[editor : Carl T. Helmers Jr.] [publisher : Virginia Peschke, Manfred Peschke] [art : Matthew Arnorld, Mary Jane Frohlich, Lynn Malo, Bill Morello] [cover : Robert Tinney, Brian McCarthy] #Magazine
#Abstract
About the Cover
As a way to highlight the history of electronic digital signalling, we dug up a picture of one of Jose ph Henry's original telegraphy keys, circa the early 1800s. Robert Tinney then placed the key in the frame and wall setting you see on the cover, using a photo supplied by Brian McCarthy.
The problem of decoding arbitrary hand generated Morse code is not a trivial one. It requires some care and thought in the design of adaptive algorithms. As one contribution to this issue's sub theme of computerized Morse code, Lt Willi am A Hickey, USN, provides some background information and suggestions on the subject.
W J Hosking, W7JSW, is an amateur radio operator in search of applications hardware and software. Read about A Ham's Application Dreams and find out how to implement one aspect of his dream with the Morse code input and output conversion technology described in detail in the balance of this issue ... .
A theme of this October issue is the application of microcomputers to the decoding of Morse code. One approach to the problem is detailed in Robert Grappel and Jack Hemenway's article on MORSER... a program to read Morse code, implemented with a Motorola 6800 computer. Lawrence Krakauer describes a technique to store Morse characters as a packed table of bit patterns for machine generated outputs - or for machine decoded inputs.
If Only Sam Morse Could See Us Now. He'd have a fistful of problems trying to copy radio transmissions at 1000 wpm generated by programs such as Way ne Sewell's CWBUFFER subroutine. But, using one of Wayne's set of sundry drivers for CWBUFFER, Mr Morse could potentially learn to copy - or at least have his computer copy - in a code practice mode.
One application of the Morse code problem solvers is documented in Bruce Fil gate's article on Morse Code Station Data Handler. This is an application program which handles direct sending of Morse outputs, from character text, adaptive interpretation of Morse inputs, storing of fixed messages (eg: ' CQ CQ CQ DE W1AW ') in a message buffer for later transmission or repetitive transmission, etc. Bruce has put it all together in the form of a comprehensive 1536 byte program for an 8008.
Once you sit down and Build This Mathematical Function Unit as described in part one of R Scott Guthrie's two part article, the world of high level mathematical functions is opened to your microcomputer. In part two this month, the software needed to interface with the calculator is described, as well as several test loops used to adjust timing parameters with an oscilloscope. As a final illustration of the calculator's use, the author provides a program called CALCULA which enables a Teletype (or other ASCII) port to drive the calculator and print results, simulating the ordinary hand calculator level of operation .
National Semiconductor announced the PACE computer some time ago, but until recently it has been somewhat hard to obtain . Now that this 16 bit minicomputer is beginning to enter its volume production stage, we Keep PACE With the Times by offering Robert Baker's Microprocessor Update on this processor. If you missed the convenience of your familiar 16 bit minicomputer when you started reading about and "dry run programming" for personal computing, then the PACE processor might be a logical choice for a homebrew or kit system.
The advent of the personal system portends a fundamental change in the ways computers are used. In Homebrewery vs the Software Priesthood, David Fylstra and Mike Wilber make some comments about the impact of widespread use and knowledge of computers.
Looking for ideas for meetings of your local computer group? Dr Charles F Douds has a few suggestions to make in his background article on the subject this month.
[author : Carl Helmers] #Edito
Extract : « The often asked question of the personal systems cynic is "What on earth do people do with home computers?" In many ways this question is analogous to what might have been asked by automotive skeptics in the early part of this century: "What on earth do you expect people to do with automobiles?" Fifty to 60 years of history have answered the latter question in numerous concrete demonstrations, and one can only expect the coming decades of computer evolution to answer the former question in numerous ways.
Of course the simplest reply to the first question is "Compute!" and is as empty of content as the analogous reply for automobiles, "Drive!". Computing without a purpose is like driving without a destination, an intrinsically enjoyable pastime on occasion but hardly touching upon the set of possibilities inherent in digital computation and control. The key to a broadened perspective on the computer and its place in human activities is the concept of the application. An application for the computer is like a destination for an automotive trip. [...] »
[theme : Applications] [author : Grappel-Hemenway] #Listing #Assembly #Encoding
Extract : « A great many amateur radio operators find Morse code operation a nuisance. It isn't easy to develop proficiency in copying code, and it often seems that those stations one wants to work are just those whose operators send code too fast to readily copy. There must be hundreds of Morse coding aids developed over the years, ranging from mechanical keys and paper tape transmitters to fancy code memories and typewriter like automatic transmitters. Nearly every advance in electronic componentry has spawned a new series of Morse code aids. Nearly all have been designed to help the operator send more effectively; the problem of reception has been more difficult to solve. [...] »
[theme : Applications] [author : Sewell] #Listing #Assembly #Encoding
Extract : « When dealing with personal computers, it is necessary for a person to be familiar with his machine from both the hardware and software point of view. It has been my observation that hardware people often tend to stay in hardware and software people in software, each faction learning just enough about the other side to get along. I am guilty of this myself — I never do in hardware what could feasibly be done in software. Hopefully, this situation will change as my knowledge of microcomputing increases, but for the time being I am assuming that the computer runs because of the little elves pushing electrons around in the processor and putting most of my effort into programming. [...] »
[theme : Applications] [author : Filgate] #Listing #Assembly #Algorithm #Encoding
Extract : « For some time, there has been a need in amateur radio for a machine that could both decode and generate Morse code; in addition, the decoder had to be capable of automatically tracking varying received code speeds. Although Morse code keyboards have been around in the amateur radio field for some time, decoders have not been so readily available. Since hardwired logic can be difficult to modify, I decided to implement the coder and decoder in software. Since a low price was desirable and high performance was not required, I used Digital Equipment Corporation's MPS Starter Set. This is an Intel 8008-1 based product which DEC has been marketing to the commercial world. This article describes my implementation using MPS. [...] »
[theme : Software] [author : Guthrie] #Listing #Assembly #Mathematics
Extract : « [...] The purpose of this design project was to develop an economical and reliable method of performing simple arithmetic, trigonometric and logarithmic functions in microcomputer systems. Software routines for floating point arithmetic and transcendental functions involve extensive algorithms and complex programming on contemporary microprocessors (indeed, on any computer). A great deal of valuable memory area is often required even for some of the simpler mathematical routines. This is especially true when using the limited instruction sets of the contemporary 8 bit microprocessors. This makes the hardware approach a desirable alternative due to the powerful software available in some calculator integrated circuits on the market today. [...] »
[theme : Applications] [author : Hickey] #Algorithm #Encoding
Extract : « So you've been reading all about these marvelous new microcomputers, and thinking about how nice it would be to have one that would translate Morse code for you. Well, it certainly sounds reasonable; it really depends upon what you expect from your computer. If you are expecting error free code translation under even the best signal conditions, you are in for a rude awakening. [...] »
[theme : Speculation] [author : Hosking] #Encoding
Extract : « Here is a short article on a theme of "wouldn't it be nice to have X" where X is defined as some automation applications for the amateur radio station. It is timely, in the context of this month's Morse code theme, in that one of the author's application goals is detailed in several different technical articles In this issue. There's still plenty of room for further explorations of computer application to amateur radio technology of course [...] »
[theme : Applications] [author : Krakauer] #Listing #Assembly #Algorithm #Encoding
Extract : « Since many of BYTE's readers are radio amateurs, a number of whom have expressed an interest in combining computing with their radio hobby, BYTE seems an appropriate place for this short note on a technique for storing Morse character codes in a minimal amount of memory space. It may not be immediately obvious that all of the possible Morse characters, up to six elements per character, can be stored using a maximum of only seven active bits per character stored. [...] »
[theme : Hardware] [author : Baker] #Review #Microprocessor
Extract : « The new National Semiconductor IPC-16A/500D microprocessor commonly called PACE for Processing And Control Element is a single chip 16 bit microprocessor packaged in a standard 40 pin dual in line package. As a 16 bit general purpose computer it is an excellent candidate for personal computing applications. [...] »
[theme : Philosophy] [author : Fylstra-Wilber] #GeneralQuestions #Software
Extract : « The movement towards personalized and individualized computing is an important threat to the aura of mystery that has surrounded the computer for its entire history. Until now, computers were understood by only a select few who were revered almost as befitted the status of priesthood. The arts of designing and programming computers have long been regarded as sacred knowledge beyond the reach of the nonspecialist. Indeed, the journeymen of the trade have protected their privileged position by keeping their knowledge to themselves. These high priests and acolytes of the holy alliance of logicians (HAL) have dominated the field so far. [...] »
[theme : Organizations] [author : Douds] #Association
Extract : « The formal organizations used for clubs and societies can range from the totally informal (one person arranging a regular meeting place) to the setting up of all sorts of corporate nonprofit organizational structures, etc. The informal versions usually work best for small groups; formal organization tends to increase with the size of the group. Whatever the case, the less time spent on long drawn out nitpicking at business meetings, the more time there is to devote to more interesting matters [...] »
#Book
Extract : « Computer Resource Book — Algebra by Thomas A Dwyer and Margot Critchfield, Houghton Mifflin, Boston, 1975; 8-1/4 x 11, 178 pages. Paperback $4.20. [...]
The Art of Computer Programming by Donald E Knuth. Volume I: Fundamental Algorithms. Addison-Wesley, Reading MA, 1975, $20.95. [...]
Humanizing Computer Systems by Keith R London, McGraw Hill, New York, $15. [...] »
#Association