A SIMPL distributed operating system and its formal definition

Abstract

In recent years there has been a phenomenal growth of interest in networks of computers sharing both data and programs. For example, Cmdr. Grace Hopper has advocated a hierarchical network of minicomputers to perform the data processing function in which the tasks to be done would be distributed over the network, with only summary or extract information being passed from one level to another. While the hardware exists to build such a network, the software mechanisms to effectively (from both a time and cost viewpoint) control such a network have not yet been developed. At the Computer Science Center of the University of Maryland a distributed operating system, which is independent of the specific number and hardware of the particular computers it is running on, is being developed and implemented. Supporting this project is the development of two linguistic tools: the design and implementation of a systems programming language called SIMPL and the use of formal semantics in the specification of both SIMPL and the distributed operating system. So far, each of these three elements has had a considerable effect on the others.