Commodore 128 - Selecting the Graphic Mode

The first one is text display, which displays only characters, such
as letters, numbers, special symbols and the graphics characters
on the front faces of most C128 keys. The C128 can display text
in both 40-column and 80-column screen formats.
The second category of display mode is used for highly detailed
graphics, such as pictures and intricate drawings. This type of
display mode includes standard bit-map mode and multicolor bit
map mode. Bit-map modes allow you to control each and every
individual screen dot or pixel (picture element). This allows
considerable detail in drawing pictures and other computer art.
The 80 column display is intended to display text.
The difference between text and bit map modes lies in the way in
which each screen addresses and stores information. The text
screen can only manipulate entire characters, each of which
covers an area of 8 by 8 pixels on your screen. The more
powerful bit-map mode exercises control over each and every
pixel on your screen.
The third type of screen display, split screen, is a mixture of the
first two types. The split screen display outputs part of the screen
as text and part in bit map mode (either standard or multicolor).
The C128 is capable of this because it uses two separate and
different parts of the computer’s memory to store the two
screens: one part for the text, and the other for the graphics
screen.
Type the following short program:
10 COLOR 0,1: REM TEXT BACKGROUND COLOR =
BLACK
20 COLOR 1,3: REM FOREGROUND COLOR FOR BIT
MAP SCREEN = RED
30 COLOR 4,1: REM BORDER COLOR = BLACK
This example colors the background black, the foreground red
and the border black.
Selecting the Graphic Mode
The next graphics programming step is to select the appropriate
graphic mode. This is done using the GRAPHIC command,
whose format is as follows:
6-6