MicroAce
The MicroAce was an unauthorized clone
of the Sinclare ZX80
It came in a kit for for about $79.
It was a UK product that would connect to a TV set.
It called for a zero ohm resistor
but was not included.
I had the unit working
but when connected to the TV set
the vertical hold had to be adjusted.
If the TV was changed back to watch
the vertical hold again had to be adjusted.
Finally, I realized the UK uses 50 cycles
and the US uses 60 cycles.
I added the zero ohm resistor
and it solved the problem.
This unit had a film keyboard
but surplus keyboards were readily available
I added a real keyboard
and also cliped in front of the TV modulator
and ran video to a monitor.
The video vastly improved.
I bought two of these usits.
The first had interger basic
and 1K of RAM
The second had floating point
and 2K of RAM.
It was amazing what could be done with 2K of RAM
Later, I bought a Sinclare ZX81
and even bought a 16K addon memory.