On Thu, 2005-07-28 at 22:45 -0400, Peter Arremann wrote:

On Thursday 28 July 2005 22:11, Paul wrote:

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On Thu, 2005-07-28 at 08:44 -0500, Bryan J. Smith wrote:

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On Thu, 2005-07-28 at 08:44 -0400, Peter Arremann wrote:

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*sighs* BS level exceeded...

DVD-RAM is the most reliable, long-term optical archiving format.

Well other than the name, it does not have anything in common with DVD because IIRC it's a Magneto Optical drive ... totally different Tech.

Close - its PD, not MO... PD means that the intensity of the laser is varied to change the phase and therefore the way the laser is reflected. Reading and writing is both done with the laster.

OK same tech as the Panasonic PD drives that stored 650MB/side ... of course I'm starting to wonder about my memory now. Either way you can't stick them in a normal DVD drive and read them.

Paul

MO means a laser is heating up the magnetic materical enough so the write head can change the magnetic domains. Once the material cools down again enough, the orientation of the domains can no longer be changed.

Peter. _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos

On Thu, 2005-07-28 at 22:31 -0500, Paul wrote:

OK same tech as the Panasonic PD drives that stored 650MB/side ...

Yes, hence why DVD-RAM support in Linux was almost since day 1.

of course I'm starting to wonder about my memory now. Either way you can't stick them in a normal DVD drive and read them.

Some drives you can, but yes, they are limited to Masushita/Panasonic data drive licenses. A lot of that has to do with the advanced error correction and MO design, things that are _not_ in CD-RW, DVD-RW and DVD +RW. The error rates are much lower in comparison, hence why I still recommend DVD-RAM.

FYI, +R/+RW compatibility wasn't very good until recently, especially on consumer players. Yes, better than -RAM, but -RAM was designed for optical archiving and longevity, and it does it well. People forget that +R/+RW/-RW do _not_ physically look like -ROM/-R at all, so there are compatibility issues as well.

And yes, -R is the ultimately compatible format when written in Disc-At- Once (DaO) mode, which requires byte-by-byte (character) record. And since DVD-R(G) came out, I adopted it as well. But for prior archiving, as well as some archiving since, DVD-RAM gets the call.

I avoid DVD+RW/-RW like I did CD-RW (and CAV/zone-CLV CD-RW, or what I retroactively call CD+RW). The error rates are too high. DVD+R isn't like DVD-R either, so I avoid it, especially with the fact that it wasn't until late 2003 that even Sony/Philips players/licenses weren't always DVD+R compatible.