What's Underneath the Xerox Star Mouse

The bottom of the Xerox Star

The Xerox 8010 Optical Star Mouse

Some observations
The bottom of the Xerox Star mouse reveals no ball.
The front of the plug says XEROX in incised relief.
A celophane sticker on the plug's back says, "Assembled in Mexico."
Three raised spheres in the black plastic provide glides.

The optical LEDs of the Xerox StarThere they are, the LEDs, no ball. I assumed that this optical Star mouse required a special pad, since the Mouse Systems optical mouses I have from the early 80's M1-M4 models do require a metal gridded pad. Some people in-the-know kindly explained it and let me post their comments on a message page>