README.txt


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unalf project README.

The ultimate goal of this project is to reimplement the ALF
compression and decompression algorithms on modern systems aka
Linux and anything else that's POSIX-ish. It's also intended to
be a repository of information about the ALF archiver (and UNALF
dearchiver).

What's here so far:

README.txt - you're reading it now.

TODO.txt - plans for the future.

src/ - the source. should be able to build with "cd src; make",
followed by "make install" if you want.

f65/ - "fake 6502" porting layer. Not for the faint of heart. The
unalf algorithm was ported from a disassembly of the 6502 code, using
a perl script to convert the 6502 mnemonics to C macros.  This means I
was able to port the code without fully understanding how it works...

doc/Arcinfo - describes the format of ARC compressed files. The ALF
file structure is almost identical to ARC's. This file was taken from
the arc-5.21q source.

doc/alf14.atr - the distribution disk for ALF version 1.4, as an Atari
8-bit single-density floppy disk image. This likely isn't the original
distribution disk, but it's the only one I've found on the various
archive sites.

doc/alf14_doc.txt - the documentation for ALF and UNALF, extracted
from the disk image and converted from ATASCII to standard ASCII. Note
that the filenames are different: LZ.COM for ALF14.COM and DZ.COM for
UNALF14.COM.

doc/fileformat.txt - documents how the ALF file format differs from ARC.

doc/review.txt - a review of the original ALFCrunch, from an Atari magazine.

examples/* - ALF files found in the wild.

testing/alfls - a Perl script that lists the contents of an ALF
archive. Run it with --help for more information. If you're packaging
unalf for a distribution, there's no need to include this script in
the package: I wrote it for testing purposes only. You can use "unalf
-l" to list .alf files, so this is redundant.