[l008com]

OK I ordered a superdrive today and it burns both +R and -R. Which is good. Then I had my friend try and explain it to me, and it makes NO sense to me at all. He was saying that one is more compatible than the other. That makes no sense to me, we're talking about a digital media, it should either be exactly compatible, or not. I totally don't understand, but if someone else does, could ya explain it to me please?

[Eug Wanker]

Originally posted by l008com:
OK I ordered a superdrive today and it burns both +R and -R. Which is good. Then I had my friend try and explain it to me, and it makes NO sense to me at all. He was saying that one is more compatible than the other. That makes no sense to me, we're talking about a digital media, it should either be exactly compatible, or not. I totally don't understand, but if someone else does, could ya explain it to me please?

Check my sig.

[l008com]

OK read it. But what is the difference? Aren't all DVD's the same format DDV-UDF or something? I don't understand what the difference in the media is? I read your report, but all it says is + is one format and - is another. (And i know about DVDRAM but i don't care about that). I'm still confused here. :-(

[Eug Wanker]

Certain drives read certain media types better than others, even if they use the same disk/file formats.

+R and -R are close in compatibility, and both are more compatible than -RW and +RW.

[l008com]

So how come no one makes a 'format' that is simply identical to the dvd video discs you buy at the store? Then they would be 100% compatible. Then more people would wanna buy them?

[Eug Wanker]

Originally posted by l008com:
So how come no one makes a 'format' that is simply identical to the dvd video discs you buy at the store? Then they would be 100% compatible. Then more people would wanna buy them?

Because then you'd have to buy millions of dollars of equipment to press DVD video discs. Those discs are physically quite different from DVD-R.

Commercial DVD video discs are simply stamped from a master, not "burned".

[l008com]

But we're still just talking about digital data right? Just one long string of bits?

[tooki]

It's not data at all unless it's been read off the disc.

The compatibility problems are at the physical level: can the drive mechanism extract the bits and bytes from the round piece of plastic or not?

Here's an analogy: you know how some people are color blind? Well, most people can distinguish red and green readily. Color blind people generally can't distinguish those colors (they become different shades of the same color to them). Now imagine that the burned DVD has the bits encoded as red and green areas. Most drives see normally and so have no trouble, but some models are color blind, so they can't distinguish red and green, and thus can't read the burned discs. (Meanwhile, in this analogy, a pressed DVD encodes bits as black and white, and so all the readers are designed to distinguish this.)

Compatibility with the data on the disc, once extracted, is another matter.

You are intermingling two separate issues: the physical format, and the logical formatting (or filesystem) on the disc. The former is the difference between +R and -R. The latter would be the difference between, for example, a disc (be it CD or any type of DVD) burned as ISO9660, HFS+, or UDF.

Note that DVD-R is the format actually approved by the DVD Forum (the industry group responsible for the DVD format). As such, it has slightly better compatibility with DVD readers than the DVD+R format, which is basically a renegade format formed by some companies who thought the DVD Forum was dragging its heels on a burnable format.

tooki