GB868840A - Improvements in or relating to circuit arrangements for dividing binary numbers - Google Patents

Abstract

868,840. Digital electric calculating-apparatus. NATIONAL RESEARCH DEVELOPMENT CORPORATION. July 8, 1957 [July 10, 1956], No. 21357/56. Class 106 (1). An electrical binary series-mode divider is adapted to effect division by a small odd integer of the form 2<SP>n</SP>+1. As shown, Fig. 5, for effecting division by five, the dividend x on a lead 40 passes via a mix 43 in true form to a line 10 and simultaneously after inversion at 12 to a line 11. The lines 10 and 11 supply respective gates a, b which control entry to five unit delays 13-17. The output from the delay 13 conditions the gate b of the delay 13 and the gate a of the delay 15. The other four delays each condition two entry gates as shown. The dividend is applied twice to the mix 43, the first application of the dividend being followed by a " gap signal " of two " 0 " digits applied through a gate 44 to the mix 43, which gap signal is followed directly by a second application of the dividend derived from a delay 41. A pulse on a lead 60 in synchronism with the first digit pulse of the second application of the dividend conditions gates 47, 48, 49 which are arranged to recede in binary form the output of that one of the delays 14-17, which is activated and which represents the decimal remainder 1-4, the serial binary form of this remainder appearing at an output R. During the second application of the dividend a gate 54 is opened to pass the quotient which appears serially from gates 21, 23 controlled respectively by the complement of x and by x, the gates 21, 23 controlling outputs from the respective delays 14, 16 and 13, 15, 17. The apparatus is reset by a pulse DV4 which inhibits a gate 56 to cut off the signals applied to the delays 14-17 when no signal is applied to the lead 40 and opens the gate b of delay 13 representing " 0," which is then maintained activated by feed-back. An arrangement for division by three is described (Figs. 2 and 3, not shown). The mathematical principles underlying the invention are set forth in detail in the Specification. Specification 789,207 is referred to.