Modeling the Video Graphics System: Procedure and Model Description.

This report presents both the process and results of generating a computer system description for simulation purposes while both hardware and software are under development. The interactive multiterminal Video Graphic System achieves low cost by using as terminals modified television sets whose pictures are continuously refreshed from a video disk by three scan converters driven by a single digital-to-analog converter. An IBM 1800 process controller receives graphic orders from user programs in the connected service machines (IBM 360s) and sends them to the converter; it also handles input from terminals. The documentation history details the activities and elapsed time of each phase of the 57-week effort; it can serve as an aid in estimating the investment required for such an undertaking, and the conclusions can help simulators to document and model more effectively. 92 pp. Ref.