Sender: itm AT dra DOT hmg DOT gb
Message-ID: <330AC180.41C67EA6@dra.hmg.gb>
Date: Wed, 19 Feb 1997 09:01:52 +0000
From: Ian Miller <itmiller AT dra DOT hmg DOT gb>
Organization: DRA
MIME-Version: 1.0
To: DJGPP workers <djgpp-workers AT delorie DOT com>
Subject: Re: Exact timming II
References: <Pine DOT SUN DOT 3 DOT 91 DOT 970218155114 DOT 20628B-100000 AT is>
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Eli Zaretskii wrote:
> ----------------------------- uclktest.c -------------------------------
<snip>

Thanks very much for the above program. Rest assured, it would have 
taken me hours to figure out how to write it myself. Here are some
results from it:

Win95 DOS box:

E:\home\t2>uclktest
Timer counter was incremented by -43127 units

E:\home\t2>uclktest
Timer counter was incremented by 21909 units

E:\home\t2>uclktest
Timer counter was incremented by 22779 units

E:\home\t2>uclktest
Timer counter was incremented by -43751 units

E:\home\t2>uclktest
Timer counter was incremented by -43039 units

Win95 DOS mode and DOS 6.22:

About 22000 every time.


It looks as though Win95 uses/resets the timer itself
every so often. I tried reducing the wait interval.
At 1ms (or so) the result was consistently positive
(780 or so). But from 2ms onwards these daft negative
answers turn up regularly.

Regards
-- 
Ian Miller, Dorset, UK
DJGPP 2.01, Win95 DOS box (LFN undefined, FNCASE=y)