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Blue Box
A blue box is an Electronics, electronic device that produces tones used to generate the in-band signaling tones formerly used within the North American long-distance telephone network to send line status and called number information over voice circuits. During that period, charges associated with long-distance calling were commonplace and could be significant, depending on the time, duration and destination of the call. A blue box device allowed for circumventing these charges by enabling an illicit user, referred to as a "Phreaking, phreaker", to place long-distance calls, without using the network's user facilities, that would be billed to another number or dismissed entirely by the telecom company's billing system as an incomplete call. A number of similar "color boxes" were also created to control other aspects of the phone network. First developed in the 1960s and used by a small phreaker community, the introduction of low-cost microelectronics in the early 1970s greatly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phone 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 sensational spelling of the word ''freak'' with the ''ph-'' from ''Telephone, phone'', and may also refer to the use of various audio Frequency, frequencies to manipulate a phone system. ''Phreak'', ''phreaker'', or ''phone phreak'' are names used for and by individuals who participate in phreaking. The term first referred to groups who had Reverse engineering, reverse engineered the system of tones used to route Long-distance calling, long-distance calls. By re-creating the signaling tones, phreaks could switch calls from the phone handset while avoiding long-distance calling charges which were common then. These fees could be significant, depending on the time, duration and destination of the call. To ease the creation of the routing tones, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whistling
Whistling, without the use of an artificial whistle, is achieved by creating a small opening with one's lips, usually after applying moisture (licking one's lips or placing water upon them) and then blowing or sucking air through the space. The air is moderated by the lips, curled tongue, teeth or fingers (placed over the mouth or in various areas between pursed lips) to create turbulence, and the curled tongue acts as a resonance, resonant chamber to enhance the resulting sound by acting as a type of Helmholtz resonance, Helmholtz resonator. By moving the various parts of the lips, fingers, tongue, and epiglottis, one can then manipulate the types of whistles produced. Techniques Pucker whistling is the most common form in much Western music. Typically, the tongue tip is lowered, often placed behind the lower teeth, and the pitch altered by varying the position of the tongue. Although varying the degree of pucker will change the pitch of a pucker whistle, expert pucker whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Battery
An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive Terminal (electronics), terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons. When a battery is connected to an external electric load, those negatively charged electrons flow through the circuit and reach the positive terminal, thus causing a redox reaction by attracting positively charged ions, or cations. Thus, higher energy reactants are converted to lower energy products, and the Gibbs free energy, free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell. Primary battery, Primary (single-use or "disposable") batter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tape Recorder
An audio tape recorder, also known as a tape deck, tape player or tape machine or simply a tape recorder, is a sound recording and reproduction device that records and plays back sounds usually using magnetic tape for storage. In its present-day form, it records a fluctuating signal by moving the tape across a tape head that polarizes the magnetic domains in the tape in proportion to the audio signal. Tape-recording devices include the reel-to-reel tape deck and the cassette deck, which uses a cassette tape (format), cassette for storage. The use of magnetic tape for sound recording originated around 1930 in Germany as paper tape with oxide lacquered to it. Prior to the development of magnetic tape, magnetic wire recording, wire recorders had successfully demonstrated the concept of magnetic recording, but they never offered audio quality comparable to the other recording and broadcast standards of the time. This German invention was the start of a long string of innovations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phonograph Record
A phonograph record (also known as a gramophone record, especially in British English) or a vinyl record (for later varieties only) is an analog sound storage medium in the form of a flat disc with an inscribed, modulated spiral groove. The groove usually starts near the outside edge and ends near the center of the disc. The stored sound information is made audible by playing the record on a phonograph (or "gramophone", "turntable", or "record player"). Records have been produced in different formats with playing times ranging from a few minutes to around 30 minutes per side. For about half a century, the discs were commonly made from shellac and these records typically ran at a rotational speed of 78 rpm, giving it the nickname "78s" ("seventy-eights"). After the 1940s, "vinyl" records made from polyvinyl chloride (PVC) became standard replacing the old 78s and remain so to this day; they have since been produced in various sizes and speeds, most commonly 7-inch discs pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doorbell
A doorbell is a signaling device typically placed near a door to a building's entrance. When a visitor presses a button (control), button, the bell rings inside the building, alerting the occupant to the presence of the visitor. Although the first doorbells were mechanical, activated by pulling a cord connected to a bell, modern doorbells are electric, operated by a pushbutton switch. Modern doorbells often incorporate intercoms and miniature video cameras to increase security. History William Murdoch, a Scottish inventor, installed a number of his own innovations in his house, built in Birmingham in 1817; one of these was a loud doorbell, that worked using a piped system of compressed air. A precursor to the electric doorbell, specifically a bell that could be rung at a distance via an electric wire, was invented by Joseph Henry around 1831. By the early 1900s, electric doorbells had become commonplace. Wired doorbells In most wired systems, a button on the outside next ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piano Roll
A piano roll is a music storage medium used to operate a player piano, piano player or reproducing piano. Piano rolls, like other music rolls, are continuous rolls of paper with holes punched into them. These perforations represent note control data. The roll moves over a reading system known as a tracker bar; the playing cycle for each musical note is triggered when a perforation crosses the bar. Piano rolls have been in continuous production since at least 1896, and are still being manufactured today; QRS Music offers 45,000 titles with "new titles being added on a regular basis", although they are no longer mass-produced. MIDI files have generally supplanted piano rolls in storing and playing back performance data, accomplishing digitally and electronically what piano rolls do mechanically. MIDI editing software often features the ability to represent the music graphically as a piano roll. The first paper rolls were used commercially by Welte & Sons in their orchestrions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Player Piano
A player piano is a self-playing piano with a pneumatic or electromechanical mechanism that operates the piano action using perforated paper or metallic rolls. Modern versions use MIDI. The player piano gained popularity as mass-produced home pianos increased in the late 19th and early 20th centuries. Sales peaked in 1924 and subsequently declined with improvements in electrical phonograph recordings in the mid-1920s. The advent of electrical amplification in home music reproduction, brought by radios, contributed to a decline in popularity, and the stock market crash of 1929 virtually wiped out production. History The first practical pneumatic piano player, manufactured by the Aeolian Company and called the "Pianola", was invented in 1896 by Edwin S. Votey, and came into widespread use in the 20th century. The name "pianola", sometimes used as a generic name for any player piano, came from this invention. The mechanism of this player piano was all-pneumatic: foot-operated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Organ
An electric organ, also known as electronic organ, is an electronic keyboard instrument which was derived from the pump organ, harmonium, pipe organ and theatre organ. Originally designed to imitate their sound, or orchestral sounds, it has since developed into several types of instruments: * #Tonewheel organs, Hammond-style organs used in pop music, pop, Rock music, rock and jazz; * #Digital church organs, digital church organs, which imitate pipe organs and are used primarily in churches; * other types including #Combo organs, combo organs, #Home organs, home organs, and #Software organs, software organs. History Predecessors ;Harmonium The immediate predecessor of the electronic organ was the pump organ, harmonium, or reed organ, an instrument that was common in homes and small churches in the late 19th and early 20th centuries. In a fashion not totally unlike that of pipe organs, reed organs generate sound by forcing air over a set of reeds by means of a bellows, usually ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piano
A piano is a keyboard instrument that produces sound when its keys are depressed, activating an Action (music), action mechanism where hammers strike String (music), strings. Modern pianos have a row of 88 black and white keys, tuned to a chromatic scale in equal temperament. A musician who specializes in piano is called a pianist. There are two main types of piano: the #Grand, grand piano and the #Upupright piano. The grand piano offers better sound and more precise key control, making it the preferred choice when space and budget allow. The grand piano is also considered a necessity in venues hosting skilled pianists. The upright piano is more commonly used because of its smaller size and lower cost. When a key is depressed, the strings inside are struck by felt-coated wooden hammers. The vibrations are transmitted through a Bridge (instrument), bridge to a Soundboard (music), soundboard that amplifies the sound by Coupling (physics), coupling the Sound, acoustic energy t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toll-free Telephone Number
A toll-free telephone number or freephone number is a telephone number that is billed for all arriving calls. For the calling party, a call to a toll-free number is free of charge, unless air-charges apply for mobile telephone service. A toll-free number is identified by a dialing prefix similar to an area code. The specific service access varies by country. History The features of toll-free services have evolved as telephone networks have evolved from electro-mechanical call switching to computerized stored program controlled networks. Originally, before the automatic system was developed, a call billed to the called party had to be placed through a telephone company operator as a collect call, often long-distance. The operator had to secure acceptance of the charges at the destination number, or even transfer that decision to a long-distance operator, before manually completing the call. Some large businesses and government offices received large numbers of collect calls, ... [...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 a toy boatswain's call whistle once given away in boxes of Cap'n Crunch breakfast cereal that for some years could be used to make free long distance phone calls, is an American computer programmer and former phone phreak. He is a widely known figure within the hacker and computer security community. He is primarily known as a colorful and unconventional figure in Silicon Valley history and lore. He befriended and influenced Steve Wozniak and Steve Jobs in the years before they founded Apple Computer. His determined probing and exploration of the telephone network earned him a reputation for his technical acumen. However, his activities sometimes crossed ethical lines, leading to criminal charges for toll fraud and prison time. In the 1970s and 1980s, he worked intermittently as a software engineer for Apple and Autodesk and briefly ran his own software company, producing the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
