From: "Alexander Russell" <alexander DOT russell AT telus DOT com>
Newsgroups: comp.os.msdos.programmer,comp.os.msdos,comp.os.msdos.djgpp,comp.os.msdos.misc
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Subject: Re: Control timing
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Date: Wed, 31 Oct 2001 06:05:40 GMT
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To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

"jeffchan" <jeffkhc AT netvigator DOT com> wrote in message
news:bf50ce95 DOT 0110301711 DOT 78e48e58 AT posting DOT google DOT com...
> Hi,
>
> That's mean i must install DOS on my PC. Can i use windows startup
> disk booting up, to make an environment as dos? Is that still same as
> dos box in win9x?
>
> And if the new_timer(void) routine is too much coding, it can't finish
> the job when the next interrupt came expected. Do i need to set some
> interrupt masking flags?
>
> How do i check the timing spent of this interrupt service routine?
>
> Jeff
>

I generally make an interrupt service as SHORT and FAST as possible. Set a
flag, store a bit of data in a global structure. then the main program polls
the vars set by the interrupt and does any longer processing.

For example, the interrupt my just store data to a queue, then the main prog
process the data in the queue and write it to disk.

As for dos 7, I haven't tried that, but its likely ok.

>
> > > > AJR - I don't see an obvious problem. Are you running under DOS? If
> >  running
> > > > under a dos box in win9x the timing will not be exactly what you
expect.
> > >
> > >       Let me know the reason.
> > >
> > Windows 9x grabs all the interrupts, and lets dos programms 'use' them
at
> > random intervals.
> >
> > > --
> > >   Peace - The choice of the new generation.