I think I can actually see what that's doing ..... It's using the extra 6 that gets added in decimal mode if the low nybble of the sum falls in the range &A .. &F, plus an extra 1 if the CMP set the C flag, to make up the 7 needed to change : to A. (Does that adjustment take an extra clock cycle, or is the 6502's adder a bit smarter than I'm giving it credit for?)
You are still never going to convince me SED -- the 6502 instruction, not the similarly-named non-interactive text editor; that's positively cuddly by comparison -- is anything but the spawn of the devil, though! For the love of all that's sane and wholesome, at least hold up a veil of SEI before it, lest its malign influence affect any unwary interrupt-handling code .....
You are still never going to convince me SED -- the 6502 instruction, not the similarly-named non-interactive text editor; that's positively cuddly by comparison -- is anything but the spawn of the devil, though! For the love of all that's sane and wholesome, at least hold up a veil of SEI before it, lest its malign influence affect any unwary interrupt-handling code .....
Statistics: Posted by julie_m — Sun Aug 04, 2024 3:06 pm