[Bug-ddrescue] GNU ddrescue suggestion - access to unaccessable Hard Disk

[wilsonstreet]

Hi Antonio,

I have a hard disk that simply won't be recognised by the
PC'sBios.
So it won't mount either.

However, it might be possible that the problem is that the
hard disk has failed in the areas where it stores the
information that it reports to the PC's Bios.
So the hard disk can not be mounted, even though it might
have undamaged data on most of its other areas.

I found the following comment on a website;

"I cannot imagine anything that could recover data from a
/dev that isn't there."
ref:
http://forum.cgsecurity.org/phpBB3/dev-disappears-using-dd-rescue-t1183.html

Is this comment totally correct?
If not, then if there are ways to access a hard disk that is
not recognised by either the OS, mount command, PC Bios Auto
detect, PC Bios manual user settings, then ;


Q1) is it possible to either include information on how to
access the hard disk, then use dd_rescue?
or even better,
Q2) is it possible to have some features in dd_rescue that
could attempt to access a device attached to a port or group
of ports on a PC, and maybe extract the data somehow?


Yours
Al