Today, at last, i got this damn thing into working order!
It's been in my hands for maybe 2 years already!
The Super IO controller chip was bad and replacing that (combined with my lack of skills) i was soldering and desoldering new controller chip on the board maybe 10 times. I had lots of accidental bridges between legs and stuff like that until i somehow killed the replacement chip.
At one point, i saw someone selling super-io controller locally, that was also used as donor before. But the chip was same and still present. Bought that scrap card for something like 0.10€ and today had a chance to try again with a new replacement chip. Tried some new techniques (for me) and amazingly, it came out 100% working!
I had already lost my hopes and was preparing myself to just desolder the controller chip and use a separate controller card in ISA slot to just get it working somehow... but now, it works perfectly with all ports that are integrated to motherboard! No non-working ports on this machine!
While at it, i was able to figure out jumper settings to get it from 128kB of cache to 256kB of cache, so that's another upgrade.
Now brought out some old CRT, keyboard and mouse, will clean them up as well (the machine itself is already cleaned) and then i have the last task - finding a good new home for it. 😀
FYI, it is this bastard - a really really weird computer:
Help to identify: MULTIPRO VII-386DXV (UR INFINITY)
"640K ought to be enough for anybody." - And i intend to get every last bit out of it even after loading every damn driver!