The FS-UAE executable can be invoked alone, or with one of – or a combination of:

• A path to a configuration file.
• Options given as program arguments

If the FS-UAE executable is invoked without the path to a configuration file, the default configuration file will be loaded.

Program Arguments

All options can be specified either in a configuration file, or as program arguments. Options must be prefixed with a double dash (--), and a equal sign must separate the option from its value. Underlines in option names may be written as hyphens for aesthetics. Example:

fs-uae --floppy-drive-0=Disk1.adf

This is the same as:

fs-uae --floppy_drive_0=Disk1.adf

Options given as program arguments always override options from configuration files.

Shorthand Arguments

Several FS-UAE options are boolean options – they take either 0 or 1 as value (for off and on, respectively). To enable the option, you can simply omit the =1 part. To disable the option, you omit the =0 part and prepend the option name with –no. Take for example the option fullscreen. To enable full-screen mode, these two commands are equivalent:

fs-uae --fullscreen=1
fs-uae --fullscreen

And to disable full-screen mode:

fs-uae --fullscreen=0
fs-uae --no-fullscreen

Default Values

All options have default values. With that, I mean that FS-UAE has a default behavior if an option is never specified at all. For example, if the fullscreen option is not used, FS-UAE will open in windowed mode. If you want to override an option and explicitly ask for the default behavior, use the nothing as the value.

To use the fullscreen option as an example again:

fs-uae /path/to/config.fs-uae --fullscreen=

This will force FS-UAE to use the default value for the fullscreen option (which is to open in windowed mode) even though fullscreen=1 may have been specified in the configuration files.