/* this program detects the installation of COM2 and reports the I/O port address assigned to it. */
	#include <stdio.h>
	#include <dos.h>
	main()
	{
	unsigned int far *xptr;		/* a far pointer */
	xptr=(unsigned int far *) 0x00000402; /* assign address */
	if(*xptr >0)
	printf("I/O base address assigned to COM2 is %X \n",*xptr);
	else printf("COM2 = None found");
	}