Kermit FAQ - Problems Using XYZMODEM External Protocols in C-Kermit

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38 Problems Using XYZMODEM External Protocols in C-Kermit

From: (Frank da Cruz)
Newsgroups: comp.unix.aix
Subject: Re: Kermit Using External Protocols - XYZ modem
Date: 21 Nov 1997 14:39:12 GMT

In article <>,
Stephen Tait  <> wrote:
: I am having problems sending a file from AIX 3.2/4.X over a modem to
: a DOS BBS system using Kermit and XMODEM. Using Kermit I dial the
: BBS, connect, enter login and password and the file name that I want
: to send to it. At this point the DOS BBS informs me to select a
: protocol:
: - for PCPLUS (DOS to DOS), I select PgUp, X for XMODEM, enter the
: filename and it all works fine.
: - for AIX, with Kermit 6.0.192 and XYZMODEM protocols from OMEN
: Technology site, I cannot send the file to the BBS because I don't
: know what the equivalent command for "PgUp"(send) in PCPLUS is in
: Kermit.  Also I have used scripting to autologin to the BBS send the
: file using the (sx) XMODEM command but all I get is a hung
: terminal:.(
: I have tried Kermit Support and they tell me, I quote "Omen Tech
: versions of sz rz ... do not allow redirection of stdio.You will
: need to find public domain versions of these protocols if you want
: to use them or purchase appropriate versions from Omen Tech."
: I find this hard to believe, and if somebody knows anything that can
: be of help I would be extremely grateful:.)
By popular demand, C-Kermit 6.0 includes the ability to run external
protocols.  X-, Y-, and ZMODEM are external protocols to Kermit.
External means external, not built-in, and that they come from
elsewhere, not from the Kermit Project; you have to find your own
source for external protocol modules.

You are no doubt using Kermit to run your external protocols because
the sz/rz/sx/rx/sb/rb programs that you have will not make connections
for you.  They were never designed or intended to do that.

Furthermore, as you have learned, these programs do not meet the
fundamental requirement for an external protocol module: to transfer
files over standard input/output, which Kermit can then redirect over
the communications connection that it has made.  That's because,
starting in about 1988, the sz/rz/sx/rx/sb/rb programs were changed to
prevent this.  In other words, they are not designed or intended to be
used as external protocols.  This has nothing to do with C-Kermit or
the Kermit Project.

So you have five choices:

 1. Use Kermit protocol instead of X-, Y-, or ZMODEM.  No worries with
    getting software from different makers to mesh.

 2. Use crz/sz which is designed to be used with Kermit and other
    programs.  The file is available from many places

 3. License modern versions of sz/rz/sx/rx/sb/rb from Omen Technology
    that can be used as external protocols.

 4. License a monolithic program such as Pro-Yamm from Omen Technology
    so you won't need to run C-Kermit at all.

 5. Something entirely different from 1-4.

Frank da Cruz
The Kermit Project
Columbia University

Kermit FAQ / Columbia University /