GB723774A - Arrangement for shifting the multiplicand in a calculating machine - Google Patents

Abstract

723,774. Digital electric calculating-apparatus. COMPAGNIE DES MACHINES BULL. June 21, 1951 [June 26, 1950], No. 14809/51. Class 106 (1). In an electronic machine for automatically performing the multiplication of two decimal numbers, a registering arrangement comprises a multiplicand register adapted to register digits of successive decimal orders on respective groups of units corresponding to predetermined coded values, groups of switching devices each associated with one register group, a first pulse generator for applying a clearing pulse to each register group, and a second generator for applying to each group of switching devices a differently-timed pulse to shift to the associated register group the digit registered on an adjacent group. The multiplicand register shown comprises five decimal denominations U, D, C, M, DM, each consisting of four hard-valve trigger pairs 20 representing coded values 1, 2, 4, 8. Each trigger, except in the highest denomination DM, applies an output potential over a line such as 28 to a gate circuit 26 so that if it is in the " on " state (represented by shading of the lower portion and of an associated neon indicating lamp 21) the gate will be open (represented by horizontal instead of vertical lines) to allow an operating pulse to be applied from a distributer D1 to the corresponding trigger in the next higher denomination. The distributer supplies pulses to the gates of denominations M, C, D, U in that order, which pulses are timed to be interspersed with, and a half-step in advance of, resetting pulses from a distributer D2. In operation, the distributers are operated to effect denominational shift after each multiplication of the multiplicand by a digit of the multiplier. The multiplication may be effected by repeated addition employing an electronic accumulator similar to that described in Specification 679,993. In a modification (Figs. 3a-3c, not shown) in which shift occurs simultaneously in all denominations, the distributers are omitted and each valve-registering trigger (A) has a second trigger (B) associated therewith. When resetting pulses are applied simultaneously to all triggers (A), the number registered is transferred to triggers (B), and on the subsequent resetting of triggers (B) the number is sent to the corresponding triggers (A) of next higher denomination.