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From: Joe Eddy Demers <Coyote+@CMU.EDU>
Newsgroups: comp.sys.ibm.pc,comp.sys.ibm.pc.misc,comp.sys.ibm.pc.hardware
Subject: BIOS timer interrupts
Date: Thu, 22 Apr 1993 14:26:53 -0400
Organization: Sophomore, Math/Computer Science, Carnegie Mellon, Pittsburgh, PA
Lines: 18
Message-ID: <IfpiBhG00Vp3QXsm0t@andrew.cmu.edu>
NNTP-Posting-Host: po2.andrew.cmu.edu

Hello,
    I'm trying to use the BIOS timer interrupts (which occur every .055
seconds, or 18.2 times a second) to time people's response times, in a
psychology experiment, and the response times are on the order of .01
seconds. Is there any way I can get better precision than by counting
ticks? Or can I make the ticks occur more frequently? I'm trying to do
this in DOS 5.0 on a 386, and it would be nice if this could also work
on our old 8086 machines running DOS 2.1 (I know, I know, I don't like
them any more than you do) but this is by no means a requirement, just a
possibility. 
    So, basically, any information on the BIOS tick scheme and the
related inrterruots would be appreciated, as well as any information on
alternate ways of improving accuracy. Email is preferred, as I'm
planning on posting this to a few boards, and I don't read all of them.
Thanks

Joe

