Ingvar I think you are absolutely RIGHT and I will test it as soon as I can.
Since the ** multiplication places the result in the upper 16 bits it is I believe the same with divide by 65536 as you say so in fact I can get rid of the FP routines.
I think the slight miscalculation of using 65536 instead of 65535 is not worth to mention.
Am I right?
This proves that although I read the manual I didn't fully understand it.(of course it is not the first time )

Thank you for pointing out this for me.
Bill