The simplicity of our "A -> B" paradigm carries over into the simplicity of the hardware needed to support it.

The "WIZ" is a very simple microprocessor. The basic circuit, called the "Frontend", shown above, is just a set of registers on a bus, with a very simple bus control circuit (the "Executor") whose only function is to cause a copy across the bus from one register ("A") to another register ("B").

The Executor circuit is very simple and can be implemented with a few dozen gates. The registers themselves are made of 32 (or 64 or any other number of) flip-flop bits and a few more gates for coordination. That is the entirety of the Frontend circuit. It is very small and straightforward.

The single function of the Frontend circuit is to copy from register A to register B.

On the next page we will introduce the "Backend". It consists of an independent collection of primitive transistor-level devices, like adders, multipliers, I/O drivers, analog converters, radio transmitters, and so on. These circuits "snap onto" our registers like "plug and play" LEGO bricks. These give a WIZ its functionality.

When we copy from register A to register B, we really copy from the device attached to register A to the device attached to register B.

And thus our "A -> B" paradigm is implemented using trivially simple hardware.