GB927083A - Improvements relating to binary magnetic stores - Google Patents

Abstract

927,083. Circuits employing bi-stable magnetic elements. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. April 5, 1960 [April 20, 1959], No. 13428/59. Class 40 (9). Each storage unit at the intersection of row and column conductors R/W, C in a magnetic storage matrix comprises a pair of cores L, O allocated respectively to binary one and binary zero registration, a read-out pulse over conductor C from a drive core causing either L or O to reset according to the digit registered and induce an output pulse of one or other direction in conductor R/W which passes over a transformer T to a transistor blocking oscillator BO. At the same time a " cancel " pulse is applied to a transformer tertiary winding or directly to the oscillator which augments a binary one output pulse and effectively cancels a binary zero. The blocking oscillator operates as described in Specification 903,094 and at the end of the output pulse causes a full-amplitude write pulse to be transmitted over conductor R/W to the storage unit. If a binary one registration was previously read, the write pulse causes core L to be set, to re-register the digit, by acting on the pair of cores in combination with halfamplitude write pulses applied coincidentally to a re-write conductor W and conductor C. On the other hand if a binary zero was read, no write pulse is transmitted over R/W and the halfamplitude write pulses in W and C cause the setting of core O. In a modification the rewrite conductor W is omitted, and the write pulses are applied to the transformer tertiary winding so as to induce a half-amplitude current in R/W in the direction opposing binary one write current from the oscillator. Separate magnetic cores may be used, or alternatively a multi-apertured ferrite block.