Editing Blue box (section)

==History==
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{{Listen
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===Automated dialing===
Local calling had been increasingly automated through the first half of the 20th century, but long-distance calling still required operator intervention. Automation was deemed essential by [[AT&T Corporation|AT&T]]. By the 1940s they had developed a system that used audible tones played over the long-distance lines to control network connections. Tone pairs, referred to as multi-frequency (MF) signals, were assigned to the digits used for telephone numbers. A different, single tone, referred to as single frequency (SF), was used as a line status signal.

This new system allowed the telephone network to be increasingly automated by deploying the dialers and tone generators on an as-required basis, starting with the busier exchanges. [[Bell Labs]] was happy to advertise their success in creating this system, and repeatedly revealed details of its inner workings. In the February 1950 issue of ''[[Popular Electronics]]'', they published an advertisement, ''Playing a Tune for a Telephone Number'', which showed the musical notes for the digits on a staff and described the telephone operator's pushbuttons as a "musical keyboard".<ref>[https://hopp.typepad.com/.a/6a00e553da444b8834014e86243835970d-popup ''Playing a tune for a telephone number''], Popular Electronics, February 1950</ref> Two keys on a piano would need to be pushed simultaneously to play the tones for each digit. The illustration did not include the tone pairs for the special control signals KP and ST, although in the picture the operator's finger on the KP key and the ST key is visible. In the 1950s, AT&T released a public relations film, "Speeding Speech", which described the operation of the system. In the film, the tone sequence for sending a complete telephone number is heard through a loudspeaker as a technician presses the keys for dialing.<ref>AT&T, [https://www.youtube.com/watch?v=oPM_j7p7YnQ ''Speeding Speech''], 1950</ref>

In November 1954, the [[Bell System Technical Journal]] published an article entitled "In-Band Single-Frequency Signaling", which described the signaling scheme used for starting and ending telephone calls for the purpose of routing over [[Trunking|trunk lines]].<ref>{{Citation |last1=Weaver |first1=A. |last2=Newell |first2=N. A. |title=In-Band Single-Frequency Signaling|journal=Bell System Technical Journal |url=http://www.historyofphonephreaking.com/docs/weaver1954.pdf }}</ref><ref>{{Cite book|url=https://books.google.com/books?id=2OPzAAAAMAAJ&q=%22In-Band+Single-Frequency+Signaling%22+blue+box|title=Telecom and Network Security: Toll Fraud & Telabuse Update|first=E. Jan|last=Wilson|date=December 6, 1998|publisher=TRI-Telecommunications Reports International, Incorporated|via=Google Books|isbn=9780938866091}}</ref> In November 1960, an article in the Bell System Technical Journal provided an overview of the technical details of signaling systems, and disclosed the frequencies of the signals.<ref>{{Citation |last1=Breen|first1=C.|last2=Dahlbom|first2=C. A.|title=Signaling Systems for Control of Telephone Switching|journal=Bell System Technical Journal|volume=XXXIX|issue=6|pages=1381–1444|url=http://www.historyofphonephreaking.org/docs/breen1960.pdf|doi=10.1002/j.1538-7305.1960.tb01611.x|quote=The keyer relay M operates and releases from signals on the M lead and alternately removes or applies 2600 cycles to the transmit line of the facility. ... Table IV—Frequencies and Digit Codes for MF Pulsing: Digit 1: Frequencies 700 + 900 ...|year=1960}}</ref>

The system was relatively complex for 1950s technology. It had to accurately decode the frequencies and ignore any signals where that frequency might be accidentally created; music playing in the background might randomly contain the SF tones and the system had to filter these out. To do this, the signaling unit compared the signal power from a bandpass filter centered on 2600{{nbs}}Hz to signal power in other parts of the audio band, and only triggered if the tone was the most prominent signal. The originating end of the call would play the tone into the trunk line when the call ended, and trigger the remote end to end the call. After a short time, the originating end reduced the tone level and continued to send tone as long as it received on hook status from its local equipment.

===Discovery and early use===
Before the technical details were published, many users discovered unintentionally, and to their annoyance, that a 2600 [[Hertz|Hz]] tone played into the caller's handset would cause a [[long-distance calling|long-distance call]] to disconnect. The 2600{{nbs}}Hz tone might be present if the caller were whistling into the telephone microphone while waiting for the called party to answer. Upon detecting the tone from the caller's end, the receiving signaling unit sent an on hook status to the connected equipment, which disconnected the call from that point forward, as if the caller had hung up.

Among the earliest to discover this effect was [[Joybubbles|Joe Engressia]], known as ''Joybubbles'', who accidentally discovered it at the age of seven by [[whistling]]. He became fascinated with the phone network, and over the next decade had built up a considerable base of knowledge about the system and how to place calls using the control tones.{{Citation needed|date=January 2022}} He and other [[phone phreak]]s, such as "[[Bill from New York]]" and "The Glitch", trained themselves to whistle 2600{{nbs}}Hz to reset a trunk line. They also learned how to route telephone calls by flashing, that is using very short pulses of the on-hook signal, to send routing instructions.

At one point in the 1960s, packages of the [[Cap'n Crunch]] breakfast cereal included a free gift: a small whistle that, by coincidence, generated a 2600{{nbs}}Hz tone when one of the whistle's two holes was covered.<ref>{{Cite book|url=https://books.google.com/books?id=kYFzBgAAQBAJ&q=blue+box+Cap'n+Crunch+breakfast+cereal&pg=PA7|title=Cyber Attack|first1=Martin|last1=Gitlin|first2=Margaret J.|last2=Goldstein|date=December 6, 2015|publisher=Twenty-First Century Books|via=Google Books|isbn=9781467725125}}</ref> The phreaker [[John Draper]] adopted his nickname "Captain Crunch" from this whistle.<ref>{{Cite web|url=https://www.popularmechanics.com/technology/a20762221/an-early-hacker-used-a-cereal-box-whistle-to-take-over-phone-lines/|title=An Early Hacker Used a Cereal Box Whistle to Take Over Phone Lines|first=Laura|last=Yan|date=October 22, 2019|website=Popular Mechanics}}</ref>

The [[Toll-free_telephone_number#United_States|"toll free" 800 service]] was launched in 1967 and gave the hackers easy numbers to call. The user would generally choose a number in the target area and then use it as above. Even if billing information were generated, it would be to a 1-800 number and thus free of charge. As before, the remote system would notice a call going to the ultimate non-free number, but could not match the other end.

===Technology===
It was technically possible to generate the tones with the technology available at the time the system was first deployed. A [[piano]] or [[electronic organ]] had keys that were close enough in frequency to work. With tuning, they could even be made dead on frequency. For dialing the phone number, the user would press two keys at a time. An experienced pianist might have found the key combinations awkward to play. But a blank [[player piano]] [[piano roll|roll]] could have been punched to operate the required keys and dial a phone number. Another strategy would have been to purchase [[doorbell]]s, remove the plungers, and mount them on a frame that could be set over the piano keyboard. Twelve DPDT pushbuttons, labelled KP, ST and the 10 digits, would operate pairs of plungers to play the phone company tones, after the E7 piano key had been pressed and released.

At the time, there were consumer devices for recording on wire or blank [[phonograph record]]s, so the piano did not have to be near the phone. Consumer [[tape recorder]]s came later and made the recording process easier. Small, [[Electric battery|battery]] powered, tape recorders allowed the tones to be played back almost anywhere.

It was possible to construct an electronic blue box with 1940s [[vacuum tube]] technology, but the device would have been relatively large and power hungry. Just as it did for radios, shrinking them from the size of toasters to the size of cigarette packages and allowing them to be powered by small batteries, transistor technology made a small, battery powered, electronic blue box practical.

AT&T security captured its first blue box in about 1962, but it probably was not the first one built.

A typical blue box had 13 pushbuttons. One button would be for the 2600{{nbs}}Hz tone, pressed and released to disconnect the outgoing connection and then connect a digit receiver. There would be a KP button, to be pressed next, 10 buttons for telephone number digits, and the ST button to be pressed last. The blue box may have had 7 oscillators, 6 for the 2 out of 6 digit code and one for the 2600{{nbs}}Hz tone, or 2 oscillators with switchable frequencies.

The blue box was thought to be a sophisticated electronic device and sold on the black market for a typical $800–1,000 or as much as $3,500. Actually, designing and building one was within the capabilities of many electronics students and engineers with knowledge of the required tones, using published designs for electronic oscillators, amplifiers and switch matrixes, and assembled with readily available parts. Furthermore, it was possible to generate the required tones using consumer products or lab test equipment. The tones could be recorded on small, battery powered, cassette recorders for playback anywhere. In the early 1980s, [[Radio Shack]] sold<ref>{{cite web | url=https://www.radioshackcatalogs.com/flipbook/1984_radioshack_catalog.html | title=1984 Radio Shack Catalog }}</ref> pairs of [[Intersil ICL8038]] voltage-controlled oscillator chips which were ideal for the purpose.  A common hack was to use a TI-30 [[Calculator#Pocket calculators|pocket calculator]] as the chassis of the device, with the diodes for the switch matrix wired into the keypad.  A miniature audio jack connected through the recharge port for the calculator's optional rechargeable battery would then be used to connect the speaker to play the tones into the handset.

To reduce call setup time, telephone numbers were transmitted from machine to machine in a "speed dial" format, about 1.5 seconds for a 10-digit number, including KP and ST. To catch the cheaters, AT&T could have connected monitors to digit receivers that were not being used for operator dialed calls and logged calls dialed at manual speed. So, some hackers went to the extra trouble of building blue boxes that stored telephone numbers and played the tones with the same timing as the machines.

===Subculture===
The widespread ability to blue box, once limited to just a few isolated individuals exploring the telephone network, developed into a subculture.<ref>{{Cite book|url=https://books.google.com/books?id=fJVcgl8IJs4C&q=bluebox+subculture&pg=PA46|title=Scene of the Cybercrime|first1=Debra Littlejohn|last1=Shinder|first2=Michael|last2=Cross|date=July 21, 2008|publisher=Elsevier|via=Google Books|isbn=9780080486994}}</ref><ref>{{Cite book|url=https://archive.org/details/iwozcomputergeek00wozn|url-access=registration|page=[https://archive.org/details/iwozcomputergeek00wozn/page/110 110]|quote=bluebox subculture.|title=iWoz: Computer Geek to Cult Icon|first=Steve|last=Wozniak|date=October 17, 2007|publisher=W. W. Norton & Company|via=Internet Archive|isbn=9780393066869}}</ref> Famous phone phreaks such as "Captain Crunch", Mark Bernay,{{sfn|Rosenbaum|1971}}{{rp|125}} and Al Bernay used blue boxes to explore the various "hidden codes" that could not be dialled by a standard telephone.{{citation needed|date=June 2017}}

Some of the more famous pranksters were [[Steve Wozniak]] and [[Steve Jobs]], founders of [[Apple Computer]].<ref name="jobsWozAtlantic">{{Cite web|url=https://www.theatlantic.com/technology/archive/2013/02/the-definitive-story-of-steve-wozniak-steve-jobs-and-phone-phreaking/273331/|title=The Definitive Story of Steve Wozniak, Steve Jobs, and Phone Phreaking|first=Phil|last=Lapsley|date=February 20, 2013|website=The Atlantic}}</ref> On one occasion, Wozniak dialed [[Vatican City]] and identified himself as [[Henry Kissinger]] (imitating Kissinger's German accent) and asked to speak to the Pope (who was sleeping at the time).<ref name="iwoz">{{Citation |last1=Wozniak |first1=S. G. |last2=Smith |first2=G. |year=2006 |title=iWoz: From Computer Geek to Cult Icon: How I Invented the Personal Computer, Co-Founded Apple, and Had Fun Doing It |location=New York |publisher=[[W. W. Norton & Company]] |isbn=0-393-06143-4 |title-link=iWoz }}</ref><ref name="jobsWozAtlantic"/> Wozniak said in 1986:<ref name="stix19860514">{{cite news | url=https://www.latimes.com/archives/la-xpm-1986-05-14-vw-5389-story.html | title=A UC Berkeley Degree Is Now the Apple of Steve Wozniak's Eye | work=Los Angeles Times | date=May 14, 1986 | access-date=January 5, 2015 | author=Stix, Harriet}}</ref>

{{blockquote
|I called only to explore the phone company as a system, to learn the codes and tricks. I'd talk to the [[London]] operator, and convince her I was a New York operator. When I called my parents and my friends, I paid. After six months I quit—I'd done everything that I could.

I was so pure. Now I realize others were not as pure, they were just trying to make money. But then I thought we were all pure.
}}

Jobs later told his biographer that if it had not been for Wozniak's blue boxes, "there wouldn't have been an Apple."<ref>{{Cite book |first=Walter |last=Isaacson |year=2015 |title=Steve Jobs |publisher=Simon and Schuster |isbn=9781501127625}} p. 30</ref>

===In the media===
Blue boxing hit the mainstream media when an article by [[Ron Rosenbaum]] titled ''Secrets of the Little Blue Box'' was published in the October 1971 issue of ''[[Esquire (magazine)|Esquire magazine]]''.{{sfn|Rosenbaum|1971}} Suddenly, many more people wanted to get into the [[phone phreaking]] culture spawned by the blue box, and it furthered the fame of Captain Crunch.

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In June 1972, [[Ramparts_(magazine)|''Ramparts'' magazine]] printed the wiring schematics necessary to create a mute box (a variant of the blue box).<ref>{{cite magazine |title=Regulating the Phone Company In Your Home|magazine=Ramparts |date=June 1972|volume=10|issue=12|pages=54–57}}</ref> All sold issues were recalled or seized from newsstands by police and officials of [[Pacific Bell]], causing financial loss to the magazine.<ref>{{cite book|last=Sterling|first=Bruce|title=The hacker crackdown: law and disorder on the electronic frontier|year=1993|publisher=Bantam|location=New York|isbn=0-553-56370-X|edition=[2nd print.]|chapter-url=https://www.mit.edu/hacker/part2.html|chapter=Part 2}}</ref> The magazine ceased operations for good in 1975.<ref>{{cite magazine |last1=Day |first1=Meagan |title=When Ramparts Reigned |url=https://jacobin.com/2018/05/when-ramparts-reigned |access-date=6 December 2022 |magazine=Jacobin |issue=29 |date=23 May 2018 |pages=52–56 |url-access=subscription |issn=2470-6930}} p. 56.</ref>

The June 1975 issue of [[73 (magazine)|''73'' magazine]] carried an article describing the rudiments of the long-distance signaling network, and how to construct and operate red and blue boxes.<ref>{{cite magazine |magazine=73 |title=Inside Ma Bell |url=http://archive.org/details/73-magazine-1975-06 |date=June 1, 1975 |access-date=May 9, 2019 |via=Internet Archive |first=Spencer |last=Whipple Jr. |pages=68–80}}</ref> This article included a blue box schematic using the Intersil 8038 voltage controlled oscillator chip.  Around the same time, do-it-yourself blue box [[Electronic kit|kits]] became available.<ref>{{Cite web|url=https://books.google.com/books?id=QeQCAAAAMBAJ&pg=PA65 |title=New York Magazine|first=New York Media|last=LLC|date=June 6, 1977|publisher=New York Media, LLC|via=Google Books}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=o2hRAAAAMAAJ |title=Technology in Postwar America: A History|first=Carroll W.|last=Pursell|date=December 6, 2007|publisher=Columbia University Press|via=Google Books|isbn=9780231123044}}</ref>

In November 1988, the [[CCITT]] (now known as [[ITU-T]]) published recommendation Q.140 for the [[Signaling System No. 5]], which caused a resurgence of blue boxing by a new generation of users.{{Citation needed|date=July 2008}}

In the early 1990s, blue boxing became popular with the international [[warez scene]], especially in Europe. Software was made to enable blue boxing using a computer to generate and play the signaling tones. For the PC there were [[BlueBEEP]], TLO, and others, and blue boxes were available for other platforms such as [[Amiga]].{{citation needed|date=June 2017}}