Sinclair ZX80 / ZX81 / Z88 Forums

Hey guys, Just brought an issue 6A spectrum back from the dead with some faulty lower and upper RAM chips. I've socketed all of the RAM chips and tested all the DRAM in another test machine using the Retroleum Diagnostics ROM and I'm sure I've got a good set of 48k chips now. Spectrum boots fine and...

Hey Mark,

Yup - it's a good phrase indeed!

Just done a 32k upgrade to the '81 and that's running well too! Maybe time to delve into the hires graphics thing now.. just gotta read up on it!

Cheers again!

Mark.

Hey Mark,

So, I took the plunge, socketed the Z80 and whilst looking under it noticed a small flake of solder sitting across 2 via's - one of them being the KBD2 line!

Thanks for making me less lazy! and thanks for for pointers - all is now good!

Cheers,

Mark.

Yeah - I thought that might be my problem, but I've looked over it with my scope and can't see any shorts at all.. pulling what's left of my hair out

Mark.

Hi all, I'm hoping someone can help with an issue I have with my poorly '81.. It had a bad ULA - replaced it with as VLA81 and all was good in the world once more... until.. I tried any of the 3,E,D,X or 8,I,K,M keys - which make the screen flash and mostly hang the '81. Traced these (looking at oth...