The El-3 is a rare and relatively expensive pajazzo game in Norway. It implements what has to be the most paranoid game logic ever made. Arcade and coin games normally leaves the coin validation part to the coin validator. This game – not so much. The game uses coin validators, but it does not trust them.
In order to prevent people from re-using their coin by attaching a string to it, the developers of this game decided to add two additional security features.
- Detect the speed of the coin as it falls into the coin box.
- Detect that the coin has a center hole.
The game achieved this by letting the coil pass two opto sensors after it had been accepted by the coin mech. Each sensor would send a pulse to the game board as the coin passed it.
The mechanism worked, but also it also locked the game to only accept coins that had a center hole.