Atari 800 User Manual

156 User's Handbook to the Atari 400/ 800 Computers
The previous example displays the current value for the right
margin of the screen. The default value is 39 .
PLOT (PL.)
The PLOT statement is used to display a character or picture
element on the display.
CONFIGURATION
PLOT a,b
The arguments
of a PLOT statement determine the position on
the screen where the character or picture element appears. The
first
argument (a) indicates the column, and the second
argument (b) indicates the row. The graphics mode specified
determines the number of rows and columns of the display. If
either of the arguments is not an integer, it is rounded off. If
either argument is negative or greater than the dimension of the
screen an
error resu Its.
In graphics mode 0, the COLOR statement indicates the
character that will appear at the next PLOT location. However,
the COLOR statement has nothing to do with the color of the
character. Table 9-7 indicates the COLOR value for each
character.
In graphics modes 1 and 2, the COLOR statement indicates the
character and location register used in the next PLOT location .
Table
9-4 indicates the COLOR value for each character in each
color register. In graphics modes 1 and 2, color registers are
available for each character. As a result, each character can be
displayed in any of 4 colors.
In
graphics modes 3 through 8, the PLOT statement illuminatesa
picture element at the screen position indicated by the
arguments of the PLOT statement. The dimensions of the display
depend on the graphics mode. The number of possible colors
also
depends on the graphics mode.

Atari 800 Specifications

General

Processor	MOS Technology 6502
Processor Speed	1.79 MHz
ROM	10 KB
Graphics	ANTIC and GTIA chips
Release Year	1979
Display Resolution	up to 320 x 192
Colors	128 colors
Sound	4 channels
Storage	Cartridge, cassette, floppy disk
Ports	Cartridge, serial, monitor
Operating System	Atari OS