Patent GB-780005-A (GB)
Title: Improvements in systems for, and methods of, storing binary information
IPC: G11C8/00
Filed: 1951-08-09
Abstract: 780,005. Electric digital-data-storage apparatus. MILLERSHIP, R. Aug. 7, 1952 [Aug. 9, 1951], No. 18794/51. Class 106 (1). In a storage system for binary information, e.g: for a digital computer, the information is stored by modifying the magnetization of spaced zones along the length of an element of material having magnetostriction properties, and is read out by injecting an acoustic pulse into the element. In a method of producing a store of information which is capable of being represented by a train of electric pulses, adjacent zones are spaced by a distance corresponding to the product of the velocity of the acoustic pulse and the time interval between successive pulse positions in the train. In the system shown in Fig. 3, binary digits are recorded on a storage tube, tape or wire 1, e.g. of nickel, by passing current pulses (e.g. positive pulse for "1," no pulse for " 0 ") through coils 9<SP>1</SP>-9<SP>8</SP>, associated with small electromagnets (not shown) so disposed that the wire 1 is in the air gaps thereof. A read-out pulse applied to coil 2 causes an acoustic pulse to travel along the wire and to produce output pulses, corresponding to the digits stored, successively in coils 3<SP>1</SP>-3<SP>8</SP> connected to an amplifier 10, the number thus appearing in series-made form at the output 11. In an alternative arrangement, the output coils 3 are used also for the recording of information. Reflection of acoustic pulses at the end of the wire 1 is prevented by supports 6 such as sleeves packed with petroleum jelly. Fig. 4 shows a recording arrangement in which a series-mode electrical-pulse train is applied to a coil 2a on a separate uniformly magnetized wire 1w so as to produce a corresponding train of acoustic pulses which are translated into parallel signals in coils t<SP>1</SP>-t<SP>4</SP> which are amplified by means 15 and applied to recording coils 9<SP>1</SP>-9<SP>4</SP> upon the timed simultaneous closure of switches 14. In a further arrangement (Fig. 5, not shown), the series-mode train is applied directly to the line 1 and a timed magnetizing pulse is applied simultaneously to all the coils 9<SP>1</SP>-9<SP>4</SP>. Fig. 6 shows a series of stores with a two-dimensional array of recording coils fed selectively from terminal 20<SP>1</SP>-20<SP>5</SP>, 22<SP>1</SP>-22<SP>4</SP> with pulses sufficient to produce only half the required magnetization, a digit being stored only when both the coils (e.g. 1923, 21<SP>23</SP>) associated with a given position are energized. The digits on a given wire are read out by applying a pulse to the associated coil 2<SP>1</SP>-2<SP>5</SP> to produce output pulses in coils 17 ; a digit position may be specified uniquely by threading each coil by two wires 1 at right angles and applying two reading pulses. A three-dimensional array also is suggested. In another two-dimensional arrangement (Fig. 7, not shown) each digit position is associated with three coils for recording, read-out and cancellation, the recording and cancellation circuits being isolated from each other by rectifiers. Reference has been directed by the Comptroller to Specification 698,061.