ELECTORNIC ARRANGEMENT FOR THE MULTIPLICATION OF A BINARY- CODED NUMBER IN A SYSTEM HAVING AN EVEN-NUMBERED RADIX GREATER THAN 2 WITH A FACTOR EQUAL TO HALF THE RADIX OF SIAD SYSTEM OF NUMBERS

摘要

1395991 Multiplying WIRTH GALLO & CO 23 Aug 1972 [24 May 1972] 39212/72 Heading G4A A number in a system having an even number radix b of a form z = #a i bSPi/SP each digit in the radix being in binary coded form is multiplied by b/2 to derive a number c = #c i bSPi/SP. The coefficients c i are of the form c i = p i + u i-1 where (1) if a i is even pi = 0 and if a i is odd p i = b/2 and (2) u i is determined by division of a i by 2 (rounded down). In the embodiment described for a radix of 10 in which the bits of the numbers z are fed in parallel coded serial form on lines 1-4, the terms p i are derived by connecting the least significant bit of each digit to the 2SP0/SP and 2SP2/SP terms of the first input of adder 13 so that 0 or 5 is applied to the adder in dependence on whether the coefficient a i is even or odd. The terms u i-1 are derived by delaying by one clock pulse (in bi-stables 14, 15, 16) the three most significant bits of each digit and then dividing them by 2 by connecting them to the three least significant inputs of the second input channel of the adder 13. The adder output 21-24 gives the required product.