From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261923AbULPLYu (ORCPT ); Thu, 16 Dec 2004 06:24:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262617AbULPLYu (ORCPT ); Thu, 16 Dec 2004 06:24:50 -0500 Received: from mailhub2.nextra.sk ([195.168.1.110]:26373 "EHLO toe.nextra.sk") by vger.kernel.org with ESMTP id S261923AbULPLYs (ORCPT ); Thu, 16 Dec 2004 06:24:48 -0500 Message-ID: <41C1709E.9000406@rainbow-software.org> Date: Thu, 16 Dec 2004 12:25:18 +0100 From: Ondrej Zary User-Agent: Mozilla Thunderbird 1.0 (X11/20041206) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Pavel Machek CC: Park Lee , dave@lafn.org, linux-kernel@vger.kernel.org Subject: Re: Issue on connect 2 modems with a single phone line References: <20041215184206.43601.qmail@web51505.mail.yahoo.com> <20041216010138.GC6285@elf.ucw.cz> In-Reply-To: <20041216010138.GC6285@elf.ucw.cz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Pavel Machek wrote: > Hi! > > >> I want to try serial console in order to see the >>complete Linux kernel oops. >> I have 2 computers, one is a PC, and the other is a >>Laptop. Unfortunately,my Laptop doesn't have a serial >>port on it. But then, the each machine has a internal >>serial modem respectively. >> Then, can I use a telephone line to directly connect >>the two machines via their internal modems (i.e. One >>end of the telephone line is plugged into The PC's >>modem, and the other end is plugged into The Laptop's >>modem directly), and let them do the same function as >>two serial ports and a null modem can do? If it is, >>How to achieve that? > > > You'd need phone exchange to do this. Most modems will not talk using > simple cable. With 12V power supply and resistor phone exchange is > quite easy to emulate, but... > Pavel I've tried it with 2 older Microcom modems and a piece of cable and it worked. Opened terminal on both sides, wrote ATDT123 (or any number you like) and ATA on the other. But if the laptop modem is a software modem, this will not work. -- Ondrej Zary