🚀 go-pugleaf

I and my friends are making a little intro. We have already made for example
textscroll, starscroll and music but now we have faced a big problem: the 
vertical blanking interval isn't long enough. We would like to add some nice
things such as wavescroll, but screen flickering follows because of the lack
of time. We have heard something about Copper interrupt. If it is timed to
occur just after last display line, additional time can be gained. That's
theory, but how is it done in practice? I think we should use level 3 
interrupt, but our playroutine (Soundtracker) uses it too. What should we do?

					      Petri Kontkanen
					      University of Helsinki,Finland