From: Philip Guenther (guenther@stolaf.edu)
Date: 09/22/92


From: guenther@stolaf.edu (Philip Guenther)
Subject: Re: How do you link/route a VC to a serial port?
Date: 22 Sep 1992 08:12:19 GMT

In article <1992Sep22.023453.17855@magnus.acs.ohio-state.edu> smccrory@magnus.acs.ohio-state.edu (Scott McCrory) writes:
        OK, now that I have the full Linux 0.96d with the 0.97 upgrade
   working perfectly, :) I want to try to allow logins to a VC through the
   serial port (direct and/or modem). I searched through the FAQs, etc. but
   could not find anything about it. Can you help?

I think there is a small misunderstanding of what a Virtual Console
is. A VC is a way to provide multiple terminals on one console. This
provides a very convenient alternative to running X and having
multiple xterms. They are *not* mere serial lines, to be connected
where ever you want, but rather are dedicated to one specific place:
the console keyboard.
  What it sounds like you want is just a serial port, like /dev/ttys0
(this depends on which naming scheme you use. The system I'm on right
now uses that.) The main point is that there is a device with major
number 4 and minor 64-127. Major device 4 is tty's. These include
VC's, serial (modem) lines, pty and tty pairs (slave/master). The
only way to tell them apart is by minor number.

1-8 VC's
64-127 Serial lines
128-191 tty's (masters)
192-255 pty's (slaves)

I could follow up with a long discussion about how and why the tty
driver uses the minor number to do differant things, but that's not
what you asked for. :-) This post is already to long...

        Thanks,
        Scott McCrory
        smccrory@magnus.acs.ohio-state.edu

Philip Guenther