Patent GB-738402-A (GB)
Title: Improvements in or relating to data storage devices
IPC: G06F3/08
Filed: 1952-12-17
Abstract: 738,402. Digital electric calculating-apparatus; statistical apparatus. INTERNATIONAL BUSINESS MACHINES, CORPORATION. Dec. 17, 1952 [Dec. 21, 1951], No. 31976/52. Class 106 (1). An electrical data storage system, e.g. for an electronic computer, comprises a storage device, e.g. consisting of electromechanical relays, settable to represent a character, and read-out means therefor consisting of a characterrepresenting device, e.g. an electronic counter, arranged to represent different characters in succession in response to discrete impulses, and circuit means connected to impulse-supplying means and the storage and character-representing devices, the circuit means being conditioned by, and for the duration of, each impulse to produce an output signal when the same character is represented in both devices. Storage device. In the system shown, the storage device comprises relay registers A, B, Fig. 1D. The register A is arranged to store the decimal number represented by differentially positioned holes in the first 8 columns of a record card 50, Fig. 1B, with its sign represented in column 9 (hole in position " 1 " for " minus "), only the relays R12-S, R13-1U to R13-8U, R14-1T to R14-8T for storing the sign, units digit and eighth digit respectively being shown. The register B is similarly associated with other card columns. Each relay has an initially energized primary coil P and a hold coil H which is maintained through contacts B and a potential applied to a line H1 or H2 for registers A, B respectively; this potential is only removed at the beginning of a card read cycle in which a new amount is to be entered into the corresponding register. The card holes are sensed by contact brushes such as 51, 52, Fig. 1B, which apply differentially timed pulses to lines such as P10, P11 connected to sign relay R12-S and digit relays R13 respectively. Each set of digit relays such as R13-1U, 2U, 4U, 8U is controlled by timed pulses representing 1, 2, 4, 8 selectively applied to lines B1, B2, B4, B8 respectively from emitters (not shown), so that the relays are selectively energized to represent in binary-coded form the decimal digit recorded on the corresponding card column. Read-out. The numbers stored in registers A, B are read out into an electronic computer, e.g. as described in Specification 673,759, in the form of differentially timed impulses on parallel lines of a channel 30, Fig. 1B, in response to a programme control pulse from the computor. This control pulse together with recurring positive pulses occurring at points 9AB and 11A- 20A of a calculate cycle, Fig. 4, are applied to electronic control circuits (Fig. 1A, not shown). The pulse 9AB causes a positive pulse to be applied over line 233 to diode 23A of coincidence circuit 23A-C. Assuming that register A is to be read out, a positive potential is applied to diode 23B, Fig. 1B, so that if a negative sign is registered by relay R12-S, Fig. 1D, and a relatively positive potential is applied also to diode 23C from the relay contacts A over line 231, the grid potentials of double triode cathode follower V18 will be raised and a sign-representing pulse will be applied via triode V26 to line S of channel 30. The pulse 9AB also causes negative pulses to be applied over lines 206-209, Fig. 1C, to reset triode trigger circuits V7-V4, series-connected to form a subtracting binary counter, to the conductive conditions (indicated by " X ") representing the value " 9." The subsequent pulses 11A-20A cause positive pulses to be applied from line 214 through a delaying double triode amplifier V3 to line 220. The trailing edge of each pulse on 220 causes a negative pulse to be applied to the first trigger V4 of the counter so that it is stepped successively through the 9, 8, 7 ... 0 conditions. Double triode cathode followers V8-V15 reflect the condition of the triggers V7-V4 so that, e.g., in the " 9 " condition shown, V9, V10, V12, V15 are conductive and positive potentials are applied to lines 252, 253, 255, 258 of the series 251-258, which are each connected to a corresponding fixed contact A, Fig. 1D, of a relay in each digit set, the movable contacts A of a set being connected to a corresponding diode coincidence circuit in Fig. 1B. Thus if, e.g., a " 9 " is registered on relays R13 by the energization of R13-1U and R13-8U, the positive potentials on 252, 253, 255, 258 will be applied over lines 236-239 respectively to diodes 24B-24E, Fig. 1B, and since, if register A is to be read out, positive pulses corresponding to 11A-20A are applied to diode 24A, the first of these pulses will raise the grid potential of double triode cathode follower V19 to cause a pulse to be sent via V27 to the units line U of channel 30. Similarly, if some other digit value is registered on relays R13 a pulse corresponding to one of 12A-20A will be applied to line U when the comparing circuits including V8-V15, Fig. 1C, detect agreement with the value registered in counter V4-V7. The other digit sets of relays of register A and the relays of register B are read out similarly.