Micrognosis Compression Archiver

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File Format
Name Micrognosis Compression Archiver
Released 1994?

Micrognosis Compression Archiver, sometimes called MAR, is a compressed archive utility for DOS (and maybe other platforms?).

The software is a bit vague about who exactly is responsible for it. No doubt Haruhiko Okumura had a lot to do with it, but it would be nice to have independent confirmation of a connection between him and Micrognosis. The credits for version 1.0 say:

Original Version By:           Stratus VOS 11.5 Version by:
  Haruhiko Okumura              Richard Schiller

Format details

MAR uses generalized LHA format, with some custom compression schemes:

ID Description and remarks
hf0 Generic Huffman
ah0 Adaptive Huffman
ari Arithmetic

It also uses the standard "lh0" scheme, for uncompressed files.

The documentation lists more compression schemes, but they don't seem to be implemented:

ID Description and remarks
arn Arithmetic N
lzs LZS IDX-12,13,14/LEN-3,4,5. (Don't know if this was intended to be the same as LArc's lzs scheme.)
lzw LZW BIT-12,13,14/LZW-fix,var


The executable file is named "MAR.EXE". MAR does not seem to have a standard filename extension, though one might logically use .MAR.


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