-=> Quoting John Howard to All <=-
 JH> stop dos from acknowledging this character?
     Hi John
     Ever since I've started programming I've been collecting odd
     bits of code that I come across just in case it might be useful.
     Below is an example.  I've never tested it, nor do I claim any 
     any credit for it.   But even if it won't compile it might give
     you some ideas.
     C yaz
this is an ISR that I use often. It disregards Ctrl-Alt-Del,
Ctrl-C, and Ctrl-Break. Borland flavored. The main() just hooks it up,
shells out to DOS (so you can test it out), then (when you type EXIT),
resets the ISR and exits.
 
#include 
#include 
 
#define C_CODE 0x2E
#define BREAK_CODE 0x46
#define DEL_CODE 0x53
 
#define CTRLMASK 0x04
#define ALTMASK 0x08
#define KBSTATUS (*(char far*)0x00400017L)
 
void far interrupt (*old0x09ISR)(void);
void far interrupt new0x09ISR(void);
 
int main(void)
{
        old0x09ISR=getvect(0x09);
        setvect(0x09, new0x09ISR);
        spawnl("C:\\COMMAND.COM", NULL, NULL);
        setvect(0x09, old0x09ISR);
        return(0);
}
 
void far interrupt new0x09ISR(void)
{
unsigned char scancode, status;
 
 scancode=inportb(0x60);
 if (!( ((scancode==C_CODE || scancode==BREAK_CODE)
        && (KBSTATUS & CTRLMASK))
    || ((scancode==DEL_CODE)
        && (KBSTATUS & (CTRLMASK|ALTMASK))) ))
 {
    old0x09ISR();
    return;
 }
 
 status=inportb(0x61);
 outportb(0x61, status | 0x80);  // Clear keyboard by disabling,
 outportb(0x61, status);         // then enabling it
 disable();
 outportb(0x20, 0x20);   // send "End of Interrupt" signal to
 enable();               // the interrupt controller port
 return;
}
... Diplomacy:  Saying "nice doggy" until you find a rock.
---
---------------