One the cutest
pointing devices I have ever seen, especially for 3D graphic manipulation.
The thing consists of ball, about the size of an orange, mounted on a pedestal (the pedestal is bolted to your desk).
The ball stem has sensors that detect force applied in every possible direction, plus torque, again on any axis.
This allows six degrees of freedom (or of control): you can really send that Autocad teapot spinning into space.
I saw this long long ago, on an Apollo terminal at a SMAU. I was young, then, and thought that HP was God.
The device does not feature in the otherwise excellent movie Spaceballs.