Improvements relating to binary register units, especially for shifting registers

763,447. Pattern movement stepping register. ELECTRIC & MUSICAL INDUSTRIES, Ltd. Aug. 6, 1954 [Aug. 15, 1953], No. 22553/53. Class 106 (1). A binary register unit, suitable for use as one stage of a shifting register, comprises a bistable device, a monostable device, means for applying shift pulses to said devices, and a source of conditioning signals coupled to said monostable device and a coupling from said monostable device to said bistable device so that the bistable device can be switched to either of its states in response to a shift pulse, in dependence upon the conditioning signal applied to the monostable device. A short positive shift pulse applied from lead 10, Fig. 1, to the emitter of a transistor 1 (the monostable device) via a condenser 18 and rectifier 17, and also to the base of a transistor 2 (the bistable device) via a rectifier 11, tends to set the transistor 1 " on " (high current flow) and to set transistor 2 " off ". However the voltage of the shift pulse is so chosen that the pulse is only effective to set transistor 1 "on" when a positive conditioning voltage is applied to the " anode " side of the rectifier 17 via a resistance 19. Every time transistor 1 goes " on," its collector lead, which is joined to the emitter of transistor 2 goes more positive and sets transistor 2 " on," the inductance 20 being such that transistor 1 stays " on " for a period longer than the duration of the shift pulse. Thus by taking an output lead 22 from the collector of transistor 2 a number of these units can be connected in cascade to form a shifting register, the voltage on lead 22, constituting the conditioning voltage for the next unit, being more positive when transistor 2 is " on ". If the register so constructed is considered to consist of a register proper (the bistable transistors) and a temporary register (the monostable transistors) the shift of a number in the register then occurs in three stages, a first stage, initiated by a shift pulse, in which simultaneously the registered number is trans-, ferred to the temporary register advanced by one stage and the register proper is cleared, a second stage, occurring immediately after the shift pulse ceases, in which the number is transferred from the temporary register to the register proper, and a third stage in which the temporary register automatically clears itself, the timing of this stage depending upon the time taken for the monostable transistors to return to their stable states.