sticks - Atari 2600 Joystick Functions for C02

This library contains a function for reading the joysticks:

  res = getstk(cntrlr);       Reads the state of the specified joystick.
                              
                              The joystick to be read is specified by
                              the argument cntrlr:
                                0 = Left Joystick  
                                1 = Right Joystick
                              
                              Returns a byte comprised of the bits:
                                Bit Hex Dec  Control
                                 0  $01   1  Up         
                                 1  $02   2  Down
                                 2  $03   4  Left
                                 3  $04   8  Right
                                 7  $05 128  Trigger
                              
                              A 1 in a bit means that the direction
                              or trigger is pressed, so the function
                              will return 0 if they joystick is 
                              centered and the trigger is not pressed.
                              This is the reverse of the raw bits from
                              the hardware ports.
                              
                              Note: The raw bits for the left joystick 
                              are stored in TEMP0, while the raw bits
                              for the right joystick are stored in TEMP1.


