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Book Review: Exploding the Phone by Phil Lapsley

Exploding the Phone, written by Phil Lapsley, (c) 2013
ISBN13: 9780802120618; Amazon Listing

You may enjoy this book. From the cover: "The Untold Story of the Teenagers and Outlaws Who Hacked Ma Bell."

In spite of the tag line, the book is very sympathetic to the phone phreaks whose exploits the author details. It includes a brief history of the evolution of the Bell System (starting as an inprovement on the telegraph) and shows how the reasonable engineering decision to use in-band signalling to control switching (after all, Ma Bell already had a huge installed base of tone capable wiring) led to a total lack of security and opened the system up to the hackers.

Imagine being blind, with limited social interaction available to you, and you find that you can explore and control the world's biggest machine, the phone system, from your home, for free - very cool! Many of the phone phreaks were in fact blind, but as the author points out, everyone is blind on the telephone.

I was never as clever as the phreaks chronicled in this book, but I did build an operational dial (by tapping on an on - off switch) telephone from spare parts when I was in Mexico at age 12 or 13, so I can really relate to the excitement of the phreaks as they experimented with the System, probed its secrets, and found out what worked and what didn't.

The key observation was the accidental discovery that 2600 Hz. could be used to "whistle off" a call. There were phone phreaks who could whistle entire dialing sequences on some of the simpler exchanges. Calls "dialed" in this manner avoided toll charges at a time when long distance calls were expensive.

The phone company seemed to treat the phreaking community gently at first. When it became apparent that they were losing serious money, and the knowledge of how to make free calls had permeated the criminal element in the country, Ma Bell was forced to respond. Eventually improved phone technology closed down the hackers playground.

Steve Jobs and Steve Wozniak sold blue boxes (tone generators used to access the system in many ways, but mainly to place free long distance calls) door to door in the Berkeley dorms.

Jobs is quoted saying "It was the magic of the fact that two teenagers could build this box for $100 worth of parts and control hundreds of billions of dollars of infrastructure in the entire telephone network of the whole world from Los Altos and Cupertino, California. That was magical!"

Jobs noted: "If we hadn't made blue boxes, there would have been no Apple."

Wozniak, the designer of the early Apple computers: "I swear to this day I have never designed a circuit that I was prouder of." - speaking of the digital blue box he build to improve the accuracy and stability of tones used to hack the System. Earlier attempts with analog oscillators had failed.

A great read. Consider adding it to your reading list.