[editor : Carl T. Helmers Jr.] [publisher : Virginia Peschke, Manfred Peschke] [art : Matthew Arnorld, Noreen Bardsley, Mary Jane Frohlich, Lynn Malo, Bill Morello] [cover : Sandra D Crandall] #Magazine
#Abstract
This month's cover is by Sandra D Crandall, Narragansett RI 02882, a first prize winner of BYTE's Computer Art Contest. When she painted her updated "American Gothic," she was completing her BFA in Art at the University of Rhode Island, and as assistant Art Department slide curator, maintained a library of over 40,000 slides. "My fiance is finishing his BS in Computer Science and is an avid BYTE subscriber from the word go," she wrote.
Many of the possible applications of small computers involve the moving of a mechanical device. One possible way to digitally control these devices is with servomechanisms such as those used in radio controlled model aircraft. In his article, Give Your Micro Some Muscles, Robert D Grappel describes how simple it is to interface these devices with your computer to control your own mechanical devices.
Since microprocessors have hit the hobby market, one of the larger difficulties of the computer hacker has been obtaining inexpensive hardware copy capabilities. Southwest Technical Products Corp has introduced a line printer that is the answer to this difficulty. Their inexpensive impact dot matrix printer is described by Gary Kay in his article A Review of the SWTPC PR-40 Alphanumeric Printer.
The audio cassette is a kluge similar to paper tape; it works but is inconvenient. The "ideal " cassette system is completely controlled by the computer's commands, the full digital cassette recording facility. In his article on Cassette Transports for the "Roll Your Own" Hobbyist, William H Freeman takes a look at three different drives which have potential as mass storage subsystems for the personal computing experimenter.
Last month we began an article on The Digital Cassette Subsystem, by jack Breimeir and Ira Rampil. In this issue, we continue the discussion with part 2, concerning digital data formats and system considerations.
Today's computer hobby wolrd is a kit oriented one. In his article, Kit Building for the Computer Hobbyist, Louis E Frenzel sets forth guidelines that allow the inexperienced kit builder, the inexperienced hardware person, or the software hacker who just wants to get the basics, to construct a working computer oriented kit on the first attempt.
Navigation has come a long way since the astrolabe, as exemplified by the Omega system. In this month's BYTE, Ralph W Burhans continues his presentation of the hardware for an inexpensive Omega navigation system with some Simplified Omega Receiver Details. (The series concludes with an article on software by Richard J Salter Jr in next month's BYTE.)
To interact with video games or graphic systems, it is often useful to interface devices such as joysticks to the microprocessor. In his article, An Inexpensive Joystick Interface, Thomas Buschbach describes one method that will enable you to implement the conversion process in hardware.
Over the years since the demise of the original Star Trek television series, there has been an increasing variety of people enamored with the ideas that the program had to offer. Among these people are personal computing enthusiasts who have turned these ideas into a large variety of computer games. In Flights of Fancy with the Enterprise, David Price introduces his own version of the Star Trek theme. His program, though small enough to be played on many microcomputers, allows a wide enough number of variations in play to satisfy even the most frequent users. This program is a must for Trekkies.
Steve Ciarcia owns and uses a Digital Group 8080A system. Read about his experiences and you might want to Try This Computer on for Size.
Want 16 digit BCD output for your calculator software? Need an octal display to replace your binary lamps? Read Jim Hogenson's article on how to Multiplex Your Digital LED Displays to find out what it takes to make numeric display output hardware.
[author : Carl Helmers] #Edito
Extract : « Accompanying this editorial is a letter from an Australian reader, Kevin C Barnes of Five Dock, New South Wales. He's writing on the conditions of the small computer person in Australia circa September 1976. We held onto the letter until it was possible to announce an arrangement which should help promote and build an indigenous small computer industry in Australia: the new Far East Asian editions of BYTE magazine.
When BYTE first began circulation, an electronics engineering consultant named John Bannister, a native of Sydney, Australia, subscribed nearly instantaneously when he heard about it from an American friend. But he soon ran into a problem which plagues all individuals on the end of a long international supply chain — it takes time and patience to await BYTE (or any US goods, for that matter) in Australia, which is perhaps the extreme case for shipment of BYTE magazines to foreign subscribers. Not satisfied with waiting three months or so for the very current information we put out in BYTE each month, he started immediately to search for alternatives. [...] »
Illustrations : (p.62) A BYTE family portrait, circa December 1976, Clockwise from top left are Manfred Peschke, Virginia Peschke, John Bannister and Carl Helmers.
TABLE OF CONTENTS
[theme : Hardware] [author : Burhans] #Electronic #Transport
Extract : « Omega Navigation is a method of determining where your boat or plane is currently located, anywhere on the globe. It is a "free" method of navigation to a certain extent ; since it is sent out by the cooperating nations via radio transmissions for shipping and defense traffic, but is available to any technological hitchhiker willing and able to build the proper interface. (Free in this instance is defined to mean the accounting for each person's share of the tax cost is so diffuse it can't be traced.) [...] »
[theme : Hardware] [author : Buschbach] #Electronic #Interface #Joystick
Extract : « In the quest to develop the ultimate in video games, the need arose to interface analog controls to a microprocessor. A common control used in most video games is the joystick. It allows you to control two axes with one device. A joystick usually has potentiometers mounted on two adjacent sides as shown in photo 1. [...] »
[theme : Games Software] [author : Price] #Listing #BASIC #Algorithm #Game
Extract : « The main objective of this version of the Star Trek game is to destroy all of the Klingon battle cruisers within 30 stardates. The Klingons and starbases are randomly positioned within a simulated galaxy. To help you better visualize this galaxy we use quadrant sector notation. [...] »
[theme : Hardware] [author : Hogenson] #Electronic #Display
Extract : « Digital LED displays were once a novelty to the hobbyist, a luxury found in expensive lab equipment. They are now a household word and a useful tool for the digital experimenter. A digital LED display can be used as the readout for almost any test instrument. A programmable LED display can be used as a computer output. A digital LED display is a handy replacement for the binary lights on a computer control panel. If you have been thinking about using an LED display for any of these or other reasons, this article may save you some time, money, and power. [...] »
[theme : Hardware] [author : Grappel] #Interface #Robotics #Electronic
Extract : « A lot of proposed microcomputer applications require the computer to control various mechanical devices. Opening and closing valves, moving things, pushing, turning, etc, are not things that computers can do without help. This article describes a surprisingly easy way to turn digital signals into mechanical motion. This will make it easier to design plotters, controllers... anything that requires motion. [...] »
[theme : Product Description] [author : Kay] #Review #Electronic #Printer
Extract : « Ever since the microprocessor's introduction, computer hobbyists everywhere have been searching for a low cost alphanumeric printer. One place the search can stop is at the unit presented here: a 5 by 7 dot matrix impact printer. It prints the 64 character upper case ASCII set with 40 characters per line at a rate of 75 lines per minute on standard 3.875 inch (9.843 cm) rolls of adding machine paper, as shown in figure 1. One complete line is printed at a time from an internal 40 character first in first out buffer memory. Printing takes place either on receipt of a carriage return or automatically whenever the line buffer memory is filled.
The printer can accept character data as fast as one character per microsecond (until the buffer is full) or as slow as you wish to send it. [...] »
[theme : Cassette Transports] [author : Freeman] #Review #Storage
Extract : « Use of the Phillips Compact Cassette as a storage medium has been well established. Articles in BYTE and other publications have made the audio cassette just about the only storage device for the computer hobbyist. However, not enough attention has been given to the machine in which the cassette is operated. From various articles the usual transport mechanism is usually referred to as a cheapie or $30 cassette recorder. The usual control is a relay used to turn on the entire device. I regard this method as less than satisfactory and suggest that there are better ways. [...] »
[theme : Hardware] [author : Bremeir-Rampil] #Electronic #Storage #Encoding
Extract : « We've now seen an illustration of the techniques involved in the recording and playback of binary strings on magnetic tape (in part one last month). These techniques are all that would be required if the cassette tape transport mechanism had instantaneous start and stop, and perfect speed regulation. The read and write electronics would need to have very wide bandwidth, as shall be seen later, and the tape itself would have to be absolutely error free. Since there are problems in meeting each of these requirements, a great deal of effort has gone into data code conversion schemes that tend to alleviate the problems. Many different codes have been developed, but only a few have found widespread application and usage. The number of codes in use, in fact, is likely to decrease in coming years, as there are strong incentives in the industry to settle on standard coding schemes which would then be used by everyone. There is no urgent reason, however, for amateurs to embrace the industrial standard, especially if there is no intent to exchange tapes using the medium. [...] »
[theme : Construction] [author : Frenzel] #Initiation #ComputerKit #Build
Extract : « Most of the personal computing equipment available to the hobbyist today is in kit form. As a result, the field of personal computing as it is now known essentially centers around the building, testing and troubleshooting of computer kits. Many individuals with a "computer hobbyist" approach to the field are electronic types who enjoy kit building and consider their work with the equipment to be the main focus of their interests.
However, many other people would rather concentrate on the programming and application of the equipment. Such individuals may not enjoy or even consider themselves capable of building some of the sophisticated computer kits available. Yet many of these nonhardware types are taking a chance on their being able to successfully learn kit building. They do so simply to be able to have the equipment that is available today. At this point in the development of the personal use computer field, being able to build a kit often means the difference between being able to own a fairly sophisticated computer or not.
There are many benefits to be gained by building a kit. [...] »
[theme : Review] [author : Ciarcia] #Review #ComputerKit
Extract : « There are a number of fine microprocessor system kits available to the home computer enthusiast. One such system, which I just recently assembled, is the Digital Group 8080A. This microcomputer is marketed by the Digital Group in Denver CO. This concern, with Dr Robert Suding as its resident genius and designer, offers in my opinion the highest price performance of any home computer available. The Digital Group is somewhat unorthodox by not jumping on the bandwagon and being Altair bus compatible but their unit contains enough bells and whistles to placate even the most demanding computer owners. [...] »
#Association