Patent GB-1099241-A (GB)
Title: Apparatus and methods for woven screen magnetic memory devices
IPC: D03D1/00
Filed: 1964-11-05
Abstract: 1,099,241. Magnetic storage apparatus. BUNKER-RAMO CORPORATION. Nov. 5, 1964 [Nov. 12, 1963], No. 45171/64. Heading H3B. [Also in Division D1] A magnetic memory device comprises a plurality of electrically conductive strands and substrate strands upon which magnetic material is subsequently deposited woven to produce a matrix of storage cells, selected strands only being woven into portions of the weave outside the cells in order to facilitate separation and identification of the strands after weaving. Metallic wires or insulated wires 32 having an outer surface treated to permit deposition of a magnetic coating thereon and electrically insulated wires 34, 36, 40 together with dummy wires 42 are woven on a loom, Fig. 1 (not shown) to produce a woven screen which, after deposition of magnetic material on substrate wires 32 forms a matrix of storage cells, Fig. 2. X and Y buffer cells are provided to minimize interference or noise and the dummy wires 42 are used so that the control wires do not pass through respective buffer cells, Fig. 3 (not shown) and also determine the manner in which the control wires thread the storage cells. In order to simplify the fabrication of the finished memory device a matrix 50 of cells is woven with a particular peripheral pattern, Fig. 4 (not shown) and Figs. 5(a) and 5(b). In order to prevent unravelling of the matrix plane 50 the various wires are interwoven in the edge trim regions 52 to provide a tight weave. Extending outwardly from the respective edge trim portions 52 are regions 53, 54 through which selected wires from the plane 50 are passed without being interwoven in any mesh. In the warp direction the substrate wires 32 pass across region 53 and also separator trim portion 56, wherein X drive wires 38 and inhibit wires 40 are interwoven, and are interwoven with the rest of the weave in plane trim region 57. The substrate wires may then be separated from the weave at the line 61. In a second step the control wires 38, 40 may be separated from the dummy wires 42 at line 62. Region 54 illustrates the way in which the sense wires 34 and Y drive wires 36 are arranged at the outer edge of the portion 52. The individual matrices are cut from the strip along lines 60 or if a threedimensional array is required the matrices are folded along this line. In the arrangement of Fig. 6 (not shown) the buffer cells are omitted and the vertical substrate wires have a larger diameter than the horizontal wires. A doubleapertured storage cell, Figs. 7, 8 (not shown) may be formed by utilizing dummy wires to control the threading of the cell apertures using plain weave or skip weave patterns. Figs. 9, 10 (not shown) illustrate how a skip weave pattern may be used to achieve cancellation of inductive noise during the readout cycle and to develop bipolar readout pulses on the sense windings. In Fig. 11 (not shown) the control wires in the warp and weft directions are arranged to provide different numbers of turns with respect to the individual storage cells. In this arrangement storage is by a coincident current method.