I meant name tables.

But anyway... the game would use horizontal mirroring... so the 2 nametables would be layed out like:

____
|.....|
|.....|
|.....|
-------
|.....|
|.....|
|.....|
____ (crude, but hopefully you get the idea)


as the game scrolls horizontally... new data is added onto the side of both nametables. When the game scrolls vertically... all it does it change the Y scroll value... no new drawing is needed.