I just had a thought in regards to interfacing the Amiga, PAL resolutions to VGA monitors. When using 60 Hz refresh, it won't match up evenly (60/25=2.4).
But using 75 Hz it will (75/25=3), this will put some extra demand on the ram memory. And it might be needed to tweak the DCM-clocks used. It would essentially work by sending the same image 3 times. Doing this 25 times per second results in 75 Hz. Which is a very common update frequency for LCD screens.
640x480 12bpp 75Hz = 32,96 MByte/s
800x600 12bpp 75Hz = 51,50 MByte/s
An 133 MHz SDRAM with an 8 bit wide interface should be able to handle this.
It might require a seperate video buffer, but some clever coding might avoid that.
Should 25 fps PAL need to be output on 30 fps NTSC. One could simple use average between the last two frames weighted with the quote corresponding to the position in time between the frames used. I suspect this however will impose some slight 5 Hz flickering
