/*Get a 4 digit number from user (Press the switch
Sequentially (Example 1256) Add the sum of
Them the sum is more than 1 digit then add
them again and show the sum on display..*/
void setup()
{
  volatile char *dir;
  volatile char *dirk;
  dir=0x30;
  dirk=0x107;
  *dir=0xFF;
  *dirk=0x00;
}

char digicode(int i)
{
  volatile char y;
  switch(i) {
    
    case 0:
    y=0x3f;
    break;

    case 1:
    y=0x06;
    break;

    case 2:
    y=0x5b;
    break;

    case 3:
    y=0x4f;
    break;

    case 4:
    y=0x66;
    break;

    case 5:
    y=0x6d;
    break;

    case 6:
    y=0x7d;
    break;

    case 7:
    y=0x07;
    break;

    case 8:
    y=0x7f;
    break;

    case 9:
    y=0x6f;
    break;
  }
    return y;
}
void loop()
{
  volatile char *out;
  volatile char *ink;
  volatile char x;
  volatile char y[4];
  volatile unsigned char z;
  volatile int i=9,count=1,k=0,prev,sum=0;
  volatile long j;
  out=0x31;
  ink=0x106;
  while(count<=4)
  {
    x=*ink;
    y[count]=x;
    sum+=y;
    count++;
    if(count==4)
    {
      if(sum/10!=0)
      {
        int ones,tens;
        ones=sum%10;
        tens=sum/10;
        sum=ones+tens;
      }
      *out=digicode(sum);
      for(j=0;j<60000;j++);
    }
  }
    
   
  
}