What do you do with 100 player piano rolls but no player piano?
You come up with a way to digitize the information for MIDI
playback. The rolls have 90 columns worth of holes, 88 for the
keys and two more for pedals. Voids in the paper cause a note or
pedal to be played, so an optical sensor can be used to
transform the analog data into digital information. Simple
enough, you’ll just need 90 sensors. But this brings up quite an
alignment issue. The solution is to use fiber optic cable to
position the IR light source in a hand-made 0.2″ spaced jig. At
least the spacing meshes nicely with standard 0.1″ protoboard,
which is what was used for mounting the sensors.