Re: hard drive test

Dan wrote:

Pooh Bear wrote:
I am in the exact same boat, BUT I have ALREADY obtained an exact
working HDD on EBay as suggested. I understand how to swap the boards
(I had already removed the one from the failed drive to inspect if for
obvious flaws, cracked traces, bad contacts, etc) and I am wondering if
anyone can suggest any good sites which go into all possible aspects of
"do it yourself" data recovery. I am holding off going any further
pending more info. I agree the fees they charge for this are pretty
extreme.

Find out before trying it where the defect map is held.

Graham

Graham - I have no idea what that is, can you elaborate?

Any hard disk platter is likely to have imperfections. When the disk is first
low-level formatted at the factory a test diagnostic finds the defects and tells
the controller not to use those areas. That info is called the defect map. I'm
not sure where the info is held though. It could conceivably be the in
non-voltatile memory on the controller card or on a special area on the disk
itself. You'll appreciate that this potentially would make for some issues when
swapping controller boards

In the early days of PC hard drives ( my first was a Seagate 32M ) there were
utilities to check the disk surfaces for any further developing defects and map
them out. I recall doing this well. I even recall performing a low-leve format
using debug !

From the command line in DOS

debug enter
g = c:8000 -g ( I think ) enter

Don't do this at home ( just in case ) Don't know if it would still do the same
with IDE drives but it's just possible Try it an old scrap PC one day.

Graham

.

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