A new development version has been released. Changes in FS-UAE 2.9.6dev:

• Changed default fade in/out duration, only fade in fullscreen.
• FS-UAE default is now to show a 692×540 image, not stretched to fill screen.
• Use scale = legacy to revert to old default behavior (Can put in Host.fs-uae or use FS-UAE Launcher set set globally).
• New option scale (choose between full, integer, legacy and no scaling).
• New option stretch (replaces keep_aspect, though it still works).
• F11 is now a dedicated toggle auto zoom function, Alt/Cmd+Z cycles through zoom modes as before.
• Render a frame around the view when not stretched (frame = 0 to disable).
• Cartridge freeze shortcut is now Alt/Cmd+C.
• Alt/Cmd+A now toggles stretch mode (aspect correction).
• Imported updated translations from crowdin.com.

In short, the default scaling/cropping behaviour has changed (though you may not see the change if you have specified certain scaling options). Also, the FS-UAE menu itself is being changed so it will work better on non-16:9 displays (not complete yet).Changes in FS-UAE Launcher 2.9.6dev:

• Imported updated translations from crowdin.com.
• Moved additional game databases to a separate settings page.

Changes in FS-UAE Arcade 2.9.6dev:

• FS-UAE Arcade now defaults to fullscreen.
• Run FS-UAE with window_border = 0 to reduce flickering on launch.