yep, I just draw it all now. Back then it was a case of having an area of memory twice as tall as the screen and moving the visible window and only drawing the "new" area of the screen twice - once on-screen and once on the off-screen "mirror" of the main screen so when you hit the top edge of the big window it could flip back to the bottom "mirror" screen. I was pretty pleased when I figured that out. Then I made it work in 4 directions (well any) for a platformer.
My next demo may be a platformer...or, um, a card game...
My next demo may be a platformer...or, um, a card game...