Whew. I thought I'd end up with like three pages of conversion formula. Instead, it took a bit over twenty pages to translate ArM5 into BRP (System used for Runequest and Call of Cthulhu). Well, hopefully, this gets a couple more folks interested in Ars. This isn't a perfect conversion, I tired to fix some loose ends.
To me this seems so radically different from ars magica that it really shouldn't have the same name. I would call it more of an imitation than a conversion- to begin with nearly everything about spell development and spell levels has been purged.