How slots work
Playing slots
COMPUTER CONTROLLED SLOT MACHINES
eBay slot machine
It might look like a regular slot machine. It might even feel like one, with a handle to pull on the side. But the only feature in common with older mechanical machines are the three spinning reels.
Inside, most of todays' machines are controlled by an internal computer, this determines when the reels will stop.
The computer uses step motors to spin each reel, and to halt them at a predermined point.
Step motors are driven by short digital pulses of electricity controlled by the computer. These pulses move the motor a set increment, or step, with great precision.
But though the computer controls where the reels will stop, the games are not pre-programmed to payout at a certain time. A random number generator (RNG) ensures that each turn of the reels has an equal chance of a winning line, even the jackpot.
Every time the machine is activated, the RNG starts spitting out numbers, hundreds of times a second. The computer selects a sequence from the RNG, then feeds these numbers through a simple program to determine where the reels will eventually stop.
Here's what happens.
You insert a coin and pull the handle, ( or push a button ) and the computer records the next three numbers from the RNG. The first number is used to determine the position of the first reel and goes on to select numbers for the next two reels.
As an example the first number could be 123,456,789.For the first reel, the computer divides the first random number by a set value.
Typically it will divide by 32, 64, 128, 256 or 512. We'll assume the set value is 64.When the computer divides the random number by the set value, it records the remainder of the quotient, and finds that that 64 goes into 123, 456, 789 a total of 1,929,012 times, with a remainder of 21.
The remainder can't be more than 64 or less than 0, leaving only 64 possible end results of this calculation. The 64 possible values act as stops on a large virtual reel.
Each of the 64 stops on the virtual reel corresponds to one of the 22 stops on the actual reel. The computer consults a table that tells it how far to move the actual reel for a particular value on the virtual reel. As there are far more virtual stops than actual stops, some of the actual stops will be linked to more than one virtual stop.
Computer control has made slot machines more versatile. Now players can bet money straight from a credit card, rather than using cash for every pull.
They can also keep track of their wins and losses more easily.
And so can the casinos.
Computerization has also made the machines more user friendly, there really is no need for a handle, simply push a button and it's game on.