> There are important details 
> however, like handling the pixel endianness & RGB layout 
> right. With extra trickery one can also save memory by making 
> the screen buffer memory actually be part of the Display form 
> bitmap - like I do on the Acorn port.

Well, actually the itsy days are long gone - these days all you need is
a little bit of support through the surface manager in order to make
your own FB display. Just for the heck of it, I've written a little FB
driver plugin which is attached. Note that these days we don't even have
to worry about endianess and colors - this has been fixed over time and
BitBlt is quite capable of handling almost everything correctly[*] (the
test case uses a 16bpp little endian display with red and green bits
swapped ;-)

[*] Under the assumption that pixel words go left-right and top-down
which is apparently _not_ true on all hardware (like PDAs).

The ST side is pretty trivial and the C part self-explanatory (I hope).
If anyone is really interested in this stuff let me know.

Cheers,
  - Andreas
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