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From: mlord@bwdls58.bnr.ca (Mark Lord)
Newsgroups: comp.binaries.ibm.pc.d,comp.sources.wanted
Subject: Re: zmodem over 7 bit line
Message-ID: <3752@bwdls58.UUCP>
Date: 11 Jul 90 14:35:07 GMT
References: <1990Jul10.222600.15940@murdoch.acc.Virginia.EDU>
Sender: mlord@bwdls58.UUCP
Reply-To: mlord@bwdls58.bnr.ca (Mark Lord)
Organization: Bell-Northern Research, Ottawa, Canada
Lines: 40

In article <1990Jul10.222600.15940@murdoch.acc.Virginia.EDU> dmm0t@hudson.acc.Virginia.EDU (David M. Meyer) writes:
>A while back, someone mentioned a way to use zmodem over a 
>7-bit line.  I'm running DSZ on my PC (registered version)
>and the latest version of rz/sz on a Sun.  I can't figure out
>how to make this thing work.

From DSZ.DOC (included in shareware distribution):

     ZMODEM over 7 bit paths:  (Not supported in DSZ.COM)

     A pair of ZMODEM-90 programs with 7-bit support operating over a 7 bit
     path should detect that fact and switch to one of two 7-bit path
     compatible encodings.  For testing, this can be forced with a "-E"
     option.

     Default 7-bit mode is RLE compression and 8th bit quoting similar to
     Kermit but more efficient because not so many control characters are
     quoted.  Use this default for text files.  Rubout and all control
     characters can be escaped with the -e option.  Individual control
     characters can be escaped with "zmtxesc" and "zmrxesc".

     Pack-7 instead of quoting is activated with the -P option.  (-P has no
     effect on 8 bit paths.) Pack-7 packs 4 bytes into 5 printing characters.
     This is more efficient than quoting for files where 25% more 8th bits
     appear than the number of characters saved by RLE compression.  (This
     statement applies to GIF, ARC, ZOO, and ZIP files.  It may or may not
     apply to other binary file formats, depending on the data.) Pack-7 will
     match or beat standard Kermit on ZIP files, even when Kermit has use of
     all 8 bits.

Note that the first line implies that one must use DSZ.EXE rather than DSZ.COM
on the PC end of things.  I have no idea whether the sz/rz actually support
7-bit transfers.. no mention of it in the man pages that accompanied them.
Perhaps a quick look through the source might reveal this..

Have Fun.
--
 ___Mark S. Lord______________________________________________
| ..uunet!bnrgate!bmerh614!mlord | These are my opinions only.|
|________________________________|____________________________|