A red box is a
phreaking
Phreaking is a slang term coined to describe the activity of a culture of people who study, experiment with, or explore telecommunication systems, such as equipment and systems connected to public telephone networks. The term ''phreak'' is a se ...
device that generates tones to simulate inserting coins in
pay phone
A payphone (alternative spelling: pay phone or pay telephone or public phone) is typically a coin-operated public telephone, often located in a telephone booth or in high-traffic public areas. Prepayment is required by inserting coins or tele ...
s, thus fooling the system into completing free calls. In the United States, a nickel is represented by one tone, a dime by two, and a quarter by a set of five. Any device capable of playing back recorded sounds can potentially be used as a red box. Commonly used devices include modified
Radio Shack
RadioShack (formerly written as Radio Shack) is an American electronics retailer that was established in 1921 as an amateur radio mail-order business. Its parent company was purchased by Tandy Corporation in 1962, which shifted its focus from ma ...
tone dialers, personal MP3 players, and audio-recording greeting cards.
History
The term "red box" to refer to a
phreaking box dates to 1973 or earlier. Red box use became more widespread in the 1990s following the publication in
2600 Magazine of instructions on how to make a red box by replacing a
crystal oscillator
A crystal oscillator is an electronic oscillator Electrical circuit, circuit that uses a piezoelectricity, piezoelectric crystal as a frequency selective surface, frequency-selective element. The oscillator frequency is often used to keep trac ...
in a tone dialer.
Red boxes grew obsolete in the 2000s as phone systems in the US and other nations updated their signaling technology.
Technical details
United States
The tones are made by playing back 1700 Hz and 2200 Hz tones together.
One 66
ms tone represents a
nickel
Nickel is a chemical element; it has symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive, but large pieces are slo ...
. A set of two 66 ms tones separated by 66 ms intervals represent a
dime, and a
quarter is represented by a set of five 33 ms tones with 33 ms pauses. A single 650 ms tone represents a dollar,
but this is rarely used.
The system that handles these tones is called the Automated Coin Toll Service, or ACTS. However, since ACTS has been phased out of service in much of the United States, combined with the integration of acoustic filters into many payphone handsets, the practice of red boxing is rarely possible any longer.
Canada
Canada formerly used a US-style ACTS coin phone system with a tone pair which would beep once for a nickel, twice for a dime and five times on receiving a quarter. These phones did not accept $1 coins (or the later $2 coin) and disappeared with the roll-out of
Nortel Millennium payphones in the 1990s. The Millennium sets do not use ACTS in-band signalling tones as all coin-handling is automated in the phone itself.
United Kingdom
In the
UK, a 1000 Hz tone for 200 ms represents a 10
p coin, and 1000 Hz for 350 ms represents a 50p coin. Prior to this system, the earliest UK pay-on-answer payphones used a resistance, inserted into the loop for one or several short periods followed by a short flash (complete disconnection), to signal units of money inserted. Phreaks simulated these signals by unscrewing the microphone cover of the handset and inserting into the microphone circuit a resistor in parallel with a press-to-open push-button, getting the timing correct was difficult and failure to do this would result in the relay set controlling the call at the exchange to release, dropping the call. This was hard to do inconspicuously in outdoor payphones, and was more common indoors (e.g., in student halls of residence). Manipulating a telephone in this way was illegal and carried the specific offence of "
abstracting electricity" from the GPO (later the Post Office and later still
BT.)
References
External links
"Frequently Asked Questions About Red Boxing"by Mr. Sandman
Red Boxing For Dummies
{{Phreaking Boxes
Red Box