Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!apple!wingo@apple.com
From: wingo@apple.com (Tony Wingo)
Newsgroups: comp.sys.mac.programmer
Subject: Re: TicksCount
Message-ID: <14242@goofy.Apple.COM>
Date: 24 Jun 91 23:35:03 GMT
References: <0B01FFFB.ihunr8@outpost.UUCP>
Sender: usenet@Apple.COM
Distribution: na
Organization: Apple Computer
Lines: 29

In article <0B01FFFB.ihunr8@outpost.UUCP>, peirce@outpost.UUCP (Michael Peirce) writes:
> 
> 
> In article <54082@apple.Apple.COM>, keith@Apple.COM (Keith Rollin) writes:
> > In article <1991Jun17.193130.1@lure.latrobe.edu.au> lhccjeh@lure.latrobe.edu.au (James Hale) writes:
> > >
> > >One tick is 1/60 of a second or 16.67 msec. 
> > >a 20 msec accuracy is not an improvement.
> > >_____________________________________________________________________________
> > >James Hale     			Lincoln School of Health Sciences
> > 
> > I think this is a rare case in which Michael misspoke. The original Time
> > Manager was rated at 1 millisecond, but there was no provision for
> > drift-free alarms. The current Time Manager (as provided in System
> > 6.0.3 or later, and documented in technotes and IM VI) is documented as
> > providing 250 microsecond drift-free timing, but you can push that down
> > to 20 microseconds if you want to try getting away with it.
> 
> Rare case where I misspoke?  I make mistakes all the time!
> 
> I did mean to say microsecond rather than millisecond.  What's a few
> zeros between friends? :-)

One small point which most people miss:  The tick frequency is actually 60.15 HZ or 16.63ms/tick (see
IM III-18 or V-566).  Not a large error, but it has been known to cause some consternation.

(I posted this comment once before, but it appears to have gotten garbled.)

-Tony