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From: jbvb@FTP.COM (James B. Van Bokkelen)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: 3270 TELNET client (tn3270 ?) and AS/400 TELNET server (TCP/IP)
Message-ID: <9011071458.AA25335@ftp.com>
Date: 7 Nov 90 14:58:36 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: jbvb@ftp.com
Organization: The Internet
Lines: 55


    IBM's AS/400 has a TCP/IP solution which supports FTP, TELNET etc.
    The TELNET server (also the client) on the IBM only supports ASCII
    streams, 3270 or 5250. For our applications we need at least the 3270
    emulation.

I have heard rumors about the "TN5250" support being developed, but no
standard has been published and for the moment it must be viewed as IBM
proprietary (anyone from IBM want to comment or publish?).

            - Does tn3270 have all this features I need ?
            - Is tn3270 usefull (speed, performance, keyboardmapping...) ?

That's hard to say: TN3270 does its best to make the terminal on your desk
into a 327x device connected to the mainframe via co-ax.  How well it
succeeds depends on how well your terminal can be mapped to the specific
model of 327x your application expects.  A PC with the proper display adapter
can do quite well for all kinds of 3278, and some varieties of 3279.  3179G
is possible, too (talk to Mitek for that).  Minshall's Unix TN3270 has a much
harder job, in that it doesn't have a directly-addressable display and has to
use curses and a keyboard-remapping scheme to transform random asynch Ascii
terminals.  Basic 3278-2 isn't too bad, but things like screen painting tend
to be slow...

            - Does tn3270 work with AS/400 TCP/IP (not only with VM/CMS) ?

Don't know, even about our own DOS product.  I haven't yet heard of an
AS/400 on the Internet that we could test against (any volunteers?).
Either there would have to be something on the AS/400 which translated a
5250 data stram into a 3270 data stream, or you'd need AS/400 applications
which understood 3270s.

            - Does tn3270 work with X-Windows(Openlook and Motif), Sunview
              and ASCII Terminals ?

The curses output can be sent to a terminal emulator running in a window.
It won't be too quick, but it works.  I don't know of anyone who has re-hacked
it to bypass curses and the emulator, but it could certainly be done, at the
cost of marrying it to a particular environment.

            - Is tn3270 also usefull over 9600 Baud Modem ?
              (Terminal->modem->UNIX->tcpip->AS/400)

I've used it that way.  Reading or writing the whole screen will be slow,
so watch out for applications for which this is a way of life...

            - Native language support ?

Our DOS product has a user-loadable Ascii-EBCDIC translation table, and
the screen and keyboard can be re-mapped.  Minshall's original version
would have to be customized in the source.  I don't know what other
vendors have done.

James B. VanBokkelen		26 Princess St., Wakefield, MA  01880
FTP Software Inc.		voice: (617) 246-0900  fax: (617) 246-0901