Quad Density CD-R writers?

GeoffM asks: "It seems strange that no company is making Double Density or Quad Density CD-R writers/readers. Most storage mediums tend to make these leaps. Why haven't CD-Rs? Given that CD-R media prices are dirt cheap a higher density standard would be very popular. With 2.8GB of storage and MPEG4 encoding a person could easily record full length movies/tv/home video on a CD-R that costs less than 50 cents! Are the new blue lasers too expensive? I'm tired of waiting for DVD recordable AND I'm not looking forward to the cost of blank DVD media. What's your take?"

Comments

problem

[StandardDeviant]

OK, say you get a shorter wavelngth laser or something to increase data density. That's great an all, but until other drives (other manufacturers, regular cd-roms, etc) support the new laser/format, the written media is basically only readable by people with that exact drive.

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Re:problem

[rwm311]

Which then leads the question: Is there such a standard in place for this? I have no idea as this is way out of my league, but would be interested to know if any standards groups are working on a specification.

I remember reading something a while back about doing this with DVDs: different color lasers, and different wavelengths. I assume this is the same principle that would be applied to CD media

Re:problem

[StandardDeviant]

well, there is ISO 9660 which defines the regular cdrom file format. I don't know if that specifies down to the physical layer though.

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Re:problem

[nconway]

Okay, let's discount this community - we're not what you might consider 'normal'.

This community, and the community of warez/gamerz/hackerz. It's "free" software, either way :-)

They would probably use it to backup something

If that was the case, few people would need a CD rewriter. I'd say people typically use them to burn music CDs (my family wants me to burn CDs for them all the time, as well as MP3s), portable documents (i.e. burn this presentation, take it in to work -- more reliable and better storage than floppy), or illegal software (even computer illiterates don't like paying for MS products :-)). The number of non-technies who back up anything is quite small, in any case.

I would definately like to get my hands on quad density CDs.

There's a good reason for no quad-density CD-RW's.

[cmowire]

There's a good reason. Each density of CD needs a different laser, or else it won't be able to read the pits on the disk.

The optical storage industry went through the same thought process. They decided that they could make multi-layer disks at the same time. And they came up with DVD's.

Your idea is just about the same as a DVD. In both cases, you need a second laser and a more accurate focusing assembley.

Besides, by the time that such a quad-density or dual-density CD-RW would be developed, DVD-RW, DVD-RAM, or DVD+RW would be on the mass market. I just hope that SOMEBODY blinks and that at least one, hopefully two, will die.

Or maybe the FMD disks will take over. That would be nice, but I've seen similar promises before that haven't actually panned out.

DVD started out as roughly quad-density CD

[Anonymous Coward]

Among its many other improvements, the DVD uses a shorter wavelength laser and more precise beam alignment for greater pit density, but also uses a more efficient error correction scheme to cram that 4.7GB on a single layer of a 4.5" platter.

However, the real reason you never saw 1.2GB or 2.4GB CDs appear in the marketplace is backward-compatibility. Unlike purely computer-oriented storage media (floppy disks, tapes, etc.), the CD-ROM and CD-R came to computers from the consumer electronics market. The market for a few million double-density or quad-density CD-R(W) drives was hugely outnumbered by the 100 million or more consumer devices equipped to read normal CDs.

In other words, nobody cared enough about double-density or quad-density CDs to bother making them. The enormous installed base of CDs virtually assured that they wouldn't be replaced until something compelling came along to require greater storage density. DVD movies were the killer app which got DVDs invented in the first place. And even with that, DVD-ROM still hasn't really taken off as a computer media format. Rewritable DVD drives will finally kill off the CD-RW in a few years.