Scrolling Text with TV out -nm math error

lets say I am using TV out for a serial terminal like device, it gets X characters then a newline, it prints those charters out one at a time on the tv screen, then moves down a line and so on

but once you go past the Y resolution the text will scroll up, like you would expect, but the lower half of the characters is cut off and continues to cut off the lower half until reset.

Anyone got an idea how to keep that from happening? I could clear the screen every page of text, but since it almost scrolls fine I would much rather have that.