POV or known as Persistence of Vision. The theory of persistence of vision is the belief that human perception of motion (brain centered) is the result of persistence of vision (eye centered). The theory was disproved in 1912 by someone. Anyway its persists in many citations in many classic and modern film-theory texts.
The awesome "propeller clock" display. On board memory holds 128 frames. It can display a static message, show a running clock, and also run animations (like the rotating cube). It also developed an easy way to load a 65x65 black and white bitmap from computer directly to the display.