CP/M

CP/M stands for Control Program for Microcomputers, and is an operating system written by Gary Kildall. He later founded the firm Digital Research, which also made the graphical user interface GEM. The original CP/M was for computers with 8080 and Z80 CPUs and was the first more or less portable operating system. Software written for a particular CPU version of CP/M should therefore work on any other CP/M machine with the same CPU. There also was CP/M-68K for 68000 CPUs, and probably one for 8086. The BBC B even had an expansion ability ot add a Z80 processor running CP/M.

IBM wanted to have CP/M for their PC, but DR didn't want to sign a non-disclosure agreement. As IBM also wanted to have the programming languages from Microsoft, Bill Gates was afraid that the deal wouldn't work if IBM didn't get a CP/M OS. So Microsoft bought a CP/M compatible operating system called QDOS from a small firm in Seattle for only $50,000. This became PC-DOS and later MS-DOS. Later on, when Digital Research went out of business, Caldera bought all rights for CP/M and the source for CP/M is now freely available.

CPM

Having owned a PC1715, a very popular CP/M computer in Germany, Peter Teichman started developing an ARM coded emulator for it. As can happen to us all, Peter ran out of time to develop his emulator and left it unfinished. Partially unfinished at least, for the Z80 CPU is entirely emulated, except for the interrupt handling and a few other bits and pieces which aren't needed for CP/M emulation. Unfortunately neither is their any disk handling. This may seem like a bit of a big problem, but Turbo Pascal, and a BASIC interpreter don't need disk access and therefore seem to run ok. Although it is unfinished, Peter will supply the source code to anyone who's interested.

Speed Rating: ARM 250 ARM 3 ARM 6 ARM 7 StrongARM

Peter's Acorn page

CP/M source
CP/M FAQ