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From:	"Carlini Alessio" <enricocarlini AT libero DOT it>
Newsgroups:	comp.os.msdos.djgpp
Subject:	problem with 8254 (Timer)
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Message-ID:	<ARo_7.42372$s04.1953960@news.infostrada.it>
Date:	Mon, 07 Jan 2002 21:57:52 GMT
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I have written a program that read (polling) the counter0 (Timer) so that
every 5us it can sample and save a byte read from the parallel port. My
scope is to monitor digital signal from parallel port with a good temporal
precision.

In my old PC this program works correctly while in my Celeron 500Mz it does
not work in DOS (real mode + CWSDPMI). It miss 350us every a lot, without
regularity. Seems like an interrupt is executed but it is impossible because
i have disabled them
whith a CLI istruction. This problem can be caused from NMI or from the
CWSDPMI ???? Help me!

Thanks and excuse me for may terrible english!

Alessio Carlini

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