Talk:Compact disc

James Russell the CD inventor

This must in History: "The Compact Disc, or CD, is an optical disc used to store digital data, originally developed for storing digital audio. In 1965, James Russell acted upon his idea that the music industry needed a new medium whereby a gramophone record and the needle on a phonograph would no longer come into contact with one another. With an interest in lasers, Russell soon began his research in an optical system that would replace a phonograph's needle and replace it with a laser that would read codes in order to record and playback sound.[173][174] At 12 inches (30 cm) in diameter, Russell in 1970 had successfully invented and built the world's first compact disc that contained digitized codes etched onto the disc that could be read from a laser.[175][176][177][178] After partnering with Digital Recording which was later acquired by Optical Recording Corporation, Russell and the parent company that he worked for, found it increasingly difficult to enforce and protect his patents from infringement by competitors such as Sony, Philips, and Time Warner who all profited from Russell's invention. The belief that Dutch and Japanese scientists "invented" the compact disc is a misconception in the sense that Philips and Sony used Russell's underlying technology in order to develop a disc more refined, practical, smaller and sophisticated. In 1982, Sony and Philips had commercially introduced the compact disc, twelve years after Russell had already created a working prototype in 1970. By 1986, Optical Recording decided to legally act by suing Sony, Phillips, and Time Warner. Two years later, the company came to a licensing settlement with Sony and soon thereafter, agreements with Phillips and others soon followed, including a June 1992 court ruling that required Time Warner to pay Optical Recording $30 million due to patent infringement." — Preceding unsigned comment added by 87.160.120.223 (talk) 15:49, 22 January 2012 (UTC)

http://inventors.about.com/od/qrstartinventors/a/CD.htm http://web.mit.edu/invent/iow/russell.html — Preceding unsigned comment added by 87.160.98.84 (talk) 16:22, 22 January 2012 (UTC)

http://www.google.de/imgres?imgurl=http://www.babusinesslife.com/Media/images/EntrepH0509-James-T-Russell-ea00887c-56f2-4649-8471-2063986ff745.jpg&imgrefurl=http://www.babusinesslife.com/Tools/Entrepreneurship/The-Digital-Music-Revolution.html&usg=__J9XXQwXyu19tJTkOCkMgmBw5AUw=&h=412&w=605&sz=49&hl=de&start=0&zoom=1&tbnid=1bYdt99WYhV0QM:&tbnh=127&tbnw=186&ei=TkEcT_eUBImCtQaTzLVH&prev=/search%3Fq%3DJames%2BT%2BRussell%26hl%3Dde%26biw%3D1170%26bih%3D639%26gbv%3D2%26tbm%3Disch&itbs=1&iact=hc&vpx=95&vpy=153&dur=177&hovh=185&hovw=272&tx=131&ty=202&sig=113535680373983037897&page=1&ndsp=21&ved=1t:429,r:0,s:0 — Preceding unsigned comment added by 87.160.96.158 (talk) 17:05, 22 January 2012 (UTC)

I think the history section of the article would be better if some reference were made to James Russell, as the above-user mentions. From everything I've read, Russell played a key role in the invention of the compact disc. Starting with Philips and Sony is, in effect, beginning in the middle, instead of at the start. (I hope this post meets the applicable criteria - it is my first post. John M. Becker173.166.126.249 (talk) 17:26, 8 January 2014 (UTC)

I was wondering about this too. The successful commercial application of a technology is certainly important but it seems strange that this article does not make any mention of Russell inventing the format decades earlier. -- 109.76.128.3 (talk) 15:23, 10 November 2023 (UTC)

a CD could store much more data than a personal computer hard disk drive

The article says: a CD could store much more data than a personal computer hard disk drive which is likely true, but I suspect people in 1980 didn't master CDs on their PC. (Which were more likely to be Apple II, or similar.) History of hard disk drives seems not to well cover the drives used by medium sized computers in the 1980s. Somewhere between IBM mainframes and PCs, such as Sun workstations, or similar. Those drives were getting close to CD sized, and systems might have had more than one. Gah4 (talk) 00:26, 14 December 2021 (UTC)

Integrity section

Could an expert please expand the Integrity section to include a comparison of life expectancies for various storage media? Thank you. 2A00:23C6:549D:C301:B579:6C3F:960:FE1F (talk) 08:02, 11 November 2022 (UTC)

Correct cleaning of the media surface

The data on a CD (e.g. audio files) is placed in concentric circles (not a spiral as on a gramophone record) and is read by a laser from the inside out (unlike a gramophone record on which the needle reads from the outside in). Therefore, in order to clean a CD safely and effectively, it should be done from the inside to the outer edge with straight movements instead of a circular motion, which gives us the advantage of not smearing the dirt on the surface of the disc but "sliding it off" and at the same time avoiding situations where possible the long scratch on the data portion caused by us (if we wipe in a circular manner) is along the data reading line and will prevent the laser from reading the disc correctly, unlike the situation when the scratch is across the laser reading line and any short damage to the track will not affect the sound quality (correct reading data) because systems and corrective data will prevent this because they can repair damage to small portions of data (scratches across), but they cannot cope with damaged large portions of data (scratches along). Miszkurka2000 (talk) 21:59, 18 March 2024 (UTC)

The data on CD is recorded in a spiral. HDDs record data in concentric tracks. Wiping along the radius is the recommended cleaning procedure. ~Kvng (talk) 16:08, 23 March 2024 (UTC)

Broken ref

This edit by InvisibleUp created a broken reference link (#29). I'm not sure how to fix this. ~Kvng (talk) 20:10, 25 April 2024 (UTC)

I found and added the missing source from CDDA article. InvisibleUp, please when adding a template:Excerpt, always fill in all sources so we don't have to search for it. Jirka.h23 (talk) 06:29, 26 April 2024 (UTC)

I added most of them, but that particular reference was being re-exported under the wrong refname and I had no idea how to fix that. Thanks for sorting that out, though. InvisibleUp (talk) 07:16, 26 April 2024 (UTC)

HeNe

As far as I know, the early CD players used HeNe gas lasers. I don't have a WP:RS, though. If so, when was the transition to semiconductor lasers? Gah4 (talk) 21:11, 7 June 2024 (UTC)

"Replaced"

This line looks like it could use some polishing to be added to the article.

 CDs have now been replaced with blu-ray and DVD disks, due to CDs very low/limited storage space space of ~600-750 MB. DVDs can store ~4.7 to 8.5 GB of data, and blu-ray disks can store ~25-100 GB of data. CDs also have very high wavelength of 780-870 nm, DVDs have less wavelength of 300-650 nm, and blu-ray disks with a wavelength of 405 nm. (nanometers)

• Pro: the evolution to Blu-ray happened indeed, for.ex. modern PlayStations normally have a Blu-Ray.
• Cons: Blu-ray didn't take the "home media" niche of burnable DVDs and CDs. Compare to the experience of DVDs and CDs being used to "burn" media at home (similar to VHS tapes being used to record TV transmission)...

81.89.66.133 (talk) 07:46, 21 October 2024 (UTC)

Other types

The article doesn't mention CD-ROM WORM (PC magazine 1987 & Boy's life 1989).
Was CD-RAM (as in random access memory) ever a thing? 46.188.152.79 (talk) 16:24, 16 November 2024 (UTC)

Hybrid CD

I think it should have its own small section.

*definition by ecma 395 (and presumably the orange book)

*colloquially used for:

**data and audio tracks CDs

**audio CD that contains additional super audio CD level

**DVD on one side and CD on the other (DualDisc)

**discs with mac and pc filesystems Setenzatsu.2 (talk) 08:03, 1 December 2024 (UTC)