Great! I didn't think your modem should require a lot to get it working, but I was beginning to wonder.
Your other question probably does belong in another thread. But I can mention a few things...
Knoppix is a spruced up and better automated Debian that can be run from CD. It is generally set up the same with some differences.
To access a drive it needs to be mounted. There needs to be a detected device in the /dev directory. One floppy drive is almost always going to be /dev/fd0. A CDROM drive is considered as a hard drive device (since it plugs into the same channel on your mainboard), and may vary depending on your actual setup. One CDROM is usually going to be /dev/hdc.
Then there needs to be a mount point to "mount the device to your filesystem". These you can completely make up or use standard choices.
My regular Debian install uses /floppy and /cdrom as the mount points. I see that the Knoppix CD uses /mnt/floppy and /mnt/cdrom as the mount points.
I have heard that some people are surprised that a Knoppix hard drive install is more like Debian than their Knoppix run from CD. I have never done a Knoppix hard drive install so I do not really know much about the differences, if any.
There could be an issue with incorrect mount points (minor), or your device not being recognized (major?).
I am not going to fool much with whether you have an icon on your desktop or not. Generally you can right click on them to correct a misconfigured icon or on your desktop to create a new one.
Assuming your devices are recognized, this is how you use the command line to make them available. (Check 'man mount' for further clairfication)
To mount the device (after inserting the media) use,
mount device mountpoint
Your floppy should work for sure with:
mount /dev/fd0 /floppy (or /mnt/floppy-there needs to be a directory by one of these names. Create one of them if it does not exhist. As root, 'mkdir /floppy' or 'mkdir /mnt/floppy')
If there are no error messages you should be able to view the contents of the floppy from either the GUI by going to the /floppy (or /mnt/floppy) directory, or the command line by typing 'ls /floppy' (or 'ls /mnt/floppy').
Same for your CDROM using:
mount /dev/hdc /cdrom (or /mnt/cdrom)
If you are able to access these devices from the command line then there just need to be a few changes to make them easily available from the GUI. Add the correct device and mount point to /etc/fstab ('man fstab'), and correctly configure or create your desktop icons.
Before removing the media you must unmount the device.
umount /floppy (or umount /mnt/floppy)
Yes, umount, not unmount.