Commodore Plus 4 - Page 217

Graphics Programming in BASIC 205
As you can see, the first three bit patterns use global color sources. This means
you have three global (whole screen) colors. The last bit pattern uses the normal
color memory to get its color (and luminance), so that each character can have an
independent foreground color.
Using the bits in pairs this way limits the resolution of your character in the
horizontal direction. Sometimes this is too restrictive. The Plus/4 allows you to
mix high-resolution and multicolor characters on the same screen. The Plus/4
must be in multicolor mode. This is accomplished with
POKE 65287,PEEK(65287)0R16
To put the chip back in high-resolution mode use
POKE 65287,PEEK(65287)AIfiD239
When the Plus/ 4 is in multicolor mode, the color (not luminance) chosen for a
given character cell determines whether the character occupying it is high resolu
tion or multicolor. If the color associated with a given cell is greater than 8
(yellow), then the cell is multicolor. The actual foreground color of the cell is not
the color chosen (color) but the color given by
color-8
If the color associated with the cell is less than or equal to 8, then the cell is high
resolution and its actual color is the color chosen. This means that, when using
multicolor text mode, only the first eight colors are available for use as fore
ground colors. However, all eight luminances are available for each of these
colors.
The background registers 65301-65303 used for coloring the nonforeground
pixel pairs can be assigned any of the 16 colors and 8 luminances. To calculate the
value needed, use
luminance* 16+color-1
where the luminance is 0 through 7 and the color is chosen from the available
colors (1-16).
Note: In multicolor mode, the cursor is invisible. It is a good idea to return to
high-resolution character mode when exiting a program.
Multicolor Custom Characters Example Program
In this example, type the small letters inside the quotes without shifting, and type
the capital letters inside the quotes shifted.