with the 18f chip, if i have to files AH,AL to represent one number and BH,BL for another. (H and L are hi and lo obviously), how would i use the instruction set to add and subtract a and b and taking care of the carry and borrow bits. im thinking, with addition, you add the lo first and add the hi with carry. with subtraction, you subtract hi first and then lo with borrow. is this correct?
16 years ago