Primos Internal Structure for the Prime Computer

3 day Course Notes

Prime Computer, Inc. was a Natick, Massachusetts-based producer of minicomputers from 1972 until 1992. The alternative spellings "PR1ME" and "PR1ME Computer" were used as brand names or logos by the company.

The first Prime system, similar to the DDP 516 but 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).

The name PRIMOS was now used for the operating system and the P400 ran PRIMOS 4. It ran a V-mode instruction set, along with the S-mode and R-mode instructions. It had a segmented virtual memory architecture, somewhat similar to Multics.

The company operating system, PRIMOS was originally written mostly in the Fortran IV programming language with some assembler. Subsequently the PL/P and Modula-2 languages were used in the Kernel. A number of new PRIMOS utilities were written in SP/L which was similar to PL/P.

We are extremely grateful to both Dawn and Kim Wakefield for the kind donation of the collection of their late father Richard Wakefield.

A PDF scan of this document is available. 

Reference Number :

Date Published : 1972

Manufacturer : Primos

Platform : Primos

Format : Paper Booklet: 100 Pages