On Mon, May 14, 2012 at 2:20 PM, Christian Weisgerber <[email protected]>wrote:
> Kevin Chadwick <[email protected]> wrote: > > [SpinRite] > > Takes for ever though but is easy to use and may recover partial > > sectors automatically too ;-) > > I really wonder how it's going to do that. > It reads the questionable sector(s) a couple hundred times with the drive's ECC logic turned off, then applies statistical analysis to guess whether a given bit should be a '0' or '1'. From what I've heard, it usually does pretty well as long as the problem is confined to just a couple of weak signals in an island of strength (caused by a power sag during write, for example), but if you've got a physically defective region (eg. the recording surface detached from the platter), all bets are off.
