Draper was part of the phone phreaking subculture in which a 2600 Hz tone could allow one to make free long distance calls. He discovered that a toy bo'sun whistle that he found in a box of Cap'n Crunch cereal could generate this precise tone, hence his nickname. Draper claimed that he used the technique to prank call who he believed to be U.S. President Richard Nixon at the White House in 1973. Draper's participation in phreaking was covered in an article by Esquire magazine, which was read by Steve Wozniak and inspired Wozniak and his friend Steve Jobs to build "blue boxes" to be able to make free calls. The two traced Draper down to a radio station in Cupertino, California and arranged to meet at Wozniak's dorm room at the University of California, Berkeley. However, Draper said he was not impressed because their box generated square waves instead of proper sine waves.
Draper met Wozniak again while he was working on the Apple I computer. Wozniak was using a cross-assembler that Draper had written for the 6502 processor. Wozniak then contracted Draper to develop a telephone interface called a "Charlie board" that would have pre-dated D.C. Hayes' own first modem. However, AT&T blocked the release of the device as they feared that it could be programmed to become another "blue box". Draper claimed to have become the 13th employee of Apple Computer, right after Jobs' college friend Dan Kottke. However, Mark Johnson also claims to have been employee #13 in the production department.
Draper's continued practice of phreaking landed him in prison for telephone fraud. He started righting EasyWriter in 1979 while on a work-release program. It became Apple's first word processor. A version for the IBM PC was released later, but was buggy and not as well received.
- The Definitive Story of Steve Wozniak, Steve Jobs, and Phone Phreaking by Phil Lapsley, The Atlantic. 2013-02-20.
- Captain Crunch on Apple – An interview with John Draper by Nicola D'Agostino, Stories of Apple. 2008-12-04.
- John Draper "Captain Crunch" Fundraiser Appeal by George, Apple iPhone Blog. 2014-11.
- Who were the first 25 employees at Apple? by Sean Owczarek, Quora. 2012-09-24.
- Silicon Valley Legend ‘Captain Crunch’ Publishes His Life Story by David Cassel, The New Stack. 2017-11-05.
- Meet John Draper, the hacker who inspired Apple’s founders by Neta Bomani, Daily Dot. 2017-10-26.
- How Blue Box Phone Phreaking Put Steve Jobs and Woz on the Road to Apple, Esquire. 2015-10-15.
- Secrets of the Little Blue Box:The Official Phreaker's Manual by Ron Rosenbaum, MyOldMac.net. 2003.
- Beyond the Little Blue Box by John T. Draper & C. Wilson Fraser, FriesenPress (2018-07-25)