Topic: Need Help With Data Recovery From Old Minidisc

[tungarbulb]

I have a data-recovery issue involving an ancient medium which tapers once swore by (and at!)

About 10 years ago, I tried to record an interview with a very prominent funk band member, using a Sharp portable mini-disc unit (can't remember the model number, but it was from the late 1990's).  Unfortunately, the battery pack inside the little sucker apparently didn't have enough juice for the job, so in the middle of the recording, it crashed. The disc registers as “blank” to any MD recorder I try to play it on since the table of contents was not written properly/was corrupted when the machine crashed.

Fast-forward to a few years ago. I read somewhere on Minidisc.org (which seems to be down as I write this) that one trick for recovering data lost in the manner described above is to first record a blank mini-disc with nothing on it but silence, end-to-end, the full 74 or 80 minutes. Then, insert that disc into a mini-disc recorder. Allow the MD recorder to read the disc's table of contents.

The net part's trickier. WITHOUT hitting the “eject” button, remove your “dummy” disc. Insert the corrupted one. Your machine will think that it's still got the “dummy” disc in it, and will work from the dummy disc's table of contents rather than the corrupt one on the disc you're trying to recover. Hit “play', and transfer your audio thus recovered to the medium of your choice.

Now, I recently found a Sony MD-S4JE70 component mini-disc recorder at a local thrift shop. It's in good condition (even has its remote!) and it works, but the loading and unloading mechanism (which I've only looked at, haven't yet tried to mess with) seems to be rather complex and delicate. How, I wonder, can I pull the ol' switcheroo and trick the sensors in the loading mechanism into thinking that a disc with a good TOC is inserted while trying to recover audio from my corrupted disc? Can a service manual for this recorder be found online so I can get a better idea of what I'm dealing with? And while I'm at it, is this method really worth trying? Has anyone else here tried the hack described above?

[beatkilla]

I looked into the same thing a few years ago,but never tried it cuz like you said it was tricky.same thing happened at ozzfest years ago,would like to recover sabbath and maiden.

[tungarbulb]

You definitely have my sympathies for your losses. There's nothing more frustrating than getting a recording of a great show but then losing it to a disc TOC problem. It's almost enough to make one think that analogue audio cassettes weren't so bad after all!

Actually, now that I think of it, I believe that the correct procedure was to record your dummy disc, and then swap discs in that machine without formally "ejecting". Then, you'd do whatever you'd do to finalize the disc and write a table of contents to it (on my portable MD, when you shut the thing off after recording it finalized the disc by writing to the TOC). After doing this, the previously-damaged MD would presumably have a new TOC and play on any MD player. You just wouldn't have track markers, which if you know how to edit sound on a PC is only a minor inconvenience; you can re-create tracks in the WAV domain.

My question remains the same - has anyone tried this, or does anyone have suggestions for alternatives?

[jethro bo deen]

tungarbulb:  Go visit http://forums.sonyinsider.com/   
   Thats where the old mindiscDOTorg    Forum  is now.     You'll see categories: Minidisc      and  subforums like Live Recording,  hi-MD, MD, Net Md etc,  Tips&Tricks...   
There is still a very small but extremely loyal group of MD enthusiasts still active over there.    You might need to post similar requests in more than one subforum to get a qualified response.   
You may catch a MD genius, that is still fond of those machines and still tunes in over there.    As you know most,  have embraced the latest Sony digital machines and similar machines that taperssection veterans use these days.    There are still some brilliant superb recordists that still use MD & hi-MD  and  "tune in" over there occasionally.     Others that moved up to Sony's latest, that were raised on MD and hi-MD  also post on other topics/forum related to the new equipment,  but still check and "tune in" occasionally to help and see whats happening with the generally "low-buck tapers" using MD and hi-MD with good results,   as some don't mind the "ease of use" issues that 'taperssection veteran pros' despise of MD and also hi-MD.    I'm an old timer that still likes those formats and machines, esp. Sharp MD-821  and   SR 60 & SR75 and MT161, Mt16 , Mt20  models   for easy use layout/level controls and good MIC IN   and line in when necessary.  I transfer in real time from a home Sony deck(edit the MD) and RCA out thru Numark EQ-2400 ten band into SONY RCD-W500C  with Super Bit Mapping (SBM) switched on.   

[nameloc01]

Sony has a department, I did have the phone # at one time, but have since lost it- that does "data recovery", I want to say the offfice was in Alabama or Loiusiana..you can call them (Sony USA HQ) and get the contact info. I had gotten busted taping a show and was forced to delete the minidiscs, however, they told me they could still likely extract the data..it was around $50 per disc. I never got around to sending them in..$100 for Foo Fighters show seems a little steep to me.

[kozakz]

I hope this will help you. I used this method on JE520 and JB930 several times. I recommend to clone a full disc's TOC to recover everything from the bad discs.

Instructions for cloning an MD TOC with a Sony MDS-JE520
David W. Tamkin (dattier@Mcs.Net)

TOC Cloning
The following procedure can be used to copy the TOC (table of contents) from one recordable MD to another. There are various reasons for wanting to do this, such as recovering recordings lost to editing errors and cloning specially made 80 minute blanks.

Definitions:
"turn the unit off" or "turn the unit on"
Press the ON/STANDBY button at the upper left of the console or the green POWER key at the upper right of the remote.
"disconnect the power"
Remove the unit from its source of electricity by unplugging its cord from the wall socket, shutting off the power strip if it is plugged into a power strip, or setting the timer [not the "TIMER" switch on the 520's console but the actual appliance timer into which the 520 is plugged] to "off" manually if the 520 is connected to an appliance timer.
"reconnect the power"
Plug the 520's cord back into the wall socket, or turn the power strip back on, or set the timer to "on" manually: whatever it takes to reverse the disconnection and supply electricity to it again.
"The TOC is dirty"
The 520 believes, correctly or incorrectly, that the TOC in its RAM differs from the TOC saved on the disc, so it lights the red "TOC" LED on the display and will write the TOC from RAM to the disc when the disc ejected or the 520 is turned off.
"The TOC is clean"
The 520 believes, correctly or incorrectly, that the TOC saved on the disc is the same as the TOC in its RAM, so the "TOC" LED is off, and the 520 can be turned off or the disc can be ejected without writing the TOC from RAM to the disc.
"dirty the TOC"
Make a clean TOC dirty by performing an edit. If no edit is necessary but the TOC is clean and must be dirtied, a quick way to dirty it without any actual edit changes is is to press NAME on the remote, give the 520 a moment to present the disc name or current track name for editing, and then press NAME again to exit titling without changing anything (nor entering anything if there was no title there before). The write-protect on the disc must be closed and the 520 must be set to continuous play mode (not shuffle or program).
"super-undo"
Hold in either the STOP button on the console or the STOP key on the remote for about ten full seconds until the 520 goes into Retry Cause Display Mode (the panel will display something like "RTs00c00e00"). Retry Cause Display Mode itself need not be used in cloning; you can exit it by pressing TIME or DISPLAY on either the console or the remote [the method of exiting is different from the JE500 and JE510]. The thing that's important here is that going into Retry Cause Display Mode when the TOC is dirty will make the 520 forget the stain and believe that the TOC is clean, so that the TOC in RAM will not be written to the disc when the 520 is turned off or the disc ejected; that is why it is called super-undoing. The RAM copy of the TOC is unchanged by super-undoing, and it can be written to the disc after all if you dirty the TOC again (dirtying the TOC after a super-undo is known as "super-redoing").
"go to test mode"
Disconnect the power, hold in the AMS knob, reconnect the power, and release the AMS knob. (The usual way to exit test mode is to press REPEAT on the console, which puts the 520 into a form of standby mode where it literally displays the word "Standby", and then turning the unit on. However, that method forcibly ejects the disc, so we're going to get out of test mode in a different way for cloning.)
"save the TOC"
Write the TOC from RAM to the disc by ejecting the disc or turning the unit off while the TOC is dirty. Saving the TOC will mark it clean.

The Procedure
To clone a TOC from one disc to another on a Sony MDS-JE520,

Insert the source disc into the 520. Let the 520 read its TOC.

CAUTION! Cloning instructions for older units say to dirty the TOC at this point. With the MDS-JE520, that is not just unnecessary but also HIGHLY inadvisable. If step 2 or 3 applies rather than step 4, you could even have the write-protect open on the source disc.

If the source disc's TOC is exactly what you want cloned to the target disc, skip to step 7.

If the TOC you want to write to the target disc is not the same as that on the source disc, but ALL the differences are such that you need to work with the target disc to figure them out, skip to step 7.

If you need to make changes from the source disc's TOC to get the TOC that you want to write to the target disc, and for some or all of those edits you need to work with the source disc to figure them out, do the editing for which you need to work with the source disc.

If you want the changes from step 4 written to the source disc as well, save the TOC now. Then reinsert the source disc if you saved the TOC by ejection or turn the unit on if you saved the TOC by turning the unit off. Skip to step 7.

Last possibility: if you made edits in step 4 but you do not want them written to the source disc, super-undo.

Go to test mode. Do NOT press REPEAT.

While you're in test mode, eject the disc and insert the target disc.

Disconnect the power. Make sure that the REC-OFF-PLAY slide switch is set to OFF.

Reconnect the power without holding the AMS knob in.

CAUTION! If you dirtied the TOC while the source disc was still in the 520 and you didn't clean it by saving it to the source disc in step 5 nor by super-undoing in step 6, the 520 will be writing the dirty TOC from step 4 to the target disc right now. That's not a problem, I thought, until the time I inserted a good disc with other valuable recordings in step 8 instead of the intended target disc, and the source disc's TOC got written to it. I had to recover its TOC from scratch. That is why it is greatly preferable to go into step 7 with a clean TOC, contrary to cloning instructions that have been given for some other decks.

At this point the target disc is inside the unit, but the TOC data in RAM -- all the track and segment pointers, titles, and timestamps, and all the SCMS, mono/stereo, and emphasis bits -- are those from the source disc (as modified by any edits made in step 4). You've managed to switch discs without the 520's realizing it.

If necessary, play selections from the disc to make sure that the results are to your liking. If you inserted the wrong disc, go back to step 7.

If you need further edits to the target disc -- if step 3 or the word "some" in step 4 applied -- make them now. They will leave the TOC dirty. Skip to step 14.

Otherwise -- if step 2 or the word "all" in step 4 applied, so you skipped step 12 -- dirty the TOC now.

Save the TOC to the target disc.

Congratulations, you have now duplicated the TOC of the source disc onto the target disc.

[Ekib]

I've had a different problem recording a show with my HI Minidisc recorder ( MZ NH1 ). Somehow after the last song my battery went dead. So there wasn't any info written to the disc. I guess there is no way to recover that data , isn't it ? ( I don't know if during recording the recorder writes data to the disc , or only afterwards ).

[beatkilla]

@ Ekib           Your recording is there,but there is no table of contents.Methods described here could salvage your recording.Do not record anything onto that minidisc. Good luck.

[sunjan]

I hope this will help you. I used this method on JE520 and JB930 several times. I recommend to clone a full disc's TOC to recover everything from the bad discs.

Instructions for cloning an MD TOC with a Sony MDS-JE520
David W. Tamkin (dattier@Mcs.Net)

Looks like the numbering/bullets on the above procedure was dropped?!
Anyway, a more recent updated version is posted here:
http://www.minidisc.org/cloning_procedure.html

For Sharp users, take a look at this very simple approach:
http://web.archive.org/web/20070421024441rn_1/www-public.tu-bs.de:8080/~y0001729/701/MDMS701clone/index.html

More links relating to TOC cloning here:
http://www.minidisc.org/part_hacking.html

Remember, you can always use the wayback machine if minidisc.org should be down.

[tungarbulb]

Many, many thanks to all of you who have replied so far. I'm checking out the articles you've linked to and the advice which you've posted here.

Of course if anyone here has any other ideas or recommendations to add, let's hear them!