Vacuum tubes replaced relays as the main elements for computation. A simplified circuit that implements the NOR logic gate, which only outputs 1 when both inputs are o, is show at the right.

Texas Instruments’ 5400 and 7400 TTL quad 2-input NAND gate has been in continuous production since 1964 and is the progenitor of what is probably the most numerous breed of integrated circuits ...

Instead of CG cell (CG1 and CG2) if simple NOR gate circuit is used to gate and un-gate clocks, the problem disappears. Below circuit and timing diagram delineates the behavior. Figure 5: Solution 2 ...