[author : Gary A. Kildall] #History #OperatingSystem
Extract : « 1973....
I was sitting quietly at my desk when Masatoshi Shima hurried into my office at Intel and asked me to follow him to his laboratory down the hall. In the middle of his work bench, among the typical snaggle of jumpers, oscilloscopes and multimeters, sat a binocular microscope with spider-leg probes, all of which were subjecting a minute piece of silicon to helpless investigation. I peered through the microscope at the enlarged regular patterns with particular interest. As a consultant, my job was to design and develop certain software tools for Intel. One was Interp/80, a program which simulated Intel’s newly evolved 8080 microprocessor to be used by Intel customers on timesharing systems. As I searched for something recognizable, I hoped my simulation resembled the operation of Shima’s first 8080 chip which had finally come to life.
My proposal to Intel had been simple: I would provide them with a language, called PL/M, to replace serious systems programming in assembly language. The compiler would first be written in FORTRAN for operation on timesharing computers and “cross compile” to the eight-bit processors. Next, we would write a PL/M compiler in PL/M and “bootstrap” from the timesharing computer to a resident compiler operating on Intel’s new Intellec-8 development system. The first part was complete. PL/M cross compilers and Interp simulators were implemented for the now-best-forgotten 8008, as well as the 8080. Programs had been written and tested by Intel’s software group, consisting of myself and two other people, and we were ready for the real machine. Things were going well: the resident compiler would be the next step. [...] »
[author : Steve Newberry] #Software #Overview
Extract : « One of the reasons I use and recommend CP/M is that there is a lot of very good software that runs under it. In what follows I will give a necessarily sketchy overview of some packages of which I have knowledge. I make no attempt to be either complete or unbiased. There is only one computer game that I care about, The Greatest Game Of All: PROGRAMMING! Therefore, most of the packages that follow will be found to reflect that outlook. [...] »
[author : Anthony Skjellum] #Listing #Assembly #Programming
Extract : « No facility is provided under CP/M to reexecute a machine language program already residing in the transient program area, nor is there a direct facility for loading binary files (.COM files) into the TPA without executing them except with the use of DDT, the debugging tool. However, both these functions can be performed through the CCP (central command processor) by way of two programming “tricks.” »
[author : Wayne Miller] #Listing #Assembly #Storage
Extract : « I have found that maintaining compatibility with others is ideal for exchanging software; however, I have had problems since I acquired a double density minidisk system. Therefore, I decided to link a cassette interface to CP/M, allowing me to exchange software with others even if they do not have disk. I decided on the Speakeasy by George Morrow because it used the KC300 baud standard. This is very slow; but the chances of losing data from bit drop-out is very unlikely. I accepted the drawbacks of the slow speed since I would only use the cassette to read the program to disk.
I am presenting this program primarily as an example to others to use when writing software to transfer data from a disk to a cassette tape [...] »
[author : Les Hancock] #Listing #C #Programming
Extract : « CP/M users finally have a compiler for the C language. It’s a subset of the C defined at Bell Labs, but a full and proper subset, perfectly adequate for most systems’ work. It was written by Leon Zolman, alias BD Software. Although he introduces the compiler as an “educational tool” in his user’s manual, I know at least one software designer who’s making serious professional use of it already. This article shows how it can be used as an implementation language on the 8080/Z80. [...] »
[author : Hollis Frampton] #Listing #Assembly #Encoding
Extract : « This routine may be administered to alleviate pain. We can’t be the only people who are making the transition from ALS-8 and its various cousins (Software Package # 1, et al.) to CP/M. There’s enough work in interfacing a library to the utilities of a new operating system, without battling the discrepancies between file formats as well. Reasoning that some drudgery is too grim even for system programmers, and faced with the transfer of some hundreds of files to the new system, I wrote CPCON and would like to share it. [...] »
[author : Jim Warner] #Listing #Assembly #OperatingSystem
Extract : « Disk operating systems—CP/M by Digital Research (D.R.) for 8080’s and CDOS by Cromemco for Z80’s —have occasionally been called “virtually identical” (DDJ # 35). Cromemco’s Users Bulletin (Dec. 1978) makes more specific claims:
“...CDOS was designed to be upwards CP/M-compatible... This means that most programs written for CP/M (versions upto [sic] and including 1.33) will run without modification under CDOS. This also means that programs written for CDOS will not generally run under CP/M.” [...] »
[author : Mark M. Zeiger] #Listing #Assembly #Encoding
Extract : « Many computer hobbyists who started a few years ago with relatively simple equipment probably used assemblers such as Processor Tech’s SPI or ALS-8. Now they have ‘graduated’ to more sophisticated operating systems, CP/M being the most prevalent. Think of all those great source programs still on your cassettes that you would love to rewrite to use with CP/M. However, who has the time to do all that retyping? Computer to the rescue! The following program will change source programs written by the SPI executive (as well as programs written by ALS-8, XEK, and the PDS assemblers to name a few) to text acceptable to CP/M assemblers and editors [...] »
[author : Rod Hallen] #Listing #Assembly #Encoding
Extract : « In March I wrote to thank you for your Electric Pencil to CPM routine (DDJ #33). I have found this to be one of my most used programs. Thanks Again.
Recently I acquired Digital Research’s “MAC” macro assembler and was looking for a project to use it on. That’s how I learn the ins and outs of any software that I add to my library. I decided to see if I could simplify and speed up your program. The enclosed PRN listings are the result.
The limited length of PEN-CPM and CPM-PEN are due to the macro routines which handle all disk I/O. Have you tried “MAC”? If not, it is well worth the price. Both of these programs were written in less than 3 hours time; an easy afternoon’s work [...] »
[author : Charles Wetherell] #Book #Programming
Extract : « This month I would like to laud a singularly courageous act by a friend of mine. George Ledin, Jr. and his brother Victor have just published A Programmer’s Book of Rules (Lifelong Learning Publications, 1979. $7.95). Before I tell you why I think George is so brave, let me describe the book. Then we shall anoint the hero. [...] »