Return-Path: Received: (qmail 7256 invoked from network); 13 Feb 2004 11:26:02 -0000 Received: from unknown (HELO ptb-mxscan03.plus.net) (212.159.14.237) by ptb-mailstore03.plus.net with SMTP; 13 Feb 2004 11:26:02 -0000 Received: (qmail 72053 invoked from network); 13 Feb 2004 11:26:02 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 Received: from ptb-mxcore03.plus.net (212.159.14.217) by ptb-mxscan03.plus.net with SMTP; 13 Feb 2004 11:26:01 -0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore03.plus.net with esmtp (Exim) id 1ArbSL-000Ic3-6a for dave@picks.force9.co.uk; Fri, 13 Feb 2004 11:26:01 +0000 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ArbRO-0002S2-Li for rs_out@blacksheep.org; Fri, 13 Feb 2004 11:25:02 +0000 Received: from [194.73.73.93] (helo=rhenium.btinternet.com) by post.thorcom.com with esmtp (Exim 4.14) id 1ArbRO-0002Rt-4y for rsgb_lf_group@blacksheep.org; Fri, 13 Feb 2004 11:25:02 +0000 Received: from [81.135.56.30] (helo=Main) by rhenium.btinternet.com with smtp (Exim 3.22 #25) id 1ArbRN-00057F-00 for rsgb_lf_group@blacksheep.org; Fri, 13 Feb 2004 11:25:01 +0000 X-Bad-Message-ID: no DNS (Main) Message-ID: <002a01c3f223$faac9f60$6507a8c0@Main> From: "Alan Melia" To: rsgb_lf_group@blacksheep.org References: <8840D182F8BB7540B173D2B1FA0CA9AB018AE32F@argos.clb.tcfr.thales> Date: Fri, 13 Feb 2004 11:24:35 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: Re: LF: Timing GPS Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.60 (1.212-2003-09-23-exp) on post.thorcom.com X-Spam-Status: No, hits=0.0 required=5.0 tests=none autolearn=no version=2.60 X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-PN-SPAMFiltered: yes X-Spam-Rating: 2 Hello again Jean-Louis. I had thought about that ( software clock drift dependent on cpu usage) and wondered whether it would be possible to force the software clock to sync with the hardware clock at regular intervals (say 30 mins) using the scheduler. This could possibly be run behind the capture program if not incorporated into it ?? I am not sufficiently knowledgable about windows to now how to do it. Cheers de Alan G3NYK alan.melia@btinternet.com ----- Original Message ----- From: To: Sent: 13 February 2004 08:59 Subject: RE: LF: Timing GPS Hi all Please keep in mind that Windows operating systems are very poor "time keepers". They drift very quickly, depending on the programs you are running. A drift of one second up to one minute per day is not uncommon (specially with "data crunchers" softwares like real time FFT computing)! I'm not talking about the drift of the PC hardware clock itself which is quite good (the time base xtal oscillator drifts around 2 s per month on my own computer), but from the Windows time management. It seems that the time management on the Windows multitask OS has a very low priority ... I verified this on Windows 95, Windows 98 and Windows Me. Any other experience with other operating systems ? 73 de Jean-Louis F6AGR