>>106945284
I don't know about that one but generally, yes
>how is the movement detected, with a mouse sensor?
Depends on the model. Some have one or two laser sensors, others have rollers like ball mice. I assume they use opto-isolators like ball mice but I wouldn't know, I've only ever had the laser kind

>>106945390
I do too. They don't, but neither compares to a real trackball.