i used to use boot floppies on one system that had a bad mbr. but if i remember right, it just had the grub bl on it. when grub loaded from the floppy, it pointed to the hda or actually root (hd0,0) and that told grub to look at the 1st hdd on the first partition. i can search for my notes if you need more help with grub as it has been a while since i used a boot floppy. maybe i should put a small howto on my site