A communication facility for interoperation among personal computers and mainframe hosts
Brian Keith Wade · 1987
The ever-increasing number of personal computers and the sizeable investment in mainframe computing power make studies of cooperation among personal computers and mainframes, or interoperation, both interesting and valuable. Studies in interoperation may proceed by either exploring the kinds of services the two machines may share with one another, or by concentrating on the connection mechanism--the communication facility--used to connect them. Studies in the former area, shared services, have been proceeding for some time, and market offerings reflect the fruits of those studies. In the latter area, though, it has usually been assumed that the PC connects to the host as a terminal. This study centers on the communication facility used to connect the PC to the mainframe. The most popular access method, terminal connection, is reviewed. Its weaknesses, particularly reliance upon the existence of a host session, are explored and analyzed. A new facility, one which overcomes the weaknesses of the current method, is presented. Its implementation, particularly on the PC side, is examined in detail. Factors affecting its performance are explored. The new facility is also compared to and contrasted with other networking schemes. Finally, the new system allows PC-host interoperation modes not possible with the terminal connection approach. An interoperation application which takes advantage of one such mode is presented and discussed.