void setup(){
  // put your setup code here, to run once:
  volatile char *ddra,*ddrb,*outa,*outb,ones,tens;
  ddra=0x21;outa=0x22;ddrb=0x24;outb=0x25;
  *ddra=0xff;*ddrb=0x03;
  volatile long i,j,k;
  int display[10]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
  while(1)
  {
    for(j=0;j<91;j++)
    { 
      for(k=0;k<20;k++)
      {
        ones=j%10;
        tens=j/10;
        *outb=0x01;
        *outa=display[ones];
        *outa=0x00;
        for(i=0;i<10000;i++);
        *outb=0x02;
        *outa=display[tens]+0x80;
        *outa=0x00;
        for(i=0;i<10000;i++);
      }
      
    }
    
  }
}