First of all, trackballs are relative devices (they return delta
coordinates).
It should be possible, but this is not a common request/application.
You may want to contact Apple's DTS for help with the project.
I think you will need to write a kext that either works with your
specific trackballs in boot protocol, or somehow supplies some
different descriptors (such as a HID report descriptor), so you can
use the HID Manger to access the data from the device, but not treat
the data as input for the cursor.
Now it might be possible to gain exclusive access to the device
through the HID manager, and if so, that would be the most
straightforward approach -- you may want to investigate this on your
own, and if you can't do it, then follow the approaches listed above.
Regards,
David Ferguson
USB Software Team
Apple Computer
