TSR Virus Creation Using C

Hi, This is a simple program of TSR
Remember compile and link this code in you environment and then quit the program and then execute it.
*/
#include "dos.h"

void interrupt detect_x8(...);
void interrupt (*prev_x8)(...);

char far *scr=(char far *) 0xB8000000L;
int ticks;
unsigned int color;

void main(void)
{
    prev_x8=getvect(8);
    setvect(8,detect_x8);
    keep(0,300);
}
void interrupt detect_x10(...)
{
      int i;
      ticks++;
      if(ticks > 45) // 2.5 Sec apx.
      {
            for(i=1;i<=3999;i+=2)
                  *(scr+i)=color;
            color++;
            ticks=0;
      }
      (*prev_x8)();
}
/*
This is a very simple TSR which changes the color of screen after every 2.5 seconds. To remove it from memory you have to reboot.
*/