Patent GB-894025-A (GB)
Title: Improvements in data storage units
IPC: G11C19/06
Filed: 1960-07-29
Abstract: 894,025. Circuits employing bi-stable magnetic elements. AMP Inc. July 29, 1960 [Aug. 6, 1959], No. 26451/60. Class 40 (9). In a shifting register comprising a series of magnetic storage cores 11-14, Fig. 1, each having a major aperture 11M-14M and two minor apertures 11R-14R and 11T-14T respectively associated with clear, receive and transmit windings, the wiring of the assembly is facilitated by positioning the odd and even numbered cores in the series in respective parallel groups with the apertures in alignment as shown in Figs. 4 and 7 to 10B. Operation of register. A basic arrangement is shown in Fig. 1 in which the cores are initially set to the same magnetic state with flux existing only around the major apertures. When an input pulse is applied to a conductor 20, a flux is established in core 11 around the minor receive aperture 11R, and a consequential reduction of the flux around the major aperture is produced. This in turn permits an advance pulse from a terminal 26 to the parallel transmit and receive windings to establish a flux around the transmit aperture 11T. While this flux is being established, a sufficient proportion of the advance pulse current is diverted through the receive winding of core 12 to establish a flux around the receive aperture 12R. A clear pulse is then applied from terminal 32 to core 11 to eliminate the fluxes around the minor apertures and so re-establish the initial flux condition. The input pulse is now stored in core 12, and is transferred to core 13 by the sequential application of advance and clear pulses to respective terminals 38 and 44. The other possible input condition is zero. In this case no flux changes occur in the core and the first advance pulse divides equally between the parallel transmit and receive windings of cores 11 and 12 respectively. Neither current value in a winding is then sufficient to establish a field around a minor aperture, in both cores this being due to the magnitude of the flux around the major apertures. Sequential shifting of an effective or zero input is continued as described by cycles of advance and clear pulses applied sequentially to terminals 26, 32, 38 and 44. A modification is described, Fig. 2, in which the advance pulse circuits from terminals 52 and 58 are respectively looped through the alternate pairs of adjacent transmit and receive apertures and through all the major apertures. In a further modification, Fig. 3, the adjacent transmit and receive windings form independent circuits 15, 16, 18, and the advance windings which are threaded through the major and minor apertures as shown effect operation by induction. Construction. To facilitate wiring, the cores 81-86, Fig. 4, are arranged in two parallel groups, one for odd and the other for even numbered cores. The input and output windings 100, 102 and the circuits 90-98 joining the adjacent transmit and receive windings are then positioned as shown, the clear windings being omitted. This basic layout is utilized in Fig. 7 to wire the cores according to the arrangement shown in Fig. 1. The aligned receive and transmit apertures are threaded by hollow or solid conductive tubes 111-114 and wiring links are provided between the tubes in the same pattern as shown in Fig. 4. The clear windings (not shown) are threaded through respective aligned major apertures. Figs. 8A and 8B together illustrate wiring for the Fig. 2 circuit, the clear windings being omitted, and show respectively the circuits for interconnecting odd to even cores and even to odd cores. Hollow tubes are used in this case, and the advance circuits between respective terminals 162, 166 and 170, 176 are first threaded through, and insulated from, the tubes and then passed through the major apertures before connecting with the tubes themselves. The same method of threading through the tubes is used in Figs. 10A and 10B, which together show the wiring for the Fig. 3 circuit, the advance circuits passing through the tubes and major apertures between terminals 202, 204 and 208, 210. Both Figs. 8B and 10B show in broken lines the connections necessary to form a circulating register. A modification of Fig. 8B, for circulating purposes, is shown in Fig. 9 in which the feedback connection comprises two metal plates 182, 184 spaced by insulation 186. The advance circuit between terminals 170, 196 is also connected to the plates in parallel with the input and output windings for the purpose of reducing spurious outputs and for augmenting the output pulse when transferred to the input. The wiring between the tubes in the several arrangements may be replaced by conductive metal sheets, Fig. 11 (not shown), which are apertured or slotted for fitting on to the tubes, are secured by solder, and serve as interference-preventing shields.