YES !!! Wiliam, you're the best ! THX !
I can see and browse my files !
So I'm trying now to copy the datas to an external usb drive but, I don't know how to do it... I checked /var/run/dmesg.boot and my external drive seems to be 'da0', than I found how to copy files 'cp -iprv origin destination' but what must I enter for the destination ?
I tried 'mount -t msdos /dev/da0s1 /mnt', 'mount -t msdosfs /dev/da0s1 /mnt', 'mount -t ufs /dev/da0s1 /mnt' but I got drive is busy
DIT : OK, I think I've found, it's copying right now, we'll see...