My PC wont boot without a keyboard being attached (its an OLD PC!), one of those with a large round keyboard plug.

I don't want to have a keyboard attached to it so is there any way to make the machine think its got one when it hasn't?

I'm prepared to cut up / modify the keyboard cable to accomplish this.

I dont know what model the motherboard is because I cant get the hard drive bracket off! The buggers have spot welded it in place.