Logitech Compress

Latest revision as of 13:10, 30 September 2025

Logitech Compress refers to a compressed file format used by Logitech for software installation.

There are two known versions, which we'll call "v1.0" and "v2.0", after the version number of the corresponding LGEXPAND.EXE decompression utility.

V1.0 is just raw PKWARE DCL Implode data.

V2.0 adds an 8-byte header, so it is a distinct format. This header includes the last character from the original file extension, a byte whose purpose is currently unknown, and the uncompressed file size as a 4-byte little-endian integer.

[edit] Identification

V2.0: Files start with bytes da fa. The two bytes at offset 8 are probably always 00 06, because the format has only been seen to use binary-4K compression, even for text files. The file ends with one of the bit patterns that PKWARE DCL Implode can end with.

[edit] Software

Packages using the format often include LGEXPAND.EXE, a decompression utility for DOS.

V1.0:

• logimw62.zip → LGEXPAND.EXE
• logi71.zip → LGEXPAND.EXE
• See also PKWARE DCL Implode#Software and TTCOMP#Software.

V2.0:

• Packard Bell FTP → Packard Bell FTP ZD.7z → Bell FTP ZD/ZDSFIUP01970100/l3dw9nt.zip → LGEXPAND.EXE
• Discos PCManía → PCMania CD79_3.iso → HTML/DATA/CONTROL/M83setup.EXE → DISK1/LGEXPAND.EXE
• DiscMaster search for LGEXPAND.EXE v2.0
• Deark

[edit] Sample files

• In most cases, the LGEXPAND.EXE utility is found alongside examples of compressed files. Refer to the Software section above.