The Megatron optical trackball
An unusual ball pattern that gives an optical sensor a surface to track.
Modern trackballs also use optical sensors. But while mouse sensors take pictures of the surface beneath them, trackballs don't have that kind of surface.
The ball itself serves as the surface, so early models had patterned balls. This is especially obvious on the red balls of older Logitech models.
I have an embedded Megatron trackball whose ball pattern might make an uninitiated observer think it was assembled from rubbish. The ball is also covered in transparent plastic.
trackball
Translated from the original Russian post.
Original post on Telegram ↗