Hi,

I'm after some help locating some information I have read on a forum somewhere, thought I had saved but now can't find.

Somebody wrote a detailed description of the data structure of a Panasonic recorder's hard drive. I think it was for a DMREH60.

It detailed how at the start of the drive there is a 'machine identifier code' (can't remember how he/she phrased that) which is unique(ish) to that machine. If you take a drive from one machine and transplant it to another machine you need to edit that code so the new machine sees the drive as its own. That code is in the very first few bytes of the first sector. If you don't edit the code the new machine will reject the drive (I think with the HDD NG message).

I am trying to resurrect an old drive that crashed in my EH60 to extract some recordings. The disc is very full and very fragmented so extracting chunks of video data as others have done would be very long winded. I have a raw disk image of the original drive before it finally started to clunk and have copied it back to a a replacement drive (the same model as the original). I have two EH60s, the original one is being used with a replacement drive. I could just try putting the re-imaged drive back into that unit as the identity code will match... but I don't want to risk screwing that machine up when I can experiment with my spare unit. If I could just find that original information I could edit the code and try the disk on the second unit without any risk. It might be the case that even if I can get the machine to see the drive successfully the original drive (and hence the image of it) became too corrupted so may not boot successfully anyway but it is worth a try. I have used some software that can extract chunks of video data from that image but due to the high fragmentation (too full for too long) rebuilding the recordings would be a real pain.

So... has anyone else come across that information and can point me to it please? I have spent quite a while googling it and also searching through all the dross on my pc but can't find it anywhere.

Many thanks,
Stu

After plenty of head scratching I managed to finally find what I was looking for on another forum. I can't remember the rules on here about mentioning other sites so I'll just copy and paste the info. (apologies to the original poster on that forum who I think is known as 'violetfi'). Haven't tried playing yet but will give it a go. Hopefully it will let me boot up the re-imaged drive in a different DMR-EH60, i.e. same model, different serial number.
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"Originally posted by violetfi: I have to share with you my excitement about my great success. I'm finally able to switch hard disks back and forth on my Panasonic DMR-E80H and DMR-HS2!!!

On 17. February 2005 rtjoby posted in this thread his way of tricking the firmware under this link in the event that the Panasonic displays UNFORMAT and requests a mandatory formatting of the hard disk. Starting from his findings, I added another step to it and here's what I found:

Whenever I replaced a hard disk in one of my Panasonic DVD Recorders (I have three DMR-E80H and one DMR-HS2), I had to format the hard disk before I could do anything with it. Here is rtjoby's way to trick the firmware to accept a hard disk containing recordings that were done previously with the same unit:

1. Replace the hard disk
2. When requested to format the hard disk, unplug the power cable from the hard disk
3. Push the Enter Button on the remote twice to have the unit start to try to format the hard disk
4. After a few seconds (like 5) either unplug the main power cable from the unit or press the power button for 10-12 seconds
5. When the unit is off connect the hard disk power cable and then the unit main power cable
6. When you turn the unit on, it may work from the new hard disk and show all the information from that new hard disk

Here come now my new findings:
The Panasonic DVD Recorders write also a number, unique per unit, to the hard disk. So the above works that easily only when the disk was last used in the same unit. If the hard disk was used last in another unit of the same model, then the following will do the trick. You will need a hard disk editing program like WinHex:
1. Find the unique number of your unit. On each hard disk the following 10 bytes are relevant:
the 6th byte is 0x53 (S)
the 7th byte is 0x48 (H)
the next 8 bytes represent the unique number
2. Once you know the number for your unit, write the correct bytes to the hard disk you would like to use in that unit (with WinHex)
3. Then do the above steps with unplugging the power and you should get the new hard disk working

One more note: To prove that this technique works, you should actually record just a little bit on the hard disk, because without that you might be able to switch hard disk back and forth without formatting...

I tried all of this with 4 hard disk and it works. I also took out the hard disk of one E80H, backup it up with WinHex, Restored it to a new hard disk with WinHex, changed the unique number for the new unit on the new hard disk, did the unplugging thing, and actually had two units with exactly the same recordings and was able to watch all of them and also add more recordings!!!

I spent hours searching the internet for this solution and couldn't find a success story. So I'm proud to share my findings. May it give some of you hope to prove it. "

Thanks for sharing. I may now consider putting a larger drive into my machine.