Can somebody guide me to a comperehensive (previous)post or similar links where split screen scrolling is discussed.
Cheers
I think you have to be a bit more specific than that. Why exactly do you need to split the screen? Are you trying to display 2 independent gameplay windows? Are you scrolling only horizontally or vertically as well?
If you are scrolling only horizontally this is dead easy. Before rendering starts you set up the scroll for the top view and set up an IRQ or sprite 0 hit for the point of the split, when that point is reached change the horizontal scroll to that of the bottom view.
If you are scrolling vertically as well it gets a little more complex. Single-screen mirroring would probably be the way to go, because each view could use its own name table. At the point of the split you'd have to switch name tables and use combined $2005 and $2006 writes to set the scroll for the bottom view.
Again, I invite you to read this :
http://jonathan.microclub.ch/NES_raster
(the server I use seems to be down at the momment, so if it don't work use the romhacking mirror intead :
http://jonathan.microclub.ch/NES_raster
Okay maybe I need to do an update of it with the recent $2004 and $2007 reading discoveries...