[ProtectOurFreedom]

"Phone Phreaking" -- there's a direct connection from direct digital dialing to our latest Apple devices...The Definitive Story of Steve Wozniak, Steve Jobs, and Phone Phreaking by Phil Lapsley, February 20, 2013, The Atlantic. It all started when Steve 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.

[Fresh Wind]

If this subject is of interest, I highly recommend the book “Exploding The Phone” by Phil Lapsley (w/foreword by Steve Wozniak), published in 2013.

This book confirms something I already knew, as did Dr. Johnny Fever, there really WERE phone cops back in those days.

[Pocketdoor]

Don’t forget Captain Crunch, who found that the toy whistle in a box of Captain Crunch cereal produced the same frequency as the touch tones.