Old intel mobo

Hello.

I was hoping I could get a little help from you guys. I was just playin around with my parent's computer. (it is old as dirt) anyway I had abunch of computers I got from university surplus - a bunch of gateway p5-75's, and I transplanted my parents p5-100 into one of the gateway mobo's and it will always boot to 75Mhz instead of 100. Now I'm sure there are some jumpers i need to switch, but I have no manual or guide.
So my question is does anyone know a site that has info for really old motherboards? This computer is from 1995.

There should be some sort of diagram on the mobo itself labelling multiplier, FSB and their accompanying jumper settings.

I'll look again, but I'm a little new to changing jumpers and such.
Thanks for replying to my question

usually setting the jumpers correctly helps