Unger, Brian WBidulock, D.S.2008-02-272008-02-271978-02-01http://hdl.handle.net/1880/46041This paper describes the design of a modular operating system for a network message processor. The basic requirements of the message processor are defined by the University of Calgary's Distributed Communication System (DCS), which is a general purpose network connecting a variety of interactive terminals, two host computers, and a trans-Canada network (DATPAC). Starting with these requirements, the operating system is decomposed into a small set of easily understood components whose interactions are both restricted and simple. A brief outline is then presented of the implementation of these components in Oasis, an extension of Simula 67 which was designed for implementing and simulating system software. Finally, it is conjectured that: (1) A new, more flexible, reliable system can be easily developed from this Oasis version, and (2) the effort required to implement and test both the Oasis simulated version and the actual system will be much less than that required for the original operating system development.EngComputer Scienceunknown1978-22-110.11575/PRISM/31071