video corruption

[zipper]

Probably it's an old demo (ie: not written for the A1200), try running a degrader like TUDE first and see if that solves the problem.

Nope. What I know it's an AGA demo for 030+.

[zipper]

Yes, downloaded it just from Aminet and ran via Amiga Forever on my laptop - no problems on the screen, it ran fine with default settings.