[author : Jim C. Warren, Jr., Editor, DDJ] #OtherMagazine #GeneralQuestions
Extract : « For those who tend to assume the validity of anything that they read, simply because it is written — and that's almost all of us — I have decided that it is time to offer a regular and careful dissection and analysis of many of the comments written by Wayne Green. Wayne is the Publisher of Kilobaud and 73 and two promotional newsletters — the Kilobaud Hobby Computer Newsletter for potential advertisers, and Computermania™ for potential exhibitors.
Those "done unto" have access to DDJ
I am also offering the pages of Dr. Dobb's Journal to everyone who feels they have been maligned — explicitly, or as is more often the case, via exquisitely phrased innuendo — by Wayne. Most of those whom Wayne attacks have, essentially, no access to the potent weapon Wayne uses so freely — the media.
Of course, two of his most regular targets, Byte and the ARRL, involve publications with far larger circulation than those Wayne controls; however, they exercise great editorial restraint and diplomacy in responding to Wayne's ongoing snidery. This is probably partially due to their concern for the ethical standards that should be exercised by every publisher, and partially due to their recognition of the ad man's hack, "There ain't no such thing as bad publicity." (Nixon might not agree with the ad man.) [...] »
#TradeAndLaws
Extract : « We have received such a volume of complaints regarding tardy product deliveries — and received them on such a continuous and growing basis — that we have decided to initiate a non-contest:
If you ordered a product and failed to receive it within a reasonable amount of time (at least a month), please send us the details for publication. We are particulatly interested in such orders where you have "fronted" money — partial or full payment. [...] »
[author : Dave Allen] #TradeAndLaws
Extract : « Neither the software nor the hardware is "a piece of cake" (contrary to Tom’s understanding). Tom is apparently a software man who has done a little work with hardware. I am just the opposite. I see remarkable similarities in hardware and software problems. Given a little time, patience, and tinkering the computer "hobbyist" can indeed concoct some simple hardware, almost like Tom’s "piece of cake". Similarly, with a little forethought, the same hobbyist can write game programs for himself, perhaps even a Tiny Basic (though he would be foolish not to use Tom’s Tiny Basic). Two years ago, after I built my first floppy-disc interface, I wrote a simple D.O.S. (in machine-code no less). I found the hardware and software tasks roughly comparable. Neither was a piece of cake, and both were within the grasp of talented "hobbyists". »
[author : Brent Longtin] #TradeAndLaws
Extract : « Dear Jim,
Bravo for Tom Pittman’s letter on support your local software vendor that appeared in the February issue. The whole issue of software development and support costs is one that deserves a good public airing. One reason why I suspect that it has not received wider attention to date is the dirth of independent software companies that are actively supplying software for the hobbyiest marketplace. Lest there be any confusion, I do not consider one individual working for Amalgamated Behemouth Industries who cranks out software in his weekends and evenings frequently in violation of his employee contract to be an example of an independent software firm. The purpose of this letter therefore is threefold; to provide support for Tom Pittman's position by describing our experience with supplying software for hobbyists, to suggest that a major element of the software problem - support costs - is yet to be recognized and finally to suggest some very positive steps that can be taken to help solve the problem. [...] »
[author : R. Broucke] #Simulation #BASIC
Extract : « The game of life is a solitaire game that consists in watching the evaluation of a population of cells on a checker board or better yet on the screen of a T.V. set connected to your computer. The game was invented in 1970 by Cambridge Mathematician John Conway and popularized by Martin Gardner in Scientific American. The whole game is ruled by three very simple genetic laws that define the survival, death and birth of the cells at each generation. [...] »
[author : R. Broucke] #Encoding
Extract : « Some confusion exists among the small computer users because of the different systems of notations in programming. Not only is there a serious confusion concerning Mnemonics in assembly language programming but also in machine language programming where two systems are in wide usage: octal and hexadecimal. [...]
In the octal system the digits are 0,1,2,3,4,5,6 and 7 while in the hexadecimal system the best known notations represents the 16 digits by the 10 decimal digits, 0 to 9 followed by the first six letters of the alphabet, A, B, C, D, E, F stand for 10, 11, 12, 13, 14 and 15. Both the octal and hexa decimal systems are well suited for microcomputers such as ALTAIR and IMSAI or any computer with a one-byte word (8-bits) and a two-byte address (16 bits). [...] »
[author : Bob Moody & Steve Williams] #Listing #BASIC #Time #Office
Extract : « Over the course of a year owning a computer store, I have come across a tremendous amount of software, some good and some not so good. The question that is asked of me a great deal is - now that I have this computer, what practical use can I put it to. So we at Byte of Palo Alto will be submitting a program a month to try and satisfy the need for useful applications for the home and office. [...] »
[author : R. Broucke] #Listing #BASIC #Graphics
Extract : « Early in 1976, Polymorphic Systems produced the Video Terminal Interface, (VTI), allowing a microcomputer to display the content of a kilobyte of memory on a regular Video Monitor or even on a regular television set. The VTI is a single board which is directly compatible with the 8080- based Altair and Imsai Computers as well as the POLY-8080 marketed by Polymorphics. It contains a read-only-memory character generator IC (MCM6571AL) capable of generating the 7x9 dot matrix of 192 different characters. Among these characters are the regular lower case alphabet, the capitals, the greek alphabet, many special signs such as /, t, <=, => and finally 64 special graphic signs. It is our intention here to describe the usage of these special signs for displaying curves on the T.V. screen. It is not possible with this system to display smooth continuous curves as are seen on an oscilloscope, due to the fact that only finite size square black-and-white blocs are available with the VTI system. Let us thus first say a few words about these questions. [...] »
[author : David Hudson] #Listing #Assembly #Graphics
Extract : « The enclosed subroutine for an M6800 will generate a circle of given center and radius on an x-y display (e.g. scope). It uses two 8-bit D/A’s connected to a PIA. Points on the "circle" are computed by the following algorithm attributed to Marvin Minsky in MIT AI Memo No. 239: [...] »
[author : Bruce Hicks] #Listing #Assembly #Audio
Extract : « [...] I describe here a simple extension of Dompier’s program which makes a computer act like a piano keyboard plus recording device, so that melodies can be played, recorded in the memory and played back. We are finding that this is a valuable educational tool in our bag of educational applications of microcomputers that we discuss with students and teachers.
Since a melody is stored as bytes in memory it is easy also to store on cassette tape. (Note the great compactness of this (primitive) type of audio recording.) It would be possible, using many unused keycodes, to add editing, recording of more than one melody and easier control of rest and note duration. But in view of the many synthesizers and software packages available for music production I do not think it is profitable to extend Dompier’s program much further. [...] »
[author : Bruce R. Kendall] #Listing #Assembly #Programming
[author : Ron Santore] #Listing #Assembly #Programming #Storage
Extract : « For those readers who have processor tech. BASIC and would like to be able to store their BASIC programs on tape. I’ve written the following two subroutines.
Since I do not have a VDM, I used memory locations 0EB0 thru 0EE3 for the TSAV & TLOAD routines. (These locations are normally part of the VDM driver so if you have a VDM, relocate the two routines elsewhere in memory). [...] »
[author : Willi Kushe] #Listing #Assembly #Programming
Extract : « [...] I received all seven issues of your publication at one time, one week ago. Talk about an information explosion! Your Dr. Dobb’s Journal is really dynamite.
Since I now own a KIM, the article on a Breakpoint Routine for the 6502 in the March, 1976 issue caught my eye. As soon as I realized how useful such a routine would be for debugging, I decided to try it out on my KIM. I am enclosing a listing of my version, as I was able to reduce the size of the routine from 224 to 124 bytes. [...] »
[author : Marvin R. Winzenread] #Listing #Assembly #Graphics
Extract : « Here is the program I mentioned last night at the Homebrew meeting. Li-Chen Wang gave me so many good ideas for improvements that it must be considered as a version 1.0.1 am sort of happy with it and would like to keep a little control over it’s dissemination. I plan to copyright TURTLE but will allow your readers to copy it for any non commerical purposes. The copyright will be held by the Educational Micro Computer Company which is my new fictitious name. [...] »
[author : S.C. Baunach] #Electronic #Interface #Listing #Assembly
Extract : « This document describes a working implementation of an IEEE 488 peripheral interface. The hardware and firmware described within are used to interface a peripheral mass storage device (the TEKTRONIX 4924 3M cartridge tape unit) to the IEEE 488 general purpose interface bus (GPIB). This implementation is suitable for medium speed applications (about 5K bytes/second) which contain a Motorola M6800 microprocessor. The design goal was to achieve a reasonable trade-off among transfer speed, cost, and firmware complexity.
Before beginning the description of this particular interface, a brief review of the IEEE 488-1975 standard’s characteristics will be presented. The IEEE 488-1975 standard is also called the ANSI MC1.1-1975 standard, the proposed IEC bus, the ASCII bus, the HP-IB, the GPIB and other names. [...] »
[author : Christopher Terry] #Electronic #Display
[author : R. Lynn Smith] #Electronic #Display