Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!think!ames!pasteur!helios.ee.lbl.gov!nosc!humu!uhccux!julian
From: julian@uhccux.uhcc.hawaii.edu (Julian Cowley)
Newsgroups: comp.protocols.misc
Subject: Re: Protocols
Message-ID: <2501@uhccux.uhcc.hawaii.edu>
Date: 19 Oct 88 03:37:52 GMT
References: <1619@nunki.usc.edu> <719@omen.UUCP> <1652@nunki.usc.edu>
Reply-To: julian@uhccux.uhcc.hawaii.edu (Julian Cowley)
Organization: University of Hawaii at Manoa
Lines: 36

In article <1652@nunki.usc.edu> jjung@nunki.usc.edu (John Jung) writes:
>  I don't want to sound ungrateful or anything, but that file doesn't help
>me a whole lot.
>
>  I don't suppose you have a high-level, detailed description of how ZMODEM
>works, without the UNIX or C references? If not, let's call the whole thing
>off...

Ok, so maybe Chuck won't win any awards for his writing style, but the
fact is that Zmodem is a well-designed protocol and should be based on
that.  But still it wouldn't hurt to have a well-written document that
includes explanations of buzzwords like sliding windows, packet-switched
networks, and such.  At the very least, maybe we could all pitch in and
buy Chuck a spelling checker.

As to your comment about the references to Unix, I don't see why they
bother you.  The Zmodem protocol is not adherent to it, and the
document itself mentions considerations about other operating systems
like MS-DOS, Macintoshes, and CP/M.

>P.S. I'm sorry, but it does me no good to hear about when to ssend a ZACK()
>packet if I don't know what the ZACK() packet is...

If Zmodem is your first attempt at programming a protocol, I would
suggest that you go back and start from scratch with vanilla Xmodem and
work your way up through the family's hierarchy.  Plain Xmodem is
really simple to understand.  By the time you get up to Ymodem-batch,
you will have enough experience behind you that Zmodem is not much more
of a hurdle.  And the fact is that if you have a properly designed
program, then it must have Ymodem built-in since Zmodem has to be able
to fall back on it in case the sender or receiver does not support it.

julian@uhccux.uhcc.hawaii.edu
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julian@uhccux.bitnet
"People who aren't amused don't talk."