Sinclair ZX80 / ZX81 / Z88 Forums

These gentlemen are right because I exactly did thing. Can you get your multimeter out and set it for a diode check or a continuity tester? Hold a probe on the 3rd "finger" of the 5 pins connector and hold another probe on an ULA's pin # 29. Inform us of the result here. Check the ULA's socket hole...

Hi Rwap, Bad luck if this new keypad has a defective strip. The reason why I replaced the keypad was the original strip in a very bad shape and broken in some areas resulting in keys not working. Cannot remember if the non working ones are the same as now. I will test both connector with a wire and ...

Yes I do see the 'K' prompt and all keys are working except the one listed on my reply above. Did not try to short the 2 connectors still but will test this as soon as possible. I have also refluxed the solder joint on the back for both connectors.

Hi Dessony,

The strip connector is not the problem I think because I cleaned it with contact spray already.

Here it is Mark,

Keys 3,8,E,I,D,K,X,M. Any Shifted function on those keys will not work also.
3,E,D and X are more or less aligned on the keyboard and same for 8,I,K and M.

Hi Guys, Desperate to have the ZX81 keyboard to be fully functional. The strip connector was in a very bad shape at the time I picked this unit up and though this was the issue so I bought a fresh new keyboard from SellMyRetro but after installing, cleaning the strip connectors and put some fresh so...

Hi B,

Thanks a lot for the links!

Hi 1024MAK

Thanks for the rom links. How can I combine then the two roms (128k editor and menu+48k basic) into a single file to burn into the Eprom?

Hi guys, Any of you has a link for a tutorial on how to replace the Eprom on the Spectrum 128k +2? Actually I have menus in French but would like to change this to the english version. I do have a bunch of 27c256 and 27c512 I can use for spare + a programmer but need to know how to combine the origi...

Hi guys,

Replacing the Z80 has solved the problem. The original CPU was missing the M1 line needed for the Divmmc to properly work
Problem solved!