Sign in with
Sign up | Sign in
Your question

Masterlink / Linux questions.

Last response: in Home Audio
Share
Anonymous
December 27, 2004 9:04:15 PM

Archived from groups: rec.audio.pro (More info?)

As I mentioned in an earlier thread I have a Masterlink rental customer who
recorded a live performance, put the machine in pause (not stop) and then
powered it down. Without first stopping the machine, the Masterlink does not
write any TOC or FAT-like information to the hard drive thereby rendering
the files inaccessible from the Masterlink. I talked to an Alesis tech
support person who emailed me the following instructions of sort:

>>>
"Maybe it's too late. But one of my first experiences with the
HD24 was also a song with length 0 after a power failure (feb.)
This week, I have recovered the data with Linux!
Here is a short description of how it works.
I have two 80Gb hard disks which are exactly the same.
The first with the song length 0 I call it disk1, the other
disk2.
> 1. First of all: I didn't use the drive since the power failure.
It's in the same state. And the hard disk was new.
> 2. On disk2 I recorded a new song (empty) with enough length and
the same settings.
> 3. I calculated at what position the data should be.
> 4. With the Linux program 'dd' I wrote the data to exactly the
same position on disk2.
That's the way I recovered the song. It's sound simple, but it
took some time to figure it out. I tried other way's, but this one
worked."

<<<<<



Tech support says the Masterlink uses the same sort of file system as the
HD24. Do these instructions make sense to anyone, and if so, could you
translate it into something more understandable to a proficient Windows XP
user? I'm happy to install Linux on one of my computers and give it a shot
if I have a bit more information and understanding. I don't understand how
one would calculate at "what position the data should be" nor do I have any
understanding or experience with the program "dd" he refers to.

Thanks for any thoughts... If you happen to be a Linux proficient person in
the Seattle area, I'd be happy to hire you to try to recover these files.
For that matter...I bet the client would gladly ship the drive to someone
who has the skills to do this if it were a fairly reasonable fee. (recording
is of a church choir on Christmas eve) The prices that data recovery houses
charge would be out of line for the value of this recording.



Charles Tomaras
Seattle, WA
Anonymous
December 28, 2004 10:48:13 PM

Archived from groups: rec.audio.pro (More info?)

Charles Tomaras wrote:
>
> Tech support says the Masterlink uses the same sort of file system as the
> HD24. Do these instructions make sense to anyone, and if so, could you
> translate it into something more understandable to a proficient Windows XP
> user? I'm happy to install Linux on one of my computers and give it a shot
> if I have a bit more information and understanding. I don't understand how
> one would calculate at "what position the data should be" nor do I have
> any understanding or experience with the program "dd" he refers to.
>
> Thanks for any thoughts... If you happen to be a Linux proficient person
> in the Seattle area, I'd be happy to hire you to try to recover these
> files. For that matter...I bet the client would gladly ship the drive to
> someone who has the skills to do this if it were a fairly reasonable fee.
> (recording is of a church choir on Christmas eve) The prices that data
> recovery houses charge would be out of line for the value of this
> recording.
>


dd is a file copy utility which understands things like offsets into files
and copying partial files....

What is being done, is that advantage is being taken of the fact that under
Linux (and in fact anything POSIX) the hard disks themselves appear as
files.

Thus the first hard disk (on an IDE system - boring detail), is /dev/hda
with the second (first IDE bus, slave), being /dev/hdb and the third hdc and
so on.

If a disk with a corrupt file allocation table (I assume the HD24 uses FAT
or VFAT) is installed as say the second device on the second bus (/dev/hdd)
and you have sufficient space in your home directory then you can create an
image of the corrupt drive by running (as root) something like:

#/dd if=/dev/hdd of=/home/dmills/diskimage


This will copy the raw filesystem into a file in /home/dmills/ called
diskimage which can then be worked on.

You want to make sure that you always work on an image of the file system
rather then the real thing as it dramatically reduces the chance of
permanent data loss.


I would start by mounting the image as a loopback mount (makes the image
file appear as a normal disk filesystem) and have a poke around, then
try something like

#dd if=diskimage of=test.raw bs=1 count=10240 skip=65535

Load the test.raw file this will create into audacity or similar and play
with the options until audio appears on the raw import preview....
You will need to play with the offset to find the start of your desired
audio.

once you have found the start of thee audio then
#dd if=diskimage of=audio.raw bs=1 skip=XXXXXX
to copy everything from the start of the audio, you can of course use count
to control how much to copy.

Now use the sox utility to convert the raw file of audio to .wav then burn
to a CD.

If you have the disk space and someone who knows filesystems, it might take
an hour or so, but without the 'nix know how I am not sure I would try it.


Regards, Dan (Who is in the UK, so too far to be worth sending a disk).
Anonymous
December 28, 2004 10:48:14 PM

Archived from groups: rec.audio.pro (More info?)

Thanks to all who have responded. I've found some local help via RAP who is
going to consider giving this Christmas Eve recording a "Resurrection"
attempt. :)  The ability to find solutions to problems on the Usenet never
ceases to amaze me. I'm also continually amazed at how little I know about
things I think I'm fairly proficent at!

Thanks again,

Charles Tomaras
Seattle, WA


"Dan Mills" <dmills@spamblock.demon.co.uk> wrote in message
news:cqsbk1$jfv$1$8302bc10@news.demon.co.uk...
> Charles Tomaras wrote:
>>
>> Tech support says the Masterlink uses the same sort of file system as the
>> HD24. Do these instructions make sense to anyone, and if so, could you
>> translate it into something more understandable to a proficient Windows
>> XP
>> user? I'm happy to install Linux on one of my computers and give it a
>> shot
>> if I have a bit more information and understanding. I don't understand
>> how
>> one would calculate at "what position the data should be" nor do I have
>> any understanding or experience with the program "dd" he refers to.
>>
>> Thanks for any thoughts... If you happen to be a Linux proficient person
>> in the Seattle area, I'd be happy to hire you to try to recover these
>> files. For that matter...I bet the client would gladly ship the drive to
>> someone who has the skills to do this if it were a fairly reasonable fee.
>> (recording is of a church choir on Christmas eve) The prices that data
>> recovery houses charge would be out of line for the value of this
>> recording.
>>
>
>
> dd is a file copy utility which understands things like offsets into files
> and copying partial files....
>
> What is being done, is that advantage is being taken of the fact that
> under
> Linux (and in fact anything POSIX) the hard disks themselves appear as
> files.
>
> Thus the first hard disk (on an IDE system - boring detail), is /dev/hda
> with the second (first IDE bus, slave), being /dev/hdb and the third hdc
> and
> so on.
>
> If a disk with a corrupt file allocation table (I assume the HD24 uses FAT
> or VFAT) is installed as say the second device on the second bus
> (/dev/hdd)
> and you have sufficient space in your home directory then you can create
> an
> image of the corrupt drive by running (as root) something like:
>
> #/dd if=/dev/hdd of=/home/dmills/diskimage
>
>
> This will copy the raw filesystem into a file in /home/dmills/ called
> diskimage which can then be worked on.
>
> You want to make sure that you always work on an image of the file system
> rather then the real thing as it dramatically reduces the chance of
> permanent data loss.
>
>
> I would start by mounting the image as a loopback mount (makes the image
> file appear as a normal disk filesystem) and have a poke around, then
> try something like
>
> #dd if=diskimage of=test.raw bs=1 count=10240 skip=65535
>
> Load the test.raw file this will create into audacity or similar and play
> with the options until audio appears on the raw import preview....
> You will need to play with the offset to find the start of your desired
> audio.
>
> once you have found the start of thee audio then
> #dd if=diskimage of=audio.raw bs=1 skip=XXXXXX
> to copy everything from the start of the audio, you can of course use
> count
> to control how much to copy.
>
> Now use the sox utility to convert the raw file of audio to .wav then burn
> to a CD.
>
> If you have the disk space and someone who knows filesystems, it might
> take
> an hour or so, but without the 'nix know how I am not sure I would try it.
>
>
> Regards, Dan (Who is in the UK, so too far to be worth sending a disk).
>
Related resources
Anonymous
December 29, 2004 12:45:27 PM

Archived from groups: rec.audio.pro (More info?)

In article <cqsbk1$jfv$1$8302bc10@news.demon.co.uk> dmills@spamblock.demon.co.uk writes:

> dd is a file copy utility which understands things like offsets into files
> and copying partial files....

and several Unix command lines for creating and working with a raw
disk image file

Do you think it's wise to turn someone loose with these instructions
without the knowledge and experience that you obviously have? Why not
just say "Send me your drive with $50 to cover a little time and
return shipping and I'll see if I can get anything off it for you."?

Like Frenchy and his electrical wiring problem, there are just some
things that most people really don't need to learn how to do, as long
as they know enough that it may be possible for an experienced
professional to solve the problem.

The best advice (which you gave) is to preserve the drive in whatever
state it's in and work with an image copy. But honestly, if I followed
your instructions as best I could, I would be very surprised if I
either (a) actually learned anything, and (b) salvaged enough data to
be useful. But I wouldn't be surprised if it wasn't salvageable by
someone who could recognize what's there and take the next step.

--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo
Anonymous
December 29, 2004 1:19:33 PM

Archived from groups: rec.audio.pro (More info?)

In article <znr1104279178k@trad>, Mike Rivers <mrivers@d-and-d.com> wrote:
>In article <cqsbk1$jfv$1$8302bc10@news.demon.co.uk> dmills@spamblock.demon.co.uk writes:
>
>> dd is a file copy utility which understands things like offsets into files
>> and copying partial files....
>
>and several Unix command lines for creating and working with a raw
>disk image file

It's actually a joke. If you look at the command line options for the dd
command, you'll see it looks nothing like a regular Unix command line. It
is, in fact, a satire on the OS/360 JCL command called "DD" but it turned out
to be useful, so it was left in the OS.

>Do you think it's wise to turn someone loose with these instructions
>without the knowledge and experience that you obviously have? Why not
>just say "Send me your drive with $50 to cover a little time and
>return shipping and I'll see if I can get anything off it for you."?

In this case, sure. All he can waste is his time. It's not like electrical
work where you can kill yourself if you make a mistake. You can waste a few
days and while you might not get the thing working, you'll at least learn
something about Unix.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Anonymous
December 29, 2004 11:45:04 PM

Archived from groups: rec.audio.pro (More info?)

"Scott Dorsey" <kludge@panix.com> wrote in message
news:cquhu5$9f5$1@panix2.panix.com...
> In article <znr1104279178k@trad>, Mike Rivers <mrivers@d-and-d.com> wrote:
> >In article <cqsbk1$jfv$1$8302bc10@news.demon.co.uk>
dmills@spamblock.demon.co.uk writes:

> >Do you think it's wise to turn someone loose with these instructions
> >without the knowledge and experience that you obviously have? Why not
> >just say "Send me your drive with $50 to cover a little time and
> >return shipping and I'll see if I can get anything off it for you."?
>
> In this case, sure. All he can waste is his time. It's not like
electrical
> work where you can kill yourself if you make a mistake. You can waste a
few
> days and while you might not get the thing working, you'll at least learn
> something about Unix.
> --scott
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."

Resurrection complete. File storage on the Alesis MasterLink appears fairly
straightforward. Learned something new in the process.

bobs

Bob Smith
BS Studios
we organize chaos
http://www.bsstudios.com
Anonymous
December 30, 2004 1:54:52 AM

Archived from groups: rec.audio.pro (More info?)

"Bob Smith" <rsmith@1nospam2.bsstudios.com> wrote in message
news:LvCdnVoLwJ1LGk7cRVn-jw@comcast.com...
> "Scott Dorsey" <kludge@panix.com> wrote in message
> news:cquhu5$9f5$1@panix2.panix.com...
>> In article <znr1104279178k@trad>, Mike Rivers <mrivers@d-and-d.com>
>> wrote:
>> >In article <cqsbk1$jfv$1$8302bc10@news.demon.co.uk>
> dmills@spamblock.demon.co.uk writes:
>
>> >Do you think it's wise to turn someone loose with these instructions
>> >without the knowledge and experience that you obviously have? Why not
>> >just say "Send me your drive with $50 to cover a little time and
>> >return shipping and I'll see if I can get anything off it for you."?
>>
>> In this case, sure. All he can waste is his time. It's not like
> electrical
>> work where you can kill yourself if you make a mistake. You can waste a
> few
>> days and while you might not get the thing working, you'll at least learn
>> something about Unix.
>> --scott
>> --
>> "C'est un Nagra. C'est suisse, et tres, tres precis."
>
> Resurrection complete. File storage on the Alesis MasterLink appears
> fairly
> straightforward. Learned something new in the process.
>
> bobs
>
> Bob Smith
> BS Studios
> we organize chaos
> http://www.bsstudios.com


Yes...Bob was great!
Anonymous
December 30, 2004 8:01:34 AM

Archived from groups: rec.audio.pro (More info?)

Bob Smith <rsmith@1nospam2.bsstudios.com> wrote:
> Resurrection complete. File storage on the Alesis MasterLink appears
> fairly straightforward. Learned something new in the process.

care to fill us in with the details?

--
Aaron J. Grier | "Not your ordinary poofy goof." | agrier@poofygoof.com
The United States is the one true country. The US is just. The US
is fair. The US respects its citizens. The US loves you. We have
always been at war against terrorism.
Anonymous
December 30, 2004 9:03:05 AM

Archived from groups: rec.audio.pro (More info?)

Bob Smith <rsmith@1nospam2.bsstudios.com> wrote:
> Use a low level disk editor to examine the storage system for data
> that looks like file structures and PCM data.
[...]

is this with 24 or 16 bit data? (16 seems a no-brainer with this
method; 24 seems like it'd be more trouble...)

--
Aaron J. Grier | "Not your ordinary poofy goof." | agrier@poofygoof.com
The United States is the one true country. The US is just. The US
is fair. The US respects its citizens. The US loves you. We have
always been at war against terrorism.
Anonymous
December 30, 2004 11:40:30 AM

Archived from groups: rec.audio.pro (More info?)

"Charles Tomaras" <tomaras@tomaras.com> wrote in message
news:KsqdnQeLnM-kO07cRVn-tA@comcast.com...
>
> "Bob Smith" <rsmith@1nospam2.bsstudios.com> wrote in message
> news:LvCdnVoLwJ1LGk7cRVn-jw@comcast.com...
> > "Scott Dorsey" <kludge@panix.com> wrote in message
> > news:cquhu5$9f5$1@panix2.panix.com...
> >> In article <znr1104279178k@trad>, Mike Rivers <mrivers@d-and-d.com>
> >> wrote:
> >> >In article <cqsbk1$jfv$1$8302bc10@news.demon.co.uk>
> > dmills@spamblock.demon.co.uk writes:
> >
> >> >Do you think it's wise to turn someone loose with these instructions
> >> >without the knowledge and experience that you obviously have? Why not
> >> >just say "Send me your drive with $50 to cover a little time and
> >> >return shipping and I'll see if I can get anything off it for you."?
> >>
> >> In this case, sure. All he can waste is his time. It's not like
> > electrical
> >> work where you can kill yourself if you make a mistake. You can waste
a
> > few
> >> days and while you might not get the thing working, you'll at least
learn
> >> something about Unix.
> >> --scott
> >> --
> >> "C'est un Nagra. C'est suisse, et tres, tres precis."
> >
> > Resurrection complete. File storage on the Alesis MasterLink appears
> > fairly
> > straightforward. Learned something new in the process.
> >
> > bobs
> >
> > Bob Smith
> > BS Studios
> > we organize chaos
> > http://www.bsstudios.com
>
>
> Yes...Bob was great!
>

Charlie,

Thanks for the pointers to the Sound Devices 302 and Trew Audio in
general. Those will be a big help to me.

bobs

Bob Smith
BS Studios
we organize chaos
http://www.bsstudios.com
Anonymous
December 30, 2004 12:32:04 PM

Archived from groups: rec.audio.pro (More info?)

Aaron J. Grier <agrier@poofygoof.com> wrote:
>Bob Smith <rsmith@1nospam2.bsstudios.com> wrote:
>> Use a low level disk editor to examine the storage system for data
>> that looks like file structures and PCM data.
>[...]
>
>is this with 24 or 16 bit data? (16 seems a no-brainer with this
>method; 24 seems like it'd be more trouble...)

Most of the audio file formats are unpacked, so they store 24-bit data as
32-bit fullwords.

But since 24 bit falls evenly across three octet boundaries, it's not too hard
to look at 24 bit packed files in hex. You can even use emacs and look at
blocks of three characters at a time if you like doing that.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Anonymous
December 30, 2004 12:32:05 PM

Archived from groups: rec.audio.pro (More info?)

"Scott Dorsey" <kludge@panix.com> wrote in message
news:cr13h4$cgd$1@panix2.panix.com...
> Aaron J. Grier <agrier@poofygoof.com> wrote:
> >Bob Smith <rsmith@1nospam2.bsstudios.com> wrote:
> >> Use a low level disk editor to examine the storage system for data
> >> that looks like file structures and PCM data.
> >[...]
> >
> >is this with 24 or 16 bit data? (16 seems a no-brainer with this
> >method; 24 seems like it'd be more trouble...)
>
> Most of the audio file formats are unpacked, so they store 24-bit data as
> 32-bit fullwords.
>
> But since 24 bit falls evenly across three octet boundaries, it's not too
hard
> to look at 24 bit packed files in hex. You can even use emacs and look at
> blocks of three characters at a time if you like doing that.
> --scott
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."

It was 44100 Hz, 16 bit but as Scott mentions, it's not that big of a deal
to look (in hex) at three or four bytes for 24 / 32 bit samples. It's a lot
easier than analyzing core dumps of the '60s without any documentation. CEP
(now Adobe Audition) allows easy importation of the various PCM schemes for
24 and 32 bit.

bobs

Bob Smith
BS Studios
we organize chaos
http://www.bsstudios.com
Anonymous
December 30, 2004 4:09:35 PM

Archived from groups: rec.audio.pro (More info?)

In article <LvCdnVoLwJ1LGk7cRVn-jw@comcast.com> rsmith@1nospam2.bsstudios.com writes:

> Resurrection complete. File storage on the Alesis MasterLink appears fairly
> straightforward. Learned something new in the process.

Oh, that was you who asked the question! In that case, I never would
have made the comment about not messing around when you weren't sure
what you were doing. I know you're smart enough to carry a shovel big
enough to dig yourself out of any hole you fall into.



--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo
Anonymous
December 30, 2004 4:09:36 PM

Archived from groups: rec.audio.pro (More info?)

"Mike Rivers" <mrivers@d-and-d.com> wrote in message
news:znr1104411526k@trad...
>
> In article <LvCdnVoLwJ1LGk7cRVn-jw@comcast.com>
rsmith@1nospam2.bsstudios.com writes:
>
> > Resurrection complete. File storage on the Alesis MasterLink appears
fairly
> > straightforward. Learned something new in the process.
>
> Oh, that was you who asked the question! In that case, I never would
> have made the comment about not messing around when you weren't sure
> what you were doing. I know you're smart enough to carry a shovel big
> enough to dig yourself out of any hole you fall into.

I do a lot of basic research these days.

Basic Research: what one is doing when one doesn't really know what one is
doing.

I could have used dd (background in Beserkley 4.2 and System V) but recently
I had a computer crash which appeared to scramble the FATs on four drives in
the primary studio computer. Now I have a few more tools than before and it
was nice to be able to help out to prevent the loss of a holiday
performance.

bobs

Bob Smith
BS Studios
we organize chaos
http://www.bsstudios.com
Anonymous
December 31, 2004 9:30:00 AM

Archived from groups: rec.audio.pro (More info?)

Scott Dorsey <kludge@panix.com> wrote:
> You can even use emacs and look at blocks of three characters at a
> time if you like doing that.

emacs? isn't that a eunuch's disease?

--
Aaron J. Grier | "Not your ordinary poofy goof." | agrier@poofygoof.com
The United States is the one true country. The US is just. The US
is fair. The US respects its citizens. The US loves you. We have
always been at war against terrorism.
Anonymous
December 31, 2004 9:30:01 AM

Archived from groups: rec.audio.pro (More info?)

In article <10t9sf87nf4fi2c@corp.supernews.com>,
agrier@poofygoof.com (Aaron J. Grier) wrote:

> Scott Dorsey <kludge@panix.com> wrote:
> > You can even use emacs and look at blocks of three characters at a
> > time if you like doing that.
>
> emacs? isn't that a eunuch's disease?

No.. I'm pretty sure you're thinking of vi. It's the only widespread
disease I can think of among eunochs.

Let the holy war commence.

-Todd
Anonymous
December 31, 2004 1:04:52 PM

Archived from groups: rec.audio.pro (More info?)

Aaron J. Grier <agrier@poofygoof.com> wrote:
>Scott Dorsey <kludge@panix.com> wrote:
>> You can even use emacs and look at blocks of three characters at a
>> time if you like doing that.
>
>emacs? isn't that a eunuch's disease?

It's an editor. It's an acronym for Eight Megs And Constantly Swapping,
or maybe for EMACS Makes Computers Slow.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Anonymous
January 3, 2005 6:21:04 PM

Archived from groups: rec.audio.pro (More info?)

On Fri, 31 Dec 2004 06:30:00 -0000, Aaron J. Grier
<agrier@poofygoof.com> wrote:
> Scott Dorsey <kludge@panix.com> wrote:
>> You can even use emacs and look at blocks of three characters at a
>> time if you like doing that.
>
> emacs? isn't that a eunuch's disease?
>

Nah. Emacs is a great operating system.

It just needs a decent editor.
!