MS-DOS Compression Format (SZDD Variant)

Summary

Name

MS-DOS Compression Format (SZDD Variant)

Identifiers

PUID: fmt/462

Format type

Aggregate

Description

The MS-DOS compression format uses the SZDD algorithm to compress a single file into another single file, replacing the last character in the filename with an underscore. It is implemented via the MS-DOS commands COMPRESS.EXE and EXPAND.EXE.

Note

A DOS compressed file will be named file.**_, so a DOS compressed .exe will be named 'file'.ex_, a DOS compressed .jpg will be named 'file'.jp_. https://www.cabextract.org.uk/libmspack/doc/szdd_kwaj_format.html

Source

Digital Preservation Department / The National Archives

Internal signatures

Changelog

• Updated in V109

  Release date

  1 November 2022

  MS-DOS Compression Format (SZDD Variant): Changed filetype to Aggregate. Submitted by National Library of the Netherlands.

• Updated in V103

  Release date

  11 March 2022

  MS-DOS Compression Format (SZDD Variant): Amended name for consistency, added link and description. Submitted by IS4.

• Updated in V91

  Release date

  25 July 2017

  MS DOS Compression Format: Removed empty 'External Signature' - should be null instead. Error identified through schema validation work with French government/Programme Vitam, France

• Added in V62

  Release date

  28 August 2012

  MS DOS Compression Format: Signature developed through PRONOM Research.

  MS DOS Compression Format: Outline Entry Added.