Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!silver!commgrp From: commgrp@silver.bacs.indiana.edu Newsgroups: sci.electronics Subject: Pay-phone hacking nostalgia Message-ID: <7200036@silver> Date: 13 Jun 89 15:17:00 GMT Organization: Indiana University CSCI, Bloomington Lines: 58 Nf-ID: #N:silver:7200036:000:2906 Nf-From: silver.bacs.indiana.edu!commgrp Jun 13 10:17:00 1989 In article <3685@tank.uchicago.edu>, barry@arthur.uchicago.edu writes: > A friend recently showed me a "technique" for making free phone > calls from a payphone... } During my highschool days it was possible to get a dial tone on a pay phone by peeling a spot of insulation from the handset cord and touching the bared wire to the phone's keyhole. Handset cords weren't armored then, nor were the handset caps screwed on by King Kong. I hadn't heard of the method of grounding the microphone by piercing the diaphragm, but even back then there were special pay-phone mikes which had louvered hard-metal covers so that a sharp object stuck through a hole in the mouthpiece grille would not damage the mike. A kid who lived near a telephone exchange used to dive their dumpster regularly. He recovered enough stuff to build his own neighborhood phone system. His best find was a coin mechanism from an old-style pay phone. Coins rolled down a ramp, then took different paths according to size and velocity. A magnet trapped steel slugs. Nickels and dimes hit cup-shaped bells, quarters hit a coiled-spring gong similar to a Seth-Thomas clock chime. There were two contact- microphones on the mechanism. Long-distance operators listened to the sounds and counted the money. My friend found that the coin/bell mechanism would make the desired sound effects when held near the mouthpiece. (It still cost 10 cents to activate the phone initially.) I once worked at a YMCA camp where the only phone was a pay unit. We discovered that a large pot from the kitchen made acceptable "quarter" sounds when struck. One guy made a long-distance call and "paid" for it by banging on the pot; after "depositing" the required amount, he continued to strike the pot. When the operator told him "That's enough money," he replied, "You've been such a good operator, I'm giving you a tip." "No! Stop! They don't give it to me!!" she said. Depositing coins in modern pay-phones triggers electronic tones, which supposedly can be faked with a simple device. "Phone Phreaking" was popular in the '70s but seems to have become passe. TPC (The Phone Company) prominently published claims of sophisticated countermeasures. Another kid-type phone hack which a friend from Chicago says they used do at O'Hare Airport: Put raw egg-white in the coin return, then observe from a distance-- Along comes Mr. Spiff businessman and makes a credit-card call, after which his coin is returned. He reaches for the coin, contacts nasty goo, goes "YUCK!!" and _leaves the money_! It doesn't work anymore, with electronic credit-card readers and phones which require no initial coin. -- Frank Reid W9MKV @ K9IU reid@gold.bacs.indiana.edu {inuxc,rutgers,uunet!uiucdcs,pur-ee}!iuvax!silver!commgrp