Take a look at this link:-

http://www.home-micros.freeserve.co.uk/zx80/zx80.html

I would love to be able to build one of these. I know nothing about electronics. Can somone produce a list of parts with part numbers and where in the UK to obtain them and a very simple (very, very simple) explanation of how to put it together? I somehow need to get the OS into ROM too.

Nick

It looks like it would be expensive to build, unless you already had a chip programmer

You should be able to get everything from that parts list from the suppliers, here.