Background of the SPEEDOS Operating System Design

Keedy's approach to computer science was strongly influenced by his early experiences as a member of the design team of ICL's VME-B operating system, a system which was designed in the late 1960s and early 1970s (see as the main operating system for the British ICL2900 computer series ( The leader of the OS design team was Brian Warboys (, who later became Professor of Software Engineering at the University of Manchester and whose influence Keedy gratefully acknowledges. Despite the fact that it was designed using an interesting computer aided software engineering system (CADES, see and was written in a high level language (S3, which was strongly influenced by Algol 68), the VME-B system unfortunately suffered from many of the problems which had previously beset other huge mainframe operating systems developed by large teams of programmers.

One of the key things which Keedy learned from his ICL experience was that it is important for the hardware and the software to be well-balanced, which often means that they should be designed together, if these are to work in harmony. Furthermore operating systems must be designed with the requirements for future applications software firmly in mind, i.e. it is important to provide mechanisms which simplify the software engineering process not only for the operating system itself, but also for applications which later run under its control.