Settings

Tap the gear (⚙) button in the library to open Settings. Everything here works with the controller too: move with the D-pad, pick with A, go back with B.

#Controller

Settings › Controller has two pages. These are the defaults:

• Button mapping lists every game button and the Thor button that presses it. Pick a row, press a button, done. A button used elsewhere swaps places with it. Reset to default restores the table above.
• Hotkeys has seven actions: open the quick menu, fast-forward (hold or toggle), quick save state, quick load state, next and previous save slot, and exit game. Each is one button, or the hotkey button plus a button. The hotkey button is none by default. While you hold it nothing reaches the game; a button it shares with a game button reaches the game when you let go. Exiting asks you first.
• BACK always opens the quick menu, so you can't lock yourself out.

#Picture

These apply to every game. Shader and color correction can also be set for one game (see Game settings).

• Shader: the default look. Off, GBA Color, LCD Grid, Scanlines or Scale2x.
• Color correction: Off, GBA screen or Game Boy Color screen, so colors look like the real handheld's screen instead of a flat monitor.
• Aspect ratio: Original, 4:3, 16:9, or Stretch to screen.
• Tilt-shift blur: Off, Light or Strong blur at the top and bottom of the picture. Also in the quick menu.
• Integer scaling: On draws exact pixels at a smaller size; Off fills the screen. Also in the quick menu.
• Performance overlay: Off, FPS, or FPS + CPU over the game.

#Game settings

In the library, press X on a game (or open its game settings) for the settings of that one game:

• Shader and Color correction: follow the defaults above, or pick one for this game.
• Cover: find one on SteamGridDB, use an image from your artwork folder, remove it, or Reset to automatic so a scrape can set it again.

Wide view is a per-game setting too, switched from the companion screen: see Wide view.

#Scraping covers

Settings › Scraping finds a cover for each game's cartridge in the library.

1. Under Providers, set up where covers come from. A scrape tries them from the top.
   • Artwork folder: a folder you choose, read only. Images are matched by ROM name, title, game code or checksum. Screenshots and logos are skipped.
   • SteamGridDB: needs a free API key (steamgriddb.com › Profile › Preferences › API). Only game titles are sent.
2. Tap Scrape library. It skips games that already have a cover, and games whose cover you removed. Replace existing covers changes that.
3. Remove all covers clears them again; your artwork folder and SteamGridDB aren't touched.

#Save folder

Every game's saves live in GBA Duo's private storage, one folder per game:

<platform>/<Title> [<code>-<CRC32>]/
    game.sav          the game's own save
    states/slotN.ss   save states
    pack.json         the companion pack picked for it

Folders are named by the ROM's checksum, so a game finds its saves wherever the ROM file is and whatever it's called.

Settings › Save folder keeps a copy of all of them in a folder you pick: the SD card, or a folder another app syncs.

• Games still play from the private copy. It's copied to the folder after each in-game save and save state, on pause and on quit.
• Newer saves already in the folder, say from another device, are taken in when a game starts.
• The first time, every save is copied over and checked before the folder is used. If any copy fails, nothing changes.
• If a save changed in both places, the newer one is kept and the other is saved next to it as game.sav.conflict-<time>. Nothing is overwritten silently.
• If the folder can't be reached (SD card out), the game plays from the private copy and the folder catches up once it's back.
• Companion packs and the ROM list stay private.

To back up, copy the folder. To move to another device, copy it there and pick it as the save folder. Stop using folder leaves the folder and the saves in it as they are.

#RetroAchievements

Earn RetroAchievements while you play.

1. Open Settings › RetroAchievements.
2. Log in with your retroachievements.org account.
3. Start a game. A summary shows how many of its achievements you've unlocked, and each new unlock pops up over the game.

• Achievements are earned in softcore for now. Hardcore needs RetroAchievements to approve GBA Duo first.
• GBA Duo keeps the login token RetroAchievements gives it, never your password.
• It only goes online while you're logged in: to identify each game you start and record your unlocks. If the connection drops, unlocks are sent later.

#Packs can change games

Some companion packs can change a game's memory when you tap them, for example to equip an item without opening the menu. This is off until you turn on Settings › Packs can change games.

When it's on:

• The first time a pack is about to change a game, GBA Duo asks, naming the pack and the game. Your answer is kept for that pack and game.
• If the pack is updated or replaced, it asks again.
• A save state is made just before the first change. Load state › Before pack changes takes you back.
• Packs only change the game from your taps, a few bytes at a time, and only the game's work RAM: never the ROM or your save file directly.

In the pack picker, packs that can do this are marked "can modify the game". A bad change can crash a game or spoil a save, so only allow packs you trust.

Pack makers: see Changing the game.

#Also in Settings

• ROM folders: where your games come from. See Add your games.
• About: version, licenses and credits.