IGT Random Number Generator---Explained

[DAVEdetroit]

The IGT RNG (Random Number Generator) Explained.

S-Plus Machine.

 While the machine is idle, its Random Number Generator (RNG) located on its SP chip is constantly generating numbers between one and four billion, according to an algorithm.

 When a patron initiates a play with, for instance, a three-coin maximum bet, the SP chip will “grabâ€� a random number and randomize it to a virtual reel position by applying another algorithm to reduce the random number to a number between one and 512.   That number is then randomized to a number between one and 22 to arrive at a physical reel stop. The reel is then stopped.

The process is repeated for reel two then reel three.

It is at this point that the final results of the game is determined or, stated another way, the “essence of the gameâ€� is completed.   These results are checksummed, i.e., verified, by repeating the mathematical process described above and then stored on the CMOS memory chip. The CMOS also stores the results of the previous five games.

Another chip, the SS chip or pay table chip, contains pay table information, reel strip information, symbol information, and winning amount information.   The computer then evaluates the results;  it compares on what the machine landed to the information on the SS chip.   The SP chip will then instruct the machine accordingly based on the results as compared to the pay table, be it a payout or a jackpot.

Primary Jackpot Winner.(Progressive Jackpot)

In the event of a primary jackpot, the secondary notification process begins, and the SP chip instructs the machine to lock up, reports the jackpot to the casino and IGT systems, and activates the bells, whistles, and lights.  Every Wheel of Fortune slot machine contributing to the primary jackpot will then reset to the $1 million base.  

 

[angryninjas]

Awesome info Dave.  I knew the random number generator stuff, but didn't know that it was randomized a second time between 1-512 using a second algorithm.    Good stuff!

[knagl]

Based on the last paragraph, this is in reference to the Wheel of Fortune Wide Area Progressive machines, which apparently have 512 virtual stops on the reels.

I'm curious about the part where it said that the number between 1 and 512 is further randomized to pick one of the 22 physical stops.  According to the PSRs, all of the virtual stops (in the case of the machine described, all 512 of them) are defined, so it would seem to me that something is amiss in the statement.

If there was another randomization process in there to bring it down to one of the 22 physical stops, it would seemingly eliminate the weighting of the symbols/blanks as defined in the PSRs with the virtual stops.

(For whatever it's worth, if Wheel of Fortune uses 512 virtual stops, and if only one stop on each reel has the WOF symbol, that makes the odds 1 in 134,217,728 of hitting the top award.  There are a lot of "ifs" in this statement.)

[DAVEdetroit]

IGT RNG (Random Number Generator)

The Information Provided--Is Testimony--
See Case: PICKLE Vs IGT  (Google Search)
This Case--Went To The State Supreme Court. (Took 4 Years Plus.)
PICKLE Hit A 4 Million +  On A Progressive Jackpot--On The WRONG Reel Strip Combination, On A WOF Machine.
The Machine Did Not Display The Winning Combination.

IGT Prevailed With The Notice "Malfunction Voids All Pays" Posting.
The Way The Machine Arrives At A Certain Reel Stop Position Was Explained--During The Trial.
DAVE