SpinRite?

[John Foust]

Steve Gibson shouldn't be a strange name for this list.
Google tells me that SpinRite's been mentioned a few 
times in 2003 and 2004.

I recently bought a copy of his SpinRite and I'm trying
to get my head around exactly when it's useful.  The manual
isn't much help.

Right now it's chugging away on a circa 1987 floppy that
lost its shutter, rattled around in an envelope, and today
has CRC errors.  Not a rare disk, just something I'd like
to see if it can recover.  It's busy re-reading bad sectors
hundreds of times to make its best guess at the data.

A few days ago I tried SpinRite on a contemporary PC's hard 
drive that would error-out when writing to two spots on
the disk.  At its strongest correction level, SpinRite 
found the errors but the disk wasn't "repaired" in the
sense that I expected: I thought it would somehow map-out
the areas that had errors, and let me continue to rescue
the drive's data.  It didn't.  Writing to the drive still
failed.

(I successfully read both partitions with a Knoppix CD and with 
R-Studio NE, but I wanted to bring the system back to life 
enough to let HP's WinXP create its recovery CDs.)

So to keep this on-topic, when exactly can SpinRite help rescue
old hard drives and floppies?

And to state the obvious, SpinRite can't raise the dead.
I tried it on a drive that was alive enough to be recognized
by the BIOS, but if SpinRite can't make it spin or read,
it can't help.

- John