GB919991A - Calculating machines - Google Patents

Abstract

919,991. Multiplying apparatus. BENDIX ERICSSON U.K. Ltd. Sept. 21 1961 [Oct. 15, 1960], No. 35419/60. Class 106 (1). The multiplication of a sterling amount is facilitated by use of an encoder which receives in turn digits of the amount and is conditioned by signals representing the denominations in that amount to deliver at output terminals signals representing the product digits (e.g. " 5 " input with " pence " conditioning signal delivers " 2 " in a first cycle and " 4 " in a second) derived when the amount is multiplied by ten. Fig. 5 shows schematically (left of the chain line) the encoder 123 and various uniselectors and relays for use with an accounting-machine of the " Addo-X " (Registered Trade Mark) type (right of the line). To effect a multiplication key 27 is first depressed to allow the numerical multiplier to be entered digit-by-digit into registers A-F. The most significant digit is entered first. into F, and any subsequent keying shifts up the contents of A-F one place and puts the new digit in F. The multiplier (no more than 3 digits) is then transferred to a magnetic core store 24, having one column for each denomination and one row for each digit (in the pence position 10 and 11 each count as single digits and corresponding keys and cores are provided). A programme switch 136 comprising two uniselectors then steps to read out in turn the multiplier digits to input terminals 122 of the encoder. The outputs are in binary coded form, and at this stage uniselectors 125 select the unchanged value of the digits which through relays 132 mark corresponding contacts of the units (U), tens (T) and hundreds (H) uniselectors 131. These hunt to find the marked contact ; if a digit is greater than five unit 130 is conditioned to add one to the next higher digit and a relay 134 moves the corresponding switch 135 from " add " to " subtract." The core store is now cleared and key 27 returned to " sterling " position, when the sterling multiplicand can be keyed into registers A-I and transfered to the core store 24. The programme switch now moves to home the units uniselector 131 ; at each step the contents of the keyboard are added into a totalizer (not shown)-or subtracted if the contacts 135 have been changed over. At the next step of the programme switch the contents of core store 24 are multiplied by 10 by reading out the digits in turn (uniselector 121) and passing them to the encoder. Uniselectors 125 stepping in synchronism with 121 select the desired product digits (the action is described in more detail in connection with Figs. 1 and 10, not shown) which now operate solenoids 126 (132 are disabled) to set up the product in register A-I by energizing the key solenoids. The programme switch then steps to cause addition or subtraction of this " 10 X multiplicand " to the contents of the totalizator in accordance with " tens " uniselector 131, and so on for the hundreds, when the final product is available for printing. The circuit is described in some detail in connection with Figs. 10-17 (not shown).