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Subject:	Re: Performance enhancement for gettimeofday()?
To:	djgpp AT delorie DOT com
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From:	Gordon DOT Schumacher AT seagate DOT com
Date:	Fri, 5 Jan 2007 09:53:34 -0700
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Gordon Schumacher/Seagate wrote on 01/04/2007 05:16:32 PM:

# Most of the data returned by the DOS int 21/2C and 21/2A functions can be
# obtained directly from the CMOS, with nothing more than port I/O: that
# will give us everything except the "hundredths" of a second field.  For
# that field, what about installing a interrupt handler to simply increment
# a counter every timer tick, and reset it to zero when the counter reaches
# 91 (signifying five seconds have elapsed)?

In fact, it would not even need to be done with an interrupt handler.  The
first time the function is called, the int21/2C function could be called
in order to determine the hundredths value that DOS is using.  Then the
clock() function could be called to align those two values, and thereafter
the clock() function could be used instead.

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