OK, I am screwed on ps2 for my mobo:
look what I found in one of it's bios releases:
Caution: This version BIOS(433AUS26) is for HOT-433 motherboard which support
PS/2 mouse. If your motherboard support does NOT PS/2 mouse, please
download different version BIOS other than this one.
To tell if your motherboard will support PS/2 mouse, just verify
if your motherboard has external keyboard BIOS. If it does, it
will support PS/2 mouse. If the keyboard BIOS socket is empty,
it will NOT support PS/2 mouse.
...and ofcourse mine does not have this chip :madashell: