AN OPERATING SYSTEM FOR A SMALL COMPUTER

Abstract

Part I is a general description of a simple operating system, which runs in a virtual machine (implemented on a real machine by an interpreter). 0S6 copes with only one user at a time, and is not a multiprogramming system; many major problems associated with large operating systems have therefore been avoided or considerably simplified. It nevertheless has several features of interest, including the fact that it is written almost entirely in the high-level language BCPL. The most important single feature, however, is the hierarchical nature of its control structure, which avoids the need for a special job-control language. Part II covers the facilities for input/output, and the handling of files on the disc. The input/output system uses a very general form of stream; the filing system is designed to have a clear and logical structure.