CP/M

CP/M (Control Program for Microcomputers^[3]) was an Operating System for computers used in the 1970s and early 1980. Originally, it supported up to 64 kb of main memory. It was command-line based, and came before MS-DOS.

CP/M

A screenshot of CP/M-80.
Developer	Digital Research, Inc. / Gary Kildall
Written in	PL/M
Working state	Historic
Source model	Originally closed source, now open source[1]
Latest release	3.1 / 1983[2]
Platforms	Intel 8080, Intel 8085, Zilog Z80, Intel 8086, Motorola 68000
Kernel type	Monolithic kernel
Default user interface	Command line interface
License	Originally proprietary, now BSD-like
Official website	Digital Research official CP/M page