Pictures show the trackball and the insides of the M$ mouse
Stefan Radke has managed to map the pinout of a Logitech laptop trackball from a Compaq Contura 400CX.
He writes: "today I managed to hook up the trackball just as a regular PS/2 mouse device to a PC. Just needs a PS/2 cable connected to the pins in the following order (pins from inner to outer ):1 - GND, 2 - GND (3), 3 - Vcc(4), 4 - Data(1), 5 - Clock(5). Numbers in () are PS/2 pins.
Cool stuff, Thanks!
It's real close but not entirely the same design as the one I had to play around with. I suspect most of these will have PS2 (or perhaps serial) connections for the older ones and possibly USB for newer ones though, so direct hookup for use in random projects (CarPC, etc..) should be possible.