1.
Digital video recorder
–
A digital video recorder is an electronic device that records video in a digital format to a disk drive, USB flash drive, SD memory card, SSD or other local or networked mass storage device. The term includes set-top boxes with direct to disk recording, portable media players and TV gateways with recording capability, and digital camcorders. Personal computers are connected to video capture devices and used as DVRs. Many DVRs are classified as electronic devices, such devices are sometimes referred to as personal video recorders. Consumer digital video recorders ReplayTV and TiVo were launched at the 1999 Consumer Electronics Show in Las Vegas, Microsoft also demonstrated a unit with DVR capability, but this did not become available until the end of 1999 for full DVR features in Dish Networks DISHplayer receivers. TiVo shipped their first units on March 31,1999, ReplayTV won the Best of Show award in the video category with Netscape co-founder Marc Andreessen as an early investor and board member, but TiVo was more successful commercially. Many DVRs use the MPEG format for compressing the digital video, video recording capabilities have become an essential part of the modern set-top box, as TV viewers have wanted to take control of their viewing experiences. Digital video recorders tied to a video service At the 1999 CES, which also included WebTV Networks internet TV. By the end of 1999 the Dishplayer had full DVR capabilities and within a year, in the UK, digital video recorders are often referred to as plus boxes. Freeview+ have been around in the UK since the late 2000s, british Sky Broadcasting markets a popular combined receiver and DVR as Sky+. TiVo launched a UK model in 2000, and is no longer supported, except for third party services, south African based Africa Satellite TV beamer Multichoice recently launched their DVR which is available on their DStv platform. Astro introduced their DVR system, called Astro MAX, which was the first PVR in Malaysia but was phased out two years after its introduction. In the case of television, there is no encoding necessary in the DVR since the signal is already a digitally encoded MPEG stream. The digital video recorder simply stores the digital stream directly to disk and it can, however, also force the manufacturer to implement non-skippable advertisements and automatically expiring recordings. The overall net effect on video recorders and related technology is unlikely to be substantial as standalone DVRs are currently readily available on the open market. In 2003 many Satellite and Cable providers introduced dual-tuner digital video recorders, in the UK, BSkyB introduced their first PVR Sky+ with dual tuner support in 2001. These machines have two independent tuners within the same receiver, kogan. com introduced a dual-tuner PVR in the Australian market allowing free-to-air television to be recorded on a removable hard drive. Some dual-tuner DVRs also have the ability to output to two television sets at the same time
2.
Optical disc drive
–
Some drives can only read from certain discs, but recent drives can both read and record, also called burners or writers. Compact discs, DVDs, and Blu-ray discs are common types of media which can be read. Optical disc drives that are no longer in production include CD-ROM drive, CD writer drive, combo drive, as of 2015, DVD writer drive supporting all existing recordable and rewritable DVD formats is the most common for desktop PCs and laptops. There are also the DVD-ROM drive, BD-ROM drive, Blu-ray Disc combo drive and they are also very commonly used in computers to read software and consumer media distributed on disc, and to record discs for archival and data exchange purposes. Floppy disk drives, with capacity of 1, USB flash drives, high-capacity, small, and inexpensive, are suitable where read/write capability is required. Large backups are often made on external hard drives, as their price has dropped to a level making this viable. The first laser disc, demonstrated in 1972, was the Laservision 12-inch video disc, the video signal was stored as an analog format like a video cassette. The first digitally recorded optical disc was a 5-inch audio compact disc in a format created by Sony. The CD-ROM format was developed by Sony and Denon, introduced in 1984, as an extension of Compact Disc Digital Audio, the CD-ROM has a storage capacity of 650 MB. Also in 1984, Sony introduced a LaserDisc data storage format, in 1987, Sony demonstrated the erasable and rewritable 5. 25-inch optical drive. The first Blu-Ray prototype was unveiled by Sony in October 2000, technically Blu-ray Disc also required a thinner layer for the narrower beam and shorter wavelength blue laser. The first BD-ROM players were shipped in mid-June 2006, the first Blu-ray Disc titles were released by Sony and MGM on June 20,2006. The first mass-market Blu-ray Disc rewritable drive for the PC was the BWU-100A, initially, CD-type lasers with a wavelength of 780 nm were used. For DVDs, the wavelength was reduced to 650 nm, two main servomechanisms are used, the first to maintain the proper distance between lens and disc, to ensure the laser beam is focused as a small laser spot on the disc. The second servo moves the head along the discs radius, keeping the beam on the track. Optical disk media are read beginning at the radius to the outer edge. This is detected by photodiodes that create corresponding electrical signals, an optical disk recorder encodes data onto a recordable CD-R, DVD-R, DVD+R, or BD-R disc by selectively heating parts of an organic dye layer with a laser. This changes the reflectivity of the dye, thereby creating marks that can be read like the pits, for recordable discs, the process is permanent and the media can be written to only once
3.
Digital recording
–
To play back a digital sound recording, the numbers are retrieved and converted back into their original analog waveforms so that they can be heard through a loudspeaker. To play back a digital recording, the numbers are retrieved and converted back into their original analog waveforms so that they can be viewed on a video monitor. 1938, British scientist Alec Reeves files the first patent describing Pulse-code modulation and it was first developed as a telephony technology. The twelve transmission points were retired after the war,1957, Max Mathews of Bell develops the process to digitally record sound via computer. 1967, the first monaural PCM recorder was developed by NHKs research facilities in Japan, the 30 kHz 12-bit device used a compander to extend the dynamic range, and stored the signals on a video tape recorder. 1969, NHK expands the PCMs capabilities to 2-channel stereo and 32 kHz 13-bit resolution,1970, James Russell patents the first digital-to-optical recording and playback system, which would later lead to the Compact Disc. January 1971, Using NHKS PCM recording system, engineers at Denon record the first commercial recordings, Something by Steve Marcus and Uzu. 1972, Denon unveils the first 8-channel digital recorder, the DN-023R, the first recording with this new system is the Smetana Quartet performing Mozarts String Quartets K.458 and K.421, recorded in Tokyo April 24–26. 1975, University of Utah professor Thomas Stockham develops a PCM digital audio recorder of his own design and he founds the company Soundstream to offer it commercially. 1976, the prototype Soundstream 37.5 kHz, 16-bit, however, the digital recorder is just a backup to the main analog multi-track recorder and the superior analog recording is used for the release by New World Records. The digital tape was presented at the 1976 AES Convention in New York,1977, Denon develops the smaller portable PCM recording system, the DN-034R. Like the DN-023R it records 8 channels at 47.25 kHz, August 28–31,1977, Soundstreams PCM system runs in the background of a California direct to disc recording session by organist Virgil Fox for Crystal Records. When initially released the resulting LPs were pressed from the direct-to-disc acetate, november 28,1977, Denon brings their DN-034R to New York and records Archie Shepps On Green Dolphin Street, making it Americas first RELEASED digitally-recorded commercial album. When this is released on CD in 1984 by Nippon Columbia it also one of the earliest digital-only CDs. Six other jazz albums are recorded with the DN-034R in New York before it returns to Japan in December, when released on LP this became the first US digitally-recorded classical release. June 2,1978, Sound 80 studios in Minneapolis records the Saint Paul Chamber Orchestra performing Aaron Coplands Appalachian Spring and this session is set up as a direct to disc recording, with an experimental 3M50.4 kHz digital recorder in the background capturing the session. It is released on LP record as Sound80 Records S80-DLR-101 although possibly this release is taken from the direct-to-disc acetate rather than the digital backup, later the session is re-released on Compact Disc by ProArte. June 1978, Sound 80 records Flim and the BBs as another direct to disc recording again with the experimental 3M recorder in the background and this time the acetate is deemed not as good as the digital backup, so the digital master is used for the LP record
4.
Digital signal (signal processing)
–
If that discrete set is finite, the discrete values can be represented with digital words of a finite width. Most commonly, these values are represented as fixed-point words or floating-point words. The process of analog-to-digital conversion produces a digital signal, common practical digital signals are represented as 8-bit, 16-bit, 24-bit and 32-bit. But the number of levels is not necessarily limited to powers of two
5.
DVD recordable
–
DVD recordable and DVD rewritable refer to part of optical disc recording technologies. DVD recordable is a term that refers to both write-once and rewritable formats, whereas DVD rewritable refers only to rewritable formats. Like CD-Rs, DVD recordables use dyes, depending on the intensity of the laser, the reflective property of the dye on a particular spot will determine whether it is a peak or a valley representation from pressed DVD. Dyes give the side of a disc a distinct color. Dyes are also the playback is not guaranteed. Their reflective properties are not as good as with stamped DVDs that commonly have aluminum as the reflective layer, the larger storage capacity of a DVD-R compared to a CD-R is achieved through smaller pit size and smaller track pitch of the groove spiral which guides the laser beam. Consequently, more pits can be written on the same physical sized disc, in order to write smaller pits onto the recording dye layer, a red laser beam with a wavelength of 640 nm is used in conjunction with a higher numerical aperture lens. Because of this wavelength, DVDs use different dyes from CDs to properly absorb this wavelength. The R format DVDs can be once and read arbitrarily many times. Thus, R format discs are suited to such as non-volatile data storage, audio. This can cause confusion because the DVD+RW Alliance logo is a stylized RW, thus, a DVD+R disc may have the RW logo, but it is not rewritable. According to Pioneer, DVD-RW discs may be written to about 1,000 times before needing replacement, RW discs are commonly used to store data in a volatile format, such as when creating backups or collections of files. They are also used for home DVD video recorders, one benefit to using a rewritable disc is, if there are writing errors when recording data, the disc is not ruined and can still store data by erasing the faulty data. The DVD-R format was developed by Pioneer in 1997 and it is supported by most normal DVD players and is approved by the DVD Forum. Has broader playback compatibility than the + especially with older players. The dash format uses a land pre-pit method to provide sector address information, DVD minus R is not correct, according to DVD-R consortium recommendations, it is, in fact, a dash. DVD-R and DVD+R technologies are not directly compatible, which created a war in the DVD technology industry. To reconcile the two competing formats, manufacturers created hybrid drives that could read both — most hybrid drives that handle both formats are labeled DVD±R and Super Multi and are very popular, developed by Philips and Sony with their DVD+RW Alliance
6.
Television studio
–
A television studio is an installation in which video productions take place, either for the recording of live television to video tape, or for the acquisition of raw footage for post-production. The design of a studio is similar to, and derived from, movie studios, a professional television studio generally has several rooms, which are kept separate for noise and practicality reasons. These rooms are connected via intercom, and personnel will be divided among these workplaces, the studio floor is the actual stage on which the actions that will be recorded and viewed take place. The on-screen talent themselves, and any guests - the subjects of the television show, a floor manager, who has overall charge of the studio area stage management, and who relays timing and other information from the television director. One or more camera operators who operate the video cameras. Master control is the hub of a broadcast operation common among most over-the-air television stations. Master control is distinct from a PCR in television studios where the such as switching from camera to camera are coordinated. A transmission control room is smaller in size and is a scaled-down version of centralcasting. The master control room houses equipment that is too noisy or runs too hot for the control room. It also makes sure that coax cable and other wire lengths and installation requirements keep within manageable lengths and this can include the actual circuitry and connections between The master control room in a US television station is the place where the on-air signal is controlled. The term studio usually refers to a place where a local program is originated. If the program is broadcast live, the signal goes from the PCR to MCR, a television studio usually has other rooms with no technical requirements beyond broadcast reference monitors and studio monitors for audio. Among them are, one or more make-up and changing rooms a reception area for crew, talent, and visitors, commonly called the green room
7.
Home cinema
–
In the 1980s, home cinemas typically consisted of a movie pre-recorded on a LaserDisc or VHS tape, a LaserDisc or VHS player, and a heavy, bulky large-screen cathode ray tube TV set. Whether home cinema enthusiasts have a stereo set-up or a 5, in the 1950s, playing home movies became popular in the United States with middle class and upper-class families as Kodak 8 mm film projector equipment became more affordable. The development of audio systems and later LaserDisc in the 1980s created a new paradigm for home video, as it enabled movie enthusiasts to add better sound. In the mid-1980s to the mid-1990s, a home cinema in the United States would have a LaserDisc or VHS player playing a movie. Some people used expensive front projectors in a viewing room. During the 1990s, watching movies on VHS at home became a leisure activity. In the 2010s, affordable large HDTV flatscreen TVs, high resolution video projectors, 3D television technology, in the 2000s, the term home cinema encompasses a range of systems meant for movie playback at home. 3D-TV-enabled home theaters make use of 3D TV sets/projectors and Blu-ray 3D players in which the viewers wear 3D-glasses, enabling them to see 3D content. Home theater designs and layouts are a choice and the type of home cinema a user can set up depends on her/his budget. Finally a set of speakers, at least two, are needed but more common are anywhere from six to eight with a subwoofer for bass or low-frequency effects. In the 2010s, many home cinema enthusiasts aim to replicate, to the degree that is possible, to do so, many home cinema buffs purchase higher quality components than used for everyday television viewing on a relatively small TV with only built-in speakers. As of 2016, home cinema enthusiasts using Smart Blu-ray players may also watch DVDs of TV shows, as well, with a Smart player, a user may be able to stream movies, TV shows and other content over the Internet. Many 2016-era DVD players and Blu-ray players also have inputs which allow users to view digital photos, video and audio input devices, One or more video/audio sources. High resolution movie media formats such as Blu-ray discs are normally preferred, some home theaters include a HTPC with a media center software application to act as the main library for video and music content using a 10-foot user interface and remote control. In 2016, some of the more-expensive Blu-ray players can stream movies, the user selects the input at this point before it is forwarded to the output stage. Some AV receivers enable the viewer to use a control to select which input device or source to use. Audio output, Systems consist of preamplifiers, power amplifiers and two or more loudspeakers mounted in speaker enclosures, the audio system requires at least a stereo power amplifier and two speakers, for stereo sound, most systems have multi-channel surround sound power amplifier and six or more speakers. Some users have 7.1 Surround Sound and it is possible to have up to 11 speakers with additional subwoofers
8.
Tuner (radio)
–
More complex transmissions like PAL/NTSC, DAB, DVB-T/DVB-S/DVB-C etc. use a wider frequency bandwidth, often with several subcarriers. These are transmitted inside the receiver as an intermediate frequency, the tuner can also refer to a radio receiver or standalone audio component that are part of an audio system, to be connected to a separate amplifier. The verb tuning in radio contexts means adjusting the radio receiver to receive the radio signal carrier frequency that a particular radio station uses. The simplest tuner consists of an inductor and capacitor connected in parallel and this creates a resonant circuit which responds to an alternating current at one frequency. Combined with a detector, also known as a demodulator, it becomes the simplest radio receiver, older models would realize manual tuning by means of mechanically operated ganged variable capacitors. Often several sections would be provided on a capacitor, to tune several stages of the receiver in tandem. A later method used a potentiometer supplying a variable voltage to varactor diodes in the oscillator and tank circuits of front end tuner. Modern radio tuners use a superheterodyne receiver with tuning selected by adjustment of the frequency of a local oscillator and this system shifts the radio frequency of interest to a fixed frequency so that it can be tuned with fixed-frequency band-pass filter. Still later, phase locked loop methods were used, with microprocessor control, in a self-contained radio receiver for audio, the signal from the detector after the tuner is run through a volume control and to an amplifier stage. The amplifier feeds either a speaker or headphones. In a tuner component of a system, the output of the detector is connected to a separate external system of amplifiers and speakers. The broadcast audio FM band is around 100 times higher in frequency than the AM band and this bandwidth is sufficient to transmit both stereo channels with almost the full hearing range. Sometimes, additional subcarriers are used for unrelated audio or data transmissions, FM stereo allows left and right channels to be transmitted. The availability of FM stereo, a quieter VHF broadcast band, in many instances the tuner may be modified to improve performance. A growing hobby trend is the electronics specialists that buy, collect, the restoration usually begins with replacing the electrolytic capacitors that may age over time. The tuner is outfitted with improved tolerance and better sounding upgraded parts, prices have increased relative to the increasing demand for the older audio tuners. Those with the most value are the best sounding, most rare, the best DX capable, most of the early tuner models were designed and manufactured to receive only the AM broadcast band. As FM became more popular, the limitations of AM became more apparent, in Europe, where a second AM broadcast band is used for longwave broadcasting, tuners may be fitted with both the standard medium wave and the additional longwave band
9.
United States
–
Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
10.
ATSC tuner
–
Such tuners may be integrated into a television set, VCR, digital video recorder, or set-top box that provides audio/video output connectors of various types. Another type of tuner is a digital television adapter with an analog passthrough. The terms tuner and receiver are used loosely, and it is more appropriately called an ATSC receiver. Examples of media reformatting include, interlace to progressive scan or vice versa, picture resolutions, aspect ratio conversions, frame rate conversion, zooming is an example of resolution change. It is commonly used to convert a low-resolution picture to a high-resolution display and this lets the user eliminate letterboxing or pillarboxing by stretching or cropping the picture. Some ATSC receivers, mostly those in HDTV TV sets, will stretch automatically, either by detecting black bars, an ATSC tuner works by generating audio and video signals that are picked up from over-the-air broadcast television. Selective tuning is the process by which the frequency of the television channel is selected by a receiver from within a band of transmitted RF signals. The tuner usually performs the function of frequency-agile selection, along with rejection of unwanted out-of-band signals, in the US, multiple digital signals are combined and then transmitted from one antenna source to create over the air broadcasts. By the reverse process, an ATSC receiver first receives the combined MPEG transport stream and then decodes it to one of its component signals on a TV set. )Since digital signals that are broadcast over the air are compressed, once they are received by the ATSC tuner. Error correction is a technology that is used by the ATSC tuner to make sure that any data that is missing can be corrected, for instance, sometimes interference or a poor-quality signal will cause the loss of some data that the ATSC tuner receives. With error correction, the tuner has the ability to perform a number of checks, error correction works by adding some extra information to the signal before transmission that can be used upon reception to fill in gaps. Compression removes redundant data, while error correction adds some redundant data, there is a subsection in the ATSC standard that allows broadcasters to add extra of error correction to their broadcast streams. This error correction service is not mandatory in the US, nor is it mandatory in Canada and it is not known how many HDTV receivers support this error correction standard. For the transmission of HDTV at 720 or 1080, an extra 1% to 3% added error correction codes will help some of ATSCs poorer performance with weak signals under adverse multipath conditions. AV synchronization is the coordination of audio and video signals being displayed on a digital TV in proper time. AV synchronization ensures that the audio does not lag behind the video that is being displayed on the TV set or vice versa, media reformatting is extremely important because the formatting of images on TV sets differs significantly according to the technology employed. For instance, some televisions have a picture, whereas others have a progressive-scan picture. Different televisions have a different aspect ratio, the current regulations are specified in the U. S. Code of Federal Regulations
11.
Federal Communications Commission
–
The FCC works towards six goals in the areas of broadband, competition, the spectrum, the media, public safety and homeland security, and modernizing itself. The FCC was formed by the Communications Act of 1934 to replace the radio regulation functions of the Federal Radio Commission, the FCC took over wire communication regulation from the Interstate Commerce Commission. The FCCs mandated jurisdiction covers the 50 states, the District of Columbia, the FCC also provides varied degrees of cooperation, oversight, and leadership for similar communications bodies in other countries of North America. The FCC is funded entirely by regulatory fees and it has an estimated fiscal-2016 budget of US$388 million. Consistent with the objectives of the Act as well as the 1993 Government Performance and Results Act and these are, Broadband All Americans should have affordable access to robust and reliable broadband products and services. Competition Competition in the provision of services, both domestically and overseas, supports the Nations economy. The competitive framework for communications services should foster innovation and offer consumers reliable, Media The Nations media regulations must promote competition and diversity and facilitate the transition to digital modes of delivery. Public Safety and Homeland Security Communications during emergencies and crisis must be available for public safety, health, defense, the Nations critical communications infrastructure must be reliable, interoperable, redundant, and rapidly restorable. The FCC is directed by five appointed by the President of the United States and confirmed by the United States Senate for five-year terms. The U. S. President designates one of the commissioners to serve as chairman, only three commissioners may be members of the same political party. None of them may have a financial interest in any FCC-related business, importantly, commissioners may continue serving until the appointment of their replacements, but may not serve beyond the end of the next session of Congress following term expiration. In practice, as of 2016 this means that commissioners may serve up to 1 1/2 years beyond the term expiration dates listed above if no replacement is appointed. The Consumer & Governmental Affairs Bureau develops and implements the FCCs consumer policies, CGB serves as the public face of the FCC through outreach and education, as well as through their Consumer Center, which is responsible for responding to consumer inquiries and complaints. CGB also maintains partnerships with state, local, and tribal governments in such areas as emergency preparedness. The Enforcement Bureau is responsible for enforcement of provisions of the Communications Act 1934, FCC rules, FCC orders, major areas of enforcement that are handled by the Enforcement Bureau are consumer protection, local competition, public safety, and homeland security. S. The International Bureau also oversees FCC compliance with the international Radio Regulations, the Media Bureau also handles post-licensing matters regarding direct broadcast satellite service. The Wireless Telecommunications Bureau regulates domestic wireless telecommunications programs and policies, the Wireline Competition Bureau develops policy concerning wire line telecommunications. The Wireline Competition Bureaus main objective is to promote growth and economical investments in technology infrastructure, development, markets
12.
TV tuner card
–
A TV tuner card is a kind of television tuner that allows television signals to be received by a computer. Most TV tuners also function as video cards, allowing them to record television programs onto a hard disk much like the digital video recorder does. The interfaces for TV tuner cards are most commonly either PCI bus expansion card or the newer PCI Express bus for many modern cards, in addition, some video cards double as TV tuners, notably the ATI All-In-Wonder series. The card contains a tuner and an analog-to-digital converter along with demodulation, some lower-end cards lack an onboard processor and, like a Winmodem, rely on the systems CPU for demodulation. More advanced TV tuners encode the signal to Motion JPEG or MPEG, some cards also have analog input and many also provide a radio tuner. A hybrid tuner has one tuner that can be configured to act as an analog tuner or a digital tuner, switching between the systems is fairly easy, but cannot be done immediately. The card operates as a digital tuner or an analog tuner until reconfigured and this is similar to a hybrid tuner, except there are two separate tuners on the card. One can watch analog while recording digital, or vice versa, the card operates as an analog tuner and a digital tuner simultaneously. The advantages over two separate cards are cost and utilization of expansion slots in the computer, as many regions around the world convert from analog to digital broadcasts, these tuners are gaining popularity. Like the analog cards, the Hybrid and Combo tuners can have specialized chips on the card to perform the encoding. The tuner cards with this hardware encoding are generally thought of as being higher quality, small USB tuner sticks have become more popular in 2006 and 2007 and are expected to increase in popularity. These small tuners generally do not have hardware encoding due to size, many TV tuners can function as FM radios, this is because there are similarities between broadcast television and FM radio. The FM radio spectrum is close to that used by VHF terrestrial TV broadcasts, and many broadcast television systems around the world use FM audio. So listening to an FM radio station is simply a case of configuring existing hardware. S, there is also a converter for watching DVB-H in Europe and elsewhere via WiFi streaming video. Video capture cards are a class of video capture devices designed to directly into expansion slots in personal computers and servers. Models from many manufacturers are available, all comply with one of the popular host bus standards including PCI and these cards typically include one or more software drivers to expose the cards features, via various operating systems, to software applications that further process the video for specific purposes. As a class, the cards are used to capture baseband analog composite video, S-Video, some specialized cards support digital video via digital video delivery standards including Serial Digital Interface and, more recently, the emerging HDMI standard. These models often support both standard definition and high definition variants, while most PCI and PCI-Express capture devices are dedicated to that purpose, AGP capture devices are usually included with the graphics adapted on the board as an all-in-one package
13.
Video capture
–
Video capture is the process of converting an analog video signal—such as that produced by a video camera or DVD player—to digital video. The resulting digital data are computer files referred to as a video stream, or more often. This is in contrast with screencasting, in which previously digitized video is captured while displayed on a digital monitor, TV tuner cards have a television tuner with the capabilities to capture broadcast television. The video capture process involves several processing steps, first the analog signal is digitized by an analog-to-digital converter to produce a raw, digital data stream. In the case of video, the luminance and chrominance are then separated. Next, the chrominance is demodulated to produce color difference video data, at this point, the data may be modified so as to adjust brightness, contrast, saturation and hue. Finally, the data is transformed by a color space converter to generate data in conformance with any of several color space standards, such as RGB, together, these steps constituted video encoding, because they encode an analog video format such as NTSC or PAL. Special electronic circuitry is required to capture video from video sources. At the system level this function is performed by a dedicated video capture card. Such cards often utilize video decoder integrated circuits to implement the video decoding process, in the 1990s, and especially with the rise of increased data storage capabilities, videogames began to incorporate video. This could either be using pre-existing full motion video, or otherwise specially acted and recorded bluescreen work, uncompressed video, Practical configuration and recording Convergence Culture. Where Old and New Media Collide, Buying Into American Idol, Henry Jenkins,2006 New York University Press
14.
Videocassette recorder
–
Use of a VCR to record a television program to play back at a more convenient time is commonly referred to as timeshifting. VCRs can also play back prerecorded tapes, in the 1980s and 1990s, prerecorded videotapes were widely available for purchase and rental, and blank tapes were sold to make recordings. These features began as simple mechanical counter-based single-event timers, but were replaced by more flexible multiple-event digital clock timers. In later models the multiple timer events could be programmed through a menu interface displayed on the playback TV screen and this feature allowed several programs to be recorded at different times without further user intervention, and became a major selling point. The history of the recorder follows the history of videotape recording in general. Ampex introduced the Quadruplex videotape professional broadcast standard format with its Ampex VRX-1000 in 1956 and it became the worlds first commercially successful videotape recorder using two-inch wide tape. Due to its price of US$50,000, the Ampex VRX-1000 could be afforded only by the television networks. In 1959 Toshiba announced a new method of recording known as helical scan, first implemented in reel-to-reel videotape recorders, the Telcan, produced by the UK Nottingham Electronic Valve Company in 1963, was the first home video recorder. It could be bought as a unit or in kit form for £60, however, there were several drawbacks, it was expensive, not easy to assemble, and could only record 20 minutes at a time. It recorded in black-and-white, the format available in the UK at the time. The half-inch tape Sony model CV-2000, first marketed in 1965, was their first VTR intended for home use, Ampex and RCA followed in 1965 with their own reel-to-reel monochrome VTRs priced under US$1,000 for the home consumer market. The EIAJ format was a standard format used by various manufacturers. EIAJ-2 used a cartridge that contained a supply reel, the reel was part of the recorder, and the tape had to be fully rewound before removing the cartridge. In 1972, videocassettes of movies became available for home use, Sony demonstrated a videocassette prototype in October 1969, then set it aside to work out an industry standard by March 1970 with seven fellow manufacturers. The result, the Sony U-matic system, introduced in Tokyo in September 1971, was the worlds first commercial videocassette format. Its cartridges, resembling larger versions of the later VHS cassettes, used 3/4-inch tape and had a playing time of 60 minutes. Sony also introduced two machines to use the new tapes, U-matic, with its ease of use, quickly made other consumer videotape systems obsolete in Japan and North America, where U-matic VCRs were widely used by television newsrooms schools and businesses. But the high cost - US$1,395 in 1971 for a combination TV/VCR, in 1970, Philips developed a home video cassette format specially made for a TV station in 1970 and available on the consumer market in 1972
15.
NTSC
–
The first NTSC standard was developed in 1941 and had no provision for color. In 1953 a second NTSC standard was adopted, which allowed for television broadcasting which was compatible with the existing stock of black-and-white receivers. NTSC was the first widely adopted broadcast color system and remained dominant until 1997, North America, parts of Central America, and South Korea are adopting or have adopted the ATSC standards, while other countries are adopting or have adopted other standards instead of ATSC. After nearly 70 years, the majority of over-the-air NTSC transmissions in the United States ceased on January 1,2010, the majority of NTSC transmissions ended in Japan on July 24,2011, with the Japanese prefectures of Iwate, Miyagi, and Fukushima ending the next year. In March 1941, the committee issued a standard for black-and-white television that built upon a 1936 recommendation made by the Radio Manufacturers Association. Technical advancements of the side band technique allowed for the opportunity to increase the image resolution. The NTSC selected 525 scan lines as a compromise between RCAs 441-scan line standard and Philcos and DuMonts desire to increase the number of lines to between 605 and 800. The standard recommended a frame rate of 30 frames per second, other standards in the final recommendation were an aspect ratio of 4,3, and frequency modulation for the sound signal. In January 1950, the committee was reconstituted to standardize color television, in December 1953, it unanimously approved what is now called the NTSC color television standard. The compatible color standard retained full backward compatibility with existing black-and-white television sets, Color information was added to the black-and-white image by introducing a color subcarrier of precisely 315/88 MHz. These changes amounted to 0.1 percent and were tolerated by existing television receivers. The FCC had briefly approved a different color standard, starting in October 1950. However, this standard was incompatible with black-and-white broadcasts and it used a rotating color wheel, reduced the number of scan lines from 525 to 405, and increased the field rate from 60 to 144, but had an effective frame rate of only 24 frames per second. CBS rescinded its system in March 1953, and the FCC replaced it on December 17,1953, with the NTSC color standard, later that year, the improved TK-41 became the standard camera used throughout much of the 1960s. The NTSC standard has been adopted by countries, including most of the Americas. With the advent of television, analog broadcasts are being phased out. Most US NTSC broadcasters were required by the FCC to shut down their analog transmitters in 2009, low-power stations, Class A stations and translators were required to shut down by 2015. NTSC color encoding is used with the System M television signal, each frame is composed of two fields, each consisting of 262.5 scan lines, for a total of 525 scan lines
16.
Analog recording
–
Analog recording is a technique used for the recording of analog signals which, among many possibilities, allows analog audio and analog video for later playback. Analog recording methods store signals as a signal in or on the media. The signal may be stored as a texture on a phonograph record. This is different from digital recording which digital signals are represented as discrete numbers, the Phonograph was the first machine used to capture analog sound, and was invented by the well-known inventor Thomas Edison in 1877. Edison incorporated various elements into his Phonograph that would become staples that can be found in recording devices to this day, for a sound to be recorded by the Phonograph, it has to go through three distinct steps. First, the sound enters a cone-shaped component of the device and that sound causes the microphone diaphragm, which is connected to a small metal needle, to vibrate. The needle then vibrates in the way, causing its sharp tip to etch a distinctive groove into a cylinder. In order to playback the sound recorded on one of the tinfoil cylinders, as the cylinder spins, the needle follows the groove created by the previous recording session. This causes the needle to vibrate, and then the diaphragm and this vibration comes out of the diaphragm, which is now functioning as a sort of sound amplification device, much like the bell on any wind instrument. The result is a reproduction of the originally recorded sound. Edisons phonograph was the first of its kind, but drawbacks were nevertheless obvious, the biggest of these, and the one that ended up being fixed first, came from the physical contact between the phonograph needle and the tinfoil diaphragm. Because the needle had to make contact with the groove in the diaphragm every time the recording was played. This meant that every time a recording was played, it was one step closer to being gone forever. Another problem with the phonograph was the permanence of its recordings, unlike music today, which can be edited endlessly, the music captured by phonograph machines were single-take, live recordings. The last problem with the phonograph was related to fidelity, fidelity is the similarity/difference between the original recorded sound, and that same sound after it has been reproduced by a playback device, in this case the phonograph. As can be expected from such an early audio recording machine and this lack of sound quality is why the phonograph was originally used to record speeches, meetings, and telephone calls, rather than music. Fans of modern players are already familiar with one very early improvement on the phonograph. Inventor Emile Berliner created the device in 1887, only ten years after Edisons original device, Berliners main improvement to the phonograph was related to the component of the device that actually held the recorded information
17.
Video
–
Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video systems vary greatly in the resolution of the display and refresh rate, video can be carried on a variety of media, including radio broadcast, tapes, DVDs, computer files etc. Video was originally exclusively a live technology, charles Ginsburg led an Ampex research team developing one of the first practical video tape recorder. In 1951 the first video tape recorder captured live images from television cameras by converting the electrical impulses. Video recorders were sold for $50,000 in 1956, however, prices gradually dropped over the years, in 1971, Sony began selling videocassette recorder decks and tapes into the consumer market. The use of techniques in video created digital video, which allowed higher quality and, eventually. After the invention of the DVD in 1997 and Blu-ray Disc in 2006, sales of videotape, the advent of digital broadcasting and the subsequent digital television transition is in the process of relegating analog video to the status of a legacy technology in most parts of the world. PAL standards and SECAM specify 25 frame/s, while NTSC standards specify 29.97 frames, film is shot at the slower frame rate of 24 frames per second, which slightly complicates the process of transferring a cinematic motion picture to video. The minimum frame rate to achieve a comfortable illusion of an image is about sixteen frames per second. Video can be interlaced or progressive, analog display devices reproduce each frame in the same way, effectively doubling the frame rate as far as perceptible overall flicker is concerned. NTSC, PAL and SECAM are interlaced formats, abbreviated video resolution specifications often include an i to indicate interlacing. For example, PAL video format is specified as 576i50, where 576 indicates the total number of horizontal scan lines, i indicates interlacing. In progressive scan systems, each refresh period updates all scan lines in each frame in sequence, when displaying a natively progressive broadcast or recorded signal, the result is optimum spatial resolution of both the stationary and moving parts of the image. Deinterlacing cannot, however, produce video quality that is equivalent to true progressive scan source material, aspect ratio describes the dimensions of video screens and video picture elements. All popular video formats are rectilinear, and so can be described by a ratio between width and height, the screen aspect ratio of a traditional television screen is 4,3, or about 1.33,1. High definition televisions use a ratio of 16,9. The aspect ratio of a full 35 mm film frame with soundtrack is 1.375,1. Therefore, a 720 by 480 pixel NTSC DV image displayes with the 4,3 aspect ratio if the pixels are thin, the popularity of viewing video on mobile phones has led to the growth of vertical video
18.
DVD
–
DVD is a digital optical disc storage format invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. The medium can store any kind of data and is widely used for software. DVDs offer higher capacity than compact discs while having the same dimensions. Pre-recorded DVDs are mass-produced using molding machines that physically stamp data onto the DVD, such discs are a form of DVD-ROM because data can only be read and not written or erased. Blank recordable DVD discs can be recorded using a DVD recorder. Rewritable DVDs can be recorded and erased many times, DVDs containing other types of information may be referred to as DVD data discs. The OED also states that in 1995, The companies said the name of the format will simply be DVD. Toshiba had been using the name ‘digital video disk’, but that was switched to ‘digital versatile disk’ after computer companies complained that it left out their applications, Digital versatile disc is the explanation provided in a DVD Forum Primer from 2000 and in the DVD Forums mission statement. There were several formats developed for recording video on optical discs before the DVD, Optical recording technology was invented by David Paul Gregg and James Russell in 1958 and first patented in 1961. A consumer optical disc data format known as LaserDisc was developed in the United States and it used much larger discs than the later formats. CD Video used analog video encoding on optical discs matching the established standard 120 mm size of audio CDs, Video CD became one of the first formats for distributing digitally encoded films in this format, in 1993. In the same year, two new optical disc formats were being developed. By the time of the launches for both formats in January 1995, the MMCD nomenclature had been dropped, and Philips and Sony were referring to their format as Digital Video Disc. Representatives from the SD camp asked IBM for advice on the system to use for their disc. Alan E. Bell, a researcher from IBMs Almaden Research Center, got that request and this group was referred to as the Technical Working Group, or TWG. On August 14,1995, an ad hoc group formed from five computer companies issued a release stating that they would only accept a single format. The TWG voted to both formats unless the two camps agreed on a single, converged standard. They recruited Lou Gerstner, president of IBM, to pressure the executives of the warring factions, as a result, the DVD specification provided a storage capacity of 4.7 GB for a single-layered, single-sided disc and 8.5 GB for a dual-layered, single-sided disc
19.
CD-ROM
–
A CD-ROM /ˌsiːˌdiːˈrɒm/ is a pre-pressed optical compact disc which contains data. The name is an acronym which stands for Compact Disc Read-Only Memory, computers can read CD-ROMs, but cannot write to CD-ROMs which are not writable or erasable. From the mid-1990s until the mid-2000s, CD-ROMs were popularly used to distribute software for computers, some CDs, called enhanced CDs, hold both computer data and audio with the latter capable of being played on a CD player, while data is only usable on a computer. An early CD-ROM format was developed by Sony and Denon, introduced at a Japanese computer show in 1984 and it was an extension of Compact Disc Digital Audio, and adapted the format to hold any form of digital data, with a capacity of 540 MiB. The Yellow Book is the standard that defines the format of CD-ROMs. One of a set of books that contain the technical specifications for all CD formats. CD-ROMs are identical in appearance to audio CDs, and data are stored and retrieved in a similar manner. Discs are made from a 1.2 mm thick disc of polycarbonate plastic, data is stored on the disc as a series of microscopic indentations. A laser is shone onto the surface of the disc to read the pattern of pits. This pattern of changing intensity of the beam is converted into binary data. Several formats are used for data stored on discs, known as the Rainbow Books. The Yellow Book, published in 1988, defines the specifications for CD-ROMs, the CD-ROM standard builds on top of the original Red Book CD-DA standard for CD audio. Other standards, such as the White Book for Video CDs, the Yellow Book itself is not freely available, but the standards with the corresponding content can be downloaded for free from ISO or ECMA. There are several standards that define how to structure data files on a CD-ROM, ISO9660 defines the standard file system for a CD-ROM. ISO13490 is an improvement on this standard which adds support for non-sequential write-once and re-writeable discs such as CD-R and CD-RW, as well as multiple sessions. The ISO13346 standard was designed to address most of the shortcomings of ISO9660, and a subset of it evolved into the UDF format, which was adopted for DVDs. The bootable CD specification was issued in January 1995, to make a CD emulate a hard disk or floppy disk, is called El Torito, data stored on CD-ROMs follows the standard CD data encoding techniques described in the Red Book specification. This includes cross-interleaved Reed–Solomon coding, eight-to-fourteen modulation, and the use of pits, the structures used to group data on a CD-ROM are also derived from the Red Book
20.
Laser
–
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term laser originated as an acronym for light amplification by stimulated emission of radiation, the first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light coherently, spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances, Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum, i. e. they can emit a single color of light. Temporal coherence can be used to produce pulses of light as short as a femtosecond, Lasers are distinguished from other light sources by their coherence. Spatial coherence is typically expressed through the output being a narrow beam, Laser beams can be focused to very tiny spots, achieving a very high irradiance, or they can have very low divergence in order to concentrate their power at a great distance. Temporal coherence implies a polarized wave at a single frequency whose phase is correlated over a great distance along the beam. A beam produced by a thermal or other incoherent light source has an amplitude and phase that vary randomly with respect to time and position. Lasers are characterized according to their wavelength in a vacuum, most single wavelength lasers actually produce radiation in several modes having slightly differing frequencies, often not in a single polarization. Although temporal coherence implies monochromaticity, there are lasers that emit a broad spectrum of light or emit different wavelengths of light simultaneously, there are some lasers that are not single spatial mode and consequently have light beams that diverge more than is required by the diffraction limit. However, all devices are classified as lasers based on their method of producing light. Lasers are employed in applications where light of the spatial or temporal coherence could not be produced using simpler technologies. The word laser started as an acronym for light amplification by stimulated emission of radiation, in the early technical literature, especially at Bell Telephone Laboratories, the laser was called an optical maser, this term is now obsolete. A laser that produces light by itself is technically an optical rather than an optical amplifier as suggested by the acronym. It has been noted that the acronym LOSER, for light oscillation by stimulated emission of radiation. With the widespread use of the acronym as a common noun, optical amplifiers have come to be referred to as laser amplifiers. The back-formed verb to lase is frequently used in the field, meaning to produce light, especially in reference to the gain medium of a laser. Further use of the laser and maser in an extended sense, not referring to laser technology or devices, can be seen in usages such as astrophysical maser
21.
Pioneer Corporation
–
Pioneer Corporation commonly referred to as Pioneer, is a Japanese multinational corporation that specializes in digital entertainment products, based in Tokyo, Japan. The company was founded by Nozomu Matsumoto in 1938 in Tokyo as a radio and speaker repair shop, the company works with optical disc and display technology and software products and is also a manufacturer. In March 2010, Pioneer stopped producing televisions, announced on 12 February 2009, on June 25,2009, Sharp Corporation agreed to form a joint venture on their optical business to be called Pioneer Digital Design and Manufacturing Corporation. 1937, Pioneer’s founder, Nozomu Matsumoto develops the A-8 dynamic speaker, January 1938, Fukuin Shokai Denki Seisakusho is founded in Tokyo. May 1947, Fukuin Denki is incorporated, december 1953, Hi-Fi Speaker PE-8 introduced. June 1961, Company name changed to Pioneer Electronic Corporation, October 1961, Shares are listed on the Tokyo Stock Exchange Second Section. June 1962, Introduces the world’s first separate stereo system, March 1966, Establishes sales companies in Europe and the U. S. February 1968, Shares are listed on the Tokyo Stock Exchange First Section. April 1968, Shares are listed on the Osaka Securities Exchange, February 1969, Shares are listed on the Amsterdam Stock Exchange. U. S. GAAP consolidated financial reporting starts November 1975, december 1976, Shares are listed on the New York Stock Exchange. December 1977, Introduces the world’s first two-way addressable CATV system in the U. S.1978, Introduces SX-1980 receiver, February 1979, Introduces the industry-use Laserdisc player. June 1980, Introduces VP-1000 LD player for use in the U. S. October 1981. October 1982, Introduces the LD Karaoke system for business use, september 1984, Introduces the world’s first LD combination player compatible with CDs and LDs. October 1984, Releases the world’s first car CD player, december 1985, Introduces the 40-inch projection monitor. June 1990, Introduces the world’s first CD-based GPS automotive navigation system, June 1992, Pioneer Corporation established its regional subsidiary in Southeast Asia, Pioneer Electronics AsiaCentre Pte. Ltd. October 1992, Introduces the world’s first 4x CD-ROM changer, June 1996, Tokorozawa Plant earns ISO14001 certification. Pioneer inaugurates and launches Pioneer Karaoke Channel, an Astro satellite television channel for music video, december 1996, Introduces DVD/CD player and the world’s first DVD/LD/CD compatible player for home use. May 1997, Starts supplying digital satellite broadcast set-top boxes in Europe, June 1997, Introduces the world’s first DVD-based GPS automotive navigation system. October 1997, Introduces the world’s first DVD-R drive, November 1997, Introduces the world’s first OEL-equipped car audio product
22.
Apple Inc.
–
Apple is an American multinational technology company headquartered in Cupertino, California that designs, develops, and sells consumer electronics, computer software, and online services. Apples consumer software includes the macOS and iOS operating systems, the media player, the Safari web browser. Its online services include the iTunes Store, the iOS App Store and Mac App Store, Apple Music, Apple was founded by Steve Jobs, Steve Wozniak, and Ronald Wayne in April 1976 to develop and sell personal computers. It was incorporated as Apple Computer, Inc. in January 1977, Apple joined the Dow Jones Industrial Average in March 2015. In November 2014, Apple became the first U. S. company to be valued at over US$700 billion in addition to being the largest publicly traded corporation in the world by market capitalization. The company employs 115,000 full-time employees as of July 2015 and it operates the online Apple Store and iTunes Store, the latter of which is the worlds largest music retailer. Consumers use more than one billion Apple products worldwide as of March 2016, Apples worldwide annual revenue totaled $233 billion for the fiscal year ending in September 2015. This revenue accounts for approximately 1. 25% of the total United States GDP.1 billion, the corporation receives significant criticism regarding the labor practices of its contractors and its environmental and business practices, including the origins of source materials. Apple was founded on April 1,1976, by Steve Jobs, Steve Wozniak, the Apple I kits were computers single-handedly designed and hand-built by Wozniak and first shown to the public at the Homebrew Computer Club. The Apple I was sold as a motherboard, which was less than what is now considered a personal computer. The Apple I went on sale in July 1976 and was market-priced at $666.66, Apple was incorporated January 3,1977, without Wayne, who sold his share of the company back to Jobs and Wozniak for $800. Multimillionaire Mike Markkula provided essential business expertise and funding of $250,000 during the incorporation of Apple, during the first five years of operations revenues grew exponentially, doubling about every four months. Between September 1977 and September 1980 yearly sales grew from $775,000 to $118m, the Apple II, also invented by Wozniak, was introduced on April 16,1977, at the first West Coast Computer Faire. It differed from its rivals, the TRS-80 and Commodore PET, because of its character cell-based color graphics. While early Apple II models used ordinary cassette tapes as storage devices, they were superseded by the introduction of a 5 1/4 inch floppy disk drive and interface called the Disk II. The Apple II was chosen to be the platform for the first killer app of the business world, VisiCalc. VisiCalc created a market for the Apple II and gave home users an additional reason to buy an Apple II. Before VisiCalc, Apple had been a distant third place competitor to Commodore, by the end of the 1970s, Apple had a staff of computer designers and a production line
23.
SuperDrive
–
The terms DVD Multi, Super AllWrite and Super Multi are used to describe optical disc drives from non-Apple manufacturers. The term was first used by Apple Computer in 1988 to refer to their 1.40 MB3.5 inch floppy drive. This drive was capable of reading and writing MS-DOS formatted disks and FAT12 file formats, using PC Exchange or other software. The controller card as well as the external Superdrive were discontinued in June 1994, the SuperDrive cannot be used with the original four Mac models, as their disk controller doesnt support high density. The next two models to be released also shipped with that controller, a SuperDrive connected to them will behave as an 800 KB drive and these two models can be upgraded via the M0244 upgrade kit and gain full use of the SuperDrive. All later models shipped with the SWIM, the first Macintosh model to include a SuperDrive floppy drive was the Macintosh IIx. Every Macintosh and PowerBook introduced from 1988–97, had a built-in SuperDrive floppy drive, the last model to include one was the beige Power Macintosh G3 series, which was manufactured until January 1999. The PowerBook G31998 model had a floppy drive module. The PowerBook 190 series, PowerBook 5300 Series, PowerBook 3400c, the drive as mounted on PowerBooks lacked the auto-inject feature of Apples initial desktop SuperDrive implementation, requiring the user to manually insert the disk all the way into the drive. The feature was dropped throughout the lineup during 1993–94, the PowerBook 1400 series also had a floppy drive module, but was incompatible with the other PowerBooks. The end of the SuperDrive coincides with the demise of Old World ROM Macs, with the advent of the New World ROM machines, the SuperDrive is not supported in Mac OS X, not even on the few Old World ROM machines that can officially run OS X. Once the use of floppy disks started declining, Apple reused the trademark to refer to the optical drives built into its Macintosh models, the early 2001 release of the Power Mac G4 was the first Macintosh to include a SuperDrive. SuperDrives featured 6–24x write speeds and supported the DVD±R, DVD±R DL, DVD±RW, CD-R, DVD-RAM support, notably, is absent though it can be unofficially enabled on some drive models. Apple never offered a Blu-Ray drive or supported playback of the format, the MacBook Air, released in 2008, was the first Macintosh to not include a SuperDrive after it became standard across the line. Apple began phasing SuperDrives out across the Macintosh line beginning in 2011, the second generation MacBook Pro, released in 2012 and discontinued in 2016, was the last Macintosh to include a SuperDrive. Apple still sells a USB-connected external SuperDrive as an accessory, the drive has faced criticism and mixed customer reviews, with 923 reviews averaging three stars. Criticism includes the lack of support for Blu-ray or mini optical discs and malfunctions that make the drive inoperable, DVD Multi is a specification for optical media drives. The specification was approved by the DVD Forum and was claimed to enable disc compatibility for all formats officially created by the DVD Forum
24.
CD-R
–
CD-R is a digital optical disc storage format. A CD-R disc is a disc that can be written once. CD-R disks are readable by most plain CD readers, i. e. CD readers manufactured prior to the introduction of CD-R and this is an advantage over CD-RW, which can be re-written but cannot be played on many plain CD readers. The CD-R, originally named CD Write-Once, specification was first published in 1988 by Philips, the Orange Book consists of several parts, furnishing details of the CD-WO, CD-MO, and CD-RW. The latest editions have abandoned the use of the term CD-WO in favor of CD-R, written CD-Rs and CD-RWs are, in the aspect of low-level encoding and data format, fully compatible with the audio CD and data CD standards. This means they use Eight-to-Fourteen Modulation, CIRC error correction, and, for CD-ROM, properly written CD-R discs on blanks of less than 80 minutes length are fully compatible with the audio CD and CD-ROM standards in all details including physical specifications. 80 minute CD-R discs marginally violate the Red Book physical format specifications, CD-RW discs have lower reflectivity than CD-R or pressed CDs and for this reason cannot meet the Red Book standard. Some hardware compatible with Red Book CDs may have difficulty reading CD-Rs and, because of their lower reflectivity, especially CD-RWs. To the extent that CD hardware can read extended-length discs or CD-RW discs, it is because that hardware has capability beyond the minimum required by the Red Book and Yellow Book standards. The dye materials developed by Taiyo Yuden made it possible for CD-R discs to be compatible with Audio CD, a standard CD-R is a 1.2 mm thick disc made of polycarbonate about 120 mm or 80 mm diameter. The 120 mm disc has a capacity of 74 minutes of audio or 650 Megabytes of data. Despite the foregoing, most CD-Rs on the market have an 80-minute capacity, there are also 90 minute/790 MiB and 99 minute/870 MiB discs, although they are less common. Also, due to the limitations of the structures in the ATIP,90 and 99 minute blanks will identify as 80 minute ones. Therefore, in order to use the capacity, these discs have to be burned using overburn options in the CD recording software. Nothing in the Red, Yellow or Orange Book standards prohibits disc reading/writing devices from having the capacity to read or write discs beyond the Compact Disc standards, the polycarbonate disc contains a spiral groove, called the pregroove, to guide the laser beam upon writing and reading information. The polycarbonate disc is coated on the side with a very thin layer of organic dye. Then, on top of the dye is coated a thin, reflecting layer of silver, finally, a protective coating of a photo-polymerizable lacquer is applied on top of the metal reflector and cured with UV-light. A blank CD-R is not empty, the pregroove has a wobble, maintaining a constant rate is essential to ensure proper size and spacing of the pits and lands burned into the dye layer
25.
CD-RW
–
CD-RW is a digital optical disc storage format. A CD-RW disc is a disc that can be written, read arbitrarily many times, erased. The technology was introduced in 1997, CD-RW discs require readers that have more sensitive laser optics than are required to read plain CDs. Consequently, CD-RWs cannot be read in many CD readers built prior to the introduction of CD-RW, CD-ROM drives that bear a MultiRead certification claim compatibility. CD-RW discs need to be blanked before reuse, fast blanking is much quicker, and is usually sufficient to allow rewriting the disc. Full blanking removes traces of the data, often for confidentiality reasons. It may be possible to data from full-blanked CD-RWs with specialty data recovery equipment, however. Their ideal usage field is in the creation of test discs, temporary short or mid-term backups, and in general, the CD-MO standard also allowed for an optional non-erasable zone on the disc, which could be read by normal CD-ROM reader units. Reading of the discs relied on the Kerr effect, the format was never released commercially, mostly because of its inherent incompatibility with standard CD reading units. A similar situation was present for early CD-R media, which suffered from either physical or logical incompatibilities. There were however some magneto-optical drives and media with the form factor that dont have this limitation. Unlike modern CD-RWs, CD-MO allowed for hybrid discs containing both an unmodifiable, pressed section, readable in standard drives, and a writable MO section, other kinds of magneto-optical media, unbound by the limitations of the typical CD-ROM filesystems, took the place intended for CD-MO. Rewritable media can, with hardware, according to some manufacturers. The CD-RW technology is based on phase change technology, so the degree of reflection reached is only 15–25%, the properties of the medium and the write and erase procedure is defined in the Orange Book Part III. To keep rotational speed precise, tracks have a slight superimposed sinusoidal excursion of 0.3 µm at a frequency of 22.05 kHz, in addition a 1 kHz frequency modulation is applied to provide the recorder with an absolute time reference. The grooves have a width of 0.6 µm and pitch of 1.6 µm, the media for CD-RW has basically the same layers as CD-R media. The reflective layer is, however, an alloy, which has in its original state. When writing the laser beam uses its power to heat the material to 500–700 °C
26.
Laptop
–
Laptops are folded shut for transportation, and thus are suitable for mobile use. Although originally there was a distinction between laptops and notebooks, the former being bigger and heavier than the latter, as of 2014, there is often no longer any difference. Laptops are commonly used in a variety of settings, such as at work, in education, Internet surfing using sites such as YouTube and for personal multimedia, most 2016-era laptops also have integrated webcams and built-in microphones. Laptops can be powered either from a battery or by an external power supply from an AC adapter. Hardware specifications, such as the speed and memory capacity. Design elements, form factor, and construction can also vary significantly between models depending on intended use, as portable computers evolved into the modern laptop, they became widely used for a variety of purposes. The terms laptop and notebook are used interchangeably to describe a computer in English. Regardless of the etymology, by the late 1990s, the terms were interchangeable, as the personal computer became feasible in 1971, the idea of a portable personal computer soon followed. A personal, portable information manipulator was imagined by Alan Kay at Xerox PARC in 1968, the IBM Special Computer APL Machine Portable was demonstrated in 1973. This prototype was based on the IBM PALM processor, the IBM5100, the first commercially available portable computer, appeared in September 1975, and was based on the SCAMP prototype. As 8-bit CPU machines became widely accepted, the number of portables increased rapidly, the Osborne 1, released in 1981, used the Zilog Z80 and weighed 23.6 pounds. It had no battery, a 5 in CRT screen, in the same year the first laptop-sized portable computer, the Epson HX-20, was announced. The Epson had an LCD screen, a battery. Both Tandy/RadioShack and HP also produced portable computers of varying designs during this period, the first laptops using the flip form factor appeared in the early 1980s. The Dulmont Magnum was released in Australia in 1981–82, but was not marketed internationally until 1984–85, the US$8,150 GRiD Compass 1101, released in 1982, was used at NASA and by the military, among others. The Sharp PC-5000, Ampere and Gavilan SC released in 1983, the Gavilan SC was the first computer described as a laptop by its manufacturer, while the Ampere had a modern clamshell design. The Toshiba T1100 won acceptance not only among PC experts but the market as a way to have PC portability. From 1983 onward, several new techniques were developed and included in laptops, including the touchpad, the pointing stick
27.
Serial ATA
–
Serial ATA is a computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives, optical drives, and solid-state drives. Although, a number of hot plug PATA offering were first invented and marketed by Core International beginning in the late 1980s for the Micro Channel architecture bus controllers, prior to SATAs introduction in 2003, the PATA was simply known as ATA. The AT Attachment name originated after the 1984 release of the IBM Personal Computer AT, the IBM AT was the first mass-produced computer where the hard disk was key to the systems performance. The IBM AT’s controller interface became a de facto industry interface for the inclusion of hard disks, SATA host adapters and devices communicate via a high-speed serial cable over two pairs of conductors. In contrast, parallel ATA uses a 16-bit wide data bus with many support and control signals. To ensure backward compatibility with legacy ATA software and applications, SATA uses the same basic ATA, SATA has replaced parallel ATA in consumer desktop and laptop computers, SATAs market share in the desktop PC market was 99% in 2008. A2008 standard, CFast to replace CompactFlash is based on SATA, Serial ATA industry compatibility specifications originate from the Serial ATA International Organization. The SATA-IO group collaboratively creates, reviews, ratifies, and publishes the interoperability specifications, the remainder of this article will try to use the terminology and specifications of SATA-IO. The term Hot Plug was a registered trademark issued by the USPTO and it was invented for computer components including PATA in the late 1980s by Hal Prewitt, founder of Core International. First patent details were disclosed in 1987 in USA and Europe related to development of the technology to connect host bus adapters to mass storage device however the filings were not completed. Core created and in 1990 marketed the worlds first disk controller, host adapter, disk drives, disk arrays, initial implementations were on the IBM PS/2 series and Micro Channel architecture bus controllers. The Serial ATA Spec includes logic for SATA device hotplugging, Devices and motherboards that meet the interoperability specification are capable of hot plugging. Unlike PATA, both SATA and eSATA support hot swapping by design, however, this feature requires proper support at the host, device, and operating-system levels. In general, all SATA devices support hot swapping, also most SATA host adapters support this command, advanced Host Controller Interface is an open host controller interface published and used by Intel, which has become a de facto standard. It allows the use of advanced features of SATA such as hotplug, if AHCI is not enabled by the motherboard and chipset, SATA controllers typically operate in IDE emulation mode, which does not allow access to device features not supported by the ATA standard. Even in those instances, a driver may have been created for a specific chipset. SATA revisions are often designated with a dash followed by roman numerals, e. g. SATA-III, to avoid confusion with the speed, revision 1. 0a was released on January 7,2003. First-generation SATA interfaces, now known as SATA1.5 Gbit/s, communicate at a rate of 1.5 Gbit/s, taking 8b/10b encoding overhead into account, they have an actual uncoded transfer rate of 1.2 Gbit/s
28.
Parallel ATA
–
Parallel ATA, originally AT Attachment, is an interface standard for the connection of storage devices such as hard disk drives, floppy disk drives, and optical disc drives in computers. The standard is maintained by the X3/INCITS committee and it uses the underlying AT Attachment and AT Attachment Packet Interface standards. The Parallel ATA standard is the result of a history of incremental technical development. The ATA interface itself evolved in stages from Western Digitals original Integrated Drive Electronics interface. As a result, many near-synonyms for ATA/ATAPI and its previous incarnations are still in informal use, in particular Extended IDE. After the introduction of Serial ATA in 2003, the original ATA was renamed to Parallel ATA, Parallel ATA cables have a maximum allowable length of only 18 in. Because of this limit, the technology normally appears as a computer storage interface. For many years, ATA provided the most common and the least expensive interface for this application and it has largely been replaced by SATA in newer systems. The PATA standard was originally conceived as the PC/AT Attachment because its primary feature was a connection to the 16-bit ISA bus introduced with the IBM PC/AT. The AT in IBM PC/AT refers to Advanced Technology, but the ATA specifications simply use the name AT Attachment, the first version of what is now called the ATA/ATAPI interface was developed by Western Digital under the name Integrated Drive Electronics. The first such drives appeared in Compaq PCs in 1986, the interface cards used to connect a parallel ATA drive to, for example, a PCI slot are not drive controllers, they are merely bridges between the host bus and the ATA interface. Since the original ATA interface is essentially just a 16-bit ISA bus in disguise, the integrated controller presented the drive to the host computer as an array of 512-byte blocks with a relatively simple command interface. All of these details of the mechanical operation of the drive were now handled by the controller on the drive itself. This also eliminated the need to design a controller that could handle many different types of drives. The host need only ask for a sector, or block, to be read or written. The interface used by these drives was standardized in 1994 as ANSI standard X3. 221-1994, after later versions of the standard were developed, this became known as ATA-1. A short-lived, seldom-used implementation of ATA was created for the IBM XT and it has been referred to as XT-IDE, XTA or XT Attachment. At the time, in combination with the drive, this was sufficient for most people
29.
USB
–
It is currently developed by the USB Implementers Forum. USB was designed to standardize the connection of peripherals to personal computers. It has become commonplace on other devices, such as smartphones, PDAs, USB has effectively replaced a variety of earlier interfaces, such as serial ports and parallel ports, as well as separate power chargers for portable devices. Also, there are 5 modes of USB data transfer, in order of increasing bandwidth, Low Speed, Full Speed, High Speed, SuperSpeed, USB devices have some choice of implemented modes, and USB version is not a reliable statement of implemented modes. Modes are identified by their names and icons, and the specifications suggests that plugs, unlike other data buses, USB connections are directed, with both upstream and downstream ports emanating from a single host. This applies to power, with only downstream facing ports providing power. Thus, USB cables have different ends, A and B, therefore, in general, each different format requires four different connectors, a plug and receptacle for each of the A and B ends. USB cables have the plugs, and the corresponding receptacles are on the computers or electronic devices, in common practice, the A end is usually the standard format, and the B side varies over standard, mini, and micro. The mini and micro formats also provide for USB On-The-Go with a hermaphroditic AB receptacle, the micro format is the most durable from the point of view of designed insertion lifetime. The standard and mini connectors have a lifetime of 1,500 insertion-removal cycles. Likewise, the component of the retention mechanism, parts that provide required gripping force, were also moved into plugs on the cable side. A group of seven companies began the development of USB in 1994, Compaq, DEC, IBM, Intel, Microsoft, NEC, a team including Ajay Bhatt worked on the standard at Intel, the first integrated circuits supporting USB were produced by Intel in 1995. The original USB1.0 specification, which was introduced in January 1996, Microsoft Windows 95, OSR2.1 provided OEM support for the devices. The first widely used version of USB was 1.1, the 12 Mbit/s data rate was intended for higher-speed devices such as disk drives, and the lower 1.5 Mbit/s rate for low data rate devices such as joysticks. Apple Inc. s iMac was the first mainstream product with USB, following Apples design decision to remove all legacy ports from the iMac, many PC manufacturers began building legacy-free PCs, which led to the broader PC market using USB as a standard. The USB2.0 specification was released in April 2000 and was ratified by the USB Implementers Forum at the end of 2001.1 specification, the USB3.0 specification was published on 12 November 2008. Its main goals were to increase the transfer rate, decrease power consumption, increase power output. USB3.0 includes a new, higher speed bus called SuperSpeed in parallel with the USB2.0 bus, for this reason, the new version is also called SuperSpeed
30.
DVD region code
–
This is achieved by way of region-locked DVD players, which will play back only DVDs encoded to their region. The American DVD Copy Control Association also requires that DVD player manufacturers incorporate the regional-playback control system, however, region-free DVD players, which ignore region coding, are also commercially available, and many DVD players can be modified to be region-free, allowing playback of all discs. DVDs may use one code, a combination of codes, every code or no codes, DVDs in Hispanophone Latin America and Mexico use both the region 1 and region 4 codes. DVDs sold in the Baltic states use both region 2 and 5 codes, Region 0 is widely used by China and the Philippines. Most DVDs in India combine the region 2, region 4, European region 2 DVDs may be sub-coded D1 to D4. D1 are the United Kingdom–only releases, D2 and D3 are not sold in the UK and Ireland, any combination of regions can be applied to a single disc. For example, a DVD designated Region 2/4 is suitable for playback in Western Europe, Oceania, so-called Region 0 and ALL discs are meant to be playable worldwide. The term Region 0 also describes the DVD players designed or modified to incorporate Regions 1–6, thereby providing compatibility with most discs, regardless of region. This apparent solution was popular in the days of the DVD format. This system is known as Regional Coding Enhancement, the scheme was deployed on only a handful of discs. The disc contained the program material region coded as region 1. But it also contained a video loop of a map of the world showing the regions, which was coded as region 2,3,4,5. The intention was that when the disc was played in a non-region 1 player and this played the aforementioned video loop of a map, which was impossible to escape from, as the user controls were disabled. However, the scheme was fundamentally flawed, as a player tries to play a disc using the last region that worked with the previously inserted disc. If it cannot play the disc, then it tries another region until one is found that works, RCE could thus be defeated by briefly playing a normal region 1 disc, and then inserting the RCE protected region 1 disc, which would now play. RCE caused a few problems with genuine region 1 players, some manufacturers of DVD players now freely supply information on how to disable regional lockout, and on some recent models, it appears to be disabled by default. Computer programs such as DVD Shrink, Digiarty WinX DVD Ripper Platinum can make copies of region-coded DVDs without RCE restriction, One purpose of region coding is controlling release dates. A practice of movie marketing threatened by the advent of home video is to release a movie to cinemas
31.
Backplane
–
A backplane is a group of electrical connectors in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus. It is used as a backbone to connect several printed circuit boards together to make up a computer system. Backplanes commonly use a circuit board, but wire-wrapped backplanes have also been used in minicomputers. Early microcomputer systems like the Altair 8800 used a backplane for the processor, a backplane is generally differentiated from a motherboard by the lack of on-board processing and storage elements. A backplane uses plug-in cards for storage and processing, backplanes are normally used in preference to cables because of their greater reliability. In a cabled system, the cables need to be flexed every time that a card is added or removed from the system, a backplane does not suffer from this problem, so its service life is limited only by the longevity of its connectors. For example, the DIN41612 connectors used in the VMEbus system can withstand 50 to 500 insertions and removals, to transmit information, Serial Back-Plane technology uses a low voltage differential signaling transmission method for sending information. These cable sets have a board located in the computer, an expansion board in the remote backplane. Backplanes have grown in complexity from the simple Industry Standard Architecture or S-100 style where all the connectors were connected to a common bus, due to limitations inherent in the Peripheral Component Interconnect specification for driving slots, backplanes are now offered as passive and active. True passive backplanes offer no active bus driving circuitry, any desired arbitration logic is placed on the daughter cards. Active backplanes include chips which buffer the various signals to the slots, the distinction between the two isnt always clear, but may become an important issue if a whole system is expected to not have a single point of failure. A passive backplane, even if it is single, is not usually considered a SPOF, active backplanes are more complicated and thus have a non-zero risk of malfunction. While there are a few motherboards that offer more than 8 slots, in addition, as technology progresses, the availability and number of a particular slot type may be limited in terms of what is currently offered by motherboard manufacturers. However, backplane architecture is somewhat unrelated to the SBC technology plugged into it, there are some limitations to what can be constructed, in that the SBC chip set and processor have to provide the capability of supporting the slot types. In addition, virtually an unlimited number of slots can be provided with 20, including the SBC slot, as a practical though not an absolute limit. Thus, a PICMG backplane can provide any number and any mix of ISA, PCI, PCI-X, for example, an SBC with the latest i7 processor could interface with a backplane providing up to 19 ISA slots to drive legacy I/O cards. Some backplanes are constructed with slots for connecting to devices on both sides, and are referred to as midplanes and this ability to plug cards into either side of a midplane is often useful in larger systems made up primarily of modules attached to the midplane. Midplanes are often used in computers, mostly in blade servers, where server blades reside on one side, orthogonal midplanes connect vertical cards on one side to horizontal boards on the other side
32.
Japan
–
Japan is a sovereign island nation in Eastern Asia. Located in the Pacific Ocean, it lies off the eastern coast of the Asia Mainland and stretches from the Sea of Okhotsk in the north to the East China Sea, the kanji that make up Japans name mean sun origin. 日 can be read as ni and means sun while 本 can be read as hon, or pon, Japan is often referred to by the famous epithet Land of the Rising Sun in reference to its Japanese name. Japan is an archipelago consisting of about 6,852 islands. The four largest are Honshu, Hokkaido, Kyushu and Shikoku, the country is divided into 47 prefectures in eight regions. Hokkaido being the northernmost prefecture and Okinawa being the southernmost one, the population of 127 million is the worlds tenth largest. Japanese people make up 98. 5% of Japans total population, approximately 9.1 million people live in the city of Tokyo, the capital of Japan. Archaeological research indicates that Japan was inhabited as early as the Upper Paleolithic period, the first written mention of Japan is in Chinese history texts from the 1st century AD. Influence from other regions, mainly China, followed by periods of isolation, from the 12th century until 1868, Japan was ruled by successive feudal military shoguns who ruled in the name of the Emperor. Japan entered into a period of isolation in the early 17th century. The Second Sino-Japanese War of 1937 expanded into part of World War II in 1941, which came to an end in 1945 following the bombings of Hiroshima and Nagasaki. Japan is a member of the UN, the OECD, the G7, the G8, the country has the worlds third-largest economy by nominal GDP and the worlds fourth-largest economy by purchasing power parity. It is also the worlds fourth-largest exporter and fourth-largest importer, although Japan has officially renounced its right to declare war, it maintains a modern military with the worlds eighth-largest military budget, used for self-defense and peacekeeping roles. Japan is a country with a very high standard of living. Its population enjoys the highest life expectancy and the third lowest infant mortality rate in the world, in ancient China, Japan was called Wo 倭. It was mentioned in the third century Chinese historical text Records of the Three Kingdoms in the section for the Wei kingdom, Wa became disliked because it has the connotation of the character 矮, meaning dwarf. The 倭 kanji has been replaced with the homophone Wa, meaning harmony, the Japanese word for Japan is 日本, which is pronounced Nippon or Nihon and literally means the origin of the sun. The earliest record of the name Nihon appears in the Chinese historical records of the Tang dynasty, at the start of the seventh century, a delegation from Japan introduced their country as Nihon
33.
United States dollar
–
The United States dollar is the official currency of the United States and its insular territories per the United States Constitution. It is divided into 100 smaller cent units, the circulating paper money consists of Federal Reserve Notes that are denominated in United States dollars. The U. S. dollar was originally commodity money of silver as enacted by the Coinage Act of 1792 which determined the dollar to be 371 4/16 grain pure or 416 grain standard silver, the currency most used in international transactions, it is the worlds primary reserve currency. Several countries use it as their currency, and in many others it is the de facto currency. Besides the United States, it is used as the sole currency in two British Overseas Territories in the Caribbean, the British Virgin Islands and Turks and Caicos Islands. A few countries use the Federal Reserve Notes for paper money, while the country mints its own coins, or also accepts U. S. coins that can be used as payment in U. S. dollars. After Nixon shock of 1971, USD became fiat currency, Article I, Section 8 of the U. S. Constitution provides that the Congress has the power To coin money, laws implementing this power are currently codified at 31 U. S. C. Section 5112 prescribes the forms in which the United States dollars should be issued and these coins are both designated in Section 5112 as legal tender in payment of debts. The Sacagawea dollar is one example of the copper alloy dollar, the pure silver dollar is known as the American Silver Eagle. Section 5112 also provides for the minting and issuance of other coins and these other coins are more fully described in Coins of the United States dollar. The Constitution provides that a regular Statement and Account of the Receipts and that provision of the Constitution is made specific by Section 331 of Title 31 of the United States Code. The sums of money reported in the Statements are currently being expressed in U. S. dollars, the U. S. dollar may therefore be described as the unit of account of the United States. The word dollar is one of the words in the first paragraph of Section 9 of Article I of the Constitution, there, dollars is a reference to the Spanish milled dollar, a coin that had a monetary value of 8 Spanish units of currency, or reales. In 1792 the U. S. Congress passed a Coinage Act, Section 20 of the act provided, That the money of account of the United States shall be expressed in dollars, or units. And that all accounts in the offices and all proceedings in the courts of the United States shall be kept and had in conformity to this regulation. In other words, this act designated the United States dollar as the unit of currency of the United States, unlike the Spanish milled dollar the U. S. dollar is based upon a decimal system of values. Both one-dollar coins and notes are produced today, although the form is significantly more common
34.
DVD+R DL
–
DVD+R DL also called DVD+R9, is a derivative of the DVD+R format created by the DVD+RW Alliance. Its use was first demonstrated in October 2003, DVD+R DL discs employ two recordable dye layers, each capable of storing nearly the 4.7 GB capacity of a single-layer disc, almost doubling the total disc capacity to 8.5 GB. Discs can be read in many DVD devices and can only be created using DVD+R DL, DL drives started appearing on the market during mid-2004, at prices comparable to those of existing single-layer drives. As of March 2011 DL media is up to twice as expensive as single-layer media, the latest DL drives write double layer discs at a slower rate than current single-layer discs. Dual-layer recording allows DVD-R and DVD+R discs to store more data, up to 8.5 gigabytes per disc. DVD-R DL was developed for the DVD Forum by Pioneer Corporation, while DVD+R DL was developed for the DVD+RW Alliance by Philips, a dual-layer disc differs from its usual DVD counterpart by employing a second physical layer within the disc itself. The drive with dual-layer capability accesses the second layer by shining the laser through the first semi-transparent layer, the layer change can exhibit a noticeable pause in some DVD players, up to several seconds. DVD recordable discs supporting this technology are compatible with some existing DVD players. Many current DVD recorders support dual-layer technology, and the price is now comparable to that of single-layer drives, the recording speeds reached by dual-layer media are still well below those of single-layer media. There are two modes for dual-layer orientation, parallel track path and opposite track path, in PTP mode, used for DVD-ROM, both layers start recording at the inside diameter with the lead-in and end at the outside diameter with the lead-out. Sectors are sequenced from the beginning of the first layer to the end of the first layer, in OTP mode, the second layer is read from the outside of the disk. For DVD-Video a variation of the technique is employed and this means that the start of the second layer may not have any recorded material present. This is in order to minimise the time that the player takes to locate and focus on the second layer. A common misconception is that the disc spins first in one direction, and then another, either for PTP or OTP recording, when in fact DVD-Writers always spin a disc in the clockwise direction. A simpler way to understand whats written above is to think of the hole in the centre of the DVD as the inside. This results in the skipping or freezing up for some time as the laser head repositions itself. For comparison, the table below shows storage capacities of the four most common DVD recordable media, stands for standard single-layer discs, while DL denotes the dual-layer variants. See articles on the formats in question for information on compatibility issues, DVD-R DL DVD DVD+R DVD+RW DVD+RW DL Book type MultiLevel Recording Bennett, Hugh
35.
Hard disk drive
–
The platters are paired with magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a manner, meaning that individual blocks of data can be stored or retrieved in any order. HDDs are a type of storage, retaining stored data even when powered off. Introduced by IBM in 1956, HDDs became the dominant secondary storage device for computers by the early 1960s. Continuously improved, HDDs have maintained this position into the era of servers. More than 200 companies have produced HDDs historically, though after extensive industry consolidation most current units are manufactured by Seagate, Toshiba, as of 2016, HDD production is growing, although unit shipments and sales revenues are declining. While SSDs have higher cost per bit, SSDs are replacing HDDs where speed, power consumption, small size, the primary characteristics of an HDD are its capacity and performance. Capacity is specified in unit prefixes corresponding to powers of 1000, the two most common form factors for modern HDDs are 3. 5-inch, for desktop computers, and 2. 5-inch, primarily for laptops. HDDs are connected to systems by standard interface cables such as PATA, SATA, Hard disk drives were introduced in 1956, as data storage for an IBM real-time transaction processing computer and were developed for use with general-purpose mainframe and minicomputers. The first IBM drive, the 350 RAMAC in 1956, was approximately the size of two medium-sized refrigerators and stored five million six-bit characters on a stack of 50 disks. In 1962 the IBM350 RAMAC disk storage unit was superseded by the IBM1301 disk storage unit, cylinder-mode read/write operations were supported, and the heads flew about 250 micro-inches above the platter surface. Motion of the head array depended upon a binary system of hydraulic actuators which assured repeatable positioning. The 1301 cabinet was about the size of three home refrigerators placed side by side, storing the equivalent of about 21 million eight-bit bytes, access time was about a quarter of a second. Also in 1962, IBM introduced the model 1311 disk drive, users could buy additional packs and interchange them as needed, much like reels of magnetic tape. Later models of removable pack drives, from IBM and others, became the norm in most computer installations, non-removable HDDs were called fixed disk drives. Some high-performance HDDs were manufactured with one head per track so that no time was lost physically moving the heads to a track, known as fixed-head or head-per-track disk drives they were very expensive and are no longer in production. In 1973, IBM introduced a new type of HDD code-named Winchester and its primary distinguishing feature was that the disk heads were not withdrawn completely from the stack of disk platters when the drive was powered down. Instead, the heads were allowed to land on an area of the disk surface upon spin-down
36.
Blu-ray
–
Blu-ray or Blu-ray Disc is a digital optical disc data storage format. It was designed to supersede the DVD format, in that it is capable of storing high-definition, the plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs. Conventional Blu-ray Disc discs contain 25 GB per layer, with dual layer discs being the standard for feature-length video discs. Triple-layer discs and quadruple layers are available for BD-XL re-writer drives, the name Blu-ray refers to the blue laser used to read the disc, which allows information to be stored at a greater density than is possible with the longer-wavelength red laser used for DVDs. The main application of Blu-ray is as a medium for video material such as films and physical distribution of video games for the PlayStation 3, PlayStation 4. Besides the hardware specifications, Blu-ray is associated with a set of multimedia formats, high-definition video may be stored on Blu-ray discs with up to 2160p resolution, at up to 60 frames per second. DVD discs had been limited to a resolution of 480p or 576p. The BD format was developed by the Blu-ray Disc Association, a group representing makers of consumer electronics, computer hardware, Sony unveiled the first Blu-ray disc prototypes in October 2000, and the first prototype player was released in April 2003 in Japan. Afterwards, it continued to be developed until its release in June 2006. During the high definition disc format war, Blu-ray Disc competed with the HD DVD format. Toshiba, the company that supported HD DVD, conceded in February 2008. According to Media Research, high-definition software sales in the US were slower in the first two years than DVD software sales, Blu-ray faces competition from video on demand and the continued sale of DVDs. As of January 2016, 44% of U. S. broadband households had a Blu-ray player, the information density of the DVD format was limited by the wavelength of the laser diodes used. Following protracted development, blue laser diodes operating at 405 nanometers became available on a production basis, Sony started two projects in collaboration with Philips applying the new diodes, UDO, and DVR Blue, a format of rewritable discs that would eventually become Blu-ray Disc. The core technologies of the formats are similar, the first DVR Blue prototypes were unveiled at the CEATEC exhibition in October 2000 by Sony. A trademark for the Blue Disc logo was filed February 9,2001, on February 19,2002, the project was officially announced as Blu-ray Disc, and Blu-ray Disc Founders was founded by the nine initial members. The first consumer device arrived in stores on April 10,2003, the Sony BDZ-S77, but there was no standard for prerecorded video, and no movies were released for this player. On October 4,2004, the name Blu-ray Disc Founders was officially changed to the Blu-ray Disc Association, the Blu-ray Disc physical specifications were completed in 2004
37.
Magnetic tape
–
Magnetic tape is a medium for magnetic recording, made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany, based on magnetic wire recording, devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders. A device that stores data on magnetic tape is a tape drive. Magnetic tape revolutionized broadcast and recording, when all radio was live, it allowed programming to be recorded. At a time when gramophone records were recorded in one take, it allowed recordings to be made in multiple parts, which were then mixed and edited with tolerable loss in quality. It was a key technology in computer development, allowing unparalleled amounts of data to be mechanically created, stored for long periods. Nowadays, other technologies can perform the functions of magnetic tape, in many cases, these technologies are replacing tape. Despite this, innovation in the technology continues, and Sony, over years, magnetic tape made in the 1970s and 1980s can suffer from a type of deterioration called sticky-shed syndrome. Caused by hydrolysis of the binder of the tape, it can render the tape unusable, the oxide side of a tape is the surface that can be magnetically manipulated by a tape head. This is the side that stores the information, the side is simply a substrate to hold the tape together. The name originates from the fact that the side of most tapes is made of an oxide of iron. Magnetic tape was invented for recording sound by Fritz Pfleumer in 1928 in Germany, based on the invention of magnetic wire recording by Oberlin Smith in 1888, pfleumers invention used a ferric oxide powder coating on a long strip of paper. This invention was developed by the German electronics company AEG, which manufactured the recording machines and BASF. In 1933, working for AEG, Eduard Schuller developed the ring-shaped tape head, previous head designs were needle-shaped and tended to shred the tape. An important discovery made in this period was the technique of AC biasing, due to the escalating political tensions, and the outbreak of World War II, these developments were largely kept secret. A wide variety of recorders and formats have developed since, most significantly reel-to-reel, the practice of recording and editing audio using magnetic tape rapidly established itself as an obvious improvement over previous methods. Many saw the potential of making the same improvements in recording television, television signals are similar to audio signals. A major difference is that video signals use more bandwidth than audio signals, existing audio tape recorders could not practically capture a video signal
38.
Generation loss
–
Generation loss is the loss of quality between subsequent copies or transcodes of data. Anything that reduces the quality of the representation when copying, and would cause further reduction in quality on making a copy of the copy, can be considered a form of generation loss. File size increases are a result of generation loss, as the introduction of artifacts may actually increase the entropy of the data through each generation. In analog systems, generation loss is due to noise and bandwidth issues in cables, amplifiers, mixers, recording equipment. Poorly adjusted distribution amplifiers and mismatched impedances can make these problems even worse, repeated conversion between analog and digital can also cause loss. Careful planning was required to minimize loss, and the resulting noise. According to ATIS, Generation loss is limited to analog recording because digital recording, used correctly, digital technology can eliminate generation loss. Copying a digital file gives a copy if the equipment is operating properly. This trait of digital technology has given rise to awareness of the risk of unauthorized copying, before digital technology was widespread, a record label, for example, could be confident knowing that unauthorized copies of their music tracks were never as good as the originals. Processing a lossily compressed file rather than an original usually results in loss of quality than generating the same output from an uncompressed original. For example, a digital image for a web page is better if generated from an uncompressed raw image than from an already-compressed JPEG file of higher quality. In digital systems, several techniques, used because of advantages, may introduce generation loss. However, copying a digital file itself incurs no generation loss--the copied file is identical to the original, some digital transforms are reversible, while some are not. Lossless compression is, by definition, fully reversible, while lossy compression throws away some data which cannot be restored, similarly, many DSP processes are not reversible. Thus careful planning of an audio or video signal chain from beginning to end, similarly, when using lossy compression, it will ideally only be done once, at the end of the workflow involving the file, after all required changes have been made. Repeated applications of lossy compression and decompression can cause generation loss, some lossy compression algorithms are much worse than others in this regard, being neither idempotent nor scalable, and introducing further degradation if parameters are changed. For example, with JPEG, changing the quality setting will cause different quantization constants to be used, causing additional loss. Further, as JPEG is divided into 16×16 blocks, cropping that does not fall on an 8×8 boundary shifts the encoding blocks and this can be avoided by the use of jpegtran or similar tools for cropping
