| Author |
Message |
Mike Rivers
Guest
|
 Posted:
Sun Oct 30, 2005 12:42 am Post subject:
Re: Media Salvage |
|
|
Paul Stamler wrote:
| Quote: | $25 to take the crummy old
cassette of their wedding or baby's first song and have it cleaned up
and put on a CD.
Which, in terms of real-world time expenditure, works out to about minimum
wage.
|
Nobody ever said this was going to be profitable. On the other hand,
with the right setup, you could probably work the counter at McDonald's
while copying cassettes to your laptop computer.
|
|
| Back to top |
|
 |
Jona Vark
Guest
|
| Posted:
Sun Oct 30, 2005 3:07 am Post subject:
Re: Media Salvage |
|
|
recorder and compact flash are NAND devices. Once they'r ehosed.. they're
hosed. There is NO getting data from a corrupted / failed device.
"J. P. Morris" <jpm@it-he.org> wrote in message
news:43637941$0$15039$ed2619ec@ptn-nntp-reader02.plus.net...
| Quote: | Mike Rivers wrote:
That's what makes the job interesting (and, at least for a while,
expensive). I didn't think data could be recovered from a physically
dead hard drive either, but people put new electronics boards in drives
with a good platter and motors, or put the platters into good drive
bodies.
This is fairly-well understood cold-war technology. With the correct
equipment, it is possible to read _erased_ data from a hard disk platter,
which is the US and various other governments have special procedures for
erasing classified data, overwriting it twenty times with random data or
whatever.
Just refreshing my memory on how flash works, it seems to be largely based
on a transistor/capacitor pair for each bit. You could probably read the
charge off each bit if the data was sufficiently important. Unless the
reason it has failed is because it has been exposed to beta radiation
(in which case the memory cells will have all been reset to 0).
Working inside a chip isn't quite as easy, even if you have a
clean room, but I'll bet that if you wanted the data badly enough,
there's some way of removing the case and you might find a bad lead
joint or something that can be repaired.
That would work. A few years ago I came across a fascinating article on
how it was possible to read data from smartcards and other secure
microcircuitry. With a scanning tunnelling microscope, you could probably
repair the fault with the flash chip and then read the data off normally.
--
JP Morris - aka DOUG the Eagle (Dragon) -=UDIC=- jpm@it-he.org
Anti-walkthroughs for Deus Ex, Thief and Ultima http://www.it-he.org
Reign of the Just - An Ultima clone http://rotj.it-he.org
The DMFA radio series project http://dmfa.it-he.org
d+++ e+ N+ T++ Om U1234!56!7'!S'!8!9!KAW u++ uC+++ uF+++ uG---- uLB----
uA--- nC+ nR---- nH+++ nP++ nI nPT nS nT wM- wC- y a(YEAR - 1976) |
|
|
| Back to top |
|
|
Les Cargill
Guest
|
| Posted:
Sun Oct 30, 2005 4:42 am Post subject:
Re: Media Salvage |
|
|
Mike Rivers wrote:
| Quote: | Les Cargill wrote:
Never say never, but the data patterns on magnetic media are
recoverable. Once a FLASH device is toast, it's utterly gone.
GOTO Top_of_message
|
???
| Quote: | Just like with toast, there are almost certainly different levels of
flash card toast.
|
Mmmmmm. Toast!
See http://computer.howstuffworks.com/flash-memory1.htm .
There are two gates per bit. If they've become unreliable,
it is because they've failed open - the "floating
gate" stops being able to be charged. The erased, or
default state for a bit of FLASH is open ( which
works out to a 1 value when read ). To my knowlege, they
cannot fail "closed".
Unlike a hard disk, the media and "controller" are
the same thing with FLASH.
I suppose mechanically distressed parts could be
reassembled, but if the epoxy is broken, I doubt
the stuff inside would be in very good shape.
--
Les Cargill |
|
| Back to top |
|
|
Mike Rivers
Guest
|
| Posted:
Sun Oct 30, 2005 4:42 am Post subject:
Re: Media Salvage |
|
|
Les Cargill wrote:
| Quote: | There are two gates per bit. If they've become unreliable,
it is because they've failed open - the "floating
gate" stops being able to be charged. The erased, or
default state for a bit of FLASH is open ( which
works out to a 1 value when read ). To my knowlege, they
cannot fail "closed".
|
Sounds like a good reason not to use it for anything you care about.
Maybe it'll just die and be replaced by something more reliable or at
least more repairable. After all, it's consumer media and if that
doesn't change every couple of years, there's no money to be made. |
|
| Back to top |
|
|
Chris Hornbeck
Guest
|
| Posted:
Sun Oct 30, 2005 4:42 am Post subject:
Re: Media Salvage |
|
|
On 29 Oct 2005 19:26:03 -0700, "Mike Rivers" <mrivers@d-and-d.com>
wrote:
| Quote: | Sounds like a good reason not to use it for anything you care about.
Maybe it'll just die and be replaced by something more reliable or at
least more repairable. After all, it's consumer media and if that
doesn't change every couple of years, there's no money to be made.
|
"Incompatability is our middle name."
Sadly, it seems that the only free market alternative
is a single dominant, but hopefully benevolent, force.
IBM, Intel, Microsoft. Two outta three ain't *that* bad,
I guess. Odd's are bound to get worse with time, though.
Thanks, as always,
Chris Hornbeck
Gen. Miller, Gen. Sanchez, Donald Rumsfeld, President Bush. |
|
| Back to top |
|
|
jakdedert
Guest
|
| Posted:
Sun Oct 30, 2005 4:42 am Post subject:
Re: Media Salvage |
|
|
Mike Rivers wrote:
| Quote: | J. P. Morris wrote:
Do you mean that they recovered data from a corrupted FAT filesystem,
or that they somehow managed to extract the datablocks from a physically
dead flash chip? Anyone could do the former
Anyone? No, I don't think so. But at least if it can be done at all, it
can be done with fairly common disk tools. Such recovery, even on
standard hard drives, isn't always 100% complete. Depends on how the
data is written.
the latter would require some
pretty strange technology. In fact, I didn't think it was even possible.
That's what makes the job interesting (and, at least for a while,
expensive). I didn't think data could be recovered from a physically
dead hard drive either, but people put new electronics boards in drives
with a good platter and motors, or put the platters into good drive
bodies. Working inside a chip isn't quite as easy, even if you have a
clean room, but I'll bet that if you wanted the data badly enough,
there's some way of removing the case and you might find a bad lead
joint or something that can be repaired. But you'll have a hard time
finding a music fan willing to spend $5,000 to recover a recording he
thought he made of a concert. He'll just go on the net asking "does
anyone know how to read a flash card?"
On the other hand, going back to the original poster's skills, there
are probably a few people willing to pay $25 to take the crummy old
cassette of their wedding or baby's first song and have it cleaned up
and put on a CD.
|
I assume the OP has access to a large variety of various playback
formats. For a start, I'd suggest Umatic, VHS, Beta, Betacam, 8mm,
Hi8mm, mini DV, DVcam machines, Digital 8mm...and that's just the common
magnetic video formats. There's also film--8mm, 16mm and Super8...also
35mm stills.
You really need almost *everything* audio that's been recorded on for
since the get-go (okay maybe you don't need and Edison cylinder
machine--right away, at least--but I saw a thread on another newsgroup
this week about recovering audio from a *wire* recorder.)
and then there are the solid-state and hard-drive media.....
I think that unless you can service all the common and obsolete formats,
you should either initially specialize in a select few, or give it up.
Perhaps you can aquire the proper playback equipment as the specific
need presents itself: but finding working gear for a particular obsolete
format might--on a schedule--may limit your options considerably.
jak |
|
| Back to top |
|
|
jakdedert
Guest
|
| Posted:
Sun Oct 30, 2005 4:42 am Post subject:
Re: Media Salvage |
|
|
Jona Vark wrote:
| Quote: | recorder and compact flash are NAND devices. Once they'r ehosed.. they're
hosed. There is NO getting data from a corrupted / failed device.
"J. P. Morris" <jpm@it-he.org> wrote in message
Yeah, but most 'recovery' will simply consist of unformatting |
accidentally formatted drives, or recovering deleted files. All this
technology was developed for magnetic media and works just as well (that
is to say: adequately) on solid state memory as well. This is because
the data structure emulates said magnetic media, and the same rules apply.
jak |
|
| Back to top |
|
|
|
|
|
|
FAQ
Memberlist
Register
Profile
Log in to check your private messages
Log in