Using And/Or Avoiding the Feeble Serial-Terminal Capabilities of MS-DOS

 //////////////////////////////////////////////////////////////////////////////

The MS-DOS CTTY command provides a rudimentary interface to the PC's
serial ports.  Use "HELP CTTY" to get the parameters.

One problem that can arise is the dreaded "Abort, Retry, Continue?"
error, the answer for which MS-DOS insists should come from the PC's own
keyboard, not from the serial-port terminal's keyboard.

 //////////////////////////////////////////////////////////////////////////////

From trg1@fn3.freenet.tlh.fl.us Wed Aug 28 22:22:53 1996
Path: stc06.ctd.ornl.gov!cs.utk.edu!news.msfc.nasa.gov!newsfeed.internetmci.com!cpk-news-hub1.bbnplanet.com!cpk-news-feed4.bbnplanet.com!news.fsu.edu!fn3.freenet.tlh.fl.us!fn3.freenet.tlh.fl.us!not-for-mail
From: trg1@fn3.freenet.tlh.fl.us (Tracy Raymond Gibson)
Newsgroups: comp.terminals
Subject: Re: Want to connect a terminal to my computer
Date: 28 Aug 1996 14:46:32 -0400
Organization: Tallahassee Free-Net
Lines: 46
Message-ID: <502468$k2i@fn3.freenet.tlh.fl.us>
References: <4vp271$ljj@iapetus.comco.com>
NNTP-Posting-Host: fn3.freenet.tlh.fl.us

First you have to make your serial cable.  This layout is for
a 9-pin AT style connector:

COMPUTER 1                    COMPUTER 2
pin 2 - - - - - - - - - - - - - - 3
    3 - - - - - - - - - - - - - - 2
    5 - - - - - - - - - - -  - - -5

Connect pins 1, 4 , and 6 together on both sides.
Connect pins 7 and 8 together on both sides.

Start up a DOS window.  Type:
MODE COM1:9600,N,8,1

Change the COM1, 9600, etc. to the com port and speed that your 
terminal is set for.

Then type:
CTTY COM1  

You will now see a DOS prompt at the terminal.  Most programs that use
DOS standard I/O will work fine.  Programs that try to write directly
to the screen may not. (I'm not sure if an andvanced OS like Windows 95
can trap DMA write attempts the way my more primitive Coherent 3.2.1
can.)

Now, minimize the window on the host machine.  When you are ready to
quit type

EXIT

at the command prompt on the terminal.  This works great on my old XT
running DOS 3.3 and PC-MIX.  But, of course Win 95 is much more
sophisticated.  You can even put those commands into a batch file on
the host machine:

MODE COM1:9600,N,8,1
ECHO Starting command shell on COM1 >COM1
PAUSE <COM1 >COM1
ECHO Type EXIT to quit . . . >COM1
CTTY COM1

All you need to do now is add an icon to your GUI and you'll be user friendly!

 -Tracy

 //////////////////////////////////////////////////////////////////////////////

Newsgroups: comp.sys.ibm.pc.hardware.misc,comp.sys.ibm.pc.misc,comp.terminals,comp.sys.ibm.pc.hardware.comm
Path: cs.utk.edu!nntp.memphis.edu!nntp.msstate.edu!gatech!news.sprintlink.net!simtel!news1.oakland.edu!newshub.gmr.com!news.delcoelect.com!c23peg
NNTP-Posting-Host: koptsy15.delcoelect.com
Message-ID: <3spvq4$29k@kocrsv08.delcoelect.com>
References: <Pine.SUN.3.91.950614120313.4249C-100000@altair.herts.ac.uk>
 <DAB4tw.7r4@twg.bc.ca>
Distribution: world
Organization: Delco Electronics Corp.
Date: 27 Jun 1995 22:13:24 GMT
From: c23peg@kocrsv01.delcoelect.com (Perry Grieb)
Subject: Re: Communicating to a dumb terminal from a PC


Try `debug filename.exe > com1 < com1' or something thereabouts.
Then you patch the filename.exe PSP so that it takes its' I/O
from the main keyboard/monitor (stdin, stdout).  The dumb terminal
is then used to control debug without getting in the way of the
application program.  This works great for graphics based programs.
Anyone who hasn't done this doesn't know what their computer's
capablity is.  Oh, now I understand.  You're a Windows user!
Have you ever looked up what `ctty' does in a good DOS book?
I wanted to try ctty just because it was there!

I have a XT running terminal emulation S/W in VT100 mode connected
to my real PC which runs linux.  There is nothing wrong with hanging
terminals on computer serial ports.  It's been done that way for a
long time.  How can you get along on your PC without doing this?
I need the extra I/O, no matter which OS I run.

Shah <csed3cl@herts.ac.uk>:
UNIX clones talk to VT100 terminals very nicely.  From DOS, I'm
not sure I've actually talked to a VT100.  To debug things, you
could probably fire up PROCOMM or TELIX in VT100 mode and configure
it for the correct baud rate and comm port.  Then you should be
able to just type on either keyboard and see results on the other
monitor (chat mode?).  You will need a serial cable, of course.
I'd keep both regular (straight through) & null modem cables handy.

In article <DAB4tw.7r4@twg.bc.ca>, bill@twg.bc.ca (Bill Irwin) writes:
|> Shah <csed3cl@herts.ac.uk> writes:
|> |
|> |I was wondering if anyone could help me, I am trying to communicate to a
|> |dumb terminal (TATUNG VT100) from my PC (486DX 2) the problems I am
|> |having at present is I haven't got any emulators to communicate, and also I
|> |am trying to write a program to do the communication. I don't really have a
|> |clue as to where to begin from, any pointer will be greatly appreciated.
|> 
|> What on earth do you think you can do by connecting a dumb
|> terminal to a PC COM port?
|> -- 
|> Bill Irwin     -      The Westrheim Group     -    Vancouver, BC, Canada
|> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|> bill@twg.bc.ca        604-431-9600 (voice) |       UNIX & Network     
|>                       604-430-4329 (fax)   |    Systems Integration
-- 

c23peg@kocrsv01.delcoelect.com
"I wouldn't have made it up if it wasn't true."

 //////////////////////////////////////////////////////////////////////////////

Newsgroups: comp.terminals
Message-ID: <7c6eed$468$1@pyrite.mv.net>
References: <36e6465d.160620269@news.interpost.no>
Organization: MV Communications, Inc.
X-Trace: pyrite.mv.net 921091341 4296 207.22.33.2 (10 Mar 1999 18:42:21 GMT)
Date: Wed, 10 Mar 1999 13:37:33 -0500
From: Mark <msweeney1999@yahoo.com>
Subject: Re: Telnet? and Vt100

Jens-Morten Dahl wrote in message <36e6465d.160620269@news.interpost.no>...
>Hi !
>
>I have a Dos based application that I have programmed myself.  I want
>to make some of the windows available for terminal sessions.  The
>windows are 20x8 characters. I want to read this windows on terminals
>with a display with 20x8 characters. I also have to put some input in
>the fields in the windows. Any suggestions ?
>
>Best Regards
>   Jens-Morten Dahl ( jmd@intermec.no )

Jens-Morten,

The problem with DOS applications is that they usually use BIOS or DOS
interrupts to read the keyboard and write to the screen display.   Telnet
requires that a program support redirection so that its input and output can
be sent over the communications line.    You will probably  need to add your
own communications functions inside your app.


Mark

 //////////////////////////////////////////////////////////////////////////////

Newsgroups: comp.terminals
Path: utkcs2!stc06.ctd.ornl.gov!fnnews.fnal.gov!uwm.edu!homer.alpha.net
      !mvb.saic.com!nntprelay.mathworks.com!news.mathworks.com
      !howland.erols.net!psinntp!news2.bis.adp.com!news
Date: Tue, 05 Aug 1997 13:48:35 -0400
Organization: ADP
Message-ID: <33E76772.89F@pcmail.bis.adp.com>
References: <5s5jug$3cu@nenevr.demon.co.uk>
To: Simon Coombs <simon@nenevr.demon.co.uk.NOJUNK>
CC: canterad@pcmail.bis.adp.com
NNTP-Posting-Host: 149.83.157.2
From: Dave Cantera <canterad@pcmail.bis.adp.com>
Subject: Re: MS-DOS terminal server software

Simon Coombs wrote:
>
> Greetings, all!
>
> Does anybody know of the existence of software for either DOS or WIN 3.11
> that allows you to make a telnet connection from a terminal attached to
> a serial port? I have an old 386sx that I would like to utilise rather than
> leave festering in the garage, and a job servicing a couple of vt220's
> seems an admirable way of serving out its retirement, to me!
>
> Thanks.


Simon,   this story cries for linux, a 4 port serial board or the 2 port
serial board as std PC equipment, and possibly an Ethernet board....  it
depends on the connection you wish.... all remote connections will most
likely be serial, local connections can include serial or Ethernet, your
choice...

just load linux on your hard drive--it will recognize all your hardware
(you don't need XF86/X11) and hook up the terminal to the serial port...
heck, if you don't want to run the VGA monitor, there are ways around
that too.  you could build a little shelf up near the ceiling to get
that piece out of the way and not even take up desk or floor space...

if you have any questions, feel free to email...

dc

   David Cantera
   canterad@pcmail.bis.adp.com  (w) (609)231-7377
   dcantera@iacnet.net          (h) (609)778-0811


 //////////////////////////////////////////////////////////////////////////////

 //////////////////////////////////////////////////////////////////////////////