You could try this:
dd if=/dev/mtdbblock3 of=/mnt/sda1/dumpfile
This'll create a file named 'dumpfile'. Although it'd contain a lot of binary rubbish, the vi editor can still handle it; you'll spot the readable text parts in it and you have to remove the rest of it (using vi). It's an old fashioned hacking session 
kind regards,
Jos