What is ISO9660?
ISO9660 is a standard file system format used for CD-ROMs and DVD-ROMs. It defines how data is organized so that computers of different types can read the disc without special software.
Let's break it down
- Standard: an agreed-upon set of rules that everyone follows.
- File system: the way a storage device keeps track of files and folders.
- CD-ROM / DVD-ROM: discs that store data and are read by a laser.
- Organized: arranged in a predictable, consistent way.
- Different types of computers: Windows, macOS, Linux, etc., all can understand the same layout.
Why does it matter?
Because it lets you create a disc once and be confident that almost any computer, old or new, can open it. This reliability is crucial for software installers, game discs, and data backups that need to work everywhere.
Where is it used?
- Installing operating systems or software from a CD/DVD.
- Distributing video games and movies on physical discs.
- Archiving important data on optical media for long-term storage.
- Creating bootable rescue discs for system recovery.
Good things about it
- Universal compatibility across all major operating systems.
- Simple structure makes it easy to implement and read.
- Well-tested and stable, having been used for decades.
- Supports basic file naming and directory hierarchy without extra software.
- Can be combined with extensions (like Joliet or Rock Ridge) for longer names and permissions.
Not-so-good things
- Limited file name length (max 8.3 characters in the original spec).
- No built-in support for modern features like large files (>2 GB) or advanced permissions.
- Case-insensitive and lacks Unicode, making it hard for non-English characters.
- Requires extensions for many modern needs, which can reduce pure compatibility.