PackIt

Revision as of 17:05, 21 November 2023

PackIt was for a time in the mid-1980s the leading archiver for the Macintosh platform, until it was eclipsed by StuffIt. It was developed by Harry Chesley.

Originally an archiver which merely appended multiple files into one file with no compression, it later added compression in the form of Huffman coding. Encryption was also supported, but not much used.

As with most Mac-specific archiving systems, PackIt stored the Resource Fork of the files along with the regular file data (data fork).

Disambiguation

Note that there are a lot of other things named "PackIt", or something similar.

Identification

Files in the known version of the format start with ASCII "PMa", and end with "PEnd".

The fourth byte of the file is either ASCII "g", or in the range "1" through "7" (though "3" and "7" were probably never used).^[1]

Specifications

• UNPAKIT.ZIP → UNPACKIT.DOC, Appendices B and C
• macutil → doc/README.unpit (Caution: This has errors.)
• Archive Formats and Data, by Raymond Clay → Section titled "PACKIT". (This is not a description of the known version of PackIt format. It's either an old version, or only part of the format.)

Software

• PackIt page with source code (archived)
• PACKIT.BIN - PackIt III (V1.3)
• PackIt, at Macintosh Repository
• macutil → macunpack
• The Unarchiver
• unPACKIT by R. McGinnis (DOS software)

Sample files

• https://telparia.com/fileFormatSamples/archive/packIt/

Links

• Wikipedia: PackIt

References

1. ↑ Based on the pitpit.c file in the PackIt III source code.