Watched a lady and guy win so much, they got bored waiting for fill ups. They were bouncing between 2 machines. Hitting, hitting, hitting. After the fourth fill, the Casino shut the slot down, saying that regs allowed them to do that as the slot could be broken. In the old days they were not as computerized as now.
The bells going off were a big distraction to the players.
This was probably in 1976.