Mail Archives: djgpp/2000/04/30/09:42:47
On Sun, 30 Apr 2000, Alexei A. Frounze wrote:
> > Not necessarily. Depending on the DPMI server and the underlying OS, the
> > INT instruction might be handled entirely in protected mode.
>
> DOS Extenders don't handle BIOS stuff in PMode, though. Neither CWSDPMI nor
> DOS4GW nor WDOSX nor DOS32 nor 32RTM do that. Thay can't. Only Windows is
> capable to do that in PMode, since it has PMode drivers for almost everything
> and it can replace/hook native BIOS and DOS services.
Yes, Windows is one case I was thinking about, where the difference
between __dpmi_int and int86 is significant. DOSEmu is another one.
I suspect that NT and Windows 2000 are yet another such case.
Note that if you run DJGPP programs not from a DOS extender (as is mostly
the case with DJGPP programs), it's the V86 monitor's responsibility to
reflect the INT instruction to the real-mode handler; the DPMI host
usually doesn't do anything with it. (In contrast, __dpmi_int is
handled by the DPMI host.) The V86 monitor is usually part of the memory
manager, such as EMM386.
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