Patent GB-1054722-A (GB)
IPC: G11C11/04
Filed: 1965-02-04
Abstract: 1,054,722. Magnetic storage apparatus. INTERNATIONAL BUSINESS MACHINES CORPORATION. Feb. 4, 1965 [Feb. 5, 1964], No. 4819/65. Heading H3B. [Also in Division G4] A thin film magnetic switching or storage matrix comprises interwoven warps and wefts in which at least some of the warps are substrates carrying thin anisotropic magnetic films and at least some of the wefts are drive or sense conductors. In three four five-digit words matrix shown in Figs. 1 and 2, thin film elements are deposited on wire-shaped insulating substrates 2 with their easy axis extending along the substrates. The column drive conductors or word conductors are connected to word drivers 3 and are in the form of a conductive film below the magnetic film. Bit conductors 5 connected to bit write-read amplifiers 4 extend in the direction of the rows and are wound about the substrates 2 in the manner of fabric weft threads. As shown in Fig. 2, the return bit conductor is formed by an immediately adjacent cross conductor 5 2  woven in a complementary fashion. Between two pairs of cross conductors are provided two neutral pairs of weft threads 7 formed by a single conductor 7. Wires 6 1  are used as return conductors for the word conductors. In order to store a bit a current pulse is applied to the appropriate word conductor to switch the magnetization vector into the direction of the hard axis and then a current pulse of the required polarity is passed through the selected bit conductor to determine which direction along the easy axis the magnetization vector returns to when the word pulse is terminated and hence which binary digit is stored.. To read out a current pulse is applied to the appropriate word conductor the polarity of the pulses induced in the bit conductors representing the stored values. The stored value is re-written after each read-out operation. The arrangement of Figs. 4a, 4b (not shown), enables stray pulses between the bit and read conductors to be eliminated, the film substrates being of rectangular cross-section and the films being located on the upper surfaces of alternate substrates and on the lower surfaces of the remaining ones. The wiring arrangement is such that current in one conductor can only induce equal and opposite currents in the other conductor. The storage film substrates may consist of glass wires, glass fibres, mica strips or conductors and may be rectangular cylindrical or square in shape. Figs. 5a to 5f (not shown). In Figs. 6a to 6d (not shown,) the substrates are shaped so that where discrete storage film cells are used the cells of a matrix are correctly aligned. Figs. 7, 8a to 8e (not shown), represent wiring schemes for high-speed memories providing a high bit density per unit area which arrangements employ strip-shaped cross conductors and neutral warp and weft threads. The arrangement of Figs. 8a to 8e is designed similar to a double fabric. Figs. 9a 9b (not shown), illustrate the construction of a memory arrangement of the type indicated by Fig. 1 in which a matrix fabric is mounted in a frame, the word and bit drivers being mounted in a staggered relationship directly on to the fabric.