Patent GB-899172-A (GB)
Title: Improvements in or relating to intelligence storage equipment
Inventor: RIDLER DESMOND SYDNEY
IPC: G11C11/08
Filed: 1958-09-15
Abstract: 899,172. Magnetic storage devices. STANDARD TELEPHONES & CABLES Ltd. Sept. 11, 1959 [Sept. 15, 1958], No. 29453/58. Class 38 (2). [Also in Group XXXIX] A binary digit is stored in a magnetic core having three holes and formed of material, e.g. ferrite, with a rectangular hysteresis characteristic, the material encircling one or two of the holes being used for information storage while the remainder of the holes are threaded with a read-out wire and are provided for read-out purposes, non-destructive detection of the stored information being effected by a pulse in the read-out wire which induces a pulse of one polarity in an output wire threaded through the storage holes at its commencement and induces a second pulse at its termination, the order of the pulses (positive-negative or negativepositive) being indicative of the digit stored. In one arrangement, Fig. 1, holes 1 and 3 constitute storage cells and are threaded by row and column wires RW, CW to which half select pulses are simultaneously applied so as to establish a binary one or zero registration as shown by full and broken arrows respectively. In both cases fluxes are established in the same sense on either side of a reading cell comprising a hole 2 threaded by a reading wire CW. A reading pulse of either polarity sets up a flux around a hole 2 which augments the flux due to one storage cell and opposes the flux due to the other cell. The magnetising force #H, Fig. 5, of the reading pulse is below the coercive force of the core material, and causes minor flux excursions +#B1 and -#B2 to take place temporarily which induce a difference output in the column and row wires. As these excursions occur in the non-linear saturation region, the core flux restores to the remanent state A when the read pulse terminates, the polarity order of the induced pulses at the commencement and termination of the read pulse being indicative of the registered information. The induced pulses are detected in one of the wires CW or RW, and preferably the amplitude of either the first or the second pulse is increased and that of the other pulse reduced by using a reading pulse having a sawtoothed waveform, the registration represented by the modified induced pulses being then readily ascertained by the use of a differential squaring amplifier. A modified wiring arrangement may be used, Fig. 6, in which the central hole is threaded by row and column wires RW, CW and a separate output wire OW and the other two holes are threaded by a reading wire, the manner of operation being the same as previously described. Various forms of storage matrices are described. In Fig. 8, the rows of storage units comprise perforated and aligned strips of magnetic material with each three hole group threaded by row RW1 ... RW3, column CW1 ... CW3 and read wires SW1 ... SW3 as in the Fig. 1 embodiment. Some of the wires may be formed by a printed process, Fig. 9 (not shown), in which all the matrix storage units are provided by three hole groups in a single magnetic plate. Alternatively, either the Fig. 1 or Fig. 6 wiring arrangements may be used in a storage matrix in which each unit comprises a separate three-hole disc, Figs. 10, 11, 14 and 15 (not shown). A single magnetic plate wired by the Fig. 6 method is shown in Fig. 12, the reading holes between adjacent storage units being shared so that the reading wires SW1 ... SW4 and the column and row wires CW1 ... CW4, RW1 . . . RW4 pass through alternate holes in a row. Four-hole disc units may also be used, Fig. 17, in which diametrically opposite holes are threaded by the reading and the row and column wires respectively so as to provide two reading and two storage cells. Alternatively, one storage hole may be left unwired, Fig. 18. A three co-ordinate array is also described, Fig. 13, in which each matrix plane comprises an apertured magnetic plate having n + 1 reading holes arranged between adjacent rows of n storage holes. In this arrangement, a read pulse in a selected reading wire such as SW12 or SW34 produces outputs in the column and row wires passing through the storage holes on either side of the selected row of reading holes, and discriminating circuits are necessary to select the outputs of a particular storage row. Specification 796,488 is referred to.