Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758277AbXFMKlt (ORCPT ); Wed, 13 Jun 2007 06:41:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757068AbXFMKlm (ORCPT ); Wed, 13 Jun 2007 06:41:42 -0400 Received: from bipbip.grupopie.com ([195.23.16.24]:37475 "EHLO bipbip.grupopie.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1757004AbXFMKll (ORCPT ); Wed, 13 Jun 2007 06:41:41 -0400 Message-ID: <466FC9E2.9060306@grupopie.com> Date: Wed, 13 Jun 2007 11:41:38 +0100 From: Paulo Marques Organization: Grupo PIE User-Agent: Thunderbird 1.5.0.12 (X11/20070509) MIME-Version: 1.0 To: "Maciej W. Rozycki" CC: Jan Engelhardt , David Schwartz , "Linux-Kernel@Vger. Kernel. Org" Subject: Re: PC speaker References: In-Reply-To: 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 Content-Length: 1619 Lines: 35 Maciej W. Rozycki wrote: > On Tue, 12 Jun 2007, Jan Engelhardt wrote: > >>> 4) It assumes the current will be sufficient to burn out the speaker. (I >>> know it will get very hot on older machines, whether it will burn out -- >>> might even depend on the exact speaker model.) >> Since you can set the x86's crystals frequency from 1193182 to 18 Hz >> (PIT_TICK_RATE / 1 to PIT_TICK_RATE / 65535) [*], you can never really >> bust it. But even then, what would a speaker do it was constanly given > > I am fairly sure you have a choice between a steady low and a steady high > level on the speaker output available if you switch the 8254 to the right > single-shot mode. In case you have not been into such details -- the 8254 > offers six modes of operation, selected for each channel separately, of > which only two are periodic. Can we please stop this non-sense thread? Anyone designing the speaker circuit would certainly place a small capacitor in series with the speaker to kill the DC component of the signal. Since the speaker itself wouldn't be able to play very low frequencies anyway, the capacitor wouldn't have to be that big. So I'm pretty sure that on any half-way decent piece of hardware, you won't be able to kill the speaker with software... -- Paulo Marques - www.grupopie.com "Don't hit a man when he's down -- kick him; it's easier." - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/