Like the DEC PDP-8, this is a 12-bit machine, but instead of the diode-transistor logic of the DEC, the substantially smaller Q2 uses a simple NMOS approach.

Kyle Hovey has decided to build his own 8-bit CPU from scratch, out of breadboard, NVRAM chips, surface-mount transistors, and lots and lots of wire -- and he's blogged his experience, so you can ...

You only needed 400 germanium transistors, 1800 resistors, and an odd number of capacitors, switches, diodes, and neon bulbs. You also needed a good bit of patience, we suspect.