Steve, I know, Tomi's is one of the first adresses to search but I found nothing on his pages. I proposed a year ago to include this Synaptics data sheet I found after "heavy searching" (which includes a good explanation of the PS/2 standard protocol) in his links.

Lance, thanx a lot for this URL to Holtek !
In the controller data sheets I found a sequence to switch to the "3D mode". I hope the Logitech Trackball accepts this as well. As far as I know some standard scrollmouse drivers can handle Microsoft and Logitech devices with the same commands. Let's see. I will check this as soon as possible.

Think it's time for another mail to our friend Tomi. :)

Olaf