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From:	"MattFlyer" <goaway AT nospam DOT me>
Newsgroups:	comp.os.msdos.djgpp
Subject:	DJGPP and hardware interrupts
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Date:	Thu, 15 Jul 2004 22:04:58 GMT
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All,

I seem to be having some problems with hooking a hardware interrupt in a
program compiled with djgpp.  Since it is a hardware interrupt, it requires
inports / outports to setup the hardware that drives the interrupt pins.
However, the code (and hardware) work fine when compiled with borland in
real mode.  Of course the ISR installer is quite different, the other
aspects are for the most part the same.  The hardware uses irq 10, or int
0x72 as it translates to the 8259.  I am enabling this int on the 8259 and
calling the _go32 functions to get the old vetor, saving it, allocating a
wrapper, creating the info structs that contain the PM offset and CS seg ..
etc, and so forth and setting (I don't care about chaining but have tried
that too) the interrupt.  I don't have any code handy, as I am writing from
home and this is at work, or else I would post an example to show.

I have read about every tutorial on interrupts I can find to no avail.  If I
try to hook a different int such as int 8 the timer int on irq 0, and vector
to the same handler, the routine executes, but I can't seem to hook the irq
10.  Again, the hardware and software that setup and enable the ints outside
of the int installer is pretty much identical - so it should work.

Has anybody done something similar to this or have any suggestions.  If
necessary I could post part of the code here.

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