Senior Member
There is a website about this computer ( ) written by the inventor himself.

It would be easy to replicate using a PICAXE, but why would you want to ?

I reminds me of the electronic calculator I was tempted to build ( Practical Electronics mag, late 70's sometime ). Dozens of TTL chips, miles of wire wrap, and a 10 month project. By the time the last part was published Sinclair had the Cambridge on sale for £30. It rather took the edge off building a desktop machine.

EDIT: I just found a scan of the project, it was 1972 !


Senior Member
Back in college during the early 70s, an acquaintance as part of its PhD dissertation was building a simple computer employing only TTL chips.
He employed a small army of undergraduates to assist him in the pre-CAD days, where absolutely everything was hand drawn and laid out.

The boards looked very similar to the ones in the photos. Hundreds of TTL packages, hundreds of interconnections, meters and meters of wire.
I was completely in awe that someone could actually understand, much less design, such a machine without getting lost with all the connections and signals.

Fortunately for me, they assigned me the power supply section. It required something like 25 amps @ 5 volts, so it was an all discrete transistor design. Arrays of TO3 transistors in fan-cooled heatsinks.
Part of the supply design was a crowbar circuit, as there was always the distinct possibility that the supply voltage would overshoot and destroy scores of ICs. The crowbar triggered a hefty SCR across the supply lines, clamping the voltage and causing the main fuse to blow.