Picture systems, PS, and the design of a channel-to-channel computer interface

摘要

This paper introduces a new simulation tool called picture systems. A picture system is (1) a set of pictures - one representing each state of a modeled computer system and (2) a transition graph which relates each picture to the set of pictures that may follow it. Picture systems can be used to model computer systems at any level of detail; however, this paper is concerned with modeling hardware/software systems at relatively high architectural levels. Picture systems, as a simulation tool, are useful to the computer architect. Perhaps more importantly, they provide an unexcelled means of communicating computer system mechanisms between people.The construction of picture systems from descriptions of the components of a computer system has been automated in PS. This paper describes a model of a channel-to-channel computer interface mechanism consisting of both hardware and software. Transition graph analysis by PS is briefly described. This powerful aid to computer system modeling eases the identification of problems such as deadlock, looping, and races.