Optical Storage - Upgrading and Repairing PCs - page 705

any individual 32KB block of data (the minimum recording unit) with a new block, ac-
curately 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 ad-
dressing information read from the groove is very 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 stan-
dalone 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) was not introduced until mid-2002, so this was a significant prob-
lem.
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 pro-
gram.
• Use a compatibility utility to change the contents of the Book Type Field for a partic-
ular DVD+RW disc as necessary. These utilities may be provided by the drive manu-
facturer (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. 599 (this chapter).
DVD+R DL
DVD+RDL,alsoknownasDVD-R9,isadual-layer versionoftheDVD+Rstandardthat
was introduced in October 2003. DVD+R DL is essentially a dual-layer version of the