The best mouse/trackball I had was an Atari video
arcade trackball that I
got from Happ Controls and wired to the guts of a cheap PC serial mouse
(optical sensors on the track ball, electronics from the mouse). This
trackball measures about 6" x 6" x 2.5" and I had it in a foamcore box.
Used
1" diameter arcade buttons to replace the mouse buttons. I made it as a
prototype for a dozen or so that I wired up for use in exhibits at the Field
Museum of Natural History in Chicago with the computer games I wrote. I used
the track ball for more than 10 years before I even needed to clean it.
Sounds very non-ergonomic, but if that's the trackball used in the Missle
Command games, that would be the best trackball I've ever seen!
Zane