List of Nintendo DS and 3DS flash cartridges
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  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).

Storage-device brands differ in their support for homebrew; DS, 3DS and Game Boy Advance ROMs; special features (such as ability to play media files); physical size and cost. Strictly speaking, a storage device is not necessary for DS with FlashMe installed because homebrew can be sent to the DS using Wireless Multiboot or WMB. However, this is not an easily portable method because the DS needs to be within range of a suitable Wi-Fi card.

First generation

GBA flash cartridge

The first method of storing homebrew applications for the Nintendo DS was the use of flash cartridges designed for the Game Boy Advance. These were effective in finding exploits, since they are a 32 MiB block of rewritable flash memory directly accessible by both CPUs of the Nintendo DS. Users of GBA homebrew tended to use GBA methods for DS homebrew as well; however, the limited storage space, variety and price of GBA flash cartridges make them unsuitable for new users. Since there were many types of flash cartridges (each with its own method for writing to the flash ROM), most homebrew programs only supported saving to the included 64 KiB of SRAM intended for game-saving.

After the creation of DLDI this was no longer a problem, and any program from 2007 or later works with any flashcart. This method of storage does not work with the Nintendo DSi, since it does not have a GBA slot.

GBA Movie Player

The GBA Movie Player (GBAMP) is a CompactFlash adapter for the Game Boy Advance. It supports playing music and movies; NES and Game Boy games (under 200kb) and Game Boy Advance games (under 256kb) from the CF card, and reading text files. Its low price and simple design make it suitable for DS homebrew. Hacked firmware is available, adding the ability to run DS homebrew while maintaining the GBA features. This is the most widely supported homebrew device; nearly every homebrew which writes to the storage medium supports it. There are three versions of the GBAMP: a large pass-through device (version 1), a small white-and-red cartridge (version 2) and a slightly smaller SD card version (version 2 SD). Version 2 has the most support.

SuperCard and M3 Perfect
Supercard and M3 Perfect are similar devices to the GBA Movie Player, with more features. M3 is made by the developers of GBAMP. Both contain a CompactFlash, Secure Digital, miniSD, or Transflash slot, and 32 MB of built-in RAM. They offer GBAMP's features, in addition to the ability to play all GBA games and homebrew with the built-in RAM as a flash cartridge. They can also play DS backups by using sequential reading (SuperCard's built-in RAM, however, is too slow to play some GBA games accurately). Some DS homebrew also uses this additional RAM; however, addressing issues and speed make it less useful than the DS' built-in memory.

SuperCard and M3 Perfect are more expensive than GBAMP (M3 more so than SuperCard), and not as well supported by homebrew. Most homebrew encounters difficulty writing to SD cards; the more complex and proprietary protocols used with SD were reverse engineered later than the well-known CF protocol. The SuperCard has full support for booting DS game backups (no problems with saving or booting, a cheat system and rumble support); however, the SuperCard only has partial support for DS Download (some games freeze on loading). Variations on these devices have been released, such as SuperCard Rumble and M3 Pro. Some feature a smaller size, which better fits the DS Lite to a reduction of the built-in RAM.

MAX Media Player
The MAX Media Player (not to be confused with Max Media Launcher, a NoPass device) is similar to the GBA Movie Player, but does not function in GBA mode. Although it is the easiest device to find (the only DS homebrew device sold in major retail stores, such as Wal-Mart) its price, power consumption and poor homebrew support make it unsuitable. Its primary attraction is the ability to play DS game backups (through homebrew known as Maximum Overload, although all DS storage devices may be used for this purpose). A version of Maximum Overload has been released which allows the playing of commercial ROMs and has full Nintendo DS ROM compatibility. A DLDI driver has been written (with 99-percent homebrew compatibility) which is compatible with Pokémon Black and White games.

Second generation
Once the DS-card encryption was broken, it became possible to design cards which boot and read directly from SLOT-1. Pass-through devices and flash firmware are no longer needed to read from external storage, which has caused a proliferation of all-in-one plug and play cards.

One drawback of second-generation storage devices is that the new cards have poor compatibility with a significant portion of homebrew applications requiring filesystem I/O. DLDI (Dynamically Linked Device Interface for libfat) patching, however, has solved this problem. All second-generation cards with a DLDI driver written for them are able to run most homebrew requiring filesystem I/O. Also, GBA games are mainly unable to be played on these cards unless you have a 2nd slot flash cart.

Acekard 2/2i
The Acekard 2  earned a 90-percent on DS-Scene.net and a Golden Award on GBAtemp. It features 99-percent game compatibility, skinnable download-play support, micro-SD/SDHC memory card support, quick loading and Action Replay cheat support. Users reported freezing problems with the first batch of cards, but the Acekard 2.1 revision (released in December 2008) addressed these issues. The newer cards have 2.1 on their stickers, and may also be identified by the lack of a microchip bulge under the sticker.

In addition to official firmware, a closed-source firmware known as AKAIO is under development. It is at version 1.9.0, with support for the EZ-Flash 3-in-1 and 3-in-1+ expansion packs. With the release of the Nintendo DSi, Acekard became the first team to release a card compatible with it: the Acekard 2i. Other than its support for the DSi, it is identical to the Acekard 2. When Nintendo released the newest version of the DSi firmware (1.4.1U in the United States), the Acekard 2i was the second manufacturer to release a patch to make the card compatible. The Acekard 2i can be used on a 3DS in DS mode, up to the 4.3 version of the firmware. It has not released an update for the 1.4.5 (DSi) and 4.4(3DS) firmware releases and has not had any updates since early December 2012.  It is possible this cart may be unable to be updated and may be discontinued.

CycloDS Evolution
The CycloDS Evolution features DLDI auto-patching and full DS download play support. It earned a 96-percent on DS-Scene.net and a gold star on GBAtemp.net.

Like most other slot-1 devices, the CycloDS Evolution uses micro SD cards for storage; media are played with a modified version of the MoonShell player. It was one of the first to use SDHC cards, ranging from 4 to 32 GB. Its enhanced mode provides features activated through an in-game menu (which other cards do not support), including slow-motion, soft reset to CycloDS GUI, built-in cheat device, real-time save feature, an in-game DS Lite LCD backlight-brightness-change option and an in-game text reader for game walk-throughs.

The card also acts as a PassMe and Slot-2 card; the 3-in-1 extension or G6 Lite may be recognized as expansion packs for the CycloDS Evolution. This permits memory expansion for DSLinux, to play GBA games launched from the Slot-1 device and to use the Opera browser (which normally requires a separate RAM-expansion pack). The CycloDS Evolution boots and patches GBA games directly from the CycloDS menu, instead of a separate homebrew program.

DS-Xtreme
The DS-Xtreme flash card is a one-card solution with 4 Gib (512 MiB)—or a newer 16 Gib model (2 GiB)—of internal flash memory, with no option to add external memory. The DS-Xtreme hardware supports generic USB mass-storage specifications, functioning as a drag and drop USB drive with no additional drivers needed. It has two color-adjustable LEDs. After connecting the DS-Xtreme to a PC via the included USB cable, files may be transferred to the DS-Xtreme memory and immediately used on the DS. The DS-Xtreme is not fully compatible; many games which will load will have errors in a number of areas, particularly download play and Nintendo Wi-Fi connection. These problems were corrected by installing the newest version of the firmware (as with any flashcart); however, support has been discontinue and many games require patching (or other advanced fixes) to operate. It is highly homebrew-compatible, and does not require extra fixes (due to the auto-patching software included). As of 2009, the price of the 16 Gib models has dropped to around $50; however, its developers abandoned the project in 2007. DS-Scene.net gave the 4 GiB DS-Xtreme a rating of 91 percent in its review.

DSTT, DSTTi and 3DSTT
The DSTT is a popular card, compatible with SDHC cards. Like the R4, it has been Cloned. Some clones change the name (e.g. DSTT-ADV or CN-DSTT), but most label their product as DSTT although they are not affiliated with a DSTT team. The DSTT website has a guide to identifying counterfeits and clones. The DSTT and DSTTi are versatile, incorporating cheat support in a variety of games. A patch exists for the DSTTi for it to work on the 3DS 2.1.0-4. DSTT and DSTTi TTMenu Kernel updated its kernel (DSTT TTMenu V1.18) on December 15, 2010. Closed-source firmware (YSMenu) was programmed by Yasu Software with YSMenu V6.72 on November 26, 2011.

EZFlash V
The EZFlash V uses microSD cards for storage. An advantage is its hybrid mode, which allows for speedy performance and less lag when using slower memory cards. The EZFlash V Plus supports microSD cards over 2 GB; the original model does not. The EZFlash Vi is an upgraded version of the EZFlash V Plus, made for the Nintendo DSi. A three-in-one expansion pack (supporting rumble, cache and GBA ROM) is also available. The EZFlash Vi card works with the Nintendo 3DS console. DS-Scene.net gave the EZFlash V a rating of 94 percent in its review.

EDGE DS
The EDGE DS card is identical to the Nintendo DS Lite cartridge, and has been compared to the R4 card (R4v2/R4v3/R4v5), DSTT card and SuperCard DSONE. The EDGE is a budget-priced variety of the full-featured CycloDS, using essentially the same system. It was sold in a distinct, triangular swivel-pack. The EDGE DS card ceased production in October 2009, and has been replaced by the iEDGE DS.

M3i Zero
The M3i Zero is an updated M3 Real card, designed for compatibility with the Nintendo DSi, which was released in July 2009. There is no GBA compatibility with the M3i Zero running on the Nintendo DSi, because it does not have a GBA expansion slot. However, the M3i Zero will run GBA games on DSs/DS Lites with a GBA expansion card. The M3i Zero is the first card to use specialist hardware to upgrade its firmware; it is supplied with a firmware cable, thus allowing it to bypass Nintendo's DSi update system.

N-Card (NAND Card)
The N-Card was previously available in 128 MB, 512 MB, 1 GB and 2 GB sizes. There are two versions of the N-Card (1 GB and 2 GB); the smaller cards are discontinued. The N-Card does not require FlashMe, PassMe, or any other device or modification. It is compatible with all commercial games, without patching. No additional software is required to transfer games from PC to the card. Firmware 1.45 supports download-play; Wi-Fi play has always been supported. The N-card uses its internal memory, making its read speed faster than microSD cards. To read the card on a computer (to add or remove files), there is a supplied adapter and USB cable.
The N-Card had at least six different clones: DS Fire Card, K6, MK5, Ultra N-Card, DS Linker and F-Card. All clones can run the original N-Card firmware.

NinjaPass
Like most cards, NinjaPass uses microSD cards for storage. Compatibility is not total, and is highly dependent on the microSD-card brand and model. The card works with most homebrew (including—but not limited to—DSAIM, DSLinux, MoonShell, NesDS, LemmingsDS and DSOrganize). It is compatible with microSD cards up to 4 GB, and works with cards of all speeds (if the speed is adjusted on the main boot menu before loading any applications). The product website provides users with all necessary startup software for download. DS-Scene.net rated the NinjaPass Evolution X9 a score of 82 percent in its review.

YushenDS Card, R4DS, M3 DS Simply, and their clones
R4DS (Revolution for DS), YushenDS Card (YDC), and M3DS Simply have essentially the same hardware. The same method is used to distinguish between Chinese, English, and Japanese (and German for the YDC) versions of the cards. The firmware for the various brand and language versions can be readily patched to work on other language (or brand) versions of the hardware.

The original R4 card was updated in early 2007 to the R4 version 2, or R4v2. In late 2007 the R4v2 was revised, eliminating the spring mechanism for inserting and releasing the microSD card. Instead, it had a slot in the back into which a user could insert a microSD card. This eliminated the problem in the original R4 Revolution DS Card where the spring mechanism malfunctioned after prolonged use. DS-Scene.net rated the original R4 at 95 percent in its review.

Further confusion has been added by poor-quality clones of the YDC R4 and M3 hardware, selling under brands including N5, E7, ND1, NPlayer, U2DS, MARS and variations of the R4 name (such as R4DS Upgrade-II, New R4, R4 Deluxe, R4 Advance, R4 DS III, R4 SDHC, R4 gold Pro and R4 Ultra). The firmware for genuine YDC R4 cards is encrypted; however, the encryption was broken in 2007 and several utilities exist for encrypting, modifying, and decrypting YDC R4 firmware. The N5 (and most other clones) use a decrypted version of the firmware; decrypted YDC R4 firmware can be used on the N5 (and some other clone cards), and encrypted clone firmware can be used on the R4. Some clone manufacturers have released modified versions of the firmware to support additional games; others have eliminated R4 firmware, replacing it with homebrew loaders (such as YSMenu).

All of these are one-card (slot-1) solutions using microSD cards for storage; all final firmware versions include Action Replay cheats, auto-DLDI patching and support for Nintendo Wi-Fi connection and download play. They also include a hardware-specific version of the MoonShell media player, selection of which is integrated with the main menu.

The R4 has been discontinued. The last firmware was version 1.18 (released on April 23, 2008), but clone manufacturer R4Li continued updates for the original R4. In addition to the official firmware a closed-source firmware, Wood R4, is under development. Wood R4, written by Yellow Wood Goblin, was updated to Wood R4 v1.30 on May 19, 2011. A Wood R4 DS patch was released on Dec 24, 2010. R4 DS users can run this patch to update online the Wood R4 kernel automatically.

The R4 has been banned from sale in Japan due to its promotion of software piracy. Nintendo won a lawsuit against an Australia-based distributor over selling the R4 card, but the technology itself remains unbanned. These cards have also been banned from sale (and import) in the UK following a high-court ruling. In November 2012 the Japanese Ministry of Economy, Trade and Industry made importing the R4 illegal.

Unlike newer cards, the R4 cannot read SDHC (Secure Digital High Capacity) cards due to hardware limitations (although certain clones add this functionality). There exist several clones of the R4 card capable of using SDHC cards, but studies suggest that certain types of these cards have high failure rates. One clone, the R4 SDHC, is reportedly reliable. R4DS is known to be outdated, as other flashcarts (Acekard 2, M3 Real Supercard One and Edge) are known to be better and cheaper; genuine R4DS cards are rare.

SuperCard DSONE
The SuperCard DSONE is a slot-1 solution using microSD cards for storage. It is made by the SuperCard team. The earlier version requires a high-speed microSD to fully utilize its gameplay function. With SDHC-compatible models games are playable with slower SD cards, solving the most significant problem with the original. The firmware includes functions such as RTS, real-time cheats and real-time game guides. The Supercard DSONE also exists in a version compatible with the Nintendo DSi, the DSONEi. DSONEi comes with a firmware writer for future firmware updates, if Nintendo releases a DSi-firmware update to block flash cards. DS-Scene.net rated the SuperCard DSONE v1 at 89 percent and the SuperCard DSONE v2 at 83 percent in its reviews.

R4i 3DS and R4i SDHC
Often confused are the R4i products with similar names R4iSDHC.com, R4i-SDHC.HK, and R4i-SDHC.com.

The first R4i-SDHC team (from r4i-sdhc.com, who released the R4i-SDHC RTS 3DS card) developed the first "original" card compatible with the micro-SDHC memory card. The first cards released were the R4-SDHC and R4i-SDHC. When Nintendo released its V1.4 update, these cards were blocked. The R4i-SDHC team responded with a new card, the R4i-SDHC V1.4, the first of a new generation of cards that could upgrade the core firmware using a flash memory patch. Another firmware update (the DSi V1.4.1) brought to light that there were more than one hardware version of the card, of which some would not patch. For the subsequent Nintendo updates, the R4i-SDHC team released a patch, as well as a new card version labeled with the update number. They also released a 3DS version which also had regular patches. When 1.45 (DSi or DSI XL) and 4.5 (3DS or 3DS XL) console software was released by Nintendo in early December 2012, software patches were not released to upgrade the cards. New R4i-SDHC cards were subsequently released which are anticipated to reduce a future issue after Nintendo updates. The current cards being named V1.45, V4.5 and V4.5 RTS.

Those R4i are clones for Gateway 3DS, the first 3DS flashcard for Nintendo 3DS.

Third generation
The third generation began with the release of the Supercard DSTWO with emulation, drag-and-drop video playback, on-the-fly anti-anti-piracy advancements, an in-game menu system, slow-motion, soft reset, a real-time cheat editor, eReader support and a hex editor. The biggest change in these flashcarts from the second generation was anti-piracy countermeasures to bypass the ROM without patching or a firmware update. These flashcarts have built-in RAM and powerful CPUs, allowing the use of powerful homebrew programs. Flashcarts offering these features are The Supercard's DSTWO, EX4i, iSmart Premium, iSmart Multimedia and CycloDS iEvolution.

SuperCard DSTWO and DSTWO Plus
The SuperCard DSTWO was released on November 20, 2009. Its features include real-time functions (saving and cheats), multiple save files, bypassing piracy blocks without patches, microSDHC support, multiple languages (English, French, Italian, Japanese, Korean, simplified Chinese, Spanish and traditional Chinese), a built-in GBA/SNES emulator, four levels of slow motion, a file-management system (to rename, copy, etc.), an iReader supporting .bmp, .jpeg, .jpg, .png, .tif, .gif, .txt and .pdf files, and support for several PC video formats (including DivX/Xvid). It is capable of functions not found in a standard slot-1 flashcart (such as GBA emulation), since the card has 32 MB of built-in RAM and an extra coprocessor. Because of this, the built-in CPUs on the card drain the battery significantly at startup. The card features rewritable firmware, like as the DSONEi. The DSTWO also supports EZ Flash three-in-one expansion and the SuperCard expansion brands. The SuperCard team released the SDK for the DSTWO flashcart to homebrew developers only when contacted by email. Their goal for the release of the SDK was for small developers to release power programs and help with debugging the EOS, GBA and SNES systems on the flashcart. The DSTWO is compatible with the DS, DSL and DSi up to the 1.4.5 firmware, and 3DS up to the 6.3.0-12 firmware. Nintendo has released 1.4.3 for North America, Europe and Japan and 1.4.4 in China to block current flashcarts. Less than 24 hours after the release of these updates, the Supercard team released a bypass patch for the DSTWO to run again on the latest DSi firmware.

The Supercard Team is efficient at updating the Supercard DSTWO; it found a way to let the Supercard DSTWO work on the 3DS, as it did for the DSi 1.4.4–1.4.5 CHN fix. The team have activated a hidden forum for those with permission for the SCDSTWO SDK (Software Development Kit). Homebrew and emulator developer Alekmaul received the SDK and a flashcart sample, and began porting his Dingoo emulators to the Supercard DSTWO. Alekmaul later released his MAME EMU for the DS2. The emulator supports the MAME 0.37b5 ROM set. Based on the included documentation, this is a port of his Dingoo MAME4ALL build (which leaves the possibility for future Dingoo EMU ports to the SCDSTWO). The DSTWO will run nearly all game systems (including DS, GBA and SNES games, movies, music, pictures, MAME, Neo Geo, NES, Apple 2, Game Boy Color, GB and Atari). DS-Scene.net praised the DSTWO in its review.

In October 2015, the Supercard Team further released the Supercard DSTWO Plus, which contains all features of the DSTWO as well as a Gateway 3DS emulation plugin to support 3DS games. It is advertised as a 4 in 1 card, meaning that it supports DS, GBA, SNES and 3DS games in a single flashcart.

iSmart Premium
iSmart Premium (the third third-generation flashcart) is a competitor to the Supercard DSTWO and DSi-compatible. The iSmartDS team's first offering has been compared to the Acekard series (in price and open-source firmware options) and the EZ Vi (on which the iSmart Premium is based). It includes an open-source SDK, in-game menu (save-states, in-game guide and soft reset), customizable skins, multilingual support, an Action Replay cheat engine, hardware-based anti-piracy circumvention and three-in-one expansion support. DS-Scene.net rated the iSmart Premium at 87 percent in its review.

3DS-exclusive storage devices
Unlike DS flashcards, which may also work in the Nintendo 3DS and allow DS ROM backups to run on these consoles, there are also 3DS-exclusive storage devices, which allow 3DS ROM backups and perhaps also 3DS homebrew to run on these consoles. Gateway3DS is the first 3DS flashcard for Nintendo 3DS. Its clones include 3DS Link, MT Card, R4i 3DS, and more. They only work on 4.1-9.2 version firmware. The Gateway 3DS emulation plugin of the Supercard DSTWO Plus may also be seen as belonging to this category. There is also the Sky3DS, which works with all versions up to and including the latest 11.13.0-45 update, and all consoles in the Nintendo 3DS line. Its clones include R5SDHC 3DS, QQ3DS, and more. However, there are several 3DS firmware releases which block flashcard usage. Custom firmwares such as Luma3DS bypass this issue.

See also
Game backup device
Nintendo DS accessories
Nintendo DS homebrew
Custom firmware

References

External links
 R4 3DS Official Website With New Firmware Updates
 Supercard Official Website For Firmware Updates
 M3 DS Official Website

Computer storage devices
Nintendo DS
Nintendo 3DS