They made
trackballs for some of the SUNs. A friend of mine has one. But I
know that
they're hard to find.
I figured it would probably be quicker/cheaper to adapt an existing
trackball than find the genuine article... even if I have to sacrifice a
real sun mouse to do so (ie, just connect the leds/photodiodes in the
trackball to the sun mouse pcb).
One supplier I know that has Sun trackballs, charges $100 for the USB
version, and $200 for the older sun mouse port version. On the plus
side, they are programmable without software drivers, so we actually
use the USB version on our special workstations for accomodating the
disabled.
-Lawrence LeMay