MiniDisc is a magneto-optical disc-based data storage format offering a capacity of 60, 74 minutes and 80 minutes, of digitized audio or 1 gigabyte of Hi-MD data. Sony brand audio players were on the market in September 1992. Sony announced the MiniDisc in September 1992 and released it in November of that year for sale in Japan and in December in Europe, the USA and other countries; the music format was based on ATRAC audio data compression, but the option of linear PCM digital recording was introduced to meet audio quality comparable to that of a compact disc. MiniDiscs were popular in Japan and found moderate success in Europe. Sony has ceased development of MD devices, with the last of the players sold by March 2013. In 1983, just a year after the introduction of the Compact Disc, Kees Schouhamer Immink and Joseph Braat presented the first experiments with erasable magneto-optical Compact Discs during the 73rd AES Convention in Eindhoven, it took, however 10 years before their idea was commercialized.
Sony's MiniDisc was one of two rival digital systems, both introduced in 1992, that were targeted as replacements for the Philips Compact Cassette analog audio tape system: the other was Digital Compact Cassette, created by Philips and Matsushita. Sony had intended Digital Audio Tape to be the dominant home digital audio recording format, replacing the analog cassette. Due to technical delays, DAT was not launched until 1989, by the U. S. dollar had fallen so far against the yen that the introductory DAT machine Sony had intended to market for about $400 in the late 1980s now had to retail for $800 or $1000 to break putting it out of reach of most users. Relegating DAT to professional use, Sony set to work to come up with a simpler, more economical digital home format. By the time Sony came up with MiniDisc in late 1992, Philips had introduced a competing system, DCC; this created marketing confusion similar to the Betamax versus VHS battle of the late 1970s and early 1980s. Sony attempted to license MD technology to other manufacturers, with JVC, Pioneer and others all producing their own MD systems.
However, non-Sony machines were not available in North America, companies such as Technics and Radio Shack tended to promote DCC instead. Despite having a loyal customer base of musicians and audio enthusiasts, MiniDisc met with only limited success in the United States, it was popular in Japan during the 1990s, but did not enjoy comparable sales in other world markets. Since recordable CDs, flash memory and HDD and solid-state-based digital audio players such as iPods have become popular as playback devices; the initial low uptake of MiniDisc was attributed to the small number of pre-recorded albums available on MD as few record labels embraced the format. The initial high cost of equipment and blank media was a factor. Mains-powered hi-fi MiniDisc player/recorders never got into the lower price ranges, most consumers had to connect a portable machine to the hi-fi in order to record; this inconvenience contrasted with the earlier common use of cassette decks as a standard part of an ordinary hi-fi set-up.
MiniDisc technology was faced with new competition from the recordable compact disc when it became more affordable to consumers beginning around 1996. Sony believed that it would take around a decade for CD-R prices to become affordable - the cost of a typical blank CD-R disc was around $12 in 1994 - but CD-R prices fell much more than envisioned, to the point where CD-R blanks sank below $1 per disc by the late 1990s, compared to at least $2 for the cheapest 80-minute MiniDisc blanks; the biggest competition for MiniDisc came from the emergence of MP3 players. With the Diamond Rio player in 1998 and the Apple iPod, the mass market began to eschew physical media in favor of file-based systems. By 2007, because of the waning popularity of the format and the increasing popularity of solid-state MP3 players, Sony was producing only one model, the Hi-MD MZ-RH1 available as the MZ-M200 in North America packaged with a Sony microphone and limited Apple Macintosh software support; the introduction of the MZ-RH1 allowed users to move uncompressed digital recordings back and forth from the MiniDisc to a computer without the copyright protection limitations imposed upon the NetMD series.
This allowed the MiniDisc to better compete with MP3 players. However, most pro users like broadcasters and news reporters had abandoned MiniDisc in favor of solid-state recorders, due to their long recording times, open digital content sharing, high-quality digital recording capabilities and reliable, lightweight design. On 7 July 2011, Sony announced that it would no longer ship MiniDisc Walkman products as of September 2011 killing the format. On 1 February 2013, Sony issued a press release on the Nikkei stock exchange that it will cease shipment of all MD devices, with last of the players to be sold in March 2013. However, it would continue to offer repair services. MD Data, a version for storing computer data, was announced by Sony in 1993 but never gained significant ground, its media were incompatible with standard audio MiniDiscs, cited as one of the main reasons behind the format's failure. MD Data could not write to audio-MDs, only the more expensive data blanks. In 1997, MD-Data2 blanks were introduced.
They were only implemented in Sony's short-lived MD-based camcorder as well as a small number of multi-track recorders.
DVD is a digital optical disc storage format invented and developed in 1995. The medium can store any kind of digital data and is used for software and other computer files as well as video programs watched using DVD players. DVDs offer higher storage capacity than compact discs. Prerecorded 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 not written or erased. Blank recordable DVD discs can be recorded once using a DVD recorder and function as a DVD-ROM. Rewritable DVDs can be erased many times. DVDs are used in DVD-Video consumer digital video format and in DVD-Audio consumer digital audio format as well as for authoring DVD discs written in a special AVCHD format to hold high definition material. DVDs containing other types of information may be referred to as DVD data discs; the Oxford English Dictionary comments that, "In 1995 rival manufacturers of the product named digital video disc agreed that, in order to emphasize the flexibility of the format for multimedia applications, the preferred abbreviation DVD would be understood to denote digital versatile disc."
The OED states that in 1995, "The companies said the official name of the format will be DVD. Toshiba had been using the name ‘digital video disc’, but, switched to ‘digital versatile disc’ 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 Forum's 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, first came to market in Atlanta, Georgia in 1978, it used much larger discs than the formats. Due to the high cost of players and discs, consumer adoption of LaserDisc was low in both North America and Europe, was not used anywhere outside Japan and the more affluent areas of Southeast Asia, such as Hong-Kong, Singapore and Taiwan.
CD Video released in 1987 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 storage formats were being developed. One was the Multimedia Compact Disc, backed by Philips and Sony, the other was the Super Density disc, supported by Toshiba, Time Warner, Matsushita Electric, Mitsubishi Electric, Thomson, JVC. By the time of the press launches for both formats in January 1995, the MMCD nomenclature had been dropped, Philips and Sony were referring to their format as Digital Video Disc. Representatives from the SD camp asked IBM for advice on the file system to use for their disc, sought support for their format for storing computer data. Alan E. Bell, a researcher from IBM's Almaden Research Center, got that request, learned of the MMCD development project. Wary of being caught in a repeat of the costly videotape format war between VHS and Betamax in the 1980s, he convened a group of computer industry experts, including representatives from Apple, Sun Microsystems and many others.
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 press release stating that they would only accept a single format; the TWG voted to boycott both formats unless the two camps agreed on a converged standard. They recruited president of IBM, to pressure the executives of the warring factions. In one significant compromise, the MMCD and SD groups agreed to adopt proposal SD 9, which specified that both layers of the dual-layered disc be read from the same side—instead of proposal SD 10, which would have created a two-sided disc that users would have to turn over; 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. The DVD specification ended up similar to Toshiba and Matsushita's Super Density Disc, except for the dual-layer option and EFMPlus modulation designed by Kees Schouhamer Immink.
Philips and Sony decided that it was in their best interests to end the format war, agreed to unify with companies backing the Super Density Disc to release a single format, with technologies from both. After other compromises between MMCD and SD, the computer companies through TWG won the day, a single format was agreed upon; the TWG collaborated with the Optical Storage Technology Association on the use of their implementation of the ISO-13346 file system for use on the new DVDs. Movie and home entertainment distributors adopted the DVD format to replace the ubiquitous VHS tape as the primary consumer digital video distribution format, they embraced DVD as it produced higher quality video and sound, provided superior data lifespan, could be interactive. Interactivity on LaserDiscs had proven desirable to consumers collectors; when LaserDisc prices dropped from $100 per
CD-R is a digital optical disc storage format. A CD-R disc is a compact disc that can read arbitrarily many times. CD-R discs are readable by most plain CD readers, i.e. CD readers manufactured prior to the introduction of CD-R; this is an advantage over CD-RW, which can be re-written but cannot be played on many plain CD readers. Named CD Write-Once, the CD-R specification was first published in 1988 by Philips and Sony in the'Orange Book'; the Orange Book consists of several parts, furnishing details of the CD-WO, CD-MO, CD-RW. The latest editions have abandoned the use of the term "CD-WO" in favor of "CD-R", while "CD-MO" were used little. Written CD-Rs and CD-RWs are, in the aspect of low-level encoding and data format compatible with the audio CD and data CD standards; this means they use Eight-to-Fourteen Modulation, CIRC error correction, for CD-ROM, the third error correction layer defined in the Yellow Book. Properly written CD-R discs on blanks of less than 93 minutes length are compatible with the audio CD and CD-ROM standards in all details including physical specifications.
93 minute CD-R discs marginally violate the Red Book physical format specifications, longer discs are noncompliant. 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 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. CD-R recording systems available in 1990 were similar to the washing machine-sized Meridian CD Publisher, based on the two-piece rack mount Yamaha PDS audio recorder costing $35,000, not including the required external ECC circuitry for data encoding, SCSI hard drive subsystem, MS-DOS control computer. By 1992, the cost of typical recorders was down to $10,000–12,000, in September 1995, Hewlett-Packard introduced its model 4020i manufactured by Philips, which, at $995, was the first recorder to cost less than $1000.
The dye materials developed by Taiyo Yuden made it possible for CD-R discs to be compatible with Audio CD and CD-ROM discs. In the United States, there was a market separation between "music" CD-Rs and "data" CD-Rs, the former being several times more expensive than the latter due to industry copyright arrangements with the RIAA. Physically, there is no difference between the discs save for the Disc Application Flag that identifies their type: standalone audio recorders will only accept "music" CD-Rs to enforce the RIAA arrangement, while computer CD-R drives can use either type of media to burn either type of content. A standard CD-R is a 1.93 mm thick disc made of polycarbonate about 120 mm in diameter. The 120 mm disc has a storage capacity of 650 Megabytes of data. CD-R/RWs are available with capacities of 93 minutes of audio or 737,280,000 bytes, which they achieve by molding the disc at the tightest allowable tolerances specified in the Orange Book CD-R/CD-RW standards; the engineering margin, reserved for manufacturing tolerance has been used for data capacity instead, leaving no tolerance for manufacturing.
Despite the foregoing, most CD-Rs on the market have a 93-minute capacity. There are 97 minute/860 MiB and 99 minute/870 MiB discs, although they are less common. Due to the limitations of the data structures in the ATIP, 97 and 99 minute blanks will identify as 93 minute ones. Therefore, in order to use the additional capacity, these discs have to be burned using "overburn" options in the CD recording software; some drives use special techniques, such as Plextor's GigaRec or Sanyo's HD-BURN, to write more data onto a given disc. However, in certain applications where discs will not be distributed or exchanged outside a private group and will not be archived for a long time, a proprietary format may be an acceptable way to obtain greater capacity; the greatest risk in using such a proprietary data storage format, assuming that it works reliably as designed, is that it may be difficult or impossible to repair or replace the hardware used to read the media if it fails, is damaged, or is lost after its original vendor discontinues it.
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 standards do require discs to mee
Photo CD is a system designed by Kodak for digitizing and saving photos onto a CD. Launched in 1992, the discs were designed to hold nearly 100 high quality images, scanned prints and slides using special proprietary encoding. Photo CDs are defined in the Beige Book and conform to the CD-ROM XA and CD-i Bridge specifications as well, they were intended to play on CD-i players, Photo CD players, any computer with a suitable software. The system failed to gain mass usage among consumers due to its proprietary nature, the decreasing scanner prices, the lack of CD-ROM drives in most home personal computers of the day. Furthermore, Photo CD relied on CRT-based TV sets for home use. However, these were designed for moving pictures, their typical flicker became an issue. The Photo CD system gained a fair level of acceptance among professional photographers due to the low cost of the high quality film scans. Prior to Photo CD, professionals who wished to digitize their film images were forced to pay much higher fees to obtain drum scans of their film negatives and transparencies.
The Kodak Pro Photo CD Master Disc contains 25 images with maximum resolution of 6144 x 4096 pixels. This type is appropriate for 120 film, 4x5, but for small picture film, if highest resolution is required. Separate from the Photo CD format is Kodak's proprietary "Portfolio CD" format, which combines Red Book CD audio and Beige Book PCD with interactive menus and hotspots on PCD images; some standalone Philips Photo/Audio CD players could play Portfolio CDs, Windows player application was available. The Kodak Portfolio CD is not defined in any particular Rainbow Book; the Photo CD system was announced by Kodak in 1990. Photo CD targeted a full range of photographic needs, ranging from consumer level point-and-shoot cameras to high-end professionals using large format 4x5 sheet film; the first Photo CD products, including scanners for processing labs and Photo CD players for consumers, became available in 1992. The project was expected to be a $600 million business by 1997 with $100 million in operational earnings.
Kodak entered into a number of partnerships grow the usage of Photo CD. This included, for example, an arrangement with L. L. Bean in 1992 by which the catalog would be distributed in Photo CD format, an arrangement with Silicon Graphics in 1993 to make all Silicon Graphics image-processing workstations capable of accepting Kodak Photo CD optical disks; these measures, together with the relatively low cost of $3 per image and convenience, made Photo CD the digital imaging solution of choice for many photographers in the mid to late 1990s. By 2000, over 140 Photo CD processing labs in the U. S. were active, with many more outside the U. S. However, by the late 1990s, Photo CD was being eclipsed by alternate formats based on the industry standard JPEG format. In the consumer segment, the Photo CD format's inefficient compression scheme meant that Photo CD files were larger than a JPEG files of similar quality, thus less convenient for transmission across the internet, etc. For example, a 16Base Photo CD image of 5.5 Mb can be encoded as a JPEG image of 2.1 Mb at 80% quality, visually indistinguishable from the original.
When the Photo CD format was designed in the early 1990s, a design goal was to allow low cost playback-to-TV devices. At that time the available technology precluded 2-dimensional compression schemes such as JPEG, but by the late 1990s, advances in microprocessor technology had moved JPEG/PNG compression to well within the range of very low cost consumer electronics. In the professional and advanced amateur segments, Photo CD had been eclipsed by low cost desktop scanners such as those from Nikon and Minolta in the mid range, by drum scanners at the high end. While the pixel resolution of Photo CD was still comparable or better than the alternatives, Photo CD suffered from a number of other disadvantages. Firstly, the Photo CD color space, designed for TV display, is smaller than what can be achieved by a low cost desktop scanner. Secondly, the color rendition of Photo CD images changed over time and with different scanner versions. Thirdly, the dynamic range of scans was lower than for desktop scanners.
Tests at the time indicated that the dmax rating of Photo CD was 2.8-3.0, while available desktop scanners were reaching 4.2, a substantial difference. As a result of this, Photo CD's problems with color rendering, by 2004 the professional segment of the user community had turned against Photo CD. In the retail segment, while Photo CD was relatively popular with consumers, it was an economic failure for processing labs. At the time of its introduction, Kodak claimed that processing costs to labs would be close to $1 per image, which would allow the lab profitably sell at the $3 per image mark; however this promise was never realized resulting in the scanning process being rushed, with a resulting fall in quality. As a result of Photo CD's loss of market share and substantial corporate losses attributed by Kodak Management to its scanning business, Kodak abandoned the format over the period 2001-2004. By 2004, Kodak 4050 Photo CD scanners were being offered for free to anyone that would pay for their removal by more than one processing lab.
This abandonment generated considerable controversy both at the time and subsequently as the Photo CD format's technical specifications have never been released by Kodak. Photo CD remains an quoted example of an “orphan format” and o
GD-ROM is a proprietary optical disc format used for the Dreamcast video game console, as well as its arcade counterpart, the Sega NAOMI and select Triforce arcade board titles. Developed by Yamaha, Sega intended to use the format to curb piracy common to standard compact discs and to offer increased storage capacity, it is similar to the standard CD-ROM except that the pits on the disc are packed more together, resulting in a higher storage capacity of 1 gigabyte, a 42% increase over a conventional CD's capacity of 700 megabytes. The Dreamcast ended up being the only sixth-generation console with a disc based on CD technology rather than DVD technology. In addition, it proved to be an ineffective anti-piracy measure when it was discovered the Dreamcast's forgotten Mil-CD functionality could be exploited to boot full games burned to CD. After the discontinuation of the Dreamcast worldwide on March 31, 2001, Sega continued to use the GD-ROM format in arcades with the Sega NAOMI 2, Triforce and Sega Chihiro.
With the release of the Sega Lindbergh in 2005, Sega moved on to DVD discs and continued to use satellite and internet technology in the arcade. The last disc-based Naomi 2 and Triforce games were released in 2006 and nothing has been released in the GD-ROM format in the following years; the format was developed for Sega by Yamaha, first commercially appeared with the Dreamcast's Japanese launch in November 1998. GD-ROM was created because the standard CD-ROM was prone to piracy and reaching the limits of its storage capacity, while implementing the brand-new DVD-ROM technology would have made console production too costly. In addition, the Dreamcast did retain the ability to read standard CD-ROM discs, thus still suffered from software piracy as bootleggers managed to fit certain games on CDs and exploit the Dreamcast console's compatibility with the MIL-CD format. Before the Dreamcast was released, Sega "confirmed that Dreamcast owners will one day be able to upgrade the GD-ROM drive to DVD," as information indicated Sony's upcoming PlayStation 2 would use the DVD format with its much larger capacity 4.7 GB single-layered up to 8.5 GB double-layered discs compared to the 1 GB capacity of the GD-ROM.
Despite displaying a Dreamcast DVD display unit at E3 2000, the plans for a DVD add-on or separate unit never materialized during the short production run of the Dreamcast. GD-ROM was made available as an upgrade for the Dreamcast's arcade cousin, Sega NAOMI and the Sega NAOMI 2, providing alternate media to its cartridge-based software, it is used as an option on both the Sega Chihiro and Triforce. There are three data areas on a GD-ROM disc; the first is in conventional CD format, contains an audio track with a warning that the disc is for use on a Dreamcast, can damage CD players. These vary by region; the CD section contains a data segment, only readable in PCs. Although most discs include only text files identifying the game, its copyright and bibliography, some contain bonus material for home computer users. There follows a separator track which contains no data except for the text Produced by or under license from Sega Enterprises LTD Trademark Sega; the final section of the disc contains the game data itself in a higher density format.
This section is 112 minutes long, with a data size of 1.0 GB. A normal CD-reader will not read beyond the first track because, according to the CD table of contents, there is no data there. With modified firmware on a few optical drive models that looks for a second TOC in the high-density region it is possible to read data from the high-density region. One can utilize a "swap-trick" by first letting the CD-reader read the TOC from an audio CD with a special 99 minute TOC and swapping that disc with a GD-ROM in a way that avoids alerting the CD-reader that a new disc has been inserted, it is possible to read as much data from the high-density region as indicated by the TOC from the first disc. The most popular way to access data from GD-ROMs, however, is to use the Dreamcast itself as a drive, copy the data to a computer by means of a "coder's cable" or a Dreamcast Broadband Adapter. Another alternative is modding the Dreamcast to add a USB connector. Sega has discontinued production of GD-ROM media.
The first section contains a message informing users that the disc can damage AV equipment. Different discs varying by region, contain different messages. NTSC-U discs contain this message: "Warning! This disc is only for use on Sega Dreamcast." Or this message: "This is a Dreamcast game disc, the first track contains game data, please do not play it on a normal CD Player." Some discs contain humorous messages from the game's characters. This is common on Japanese NTSC-J discs. PAL region discs contain this message: "This is a Dreamcast disc and is for use only on a Dreamcast unit. Playing this disc on a Hi-Fi or other audio equipment can cause serious damage to its speakers. Please stop this disc now." The message is repeated in French, German and Italian. Some PAL region games however; the GD-ROM in the Dreamcast works in constant angular velocity mode, like the majority of modern optical drives. Old CD-ROM drives r
In computing and optical disc recording technologies, an optical disc is a flat circular disc which encodes binary data in the form of pits and lands on a special material on one of its flat surfaces. The encoding material sits atop a thicker substrate which 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 is stored on the disc with a laser or stamping machine, can be accessed when the data path is illuminated with a laser diode in an optical disc drive which spins the disc at speeds of about 200 to 4,000 RPM or more, depending on the drive type, disc format, the distance of the read head from the center of the disc. Most optical discs exhibit a characteristic iridescence as a result of the diffraction grating formed by its grooves; this side of the disc contains the actual data and is coated with a transparent material lacquer.
The reverse side of an optical disc has a printed label, sometimes made of paper but printed or stamped onto the disc itself. Unlike the 3½-inch floppy disk, most optical discs do not have an integrated protective casing and are therefore susceptible to data transfer problems due to scratches and other environmental problems. Optical discs are between 7.6 and 30 cm in diameter, with 12 cm being the most common size. A typical disc is about 1.2 mm thick. An optical disc is designed to support one of three recording types: read-only, recordable, or re-recordable. Write-once optical discs have an organic dye recording layer between the substrate and the reflective layer. Rewritable discs contain an alloy recording layer composed of a phase change material, most AgInSbTe, an alloy of silver, indium and tellurium. Optical discs are most used for storing music, video, or data and programs for personal computers; the Optical Storage Technology Association promotes standardized optical storage formats.
Although optical discs are more durable than earlier audio-visual and data storage formats, they are susceptible to environmental and daily-use damage. Libraries and archives enact optical media preservation procedures to ensure continued usability in the computer's optical disc drive or corresponding disc player. For computer data backup and physical data transfer, optical discs such as CDs and DVDs are being replaced with faster, smaller solid-state devices the USB flash drive; this trend is expected to continue as USB flash drives continue to increase in capacity and drop in price. Additionally, music purchased or shared over the Internet has reduced the number of audio CDs sold annually; the first recorded historical use of an optical disc was in 1884 when Alexander Graham Bell, Chichester Bell and Charles Sumner Tainter recorded sound on a glass disc using a beam of light. An early optical disc system existed in 1935, named Lichttonorgel. An early analog optical disc used for video recording was invented by David Paul Gregg in 1958 and patented in the US in 1961 and 1969.
This form of optical disc was a early form of the DVD. It is of special interest that U. S. Patent 4,893,297, filed 1989, issued 1990, generated royalty income for Pioneer Corporation's DVA until 2007 —then encompassing the CD, DVD, Blu-ray systems. In the early 1960s, the Music Corporation of America bought Gregg's patents and his company, Gauss Electrophysics. American inventor James T. Russell has been credited with inventing the first system to record a digital signal on an optical transparent foil, lit from behind by a high-power halogen lamp. Russell's patent application was first filed in 1966 and he was granted a patent in 1970. Following litigation and Philips licensed Russell's patents in the 1980s. Both Gregg's and Russell's disc are floppy media read in transparent mode, which imposes serious drawbacks. In the Netherlands in 1969, Philips Research physicist, Pieter Kramer invented an optical videodisc in reflective mode with a protective layer read by a focused laser beam U. S. Patent 5,068,846, filed 1972, issued 1991.
Kramer's physical format is used in all optical discs. In 1975, Philips and MCA began to work together, in 1978, commercially much too late, they presented their long-awaited Laserdisc in Atlanta. MCA delivered the Philips the players. However, the presentation was a commercial failure, the cooperation ended. In Japan and the U. S. Pioneer succeeded with the videodisc until the advent of the DVD. In 1979, Philips and Sony, in consortium developed the audio compact disc. In 1979, Exxon STAR Systems in Pasadena, CA built a computer controlled WORM drive that utilized thin film coatings of Tellurium and Selenium on a 12" diameter glass disk; the recording system utilized blue light at red light at 632.8 nm to read. STAR Systems was bought by Storage Technology Corporation in 1981 and moved to Boulder, CO. Development of the WORM technology was continued using 14" diameter aluminum substrates. Beta testing of the disk drives labeled the Laser
Universal Media Disc
The Universal Media Disc is a discontinued optical disc medium developed by Sony for use on their PlayStation Portable handheld gaming and multimedia platform. It can hold up to 1.8 gigabytes of data and is capable of housing video games, feature-length films, music. UMD was the trademark of Sony Computer Entertainment for their optical disk cartridge. While the primary application for UMD discs is as a storage medium for PSP games, the format is used for the storage of motion pictures and, to a lesser degree, television shows for playback on the PSP; the video is encoded with the audio in ATRAC3plus. Video stored on UMD is encoded in 720×480 resolution, but is scaled down when displayed on the PSP; the American punk rock band The Offspring released their Complete Music Video Collection on the format. The BBC released a number of its programmes on UMD in the UK, including The Office, The Mighty Boosh, Doctor Who and Little Britain; some adult films have been released on UMD in Japan. UMD VIDEO Case dimensions: H×W×D = 177×104×14mm ECMA-365: Data Interchange on 60 mm Read-Only ODC – Capacity: 1.8 GB Dimensions: approx.
64 mm × 4.2 mm Maximum capacity: 1.80 GB, 900 MB Laser wavelength: 660 nm Numerical aperture: 0.64 Track pitch: 0.70 µm Minimum pit length: 0.1384 µm Modulation: 8-to-16 RLL Encryption: AES 128-bit According to the official ECMA specification Sony designed the UMD to support two possible future enhancements and products. Protective Shutter: Similar to the MiniDisc and 3½-inch floppy disk, this protective shutter will shield the inner disc from accidental contact. Auto-Loading: UMDs were designed for possible future slot loading devices with Auto-Loading mechanisms; these would be similar to the auto-loading mechanism used in slot loading MiniDisc home and car decks. It would be similar to the Sony U-Matic auto-loading mechanism. Unlike the current clamshell loading design the PSP uses, a slot loading device using an Auto-Loading mechanism would be motorized and automatic; the user would insert the disc into the device slot, the motorized mechanism would take over and draw the disc inside the drive completing the loading process.
The disc would be ejected automatically by the motorized mechanism, like a VCR. This would mean that power would be required in order to insert or eject a disc. In comparison to Sony's MiniDisc format the sliding shield which prevents direct disc contact on MiniDiscs is absent from all UMDs released, though it is an option according to the ECMA specification. DVD region coding has been applied to music; however regional lockout is not applied to games, making them region-free Region 0: Worldwide Region 1: Northern America + Central America Region 2: Northern Europe + Western Europe + Southern Europe + Japan + Middle East + Egypt + South Africa + Greenland + French territories + British territories Region 3: Thailand + Singapore + Malaysia + Taiwan + South Korea + Philippines + Indonesia + Hong Kong Region 4: Oceania + South America Region 5: Russia + Eastern Europe + India + Pakistan + Africa + North Korea + Mongolia Region 6: Mainland China UMDs offer large capacity and the capability to store quality audio/video content.
The UMD format never saw implementation on any device other than the PlayStation Portable, as a result the market was limited compared to those for other optical media formats. Buyers were put off by the high price of UMD releases, which retailed at comparable prices to but lacked the extra content found on DVDs. Poor sales of UMD movies early in the format's life had caused major studios Universal and Paramount to rescind their support. Retail support of the format experienced similar troubles, in 2006 Wal-Mart began phasing out shelf space devoted to UMD movies, with other chains soon following suit. By 2006 most non-specialty retail stores had stopped bringing in new UMD movies and no longer had a separate section devoted to them, with a few stray unsold titles mixed in amongst the regular PSP games. Since 2011, there have been no more movies released on UMD.. In August 2007, Multimedia Recovery brought to the market their UMD Replacement Case after many complaints from PlayStation Portable owners that the outer casing of the UMD disc was cracking or pulling apart due to the poor design, which causes the UMD to become unreadable in the PlayStation Portable.
In late 2009, Sony began pushing developers away from the UMD format and towards digital distribution on the PlayStation Network in preparation for the launch of the digital-download-only PSP Go, the first PSP model to not include a UMD drive. However the system experienced lackluster sales compared to previous models, with most consumers still choosing the UMD-compatible PSP-3000 model, which continued to be sold alongside the PSP Go. Despite the earlier push for PlayStation Network releases around the PSP Go's launch, over half of the PSP's library is still only available in UMD format including Crisis Core: Final Fantasy VII and Kingdom Hearts Birth by Sleep, though there have been a few PlayStation Network-only releases since the PSP Go's launch, such as LocoRoco Midnight Carnival. Still, most new games continue to be distributed via UMD, aside from those published by SCE, not all have been released on PlayStation Network. In 2011, the PSP-E1000, a budget PSP model with a UMD slot but without Wi-Fi, was released, is the final revision of the PlayStation Portable.
The successor of the PlayStation Portable, the PlayStation Vita