I have read in the past that the hard disk in my JVC HN-HDS1 can be upgraded with, I believe, the hard disk from the HM-HDS4 provided you also upgrade "the firmware chip" as well. Does anybody know if this is really possible, and if it is, where can I get the parts and instructions. I contacte JVC who, not surprisingly, said it was not possible. Any help much appreciated!

[GaryB]

You can fit the HDD from the HM-HDS4, in fact you have to if your HDD ever fails as the 40Gb drive used in the HM-HDS1 is no longer available, Unfortunately, you can still only use 40Gb of the 80Gb available. If you order an HM-HDS1 HDD you get the new 80Gb drive and the new chip.

[maldonian]

Hello Gary

It sounds like you may have done this. Do you know if the replacement HDD has the OS pre-installed, or is it stored on the chip? I was under the impression that at least part of the OS is stored on the HDD.

Ian

[GaryB]

Most of the OS is on the HDD. The chip is similar to the BIOS chip in a PC. It enables the electronics in the HM-HDS1 to talk to the HDD which is why it has to be replaced to allow for the different drive.

[maldonian]

I wonder if you've come across, or heard of, occasional crashes in the HM-HDS4?

The most frequent form of crash with mine is a full reboot. Usually it happens when you're doing something - e.g. scrolling through the thumbnails in the navigation screen - though it has happened once or twice while just watching a recording.

Less frequent types of 'crash' are: Sometimes it locks up completely and I have to unplug at the mains. On a few occasions it has stopped displaying a picture, source or recorded, but the graphics and thumbnails were ok. Again, the only way out was to unplug at the mains.

It has done it since I bought it, I don't think it's getting any worse. I just wondered if it's a known problem in the HM-HDS4.

[Cippico]

I managed to clone the HDD in my HM-HDS1 but never managed to upgrade it. I spoke to a JVC repair shop who told me that even though the later 80GB replacement drives will work in an HM-HDS1 with a replacement EEPROM, you still only get 40GB.
Unfortunately my unit has now died so if anyone wants to buy it for spares or repair then let me know. It was a pretty unreliable unit throughout its 3 years of service so the problems people have with the HDS4 do not surprise me. It's a real shame as it was a fantastic beast to own. It revolutionised my viewing and recording habits.

Andy

[tabatha]

MY HMHDS4 does crash in the same way as Maldonians. I would say around once every three months or so - but I do use it every day. Despite also having other HDD recorders, I still like much appreciate some of the features that the JVC has that the others do not. I don't know if these extend to their HDD/DVD combos.

The HMHDS4 does seem to crash from time to time like this, with no adverse effects. Unlike the earlier HMHDS1 which seems to corrupt itself and require a new drive!!!
Its worth noting that an HMHDS4 80 gig drive does not have the OS for an HMHDS1 on it so won't directly work in a HDS1 even with the eeprom change, you need to order the new HDS1 80gig drive pre-loaded + eeprom together cost around £110. Not very cheap considering you can pickup 80 gig drives for £40~

AW

[bakerrev]

Any definitive answer on how to clone the HMDS4 hard drive in case of drive failure? Even if the OS were cloned onto a smaller drive it might be useful as a backup.

PS. Never had a crash on my HMDS4 ...yet!

We don't think you can clone just the OS. YOu can clone the disc- using Ghost v8 I've heard. I have a contact whose cloned the orig HMHDS1 onto a DVDR (compressed). It should allow recovery onto an orig HDD not a copy... as for the HDS4 it should be pretty straight forward- though they only guarantee the orig drives not just any make/model

[tabatha]

I made a clone of my original HMHDS4 drive that was made using "Replica" which is a DOS disc copier programme made for making forensically sound copies of data. I kept the original hard disc and have used the cloned drive ever since I bought the machine nearly two years ago. I used an identical drive for the clone - a Maxtor DiamondMax 16 80Gb ATA/133 drive. I did not try Ghost but see no reason why it would not do the job.

Interesting.
I assume the clone requires the full 80gig. ie Its not possible to clone the small 'used' area of the disc where the OS is- so that an easier recovery method could be found? Onto a CDR/DVDR for example?

[maldonian]

I think recent versions of Ghost can create a compressed image of a drive on an external USB or firewire drive. I don't know if it works with drives containing OS's Ghost does not recognise, if it's a sector by sector copy presumably it does.

As I said in another thread, one problem I had with my HDS4 happened when I was creating a playlist at the time a timer recording was supposed to start. I noticed it hadn't started, came out of the playlist editing and the recording appeared to start. I opened the navigator and couldn't see the recording. So I stopped the recording and it appeared to stop normally, went back into the navigator screen and the recording still wasn't there. I then started the recording manually (having missed the beginning) and that worked ok. So where did the timer recording go?

Just after this happened I noticed a lot of the on screen messages were missing. If there wasn't enough room on the drive for a timer recording for example it just finished without setting the timer and with no on screen message, which was a bit confusing. Obviously I tried unplugged the power but that didn't help. I guessed the timer recording had overwritten part of the OS space where the messages were stored. Then quite some time later I was aware that at least some of the messages were back again.

This makes me wonder if the OS contains some form of self repair routine using a second copy of the OS on the drive. I often hear the drive running for a few minutes while the machine is in standby, though I suppose it could just be defragmenting.

[tabatha]

Before I made the clone of the unused HMHDS4 drive, I examined it with a "disk doctor" type program (R-Studio) and I could not find anything that appeared recognisable, I looked at random sectors and everywhere I looked, there appeared to be random information. I am sure it was not random and could have been to do with some sort of drive testing that JVC do. The net effect was that I could not be sure where the operating system started and ended - hence cloning the whole drive.

The HMHDS4 and HMHDS1 drives though uncompatible with each other are basically similar. We (A group of interested parties) are at present trying to unravel the secrets of the OS and filesystem on the drive, (HMHDS1) and work out the best ways of recovering either the original drive 40gig or the JVC replacement model 80gig (formatted to 1/2 way). I am not the expert regarding this breakdown, but it appears that there are 4 sections to this 'random' data... The OS, the Nav data, a movie file , then the prog data area. A clone needs to copy all these areas, so a compressed Ghost (raw) image or similar at around 6GB seems to be the smallest space you can make this instead of imaging in full to another drive. As for the HMHDS4 a straight forward (raw) clone to another 80gig drive is all that should be needed. A backup therefore (compressed 80gig) must need around 12Gb - 3 DVD-Rs - not too bad. AW

[Cippico]

For all those who are interested in this beast:

Myself, AndyWilks (hi Andrew!) and a top boffin in the Netherlands, are all slowly drawing up a technical map of the JVC HM-HDS1. Details on how to clone, backup and other stuff can be found here: www.cippico.com/cippico/technical

Andy

[tabatha]

Excellent work - If only I had this info several years ago! It seems a number of us have trodden a similar path - some totally alone! I sold my HDS1 some time ago and replaced it with the larger and more reliable HDS4. The first thing I did when I got it home was to clone the drive having learnt from the HDS1!

I bought an HDS4 Friday 21st January 2005 as I wanted
an HDD that had DV 25 MBPS output.

The picture and sound are good but about 50 percent of the
time, the recordings on the HDD have audio which occurs
slightly ahead of the video. Things are not lip-synched and look
awful.

This occurs from both off-air and dubbing from S-VHS/VHS

I'd rather keep the machine if possible. Has any one seen this fault?

I've got untill next Friday before I'll ask for a refund.

My HM-HDS1 unit is starting to shut down of it's own accord. Recently trying to copy from HD to VCR it took about 6 attempts - it would start then shut down after 2 to 20 minutes.
I suspect maybe the Hard Drive is starting to fail.
From the messages so far I gather 40GB is the most I can hope for anyway - but can I not just buy an off the shelf 40GB drive and clone the contents ? Some messages seem to suggest I have to but the HDS4's drive and use this (?).

Out of interest, what file system is used on the drives ?

Your help is much appreciated :-)