50 years ago, CP/M started the microcomputer revolution

CP/M is turning 50 this year.

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.

Liam Proven

I'm a little too young to have experienced CP/M as anything other than a retro platform - I'm from 1984, and we got our first computer in 1990 or so - but its importance and influence cannot be overstated. Many of the conventions set by CP/M made their way to the various DOS variants, and in turn, we still see some of those conventions in Windows today. Had Digital Research, the company CP/M creator Gary Kildall set up to sell CP/M, accepted the deal with IBM to make CP/M the default operating system for the then newly-created IBM PC, we'd be living in a very different world today.

Digital Research would also create several other popular and/or influential software products beyond CP/M, such as DR DOS and GEM, as well as various other DOS variants and CP/M versions with DOS compatibility. It would eventually be acquired by Novell, where it faded into obscurity.