#define Com1	  0x3f0
#define Com2	  0x2f0
#define Com3	  0x3e0
#define Com4	  0x2e0

#define Txbuf0  0x3f8     /* Transmitter Holding Register, tx buffer */
#define Rxbuf0  0x3f8     /* Receiver Buffer Register    , rx buffer */
#define Dll0	  0x3f8     /* Baud LSB */
#define Dlh0	  0x3f9     /* Baud MSB */
#define Ier0	  0x3f9     /* Interrupt Enable Register */
#define Fcr0	  0x3fa     /* FIFO Control Register */
#define Lcr0	  0x3fb     /* Linear Control Register */
#define Dfr0	  0x3fb     /* Data Format Register */
#define Mcr0	  0x3fc     /* Modem Control Register */
#define Lsr0	  0x3fd     /* Linear Status Register */
#define Msr0	  0x3fe     /* Modem Status Register */

#define Txbuf1  0x2f8     /* Transmitter Holding Register, tx buffer */
#define Rxbuf1  0x2f8     /* Receiver Buffer Register    , rx buffer */
#define Dll1	  0x2f8     /* Baud LSB */
#define Dlh1	  0x2f9     /* Baud MSB */
#define Ier1	  0x2f9     /* Interrupt Enable Register */
#define Fcr1	  0x2fa     /* FIFO Control Register */
#define Lcr1	  0x2fb     /* Linear Control Register */
#define Dfr1	  0x2fb     /* Data Format Register */
#define Mcr1	  0x2fc     /* Modem Control Register */
#define Lsr1	  0x2fd     /* Linear Status Register */
#define Msr1	  0x2fe     /* Modem Status Register */