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From: walton@tybalt.caltech.edu (Steve Walton)
Newsgroups: comp.sys.amiga
Subject: Re: XMODEM
Message-ID: <3280@cit-vax.Caltech.Edu>
Date: Mon, 20-Jul-87 12:33:07 EDT
Article-I.D.: cit-vax.3280
Posted: Mon Jul 20 12:33:07 1987
Date-Received: Tue, 21-Jul-87 05:11:15 EDT
References: <8707200126.AA15199@cogsci.berkeley.edu>
Sender: news@cit-vax.Caltech.Edu
Reply-To: walton@tybalt.caltech.edu.UUCP (Steve Walton)
Organization: Calfornia Institute of Technology
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In article <8707200126.AA15199@cogsci.berkeley.edu> bryce@COGSCI.BERKELEY.EDU (Bryce Nesbitt) writes:
>I have several different terminal emulator programs for the Amiga.  All support
>XMODEM transfer.  Only one supports XMODEM CRC.  XMODEM CRC is *EASY* to add,
>and gives a big reliability boost for transfer over noisy lines.  I'd like to
>have this feature on all the programs I use, and to this end I have dug up
>the actual specification for XMODEM and XMODEM CRC.

While we're wish-listing for terminal programs, here's mine in order
of importance:
(1) Kermit--the single best protocol for communication between heterogenous
    machines.  The basic protocol can be implemented with very few lines.
    Also has options for 1-byte checkum, or 2 or 3-byte CRC's.
(2) Long packet XMODEM--same as normal XMODEM but with 1024-byte packets.
    A big win over packet switched networks.  CRC nearly mandatory here.
(3) Batch XMODEM, sometimes called YMODEM--Simple:  interpret the first
    128-byte packet you receive as containing a null-terminated file name.
    Also contains the exact length of the file in bytes--no more chopping!
    Optionally contains file mod date and mode.
(4) Windowed protocol, Kermit (hard) or WXMODEM (somewhat easier)--These
    are full duplex protocols which simultaneously send data both ways.
    I find 1200 baud WXMODEM achieves an 1150 baud transfer rate over
    good ol' Telenet.

    Steve Walton, guest as walton@tybalt.caltech.edu
    AMETEK Computer Research Division, ametek!walton@csvax.caltech.edu
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