Patent GB-1059521-A (GB)
Title: Wire memory matrix
IPC: G11C11/04
Filed: 1963-09-20
Abstract: 1,059,521. Magnetic storage apparatus. KOKUSAI DENSHIN DENWA KABUSHIKI KAISHA. Sept. 20, 1963 [Jan. 28, 1963; Feb. 9, 1963 (2); May 6, 1963; May 13, 1963 (2); June 22, 1963; Aug. 22, 1963; Aug. 23, 1963; Sept. 4, 1963], No. 37156/63. Heading H3B. Various magnetic matrix stores are described in which either the row or the column conductors are coated with ferromagnetic material having an easy direction of magnetization or are constituted wholly of such material, and in which the column conductors each comprise a pair of series-connected wires forming a loop in insulated contact with the row conductors, independent storage elements being formed by those parts of the ferromagnetic material at the row and column crossing points. The magnetic conductors may be formed of copper, phosphor bronze, beryllium copper or aluminium wire which is coated with a thin layer of permalloy either directly or on to an insulating coating, Figs. 1A, 1B (not shown). Alternatively the magnetic conductors may be wholly formed of permalloy. In each case the magnetic material has an easy direction of magnetization which may be parallel to or circumferentially of the axis of the wire, Figs. 2(A), 2(B) (not shown). Information is stored in the usual manner by applying a pulse Id, Fig. 3, to a selected matrix conductor to rotate the magnetization axis to the hard direction, and subsequently terminating the pulse while an information pulse Ii+ or Ii - is applied to an orthogonal conductor. Consequently the magnetic state reverts along the easy axis in a direction determined by the information pulse polarity. Read-out is effected by the leading part of the Id pulse which induces an output Ip+ or Ip - in the orthogonal conductor of polarity determined by the direction of magnetization along the easy axis. Alternating pulses may also be used. In Fig. 5 information write-in and non-destructive read-out is effected by alternating Id pulses and unidirectional pulses Ii +, Ii - , the induced alternating output Ip + (0) or Ip - (#) being of twice the frequency and having a phase 0 or # determined by the data stored. Similar outputs are obtained in Fig. 6 in which the pulse Id and Ii are both alternating, the identity of the data to be stored being determined by the phase 0 or # of the higher frequency Ii. Fig. 7 illustrates a basic arrangement in which magnetic row conductors X 1 -X n  are each in contact with the equivalent of one turn of each column conductor Y 1 -Y n , pairs of wires 6a, 6b arranged on opposite sides of the row conductors and connected in series forming respective column conductors. In a modification, Fig. 8 (not shown), the row conductors are non-magnetic and the column conductor wires magnetic. Closer coupling is provided by arranging the wires 6a, 6b so as to partially encircle the magnetic conductors 3 as shown in Fig. 9 (A). Wires in strip form may alternatively be used, Figs. 10(A), 10(B) (not shown). These strips 6 may be embedded in or adhered to synthetic resin substrata 8a, Fig. 10(C), which maintain the row conductors in spaced relationship when assembled face-to-face as shown in Fig. 10 (D). An alternative supporting arrangement uses parallel clips 11a, 11b, Fig. 10 (F), which are secured by adhesive or welding. Straight conductors with the column wires in round or strip form are used in further embodiments, Figs. 11-14 (not shown), the conductors being adhered to or embedded in respective substrata, or only the row conductors being embedded in a substrate with the column wires adhered on either surface. Where strip conductors are used they are formed by printing. In Fig. 15(A) and Fig. 16 (not shown), the column conductors are formed by single conductors 6 adhered to a flexible substrate 14 which is folded so as to envelop the row conductors 3. Magnetic coupling between adjacent storage elements may be reduced by the use of discrete magnetic coatings spaced along each conductive row wire. The coatings may be formed by providing an insulating layer 16, Fig. 18 (C) on the conductor row conductors spaced portions of which are removed by photoetching. The insulating layer portions remaining are then coated with magnetic material. An alternative process is to photo etch a magnetic layer applied to the whole of the conductor. A further method of preventing magnetic coupling between adjacent storage elements on uniformlycoated conductors is to provide non-magnetic conductive rings around the row conductors intermediate the crossing points as shown at 20 in Fig. 21. These rings may be separate integers or conductive layers, or as shown in Fig. 22 may be pairs S1-S3 of shaped strips in electrical contact. Another form of conductive rings is provided by notched plates 24a, 24b in electrical contact, Fig. 23(A). A further form is shown in Figs. 24(A) and 24(B) in which the row conductors are located in slots 32 of a conductive member 26. Projections 27 on each side of the slots engage in corresponding apertures 30 in an insulating strip 28, and are soldered at 31 to a printed circuit 29 on the rear surface of the strip. In the arrangement shown in Figs. 25(A) and 25(B), the column wires 6a, 6b are also coated with magnetic material 33 and are insulated from each other and from the row conductor by insulation 35. These magnetic coatings are not provided on the adjacent surfaces of the column wire pairs. The coating may extend the whole length of each wire or may be restricted to the regions adjacent the crossing points, Fig. 26 (not shown). Fig. 28 shows a modified matrix in which the magnetic row conductors 3 are duplicated and are outside the column wires 6, 6a which are adhered to a central substrate 36.