Abstract: A microprogrammed control system capable of overlapping the fetch and execution of microinstructions even when a conditional jump microinstruction is being executed. The control system comprises a pipeline register for storing the microinstruction currently being executed. The system also includes address circuitry for forming an "ordinary address" which is one greater than the address of the microinstruction in the pipeline register and for forming at least one "jump address" of a microinstruction occurring elsewhere in the program. A conditional jump microinstruction identifies a jump address for the microinstruction to be executed next, which jump address is only valid after the condition identified by the conditional jump instruction is tested and indicates that the jump address is to be used. Otherwise, the next microinstruction has an ordinary address.

Abstract: In a card punch machine there is provided a photoelectromechanical punch checking system. A shutter is mounted on each punch pin in the card punch machine and movement of each shutter is monitored by a photoelectronic sensor. Signals from the electronic sensors are compared with data employed to select and actuate the punch pins to provide verification that the data signals have caused the selected punch pins to be actuated through a punching operation cycle.