Path: utzoo!attcan!uunet!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!rpi!uupsi!rodan.acs.syr.edu!isr
From: isr@rodan.acs.syr.edu (Michael S. Schechter - ISR group account)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Timer
Message-ID: <1990Oct22.134917.5562@rodan.acs.syr.edu>
Date: 22 Oct 90 13:49:17 GMT
References: <10719.271f09c1@amherst.bitnet>
Organization: Institute for Sensory Research
Lines: 21

In article <10719.271f09c1@amherst.bitnet> mbabramowicz@amherst.bitnet writes:
>	Time = Ticks();
>	for (count = 0; (count<= 2000) && (!Button()); count++);
>	Time = Ticks() - Time;
>	oneTick = 2000/Time;
>
>The variable oneTick is now set equal to the number of times you go through
>the for loop in a Tick.
      This loop has variable time to execute due to
      interupts occurring during it. And, yes, these interrupts
      take up of **lots** of time at times.
      Even if a machine is sitting idle you still have some
      interrupts in there taking up unknown amount of time.
      (on a II, there's something that takes up  80-120usec
      and happens at least a few times every second)
      and that's without even worrying about what happens when the
      mouse moves (more interupts)

-- 
Mike Schechter, Computer Engineer,Institute Sensory Research, Syracuse Univ.
InterNet: Mike_Schechter@isr.syr.edu isr@rodan.syr.edu Bitnet: SENSORY@SUNRISE