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Author Topic: minidiscs and the data on them - who knows about them?  (Read 4851 times)

lyner

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My neighbour has a minidisc with some important data on it (some important recorded interviews). In both her and my minidisc machines, the disc whirrs and clunks - then says Read Error and offers to reformat / erase the disc.

I remember that it was possible to look at floppies with hideous physical damage to them and to retrieve at least some data from them - a sector at a time.
I appreciate that a minidisc  is probably not formatted in sectors like a floppy but more like a CD - as a serial data stream-  but it should be possible, with appropriate control of the drive, to make the read head go to 'somewhere' on the disc and to start reading stuff from it.
Has anyone ever done this sort of thing? Problem is that the minidisc was a bit of a one-off system and will probably not have made much 'nerd-attention'.
Still - it's always worth asking. (Alternatively, a link to somewhere else would be appreciated)


 

Offline chris

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minidiscs and the data on them - who knows about them?
« Reply #1 on: 25/08/2009 10:28:32 »
I am pretty sure that the read error is analogous to the corruption of the file allocation table on the disc - they work the same way as a CD or floppy and encode the data digitally in a compressed format. What I do not know is if anyone offers a recovery service for MDs like they do for discs. If they do it will simply be a case of running a bit-image copier over the disc and grabbing whatever data is there...

Chris
 

lyner

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minidiscs and the data on them - who knows about them?
« Reply #2 on: 25/08/2009 11:11:43 »
But do minidiscs have a FAT? It's very wasteful when you're trying to cram as much sequential data as possible on a small area of disc. I think they will be more like a CD than a floppy / hard drive.
I think the problem is with making the drive do what you want - i.e. Send the head to an arbitrary position. Normally they will only move until they find a track start.
Maybe the on board controller won't even do it.
 

Offline peppercorn

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lyner

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minidiscs and the data on them - who knows about them?
« Reply #4 on: 25/08/2009 11:42:05 »
Brilliant. Thanks, peppercorn.
I have passed the info to my neighbour.
 

Offline RD

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minidiscs and the data on them - who knows about them?
« Reply #5 on: 25/08/2009 12:02:57 »
Make sure your neighbour is sitting down when told the cost of data recovery ...

Quote
Removable Media Devices -
 CompactFlash/Smart USB Media drives, CDs/DVDs, floppy discs, ZIP, etc. Pricing ranges average from $200 - $900
http://www.salvagedata.com/terms/service-level/

$200 - $900 is their economy not-in-a-hurry price range  [:0]


Here is a possible soure of an alternative (UK) quote ...

Quote
Also Data Recovery from :
CD, DVD, MiniDisc, Magneto Opticial, SmartMedia, CompactFlash, Secure Digital Card, MultiMedia Card, Memory Stick, x-D Picture Cards, Digital Cameras, PDA, Mobile phone sim cards, Pocket PC / PSION, MicroDrive, Zip Disk, Jaz Drive, Syquest, Floppy Disk
http://www.logical.btinternet.co.uk/sserv1.html
« Last Edit: 25/08/2009 12:24:01 by RD »
 

Offline peppercorn

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minidiscs and the data on them - who knows about them?
« Reply #6 on: 25/08/2009 12:27:01 »
Brilliant. Thanks, peppercorn.
I have passed the info to my neighbour.

Hey! Nice for Me to be able to offer You some useful info for a change!
I doubt it'll cost as much as RD indicates for this software. They might even have a trial version.
 

Offline RD

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minidiscs and the data on them - who knows about them?
« Reply #7 on: 25/08/2009 12:42:13 »
I doubt it'll cost as much as RD indicates for this software.

This type of data salvage is not via software download, you send them the disc...

Quote
we require that the defective discs be mailed to us for an initial evaluation.
http://www.esdl.co.uk/body/md_data_recovery/md_recovery.htm

Very suspicious. I cannot see any indication of a price list on the EDL site,
the US company I quoted at least tell you their extortionate prices up front.
« Last Edit: 25/08/2009 12:53:39 by RD »
 

lyner

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minidiscs and the data on them - who knows about them?
« Reply #8 on: 25/08/2009 12:51:10 »
If they've got the only bit of kit available then they can define the market rate, I suppose. I should have smelled a rat when I found no prices on their site.
It rather confirms my suspicion that it requires something special in the way of hardware/ firmware.

I was so cross when, having paid a lot for a really nice Sony Net Player, rather than the original version, everything went 'solid state' and a fraction of the cost. I guess it would still better for good quality live recordings but I don't do them!
 

lyner

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minidiscs and the data on them - who knows about them?
« Reply #9 on: 25/08/2009 13:01:15 »
chris
I talked to 'the man' who runs a recovery service.
You are correct that they do use a Table Of Contents - and this makes sense because, unlike a CD, which is written once, they have to be able to overwrite bits of the disc. That means that they have to use a format so that they can locate the pieces of each file. I should have thought of that!!
 

Offline RD

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minidiscs and the data on them - who knows about them?
« Reply #10 on: 25/08/2009 13:22:08 »
Quote
The following procedure can be used to copy the TOC (table of contents) from one recordable MD to another...
http://www.minidisc.org/cloning_procedure.html
« Last Edit: 25/08/2009 13:36:06 by RD »
 

lyner

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minidiscs and the data on them - who knows about them?
« Reply #11 on: 25/08/2009 14:23:49 »
Problem is that the only machines we have are portable MZ N1(?) and, unlike a computer drive, which you can tell to do 'anything', you can only play, record etc using the nasty little buttons. Also, it was recorded using Hi MD, which means it's going to be even more difficult, apparently.

I think it has to be kicked into the long grass.
Thanks for the advice chaps.
 

Offline RD

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minidiscs and the data on them - who knows about them?
« Reply #12 on: 25/08/2009 15:15:48 »
Found "Sony Media Services" (USA) 2007 price list for data recovery ...
http://www.sonymediaservices.com/docs/Service%20Price%20List.pdf

Prices seem reasonable: $20 - $35 for audio recovery. For Hi-MD says "call for service availability".

http://www.sonymediaservices.com
« Last Edit: 25/08/2009 15:40:57 by RD »
 

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minidiscs and the data on them - who knows about them?
« Reply #12 on: 25/08/2009 15:15:48 »

 

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