For those interested in those fantastic little Sinclair machines (ZX80 and
81), check out the following web site:

http://www.babytalk.demon.co.uk/zx80/zx80.html

Show's you how to build both machines from scratch without using discreet
logic and no ASIC's and the schematics and descriptions should give a good
deal of insight into the operation of these machines.  The guy that wrote
the ROM for these machines (Was it Clive Sinclair himself?)  was some kind
of master genius.

Regards

Mike Rigby-Jones
mrjones@nortel.co.uk