Andy McFadden wrote:
> In comp.sys.apple2 mdj  wrote:
>> Unless such a format can allow for a bitream that records every
>> readable flux transition in a continuous track at every possible track
>> position, there's no way to guarantee it will not prove inadequate for
>> some software title or another :(
> 
> The canonical example is a disk with physical damage; I think Mask of the
> Sun used this approach.  The disk has a tiny pinhole bored in it.  You
> get inconsistent data back when reading it, and you will certainly never
> read back what you write.

Which is one case demonstrating the need to read each "track" multiple
times to distinguish the "hard" transitions (repeatable) from the
"soft"
transitions (noise).

This information is also required when part of the protection is the
detection of an *unrecorded* area on the disk (same as a physical hole).

-michael

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