#Magazine #Review
Extract : « With this issue, we are initiating what we expect to be a regular feature in Dr. Dobb’s Journal: reports of independent product and software tests and evaluations. We propose that these will be "independent" in that we have no financial ties or obligations to these manufacturers, the producers of these products. We carry no paid advertising.
Ever since the computer hobby began, there have been regular pleas for such independent testing and evaluation. Until recently, we have been rather haphazard in our attempts to assist consumers in judging the quality of products being marketed to them. We have pursued this primarily through the publication of complimentary and complaining letters regarding products. With such letters, we generally have no knowledge of the expertise, fairness, honesty or bias of the writers (thus, they have been published as "letters" rather than as "articles"). Recognition of this fact prompted us to adopt a policy [see Editorial in October, 1976, DDJ] regarding the treatment of letters of complaint. Though we will continue to publish such letters within the constraints of that policy [see several examples in this issue], we feel that a formal, orderly product testing and evaluation program would be more fair and more useful to our readers. It will also be perfectly in keeping with the Charter of our publisher, People's Computer Company. PCC is a California-licensed, non-profit educational corporation. [...] »
[author : Stuart Fallgatler & DDJ]
[author : Board of Directors SCCS Interface] #OtherMagazine
Extract : « Good news! Your regular SCCS Interface will be coming again to you soon! This is to bring you further up to date on the Southern California Computer Society publication. [...]
You may have received copies of Interface Age in the mail. The Society did not mail it to its members. The logotype on Interface Age and the format of the magazine are very similar to SCCS Interface and you may not have even noticed the change. Interface Age is not an authorized publication of the Society. [...] »
#TradeAndLaws
Extract : « Before you do, consider the following financial figures. These were generated in September, 1976, by an independent ream of professional cost analysis consultants. They are projected or "reasonable expectation" figures for two classes of computer stores; a $20K/month store and a $30K/month store (gross). They are based on a number of in-person and in-depth telephone interviews with a large number of existing computer stores. [...] »
[author : Jim McCord] #Computer
Extract : « Dear Bob and Jim,
To follow up my conversation with Bob of a couple of weeks ago, this is to tell you about the LSI-11 stuff.
At last count there were about 15 people in the S. Calif, area who were using the LSI-11. I understand that there are about an equal number in the Bay Area. Other than those two groups I know of no other "large" bodies of hobbyists using the machine, although there are undoubtably isolated people around the country who bought them from various distributors. Perhaps an announcement in PCC or Dr. Dobb’s will help pull us together. [...] »
[author : Donald E. Tarbell] #Interface #Storage
Extract : « Dear Jim,
Thank you for giving me the opportunity to reply to the notes about my cassette interface in your Volume 1, Number 8 issue.
I believe that no product is ever perfect, so I continually revise both the documentation and the interface itself. Since I started delivering these units over a year ago, I have gone through four revisions of the boards, and at least six revisions of the manual. These changes were largely the result of complaints, suggestions, and returned survey forms, which are at the end of each manual. The first ten kits especially, were followed very closely, and the owners were asked to immediately inform me of any problems they had with either the manual or the board. In this sense, the kits were "tested on persons unfamiliar with the device." [...] »
[author : Glenn S. Tenney, ] #ComputerKit #Microprocessor
Extract : « Dear Jim,
I have just entered a real-life description of "compatibility". While trying to figure out why a simple three instruction program would not work as documented in the Intel 8080A manual being executed on my IMSAI 8080,1 discovered that the flag bits (as stored in memory via PUSH PSW) were not as Intel describes.
For openers, bit-5 and bit-3 are supposed to be '0'. On my IMSAI 8080 bit-3 was always '1', and bit-5 fluctuated with, as yet, no pattern sometimes being '0' and other times being '1'. At this time I played around a bit and found that the XRA A instruction did not work as documented. At this point, I contacted IMSAI. [...] »
[author : Jef Raskin] #Review #ComputerKit
PLUS NOTES ON SOME S-100 "GOTCHAS" — CATCH 16 HEX [...]
Extract : « In our last "Gotcha" a few manufacturers were taken to task, and fewer still were praised for the quality of their products and documentation. This time we take a brief look at the familiar Altair and IMSAI chassis, and a long look at the very interesting Poly 88. [...]
The Poly 88’s almost S-l00 bus (hobbyist bus, Altair bus, I could care less) has the best switches of all: there aren’t any. Polymorphic Systems, in Goleta (rhymes with "Lolita") California makes this very unassuming little box that does a lot of things right, which the bigger names (with bigger boxes and price tags) are doing wrong. Not that Poly is perfect. My corrections to their manuals were extensive and numerous. [...] »
[author : Editor, DDJ] #Graphics #SoftwareDistribution
Extract : « [...] The basic idea is that programs and data that are of widespread interest can be encoded in a standard bar-code format, printed in a book or magazine (presumably with the human readable form on nearby pages), and loaded into an individual’s home computer by simply waving an optical scanning wand over the machine-readable pages. Programs and data could then be truly "published" — printing them instead of using the far more expensive and less convenient punched or recorded formats. The reading mechanism — the scanning wand — has the advantage of no mechanical parts, depending on the human hand for its motive power. It’s simple; it’s nonmechanical; it should be cheap. Data transfer rates are obviously limited only by the speed of the hand and the speed of the processor that is interpreting the input from the scanner. [...] »
[author : Jim Warren] #Interface #Storage
Extract : « Steve Moore* just phoned in a hot idea. Why not use a data communications modem or acoustic coupler to read from and write to audio cassettes?
Here are the advantages: By doing so, suddenly all of the "recording standards" problems disappear. The standards for couplers and modems have been accepted and in use for some years — and are well debugged. Why waste our time haggling over which homegrown standard to adopt, when we can "steal" the standards that have been proven in industrial use for well over a decade? [...] »
[author : Bob Van Valzah] #BASIC #APL
A Homebrewed Language & Interpreter from Chicago - Complete Documentation & Code
Extract : « Dear Jim,
Here is my entry in the hobby software field. It’s a tiny language called CASUAL. That’s the Chicago Area Small Users Algorthmic Language. Here are the design goals used:
• Must run on any 8080 system with a terminal and 2K of RAM starting at 000 000.
• Complete machine control is possible — inputting from and outputing I/O ports, memory READ and WRITE (PEEK and POKE), machine language CALL.
• 16 bit everything — line numbers, expression values.
• Arrays
• String I/O
• One tape works on any system — POKE’S itself for most popular I/O boards (like MITS BASIC).
• Deletion of unwanted features at initialization time. [...]
»
[author : Mark Alexander] #BASIC #Listing #Assembly
Complete Documentation & Fully Annotated Code Listings
Extract : « NIBL (National Industrial Basic Language) is a machine- oriented programming language for the SC/MP. It is a language similar to Tiny BASIC, but it also has some unique features. Many of these features, such as a genuinely useful control structure (the PASCAL-influenced DO/UNTIL) and the indirect operator (“@”) have been added to the language to allow NIBL to be nearly as flexible as machine language in such applications as medium-speed process control.
By using NIBL, one trades the high execution speed and low memory consumption of machine language for some very tangible advantages: Program readability, modifiability, and reliability, which are truly difficult to achieve in machine language programs.
NIBL programs are interpreted by a large (4K byte) SC/MP program that resides in ROM. The interpreter is broken into two blocks: a program written in an Intermediate (or Interpretive) Language — I.L. for short — which does the actual interpretation; and a collection of SC/MP machine language subroutines invoked by the I.L. program. The I.L. approach is well-documented in Vol. 1, No. 1 of Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, and readers should refer to that issue for a more detailed description of the interpretation process. [...] »
[author : Digital Research] #OperatingSystem
Extract : « CP/M is a disk operating system designed for diskette-based computer systems which use the Intel 8080 microcomputer. The CP/M software package is now being offered to the small computer user community.
Previously available only to OEM’s, CP/M has been in existence for over two years in various manufacturers’ products, and thus has had extensive field testing. CP/M functions include file management, with console interaction, batch processing, and program loading facilities. The overall operation of CP/M closely resembles the standard features of the DEC System-10. [...] »
[author : Jim Abshire] #Listing #BASIC #Mathematics
[author : Martin Buchanan, Greg Townsend] #BASIC
Extract : « Dear DDJ,
Enclosed are about a dozen changes in TINY HI, an updated language summary, and a brief description of HI. None of the changes significantly effect the scope of TINY, but I believe they make it an even nicer language. I am shelving TINY LISP, TINY SNOBOL, and the extensible language I mentioned; my system is up and I want to implement TINY. I renege on the promise to describe FORTH as Interface has had a good article on it. [...] »
[author : Dennis Sutherland, et al.] #Electronic
[author : Marvin Winzenread] #Game #Simulation #Listing #Assembly
CHASE: A One or Two Player Video Game
LIFE on an 8080 with a VDM
Extract : « Try to catch the bouncing dot or convert the program to a two person chase game. It requires 256 bytes of memory and a Processor Technology VDM or similar video display. [...]
The game of life seems to be a natural for the VDM. So much has been written about it.
Here is a short version that requires toggling only 116 bytes. An earlier version (PCC, Vol. 4 No. 2) required 218 bytes. This program does however RAM equal to the VDM memory to store the next generation. If you are really strapped for memory, use half of the VDM for each generation. [...] »
#SoftwareDistribution
Extract : « The CCC Program Repository currently furnishes programs on roll paper tape; not on fan-fold, as was previously announced.
The Community Computer Center (CCC) will act as a repository for program tapes; both source tapes and binary tapes. Everyone wishing to contribute programs to the public domain may do so by forwarding appropriate paper tapes to CCC. In particular, if you are hesitant about submitting a program for publication in Dr. Dobb's Journal because you don't want to hassle with its distribution, you are encouraged to forward the tapes to CCC and the documentation to the Journal for publication. [...] »