Want to enable DEC VT320 to login on ttys0

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rAllcorn
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Want to enable DEC VT320 to login on ttys0

Post by rAllcorn » Thu Jun 21, 2018 5:51 pm

I have looked just about everywhere I can think of to find out how to configure a serial terminal in LINUX MINT. But everybody keeps telling me how to set up a serial console (not just a terminal port) or dial-in ...

I just want to enable my dec vt320 to login on ttys0 ...

Can anyone help me?

Let me emphasize ... I don't want it to be the console (at least not yet)


-rAllcorn-
Richard A. Allcorn
eMail: <e-mail address removed by moderator>

P. S. I used to be able to easily configure a port to do dial-in and out, or hardwired, but we keep changing the process.
Last edited by karlchen on Thu Jun 21, 2018 6:26 pm, edited 1 time in total.
Reason: split off from a 4 year old thread, https://forums.linuxmint.com/viewtopic.php?f=90&t=159214


rAllcorn
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Re: Want to enable DEC VT320 to login on ttys0

Post by rAllcorn » Sat Jun 23, 2018 1:10 am

I am trying to be nice about this ...
Everyone seems to think when I say "terminal" that I mean a virtual terminal.
I am talking about a DEC VT320 serial ascii terminal from the 1990's guys, NOT a virtual terminal.
I should not have to download some emmulator ... UNIX/LINUX is designed to work with serial terminals.
And it used to be easy, with configuration files, etc. but somebody decided it would be neat to change a standard.
Now, I cannot seem to find "anyone" who knows how to simply initial a serial terminal on ttyS0

PORT: /dev/ttyS0
UART: 9600, 8/N/1
It should initiate a "getty" session, for login.

HELP!!!

rAllcorn
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Re: Want to enable DEC VT320 to login on ttys0

Post by rAllcorn » Thu Jul 19, 2018 6:44 pm

Does anyone check these posts, or is this just on a screen in somebody's garage?

lazarus
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Re: Want to enable DEC VT320 to login on ttys0

Post by lazarus » Thu Jul 19, 2018 10:27 pm

/dev/ttyS0 equates to the old COM1:

As few modern computers actually have an RS-232 port nowadays, I'm curious what you're using. An RS-232->USB adapter? (Somehow I doubt you're using the MMJs... :lol: )

What, if any, signs of connectivity do you have? if you type "echo test > /dev/ttyS0" on the host is there output on the VT?

Dredging from old, old memories here... the VT-300 series had two operating modes. Online & Local. Are you sure it's online? Come to that, I'm sure it'll also run in VT-200 & -100 modes as 7-N-1. Have you tried setting it as a VT-100 and seeing if the host detects? Can't get much more "base standard" than a 100!
- Andy

I may be weird but I'm saving up to become eccentric.

rAllcorn
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Re: Want to enable DEC VT320 to login on ttys0

Post by rAllcorn » Thu Jul 19, 2018 10:31 pm

My only problem was in setting up the getty process to begin.
I can echo text to the terminal screen ... no problem.

I finally stumbled upon this:

(I am beginning to seriously hate SYSTEMD)

Defining a Serial Terminal Using systemd

If your init system is systemd, become root; then issue the following commands:


cd /etc/systemd/system
mkdir serial-getty@ttyS0.service.d
cd serial-getty@ttyS0.service.d

Now create a file in the current directory called "override.conf". It should look like this:


[Service]
ExecStart=
ExecStart=-/sbin/agetty -8 --noclear -I \033H\033J 38400 %I ibm3151

Save the file and exit the editor. "%I" will be substituted with the name of the serial port at execution time (ttyS0). The definitions of the other parameters are given in the sysvinit section above. Make sure that the terminal is connected and powered on. Tell systemd to reload the configuration by issuing


systemctl daemon-reload

Check that your changes have been recognized by systemd by issuing


systemctl cat serial-getty@ttyS0.service|tail -n 5

You should see output something like this:


# /etc/systemd/system/serial-getty@ttyS0.service.d/override.conf
[Service]
ExecStart=
ExecStart=-/sbin/agetty -8 --noclear -I \033H\033J 38400 %I ibm3151

(The first line of output should be blank.) Start the service by issuing


systemctl start serial-getty@ttyS0.service

You should now see a login prompt on your serial terminal. Finally, make the service permanent, so that it will start automatically at the next reboot, by issuing


systemctl enable serial-getty@ttyS0.service

rAllcorn
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Re: Want to enable DEC VT320 to login on ttys0

Post by rAllcorn » Thu Jul 19, 2018 10:34 pm

Oh, and in answer to your question ... there is only 1 serial port.
This is standard for a server, should you need to control a UPS system, or console in serially.

I have a DEC VT320, connected to the serial port (in MS-DOS called COM1:) /dev/ttyS0
I didn't want to substitute the console to be serial, I just wanted login on the serial port for a terminal.
Following the last instructions I posted, fixed it.

... but I "hate" SYSTEMD.

Why do we always have to change something that works!

lazarus
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Re: Want to enable DEC VT320 to login on ttys0

Post by lazarus » Thu Jul 19, 2018 10:53 pm

Glad you got there. I know how you feel about systemd...

Looking back you didn't actually say you were trying to connect to server hw so I was assuming you were connecting to a desktop PC. [shrug] Could've been frustrating for both of us. :wink:
- Andy

I may be weird but I'm saving up to become eccentric.

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