50 years ago, CP/M started the microcomputer revolution

Late in the summer of 1974, CP/M first started running on hardware. It became one of the first cross-platform microcomputer OSes, and revolutionized the hardware and software industries.

The ancient Control Program for Microcomputers, or CP/M for short, has been enjoying a modest renaissance in recent years. By 21st century standards, it’s unimaginably tiny and simple. The whole OS fits into under 200 kB, and the resident bit of the kernel is only about 3 kB. Today, in the era of end-user OSes in the tens-of-gigabytes size range, this exerts a fascination to a certain kind of hobbyist. Back when it was new, though, this wasn’t minimalist – it was all that early hardware could support.

The late great Dr Gary Kildall developed CP/M in his spare time from teaching at the Naval Postgraduate School in Monterey, California. On the side, he was moonlighting for a small five-year-old tech startup called Intel, which was working on its second microprocessor, the eight-bit 8008. First, Kildall wrote a small programming language for the 8008, which he called PL/M (Programming Language for Microprocessors) in playful reference to IBM’s PL/I. Lacking working 8008 hardware yet, he prototyped this on a DEC PDP-10.

Check out the complete history in the article here.

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Filed under: history, Operating System, software, vintage computing —
Tags: , — by Anne Barela

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