The original R4 DS Card, produced by the self-titled “Team R4″, came into existence in early 2007. The original R4 Revolution DS Card looked much the same as the R4v2 Card, but there was a noticeable difference.
The top of the original R4 Revolution DS Card had a small groove to push-lock a Micro-SD card inside. This made use of a spring mechanism so that a Micro-SD card would lock into place when pushed. A simple second push would allow it to come back out of the R4 Card.
The R4 Card in its original guise was produced for just under one year. Team R4 realised that the spring mechanism in the R4 Card had problems, affecting up to 5% of the card’s production. Problems with the spring could cause the mechanism to break.
This meant that Micro-SD cards would no longer go into the R4 DS Card properly. Obviously, this was a big problem. Therefore, Team R4 set out to create a newer version of the R4 Card, fixing the problem and helping reliability. They called this card the “R4v2 Card”.