outportb(PORT1 + 1 , 0);       /* Turn off interrupts - Port1 */
 outportb(0x21,(inportb(0x21) | 0x10));  /* MASK IRQ using PIC */
					 /* COM1 (IRQ4) - 0x10  */
					 /* COM2 (IRQ3) - 0x08  */
					 /* COM3 (IRQ4) - 0x10  */
					 /* COM4 (IRQ3) - 0x08  */
 setvect(INTVECT, oldport1isr); /* Restore old interrupt vector */