The slot machine or one-arm bandit is a mechanical device that will absorb coins just about as fast as you can feed it. After inserting a coin, you pull a handle that sets three independent reels spinning. If the reels stop with certain symbols appearing in the pay line, you get a certain payoff. The original slot machine, called the Liberty Bell, was invented in 1895 by Charles Fey in San Francisco. Fey refused to sell or lease the manufacturing rights, so H.S. Mills in Chicago built a similar, but much improved machine called the Operators Bell. This has survived nearly unchanged to today.
On the Operators Bell and other standard slot machines, there are 20 symbols on each wheel but they are not distributed evenly among the objects (cherries, bar, apples, etc.). Of the 8,000 passible combinations, the expected payoff (to the player) is 7,049 or $89.11 for every $100.00 put in, one of the lowest expected payoffs in all casino games.
In the program here, the payoff is considerably more liberal; indeed it appears to favor the player by 11% — i.e., an expected payoff of $111 for each $100 bet.
The program was originally written by Fred Mirabella and Bob Harper.
As published in Basic Computer Games (1978):
Downloaded from Vintage Basic at http://www.vintage-basic.net/games.html
- The original program does not correctly detect identical draws in the first and third position as a double (instead, it counts as a loss). This is probably not intended. Some of the ports fix this, so that any two matches count as a double.
(please note any difficulties or challenges in porting here)