From owner-freebsd-hackers@FreeBSD.ORG Wed Apr 26 18:13:12 2006 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4CB3A16A400 for ; Wed, 26 Apr 2006 18:13:12 +0000 (UTC) (envelope-from rick@kiwi-computer.com) Received: from kiwi-computer.com (megan.kiwi-computer.com [63.224.10.3]) by mx1.FreeBSD.org (Postfix) with SMTP id 6BF8B43D49 for ; Wed, 26 Apr 2006 18:13:09 +0000 (GMT) (envelope-from rick@kiwi-computer.com) Received: (qmail 64789 invoked by uid 2001); 26 Apr 2006 18:13:08 -0000 Date: Wed, 26 Apr 2006 13:13:08 -0500 From: "Rick C. Petty" To: Lucas Holt Message-ID: <20060426181308.GA64085@megan.kiwi-computer.com> References: <20060425202009.50F9143D75@mx1.FreeBSD.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Cc: freebsd-hackers@freebsd.org Subject: Re: Keyboard Boot Disable X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Apr 2006 18:13:12 -0000 On Tue, Apr 25, 2006 at 06:27:53PM -0400, Lucas Holt wrote: > I worked with someone once that said they blew out the ps/2 port on > the motherboard. As an alternative, maybe you could consider a kvm > switch? Maybe on an ancient motherboard?? Most motherboards have overvoltage/overcurrent protection circuitry. A PS/2 port is just a glorified serial port: 5v signals vs. +/- 7.5v. The only problem I've ever had with hot-swapping PS/2 is tricking the OS to reinitialize the device. FreeBSD seems to handle this better than most. Smart KVMs work much better because they keep the virtual device connected, and they keep keyboard initialization state so they can reinitialize the keyboard when it's plugged in again. Even dumb KVMs seem to handle hot-swapping better; likely the onboard logic behaves better than the onboard keyboard controllers. USB works much better because it guarantees power & ground connection is established before the data pins. Many KVMs buffer the keyboard I/O so it can wait until power & ground are established before trying to send/recv data. I've never blown out a PS/2 port or device, and I hot swap much more than I should... -- Rick C. Petty