Abstract of INFO-MAC archived Text file
   'dev/info/binhex-40-specs.txt'
  Uploaded 09/02/1991   9202 bytes

Date: Tue, 13 Aug 91 09:18:07 WST 
From: Peter N Lewis <peter@cujo.curtin.edu.au>
Subject: info-mac/tech/binhex-definition.txt 

Hi All,
   This is a definition of the BinHex 4.0 standard as I see it.  When I
first tried to write DeHQX, I had to post several questions to the net
to get a full definition of this standard.  Hopefully this file will
make it easier for anyone who wants to add BinHex compatability to there
application.

Have fun,
   Peter <Lewis_P@cc.curtin.edu.au>

__________________________________________________________________________
BinHex 4.0 Definition by Peter N Lewis, Aug 1991.

    For a long time BinHex 4.0 has been the standard for ASCII encoding of
Macintosh files.  To my knowledge, there has never been a full definition
of this format.  Info-Mac had an informal definition of the format, but
this lacked a description of the CRC calculation, as well as being vague in
some areas.  Hopefully this document will fully define the BinHex 4.0
standard, and allow more programmers to fully implement it.  Note, however,
that this definition is how I see the BinHex standard, and since I had no
part whatsoever in defining it initially, this document can have no real
claim to being the one true definition.  If anyone feels that I have not
got the facts straight, or that it is ambiguous in any details, please
contact me at the address at the bottom of this document.

Format:

It is necessary to distinguish between the encoding format and decoding
format since we wish to allow all decoders to read all versions of the
BinHex format, while trying to reduce the variation in encoding.

All numbers are decimal unless they have the format 0xFF, in which case
they are hex.

<tab> is a tab, character value 9.
<lf>  is a linefeed, character value 10.
<cr> is a carriage return, character value 13.
<spc> is a space, character value 32.
<return> means to the encoder:
    The sequence <cr> <lf>.  Either (but not both) may be omitted.  Use
whatever is appropriate for your system (<cr> for Mac, <lf> for Unix,
<cr><lf> for MS-DOS).
<return> means to the decoder:
    Any sequence of zero or more of <cr>, <lf>, <tab>, <spc>.  (The <tab> 
and <spc> are required because some old programs produced these characters).
For example, <cr> <tab> <lf> <spc> <lf> <cr> would be perfectly acceptable.