No abstract

As part of its effort to periodically investigate various new promising concepts and techniques, the Digital Equipment Corporation has sponsored a research project whose purpose it was to effect a limited implementation of a protective operating system framework, based on the kernel/domain architecture which has increasingly been propounded in recent years. The project was carried out in 1972, and its successful completion has led to a substantial number of observations and insights. This paper reports on the more significant ones, specifically: 1) the techniques used in mapping a conceptual model onto commercially available hardware (the PDP-11/45 mini-computer), 2) the domain's memory mapping properties, and their impact on programming language storage-class semantics, 3) this architecture's impact on the apparent simplification of various traditionally-complex operating systems monitor functions, and 4) the promise this architecture holds in terms of increased functional flexibility for future-generation geodesic operating systems.