From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936232AbXGLA7n (ORCPT ); Wed, 11 Jul 2007 20:59:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S936338AbXGLA7S (ORCPT ); Wed, 11 Jul 2007 20:59:18 -0400 Received: from terminus.zytor.com ([192.83.249.54]:38982 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936155AbXGLA7Q (ORCPT ); Wed, 11 Jul 2007 20:59:16 -0400 Message-ID: <46957CBF.1000101@zytor.com> Date: Wed, 11 Jul 2007 17:58:39 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.0 (X11/20070419) MIME-Version: 1.0 To: Bodo Eggert <7eggert@gmx.de> CC: Linux Kernel Mailing List , Linus Torvalds Subject: Re: [PATCH] Use BIOS Keyboard variable to set Numlock References: In-Reply-To: X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Bodo Eggert wrote: > > Instead of the byte at 0x497 as suggested in that thread, I'm using the > byte at 0x417, which reflects the intended LED state. In order to change > the keyboard LED, DOS programs would change this byte and call INT 5 > (which is the keyboard software interrupt). > 0x417 is actually the current keyboard modifier state, which is the right thing to use. Presumably you meant INT 9 (IRQ 1), not INT 5 which is the print screen interrupt (also used by the CPU for BOUND error, which has some amusing consequence if anyone ever used the BOUND instruction in DOS.) That being said, one could argue that since this is a BIOS interface it should be queried via INT 16h, AH=02h and stuffed in the zeropage structure. This would also solve the issue of it not being supported by non-BIOS firmware. -hpa