Patent GB-1110578-A (GB)
Title: Data stores
IPC: G11C11/061
Filed: 1965-09-01
Abstract: 1,110,578. Magnetic storage apparatus. INTERNATIONAL BUSINESS MACHINES CORPORATION. 1 Sept., 1965 [26 Oct., 1964], No. 37318/65. Heading H3B. A binary data storage system comprises planar arrays of a first set of parallel tubular magnetic members disposed in contact with and transversely to a second set of parallel tubular magnetic members, respective X conductors longitudinally threading each member of the first set, respective Y conductors longitudinally threading each member of the second set, and Z conductors threading some of the apertures between the members. In the embodiment shown in Fig. 1, a storage cell 10 comprises portions of four members 12, 14, 16, 18 surrounding a Z conductor 34; a common X conductor threads the pair of horizontal members 12, 14, a common Y conductor threads the pair of vertical members 16, 18, and information is stored as the direction of remanent magnetic flux in the closed flux path 32. Writing in is by energizing the X and Y conductors simultaneously with or overlapping an information pulse in the Z conductor, the polarity of the information pulse determining the direction of the remanent magnetization in the closed flux path 32. To read out, the Z conductor is connected to a sense amplifier 42 and the X and Y conductors are energized, the polarity of the current induced in the Z conductor being representative of the information. A matrix of four two-bit words comprising storage cells of the type shown in Fig. 1 is described with reference to Fig. 4 (not shown). In a modification described with reference to Fig. 2 (not shown), a storage cell (10<SP>1</SP>) comprises four members (12, 14, 16, 18) and a Z conductor (34) arranged as in Fig. 1, but information is stored as the direction of remanent magnetic flux in a closed flux path round the circumference of the horizontal members (12, 14). Writing in is by energizing the Z conductor simultaneously with or overlapping an information pulse in the X conductor. Subsequently, the Y conductor is energized to destroy magnetization about the Z conductor. To read out, the X conductor is connected to a sense amplifier (42) and the Z conductor is energized to induce a pulse in the X conductor. A matrix of four two-bit words comprising storage cells of the type described with reference to Fig. 2 is described with reference to Fig. 5 (not shown). In the embodiment shown in Fig. 3, each of the four portions of members 12, 14, 16, 18 is a separate storage cell having a respective X or Y conductor and sharing a common Z conductor. Information is stored as the direction of remanent magnetic flux in a closed flux path round the circumference of the member concerned. Writing in to storage cell 10A (member 12) is by energizing the Z conductor 34A simultaneously with or overlapping an information pulse in the X conductor 22A. To read out from storage cell 10A, X conductor 22A is connected to sense amplifier 42A and Z conductor 34A is energized to induce a pulse in X conductor 22A. A matrix of four eight-bit words comprising storage cells of the type shown in Fig. 3 is described with reference to Fig. 6 (not shown). In the matrix of Fig. 6, a word consists of the eight storage cells, e.g. (10À02, 10À04, 10À11, 10À12, 10À18, 10À20, 10À27, 10À28), associated with the same Z conductor, e.g. (143). In an alternative method of operation, the two digits of binary information may be represented by a magnetization set up by a unipolar current pulse in the Z line for one digit with the other digit represented by a magnetization set up by a unipolar current pulse in the X or Y lines.