How They Work - Double or Nothing
Many of the late model 6-card games starting with Stock Market had the double-or-nothing feature, and the feature also appeared on Miss America '75. We'll take a look at the Stock Market circuit. Later games had variations, but worked in a similar manner.
When a win was detected, instead of immediate payout the machine would stop and allow the player to push buttons on the foot rail to either collect the win or try for double-or-nothing. There was no skill involved in doubling, you simply pushed the button and based on the position of some wipers on a unit inside the game, you won or lost.
The Principle Ingredients
Winner detection happens in the usual fashion - search disc wipers scan for a winning combination, and if found the game stalls while the search index unit is holding the search wipers on the winner. A light flashes asking if you want to collect the win by pushing one button, or try for double by pushing another button.
In some games, the probability/random unit motor and index coil have been unpowered by the search index powering. The outcome of a double attempt is already determined - before you push the double button! If you could peek into the game, you'd know if pushing the double button would win. Other designs of the random unit ran the motor contunuously when the search wipers were not in their home/locked position, and there was no index assembly. Pushing the double button turned off the motor, so when you pushed the button decided the outcome.
Assuming you pushed the double button, the following sequence occurs:
- the double play relay powers to activate the doubling circuits
- if the double play relay controlled the probability/random unit motor, the motor stops
- if the probability/random unit wipers (and maybe things like the reflex unit) are all positioned to complete a circuit, the double win relay #1 powers and the double trip relay belonging to the winning card trips.
- when a double trip relay trips, the double win relay #2 powers and releases the replay cams for payout. A switch on this relay is also in the replay counter step-up circuit and causes the counter to step-up at half it's normal rate, thus doubling the number of credits put on the replay register.
- a capacitor connected across the double delay relay is discharging. When the charge drops low enough, the double delay relay loses power. If a double trip relay hasn't tripped due to a win, then a missed trip relay trips, the missed light comes on, and you get nothing.