Date: Sat, 1 Nov 1997 09:56:46 +0000 (   )
From: "Gurunandan R. Bhat" <grbhat AT unigoa DOT ernet DOT in>
To: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
Cc: djgpp AT delorie DOT com
Subject: Re: Tracing the path of Software Interrupts
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On Sun, 2 Nov 1997, Eli Zaretskii wrote:

> 
> On Sat, 1 Nov 1997, Gurunandan R. Bhat wrote:
> 
> >       	Int 0x1c is called by the Int 0x8 handler during 
> > 	its operation which requires a lot of RM operations.
> > 	If the Int 0x8 handler is optimised to avoid an 
> > 	expensive mode switch merely to iret (the default
> > 	Int 0x1c operation) then Int 0x1c will be called
> > 	when the CPU is in real mode. This explains the r's
> > 
> > Please correct me if I am wrong
> 
> I'm not sure.  What do you get when you hook 1Ch in PM only?  Do you 
> indeed get all the ticks in your PM handler, or do some of them get lost?
> (You need to do som DOS I/O, or call some BIOS services, to see the 
> effect.)

Yes. I will do that and report back. Though from the top of my head I 
cannot guess how to detect the *lost* ticks without installing another 
int 0x8 handler.... Anyway, let me think more carefully....

Thanks