Commodore Plus 4 - Multi-color graphics

MULTI- Tne plus/4 high resolution graphics give you control over every single ■—■
COLOR cio*or Pixel on the screen, but you have seen that the ability to put
colors close together is limited. Most high-res programs can use only
one or two colors.
For including more different colors, your Plus/4 has a special "in-
between" graphics mode called multi-color graphics. In multi-color
graphics, you control half as many dots on each row as in high-res be
cause each dot is twice as wide. You get 160 dots on each row, while
still getting 200 rows, There is a trade-off for the use of multiple colors,
which is slightly lower resolution. •—'
To begin using multi-color graphics, review the GRAPHIC command
earlier in this chapter You'll see that the multi-color screen without
text is GRAPHIC 3 and the multi-color screen with 5 lines of text is
GRAPHIC 4.
Now look at the table listing the COLOR command. There are two
areas that we haven't used yet, areas 2 and 3. These areas hold two —
extra colors. You can use any of the three colors (1. the text color; 2, an
extra color; and 3, another extra color) These colors do not interfere
with each other on the screen the way the high-res colors do in some
previous programs in this chapter
These two programs make use of multi-color graphics, the first with the
rings and ihe second showing a "neon sign" effect. . -
10 COLOR 0,1
20 GRAPHIC 4,1
30FORL = 1 TO 4
40Q = L: IFQ>3THENG=Q-3
50 COLOR Q,L+1
60Y-50
70IFL 2ORL 4 THEN Y-100
80X- L'18 ■ 25
90 CIRCLE Q,X,Y, 25,42
100 NEXT L
102-