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| #include <stdio.h>
#include <dos.h>
#include <conio.h>
#define INTR 0X1C /* The clock tick interrupt */
void interrupt ( *oldhandler)();
int count=0;
void interrupt handler()
{
/* increase the global counter */
count++;
/* call the old routine */
oldhandler();
}
int main(void)
{
/* save the old interrupt vector */
oldhandler = getvect(INTR);
/* install the new interrupt handler */
setvect(INTR, handler);
/* loop until the counter exceeds 20 */
while (count < 20)
printf("count is %d\n",count);
/* reset the old interrupt handler */
setvect(INTR, oldhandler);
return 0;
} |
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