Date: Wed, 16 Aug 2000 19:24:05 +0200
From: "Eli Zaretskii" <eliz AT is DOT elta DOT co DOT il>
Sender: halo1 AT zahav DOT net DOT il
To: djgpp AT delorie DOT com
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In-reply-to: <2ralpso9m947iusuolq5a6k4kthf0dq5u9@4ax.com> (message from Damian
	Yerrick on Wed, 16 Aug 2000 14:55:45 GMT)
Subject: Re: read a character string from a serial port ......
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> From: Damian Yerrick <Bullcr_pd_yerrick AT hotmail DOT comRemoveBullcr_p>
> Newsgroups: comp.os.msdos.djgpp
> Date: Wed, 16 Aug 2000 14:55:45 GMT
> >
> >Why are you delaying the execution for 55 milliseconds (1 clock tick)?
> 
> Doesn't delay(1) wait 1 millisecond by reading the 8254?

Oops, you are right: the DJGPP version accepts the argument in
milliseconds, not in clock ticks.  I looked at a Unix man page, and
assumed our delay behaves the same.  Shame on me.

> Or does it round to the nearest clock tick?

No, it doesn't round, it really works in units of 1msec (actually, 936
microseconds, I think).  It can do that because it uses a function of
Int 15h to wait, and Int 15h works with the CMOS clock, not the system
timer chip.  The CMOS clock runs at 1024 Hz by default.

My apologies for the noise.