The suggestion is not entirely out-to-lunch. Computers certainly used to use the line frequency for the real-time clock; the PDP-11 comes to mind.
In fact the line frequency is a better solution than crystal because, at least here in the UK, the _average_ line frequency is guaranteed to be 50Hz to a very high precision - much better than a crystal. This is achieved by adjusting the short-term line frequency to correct accumulated errors. My old bed-side alarm clock used line frequency and it never needed adjusting except for power-cuts and summer time. You would, of course transform it down to a lower voltage first, but nobody suggested otherwise. It wouldn't blow up a motherboard just because it was AC. In fact it would be dead simple to design a PC board to take a feed from the AC and provide a Linux driver with a 50/60Hz signal. The hardest bit would be getting the AC feed from the self-contained power supply. Does the GMT/LOCALTIME mismatch solve the problem? If so the clock errors would all be of the form "Damn! The clock is off by exactly an hour again!" (or three hours...) And first in one direction (using Linux) and then the other (using Windows.) Neither of these actually alter the hardware clock unless you tell it to, except for summer time, which is topical right now, but each OS should only ever do it once and only by an hour. If it is ever off by some minutes and seconds GMT/LOCALTIME is not the answer. It can only make errors of whole numbers of hours. -- Richard Urwin, Private "No 9000 series computer has ever made a mitsake or corrubiteddatatato." -----Original Message----- From: [EMAIL PROTECTED] [mailto:newbie-owner@;linux-mandrake.com]On Behalf Of Lyvim Xaphir Sent: 03 November 2002 21:02 To: NewbieMandrake-List Subject: Re: [newbie] clock help On Fri, 2002-11-01 at 15:31, Frans Ketelaars wrote: > Uhm, I don't think the power line frequency has anything to do with timing > in computers like PC's that use crystals for timing :) That is correct. 60 cycle ac is rectified and filtered to 12 and 5 volt DC current in the power supply; that is it's purpose. The motherboards have no exposure whatsoever to AC utility current (and would be destroyed if they did). Mobos source their clock signal from a quartz crystal IC, or in some cases electrical IC's generate clock signals without the help of a crystal; although I've been given to understand that the latter is not as accurate or stable a method. The clock case here in this thread is probably an instance of the hardware clock being set to GMT instead of LOCAL time. As David Rankin suggested. > On Fri, 01 Nov 2002 08:59:46 -0500 > Bob Read <[EMAIL PROTECTED]> wrote: > > > Sounds like the system clock is set for 50Hz power line frequency, > > and you are using 60Hz power line. > > > > Bob > > l8r, LX -- 같같같같같같같같같같같같같같같같같같같같같같같같같� Kernel 2.4.18-6mdk Mandrake Linux 8.2 Enlightenment 0.16.5-11mdk Evolution 1.0.2-5mdk Registered Linux User #268899 http://counter.li.org/ 같같같같같같같같같같같같같같같같같같같같같같같같같� ________________________________________________________________________ This email has been scanned for all viruses by the MessageLabs SkyScan service. For more information on a proactive anti-virus service working around the clock, around the globe, visit http://www.messagelabs.com ________________________________________________________________________
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