MCR_OUT1
#define MCR_OUT1 0x0400 /* Out 1 */
#define MCR_OUT1 0x04 /* OUT1 output (not accessible in RS232) */
#define MCR_OUT1 0x04 // Loopback only: Sets state of RI
#define MCR_OUT1 0x04 /* Loopback only: Sets state of RI */