From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 27 Jan 2001 05:20:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 27 Jan 2001 05:20:25 -0500 Received: from 13dyn73.delft.casema.net ([212.64.76.73]:32777 "EHLO abraracourcix.bitwizard.nl") by vger.kernel.org with ESMTP id ; Sat, 27 Jan 2001 05:20:12 -0500 Message-Id: <200101271020.LAA22568@cave.bitwizard.nl> Subject: Re: Linux Post codes during runtime, possibly OT In-Reply-To: <94q96s$9b2$1@cesium.transmeta.com> from "H. Peter Anvin" at "Jan 25, 2001 02:26:36 pm" To: "H. Peter Anvin" Date: Sat, 27 Jan 2001 11:20:04 +0100 (MET) CC: linux-kernel@vger.kernel.org From: R.E.Wolff@BitWizard.nl (Rogier Wolff) X-Mailer: ELM [version 2.4ME+ PL60 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org H. Peter Anvin wrote: > Followup to: <3A709E99.25ADE5F6@echostar.com> > By author: "Ian S. Nelson" > In newsgroup: linux.dev.kernel > > > > I'm curious. Why does Linux make that friendly 98/9a/88 looking > > postcode pattern when it's running? DOS and DOS95 don't do that. > > > > I'm begining to feel like I can tell the system health by observing it, > > kind of like "seeing the matrix." > It output garbage to the 80h port in order to enforce I/O delays. > It's one of the safe ports to issue outs to. Yes, because it is reserved for POST codes. You can get "POST debugging cards" that simply have a BIN -> 7segement encoder and two 7 segment displays on them. They decode 0x80. That's what it's for. Roger. -- ** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2137555 ** *-- BitWizard writes Linux device drivers for any device you may have! --* * There are old pilots, and there are bold pilots. * There are also old, bald pilots. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/