I'd like to expand my PS/2 driver code.

Our physicists use my stepper motor controllers with attached trackball to position semiconductor probes in a laser spectrometer. But my customers are never satisfied. At last they discovered the scroll wheel and they asked me to put some functions onto this wheel. It's a Logitech TrackMan.

Does anybody know how to initialize the scroll wheel and how the up and down information is coded in the PS/2 protocol ? (maybe there's a 4th byte...?) At the moment my logic analyser is out of order -> I can't catch the bitstream of a running trackball attached to a PC.

Logictech doesn't even provide you with the pinning of a power plug.

Olaf