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 Post subject: Reading SA by tracks
PostPosted: December 24th, 2017, 18:21 
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Joined: September 30th, 2005, 7:33
Posts: 849
Many tools claim to read SA tracks, but they do it by reading PBA's ( sector by sector). Is it possible to read (or verify) SA track by track, assuming we know the proper SuperOn command?


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 Post subject: Re: Reading SA by tracks
PostPosted: December 26th, 2017, 5:44 
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Joined: September 30th, 2005, 7:33
Posts: 849
I'm talking about something like this:
Drive Commands (Samsung VU Commands)
function syntax OP parameter/description requirement
prtk 86h Physical Read Track Physical C/H should be set


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 Post subject: Re: Reading SA by tracks
PostPosted: December 27th, 2017, 2:04 
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Spildit wrote:
It should be possible on "some" Samsung drives to get the entire M/C with a single VSC ....

But i don't think this is what you are looking for.

This is exactly what I'm looking for - a way to read the entire SA without a risk of errors. Then I could examine the effect of some VSC on the drive by comparing the SA before and after applying the VSC.
Recently I found out that Sediv Toshiba miscalculates in some cases the position of SA and reads wrong tracks. This may happens with other tools , too...They are out of control!


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 Post subject: Re: Reading SA by tracks
PostPosted: December 27th, 2017, 2:27 
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Location: Australia
BGman wrote:
Recently I found out that Sediv Toshiba miscalculates in some cases the position of SA and reads wrong tracks.

The following thread claims that there is a hidden area in the SA of Toshiba HDDs. Could this be somehow involved?

https://www.data-medics.com/forum/anyon ... t1410.html

mikem wrote:
During imaging a drive, resets are important to get a drive out of a particular error state or to flush the drive's buffer memory, this can happen several tens of times an hour and so requires constant resetting. The breakthough we have made is we found a hidden module within the SA of the [Toshiba] drive and have located the exact bit of a byte that stores this flag. We found that changing the flag and saving back to the drive's firmware permanently disables the re-allocation meaning that drives will image normally without lots of intervention and restarting and allows all types of automatic reset and power cycling during imaging.
...
This is not the translator issue. There is a terminal command that turns off bad sector reallocation, it is well known so I wont repost it here, however, when the drive soft or hard resets and on power cycle the reallocation flag is turned back on resulting with slow reads. What was discovered turns off reallocation permanently that survives soft, hard and power cycles. The flag is in a module that is not listed in the standard module list, and is hidden in SA HPA area.

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 Post subject: Re: Reading SA by tracks
PostPosted: December 27th, 2017, 6:27 
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Joined: September 30th, 2005, 7:33
Posts: 849
@fzabkar
I think the term HPA is used wrongly, but yes we know too little about the modules in the SA of Toshiba drives.


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 Post subject: Re: Reading SA by tracks
PostPosted: December 27th, 2017, 10:05 
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Joined: January 29th, 2012, 1:43
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I think it all depends on how much is known about a particular brand / model. It is not too hard to dump SA by head on WD drives, considering all the information needed can be found. You just have to know the VSC command to read CHS, and of course put the drive in kernel (safe) mode to get access to the negative SA tracks. However, it is not as easy as just sending a single command to read a track.

If it was easy, don't you think all the tools would be doing it?

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 Post subject: Re: Reading SA by tracks
PostPosted: December 27th, 2017, 15:10 
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maximus wrote:
If it was easy, don't you think all the tools would be doing it?

Not at all. For them "easy" means "easy to sniff out", so they try to avoid it... :D :D :D

By the way, the SA tracks are not always negative ...


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 Post subject: Re: Reading SA by tracks
PostPosted: December 27th, 2017, 21:07 
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Joined: January 29th, 2012, 1:43
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BGman wrote:
maximus wrote:
If it was easy, don't you think all the tools would be doing it?

Not at all. For them "easy" means "easy to sniff out", so they try to avoid it... :D :D :D

By the way, the SA tracks are not always negative ...

Are you a programmer? Or are you just trying to figure out how to do something complicated by using simple commands (which most likely is not possible)?

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 Post subject: Re: Reading SA by tracks
PostPosted: December 28th, 2017, 6:23 
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Joined: September 30th, 2005, 7:33
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maximus wrote:
Are you a programmer? Or are you just trying to figure out how to do something complicated by using simple commands (which most likely is not possible)?

I'm not a programmer. The programmers make things to look complicated, but they are not....


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 Post subject: Re: Reading SA by tracks
PostPosted: December 28th, 2017, 7:47 
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Joined: May 29th, 2011, 8:47
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Location: Russia
BGman wrote:
The programmers make things to look complicated, but they are not....

:lol:


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 Post subject: Re: Reading SA by tracks
PostPosted: December 28th, 2017, 8:39 
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BGman wrote:
I'm not a programmer. The programmers make things to look complicated, but they are not....

Maybe that is my problem, I am a programmer so I always have to do things the hard way... :D :D :D

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 Post subject: Re: Reading SA by tracks
PostPosted: December 28th, 2017, 12:10 
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Joined: September 30th, 2005, 7:33
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maximus wrote:
Maybe that is my problem, I am a programmer so I always have to do things the hard way... :D :D :D

No, you don't. But maybe you preffer to do things in this way...


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 Post subject: Re: Reading SA by tracks
PostPosted: December 28th, 2017, 12:29 
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Joined: January 29th, 2012, 1:43
Posts: 982
Location: United States
If I could only get this darn button to work...
Attachment:
easypushbutton.gif
easypushbutton.gif [ 624.88 KiB | Viewed 24998 times ]

Wait, I think I got it...
Attachment:
0gKvND.gif
0gKvND.gif [ 564.7 KiB | Viewed 24998 times ]

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