CJR Archive File Format
=======================

As used by the Arch/DeArch programs by Chris Richardson and supported by the
Archive program updated by J.G.Harston http://mdfs.net/Apps/Archivers/Archive.

The format of a CJR archive is as follows:
       Read using INPUT#:
        000000 : 40 hi nn mm lo : ptr%(0) \
        000005 : 40 hi nn mm lo : ptr%(1)  \
        00000A : 40 hi nn mm lo : ptr%(2)   } Pointers to entries
           :                               /
        0000FA : 40 hi nn mm lo : ptr%(50)/
        0000FF

   Each entry:
       Read using INPUT#:
        name$  : 00 nn ...      : Filename, last char...first char
        load%  : 40 hi nn mm lo : load address
        exec%  : 40 hi nn mm lo : execution address
        len%   : 40 hi nn mm lo : file length
        attr%  : 40 hi nn mm lo : file attributes
       Read using BGET:
        The bytes of the file

If a pointer is zero, it doesn't point to anything. Usually, the files run
straight after each other. There should not be null pointers in the middle
of the pointer list.

Filenames are in Acorn format, ie '.' directory seperators.

The bottom three bytes of len% is the actual data length occupied within the
archive, even if this data expands to form a larger file. The top byte of
len% is a flag. Current meanings are as follows:
        &00     Stored file
        <>&00   Not a file
        &FF     Ignore this data

Future versions will use this flag to indicate actual file compression
methods.