The design of the control unit of an electronic digital computer

The function of the control unit of an electronic digital computer is to provide the sequences of pulses, which, when applied to the store, arithmetic unit and other units of the machine, cause the orders of the programme to be executed. The paper discusses a number of related ways in which a systematic and flexible design for a control unit may be achieved. In one group of systems the order code is determined by the arrangement of diodes in a diode matrix, and in another by the appropriate threading of wires through a matrix of ferrite cores. The first part of the paper is concerned with logical design, and the second part with the practical design of a system using a ferrite matrix.