[net.micro.6809] Coco artifact colors, games

knudsen@ihnss.UUCP (09/19/83)

SSome points about JL Wood's article:
(1) Yes, these are "artifact colors", due to harmonics of the luminance
signal getting into the chroma bandpass of American TV sets.
You get Red vs blue/green in PMODE 4 by setting every other pixel.
Odd pixels give one color, evens the other.
Easiest way is to draw & paint in PMODE3, then switch to PMODE 4.

(2) Which color is which seems to be random on how the SAM & VDG initially
sync to each other.  RESET is the quick & dirty solution.  Has anyone tried
the SYNC instruction in the 6809?  Does that just affect the CPU/SAM sync?

(3) If you "purchased" a recent copy of Donkey/The King, the instructions
should tell you that the opening raster should be red.  If so, hit ENTER;
if blue/green, hit SPACE bar instead.  Do read the little instruction card
(magnifying glass?); it tells how to save & restore high scores, save
copies to tape/disk, etc.

(4) I'd thought the King authorss knew something special about (2) above,
till I read that hitting the space bar reversess the colors simply
by redefining in software, which color writess what.

(5) Amazing pastels and acrylics can be had with artifacts.  Maybe I'll
post my nice random color program.  For practical approach, read the
August and Sept issues of THE RAINBOW magazine.  (Every Coconut should
subscribe to this and/or HOT COCO).
	mike k