Andrew Gabriel wrote:

A friend of mine bought a ZX80 or XZ81 kit (can't recall which).
The diodes for the power supply bridge rectifier were rejects
because the band was marked on the wrong end, it turned out
after he powered the thing up...

Ah...

Remember the germanium "micro alloy transistors" used in many of his
earlier efforts (I still have an original X10 (PWM) amplifier
somewhere)? Those are documented somewhere as being a job lot of
rejects he bought from AEI.

--
Andy