Talk:Compact disc

Logos section

Please leave the Logos section alone while I work to get the images restored that were deleted by overeager wikicops. Thank you. --John Navas 21:06, 3 September 2007 (UTC)

Please tell us why you think this section should be here in the first place. Most of these logos are practically identical except for their text; the section is badly formatted and results in an over-wide page; and in general, I don't see what useful information it adds to the article. +ILike2BeAnonymous 21:15, 3 September 2007 (UTC)

The reason for this section is that these are the official logos for the various compact disc formats, clearly the kind of reference that belongs in a comprehensive encyclopedia. I'm restoring them. Per your comment, I'm narrowing it by one column. If you have any other formatting suggestions, please let me know. In the future, please have the courtesy to message me before taking action. Thank you. --John Navas 18:07, 18 September 2007 (UTC)

They are still a gallery of fair-use images, and as such are not allowed. Plus they all look pretty much the same. So I'm sorry, but they have to go. — Edokter • Talk • 19:19, 18 September 2007 (UTC)

This is not an image "gallery" -- it's a reference collection of the authoritative logos for the various different compact disc formats. That these logos all look similar is hardly surprising, but they nonetheless are quite distinct, and each one serves a specific purpose. Are you actually familiar with compact disc standards, or are you simply rushing to judgment? Why have you summarily deleted the section again without meaningful discussion? I've restored the section again pending a full justification of your rationale. --John Navas 02:40, 19 September 2007 (UTC)

Jnavas, please start a new page of official CD logos if you want them shown somewhere. I don't think they are appropriate within the body of this article. They take up too much space relative to their importance. Make a new page and link to it from this article. Binksternet 03:40, 19 September 2007 (UTC)

How would that not then be just a "gallery" of images that would be rapidly deleted? In the Compact disc page they are clearly related to and support the other content. --John Navas 17:00, 19 September 2007 (UTC)

Likewise. The logos serve no usefull purpose. Plus they are all fair use, and use of such images should be limited to a minimum anyway. No doubt the "overeager wikicops" had every reason to delete them. — Edokter • Talk • 21:36, 3 September 2007 (UTC)

---

Here are the provisions of Wikipedia:Non-free content criteria that I believe these logos violate, which is why I'm removing them, again (numbers are item numbers from that policy page):

Please be good enough to leave the section alone until discussion has run its course -- there's no good reason to keep deleting the section before discussion has run its course. --John Navas 09:25, 20 September 2007 (UTC)

• 3. (a) Minimal number of uses. As few non-free content uses as possible are included in each article and in Wikipedia as a whole. Multiple items are not used if one will suffice; one is used only if necessary.

Comment: It can be argued that one or a few of these logos would suffice, and that including all of them is not only unnecessary but overkill.

These logos are not redundant -- they identify different Compact Disc formats. Including only a few of these logos would be (a) not encyclopedic and (b) confusing and misleading. --John Navas 09:25, 20 September 2007 (UTC)

• 8. Significance. Non-free content is used only if its presence would significantly increase readers' understanding of the topic, and its omission would be detrimental to that understanding. Non-free media files are not used if they can be replaced by text that serves a similar function.

Comment: It's hard to see how an argument could successfully be made that these logos "significantly increase readers' understanding of the topic, and [their] omission would be detrimental to that understanding". So I think it blatantly violate this provision.

I respectfully disagree: The different Compact Disc formats identified by these logos are largely incompatible with each other. (For example, try playing a Video CD in an audio CD player.) It would be good to expand this article and companion articles to further identify and explain these formats. --John Navas 09:25, 20 September 2007 (UTC)

• 10. Image description page. The image or media description page contains the following:
  • (a) Attribution of the source of the material, and of the copyright holder if different from the source. See: Wikipedia:Citing_sources#Images.
  • (b) A copyright tag that indicates which Wikipedia policy provision is claimed to permit the use. For a list of image copyright tags see Wikipedia:Image copyright tags/Non-free content.
  • (c) The name of each article in which fair use is claimed for the item, and a separate fair use rationale for each use of the item, as explained at Wikipedia:Non-free use rationale guideline. The rationale is presented in clear, plain language, and is relevant to each use.

Comment: I don't see this in the description of these images.

Please look more carefully. These things are there. If you think they need improvement, then please be specific. --John Navas 09:25, 20 September 2007 (UTC)

Therefore I'm removing them until the one editor who's all intent on including them can explain this. +ILike2BeAnonymous 01:26, 20 September 2007 (UTC)

Since no rationale has been given for immediate deletion, I'm restoring it (again) until discussion has run its course (at least). Unless and until you provide a rationale for immediate deletion, please be good enough to leave it alone until then. Thank you. --John Navas 09:25, 20 September 2007 (UTC)

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The repeated deletion of the Logos section is needlessly hasty, inappropriate, and inconsistent with WP:DR.

Please have the courtesy to first engage in discussion and to follow the WP:DR.

Since a Logos section seems to be so inflammatory to a few, I'm revising it into a Logical Formats section, in which the audio CD material will become a subsection. Each format will of course be identified by its appropriate logo.

--John Navas 16:37, 20 September 2007 (UTC)

Name shouldn't be capitalized

One editor (ProhibitOnions) has taken it upon themselves, apparently, to lord over this article, and in particular to insist on moving it to its present name (Compact Disc). I challenge this; there is nothing currently cited in the article, so far as I can tell, that shows that this name is a registered trademark, and that this is the correct name for the thing. (If I'm wrong, please point it out.) The name should be "compact disc". +ILike2BeAnonymous 18:26, 15 September 2007 (UTC)

Let's keep the tone neutral, shall we? Chicage manual of style online says don't capitalize. Lower case "compact disc" or upper case "CD" but not both. Binksternet 18:53, 15 September 2007 (UTC)

That's true, but the whole thing really hinges on whether "Compact Disc" is a registered trademark and, as such, must be written that way (like the way the real-estate industry has hijacked the word "Realtor"™ so that it is now always capitalized when you see it in newspapers, etc.). Otherwise, yes, the standard capitalization rules apply as you described. +ILike2BeAnonymous 23:09, 15 September 2007 (UTC)

Here is the "compelling case" from the United States Patent and Trademark Office
608.01(v) Trademarks and Names Used in Trade (R-2) - 600 Parts, Form, and Content of Application:

Although the use of trademarks having definite meanings is permissible in patent applications, the proprietary nature of the marks should be respected. Trademarks should be identified by capitalizing each letter of the mark (in the case of word or letter marks) or otherwise indicating the description of the mark (in the case of marks in the form of a symbol or device or other nontextual form). Every effort should be made to prevent their use in any manner which might adversely affect their validity as trademarks. [emphasis added]

--John Navas 03:10, 20 September 2007 (UTC)

Not again!

Please check the move log for this page, you will be horrified how often this debate has been held. Compact Disc is a trademarked name (no cite is needed for this patently obvious fact) and as such should be regarded as a product name, thus be capitalised. So let's leave it as it is, because I'm growing tired having to resolve all double redirects yet again! — Edokter • Talk • 23:17, 15 September 2007 (UTC)

What do you mean, "no cite is needed for this patently obvious fact"? It sure the hell is. Until such cite is forthcoming (and nobody has shown me that I missed it in the article), I challenge this and the capitalization of the term. If it is "patently obvious", as you say, then it should be a piece of cake for someone to dig up a reference, no? +ILike2BeAnonymous 23:25, 15 September 2007 (UTC)

I looked throughout Philips' website (especially the section regarding trademarks and intellectual property) and they don't use anything but "CD" or "COMPACT DISC" to denote a compact disc. They sidestep the question by capitalizing every letter. Binksternet 23:51, 15 September 2007 (UTC)

I say that, unless someone can show a compelling reason why the name must be written "Compact Disc" throughout, we change it to use the conventional spelling (uncapitalized unless at the beginning of a sentence). So far, nobody has made such a compelling case. +ILike2BeAnonymous 23:55, 15 September 2007 (UTC)

Here is the "compelling case" from the United States Patent and Trademark Office
608.01(v) Trademarks and Names Used in Trade (R-2) - 600 Parts, Form, and Content of Application:

Although the use of trademarks having definite meanings is permissible in patent applications, the proprietary nature of the marks should be respected. Trademarks should be identified by capitalizing each letter of the mark (in the case of word or letter marks) or otherwise indicating the description of the mark (in the case of marks in the form of a symbol or device or other nontextual form). Every effort should be made to prevent their use in any manner which might adversely affect their validity as trademarks. [emphasis added]

--John Navas 03:08, 20 September 2007 (UTC)

It's hard to say just what that means without knowing the context. Does this refer simply to an application for a patent, or to usage of a trademarked name in general? And who is being addressed here, the patentee, or anyone who uses the trademarked term in writing? Need more information. +ILike2BeAnonymous 05:03, 20 September 2007 (UTC)

I respectfully suggest you follow the link to learn the context. --John Navas 08:49, 20 September 2007 (UTC)

Wikipedia:Manual of Style (trademarks):

General rules

• Capitalize trademarks, as with proper names.

--John Navas 08:49, 20 September 2007 (UTC)

Is "Compact Disc" really a trademark?

Has the capitalization of the title of this article this been resolved? All that the discussion above seems to indicate is that if the phrase "Compact Disc" is a trademark, then it should be capitalized, which seems fair. As far as I can tell, though, no one has actually provided evidence that "Compact Disc" is indeed a trademark. I certainly didn't think it was, and out of the six dictionaries I just checked (Merriam–Webster's Eleventh Collegiate, Chambers, Webster's Third New International, Random House Unabridged, Oxford English Dictionary, and Oxford American Dictionary) only the Random House labels "Compact Disc" a trademark—though it also has "compact disk" as a separate entry, with no trademark indication. Of course, dictionaries aren't the authority on trademark issues, but I can't believe that "compact disc" is actually a trademark. If it's a trademark, then what's the generic name for these round shiny discs? —Bkell (talk) 07:37, 12 March 2008 (UTC)

Dictionaries aren't conclusive at all. A search by the US Patent and Trademark office should be though. [1]

"COMPACT DISC" is a trademark, "Serial Number 73281719" filed in "October 14, 1980" owned by "N.V. PHILIPS' GLOEILAMPENFABRIEKEN CORPORATION". However, it was officially "ABANDONED" on "August 31, 1983" and is now "DEAD". [2] I hope this will settle the issue. Rcooley (talk) 19:40, 12 March 2008 (UTC)

Okay, so does that mean it's no longer a trademark—it's been genericized? —Bkell (talk) 20:40, 12 March 2008 (UTC)

I don't believe it entirely fits the definition of genericized. But in any case it is no longer a trademark, and has been in the public domain for 25 years. Rcooley (talk) 23:54, 12 March 2008 (UTC)

All right. If I don't hear any objections, I'll move this article to Compact disc (no capitalization) in about a week and a half. —Bkell (talk) 00:33, 13 March 2008 (UTC)

Article has been moved. —Bkell (talk) 19:34, 23 March 2008 (UTC)

And reverted. The terms is clearly a trademark, even if it is often used generically. Even though it is ubiquitous, it is a proprietary standard, with a trademark and logo use governed by compliance to the Red Book. ProhibitOnions ^(T) 09:27, 27 March 2008 (UTC)

The link to the USPTO I posted clearly says the term is officially NOT a trademark in the US. The onus is on you to prove that it IS a trademark (somewhere). The fact that there is a trademarked logo that CONTAINS the term does not then make the term a trademark (see Winamp/Win-Amp). I'll wait a couple days, but if you can't provide some solid evidence, I'm going to move it back (that is, if Bkell or someone else doesn't beat me to it). Rcooley (talk) 09:52, 27 March 2008 (UTC)

No, it indicates that a patent has expired. This has been discussed many times. All the named audio formats are capitalized on Wikipedia, regardless of patent status or generic use (Compact Cassette, for one). ProhibitOnions ^(T) 10:40, 27 March 2008 (UTC)

That link has NOTHING to do with any patents. "trademark" appears four (4) times on that page, while "patent" never does (0). Every single bit of information there indicates a trademark, not a patent. The fact that other articles may be using improper capitalization isn't exactly compelling. The question of it being a name is an interesting possibility, but the fact that most dictionaries do not capitalize it suggests otherwise. You're also welcome to point out WHERE this issue has been discussed before, I don't accept assertions or blind appeals to authority. Rcooley (talk) 19:31, 27 March 2008 (UTC)

Let's try looking at common usage. Can anyone find one use of "Compact Disc" instead of "compact disc" in english-language news media? Here's a link to a New York Times article[3] that uses the uncapitalized form, which I cite in an appeal to the ridiculous attention to detail of the copy-editors at the New York Times. —Preceding unsigned comment added by 207.172.135.54 (talk) 22:22, 4 June 2008 (UTC)

Compact Disc is not synonymous with audio CD!

This article suffers from the fundamental flaw of confusing Compact Disc in general with Red Book audio CD in particular (with a minor nod to Yellow Book CD-ROM), and needs to be substantially revised, rewritten, and expanded to include the other Compact Disc formats.

Compact Disc is both:

• Physical specifications (types of optical disc, including pressed, recordable CD-R, and rewritable CD-RW)
• Logical specifications (data recording formats, including a multitude of largely incompatible formats defined in "Rainbow Books", not just Red Book audio CD -- for example, Video CD (White Book) is just as much a Compact Disc as Audio CD (Red Book))

The logos that apply to these different formats should be included with these formats for informational and identification purposes. (The minor but heated controversy over these logos reflects the same fundamental confusion as the Compact Disc article itself.)

Each Compact Disc format should have the bulk of its material on a separate page, as per the Rainbow Books page and pages, with a summary and link on the Compact Disc page. Thus the bulk of audio CD material should be on the Red Book audio CD page, not on the general Compact Disc page.

I intend to edit the article accordingly, probably by adding a new Logical Formats section, with subsections for all the different Compact Disc formats (including the appropriate logo in each case).

--John Navas 16:20, 20 September 2007 (UTC)

Your comments here, especially your declarations ("I intend to edit the article accordingly", etc.) raise another serious issue: the appearance that you somehow own this article. +ILike2BeAnonymous 17:21, 20 September 2007 (UTC)

I could say the same about you (for your immediate deletions without prior discussion, the pot calling the kettle black), but ad hominen has no place here. Do you have a substantive comment, any real disagreement with I've written, or are you just attacking me personally? --John Navas 17:29, 20 September 2007 (UTC)

I have a comment to make. We still have a bunch of free-floating images which do not correspond to anything the article discusses. Which not only represents an infraction of the use of non-free content, but also represents a partial revert on your part. As you've gone over 3RR on this issue already, and have been alerted to that fact, would you like to correct yourself and remove the gallery? --Mark H Wilkinson ^{(t, c)} 17:44, 20 September 2007 (UTC)

"We" actually don't "have a bunch of free-floating images which do not correspond to anything the article discusses" and there is no revert (the pot trying to call the kettle black, and I don't take kindly to such threats). What we actually have, what I am doing, is a substantial ongoing revision to the document to (a) remove its bias toward audio CD and (b) make it much more complete and authoritative, as is clearly evident from the changes I've already made. The remaining array of logos is a placeholder for other subsections as the work progresses. The need for keeping the remaining array on the page is to avoid having them summarily deleted by other wikicops while the revision work is in progress. If you've actually got any real knowledge of the subject material and are really interested in improving Wikipedia, then I suggest you roll up your sleeves and help. Otherwise please have the courtesy to take a break from your axe (as per WP:DR) while I do the heavy lifting alone. Thanks. --John Navas 18:02, 20 September 2007 (UTC)

Non-free content is not for the purpose of creating placeholders. Nor can you justify their use in an article purely so that they don't get deleted. If they get deleted before content for which they can be used is created, that is no tragedy; once the content is there, then they can be uploaded again. It's that simple.

Horse before cart — not the other way around. --Mark H Wilkinson ^{(t, c)} 18:12, 20 September 2007 (UTC)

I respectfully disagree. These logos clearly do apply to the article, and they don't violate WP:NFCC even without my expansion, as I've explained in detail above. If you disagree, please have the courtesy to substantively discuss it in advance, and to follow WP:DR, instead of rushing to judgment. Thanks. --John Navas 18:51, 20 September 2007 (UTC)

(Deindent) John, you still seem to be under the impression that WP:NFCC is optional. You have been told by several editors that the images under 'Other formats' fails NFCC. This is not negociable. The only problem we have is the images. Otherwise, I think you actually have a good point about Compact Disc not being an Audio CD, actually I agree with you on that. You are the only one that wants the images included, therefor you must build the consensus to include them. But as we have pointed out several times now, consensus is that it voilates policy. Therefor the images that do not relate to any article content must go. — Edokter • Talk • 19:32, 20 September 2007 (UTC)

My responses:

1. Please do not put words in my mouth. I've never even suggested, much less said, that WP:NFCC is "optional". What I have done is to explain in detail why it's not being violated. There still has been no rebuttal to my detailed responses.
2. I do not agree that there is any consensus. What's happened is that actions were taken by a very few without discussion or warning, which are now trying to be justified after the fact, still with almost no substantive discussion.
3. Comments by the very few people objecting to the logos have made it clear that they don't understand the technical purposes of the different logos (and still haven't had the courtesy to acknowledge that).
4. Your disagreement with me is a dispute, not certainty, yet WP:DR is still being ignored.
5. I've been consistently polite, and worked hard to find a reasonable outcome, yet have consistently gotten comments that have been overbearing, disparaging, belittling, and unhelpful.
6. This is a huge waste of our time. Wikipedia would be much better served by creating appropriate content, instead of cavalierly making life harder for those trying to create such content. Why not at least offer constructive suggestions in advance, if not contribute to the article yourself (now there's a thought), instead of just tearing down?

--John Navas 20:44, 20 September 2007 (UTC)

1. Inclusion of the images failes several points of NFCC, which are non-negociable. You simply refuse to recognize those infractions, hence the impression.
2. When there are 'few' editors constantly reverting a single editor, that should be a hint that consensus is against you. And there was plenty of substansive discussion, but you keep ignoring our arguments.
3. Irrelevant. Understanding the technical purpose for the images has nothing to do with with weather the logos are allowed on the page.
4. This discussion is part of dispute resolution. There are other ways too, but they are way less pleasant and only to be used as a last resort.
5. So have we. Please realise that we are trying to work with you here. Someone could have reported you to WP:3RR, probably resulting in a block, but we didn't. We recogzine that the main problem is your interpretation of the NFCC policy, which, among all other policies, is what we all have to work with.
6. We have given you suggestions: write the content first, then add the images so they have context. We can't read your mind however; otherwise I'd be glad to help.

I appriciate your enthousiasm, but your knowledge of copyright policy needs work, because that is what's causing the wasting of time here. I think you could defenitely use some coaching at Wikipedia:Editor review. — Edokter • Talk • 22:00, 20 September 2007 (UTC)

We'll just have to respectfully agree to disagree on that. (And please stop the ad hominem.) --John Navas 17:55, 23 September 2007 (UTC)

Thumb attributes on logos

Why were the thumb attributes removed from the logos, which thus wiped out the borders and captions? What is the authority? Thanks. --John Navas 20:53, 20 September 2007 (UTC)

Just though they looked less cluttered; they captions are still in the hints. And like any other editor, I don't have 'authority'. Anyone can edit. — Edokter • Talk • 20:57, 20 September 2007 (UTC)

I didn't think so, but wanted to be sure, and give you the courtesy of a chance to make your feelings known in advance before undoing the change (even though you haven't shown me that same courtesy).

I prefer them with borders and captions, like the other images on that page, as I created them.

Are you just trying to annoy me? Can't you think of some more constructive contribution to make?

--John Navas 21:42, 20 September 2007 (UTC)

Please stop thinking that everyone is out to get you. Like I said, anyone can edit. Anyone can change the article, and they don't need approval upfront, especially not on uncontroversial edits like cosmetic changes. — Edokter • Talk • 22:04, 20 September 2007 (UTC)

I haven't said, much less thought, "everyone" is out to get me. I'm familiar with freedom to edit. Please stop putting words in my mouth ad hominem. --John Navas 00:53, 21 September 2007 (UTC)

500Gig CD?

I recently read an article now too long ago that a group of scientists put together an HDDVD with 500Gigs of memory. It was supposedly done so by using the entire disk itself, instead of just the surface. For each layer of the disk, they were able to put another 2D section of data, although no player was ever invented to read that kind of disk. At the end of the article it stated that they were aiming for one TB and to invent a player that could read it holographically instead of just the regular "laser-reflecting-off-2D-surface" way. I can't find it, although I remember it was on www.Neoseeker.com, a computer hardware store.

DOes anyone know anything about this? —Preceding unsigned comment added by 68.196.141.53 (talk) 21:31, 18 October 2007 (UTC)

I figure I should contribute something else here besides a short rant, so here goes. The two big potential industry players right now seem to be HVD and Tapestry Media. However, Constellation 3D also provided a format referenced as FMD, which transferred to D Data Inc when the former company went bust because of a scandal regarding alleged demonstration rigging. If I'm reading the article correctly, D Data intends to re-release whatever they can salvage from that last effort as DMD. --Orethrius 16:04, 10 November 2007 (UTC)

The logos need to go

This has been brought up may times, and I have laid low for a while, but regardless of policy, all the CD logos are still here, breaking WP:NFCC. And no thanks to Jnavas' aggressive campaign, we now have an article cluttered beyond recognition with images and table code, making it hard to edit. The tables and logos need to go. — Edokter • Talk • 16:15, 1 November 2007 (UTC)

I agree. Please feel free to go ahead and remove them; I'll back you up there. +ILike2BeAnonymous 17:16, 1 November 2007 (UTC)

I disagree, and object to any precipitous action. I've invested a great deal of time and effort in responding to all substantive objections, and ensuring compliance with Wikipedia Guidelines (including WP:NFCC). No rationale for the objection has been provided other than another vague reference to WP:NFCC, which I've already rebutted in detail, but to which I've nonetheless responded with a substantial good faith effort. My editing efforts have substantially expanded and improved the article, which is no harder to edit than anything else on Wikipedia, and the logos are unquestionably relevant to and necessary for a full understanding of the content. --John Navas 20:12, 1 November 2007 (UTC)

Holy Christ, this is how I get to see Wikipedia after a loooooong hiatus? So, funny story, I walk into the Compact Disc article - where, incidentally, nobody can agree on the capitalisation - and find out other editors are no longer welcome there because somebody decided he'd throw WP:OWN out the bloody window! For the love of God, please John - get some distance from this article, and a little perspective can't hurt either - the notion that you're being persecuted for your valiant contributions gets beyond the point of ridicule after a while. Really, I know I'm stepping into the middle of a huge firestorm here, but I think how you reply to this comment will make your intent known. Speak carefully. Orethrius 15:38, 10 November 2007 (UTC)

This Talk page is for the Compact Disc Article. Personal comments should only be made on User Talk pages. (I've accordingly deleted the personal comment from my prior response above.) Do you have anything substantive and relevant to add to this issue on the Compact Disc Article? If so, I'll be happy to respond further. For my response to your personal comments, see my Talk page. --John Navas (talk) 20:04, 19 December 2007 (UTC)

On the contrary, WP:OWN is not a strictly personal issue - it has ramifications that affect the entire project. If you cannot deal with me commenting on the outright lunacy that has taken place on this article - and I'm not saying that you're the only "offender" here - then perhaps your efforts would better be invested elsewhere. Orethrius (talk) 15:36, 21 December 2007 (UTC)

I have requested input from other admins here. — Edokter • Talk • 21:37, 19 December 2007 (UTC)

Monaural/monophonic

Hi, don't monaural CDs also exist? I mean mono, not stereo. I distinctly remember reading about it in my university library. (FYI it was a Korean book that dealt with everything about CDs from the physical transport to the CRC checksum algorithms.) --Kjoonlee 17:23, 18 December 2007 (UTC)

Here's one link from 1992, where such a disc is mentioned: RECORDINGS VIEW; Playing Variations On Shostakovich --Kjoonlee 17:27, 18 December 2007 (UTC)

If you have a mono recording, you could double the playing time of a CD by recording half the sound on the left track and half on the right. The sound would be recorded as two monaural files, and then merged into a single stereo file with a sound editor like Cool Edit.Izab1 (talk) 09:40, 26 December 2007 (UTC)

This has more to do with pressing rather than burning. --Kjoonlee 14:53, 30 December 2007 (UTC)

I dont think so, why do you think so? Izab1 (talk) 19:00, 30 December 2007 (UTC)

Let's think about a gapless monaural album with track lenths of 1 minute, 3 minutes, 5 minutes, 7 minutes, with total playtime going up to above 90 minutes. How would you burn that onto a single stereo disc while preserving track lengths? --Kjoonlee 23:48, 30 December 2007 (UTC)

Will you please stop adding a fact tag? The Red Book states that stereo is the default mode. We can't link'to the Red Book becuase it isn't online and costs $5000. However, everyone knows it is de defacto standard, so that really does not need a ref. — Edokter • Talk • 01:31, 31 December 2007 (UTC)

No, but we can cite it. Is there a <ref> tag somewhere on the page we can reuse? {{fact}} tags don't mean we need to link to the material but that we should cite where the fact comes from. Padillah (talk) 15:54, 31 December 2007 (UTC)

No CD player will play a monaural CD without the user turning the balance knob fully left for half the program and then fully right for the other half. The Red Book standard only allows two or four channels; not one. Almost all implementations of monaural audio on CD are offered as two identical audio streams laid down on both the left and right channels and played back simultaneously. Binksternet (talk) 01:28, 31 December 2007 (UTC)

OK, then my memory was incorrect, sorry. But my point about the citation still stands; you could mention the page where it's mentioned, right? --Kjoonlee 13:45, 31 December 2007 (UTC)

I have added a barebones description of monaural sound on CD to the article. Is that what you were looking for? Or did you want a mention of mono on Left then different mono material on Right? Binksternet (talk) 02:33, 1 January 2008 (UTC)

Removing "Audio CD" from the lead.

What are the opinions regarding moving the info about "audio CD" from the lead and put it in a section dealing specifically with audio CD formats. Having this information in the lead gives undue weight to the audio format and, as John Navas has rightly pointed out, Compact Disc covers more than just audio. These could be rephrased to speak to the size constraints very easily thus removing the audio bias. Just checking before I get too far in. Padillah (talk) 20:18, 31 December 2007 (UTC)

After reviewing the lead, I'd say not to remove audio CDs from it, but rather to mention earlier on that CDs are also used for data storage as well. It's arguable that most folks tend to think of CDs as music discs exclusively, so perhaps just a sentence dispelling this would be sufficient. +ILike2BeAnonymous (talk) 20:33, 31 December 2007 (UTC)

Looking at it and WP:LEAD I think the paragraph that starts "An audio CD consists..." can be moved to the bottom of the lead and the paragraph that starts "The technology was later adapted..." expanded to include the other formats. How does that sound? Like so...

A Compact Disc or CD is an optical disc used to store digital data, originally developed for storing digital audio. The CD, available on the market since late 1982, remains the standard playback medium for commercial audio recordings to the present day, though it has lost ground in recent years to MP3 players.

Standard CDs have a diameter of 120 mm and can hold at most 80 minutes of audio. There are also 80 mm discs, sometimes used for CD singles, which hold at most 20 minutes of audio.
The technology was later adapted and expanded to include data storage (CD-R), reWritable media (CD-RW), SACD, VCD, SVCD, PhotoCD, PictureCD, CD-i, Enhanced CD, and CD-ROM. CD-ROMs and CD-Rs remain widely used technologies in the computer industry as of 2007. The CD and its extensions have been extremely successful: in 2004, the worldwide sales of CD audio, CD-ROM, and CD-R reached about 30 billion discs. By 2007, 200 billion CDs had been sold worldwide.

An audio CD consists of one to 99 stereo tracks stored using 16-bit PCM coding at a sampling rate of 44.1 kHz per channel. Early CDs could hold 74 minutes of stereo sound; 80 minute CDs are now common. A Red Book standard CD can contain up to four channels though it will only have half the playback time. Monaural audio has no existing standard on a CD; it is usually presented as two identical channels on a stereo track.

Thoughts? Padillah (talk) 20:46, 31 December 2007 (UTC)

Nothing pops out on a quick read. (I took the liberty of removing excess line breaks.) This looks like it can easily be tweaked into a much better introduction. +ILike2BeAnonymous (talk) 21:22, 31 December 2007 (UTC)

---

I Wuz Bold and replaced the lead with a slightly revised version of what you wrote above. Hope everyone likes it. +ILike2BeAnonymous (talk) 00:47, 1 January 2008 (UTC)

Who Invented the CD?

I'm new to the concept of editing a wiki entry, but I noticed a problem with this article. Some might classify this as a glaring omission or a downright fallacy of this portion of the article, but the compact disc was invented by James T. Russell back in the late 60's. Massachusetts Institute of Technology; Inventor of the Week: James T. Russell RoetherB (talk) 01:05, 6 January 2008 (UTC)

Forgive me for being a bit sceptical on the story... but James T. Russell turns up very few hits, and the few that do come up, feature the very same text as the page you link to. We need more references if this is actually true. — Edokter • Talk • 01:16, 6 January 2008 (UTC)

Sony and Phillips even ended up paying royalties to Battelle (Russell's company) following infringement lawsuits. Reed Magazine; 'The Discoverer' Russell seems to acknowledge the fact that the technology could have been invented by two people in different places at the same time, but the bottom line is that his patent was the first on the books. RoetherB (talk) 01:38, 6 January 2008 (UTC)

I think the bottom line is that he didn't invent the CD. "So I came up with the optical process." His optical process is not the CD. This is an article about compact discs, not a process for... whatever it was he came up with. There isn't even any information that goes into detail about his digital optical discs. Philips developed a similar technology from the same idea, that doesn't mean the end product is the same.

The same procedure as every year: everytime an American sees an invention, he must make the world believe it's genuine American. In fact, the list of American inventions is a very short one compared to the European list. I have seen articles claiming cars, photography, electric generators, steam pumps and so on are American inventions. Sheer propaganda. End of story. --77.186.131.252 (talk) 20:11, 24 October 2008 (UTC)

Longest CDs

Whats is the longest release on a single CD (album), as I know that 80 minutes is not strictly the limit. AJUK ^Talk!! 23:36, 11 January 2008 (UTC)

Within the limits of the Red Book specifications, 80 minutes is the maximum playing time. Louiskou (talk) 01:37, 12 January 2008 (UTC)

Yeah I know but has a commercial release ever gone beyond this? AJUK ^Talk!! 11:48, 12 January 2008 (UTC)

No, as it would not play on standard CD players. — Edokter • Talk • 12:45, 12 January 2008 (UTC)

I think it probably would as long as it didn't creep too far over. AJUK ^Talk!! 17:28, 13 January 2008 (UTC)

80 minutes is already "creeping to far". The minimun track width gap for CD lasers has already been reached, so any more incurs too much chance of failure to play the CD. — Edokter • Talk • 19:00, 13 January 2008 (UTC)

A slight bit of an old thread here, but I'm surprised no one looking at this page never encountered CDs over 80 minutes. I actually have a few, including one that gets to 82:27, and never had any issues playing them in either my computer or a portable Sony player. The founder of the record label BIS actually claims the limit is 82:30, and that 77:30 is the place where it stops being 'safe' or whatever -- but that their return rate is zero on longer CDs (here's a ref for the above, for what it's worth). ♫ Melodia Chaconne ♫ (talk) 18:06, 5 June 2008 (UTC)

I bought a new release (2008) this week which is the first one I've ever seen - the second disc of a Baden Powell MPS label recordings collection - it clocks in at 81:14. —Preceding unsigned comment added by 74.138.236.178 (talk) 04:07, 15 June 2008 (UTC)

CD versus vinyl

For a decade or more after CDs came out, people complained that the sound was not as full or enveloping as that of vinyl, and that this could only be remedied via use of things like Bose wave technology additions to one's system. After a while, new generations forgot or never knew how vinyl sounded, and we succumbed to the victory and convenience of the CD. Why has no one mentioned this in the article, and how and where can it be properly discussed? Softlavender (talk) 11:34, 17 January 2008 (UTC)

First off this is loaded with POV ("we succumbed to the ...convenience"?). Second, this is an article about a format, not the contents of the format. Third it looks like it should go in a digital audio article. The complaints weren't about CD's per say, they were about the digital music on the CD. Now that we have digital music players like the iPod people know the difference between the medium and the delivery mechanism. Have you checked out the article on digital audio? It has a section dedicated to this point of view. Try adding to or expanding that. Padillah (talk) 13:48, 17 January 2008 (UTC)

You could also contribute to the article analog sound vs. digital sound. This particular controversy is not that hard to find. Padillah (talk) 14:01, 17 January 2008 (UTC)

There should be a section talking about the pros and cons of this audio format compared to other formats. It is well documented that one cannot get the full sound in cds that can be gotten from vinyl records. This is science. I see no reason why it cannot be added to the article regarding the social backlash among audiophiles and others against cds. 72.129.131.185 (talk) 11:36, 20 August 2008 (UTC)

Read two lines above your post, please. What you ar talking about is the DS VS.AS controversy. It's not like digital music on an iPod is any better worse or indifferent than that same music on a CD. This article is about the formatand medium of CD's. Content is discussed elsewhere. padillaH ^{(review me)}_{(help me)} 12:08, 20 August 2008 (UTC)

CD rot

The maximum correctable burst error in a CD audio is around 1 cm. All burst errors shorter than 1 cm can therefore be corrected and cannot be heard. It is therfore extremely unlikely that CD rot will result in audible clicks. It is much more likely that the CDs cannot be played because of servo problems, skipping etc. So unless someone offers tangible evidence the sound clicking is unproven. Dumas1212 (talk) 01:17, 5 February 2008 (UTC)

I know this isn't usable in the article as it falls under the heading of "original research", but I can definitely tell you that it's possible for a[n audio] CD to deteriorate (or "rot" if you will) to the point that the disc is playable but with clearly audible artifacts, some even somewhat similar to phonograph-record noise. I have at least one such disc (it's a CD-R sold as a commercial music album). Not sure what the metric "max. length = 1 cm" applies to; seems like the number of bytes/blocks involved, or length of time, would be a better measure. In any case, keep in mind that the error detection and correction for audio (Red Book) CDs is much more forgiving than that for "data" CDs, and that the player will attempt to fill in the gaps of any playable errors.

I assume that some reliable source confirming this is probably lurking around out there somewhere, so it's just a matter of tracking it down. +ILike2BeAnonymous (talk) 05:40, 5 February 2008 (UTC)

I am not sure what 'better' means in this context. Max error burst length means just what it says: it is the maximum burst of errors that the circ can cope with. Longer bursts may cause clicks. See the book chapter Reed-Solomon Codes and the Compact Disc in S.B. Wicker and V.K. Bhargava, Edrs, Reed-Solomon Codes and Their Applications, IEEE Press, 1994. I used 1 cm instead of frames or number of bits, since it gives a direct relationship with the huge ecc capacity expressed in missng data track length. The length of a bit is around 0.5 microm, so 1 cm = 10.000 micron is equivalent with around 20.000 bits. As there are around 200 (user) bits per EFM frame, we deduct that 1 cm is equivalent with around 100 EFM frames. Noise from a cd player caused by imperfections, as you stipulate, is essentially impossible unless, of course, one uses a cheap, ill-engineered player without suitable ecc/concealment. Dumas1212 (talk) 09:58, 5 February 2008 (UTC)

For what it's worth, I don't think we should mention "noise" but rather "artifacting". CD's are digital and as such either the sound is there (or can be rebuilt) or it's not (and can't). I have yet to know of a player that will "make up a noise" and play that instead. If there is substantial rot (and I've got the CD's to prove it) the song will simply skip that part and start later(at best) or won't play at all (at worst). It will not make a click. Padillah (talk) 13:04, 5 February 2008 (UTC)

That is not true. Tiny (as in 1mm) gaps are theoreticcally enough to produce errors that throw the error correction, and subsequentially the D/A converter off, which produces clicks. Error correction works on a per-frame basis, so 1cm gaps will definitely be uncorrectable. This is especially true for early generation players, which do not actually conceal these errors. The newer players have far more intelligent logic to hide these errors, but we are talking about the original red book standards, which does not take this modern login into consideration. — Edokter • Talk • 15:18, 5 February 2008 (UTC)

Yes, the equipment I use to play CDs is older-school stuff. And I agree that we should discuss this problem (in the article) in terms of "artifacts" rather than "noise", although it would be fair to point out that the result to the listener is noise. +ILike2BeAnonymous (talk) 16:59, 5 February 2008 (UTC)

Good point. I'm not only an amateur producer but a professional programmer and I can get a little technical at times. Stick with the more common phrases until we need to be technical, that way the article is more accessible. Padillah (talk) 18:26, 5 February 2008 (UTC)

Intro

The last paragraph of the introduction reads: A standard audio CD consists of from one to 99 stereo tracks stored using 16-bit PCM coding at a sampling rate of 44.1 kHz per channel. Early CDs could hold 74 minutes of stereo sound; 80 minute CDs are now common.

The last sentence is already said in the same intro. The first sentence is too detailed for an introduction. So better delete these two sentences. As a result, the intro is less redundant and more readable for larger readership. Louiskou (talk) 04:51, 7 February 2008 (UTC)

Prominent members

I do not believe it is a good idea to list all people of Sony's board of directors, or even more, as 'prominent' members of the CD design group. Nakajima was in 1980 responsible as a director of the audio division. His technical contributions to CD are nihil as can be verified from the fact that he is not listed as an author of a technical article or as an inventor on a patent. Therefore his name should not be listed as a prominent member. Louiskou (talk) 15:36, 21 March 2008 (UTC)

Read newly linked Sony History in Japanese, not all member, how only both Nakajima and Doi contributed technically. Nakajima is engineer and Mgr of Sony tech. lab also, but not only manage but also worked for CD and other audio development. Nakajima's contribution may not be ignored as the record as well as Doi's on Wikipedia.
Summary of History written in Japanese and summaries from other sources are:
1978 July, Norio Ohga visited Philips and saw the same development of optical audio recording disc that is almost the same Nakajima and Doi is under research in Sony. 1989 End of August, Joint develop with Philips started. 1981 autumn, Prototype exhibited to public at Audio fair, and 1982 August Sony announced CD and CD player CDP-101 on sale from Autumn 1982. http://www.ieee.org/web/aboutus/history_center/oral_history/abstracts/nakajimahab.html #18, June 1971 he was executive searched (informally headhunting) to Sony as board of director (常務取締役） and at the same time Mfg of Sony Tech lab (from start at Sony in 1971), from NHK where he was already NHK Science Fundamental lab Mgr since 1968. As you see the case of Shuji Nakamura 's suit in 2001-2005, Nakajima is listed or not on the patent as inventor is different system from that of EU & US. Wikipedia Japanese edition call Nakajima as "father of CD" and I guess he is eligible to put his name on CD article here. He is also auther of book, reader of compact disc with illustration (図解 コンパクトディスク読本（小川博司との共著、1982年第1版、ISBN 4274029654）. 1993, Nakajima received Medals of Honour (Japan)#Medal with Purple Ribbon for CD development. --Namazu-tron (talk) 17:32, 21 March 2008 (UTC)

It is clear that we both agree that Nakajima was in charge of Sony’s CD development. I have read his IEEE interview. I quote his statement ’’Because I don't speak English very much, I tended to take a back seat, listen very carefully to what was going on, and just let the experts on each different technology go to work, as it were.’’ So, he clearly states he did not contribute to CD technology. That is exactly the point I try to make. Furthermore, his name is not listed in the articles at AES conventions and the patent literature. Note that Nakajima was educated as a room acoustics engineer, and therefore he could, and did not, contribute to modern digital technology. The fact that Nakajima (with Ogawa) wrote a book, as you say, on CD technology is not relevant as also Ken Pohlman wrote a book (the main source in this field), but nobody would name Pohlman a prominent member of the task force. I conclude: we both agree on the fact that Nakajima was a manager of Sony’s CD development, but he was not a top-engineer who carried out the main design of the CD system. So, it seems that we should not list him. Unless, of course, you also like to list many others such as Ohga or his wife, who, as rumor has it, 'invented' the 12 cm disc by demanding that Beethoven's Ninth could be recorded on a single disc. Louiskou (talk) 18:46, 21 March 2008 (UTC)

Pit depth (Draft)

CD pit depth is described 125nm, 1/4 of 503.2nm wave length, but actually pit depth is 110nm. The following is a draft of "article" before put there, herein "discussion", I would like describe background facts. I would also like to have all your comment, suggestion and/or correction and rewrite for article section, more to have suitable picture(s) hopefully moving gif file to illustrate and demonstration of wave reflection and tracking beam detection system within Wikipedia rather than refer to many external links. Thank you. --Namazu-tron (talk) 08:24, 23 March 2008 (UTC)

Binary data , "1" and "0" is recorded by land and pit on CD. Near infrared 780nm wavelength is used to detect this binary data from reflective aluminum layer through main material of CD, Polycarbonate. The ray of wavelength 780nm is changed to 503.2nm by Refractive index of 1.55 of Polycarbonate (780/1.55=503.2). In order detect binary data by reflection, no phase shift and 180 degree phase shift is best to discriminate binary 1 or 0. 180 degree phase shift is achieved by pit depth 1/4 of wavelength of 503.2nm, which is 125.8nm pit depth.CD Physical Structure and Optical Storage Technology,page 8/99 & 45/99 and Optical CD Code, More Pit Info.

The pit depth (actually pit, protrude height) 125.8nm is theoretical value. CD is comprised with single spiral line, and consists as with multiple tracks. CD player is designated to detect deviation from correct position when reading CD, and positional deviation is physically 3D axis. CD rotation is controlled by means of Constant linear velocity, too far or too close to CD surface is adapted by moving objective lens according to correct focus detected by photo sensor. The remaining axis of 3D is deviation from correct position on the track where binary data is represented by pit.

Generally, three circled spots with Near infrared 503.2nm in Polycarbonate is applied to detect deviation from track and reflected beam light detected by photo sensor corrects track deviation by feedback. The web site CD control mechanism (CD の制御機構 ) best demonstrate tracking reflective signals and three Photo diodes chip in Photo detect IC . ( Click at center of graph, then click rectangle to start, "<<" or ">>" changes CD rotation speed). See also pit depth change and reflection wave "<<" ">" changes speed, two arrow on left varies pit depth.

The central large spot is detecting data 1 or 0. Two small spots aside is also reflect from pit and land, and changes reflection value as seen two pink colored vertical bar changes its height. There are three methods of track deviation detect system, (1) Three beam system, (2) Push-pull system and (3) DPD (Differential Phase Detect) which is improved version of push-pull system by described by the book, Reader of compact disc with illustration (Japanese book, Author Heitaro Nakajima and Hiroshi Ogawa (図解 コンパクトディスク読本（中島平太郎&小川博司との共著、1982年第1版、ISBN 4274029654)).

The theoretical pit depth is 1/4 of wave length 503.2nm that is 125.8nm in depth.

The pit depth for, off-track deviation, tracking however, it is told that best value is 1/8 of wavelength of 503.2nm with push-pull system which is 62.9nm depth. In reality, pit depth, of CD generally produced and on the market, is 110nm in depth used as compromised value between theoretical the best value of 1/4 data of 125.8nm for 1 or 0 data and 1/8 of 62.9nm for tracking feedback mechanism.

The pit depth 110nm is 1/4.57 of 503.2nm wavelength and the vale is between 1/4 and 1/8 as best compromised for tracking system. The book Reader of compact disc with illustration describes Photo diode arrangement for data and tracking signal detection with one 田 shaped 140nm square with four photo diodes and two 180nm square diodes aside, namely A, B, C, D, E and F. Binary data is obtained from total value of A+B+C+D. Also if A=C and B=D value presents correct position on the track. For more accurate tracking control, E=F reflection value indicates tracking is on correct position and differential value of E & F indicates deviation from track with much larger value than deviation detected by A though D diodes.

Various Photo diodes for data and track deviation Detector layout pattern use 6 diodes:

• Sony PDIC IC CXA2586M, Fig-3, in Japanese the same to description A-F above except improved and deformed 田 shape four diodes.
• Sony IC CXA2586M PDIC for CD-RON/DVD-ROM, in English
• AMTEL IC ATR0874, 5. Photo Diode Arrangement Twelve diodes, but logically 6 with E & F improved by four each implement.
• Kodenshi Corp. IC PIC2410, in Japanese
• Kodenshi Corp. IC PIC6710, in Japanese
  

The following web site are informative references:

• http://mediacoder.sourceforge.net/wiki/index.php/CD the best choice is λ/8n = 65 nm, Physical details
• http://www.ip.philips.com/download_attachment/164/sl00332LeafletCDcalibrationDisc.pdf
• http://www.chipchapin.com/CDMedia/
• http://www.tuat.ac.jp/~katsuaki/STEP/STEP041214OHP.ppt Page9
• http://benz.nchu.edu.tw/~imtech/course/ods/Chapter%202%20-%20The%20Compact%20Disc.pdf
• Note large 8MB file, http://www.minidisc.org/magneto_md_paper.pdf
• Microsoft PowerPoint file:Introduction to Optoelectronics Optical Storage (2), 9/41 page —Preceding unsigned comment added by Namazu-tron (talk • contribs) 09:53, 23 March 2008 (UTC)
• http://www.laesieworks.com/digicom/Storage_CD.html
• http://www.google.com/products?hl=en&q=Principles+of+Digital+Audio+&um=1&ie=UTF-8 Principle of Digital Audio
• http://www.ip.philips.com/download_attachment/164/sl00332LeafletCDcalibrationDisc.pdf CD Calibration Disc, Philips, pit depth is not shown though.
• http://www.infonet.co.jp/ueyama/ip/hardware/cdrom_drv.html

--Namazu-tron (talk) 08:24, 23 March 2008 (UTC)

The pits on CDs are typically about lambda/6 deep. This enables the use of both a push-pull tracking error scheme, which works best at a pit depth of lambda/8, and three-beam and differential phase tracking methods, which work best at a pit depth of lambda/4. Hence CD’s pit depth is 780/6=125-130 nm (and not 100 nm as mentioned in the article). Louiskou (talk) 09:27, 23 March 2008 (UTC)

Russell

The statements regarding Russell cannot be verified, and were therefore deleted. Note that the threshold for inclusion in Wikipedia is verifiability, not truth. "Verifiable" in this context means that any reader should be able to check that material added to Wikipedia has already been published by a reliable source. A sweeping statement such as Russell's concepts, patents, prototypes, and literature instigated and in some measure guided the optical digital revolution was not verified. For example, where can his literature and concepts be found, and where are the descriptions of his prototypes? Books, articles etc. How did Russell guide the optical digital revolution?

The Russell text has been tagged ‘intangible’ and challenged since the moment it was added by an anonymous contributor. So unless somebody comes up with verifiable data, Russell's so-called contributions should be deleted.Louiskou (talk) 06:24, 31 March 2008 (UTC)

James T. Russell, The Digital Compact Disc This web site by MIT titled "Digital compact Disc", and interestingly web site is mentioning that, but eventually, Sony and other audio companies realized the implications and purchased licenses. and, MIT defines This was the first compact disc. As he mentioned, he did not work on CD, but James T. Russell is the one to be included in article of CD herein Wikipedia in historical course of development of Optical Recording before CD or idea of CD. Sony and might be Philips purchased licenses, or at least they knew Russell's idea. The MIT web site is provide us enough as the source and MIT educate students what James Russell contributed Optical recording and playback.--Namazu-tron (talk) 08:09, 1 April 2008 (UTC)

James Russell and the Compact Disk and David Gregg and the Optical Disk is also relating not all but about another story of CD and optical means.--Namazu-tron (talk) 14:40, 1 April 2008 (UTC)

Note that the contributions to videodisc technology by Gregg are nicely listed in the article laserdisc. The article says that Gregg first invented the optical disc in 1958. Gregg first filed an optical recording patent for a transparent optical disc in April 1967 (the article notes that Gregg first filed his patent in 1961 and 1990, but the patent itself specifies it is filed in 1967. It is not clear why there is a difference in the dates in the article text and patent. The efforts by Gregg and Philips engineers led to the introduction of the videodisc in 1975, Atlanta, USA. The above videodisc technology was used by Philips and Sony to construct the prototypes of a digital audio disk. The task force defined a joint digital layer, and the CD standard was a fact in 1979.

I am quite amazed that the MIT web site claims that Russell made the first ‘compact disc’. Strictly speaking this statement is clearly false, as the ‘’Compact Disc’’ is a product specified by the red book, which was not yet available at that time. May be they mean something else, but I do not know what. In this context, what is a good definition of CD or CD player? I think a good definition of a CD player is a device that uses laser light for reading the digital audio on the disc. Russell first filed his first patent in Sept 1966. I studied this patent, and it indeed specifies a digital optical video medium. Note that this medium does not necessarily mean a disc. Russell’s preferred medium is a transparent overhead sheet (foil), which can be copied by a Xerox-copier machine or by photographic means. A laser is not used for reading the sheet. Instead the sheet is lighted from the back by a UV lamp, like in an X-ray box or overhead projector. The sheet itself is fixed (not rotating), and the player scans the sheet. This machine is a far cry from a regular compact disc player. Clearly, Russell’s invention and patent claims do not read on the above definition of a CD player, as a laser is not used in his apparatus. There are many more significant differences between Russell’s technology (as described in his patents, I have never seen product descriptions) and the CD.

The only site supporting Russell’s claims as ‘the CD inventor' seems to be the MIT site plus of course lots of copycat sites. I believe we need much more supportive data for such a significant claim than the one by the MIT site. In conclusion: Russell has nothing to do with the compact disc (videodisc) technology, and his name should therefore be omitted in the compact disc article. It could be a good idea to start a new article on the history of optical recording in general, and clearly Russell’s early contributions to the art should be mentioned. Louiskou (talk) 10:27, 3 April 2008 (UTC)

I have again reviewed, the book, Reader of compact disc with illustration (Japanese book, Author Heitaro Nakajima and Hiroshi Ogawa (図解 コンパクトディスク読本（中島平太郎&小川博司との共著、1982年第1版、ISBN 4274029654)) describing various historical inventions and experiments by naming many people and/or organization such as Ampex tried to record digitized audio on mag. tape, but none of story about Russell on the book. I agree with you, Louiskou, MIT web site does not cite with references. MIT web site, Russell had contributed for very fundamental technologies before CD, but it is questionable or very marginal that web site mentioning as he was a inventor of CD. By natural view of Wikipedia, even MIT said so, deleting about Russell from here is appropriate. Before CD, A/D & D/A converter is well popular in Analog/digital computer area, and laser is well established and photo diode is widely used for sensing. CD is very integrated technologies of various methodology, even Sony purchased some patents from Russell is true, it might be a one of the hint, and not directly concerned to be Russell is inventor of CD. Any way, need more citations for his past activities to put on the article. --Namazu-tron (talk) 08:43, 13 April 2008 (UTC)

Bootable CD

Request addition of description of format for Bootable CDs in the Logical formats section. —Preceding unsigned comment added by 99.247.28.157 (talk) 09:47, 16 May 2008 (UTC)

CD

This is silly. CD clearly redirects to here. Please stop removing the template, or go actually change the disambig page to it (which will probably require an admin to do, if they even agree.) I can't even believe there needs to be an edit war here. ♫ Melodia Chaconne ♫ (talk) 13:30, 16 June 2008 (UTC)

Hey, I'm sorry. When I did a search on "CD" I got the dambig page. As I look now I see the redir was put on the CD page back in March so I have no idea what is going on. I changed this based on the fact that I did not get redirected when I searched for CD, other than that I'm sorry. Padillah (talk) 14:07, 16 June 2008 (UTC)

Did you hit 'go' or did you hit 'search'? The former will give the redirect, the latter gives a normal search page -- this is the nature of the search engine (and in fact, I believe the behavior when hitting enter can be changed too). ♫ Melodia Chaconne ♫ (talk) 14:19, 16 June 2008 (UTC)

Ah, I found it (I'm a software tester so...). If you type lowercase "cd" and click GO it will take you to the dambig page. If you use uppercase "CD" it will redirect appropriately. Sorry for the confusion, the wikilink obviously redirects correctly and that's what the tag is for so, leave it. Padillah (talk) 15:09, 16 June 2008 (UTC)

Yeah, WP differentiates between the upper and lower case (outside the first letter), so 'Cd' or 'cd' (which are the same) is NOT the same as 'CD'. I changed the target so the confusion won't happen in the future. ♫ Melodia Chaconne ♫ (talk) 15:16, 16 June 2008 (UTC)

Yep, that got them all. Nice work. Padillah (talk) 15:20, 16 June 2008 (UTC)

Bleh. Sorry about all that, guys. - Snip3rNife (talk) 08:03, 18 June 2008 (UTC)

Images

Where does this go? Image:Blank_cd.png --Doggitydogs (talk) 21:39, 9 August 2008 (UTC)

Dubbeltje & Central Spindle Hole

Before the Netherlands switched to Euros, the Dutch currency had the smallest coin in the world: the "dubbeltje", the Dutch equivalent of the dime. It's about 14 mm in diameter. In other words: it fits perfectly in the central spindle hole. Now the story goes (at least, as told to me by a researcher at Philips R&D) that this was the result of a long, long meeting between the Dutch (Philips) engineers and the Japanese (Sony) engineers on the topic of deciding its size. It had to be significantly larger than that of a LP, yet smaller than that of a Laserdisc, so it wouldn't be accidentally be put in record players for either format. So near the end of a long fruitless meeting a Dutch engineer jokingly suggested to make it the size of a dubbeltje. "A what?", the Japanese responded, undoubtedly in a much more formal tone than I'm using right now. So the Dutch engineer showed them. The Japanese engineers immediatly consiscated the coin for precise measurements; and as a result of that meeting the spindle hole of Compact Discs is exactly the size of a dubbeltje. Of course, I know this is just a rumour; the man in question wasn't on the engineering team (I think... maybe he actually was), and even if he was, I can't really cite any sources. But I was just wondering if anyone else ever heard this story, and might be able to confirm or deny this story. —Preceding unsigned comment added by 129.125.108.20 (talk) 21:34, 15 September 2008 (UTC)

The earliest CDs

Does anyone know what the earliest pop albums to be released on CD were? This is prompted by a fan site on The Nolans, who say that their album "Portrait" was released on CD in Japan in October 1982 and it's one of the first 50 albums to be released on CD. Link:http://groups.msn.com/MakingWaves/theepicyears.msnw . Now, given that the site is such as it is, it's not great as a reference, but I believe it's probably true, given that this group were one of the biggest in Japan at the time and the album was their latest release (and as this aricle states, the first CD was released October 1 1982). Anybody know any others?--Tuzapicabit (talk) 21:27, 24 October 2008 (UTC)

MiB or MB?

I may recall incorrectly, but I believe a CD can actually hold 700MiB (rather than MB) so for sake of consistent terminology, should the term on this article be changed from "MB" to "MiB"? 88.110.225.33 (talk) 07:09, 13 November 2008 (UTC)

To further expand on why I feel it should be changed to MiB, there are links to the "MB" page which gives a different definition to what is actually meant in this instance (MiB). This leads to confusion. —Preceding unsigned comment added by 88.110.225.33 (talk) 07:17, 13 November 2008 (UTC)

Phase out

I just removed the newly-added "Phase out" section which was only supported by one reference: an announcement of non-moving recording media. No reference was given to support the written text which consisted of speculation about the schedule of CD hardware phase outs. Binksternet (talk) 23:14, 1 December 2008 (UTC)

Origins of storage capacity and playing time

Under 3.1.1, "storage capacity and playing time", the article states The partners aimed at a playing time of 60 minutes with a disc diameter of 100 mm (Sony) or 115 mm (Philips).10 Von Karajan suggested extending the capacity to 74 minutes to accommodate a performance of Beethoven’s 9th Symphony at the Bayreuth Festival.11 12

Citation 11 is: Philips. "Beethoven's Ninth Symphony of greater importance than technology" Retrieved on 2007-02-09.

However the source now no longer exists on Phillips' website. Searching for "Beethoven" returns three results, but the URLs are all defunct. Is there a cache of the cited page? The best record I've found of what the page used to be is a slashdot post, which I'm guessing is quoting the following from the missing article However, Sony vice-president Norio Ohga, who was responsible for the project, did not agree. "Let us take the music as the basis," he said. He hadn't studied at the Conservatory in Berlin for nothing. Ohga had fond memories of Beethoven's Ninth Symphony ('Alle Menschen werden Brüder'). That had to fit on the CD. There was room for those few extra minutes, the Philips engineers agreed. The performance by the Berlin Philharmonic, conducted by Herbert von Karajan, lasted for 66 minutes. Just to be quite sure, a check was made with Philips' subsidiary, PolyGram, to ascertain what other recordings there were. The longest known performance lasted 74 minutes. This was a mono recording made during the Bayreuther Festspiele in 1951 and conducted by Wilhelm Furtwängler. This therefore became the playing time of a CD. A diameter of 12 centimeters was required for this playing time. In this way the specifications of the CD were determined by means of intensive contact between Philips and Sony.

I'm not sure that the Beethoven association is encyclopedic content. Why did the Phillips source disappear? Furthermore, in 1998, issue 46 of the Journal of the Audio Engineering Society was published. This included The Compact Disc Story, which was written by Kees A. Schouhamer Immink. It reads, near the end of page 2 onto page 3 under the header "deciding the parameters", The disk diameter is a very basic parameter, because it relates to playing time. All parameters then have to be traded off to optimise playing time and reliability. The decision was made by the top brass of Philips. 'Compact Cassette was a great success', they said, 'we don't think CD should be much larger'. As it was, we made CD 0.5 cm larger yielding 12 cm. (There were all sorts of stories about it having something to do with the length of Beethoven's 9th Symphony and so on, but you should not believe them.)

Considering Immink's involvement in the development of the CD, that completely disproves the purported Beethoven association. Additionally, a still functional citation for the Beethoven association is citation 10, "Shannon, Beethoven, and the Compact Disc" which was published December 2007, in Volume 57 of the IEEE Information Theory Society Newsletter. But in that, though Immink gives Beethoven association more attention then a cursory dismissal, he never claims it to be true, and I feel that he's essentially implying that even though it's a popular idea, the purported Beethoven association can be dismissed after merely a cursory examination. Both disc diameter and playing time differ significantly from the preferred values listed during the Tokyo meeting in December 1979. So what happened during the six months? The minutes of the meetings do not give any clue as to why the changes to playing time and disc diameter were made. According to the Philips’ website with the ‘official’ history: "The playing time was determined posthumously by Beethoven". The wife of Sony's vice-president, Norio Ohga, decided that she wanted the composer's Ninth Symphony to fit on a CD. It was, Sony’s website explains, Mrs. Ohga's favorite piece of music. The Philips’ website proceeds: (same quote as the Slashdot post) Everyday practice is less romantic than the pen of a public relations guru. It was not about Mrs. Ohga’s great passion for music, but the money and competition in the market of the two partners. The decision regarding diameter/playing time was taken outside of the group of experts responsible for the CD format. So I, a former member of that group, can only guess what happened at the upper floor. But something unforeseen happened: at the last minute we changed the code. Popular literature, as exemplified in Philips’ website mentioned above, states that the disc diameter is a direct result of the requested playing time. And that the extra 14 minutes playing time for Furtwängler’s Ninth subsequently required the change from 115mm to a 120 mm disc. It suggests that there are no other factors affecting playing time. Note that in May 1980, when disc diameter and playing time were agreed, the channel code, a key factor affecting playing time, was not yet settled.

I think that makes it pretty clear that it's purely coincidental that 4 people closely associated with the project liked Beethoven's 9th. Especially considering that Furtwängler's recording of the 9th couldn't actually fit on the final format anyway, because of the U-Matic video recorder issue. I would assume that if the disc had been changed to 120mm so that that version of the 9th could fit on one disc, then that version of the 9th would actually fit on the disc. I'd suggest the section be changed to reflect that the Beethoven story is urban legend/corporate myth and unverified, even if it's plausible. Has anyone else found anything more on the subject? Amide10806 (talk) 00:24, 17 December 2008 (UTC)

Your assessment is completely correct, and I have print sources reflecting this. Let me track them down. tgies (talk) 05:27, 17 December 2008 (UTC)

Physical Specifications

At various points in the article there are references to track pitch of 1.6 micrometers (and other physical properties), which I think should be referenced to IEC 60908 (specifications for audio CDs), and ISO/IEC 10149 (for data CDs/CD-ROMs). More importantly, which is why I comment, it should be noted that ISO/IEC 10149 is equivalent to EMCA-130, the latter of which is avaiable for free. 204.191.138.90 (talk) 02:47, 13 February 2009 (UTC)

Longevity

A nice addition would be a section on the longevity of CDs. There is a lot of conflicting information on this topic.