Hmm, not sure what I was thinking- there is a slot at the top of the PCB with an LED on one side and a phototransistor on the other; one is connected to R8, and for some reason I was thinking that was the input. I'll double-check the PCB and figure out which of the K inputs is used.
The top of the cylinder has a black plastic cylinder attached that has 8 slots; one for each position. One of the slots is a lot larger than the others. There are several pics of it from different angles.
The cylinder rotates counter-clockwise as seen from the top of the game. It takes about 3.5 seconds to make one revolution.
Edit- OK, I found it in my notes; the phototransistor (they might actually both be LEDs- I can't tell any difference between them) is connected to K8.
Last edited by seanriddle; 03/22/1507:53 PM. Reason: added K8 info