Sinclair ZX80 / ZX81 / Z88 Forums

Hi all,

I and someone else (maybe someone here?) managed to secure a ZX81 issue 1 motherboard each from eBay last night, for about a tenner apiece. Nice! Sold as tested and working, but in the photo it looks a real mess. I think they were built from kits. I'll post some pics when it arrives, and you can all let me know if I've been sold a dud!

My own original ZX81 is down in England at the moment. I'm not sure what issue it is, but I went through 2 or 3 replacements during the guarantee period so the one I ended up with may have been one of the final issues. That final replacement was at the end of 1983. Anyway, it's certainly not an issue 1, so I've expanded my collection a little.

If it's not an issue 1, then if it is a UK ZX81, it must be an issue 3. As no issue 2 boards have been found.

Mark

I'm 99% sure that's what it is. But you never know, with Sinclair's habit of fixing returns and reselling them. So I won't know for certain until I get my hands on it again!

I saw those two boards and one of them had the later ULA fitted. The type face on that ULA was slightly different to the norm IE big bright and bold covering nearly the whole of the chip, a bit of a rarity perhaps?

They looked to me like the owner had swapped chips back and forth perhaps... so either a rarity or an anachronism lol. But the chips look to be socketed, so it shouldn't be hard to improve the authenticity of it in future if appropriate.