Date   : Tue, 29 Mar 1983 11:18:24-PST
From   : Lauren Weinstein <vortex!lauren@lbl-csam.arpa>
Subject: ITS binary format

I've had lots of problems with "com" binary files on ITS over the years,
and not just from Unix systems -- so don't blame Unix!  The issue is that
ITS stores these files in a sort of "packed" format that is oriented
around its 36 bit words, and includes some other header information
as well.  For example, let's say you have a file that you uploaded
to ITS using the LMODEM "com file" mode.  Now you try to FTP the file
from ITS to a non-ITS system (in binary/image mode).  The file you get
has this packing and strange header information included.  Small wonder
that squeezed files won't unsqueeze!  When instead you download such a file
through LMODEM, ITS performs the conversions and you get a "proper"
binary file again.

Ideally, ITS should have a special FTP mode which would convert
the ITS com file format back to "real" binary on the fly during
transfer.  I suspect that the ITS folks never considered FTP'ing
of com binaries to non-ITS systems to be a "high-demand" type project.

--Lauren--