Well, I resolved my problem:

Basically, I run a script called rescan-scsi-bus-.sh, and after that running it, the system recognized both the external drive and the dvd writter. Then I mounted the sda1 into a newly created /fw folder.
While now knoppix is recognizing both devices, I still need to learn how access such files, as well as to bring them back automatically when booting knoppix.

Regards

Copeloa