There's a reason the Alto file system had the
scavanger and was designed to
be recovered...
I wonder if it's a conincidence that the PERQ POS filesystem recovery
tool is also called 'scavenger' and that the PERQ filesystem also stores
all the pointers at least twice so it's posisble to recover from quite
bad disk corruption. Not that any PERQ had a dmountable hard disk.
-tony