Many people are suspicious towards the R4i / R4 card for Nintendo DS. I've seen countless posts asking about the R4i SDHC / R4 SDHC flash cards, and whether they legitimately work or not. When it comes to electronics manufactured in China, people are usually skeptical towards them. It's not an unnatural reaction, of course. In this article, I will try to explain what R4i / R4 cards are, and attempt to disprove some rumours about them that have been floating around on the internet.
A DS R4 / R4i card is a storage device that enables you to store and view data such as JPGs, documents, videos, MP3s or homebrew games. The R4 / R4i card bypasses the encryption on the Nintendo DS, enabling files to be run straight from a storage medium such as a Micro SD card. Second generation flash cards such as the R4 / R4i utilize the DS game card slot (SLOT-1), instead of the GBA game card slot (SLOT-2), making them much more convenient.
In essence, the R4 / R4i is just a card which enables you to run multimedia files or game files on your DS. No hacking is required; it is strictly a 'soft mod' that will not harm your NDS in any way. You just insert the R4i / R4 card into the cartridge slot, and the R4 / R4i software will run.
Now, a lot of people ask why there are so many variations of the R4 / R4i flash card out there. This happens because there are many companies out there who make knockoffs of the original R4 SDHC card. A lot of these cards, particularly the ones that are linked to Taiwanese websites may harm your DS. Make sure to always do research online before buying your R4 / R4i card.