Patent GB-640513-A (GB)
Title: Improvements relating to calculating apparatus
IPC: G06F7/498
Filed: 1947-03-21
Abstract: 640,513. Calculating-apparatus; transfer devices. NATIONAL CASH REGISTER CO. March 21, 1947, No. 7859. Convention date, Oct. 18, 1945. [Class 106 (i)] An electronic multiplying apparatus comprises on impulse generator which generates, at each cycle of its operation, a number of impulses in each denomination equal to the corresponding denominational digit of the multiplicand, the impulses being generated in the several denominations simultaneously and being passed through a denomination-shifting distributer to a totalizer, the generator being controlled by a multiplier unit which causes the distributer to operate through a number of cycles equal to the units digit of the multiplier, which then causes the denominationshifting distributer to advance one step, and which then controls the generator to operate through a number of cycles equal to the tens figure of the multiplier, and so on, each repeated operation of the multiplier unit being controlled by the arrival of a signal denoting that a transfer cycle in the totalizer has been completed. The example chosen to illustrate the invention is the multiplication of the multiplicand " 658 " by the multiplier " 123." In the embodiment shown, the multiplicand and multiplier are. set on the keys of a multiplicand impulse generator, Figs. 1, 2, and a multiplier unit, Figs. 1, 3, respectively, and a starting key in a stagecontrol unit, Figs. 1, 5, is operated. This last causes the firing of a gasfilled electric-discharge starting tube 250 which in turn fires a stage I control tube 251 which remains fired to prime through a connection 190 the left-hand or stage I column of gasfilled discharge tubes 186, 183, 180 in a denominational distributer, Fig. 4. The firing of the stage I control tube 251 also sends an impulse through a connection 291 to the 10‹ input line 299 of the multiplier unit Fig. 3. Since the 3 key is depressed in the 10‹ denomination, this impulse is routed via the connections shown to fire the No. 7 tube 306. The resulting impulse fires in turn two delay tubes 310, 311 which transmit an impulse through a connection 100 to the multiplicand impulse generator, Fig. 2. The multiplier tube 306, Fig. 3, remains fired and so primes the No. 8 tube 307. The arrival of the impulse at the connection 100 of the multiplicand impulse generator, Fig. 2, causes each of the gas-filled electricdischarge tubes Nos. 1 ... 9 thereof to fire in turn, each tube producing an impulse at a corresponding point 108, 109.... The points 108, 109 ... are connected by rectifiers 111 which can pass impulses from right to left, but not vice versa. With the key connections shown, and keys 6, 5 and 8 depressed in the 102, 101 and 10‹ denominations respectively, impulses generated by tubes Nos. 1 ... 5 are passed to all the output terminals 160, 161, 162, impulses generated by tube No. 6 pass to output terminal 160 (10‹) and 162 (10<SP>2</SP>) only, and impulses from tubes Nos. 7, 8 reach output terminal 160 (10‹) only ; thus the 10 output terminal receives 8, the 10<SP>1</SP> terminal receives 5 and the 10<SP>2</SP> terminal receives 6 impulses respectively. These impulses are passed to the corresponding input terminals 160 ... 162 of the denominational distributer, Fig. 4, the stage I tubes 186, 183, 180 of which, being primed as previously described, thus fire and send impulses to the 10‹ and 101 denominations of the accumulator, Fig. 6 over lines 170, 171. Only the 10‹ and 10<SP>1</SP> denominations of the accumulator are shown in Fig. 6. After the No. 9 tube of the generator, Fig. 2, has fired, a transfer initiator tube 104 is fired to send an impulse over a line 148 to fire the 10‹ transfer control tube 439, Fig. 6. If, during the preceding impulse-entering operation, the O tube fired, a transfer tube T has also fired with it. When the transfer control tube 439 is fired, the circuit is such that the fired transfer tube T is extinguished and, in so becoming, originates an impulse which passes through a condenser 441 into the next higher denomination of the accumulator to add 1 therein. The rise in potential at point 453 in the cathode circuit of the 10‹ transfer control tube 439, after charging a condenser 455, is used to fire the 101 transfer control tube 470 to effect transfer from that denomination to the next higher, if the 101 transfer tube has been fired. The 101 transfer control tube 470 also fires the 102 transfer control tube, and this in turn fires the 10<SP>3</SP> control tube, and so on, the impulse from the highest control tube passing to an input point 175, Fig. 3, on the multiplier unit and so fires the primed No. 8 tube to cause another cycle of the multiplicand impulse generator and then another set of transfer operations which causes the arrival of another impulse at the multiplier unit input point 175 to fire the primed No. 9 tube to cause a third cycle. The multiplicand " 658 " has now been added 3 times into the accumulator. The arrival of the next impulse at the multiplier unit input point 175 finds a stage shift control tube 309 primed (because the 9 tube 308 was the last to be fired) and so fires this tube 309 to send an impulse over a line 339, 292 to the stage control unit, Fig. 5. The stage I tube 251 is at this time firing and priming the stage II tube 252. This latter tube thus fires, extinguishing the stage I tube 251 and causing the priming over a line 191 of the stage II tubes 187, 184, 181 in the denominational distributer, Fig. 4. The stage II control tube 252 also sends an impulse over a line 294 to the 10<SP>1</SP> denomination input terminal of the multiplex unit, Fig. 3. This unit then operates to cause the multiplicand impulse generator to perform two complete cycles (the tens figure of the multiplier being " 2 "). Since the stage II tubes 187, 184, 181 of the distributor, Fig. 4, are primed, impulses coming from the multiplicand impulse generator on the 10‹ line 160 cause impulses to pass to the 101 input line 171 of the accumulator, 10<SP>1</SP> impulse from the generator cause 10<SP>2</SP> impulses to pass to the accumulator, and so on. After the completion of stage II, a stage III control tube 253, Fig. 5, is fired. This primes stage III distributer tubes 188, 185, 182 to cause impulses from the multiplicand impulse generator to be in effect multiplied by one hundred before passing to the accumulator. The multiplier unit, Fig. 3, during this stage causes one cycle only of the generator (the hundreds figure of the multiplier being " 1 "). When, at the end of this stage, the stage shift control tube 309 fires, it has no effect since there is no further primed tube in the stage control unit.