Date: Mon, 24 Jul 1995 09:01:50 +0600 (GMT+0600) From: "Serge A. Babkin" <babkin@hq.icb.chel.su> To: terry@cs.weber.edu (Terry Lambert) Cc: ache@astral.msk.su, bde@zeta.org.au, hackers@freebsd.org, harry@hgac.com, jkh@violet.berkeley.edu Subject: Re: dial up at > 9600 baud Message-ID: <199507240301.JAA13278@hq.icb.chel.su> In-Reply-To: <9507232324.AA03440@cs.weber.edu> from "Terry Lambert" at Jul 23, 95 05:24:44 pm
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>
> > I think that getty don't play role here. Most modern modems are
> > able to sense local interface speed somehow, maybe initial
> > connect handshake involved or other tricks, I don't know
> > exactly.
>
> This is critically bogus unless you cn back this up with documentation
> on external clock signal support.
>
> The modem must interact with the computer to sense the port speed.
^^^^^^^^
And do this in _command_ mode.
> Period.
>
> If getty is spitting crap out before setting the port speed, then that
> is a getty problem, and should be fixed.
With getty modem _never_ enters the command mode. IMO the sequence of
cations for getty is:
1. Initial state: DTR is off, modem ignores everything
2. Getty opens the port (more accurately, it calls open() and sleeps
until DCD is detected), DTR rises, modem starts to wait for the incoming
calls. Modem should be set up to reset to non-volatile memory settings
at DTR off-to-on transition. These settings have to include echo off,
no reports on carrier detect and fixed DCE-to-DTE rate.
3. Modem gets carrier, DCD rises, modem enters the data mode, getty
finishes its open() call and begins to work.
I see absolutely no place in this sequence where modem should get any
command. The only problam may be if getty opens the port with ONDELAY
and then puts some text into it before setting the speed. If so, IMHO
it's a wrong behavior that should be fixed. If not, everything should go
fine without any changes.
Serge Babkin
! (babkin@hq.icb.chel.su)
! Headquarter of Joint Stock Commercial Bank "Chelindbank"
! Chelyabinsk, Russia
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