Case Study in Interactive Computer Graphics. Computer-Aided Design of Logical Circuits

摘要

A software package was written for a computer-aided design of logical circuits. Using a graphic terminal and a light-pen, the user may build a logical circuit choosing the components from a set offered to him, and connecting them to each other. During this highly interactive process, all the user's mistakes may be corrected. The software system organizes the data from the picture in a data structure specifically designed to allow easy manipulation of the picture on one hand, and for a subsequent simulation of the circuit on the other hand. The first part (creation of the circuit) makes use of a PDP-9 computer with 8K of core, a GRAPHIC-2 terminal and a 250 K disk. The second part (simulation) is done by the LOGICS program on a GE-635 Time-Sharing to which the PDP-9 is connected by a high-speed line. The user has a choice between 10 to 12 different components. Practically, the circuit may have approximately 30 to 40 components. (Author)