Sinclair ZX80 / ZX81 / Z88 Forums

I just wanted to say another big thanks for your help. I have now fitted the Traco Power regulator and replaced the failing 3.5mm sockets with new gold plated ones. It works a treat now. Here is my 6 year old (Grandpa’s Great Grand Daughter) enjoying playing “Adventure A - Planet of Death” AED8CF64-...

I use Recom types (because I bought a load when the price was low), as detailed (and shown) in this topic . But other similar types like from Traco Power and MuRata are fine as well. Mark Thanks, I'll see what I can find. Are not dangerous for the vLA81 using the RF? Or is possible? Thanks, Matt It...

Moggy wrote: ↑Mon Nov 23, 2020 7:47 pm Another one lives well done Mikeyp.

Add a switching reg to it and it will run a damn sight cooler and should last for ages.

I was thinking about that. Any particular recommendations?

It’s alive! Thank you for all your help!

That's awesome thank you. I wouldn't have thought to look in the sales forum, the title isn't what I would have expected and searching ULA in the forum gives "The following words in your search query were ignored because they are too common words: ula. You must specify at least one word to search fo...

Does anyone have a copy of Andy Rea's ULA page? The original is no longer online and the archive.org copy is missing all the pictures.

https://web.archive.org/web/20090426221 ... A/ula.html

PokeMon wrote: ↑Sat Nov 21, 2020 12:07 am A NAND gate with inverted inputs and inverted output is logically the same as an OR gate.
Personally I prefer using an OR symbol rather than an AND symbol with all inverted.

Super, thank you for clarifying that for me.

I've been looking at your schematics and I'm a little confused. Aren't these meant to be 74LS00? 74LS32 is a Quad 2-input OR gate. 74LS32.png Love the project though. Will likely make one once it's all sorted. I was actually wondering about the possibility of using your logic to create a logic based...

Old ULA removed in readiness.

Right, thank you. Sad as it is, this is positive news though. I now have a diagnosis and have therefore ordered a vLA81 and a socket. I shall set to (carefully) desoldering the old ULA and will report back with my results once the vLA81 arrives and is installed. Thank you again. I shall check in in ...