By now we are wondering how any circuitry could possibly manage all these control points for such a complex instruction set. It is not merely a question of which wires to turn on, given, say the ADD instruction, but they must be turned on and off in a certain sequence and at certain times. Computer designers have to worry about waiting the proper amount of time for the memory to do its operation, for values to emerge from decoders, for bits to latch into flip-flops, and for many other things.