On the Amiga you can alternate between two images with different palettes to get dithering. Al you need is a suitable frame rate, and some software to convert an image to this format. They have some of this stuff on the Atari ST (special color modes like on the C64).
You can also do interlace based dithering. Works well enough in 50 hertz interlace, but with AGA you can increase the screen refresh rate to things like 94 hertz interlaced (works great on SVGA CRT monitors), and that will make interlace dithering even more effective.
These kinds of dithering may also work on the peecee (perhaps to get ten bits per color channel on eight bits per channel hardware).
