[editor : Carl T. Helmers Jr.] [publisher : Virginia Peschke, Manfred Peschke] [art : Wai Chiu Li, Ellen Shamonsky] [cover : Robert Tinney] #Magazine
#Abstract
About the Cover: The conceptual target of the cover painting for September was a theme of music and sound. Taking this theme, Robert Tinney implemented this cover, entitled "Breaking the Sound Barrier." It was inspired by the legend of opera star Enrico Caruso breaking a wine glass through sympathetic resonances with his voice. The sound barrier we're referring to, of course, is the physical barrier between a program and the real world, which is crossed by one of a number of musical and audio output devices and software presently on the market or about to come to the marketplace.
Experimenting with music on your computer can be very rewarding. If you're looking for a streamlined way to input musical material into your system, look no further. Hal Taylor shows you how in SCORTOS: Implementation of a Music Language. Who knows, with SCORTOS you could have your synthesized concerto for alpenhorn and orchestra up, running and debugged by next week.
A naked microcomputer board is unprotected from a harsh environment. In his article this month, R Travis Atkins turns couturier as he fashions external garb in the form of A New Dress for KIM.
Steve Ciarcia returns this month with a combination of tutorial ideas and practical details so characteristic of his style. Read Steve's Control the World! (Or at Least a Few Analog Points) to review digital to analog conversion, and learn how BASIC can be used to compute and represent wave forms through a converter using a scope as a display.
A Tiny Assembler need not have tiny features, as Jack Emmerichs explains in his article on Expanding the Tiny Assembler. Jack adds structured programming features and incremental improvements to the Tiny Assembler design he described in April and May issues of BYTE this year. By reorganizing the symbol table to add the "begin" pseudo operation, "Tiny" takes on a number of "big" features while preserving practical operation as Version 3.1 in under 4 K bytes of memory.
Looking for a very simple way to build a wire wrap board? Ira Rampil has an idea in A One-Sided View of Wire Wrap Sockets.
Are you interested in making music with your computer? Hal Chamberlin's A Sampling of Techniques for Computer Performance of Music is one of the best ways to get acquainted with this fascinating field. The article will give you complete directions for creating 4 part harmony on your microprocessor for a very modest investment. Get out those 4 voice fugues that have been languishing in your music drawer and bring them to life!
Did you ever want your computer to sing you a lullaby? Well, as Ted Sierad points out, it's not too hard to do so if you Tune In With Some Chips, using the circuit and software he describes.
The roster of "complete" computer systems for the amateur computing person expanded considerably with the introduction of the Noval 760. Turn to an account by designers Lane T Hauck and James D Nash, System Description: the Noval 760, for details of the philosophy and overall design behind this product.
A double feature written by Carl Helmers and Chris Morgan of BYTE covers key details of an interesting musically oriented peripheral which can be added to the personal computer: acoustic pianos with pneumatic player actions . Notes on Anatomy: The Piano's Reproductive System gives global morphology of a Duo-Art upright reproducing piano. Notes on Interfacing Pneumatic Player Pianos covers some details of how to engineer a computer interface for the pneumatic control lines using valve elements manufactured for the pipe organ industry .
With this issue, readers will note the continued progression of information on APL, and several articles introducing the theme of music representation and performance with computers. Readers can look forward to further information on these themes in future issues.
APL is one of the most interesting high level languages around these days. If you want to continue learning what goes on in an APL interpreter, read part 2 of Mike Wimble's An APL Interpreter for Microcomputers. Here Mike covers the expression evaluation sections of the interpreter.
Many people are familiar with use of orthogonal basis functions such as sines and cosines to compute arbitrary waveforms. But how many readers have heard of Walsh Functions: A Digital Fourier Series which forms arbitrary repetitive waveforms as weighted sums of digital waveforms? Read Benjamin F Jacoby's tutorial to find out a bit about these functions and their generation.
[author : Carl Helmers] #Edito
The September 1977 BYTE marks the end of the second year of our publication's existence in the public eye, although actual work on the magazine began at the end of May 1975. Since that time, the phenomenon of personal computing has expanded considerably as more people become aware of it through mass media publications, radio and television shows, trade fairs such as the First West Coast Computer Faire and the National Computer Conference. Good sense says a peak must be reached in any new and expanding marketplace, but to date we have seen no signs of the traditional "shakeout" (intense competition such as that which occurred recently in the calculator and watch marketplaces). For whatever reasons, a few firms have fallen by the wayside, but the general trend still remains one of expansion and exploration, to the ultimate benefit of the user of personal computing products who is presented with new options and lower prices for older options.
The "appliance" computer, a complete system presented in an assembled and tested package is on the threshold of its ultimate dominance in the general purpose personal computer field: from the high end, moving down in price, we find products like the Apple-II and the Commodore PET 2001 machines; from the low end, moving up in function at the same price, we find the increasing versatility and capability of programmable calculators such as the newly announced Texas Instruments SR-59 with its optional ROM software modules and expanded printing and magnetic card peripheral capabilities. And for the discriminating or experienced user, the wealth of options available in the many varieties and permutations of 8080, Z-80, 6502, 6800 and 9900 systems at reasonable prices make it less and less likely that our readers will continue to be frustrated and annoyed by such devices of torture as job control, account numbers, contention for the use of a system, and the host of limitations encountered when commercial and industrial systems are twisted to personal purposes in "off" hours.
During the coming year, our third as a magazine born out of and devoted entirely to personal computing, we expect to see continued evolution in the field. The last half of 1977 represents the entry of several relatively large concerns into the marketplace, in the form of Heathkit this summer and Commodore soon to follow. Rumors have it that companies ranging from Atari and Bally Manufacturing (arcade games) to Radio Shack and Texas Instruments are in the process of developing general purpose systems appropriate for personal computing uses. This sort of "confirmation" of the marketplace's existence is bound to keep all firms on their competitive toes and ultimately benefit the user who is presented with more options and ways of achieving the personal computing function. (We even see the same phenomenon in our own subbranch of the industry, the publications devoted to personal computing.) Like all industries, we can expect to see ups and downs in the trend, but for the moment we certainly relish and enjoy the heady expansion and growth evident all around us. Once again, technology in its application to human affairs is having its effect, and our lives as individuals are being improved as a result, despite the pessimists, gainsayers and prophets of doom chattering on about their usual maudlin spectres. We have yet to see large and useful personal data banks, practical automatons and similar challenges which have been projected by the writers of "hard" science fiction. But even if such are seen in our lifetimes, one thing is certain: the challenge of technology and invention which so marks the human race will continue with new horizons, just as today's computer technology could scarcely have been envisioned 20 years ago."
TABLE OF CONTENTS
[theme : Software, Music] [author : Taylor] #Review #OperatingSystem #Audio
Extract : « Perhaps nowhere can technology better serve the creative end of the music arts than through the computer. The computer has a natural affinity for the application to music since it is capable of carrying out processes which create and perform music. It can be programmed to learn any language the composer wishes to use to describe his musical ideas. It can manipulate the symbols of that language to produce transformations of the composer's original ideas. It can enlarge and improve the quality of the composer's creative output by allowing him to work in an interactive mode where he can hear his musical works performed within minutes of their conception. [...] »
[theme : Peripheral Interfaces] [author : Ciarcia] #Electronic #Interface #Listing #BASIC
Extract : « [...] I was indeed an engineer descended from the puzzle factory and my mission was to discover why we were having so much trouble life test qualifying one of the pressure detectors we intended for future manufacture. Hearing the preceding commentary as I approached the testing lab, I decided that an authoritative professional type would not be very popular at the moment, so I went into my innocent nonmanagerial mode and entered the lab. This lab was not unlike any other small production qualification and testing lab. It had the usual machinery and instrumentation and many artifacts of former test programs lying about. The most prominent artifact was the leader of the instrumentation group, Ned. Ned's large frame amply filled the white lab coat though it was barely discernable in the dense cloud of cigar smoke. The combined scent of hydraulic oil, burned resistors, and cigar smoke convinced me that today was not going to be my day. [...]
[...] REFERENCES
1. Digital to Analog Converter Handbook, Hybrid Systems Corporation, Crosby Dr, Bedford MA.
2. Graeme, Jerald G, Applications of Operational Amplifiers — Third Generation Techniques, McGraw Hill Book Company, NY, 1973.
3. Sheingold, Daniel H (ed), Analog-Digital Conversion Handbook, Analog Devices Inc. Norwood MA.
4. Stout, David F, and Kaufman, Milton, Handbook of Operational Amplifier Circuit Design, McGraw Hill Book Company, NY, 1976.
5. Tobey, et al. Operational Amplifiers — Designs and Applications, McGraw Hill Book Company, NY, 1971.
6. Wylie Jr, C R, Advanced Engineering Mathematics, McGraw Hill Book Company, NY. »
[theme : Computer Music] [author : Chamberlin] #Electronic #Listing #Assembly #Audio
Extract : « Computer music is probably one of the most talked about serious applications for home computers. By serious I mean an application that has a degree of complexity and open-endedness which can totally preoccupy experimenters and funded institutions for years. Computer performance of music is a discipline so vast that the final, "best" technique for its implementation or even a good definition of such a technique may never be discovered. [...]
REFERENCES
1. Mathews, Max, The Technology of Computer Music, MIT Press, Cambridge MA, 1969. Contains a detailed description of MUSIC V, the high level music language.
2. Smoliar, Stephen, "A Parallel Processing Model of Musical Structures," PhD dissertation, Massachusetts Institute of Technology, September 1971.
3. Oppenheim, A and Schafer, R, Digital Signal Processing, Prentice-Hall, NJ, 1975. »
[theme : Applications] [author : Sierad] #Electronic #Algorithm #Audio
Extract : « Are you fascinated with tiie idea of computerized music, but find the mechanics of producing such effects too complex? I've come up with a simple technique which is the subject of this article, and which is well within the capabilities of the novice computer experimenter. With less than a dozen inexpensive integrated circuits, a few resistors, capacitors and a small prototyping board you can be well on the way to creating interesting music with your Altair, IMSAI or similar computer. My design creates a programmable music tone generator peripheral which has outputs that sound somewhat reminiscent of a clarinet when it is programmed by simple or complex software used to sequence notes in time. The first attempts I made at music generation required complicated programs and many integrated circuits. But as I gained more familiarity with the problem, the project reduced into a relatively simple solution as illustrated here. [...] »
[theme : Interpreter Design] [author : Wimble] #Algorithm #Programming
Extract : « Backus-Naur Form (BNF)
BNF is a notation used quite often in the description of computer language grammar and semantic information. Many of the figures in this series of articles contain a short BNF description of the formal elements of APL treated by the flowchart in question. A BNF statement looks like: <A> ::= <B>|<C>|<A> <B>
In BNF, brackets (" < " and " > ") are used to enclose tokens or "terminal elements," and the symbol "::=" means "may be composed of." The symbol " | " is the notation of a logical "or." This notation was first developed for the description of the ALGOL language, and has since been used widely in numerous books and papers on language design and compiler writing. The example statement above can be translated into words as follows: "An A token is composed of either a single B token, or a single C token, or an A token followed by ("concatenated with") a B token." There is no restriction against possible recursion in BNF syntax descriptions, a feature which allows very simple language constructs to form very complicated statements which can be correctly parsed by the interpreter or compiler. [...] »
[theme : Design] [author : Atkins] #ComputerKit #Build
Extract : « At first I was reluctant to take KIM out in public because she was so small and homely compared to other systems her age. No one actually ever laughed at her in my presence, but I could sense the pity that they had for me. I wondered, would my KIM forever be overshadowed by those bristling brutish Altairs and IMSAIs at every social gathering? I knew KIM's strengths and her weaknesses, and I wondered if there was anything that I could do to help her find acceptance in the world. Then, one evening, while talking to a friend whose IMSAI was drawing considerable attention, as usual, it occurred to me that it wasn't his central processing unit's IQ that set it apart from my humble KIM. No, it was the way that it was dressed that did so much toward creating the image of great sophistication and power. [...] »
[theme : Software Design] [author : Emmerichs] #Listing #Assembly #Programming
Extract : « It is worth noting that the group of people who have been using the Tiny Assembler since the end of 1976 as listed on page 133 of the March 1977 BYTE excludes the author: ME! Well, I have finally gotten my own computer system up and running and have been able to get some use out of the assembler myself. I soon found that there were a few things here and a few things there that could be changed or added that would make the whole assembly process more convenient. I guess there is just no pleasing some people.
The problem is that, as predicted, I have a minimal configuration system. It is a SwTPC 6800 with (at the moment) no extras. The assembler just fits, so there is no place to put patches or additions except at the top of the symbol table. This of course reduces the capacity of the program. It became obvious that the proper approach to further modifications would be to increase the efficiency of the assembler so that additions could be made while maintaining or increasing the symbol table capacity. The first modification, therefore, would have to be the ability to delete symbols when no longer needed so that the symbol table space could be reused. This would allow a smaller table to handle a larger number of symbols. [...] »
[theme : Hardware] [author : Rampil] #Electronic #Build
Extract : « Recently, while laying out the components for a new PDP-11 device controller, a devilishly simple construction technique revealed itself to me. Digital Equipment Corporation specifies that their printed circuit modules be restricted to component heights of 0.38 inch (0.97 cm), and on the solder side only 0.06 inch (0.15 cm) are allowed for the height of soldered and clipped off leads. These specifications enable boards to be mounted on half inch centers on a backplane. [...] »
[theme : System Description] [author : Hauck-Nash] #Review #Computer
Extract : « The first wave of personal computing hysteria seems to have subsided. A casual stroll through the West Coast Computer Faire last spring served as a pretty clear indication that the small computer user has grown up in a big hurry. We now hear these alleged "kids" rapping about relocatability, graphics generation and memory design, a far cry from the "dumb" user concept.
The Noval 760 computer was designed to fill the needs of the advanced hobbyist, who has a serious interest in learning about writing and using software. The system emphasis at Noval has been placed on provision of a unified hardware and software package which facilitates program development. The Noval 760 system does not allow the user to pick up a 4 year degree in computer science within two weeks by following the manual, but it does simplify some of the "dog" work required to design, write and debug programs written for amusement or more serious business. [...] »
[theme : Music Peripherals] [author : Helmers] #Electronic #Interface #Audio
Extract : « Everyone is familiar with the concept of the player piano, a complex mechanical monstrosity which had its heyday in the early part of this century as the prime home entertainment device before the invention of electronic media which now dominate the home entertainment scene. But player pianos are far from dead. Just as there is an active subculture of computer aficionados, there is a whole cult of player piano and mechanical music freaks. Thanks largely to these people a working player piano is not an uncommon sight in the parlors, dens and living rooms of contemporary suburbia. [...] »
[theme : Software History] [author : Morgan] #Robotics #Audio
Extract : « When was the binary number system first used for control purposes in a mass produced machine? The early nineteenth century Jacquard punch card controlled loom comes immediately to mind; but, surprisingly enough, a more widespread application occurred in the first quarter of this century: the reproducing player piano!
The reproducer was so-called because it went one step beyond the player piano in its ability to "reproduce" the dynamics and subtle shadings of the pianist who recorded the roll. [...] »
[theme : Interface Technology] [author : Jacoby] #Electronic #Audio #Book
Extract : « Using a mathematical technique called Fourier analysis, it is possible to build arbitrary wave forms by adding together various "components." While a full appreciation of the inner workings of the Fourier series requires a knowledge of advanced mathematics far beyond the capacity of many persons interested in electronics, that in no way deters them from using the concepts or even simplified portions of the math in practical applications. Even beginners are aware that wave forms can be broken into a set of harmonics and that a set of sinewaves of integer multiple frequencies can be summed to build up a complex wave form. In a like manner, Walsh function concepts can be put to work once a few fundamental ideas are mastered. A key to generating complicated sounds in computerized music and voice outputs is the ability to generate arbitrary wave forms from digital codes. [...]
BIBLIOGRAPHY
J L Walsh: "A Closed Set of Orthonormal Functions," American Journal of Math, Vol 45 pp 5-24, 1923.
H Rademacher: "Einige-Saltze von allgemeinen Orthogonalfunktionen," Math Annalen, Vol 87 pp 112-138, 1922.
H F Harmuth: "Applications of Walsh Functions in Communications," IEEE Spectrum, Nov 1969.
M S Corrington: "Solution of Differential and Integral Equations with Walsh Functions," IEEE Transactions on Circuit Theory, Vol CT-20 No. 5, Sept 1973.
W M Walmsley: "Walsh functions, transforms and their applications," Electronic Engineering, June 1974. »
Adding New Transcendentals to Limited BASICs
On Finite State Machines and Their Uses
Comments on Floating Point Representation
#Association
#Book
Extract : « CMOS Cookbook by Don Lancaster, Howard W Sams and Company, Indianapolis IN, 1977. $9.95. [...] »