Talk:CD-R

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Needs to be merged:

A CD recorder is a computer peripheral that writes data to a CD disk. There are two main types -- CD-R and CD-RW. CD-R is CD-Recordable. CD-RW is CD-Rewritable.

CD recorders are also known as CD burners. To record a CD is often called burning a CD.

Contents

[edit] CD-Rs and 'normal' CDs

-How come the normal CDs with things already written on them are all smooth on the "burned surface", when CD-Rs have a sharp mark of where the writing has ended?(Henningklevjer 17:38, 20 April 2006 (UTC))

normal CDs are reflective all over, they just reflect to a slightly different place depending on if a site is pit or non-pit so to the human eye under normal lighting they look even. CD-Rs use a reflective layer into which dark marks are burnt and while the individual marks are still too small to see thier effect on the average color is noticeable. Plugwash 02:03, 9 July 2006 (UTC)

[edit] MiB vs. MB

-I thought the 650MB CD-R stored 650MiB, not 650000000B: 333000sectors * 2048bytes/sector / 1024 / 1024 = 650.390625. see http://www.cdrfaq.org/faq07.html#S7-6.

-Yeah, me too. CD-Rs seem to be measured in MiB (though they say MB as just about nobody uses the term MiB, while DVD-Rs seem to be measured in GB (not GiB).

- Yep. The reason why it says MB on Dan100's CDs is because the MiB terminology has not been adopted anywhere in the industry, thus the "(though MB is printed on CDs as the binary prefixes haven't caught on in the industry)" I added to the article. (odd that you would change it back to MB but not change that).

So, I suppose it would be possible to refer to it as a 650MB CD (though confusing, and we want to eliminate as much of that as possible in an encyclopedia, right?), but the way it was before I edited it "650MB (not MiB)" was flat out wrong. Psxer 08:08, 7 Jan 2005 (UTC)

Wuh? CDs, like any other storage media, are measured in megabytes. As said, these 'MiBs' have "not caught on in the industry", and they certainly haven't outside it, either. Dan100 19:02, Jan 7, 2005 (UTC)

I mean, I kinda see where you're coming from, but the bottom line is that MB is the accepted and universally-used terminology, for all its faults. Dan100 19:22, Jan 7, 2005 (UTC)

Oh and it's madness to use "650.390625", as that rounds to 650. You would no more say "650.390625" rather than "650" than, when asked by a collegue how far you travel in to work each day, you would say "19.74673 km" instead of "20 km". Dan100 19:26, Jan 7, 2005 (UTC)

Please read A Plea For Sanity before complaining about the use of MiB. Metamatic 19:56, 17 May 2006 (UTC)

[edit] burning pits?

it isn't burning pits into the dye; it's changing the color of the dye to make it less reflective, right? - Omegatron 05:30, Jan 15, 2005 (UTC)

The dye isn't reflective... the reflective layer (usually silver or a silver alloy) is. You don't burn pits in a CD-R, you burn dark spots in the dye layer. These dark spots absorb the light from the laser in the CD player's pickup more than the unexposed areas of dye, and so the reflected light and the resulting signal goes down whenever the read laser encounters a burned mark. The effect on the returning laser signal is similar to what happens on a replicated CD... similar, but different.

A replicated CD has a track of pits that are molded into the disc. These pits are molded in clear plastic, and they are coated with a reflective layer of aluminum. Although aluminum has lower reflectivity than silver, there is no dye layer on a replicated CD, so very little laser light is absorbed. When the focused laser spot of the CD player's pickup encounters a pit the light is diffracted, and the reflected light is greatly reduced (and the resulting signal voltage goes down).

So, while CD-Rs have burned marks that absorb the light and CDs have pits that diffract the light, the effect is that recorded CD-Rs emulate replicated CDs, which is what they were designed to do.

Actually, a replicated CD has pits molded into it, but it is read from the underside through the 1.2 mm thick polycarbonate disc, so the laser is actually focused on a track of bumps. But the diffraction is the same. Now, some people will tell you that the optical effect is the phase cancellation of the light being reflected from the bottom of the pit (top of the bump), versus the light that is reflected from the land areas around the pit (since the read laser spot is twice as wide as the pits are), but at these geometries the physics can be understood as pure diffraction. Keep in mind that the pit geometries are a fraction of the laser wavelength. Tvaughan1 21:27, 18 August 2006 (UTC)

[edit] Mene, mene, tekel, upharsin?

Compatibility of CD-R and conventional read-only discs, CD and CD-ROM, is a miraculous achievement which was made possible by the dye materials developed by Taiyo Yuden.

I like Taiyo Yuden, too, but I don't think we should ascribe divine powers to them. Perhaps it was merely a wondrous achievement? Stunning, maybe? Gob-stopping? --68.41.122.213 11:02, 13 December 2005 (UTC)

[edit] Possible plagiarism

http://tech.msn.com/howto/article.aspx?cp-documentid=23697

From the above article: The problem is material degradation. Optical discs commonly used for burning, such as CD-R and CD-RW, have a recording surface consisting of a layer of dye that can be modified by heat to store data. The degradation process can result in the data "shifting" on the surface and thus becoming unreadable to the laser beam. "Many of the cheap burnable CDs available at discount stores have a life span of around two years," Gerecke says. "Some of the better-quality discs offer a longer life span, of a maximum of five years." Distinguishing high-quality burnable CDs from low-quality discs is difficult, he says, because few vendors use life span as a selling point.

From the Wiki page: Burned CD-Rs suffer from material degradation, just like most writeable media. Optical discs commonly used for burning, such CD-R and CD-RW have a recording surface consisting of a layer of dye that can be modified by heat to store data. The degradation process can result in the data "shifting" on the surface and thus becoming unreadable to the laser beam. Many of the cheap burnable CDs available at discount stores have a life span of around two years. Some of the higher quality discs offer a longer life span, of a maximum of five years. Distinguishing high-quality burnable CDs from low-quality discs is difficult, because few vendors use life span as a selling point. 65.118.253.68 18:09, 18 January 2006 (UTC)

Possible? That's outright plagiarism. Plus, that is an opinion. Listen to the most recent This Week In Tech podcast (#39), where they discuss how some CDs from 1988 still work perfectly. --worthawholebean talkcontribs 01:24, 25 January 2006 (UTC)

[edit] Miraculous?!?!?

calling something a miraculous achievement is certainly POV - a miracle is about as pov as you can get. 65.35.93.97 15:09, 20 February 2006 (UTC)

I looked in the thesaurus briefly, but I thought it would be best just to drop the adjective and rewrite the sentence. Rhobite 02:59, 28 February 2006 (UTC)

[edit] CD+R

Does anybody know anything about CD+R? There's no article about it.Rt66lt 01:35, 4 March 2006 (UTC)

It doesn't exist, which is why there is no article about it.
No, actually, it does exist. My DVD player supports it, even DVD+RW, but I don't know anything about it. 66.218.46.140 00:13, 9 July 2006 (UTC)ninetigerr
There's DVD+R but CD+R as far as I know. It might be typo or misunderstanding. Manuals and descriptions on wrappings always contain some mistakes. There's "CD plus" which refers to CDs with a data track and one or more audio tracks. I believe it's the same as "CD extra" but there might be some differences. --82.141.58.211 18:34, 30 July 2006 (UTC)

There is no such thing as CD+R... only CD-R. There is a "CD Plus", which is a multi-session CD with CD-Audio tracks in the first session and a CD-ROM track in the second session. Tvaughan1 21:13, 18 August 2006 (UTC)

[edit] Cleaning CDs

I've used simple liquid disk washing detergent for 10 yrs. Cleans off sticky stuff, oils, and dirt. I always pat dry with a clean soft cloth.

. . . regarding "use a circular motion to remove all the toothpaste"; why circular when the previous instructions were to move in a radial direction ? - Sue 08:40, 14 August 2006 (UTC)

[edit] Putting files onto the cd-r

Just a question..... how do you put files onto a cd-r? I tried and all it said was, it is not compatible, it is not formatted..... How.....

Using a CD-Recorder (a drive in your computer) in combination with a burning program such as Nero Burning Rom??? 62.238.92.181 14:45, 18 April 2006 (UTC)
You can't normally write files to a CD through the filesystem mechanism (the exception is if you use something like directCD or inCD but those tended to be a bit slow and buggy and seem to have fallen out of favour)
In winxp explorer will let you drop files onto a CD but they aren't actually written until you press a burn button and the options are very limited. For more control or to use the burner on an earlier version of windows requires third party software (easy CD creater, nero burning rom etc). Plugwash 15:24, 19 August 2006 (UTC)

[edit] CIRC Link

"They use Eight-to-Fourteen Modulation, CIRC error correction plus the third error correction layer defined for CD-ROM. The first CD-Rs were produced in 1988"

CIRC linked to a disambiguation-page, so I changed the target page to the appropriate one, namely http://en.wikipedia.org/wiki/Cross-Interleaved_Reed-Solomon_Coding. 62.238.92.181 14:51, 18 April 2006 (UTC)

[edit] Well, duh.

Deep scratches on the data side can interfere with the focus of the laser and render a disc unreadable.

[edit] spit and a corner of my T shirt

is the above method of cleaning likely to damage a CD? it certainly seems effective at getting the grime off them. Plugwash 11:59, 22 May 2006 (UTC)

No, it is not likely to damage a CD as long as your t-shirt is clean (no dirt particles that could scratch the disc). Tvaughan1 21:15, 18 August 2006 (UTC)

[edit] 80 minute CD-Rs

non-standard CD-Rs are available with capacities of 79 minutes, 59 seconds and 74 frames (marketed as 80 minuites) /736,966,656 bytes (702 MiB), which they achieve by slightly exceeding the tolerances specified in the Orange Book CD-R/CD-RW standards.

My understanding was that most 80 minute CD-Rs in fact fully complied with the standard. The standard specified large tolerances due to the manufacturing tech at the time but as this improved, it became possible to make 80 minutes CD-Rs which fully complied with the standard but were obviously at the upper end of the tolerances. Perhaps what I've heard is wrong and tolerances and manufacturing tech doesn't actually allow 80 minutes CD-Rs to be produced which fully comply or they're mostly not fully compliant but if there is some truth to this story, e.g. tolerances and tech allow up to 78 minute fully complaint CDRs, we should make it clear this idea clear, that the tolerances were rather loose and better manufacturing tech allowed CD-Rs to be produced which only marginally broke the tolerances... Nil Einne 11:59, 26 May 2006 (UTC)

Nil is correct... 80 minute CD-Rs can be manufactured when all relevant parameters are at the edge of the specification (program start radius, program end radius, track pitch and linear velocity). If the accuracy of the LaserBeam Recorder (LBR) that cuts the glass master is good, pushing a CD-R to the edge of the specification isn't a problem at all. DVDs use a track pitch that is half of CD. The theoretical maximum capacity of a CD-ROM or CD-R is about 79 minutes and 58 seconds, or 702 MB (I hate MiB... please don't subject us to it... a Megabyte is 2^20 bytes). Tvaughan1 22:17, 17 August 2006 (UTC)

[edit] Clean-up

The part of this article containing facts about how to keep them clean doesn't sound right. Try to remove the second person (you).

I have cleaned it up somewhat, removing 1st and 2nd person and some of the randomly sprinkled apostrophes and corrected some spellings. The whole section seems a bit technically dubious to me - is there any real proof that higher speeds are consistently unreliable on all burners, and mulitasking is dangerous no matter how fast the PC? Still, not being an expert in these matters, I will leave it as is. 82.7.104.138

[edit] Lede

The lede ends with this: "The CD-R retains all the abilities of the CD standard but adds the functionality of being able to store either music or data." I have plenty of regular CDs that contain music and data. Isn't the real distinguishing characteristic of CD-Rs that music and data can be recorded onto them? --Rob Kennedy 07:27, 7 July 2006 (UTC)

No, that's nonsense. The physical variant of a CD has nothing to do with what can be stored on it. Pressed CDs containing music and data are/were just rather uncommon. Some audio CD players would try to play the data track which can damage the speakers and it sounds awful anyway. Game CDs often contain audio CD tracks especially older consoles used this. --82.141.58.211 18:39, 30 July 2006 (UTC)
Are you saying that my question is nonsense, or that the sentence I’m asking about is nonsense and should be removed or reworded? --Rob Kennedy 01:41, 6 August 2006 (UTC)

You are both correct, depending on how you read the above statement. CD-R is a physical format. For the most part, the physical format is independent of the application format (CD-Audio, CD-ROM, CD-Interactive, etc.). I think the original author of the above sentence meant for the focus to be on the words "adds the ability to store", rather than on the words "either music or data". Perhaps if we substituted the word "record" for "store" and the word "content" for "either music or data", the phrase would be more accurate. Or perhaps we could simply say something like "The CD-R is designed to behave identically to a standard CD-Audio or CD-ROM which is mass replicated. However, the CD-R can be recorded by anyone with a CD-R recorder and a blank CD-R disc." Tvaughan1 22:28, 17 August 2006 (UTC)

[edit] audio CD-R

Could someone add a section describing 'audio CD-R'? In the UK at least, most consumer audio cd writers are restricted to this type of disc so that a levy can be paid to the music publishers. Many users are confused about this.--137.205.146.206 09:20, 3 August 2006 (UTC) roger thorpe

[edit] max burning limits?

According to a Maxell press release from 2002, burning CDs at or faster than 52X carries with it some risk.

“ Maxell engineers determined that the minimal speed advantage offered by 52X drives is outweighed by the performance and safety issues of operating CD-R media in excess of 10,000 rpm. Research has shown that naturally occurring minute defects or cracks in the CD-R hub area can quickly expand when exposed to the physical stresses of 52X operations. These small, virtually undetectable defects can easily cause discs to break apart at 52X speed, destroying not only critical data stored on the CD-R media, but potentially damaging or destroying the CD drive. ”

If this is correct, maybe it should be incorporated into this article, somehow? Looking at Maxell's webpage, I see that the fastest CD-Rs they produce are still 48X ones... TerraFrost 17:04, 27 November 2006 (UTC)

[edit] taxes

There is nothing in article about any countries taxing CD-R as a way to combat music piracy. Germany, France, Italy, The Netherlands and Spain all have CD-R taxes and Canada is considering it. Jon513 14:10, 30 November 2006 (UTC)

According to [1], Canada has been taxing CD-Rs as early as 2002 TerraFrost 16:21, 30 November 2006 (UTC)

[edit] Optimal storage conditions and expected lifespan

"most markers can bleed-through the CD/DVD and destroy your data"

The article on disk care linked in this section contains related product advertisement ("Maxell Disc Writer Pen"). I am not sure if it would be considered indirect advertising. 124.168.184.54 10:25, 28 January 2007 (UTC)

[edit] Writing Process

I rewrote the paragraph on the writing process. Got rid of the repetition of the the term "burn"; removed phrase calling the dye layer "magnetic". I intentionally left it vague as to whether heating the dye causes a lowering or a raising of the reflectivity. Does anyone know for certain which it is? Spiel496 04:22, 17 February 2007 (UTC)

[edit] Question

Why is that you can only put 80 minutes worth of music on a CD when the full capacity is 700mb? Seems like a waste. —The preceding unsigned comment was added by 70.48.32.149 (talk) 01:12, 8 April 2007 (UTC).

Obviously because 700 MB equate to 80 minutes of CD-quality music. EpiVictor 15:56, 8 April 2007 (UTC)
oh rly? —The preceding unsigned comment was added by 67.70.109.90 (talk) 09:34, 11 April 2007 (UTC).
Ya rly. CD-audio is measured as time, not filesize. CDs can fit 80 minutes OR 700MB. To burn a collection of MP3s to a CD you can play in a CD player requires software that converts MP3 audio into CDA audio format - thereby limiting you to only 80 minutes.
Of course, if you were to burn an MP3-CD (which can be played on PCs as well as newer in-car CD players) then you're limited by file-size, meaning you can fit hundreds of tracks onto one CD. Thepineapplehead 10:58, 25 May 2007 (UTC)

[edit] When did CD-Rs become generally available?

In all the incredible techy detail here, everyone's rather overlooked the retail history of the CD-R format. All I can tell from this article is that the spec was published in 1988. Please someone expand the History section before adding even more geeky stuff. (And I say that as someone really interested in the geeky stuff!) 86.143.52.241 02:27, 3 June 2007 (UTC)

I personally remember recordable CDs of some form (though perhaps not 100% "Orange Book" compliant implementations)to be available to the general public since 1991, at least. The downside was that the recorders were usually external, bulky units with parallel or SCSI or custom interfaces, and their usability was nowhere near close to that offered by modern CD-burning tools: they were meant mostly for traditional data backup, and even the file systems or pit/land encoding methods could differ greatly between manufacturers, rendering these "CD-R" largely incompatible with each other. The mainstream and affordable CD-R with ISO-standard file systems and without weird recording quirks became widely available only after 1994 or so. EpiVictor 21:00, 31 August 2007 (UTC)

[edit] Record Companies receives money from illegally-burned Music CD-Rs

I'd like to add this information to the article, but I'm not sure how to do it. I will leave it up to someone more experienced than I. The following comes from Janis Ian, a former singer from the era of the 60s and 70s:

"Several years ago the music industry reached an agreement with CD manufacturers to receive a royalty on blank, recordable CDs to compensate for the effects of copying music. The recording industry is receiving a royalty for the "Audio" CD so that it can be used for copying music, taking that money, and then turning around and complaining that the CD is being used to make "unauthorized" copies. Now what is up with that? - http://www.janisian.com/article-internet_debacle.html and http://www.janisian.com/articles-perfsong/Fallout%20-%20rev%2011-23-05.pdf - Theaveng 17:44, 31 August 2007 (UTC)

This is the old story of the CD Audio "for consumer" disks. Read the CDR FAQ for more info on that. Considering how this was as stopgap measure that only seriously affects stand-alone audio CD recorders (not computer CD burners), it's hardly a case of the industry making much money out of illegally copied music. Quite the opposite, a standalone CD Audio recorder is actually the less likely tool for a true music pirate to operate. Surely those "CD Audio" recordables aren't the first choice for music pirates either, due to cost. Pirates just buy the cheapest general purpose CD-R and are perfectly happy with those, the royalty system is hardly paying itself. EpiVictor 21:01, 31 August 2007 (UTC)

[edit] Burn Speed Meme?

"Burn speed can also affect the compatibility due to poorer pit definition on disks burnt at high speed, selecting the slowest supported speed for the burner/media combination is strongly recommended when burning audio CDs, to maximize compatibility."

Is this accurate? Does burn speed really affect readability of the data on CD-R's? Or does it affect audio only? --LKRaider 18:31, 3 September 2007 (UTC)

Audio on a CDR is data--there's no difference in pits or burns. I have seen no scientific evidence but the way I heard is that there's a limit to how much more definition you can get by slowing down your burn speed. Different burners respond differently to burn speed; choosing a middlin' speed is where a bunch of them should be set. Like 16x or 8x, not 2x or 1x. There's got to be a list of study results out there somewhere... Binksternet 20:03, 3 September 2007 (UTC)

I think this is a popular half-truth being propagated due to the fact that a lot of CD-R users are casual pirates and as a result they tend to be cheap and buy low-quality hardware and/or low-quality media to make copies. When you have a cheap burner, it's not surprising that it may make marginal copies that, even fresh, are on the verge of degradation and the media isn't given a reasonable chance to maintain it. Cheap media on the other hand is probably halfway rotted before you even make the burn, so it's only a short matter of time before it degrades completely. And if you're using cheap stuff on both fronts, then I wouldn't expect copies to work well or last long at all. This is not to say, however, that such superstition needs to be taken into account for every burner and every brand of media. If you have a good quality burner and use decent media (the 40 cents per disc range is fine, no need for fancy stuff unless you are using it for commercial production) you will rarely see this kind of problem. On the other hand, if you have a no-name burner and/or use the super cheap unbranded 20-cent discs I would most certainly take some precautions to ensure a working copy with a reasonable shelf life. I have yet to read an actual report that statistically studies the longevity of CD-Rs produced under different burn conditions and using different hardware/media, but I suspect that it is the quality of the hardware/media that is at issue, rather than the speed of the technology. Basically, whenever there is a large differential in price for items that claim the same performance, people need to stop assuming that everything is going to work the same way. Nobody makes this assumption for a car, why do they do it for computer parts...? Ham Pastrami 08:07, 1 November 2007 (UTC)

Actually, while the data levels are "digital", the timing can be considered analogue. The higher the speed, the larger the jitter. Some CD players can reclock the signal, some apparently don't. Without a fully reclocked data sream, jitter may get through to the DAC and beyond, where it will be audible. This was a quality issue in Audio CD production when the mastering machines in the factories were sped to 2x speed. It was a Pink Floyd CD where an unexpected drop in quality was first found, and it was finally tracked down to the speed increase at the manufacturing of the master discs. The problem was addressed by Sony, and, as an employee of a CD fab told me, solved by improving the mastering machines to yield perfect results at the higher speeds. --80.134.6.41 (talk) 09:58, 1 June 2008 (UTC)

[edit] Bogus speed table?

The numbers in the column "Write time for 80 minute/700 MB CD-R" appear to be simply 80 minutes divided by the speed. Is there evidence to support these numbers? It is my understanding that above about 16x the discs are spun at constant angular velocity, and that the read/write speeds then refer to the speed at the outer radii. In other words, 52x is achieved only at the outer edge of the disc; the inner radii will be written at the same RPM, which works out to about 20x. So you're not going to be able to write a whole disc in 80/52 minutes. Does anyone know for sure? Spiel496 (talk) 18:10, 14 January 2008 (UTC)

You are right, all CD-R wriers I know use Zone-LV beginning at 24x speed. So it's not possible to write 700MB in 1.5 minutes. The time span at which 24x speed recording takes place is much larger than the time span of 52x speed recording. --80.134.6.41 (talk) 09:48, 1 June 2008 (UTC)

[edit] CD Life!

Guys I saw a French news in Sydney, FRANCE 20HR of 03/03/2008 saying that CD only last as much as 10 years! The research was conducted and they concluded from the word of the researcher of Jacques Perdereau that it can only last as much as 5 (30% to 50% damage)!!!

Results seen: FRANCE 20HR of 03/03/2008

I cannot fully understand the research organization... But it is true!

I mean, it is quite shocking... Can we actually upload videos!?

Anyone target other proof will be helpful. —Preceding unsigned comment added by Derwin (talk • contribs) 10:27, 4 March 2008 (UTC)