[Coco] More colors on CoCo 1?

[Roger Taylor]

At 06:55 AM 1/21/2007, you wrote:

>Although your choice of extra colours is limited to 13 extra ones in this
>case, the flickering should be much reduced. If you're prepared to tolerate
>a little more flickering, you could allow colour combinations between
>colours having adjacent brightness levels, e.g. 0/1, 1/2, 2/3.


You could even alternate the combination positioning for each 
scanline or the other flickered page if you're mixing that way in 
addition to the single-page half-tone dithering.  I think the 
following might yield about 43 to 49 grayscales that are more 
accurate than just using a set of 7 pairs per screen like 
(0,0  0,1  1,1  1,2  2,2  2,3  3,3).  The even/odd line patterning 
can reduce artifacts and vertical striping.

page 1, even lines
0,0
0,1
1,1
1,2
2,2
2,3
3,3
3,3

page 1, odd lines
0,0
0,0
1,0
1,1
2,1
2,2
3,2
3,3

You can also achieve a simulated vertical resolution increase like 
for tall Macintosh pictures, by dividing the picture into two 
screens, one containing just the even lines, and the other containing 
just the odd lines.