Patent GB-750636-A (GB)
Title: Static magnetic core storage devices
IPC: G06F3/08
Filed: 1953-12-30
Abstract: 750,636. Electrical digital-data-storage apparatus. INTERNATIONAL BUSINESS MACHINES CORPORATION. Dec. 30, 1953 [Jan. 2, 1953], No. 36172/53. Class 106 (1). A storage device comprises a magnetic core matrix having sets of column and row windings and a control winding passing through every core, means for successively energizing the row windings, means for selectively energizing the column windings and read-out means. Information is transferred from a punch card to an 80 x 12 core matrix, each core corresponding to one data position on the card, by successively energizing the rows of the matrix in synchronism with the sensing of rows on the card and selectively energizing columns of the matrix by the sensing of holes in the card, the particular columns energized corresponding to the columns of the card in which the sensed holes lie. Camoperated contacts CF37-CF48, Fig. 1, are arranged to successively energize the row windings 11 of the matrix (only two columns of which are shown, namely columns 1 and 80) and the sensing of holes causes the column windings 12 to be energized, the current path for energizing column 1, for example, being from a 56 v. battery through spark preventing contacts CB1-CB4, CF17, CF18, to a roller 4, through a sensing brush 3, a resistor, contact RA1, column winding 12 and to earth via contacts RB1, Fig. 2. The effect on a core of a simultaneous column and row energization is to change its magnetic state from " a<SP>1</SP> ," Fig. 4, where it is held by a negative biasing current through the control winding 13, to state " b." On removal of the simultaneous energization the core assumes state " c<SP>1</SP> " in which state it is storing information. For read out " a commutator 33, Fig. 3, by successively firing a set of 12 selfextinguishing thyratrons 31, Fig. 2, causes successive pulsing of the row windings of the matrix. These pulses are sufficiently large to cause any core that was recording information to change its state from " c<SP>1</SP> " to " a<SP>1</SP> ", Fig. 4, and induce a pulse in its column winding 12 which fires one of a set of 80 thyratrons 38 to energize one of a set of electromagnets 30. Thus the differentially timed energizations of the coils 30 are representative of the contents of the store. Thyratrons 38 are not self-extinguishing and in addition to passing current through the coils 30 they pass current through the column windings of the matrix, which enables information " read-out to be immediately re-recorded. For this latter operation with a switch 52, Fig. 2, in the position shown, cam-operated contacts R39-R50 successively energize the rows of the matrix in synchronism with the commutator, the energizations being timed to occur just after the firing of the " readout " thyratrons 31 and lasting until the thyratrons 38 are cut off, which occurs when spark preventing contacts Ro14-Ro18 open prior to the " reading " of the next row. Thus cores that contained information which was destroyed by the " read-out " pulse are subjected to a simultaneous energization of their row and column windings, and return to the magnetic state " c<SP>1</SP>," Fig. 4. The matrix is " cleared " prior to the next " read-in " cycle by the passage of a relatively high current through the control winding 13. Specification 749,796 is referred to.