The 'bitch' about scroll is that you need to synchronize it with the workloop (refresh, change, update etc).

My signs at power up measure the workloop time and when the specificcation of scroll speed comes in picks the nearest multiple of work loops as the scroll speed.

If you do anything else (believe me, I've tried) the scroll will be jittery.

Of course if you have an extremely small sign and you can do all updates in a timer int that would work, but that is out of the question for a sign of any size.

Erik