A virtual terminal protocol based upon the “communication variable” concept

Abstract The ideas presented here have emerged from discussions within the PIX working groups “Higher level protocols” and “Virtual Terminal protocol” and present the agreement of the PIX virtual terminal protocol. PIX = A cooperation between several network activities in the technical/scientific area in the FRG, sponsored by the Ministry of Research and Technology. The proposal is based on a general model of interprocess communication and describes how this model is used to fit the requirements of terminal control. The resulting class of terminal protocols uses one simple command set whereas the protocol for one specific terminal is derived by defining the appropriate data structure for that terminal. The complexity of a given terminal protocol therefore solely depends upon the complexity of its data structure. As an example, a protocol definition for a simple “line” and “page” mode terminal is given.