Message-ID: <37F871DE.C5C687E5@virtualis.com>
Date: Mon, 04 Oct 1999 19:22:39 +1000
From: Alex Mendes da Costa <alexmdc AT virtualis DOT com>
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Newsgroups: comp.os.msdos.djgpp
Subject: Problem with interrupts
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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

Hi all again.

I don't know if this is against the rules of the list, and I'm really
sorry if it is, but I can't get this code to work. I have read through
just about all of the Documentation and FAQ and sent a few posts to this
list, but I can't get my code to work!! So if anyone would be as kind to
browse this and see where I have slipped up, I would appreciate it
greatly. 
This code stuffs up my computer completely every time I try to run it,
but it compiles alright.

NOTE: I changed the asm interrupt to contain the bare essentials cause I
wasn't sure if that was the problem.
My code:

#include <stdio.h>
#include <dpmi.h>

void main();
void keyboard_handler();
void keyboard_handler_end();

char keystatus[128];
int i;
unsigned long baseaddr;

__dpmi_paddr old_keyboard_handler, new_keyboard_handler;
__dpmi_meminfo region;

void main()
{

  __dpmi_get_protected_mode_interrupt_vector(0x09,
&old_keyboard_handler);

  /* Lock the interrupt code */
  __dpmi_get_segment_base_address(_my_cs(), &baseaddr);
  region.handle = 0;
  region.size = (keyboard_handler_end - keyboard_handler);
  region.address = baseaddr + keyboard_handler;
  __dpmi_lock_linear_region(&region);

  /* Lock the keystatus array */
  __dpmi_get_segment_base_address(_my_ds(), &baseaddr);
  region.handle = 0;
  region.size = 128;
  region.address = baseaddr + keystatus;
  __dpmi_lock_linear_region(&region);

  new_keyboard_handler.offset32 = (int)keyboard_handler;
  new_keyboard_handler.selector = _my_cs();
  __dpmi_set_protected_mode_interrupt_vector(0x09,
&new_keyboard_handler);
 
  i = 0;
  do {
    printf("%d\n",(keyboard_handler_end - keyboard_handler));
    /* Endless Loop? */
  } while (i == 0);

  __dpmi_set_protected_mode_interrupt_vector(0x09,
&old_keyboard_handler);
}

void keyboard_handler()
{
  asm("pushw %ax
       movb $0x20, %al
       outb %al, $0x20
       popw %ax
       sti
       iret");
}

void keyboard_handler_end()
{
}