Patent GB-849952-A (GB)
Title: Static computer register and electronic data processing unit employing such register
IPC: G11C8/02
Filed: 1958-05-15
Abstract: 849,952. Circuits employing bi-stable magnetic elements. NATIONAL CASH REGISTER CO. May 15, 1958 [May 22, 1957], No. 15608/58. Class 40 (9). [Also in Groups XIX and XL (c)J A static computer register for an electronic data processing unit comprises magnetic storage cores arranged in rows and columns to form a first and second storage bank, and row and column selection devices, the column selection devices comprising a reading gate and a writing gate for each column, and the outputs of a sequence control counter (109) being connected to the reading gates according to one arrangement and the writing gates according to another, whereby data is simultaneously read from a selected column in one storage bank and written into a selected column in the other bank. The computer shown comprises storage unit 104 having two banks of 10 columns, each comprising 7 cores for storing a 6-bit binary coded decimal digit plus a check bit. Data bits read from a column are passed in parallel via amplifiers 136, Fig. I, to bi-stable flip-flops Sd 1-7 and are shifted by the next clock pulse C, Fig. 1a, into flip-flops S1-S7. The output of S7 is passed, together with the output of check logic network 135, to error flip-flop Ke which stops computer operations of these outputs indicate different check bits. The digit set up on S1-S6 is applied together with a similarly coded decimal digit from " M register " 139, shifted on to lines M 1 -M 6 , to arithmetic network 132 whose outputs are set up on flip-flops wS1-wS6. The digit from wS1-wS6 together with a new check bit from network 134 is written back into unit 104 via gates 116, the column selected for this writing operation being the same as that from which data was read two clock periods earlier. The column selection is controlled by the 20-state counter 109 comprising flip-flops D1-D5 whose outputs are applied to a network 110 which produces a signal on one of the output lines  0 Ps0- 0 Ps9,  1 Ps0- 1 Ps9 for each counter state. These lines are connected to read and write gates 115b and 115a, Fig. 2 (115, Fig. 1) in such a manner that in each storage bank a pair of read. gates are opened sequentially followed by the associated pair of write gates; e.g. read gates 162 and 187 are opened by  0 Ps0 and  0 Ps1 respectively and the corresponding write gates 161 and 163 are opened two clock periods later by  0 Ps2 and  0 Ps3. The computer clock periods P0-P23, Fig. 1a, are marked by cycle counter 140. The read driver 106 is operative during the 10-digit or "word" period P23,0-8 and therefore the network 132 and write driver 107 are rendered operative during the periods P0-P9 and P1-P10 respectively. Sequence control counter; shift.-The flip-flops D1-D5 of counter 109, Fig. 1, are set at period P21, Fig. 1a, via gates 108 in accordance with the setting of an " F register " (not shown), and the counter is stepped by clock pulses C applied through gates 112 during periods P23,0-9. The setting and stepping circuits comprise diode coincidence gates (Figs. 3a and 3b, not shown) for each flip-flop stage, the gate connections being such that flip-flops D1-D4 count in normal binary fashion from  0 Ps0 to  0 Ps9 and from  1 Ps0 to  1 Ps9 the latter group of counts being distinguished by a " 1 " in D5. By altering the F register setting the data stored in the cores may be effectively column shifted left or right in relation to the computer cycle. Reading from storage unit.-During each of the clock periods P23,0-8, driving current from 106 passes through a selected column read gate such as 162, Fig. 2, and associated column wire (169) to voltage source 172. This causes any core in the column in the " 1 " state to be driven to " 0 " this inducing a pulse in the associated sense lines (178). Then pulses after passing through amplifiers 136a or 136b are applied over output lines sd1-sd7 to flip-flops sd1-sd7, Fig. 1. Auxiliary driver 173 conducts when driver 106 is shut off whereby a constant current passes through an inductance load in 172. Writing into storage unit.-During each of the clock periods P1-P10, a half-write driving current from 107 passes through a selected column write gate such as 161, Fig. 2, and associated column write (168) to voltage source 167. This current switches over one of two timing cores 146, 147 which causes a pulse to be applied via timing amplifier circuit 164 to row driver 117 which energizes gates 116a under control of flip-flops wS1-wS6 and network 134, Fig. 1. For each row in which a " 1 " is to be written, a half-write pulse from 116a is passed through one of gates 116b or 116c, according to the state of bank selector 113, Fig. 1, to the appropriate row wire such as 155, to cause the required core such as 148 to be driven to the " 1 " state. Spurious signals due to the halfwrite row pulses are cancelled by cores 151 or 152. As for the read driver, an auxiliary driver 166 is associated with driver 107. Specification 845,466 is referred to.