Can a Cdr Be Recorded on Again

Compact disc-recordable

Media type	Optical disc
Encoding	Various
Chapters	Typically up to 700 MiB (upwards to 80 minutes audio)
Readmechanism	600-780 nm wavelength (infrared and cherry-red edge) semiconductor laser, 1200 Kibit/s (1×) to 100Mb/s (56x)
Writemechanism	780 nm wavelength (infrared and ruby edge) semiconductor laser
Standard	Rainbow Books
Developedby	Philips, Sony
Usage	Sound and information storage
Extendedfrom	Recordable LaserDisc CD-ROM
Extendedto	CD-RW DVD-R
Released	1988; 34 years ago  (1988) [ citation needed ]

Recordable optical disc technology

CD-R (Compact disc-recordable) is a digital optical disc storage format. A CD-R disc is a meaty disc that can be written once and read arbitrarily many times.

CD-R discs (CD-Rs) are readable by most CD readers manufactured prior to the introduction of CD-R, unlike CD-RW discs.^[1]

History [edit]

Originally named CD Write-Once (WO), the CD-R specification was get-go published in 1988^{[ commendation needed ]} by Philips and Sony in the Orangish Book, which consists of several parts that provide details of the CD-WO, CD-MO (One thousandagneto-Optic), and later on CD-RW (ReastwardWritable). The latest editions have abandoned the employ of the term "CD-WO" in favor of "CD-R", while "CD-MO" was niggling used. Written CD-Rs and CD-RWs are, in the aspect of low-level encoding and data format, fully compatible with the sound CD (Scarlet Volume CD-DA) and information CD (Yellow Book CD-ROM) standards. The Yellow Book standard for CD-ROM only specifies a loftier-level information format and refers to the Ruby Book for all physical format and low-level code details, such as track pitch, linear chip density, and bitstream encoding. This ways they employ Eight-to-14 Modulation, CIRC error correction, and, for CD-ROM, the third error correction layer defined in the Yellow Book. Properly written CD-R discs on blanks of less than 80 minutes in length are fully uniform with the audio CD and CD-ROM standards in all details including concrete specifications. 80-minute CD-R discs marginally violate the Scarlet Volume physical format specifications, and longer discs are noncompliant. CD-RW discs have lower reflectivity than CD-R or pressed (not-writable) CDs and for this reason cannot meet the Red Book standard. Some hardware compatible with Red Book CDs may take difficulty reading CD-Rs and, because of their lower reflectivity, especially CD-RWs. To the extent that CD hardware tin read extended-length discs or CD-RW discs, it is considering that hardware has capability across the minimum required by the Ruddy Volume and Xanthous Volume standards (the hardware is more than capable than it needs to be to bear the Compact Disc logo).^{[ commendation needed ]}

CD-R recording systems available in 1990 were similar to the washing machine-sized Meridian CD Publisher, based on the two-slice rack mount Yamaha PDS audio recorder costing $35,000,^{[ commendation needed ]} not including the required external ECC circuitry for data encoding, SCSI hard drive subsystem, and MS-DOS command computer.

On July three, 1991, the outset recording of a concert straight to CD was made using a Yamaha YPDR 601. The concert was performed by Claudio Baglioni at the Stadio Flaminio in Rome, Italy. At that fourth dimension, information technology was generally predictable that recordable CDs would have a lifetime of no more than x years. However, as of July 2020 the CD from this live recording nonetheless plays back with no uncorrectable errors.^{[ citation needed ]}

Also in 1991, the first visitor to successfully & professionally duplicate CD-R media was CDRM Recordable Media. With quality technical media existence limited from Taiyo Yuden. Early on CD-R Media had Phthalocyanine dye, which has a low-cal aqua color was used for duplication. By 1992, the cost of typical recorders was down to $10,000–12,000, and in September 1995, Hewlett-Packard introduced its model 4020i manufactured by Philips, which, at $995, was the offset recorder to cost less than $1000.^[ii] As of the 2010s, devices capable of writing to CD-Rs and other types of writable CDs could be institute nether $twenty.

The dye materials developed past Taiyo Yuden made it possible for CD-R discs to be compatible with Audio CD and CD-ROM discs.

In the United states of america, there is a market separation betwixt "music" CD-Rs and "data" CD-Rs, the former being notably more than expensive than the latter due to industry copyright arrangements with the RIAA.^[3] Specifically, the toll of every music CD-R includes a mandatory royalty disbursed to RIAA members by the disc manufacturer; this grants the disc an "application flag" indicating that the royalty has been paid. Consumer standalone music recorders turn down to burn CD-Rs that are missing this flag. Professional person CD recorders are non bailiwick to this brake and can record music to data discs. The 2 types of discs are functionally and physically identical save for this, and estimator CD burners can tape data and/or music to either.^[4] New music CD-Rs are all the same existence manufactured as of the tardily 2010s, although demand for them has declined every bit CD-based music recorders take been supplanted by other devices incorporating the same or similar functionality.^[v]

Physical characteristics [edit]

Isolated data layer of a CD-R

This graphic demonstrates some of the visible features of a CD-R, including the atomic number 82-in, program area, and atomic number 82-out. A microscopic screw of digital data begins near the disc's center and progresses toward the edge. The end of the data region and the lead-out can actually be anywhere, depending on how much data is recorded. Data-free areas of the disc and silent portions of the screw reflect low-cal differently, sometimes allowing rail boundaries to exist seen

A standard CD-R is a ane.2 mm (0.047 in) thick disc made of polycarbonate about 120 mm (5") in diameter. The 120 mm (5") disc has a storage capacity of 74 minutes of audio or 650 Megabytes of information. CD-R/RWs are available with capacities of fourscore minutes of audio or 737,280,000 bytes (700 MiB), which they reach by molding the disc at the tightest allowable tolerances specified in the Orange Book CD-R/CD-RW standards. The technology margin that was reserved for manufacturing tolerance has been used for data chapters instead, leaving no tolerance for manufacturing; for these discs to be truly compliant with the Orange Book standard, the manufacturing process must be perfect.^{[ citation needed ]}

Despite the foregoing, most CD-Rs on the marketplace take an 80-minute capacity. There are also 90 infinitesimal/790 MiB and 99 infinitesimal/870 MiB discs, although they are less common and depart from the Orange Book standard. Due to the limitations of the data structures in the ATIP, 90 and 99-minute blanks volition identify as 80-minute ones. Every bit the ATIP is role of the Orange Book standard, its design does not support some nonstandard disc configurations. In order to employ the additional capacity, these discs have to be burned using overburn options in the CD recording software. Overburning itself is so named because it is outside the written standards, but, due to market demand, information technology has nonetheless go a de facto standard office in virtually CD writing drives and software for them.

Some drives use special techniques, such every bit Plextor's GigaRec or Sanyo's HD-BURN, to write more data onto a given disc; these techniques are deviations from the meaty disc (Red, Yellow, and/or Orangish Book) standards, making the recorded discs proprietary-formatted and not fully compatible with standard CD players and drives. In certain applications where discs volition not be distributed or exchanged outside a private group and volition not exist archived for a long time, a proprietary format may be an adequate style to obtain greater chapters (up to i.2 GiB with GigaRec or 1.8 GiB with Hard disk-Fire on 99-minute media). The greatest take a chance in using such a proprietary data storage format, assuming that it works reliably as designed, is that it may exist difficult or impossible to repair or replace the hardware used to read the media if information technology fails, is damaged, or is lost after its original vendor discontinues it.

Nix in the Red, Yellow, or Orange Book standards prohibits disc reading/writing devices from having the chapters to read/write discs beyond the meaty disc standards. The standards do require discs to meet precise requirements in guild to be called compact discs, simply the other discs may be called past other names; if this were not truthful, no DVD bulldoze could legally bear the compact disc logo. While disc players and drives may have capabilities beyond the standards, enabling them to read and write nonstandard discs, in that location is no assurance, in the absence of explicit additional manufacturer specifications beyond normal compact disc logo certification, that any particular player or drive will perform beyond the standards at all or consistently. If the aforementioned device with no explicit functioning specs beyond the compact disc logo initially handles nonstandard discs reliably, there is no assurance that it will not later on end doing and then, and in that instance, in that location is no assurance that it can be made to do so again past service or aligning. Discs with capacities larger than 650 MB, and especially those larger than 700 MB, are less interchangeable amid players/drives than standard discs and are not very suitable for archival utilize, as their readability on time to come equipment, or even on the same equipment at a future time, is not assured unless specifically tested and certified in that combination, even under the assumption that the discs will non degrade at all.

Photomicrograph of the groove in a CD-R disc

The polycarbonate disc contains a screw groove, called the pregroove because it is molded in before data are written to the disc; it guides the laser beam upon writing and reading information. The pregroove is molded into the meridian side of the polycarbonate disc, where the pits and lands would be molded if it were a pressed, nonrecordable Red Book CD. The bottom side, which faces the laser beam in the role player or drive, is flat and smooth. The polycarbonate disc is coated on the pregroove side with a very thin layer of organic dye. Then, on top of the dye is coated a sparse, reflecting layer of silver, a silver alloy, or golden. Finally, a protective blanket of a photo-polymerizable lacquer is applied on summit of the metal reflector and cured with UV lite.

A blank CD-R is not "empty"; the pregroove has a wobble (the ATIP), which helps the writing laser to stay on track and to write the data to the disc at a constant rate. Maintaining a constant rate is essential to ensure the proper size and spacing of the pits and lands burned into the dye layer. As well as providing timing data, the ATIP (absolute time in pregroove) is also a data runway containing information virtually the CD-R manufacturer, the dye used, and media information (disc length and so on). The pregroove is not destroyed when the information are written to the CD-R, a point which some copy protection schemes use to distinguish copies from an original CD.

Dyes [edit]

There are three bones formulations of dye used in CD-Rs:

1. Cyanine dye CD-Rs were the earliest ones adult, and their formulation is patented by Taiyo Yuden. CD-Rs based on this dye are mostly green in color. The earlier models were very chemically unstable and this made cyanine-based discs unsuitable for archival use; they could fade and go unreadable in a few years. Many manufacturers similar Taiyo Yuden use proprietary chemical additives to brand more stable cyanine discs ("metallic-stabilized Cyanine", "Super Cyanine"). Older cyanine dye-based CD-Rs, as well equally all the hybrid dyes based on cyanine, are very sensitive to UV-rays and tin can get unreadable afterward only a few days if they were exposed to direct sunlight. Although the additives used have made cyanine more than stable, it is still the nigh sensitive of the dyes in UV rays (showing signs of degradation within a calendar week of direct sunlight exposure). A common mistake users make is to leave the CD-Rs with the "clear" (recording) surface upwards, in social club to protect it from scratches, as this lets the lord's day striking the recording surface directly.
2. Phthalocyanine dye CD-Rs are usually argent, aureate, or low-cal green. The patents on phthalocyanine CD-Rs are held past Mitsui and Ciba Specialty Chemicals. Phthalocyanine is a natively stable dye (has no need for stabilizers) and CD-Rs based on this are often given a rated lifetime of hundreds of years. Unlike cyanine, phthalocyanine is more resistant to UV rays, and CD-Rs based on this dye show signs of deposition just later 2 weeks of direct sunlight exposure.^{[ clarification needed ] [ commendation needed ]} However, phthalocyanine is more than sensitive than cyanine to writing laser power scale, significant that the power level used by the writing laser has to be more accurately adjusted for the disc in club to get a practiced recording; this may erode the benefits of dye stability, every bit marginally written discs (with higher correctable error rates) volition lose data (i.due east. have uncorrectable errors) after less dye degradation than well-written discs (with lower correctable mistake rates).
3. Azo dye CD-Rs are night bluish in color, and their conception is patented by Mitsubishi Chemical Corporation. Azo dyes are likewise chemically stable, and Azo CD-Rs are typically rated with a lifetime of decades. Azo is the most resistant dye against UV light and begins to dethrone only afterwards the third or fourth week of directly sunlight exposure. More modernistic implementations of this kind of dye include Super Azo which is not every bit deep blue equally the earlier Metallic Azo. This modify of composition was necessary in order to accomplish faster writing speeds.

There are many hybrid variations of the dye formulations, such as Formazan by Kodak (a hybrid of cyanine and phthalocyanine).

Unfortunately, many manufacturers have added additional coloring to disguise their unstable cyanine CD-Rs in the past, so the formulation of a disc cannot be adamant based purely on its color. Similarly, a gold reflective layer does not guarantee the use of phthalocyanine dye. The quality of the disc is too not only dependent on the dye used, it is also influenced by sealing, the meridian layer, the reflective layer, and the polycarbonate. Just choosing a disc based on its dye blazon may be problematic. Furthermore, correct power calibration of the laser in the writer, as well as correct timing of the light amplification by stimulated emission of radiation pulses, stable disc speed, then on, is critical to non only the immediate readability but the longevity of the recorded disc, so for archiving it is important to have non but a high-quality disc but a high-quality writer. In fact, a high-quality writer may produce adequate results with medium-quality media, but high-quality media cannot recoup for a mediocre writer, and discs written by such a writer cannot achieve their maximum potential archival lifetime.

Speed [edit]

Data writing speed	Data writing charge per unit	Write time for fourscore minute/700 MiB CD-R
1×	150 kB/due south	80 minutes
2×	300 kB/southward	forty minutes
4×	600 kB/s	20 minutes
eight×	one.2 MB/south	10 minutes
12×	1.8 MB/southward	7 minutes
xvi×	ii.4 MB/s	5 minutes
twenty×	3.0 MB/s	4 minutes
24×	3.6 MB/s	iii.4 minutes (come across below)
32×	4.viii MB/s	2.5 minutes (meet beneath)
40×	6.0 MB/s	ii minutes (see below)
48×	vii.2 MB/southward	1.vii minutes (see below)
52×	7.eight MB/s	1.5 minutes (see below)

These times only include the actual optical writing laissez passer over the disc. For most disc recording operations, boosted fourth dimension is used for overhead processes, such as organizing the files and tracks, which adds to the theoretical minimum total time required to produce a disc. (An exception might exist making a disc from a prepared ISO paradigm, for which the overhead would probable be petty.) At the lowest write speeds, this overhead takes and so much less time than the actual disc writing pass that information technology may be negligible, just at higher write speeds, the overhead fourth dimension becomes a larger proportion of the overall time taken to produce a finished disc and may add significantly to it.

Too, above twenty× speed, drives utilise a Zoned-CLV or CAV strategy, where the advertised maximum speed is only reached near the outer rim of the disc.^{[half dozen]} This is not taken into account by the higher up table. (If this were not done, the faster rotation that would be required at the inner tracks could cause the disc to fracture and/or could cause excessive vibration which would make accurate and successful writing impossible.)

Writing methods [edit]

The blank disc has a pre-groove runway onto which the data are written. The pre-groove track, which as well contains timing information, ensures that the recorder follows the same spiral path as a conventional CD. A CD recorder writes data to a CD-R disc past pulsing its laser to rut areas of the organic dye layer. The writing procedure does not produce indentations (pits); instead, the estrus permanently changes the optical properties of the dye, irresolute the reflectivity of those areas. Using a depression light amplification by stimulated emission of radiation power, so as not to further alter the dye, the disc is read back in the same way as a CD-ROM. Nonetheless, the reflected lite is modulated non by pits, but by the alternating regions of heated and unaltered dye.^[vii] The change of the intensity of the reflected laser radiation is transformed into an electrical signal, from which the digital information is recovered ("decoded"). One time a section of a CD-R is written, it cannot exist erased or rewritten, unlike a CD-RW. A CD-R can exist recorded in multiple sessions. A CD recorder can write to a CD-R using several methods including:

1. Disc At Once – the whole CD-R is written in one session with no gaps and the disc is "airtight" meaning no more data can exist added and the CD-R effectively becomes a standard read-only CD. With no gaps between the tracks, the Disc At Once format is useful for "live" audio recordings.
2. Track At In one case – data are written to the CD-R one track at a time but the CD is left "open up" for further recording at a after phase. It also allows data and audio to reside on the same CD-R.^[8]
3. Packet Writing – used to record information to a CD-R in "packets", allowing extra information to be appended to a disc at a later fourth dimension, or for data on the disc to exist made "invisible". In this way, CD-R can emulate CD-RW; notwithstanding, each time data on the disc is altered, more information has to be written to the disc. There can be compatibility issues with this format and some CD drives.

With careful examination, the written and unwritten areas can be distinguished past the naked heart. CD-Rs are written from the center outwards, so the written area appears as an inner ring with slightly dissimilar shading.

CDs accept a Ability Calibration Surface area, used to calibrate the writing laser before and during recording. CDs comprise ii such areas: i close to the inner edge of the disc, for depression-speed scale, and another on the outer edge on the disc, for high-speed calibration. The scale results are recorded on a Recording Direction Surface area (RMA) that can hold up to 99 calibrations. The disc cannot be written later the RMA is full, however, the RMA may be emptied in CD-RW discs. ^[nine]

Lifespan [edit]

An case of a CD-R burned in 2000 showing dye degradation in 2008. Part of the data on it has been lost.

Real-life (not accelerated aging) tests have revealed that some CD-Rs degrade rapidly even if stored ordinarily.^{[10] [11]} The quality of a CD-R disc has a large and directly influence on longevity—low-quality discs should not be expected to last very long. Co-ordinate to research conducted by J. Perdereau, CD-Rs are expected to take an average life expectancy of x years.^[12] Branding isn't a reliable guide to quality, because many brands (major as well as no name) do not manufacture their own discs. Instead, they are sourced from different manufacturers of varying quality. For all-time results, the actual manufacturer and material components of each batch of discs should be verified.

Burned CD-Rs suffer from textile degradation, simply similar most writable media. CD-R media take an internal layer of dye used to shop data. In a CD-RW disc, the recording layer is fabricated of an alloy of silver and other metals—indium, antimony, and tellurium.^[13] In CD-R media, the dye itself can degrade, causing data to get unreadable.

Also every bit degradation of the dye, failure of a CD-R can be due to the reflective surface. While silver is less expensive and more than widely used, information technology is more prone to oxidation resulting in a non-reflecting surface. Gold on the other hand, although more expensive and no longer widely used, is an inert fabric, then gilt-based CD-Rs practice not endure from this problem. Manufacturers have estimated the longevity of gold-based CD-Rs to exist as high as 100 years.^[14]

By measuring the rate of correctable data errors, the data integrity and/or manufacturing quality of CD-R media can be measured, allowing for a reliable prediction of future data losses acquired by media degradation.^[15]

Labeling [edit]

It is recommended if using agglutinative-backed paper labels that the labels exist specially made for CD-Rs. A balanced CD vibrates only slightly when rotated at high speed. Bad or improperly made labels, or labels practical off-eye, unbalance the CD and can cause information technology to vibrate when it spins, which causes read errors and even risks damaging the drive.^[16]

A professional person alternative to CD labels is pre-printed CDs using a 5-color silkscreen or outset printing. Using a permanent marker pen is likewise a common practice. However, solvents from such pens can affect the dye layer.

Disposal [edit]

Information confidentiality [edit]

Since CD-Rs, in general, cannot be logically erased to whatsoever degree, the disposal of CD-Rs presents a possible security issue if they contain sensitive/individual data. Destroying the information requires physically destroying the disc or data layer. Heating the disc in a microwave oven for 10–15 seconds effectively destroys the information layer past causing arcing in the metal reflective layer, but this same arcing may cause damage or excessive article of clothing to the microwave oven. Many office paper shredders are as well designed to shred CDs.

Some contempo burners (Plextor, LiteOn) support erase operations on -R media, by "overwriting" the stored data with strong laser power, although the erased area cannot be overwritten with new data.

Recycling [edit]

The polycarbonate textile and possible gold or silver in the reflective layer would make CD-Rs highly recyclable. Nonetheless, the polycarbonate is of very picayune value and the quantity of precious metals is so small that it is not profitable to recover them.^[17] Consequently, recyclers that take CD-Rs typically do not offer compensation for altruistic or transporting the materials.^{[eighteen] [19]}

See likewise [edit]

• Absolute Time In Pregroove
• Blu-ray Disc
• CD recorder
• CD-R caddy
• CD-ROM, GD-ROM
• CD-RW, DVD-RW
• DVD, DVD-R, DVD+R, DVD+R DL
• Hd DVD
• Labelflash
• LightScribe
• MultiLevel Recording, an obsolete engineering science (with not-binary modulation)
• Optical disc authoring
• Rainbow Books
• GD-ROM
• MIL-CD
• List of optical disc manufacturers

References [edit]

1. ^ Wempen, Faithe (17 April 2001). "All about CD-R and CD-RW". TechRepublic. Archived from the original on 2013-08-03. Retrieved 27 November 2021.
2. ^ Roxio history of CD-R from Roxio Newsletter 17 January 2000. Retrieved 19 September 2009
3. ^ "A New Spin", Fourth dimension, Baronial 24, 1998
4. ^ "What's the difference betwixt "data" and "music" blanks?". Cdrfaq.org. Retrieved 2011-12-16 .
5. ^ Savage, Mark (3 January 2019). "Is this the finish of owning music?". BBC . Retrieved 27 Nov 2021.
6. ^ "Explanation of CLV, CAV, P-CAV and Z-CLV with diagrams". Cdspeed2000.com. Retrieved 2011-12-16 .
7. ^ "The Side by side Generation 1996 Dictionary A to Z: CD-Recordable". Adjacent Generation. No. 15. Imagine Media. March 1996. p. 31. In bodily CDs, pits carved into the surface of the CD are read past the light amplification by stimulated emission of radiation in the CD-ROM drive. CD-Recordables, or CD-Rs, simulate the pits by putting ink spots on the CD.
8. ^ "Audio Mastering Is At present Possible". digitalexpressmastering.com. Archived from the original on 2014-05-22. Retrieved 2017-02-21 .
9. ^ "Everything you Wanted to Know About CDs". world wide web.co-bw.com. Archived from the original on February 21, 2017.
10. ^ "CD-R Unreadable in Less Than 2 Years". myce.com. 19 August 2003. Retrieved 2007-02-01 .
11. ^ Horlings, Jeroen (August 19, 2003). "CD-R'southward binnen twee jaar onleesbaar; Steekproef levert verontrustende resultaten op" [CD-Rs within ii years unreadable; Sample produces troubling results]. PC-Agile.com via archive.org (in Dutch). Archived from the original on 2005-03-09. Retrieved 2007-02-01 .
12. ^ "Periodical de twenty Heures". approximately infinitesimal thirty of the TV news broadcast. Retrieved March three, 2008.
13. ^ "CD-R & CD-RW Media Applied science Primer". imation.com. Archived from the original on 2007-03-02. Retrieved 2007-05-06 .
14. ^ "Archival Gold CD-R "300 Twelvemonth Disc" Folder of 10 Discs with Scratch Armor Surface". Cyberspace Archive. Archived from the original on September 27, 2013.
15. ^ "QPxTool glossary". qpxtool.sourceforge.io. QPxTool. 2008-08-01. Retrieved 22 July 2020.
16. ^ "CD-R Labeling". Dpfwiw.com. 2004-07-27. Archived from the original on June 10, 2014. Retrieved 2011-12-xvi .
17. ^ "The Consumer Recycling Guide: Recycling More than Obscure Materials (toxics, batteries, mercury, computers, eyeglasses, cream peanuts)". Obviously.com. 2011-05-xxx. Archived from the original on 2011-12-29. Retrieved 2011-12-16 .
18. ^ "CD Recycling Center – Suggested_programs – CD and DVD Recycling". Cdrecyclingcenter.com. Archived from the original on January 25, 2010. Retrieved 2011-12-16 .
19. ^ "GreenDisk [Technotrash Pack-IT]". Greendisk.com. Retrieved 2011-12-16 .

External links [edit]

• ECMA-394: Recordable Compact Disc Systems CD-R Multi-Speed (standardized Orange Book, Office Ii, Book 2)
• The CD-R FAQ
• Agreement CD-R & CD-RW at the Optical Storage Technology Clan site.

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Source: https://en.wikipedia.org/wiki/CD-R

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