# 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 = 24.2µ + ( 0.011µ * 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.