Hardware Reference
In-Depth Information
• UDF (Universal Disc Format) file system.
• Defect management integral to the drive.
• Quick formatting.
• Uses same 8-to-16 modulation and error-correcting codes as DVD-ROM.
• Sequential and random recording.
• Lossless linking. (Multiple recording sessions don't waste space.)
• Spiral groove with radial wobble.
• After recording, all physical parameters comply with the DVD-ROM specification.
DVD+RW technology is similar to CD-RW, and DVD+RW drives can read DVD-ROMs and all CD
formats, including CD-R and CD-RW.
With DVD+RW, the writing process can be suspended and continued without a loss of space linking
the recording sessions together. This increases efficiency in random writing and video applications.
This “lossless linking” also enables the selective replacement of any individual 32KB block of data
(the minimum recording unit) with a new block, accurately positioning with a space of 1 micron. To
enable this high accuracy for placement of data on the track, the pre-groove is wobbled at a higher
frequency. The timing and addressing information read from the groove is accurate.
The quick formatting feature means you can pop a DVD+R or DVD+RW blank into the drive and
almost instantly begin writing to it. The actual formatting is carried out in the background ahead of
where any writing will occur.
DVD+R/RW is the format I prefer and recommend, and it has been the format most users prefer for
data recording. However, today's multiformat drives support both DVD+R/RW and DVD-R/RW (and
Super Multi Drives support DVD-RAM), so you can choose the right media for a particular task.
When DVD+RW drives were introduced in 2001, some users of DVD-ROM and standalone DVD
players were unable to read DVD+RW media, even though others were able to do so. The first drives
to support DVD+R (writable) media (which works with a wider range of older drives) were not
introduced until mid-2002, so this was a significant problem.
The most common reason for this problem turned out to be the contents of the Topic Type Field
located in the lead-in section of every DVD disc. Some drives require that this field indicate that the
media is a DVD-ROM before they can read it. However, by default, DVD+RW drives write
DVD+RW as the type into this field when DVD+RW media is used.
The following are three possible solutions:
• Upgrade the firmware in the DVD+RW recorder so it writes compatible information into the
Book Type Field automatically.
• Change the Book Type Field during the creation of a disc with a DVD mastering program.
• Use a compatibility utility to change the contents of the Book Type Field for a particular
DVD+RW disc as necessary. These utilities may be provided by the drive manufacturer
(sometimes a firmware upgrade is also necessary) or by a third-party utility.
Changing the Book Type Field is known as bitsetting .
See “ Updating the Firmware in an Optical Drive , p. 607 .
DVD+R DL
 
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