Commodore Plus 4 - Page 219

Graphics Programming in BASIC 807
120 Read the multicolor characters in the DATA statements, and replace
the parentheses characters (screen codes 40 and 41) with them.
8192+40*8=8512
130 PRINT a CHR$(154) to be in multicolor with foreground color blue,
followed by the sentence. When you run this program, note the
appearance of the standard characters PRINTed in multicolor. This
is because the bits are being interpreted as multicolor pairs.
140 PRINT a multicolor blue butterfly. Then change to multicolor green
(CHR$(153)) and PRINT a green butterfly. Note that in both butter
flies the spot is light blue and the body is black. These areas use the
shared background color registers for their color information.
150 PRINT a CHR$(144) for high resolution with foreground color
black, followed by the message. Note that the characters now look
normal because their bits are being interpreted one at a time as high-
resolution on or off messages.
160 Wait for a key.
170 Restore graphics chip looking at the location of the character ROM.
180 Restore graphics chip looking at ROM.
190 Get out of multicolor mode.
200 Restore £§ SHIFT keys.
210 End of execution.
220-230 Data for the two halves of the butterfly.
Extended Color Mode In this mode each dot is individually controlled, as they
are in high-resolution characters; the difference is that you can specify any of four
background colors (of the bits that are 0) for each character. You can also still
choose an individual foreground color (of the bits which are 1) for each character
cell. In extended color mode, the number of characters available is cut to 64
(representing settings for 6 bits). The setting of the two high bits in the screen code
for a character determines which background color it will use.
Screen Code Character Pattern Background Color Register
0
64
128
192
- 63
-127
-191
-255
0-63
0-63
0-63
0-63
65301
65302
65303
65304