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CD-R (Compact disc-recordable) is a
digital Digital usually refers to something using discrete digits, often binary digits. Technology and computing Hardware *Digital electronics, electronic circuits which operate using digital signals **Digital camera, which captures and stores digital i ...
optical disc storage format. A CD-R disc is a compact 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 CD-RW (Compact Disc-Rewritable) is a digital optical disc storage format introduced in 1997. A CD-RW compact disc (CD-RWs) can be written, read, erased, and re-written. CD-RWs, as opposed to CDs, require specialized readers that have sens ...
discs.


History

Originally named CD Write-Once (WO), the CD-R specification was first published in 1988 by Philips and
Sony , commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
in the Orange Book, which consists of several parts that provide details of the CD-WO, CD-MO (Magneto-Optic), and later CD-RW (ReWritable). The latest editions have abandoned the use of the term "CD-WO" in favor of "CD-R", while "
CD-MO CD-RW (Compact Disc-Rewritable) is a digital optical disc storage format introduced in 1997. A CD-RW compact disc (CD-RWs) can be written, read, erased, and re-written. CD-RWs, as opposed to CDs, require specialized readers that have sensi ...
" was rarely used. Written CD-Rs and CD-RWs are, in the aspect of low-level encoding and data format, fully compatible with the audio CD (''Red Book''
CD-DA Compact Disc Digital Audio (CDDA or CD-DA), also known as Digital Audio Compact Disc or simply as Audio CD, is the standardization, standard format for audio compact discs. The standard is defined in the ''Red Book'', one of a series of Rainbo ...
) and data CD (''Yellow Book''
CD-ROM A CD-ROM (, compact disc read-only memory) is a type of read-only memory consisting of a pre-pressed optical compact disc that contains data. Computers can read—but not write or erase—CD-ROMs. Some CDs, called enhanced CDs, hold both compute ...
) standards. The Yellow Book standard for CD-ROM only specifies a high-level data format and refers to the Red Book for all physical format and low-level code details, such as track pitch, linear bit density, and bitstream encoding. This means they use
Eight-to-Fourteen Modulation Eight-to-fourteen modulation (EFM) is a data encoding technique – formally, a ''line code'' – used by compact discs (CD), laserdiscs (LD) and pre-Hi-MD MiniDiscs. EFMPlus is a related code, used in DVDs and Super Audio CDs (SACDs). EFM and E ...
, CIRC error correction, and, for
CD-ROM A CD-ROM (, compact disc read-only memory) is a type of read-only memory consisting of a pre-pressed optical compact disc that contains data. Computers can read—but not write or erase—CD-ROMs. Some CDs, called enhanced CDs, hold both compute ...
, 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 compatible with the audio CD and CD-ROM standards in all details including physical specifications. 80-minute CD-R discs marginally violate the Red Book physical format specifications, and longer discs are noncompliant. CD-RW discs have lower reflectivity than CD-R or pressed (non-writable) CDs and for this reason cannot meet the Red Book standard. Some hardware compatible with Red Book CDs may have difficulty reading CD-Rs and, because of their lower reflectivity, especially CD-RWs. To the extent that CD hardware can read extended-length discs or CD-RW discs, it is because that hardware has capability beyond the minimum required by the Red Book and Yellow Book standards (the hardware is more capable than it needs to be to bear the Compact Disc logo). CD-R recording systems available in 1990 were similar to the washing machine-sized Meridian CD Publisher, based on the two-piece rack mount
Yamaha Yamaha may refer to: * Yamaha Corporation, a Japanese company with a wide range of products and services, established in 1887. The company is the largest shareholder of Yamaha Motor Company (below). ** Yamaha Music Foundation, an organization esta ...
PDS audio recorder costing $35,000, not including the required external ECC circuitry for data encoding, SCSI hard drive subsystem, and
MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few oper ...
control computer. On July 3, 1991, the first recording of a concert directly to CD was made using a
Yamaha YPDR 601 Yamaha may refer to: * Yamaha Corporation, a Japanese company with a wide range of products and services, established in 1887. The company is the largest shareholder of Yamaha Motor Company (below). ** Yamaha Music Foundation, an organization estab ...
. The concert was performed by
Claudio Baglioni Claudio Baglioni (; born 16 May 1951) is an Italian pop singer-songwriter and musician. His career has been going on for over 50 years. Some songs from the 70s are part of Italian culture such as ''E tu come stai?''. In the 80s he released the ...
at the Stadio Flaminio in Rome, Italy. At that time, it was generally anticipated that recordable CDs would have a lifetime of no more than 10 years. However, as of July 2020 the CD from this live recording still plays back with no uncorrectable errors. In the same year, the first company to successfully & professionally duplicate CD-R media was CDRM Recordable Media. With quality technical media being limited from
Taiyo Yuden is a Japanese materials and electronics company, situated in Kyobashi, Chuo, Tokyo, that helped pioneer recordable CD technology (CD-R) along with Sony and Philips in 1988. Founded 70 years ago, Taiyo Yuden currently operates factories in Japa ...
, Early CD-R Media used Phthalocyanine dye for duplication, which has a light aqua color. 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 first recorder to cost less than $1000. As of the 2010s, devices capable of writing to CD-Rs and other types of writable CDs could be found under $20. The dye materials developed by
Taiyo Yuden is a Japanese materials and electronics company, situated in Kyobashi, Chuo, Tokyo, that helped pioneer recordable CD technology (CD-R) along with Sony and Philips in 1988. Founded 70 years ago, Taiyo Yuden currently operates factories in Japa ...
made it possible for CD-R discs to be compatible with Audio CD and CD-ROM discs. In the United States, there is a market separation between "music" CD-Rs and "data" CD-Rs, the former being notably more expensive than the latter due to industry copyright arrangements with the RIAA. Specifically, the price of every music CD-R includes a mandatory
royalty Royalty may refer to: * Any individual monarch, such as a king, queen, emperor, empress, etc. * Royal family, the immediate family of a king or queen regnant, and sometimes his or her extended family * Royalty payment for use of such things as in ...
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 refuse to burn CD-Rs that are missing this flag. Professional CD recorders are not subject to this restriction and can record music to data discs. The two types of discs are functionally and physically identical other than this, and computer CD burners can record data and/or music to either. New music CD-Rs are still being manufactured as of the late 2010s, although demand for them has declined as CD-based music recorders have been supplanted by other devices incorporating the same or similar functionality. Prior to CD-R, Tandy Corporation had announced a rewritable CD system known as the Tandy High-Density Optical Recording (THOR) system, claiming to offer support for erasable and rewritable discs, made possible by a "secret coating material" on which Tandy had applied for patents, and reportedly based partly on a process developed by Optical Data Inc., with research and development undertaken at Tandy's Magnetic Media Research Center. Known also as the Tandy High-Intensity Optical Recording system, THOR-CD media was intended to be playable in existing CD players, being compatible with existing CD audio and CD-ROM equipment, with the discs themselves employing a layer in which the "marks", "bumps" or "pits" readable by a conventional CD player could be established in, and removed from, the medium by a laser operating at a different frequency. Tandy's announcement was surprising enough to "catch half a dozen industries off guard", claiming availability of consumer-level audio and video products below $500 by the end of 1990, and inviting other organisations to license the technology. The announcement attracted enthusiasm but also skepticism of Tandy's capability to deliver the system, with the latter proving to be justified, the technology having been "announced... heavily promoted; then it was delayed, and finally, it just never appeared".


Physical characteristics

A standard CD-R is a 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 data. CD-R/RWs are available with capacities of 80 minutes of audio or 737,280,000 bytes (700 
MiB The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...
), which they achieve by molding the disc at the tightest allowable tolerances specified in the Orange Book CD-R/CD-RW standards. The engineering margin that was reserved for manufacturing tolerance has been used for data capacity instead, leaving no tolerance for manufacturing; for these discs to be truly compliant with the Orange Book standard, the manufacturing process must be perfect. Despite the foregoing, most CD-Rs on the market have an 80-minute capacity. There are also 90 minute/790 MiB and 99 minute/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 will identify as 80-minute ones. As the ATIP is part of the Orange Book standard, its design does not support some nonstandard disc configurations. In order to use the additional capacity, these discs have to be burned using
overburn Optical disc authoring requires a number of different optical disc recorder technologies working in tandem, from the optical disc media to the firmware to the control electronics of the optical disc drive. Types of recordable optical disc The ...
options in the CD recording software. Overburning itself is so named because it is outside the written standards, but, due to market demand, it has nonetheless become a de facto standard function in most CD writing drives and software for them. Some drives use special techniques, such as Plextor's GigaRec or Sanyo's HD-BURN, to write more data onto a given disc; these techniques are deviations from the compact disc (Red, Yellow, and/or Orange Book) standards, making the recorded discs proprietary-formatted and not fully compatible with standard CD players and drives. In certain applications where discs will not be distributed or exchanged outside a private group and will not be archived for a long time, a proprietary format may be an acceptable way to obtain greater capacity (up to 1.2 GiB with GigaRec or 1.8 GiB with HD-BURN on 99-minute media). The greatest risk in using such a proprietary data storage format, assuming that it works reliably as designed, is that it may be difficult or impossible to repair or replace the hardware used to read the media if it fails, is damaged, or is lost after its original vendor discontinues it. Nothing in the Red, Yellow, or Orange Book standards prohibits disc reading/writing devices from having the capacity to read/write discs beyond the compact disc standards. The standards do require discs to meet precise requirements in order to be called compact discs, but the other discs may be called by other names; if this were not true, no DVD drive 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, there 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 same device with no explicit performance specs beyond the compact disc logo initially handles nonstandard discs reliably, there is no assurance that it will not later stop doing so, and in that case, there is no assurance that it can be made to do so again by service or adjustment. Discs with capacities larger than 650 MB, and especially those larger than 700 MB, are less interchangeable among players/drives than standard discs and are not very suitable for archival use, as their readability on future 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 not degrade at all. The polycarbonate disc contains a spiral groove, called the pregroove because it is molded in before data are written to the disc; it guides the
laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The firs ...
beam upon writing and reading information. The pregroove is molded into the top 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 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 thin, reflecting layer of silver, a silver
alloy An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, ...
, or gold. Finally, a protective coating of a photo-polymerizable lacquer is applied on top of the metal reflector and cured with UV light. 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 information, the ATIP (absolute time in pregroove) is also a data track containing information about the CD-R manufacturer, the dye used, and media information (disc length and so on). The pregroove is not destroyed when the data are written to the CD-R, a point which some
copy protection Copy protection, also known as content protection, copy prevention and copy restriction, describes measures to enforce copyright by preventing the reproduction of software, films, music, and other media. Copy protection is most commonly found o ...
schemes use to distinguish copies from an original CD.


Dyes

There are three basic formulations of dye used in CD-Rs: #
Cyanine Cyanines, also referred to as tetramethylindo(di)-carbocyanines are a synthetic dye family belonging to the polymethine group. Although the name derives etymologically from terms for shades of blue, the cyanine family covers the electromagnetic ...
dye CD-Rs were the earliest ones developed, and their formulation is patented by
Taiyo Yuden is a Japanese materials and electronics company, situated in Kyobashi, Chuo, Tokyo, that helped pioneer recordable CD technology (CD-R) along with Sony and Philips in 1988. Founded 70 years ago, Taiyo Yuden currently operates factories in Japa ...
. 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 become unreadable in a few years. Many manufacturers like Taiyo Yuden use proprietary chemical additives to make more stable cyanine discs ("metal-stabilized Cyanine", "Super Cyanine"). Older cyanine dye-based CD-Rs, as well as all the hybrid dyes based on cyanine, are very sensitive to UV-rays and can become unreadable after only a few days if they were exposed to direct sunlight. Although the additives used have made cyanine more stable, it is still the most sensitive of the dyes in UV rays (showing signs of degradation within a week of direct sunlight exposure). A common mistake users make is to leave the CD-Rs with the "clear" (recording) surface upwards, in order to protect it from scratches, as this lets the sun hit the recording surface directly. #
Phthalocyanine Phthalocyanine () is a large, aromatic, macrocyclic, organic compound with the formula and is of theoretical or specialized interest in chemical dyes and photoelectricity. It is composed of four isoindole units linked by a ring of nitrogen atom ...
dye CD-Rs are usually silver, gold, or light green. The patents on phthalocyanine CD-Rs are held by
Mitsui is one of the largest ''keiretsu'' in Japan and one of the largest corporate groups in the world. The major companies of the group include Mitsui & Co. ( general trading company), Sumitomo Mitsui Banking Corporation, Nippon Paper Industrie ...
and
Ciba Specialty Chemicals Ciba was a chemical company based in and near Basel, Switzerland. "Ciba" stood for "Chemische Industrie Basel" (Chemical Industries Basel). It was formed as the non-pharmaceuticals elements of Novartis were spun out in 1997, following the merger ...
. 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 Cyanines, also referred to as tetramethylindo(di)-carbocyanines are a synthetic dye family belonging to the polymethine group. Although the name derives etymologically from terms for shades of blue, the cyanine family covers the electromagnetic ...
, phthalocyanine is more resistant to UV rays, and CD-Rs based on this dye show signs of degradation only after two weeks of direct sunlight exposure. However, phthalocyanine is more sensitive than cyanine to writing laser power calibration, meaning that the power level used by the writing laser has to be more accurately adjusted for the disc in order to get a good recording; this may erode the benefits of dye stability, as marginally written discs (with higher correctable error rates) will lose data (i.e. have uncorrectable errors) after less dye degradation than well-written discs (with lower correctable error rates). #
Azo dye Azo dyes are organic compounds bearing the functional group R−N=N−R′, in which R and R′ are usually aryl and substituted aryl groups. They are a commercially important family of azo compounds, i.e. compounds containing the C-N= ...
CD-Rs are dark blue in color, and their formulation is patented by Mitsubishi Chemical Corporation. Azo dyes are also 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 degrade only after the third or fourth week of direct sunlight exposure. More modern implementations of this kind of dye include Super Azo which is not as deep blue as the earlier Metal Azo. This change of composition was necessary in order to achieve faster writing speeds. There are many hybrid variations of the dye formulations, such as
Formazan The formazans are compounds of the general formula -N=N-C(R')=N-NH-R" formally derivatives of formazan 2NN=CHN=NH unknown in free form. Formazan dyes are artificial chromogenic products obtained by reduction of tetrazolium salts by dehydrogenase ...
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 determined based purely on its color. Similarly, a gold reflective layer does not guarantee the use of phthalocyanine dye. The quality of the disc is also not only dependent on the dye used, it is also influenced by sealing, the top layer, the reflective layer, and the polycarbonate. Simply choosing a disc based on its dye type may be problematic. Furthermore, correct power calibration of the laser in the writer, as well as correct timing of the laser pulses, stable disc speed, and so on, is critical to not only the immediate readability but the longevity of the recorded disc, so for archiving it is important to have not only 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 compensate for a mediocre writer, and discs written by such a writer cannot achieve their maximum potential archival lifetime.


Speed

These times only include the actual optical writing pass over the disc. For most disc recording operations, additional time 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 be making a disc from a prepared ISO image, for which the overhead would likely be trivial.) At the lowest write speeds, this overhead takes so much less time than the actual disc writing pass that it may be negligible, but at higher write speeds, the overhead time becomes a larger proportion of the overall time taken to produce a finished disc and may add significantly to it. Also, above 20× speed, drives use a Zoned-CLV or CAV strategy, where the advertised maximum speed is only reached near the outer rim of the disc. This is not taken into account by the above 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

The blank disc has a pre-groove track onto which the data are written. The pre-groove track, which also contains timing information, ensures that the recorder follows the same spiral path as a conventional CD. A
CD recorder In computing, an optical disc drive is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only ...
writes data to a CD-R disc by pulsing its laser to heat areas of the organic dye layer. The writing process does not produce indentations (pits); instead, the heat permanently changes the optical properties of the dye, changing the reflectivity of those areas. Using a low laser power, so as not to further alter the dye, the disc is read back in the same way as a CD-ROM. However, the reflected light is modulated not by pits, but by the alternating regions of heated and unaltered dye. The change of the intensity of the reflected laser radiation is transformed into an electrical signal, from which the digital information is recovered ("decoded"). Once a section of a CD-R is written, it cannot be erased or rewritten, unlike a
CD-RW CD-RW (Compact Disc-Rewritable) is a digital optical disc storage format introduced in 1997. A CD-RW compact disc (CD-RWs) can be written, read, erased, and re-written. CD-RWs, as opposed to CDs, require specialized readers that have sens ...
. A CD-R can be recorded in multiple sessions. A
CD recorder In computing, an optical disc drive is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only ...
can write to a CD-R using several methods including: # Disc At Once – the whole CD-R is written in one session with no gaps and the disc is "closed" meaning no more data can be 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. # Track At Once – data are written to the CD-R one track at a time but the CD is left "open" for further recording at a later stage. It also allows data and audio to reside on the same CD-R. # Packet Writing – used to record data to a CD-R in "packets", allowing extra information to be appended to a disc at a later time, or for information on the disc to be made "invisible". In this way, CD-R can emulate CD-RW; however, each time information on the disc is altered, more data 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 by the naked eye. CD-Rs are written from the center outwards, so the written area appears as an inner band with slightly different shading. CDs have a Power Calibration Area, used to calibrate the writing laser before and during recording. CDs contain two such areas: one close to the inner edge of the disc, for low-speed calibration, and another on the outer edge on the disc, for high-speed calibration. The calibration results are recorded on a Recording Management Area (RMA) that can hold up to 99 calibrations. The disc cannot be written after the RMA is full, however, the RMA may be emptied in CD-RW discs.


Lifespan

Real-life (not accelerated aging) tests have revealed that some CD-Rs
degrade Degradation may refer to: Science * Degradation (geology), lowering of a fluvial surface by erosion * Degradation (telecommunications), of an electronic signal * Biodegradation of organic substances by living organisms * Environmental degradation ...
quickly even if stored normally. The quality of a CD-R disc has a large and direct influence on longevity—low-quality discs should not be expected to last very long. According to research conducted by J. Perdereau, CD-Rs are expected to have an average life expectancy of 10 years. 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 best results, the actual manufacturer and material components of each batch of discs should be verified. Burned CD-Rs suffer from material degradation, just like most writable media. CD-R media have an internal layer of dye used to store data. In a
CD-RW CD-RW (Compact Disc-Rewritable) is a digital optical disc storage format introduced in 1997. A CD-RW compact disc (CD-RWs) can be written, read, erased, and re-written. CD-RWs, as opposed to CDs, require specialized readers that have sens ...
disc, the recording layer is made of an alloy of silver and other metals—indium, antimony, and tellurium. In CD-R media, the dye itself can degrade, causing data to become unreadable. As well as degradation of the
dye A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and ...
, failure of a CD-R can be due to the reflective surface. While silver is less expensive and more widely used, it 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 material, so gold-based CD-Rs do not suffer from this problem. Manufacturers have estimated the longevity of gold-based CD-Rs to be as high as 100 years. 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 caused by media degradation.


Labeling

It is recommended if using adhesive-backed paper labels that the labels be specially made for CD-Rs. A balanced CD vibrates only slightly when rotated at high speed. Bad or improperly made labels, or labels applied off-center, unbalance the CD and can cause it to vibrate when it spins, which causes read errors and even risks damaging the drive. A professional alternative to CD labels is pre-printed CDs using a 5-color silkscreen or offset press. Using a permanent marker pen is also a common practice. However, solvents from such pens can affect the dye layer.


Disposal


Data confidentiality

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

The polycarbonate material and possible gold or silver in the reflective layer would make CD-Rs highly recyclable. However, the polycarbonate is of very little value and the quantity of precious metals is so small that it is not profitable to recover them. Consequently, recyclers that accept CD-Rs typically do not offer compensation for donating or transporting the materials.


See also

*
Absolute Time In Pregroove Absolute Time in Pregroove (ATIP) is a method of storing information on an optical medium, used on CD-R and CD-RW . ATIP information is only readable on CD-R and CD-RW drives, as read-only drives don't need the information stored on it. The infor ...
*
Blu-ray Disc The Blu-ray Disc (BD), often known simply as Blu-ray, is a digital optical disc data storage format. It was invented and developed in 2005 and released on June 20, 2006 worldwide. It is designed to supersede the DVD format, and capable of stori ...
*
CD recorder In computing, an optical disc drive is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only ...
* CD-R caddy *
CD-ROM A CD-ROM (, compact disc read-only memory) is a type of read-only memory consisting of a pre-pressed optical compact disc that contains data. Computers can read—but not write or erase—CD-ROMs. Some CDs, called enhanced CDs, hold both compute ...
, GD-ROM *
CD-RW CD-RW (Compact Disc-Rewritable) is a digital optical disc storage format introduced in 1997. A CD-RW compact disc (CD-RWs) can be written, read, erased, and re-written. CD-RWs, as opposed to CDs, require specialized readers that have sens ...
,
DVD-RW DVD recordable and DVD rewritable are optical disc recording technologies. Both terms describe DVD optical discs that can be written to by a DVD recorder, whereas only 'rewritable' discs are able to erase and rewrite data. Data is written ('bur ...
*
DVD The DVD (common abbreviation for Digital Video Disc or Digital Versatile Disc) is a digital optical disc data storage format. It was invented and developed in 1995 and first released on November 1, 1996, in Japan. The medium can store any kin ...
,
DVD-R DVD recordable and DVD rewritable are optical disc recording technologies. Both terms describe DVD optical discs that can be written to by a DVD recorder, whereas only 'rewritable' discs are able to erase and rewrite data. Data is written ('bur ...
, DVD+R,
DVD+R DL DVD+R DL (DL stands for Double Layer) also called DVD+R9, is a derivative of the DVD+R format created by the DVD+RW Alliance. Its use was first demonstrated in October 2003. DVD+R DL discs employ two recordable dye layers, each capable of stori ...
* HD DVD * Labelflash * LightScribe *
MultiLevel Recording MultiLevel Recording (ML, also known as M-ary) was a technology originally developed by Optex CorporationEarman, Allen, "Optical Data Storage With Electron Trapping Materials Using M-ary Data Channel Coding," Proceedings of the Optical Data Storag ...
, an obsolete technology (with non-binary modulation) * Optical disc authoring * Rainbow Books * GD-ROM *
MIL-CD MIL-CD or Music Interactive Live CD is a compact disc format created by the video game company Sega in 1998. The main purpose of MIL-CD was to add multimedia functions to music CDs, for use in Sega's Dreamcast video game console. For example, MIL- ...
*
List of optical disc manufacturers This aims to be a complete list of optical disc manufacturers, including pre-recorded/pressed/replicated, record-able/write-once and re-writable discs. This list is not necessarily complete or up to date - if you see a manufacturer that should be ...


References


External links


ECMA-394: Recordable Compact Disc Systems CD-R Multi-Speed
(standardized Orange Book, Part II, Volume 2)
The CD-R FAQ


at the Optical Storage Technology Association site. {{DEFAULTSORT:Cd-R Audiovisual introductions in 1988 Compact disc Optical computer storage media Audio storage Video storage Japanese inventions Dutch inventions Information technology in the Netherlands Science and technology in the Netherlands Information technology in Japan Science and technology in Japan