You've made awesome progress in the last 6 weeks. +1 Perhaps you should take a look at id:2999520 once more, it has a super small component to add 1 to any number (incrementor) and another component to subtract 1 from any number (decrementor), you can easily convert these to subframe. These are very useful for example to calculate the next rom address. (So the incrementor does output = input + 1 and the decrementor does output = input - 1.)