Games & Preservation

Backing Up Nintendo DS Games

The Nintendo DS keeps each game on a tiny solid-state Game Card, and the handiest tool for copying one is a DS-family console you may already own — a homebrew-enabled DS, DSi, or 3DS dumps your own cards to a .nds file with no extra reader. Begin with the legal ground rules: own it, dump it yourself, keep it private.

Media
Slot-1 Game Card — solid-state mask ROM, no moving parts.
Hardware
A homebrew-enabled DS / DSi / 3DS running a card dumper, or a dedicated Slot-1 USB reader.
Software
GodMode9i (on a DS/DSi/3DS) — a free homebrew file manager that dumps cards and saves.
Output
.nds — the full card image.
Typical size
8 MB – 512 MB (most games 16–128 MB).
BIOS
Not needed. The OWL player’s DS core supplies the firmware it needs.
An original Nintendo DS handheld, open, in blue
The original Nintendo DS. Its games live on solid-state Slot-1 cards — data a homebrew dumper copies out in full. Image: Evan-Amos, public domain, via Wikimedia Commons.

What You Need

  • A DS-family console that runs homebrew. An original DS or DS Lite with a Slot-1 flashcart, or — easiest today — a DSi or 3DS with its free, well-documented homebrew environment. That console becomes the card reader; nothing else is required.
  • GodMode9i — the standard homebrew dumper. Insert your Game Card, pick it, and it writes Game.nds (and the save) to the SD card.
  • Or a dedicated Slot-1 USB reader if you would rather not set up homebrew — a small dongle that dumps a card straight to your PC.

Inside the Game Card

A DS Game Card is a mask-ROM chip with a small save chip beside it. The card carries a short encrypted boot header — the part that handshakes with the console at power-on — but the game itself is ordinary data, and a dumper reads the card end to end. That is why homebrew tools can produce a complete, verifiable .nds from a card you own: they read what the console reads.

ROM + saveDS Game Card1DS / DSi / 3DSGodMode9i reads the card2Game.nds+ Game.sav3OWL media libraryplays in the browser — no console needed
The DS dump: (1) the Game Card holds the ROM and its save chip, (2) a homebrew-enabled console reads the card in full, (3) you get a complete .nds (and the save) for your library. Diagram: NDEVR.

Dumping, Step by Step

  1. Prepare the console. Set up homebrew on your DSi or 3DS (or use a flashcart on a DS), and copy GodMode9i to the SD card.
  2. Insert the Game Card you own and launch the dumper.
  3. Dump the save first (see below), then dump the ROM to Game.nds.
  4. Verify. Check the file’s checksum against the No-Intro database to confirm a clean read of your card.
★

Trim nothing, keep the header

Some old guides “trim” the padding off a .nds to save space. Don’t — a full, untrimmed dump is the archival copy, verifies against the preservation databases, and is what the OWL player expects. Storage is cheap; a clean master is worth more.

Save Data

DS games store saves on a small chip in the card — usually flash or EEPROM, which (unlike the battery-backed SRAM of older cartridges) does not depend on a coin cell and is far less likely to have degraded. Dump it anyway: GodMode9i writes the save to a .sav beside the ROM, and it is the one part of a card that is genuinely irreplaceable if the chip ever fails.

Playing Your Backup

Upload Game.nds to your OWL media library and it lands in the Games collection with box art and per-console settings. The player’s DS core runs it in the browser — both screens and touch input — with save states synced across your devices, all inside your own end-to-end encrypted storage.