Patent GB-903094-A (GB)
Title: Improvements relating to binary magnetic storage devices of the matrix type
Inventor: WARMAN BLOOMFIELD JAMES
IPC: G11C11/06
Filed: 1958-09-02
Abstract: 903,094. Electrical digital-data-storage apparatus. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Aug. 19, 1959 [Sept. 2, 1958], No. 28176/58. Class 106 (1). [Also in Group XXXIX] In a magnetic information storage matrix in which an interrogation signal applied to a selected column conductor produces read-out signals in parallel form in the row conductors, each row conductor is connected to a respective read/write circuit comprising a transistor blocking oscillator which first lengthens the duration of the read-out signal, and then produces a signal of opposite polarity for the purpose of re-writing the read out information. As shown in Fig. 1, an array of storage cores C1-C5 has two column conductors for each column of cores, one conductor being connected to the output of a sequential access driving core DR1-DR5 which is controlled by a drive core counter circuit, while the other conductor is connected to the output of a random access driving core RA1-RA5. In operation, one driving core is switched by a random or sequential input signal, and an interrogation signal is produced in the associated column conductor which restores those cores in the column in a magnetic state " 1 " to a reset state " 0." Outputs are induced as a result in the associated row conductors L1-L5 which pass to read/write circuits R/W1-R/W5, each circuit comprising a transistor blocking oscillator, Fig. 2. A read output passes over a transformer T1 and raises the potential at the emitter of a transistor S1 so that collector current flows. Regenerative action takes place over a saturable transformer T2 which lengthens the read-out pulse duration. When transformer T2 saturates the regenerative action ceases and the circuit restores to its quiescent state. During the restoration period the fall in emitter current induces a write pulse in the associated row conductor Ln. This pulse is coincident with the restoration of the switched driving core to its original state, and coincident pulses are thus applied to those storage cores which were originally in state " 1 " so that they are restored to their initial state. A modified blocking oscillator is described, Fig. 8, which includes a transistor S12 in the base circuit of S1, the oscillator being inhibited by an erase pulse applied to the base of S12 to prevent information from being re-written, while a trigger pulse applied to the emitter of S1 triggers the oscillator and enables a state " 1 " to be recorded in a selected position in the matrix. A three coordinate array is also described, Fig. 3 (not shown), in which each matrix plane is brought into use separately by the selective removal of bias applied from a random access or counter unit to all the switching cores of each plane. A counter unit is described, Fig. 6, comprising magnetic cores C1-Cn with respective input and output windings A, B connected to the collectors and emitters of transistors S6, S7 ..., stepping of a magnetic " 1 " state taking place under the control of pulses applied alternately to DRIVE 1 and DRIVE 2 circuits. Specification 903,095 is referred to.