This is an old post, preserved for reference.
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I've been doing a number of projects recently on the ZX81, and one of the things that comes up from time to time, is its predecessor, the Sinclair ZX80. This was a similar machine, in many ways the ZX81 is a cost reduced version of the ZX80.
10 PRINT "HELLO ZX80"
20 GOTO 10.
Apologies for the photo, I haven't done the composite video mod (and don't intend to), so it's on a CRT monitor. However, you can still just see the ZX80 is has a winder font.