CRUSH

File Format
Name	CRUSH
Ontology	Electronic File Formats Archiving CRUSH
Extension(s)	.cru, .cri, special
Released	1994

CRUSH is an archiving utility for DOS. It was developed by Jeff Rollason and PocketWare, and distributed as shareware.

Disambiguation

Not to be confused with:

• The "crushed" compression method used by PAK (ARC extension)
• ARQ Crusher!, or the Crusher data compression software by DC Micro Development
• CRUSH - An experimental file compressor by Ilya Muravyov [1]

Discussion

CRUSH writes files to its native uncompressed .CRU archive format, then uses an external compression program, such as PKZIP, to compress the CRU file. The theory is that a single large file usually compresses better than multiple small files. CRUSH tries to order the files so as to optimize the compression ratio.

CRUSH can optionally create and use an index file (.CRI), outside of the compressed archive.

Identification

CRU and CRI files start with ASCII "CRUSH v", and apparently have 0x0a 0x1a 0x00 at offset 10.

The 4-byte integer at offset 22 has value 26 (1a 00 00 00) for CRI, or a generally larger value for CRU.

Specifications

• CRUSH18.ZIP → MANUAL.DOC, "Technical Details" section

Sofware

• CRUSH (DOS software)
  • v1.0
  • Best of Walnut Creek CD ROM (April 1995) → DISCS/SIMTEL/CRUSH11.ZIP - v1.1
  • v1.3
  • v1.8

Sample files

• dexvert samples — archive/crush