Click above to get retro games delivered to your door ever month!

                        Joystick / Game Port (201h)

        |7|6|5|4|3|2|1|0|  Port at 201h used with Joysticks
         | | | | | | | +---- joystick a, x coord (0 = timing active)
         | | | | | | +----- joystick a, y coord (0 = timing active)
         | | | | | +------ joystick b, x coord (0 = timing active)
         | | | | +------- joystick b, y coord (0 = timing active)
         | | | +-------- joystick a, button 1 (0=pressed)
         | | +--------- joystick a, button 2 (0=pressed)
         | +---------- joystick b, button 1 (0=pressed)
         +----------- joystick b, button 2 (0=pressed)

        |7|6|5|4|3|2|1|0|  Port at 201h used with Paddles
         | | | | | | | +---- paddle a coord (0 = timing active)
         | | | | | | +----- paddle b coord (0 = timing active)
         | | | | | +------ paddle c coord (0 = timing active)
         | | | | +------- paddle d coord (0 = timing active)
         | | | +-------- paddle a, button (0=pressed)
         | | +--------- paddle b, button (0=pressed)
         | +---------- paddle c, button (0=pressed)
         +----------- paddle d, button (0=pressed)


        - accessed through port 201h
        - bits 3-0 are resistive inputs with the length of the pulse
          determined by 0-100K ohm resistive load.   Use this formula:

      time = 24.2. + ( 0.011. * resistance )
        or
      resistance = ( time - 24.2 ) / 0.011


        - a read should be immediately preceded by a write (any data)
          to start timing for the resistive values.