A new standard for rewritable DVD disks being promoted by Hewlett-Packard, Philips and Sony. It is competing with another standard, called DVD-RAM, developed by the DVD Consortium. The two standards are incompatible. DVD+RW disks have a slightly higher capacity -- 3 GB per side, versus 2.6 GB per side for DVD-RAM disks.
DVD-RW uses a phase-change recording layer, much like CD-RW. In fact, the relationship between DVD-R and DVD-RW finds its closest analogy in the relationship between CD-R and CD-RW-and this is a comforting truth to fall back on in the "everything you know is wrong" atmosphere that surrounds the writable DVD formats. In another triumph of what common sense would dictate, DVD-R media is reliably readable in most existing read-only DVD drives and DVD-Video players (although there have been a few isolated reports of playback inconsistencies in certain brands of DVD-Video players, this is largely attributable to firmware issues and easily correctable). DVD-RW also promises an easy backwards-compatibility path; while it was originally thought to be as nearly universally compatible as DVD-R, it turns out that this was a bit optimistic. It seems that some DVD-Video players, when fed a DVD-RW disc, "see" the lower reflectivity and "assume" that they should be trying to read a dual-layer disc. Even this is a minor logical hiccup that can be remedied by a simple, no-cost change in firmware. Also, neither DVD-R nor DVD-RW media require a caddy or cartridge, though some drives may take the additional precaution of requiring that the disc be in a caddy, just as most early CD-R drives did in their infancy.
Backwards Compatibility with CD formats
The rewritable capability is simply an extension onto the familiar DVD-ROM format. The DVD+RW drive offers the user full read and write backward compatibility with CD formats including CD-ROM, CD-R, CD-RW, CD-audio and video, DVD-ROM, DVD-R and even DVD-video discs. The DVD+RW drive is the natural extension of CD technology.
ReWritable Feature
The DVD+RW drive allows the user to read, write, erase and rewrite to a 3.0 GB+RW disc. The new format adds only minimal features to the existing DVD-ROM spec to allow random rewritability, thus allowing DVD-ROM drives to read +RW discs at low cost to DVD-ROM manufacturers.
High Capacity Storage (3.0 GB, CAV Mode)
The 3.0 GB capacity can be used for network archiving, high capacity data distribution or multimedia storage among many other uses. The DVD+RW drive offers high performance in addition to the +RW media. In the Constant Angular Velocity (CAV) mode, the high-performance random-access and transfer rates are achieved by using techniques similar to those used in hard disk drives.
Familiar format
+RW media has the familiar look and feel of a CD or DVD-ROM disc. Since +RW media uses the exact same method to write the adress and clock signal as DVD-ROM, future DVD-ROM drives can easily and cost effectively be made to read +RW discs. The +RW disc is as robust as a CD or DVD-ROM disc against dust, fingerprints or scratches.
---------------------------------
Entnommen aus:
www.dvdutils.com
Dort steht auch ein Artikel über die neuen 140GB Discs con C3D.
DVD-RW uses a phase-change recording layer, much like CD-RW. In fact, the relationship between DVD-R and DVD-RW finds its closest analogy in the relationship between CD-R and CD-RW-and this is a comforting truth to fall back on in the "everything you know is wrong" atmosphere that surrounds the writable DVD formats. In another triumph of what common sense would dictate, DVD-R media is reliably readable in most existing read-only DVD drives and DVD-Video players (although there have been a few isolated reports of playback inconsistencies in certain brands of DVD-Video players, this is largely attributable to firmware issues and easily correctable). DVD-RW also promises an easy backwards-compatibility path; while it was originally thought to be as nearly universally compatible as DVD-R, it turns out that this was a bit optimistic. It seems that some DVD-Video players, when fed a DVD-RW disc, "see" the lower reflectivity and "assume" that they should be trying to read a dual-layer disc. Even this is a minor logical hiccup that can be remedied by a simple, no-cost change in firmware. Also, neither DVD-R nor DVD-RW media require a caddy or cartridge, though some drives may take the additional precaution of requiring that the disc be in a caddy, just as most early CD-R drives did in their infancy.
Backwards Compatibility with CD formats
The rewritable capability is simply an extension onto the familiar DVD-ROM format. The DVD+RW drive offers the user full read and write backward compatibility with CD formats including CD-ROM, CD-R, CD-RW, CD-audio and video, DVD-ROM, DVD-R and even DVD-video discs. The DVD+RW drive is the natural extension of CD technology.
ReWritable Feature
The DVD+RW drive allows the user to read, write, erase and rewrite to a 3.0 GB+RW disc. The new format adds only minimal features to the existing DVD-ROM spec to allow random rewritability, thus allowing DVD-ROM drives to read +RW discs at low cost to DVD-ROM manufacturers.
High Capacity Storage (3.0 GB, CAV Mode)
The 3.0 GB capacity can be used for network archiving, high capacity data distribution or multimedia storage among many other uses. The DVD+RW drive offers high performance in addition to the +RW media. In the Constant Angular Velocity (CAV) mode, the high-performance random-access and transfer rates are achieved by using techniques similar to those used in hard disk drives.
Familiar format
+RW media has the familiar look and feel of a CD or DVD-ROM disc. Since +RW media uses the exact same method to write the adress and clock signal as DVD-ROM, future DVD-ROM drives can easily and cost effectively be made to read +RW discs. The +RW disc is as robust as a CD or DVD-ROM disc against dust, fingerprints or scratches.
---------------------------------
Entnommen aus:
www.dvdutils.com
Dort steht auch ein Artikel über die neuen 140GB Discs con C3D.
