Chapter 1

124 Everything You Ever Wanted to Know About DVD
TABLE 4-2 DVD-R compatibility
DVD-R(G) DVD-R(A) DVD-RW DVD-RAM DVD�RW
DVD unit unit unit unit unit unit
DVD-ROM
disc
reads reads reads reads reads reads
DVD-R(G) often reads, reads reads, reads reads
discreads writes writes
DVD-R(A) usually reads reads, reads reads reads
discreads writes
DVD-RW often reads reads reads, usually usually
discreads writes reads reads
DVD-RAM rarely doesn’t doesn’t doesn’t reads, doesn’t
discreads read read read writes read
DVD�RW often usually usually usually usually reads,
discreads reads reads reads reads writes
DVD�R often usually usually routinely reads reads,
discreads reads reads reads usually writes
around 70 percent. The situation is steadily improving. In another few years
compatibility problems will mostly be behind us, just as with CD-R (did you
know that early CD-Rs had all kinds of compatibility problems?).
Table 4-2 is a summary of recordable DVD compatibility. Below each
drive is a column indicating how well it can read or write each format (for
simplicity, “doesn’t write” is implied if something else is not specified).
DVD-R
DVD-R (which is pronounced “dash R” not “minus R”) uses organic dye
technology, like CD-R, and is compatible with most DVD drives and players.
First-generation capacity was 3.95 billion bytes, later extended to 4.7 billion
bytes. Matching the 4.7G capacity of DVD-ROM was crucial for desktop
DVD production. In early 2000 the format was split into an “authoring” version
and a “general” version. The general version, intended for home use,
writes with a cheaper 650-nm laser, the same as DVD-RAM. DVD-R(A) is
intended for professional development and uses a 635-nm laser. DVD-R(A)
discs are not writable in DVD-R(G) recorders, and vice-versa, but both kinds
of discs are readable in most DVD players and drives. The main differences,