Media type | Optical disk |
---|---|
Encoding | Digital signal |
Usage | Data storage |
Extended to | DVD-RAM |
Phase-change Dual (or Phase-change Disc) is a rewritable optical disc and a standard for it, developed by Matsushita Electric Industrial Co., Ltd. in April 1995.
It has a capacity of 650 MB on one side, and the size of the disc is 12 cm in diameter (5 inches) similar to a general CD or DVD, and it is used in a state where it is housed in a square cartridge. The phase change recording technology using red laser light is adopted, and about 500,000 times of rewriting is possible.
The built-in PD drive and the external type are sold, respectively, and both of them can read the CD-ROM. Both drive and media, most of which are manufactured by Matsushita Electric Appliances only, the company also released a notebook PC with a 650 MB auxiliary storage device and a 4× CD-ROM drive, a PRONOTE PD (August 1996).
CD-RW can be cited as a re-writable medium at the same time, but it is characterized by being able to write and delete on a file basis, which is close to the feeling of handling CD-RW and floppy disk using packet write system. Also, due to the characteristics contained in the cartridge, it does not touch the recording surface directly, so it is resistant to dust and scratches and is relatively reliable. CD-R and CD-RW were not so popular at the time, and there were instabilities such as many write failures. Although the writing speed of PD is not fast, it is about to be faster than writing to floppy, but at the time of sale, it was not a speed that made it so difficult.
Meanwhile, MO, ZIP drive, SyQuest, etc. existed as re-writable media close to the feeling of handling floppy disks, but the advantage that the PD drive can be read by the CD-ROM was merit compared with those. At that time the CD-ROM drive was becoming an essential peripheral device, but it was not necessarily built in every PC yet, desktop machines that were mainstream at that time had many models with only one drive bay. In such an environment, a PD capable of serving as both a CD-ROM drive and a large capacity (then) auxiliary storage device was advantageous both in terms of cost and installation.
DVD-RAM appeared as a successor technology in April 1997, DVD-RAM adopts a cartridge similar to PD, and the 2.6 GB version 1.0 standard, which has just one side capacity equal to 4 times the PD, DVD - It was possible to read and write PD in the RAM drive. However, in the summer of 2000, compatibility with PD was not taken into consideration when creating DVD-RAM version 2.0, which has the same with 4.7 GB standard capacity as other DVDs. At this point PD drives and media effectively disappeared from the market.
Computer data storage or digital data storage is a technology consisting of computer components and recording media that are used to retain digital data. It is a core function and fundamental component of computers.
An optical disc is a flat, usually disc-shaped object that stores information in the form of physical variations on its surface that can be read with the aid of a beam of light. Optical discs can be reflective, where the light source and detector are on the same side of the disc, or transmissive, where light shines through the disc to be detected on the other side.
Universal Disk Format (UDF) is an open, vendor-neutral file system for computer data storage for a broad range of media. In practice, it has been most widely used for DVDs and newer optical disc formats, supplanting ISO 9660. Due to its design, it is very well suited to incremental updates on both write-once and re-writable optical media. UDF was developed and maintained by the Optical Storage Technology Association (OSTA).
The Zip drive is a removable floppy disk storage system that was announced by Iomega in 1994 and began shipping in March 1995. Considered medium-to-high-capacity at the time of its release, Zip disks were originally launched with capacities of 100 MB, then 250 MB, and finally 750 MB.
In computing, an optical disc drive (ODD) is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only read from certain discs, while other drives can both read and record. Those drives are called burners or writers since they physically burn the data onto on the discs. Compact discs, DVDs, and Blu-ray discs are common types of optical media which can be read and recorded by such drives.
SuperDrive is the product name for a floppy disk drive and later an optical disc drive made and marketed by Apple Inc. The name was initially used for what Apple called their high-density floppy disk drive, and later for the internal CD and DVD drive integrated with Apple computers. Though Apple no longer manufactures computers that feature built-in SuperDrives, the name is still used when referring to Apple's external CD and DVD drive accessory (pictured).
A magneto-optical drive is a kind of optical disc drive capable of writing and rewriting data upon a magneto-optical disc. 130 mm (5.25 in) and 90 mm (3.5 in) discs are the most common sizes.
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The Jaz drive is a removable hard disk storage system sold by the Iomega company from 1995 to 2002.
The Holographic Versatile Disc (HVD) is an optical disc technology that was expected to store up to several terabytes of data on an optical disc 10 cm or 12 cm in diameter. Its development commenced in April 2004, but it never arrived due to lack of funding. The company responsible for HVD went bankrupt in 2010.
The double-density compact disc (DDCD) is an optical disc technology developed by Sony and Philips using the same 780 nm laser wavelength as a compact disc. The format was announced in July 2000 and is defined by the Purple Book standard document. Unlike the compact-disc technology it is based on, DDCD was designed exclusively for data, with no audio capabilities.
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DVD recordable and DVD rewritable are a collection of optical disc formats that can be written to by a DVD recorder and by computers using a DVD writer. The "recordable" discs are write-once read-many (WORM) media, where as "rewritable" discs are able to be erased and rewritten. Data is written ('burned') to the disc by a laser, rather than the data being 'pressed' onto the disc during manufacture, like a DVD-ROM. Pressing is used in mass production, primarily for the distribution of home video.
Optical disc authoring requires a number of different optical disc recorder technologies working in tandem, from the optical disc media to the firmware to the control electronics of the optical disc drive.
Ultra Density Optical (UDO) is an optical disc format designed for high-density storage of high-definition video and data. The format was introduced by Sony to replace the Magneto-optical disc format.
A compressed audio optical disc, MP3 CD, or MP3 CD-ROM or MP3 DVD is an optical disc that contains digital audio in the MP3 file format. Discs are written in the "Yellow Book" standard data format, as opposed to the Red Book standard audio format.
As of 2021, multiple consumer-oriented, optical-disk media formats are or were available:
A CD-ROM is a type of read-only memory consisting of a pre-pressed optical compact disc that contains data computers can read, but not write or erase. 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.