by Micro Surgeon/West Coast Phreaks
Remember in the movie WarGames when David needed to make a call, and had no money. He did so by opening the mouthpiece and touching a piece of metal from the inside of mouthpiece to the plate of the payphone.
Believe it or not, this archaic technique still works in the most sophisticated areas, including all Bell Operating Companies' (BOC) Dial-Tone First (DTF) pay phones.
This technique does not, however, work on private payphones.
To make a local call, without using coins (or slugs), first punch a small hole (see diagram) with something sharp (i.e. a nail) through the existing outer plastic holes into the inner (metal) mouthpiece.
This gives access to the inner magnetic coil. Next, dial the first six digits of the local number and before dialing the last digit, touch the nail to the face plate, holding it there as you press the last digit.
This whole process of touching the nail to the face plate, pressing the seventh digit, and simultaneously releasing it from face plate as the button is let go, should all be done within one second.
Timing can be critical. Essentially the phone is being grounded, and as a result BOC's are fooled into thinking that sufficient funds have been deposited for local calls.
As with any ploy there are limitations and problems. Long distance calls cannot be made, because a different method is used to verify the deposited coins.
One of the main problems is that a mild shock (not to death of course) may be experienced. A less serious problem can be that the mouthpiece may be damaged, by punching to hard or in the wrong place, rendering the phone useless. Punching pay phones is nothing new, and I certainly didn't discover this art. Of course, a Red Box will work much better, but it could have inadvertently been left at home.
What one should understand is that this technique will work and that it's not just a bit of telephone history.