Hi,
I would like to use SDL on pocket pc but unfortunately on this platform
SDL only seem to support fullscreen mode. From what I saw in source code
gapi is used to access video but GAPI is now deprecated.
The recommended approach is to use DirectDraw (available since WM5).
Since you already have a DD driver for desktop I suppose the porting
would not be difficult and it will allow to choose between
windows/fullscreen mode.
I think it would event be better to use framebuffer access instead of GAPI.
There is a good article about this subject here :
http://www.codeproject.com/ce/Caleidoscope.asp
So for devices <= Pocket PC 2003 it would be possible to use
GAPI/Framebuffer
and devices >= WM5 - Direct Draw