Nintendo DS storage devices

Nintendo DS and 3DS storage devices are used to store a licensed developer's work-in-progress images, homebrew video games, and downloaded commercial games (since the Nintendo DS is not sold with a rewritable storage medium). Licensed developers, however, can use a blue Intelligent Systems Nitro Emulator box to flash cards. These devices are also known as "flashcarts" or "flashcards". There are two main classes of flashcarts: older devices which fit in Slot-2 (the Game Boy Advance Game Pak slot) and newer devices that fit in Slot-1 (the DS Game Card slot). Slot-2 (or first-generation) devices have been historically cheaper due to economies of scale (inherited from their use with Game Boy Advance), but require a booting tool in Slot-1 in order to use the touch screen and other DS features. Second-generation devices (those which only use Slot-1) do not work with GBA homebrew, but as of 2007^[update] became less expensive and easier to use, rivaling many Slot-2 devices in price.

First-generation devices include GBA flash cartridges, GBAMP CF, SuperCard, and M3. Second-generation devices include R4 Revolution, CycloDS, G6 Real and DS-X. Many of these devices also work with the Nintendo 3DS as DS flash cartridges, allowing DS ROM backups to run in game consoles of the Nintendo 3DS line. There are also flash cartridges made exclusively for the Nintendo 3DS, such as the Gateway 3DS and Sky3DS, which allow 3DS ROM backups to run in these systems. The storage device either contains flash memory or a slot for a memory card to store homebrew. Storage devices with a memory-card slot usually have more storage capacity than flash-memory devices. Although flash-memory capacity is usually measured in megabits (Mb), memory-card capacity is usually measured in megabytes (MB) (where 8 Mb is 1 MB).

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