Atari XL User Manual

Player-Missile Graphics
185
REGISTER MEANING LOCATION
MODISP
Missile O/Display
53248
M1 DISP
Missile 1/Display 53249
M2DISP
Missile 2/Display 53250
M3DISP Missile 3/Display 53251
PODISP
Player O/Display 53252
P1 DISP
Player 1/Display 53253
P2DISP
Player 2/Display 53254
P3DISP Player 3/Display 53255
MOPL Missile O/Player
53256
M1PL Missile 1/Player 53257
M2PL Missile 2/Player 53258
M3PL Missile 3/Player
53259
POPL
Player O/Player
53260
P1PL
Player 1/Player 53261
P2PL
Player 2/Player
53262
P3PL Player 3/Player
53263
HITCLR
Clear collisions 53278
Collision Registers
Bit 2 set indicates a collision with Player 2.
Bit 3 set indicates a collision with Player 3.
(A
player cannot collide with itself.)
Note that the addresses of these registers are the
same as those of some of the control registers we
have already described. This does not matter, as
you will only be reading from the collision registers
and writing to the control registers. The Atari
hardware directs the signals to two different

Atari XL Specifications

General

Release Year	1983
CPU	MOS Technology 6502C
Graphics	ANTIC, GTIA
Sound	POKEY (4 channels)
Storage	Cassette tape
Ports	Cartridge
Operating System	Atari BASIC
CPU Speed	1.79 MHz
RAM	64 KB