Cruise Control Explanation Please

I've got a 91 LX with cruise and before I ask this question you should know that I'm only asking for the benefit of learning how it works exactly.In otherwords,I'm not having any issues with it right now,but I'm tryin to learn just in case it goes out.When you push the cruise on button then push set,what component in the system holds the gas pedal in place?If you push accel to speed up or decel to slow down and you can physically watch the pedal move,is vacuum applied to some type of solenoid inside of the servo that turns a vacuum signal into a mechanical signal to move the pedal?When you're doin 70mph steady with the cruise on then tap the brake pedal to turn the cruise off,does the dump valve under the dash just turn the vacuum off and that releases the pedal quickly?My Chiltons manual shows a few pictures of the servo inside the fender and the dump valve and round cylinder looking part under dash,lists removal and installation steps,etc but it doesn't explain or show detailed pics of how the system functions and how to trouble shoot it in case there's an issue.Any pictures and input would be appreciated.Thanks
 
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There is a magic troll in the canister. He pulls the throttle cable with one hand and measures engine vacuum with a tool in the other hand. The troll gets old and so replacement ones are hard to find in good shape. Other systems have the troll in a square box measuring magnetic pulses from the drive shaft. At least those are the most likely explanations I have heard.
 
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I haven't clicked on richkers links yet to know whether your makin sense or not,but your description makes total sense and is funny as hell at the same time sho.I don't know if its just me or not,but I rarely ever hear anybody that's having problems with their cruise other than maybe a blown fuse.Its either a really well designed system or maybe it just doesn't get used enough to wear out
 
I have never read anything by @jrichker that was not right on about Mustangs. But I have never seen a better explanation of how the servo on any cruise from the 70s or 80s works. It has to be magic or a mythical creature inside.