Can You Download Games Directly to a DSi Action Replay?

No. The DSi Action Replay (and all Action Replay carts) is a cheat device only. It lacks the hardware to store or launch game backups (ROMs).

Technical Limitations

• No Internal Storage: It has volatile RAM for cheat codes and a tiny EEPROM for save management/settings—zero capacity for .nds ROMs (128MB–512MB each).
• No SD Slot (on the cart): Unlike flashcarts (R4, Acekard, DSTWO), it cannot read microSD cards.
• DSi Mode Lockout: The DSi/3DS firmware blocks unauthorized Slot-1 carts. Action Replay DSi works in "DS Mode" only (no DSi camera/CPU access).

What It *Actually* Does

• Boots retail DS carts (Slot 1) and applies cheat codes (.cht/.xml) from its internal database.
• Can backup/restore save files (.sav) from retail carts to its internal memory or a connected PC via USB (older models).
• Cannot launch homebrew or ROMs.

To Play Backups/Homebrew on DSi/3DS

1. Install custom firmware (CFW): HiyaCFW (DSi) or Luma3DS (3DS).
2. Use TWiLight Menu++ (DSi/3DS) or nds-bootstrap (3DS) to launch .nds files from SD card.
3. Or buy a modern flashcart compatible with your firmware (e.g., R4i Gold 3DS Plus, Ace3DS X, R4i-B9S).

Legal Note: Dumping your own carts for personal use is legally ambiguous (DMCA 1201). Downloading ROMs you don't own is piracy.