uint8 normalChecksum8(uint8 *b, int n)
{
  int i;
  uint16 a, bb;

  //Sums bytes 1 to n-1 unsigned to a 2 byte value. Sums quotient and
  //remainder of 256 division.  Again, sums quotient and remainder of
  //256 division.
  for(i = 1, a = 0; i < n; i++)
    a+=(uint16)b[i];

  bb = a / 256;
  a = (a - 256 * bb) + bb;
  bb = a / 256;

  return (uint8)((a-256*bb)+bb);
}