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Format

ISO 9660 Disk Image File

Summary

Name
ISO 9660 Disk Image File
Identifiers
PUID: fmt/468
Format type
Aggregate
Description
ISO 9660 Disk Image File is a virtual image of optical disk, storing content and structure of an optical disc which can be transferred on the other media. This format specifically uses ISO 9660, a so-called original standard for file system for optical disc media, written by International Organization for Standardization (ISO) and considered an international technical standard available for many operating systems. A disk image is a uncompressed copy of the contents of a disk or a folder, it can facilitate certain types of backup and recovery strategies. Please see ID: fdd000348 from Library of Congress and other the links attached to this entry for further information.
Note
http://fileformats.archiveteam.org/wiki/ISO_image https://www.loc.gov/preservation/digital/formats/fdd/fdd000348.shtml https://en.wikipedia.org/wiki/Optical_disc_image https://docs.microsoft.com/en-us/windows/win32/imapi/disc-formats
File extensions
iso, toast, cdr, dmg, bin
Source
Digital Preservation Department / The National Archives

Relationships

Has lower priority than
Has priority over
Is subtype of

Internal signatures

ISO Disk Image File

Note
BOF: CD001{1-16384}ÿCD001 with offset of (32700- 37700). Beginning at byte 32768, an ISO file will hold two-to-many volume descriptors, each of 2048 bytes and starting with '*CD001', where * represents the volume desciptor type as defined within the specification.

Byte sequences

Min Frag Length
Absolute from BOF
Offset
32700
Max offset
37700
Byte Sequence
4344303031{1-16384}FF4344303031
Endianness
None

Changelog

  • Updated in V114

    Release date
    22 August 2023

    ISO 9660 Disk Image File: Max-offset modified for BOF signature to allow for more exact signature identification. Submitted by Digital Preservation Department, The National Archives (UK).

  • Updated in V108

    Release date
    5 September 2022

    ISO 9660 Disk Image File: Updated name and description. Added extensions: toast; cdr; dmg and bin. Added format type. Added priority over fmt/1743. Submitted by The Church of Jesus Christ of Latter-day Saints.

  • Updated in V101

    Release date
    15 February 2022

    ISO Disk Image: Broadened the BOF offset from 32769 to a range (32700- 37700). Submitted by The National Library of Australia.

  • Added in V65

    Release date
    25 October 2012

    ISO Disk Image: Signature developed through PRONOM Research.

    ISO Disk Image: Outline Entry Added.