Atari XL User Manual

174
The Ateri XL Handbook
Gold is colour 1, so for a bright gold player, try
POKE 704, 16*1 + 12
The value in location 53256 controls the width of
the player. A value of 0 gives normal width, 1 gives
double width, and 3 quadruples the player's width.
To shrink the player a li ttle, try:
POKE 53256, 1
The fourth control register has the most dramatic
effect. Location 53248 controls the horizontal
position of the player on the screen. The value may
range from 0 to 255, and the corresponding player
posi tions range beyond the edges of the screen on
both sides, allowing players to be (hidden'. Try
adding these lines to the first example program:
130 FOR X=O TO 255
140 POKE POHPOS, X
150 NEXT X
160 GOTO 130
The player will move across the screen from left to
right as the value in the horizontal position
register is increased.
CONTROLLING THE SHAPES OF PLAYERS
The four players may all be controlled in the same
way as Player o. The registers to be used for the
players are shown in the table oppositee These
registers all control the GTIA (the special purpose
chip which controls the display).
So
far you have seen nothing very impressive.
Moving bands, yes, but these are hardly the stuff of
which exciting video games are made. To find out

Atari XL Specifications

General

Brand	Atari
Model	XL
Category	Desktop
Language	English