[Coco] hardware scrolling

[Nick Marentes]

So, in order to create an endless scroll, like Super Mario or Scramble, 
you would need to scroll the 42 byte window till it reaches its limit 
then you would have to do a software copy of the region back and repeat 
the scroll.

You would need to draw the new graphics just off screen from the 
incoming edge.

If I'm reading this right, the bottleneck will be the block copy to 
achieve the loopback.

You are playing with the restriction of 64K. Unless you allocate more 
RAM for video display to scroll across into (reposition the start of 
screen). Maybe move across to a 2nd 6K page, copying the disappearing 
edge back to the start point so when you reach the end point, you can 
shift the entire screen back to the start and repeat the process.

... That's if I'm understanding your technique right.

Since you can do split screen, you won't have to copy the entire screen 
but a smaller band across the screen. This buys you cycles.

Have you explored your technique in a semigraphics mode?

Nick