Date: Thu, 8 Feb 2001 02:57:35 -0800 From: "Ted Mittelstaedt" <tedm@toybox.placo.com> To: "Jason F Wells" <jason+freebsd@routermonkey.com>, <freebsd-questions@FreeBSD.ORG> Subject: RE: Keyboard detection in 4.2-RELEASE, 4.2-STABLE Message-ID: <004601c091bd$f1e161a0$1401a8c0@tedm.placo.com> In-Reply-To: <20010207101923.B6097@fry.routermonkey.com>
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> -----Original Message----- > From: owner-freebsd-questions@FreeBSD.ORG > [mailto:owner-freebsd-questions@FreeBSD.ORG]On Behalf Of Jason F Wells > Sent: Wednesday, February 07, 2001 9:19 AM > To: freebsd-questions@FreeBSD.ORG > Subject: Re: Keyboard detection in 4.2-RELEASE, 4.2-STABLE > > > > I'm aware of the risks of hot-plugging; I've had very few problems > considering the number of servers I've worked on. I've had far worse > luck with serial cables than keyboards. > If you want to take risks that's your business, but before anyone else does let me just reprint the relevant section of the serial port standard (RS232) here: "The generator is designed to withstand an open-circuit (unconnected) condition, or short-circuit condition between its signal conductor and any other signal conductor, including ground, without sustaining damage to itself or causing damage to any associated circuitry. The receiver is also designed to accept any signal voltage within the range of ±25 volts without sustaining damage." Basically you can short out the serial port without damaging it. The keyboard ports and PS/2 ports are an entirely different matter because they are unstandardized and the manufacturer has no obligation to put any kind of protection circuitry on the keyboard or PS/2 ports. This also means that if you have had a serial port burned out by hot plugging your legally within the law to return the computer as a defect - because the port on it is not compliant to the published standard. I know for myself I've never seen a serial port burned out by hot plugging or by a messed up switchbox, but I've seen keyboard ports ruined this way. Ted Mittelstaedt tedm@toybox.placo.com Author of: The FreeBSD Corporate Networker's Guide Book website: http://www.freebsd-corp-net-guide.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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