SWG

File Format
Name	SWG
Ontology	Electronic File Formats Archiving SWG
Extension(s)	.swg
Released	1993?

SWG (SWAG packet) is a specialized archive format associated with the SourceWare Archival Group (SWAG). SWAG is a historical collection of Pascal source code.

There are at least two different SWG formats, which we'll call "old" and "new".

Format details

New SWG format is a derivative of LHA format, apparently based on LHA header level 0, with an extra 165 bytes worth of headers preceding the filename field. It has a custom "-sw1-" compression method, the details of which are apparently undocumented.

Identification

New format: At offset 2 is ASCII "-sw1-" (if the first member file was compressible), or "-sw0-" (if not).

At least some old format files start with "SWAGOLX.EXE".

Specifications

• SWAG.ZIP → SWAGADD.DOC - Has partial documentation of new format.
  • swg.txt - Excerpt from SWAGADD.DOC

Software

• [1] → SWAG.ZIP - GDSOFT SWAG Packet Reader v3.13 (DOS software)
  • Note that the Reader is also included in the ALLSWAGS.ZIP file.
• [2] → SWAGWIN.ZIP - SWAG for WINDOWS, v1.04
• SWAG.ZIP - Maybe the first version (DOS software)

Sample files

• GARBO Shareware Archive → allswags.zip
• [3] → ALLSWAGS.ZIP
• SWAGABC.ZIP - Old format
• https://telparia.com/fileFormatSamples/archive/swagPacket/

Links

• The HTML SWAG Home Page - The contents of SWAG are available here, but maybe not in SWG format.