There are several different types of R4 cards and it can be quite confusing with words like R4DS, YushenDS and M3DS all being banded around. The reality is that these are all the same, and are actually only using those different titles, R4DS stands for Revolution for DS and is more commonly found in the UK and US (the R4 cards) and the YushenDS cards as you may have guessed are aimed at the chinese market. It is important to remember that if you are looking for an endorsed version of the R4 card or one manufactured by Nintendo or other major gaming accessory manufacturers, you will be disappointed. The R4 cards are not only unlicensed and unauthorised but are actually disliked by Nintendo who have gone to extreme lengths to try and have the cards banned. This is due to the fact that the R4 cards essentially allow owners to use pirate films and music, but more worryingly for Nintendo they also allow users to download and play pirated video games. Subsequently, the cards are only being manufactured by smaller scale producers and why you may not have heard of these manufacturers when you are searching for the cards.
The first version of the R4 card was updated at the beginning of 2007 and became the R4v2 or R4 version 2. By the end of that year it had once again be updated to remove the spring insertion/removal mechanism when it comes to the SD memory card, which replaced the original mechanism where many users had reported problems over time. Just to make life even harder for gamers around the world, a flood of similar products came onto the market - typically lower cost but lower quality. These were given names such as N5, E7, ND1, NPlayer, U2DS, MARS, as well as more direct variations on the original R4 name to ingratiate themselves with potential buyers, for example as "R4DS Upgrade-II", New R4, R4 Deluxe, R4 Advance, R4 DS III, R4 SDHC, R4 Pro, and the R4 Ultra.
It’s difficult to say exactly which of the cards is the best to choose when looking to buy, but as with any product (especially unlicensed ones) words such as ultra, advance and deluxe do not necessarily mean that they will be the best on the market. Luckily however, the various gaming forums online allows you to speak with and get the opinions of other gamers who have tried the various different cards.
Unfortunately the R4 firmware has been discontinued by it’s manufacturers, and whilst gamers around the world continue to try and form their own updates which are uploaded to the internet, the last manufacturer released firmware update was 1.18 and was released in Spring 2008. As well as the gamers, another company that manufacturers similar cards called R4Li have continued to bring out further firmware updates that work both with their version of the R4 cards but also the original ones as well.