#include "dos.h"

#include "iostream.h"

int adapter=0x3d8;

int clkcnt=0,mntr=1,sf=0;

int mtick=182;

unsigned ax,dx,si,es;

void interrupt (*prev_9)();

void interrupt our_9();

void interrupt (*prev_8)();

void interrupt our_8();

main()

{

unsigned long far *ptr_9;

unsigned long far *ptr_8;

ptr_9=(unsigned long far*)(9*4);

prev_9=(void (interrupt far*)())*ptr_9;

*ptr_9=(unsigned long)our_9;

ptr_8=(unsigned long far*)(8*4);

prev_8=(void (interrupt far*)())*ptr_8;

*ptr_8=(unsigned long)our_8;

keep(0,2500);

return 0;

}

void interrupt our_9()

{

void monitoron();

cout<<"\into out_9";

ax=_AX;

enable();

sf=1;

if(mntr!=1)

monitoron();

_AX=ax;

disable();

(*prev_9)();

return;

}

void interrupt our_8()

{

void monitoroff();

ax=_AX;

if(sf!=1)

{

if(clkcnt>=mtick)

{

sf=1;

monitoroff();

}

else

clkcnt++;

}

else

{

clkcnt=0;

sf=0;

}

_AX=ax;

(*prev_8)();

return;

}

void monitoron()

{

disable();

cout<<"\ninto on";

ax=_AX;

dx=_DX;

es=_ES;

si=_SI;

_AL=peekb(0x40,0x65);

_SI=si;

_ES=es;

outportb(adapter,_AL);

mntr=1;

_DX=dx;

_AX=ax;

enable();

return;

}

void monitoroff()

{

disable();

cout<<"\ninto off";

ax=_AX;

dx=_DX;

outportb(adapter,0x25);

mntr=2;

_DX=dx;

_AX=ax;

enable();

return;

}