On Wed, 25 Jul 2001, Alexander Schreiber wrote:
> Yes. More correctly, the 2600 refers to the 2600 Hz signalling tone
> used in the old (before going digital) telephone network. And by
> coincidence, a toy whistle contained in a series of "Captain Crunch"
> cereal boxes was producing exactly the same frequency. The guy first
> finding this out then went by the nickname "Captain Crunch".
More specifically, the 2600Hz tone enabled you to "seize" a "trunk". A
"trunk" is basically a line at the central office going out into the rest
of the network. The easiest way was to call an 800 number (a free call,
and you were always guaranteed a trunk) and then blast the 2600Hz tone.
You would then get a supervisory tone (like a dial tone). You would then
use MF (like DTMF but it used different frequencies) to dial a sequence to
connect you to where you wanted to go. There were also special tones,
like KP (keypulse) and ST (start), which were sort of like protocol
markers. KP meant you were starting a destination address, ST meant to
route you to that destination. So you would dial KP + <destination
number> + ST and off the call would go.
If you knew enough, you could connect yourself to various internal telco
operators and find out all sorts of cool stuff. You could also connect
yourself to operators in foreign countries and then snoop around their
networks. One of Wozniak's more famous stories is calling the Pope by
BSing his way through their operators (I think he was pretending to be
Henry Kissinger). John Draper used to setup calls from one payphone,
route it through various telcos around the world, then back to another
payphone next to the one he was at, so that he could say a word into one
payphone and hear it come out the other a few seconds later :)
I wish the phone networks were still that much fun. Nowadays, all
signalling is out-of-band, being handled on a separate X.25 packet network
(SS7). You can get an SS7 drop to your business (maybe even your house)
but you'd have to pay for it, so any snooping would be on your dime :(
Sellam Ismail Vintage Computer Festival
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International Man of Intrigue and Danger
http://www.vintage.org
Received on Wed Jul 25 2001 - 10:29:37 BST