Atari 800 Basic Reference Manual

GRAPHICS
MODES
3, 5, AND 7
GRAPHICS
MODES
4AND6
GRAPHICS
MODE8
Unless otherwise specified, all characters are displayed in upper case non-
inverse form. To print lower case letters and graphics characters, use a POKE
756,226. To return to upper case, use POKE 756,224.
In graphics modes 1 and 2, there is no inverse video, but it is possible to get all
the rest of the characters in four different colors (see end of section).
(X=Ol
(Y=O)
S:
Graphics Window
(graphics or tt>xt)
E:
Text Window
(4 lines)
border (size
depends on
individual
TV's overscan)
Figure 9-1. Split-Screen Display For Graphics Modes 1 and 2
The X and Y coordinates start at 0 (upper left of screen). The maximum values
are the numbers of rows and columns minus 1 (see Table 9-1).
This split-screen configuration can be changed to a full screen display by adding
the characters + 16 to the mode number.
Example: GRAPHICS 1 + 16
These three 4-color graphics modes are also split-screen displays in their default
state, but may be changed to full screen by adding + 16 to the mode number.
Modes 3, 5, and 7 are alike except that modes 5 and 7 use more points (pixels) in
plotting, drawing, and positioning the cursor; the points are smaller, thereby
giving a much higher resolution.
These two 2-color graphics modes are split-screen displays and can display in
only two colors while the other modes can display 4 and 5 colors. The advantage
of a two-color mode is that it requires less RAM space (see Table 9-1). Therefore,
it is used when only two colors are needed and RAM is getting crowded. These
two modes also have a higher resolution which means smaller points than
Graphics mode 3.
This graphics mode gives the highest resolution of all the other modes. As it
takes a lot of RAM to obtain this kind of resolution, it can only accomodate a
maximum of one color and two different luminances.
Graphic Modes and Commands 47

Atari 800 Specifications

General

Brand	Atari
Model	800
Category	Desktop
Language	English