Whether a source of this kind gives positions that were measured. A
roll reader measures when each perforation passes its bar. An
emulation and a recording give the reading somebody else made: the
roll has been turned into notes and commands already, and turning
those back into chains of holes reconstructs them.
Whether a source of this kind gives positions that were measured. A roll reader measures when each perforation passes its bar. An emulation and a recording give the reading somebody else made: the roll has been turned into notes and commands already, and turning those back into chains of holes reconstructs them.