The Rise and Fall of CP/M

Before DOS established dominance, Gary Kildall's operating system offered a glimpse into a very different computing future — one the industry came remarkably close to choosing.

In the late 1970s, CP/M was the closest thing the microcomputer world had to a standard operating system. Written by Gary Kildall at Digital Research, it ran on the dominant Intel 8080 and Zilog Z80 processors and gave software a consistent place to live.

Its command interface will look familiar to anyone who later used DOS — which is rather the point:

A>DIR
WORDSTAR COM
MAILMRGE OVR
A>TYPE README.TXT

The story of how IBM ended up shipping a different operating system on its PC has been told many times, often unfairly. What matters for preservation is that CP/M's conventions outlived the product itself, shaping decades of software that followed.

"The interfaces we take for granted were once radical decisions made by a handful of people."

Preserving CP/M means keeping its disks readable and its context legible — work that continues in the Foundation's exhibits and the recovery lab.