Hi,
In my mind this will work out the seconds for both hours and minutes then add them together and divide the result by 255 ??
I believe that's exactly what mine does. Multiplication and division has precedence over addition and subtraction. So mine will take the hours and multiply that by 3600, then it'll take the minutes and multiply those by 60. It will then add those two results together because they are enclosed within brackets and THEN divide that result by 255 - which I believe is what you want.

/Henrik.