M3 Won't work on DSi XL Help!

Hey, I'm new to this forum so sorry if my question is stupid. But yeah, I have an ooold flashcart, I think it's one of the oldest M3 ones.
At least I remember playing with it on my nDS Lite, however, I now have a DSi XL and I can't seem to make it work. Does there exist any type of firmware and prefferably a tutorial on how to install it and such, to make it work on the DSi XL?Thanks for any help guys.. :D

Your card will most likely not work on the DSi.
Is it an M3i Zero?

If your M3 cart didn't state it as compatible with DSi, or was bought before the DSi was sold. Obviously then it will not support the DSi. Furthermore, I believe the M3 had been removed from production and even their site gone. So buy one that does support your DSi XL; R4i Gold 3DS or Supercard DSTwo would be among the better choice for DSi and 3DS consoles wanting to play NDS rom.