DVD Demystified

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TABLE 5.3
Compatibility of
Writable DVD
Formats
another portion is writable. This could be a disc with two layers, one prerecorded
and one writable, or it could be a disc where part of one layer is
stamped and the rest is writable.
The three erasable formats (DVD-RAM, DVD-RW, and DVD+RW) are
essentially in competition with each other. DVD-RAM has a head start of
about 2 years. A major problem is that none of the writable formats are fully
compatible with each other or even with existing drives and players. As
time goes by, they will become more compatible and more intermixed. For
example, combination DVD-ROM/CD-RW drives were released near the
end of 1999. Video recorders from Pioneer released near the end of 2000
combine DVD-RW and DVD-R. Future DVD-RAM drives will write to DVD-
R discs as well as CD-R/RW. See Table 5.3 for compatibility details.
Each writable DVD format is detailed in the next sections, followed by a
summary and comparison.
DVD-R
Chapter 5
DVD-R is the record-once version of DVD-ROM, similar in function to CD-
R. Data can only be written permanently to the disc, which makes DVD-R
well suited for archiving, especially for data that requires an audit trail.
DVD-R is compatible with most DVD drives and players. First-generation
DVD DVD-R(G) DVD-R(A) DVD-RW DVD-RAM DVD+RW
Unit Unit Unit Unit Unit Unit
DVD-ROM Reads Reads Reads Reads Reads Reads
disc
DVD-R(G) Usually Reads, Reads, does Reads, Reads Reads
disc reads writes not write writes
DVD-R(A) Usually Reads, does Reads, Reads, does Reads Reads
disc reads not write writes not write
DVD-RW Usually Reads Reads Reads, Usually Usually
disc reads writes reads reads
DVD-RAM Rarely Does not Does not Does not Reads, Does not
disc reads read read read writes read
DVD+RW Usually Usually Usually Usually Usually Reads,
disc reads reads reads reads reads writes