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Date: Fri, 14 Feb 1997 09:04:15 -0500 (EST)
From: Thomas David Rivers <ponds!rivers@dg-rtp.dg.com>
Message-Id: <199702141404.JAA10823@lakes.water.net>
To: ponds!via.net!joe, ponds!freebsd.org!questions
Subject: Re: tn5250 !
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> 
> 
> Does anyone know how a tn5250 session differs from a regular telnet 
> session? I'm trying to persuade a tn5250 emulator to work with the
> fwtk telnet proxy.
> 
> Is there source to a tn5250 program available somewhere?
> 
> Thanks,
> 
> Joe
> 

 There are several differences; mostly that it negotiates a binary
sessions instead of text one.

 tn5250 emulates an IBM EBCDIC terminal that deals in things called
3270-control codes; or a 3270-data stream.    The terminal accepts
this stream; draws stuff on the screen based on it. Let's the user
fill in certain areas and when <ENTER> (or, more generically, SEND) is 
pressed; sends the filled in information back to the machine.

 If could be your proxy isn't working for binary sessions.

 For more information, you should see the tn3270 sources in 
/usr/src/usr.bin or the tn3270 man page.  [A 5250 is just an
improved variant of this scheme.]

 Also, you can look up the X11 variant (tn3270 is a curses program),
x3270 - written at Georgia Tech.  It's available in the ports.

	- Dave Rivers -