Prime Computer, Inc. was a Natick, Massachusetts-based producer of minicomputers from 1972 until 1992. With the advent of PCs and the decline of the minicomputer industry, Prime was forced out of the market in the early 1990s, and by the end of 2010 the trademarks for both PRIME and PRIMOS no longer existed The alternative spellings "PR1ME" and "PR1MOS" were used as brand names or logos by the company. Founders The company was started by seven founders, some of whom worked on the Multics project at MIT. Robert Baron (President) Sidney Halligan (VP Sales) James Campbell (Director of Marketing) Joseph Cashen (VP Hardware Engineering) Robert Berkowitz (VP Manufacturing) William Poduska (VP Software Engineering) John Carter (Director of Human Resources) The company started with the motto "Software First". Poduska left in 1981, to start Apollo Computer. His successor was 27-year IBM executive Joe M. Henson, although Prime's president, Kenneth G. Fisher, had briefly been the interim top executive. Minicomputer products The initial offerings by Prime were clones of Honeywell's DDP 316 and 516 minicomputers. Their main competitors were Digital Equipment Corporation, Data General and Hewlett-Packard. 1972: Prime 200 The first Prime system was similar to the 16-bit DDP 516, but was a 32-bit machine with paging. It ran an operating system called DOS, also referred to as PRIMOS 2 (not to be confused with MS-DOS, PC DOS, etc.). 1973: Prime 100 The Prime 100 was a stripped down version of the Prime 200 (no memory parity or floating point). 1974: Prime 300 The Prime 300 had a main store of 32 KB to 512 KB and from 6 MB of Pertec disc storage. It ran DOSVM operating system, also referred to as PRIMOS 3, but still used earlier DOS for booting. One of the first minicomputers with microcode-supported virtual memory capability. The virtual memory was simpler than used in later systems. Addresses were 16 bits, with each of up to 32 time-sharing (time slice) users, receiving a virtual 64 K-word address space. It had S-mode and R-mode instructions. An example of the Prime 300 was installed in the mathematics department of the University of Aston in Birmingham, UK and at the Medical University of Hannover, Germany. 1976: Prime 400 The Prime 400 ran at 0.5 MIPS, had a main store of up to 8 MB and 160 MB of disc storage. The name PRIMOS was now used for the operating system,