From owner-freebsd-hackers Sun Jan 28 17:39:19 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id RAA17303 for hackers-outgoing; Sun, 28 Jan 1996 17:39:19 -0800 (PST) Received: from hauki.clinet.fi (root@hauki.clinet.fi [194.100.0.1]) by freefall.freebsd.org (8.7.3/8.7.3) with ESMTP id RAA17298 for ; Sun, 28 Jan 1996 17:39:15 -0800 (PST) Received: from katiska.clinet.fi (root@katiska.clinet.fi [194.100.0.4]) by hauki.clinet.fi (8.7.3/8.6.4) with ESMTP id DAA27849; Mon, 29 Jan 1996 03:38:48 +0200 (EET) Received: (hsu@localhost) by katiska.clinet.fi (8.7.3/8.6.4) id DAA07721; Mon, 29 Jan 1996 03:38:48 +0200 (EET) Date: Mon, 29 Jan 1996 03:38:48 +0200 (EET) Message-Id: <199601290138.DAA07721@katiska.clinet.fi> From: Heikki Suonsivu To: Terry Lambert Cc: hsu@clinet.fi (Heikki Suonsivu), hm@altona.hamburg.com, freebsd-hackers@freebsd.org Subject: Re: Multi-Port Async Cards In-Reply-To: <199601282257.PAA01785@phaeton.artisoft.com> References: <199601280246.EAA23330@newzetor.clinet.fi> <199601282257.PAA01785@phaeton.artisoft.com> Organization: Clinet Ltd, Espoo, Finland Sender: owner-hackers@freebsd.org Precedence: bulk Terry Lambert writes: > > mgetty would be useful as it can > > actively reply calls instead of modems answering automatically, thus > > avoiding callers getting modem answer when the terminal server has crashed > > and won't be there. > > A properly configured modem and getty will do this as well. > > A properly configured modem will not answer unless DTR is asserted. > When the open count coes from 1->0, the DTR is dropped. This causes a > correctly configured modem to reset (reset on on-to-off transition of DTR). Rockwell chipset based modems (all the ones I have seen) don't have DTR option which would allow this. It can either reset itself when DTR goes off (&D3), but then it will answer the phone even when DTR is off. If it does not reset itself (&D2), it works correctly with DTR. The lesson is not to use rockwell based modems, but they didn't have much competition until last six months. > If the machine crashes, getty goes away (the POST state on a proper serial > port is to not assert DTR), and so the modems are not answered. If the machine deadlocks, gettys won't go away. At least 1 of four crashes are deadlocks where the machine freezes. -- Heikki Suonsivu, T{ysikuu 10 C 83/02210 Espoo/FINLAND, hsu@clinet.fi work +358-0-4375209 fax -4555276 home -8031121