PC Hardware in a Nutshell, 3rd Edition

ISO-9660 Variants

The very real limitations of ISO-9660 formatted discs gave rise to several alternative formats, all of which were based on ISO-9660:

Rock Ridge

The Rock Ridge format is an extension of the ISO-9660 format, intended for use on Unix systems, which have much more liberal restrictions on the length of and characters used in filenames and directory names, as well as the depth of directories. Using Rock Ridge allows a CD to support long mixed-case filenames, symbolic links, and other conventions common to Unix systems. Although full Rock Ridge support is available only on Unix systems, a system running MS-DOS, Windows, or the Mac OS can still access the data on a Rock Ridge disc, but not the long filenames and other extended information. The Rock Ridge standard is available at ftp://ftp.ymi.com/pub/rockridge if you want to learn more about it.

Romeo

The Romeo format is an obsolete extension to ISO-9660, developed by Adaptec as a stopgap measure for early versions of its EasyCD premastering software. The raison d'être for the cutely named Romeo format was that Windows NT 3.5a did not support the proprietary Microsoft Joliet format, described next. Romeo supports filenames of up to 128 characters, including spaces. However, unlike Joliet, Romeo supports neither the Unicode character set nor associated short (MS-DOS 8.3) filenames. Romeo-formatted discs can be read under Windows NT 3.51 and 4.0, Windows 98/SE/Me, and Windows 2000/XP. Because there is no associated short ...