Resources
Unfortunately my Quartz does not work. It has a PROM chip broken. If you happen to have a working machine and can ship me the chip to clone, please let me know.
Documents
Internals
Motherboard
Keyboard and Speaker
The keyboard was missing the “I” key cap with label. I recreated it and replaced – here is the GIMP project file.
Metal Cover
The casing was originally all bent and distorted. It needed some anvil, hammer and paint job to get it straight.
Reassembly
If this is a Sinclair clone, could you use a PROM from an original Z80 or Z81?The really interesting Soviet home computers have K1801VM1 series processors, including BK0010 series computers. K1801VM1(2,3) are unique 16-bit devices with PDP-11 instruction. And yet they were also making Sinclair clones (of which this may be one) except with much better keyboards (that’s a very low bar to beat compared to Z80s and Z81s)
Unfortunately, this is not a schematic-level clone, but functional one. For example there is no ULA chip. Unlikely that PROM chips would be identical to ZX. I know of one other Kwarc which is working, but it is in Russia and there is no easy method of decoding function implemented in a PROM chip.
excuse me, the speccy.info page says this “Quartz” is a clone of a 48K ZX Spectrum, not a clone of the Z80 or Z81, but that still makes me curious about the possibility of getting replacement parts of something other than an exact match. Perhaps from other Easter European clones?