The journal was intended only for Bell's own technical staff, but the company had apparently forgotten that most engineering colleges subscribed to it as well. The articles proved to be the combination to Bell's safe. Belatedly realizing its error, Bell tried to recall the two issues. But they had already become collectors' items, endlessly photocopied and passed around among engineering students all over the country.
Once Bell's tone system was known, it was relatively simple for engineering students to reproduce the tones, and then--by knowing the signaling methods--to employ them to get around the billing system. The early blue boxes used vacuum tubes (the forerunners of transistors) and were just slightly larger than the telephones they were connected to. They were really nothing more than a device that reproduced Bell's multifrequency tones, and for that reason hard-core phreakers called them MF-ers--for multifrequency transmitters. (The acronym was also understood to stand for "motherfuckers," because they were used to fuck around with Ma Bell.) Engineering students have always been notorious for attempting to rip off the phone company. In the late 1950S Bell was making strenuous efforts to stamp out a device that much later was nicknamed the red box--presumably to distinguish it from the blue box. The red box was a primitive gizmo, often no more than an army-surplus field telephone or a modified standard phone linked to an operating Bell set. Legend has it that engineering students would wire up a red box for Mom and Dad before they left for college so that they could call home for free. Technically very simple, red boxes employed a switch that would send a signal to the local telephone office to indicate that the phone had been picked up. But the signal was momentary, just long enough to alert the local office and cause the ringing to stop, but not long enough to send the signal to the telephone office in the city where the call was originated. That was the trick: the billing was set up in the originating office, and to the originating office it would seem as though the phone was still ringing. When Pop took his finger off the switch on the box, he and Junior could talk free of charge.
The red boxes had one serious drawback: the phone company could become suspicious if it found that Junior had ostensibly spent a half an hour listening to the phone ring back at the family homestead. A more obvious problem was that Mom and Pop--if one believes the legend that red boxes were used by college kids to call home--would quickly tire of their role in ripping off the phone company only to make it easier for Junior to call and ask for more money.
Inevitably there were other boxes, too, all exploiting other holes in the Bell system. A later variation of the red box, sometimes called a black box, was popular with bookies. It caused the ringing to cease prior to the phone being picked up, thereby preventing the originating offlce from billing the call. There was also another sort of red box that imitated the sound of coins being dropped into the slot on pay phones. It was used to convince operators that a call was being paid for.
The blue box, however, was the most sophisticated of all. It put users directly in control of long-distance switching equipment. To avoid toll-call charges, users of blue boxes would dial free numbers--out-of-area directory enquiries or commercial 1-800 numbers--then reroute the call by using the tones in the MF-er.
This is how it worked: long-distance calls are first routed through a subscriber's own local telephone office. The first digits tell the office that the call is long-distance, and it is switched to an idle long-distance line. An idle line emits a constant 2600-cycle whistling tone, the signal that it is ready to receive a call. As the caller finishes dialing the desired number--called the address digits--the call is completed--all of which takes place in the time it takes to punch in the number.
At the local office, billing begins when the long-distance call is answered and ends when the caller puts his receiver down. The act of hanging up is the signal to the local office that the call is completed. The local office then tells the line that it can process any other call by sending it the same 2600-cycle tone, and the line begins emitting the tone again.
