Sinclair ZX80 / ZX81 / Z88 Forums

Moggy wrote: ↑Tue Aug 01, 2023 10:07 pm I've edited my post to say that I think it's a Sinclair board made for the US and not a Timex one and has been butchered for UK use.

BEWARE: If its the Republician version ROM on startup it will check the 1k RAM to 1024 and demand a recount

Shame on you Moggy...

I luv what you have done to your machine, but its dirty around the Sinclair logo... I hope thats just coffee and buscuit crumbs

Thanks. When I mod these I use a ZX8-CCB as they give great results on every TV I have tried. I also fit a ZX8-KDLX keyboard, replace the caps and voltage regulator, fit 16K internal RAM and a Wespi (wifi fast loader) so its a bit involved! Just been looking at the curcuit for the ZX8-CCB, very nic...

Hi, My orginal kit ZX81 back in the day suffered this problem and it was the Cermic Resonator. Swapped it out and the problem went away. But, it was always a question of tweaking the vertical hold when I went back to 625 line B&W TV. I would recommend the usual fix, a video buffer board with the 555...

Its a Mystery to me but someone here may have seen one? Or know something about it? I bought an Ebay ZX81 for a spare ULA. Its an Issue 3 factory build. There are various mods around the Cermaic Resonator and this chip I am almost certain is a factory mod. PXL_20230723_085120232.jpg This one is inte...

Hi everyone, I have a few ZX81, Spectrums and other Retro machines I spent my spare time reburbishing. PXL_20230618_131531430.jpg This one was my first machine with a Kayde Keyboard from 1981, a dream to use. I was shocked to find it in a box in the attic after I thought it was long gone. Its nice t...