Atari 400 Basic Reference Manual

GAME
CONTROLLER
FUNCTIONS
PADDLE
PTRIG
STICK
Figure 10-2 is an illustration of the three controllers used with the Atari Per-
sonal Computers. The controllers can be attached directly to the Atari Per-
sonal Computer or to external mechanical devices so that outside events can be
fed directly to the computer for processing and control purposes.
Format:
Example:
Figure 10-2. Game Controllers
P ADDLE(aexp)
PRINT P ADDLE(3)
This function returns the status of a particular numbered controller. The paddle
controllers are numbered 0-7 from left to right. This function can be used with
other functions or commands to "cause" further actions like sound, graphics
controls, etc. For example, the statement IF PADDLE(3) = 14 THEN PRINT
"PADDLE ACTIVE." Note that the PADDLE function returns a number bet-
ween 1 and 228, with the number increasing in size as the knob on the con-
troller is rotated counterclockwise (turned to the left).
Format:
PTRIG(aexp)
Example: 100 IF PTRIG(4)"'0 THEN PRINT "MISSILES FIRED!"
The PTRIG function returns a status ofO ifthe trigger button ofthe designated
controller is pressed . Otherwise, it returns a value of 1. The aexp must be a
number between 0 and 7 as it designates the controller.
Format: STICK(aexp)
Example: 100 PRINT STICK(3)
This function works exactly the same way as the PADDLE command, but can be
used with the joystick controller. The joystick controllers are numbered from
0-3 from left to right.
Controller 1 = STICK(O)
Controller 2 = STICK(l)
Controller 3 == STICK(2)
Controller 4 = STICK(3)
Figure 10-3 shows the numbers that will be returned when the joystick con-
troller is moved in any direction.
Sounds and Game Controllers 59

Atari 400 Specifications

General

Manufacturer	Atari
Model	400
Type	Home Computer
Release Year	1979
CPU	MOS Technology 6502
CPU Speed	1.79 MHz
ROM	10 KB
Operating System	Atari OS
Keyboard	Membrane keyboard
RAM	8 KB (expandable to 48 KB)
Graphics	ANTIC and GTIA chips
Sound	4 channels
Display	RF output for connection to TV
Storage	Optional cassette tape drive or floppy disk drive
Ports	Cartridge
Display Resolution	320x192 (16 colors)