From: dmhills{at}attglobal.net (Don Hills)

In article , "Frank Haber"
 wrote:
>The data CD formats have sectors, with headers, like other rotating-storage
>media.  They do *not* use the interleaved-and-offset
"burst-error-reduction"
>schemes of the original (redbook later) audio format.  So in theory.....

Nope. Exact same structure at the physical bit level on disk. Sorry. The
data sector structure is another (logical) layer on top of the Red Book
structure. Red Book sector is 2352 bytes, data sector is 2048 bytes. The
other 304 bytes contain another layer of ECC and a unique sector number so
that the drive can return exactly the requested sector, not approximately
the requested sector as can happen with audio.

>In practice, lots of luck in glueing on the shattered piece at the proper
>diameter and angular orientation, balancing the resultant mess, etc., etc.
>Now, with about $80 million and a polar-coordinate  machine tool or plotter,
>who knows what you could do?

In theory, recovery is possible. But it can be considered unrecoverable,
because as you point out the cost of recovery (time, equipment) will exceed
the worth of its contents many times over in almost all cases. The local
equivalent of Radio Shack sells a CDROM "shredder" that has two
sets of toothed rollers squeezed together by springs. Pass a CD between
them and it becomes covered in thousands of tiny punctures which
effectively destroy the data layer.

--
Don Hills    (dmhills at attglobaldotnet)     Wellington, New Zealand
It's ironic that people who are too smart to engage in politics are
governed by people who are not as smart.

--- BBBS/NT v4.01 Flag-5