
The original Revolution for DS card is no longer available in stores, although it can be bought online. The original R4 cards use a microSD (<=2GB) card for its firmware and games, and does not support SDHC microSD cards. Since the 3DS's secure boot signature validation has been broken, this provides a useful means of installing custom firmware on a 3DS. Some of these cartridges can also store a 3DS boot image a 3DS can in turn be made to boot from the cartridge by way of an undocumented button combination recognized by the system's bootloader. The R4 flashcard's original developer stopped producing the R4 Card that plays ROMs and homebrew for the Nintendo DS, however, there are a new line of R4 clones that have taken its place, notably the R4 3DS, R4 Gold, R4 DSi and R4 NES, which are used to play ROMs and homebrew from various Nintendo platforms such as the Nintendo 3DS, Nintendo DSi, Nintendo DSi XL and Nintendo Entertainment System. This allows the user to run homebrew applications, to store multiple games on a single memory card, and to play games that have been backed up by the user. It allows ROMs and homebrew to be booted on the Nintendo DS handheld system from a microSD card.



The R4 (also known as Revolution for DS) is a series of flash cartridges for the Nintendo DS handheld system. The R4i Gold 3DS, a later clone of the original R4 Card.
