GB814941A - Improvements in or relating to apparatus for the storage of digital information - Google Patents

Abstract

814,941. Electric digital-data-storage apparatus. NATIONAL RESEARCH DEVELOPMENT CORPORATION. Aug. 24, 1955 [Aug. 31, 1954], No. 25301/54. Class 106 (1). [Also in Group XXXIX] A matrix for storing binary number digits comprises magnetic storage elements with cores which may be saturated in parts by electric currents therein as described in Specification 814,942. In one arrangement, Fig. 1a, the cores each have two parts 10, 14 of low and high retentivity respectively, the parts 10 being saturable by currents therein without affecting the parts 14. Rows a, b, c of elements are connected in series so that parts 10 of all the elements of a row can be saturated together. Conductors 17 are linked with the elements of columns and are used for reading into or reading out from an element. To write into an element x, direct currents are applied to rows a and c to saturate the parts 10 but not the parts 14 and a pulse is applied to conductor 17 in column b<SP>1</SP> to saturate parts 10 and 14 of element x alone, the record being retained by the retentive part 14. To read out from x, an interrogating current in the form of a pulse, a series of pulses or an alternating current is applied to conductor 12 of row b to change the reluctance of the parts 10 and a read-out signal appears on conductor 17 of the column b<SP>1</SP> if part 14 of element x is saturated. Matrix construction.-The parts 14 may be strips of retentive material common to a row of elements or a sheet of retentive material common to a whole matrix. In one arrangement, Fig. 2, the non-retentive parts of a row of elements and the intervening conductors are formed as a strip 20 of " Mu-metal " (Registered Trade Mark). The strip 20 is laid over a strip of retentive material 15 with an intervening layer of insulating material to prevent conduction across the gaps 13. In another arrangement, Fig. 3, complete rings 10c and intervening conductors 12a are punched from retentive material. The rings 10c may be broken as at 13b to facilitate introduction of the conductors 17. In a third arrangement, Fig. 4, strips 10a of non- retentive material and conductors 24 are mounted on sheets 26, 25 of thin insulating material which are then assembled with a sheet of retentive magnetic material 22. An equivalent arrangement is shown in Fig. 5. A channelled sheet 30 and channelled strips 31 are of non- retentive magnetic material and together form tunnels or holes of rectangular section for the conductors 33. Between the sheet 30 and the strips 31 are strips 32 of retentive magnetic material on which the digits are recorded. Electric currents are passed along strips 31 to produce saturation when necessary. The sheet 30 may be dispensed with and the strips 32 may be replaced by a sheet of retentive material.