Re: including ISR in euphoria program

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Jacques Deschenes writes:
> As I'm writing an include file to play wave file on sound blaster card
> I'm stock with a bug regarding the interrupt service routine. it's
> doesn't work.
> I need to known if ISR are running in protected mode or real, or virtual
> mode
> Here is my ISR code.

As you know, Euphoria uses the Causeway DOS extender.
This allows the ex.exe interpreter run in 32-bit
protected mode for most computations. However to
remain compatible with DOS, the DOS extender must
switch into real mode to call operating system functions
such as I/O etc.

According to the Causeway DOS extender manual ...
"Hardware interrupts are always reflected to protected mode handlers even
when signalled during real mode operations. This ensures that protected
mode applications always retain control without requiring you to patch
real mode interrupt vectors."

Apparently there is an interrupt vector table for real mode and another one
for protected mode. Causeway has a routine that lets you set an interrupt
address in the protected mode interrupt table.

If you need more help let me know. I have a few code examples and
more documentation that might be useful. I don't have much practical
experience with handling hardware interrupts on PCs. Maybe some other
people out there have done this sort of thing?

      Rob Craig
      Rapid Deployment Software

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