RAID

> Simple: All stage1 copies load stage2 of disk 0x80.
> If the broken disk is still seen by the BIOS and disk 0x80, you're screwed > anyway, because
it will _not_ fall back to booting disk 0x81.
> And if the disk disappears the next one becomes disk 0x80 and booting works.

In theory, sure.  But in practice I've seen all sorts of strange behavior from BIOS (both the
motherboard BIOS and whatever's provided by add-on cards, and the interactions between the
two) in the case of failing/failed disks, and I've definitely had the case where I ended up
booting off 0x81.  So I do what you do, but I also have other plans for when that doesn't
work.