If it has a little round DIN connector, try '/dev/psaux' as the device. You will need to 'modprobe psaux' before you do try the mouse.
I recommend installing gpm, which has a nifty mouse-test program that can usually figure out automatically the type/port/etc of your mouse - but you may have to run the program a few times, as it proresses too quickly for most people to follow the first time. Once you know what to expect, you can follow it. Install the psaux driver (modprobe it) before you try to he mouse-test prgram (which i think is calld gpm-mouse-test). Carl
