Optical Data Storage
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Optical Data Storage
IBM defines optical storage as "any storage method that uses a laser to store and retrieve data from optical media." '' Britannica'' notes that it "uses low-power laser beams to record and retrieve digital (binary) data." Compact disc (CD) and DVD are examples of ''optical media''. Overview Optical storage is the storage of data on an optically readable medium. Data is recorded by making marks in a pattern that can be read back with the aid of light, usually a beam of laser light precisely focused on a spinning optical disc. An older example of optical storage that does not require the use of computers, is microform. There are other means of optically storing data and new methods are in development. An optical disc drive is a device in a computer that can read CD-ROMs or other optical discs, such as DVDs and Blu-ray discs. Optical storage differs from other data storage techniques that make use of other technologies such as magnetism, such as floppy disks and hard disks, or s ...
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Hard Disk
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnetic material. 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 random-access manner, meaning that individual blocks of data can be stored and retrieved in any order. HDDs are a type of non-volatile storage, retaining stored data when powered off. Modern HDDs are typically in the form of a small rectangular box. Introduced by IBM in 1956, HDDs were the dominant secondary storage device for general-purpose computers beginning in the early 1960s. HDDs maintained this position into the modern era of servers and personal computers, though personal computing devices produced in large volume, like cell phones and tablets, rely on ...
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Optical Storage Technology Association
The Optical Storage Technology Association (OSTA) was an international trade association formed to promote the use of recordable optical data storage IBM defines optical storage as "any storage method that uses a laser to store and retrieve data from optical media." '' Britannica'' notes that it "uses low-power laser beams to record and retrieve digital (binary) data." Compact disc (CD) an ... technologies and products. It was responsible for the creation and maintenance of the Universal Disk Format (UDF) file system specification (derived from ISO/IEC 13346 and ECMA-167), which was notably adopted for DVD-Video. It was incorporated in California in 1992 and dissolved in 2018. In the autumn of 2007, OSTA spearheaded a campaign to encourage families and photographers to back up their digital photographs on compact discs. External links OSTA*Understanding Recordable & Rewritable DVD**Running Optimum Power Control: Data Integrity in CD-Recording Technology trade associatio ...
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Optical Disc
In computing and optical disc recording technologies, an optical disc (OD) is a flat, usually circular disc that encodes binary data (bits) in the form of pits and lands on a special material, often aluminum, on one of its flat surfaces. Its main uses are physical offline data distribution and long-term archival. Changes from pit to land or from land to pit correspond to a binary value of 1; while no change, regardless of whether in a land or a pit area, corresponds to a binary value of 0. Non-circular optical discs exist for fashion purposes; see shaped compact disc. Design and technology The encoding material sits atop a thicker substrate (usually polycarbonate) that makes up the bulk of the disc and forms a dust defocusing layer. The encoding pattern follows a continuous, spiral path covering the entire disc surface and extending from the innermost track to the outermost track. The data are stored on the disc with a laser or stamping machine, and can be accesse ...
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LaserDisc
The LaserDisc (LD) is a home video format and the first commercial optical disc storage medium, initially licensed, sold and marketed as DiscoVision, MCA DiscoVision (also known simply as "DiscoVision") in the United States in 1978. Its diameter typically spans . Unlike most optical disc standards, LaserDisc is not fully Digital data, digital, and instead requires the use of analog video signals. Although the format was capable of offering higher-quality video and audio than its consumer rivals—VHS and Betamax videotape—LaserDisc never managed to gain widespread use in North America, largely due to high costs for the players and the inability to record TV programmes. It eventually did gain some traction in that region and became somewhat popular in the 1990s. It was not a popular format in Europe and Australia. By contrast, the format was much more popular in Japan and in the more affluent regions of Southeast Asia, such as Hong Kong, Singapore and Malaysia, and was the ...
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The New York Times
''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid digital subscribers. It also is a producer of popular podcasts such as '' The Daily''. Founded in 1851 by Henry Jarvis Raymond and George Jones, it was initially published by Raymond, Jones & Company. The ''Times'' has won 132 Pulitzer Prizes, the most of any newspaper, and has long been regarded as a national " newspaper of record". For print it is ranked 18th in the world by circulation and 3rd in the U.S. The paper is owned by the New York Times Company, which is publicly traded. It has been governed by the Sulzberger family since 1896, through a dual-class share structure after its shares became publicly traded. A. G. Sulzberger, the paper's publisher and the company's chairman, is the fifth generation of the family to head the pa ...
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Format War
A format war is a competition between similar but mutually incompatible technical standards that compete for the same market, such as for data storage devices and recording formats for electronic media. It is often characterized by political and financial influence on content publishers by the developers of the technologies. Developing companies may be characterized as engaging in a format war if they actively oppose or avoid interoperable open-industry technical standards in favor of their own. A format war emergence can be explained because each vendor is trying to exploit cross-side network effects in a two-sided market. There is also a social force to stop a format war: when one of them wins as ''de facto'' standard, it solves a coordination problemEdna Ullmann-Margalit: ''The Emergence of Norms'', Oxford Un. Press, 1977. (or Clarendon Press 1978) for the format users. 1800s * Rail gauge. The Gauge War in Britain pitted the Great Western Railway, which used broad gauge, ag ...
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Megabyte
The megabyte is a multiple of the unit byte for digital information. Its recommended unit symbol is MB. The unit prefix ''mega'' is a multiplier of (106) in the International System of Units (SI). Therefore, one megabyte is one million bytes of information. This definition has been incorporated into the International System of Quantities. In the computer and information technology fields, other definitions have been used that arose for historical reasons of convenience. A common usage has been to designate one megabyte as (220 B), a quantity that conveniently expresses the binary architecture of digital computer memory. The standards bodies have deprecated this usage of the megabyte in favor of a new set of binary prefixes, in which this quantity is designated by the unit mebibyte (MiB). Definitions The unit megabyte is commonly used for 10002 (one million) bytes or 10242 bytes. The interpretation of using base 1024 originated as technical jargon for the byte SI prefix, mult ...
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Compact Discs
The compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then released in October 1982 in Japan and branded as '' Digital Audio Compact Disc''. The format was later adapted (as CD-ROM) for general-purpose data storage. Several other formats were further derived, including write-once audio and data storage (CD-R), rewritable media (CD-RW), Video CD (VCD), Super Video CD (SVCD), Photo CD, Picture CD, Compact Disc-Interactive (CD-i) and Enhanced Music CD. Standard CDs have a diameter of and are designed to hold up to 74 minutes of uncompressed stereo digital audio or about 650  MiB of data. Capacity is routinely extended to 80 minutes and 700  MiB by arranging data more closely on the same sized disc. The Mini CD has various diameters ranging from ; they are sometimes used for CD singles, storing up to 24 min ...
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Optical Jukebox
An optical jukebox is a robotic data storage device that can automatically load and unload optical discs, such as Compact Disc, DVD, Ultra Density Optical or Blu-ray and can provide terabytes (TB) or petabytes (PB) of tertiary storage. The devices are often called optical disk libraries, "optical storage archives", robotic drives, or autochangers. Jukebox devices may have up to 2,000 slots for disks, and usually have a picking device that traverses the slots and drives. Zerras Inc. provides a removeable capsule that holds up to 200 discs per library which can be scaled-out to manage 1600 discs per 42U rack unit. The arrangement of the slots and picking devices affects performance and maintenance costs, depending on the robotics design, the space between a disk and the picking device. Seek times and transfer rates vary depending upon the optical technology used. History and function One of the first examples of an optical jukebox was the unit designed and built at the Royal Ae ...
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Environmentalism
Environmentalism or environmental rights is a broad philosophy, ideology, and social movement regarding concerns for environmental protection and improvement of the health of the environment, particularly as the measure for this health seeks to incorporate the impact of changes to the environment on humans, animals, plants and non-living matter. While environmentalism focuses more on the environmental and nature-related aspects of green ideology and politics, ecologism combines the ideology of social ecology and environmentalism. ''Ecologism'' is more commonly used in continental European languages, while ''environmentalism'' is more commonly used in English but the words have slightly different connotations. Environmentalism advocates the preservation, restoration and improvement of the natural environment and critical earth system elements or processes such as the climate, and may be referred to as a movement to control pollution or protect plant and animal diversity. Fo ...
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Digital Audio
Digital audio is a representation of sound recorded in, or converted into, digital form. In digital audio, the sound wave of the audio signal is typically encoded as numerical samples in a continuous sequence. For example, in CD audio, samples are taken 44,100 times per second, each with 16-bit sample depth. Digital audio is also the name for the entire technology of sound recording and reproduction using audio signals that have been encoded in digital form. Following significant advances in digital audio technology during the 1970s and 1980s, it gradually replaced analog audio technology in many areas of audio engineering, record production and telecommunications in the 1990s and 2000s In a digital audio system, an analog electrical signal representing the sound is converted with an analog-to-digital converter (ADC) into a digital signal, typically using pulse-code modulation (PCM). This digital signal can then be recorded, edited, modified, and copied using computer ...
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