I have a mostly-working SDL port of Squeak, but a few issues need to be 
resolved. Perhaps someone who knows the system better than I do can suggest a 
solution.

As far as I know, Squeak always uses the same byte order (big endian) for its 
framebuffer. This means that little endian systems (such as the x86) have to 
perform byte swapping to properly display the data. This is a simple 
operation (just swap the first and last bytes of each 32-bit word, as well as 
the middle two), but it results in a considerable performance hit. SDL's 
blitters are quite capable of converting between display formats on the fly, 
but this is an unusual situation. Is it possible to have Squeak use a 
framebuffer in the local machine's native endianness? If this is possible, it 
would be extremely simple to have SDL automatically support all possible 
colordepth combinations.

Here's a screenshot of Squeak running in an 8-bit SDL window:
http://www.patentburner.com/~overcode/pics/squeak-sdl.png

It's just Squeak 2.8 for now, but I'll migrate it to 3.x in the near future.

Thanks,
-John

-- 
Underfull \account (badness 10000) has occurred while \spend is active
John R. Hall  -  Student, Georgia Tech  -  Contractor, Loki Software