AT&T 6300 Programmer's Manual page 131

Graphics
MEDIUM RESOLUTION MODE
In this mode, there are 320 pixels on the
horizontal axis and 200 pixels on the vertical
axis. These are numbered from left to right and
from top to bottom; thus the upper left corner
pixel is (0,0) and the lower right corner pixel is
(319, 199).
You can display four colors at a time if a color
monitor is used, otherwise the four colors will
appear as shades of grey.
Drawing Pictures
When you draw pictures on the screen using the
graphics statements (PSET, PRESET, LINE,
CIRCLE, PAINT or DRAW), you can specify a
color number of 0, 1, 2, or 3. This selects the
color from the current "palette" as defined by
the COLOR statement.
If you do not specify a color number, the
default is the graphics foreground specified by
the COLOR statement, or 3 (if no graphics
foreground is given).
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