<Anyone know what the clock speed of the 4004 is? Courson's web page <mentions it not. I'd guess around 500khz (typical for silicone gate Pmos) but the published instruction cycle time is 10.8uS(likely a trivial register move). It took something like 4-5 clock cycles to get an instruction cycle minimum as address (4bits at a time were output) and instruction was input the same way. Instruction could and did take several cycles so this CPU was NOT fast. ;) Allison