduced not a kit, but a completely assembled, tested and warranteed microcomputer with a price tag of only $250! Using the 6502 processor chip (a 6501 with an on-chip clock), the microcomputer features 1 K of RAM, 2 K of ROM containing the system executive, a complete audio cassette interface, a serial terminal interface, 15 bidirectional IO lines, a 23 key keypad and a six digit LED display. This completely assembled one board computer has all the programming features of the 6502 at a very competitive price. [...]  »

[theme : Systems] [author : Boudinot] #TradeAndLaws #Glossary

Extract : «  The practice of one company supplying an assembly or a component which is equivalent to a product of another company is called second sourcing. In fact, there are often many alternatives to the original supplier; thus the title of this article. We shall discuss the history of second sourcing, why second sourcing has flourished, what the buyer's risks are, and how to approach the decision process within the second source environment with specific application to personal microcomputer systems. [...]  »

[theme : Systems] [author : Eichbauer] #Memory

Extract : «  In an earlier BYTE (see "Read Only Memory Technology," page 64, December 1975), Don Lancaster introduced the use of read only memories as a tool for design at the hardware level. This application is but one of a multitude of uses for ROMs, especially when you consider a ROM as part of the main memory address space for your computer. The important advantages of a ROM in microcomputer use are nonvolatility and write protection for whatever data it holds. It relieves the user from the chore of reentering frequently used programs each time his machine is fired up or after data is accidentally modified. To put it simply, your data is always in the machine whenever you need it. [...]  »

[theme : Hardware] [author : Nelson] #Review #Microprocessor #Simulation

Extract : «  If you are looking for an answer to the software availability problem, this microprocessor may be it.

Of all the computers in the world today, there are probably more Digital Equipment Corporation (DEC) PDP-8s than any other kind.* A recent article in Electronic Engineering Times (October 20, 1975, page 2) estimates "... there are upwards of 70,000 PDP-8s in use in the field, and that 60 percent of all recent electrical engineering graduates have been exposed to the PDP-8 and its software." The PDP-8 at this point may truly be the universal computer. The latest version from DEC is the PDP-8/E. [...]  »

[theme : Software] [author : Jewell] #Method #Assembly

Extract : «  Our primary goal in the design of a simple assembler is to eliminate the need to parse a line in order to determine what information is contained in that line. Rather than asking "What are you trying to give me?", our assembler will demand, "I know where I am, so give me what I want." [...]  »

#Association

#Book

Extract : «  EDN Microprocessor Design Series Volume II written and edited by EDN staff, Cahners Publishing Co, 221 Columbus Av, Boston MA 02116, 1975, $7.95 (USA) or $8.95 (foreign). A combination package of Volume I and II is available for $11 (USA) while the supply of Volume I lasts. [...]  »