A new five-digit plugboard system for card-programmed calculator

THE International Business Machines Corporation´s card-programmed calculator (CPC) is one of the most extensively used automatic digital computers in the world today and has been discussed in several technical articles.1¿4 Scientific calculations, engineering problems, and accounting procedures have all been applied to the CPC with success. This flexibility may be attributed to the fact that all of the computer elements of the CPC are wired to plugable terminals on removable plugboards as shown in Fig. 1. Thus, by changing wires on the plugboard, the internal design of the CPC may be altered and optimized for a particular application. The purpose of this paper is to present the features of a new CPC plugboard system developed by the Power Transformer Engineering Section of the General Electric Company primarily for engineering design calculations. This system may be used for any calculations where slide-rule accuracy is adequate.