title: Fallout 3

text: On October 22, 2008, Microsoft announced that the game would not be released in India on the Xbox 360 platform. Religious and cultural sentiments were cited as the reason. The statement read that "Microsoft constantly endeavors to bring the best games to Indian consumers in sync with their international release. However, in light of cultural sensitivities in India, we have made the business decision to not bring "Fallout 3" into the country." Although the specific reason was not revealed in public, it is possible that it is because the game contains two-headed mutated cows called Brahmin, or that Brahmin is also the name of an ancient, powerful hereditary caste of Hindu priests and religious scholars in India, or its similarity to the spelling of brahman, a type of cow that originated in India. Brahman, a breed of Zebu, are revered by Hindus.


title: Fallout 3

text: Bethesda Softworks changed the side quest "The Power of the Atom" in the Japanese version of "Fallout 3" to relieve concerns about depictions of atomic detonation in inhabited areas, as the memory of the atomic bombings of Hiroshima and Nagasaki remains strong in the country. In non-Japanese versions, players are given the option of either defusing, ignoring, or detonating the dormant atomic bomb in the town of Megaton; in the Japanese version, the character of Mr. Burke is absent, making it impossible to choose the detonation option. Also in the Japanese release, the Fat Man nuclear catapult weapon was renamed Nuka Launcher, as the original name was a reference to Fat Man, the bomb used on Nagasaki. According to Tetsu Takahashi, responsible for localizing "Fallout 3" to Japan under his company ZeniMax Asia, the available actions prior to localizing "The Power of the Atom" and the ability to kill civilians almost got the game banned by CERO before it received an Adult Only Rating.


title: Mazda CX-5

text: The Mazda CX-5 is a compact crossover SUV produced by Mazda since 2012. A successor to both the Tribute and the slightly larger CX-7, it is Mazda's first model to feature the "Kodo" design language and the first model to be fully developed with a range of technologies branded as Skyactiv, including a rigid, lightweight platform combined with a series of engines and transmissions to reduce emissions and fuel consumption.


title: Mazda CX-5

text: Since 2019, the CX-5 is positioned above the smaller CX-30. , depending on the region, the CX-5 is positioned right below the larger CX-50, CX-60 or the CX-8 within Mazda's crossover SUV line-up.


title: Mazda CX-5

text: The CX-5 has been the worldwide best-selling model offered by the brand every year since 2014, with record sales in 2019 when 444,262 units were sold globally. , cumulative sales of the CX-5 has reached around 3.5 million vehicles.


title: Mazda CX-5

text: The concept car, unveiled at the 2011 Geneva Motor Show, was the first Mazda vehicle to combine the company's Kodo design language and Skyactiv technologies. Its design served as a preview of the CX-5.


title: Mazda CX-5

text: In rapid development from 2009 to 2011 under Hideaki Tanaka and styled under Masashi Nakayama from 2009 to 2010, the CX-5 was first shown at the September 2011 Frankfurt Motor Show. The Japanese model was unveiled at the 2011 Tokyo Motor Show, while a customized variant featuring a red exterior body colour, alloy wheels painted in matte black, and a slightly lower body height was unveiled in 2012 at the Tokyo Auto Salon.


title: Mazda CX-5

text: The production model went on sale in February 2012, with initial choice of a Skyactiv-G 2.0 petrol engine or a Skyactiv-D 2.2 diesel engine matched to a Skyactiv-Drive six-speed automatic transmission or a six-speed manual transmission.


title: Mazda CX-5

text: Japanese production of the CX-5 fitted with a began in January 2012 at the Ujina plant near Mazda's headquarters in Hiroshima. In July 2012, production of the model at Ujina was set to increase to 240,000 units per year by expanding production from Ujina Plant No.2 to Ujina Plant No.1.


title: Mazda CX-5

text: The CX-5 is available with both front-wheel and all-wheel drive, powered by the "PE-VPS" 2.0-liter petrol four-cylinder engine capable of and averaging an estimated and emitting around 139 g/km of carbon dioxide.


title: Mazda CX-5

text: It is also available with the "SH-VPTS" 2.2-liter two-stage turbocharged diesel engine with either and or or , emitting an estimated 119 and 139 g/km of CO, respectively. Fuel consumption for the entry-level diesel engine with front-wheel drive is .


title: Mazda CX-5

text: The Japan domestic market CX-5 achieved monthly sales 8 times higher than forecast just after its launch in February 2012, with the Skyactiv-D 2.2 diesel engine marketed as a "clean diesel" accounting for 73 percent of the sales.


title: Mazda CX-5

text: The first-generation CX-5 was launched in Malaysia in May 2012 as a fully imported model. At launch, only one trim level was offered, with the 2.0 L Skyactiv-G engine and 6-speed automatic transmission with a choice of FWD or AWD. In June 2013, locally assembled models became available. The fully imported trim was renamed to High Spec, and a new lower trim level, Mid Spec, was launched. The Mid Spec was only available with FWD, while the High Spec continued to be offered with both FWD and AWD. In April 2015, a new base variant, dubbed the GL, was launched.


title: Mazda CX-5

text: The first-generation facelift was launched in Malaysia in May 2015. Initially, the facelift version was fully imported and only available with the 2.5 L engine, but again, consumers could choose between FWD or AWD. The locally assembled facelift version was made available in early 2016 with either a 2.0 L Skyactiv-G engine or a 2.5 L Skyactiv-G engine. The 2.0 L engine could be had with only FWD but two trim levels: Mid Spec and High Spec, with Mid Spec being the more affordable of the two. The 2.5 L engine was only available with one trim level, but with either FWD or AWD. In July 2016, a 2.2 L Skyactiv-D powered, FWD, locally assembled variant was launched in Malaysia. It was positioned in between the 2.5 L Skyactiv-G FWD and 2.5 L Skyactiv-G AWD variant.


title: Mazda CX-5

text: The Australian version of the CX-5 was first introduced in 2012 and was available in Maxx, Maxx Sport, Grand Touring and Akera trim levels. Initial models were available with either a 2.0 L petrol engine or a diesel engine, with front-wheel drive and all-wheel drive as options (FWD was only available with a 2.0-equipped CX-5). An automatic transmission was standard on all-wheel drive models, with manual available on the 2.0 Maxx FWD petrol).


title: Mazda CX-5

text: The CX-5 debuted in the U.S. at the November 2012 Los Angeles Auto Show. Initially, the only engine available was a direct-injected Skyactiv-G 2.0-liter inline-four petrol engine with . It is rated at in city and highway with an automatic transmission, and city and highway with a manual transmission.


title: Mazda CX-5

text: For the 2014 model year, an optional 2.5-liter four-cylinder Skyactiv petrol engine was introduced to address the main criticism of the CX-5. It is rated at and , with EPA MPG ratings of 25/32 (FWD), 24/30 (AWD). Only the six-speed automatic transmission is available for this engine, which is standard on the Touring and Grand Touring trim levels. The base Sport trim level is still offered with the 2.0 L engine. Front-wheel drive and all-wheel drive are offered for all trim levels.


title: Mazda CX-5

text: The 2013 Mazda CX-5 was one of the five finalists for the 2013 Green Car of the Year awarded by the Green Car Journal at the 2012 Los Angeles Auto Show.


title: Mazda CX-5

text: In 2022, Mazda CX-5 was ranked at third place on US News. It has sleek, quiet interior with thought-out details and high-quality materials.


title: Mazda CX-5

text: The facelifted Mazda CX-5 was unveiled at the 2014 Los Angeles Auto Show as a 2016 model. Notable changes include updates to exterior styling, reductions in road noise, an improved infotainment system, and a sport mode for the six-speed automatic transmission. LED headlights, LED fog lights and combination LED tail lights was also offered as for higher grade levels.


title: Mazda CX-5

text: In the U.S. and Canada, the update was designated as a 2016.5 model year iteration. The Skyactiv-G 2.5 engine was made standard on all United States trim levels, except the base-level Sport equipped with the six-speed manual transmission and front wheel drive, which retained the 2.0-liter powerplant.


title: Mazda CX-5

text: According to the Insurance Institute for Highway Safety, the 2013 CX-5 achieved Good crash test ratings in the Moderate Overlap Front, Side, Roof Strength, and Head Restraint & Seats categories, while achieving only a Marginal rating in the Small Overlap Front crash test. Design changes were subsequently made that brought up the Small Overlap Front rating up to a Good rating.


title: Mazda CX-5

text: The small overlap test, introduced in 2012 by the IIHS, simulates a frontal collision on 25 percent of the driver's side front corner. Since its adoption, the IIHS has noticed several automakers making non-symmetrical modifications to their vehicles to improve ratings. Another small overlap test was conducted on a number of vehicles, including a 2015 CX-5, but was conducted on the passenger side instead and earned an acceptable rating. Testing showed substantially more intrusion into the passenger side than into the driver's side of the CX-5.


title: Mazda CX-5

text: The second generation CX-5 was unveiled with an overhauled design and new technologies on November 15, 2016, at the Los Angeles Auto Show. The model is available with Skyactiv-G 2.0 petrol, Skyactiv-G 2.5 petrol and Skyactiv-D 2.2 diesel engines. New features include a new 'Soul Red Crystal' paint colour as well as a new remote-controlled powered tailgate.


title: Mazda CX-5

text: In November 2018, Mazda added a new turbocharged petrol engine option from the CX-9 for the 2019 model year CX-5. It is a Skyactiv-G 2.5-liter turbocharged four-cylinder unit which produces at 5,000 rpm on 93 AKI octane fuel and 227 hp on 87 AKI. Under U.S. fuel economy standards, Mazda claims the new engine delivers city, highway, and combined with AWD, regardless of octane.


title: Mazda CX-5

text: In the U.S., the 2017 CX-5 was offered with front-wheel or all-wheel drive in Sport, Touring and Grand Touring trims. The Sport and Touring models came with 17-inch wheels, while the GT had 19-inch wheels. The Skyactiv-G 2.5L 16-valve DOHC 4-cylinder engine with VVT was the only choice offered for the 2017 model year.


title: Mazda CX-5

text: Mazda announced the availability of a diesel engine for 2017; however, that engine did not arrive in the US until the 2019 model year. However, the diesel engine was only sold for the 2019 model year and was only offered on the top-of-the-line Signature trim level. Mazda cited low consumer demand as well as emissions certification issues.


title: Mazda CX-5

text: For the 2018 model year, Mazda added standard cylinder deactivation and made the i-ACTIVSENSE Package available on the Sport trim.


title: Mazda CX-5

text: For the 2019 model year, Mazda made available a new turbocharged SKYACTIV-G 2.5T engine and added new Grand Touring Reserve and Signature range-topping trims. A torque vectoring system marketed as G-Vectoring Control Plus was also added on all models.


title: Mazda CX-5

text: Changes for the 2020 model year include a new key fob design, an updated font used throughout the vehicle, a new Cylinder Deactivation System status display in the infotainment system. Mazda also made automatic headlights, i-Activsense safety features, and automatic rain-sensing windshield wipers standard and the Grand Touring trim received paddle shifters. Mazda claimed to have also improved road noise, vibration, and hardness across all trims. The Grand Touring Reserve trim received a new Engine Harmonics Enhancer to simulate engine noise, a new off-road traction assist system, and a new eight-inch infotainment system.


title: Mazda CX-5

text: For the 2021 model year, Mazda introduced a new standard 10.25-inch infotainment system with new Mazda Connect Software. A new Touring Preferred SV Package was offered as well as a new Carbon Edition trim, which offered exclusive exterior and interior styling elements. Models equipped with the 2.5 Turbo engine received a new turbo badge. Signature trims received new safety features such as reverse automatic braking and driver attention alert as well as improved clarity for the 360-degree camera.


title: Mazda CX-5

text: For 2022, the CX-5 received facelift changes announced by Mazda in September 2021. Along with exterior changes to the front and rear, Mazda introduced new 17-inch wheels for the S trim and updated the seats to improve comfort. Suspension-wise, the dampening control structure was improved and frame rigidity was increased, helping to reduce vibrations and road noise. All models became equipped with standard all-wheel drive and horsepower for the turbo engine was increased from while using 93 octane fuel. Mazda also revised the naming of trims.


title: Mazda CX-5

text: For 2023, Mazda has introduced a new color Rhodium White. There are almost no substantial upgrades but its still one of the best in the small SUV segment.


title: Mazda CX-5

text: In Australia, the second generation Mazda CX-5 was released in March 2017. The range consisted of the base model Maxx, continuing onto the Maxx Sport, Touring, GT & Akera editions. It was available with AWD (except the Maxx, which came as 2WD) as standard. The engines available for the car were a 2.2 L twin-turbo diesel engine, a 2.0 L petrol engine, and a 2.5 L petrol engine.


title: Mazda CX-5

text: The Philippines was the first ASEAN market to get the second generation CX-5, and is fully imported from Malaysia. The car debuted at the 2017 Manila International Auto Show. Initially offered in 3 trim levels: 2.0 petrol FWD Pro, 2.5 petrol AWD Sport and 2.2 diesel AWD Sport. In late 2019, the 2.5 FWD Sport was added to the lineup. In February 2020, the 2.2 Signature AWD was added to the lineup.


title: Mazda CX-5

text: Mazda Singapore officially launched the second-generation CX-5 on July 21, 2017, offered in either 2.0L 2WD or 2.5L 2WD models. Variants include the 2.0L Standard Plus, 2.0L Premium, 2.5L Luxury and 2.5L Super Luxury.


title: Mazda CX-5

text: The second generation CX-5 debuted at the GIIAS 2017. 2 trim levels are sold: 2.5 GT & 2.5 Elite and both are only available in 2WD drivetrains. The facelifted model was released on April 1, 2022, and is offered in Elite and Kuro trim levels.


title: Mazda CX-5

text: The second generation Mazda CX-5 was launched in Malaysia in October 2017. It was available in five variants: the 2.0 2WD GL, 2.0 2WD GLS, 2.5 2WD GLS, 2.2D 2WD GLS and 2.2D AWD GLS. In late 2019, the updated Mazda CX-5 range was launched, with five variants available on sale. The line-up starts with the entry-level 2.0 2WD Mid, 2.0 2WD High, 2.5 2WD High, 2.2D 2WD High, and 2.5 turbo 4WD High. All models are now locally assembled at the Inokom plant in Kulim, Kedah.


title: Mazda CX-5

text: In Thailand, the second generation Mazda CX-5 was released on 14 November 2017, and it's fully imported from Malaysia. It is available in five trim levels: the 2.0 petrol 2WD Core (C), 2.0 petrol 2WD High (S), 2.0 petrol 2WD High Plus (SP), 2.2 diesel 2WD XD and 2.2 diesel AWD XDL. In 2019, a new trim level, the 2.5 turbo petrol AWD High Plus (SP), was added.


title: Mazda CX-5

text: In September 2021, Mazda revealed a facelift for the second-generation 2022 CX-5 with updated styling and kit. Highlights include restyled bumpers and tailgate with new headlights and tail lights, larger tailpipes, a new Mi-Drive drive selector control, updated seats, wireless charging and a revised suspension.


title: Phonograph record

text: A phonograph record (also known as a gramophone record, especially in British English), or simply a record, 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 periphery and ends near the center of the disc. At first, the discs were commonly made from shellac, with earlier records having a fine abrasive filler mixed in. Starting in the 1940s polyvinyl chloride became common, hence the name vinyl.


title: Phonograph record

text: The phonograph record was the primary medium used for music reproduction throughout the 20th century. It had co-existed with the phonograph cylinder from the late 1880s and had effectively superseded it by around 1912. Records retained the largest market share even when new formats such as the compact cassette were mass-marketed. By the 1980s, digital media, in the form of the compact disc, had gained a larger market share, and the record left the mainstream in 1991. Since the 1990s, records continue to be manufactured and sold on a smaller scale, and during the 1990s and early 2000s were commonly used by disc jockeys (DJs), especially in dance music genres. They were also listened to by a growing number of audiophiles. The phonograph record has made a niche resurgence as a format for rock music in the early 21st century—9.2 million records were sold in the US in 2014, a 260% increase since 2009. Likewise, sales in the UK increased five-fold from 2009 to 2014.


title: Phonograph record

text: , 48 record pressing facilities exist worldwide, 18 in the US and 30 in other countries. The increased popularity of the record has led to the investment in new and modern record-pressing machines. Only one producer of lacquers (acetate discs or master discs) remains: MDC in Japan. On 6 February 2020, a fire destroyed the Apollo Masters plant, which was the last remaining lacquers plant in the US. According to the Apollo Masters website, their future is still uncertain.


title: Phonograph record

text: Phonograph records are generally described by their diameter in inches (12-inch, 10-inch, 7-inch) (although they were designed in millimeters), the rotational speed in revolutions per minute (rpm) at which they are played (, , , 45, 78), and their time capacity, determined by their diameter and speed (LP [long playing], 12-inch disc,  rpm; SP [single], 10-inch disc, 78 rpm, or 7-inch disc, 45 rpm; EP [extended play], 12-inch disc or 7-inch disc, or 45 rpm); their reproductive quality, or level of fidelity (high-fidelity, orthophonic, full-range, etc.); and the number of audio channels (mono, stereo, quad, etc.).


title: Phonograph record

text: The phrase "broken record" refers to a malfunction when the needle skips/jumps back to the previous groove and plays the same section over and over again indefinitely.


title: Phonograph record

text: The phonautograph was invented on 25 March 1857 by Frenchman Édouard-Léon Scott de Martinville, an editor and typographer of manuscripts at a scientific publishing house in Paris. One day while editing Professor Longet's "Traité de Physiologie", he happened upon that customer’s engraved illustration of the anatomy of the human ear, and conceived of "the imprudent idea of photographing the word." In 1853 or 1854 (Scott cited both years) he began working on "le problème de la parole s'écrivant elle-même" ("the problem of speech writing itself"), aiming to build a device that could replicate the function of the human ear.


title: Phonograph record

text: Scott coated a plate of glass with a thin layer of lampblack. He then took an acoustic trumpet, and at its tapered end affixed a thin membrane that served as the analog to the eardrum. At the center of that membrane, he attached a rigid boar's bristle approximately a centimeter long, placed so that it just grazed the lampblack. As the glass plate was slid horizontally in a well formed groove at a speed of one meter per second, a person would speak into the trumpet, causing the membrane to vibrate and the stylus to trace figures that were scratched into the lampblack. On 25 March 1857, Scott received the French patent #17,897/31,470 for his device, which he called a phonautograph. The earliest known surviving recorded sound of a human voice was conducted on 9 April 1860 when Scott recorded someone singing the song "Au Clair de la Lune" ("By the Light of the Moon") on the device. However, the device was not designed to play back sounds, as Scott intended for people to read back the tracings, which he called phonautograms. By late 1857, with support from the Société d'encouragement pour l'industrie nationale, Scott’s phonautograph was recording sounds with sufficient precision to be adopted by the scientific community, paving the way for the nascent science of acoustics.


title: Phonograph record

text: The device’s true significance in the history of recorded sound was not fully realized prior to March 2008, when it was discovered and resurrected in a Paris patent office by First Sounds, an informal collaborative of American audio historians, recording engineers, and sound archivists founded to make the earliest sound recordings available to the public. The phonautograms were then digitally converted by scientists at the Lawrence Berkeley National Laboratory in California, who were able to play back the recorded sounds, something Scott had never conceived of. Prior to this point, the earliest known record of a human voice was thought to be an 1877 phonograph recording by Thomas Edison. The phonautograph would play a role in the development of the gramophone, whose inventor, Emile Berliner, worked with the phonautograph in the course of developing his own device.


title: Phonograph record

text: Edison invented the phonograph in 1877. Unlike the phonautograph, Edison's phonograph could both record and reproduce sound. Edison first tried recording sound on a wax-impregnated paper tape, with the idea of creating a "telephone repeater" analogous to the telegraph repeater he had been working on. Although the visible results made him confident that sound could be physically recorded and reproduced, his notes do not indicate that he actually reproduced sound before his first experiment in which he used tinfoil as a recording medium several months later. The tinfoil was wrapped around a grooved metal cylinder and a sound-vibrated stylus indented the tinfoil while the cylinder was rotated. The recording could be played back immediately. The "Scientific American" article that introduced the tinfoil phonograph to the public mentioned Marey, Rosapelly and Barlow, as well as Scott as creators of devices for recording but, importantly, not reproducing sound.


title: Phonograph record

text: In 1910, Edison realized that cylinders had peaked, and finally embraced discs with the introduction of the Edison Disc Phonograph.


title: Phonograph record

text: In August 1900, after a brief period working in Philadelphia for the Berliner Gramophone Co., which was closed by a legal action, Leon Douglass agreed to go into business with Eldridge R. Johnson, who owned a machine shop in Camden, New Jersey and had supplied machines to Berliner. The company started doing business in September 1900 as The Consolidated Talking Machine Company but changed to using Johnson’s name because of a conflict with a Berliner company name. On 3 October 1901 it incorporated as the Victor Talking Machine Company.


title: Phonograph record

text: Emile Berliner improved the quality of recordings while his manufacturing associate Eldridge R. Johnson eventually improved the mechanism of the gramophone with a spring motor and a speed regulating governor, resulting in a sound quality equal to Edison's cylinders. Abandoning Berliner's "Gramophone" trademark for legal reasons in the United States, in 1901 Johnson's and Berliner's separate companies reorganized to form the Victor Talking Machine Company in Camden, New Jersey, whose products would come to dominate the market for many years.


title: Phonograph record

text: The factory, which became the Canadian branch of RCA Victor, still exists. There is a dedicated museum in Montreal for Berliner (Musée des ondes Emile Berliner).


title: Phonograph record

text: Early disc recordings were produced in a variety of speeds ranging from 60 to 130 rpm, and a variety of sizes. As early as 1894, Emile Berliner's United States Gramophone Company was selling single-sided 7-inch discs with an advertised standard speed of "about 70 rpm".


title: Phonograph record

text: One standard audio recording handbook describes speed regulators, or governors, as being part of a wave of improvement introduced rapidly after 1897. A picture of a hand-cranked 1898 Berliner Gramophone shows a governor, and says that spring drives had replaced hand drives. It notes that:


title: Phonograph record

text: The speed regulator was furnished with an indicator that showed the speed when the machine was running so that the records, on reproduction, could be revolved at exactly the same speed...The literature does not disclose why 78 rpm was chosen for the phonograph industry, apparently this just happened to be the speed created by one of the early machines and, for no other reason continued to be used.


title: Phonograph record

text: In 1912, the Grammophone Company set 78 rpm as their recording standard, based on the average of recordings they had been releasing at the time, and started selling players whose governors had a nominal speed of 78 rpm. By 1925, 78 rpm was becoming standardized across the industry. However, the exact speed differed between places with alternating current electricity supply at 60 hertz (cycles per second, Hz) and those at 50 Hz. Where the mains supply was 60 Hz, the actual speed was 78.26 rpm: that of a 60 Hz stroboscope illuminating 92-bar calibration markings. Where it was 50 Hz, it was 77.92 rpm: that of a 50 Hz stroboscope illuminating 77-bar calibration markings.


title: Phonograph record

text: Early recordings were made entirely acoustically, the sound being collected by a horn and piped to a diaphragm, which vibrated the cutting stylus. Sensitivity and frequency range were poor, and frequency response was very irregular, giving acoustic recordings an instantly recognizable tonal quality. A singer almost had to put his or her face in the recording horn. A way of reducing resonance was to wrap the recording horn with tape.


title: Phonograph record

text: Even drums, if planned and placed properly, could be effectively recorded and heard on even the earliest jazz and military band recordings. The loudest instruments such as the drums and trumpets were positioned the farthest away from the collecting horn. Lillian Hardin Armstrong, a member of King Oliver's Creole Jazz Band, which recorded at Gennett Records in 1923, remembered that at first Oliver and his young second trumpet, Louis Armstrong, stood next to each other and Oliver's horn could not be heard. "They put Louis about fifteen feet over in the corner, looking all sad."


title: Phonograph record

text: During the first half of the 1920s, engineers at Western Electric, as well as independent inventors such as Orlando Marsh, developed technology for capturing sound with a microphone, amplifying it with vacuum tubes, then using the amplified signal to drive an electromechanical recording head. Western Electric's innovations resulted in a broader and smoother frequency response, which produced a dramatically fuller, clearer and more natural-sounding recording. Soft or distant sounds that were previously impossible to record could now be captured. Volume was now limited only by the groove spacing on the record and the amplification of the playback device. Victor and Columbia licensed the new electrical system from Western Electric and recorded the first electrical discs during the Spring of 1925. The first electrically recorded Victor Red Seal record was Chopin's "Impromptus" and Schubert's "Litanei" performed by pianist Alfred Cortot at Victor's studios in Camden, New Jersey.


title: Phonograph record

text: A 1926 Wanamaker's ad in "The New York Times" offers records "by the latest Victor process of electrical recording". It was recognized as a breakthrough; in 1930, a "Times" music critic stated:


title: Phonograph record

text: ... the time has come for serious musical criticism to take account of performances of great music reproduced by means of the records. To claim that the records have succeeded in exact and complete reproduction of all details of symphonic or operatic performances ... would be extravagant ... [but] the article of today is so far in advance of the old machines as hardly to admit classification under the same name. Electrical recording and reproduction have combined to retain vitality and color in recitals by proxy.


title: Phonograph record

text: The Orthophonic Victrola had an interior folded exponential horn, a sophisticated design informed by impedance-matching and transmission-line theory, and designed to provide a relatively flat frequency response. Its first public demonstration was front-page news in "The New York Times", which reported:


title: Phonograph record

text: The audience broke into applause ... John Philip Sousa [said]: '[Gentlemen], that is a band. This is the first time I have ever heard music with any soul to it produced by a mechanical talking machine' ... The new instrument is a feat of mathematics and physics. It is not the result of innumerable experiments, but was worked out on paper in advance of being built in the laboratory ... The new machine has a range of from 100 to 5,000 [cycles per second], or five and a half octaves ... The 'phonograph tone' is eliminated by the new recording and reproducing process.


title: Phonograph record

text: Sales of records plummeted precipitously during the early years of the Great Depression of the 1930s, and the entire record industry in America nearly foundered. In 1932, RCA Victor introduced a basic, inexpensive turntable called the Duo Jr., which was designed to be connected to their radio receivers. According to Edward Wallerstein (the general manager of the RCA Victor Division), this device was "instrumental in revitalizing the industry".


title: Phonograph record

text: The production of shellac records continued throughout the 78 rpm era, which lasted until 1948 in industrialized nations.


title: Phonograph record

text: During the Second World War, the United States Armed Forces produced thousands of 12-inch vinyl 78 rpm V-Discs for use by the troops overseas. After the war, the use of vinyl became more practical as new record players with lightweight crystal pickups and precision-ground styli made of sapphire or an exotic osmium alloy proliferated. In late 1945, RCA Victor began offering "De Luxe" transparent red vinyl pressings of some Red Seal classical 78s, at a "de luxe" price. Later, Decca Records introduced vinyl Deccalite 78s, while other record companies used vinyl formulations trademarked as Metrolite, Merco Plastic, and Sav-o-flex, but these were mainly used to produce "unbreakable" children's records and special thin vinyl DJ pressings for shipment to radio stations.


title: Phonograph record

text: The playing time of a phonograph record is directly proportional to the available groove length divided by the turntable speed. Total groove length in turn depends on how closely the grooves are spaced, in addition to the record diameter. At the beginning of the 20th century, the early discs played for two minutes, the same as cylinder records. The 12-inch disc, introduced by Victor in 1903, increased the playing time to three and a half minutes. Because the standard 10-inch 78 rpm record could hold about three minutes of sound per side, most popular recordings were limited to that duration. For example, when King Oliver's Creole Jazz Band, including Louis Armstrong on his first recordings, recorded 13 sides at Gennett Records in Richmond, Indiana, in 1923, one side was 2:09 and four sides were 2:52–2:59.


title: Phonograph record

text: In January 1938, Milt Gabler started recording for Commodore Records, and to allow for longer continuous performances, he recorded some 12-inch discs. Eddie Condon explained: "Gabler realized that a jam session needs room for development." The first two 12-inch recordings did not take advantage of their capability: "Carnegie Drag" was 3m 15s; "Carnegie Jump", 2m 41s. But at the second session, on 30 April, the two 12-inch recordings were longer: "Embraceable You" was 4m 05s; "Serenade to a Shylock", 4m 32s. Another way to overcome the time limitation was to issue a selection extending to both sides of a single record. Vaudeville stars Gallagher and Shean recorded "Mr. Gallagher and Mr. Shean", written by themselves or, allegedly, by Bryan Foy, as two sides of a 10-inch 78 in 1922 for Victor. Longer musical pieces were released as a set of records. In 1903 HMV in England made the first complete recording of an opera, Verdi's "Ernani", on 40 single-sided discs. In 1940, Commodore released Eddie Condon and his Band's recording of "A Good Man Is Hard to Find" in four parts, issued on both sides of two 12-inch 78s. The limited duration of recordings persisted from their advent until the introduction of the LP record in 1948. In popular music, the time limit of minutes on a 10-inch 78 rpm record meant that singers seldom recorded long pieces. One exception is Frank Sinatra's recording of Rodgers and Hammerstein's "Soliloquy", from "Carousel", made on 28 May 1946. Because it ran 7m 57s, longer than both sides of a standard 78 rpm 10-inch record, it was released on Columbia's Masterwork label (the classical division) as two sides of a 12-inch record.


title: Phonograph record

text: In the 78 era, classical-music and spoken-word items generally were released on the longer 12-inch 78s, about 4–5 minutes per side. For example, on 10 June 1924, four months after the 12 February premier of "Rhapsody in Blue", George Gershwin recorded an abridged version of the seventeen-minute work with Paul Whiteman and His Orchestra. It was released on two sides of Victor 55225 and ran for 8m 59s.


title: Phonograph record

text: German record company Odeon pioneered the album in 1909 when it released the "Nutcracker Suite" by Tchaikovsky on 4 double-sided discs in a specially designed package.


title: Phonograph record

text: In 1968, Reprise planned to release a series of 78 rpm singles from their artists on their label at the time, called the Reprise Speed Series. Only one disc actually saw release, Randy Newman's "I Think It's Going to Rain Today", a track from his self-titled debut album (with "The Beehive State" on the flipside). Reprise did not proceed further with the series due to a lack of sales for the single, and a lack of general interest in the concept.


title: Phonograph record

text: In 1978, guitarist and vocalist Leon Redbone released a promotional 78 rpm record featuring two songs ("Alabama Jubilee" and "Please Don't Talk About Me When I'm Gone") from his "Champagne Charlie" album.


title: Phonograph record

text: In the 1990s Rhino Records issued a series of boxed sets of 78 rpm reissues of early rock and roll hits, intended for owners of vintage jukeboxes. The records were made of vinyl, however, and some of the earlier vintage 78 rpm jukeboxes and record players (the ones that were pre-war) were designed with heavy tone arms to play the hard slate-impregnated shellac records of their time. These vinyl Rhino 78's were softer and would be destroyed by old juke boxes and old record players, but play very well on newer 78-capable turntables with modern lightweight tone arms and jewel needles.


title: Phonograph record

text: As a special release for Record Store Day 2011, Capitol re-released The Beach Boys single "Good Vibrations" in the form of a 10-inch 78 rpm record (b/w "Heroes and Villains"). More recently, The Reverend Peyton's Big Damn Band has released their tribute to blues guitarist Charley Patton "Peyton on Patton" on both 12-inch LP and 10-inch 78 rpm. Both are accompanied with a link to a digital download of the music, acknowledging the probability that purchasers might be unable to play the vinyl recording.


title: Phonograph record

text: In 1931, RCA Victor launched the first commercially available vinyl long-playing record, marketed as program-transcription discs. These revolutionary discs were designed for playback at  rpm and pressed on a 30 cm diameter flexible plastic disc, with a duration of about ten minutes playing time per side. RCA Victor's early introduction of a long-play disc was a commercial failure for several reasons including the lack of affordable, consumer playback equipment and consumer rejection during the Great Depression.


title: Phonograph record

text: Unwilling to accept and license Columbia's system, in February 1949, RCA Victor released the first 45 rpm single, 7 inches in diameter with a large center hole. The 45 rpm player included a changing mechanism that allowed multiple disks to be stacked, much as a conventional changer handled 78s. The short playing time of a single 45 rpm side meant that long works, such as symphonies, had to be released on multiple 45s instead of a single LP, but RCA Victor claimed that the new high-speed changer rendered side breaks so brief as to be inaudible or inconsequential. Early 45 rpm records were made from either vinyl or polystyrene. They had a playing time of eight minutes.


title: Phonograph record

text: At least one attempt to lengthen playing time was made in the early 1920s. World Records produced records that played at a constant linear velocity, controlled by Noel Pemberton Billing's patented add-on speed governor.


title: Phonograph record

text: In the 1920s, 78.26 rpm was standardized when stroboscopic discs and turntable edge markings were introduced to standardize the speeds of recording lathes. At that speed, a strobe disc with 92 lines would "stand still" in 60 Hz light. In regions of the world that use 50 Hz current, the standard was 77.92 rpm (and a disk with 77 lines).


title: Phonograph record

text: The older 78 rpm format continued to be mass-produced alongside the newer formats using new materials in decreasing numbers until the summer of 1958 in the U.S., and in a few countries, such as the Philippines and India (both countries issued recordings by the Beatles on 78s), into the late 1960s. For example, Columbia Records' last reissue of Frank Sinatra songs on 78 rpm records was an album called "Young at Heart", issued in November, 1954.


title: Phonograph record

text: The Seeburg Corporation introduced the Seeburg Background Music System in 1959, using a  rpm 9-inch record with 2-inch center hole. Each record held 40 minutes of music per side, recorded at 420 grooves per inch.


title: Phonograph record

text: The commercial rivalry between RCA Victor and Columbia Records led to RCA Victor's introduction of what it had intended to be a competing vinyl format, the 7-inch (175 mm) 45 rpm disc, with a much larger center hole. For a two-year period from 1948 to 1950, record companies and consumers faced uncertainty over which of these formats would ultimately prevail in what was known as the "War of the Speeds" (see also Format war). In 1949 Capitol and Decca adopted the new LP format and RCA Victor gave in and issued its first LP in January 1950. The 45 rpm size was gaining in popularity, too, and Columbia issued its first 45s in February 1951. By 1954, 200 million 45s had been sold.


title: Phonograph record

text: Eventually the 12-inch (300 mm)  rpm LP prevailed as the dominant format for musical albums, and 10-inch LPs were no longer issued. The last Columbia Records reissue of any Frank Sinatra songs on a 10-inch LP record was an album called "Hall of Fame", CL 2600, issued on 26 October 1956, containing six songs, one each by Tony Bennett, Rosemary Clooney, Johnnie Ray, Frank Sinatra, Doris Day, and Frankie Laine.


title: Phonograph record

text: The 45 rpm discs also came in a variety known as extended play (EP), which achieved up to 10–15 minutes play at the expense of attenuating (and possibly compressing) the sound to reduce the width required by the groove. EP discs were cheaper to produce and were used in cases where unit sales were likely to be more limited or to reissue LP albums on the smaller format for those people who had only 45 rpm players. LP albums could be purchased one EP at a time, with four items per EP, or in a boxed set with three EPs or twelve items. The large center hole on 45s allows easier handling by jukebox mechanisms. EPs were generally discontinued by the late 1950s in the U.S. as three- and four-speed record players replaced the individual 45 players. One indication of the decline of the 45 rpm EP is that the last Columbia Records reissue of Frank Sinatra songs on 45 rpm EP records, called "Frank Sinatra" (Columbia B-2641) was issued on 7 December 1959.


title: Phonograph record

text: From the mid-1950s through the 1960s, in the U.S. the common home record player or "stereo" (after the introduction of stereo recording) would typically have had these features: a three- or four-speed player (78, 45, , and sometimes  rpm); with changer, a tall spindle that would hold several records and automatically drop a new record on top of the previous one when it had finished playing, a combination cartridge with both 78 and microgroove styli and a way to flip between the two; and some kind of adapter for playing the 45s with their larger center hole. The adapter could be a small solid circle that fit onto the bottom of the spindle (meaning only one 45 could be played at a time) or a larger adapter that fit over the entire spindle, permitting a stack of 45s to be played.


title: Phonograph record

text: RCA Victor 45s were also adapted to the smaller spindle of an LP player with a plastic snap-in insert known as a "spider". These inserts, commissioned by RCA president David Sarnoff and invented by Thomas Hutchison, were prevalent starting in the 1960s, selling in the tens of millions per year during the 45 rpm heyday. In countries outside the U.S., 45s often had the smaller album-sized holes, e.g., Australia and New Zealand, or as in the United Kingdom, especially before the 1970s, the disc had a small hole within a circular central section held only by three or four lands so that it could be easily punched out if desired (typically for use in jukeboxes).


title: Phonograph record

text: Capacitance Electronic Discs were videodiscs invented by RCA, based on mechanically tracked ultra-microgrooves (9541 grooves/inch) on a 12-inch conductive vinyl disc. Only a small portion of the tracking stylus was electrically active; this sensing electrode detected the changing capacitance between it and microscopic peaks and valleys of the conductive disc surface, while the entire stylus rides over many crests at once.


title: Phonograph record

text: The term "high fidelity" was coined in the 1920s by some manufacturers of radio receivers and phonographs to differentiate their better-sounding products claimed as providing "perfect" sound reproduction. The term began to be used by some audio engineers and consumers through the 1930s and 1940s. After 1949 a variety of improvements in recording and playback technologies, especially stereo recordings, which became widely available in 1958, gave a boost to the "hi-fi" classification of products, leading to sales of individual components for the home such as amplifiers, loudspeakers, phonographs, and tape players. "High Fidelity" and "Audio" were two magazines that hi-fi consumers and engineers could read for reviews of playback equipment and recordings.


title: Phonograph record

text: In this system, each of two stereo channels is carried independently by a separate groove wall, each wall face moving at 45 degrees to the plane of the record surface (hence the system's name) in correspondence with the signal level of that channel. By convention, the inner wall carries the left-hand channel and the outer wall carries the right-hand channel. While the stylus only moves horizontally when reproducing a monophonic disk recording, on stereo records the stylus moves vertically as well as horizontally. During playback, the movement of a single stylus tracking the groove is sensed independently, e.g., by two coils, each mounted diagonally opposite the relevant groove wall.


title: Phonograph record

text: In 1957 the first commercial stereo two-channel records were issued first by Audio Fidelity followed by a translucent blue vinyl on Bel Canto Records, the first of which was a multi-colored-vinyl sampler featuring A Stereo Tour of Los Angeles narrated by Jack Wagner on one side, and a collection of tracks from various Bel Canto albums on the back.


title: Phonograph record

text: A similar scheme aiming at the high-end audiophile market, and achieving a noise reduction of about 20 to 25 dB(A), was the Telefunken/Nakamichi High-Com II noise reduction system being adapted to vinyl in 1979. A decoder was commercially available but only one demo record is known to have been produced in this format.


title: Phonograph record

text: Yet another noise reduction system for vinyl records was the UC compander system developed by (ZWT) of (RFT). The system deliberately reduced disk noise by 10 to 12 dB(A) only to remain virtually free of recognizable acoustical artifacts even when records were played back without an UC expander. In fact, the system was undocumentedly introduced into the market by several East-German record labels since 1983. Over 500 UC-encoded titles were produced without an expander becoming available to the public. The only UC expander was built into a turntable manufactured by .


title: Phonograph record

text: Sizes of records in the United States and the UK are generally measured in inches, e.g. 7-inch records, which are generally 45 rpm records. LPs were 10-inch records at first, but soon the 12-inch size became by far the most common. Generally, 78s were 10-inch, but 12-inch and 7-inch and even smaller were made—the so-called "little wonders".


title: Phonograph record

text: Flexi discs were thin flexible records that were distributed with magazines and as promotional gifts from the 1960s to the 1980s.


title: Phonograph record

text: In March 1949, as RCA Victor released the 45, Columbia released several hundred 7-inch,  rpm, small-spindle-hole singles. This format was soon dropped as it became clear that the RCA Victor 45 was the single of choice and the Columbia 12-inch LP would be the album of choice.


title: Phonograph record

text: The first release of the 45 came in seven colors: black 47-xxxx popular series, yellow 47-xxxx juvenile series, green (teal) 48-xxxx country series, deep red 49-xxxx classical series, bright red (cerise) 50-xxxx blues/spiritual series, light blue 51-xxxx international series, dark blue 52-xxxx light classics. Most colors were soon dropped in favor of black because of production problems. However, yellow and deep red were continued until about 1952.


title: Phonograph record

text: The first 45 rpm record created for sale was "PeeWee the Piccolo" RCA Victor 47-0147 pressed in yellow translucent vinyl at the Sherman Avenue plant, Indianapolis on 7 December 1948, by R. O. Price, plant manager.


title: Phonograph record

text: In the 1970s, the government of Bhutan produced now-collectible postage stamps on playable vinyl mini-discs.


title: Phonograph record

text: Increasingly from the early 20th century, and almost exclusively since the 1920s, both sides of the record have been used to carry the grooves. Occasional records have been issued since then with a recording on only one side. In the 1980s Columbia records briefly issued a series of less expensive one-sided 45 rpm singles.


title: Phonograph record

text: Since its inception in 1948, vinyl record standards for the United States follow the guidelines of the Recording Industry Association of America (RIAA).


title: Phonograph record

text: The sound quality and durability of vinyl records is highly dependent on the quality of the vinyl. During the early 1970s, as a cost-cutting move, much of the industry began reducing the thickness and quality of vinyl used in mass-market manufacturing. The technique was marketed by RCA Victor as the Dynaflex (125 g) process, but was considered inferior by most record collectors. Most vinyl records are pressed from a mix of 70% virgin and 30% recycled vinyl. Vinyl is a material that is sensitive for high temperatures as well as uneven temperatures on different parts of a record.


title: Phonograph record

text: New or "virgin" heavy/heavyweight (180–220 g) vinyl is commonly used for modern audiophile vinyl releases in all genres. Many collectors prefer to have heavyweight vinyl albums, which have been reported to have better sound than normal vinyl because of their higher tolerance against deformation caused by normal play.


title: Phonograph record

text: 180 gram vinyl is more expensive to produce only because it uses more vinyl. Manufacturing processes are identical regardless of weight. In fact, pressing lightweight records requires more care. An exception is the propensity of 200 g pressings to be slightly more prone to non-fill, when the vinyl biscuit does not sufficiently fill a deep groove during pressing (percussion or vocal amplitude changes are the usual locations of these artifacts). This flaw causes a grinding or scratching sound at the non-fill point.


title: Phonograph record

text: Since most vinyl records contain up to 30% recycled vinyl, impurities can accumulate in the record and cause even a brand-new record to have audio artifacts such as clicks and pops. Virgin vinyl means that the album is not from recycled plastic, and will theoretically be devoid of these impurities.


title: Phonograph record

text: The "orange peel" effect on vinyl records is caused by worn molds. Rather than having the proper mirror-like finish, the surface of the record will have a texture that looks like orange peel. This introduces noise into the record, particularly in the lower frequency range. With direct metal mastering (DMM), the master disc is cut on a copper-coated disc, which can also have a minor "orange peel" effect on the disc itself. As this "orange peel" originates in the master rather than being introduced in the pressing stage, there is no ill effect as there is no physical distortion of the groove.


title: Phonograph record

text: Original master discs are created by lathe-cutting: a disc cutting lathe is used to cut a modulated groove into a blank record. The blank records for cutting used to be cooked up, as needed, by the cutting engineer, using what Robert K. Morrison describes as a "metallic soap", containing lead litharge, ozokerite, barium sulfate, montan wax, stearin and paraffin, among other ingredients. Cut "wax" sound discs would be placed in a vacuum chamber and gold-sputtered to make them electrically conductive for use as mandrels in an electroforming bath, where pressing stamper parts were made. Later, the French company Pyral invented a ready-made blank disc having a thin nitro-cellulose lacquer coating (approximately 7 mils thickness on both sides) that was applied to an aluminum substrate. Lacquer cuts result in an immediately playable, or processable, master record. If vinyl pressings are wanted, the still-unplayed sound disc is used as a mandrel for electroforming nickel records that are used for manufacturing pressing stampers.


title: Phonograph record

text: The electroformed nickel records are mechanically separated from their respective mandrels. This is done with relative ease because no actual "plating" of the mandrel occurs in the type of electrodeposition known as electroforming, unlike with electroplating, in which the adhesion of the new phase of metal is chemical and relatively permanent. The one-molecule-thick coating of silver (that was sprayed onto the processed lacquer sound disc in order to make its surface electrically conductive) reverse-plates onto the nickel record's face. This negative impression disc (having ridges in place of grooves) is known as a nickel master, "matrix" or "father". The "father" is then used as a mandrel to electroform a positive disc known as a "mother". Many mothers can be grown on a single "father" before ridges deteriorate beyond effective use. The "mothers" are then used as mandrels for electroforming more negative discs known as "sons". Each "mother" can be used to make many "sons" before deteriorating. The "sons" are then converted into "stampers" by center-punching a spindle hole (which was lost from the lacquer sound disc during initial electroforming of the "father"), and by custom-forming the target pressing profile. This allows them to be placed in the dies of the target (make and model) record press and, by center-roughing, to facilitate the adhesion of the label, which gets stuck onto the vinyl pressing without any glue. In this way, several million vinyl discs can be produced from a single lacquer sound disc. When only a few hundred discs are required, instead of electroforming a "son" (for each side), the "father" is removed of its silver and converted into a stamper. Production by this latter method, known as the "two-step process" (as it does not entail creation of "sons" but does involve creation of "mothers", which are used for test playing and kept as "safeties" for electroforming future "sons") is limited to a few hundred vinyl pressings. The pressing count can increase if the stamper holds out and the quality of the vinyl is high. The "sons" made during a "three-step" electroforming make better stampers since they don't require silver removal (which reduces some high fidelity because of etching erasing part of the smallest groove modulations) and also because they have a stronger metal structure than "fathers".


title: Phonograph record

text: One problem with shellac was that the size of the disks tended to be larger because it was limited to 80–100 groove walls per inch before the risk of groove collapse became too high, whereas vinyl could have up to 260 groove walls per inch.


title: Phonograph record

text: Although vinyl records are strong and don't break easily, they scratch due to its soft material sometimes resulting in ruining the record. Vinyl readily acquires a static charge, attracting dust that is difficult to remove completely. Dust and scratches cause audio clicks and pops. In extreme cases, they can cause the needle to skip over a series of grooves, or worse yet, cause the needle to skip backwards, creating a "locked groove" that repeats over and over. This is the origin of the phrase "like a broken record" or "like a scratched record", which is often used to describe a person or thing that continually repeats itself.


title: Phonograph record

text: A further limitation of the gramophone record is that fidelity steadily declines as playback progresses; there is more vinyl per second available for fine reproduction of high frequencies at the large-diameter beginning of the groove than exist at the smaller diameters close to the end of the side. At the start of a groove on an LP there are 510 mm of vinyl per second traveling past the stylus while the ending of the groove gives 200–210 mm of vinyl per second — less than half the linear resolution.


title: Phonograph record

text: There is controversy about the relative quality of CD sound and LP sound when the latter is heard under the very best conditions (see Comparison of analog and digital recording). It is notable, however, that one technical advantage with vinyl compared to the optical CD is that if correctly handled and stored, the vinyl record will be playable for decades and possibly centuries, which is longer than some versions of the optical CD. For vinyl records to be playable for years to come, they need to be handled with care and stored properly. Guidelines for proper vinyl storage include not stacking records on top of each other, avoiding heat or direct sunlight and placing them in a temperature controlled area that will help prevent vinyl records from warping and scratching. Collectors store their records in a variety of boxes, cubes, shelves and racks.


title: Phonograph record

text: Further, even after officially agreeing to implement the RIAA equalization curve, many recording labels continued to use their own proprietary equalization even well into the 1970s. Columbia is one such prominent example in the US, as are Decca, Teldec and Deutsche Grammophon in Europe.


title: Phonograph record

text: At the time of the introduction of the compact disc (CD) in 1982, the stereo LP pressed in vinyl continued to suffer from a variety of limitations:


title: Phonograph record

text: The stereo image was not made up of fully discrete Left and Right channels; each channel's signal coming out of the cartridge contained a small amount of the signal from the other channel, with more crosstalk at higher frequencies. High-quality disc cutting equipment was capable of making a master disc with 30–40 dB of stereo separation at 1,000 Hz, but the playback cartridges had lesser performance of about 20 to 30 dB of separation at 1000 Hz, with separation decreasing as frequency increased, such that at 12 kHz the separation was about 10–15 dB. A common modern view is that stereo isolation must be higher than this to achieve a proper stereo soundstage. However, in the 1950s the BBC determined in a series of tests that only 20–25 dB is required for the impression of full stereo separation.


title: Phonograph record

text: Thin, closely spaced spiral grooves that allow for increased playing time on a  rpm microgroove LP lead to a tinny pre-echo warning of upcoming loud sounds. The cutting stylus unavoidably transfers some of the subsequent groove wall's impulse signal into the previous groove wall. It is discernible by some listeners throughout certain recordings, but a quiet passage followed by a loud sound will allow anyone to hear a faint pre-echo of the loud sound occurring 1.8 seconds ahead of time. This problem can also appear as "post"-echo, with a tinny ghost of the sound arriving 1.8 seconds after its main impulse.


title: Phonograph record

text: Audiophiles have differed over the relative merits of the LP versus the CD since the digital disc was introduced. In large part, the claim for vinyl superiority is due to the necessity for digital recordings to presume upper and lower bounds, sampling the tones and soundwaves within those limits and using the resulting information to store and recall the audio. Effectively, the digital recording is an idealized representation of a physical soundwave, while an analog recording captures the physical vibrations across their full frequency. Because most modern vinyl records are made from playbacks of files recorded digitally, there is no out-of-bounds audio to transfer to the disc. Vinyl's drawbacks, however, include surface noise, less resolution due to a lower dynamic range, and greater sensitivity to handling. Modern anti-aliasing filters and oversampling systems used in digital recordings have eliminated perceived problems observed with very early CD players.


title: Phonograph record

text: There is a theory that vinyl records can audibly represent higher frequencies than compact discs, though most of this is noise and not relevant to human hearing. According to Red Book specifications, the compact disc has a frequency response of 20 Hz up to 22,050 Hz, and most CD players measure flat within a fraction of a decibel from at least 0 Hz to 20 kHz at full output. Due to the distance required between grooves, it is not possible for an LP to reproduce as low frequencies as a CD. Additionally, turntable rumble and acoustic feedback obscures the low-end limit of vinyl but the upper end can be, with some cartridges, reasonably flat within a few decibels to 30 kHz, with gentle roll-off. Carrier signals of Quad LPs popular in the 1970s were at 30 kHz to be out of the range of human hearing. The average human auditory system is sensitive to frequencies from 20 Hz to a maximum of around 20,000 Hz. The upper and lower frequency limits of human hearing vary per person. High frequency sensitivity decreases as a person ages, a process called presbycusis.


title: Phonograph record

text: As the playing of gramophone records causes gradual degradation of the recording, they are best preserved by transferring them onto other media and playing the records as rarely as possible. They need to be stored on edge, and do best under environmental conditions that most humans would find comfortable.


title: Phonograph record

text: Where old disc recordings are considered to be of artistic or historic interest, from before the era of tape or where no tape master exists, archivists play back the disc on suitable equipment and record the result, typically onto a digital format, which can be copied and manipulated to remove analog flaws without any further damage to the source recording. For example, Nimbus Records uses a specially built horn record player to transfer 78s. Anyone can do this using a standard record player with a suitable pickup, a phono-preamp (pre-amplifier) and a typical personal computer. However, for accurate transfer, professional archivists carefully choose the correct stylus shape and diameter, tracking weight, equalisation curve and other playback parameters and use high-quality analogue-to-digital converters.


title: Phonograph record

text: As an alternative to playback with a stylus, a recording can be read optically, processed with software that calculates the velocity that the stylus would be moving in the mapped grooves and converted to a digital recording format. This does no further damage to the disc and generally produces a better sound than normal playback. This technique also has the potential to allow for reconstruction of broken or otherwise damaged discs.


title: Phonograph record

text: Groove recordings, first designed in the final quarter of the 19th century, held a predominant position for nearly a century—withstanding competition from reel-to-reel tape, the 8-track cartridge, and the compact cassette. The widespread popularity of Sony's Walkman was a factor that contributed to the vinyl's lessening usage in the 1980s. In 1988, the compact disc surpassed the gramophone record in unit sales. Vinyl records experienced a sudden decline in popularity between 1988 and 1991, when the major label distributors restricted their return policies, which retailers had been relying on to maintain and swap out stocks of relatively unpopular titles. First the distributors began charging retailers more for new products if they returned unsold vinyl, and then they stopped providing any credit at all for returns. Retailers, fearing they would be stuck with anything they ordered, only ordered proven, popular titles that they knew would sell, and devoted more shelf space to CDs and cassettes. Record companies also removed many vinyl titles from production and distribution, further undermining the availability of the format and leading to the closure of pressing plants. This rapid decline in the availability of records accelerated the format's decline in popularity, and is seen by some as a deliberate ploy to make consumers switch to CDs, which unlike today, were more profitable for the record companies.


title: Phonograph record

text: In the United Kingdom, the popularity of indie rock caused sales of new vinyl records (particularly 7 inch singles) to increase significantly in 2006.


title: Phonograph record

text: In the United States, annual vinyl sales increased by 85.8% between 2006 and 2007, although starting from a low base, and by 89% between 2007 and 2008. However, sales increases have moderated over recent years falling to less than 10% during 2017.


title: Phonograph record

text: Figures released in the United States in early 2009 showed that sales of vinyl albums nearly doubled in 2008, with 1.88 million sold—up from just under 1 million in 2007. In 2009, 3.5 million units sold in the United States, including 3.2 million albums, the highest number since 1998.


title: Phonograph record

text: Sales have continued to rise into the 2010s, with around 2.8 million sold in 2010, which is the most sales since record keeping began in 1991, when vinyl had been overshadowed by Compact Cassettes and compact discs.


title: Phonograph record

text: In 2021, Taylor Swift sold 102,000 copies of her ninth studio album Evermore on vinyl. The sales of the record beat the largest sales in one week on vinyl since Nielsen started tracking vinyl sales in 1991. The sales record was previously held by Jack White who sold 40,000 copies of his second solo release, "Lazaretto", on vinyl in 2014. In 2014, the sale of vinyl records was the only physical music medium with increasing sales with relation to the previous year. Sales of other mediums including individual digital tracks, digital albums and compact discs have fallen, the last having the greatest drop-in-sales rate.


title: Phonograph record

text: In 2011, the Entertainment Retailers Association in the United Kingdom found that consumers were willing to pay on average £16.30 (€19.37, US$25.81) for a single vinyl record, as opposed to £7.82 (€9.30, US$12.38) for a CD and £6.80 (€8.09, US$10.76) for a digital download.


title: Phonograph record

text: In 2015 the sales of vinyl records went up 32%, to $416 million, their highest level since 1988. There were 31.5 million vinyl records sold in 2015, and the number has increased annually ever since 2006. Vinyl sales continued to grow in 2017, comprising 14% of all physical album sales. The number one vinyl LP sold was the re-release of The Beatles' "Sgt. Pepper's Lonely Hearts Club Band".


title: Phonograph record

text: According to the RIAA's midyear report in 2020, phonograph record revenues surpassed those of CDs for the first time since the 1980s.


title: Phonograph record

text: VinylVideo is a format to store a low resolution black and white video on a vinyl record alongside encoded audio.


title: Apocalypse

text: Apocalypse () is a literary genre in which a supernatural being reveals cosmic mysteries or the future to a human intermediary. The means of mediation include dreams, visions and heavenly journeys, and they typically feature symbolic imagery drawn from the Hebrew Bible, cosmological and (pessimistic) historical surveys, the division of time into periods, esoteric numerology, and claims of ecstasy and inspiration. Almost all are written under pseudonyms (false names), claiming as author a venerated hero from previous centuries, as with Book of Daniel, composed during the 2nd century BCE but bearing the name of the legendary Daniel.


title: Apocalypse

text: Eschatology, from Greek "eschatos", last, concerns expectations of the end of the present age, and apocalyptic eschatology is the application of the apocalyptic world-view to the end of the world, when God will punish the wicked and reward the faithful. An apocalypse will often contain much eschatological material, but need not: the baptism of Jesus in Matthew's gospel, for example, can be considered apocalyptic in that the heavens open for the presence of a divine mediator (the dove representing the spirit of God) and a voice communicates supernatural information, but there is no eschatological element.


title: Apocalypse

text: Scholars have identified examples of the genre ranging from the mid-2nd century BCE to the 2nd century CE, and examples are to be found in Persian and Greco-Roman literature as well as Jewish and Christian. The sole clear case in the Jewish Bible (Old Testament) is chapters 7-12 of the Book of Daniel, but there are many examples from non-canonical Jewish works; the Book of Revelation is the only apocalypse in the New Testament, but passages reflecting the genre are to be found in the gospels and in nearly all the genuine Pauline epistles.


title: Apocalypse

text: "Apocalypse" has come to be used popularly as a synonym for catastrophe, but the Greek word "apokálypsis", from which it is derived, means a revelation. It has been defined by John J Collins as "a genre of revelatory literature with a narrative framework, in which a revelation is mediated by an otherworldly being to a human recipient, disclosing a transcendent reality which is both temporal, in that it envisages eschatological salvation, and spatial, insofar as it involves another, supernatural world." Collins later refined his definition by adding that apocalypse "is intended to interpret present, earthly circumstances in light of the supernatural world and of the future, and to influence both the understanding and the behaviour of the audience by means of divine authority."


title: Apocalypse

text: The genre of Jewish and Christian apocalypse flourished c.250 BCE-250 CE, but its antecedents can be traced back much further, in the Jewish prophetic and wisdom traditions (e.g., Ezekiel 1-3 and Zechariah 1-6), and in the mythologies of the Ancient Near East, which have left a legacy of symbology (e.g., the sea as a symbol of chaos in Daniel 7 and Revelation 13:1). Zoroastrian dualism may also have played a role. The reasons for its rise are obscure, but there seems to be a connection to times of crisis, such as the 2nd century BCE persecution of the Jews reflected in Daniel's final vision, or the destruction of the Temple in 70 CE reflected in 4 Ezra and 2 Baruch.


title: Apocalypse

text: Jewish apocalypses include chapters 7–12 of the Book of Daniel (the previous chapters do not fall into the apocalyptic genre) and non-canonical works such as the Book of Enoch, 2 Enoch, 4 Ezra, 2 Baruch, 3 Baruch, the Apocalypse of Abraham, the Testament of Levi 2-5, the Apocalypse of Zephaniah, and portions of the Book of Jubilees and the Testament of Abraham; these are all Second Temple works. Christian apocalypses include the Revelation of John, the "little apocalypse" of Mark 13:5-37 and the equivalent passages in Matthew 24:4-36 and Luke 21:8-36 in which Jesus supposedly predicts the destruction of Jerusalem and the coming of the abomination of desolation, and various passages in the Pauline epistles, the pseudo-Pauline 2 Thessalonians, and other letters such as Jude, James, and 1 and 2 Peter.


title: Apocalypse

text: Apocalyptic revelations are typically mediated through such means as dreams and visions (the ancient world did not distinguish between these), angels, and heavenly journeys. These serve to connect two sets of axes, the spatial axis which has God and the heavenly realm above and the human world below, and the temporal axis of the present and the future. The revelation thus demonstrates that God rules the visible world, and that the present days are leading to an end-time in which divine justice will be done and God's rule will become visible. Mythic images with their roots in texts from the Hebrew Bible and rich in symbolic meaning are a significant characteristic of the genre. Further characteristics include transcendentalism, mythology, pessimistic cosmological and historical surveys, dualism (including a doctrine of two ages and the division of time into periods), numerology (e.g., the "number of the beast" in Revelation), claims of ecstasy and inspiration, and esotericism.


title: Apocalypse

text: With the exception of the Apocalypse of John the authors of apocalyptic works released their books under pseudonyms (false names): the Book of Daniel, for example, was composed during the 2nd century BCE but took the name of the legendary Daniel for its hero. Pseudonymity may have been used to secure acceptance for the new works, to protect the real authors from reprisals, or because the authors had experienced what they believed to be genuine revelations from the famous past figure or identified with him and claimed to write on his behalf.


title: Internet Relay Chat

text: Internet Relay Chat (IRC) is a text-based chat system for instant messaging. IRC is designed for group communication in discussion forums, called "channels", but also allows one-on-one communication via private messages as well as chat and data transfer, including file sharing.


title: Internet Relay Chat

text: Internet Relay Chat is implemented as an application layer protocol to facilitate communication in the form of text. The chat process works on a client–server networking model. Users connect, using a clientwhich may be a web app, a standalone desktop program, or embedded into part of a larger programto an IRC server, which may be part of a larger IRC network. Examples of programs used to connect include Mibbit, IRCCloud, KiwiIRC, and MIRC.


title: Internet Relay Chat

text: IRC usage has been declining steadily since 2003, losing 60 percent of its users. In April 2011, the top 100 IRC networks served more than half a million users at a time.


title: Internet Relay Chat

text: IRC was created by Jarkko Oikarinen in August 1988 to replace a program called MUT (MultiUser Talk) on a BBS called OuluBox at the University of Oulu in Finland, where he was working at the Department of Information Processing Science. Jarkko intended to extend the BBS software he administered, to allow news in the Usenet style, real time discussions and similar BBS features. The first part he implemented was the chat part, which he did with borrowed parts written by his friends Jyrki Kuoppala and Jukka Pihl. The first IRC network was running on a single server named tolsun.oulu.fi. Oikarinen found inspiration in a chat system known as Bitnet Relay, which operated on the BITNET.


title: Internet Relay Chat

text: Jyrki Kuoppala pushed Oikarinen to ask Oulu University to free the IRC code so that it also could be run outside of Oulu, and after they finally got it released, Jyrki Kuoppala immediately installed another server. This was the first "IRC network". Oikarinen got some friends at the Helsinki University and Tampere University to start running IRC servers when his number of users increased and other universities soon followed. At this time Oikarinen realized that the rest of the BBS features probably wouldn't fit in his program.


title: Internet Relay Chat

text: Oikarinen got in touch with people at the University of Denver and Oregon State University. They had their own IRC network running and wanted to connect to the Finnish network. They had obtained the program from one of Oikarinen's friends, Vijay Subramaniam—the first non-Finnish person to use IRC. IRC then grew larger and got used on the entire Finnish national network—FUNET—and then connected to Nordunet, the Scandinavian branch of the Internet. In November 1988, IRC had spread across the Internet and in the middle of 1989, there were some 40 servers worldwide.


title: Internet Relay Chat

text: In August 1990, the first major disagreement took place in the IRC world. The "A-net" (Anarchy net) included a server named eris.berkeley.edu. It was all open, required no passwords and had no limit on the number of connects. As Greg "wumpus" Lindahl explains: "it had a wildcard server line, so people were hooking up servers and nick-colliding everyone". The "Eris Free Network", EFnet, made the eris machine the first to be Q-lined (Q for quarantine) from IRC. In wumpus' words again: "Eris refused to remove that line, so I formed EFnet. It wasn't much of a fight; I got all the hubs to join, and almost everyone else got carried along." A-net was formed with the eris servers, while EFnet was formed with the non-eris servers. History showed most servers and users went with EFnet. Once A-net disbanded, the name EFnet became meaningless, and once again it was the one and only IRC network.


title: Internet Relay Chat

text: Around that time IRC was used to report on the 1991 Soviet coup d'état attempt throughout a media blackout. It was previously used in a similar fashion during the Gulf War. Chat logs of these and other events are kept in the ibiblio archive.


title: Internet Relay Chat

text: Another fork effort, the first that made a lasting difference, was initiated by "Wildthang" in the United States in October 1992. (It forked off the EFnet ircd version 2.8.10). It was meant to be just a test network to develop bots on but it quickly grew to a network "for friends and their friends". In Europe and Canada a separate new network was being worked on and in December the French servers connected to the Canadian ones, and by the end of the month, the French and Canadian network was connected to the US one, forming the network that later came to be called "The Undernet".


title: Internet Relay Chat

text: The "undernetters" wanted to take ircd further in an attempt to make it use less bandwidth and to try to sort out the channel chaos (netsplits and takeovers) that EFnet started to suffer from. For the latter purpose, the Undernet implemented timestamps, new routing and offered the CService—a program that allowed users to register channels and then attempted to protect them from troublemakers. The first server list presented, from 15 February 1993, includes servers from the U.S., Canada, France, Croatia and Japan. On 15 August, the new user count record was set to 57 users.


title: Internet Relay Chat

text: In May 1993, RFC 1459 was published and details a simple protocol for client/server operation, channels, one-to-one and one-to-many conversations. It is notable that a significant number of extensions like CTCP, colors and formats are not included in the protocol specifications, nor is character encoding, which led various implementations of servers and clients to diverge. Software implementation varied significantly from one network to the other, each network implementing their own policies and standards in their own code bases.


title: Internet Relay Chat

text: During the summer of 1994, the Undernet was itself forked. The new network was called DALnet (named after its founder: dalvenjah), formed for better user service and more user and channel protections. One of the more significant changes in DALnet was use of longer nicknames (the original ircd limit being 9 letters). DALnet ircd modifications were made by Alexei "Lefler" Kosut. DALnet was thus based on the Undernet ircd server, although the DALnet pioneers were EFnet abandoners. According to James Ng, the initial DALnet people were "ops in #StarTrek sick from the constant splits/lags/takeovers/etc".


title: Internet Relay Chat

text: DALnet quickly offered global WallOps (IRCop messages that can be seen by users who are +w (/mode NickName +w)), longer nicknames, Q:Lined nicknames (nicknames that cannot be used i.e. ChanServ, IRCop, NickServ, etc.), global K:Lines (ban of one person or an entire domain from a server or the entire network), IRCop only communications: GlobOps, +H mode showing that an IRCop is a "helpop" etc. Much of DALnet's new functions were written in early 1995 by Brian "Morpher" Smith and allow users to own nicknames, control channels, send memos, and more.


title: Internet Relay Chat

text: In July 1996, after months of flame wars and discussions on the mailing list, there was yet another split due to disagreement in how the development of the ircd should evolve. Most notably, the "European" (most of those servers were in Europe) side that later named itself IRCnet argued for nick and channel delays whereas the EFnet side argued for timestamps. There were also disagreements about policies: the European side had started to establish a set of rules directing what IRCops could and could not do, a point of view opposed by the US side.


title: Internet Relay Chat

text: Most (not all) of the IRCnet servers were in Europe, while most of the EFnet servers were in the US. This event is also known as "The Great Split" in many IRC societies. EFnet has since (as of August 1998) grown and passed the number of users it had then. In the (northern) autumn of the year 2000, EFnet had some 50,000 users and IRCnet 70,000.


title: Internet Relay Chat

text: IRC has changed much over its life on the Internet. New server software has added a multitude of new features.


title: Internet Relay Chat

text: , a new standardization effort is under way under a working group called IRCv3, which focuses on more advanced client features like instant notifications, better history support and improved security. , no major IRC networks have fully adopted the proposed standard.


title: Internet Relay Chat

text: After its golden era during the 1990s and early 2000s (240,000 users on QuakeNet in 2004), IRC has seen a significant decline, losing around 60% of users between 2003 and 2012, with users moving to newer social media platforms like Facebook or Twitter, but also to open platforms like XMPP which was developed in 1999. Certain networks like Freenode have not followed the overall trend and have more than quadrupled in size during the same period. However, Freenode, which in 2016 had around 90,000 users, has since declined to about 9,300 users.


title: Internet Relay Chat

text: The largest IRC networks have traditionally been grouped as the "Big Four"—a designation for networks that top the statistics. The Big Four networks change periodically, but due to the community nature of IRC there are a large number of other networks for users to choose from.


title: Internet Relay Chat

text: IRC reached 6 million simultaneous users in 2001 and 10 million users in 2003, dropping to 371k in 2018.


title: Internet Relay Chat

text: IRC is an open protocol that uses TCP and, optionally, TLS. An IRC server can connect to other IRC servers to expand the IRC network. Users access IRC networks by connecting a client to a server. There are many client implementations, such as mIRC, HexChat and irssi, and server implementations, e.g. the original IRCd. Most IRC servers do not require users to register an account but a nickname is required before being connected.


title: Internet Relay Chat

text: IRC was originally a plain text protocol (although later extended), which on request was assigned port 194/TCP by IANA. However, the "de facto" standard has always been to run IRC on 6667/TCP and nearby port numbers (for example TCP ports 6660–6669, 7000) to avoid having to run the IRCd software with root privileges.


title: Internet Relay Chat

text: The protocol specified that characters were 8-bit but did not specify the character encoding the text was supposed to use. This can cause problems when users using different clients and/or different platforms want to converse.


title: Internet Relay Chat

text: All client-to-server IRC protocols in use today are descended from the protocol implemented in the irc2.4.0 version of the IRC2 server, and documented in RFC 1459. Since RFC 1459 was published, the new features in the irc2.10 implementation led to the publication of several revised protocol documents (RFC 2810, RFC 2811, RFC 2812 and RFC 2813); however, these protocol changes have not been widely adopted among other implementations.


title: Internet Relay Chat

text: Although many specifications on the IRC protocol have been published, there is no official specification, as the protocol remains dynamic. Virtually no clients and very few servers rely strictly on the above RFCs as a reference.


title: Internet Relay Chat

text: Microsoft made an extension for IRC in 1998 via the proprietary IRCX. They later stopped distributing software supporting IRCX, instead developing the proprietary MSNP.


title: Internet Relay Chat

text: The standard structure of a network of IRC servers is a tree. Messages are routed along only necessary branches of the tree but network state is sent to every server and there is generally a high degree of implicit trust between servers. However, this architecture has a number of problems. A misbehaving or malicious server can cause major damage to the network and any changes in structure, whether intentional or a result of conditions on the underlying network, require a net-split and net-join. This results in a lot of network traffic and spurious quit/join messages to users and temporary loss of communication to users on the splitting servers. Adding a server to a large network means a large background bandwidth load on the network and a large memory load on the server. Once established, however, each message to multiple recipients is delivered in a fashion similar to multicast, meaning each message travels a network link exactly once. This is a strength in comparison to non-multicasting protocols such as Simple Mail Transfer Protocol (SMTP) or Extensible Messaging and Presence Protocol (XMPP).


title: Internet Relay Chat

text: An IRC daemon can also be used on a local area network (LAN). IRC can thus be used to facilitate communication between people within the local area network (internal communication).


title: Internet Relay Chat

text: IRC has a line-based structure. Clients send single-line messages to the server, receive replies to those messages and receive copies of some messages sent by other clients. In most clients, users can enter commands by prefixing them with a '/'. Depending on the command, these may either be handled entirely by the client, or (generally for commands the client does not recognize) passed directly to the server, possibly with some modification.


title: Internet Relay Chat

text: Due to the nature of the protocol, automated systems cannot always correctly pair a sent command with its reply with full reliability and are subject to guessing.


title: Internet Relay Chat

text: The basic means of communicating to a group of users in an established IRC session is through a "channel". Channels on a network can be displayed using the IRC command "LIST", which lists all currently available channels that do not have the modes +s or +p set, on that particular network.


title: Internet Relay Chat

text: Users can "join" a channel using the "JOIN" command, in most clients available as "/join #channelname". Messages sent to the joined channels are then relayed to all other users.


title: Internet Relay Chat

text: Channels that are available across an entire IRC network are prefixed with a '#', while those local to a server use '&'. Other less common channel types include '+' channels—'modeless' channels without operators—and '!' channels, a form of timestamped channel on normally non-timestamped networks.


title: Internet Relay Chat

text: Users and channels may have "modes" that are represented by individual case-sensitive letters and are set using the "MODE" command. User modes and channel modes are separate and can use the same letter to mean different things (e.g. user mode "i" is invisible mode while channel mode "i" is invite only.) Modes are usually set and unset using the mode command that takes a target (user or channel), a set of modes to set (+) or unset (-) and any parameters the modes need.


title: Internet Relay Chat

text: Some channel modes take parameters and other channel modes apply to a user on a channel or add or remove a mask (e.g. a ban mask) from a list associated with the channel rather than applying to the channel as a whole. Modes that apply to users on a channel have an associated symbol that is used to represent the mode in names replies (sent to clients on first joining a channel and use of the names command) and in many clients also used to represent it in the client's displayed list of users in a channel or to display an own indicator for a user's modes.


title: Internet Relay Chat

text: In order to correctly parse incoming mode messages and track channel state the client must know which mode is of which type and for the modes that apply to a user on a channel which symbol goes with which letter. In early implementations of IRC this had to be hard-coded in the client but there is now a de facto standard extension to the protocol called ISUPPORT that sends this information to the client at connect time using numeric 005.


title: Internet Relay Chat

text: There is a small design fault in IRC regarding modes that apply to users on channels: the names message used to establish initial channel state can only send one such mode per user on the channel, but multiple such modes can be set on a single user. For example, if a user holds both operator status (+o) and voice status (+v) on a channel, a new client will be unable to see the mode with less priority (i.e. voice). Workarounds for this are possible on both the client and server side but none are widely implemented.


title: Internet Relay Chat

text: Many daemons and networks have added extra modes or modified the behavior of modes in the above list.


title: Internet Relay Chat

text: IRC channel operators can be easily seen by the a symbol or icon next to their name (varies by client implementation, commonly a "@" symbol prefix, a green circle, or a Latin letter "+o"/"o").


title: Internet Relay Chat

text: There are also users who maintain elevated rights on their local server, or the entire network; these are called IRC operators, sometimes shortened to IRCops or Opers (not to be confused with channel operators). As the implementation of the IRCd varies, so do the privileges of the IRC operator on the given IRCd. RFC 1459 claims that IRC operators are "a necessary evil" to keep a clean state of the network, and as such they need to be able to disconnect and reconnect servers. Additionally, to prevent malicious users or even harmful automated programs from entering IRC, IRC operators are usually allowed to disconnect clients and completely ban IP addresses or complete subnets. Networks that carry services (NickServ et al.) usually allow their IRC operators also to handle basic "ownership" matters. Further privileged rights may include overriding channel bans (being able to join channels they would not be allowed to join, if they were not opered), being able to op themselves on channels where they would not be able without being opered, being auto-opped on channels always and so forth.


title: Internet Relay Chat

text: A hostmask is a unique identifier of an IRC client connected to an IRC server. IRC servers, services, and other clients, including bots, can use it to identify a specific IRC session.


title: Internet Relay Chat

text: The format of a hostmask is codice_1. The hostmask looks similar to, but should not be confused with an e-mail address.


title: Internet Relay Chat

text: The user part is the username reported by ident on the client. If ident is not available on the client, the username specified when the client connected is used after being prefixed with a tilde.


title: Internet Relay Chat

text: The host part is the hostname the client is connecting from. If the IP address of the client cannot be resolved to a valid hostname by the server, it is used instead of the hostname.


title: Internet Relay Chat

text: Because of the privacy implications of exposing the IP address or hostname of a client, some IRC daemons also provide privacy features, such as InspIRCd or UnrealIRCd's "+x" mode. This hashes a client IP address or masks part of a client's hostname, making it unreadable to users other than IRCops. Users may also have the option of requesting a "virtual host" (or "vhost"), to be displayed in the hostmask to allow further anonymity. Some IRC networks, such as Libera Chat or Freenode, use these as "cloaks" to indicate that a user is affiliated with a group or project.


title: Internet Relay Chat

text: There are three provisional recognized uniform resource identifier (URI) schemes for Internet Relay Chat: codice_2, codice_3, and codice_4. When supported, they allow hyperlinks of various forms, including


title: Internet Relay Chat

text: (where items enclosed within brackets ([,]) are optional) to be used to (if necessary) connect to the specified host (or network, if known to the IRC client) and join the specified channel. (This can be used within the client itself, or from another application such as a Web browser). irc is the default URI, irc6 specifies a connection to be made using IPv6, and ircs specifies a secure connection.


title: Internet Relay Chat

text: Per the specification, the usual hash symbol (#) will be prepended to channel names that begin with an alphanumeric character—allowing it to be omitted. Some implementations (for example, mIRC) will do so "unconditionally" resulting in a (usually unintended) extra (for example, ##channel), if included in the URL.


title: Internet Relay Chat

text: Issues in the original design of IRC were the amount of shared state data being a limitation on its scalability, the absence of unique user identifications leading to the nickname collision problem, lack of protection from netsplits by means of cyclic routing, the trade-off in scalability for the sake of real-time user presence information, protocol weaknesses providing a platform for abuse, no transparent and optimizable message passing, and no encryption. Some of these issues have been addressed in "Modern IRC".


title: Internet Relay Chat

text: Because IRC connections may be unencrypted and typically span long time periods, they are an attractive target for DoS/DDoS attackers and hackers. Because of this, careful security policy is necessary to ensure that an IRC network is not susceptible to an attack such as a takeover war. IRC networks may also K-line or G-line users or servers that have a harming effect.


title: Internet Relay Chat

text: Some IRC servers support SSL/TLS connections for security purposes. This helps stop the use of packet sniffer programs to obtain the passwords of IRC users, but has little use beyond this scope due to the public nature of IRC channels. SSL connections require both client and server support (that may require the user to install SSL binaries and IRC client specific patches or modules on their computers). Some networks also use SSL for server-to-server connections, and provide a special channel flag (such as codice_5) to only allow SSL-connected users on the channel, while disallowing operator identification in clear text, to better utilize the advantages that SSL provides.


title: Internet Relay Chat

text: IRC served as an early laboratory for many kinds of Internet attacks, such as using fake ICMP unreachable messages to break TCP-based IRC connections (nuking) to annoy users or facilitate takeovers.


title: Internet Relay Chat

text: One of the most contentious technical issues surrounding IRC implementations, which survives to this day, is the merit of "Nick/Channel Delay" vs. "Timestamp" protocols. Both methods exist to solve the problem of denial-of-service attacks, but take very different approaches.


title: Internet Relay Chat

text: The problem with the original IRC protocol as implemented was that when two servers split and rejoined, the two sides of the network would simply merge their channels. If a user could join on a "split" server, where a channel that existed on the other side of the network was empty, and gain operator status, they would become a channel operator of the "combined" channel after the netsplit ended; if a user took a nickname that existed on the other side of the network, the server would kill both users when rejoining (a "nick collision"). This was often abused to "mass-kill" all users on a channel, thus creating "opless" channels where no operators were present to deal with abuse. Apart from causing problems within IRC, this encouraged people to conduct denial-of-service attacks against IRC servers in order to cause netsplits, which they would then abuse.


title: Internet Relay Chat

text: The nick delay (ND) and channel delay (CD) strategies aim to prevent abuse by delaying reconnections and renames. After a user signs off and the nickname becomes available, or a channel ceases to exist because all its users parted (as often happens during a netsplit), the server will not allow any user to use that nickname or join that channel, until a certain period of time (the "delay") has passed. The idea behind this is that even if a netsplit occurs, it is useless to an abuser because they cannot take the nickname or gain operator status on a channel, and thus no collision of a nickname or "merging" of a channel can occur. To some extent, this inconveniences legitimate users, who might be forced to briefly use a different name after rejoining (appending an underscore is popular).


title: Internet Relay Chat

text: The timestamp protocol is an alternative to nick/channel delays which resolves collisions using timestamped priority. Every nickname and channel on the network is assigned a timestampthe date and time when it was created. When a netsplit occurs, two users on each side are free to use the same nickname or channel, but when the two sides are joined, only one can survive. In the case of nicknames, the newer user, according to their TS, is killed; when a channel collides, the members (users on the channel) are merged, but the channel operators on the "losing" side of the split lose their channel operator status.


title: Internet Relay Chat

text: TS is a much more complicated protocol than ND/CD, both in design and implementation, and despite having gone through several revisions, some implementations still have problems with "desyncs" (where two servers on the same network disagree about the current state of the network), and allowing too much leniency in what was allowed by the "losing" side. Under the original TS protocols, for example, there was no protection against users setting bans or other modes in the losing channel that would then be merged when the split rejoined, even though the users who had set those modes lost their channel operator status. Some modern TS-based IRC servers have also incorporated some form of ND and/or CD in addition to timestamping in an attempt to further curb abuse.


title: Internet Relay Chat

text: Most networks today use the timestamping approach. The timestamp versus ND/CD disagreements caused several servers to split away from EFnet and form the newer IRCnet. After the split, EFnet moved to a TS protocol, while IRCnet used ND/CD.


title: Internet Relay Chat

text: In recent versions of the IRCnet ircd, as well as ircds using the TS6 protocol (including Charybdis), ND has been extended/replaced by a mechanism called SAVE. This mechanism assigns every client a UID upon connecting to an IRC server. This ID starts with a number, which is forbidden in nicks (although some ircds, namely IRCnet and InspIRCd, allow clients to switch to their own UID as the nickname).


title: Internet Relay Chat

text: If two clients with the same nickname join from different sides of a netsplit ("nick collision"), the first server to see this collision will force "both" clients to change their nick to their UID, thus saving both clients from being disconnected. On IRCnet, the nickname will also be locked for some time (ND) to prevent both clients from changing back to the original nickname, thus colliding again.