Forgot to add this earlier. Later versions of AmigaOS that support non-15kHz rates will promote all screens to the lowest screen mode that can suppprt all visible screen resolutions. So, if you drag a NTSC:High Res Interlaced (640x400@60i) screen down in front of a Multiscan:Productivity (640x400@70p) screen, then the front screen will also display in Prpductivity mode.