Path: utzoo!attcan!utgpu!watserv1!maytag!watstat.waterloo.edu!dmurdoch
From: dmurdoch@watstat.waterloo.edu (Duncan Murdoch)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Fixed clock speed on pc?  CLK_TCK == 18.2 is TRUE??
Message-ID: <1990Dec21.143605.20997@maytag.waterloo.edu>
Date: 21 Dec 90 14:36:05 GMT
References: <15779.2770e40e@levels.sait.edu.au> <82583.2771ee24@vaxc.cc.monash.edu.au>
Sender: daemon@maytag.waterloo.edu (Admin)
Organization: University of Waterloo
Lines: 12

In article <82583.2771ee24@vaxc.cc.monash.edu.au> apm233m@vaxc.cc.monash.edu.au writes:
>
>I don't know why CLK_TCK is defined in time.h, but the nominal 18.2 "ticks" per
>second should be the same on all machines running MS-DOS.

As an aside:  someone in the Fidonet Pascal who was writing programs to use
at timing races commented on this.  He found the tick rate is very stable
on most machines, but varies from the IBM standard rate by as much as a few
percent (I think) on some clones.  If you need high accuracy, it's necessary
to calibrate it against a reliable external clock.

Duncan Murdoch