APPENDIX FIVE



With GRAPHICS 9, the COLOR command is used to set the luminance
level to one of sixteen possible values; the value you use with the
COLOR statement is equal to the luminance used (so you can have
COLOR 15, COLOR 10, etc. Actually you can use any value up to 255
with COLOR and not get an error message; see the demo program for
GR.11 in location 623). SETCOLOR 4 defines the background and
graphics color. There is only one color in GR.9. In GRAPHICS 11,
COLOR is used to define the color the same way it is used for
luminance in GR.9, while the luminance of each color is the same
value; you can have sixteen colors all of the same luminance.
GRAPHICS 10 allows you to set the nine color registers to individual
colors and luminances, but you must use POKE commands for the
registers 704 to 707.

For more information on the GTIA modes, see COMPUTE!, July to
September 1982, and De Re Atari. There are many good programs for
drawing your own pictures in various GRAPHICS modes;
Micropainter from Datasoft is one of my favorites; then there's Drawpic
from Artworx, The Graphics Machine from Santa Cruz, Graphic
Master from Datasoft, Graphics Composer from Versaware and The
Next Step from Online which is really a utility for character creation
and color set selection. COMPUTE! published an interesting program
called "Supercube" over many issues in 1980 and 1981.