SpinRite?

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