As promised, Here is a General view of the workings of a modern slot machine but first a view backwards to put this into perspective.

The older machines..."WHAT YOU SAW IT WHAT YOU GOT!!
The older slots which are no longer around, had a symbols on the reels with CORRESPONDING notches in a disk on the side of the reel. Usually there were 22 stops (positions) and 22 spaces/symbols. When you pulled the handle, the reels spun and were stopped by a small gear box with different size gears (called a clock). (This little gear box created randomness, but poorly, and was open to attack from cheats) A kicker arm fell into the disk's cut out slot (stopping the reel) and a "wiper (contact arm) made contact with wired buttons on a board which sent the electrical signal to the payout disk on the machines hopper...Voila, you were paid.

Today's machines...WHAT YOU SEE IS NOT WHAT YOU GET!!

The modern electronic machne is microprocessor controlled and each reel spins via an electronic stepper motor. When you pull the handle (connected to a switch just the same as the one on the front panel)the microprocessor (through random number generator) tells each reel where to stop via a brake. Here is the catch. The machine's program tells the reels how many stops there are.
Example, there may be only 22 symbols physically, but the program may have 72 stops per reel!! This means there are many places in between the symbols where the reels can stop!!!!
For those of you believing you can play through a machine's theoretical "cycle", the cycle would be 72 cubed or 72x72x72= 373,248 spins!!!!! And that is strictly theoritical!! Now, if I remember, a strke machine does have 72 stops. Common stops per reel are 64,72,100,128,256 and VIRTUAL as in the linked progressives like megabucks) The rest of the game is governed by symbol placement and the number of certain symbols on each reel.

So a single machine may have many programs with many different hold %'s but look completely alike to the player!!! Ie a machine with a car as the top award will most likely use a 256 stop per reel program, making the theoretical cycle over 16 million pulls!!!! and it gets worse with Virtual programs!!!!

Again, I think there was one initial program for the strike machines before the new one at caesar's lake tahoe. That means ALL strike machines other than the one at the Lake (maybe elsewhere and unknown to me) are the SAME!!!

Each company has its own algorithm for random number generation...(closely guarded)The Strike machines in Nevada have very primitive random number generators FYI!

That's it for this lesson....hope it is understandable!
jeff