[Coco] Artifacting (again)

[Ciaran Anscomb]

Mark McDougall wrote:
> I've taken a quick look at the MESS code and I'm afraid it's way too complex 
> for my requirements. I was looking at a middle-ground between the simple 
> pixel-pair and the real thing.

The way I do it is with a 5-bit lookup table, indexed by the value formed
by the bits two pixels before to two bits after the pixel being considered.

So for say, the 8th pixel across, the number formed by the 6th to 10th
bits of the scanline indexes into the colour table.

..ciaran