Zkrolly is a simple scrolling demo that I've added to show you that scrolling is indeed possible, though not necessarily easy to do really good.
It uses a rather small window, where we follow one of the sprites moving around. It uses "safe" drawing by default, but by pressing the option key, you can switch to the blitters ("fast"). No, there won't be any big difference in 256 colors, but in b/w or 16 colors, there is a significant speedup.
The demo does not only show that scrolling is possible, but also demonstrates some of the problems. Scrolling sideways in "fast mode" makes it jumpy, since SATCopyBits in fast mode does not shift the bits within a byte (for speed).
