Grml again

[Christian]

Hi all,
OK, I have now downloaded and managed to boot the CD with something like the following for my Powrebraille 40 braille display:
grml brltty=ts,ttyS0,de
I launched the fdisk utility like the following:
fdisk /dev/sda
But i am not able to do anything. When i press enter to confirm a choice i just get strange characters.
Also, if I want to perform a debian isntallation using GRML I suppose i should use debootstrap. Is this correct?
How do I do that?
Many thanks,
Christian