CP/M

CP/M was an early OS for microcomputers. It was ported to several CPUs, the most popular ports were for the 8080 and the Z80.

{{Infobox OS | name = CP/M | creator = Gary Kildall at Digital Research, Inc. | current version = 3.1 | architecture = 8080, [[Zilog Z80], 8086, 68000 }}

CP/M was the inspiration to MS-DOS. It assigns letters for each drive, however it doesn't use directories. CP/M was a portable operating system, that was popularized because it was cheap, and was not resource intesnsive, unlike Unix which had very restrictive licensing. CP/M was also seen as a popular choice of an OS on the S-100 type machines, although not all machines that ran CP/M had S-100 slots (The Commodore 128 would be a good example of such).

Without doubt the 'killer' application that CP/M had was visicalc. Not to mention there was a port of Zork to the CP/M z80 platform.