NOR, XOR and XNOR). Electronic gates operate on two nominal voltages, normally 0 V and 5 V, representing the logic 0 and the logic 1, respectively. The AND gate has two inputs A and B.

It’s a surprise then to find that a working CPU can be made with just a single NOR gate — which is what is at the heart of [Dennis Kuschel]’s My4th single board discrete logic computer.

NOT, AND, and OR logic gates are considered to be functionally complete because they can be used to generate any function. Complex applications use numerous NOT, AND, and OR gates, along with NAND, ...