I am trying to make an 100MHz IBM 5x86C (model 5x86-3V3100GF P50J12) work in ABIT PB4 rev 1.3 mainboard. It is a pretty late PCI board with FinALI chipset and has jumper settings for Cyrix Cx586 so it should be compatible.

But there was one problem, PCB with this CPU was too wide and it was colliding with jumpers on mainboard, so I raised that by 5mm using bunch of SIP pin sockets.

Then I noticed that this CPU has 9 additional pins, so I didn't extend them and installed it in this socked with remaining pins unconnected.

And the CPU didn't work. The electricity was flowing because it was getting warm, but mainboard wasn't booting. I tried messing with jumper settings but I couldn't get it to work.

Does anyone know if there are any possible modifications which will make this CPU work?

//edit: i can see that someone already did it here: Re: So you want a Cyrix 5x86-133?

it would be nice to have the instructions (pins to connect, etc).