Late in the summer of 1974, CP/M began running on hardware. It became one of the first cross-platform microcomputer operating systems and revolutionized the hardware and software industries.
First microcomputer OS: CP/M – Computerphile
You can now legally run the raw unbridled power of CP/M 2.2 anywhere – click to enlarge
The ancient microcomputer control program, or CP/M for short, has enjoyed a modest renaissance in recent years. By 21st century standards, it is unbelievably small and simple. The entire operating system fits into less than 200 KB, and the native chunk of the kernel is only about 3 KB. Today, in an age of end-user operating systems in the tens of gigabytes range, this fascinates a certain type of hobbyist. When new, however, 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 moonlighted 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.
