Sinclair ZX80 / ZX81 Forums

I see. Didn't realise it wasn't a normal Z80.

Just spotted this (it's not mine). Some kind of homemade interface. Looks like a Z80 on it. From the short connector I'd assume it was for a ZX81.

But what does it do?

https://www.ebay.de/itm/I-O-Interface-m ... 3366882732

I bought a couple I think in Nov/Dec and then he put up a message (as an item) saying that he would be away to the 3rd Jan.

Ok. If you 'see' him, tell him I'd like 5x ZX8-CCB's. I know they take time and parts to make, but there must be an Aldi shopping basket for him at the end of it

Anyone know what has happened to Karl-Heinz lately? No response on SMR and I could do with some ZX8-CCB's (also, in case anyone else has a couple spare).

Hope he's alright.

Good idea. But it is proving quite tricky! I shall persevere.

Everything on the Z80 and the RAM looks the same as the known good ZX80, as far as I can tell.

Ignore the above. One was set to AC, the other DC!

Edit: IGNORE this post, I noticed one probe was set to AC and the other DC! Ok, I think there is activity where there should be and highs where they should be. I compared the dodgy new ZX80 to my known good original. Here is a pic showing the read out for pin 16 on the Z80. Yellow is the good one, ...

Thanks so much Mark. I will check those things in due course. I did also try with a known good 16k RAM pack and there was no change. The RAM chips I got with the board are: MM2114N-2L and MM2114-3. Interesting about them having to be different, as I changed them for 2 from a ZX81 (because I knew bot...