Digital IO (GPIO) ?

electricitylikesme

I have a mini-ITX motherboard with a 8 "Digital I/O" ports on the mainboard, and I have absolutely no idea what they're for or how to use them. I understand they're basically similar to a microcontrollers IO lines (and use TTL voltage levels) but I can't find much on how you interface with them (or what I really want - a driver API to let me do it easily).

Does anyone know anything about this type of interface? Ideally I'd like to use it on Win XP, but Linux would also work (and be more likely).