void setup()
{
    volatile unsigned char *dir;

    dir = (volatile unsigned char *)0x30;   
    *dir = 0xFF;                            
}

void loop()
{
    volatile unsigned char *out;

    out = (volatile unsigned char *)0x31;  

                          

    while(1)
    {
      *out = 0X80;
      delay(1000);
      *out = 0X40;
      delay(1000);
      *out = 0X20;
      delay(1000);
      *out = 0X10;
      delay(1000);
    }                             
}