I sounds like knoppix is not detecting your floppy drive. When you start up you should see a line ( in green) 'Automounter started for cdrom floppy'. Is it there?
Do you have a /dev/fd0? Check with 'ls /dev/fd0'? You should get a response '/dev/fd0'. Do you have the line quoted above in your /etc/fstab file? Check with 'cat /etc/fstab'.
Try 'sudo mount /floppy' (or just 'mount /floppy' if you're already root). If you don't get any error message the try 'ls /floppy'. If the disk is mounted you should get a directory. Here's what I get with a disk which has a file called nddundo.dat on it:

root@1[knoppix]# mount /floppy
root@1[knoppix]# ls /floppy
nddundo.dat
root@1[knoppix]# umount /floppy
root@1[knoppix]# ls /floppy
root@1[knoppix]# ls /dev/fd0
/dev/fd0
root@1[knoppix]#