🚀 go-pugleaf

Some games I have seen seem to scroll through a buffer in a window on the 
screen. I have experimented with the Start Hi/Lo registers and so on, but
I can't figure out how they can scroll in a window like that.. What I'd
like to be able to do is have a vertical scroll in say a 300x150 window
centered on the screen. What is the best method to update the buffer for
the scrolling? I have tried storing a long image in memory and moving it
one chunk (4 rows of 320 pixels) at a time to the invisible part of the
buffer during the scroll. I can't find a better way to do it. I'd really
like to learn more about this sort of programming and this newsgroup has
been the best place to learn.