Sinclair ZX80 / ZX81 / Z88 Forums

Of the 2 ZX80's that I seem to be getting frustrated about and am just about to give up on, this one possibly has the best chance of working, so this is what I've found. Going by a list Mark once wrote re Z80 pins, and also comparing the broken one to a working ZX80, this is what I have: Pin Functio...

Don't think I'm a member there, but will do if I get no response after a few days.

I have 2 non working ZX80s. I've been off and on trying to repair them for what feels like years and have made some progress, but they aren't quite there and I'd really love to find someone with the knowhow to look at them, investigate and then tell me what was wrong, so that perhaps I may learn som...

I did the mod. Used a SIL05-1A72-71D relay.

And it works a treat, no buzz on the audio, unless the motor is operating.

My +2 grey has loud audio hum from the tape amplifier. It goes away when the tape part isn't plugged in, so it is definitely the cause. I read about adding a reed relay across the tape motor here: https://worldofspectrum.org/forums/index.php?p=discussion/42171/correction-of-2-hardware-errors/p1 The ...

And here it is. Quality wasn't amazing to start with, but it looks like it's all legible. Thank you so much this is fantastic. I was thinking of expanding the Nuclear Reactor software https://www.sinclairzxworld.com/viewtopic.php?f=6&t=4278 to control some real hardware. May end up trying something...

And here it is. Quality wasn't amazing to start with, but it looks like it's all legible.

Spooky massive coincidence alert! I was sorting through some ZX81 paperwork and books earlier today to sort out a selection of spare German computer books to put on ebay and I re-discovered this: 20210727_211552.jpg I never actually had the device. This 8 page instruction sheet came with a German j...

I did it all at the weekend. I went for the OZ 4.7.1 official public release instead of looking into the v5 yet. It'll still be a massive improvement. Mine is actually a German model with German k/b so great that the newer OZ versions lets you configure the k/b type. I programmed the SST flash chip ...

Excellent clear write-up. I now have the required bits to do this to my Z88. The website with the OZ ROMs is probably the most confusing part! There is a read-me that explains the naming, but there are a lot listed, mostly development versions.