Vb.net Telnet VT100

G

Guest

I know how to use telnet in vb.net but now I need to connect a dial-up modem
first using vt100. Is there an built-in api for this?
 
N

Nick Malik [Microsoft]

actually, vt100 is an old terminal type (from Digital Equipment Corp, which
merged with Compaq before it merged with HP... not much left of old DEC
these days). When folks refer to vt100, they are usually referring to the
fact that this terminal had the ability to intercept the text data coming in
to it and look for "escape sequences." These escape sequences could move
the cursor around on the screen. clear lines and groups of lines, and place
text in a specific place. This was advanced stuff at the time (late 1970s,
if I recall). I'm pretty sure the vt52 had 17 lines of text and the vt100
had 42 lines, but that is really pushing it. The escape sequences
themselves became a de-facto standard and many manufacturers adopted the
command set for controlling the terminals. I'm fairly sure that the
sequences became a standard along the way (although I don't know if the
terminal came before the standards, or if the standards came first).

For a list of some of the vt100 command set, see:
http://www.termsys.demon.co.uk/vtansi.htm

You don't actually make a connection on a modem using vt100. You make a
connection on a modem using AT commands. These were introduced by a modem
manufacturer called Hayes in the 1980s(?). Here's a summary of some of the
major AT commands http://www.computerhope.com/atcom.htm

You are probably best off creating a dial-up modem connection in Windows to
drive the modem, and using that connection from your code. Windows will
handle setting up the connection for you.

Once your connection is made, the other end responds by sending you ASCII
text with escape sequences embedded in it.

There isn't an API but there is a product...two products actually. Take a
look at WRQ Verastream and WRQ Reflection (depending on whether you need to
access the remote legacy environment from a server or from a client,
respectively). They can really make the difference in hiding the complexity
of contacting a legacy ASCII terminal environment.

--
--- Nick Malik [Microsoft]
MCSD, CFPS, Certified Scrummaster
http://blogs.msdn.com/nickmalik

Disclaimer: Opinions expressed in this forum are my own, and not
representative of my employer.
I do not answer questions on behalf of my employer. I'm just a
programmer helping programmers.
 
C

Cor Ligthert

Nick,
This was advanced stuff at the time (late 1970s,
if I recall). I'm pretty sure the vt52 had 17 lines of text and the vt100
had 42 lines, but that is really pushing it.

No it was not advanced it was much longer, it where called intelligent
screens (not workstations).

http://www.columbia.edu/acis/history/3270.html
I am almost sure that when you sees this say, oh yes, I knew that.

And there where in my opinion already better at that time, however that is
the most famous one.

An original VT100 as well
http://www.columbia.edu/acis/history/vt100.html

(When the OP reads the text by this it explains it all in my opinion)

Cor
 
N

Nick Malik [Microsoft]

Hi Cor,
No it was not advanced it was much longer, it where called intelligent
screens (not workstations).

http://www.columbia.edu/acis/history/3270.html
I am almost sure that when you sees this say, oh yes, I knew that.

This article is about the IBM3270, which was a block-mode terminal (still in
use today, I might add). The VT52 and VT100 were character mode terminals.
You are comparing apples and oranges. Nothing I said would challenge the
notion that the 3270 was a good solution for its time.
And there where in my opinion already better at that time, however that is
the most famous one.

Both of these technologies have faded. It does no one any good to argue
about which was better in 1978.

--
--- Nick Malik [Microsoft]
MCSD, CFPS, Certified Scrummaster
http://blogs.msdn.com/nickmalik

Disclaimer: Opinions expressed in this forum are my own, and not
representative of my employer.
I do not answer questions on behalf of my employer. I'm just a
programmer helping programmers.
--
 
C

Cor Ligthert

Nick,

The thing was that it was as well intelligent, the 3270 where called
synchrone and there where more differences. I showed the 3270 because I
could not find older types that had even better possibilities.

And you said the VT100 was advanced stuff. That it was only in my opinon for
people who were using the original teletype. (A kind of online typewriter).

There where already ones before the VT100 which had by instance inbuild form
mode.

Cor
 

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