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 scheme of the same ID.)
-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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