ISO 9660 Support for CD-ROM

• Microsoft Windows NT operating system version 3.1

SUMMARY

Windows NT supports ISO 9660 CD-ROM format, but does not support any of the RockRidge CD-ROM format extensions. ISO 9660 is an international standard that defines a file system for compact discs. Almost all systems support ISO 9660.

MORE INFORMATION

Level one ISO 9660 is similar to the MS-DOS file system. Filenames are limited to eight single-case characters, a period, and a three-character extension. Filenames cannot contain special or extended characters, (no hyphens, tildes, equal or plus signs), only single-case letters, numbers, and underscores. Directory names cannot contain three-digit extensions, just eight single-case characters.

All alphabetic characters are in uppercase letters; some software maps these to lowercase letters. Either the filename or the extension may be empty, but not both ("F." and ".E" are both legal filenames).

There is a "file version number" that can range from 1 to 32,767 and is separated from the extension by a semicolon. The file version number is ignored on many systems.

Subdirectories are allowed to nest up to eight levels deep.

Level two ISO 9660 allows longer filenames, up to 32 characters; however, most of the other restrictions still apply. Level two discs cannot be used on some systems, such as MS-DOS.

The RockRidge extensions use some undefined fields in the ISO 9660 standard to allow full UNIX-like filenames, symbolic links, and deep directories.