If many people today know of CP/M at all, they think of it as the predecessor to DOS. CP/M was developed on Intel’s 8008 emulator under DEC’s TOPS-10 operating system, so naturally many parts of CP/M were inspired by it, including the eight character filenames with a three-character extension that every early Windows user was familiar with.
The CP/M operating system has its roots in the very genesis of microcomputing. Gary Kildall was a software consultant for Intel in the early 1970’s. They were one of the first manufacturers of integrated circuits, and the inventor of the first “microcomputer on a chip,” the 8088. Kildall’s everyday job was as a computer science professor at the Naval Postgraduate School in Monterey, CA. His two jobs put him in a unique position to observe and tinker with the fledgling microcomputer industry. Gary began collecting the pieces, that by 1973, formed a home grown microcomputer system. The main processor (the brains of the computer) and its memory were integrated circuits from Intel; the disk drive was a recycled computing drive from Shugart; the input and output console consisted of a Teletype device.
Needing something to tie all these components together into something that could be used, Kildall wrote a simple “operating system” in his then-favorite language, PL/M. The result he called Control Program/Monitor, or CP/M for short. CP/M, then, is a set of software that controls the basic components of the computer–an operating system.
