FS-UAE Launcher has the Video setting "Keep aspect ratio when scaling (do not stretch)"
When the option is changed, the Launcher stores the setting in the "Data\Settings.ini" using the name "keep_aspect = "
When starting a configuration, you can see that the FS-UAE emulator ignores this option as this was deprecated and previously changed to "stretch =" in v2.9.6dev
(Last tested in Windows with portable version of FS-UAE Launcher 3.2.11-beta and FS-UAE v3.1.66)
As a workaround, you can add any of the following settings as a row in "FS-UAE Launcher" -> "Settings" -> "Advanced"
Add the following row to Keep aspect ratio: On - equivalent to " keep_aspect = 1 "
stretch = 0
Add the following row to Keep aspect ratio: Off - equivalent to " keep_aspect = 0 "
FS-UAE Launcher has the Video setting "Keep aspect ratio when scaling (do not stretch)" When the option is changed, the Launcher stores the setting in the "Data\Settings.ini" using the name "keep_aspect = " When starting a configuration, you can see that the FS-UAE emulator ignores this option as this was deprecated and previously changed to "stretch =" in v2.9.6dev (Last tested in Windows with portable version of FS-UAE Launcher 3.2.11-beta and FS-UAE v3.1.66)
As a workaround, you can add any of the following settings as a row in "FS-UAE Launcher" -> "Settings" -> "Advanced"
Add the following row to Keep aspect ratio: On - equivalent to " keep_aspect = 1 "
stretch = 0
Add the following row to Keep aspect ratio: Off - equivalent to " keep_aspect = 0 "
stretch = 1