Path: utzoo!utgpu!watmath!att!dptg!rutgers!usc!cs.utexas.edu!uunet!intercon!amanda@intercon.uu.net
From: amanda@intercon.uu.net (Amanda Walker)
Newsgroups: comp.lang.postscript
Subject: Re: Illustrator 88, EPS, Printing
Message-ID: <1420@intercon.UUCP>
Date: 30 Aug 89 17:12:42 GMT
References: <4341@cps3xx.UUCP> <1051@pbs.uucp> <1415@intercon.UUCP> <3436@daisy.UUCP>
Sender: news@intercon.UUCP
Reply-To: amanda@intercon.uu.net (Amanda Walker)
Organization: InterCon Systems Corporation
Lines: 23

In article <3436@daisy.UUCP>, cplai@daisy.UUCP (Chung-Pang Lai) writes:
> I think Dark Star is correct.  The preview image may contain some binary
> data.  Frame Technology sells a filter called FrameEPSF on macintosh.  It
> takes an EPSF with mac preview image and translates it into EPSI for the
> unix system.  EPSI is a pure ASCII format unlike the EPSF.

On a Macintosh, files have two separate byte streams, called "forks"--the
"data fork" and the "resource fork".  A text file has an ASCII stream in
the data fork.  An EPSF file has an ASCII stream in the data fork and a
"PICT" resource (the standard Mac graphics interchange format) in the
resource fork.  Most file transfer programs will let you (some, in fact,
will *only* let you) transfer the data fork of a file as text.  If this
is what you do, it doesn't matter whether or not you've saved the preview
image or not.  The *only* difference between a Mac text file and a Mac EPSF
file is the presence or absence of this PICT resource.  Now, if you save
the file in PC EPSF format, you get a binary header followed by the text
and a bitmap...

--
Amanda Walker
InterCon Systems Corporation

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