The big problem for Amiga programmers was that the Amiga was sold in NTSC and PAL versions, which ran at different framerates (50 and 60hz) with different resol

The big problem for Amiga programmers was that the Amiga was sold in NTSC and PAL versions, which ran at different framerates (50 and 60hz) with different resolutions. While PAL Amigas could play NTSC games (and most TVs could render the screen properly) I don't remember it working the other way around (although I could be wrong - any American miggy owners care to correct?). Anyway, consequently things like funky horizontal copper manipulation relied on the Amiga either running in NTSC or PAL mode, but not both. This is why a lot of people would use the copper for gradients on the earlier Amiga 500 games, that and the fact that a lot of earlier Amiga 500 games were ports of ST code.