@potatohead - Hmm, a double cog solution seems akward. Its doable but such a driver will instantly not be easy to use and ... requires two cogs.
I much prefer the bitmap idea, but the memory requirement is too much.
Maybe there is another way? I can code the bitmap driver in a few hours... not like I have a few hours in the coming days but I can post a 160x120 6 bit RGB bitmap driver in a couple of weeks if you would like.
But, without some sort of trick to fix the buffering the image will look bad when being updated.
But, on the bright side. Since each pixel is a byte it should be really easy to fill the screen quickly.
... You know more about this than me, is there a way in which a single bitmap frame buffer can be used to hold the screen... but be updated nicely? We have vsync to use still, and memory access should be fast.
Having a scanline buffer means that the driver will not be user friendly.