/* Definition of the Ports used to control Laurino */
/* Interrupt inputs for feelers and switches */

sfr   P1L = 0xFF04;
sfr   P1H = 0xFF06;
sfr   P2  = 0xFFC0;
sfr   P3  = 0xFFC4;


    sbit contact_left  = P2^9;
    sbit contact_right = P2^10;
    sbit feeler_left   = P2^11;
    sbit feeler_right  = P2^12;

/* interrupt addresses */

    #define intaddr_contact_left   0x19
    #define intaddr_contact_right  0x1A
    #define intaddr_feeler_left    0x1B
    #define intaddr_feeler_right   0x1C

/* interrupt control register    */

  sfr  icntrl_contact_left  = 0xFF8A;
  sfr  icntrl_contact_right = 0xFF8C;
  sfr  icntrl_feeler_left   = 0xFF8E;
  sfr  icntrl_feeler_right  = 0xFF90;

/* interrupt enable bits    */

  sbit ien_contact_right = icntrl_contact_right^6;
  sbit ien_contact_left  = icntrl_contact_left^6;
  sbit ien_feeler_right  = icntrl_feeler_right^6;
  sbit ien_feeler_left   = icntrl_feeler_left^6;

/* interrupt flags    */

  sbit ifl_contact_right = icntrl_contact_right^7;
  sbit ifl_contact_left  = icntrl_contact_left^7;
  sbit ifl_feeler_right  = icntrl_feeler_right^7;
  sbit ifl_feeler_left   = icntrl_feeler_left^7;

/* Output for motor control */

  sfr   motor_out  = 0xFFD0;
  sfr   ctrlreg_motor_out = 0xFFD2;

/* Output for LEDs */

    sfr  ctrlreg_LED_out = 0xFFC2;
    sfr  LED_out = 0xFFC0;

    sbit LED_eng_left_forward   = P2^0;
    sbit LED_eng_left_backward  = P2^1;
    sbit LED_contact_left       = P2^2;
    sbit LED_feeler_left        = P2^3;
    sbit LED_feeler_right       = P2^4;
    sbit LED_contact_right      = P2^5;
    sbit LED_eng_right_backward = P2^6;
    sbit LED_eng_right_forward  = P2^7;

/* Laurino movements */

    #define turn_right      0x01
    #define turn_left       0x04
    #define forward         0x05
    #define backward        0x0A
    #define stop_right_eng  0xF3
    #define stop_left_eng   0xFC
    #define stop_engines    0xF0

/* Serial port registers */
 sfr   P3       = 0xFFC4;
 sfr   DP3      = 0xFFC6;
 sfr   S0TIC    = 0xFF6C;
 sfr   S0RIC    = 0xFF6E;
 sfr   S0BG     = 0xFEB4;
 sfr   S0CON    = 0xFFB0;

/* Auxiliary registers */
 sfr   EXICON   = 0xF1C0;
 sfr   PSW      = 0xFF10;
 sbit  IEN      = PSW^11;