This is an experimental feature where you can get a “fifth joystick port”. This is not a joystick port the emulated Amiga knows about – but it is instead used to create a virtual joystick which sends custom key presses to the Amiga.
For example, you can use it to add joystick support for a game which normally only allows use of cursor keys.
Here’s an example (which speaks for itself):
joystick_port_4_mode = joystick joystick_port_4_down = action_key_cursor_down joystick_port_4_left = action_key_cursor_left joystick_port_4_right = action_key_cursor_right joystick_port_4_up = action_key_cursor_up joystick_port_4_primary = action_key_space
With this configuration active, you’ll be able to select a host device in the “Custom Joystick Port”, both in FS-UAE and in FS-UAE Launcher. You need at least version 2.1.19. Available input actions are listed here.
Why a “Custom Joystick Port”?
Mapping joystick events to Amiga keyboard actions has been possible for a while in FS-UAE. But the existing mapping features are tied to specific devices (i.e. you can set up a rule to map a certain button on joystick number two to a keyboard key). With this new feature, you’ll instead be able to swap which device uses this configuration -even while playing.
Online Database Support
You can configure a custom joystick port for games in the online database as well. In this case, a shorthand notation is used, and the configuration becomes:
joystick_port_4_mode = joystick, left = key_cursor_left, right = key_cursor_right, up = key_cursor_up,
down = key_cursor_down, primary = key_space,
secondary = key_shift_right
When the game variant is loaded by FS-UAE Launcher, this shorthand configuration will be automatically expanded to the full configuration.