[editor : Carl T. Helmers Jr.] [publisher : Virginia Londner, Gordon R Williamson] [art : Stephen Kruse, Wai Chiu Li, Dorothy Shamonsky, Ellen Shamonsky] [cover : Robert Tinney] [nota bene : Some missing pages in archive.org. Full version in vintageapple.org] #Magazine
#Abstract
Robert Tinney's painting on the cover this month is a fanciful image of computer chess. A Knight floats above an ancient stone chessboard with the ubiquitous floppy disk beneath. Four articles in this issue are devoted to the art of computer chess, including the first part of a 4 part series by the creators of Chess 4.6, the world championship chess program.
One cause of seemingly unexplainable program errors may be incorrectly operating memory. A Memory Pattern Sensitivity Test discussed by Don Kinzer will help to determine if your memory is operating correctly. page 12
If you need -12 or +15 V for your latest hardware design, and have only +5 V, what can you do? Read No Power for Your Interfaces? Build a 5 W DC to DC Converter by Steve Ciarcia. Several inexpensive, practical designs are described, to give you everything from - 15 to +15 V from a +5 V source. page 22
In Part 1 of A "Tiny" Pascal Compiler, in the September 1978 BYTE, Kin-Man Chung and Herbert Yuen described the syntax of a Pascal subset and described a hypothetical stack machine, called a p-machlne. This month they describe a compiler that generates codes for the p-machine. page 34
Would you like a fast and easy way to test your new memory board? Author Russell Adams shows you how in Testing Memory in BASIC. A simple program loads the memory locations with alternating 1s and 0s to spot those bad bits. page 58
The H8 computer from Heath features a novel firmware front panel monitor comprised of both hardware and software elements. Gordon Letwin, Heath software designer, describes the design philosophy and the features of the system in PAM/8: A New Approach to Front Panel Design. page 70
The winning program at the Second West Coast Computer Faire's Microcomputer Chess Tournament in March of 1978 was Sargon, written in Z-80 assembler language. Sargon's creators, Dan and Kathe Spracklen, describe the move generating portion of their program in First Steps in Computer Chess Programming. page 86
A computer allows you to try out a variety of ideas with nothing more than a program to see if they will work. One way to use this potential is to model electrical circuits in software. Leonard H Anderson describes how to perform Linear Circuit Analysis on your computer. page 100
The eight Queens problem is a venerable puzzle in recreational mathematics. Terry Smith describes his thought processes in working out a solution in his article, Solving the Eight Queens Problem. An occasional dose of cleverness is often the key to solving a difficult problem, as Terry demonstrates. page 122
For someone who is looking for a good quality video terminal which is easy to work with and will be user serviceable, the Heathkit H9 is the solution. Terry Steeden describes his pleasant experiences Assembling the H9 Video Terminal and having it work correctly the first time. page 130
Digital recording of computer programs and data is an attractive alternative to standard audio cassette recording techniques because of its reliability. and simplicity. Ralph Burhans describes an updated version of earlier digital recording schemes in A Simpler Digital Cassette Tape Interface. page 142
If you own a SwTPC 6800 computer and want to increase the processor clock speed with a minimum of fuss, read Souping Up Your SwTPC 6800 by Steve A Hughes. The article describes a simple circuit that plugs directly into a socket on the 6800 processor board. Changing the clock speed is then done by simply plugging in a new crystal oscillator. page 144
Last year we ran a contest in which readers were asked to design their own PAPERBYTEtm bar code readers and submit them to us. One of the winning entries, by Campbell Farnell and Glen Seeds, is described in their article, A Novel Bar Code Reader. page 162
For a short introduction to the world of computer chess, read Norman Whaland's A Computer Chess Tutorial. The basic principles of chess strategy and tactics are covered in discussions of game trees, alpha-beta pruning, minimax strategies and so on. page 168
Creating a Chess Player was written by two people at the forefront of research in computer chess: David Frey, editor of Chess Skill in Man and Machine, and Larry Atkins, coauthor of Chess 4.6, the world champion chess program that recently beat a Grandmaster in a simultaneous exhibition. The article discusses the thinking processes in the chessplayer's mind and how such processes are transformed into a computer program. page 182
[author : Carl Helmers] #Edito
Extract : « Finally, it had to happen to me. We all know that personal computers are supposed to be a cross between a necessity and a luxury. But the critics tend to harp on our tendency to get carried away by the fun and to ignore the practical uses of our wonderful servants. As if to answer that justified criticism, I finally came up with a genuine practical use for a small computer in the monthly operations of BYTE's editorial office. Now this practical application is by no means the kind of automated editing and type preparation facility I would like to have some day if and when I ever become rich and famous. But this is a genuine, once a month, cyclically run application program.
At BYTE, we have so far purchased two Apple II computers (among others) for use in educating our employees, and in order to have some facilities around the office. One of these Apple II computers sits in my office, and at the time of this exercise it had only the usual audio tape cassette interface for mass storage, and television for display purposes, (I have since ordered and received a floppy disk drive, which was plugged in and working within five minutes of setup.)
The immediate spur to writing this practical program was the need to analyze the editorial preferences section of the BYTE 1978 reader survey. [...] »
TABLE OF CONTENTS
[theme : Hardware] [author : Ciarcia] #Electronic #Interface
Extract : « Recently I attended a local computer club meeting where we discussed the question of power supplies. Many people were remarking that, while they enjoyed building the projects in my articles, often their power supplies were not compatible with the multiple voltages I required. Many of the newer single board computers that some members owned contained only a hefty +5 V supply and a note that the user should add additional supplies if the basic board is expanded. [...] »
[theme : Pascal] [author : Chung-Yuen] #Programming #Listing #BASIC #Pascal #Book
Extract : « When Niklaus Wirth introduced Pascal in 1971, one of the design objectives was to allow efficient program compilation. As far as we know, all existing Pascal compilers use the one pass compilation technique.
Newcomers to Pascal sometimes criticize features of the language such as declaring variables before use, and having constant and type declarations precede variable declarations. But such features are necessary to make a one pass compiler work (aside from the fact that it is also good programming practice to declare identifiers before use). Compared with multipass compilers, the job of writing a one pass compiler is relatively simple, since there is no need to store the program in its intermediate form. [...] »
[theme : Software] [author : Adams] #Listing #BASIC #Memory #Diagnostic
Extract : « I hate to toggle in a program through the front panel of my computer. Yet every time I finish a new memory board I have to do this to a machine language memory test program. I therefore resolved to write a memory test program in BASIC which could be loaded with an 8 K interpreter in 8 K of proven memory. The BASIC program in listing 1 is the result. [...] »
[theme : Software Chess] [author : the Spracklens] #GameBoard #Programming #Listing #Assembly #Algorithm #Book
Extract : « The fascination of chess gains a new dimension with microcomputer chess. No longer are the struggles confined to giant machines. With the advent of the Chess Mate, Chess Challenger, Boris, and Compuchess, as well as some custom software packages, the day of microcomputer chess has dawned. Writing a program to play chess on a small system is no small matter, though. Consider just for a start the challenge of meaningfully representing the board and its pieces in computer memory: there are 64 squares, 32 pieces, 6 piece types and 2 piece colors. Since the machine is a microcomputer, storage requirements must be kept to a minimum. Next comes the job of moving the pieces. Only when these first problems of piece representation and move generation have been solved can the chess programmer go on to consider strategy. [...] »
[theme : Simulation] [author : Anderson] #Electronic #Simulation #Algorithm #Book
Extract : « Circuit analysis programs are valuable tools that can tell you how a circuit will work before you build it - "paper breadboards" in effect that don't require any component purchases, expensive equipment or debugging time spent on the bench. Analysis programs fall into two general categories: frequency domain and time domain. Presented here are the fundamentals of a frequency domain linear analysis program. In practice, linear analysis means that no active devices are operated at saturation or cutoff. Frequency domain tells us what circuits do at different frequencies, a type of analysis well-suited to model amplifiers, filters and operational amplifier circuits operating over any desired frequency range. You can make voltage and impedance readings at any point in the circuit without experiencing the loading problems that can occur with conventional equipment.
Because of the variations in small computer systems, primarily in memory, no specific language is given. All of the necessary flowcharts are presented along with necessary mathematical operations. You will need the four basic floating point functions plus array handling (single dimension arrays are acceptable, but two-dimensional arrays are preferred) and at least arctangent and logarithmic functions.
Matrix operations are done but you don't need BASIC MAT functions; the matrix is fully explained later. Using charts and ex- planations, you can write the program in any form from assembler to BASIC and higher languages. Assembler will work faster since this is a "number crunching" program. The main constraints are memory and the ability to hold many arrays in main memory. [...] »
[theme : Software] [author : Smith] #GamePuzzle #Listing #BASIC
Extract : « The eight Queens problem is a chess related puzzle, the object of which is to place eight chess Queens on an 8 by 8 chessboard in such a way that no Queen can take another. [For the benefit of nonchesspiaying readers, the Queen can capture any piece that is in direct line with it horizontally, vertically or diagonally. No detailed knowledge of chess is required in order to understand the rest of this article....CM] 8 is the maximum number that is not obviously impossible, since 9 would force one Queen to be in at least one other Queen's row or column. I will explain how I solved this problem using a computer, since a look into the mind of a problem solver from start to finish might help you with your own problems. [...] »
[theme : Hardware] [author : Burhans] #Storage #Interface #Devices #Electronic
Extract : « To our department at Ohio University, "Saturation Recording's Not All That Hard" by David M Allen, page 34, January 1977 BYTE, was a sleeper until we happened to visit Abex Corporation here in Athens OH. While we were there, Dave Weeks showed us a direct digital interface which he was building from an old cassette deck. [...] »
[theme : Hardware] [author : Hughes] #Electronic
Extract : « One of the design economies in the SwTPC 6800 is the use of the same clock to set data transfer rate and to control processing speed. It avoids the need to build a separate processor clock and reduces the processing speed by only 10 percent. For most applications, this speed loss is unimportant, but it can become important if you are interested in heavily processor based activities such as process control or robotics. It is also inconvenient if you use timing loops frequently, since it is more difficult to calculate timing loops which are based on a slightly more than 1 μs period rather than on an even 1.0 μs period for the processor states. Therefore, I decided a little "souping up" was in order. [...] »
[theme : Hardware] [author : Farnell] #OpticalInput #Build #Electronic #DataEntry
Extract : « Our Paperbyte™ bar code reader consists of three parts: (1) an old turntable set at 33 RPM on which sits the page to be read, attached to a 48 ounce juice can; (2) a read head with light source which is attached to a parallelogram assembly to allow the head to be moved up and down while remaining level; (3) an interface that brings the output of the phototransistor in the read head up to a 5 V digital level. [...] »
[theme : Computer Chess] [author : Whaland] #GameBoard #Algorithm #Initiation #Book
Extract : « On February 20 1977, the Minnesota Open chess tournament was won by a computer program, Northwestern University's Chess 4.5. This was a far better result than any program had previously achieved, considering that all the other entrants in the tournament were human beings. An improved version, Chess 4.6, went on to wrest the world computer chess championship from the Soviet program KAISSA (see "The Second World Computer Chess Championships" by Peter Jennings, January 1978 BYTE, page 108). Professional chessplayers are beginning to worry about the competition from machines. They would seem to have little to fear at the moment, however. The consensus is that Chess 4.5's tactical skill is impressive but its strategy is weak.
Against such competition, what can a personal computer experimenter expect to accomplish? Perhaps a great deal. There have been few new ideas in computer chess since Claude Shannon (see references) outlined the basic principles in a paper published in 1950. (The superiority of Chess 4.6 is due primarily to faster hardware.) Experimenters can participate in the search for the conceptual breakthroughs that will be needed before computer programs can be a match for the best human players. With that thought in mind, this article deals with the questions: What is a good structure for a chess program? What are the major functions that it must perform? In what directions can we seek innovations? [...] »
[theme : Debugging] [author : Kinzer] #Memory #Listing #Assembly #Diagnostic
Extract : « Faulty memory is a very difficult problem to detect. Most distributors of memory board kits supply a simple memory test designed to detect assembly errors such as misplaced components, solder bridges, etc. These tests are ineffective in detecting certain types of memory related problems. One of these problems, called pattern sensitivity, manifests itself in the very disturbing fact that accessing one memory location alters another memory location, but only when the memory contains a certain pattern of bits. [...] »
[theme : Computer Design] [author : Letwin] #Keyboard #Display
Extract : « Since the first personal computers appeared about three years ago, the field has been growing and advancing at an ever increasing rate. The variety and complexity of products increases even while the cost decreases. Indeed, the field has evolved so rapidly that it has gone through two generations (using the term somewhat loosely) in those three years. The first generation machines were typified by the first 8800 system sold by MITS, a bare bones machine festooned with switches and lights. It took a fair amount of technical know how to build one of these to get it operational. Before long, however, a new generation of machines was available. These, such as the SwTPC 6800, were usually cheaper and simpler to build, using fewer but more powerful integrated circuits.
And in July 1977, the Heath Company announced its two versions of the home computer idea, the H8 and H11 systems. I write as one of the persons who took part in the design of the H8's front panel firmware, an 8080 program called "PAM/8" which shows how software and hardware are often intimately related. [...] »
[theme : Product Description] [author : Steeden] #ComputerTerminal #Build #Display #Keyboard
Extract : « I have just completed one of the more satisfying electronic experiences in my life. I think a lot of the feeling is a result of everything working the first time. Everyone should have such an experience at least once every ten years. More often is preferable, but Murphy's Law usually prevents it. I have just finished assembling the Heathkit Model H9 video terminal.
At first I thought that everything worked the first time because of my great skill as an assembler. However, as a longtime Heathkit builder (automotive testers, amateur radio equipment, and now microprocessor equipment), I have sensed something better about this kit and its construction manual. While they appear in the familiar and efficient format of past Heathkits, there is something which made them easier to follow, and therefore helped contribute to the "works the first time" result. First, the printed circuit boards are clearly and legibly marked. [...] »
[theme : Chess Tutorial] [author : Frey-Atkin] #GameBoard #Programming #Initiation #Method #Book
Extract : « In a recent Time essay (see references) Robert Jastrow, director of NASA's Goddard Institute for Space Studies, predicted that history is about to witness the birth of a new intelligence, a form superior to humanity's. The pitiful human brain has "a wiring defect" that causes it to "freeze up" when faced with "several streams of information simultaneously." Jastrow suggests that "the human form is not likely to be the standard form for intelligent life" in the cosmos. Even on our own small planet, a new day is near at hand: "In the 1990s,... the compactness and reasoning power of an intelligence built out of silicon will begin to match that of the human brain."
We have always been fascinated by the idea of a machine that is capable of rational thought. Jastrow is neither the first nor the last person who is betting on rapid improvements in machine intelligence. His expectation that computers will rival humanity within 15 years seems optimistic to anyone who has watched half-a-dozen excited technicians flutter about for several hours trying to bring a crashed system back to life. This prophecy seems even more fanciful to those who have attempted to program machines to cope with pattern recognition, language translation or a complex game such as chess. [...] »
#Book
Extract : « Microprocessor Programming for Computer Hobbyists by Neil Graham, Tab Books (number 952), Blue Ridge Summit PA 17214 $8.95 [...] »
#Association
