Date   : Wed, 30 Mar 1983 00:06:00 EST
From   : Gail Zacharias <GZ@mit-mc.arpa>
Subject: ITS binary format

There are two separate issues here.  First is packing 8 bit bytes into PDP-10's
36 bit words.  This is unavoidable, standard, and the ITS ftp server deals with
it just fine.  The problem is getting the unix user end to tell ITS to do it.
SEE BELOW FOR HOW TO DO THIS.

The second problem is the 4-byte header put in the binary CP/M files stored in
the CPM; directory. This has nothing to do with ITS, and was a decision made by
those involved with maintaining this directory and related programs.  There is
no reason on earth for ITS system programs such as FTP to understand the
conventions used by a small segment of the user population (and believe it or
not, providing CP/M software to unix hackers is not MC's rason d'etre).  In any
case, SEE BELOW FOR HOW TO DEAL WITH THIS.

I might suggest that instead of dreaming about what ITS FTP could or could not
be made to do, someone fix umodem to recognize those header bytes (they are
93H,3AH,D8H,00H) and strip them off.  umodem could also use them for their
intended purpose, differentiating between ascii and binary files, so the user
wouldn't have to give a "b" switch (I assume that's what the -sb below does).
The TOPS-20 modem program already does this.

Anyhow, unix people, here are the answers (if unix is so wonderful, how come
everybody has so much trouble figuring this out? (don't bother answering that))

Date: Wednesday,  9 Mar 1983 12:56-PST
From: bridger at rand-unix
To:   Gail Zacharias <GZ>
cc:   FJW, W8SDZ, guyton at rand-unix
Re:   downloading .com files

Thanks for the protocol, which enabled our resident expert, jim guyton,
to develop this method of downloading binary files.
At Rand-unix we are using a version of the BBN ftp program.

If you think it's of general interest, please post it.


1. to retrieve "AR14:CPM;NAMEXX COM" from mit-mc:

       ftp mit-mc
       type i
       quote
       type "l 8"
       get
       "AR14:CPM;NAMEXX COM"
       longnamexx.com
       bye

2. to strip off the 4 header bytes:

       dd if=longnamexx.com of=namexx.com bs=1 skip=4

3. to download to a cpm machine:

       umodem -sb namexx.com                   

                                       bridger