Understanding IVT Table

#include
#include
main()
{
unsigned long far *address = (unsigned long far *)0x00000000;
unsigned long intadd[256];
unsigned int segment, offset;
int i;
FILE *fp;
fp = fopen("IVT.txt", "wb");
for(i = 0; i < 256; i++)
{
intadd[i] = *(address++);
segment = FP_SEG(intadd[i]);
offset = FP_OFF(intadd[i]);
fprintf(fp, "interrupt %3X : vector %Fp(hex) : %lu(dec)
",
i, intadd[i], (unsigned long)segment * 16 + offset);
}
fclose(fp);
}