The Definitive Story of Steve Wozniak, Steve Jobs, and Phone Phreaking

Every company has a creation myth, and Apple's centers on the two Steves, and their early, illicit foray into the nation's telephone system.


Ed Piskor/Internet Archive

Editor's note: The following essay is excerpted from Phil Lapsley's Exploding the Phone.

Like the flap of a butterfly's wings causing a hurricane half a world away, the ripples of unintended consequences from Ron Rosenbaum's "Secrets of the Little Blue Box" continued to spread. "You know how some articles just grab you from the first paragraph? Well, it was one of those articles," Steve Wozniak recalls. "It was the most amazing article I'd ever read!"

Wozniak happened to pick up a copy of Esquire from his mother's kitchen table the day before starting classes at Berkeley in the fall of 1971. Rosenbaum's article "described a whole web of people who were doing this: the phone phreaks. They were anonymous technical people who went by fake names and lived all over the place," he recalls, how they were "outsmarting phone companies and setting up networks that nobody imagined existed." It seemed unbelievable. And yet, he says, "I kept reading it over and over, and the more I read it, the more possible and real it sounded."

Oddly enough, part of what made the article seem so real to him were the characters. Despite their fanciful nature and funny names, Wozniak remembers, "I could tell that the characters being described were really tech people, much like me, people who liked to design things just to see what was possible, and for no other reason, really." There was something about the whole thing that just rang true, despite how crazy it seemed. "The idea of the Blue Box just amazed me," he says. The article even gave a few of the frequencies it used. As for Joe Engressia being able to whistle free calls? "I couldn't believe this was possible, but there it was and, wow, it just made my imagination run wild."

The twenty-year-old Wozniak put down the magazine. He picked up the phone and called his friend Steve Jobs--then a seventeen-year-old senior in high school--to tell him about it. Less than an hour later the duo were on their way to raid the library at the Stanford Linear Accelerator Center. SLAC was the atom smasher at Stanford University. It had a great technical library, Wozniak says, and he had a long history of sneaking into it to look stuff up. "If there was any place that had a phone manual that listed tone frequencies," he says, it would be SLAC.

The two dug through the reference books and before long they struck pay dirt: an international telephone technical standard that listed the MF frequencies. "I froze and grabbed Steve and nearly screamed in excitement that I'd found it. We both stared at the list, rushing with adrenaline. We kept saying things like 'Oh, shit!' and 'Wow, this thing is for real!' I was practically shaking, with goose bumps and everything. It was such a Eureka moment. We couldn't stop talking all the way home. We were so excited. We knew we could build this thing. We now had the formula we needed! And definitely that article was for real." Jobs agrees: "We kept saying to ourselves, 'It's real. Holy shit, it's real.'"

That very day Wozniak and Jobs purchased analog tone generator kits from a local electronics store; this was the Silicon Valley in 1971, after all, and such things were easily available. Later that night they had managed to record pairs of tones on cassette tape, enough to make a blue box call. But it didn't quite work. They were able to disconnect a call to 555-1212 with 2,600 Hz--they heard the kerchink! of the trunk--but their MF tone tape recordings didn't do anything. They worked late into the night trying to figure out what was wrong. In the end Wozniak concluded that the tone generator just wasn't good enough to make the telephone network dance to his tunes.

Wozniak started classes at Berkeley the next day. But he couldn't get his mind off of blue boxes and phone phreaking.

He thought more about the analog blue box that he and Jobs had tried to build. The problem with analog circuits is that they are imprecise. This is because the components they are constructed with--resistors and capacitors and inductors and such--are themselves inexact. For example, if you want an analog circuit to generate a tone at a particular frequency, as you would for a blue box, you might need a resistor of 1000 ohms and a capacitor of 0.1 microfarads. Unfortunately, when you buy a resistor, you can't get one that is exactly 1000 ohms; rather, it is guaranteed to be only within 10 percent of that value. If you want to spend more money, you can get ones that are more accurate--ones whose values vary by only 5 percent or even 1 percent--but there is always some inaccuracy in the individual components. When you combine them to build a circuit the inaccuracies often compound. Worse, the component values vary with temperature. So you might spend time tuning your blue box in the warmth of your dorm room and get it all working and then go out to a pay phone in the cold night air only to find that it doesn't work anymore.

Steve Wozniak had been designing electrical circuits for years; just a year earlier he had designed his own tiny computer, the "Cream Soda Computer," so named because he and a friend drank tons of cream soda while they were building it. Computers are made out of digital circuits, circuits that deal with 1s and 0s rather than the full range of values that analog circuits can handle. While this may seem like a limitation, it gives digital circuits a huge advantage. Digital circuits are exact and their building block components don't vary from one to another, nor do they vary with temperature. With this in mind Wozniak started thinking about how to build a digital blue box, which would be made up of the chips used to build computers, not analog components such as resistors and capacitors and transistor oscillators. It would use a quartz crystal, like those used in the then newfangled digital watches, for ultimate accuracy and rock-solid stability.

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Phil Lapsley is a cofounder of two high-tech companies and a former consultant at McKinsey & Company. 

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