unsigned short icrc1(unsigned short crc, unsigned char onech)
{
	int i;
	unsigned short ans=(crc ^ onech << 8);

	for (i=0;i<8;i++) {
     if (ans & 0x8000){
#if defined(__DECC)
      ans <<= 1;
      ans = ans ^ 4129;
#else
			ans = (ans <<= 1) ^ 4129;
#endif
    }
		else
			ans <<= 1;
	}
	return ans;
}