Beyond the Little Blue Box

Illustration via Craig Wilson Fraser (Licensed)

How Captain Crunch built the blue box that fascinated Steve Jobs

Be the first to read part of Draper's brand new biography.


David Gilmour


Posted on Oct 28, 2017   Updated on May 22, 2021, 12:58 pm CDT

A computing pioneer and legendary proto-hacker, John Draper has been at the center of several revolutionary moments—all of which have influenced and inform our world and attitudes to technology today. A mischievous phone phreak, antagonizing corporations and the FBI, an innovator at Apple in its early days and an underground privacy activist with the rebellious cypherpunks.

Now, for the first time, he is ready to tell his own life story in narrative biography Beyond the Little Blue Box.

Heartily endorsed by Apple’s co-founder Steve Wozniak and co-authored by Craig Wilson Fraser, the book tells the story of the eccentric Silicon Valley wunderkind and nomad best known by his pseudonym Captain Crunch, master of the blue box—a small and illegal homemade phone hacking device Draper is infamous for developing.

Publishing for the book is set to be funded through a Kickstarter campaign launching officially on Oct 28, 2017, which offers signed copies and replica Cap’n Crunch toy whistles used by the early phone phreaks in the 1970s to disconnect phone lines. The early bird drive alone has raised nearly $9,000 of the $26,000 target required to get this labor of love onto bookshelves, as of Friday afternoon.

“I’ve known I was going to end up writing it for over 10 years [and] known all these years what the opening line was going to be,” Fraser tells the Daily Dot. “I have always considered him a highly interesting case for character study and an unfathomable wealth of complexities and paradoxes. I hope to have portrayed him in an honest but affectionate light. A balanced portrait of the unique and incredible adventure that is his life.”

Here, in an excerpt from Beyond the Little Blue Box exclusive to the Daily Dot, Draper builds his blue box for the first time and coins his legendary nickname.



Denny called me and told me about this whistle that blew the magic tone that disconnects long distance phone calls, and that he had a spare. He asked me if I could drive him to San Francisco so he could show me how it worked. It wasn’t possible to use the whistle to switch calls from San Jose because no direct trunks went between there and Vancouver, but from closer to San Francisco it could be done. So, that following weekend Denny, Jim (another blind phone phreak) and I headed out to Burlingame, which was near the airport, and the closest place we could get that direct trunk. We picked a bank of about six phones, and each one of us would practice using the whistle. I actually wasn’t that good at it.

A few days later, Denny called me and said they’d found a conference line, a kind of party line that can accommodate about eight people. Denny and Jim were on there of course, and they introduced me to another two Phreaks, JD and Bill Acker. When the discussion got around to our trip to Burlingame, we talked about what my Phreak handle should be. Most people had just chosen their first name and city, like Denny San Jose or Bill From New York. Well, John San Jose was already taken, so I said: “how about Captain Crunch?” They thought it was pretty funny, since I wasn’t that good at using the whistle, but the name stuck.

Next was my first visit to Denny’s place, where he welcomed me into his ‘circle of trust’ a little more, and told me all about the Blue Box. He showed me a demonstration, and let me try using his box. After that meeting, I rushed home on a mission.

Dad was camped out in the kitchen, mom was flitting around the house, and my brother Ron was in his room studying. I headed toward my room at top speed, hindered momentarily by my mom nagging me about forgetting to take out the garbage, or some other nit-picking thing.

I’m said to myself, ’I can’t believe it’s that easy, this blows my mind’. I thought it was just the normal tones of a touch-tone phone, and maybe some special number you dial into. I had no idea that there was a much larger and more complex set of tones.

At Denny’s I had called a friend in Mountain View, and I could hear these soft tones, but since I didn’t have a touch-tone phone at home, I had nothing to compare them to. I had been eager for my local phone service to move over to touch tone, but it hadn’t happened yet. It was time to raid my parts supply and get to building something.

I really needed to get out of my parents’ house. My mothers’ nagging was relentless, and my father just sat in the kitchen, smoking cigarette after cigarette. Ron would drive me insane too, playing and practicing the piano, going up and down the scales, but we finally settled on a 9 p.m. curfew on that.

So after ignoring my mom’s nagging, I got to work. ‘If this thing actually works’, I thought, ‘job searching is going to open up the whole country’. I didn’t have a frequency counter, but I could measure short time intervals accurately, and I knew the piano keys that would help me find and generate the proper frequencies I needed.

First I needed to calculate a chart to make this easy, and then I could tweak the resistors. I got out my trusty old Electronic Circuits book. To generate the tones, I used a Bridge T circuit, which is standard for an oscillator, and the simplest and cheapest. That would work for starters, and then I would need to calculate the resistor and capacitor values from the formulas in the book. Easy enough. Next, raid my resistor supply and find the nearest ones, always picking the higher value. I figured that once I get the thing to oscillate, I could use my ears to get it really close.

So, it turned out I never used that silly chart. So much for applying what I learned in school. The teacher always stressed, ‘make a chart’. Too much trouble. It only took me five minutes to ‘breadboard’ up the circuit, using Bakelite boards with holes in them to support electronic components.

‘Good, I got a tone, and it sounds pretty close. The formulas work. I need one for 700, 900, 1100, 1300, 1500, 1700 and of course 2600. Crap, I don’t have enough diodes to make a diode matrix to map the keys to the tones.’ I needed two diodes per key, one for each frequency. So just to test it out, I made one button per tone, so you would have to press two at a time to make up the Numbers.

I had been at it for over an hour. Almost done, but I needed to make sure the tones were just right since there was no telling what kind of sensing equipment they might have on these lines. I needed to connect it to the phone, so I used my audio amplifier and connected like a transformer. It worked! So, I’m running back and forth from my bedroom to the living room to play notes on the piano, then running back to verify the pitch. I have pretty perfect pitch so once I nailed it in my head, I didn’t need the piano anymore. All the while my mom is screaming and yelling at me, probably thinking I was ready for the funny farm.

Back in my room for a first trial. I had already gotten some pretty cool numbers to test it on, so I thought I would try to call an inward operator in Chicago. I remember another phone phreak, Jimmy, telling me that these were used only by other operators. In this era, all operators were female, so I figured I should play it safe and bullshitted her that I was a test board technician testing the lines.

I dialed a working 800 number that I knew would answer, and hit the 2600 tone. I hear a ker-chink sound, just like at Denny’s place. I punched out ‘KP’ (1100 and 1700 buttons together), then 312-121. Nothing. Then I realized I had forgotten to do the closing tone, 1500 + 1700. The closing tone did it. I was now talking directly to the Chicago operator on a line that I would have normally been incapable of.

I was running around the house shouting ‘It works, it works, it works!’. My dad told me to settle down, my mom was screaming at me to be quiet, and Ron just stood there scratching his chin. I didn’t dare tell any of them what I was actually up to.

It was 12:30 a.m. when I finally tried to get some rest. I was so excited that I hardly slept at all, and when I did fall asleep I had this amazing dream that I was in control of all the phone companies in the world. The next morning, I wanted to call Motorola in Phoenix to see if they had received the resume I had sent two weeks before. I had tried calling a few days earlier and they couldn’t find my resume and kept me on the phone a long time, which I couldn’t afford. Calls were $0.85/minute back then, daytime rates.

My next important call was to Chicago to Allied Electronics to find out when they were going to repair my power inverter I needed for my VW bus so I could run appliances from it. They finally agreed to send me a new one because they had lost it.

Then I called the USAF Base I was stationed just before I was discharged. I wanted to ask some important questions about the GI Bill and get them to sign some papers. In one day, I completed what it would take me a week to do normally. I had the key to the world and I knew it.

As time went on, I made frequent visits to Denny and Jimmy to learn more about what you can do with the box. There were also rumors going around that the phone company could tell if numbers had been dialed by hand, so I visited a friend who had worked for National Semiconductor and told him about this. After our discussion, we decided to build a box that would ‘out-pulse’ – dial the tones exactly at the rate of 60ms on, 60ms off, so that the phone company’s detector would see us as a machine. After a few days, we came up with a fully workable and ‘safe’ box.

Once the box was safe, one of the first things I did was to placate my dad. I used the box to connect him to some of his old Air Force buddies still at Travis, and of course, he enjoyed that and thought it was pretty clever. He was skeptical at first, until the bill arrived, and there was nothing on it. Not long after that, my dad proudly sold our house in San Jose for eight times what he paid for it, and bought a nice retirement cabin up in Train Harte. I moved into an apartment in Los Gatos.

By the late summer, I had earned enough money to pay for college next year, plus take a $199 round trip to England. John Arthur had made some pot brownies so I could take a couple to eat on the flight. I ate one, and I swear, I must have been flying 10,000 feet above the aircraft. I was so ripped I didn’t eat the other one. I tossed it before entering the U.K. border. I was picked up by a friend of a friend who worked for Melody Maker magazine. We drove from Gatwick Airport to Minnis Bay, to the house I stayed in for most of the trip, which was literally a few feet from the beach.

After a few hours nap, I wanted to check out all the radio stations. I found a pirate station called Radio Nordsea International, who broadcast from a ship in the North Atlantic. The U.K. government were trying unsuccessfully to shut them down or jam them. I tried to hire a boat to get me out there, but British ships were banned from taking people. I could have gotten there from the Netherlands, but that seemed like too much of a hassle.

I had taken my newly built Blue Box to the U.K., but it didn’t work there. That was quite a disappointment, but Bill Acker had just discovered how to make overseas calls by MF-ing into a sender, so we spent quite a time talking. After numerous calls from Bill, my hosts got this threatening call from the GPO (General Post Office, the main U.K. phone company at the time), asking why people were calling me and talking unusually long on an overseas call. International rates to the U.K. were about $15 for the first 3 minutes back then. I told them it was work-related, and it was none of the GPO’s business anyway. My hosts were a bit paranoid after that.

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*First Published: Oct 28, 2017, 1:00 pm CDT