How to set up a serial port for a modem

Steve Lovett

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Jul 27, 1999, 3:00:00 AM7/27/99

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Hi all,

I am running 5.0.2 and want to add a second modem. When I look at the
serial port configuration in scoadmin, tty2A (where I already have a working
modem) has an M to the left of it. When I configure tty1A, it has a T - and
it acts like a terminal port instead of a modem port.

How do I configure tty1A as a modem port?

TIA for any help.
Steve

Jean-Pierre Radley

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Jul 27, 1999, 3:00:00 AM7/27/99

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Steve Lovett averred (on Tue, Jul 27, 1999 at 11:29:34AM -0500):

disable tty1a; enable tty1A

--
Jean-Pierre Radley <j...@jpr.com> XC/XT Custodian Sysop, CompuServe SCOForum

Steve L.

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Jul 28, 1999, 3:00:00 AM7/28/99

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Jean-Pierre Radley <j...@jpr.com> wrote:

> disable tty1a; enable tty1A

The first thing I did was to make tty1a/A look just like tty2a/A in
inittab and disable tty1a and enable tty1A. That is why I am
confused; When tty1A is enabled, it acts like tty1a, i.e. one can see
getty accessing the port periodically, causing the modem lights to
flicker. I have seen this happen when tty2a was enabled by mistake.
When I look at it in scoadmin-configure-serial, tty1A shows "login
enabled." tty2A shows "answer on" - another indication that one is
being treated as a terminal and one as a modem. Could something have
been done to make tty1A behave as a terminal? Can I start over by
deleting and re-installing com1?
Thanks for your reply...

Jean-Pierre Radley

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Jul 28, 1999, 3:00:00 AM7/28/99

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Steve L. averred (on Wed, Jul 28, 1999 at 02:45:11AM +0000):

| >| I am running 5.0.2 and want to add a second modem. When I look at
| >| the serial port configuration in scoadmin, tty2A (where I already
| >| have a working modem) has an M to the left of it. When I configure
| >| tty1A, it has a T - and it acts like a terminal port instead of a
| >| modem port.
| >|
| >| How do I configure tty1A as a modem port?
|
| > disable tty1a; enable tty1A
|
|

| The first thing I did was to make tty1a/A look just like tty2a/A
| in inittab and disable tty1a and enable tty1A. That is why I am
| confused; When tty1A is enabled, it acts like tty1a, i.e. one can see
| getty accessing the port periodically, causing the modem lights to
| flicker. I have seen this happen when tty2a was enabled by mistake.
| When I look at it in scoadmin-configure-serial, tty1A shows "login
| enabled." tty2A shows "answer on" - another indication that one is
| being treated as a terminal and one as a modem. Could something have
| been done to make tty1A behave as a terminal? Can I start over by
| deleting and re-installing com1? Thanks for your reply...

Nothing in the Operating System directly affects the answer light on
a modem. It's on if S0 is set to something other than 0 (and in some
modems, it's on providing another condition is also met: that the port
is enabled.)

Getty is awake and running only if the lower case port is enabled, since
then getty ignores the status of the DCD (Carrier Detect) pin. That's
what you want for a terminal.

For a modem, you enable the upper case port, in which case getty sleeps
until the DCD pin comes alive, which occurs when the modem has answered
the phone and there's a carrier between the the local and remote modems.
Do not frustrate this scheme by having &C0 set in the modem, since that
causes the DCD pin to always be high, instead of tracking the actual
status of the carrier. Set &C1 &D3 Q E1 in your modem, and save that to
NVRAM.

Edmond Ying

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Jul 29, 1999, 3:00:00 AM7/29/99

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To make to modem all you need is "ats=1" answer after 1 ring

Jean-Pierre Radley <j...@jpr.com> wrote in message
news:1999072723...@jpradley.jpr.com...