the.com/phreaking
hacking before hacking had computers — just a whistle and a phone line.
means the art of exploiting telephone networks to make free calls or explore the system, using tones instead of code.
from from phone plus freak, born in the 1960s-70s when hobbyists discovered the phone system ran on audible tones you could reverse-engineer with a toy whistle from a cereal box, notably the cap n crunch whistle that produced the exact 2600hz tone needed to seize an AT&T trunk line.
famous phreakersteve wozniak built blue boxes before apple
the whistlecap n crunch prize hit 2600hz perfectly
magazine legacy2600 the hacker quarterly named after it
gateway drugmany phreakers became the first computer hackers