License: CC-BY
I turn 30 this year, so I’m sure a lot of folks will say “do you even know what a rotary phone or a pay phone is?” Yes, I’ve used both a rotary dial phone and a pay phone. In this day and age of digital communication, why am I interested in the history of the Bell System and phone phreaking? I don’t know if I have a definitive answer beyond the fact that I’m fascinated in the history of folks exploring the telephone network. Switchboard operators connected customers’ phone calls before dialing. In a lot of older movies you hear the character pick up the telephone and hear a voice on the other end say “number please?” As technology advanced, so did the phone network, and then the implementation of the dialing system. Mechanical crossbar switches, and later electronic switching systems, supplemented (and replaced) human operators as the number of customers on the Bell System grew.
The Bell System’s way of handling telephone switching through these newfangled machines was through various signals. Unfortunately for AT&T, there was a flaw. Those signals that would automatically handle the switching of telephone calls was in the same frequency your voice. This design would allow people to explore the extent of the telephone network. These folks eventually became to be known as “phone phreaks”. The book “Exploding The Phone” by Phil Lapsley discusses the exploits and explorations of a lot these phone phreakers. Exploring the telephone network wasn’t illegal in and of itself, but a lot phreakers did take advantage of being able to whistle into the phone and make free long-distance phone calls….which was illegal. (Be advised: don’t commit wire fraud or any other illegal acts when tinkering.)
What is probably the most interesting about the phreakers were that a lot of them were blind. It was a world that was accessible to them to meet other folks who were like them and had similar interests. Joe Engressia, who later changed his name to Joybubbles, was one of those blind phreakers. From Lapsley’s book:
Engressia’s whistling trick combined two of the things he had learned ten years earlier: hook switch dialing and whistling to disconnect a call. Engressia knew that if he whistled seventh octave E, that is, 2,600 cycles per second, he could disconnect a long-distance phone call. But then what? Engressia figured out that by whistling short bursts of 2,600 Hz he could mimic the telephone company’s single-frequency (SF) dialing system, just like others had figured out before him. To dial the area code 212, for example, Engressia would whistle two quick bursts of 2,600, followed by one quick burst, followed by two more quick bursts: beep beep … beep … beep beep! So the entire dance went like this. First, dial a call to a free long-distance number, such as directory assistance. Then give one long whistle to reset the long-distance trunk. Then whistle the pulses that made up the ten-digit phone number, one digit — and one pulse — at a time. it was simply the whistling equivalent of the hook switch dialing he had learned as a little kid.
Engressia had perfect pitch and the ability to manipulate the internal switching of his telephone calls. This ability allowed him, and phreakers like him, to set up conference calls on busy signals and certain test numbers that installers and engineers used.
Hackers (and I mean hackers who enjoy building computers and tinkering with electronics…not necessarily those of the malicious intent) and computer innovators were experimenting with the telephone network. Folks like Steve Wozniak and Steve Jobs built blue boxes (which generated tones to manipulate multi-frequency switching equipment) and sold them. Wozniak even said that if they hadn’t built blue boxes, there may have never been an Apple Computer. Kevin Mitnick, who was arrested and spent a few years in prison for computer and wire fraud and is now a cybersecurity consultant and expert, also spent his youth as a phone phreaker. On a related note, Mitnick’s book “Ghost In The Wires” is a great autobiography of his exploits of social engineering and hacking systems.
Technology is an ever-changing field. The old telephone network is now mostly digital switches and fiber optic cable, and even the “Plan Ol’ Telephone System” is being integrated, and may even be superseded, by the Internet. Gone are the days of Ma Bell and the ability to whistle into your telephone and dial your next door neighbor, but I believe this shows us that people are naturally curious. Today, there are legal ways to explore and try different things. You now have companies, like Codecademy, who want to teach people how to programs, and you have very affordable computers, like the Raspberry Pi, that give people the ability to try out electronics and code up programs to control physical things (like LEDs on a breadboard).
Learning about the hey-day of the Bell System and the early history of the computer industry is fascinating to me. A lot of these people were curious and wanted to explore and experiment. Unfortunately, AT&T didn’t exactly look too kindly upon these people using their network as their playground, but it’s interesting to see what was created (like Apple) by these phreaks, and I think it points to the spirit of innovation. I don’t believe you’re ever too old or too young experiment with electronics. If you are looking for a couple of books to read this year and enjoy the history of the tech industry, I’d highly recommend “Exploding The Phone” by Phil Lapsley and “Ghost In The Wires” by Kevin Mitnick and William Simon.