Hardware Reference
In-Depth Information
If you are unable to read a disc written with UDF on another system, return it to the ori-
ginal system andclose themedia. Thisoptionisusually displayed aspartoftheEject Set-
tings dialog box. Closing the disc converts the filenames to Joliet format and causes them
to be truncated to 64 characters.
You can download the latest (revision 2.60) version of the Universal Disk Format spe-
cification from the OSTA website at
www.osta.org/specs/index.htm
.
Tip
UDF discs can become unreadable for a variety of reasons, including incompatible UDF
reader installed, disc not closed before removal of drive, table of contents not written due to
system lockup, and so on. To recover data from UDF discs, try CD Roller (available from
www.cdroller.com
)
. It supports the most commonly used UDF versions (v1.02 through 2.01,
and UDF Bridge) and also works with optical discs created by digital cameras, DVD re-
corders, and DVD-based camcorders. Another optical disc recovery program to consider is
IsoBuster (
www.isobuster.com
)
. IsoBuster also works with BD formats.
Macintosh HFS
HFS is the file system used by the Macintosh OS. HFS can also be used on optical discs;
however, if that is done, they will not be readable on a PC. A hybrid disc can be produced
with both Joliet and HFS or ISO 9660 and HFS file systems, and the disc would then be
readableonbothPCsandMacs.Inthatcase,thesystemwillseeonlythediscthatiscom-
patible, which is ISO 9660 or Joliet in the case of PCs.
Rock Ridge
The Rock Ridge Interchange Protocol (RRIP) was developed by an industry consortium
called the Rock Ridge Group. It was officially released in 1994 by the IEEE CD-ROM
File System Format Working Group and specifies an extension to the ISO 9660 stand-
ard for CD-ROM that enables the recording of additional information to support UNIX/
POSIX file system features. Neither DOS nor Windows includes support for the Rock
Ridgeextensions.However,becauseitisbasedonISO9660,thefilesarestillreadableon
a PC and the RRIP extensions are simply ignored.
Note
An interesting bit of trivia is that the Rock Ridge name was taken from the fictional Western
town in the movie Blazing Saddles.
