Design of an All-Magnetic Computing System: Part I-Circuit Design

This paper describes the circuits used in a decimal arithmetic unit which utilizes ferrite magnetic elements and copper conductors only. The arithmetic operations of addition, subtraction, and multiplication are performed with a product and sum capacity of three decimal digits. The sole logical building block of this system is a two-input inclusive-OR module with a fan-out capability of three with any desired logical positive and negative combination. The system involves the use of some 325 modules, each of which contains two magnetic multiaperture devices (MAD\´s). This paper gives a complete description of the circuit and physical arrangement of the machine. The system is controlled from a manual keyboard, and readout from the machine is via incandescent lamps controlled directly from the MAD elements, no intermediate elements being required. The "worst case" drive-pulse amplitude range for the completed machine, varying all clock pulses simultaneously, is ± 10 per cent.