Sinclair ZX80 / ZX81 / Z88 Forums

I've had a chance to use my ZXpand for a week or so now and its performed faultlessly. Now Im looking for more information. When I boot it displays a version 2.3. The manual only talks about version 1 and I found some info up to v2.2. Sirmorris/anyone, do you have a definitive list of the commands a...

Thanks guys, got the schematics. Transistors and caps ordered. Though I think I've messed up the ceramic caps (one on the board is broken at the edge and its inside is visible). They are 473Z which I read as 47000 nF so I ordered 47 uF one but I think the ones I should have got were 47pF but now Im ...

Hi, I've more questions, trying to resurrect the board I dropped a screwdriver across... What are the values of the transistors on an Issue 3 board between the ROM and CPU, and the one next to the regulator? Is there an equivalent for the ztx transistor? Also, are there any decent circuit diagrams a...

That worked. Thanks a lot sirmorris

Thanks, tried to get it and got a login/registration screen for Bitbucket. Registered and now get told that I dont have access to wherever that link goes.

Any chance you could send it to daveatscotekdotnet?

I tried backing off the sync trim but all I get is a white screen which the pixel trim doesnt change. At one point I did get a perfect cursor when I pressed a little harder with the screwdriver, but I couldn't replicate it. I think I will give up on this for now until I can get an issue 3 to try. Th...

Hi, I had a ZX81, dk'Tronics keyboard and some uncased Rampack back in the early 80s and always regret selling them. So I'd like to say a big thanks to SirMorris and Pokemon for producing the ZXpand and ZX8CCb addons. Like many others I have been getting back into the hobby again and bought some zed...

Hi Karl I think there is a problem with my interpretation of the setup instructions. You say: 1 - to turn the pixel/R2 trimmer fully clockwise to get a white picture. 2 - to adjust the sync/R1 trimmer to get a valid picture without sync failures 3 - to adjust the pixel trimmer to find the K cursor W...

Got the ZXPand today. One day delivery - fantastic service Rich. I'm using it with a MemoPak keyboard, output is composite using the ZX8 module and I'm more than happy with it. I believe its possible to put the ZXPand into a MemoPak RAM case and that the end needs a slot cut for the SD Card. Does th...

Thanks for your help Karl, no - I don't have an oscilloscope. yes - you did test the ZX8 modules. This is the one I couldn't get any picture on originally. The other and one I bought from eBay are installed and working on my two Issue3 ZX81s I can get a picture with RF. Could faulty ULA be OK on RF ...