Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!usc!trwind!venice!press
From: press@venice.SEDD.TRW.COM (Barry Press)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Elapsed time finer than 55 ms on PC?
Keywords: PC CLOCK TIME
Message-ID: <63@venice.SEDD.TRW.COM>
Date: 10 Oct 89 14:52:17 GMT
References: <2402@loral.UUCP>
Reply-To: press@venice.sedd.trw.com (Barry Press)
Organization: TRW Systems Engineering & Development Division, Redondo Beach, CA
Lines: 4

If you're running on an AT (and many compatibles), then  you can use the
real-time clock implemented in the CMOS RAM.  By default, it runs at 1KHz.
It's fairly simple to catch the interrupt and do the EOI stuff -- see the
BIOS source in the IBM Tech Reference for an example if needed.