Minidisc recordings have disappeared

From memory (no pun intended) MD's have 63/64 mins max length.
I always assumed they were quite simple, in that they just keep filling until full, then stop and little in the way of post recording file shuffling to do (unlike say video media).

In view of the oddities you describe, I'm wondering if some of the content is held in the recorder itself as a buffering mechanism and when you turned off, either it had finalised post recording updates or more likely you'd run over the (64-47) 17 mins you had left?

The repeat playback you heard, was then perhaps from the buffer.

Or.. is it possible it was done as an append to end of an existing recording, rather than extra file on TOC. In theory, this would increase the TOC from 47 mins, but you never know.

I just can't reconcile it doing a change, then backing it out, so hope it's still there...somewhere.

Isn't there a setting on MD recorders: "start new recordings from here" or "start new recordings from beginning of disc"?

Maybe it got changed, or defaulted if the batteries ran down??
----
Edit: Actually this would only explain the reverse situation: missing OLD recordings, not missing new ones.

Thanks for your replies (Ah, it's so good to have the Forum back again!). The recorder is a mains-powered Sony JDE510. It's never done anything like this in the past. The disc was a Sony Premium of 74 mins recording time, so my four short recordings (no more than a total of ten mins) should not have exceeded its capacity.

The recorder operates in the normal minidisc fashion - each time you press the Record button it goes into Record Pause and when the Play button is pressed it starts recording from the end of the previous recording.

There is no buffering circuitry, as far as I'm aware. To end a recording, the Stop button is pressed and there are a few moments while (I presume) the TOC is being updated. Because I made four recordings, then even if the last one failed, the previous three should be safely noted in the TOC. That's the big puzzle - why all four recordings have apparently disappeared - if it was just the last one it would be more understandable.

Ray

ray,

there's something called TOC cloning that might be able to get you out of this?

http://www.minidisc.org/cloning_procedure.html

hmmm baffling.
I agree with your thoughts.
Possibilities:
i)Try another MD player.
ii)It was a late late night and you're testing the wrong MD (.. I said possible not probable ;-) )
iii)Something wrong with toc functioning - perhaps even a Y2k problem. Is there a time/date memory setting within it - front clock etc.

Try another non critical MD with an old recording and see if it accepts extra recordings, and see if still there - especially after turned off over night.

Thanks for the new replies. Unfortunately, the TOC cloning instructions say that it is NOT possible with the 510 model that I have.

>>)Try another MD player.<< On my list of things to try

>>ii)It was a late late night and you're testing the wrong MD (.. I said possible not probable ;-) )<< No, it's the only MD that is not in a storage box.

>>iii)Something wrong with toc functioning - perhaps even a Y2k problem. Is there a time/date memory setting within it - front clock etc.<< No clocks, dates, it's just a basic machine.

>>Try recording on another disk<< Also on the 'to-do' list

Ray

(Next morning)

Made four test recordings on a blank MD last night - still there this morning.

Also checked the MD with the missing recordings on my other (portable) MD player - also shows recordings as missing.

These are (luckily) not recordings that are vital to a job - just recordings that it would have been really useful to keep (they are rehearsals of songs that define the arrangement, key, tempo, etc).

Any other ideas?

Ray

Ray,

I have a 520.

I've never done it but if you wanted me to have a go I'm happy to try
(especially as you say it's not vital!)

Dave

That's very generous. If we move to PMs, perhaps you could give me your address and I'll pop the disc in the post.

Thanks

Ray

510s and to be honest, 520s too have this problem. What happened was that it didn't write the TOC before you switched it off. Hitting eject triggers a TOC write, but for some very odd reason, they sometimes forget to do it.

The best solution in terms of repair was the old Tascam 801 - how I wish I'd not flogged mine. This has a repair function and can re-create a new TOC, however, what it does is recover every complete file, in sequential order, including any edits - so you might recover 100s of tracks, but spending an hour or two listening and sorting is worth it. The Denon machines will also play many discs that others won't - but I've never found anything as good as the 801. See if you can find anyone with one - maybe a local broadcaster may still have one and will let you at least try?

Thanks for your suggestion, Paul.

I'm puzzled about this TOC writing business. Since the MD is ejected as soon as the Eject button is pressed, how does it have time to write the TOC?

And if the TOC is written only when ejected, why are there several seconds at the end of a recording if this is not the TOC being re-written to include that recording?

And surely the TOC would have to be re-written after each recording so that the machine knows where to start the next recording?

Ray

TOC should really be called UTOC on a MD recorder - it's a user table of contents. What happens is that there's an on-board memory that should keep track of everything until you power off, or eject, when the memory copy gets written to disc. This is pretty quick on a Sony, while my Tascam takes a bit longer. I've just tried to re-create the error on a Sony in the rack by flipping off the mains power while it was doing the writing and have wrecked it. I don't mean just the MD - the machine now won't read anything, so I'll have to remove it from the rack and see if I can work out what's going on. As for the several seconds at the end of the recording, I'm confused. All my machines stop when I hit stop. The Sony does (did) hang for a second, perhaps less than half a second on stop, but I can't say for certain if this is a writing operation.

My minidisc portable recorder ( mz-r3 ), very early model , explicitly stated that once you pressed stop , wait till the animated display stopped before ejecting disks.

I have 2 x desktop units , 470 and 520 , which i use for playback mostly.

I have not yet had a TOC problem.

I now have a mz-r50 too , but have no psu for it or the mz-r3 , so can no longer charge the lithium batteries , but can use AA's in the mz-r3.

Presumably your mz-r3 had a mechanical eject system. My Aiwa portable (AM-F5) is similar and your message triggered me to look in the handbook. Under 'To stop recording' it states:

Press Stop. The unit stops after registering the information concerning the contents of a recording (TOC)
a) Number of all tracks on the MD
b) Disc Rotating symbol disappears after registering the TOC
c) Total recorded time of the MD

This would seem to confirm that the TOC of an MD is re-written after each Stop operation and does nothing to lighten the mystery of why all four of my missing recordings (each of which had a Stop operation at the end of the recording period) have disappeared.

It would be perhaps more understandable if just the last recording had gone (because maybe I didn't put the 150 into Standby before I powered down the stack? But why should that make a difference?) but all of them?

Ray

Sorry if I've missed it, but how much remaining time does the disc show?
Also, I always set my portable minidisc to record in mono and get double duration times.

Can't be sure what time is shown as being left for two reasons

a) As soon as I saw there was a problem I moved the MD shutter to 'Record Disable' for safety and the 'remaining time' is only shown when in Record Pause or Record.

b) The disc is on it's way to a fellow member of this Forum who is kindly going to attempt to revive the missing recordings via a TOC Clean.

Agreed that mono gives double the duration, but directional information adds so much to musical enjoyment.

Ray

I recently had a mini-disk fail to write TOC but found a way round via this kink.

http://www2.informatik.hu-berlin.de/~pilop/HOWTO_MD_TOC-cloning/index.shtml

I did'nt need the extra pairs of hands just some masking tape to hold down the pins so the recorder thinks the door is still shut. It worked for me!!!! Stunned.

Also tried it on a disk from years ago which I had deleted and it brought back the audio.

Martyn

Thanks, Martyn.

At present the disc is away while the earlier method of TOC cloning is tried but it's a useful second second option.

Ray

It's nice to be able to report a happy ending to this little saga. Dave M of this forum offered to use his Sony 520 to perform the TOC Clean described earlier. I'm sure he won't mind me quoting part of his message after the event

The basic idea was to insert an MD with some kind of TOC (silence for a full disc) and then fool the machine into not seeing the swap over to your disc. I did it several times and could hear your band, but lost it on the eject.

I eventually figured that if I added a new track marker using your disc, it wrote the TOC back Your stuff starts at track 4 - I didn't try to add any more

Even here the story is not complete, because when I tried to play the 'TOC Cleaned' disc on my Sony 150 all I got was the 47 min radio programme. The TOC showed four tracks totalling 80 mins and 50 secs, with the unwanted radio programmme occupying tracks 1, 2 and 3 (47 mins) and track 4 being a second or two of silence - ie no music.

Fortunately, I tried it on my Aiwa portable and this played Track 4 correctly. Not only did I get the music that I wanted, I also found that after it was 27 mins of an amateur production of 'Grease' which I had 'erased' (supposedly) so that I could re-use the disc.

I'm sure an MD expert could explain why my Sony reads the TOC Cleaned disc differently from my Aiwa, but for now I'm just grateful to get those recordings back!

Thanks again to Dave M!

Ray

Ahhhhh.
Innit nice to have a happy ending.
I bet Dave M had the 'Mission Impossible' theme playing in the background to aide his knowledge and stealth.:cool: :cool: :cool:
Next week Dave will be teaching us how to walk on water. ;)

MiniDisc contents are a black art. We had an unreadable disc here recently - I could only conclude that it may have been in the later "HiMD" format.

I never really got my head around the format despite having a portable recorder and an office player. I think the user interface on my portable unit left me with little or no confidence that it was working - even though it was.....

The very first time I took it on a job it saved my bacon - the VX9000 audio died part way through a job - the MD was my back-up.