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Universal Disk Format (UDF):

A File System Format in Transition... Defect Management From Software to Hardware

It was designed for read-write interoperability between all the major operating systems as well as compatibility between rewritable and write-once media. DVDs are based on the UDF Format, and UDF is an optional second standard for CD-R and CD-RW disks in a process termed Packet Writing using Roxio's DirectCD or Nero's InCD.

CD-MRW will of course change all of that since new CD-MRW Drives will have this Packet Writing capability built-in for driver letter access. Unlike UDF version 1.50, where defect management relied on software, (CD Mount Rainier Rewrite) CD-MRW ensures that defect management is handled through hardware (directly by the recorder itself).

DVDs are based on the UDF File System Format. UDF is an optional second standard for CD-R and CD-RW Disks. CD-RWs support UDF (Universal Disk Format), which is similar to the File System on a Hard Drive.

Expect the floppy to disappear when CD Mount Rainier Rewrite (UDF 2.0.1 File System) Technology takes over! And Iomega came out with a Zip750 Magnetic Storage? Iomega is way out of touch with Reality & Technology! What were they thinking?

Note: Slipstream Technology - USB Boot Devices - It's here and it works IF the MotherBoard Bios supports it! (3/19/2003)

  1. osta.org:  Universal Disk Format:
  2. MDI.com - Storage Your Way - UDF: MDI UDF is File System Technology capable of reading a variety of Media Formats.
  3. Universal Disk Format - a searchStorage definition
  4. yamaha.ca:  CD-MRW
  5. www.mt-rainier.org: Mount Rainier explanation from Philips
  6. www.licensing.philips.com

This specification describes the Universal Disk Format, a file system for Optical Media developed by OSTA - Optical Storage Technology Association.

This specification, fully compliant with the ISO 13346 standard, is intended for developers who intend to implement UDF to enable file interchange among different operating systems. DVDs are based on the UDF format, and UDF is an optional second standard for CD-R and CD-RW disks. A OSTA Multiread Specifications drive can read (Redbook) CD-DA Digital Audio, CD-ROM, CD-R and CD-RW disks.

  1. CDFS - The CDFS format has a number of restrictions due to its' simplicity.
    1. Directory and file names must be fewer than 32 characters long.
    2. Directory trees can be no more than eight levels deep.

    CDFS is considered a legacy format because the industry has adopted the Universal Disk Format (UDF) as the standard for read-only media.


  2. ECMA TR-71: UDF Bridge Format
  3. UDF - The Windows 2000 UDF file system implementation is compliant with ISO 13346 and supports UDF versions 1.02 and 1.5. OSTA (Optical Storage Technology Association) defined UDF in 1995 as a format to replace CDFS for magneto-optical storage media, mainly DVD-ROM. UDF is included in the DVD specification and is more flexible than CDFS. UDF file systems have the following traits:


    1. File names can be 255 characters long.
    2. The maximum path length is 1023 characters.
    3. File names can be uppercase and lowercase.

    Although the UDF format was designed with rewritable Media in mind, the Win2000 UDF driver (\Winnt\System32\Drivers\Udfs.sys) provides read-only support.


UDF Readers:
  1. Software Architects SAI:
    1. Disk Drive Tune Up: "The OSTA UDF specification allows for 1 terabyte and above volume sizes in UDF." Claims cross platform compatibility (PC & MAC) for Hard Disk Drives by formatting same for UDF (12/8/2002).
    2. Products supporting UDF: "The overall goal of UDF is to facilitate data interchange independent of hardware, software and operating system by standardizing on the way the information is stored and organized on the disk."

      "Supports very large capacity disks - UDF can store and manage data at the TeraByte level on a single Volume." (1/17/2004)

  2. CDRoller: UDF Reader with extended capabilities to search and recover the lost files (8/26/2002).
  3. r o x i o UDF Volume Reader for Windows: This file enables some MultiRead CD-ROM drives to read UDF formatted CD-RW discs such as those written with Roxio's DirectCD.
  4. nero.com:  Download site: InCD & EasyWrite Reader
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Web Development, Gill Boyd & Team - Posted 08/25/2001; Updated 01/17/2004