Patent GB-1245814-A (GB)
Title: Information storage arrangements
Inventor: SMITH JAMES LANSON
IPC: H04M1/276
Filed: 1968-11-22
Abstract: 1,245,814. Data storage. WESTERN ELECTRIC CO. Inc. 22 Nov., 1968 [22 Nov., 1967], No. 55515/68. Heading G4C. [Also in Divisions H3 and H4] Data in the form of reverse-magnetized single wall domains is stored in a plurality of word-set locations W1-W50, Fig. 1, in a sheet 11 of a rare earth orthoferrite, and a selected word-set is read out non-destructively or is replaced by using a three-phase system of driving conductors to propagate the reversed single wall domains from the appropriate location along a closed path comprising an entrance highway EH, a read-write area RWA and a return highway RH. Particularly, the arrangement forms part of a repertory dialler in a telephone system, with each word-set consisting of sixteen 4-bit words identifying a telephone number of up to sixteen decimal digits. The three-phase system of driving conductors is shown in part in Fig. 2, and comprises X1, X2, X3 and Y1, Y2, Y3 phase conductors for moving reversed domains in the X and Y directions, respectively. In unselected word-set locations the X1 conductors are disconnected from the appropriate phase of the three-phase system drivers 12, 13 by normal open switches SW1-SW50, and the reversed domains in these locations merely oscillate between the positions occupied by adjacent X2 and X3 conductors. Non-destructive read-out of a selected word set.-The subscriber lifts his receiver and depresses a number select button to close a switch SW1-SW50 of the word-set to be transmitted. This renders the X1 phase effective in the selected word-set location, and the reverse domains stored are stepped first into the entrance highway and then into the read-write area. Reversed domains in a connecting highway CH are prevented from progressing along the entrance highway and intermingling with the propagated word-set by a neutralizing loop of the X1 phase conductor (see X1W2, Fig. 2). Concomitant with the propagation of the stored reversed domains, a single domain D1 in a counter C is stepped in synchronism from a home position. The word-set stored includes a home position zero code (i.e. no reversed domains in a positional pattern) which is detected by couplings A1 to A4 and causes the propagation rate to be reduced to that acceptable by the telephone system for outpulsing the recorded number. The zero code also reverses the direction of domain propagation of counter C. The stored word-set is detected by the couplings A1 to A4 and applied to a utilization circuit under the control of a control circuit 15. An all-one code (i.e. all domains reversed) indicates that all the stored data has been read. The word-set pattern after read-out is stepped into the return highway and back into the same storage location from which it was extracted, its propagation being terminated when the single domain D1 in the counter C returns to its home position. Replacement of a word set.-The subscriber lifts his receiver and depresses a write button before depressing a number select button. A selected switch SW1-SW50 is closed, and pulses synchronized with the Y2 pulses are applied from a driver 22 to a conductor 21 so that reversed domains are fed continuously from a permanent source 20 to the entrance highway. These domains fill the zero spaces between the reversed domains propagated from the selected word-set location and destroy the stored information. When all the zero spaces in the various propagation channels and in the word-set location read-out have been filled by reversed domains, a timer stops propagation and a fresh home position zero code is entered in the read-out word-set location by an annihilate driver 41 which pulses a conductor 40, Fig. 3. The home position zero code is then stepped to a position immediately past the couplings A1-A4, the counter C being started to keep track of the movement. The subscriber then dials the new number to be stored which is transmitted as a two-out-of-seven code and is applied to appropriate couplings A1-A4 under the control of circuit 15, the domains being stepped onwards as rewording takes place. The recorded reversed domain pattern is advanced into the vacant word-set location, where it is stopped by the counter C which reversed its count on the arrival of the home position zero code at the coupling positions. The subscriber replaces his receiver on completion of recording.