cannot unmount knoppix cd

After booting knoppix from the cd, how do I change that cd?
My pc only has 1 cd drive, and the knoppix cd needs to be mounted
to run programs from it. The command: "umount /cdrom" logically fails.
But to access files from another cd, I need to remove the knoppix cd,
in such a way that the knoppix system keeps working.
Now what is the secret little trick to temporarily unmount the knoppix cd???

Thanks in advance, because apart from this little problem, knoppix is really neat.

I think you need to use the cheatcode toram to be able to eject the CD. This would need ~1 GB ram.
If you don't have the ram for this, you could try a lighter version like DamnSmallLinux of FeatherLinux.

Yeah, Markus, I think that you are right.
As formulating a question is often answering it, I started to realize that unmounting the cd isn't really possible, just as you cannot unmount the root disk with any other *nix.
I am now going to install knoppix on the hard disk, using another cheatcode to a similar effect.

It still tickles me, though, how the cd burn program managed to eject the knoppix cd ...