🚀 go-pugleaf

In article <xsvarshney-0312951335230001@fdlmini.fullerton.edu>,
   xsvarshney@ccvax.fullerton.edu (S Varshney) writes:
>
> Hello, I've been using Qmodem pro 95 to connect to an IBM mainframe
> and have used 3270 emulation as my terminal emulation.


If Qmodem 95 can really emulate an IBM 3270, that is a big surprise!

I rather suspect that what you are really doing is connecting to a
protocol converter that relays data back and forth between your PC
and the IBM mainframe.

Or possibly you are first connecting to a Unix host and running the
"tn3270" application, which essentially acts like a protocol converter.


> The problem is that I get to see chars like "1;2555H" when I hit a
> return upon connecting and
> then the entire screen that has the text is completely misaligned and
> full of chars like the one mentioned above.
>
> What exactly is going wrong here? Please email me any solutions!
> Suvrit <xsvarshney@ccvax.fullerton.edu>

   (I may or may not send you email.  You asked your question in the
    newsgroup, and it is appropriate that the answer be posted there.
    Sometimes I think that "comp.terminals" must be flagged somewhere
    as a write-only newsgroup.)


You may be surprised to learn how vast the difference is between the
communication methods employed in the PC world and the IBM mainframe
world.

For a start, consider this:  the IBM mainframe does not think in ASCII.

An IBM mainframe (370s, 4341s, etc.) or traditional mid-range machine
(AS/400, System/38, etc.) speaks EBCDIC (Extended Binary-Coded-Decimal
Interchange Code) as its native tongue.  If it can handle ASCII
(American Standard Code for Information Interchange) at all, it is
through some translation process.

Without going into all the translation details, suffice it to say that
the protocol converter does a little dance that makes it SEEM to your
PC that the IBM host is communicating in ASCII, and makes it SEEM to
the IBM host that your PC is really a 3270 terminal speaking EBCDIC.

The protocol converter, then, needs to know what type of ASCII-speaking
terminal your computer is emulating.  It is quite common for a protocol
converter to be used with a DEC VT100 or VT320 terminal, so probably
that is how the system you dial up is configured by default.

The "1;2555H" you are seeing is probably a garbled version of a control
sequence that the VT100 understands perfectly well.  However, Qmodem
seems to be set for some other emulation and does not understand the
sequence.

The ANSI X3.64 CUP (cursor position) editing function to position the
cursor to line 1 and column 25 would be (7-bit, without spaces):

    Escape [ 1 ; 25 H

So you might just be able to set Qmodem to VT100 and be able to operate.

But Qmodem was really designed for the BBS market, so the VT100
emulation may or may not be good enough for your needs.  If not, there
are dozens of other VT100 emulation packages available.  Some are
good; some are bad.  Your mileage may vary.

Other info:

    http://www.cs.utk.edu/~shuford/terminal_index.html




-- 
 ...Richard S. Shuford  |"Do not gaze at wine when it is red, when it goes down
 ...shuford@cs.utk.edu  | down smoothly!  Your eyes will see strange sights and
 ...Info-Stratus contact| your mind imagine confusing things."   Proverbs 23:31