Search results
Results from the WOW.Com Content Network
MD Data disks can be fully read-only, fully rewritable, or be a hybrid of the two, with a portion of a disk being read-only and while another is rewritable. With 140 MB disks, MD Data offered about 100 times as much storage capacity as ordinary diskettes, and more than its competitors like the Zip (100 MB), SuperDisk (120 MB), and EZ 135 (135 ...
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.
The media for CD-RW has the same layers as CD-R media. The reflective layer is, however, a silver-indium-antimony-tellurium alloy with a polycrystalline structure and reflective properties in its original state. When writing the laser beam uses its maximum power (8-14 mW) [6] to heat the material to 500–700 °C causing material liquefaction.
As of 2021, multiple consumer-oriented, optical-disk media formats are or were available: Compact Disc ("CD"): digital audio disc CD-R: write once read many (WORM) CD; CD-RW: rewriteable CD; DVD: digital video disc DVD-R: WORM DVD defined by the DVD Forum; DVD-RW: rewritable DVD defined by DVD Forum; DVD+R: WORM DVD defined by the DVD+RW Alliance
Retail recordable/writable optical media contain dyes in/on the optical media to record data, whereas factory-manufactured optical media use physical "pits" created by plastic molds/casts. As a result, data storage on retail optical media does not have the life-span of factory-manufactured optical media.
For rewritable CD-RW, DVD-RW, DVD+RW, DVD-RAM, or BD-RE media, the laser is used to melt a crystalline metal alloy in the recording layer of the disc. Depending on the amount of power applied, the substance may be allowed to melt back (change the phase back) into crystalline form or left in an amorphous form, enabling marks of varying ...
Various forms of optical media, mostly disk form, competed with magnetic recording through most of the 1960s and 70s, but never became widely used. It was the introduction of semiconductor lasers that provided the technology needed to make optical storage more practical in both storage density and cost terms.
Burned CD-Rs suffer from material degradation, just like most writable media. CD-R media have an internal layer of dye used to store data. In a CD-RW disc, the recording layer is made of an alloy of silver and other metals—indium, antimony, and tellurium. [20] In CD-R media, the dye itself can degrade, causing data to become unreadable.