Can trackballs do things mice can ?
A. Yes. While often called “an upside down mouse” a trackball is actually quite different. Most significant is that trackballs while optical mice and trackballs use similar sensing technology, opto-mechanical trackballs use the downward pressure on the ball to directly drive their encoders while mice must roll on a surface to operate correctly. Doesn’t sound like much of a difference but we know for a fact that the mission specialist laptop PCs on some early space shuttle missions used trackballs because mice would not work in a zero gravity environment. Also, because they can roll continuously without re-positioning, trackballs are much faster to position the cursor on a large screen which is why they are often found on guided missile fire control systems and arcade games (can you imagine playing “Centipede” or “Missile Command” with a mouse!!).
