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Constant Angular Velocity
In optical storage, constant angular velocity (CAV) is a qualifier for the rated speed of any disc containing information, and may also be applied to the writing speed of recordable discs. A drive or disc operating in CAV mode maintains a constant angular velocity, contrasted with a constant linear velocity (CLV). A typical CD-ROM drive operates in CLV mode, in contrast to a floppy or hard disk drive, or gramophone, which operates in CAV mode. In CAV mode, the spindle motor turns at a constant speed, which makes the medium pass by the read/write head faster when the head is positioned at the outside of the disk. In contrast, in CLV mode, the spindle motor speed varies so that the medium passes by the head at the same speed regardless of where on the disk the head is positioned. If the disk is recorded at the same areal density throughout, then when read or written in CAV mode, the data rate is higher for the outer tracks than for the inner tracks (because for the same r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Disk Storage
Comparison or comparing is the act of evaluating two or more things by determining the relevant, comparable characteristics of each thing, and then determining which characteristics of each are similar to the other, which are different, and to what degree. Where characteristics are different, the differences may then be evaluated to determine which thing is best suited for a particular purpose. The description of similarities and differences found between the two things is also called a comparison. Comparison can take many distinct forms, varying by field: To compare things, they must have characteristics that are similar enough in relevant ways to merit comparison. If two things are too different to compare in a useful way, an attempt to compare them is colloquially referred to in English as "comparing apples and oranges." Comparison is widely used in society, in science and the arts. General usage Comparison is a natural activity, which even animals engage in when decidin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disk Read-and-write Head
A disk read-and-write head is the small part of a disk drive that moves above the disk platter and transforms the platter's magnetic field into electric current (reads the disk) or, vice versa, transforms electric current into magnetic field (writes the disk). The heads have gone through a number of changes over the years. In a hard drive, the heads ''fly'' above the disk surface with clearance of as little as 3 nanometres. The flying height has been decreasing with each new generation of technology to enable higher areal density. The flying height of the head is controlled by the design of an air bearing etched onto the disk-facing surface of the ''slider''. The role of the air bearing is to maintain the flying height constant as the head moves over the surface of the disk. The air bearings are carefully designed to maintain the same height across the entire platter, despite differing speeds depending on the head distance from the center of the platter. If the head hit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Storage
Sound recording and reproduction is the electrical, Mechanical system, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording. Acoustic analog recording is achieved by a microphone diaphragm that senses changes in atmospheric pressure caused by acoustics, acoustic sound waves and records them as a mechanical representation of the sound waves on a medium such as a phonograph record (in which a stylus cuts grooves on a record). In magnetic tape recording, the sound waves vibrate the microphone diaphragm and are converted into a varying electric current, which is then converted to a varying magnetic field by an electromagnet, which makes a representation of the sound as magnetized areas on a plastic tape with a magnetic coating on it. Analog sound reproduction is the reverse process, with a large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotating Disc Computer Storage Media
Rotation or rotational/rotary motion is the circular movement of an object around a central line, known as an ''axis of rotation''. A plane figure can rotate in either a clockwise or counterclockwise sense around a perpendicular axis intersecting anywhere inside or outside the figure at a ''center of rotation''. A solid figure has an infinite number of possible axes and angles of rotation, including chaotic rotation (between arbitrary orientations), in contrast to rotation around a axis. The special case of a rotation with an internal axis passing through the body's own center of mass is known as a spin (or ''autorotation''). In that case, the surface intersection of the internal ''spin axis'' can be called a ''pole''; for example, Earth's rotation defines the geographical poles. A rotation around an axis completely external to the moving body is called a revolution (or ''orbit''), e.g. Earth's orbit around the Sun. The ends of the external ''axis of revolution'' can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zone Bit Recording
In computer storage, zone bit recording (ZBR) is a method used by disk drives to optimise the tracks for increased data capacity. It does this by placing more sectors per zone on outer tracks than inner tracks. This contrasts with other approaches, such as '' constant angular velocity'' (CAV) drives, where the number of sectors per track are the same. On a disk consisting of roughly concentric tracks, whether realized as separate circular tracks or as a single spiral track, the physical track length (circumference) is increased as it gets further from the centre hub. The inner tracks are packed as densely as the particular drive's technology allows. The packing of the rest of the disks is changed depending on the type of disk. Zone recording was pioneered and patented by Chuck Peddle in 1961 while working for General Electric. With a CAV-drive the data on the outer tracks are the same angular width of those in the centre, and so less densely packed. Using ZBR instead, the inner ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DVD-RAM
DVD-RAM (DVD Random Access Memory) is a DVD-based disc specification presented in 1996 by the DVD Forum, which specifies rewritable DVD-RAM media and the appropriate DVD writers. DVD-RAM media have been used in computers as well as camcorders and personal video recorders since 1998. In May 2019, Panasonic, the only remaining manufacturer of DVD-RAM discs, announced that it would end production of DVD-RAM media by the end of that month, citing shrinking demand as the primary motivation. Panasonic made these discs under its own brand name and also under the Verbatim brand. The "RAM" in its name is related to random-access memory that computers use as main memory, not in the technology but in sense that it can be used as a random-access memory unit rather than a sequential-access memory unit such as a magnetic tape drive. Format DVD-RAM works by means of phase change technology which was chosen instead of magneto-optical technology (an already existing rewritable solutio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GD-ROM
The GD-ROM (gigabyte disc read-only memory) is a proprietary optical disc format developed as a collaboration between Sega and Yamaha for the Dreamcast and other Sega systems. Specification A double-density format based on the CD-ROM that could hold up to , it consists of a single-density track near the disc's center surrounded by a double-density track comprising much of the disc's capacity. The GD-ROM was created in response to developers exceeding the typical storage capacity of the CD-ROM; while DVD-ROM would have addressed this limitation, implementing its then-new technology would have made console production cost prohibitive. Along with the format's general novelty, the extra capacity also had the theoretical benefit of curbing video game piracy, a major concern of CD-based consoles that was validated by its rampancy on the PlayStation. Dreamcast console The Dreamcast was considered by the video game industry as one of the most secure consoles on the market with i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xbox (console)
The Xbox is a home video game console manufactured by Microsoft that is the first installment in the Xbox series of video game consoles. It was released as Microsoft's first foray into the gaming console market on November 15, 2001, in North America, followed by Australia, Europe and Japan in 2002. It is classified as a sixth-generation console, competing with Sony's PlayStation 2, Sega's Dreamcast and Nintendo's GameCube. It was also the first major console produced by an American company since the release of the Atari Jaguar in 1993. The console was announced in March 2000. With the release of the PlayStation 2, which featured the ability to playback CD-ROMs and DVDs in addition to playing games, Microsoft became concerned that game consoles would threaten the personal computer as an entertainment device for living rooms. Whereas most games consoles to that point were built from custom hardware components, the Xbox was built around standard personal computer components, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nintendo Optical Disc
Nintendo optical discs are physical media used to distribute video games on three of Nintendo's consoles that followed the Nintendo 64. These are the GameCube Game Disc, Wii Optical Disc, and Wii U Optical Disc. The physical size of a GameCube Game Disc is that of a miniDVD; Wii Optical Discs are based on DVD format, and Wii U Optical Discs are based on Blu-ray format. To maintain backward compatibility between generations of game consoles, GameCube discs are compatible with the first model of the Wii, and Wii Optical Discs are compatible with the Wii U. A burst cutting area is located at the inner ring of the disc surface. All official discs and their formats were manufactured and developed by Panasonic. In 2017, Nintendo discontinued disc-based media for physical game releases in favor of game cards for the Wii U's successor, the Nintendo Switch, although it would license several more physically released Wii and Wii U games for many more months, with the last one being a por ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Special Edition
The terms special edition, limited edition, and variants such as deluxe edition, collector's edition or expanded edition are used as a marketing incentive for various kinds of products, originally published products related to the arts, such as books, prints, recorded music and films, and video games, but now including clothing, cars, fine wine, and whisky, among other products. A limited edition is restricted in the number of copies produced, although in fact the number may be very low or very high. Suzuki (2008) defines limited edition products as those “sold in a state that makes them difficult to obtain because of companies limiting their availability to a certain period, quantity, region, or channel". A special edition implies there is extra material of some kind included. The term is frequently used on DVD film releases, often when the so-called "special" edition is actually the only version released. Collector's edition Collector's edition may just be another term for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LaserDisc
LaserDisc (LD) is a home video format and the first commercial optical disc storage medium. It was developed by Philips, Pioneer Corporation, Pioneer, and the movie studio MCA Inc., MCA. The format was initially marketed in the United States in 1978 under the name DiscoVision, a brand used by MCA. As Pioneer took a greater role in its development and promotion, the format was rebranded LaserVision. While the LaserDisc brand originally referred specifically to Pioneer's line of players, the term gradually came to be used generically to refer to the format as a whole, making it a genericized trademark. The discs typically have a diameter of , similar in size to the phonograph record. Unlike most later optical disc formats, LaserDisc is not fully Digital data, digital; it stores an analog video signal. Many titles featured Compact Disc Digital Audio, CD-quality digital audio, and LaserDisc was the first home video format to support surround sound. Its 425 to 440 horizontal lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
