Time-shared hybrid computers: A new concept in computer-aided design

A hybrid computer system with electronic patching at the University of Michigan Simulation Center is described. The system allows automatic digital setup of problems on the analog subsystem within 20 ms. This fast turnaround permits time sharing of the hybrid computer using remote terminals. In addition to generating high-speed solutions to non-linear differential equations, the hybrid system also generates alphanumeric and graphic displays for use at each terminal. A high-level compiler using simulation-language statements to program automatically the analog subsystem is decribed, along with an example problem. The authors feel that this time-shared hybrid system, which provides two to three orders of magnitude speed advantage in access time and solution time when compared with digital terminal systems, offers a new dimension to computer-aided design of dynamic systems.