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2600 Hertz
2600 hertz (2600 Hz) is a frequency in hertz (cycles per second) that was used by AT&T as a steady signal to mark currently unused long-distance telephone lines. During the 1960s, in-band signaling was used, so the same line for both voice conversations and telephone connection management signals. Since a pause in a voice conversation would produce silence, another method was required for switches to determine whether a line was in use. The solution AT&T created was to produce a 2600 Hz tone on idle trunks. In phreaking In phreaking, a device known as a blue box was used to generate the 2600 Hz signal on a line being used. This indicated to switch that the line was idle. After the tone, the switch believed another call was starting and used the subsequent dialed digits to connect the call. This technique only affected interoffice multi-frequency (MF) trunks; local calls that originate and terminate on the same switch do not use a 2600 Hz signal. By plac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is equal to one event per second. The period is the interval of time between events, so the period is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times a minute (2 hertz), the period, —the interval at which the beats repeat—is half a second (60 seconds divided by 120 beats). Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. Definitions and units For cyclical phenomena such as oscillations, waves, or for examples of simple harmonic motion, the term ''frequency'' is defined as the number of cycles or vibrations per unit of time. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cap'n Crunch
Cap'n Crunch is a maize, corn and oat breakfast cereal manufactured by Quaker Oats Company, a subsidiary of PepsiCo since 2001. After introducing the original cereal in 1963, marketed simply as ''Cap'n Crunch'', Quaker Oats has since introduced numerous flavors and seasonal variations, some for a limited time—and currently offers a Cap'n Crunch product lining, product line. The original Cap'n Crunch cereal was developed to recall a recipe of brown sugar and butter over rice. It was one of the first cereals to use an oil coating to deliver its flavoring, which required an innovative baking process. The taste has been described as similar to the UK and Ireland cereal Golden Nuggets. Product history Pamela Low, a flavorist at Arthur D. Little, developed the original Cap'n Crunch flavor in 1963—recalling a recipe of brown sugar and butter her grandmother Luella Low served over rice at her home in Derry, New Hampshire, Derry, New Hampshire. Low created the flavor coating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Falsing
In telecommunications, falsing is when a decoder assumes that it is detecting a valid input even though one is not present. This is also known as a false decode. This article will discuss analog circuits used before digital signal processing. Examples of decoder falsing include: * a telephone answering machine detecting dial pulses from a rotary dial as ringing voltage, with the result that the answering machine answers in response to dialing. * a two-way radio with an enabled CTCSS decoder turns on the receive audio for one or two syllables of a signal with a close-in-tone-frequency (but wrong) CTCSS tone. The person listening to the radio occasionally hears nonsense partial words from the receiver's speaker: "et"... "up"... * a ringy telephone circuit with SF single-frequency signaling and poor level discipline drops calls because it sees harmonic frequencies or the distorted waveform as a valid "circuit idle" or "on-hook" SF signal. * power line transients cause a telemetry dec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Box (phreaking)
Black boxes were devices which, when attached to home phones, allowed all incoming calls to be received without charge to the caller. The black box (as distinguished from blue boxes and red boxes) was a small electronic circuit, usually a resistor or zener diode in series with the line. It relied on (now-obsolete) telephone exchanges controlled by mechanical relays. These exchanges used a relay to detect a drop in line voltage (usually to less than -10V off-hook, compared to -48V when on-hook) to begin billing for a call; a separate relay controlled ringing on the line. The black box placed a resistor in series with the line, so that the off-hook voltage was closer to -36V: just enough to stop the ringing, but not enough to trigger billing. A bypass capacitor was often added to prevent the device from attenuating AC signals such as transmitted voice.http://www.textfiles.com/phreak/BOXES/black A call originating from a telephone fitted with a black box would still be charged for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Hacker Quarterly
''The'' () is a grammatical article in English, denoting persons or things that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with nouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of the archaic pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communication Channel
A communication channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunications and computer networking. A channel is used for information transfer of, for example, a digital bit stream, from one or several '' senders'' to one or several '' receivers''. A channel has a certain capacity for transmitting information, often measured by its bandwidth in Hz or its data rate in bits per second. Communicating an information signal across distance requires some form of pathway or medium. These pathways, called communication channels, use two types of media: Transmission line (e.g. twisted-pair, coaxial, and fiber-optic cable) and broadcast (e.g. microwave, satellite, radio, and infrared). In information theory, a channel refers to a theoretical ''channel model'' with certain error characteristics. In this more general view, a storage device is also a communication channel, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signaling System 7
Signalling System No. 7 (SS7) is a set of telephony signaling protocols developed in 1975, which is used to set up and tear down telephone calls in most parts of the world-wide public switched telephone network (PSTN). The protocol also performs number translation, local number portability, prepaid billing, Short Message Service (SMS), and other services. The protocol was introduced in the Bell System in the United States by the name ''Common Channel Interoffice Signaling'' in the 1970s for signalling between No. 4ESS switch and No. 4A crossbar toll offices. In North America SS7 is also often referred to as ''Common Channel Signaling System 7'' (CCSS7). In the United Kingdom, it is called ''C7'' (CCITT number 7), ''number 7'' and ''Common Channel Interoffice Signaling 7'' (CCIS7). In Germany, it is often called ''Zentraler Zeichengabekanal Nummer 7'' (ZZK-7). The SS7 protocol is defined for international use by the Q.700-series recommendations of 1988 by the ITU-T. Of the many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Out-of-band Signaling
In telecommunication, signaling is the use of signals for controlling communications. This may constitute an information exchange concerning the establishment and control of a telecommunication circuit and the management of the network. Classification Signaling systems may be classified based on several principal characteristics. In-band and out-of-band signaling In the public switched telephone network (PSTN), in-band signaling is the exchange of call control information within the same physical channel, or within the same frequency band, that the telephone call itself is using. An example is dual-tone multi-frequency signaling (DTMF), which is used on most telephone lines to customer premises. Out-of-band signaling is telecommunication signaling on a dedicated channel separate from that used for the telephone call. Out-of-band signaling has been used since Signaling System No. 6 (SS6) was introduced in the 1970s, and also in Signalling System No. 7 (SS7) in 1980 which became ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-frequency Signaling
In telephony, single-frequency signaling (SF) is line signaling in which dial pulses or supervisory signals are conveyed by a single voice-frequency tone in each direction. SF and similar systems were used in 20th-century carrier systems. An SF signaling unit converts direct current, DC signaling (usually, at least in long-distance calling, long-distance circuits, E and M signaling, E&M signaling) to a format (characterized by the presence or absence of a single voice-frequency tone), which is suitable for transmission (telecommunications), transmission over an alternating current, AC path, ''e.g.'', a carrier system. The SF tone is present in the on-hook or idle state and absent during the seized state. In the seized state, dial pulses are conveyed by bursts of SF tone, corresponding to the interruptions in dc continuity created by a rotary dial or other DC Dialling (telephony), dialing mechanism. The SF tone may occupy a small portion of the User (telecommunications), user da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nickname
A nickname is a substitute for the proper name of a familiar person, place or thing. Commonly used to express affection, a form of endearment, and sometimes amusement, it can also be used to express defamation of character. As a concept, it is distinct from both pseudonym and stage name, and also from a title (for example, City of Fountains), although there may be overlap in these concepts. Etymology The compound word ''ekename'', literally meaning "additional name", was attested as early as 1303. This word was derived from the Old English phrase ''eac'' "also", related to ''eacian'' "to increase". By the 15th century, the misdivision of the syllables of the phrase "an ekename" led to its rephrasing as "a nekename". Though the spelling has changed, the pronunciation and meaning of the word have remained relatively stable ever since. Conventions in various languages English nicknames are generally represented in quotes between the bearer's first and last names (e.g., '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Draper
John Thomas Draper (born March 11, 1943), also known as Captain Crunch, Crunch, or Crunchman (after the Cap'n Crunch breakfast cereal mascot), is an American computer programmer and former phreaking, phone phreak. He is a widely known figure within the computer programming world and the Security hacker, hacker and security community, and generally lives a nomadic lifestyle. Following the emergence of the Me Too movement in 2017, allegations against him dating back decades surfaced in media reports and in social media posts concerning claims of inappropriate sexual behavior. Draper denied any sexual intent but did not address all of the allegations directly. Early life Draper is the son of a United States Air Force engineer. As a child, he built a home radio station from discarded military components. He was frequently bullied in school and briefly received psychological treatment. After taking college courses, Draper enlisted in the U.S. Air Force in 1964. While stationed in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breakfast Cereal
Cereal, formally termed breakfast cereal (and further categorized as cold cereal or warm cereal), is a traditional breakfast food made from processed cereal grains. It is traditionally eaten as part of breakfast, or a snack food, primarily in Western societies. Although warm cereals like porridge and grits have the longest history, ready-to-eat cold cereals appeared around the late 19th century, and are most often mixed with milk (traditionally cow's milk), but can also be paired with yogurt instead or eaten plain. Fruit or Nut (fruit), nuts are sometimes added. Many cereals are produced via Food extrusion, extrusion. Some companies promote their products for the health benefits that come from eating oat-based and high-Dietary fiber, fiber cereals. In the United States, cereals are often Food fortification, fortified with vitamins but can still lack many of the vitamins needed for a healthy breakfast. A significant proportion of cereals have a high sugar content ("sugar cerea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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