by Dave » Sun Feb 21, 2010 10:44 am
It is probably a counter that counts the number of jackpots (7 7 7) were hit.
This was needed because it is a hand-pay jackpot and the operator needed to know how many jackpots were paid out.
I am guessing the two counters counted the same. One was visible from the outside so they didn't need to open the machine.