STK1000/PS2 connectors
From AVRFreaks Wiki
PS2 connectors and interfaces allow you to connect a PS2 compatible mouse or keyboard to STK1000. Mouse and keyboard can be used as input to Linux.
STK1000 have two PS2 connectors labeled MOUSE and KEYBOARD.
Signals
These PS2 interfaces does not have any level conversion so 3.3V compatible keyboard and mouse must be used. Most keyboards and mice does not support 3.3V signaling so you have to look specifically for devices that allow 3.3V communication.
Pin out
Interfaces
Refer the help files of the daughter board to find out what interfaces are used and which peripheral on the processor are connected to the interface.