SIMCON: an advancement in the simulation of physical systems

Abstract

The simulation of physical systems, once exclusively the domain of analog computers, is also being performed today by a variety of large-scale digital systems. Many specialized programs have been developed to permit the study of electronic circuits, biological organisms, and chemical processes, etc., by mathematical and empirical modeling techniques. So often these programs are written in procedural computer languages and may require months of developmental investment (and debugging) to yield a handful of computer-produced results. In addition, if simulation parameters are not well known, it may take hundreds of test runs to produce a simulation model that realistically portrays the actual processes involved. When the digital computer utilized to perform the simulation is operated in a batch-processing environment, such determination of model fidelity may take weeks because of the time lag from submission of test data to receipt of program results. Smaller computer systems may permit almost instantaneous turnaround and even on-line interaction, but too often do not have sufficient memory size, precision, or speed to be of much use in complicated digital simulations. The SIMCON simulation system is an integrated hardware/software system developed for the purpose of overcoming the difficulties of applying large-scale digital computers to the simulation of physical systems. The SIMCON system, which is used in conjunction with the IBM 360/91 computer, consists of the DSL/91 programming language, the SIMCON control console, a hybrid data interface, and a number of analog graphical peripherals. The SIMCON simulation system shown in Figure 1 includes the SIMCON console, incremental recorder and duel-channel X-Y plotter. The discussion of the SIMCON system presented herein includes the results from several hybrid satellite study programs, as examples of its application.