A multiprogramming operating system for a minicomputer

Abstract

Described in this paper is a small, modular operating system which was written for an Interdata-70 machine. The total operating system is memory resident and occupies 5K bytes. The primary motivation in redesigning the operating system was to structure it so that students and general system users could easily expand or modify the basic services of the supervising system. Towards this end, the following system principles are embodied in the design: (1) clearly defined separation of system functions, (2) separate object modules for each system routine, and (3) simple system design. Although specifics of implementation are discussed, general design concepts are covered which should aid the reader in any similar attempt (either by example or counter example).