Москва-128

[Shockwav3]

I'll give that a try ... about schematics, I've been largely using this one, albeit having some small errors/deviations: https://github.com/romychs/moscow-12...128_v1.1.1.pdf

EDIT: Some kind of progress I assume after adding diodes for D0-D4 of the keyboard. Sometimes I get the testcard on bootup, sometimes the keyboard can be used with keys being dropped, but hey, the SRAM (6116-15) outputs random characters at random intervals. I guess adding some kind of latching busdriver (IR22?) for the output of the SRAM probably isn't a bad idea either?

[Advertiser]

[Serg6845]

EDIT: Some kind of progress I assume after adding diodes for D0-D4 of the keyboard. Sometimes I get the testcard on bootup, sometimes the keyboard can be used with keys being dropped, but hey, the SRAM (6116-15) outputs random characters at random intervals. I guess adding some kind of latching busdriver (IR22?) for the output of the SRAM probably isn't a bad idea either?

6116 outputs are inputs when programming, with just adding IR22 (373) you will not be able to program 6116. with diodes at keyboard D0-D4 there seems to be another problem - R66-R70 are too low. R3-R10 pull data bus up, R66-R70 pull it down via VD12-VD16, so when no keys pressed you get some lower levels on data bus D0-D4. Try to increase R66-R70 to maybe 10-20kOhms.

[Shockwav3]

You're a hero! I did increase those to 11.1K (2k + 9.10k inline) and the interface now works!
Thank you very much. Looks like a mess at the moment but I'll clean it up and make it tidy.