Sinclair ZX80 / ZX81 / Z88 Forums

But also, crediting authors and with their authorization. Once you are able to send private messages (PMs), you can try to contact the authors. At the moment, they don’t visit the forum that often, but if they have their account set up to send them a email when they get sent a PM, one or more may r...

I'd like to gather all information in one place and with simple details (maybe create a gerber file), so that everyone could build ur own. But also, crediting authors and with their authorization. Another way is for me to create my own project but it should take longer. If those who already did it c...

If your ULA does end up being found to be dead after following Marks advice, and you still wish to create your own,then both Andy and RetroTechie have details regarding their ULA's available on the forum which a quick search would have lead you to. Zip files for both ULA's can be found here... http...

What do you have on pin 16 of the ULA? Also, what test gear are you using? Mark Hi Mark, used probe 10x on pin 35 - getting osc 6.5mhz and min/max about 3v-4v I've disconnected pin 14 from my board (just lifted the pin) and it's 0v (1x or 10x... nothing) pin 16 had response but now its 0v also...

Hi folks, I'm trying to bring my zeddy back to life but I guess my ULA is dead. I've read all topics about this but I still have some doubts about it. For example: My ULA has oscilation from the XTAL (6.5mhz) between 3v and 4v on pin 35 but I have zero volts on pin14. Is it posssible that maybe it's...