The First PC Operating System

In 1974, Dr. Gary A. Kildall, while working for Intel Corporation, created CP/M as the first operating system for the new microprocessor. By 1977, CP/M had become the most popular operating system (OS) in the fledgling microcomputer (PC) industry. The largest Digital Research licensee of CP/M was a small company which had started life as Traf-0-Data, and is now known as Microsoft. In 1981, Microsoft paid Seattle Software Works for an unauthorized clone of CP/M, and Microsoft licensed this clone to IBM which marketed it as PC-DOS on the first IBM PC in 1981, and Microsoft marketed it to all other PC OEMs as MS-DOS.


This paper describes the first operating system was designed for the first internally programmed electronic digital computer: the EDVAC. This operating system was developed during 1952 and was implemented early in 1953. Devised for one of the earliest electronic digital computers, its capacities were modest compared to later standards, yet some of its features are recognizable in later operating systems. It was planned carefully, and it was comprehensive and useful in the context of its time.