When i put an NTCS game in my PAL A1200, lets say NTSC version of Lamborghini challenge, the game will work fine...
there is a little extra space on the bottom of the picture, BUT if i put my Amiga in 60hz mode via the early boot menu, the game runs perfectly... its a crap game, but still it exists to prove this point LOL
A cheap trick to improve the speed of some PAL versions of flight simms, would be to switch to 60Hz giving you a 20% speed increase in graphics
hey, when all you had was an 8mb A1200 and needed to play DOOM, you would DO ANYTHING you could LOL
the real truth is that an NTCS is an Amiga at 60Hz with the NTSC colour enconding on the composite and rf out. when using the RGB port, you have a 60hz Amiga which will reduce the Y of the screen by 20% at the bottom this can be from 576(PAL) scanlines to 480(NTSC) Scanlines.
hmmm its late and when I read what I have wrote... its kinda seems like imma going round in circles lol
have a look here for NTSC / PAL explinations
ignore the DVD rates for the most part and have a lookie from frame and field rates
that will help