Question: What year did Sony and Philips release CD-Recordable?

Answer: 1990

The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. From its origins as a musical format, CDs have grown to encompass other applications. In 1983, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. <hl> In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990 , CD-Recordable were introduced, also developed by both Sony and Philips. <hl> Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.

The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. From its origins as a musical format, CDs have grown to encompass other applications. In 1983, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. In June 1985, the computer-readable CD-ROM (read-only memory) and, in <hl> 1990 <hl>, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.

In June 1985, the computer-readable CD-ROM (read-only memory) and, in <hl> 1990 <hl> , CD-Recordable were introduced, also developed by both Sony and Philips.

question: What year did Sony and Philips release CD-Recordable?, context: The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. From its origins as a musical format, CDs have grown to encompass other applications. In 1983, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.


Question: What was the original intended format for CDs?

Answer: musical format

The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. <hl> From its origins as a musical format , CDs have grown to encompass other applications. <hl> In 1983, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.

The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. From its origins as a <hl> musical format <hl>, CDs have grown to encompass other applications. In 1983, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.

From its origins as a <hl> musical format <hl> , CDs have grown to encompass other applications.

question: What was the original intended format for CDs?, context: The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. From its origins as a musical format, CDs have grown to encompass other applications. In 1983, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.


Question: What year was the 73rd AES Convention?

Answer: 1983

The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. From its origins as a musical format, CDs have grown to encompass other applications. <hl> In 1983 , following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. <hl> In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.

The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. From its origins as a musical format, CDs have grown to encompass other applications. In <hl> 1983 <hl>, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.

In <hl> 1983 <hl> , following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention.

question: What year was the 73rd AES Convention?, context: The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. From its origins as a musical format, CDs have grown to encompass other applications. In 1983, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.


Question: What was the CDs predecessor?

Answer: the gramophone record

<hl> The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. <hl> From its origins as a musical format, CDs have grown to encompass other applications. In 1983, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.

The CD was planned to be the successor of <hl> the gramophone record <hl> for playing music, rather than primarily as a data storage medium. From its origins as a musical format, CDs have grown to encompass other applications. In 1983, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.

question: What was the CDs predecessor?, context: The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. From its origins as a musical format, CDs have grown to encompass other applications. In 1983, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.


Question: What was the CDs predecessor?

Answer: gramophone record

<hl> The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. <hl> From its origins as a musical format, CDs have grown to encompass other applications. In 1983, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.

The CD was planned to be the successor of the <hl> gramophone record <hl> for playing music, rather than primarily as a data storage medium. From its origins as a musical format, CDs have grown to encompass other applications. In 1983, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.

question: What was the CDs predecessor?, context: The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. From its origins as a musical format, CDs have grown to encompass other applications. In 1983, following the CD's introduction, Immink and Braat presented the first experiments with erasable compact discs during the 73rd AES Convention. In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. Recordable CDs were a new alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray use the same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CD.


Question: When did CD sales experience their original decline?

Answer: the 2000s

<hl> Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s . <hl> For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.

Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in <hl> the 2000s <hl>. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.

Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in <hl> the 2000s <hl> .

question: When did CD sales experience their original decline?, context: Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.


Question: What portion of music sales did CDs and DVDs account for in the United States as of 2012?

Answer: 34 percent

Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. <hl> As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. <hl> In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.

Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only <hl> 34 percent <hl> of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.

question: What portion of music sales did CDs and DVDs account for in the United States as of 2012?, context: Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.


Question: Which country attributes over 80 percent of its music sales to physical formats?

Answer: Japan

Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. <hl> In Japan , however, over 80 percent of music was bought on CDs and other physical formats as of 2015. <hl>

Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In <hl> Japan <hl>, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.

In <hl> Japan <hl> , however, over 80 percent of music was bought on CDs and other physical formats as of 2015.

question: Which country attributes over 80 percent of its music sales to physical formats?, context: Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.


Question: How are MP3s compressed?

Answer: lossily-compressed

<hl> Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. <hl> For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.

Meanwhile, with the advent and popularity of Internet-based distribution of files in <hl> lossily-compressed <hl> audio formats such as MP3, sales of CDs began to decline in the 2000s. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.

question: How are MP3s compressed?, context: Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.


Question: When did CD sales experience their original decline?

Answer: 2000s

<hl> Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s . <hl> For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.

Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the <hl> 2000s <hl>. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.

Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the <hl> 2000s <hl> .

question: When did CD sales experience their original decline?, context: Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.


Question: What has caused a decrease in CD sales?

Answer: Internet-based distribution of files

<hl> Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. <hl> For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.

Meanwhile, with the advent and popularity of <hl> Internet-based distribution of files <hl> in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.

question: What has caused a decrease in CD sales?, context: Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.


Question: How are CDs mass produced?

Answer: hydraulic press

<hl> Replicated CDs are mass-produced initially using a hydraulic press . <hl> Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring) is created. The time it takes to "stamp" one CD is usually two to three seconds.

Replicated CDs are mass-produced initially using a <hl> hydraulic press <hl>. Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring) is created. The time it takes to "stamp" one CD is usually two to three seconds.

Replicated CDs are mass-produced initially using a <hl> hydraulic press <hl> .

question: How are CDs mass produced?, context: Replicated CDs are mass-produced initially using a hydraulic press. Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring) is created. The time it takes to "stamp" one CD is usually two to three seconds.


Question: What type of material is used to make CDs?

Answer: raw polycarbonate plastic

Replicated CDs are mass-produced initially using a hydraulic press. <hl> Small granules of heated raw polycarbonate plastic are fed into the press. <hl> A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring) is created. The time it takes to "stamp" one CD is usually two to three seconds.

Replicated CDs are mass-produced initially using a hydraulic press. Small granules of heated <hl> raw polycarbonate plastic <hl> are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring) is created. The time it takes to "stamp" one CD is usually two to three seconds.

question: What type of material is used to make CDs?, context: Replicated CDs are mass-produced initially using a hydraulic press. Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring) is created. The time it takes to "stamp" one CD is usually two to three seconds.


Question: What size is the diameter of the center hole in a CD?

Answer: 15 mm

Replicated CDs are mass-produced initially using a hydraulic press. Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. <hl> Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring) is created. <hl> The time it takes to "stamp" one CD is usually two to three seconds.

Replicated CDs are mass-produced initially using a hydraulic press. Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a <hl> 15 mm <hl> diameter center hole (called a stacking ring) is created. The time it takes to "stamp" one CD is usually two to three seconds.

question: What size is the diameter of the center hole in a CD?, context: Replicated CDs are mass-produced initially using a hydraulic press. Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring) is created. The time it takes to "stamp" one CD is usually two to three seconds.


Question: How long does it take to stamp out one CD?

Answer: two to three seconds

Replicated CDs are mass-produced initially using a hydraulic press. Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring) is created. <hl> The time it takes to "stamp" one CD is usually two to three seconds . <hl>

Replicated CDs are mass-produced initially using a hydraulic press. Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring) is created. The time it takes to "stamp" one CD is usually <hl> two to three seconds <hl>.

The time it takes to "stamp" one CD is usually <hl> two to three seconds <hl> .

question: How long does it take to stamp out one CD?, context: Replicated CDs are mass-produced initially using a hydraulic press. Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring) is created. The time it takes to "stamp" one CD is usually two to three seconds.


Question: What is the term for the center hole in a CD?

Answer: stacking ring

Replicated CDs are mass-produced initially using a hydraulic press. Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. <hl> Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring ) is created. <hl> The time it takes to "stamp" one CD is usually two to three seconds.

Replicated CDs are mass-produced initially using a hydraulic press. Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a <hl> stacking ring <hl>) is created. The time it takes to "stamp" one CD is usually two to three seconds.

Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a <hl> stacking ring <hl> ) is created.

question: What is the term for the center hole in a CD?, context: Replicated CDs are mass-produced initially using a hydraulic press. Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring) is created. The time it takes to "stamp" one CD is usually two to three seconds.


Question: What materials can be used to make the reflective layer on a CD?

Answer: usually aluminium, but sometimes gold or other metal

This method produces the clear plastic blank part of the disc. <hl> After a metallic reflecting layer ( usually aluminium, but sometimes gold or other metal ) is applied to the clear blank substrate, the disc goes under a UV light for curing and it is ready to go to press. <hl> To prepare to press a CD, a glass master is made, using a high-powered laser on a device similar to a CD writer. The glass master is a positive image of the desired CD surface (with the desired microscopic pits and lands). After testing, it is used to make a die by pressing it against a metal disc.

This method produces the clear plastic blank part of the disc. After a metallic reflecting layer (<hl> usually aluminium, but sometimes gold or other metal <hl>) is applied to the clear blank substrate, the disc goes under a UV light for curing and it is ready to go to press. To prepare to press a CD, a glass master is made, using a high-powered laser on a device similar to a CD writer. The glass master is a positive image of the desired CD surface (with the desired microscopic pits and lands). After testing, it is used to make a die by pressing it against a metal disc.

After a metallic reflecting layer ( <hl> usually aluminium, but sometimes gold or other metal <hl> ) is applied to the clear blank substrate, the disc goes under a UV light for curing and it is ready to go to press.

question: What materials can be used to make the reflective layer on a CD?, context: This method produces the clear plastic blank part of the disc. After a metallic reflecting layer (usually aluminium, but sometimes gold or other metal) is applied to the clear blank substrate, the disc goes under a UV light for curing and it is ready to go to press. To prepare to press a CD, a glass master is made, using a high-powered laser on a device similar to a CD writer. The glass master is a positive image of the desired CD surface (with the desired microscopic pits and lands). After testing, it is used to make a die by pressing it against a metal disc.


Question: What type of light is used to cure CDs?

Answer: UV

This method produces the clear plastic blank part of the disc. <hl> After a metallic reflecting layer (usually aluminium, but sometimes gold or other metal) is applied to the clear blank substrate, the disc goes under a UV light for curing and it is ready to go to press. <hl> To prepare to press a CD, a glass master is made, using a high-powered laser on a device similar to a CD writer. The glass master is a positive image of the desired CD surface (with the desired microscopic pits and lands). After testing, it is used to make a die by pressing it against a metal disc.

This method produces the clear plastic blank part of the disc. After a metallic reflecting layer (usually aluminium, but sometimes gold or other metal) is applied to the clear blank substrate, the disc goes under a <hl> UV <hl> light for curing and it is ready to go to press. To prepare to press a CD, a glass master is made, using a high-powered laser on a device similar to a CD writer. The glass master is a positive image of the desired CD surface (with the desired microscopic pits and lands). After testing, it is used to make a die by pressing it against a metal disc.

question: What type of light is used to cure CDs?, context: This method produces the clear plastic blank part of the disc. After a metallic reflecting layer (usually aluminium, but sometimes gold or other metal) is applied to the clear blank substrate, the disc goes under a UV light for curing and it is ready to go to press. To prepare to press a CD, a glass master is made, using a high-powered laser on a device similar to a CD writer. The glass master is a positive image of the desired CD surface (with the desired microscopic pits and lands). After testing, it is used to make a die by pressing it against a metal disc.


Question: What is a glass master?

Answer: positive image of the desired CD surface

This method produces the clear plastic blank part of the disc. After a metallic reflecting layer (usually aluminium, but sometimes gold or other metal) is applied to the clear blank substrate, the disc goes under a UV light for curing and it is ready to go to press. To prepare to press a CD, a glass master is made, using a high-powered laser on a device similar to a CD writer. <hl> The glass master is a positive image of the desired CD surface (with the desired microscopic pits and lands). <hl> After testing, it is used to make a die by pressing it against a metal disc.

This method produces the clear plastic blank part of the disc. After a metallic reflecting layer (usually aluminium, but sometimes gold or other metal) is applied to the clear blank substrate, the disc goes under a UV light for curing and it is ready to go to press. To prepare to press a CD, a glass master is made, using a high-powered laser on a device similar to a CD writer. The glass master is a <hl> positive image of the desired CD surface <hl> (with the desired microscopic pits and lands). After testing, it is used to make a die by pressing it against a metal disc.

question: What is a glass master?, context: This method produces the clear plastic blank part of the disc. After a metallic reflecting layer (usually aluminium, but sometimes gold or other metal) is applied to the clear blank substrate, the disc goes under a UV light for curing and it is ready to go to press. To prepare to press a CD, a glass master is made, using a high-powered laser on a device similar to a CD writer. The glass master is a positive image of the desired CD surface (with the desired microscopic pits and lands). After testing, it is used to make a die by pressing it against a metal disc.


Question: How are glass masters created?

Answer: high-powered laser

This method produces the clear plastic blank part of the disc. After a metallic reflecting layer (usually aluminium, but sometimes gold or other metal) is applied to the clear blank substrate, the disc goes under a UV light for curing and it is ready to go to press. <hl> To prepare to press a CD, a glass master is made, using a high-powered laser on a device similar to a CD writer. <hl> The glass master is a positive image of the desired CD surface (with the desired microscopic pits and lands). After testing, it is used to make a die by pressing it against a metal disc.

This method produces the clear plastic blank part of the disc. After a metallic reflecting layer (usually aluminium, but sometimes gold or other metal) is applied to the clear blank substrate, the disc goes under a UV light for curing and it is ready to go to press. To prepare to press a CD, a glass master is made, using a <hl> high-powered laser <hl> on a device similar to a CD writer. The glass master is a positive image of the desired CD surface (with the desired microscopic pits and lands). After testing, it is used to make a die by pressing it against a metal disc.

question: How are glass masters created?, context: This method produces the clear plastic blank part of the disc. After a metallic reflecting layer (usually aluminium, but sometimes gold or other metal) is applied to the clear blank substrate, the disc goes under a UV light for curing and it is ready to go to press. To prepare to press a CD, a glass master is made, using a high-powered laser on a device similar to a CD writer. The glass master is a positive image of the desired CD surface (with the desired microscopic pits and lands). After testing, it is used to make a die by pressing it against a metal disc.


Question: What is the term for a negative image of the glass master?

Answer: die

<hl> The die is a negative image of the glass master: typically, several are made, depending on the number of pressing mills that are to make the CD. <hl> The die then goes into a press, and the physical image is transferred to the blank CD, leaving a final positive image on the disc. A small amount of lacquer is applied as a ring around the center of the disc, and rapid spinning spreads it evenly over the surface. Edge protection lacquer is applied before the disc is finished. The disc can then be printed and packed.

The <hl> die <hl> is a negative image of the glass master: typically, several are made, depending on the number of pressing mills that are to make the CD. The die then goes into a press, and the physical image is transferred to the blank CD, leaving a final positive image on the disc. A small amount of lacquer is applied as a ring around the center of the disc, and rapid spinning spreads it evenly over the surface. Edge protection lacquer is applied before the disc is finished. The disc can then be printed and packed.

question: What is the term for a negative image of the glass master?, context: The die is a negative image of the glass master: typically, several are made, depending on the number of pressing mills that are to make the CD. The die then goes into a press, and the physical image is transferred to the blank CD, leaving a final positive image on the disc. A small amount of lacquer is applied as a ring around the center of the disc, and rapid spinning spreads it evenly over the surface. Edge protection lacquer is applied before the disc is finished. The disc can then be printed and packed.


Question: How is the positive image on a CD protected?

Answer: lacquer

The die is a negative image of the glass master: typically, several are made, depending on the number of pressing mills that are to make the CD. The die then goes into a press, and the physical image is transferred to the blank CD, leaving a final positive image on the disc. <hl> A small amount of lacquer is applied as a ring around the center of the disc, and rapid spinning spreads it evenly over the surface. <hl> Edge protection lacquer is applied before the disc is finished. The disc can then be printed and packed.

The die is a negative image of the glass master: typically, several are made, depending on the number of pressing mills that are to make the CD. The die then goes into a press, and the physical image is transferred to the blank CD, leaving a final positive image on the disc. A small amount of <hl> lacquer <hl> is applied as a ring around the center of the disc, and rapid spinning spreads it evenly over the surface. Edge protection lacquer is applied before the disc is finished. The disc can then be printed and packed.

question: How is the positive image on a CD protected?, context: The die is a negative image of the glass master: typically, several are made, depending on the number of pressing mills that are to make the CD. The die then goes into a press, and the physical image is transferred to the blank CD, leaving a final positive image on the disc. A small amount of lacquer is applied as a ring around the center of the disc, and rapid spinning spreads it evenly over the surface. Edge protection lacquer is applied before the disc is finished. The disc can then be printed and packed.


Question: How is lacquer distrubted on a CD?

Answer: rapid spinning

The die is a negative image of the glass master: typically, several are made, depending on the number of pressing mills that are to make the CD. The die then goes into a press, and the physical image is transferred to the blank CD, leaving a final positive image on the disc. <hl> A small amount of lacquer is applied as a ring around the center of the disc, and rapid spinning spreads it evenly over the surface. <hl> Edge protection lacquer is applied before the disc is finished. The disc can then be printed and packed.

The die is a negative image of the glass master: typically, several are made, depending on the number of pressing mills that are to make the CD. The die then goes into a press, and the physical image is transferred to the blank CD, leaving a final positive image on the disc. A small amount of lacquer is applied as a ring around the center of the disc, and <hl> rapid spinning <hl> spreads it evenly over the surface. Edge protection lacquer is applied before the disc is finished. The disc can then be printed and packed.

question: How is lacquer distrubted on a CD?, context: The die is a negative image of the glass master: typically, several are made, depending on the number of pressing mills that are to make the CD. The die then goes into a press, and the physical image is transferred to the blank CD, leaving a final positive image on the disc. A small amount of lacquer is applied as a ring around the center of the disc, and rapid spinning spreads it evenly over the surface. Edge protection lacquer is applied before the disc is finished. The disc can then be printed and packed.


Question: What is the priciest component of a CD?

Answer: jewel case

<hl> The most expensive part of a CD is the jewel case . <hl> In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.

The most expensive part of a CD is the <hl> jewel case <hl>. In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.

The most expensive part of a CD is the <hl> jewel case <hl> .

question: What is the priciest component of a CD?, context: The most expensive part of a CD is the jewel case. In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.


Question: Why did the cost of audio music increase when the production costs decreased?

Answer: value increased

The most expensive part of a CD is the jewel case. In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. <hl> This was done because the apparent value increased . <hl> This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.

The most expensive part of a CD is the jewel case. In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent <hl> value increased <hl>. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.

This was done because the apparent <hl> value increased <hl> .

question: Why did the cost of audio music increase when the production costs decreased?, context: The most expensive part of a CD is the jewel case. In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.


Question: What did CDs retail for in 1995?

Answer: $16.98

The most expensive part of a CD is the jewel case. In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. <hl> Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98 . <hl> On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.

The most expensive part of a CD is the jewel case. In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for <hl> $16.98 <hl>. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.

Wholesale cost of CDs was $0.75 to $1.15, which retailed for <hl> $16.98 <hl> .

question: What did CDs retail for in 1995?, context: The most expensive part of a CD is the jewel case. In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.


Question: Who received the most profit from the sale of CDs?

Answer: the store

The most expensive part of a CD is the jewel case. In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. <hl> On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. <hl> When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.

The most expensive part of a CD is the jewel case. In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. On average, <hl> the store <hl> received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.

question: Who received the most profit from the sale of CDs?, context: The most expensive part of a CD is the jewel case. In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.


Question: How much did a jewel case cost in 1995?

Answer: 30 cents

The most expensive part of a CD is the jewel case. <hl> In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. <hl> Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.

The most expensive part of a CD is the jewel case. In 1995, material costs were <hl> 30 cents <hl> for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.

question: How much did a jewel case cost in 1995?, context: The most expensive part of a CD is the jewel case. In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.


Question: How long are CDs expected to last?

Answer: 20 to 100 years

CD-R recordings are designed to be permanent. Over time, the dye's physical characteristics may change causing read errors and data loss until the reading device cannot recover with error correction methods. <hl> The design life is from 20 to 100 years , depending on the quality of the discs, the quality of the writing drive, and storage conditions. <hl> However, testing has demonstrated such degradation of some discs in as little as 18 months under normal storage conditions. This failure is known as disc rot, for which there are several, mostly environmental, reasons.

CD-R recordings are designed to be permanent. Over time, the dye's physical characteristics may change causing read errors and data loss until the reading device cannot recover with error correction methods. The design life is from <hl> 20 to 100 years <hl>, depending on the quality of the discs, the quality of the writing drive, and storage conditions. However, testing has demonstrated such degradation of some discs in as little as 18 months under normal storage conditions. This failure is known as disc rot, for which there are several, mostly environmental, reasons.

The design life is from <hl> 20 to 100 years <hl> , depending on the quality of the discs, the quality of the writing drive, and storage conditions.

question: How long are CDs expected to last?, context: CD-R recordings are designed to be permanent. Over time, the dye's physical characteristics may change causing read errors and data loss until the reading device cannot recover with error correction methods. The design life is from 20 to 100 years, depending on the quality of the discs, the quality of the writing drive, and storage conditions. However, testing has demonstrated such degradation of some discs in as little as 18 months under normal storage conditions. This failure is known as disc rot, for which there are several, mostly environmental, reasons.


Question: What can cause sudden disc degradation?

Answer: disc rot

CD-R recordings are designed to be permanent. Over time, the dye's physical characteristics may change causing read errors and data loss until the reading device cannot recover with error correction methods. The design life is from 20 to 100 years, depending on the quality of the discs, the quality of the writing drive, and storage conditions. However, testing has demonstrated such degradation of some discs in as little as 18 months under normal storage conditions. <hl> This failure is known as disc rot , for which there are several, mostly environmental, reasons. <hl>

CD-R recordings are designed to be permanent. Over time, the dye's physical characteristics may change causing read errors and data loss until the reading device cannot recover with error correction methods. The design life is from 20 to 100 years, depending on the quality of the discs, the quality of the writing drive, and storage conditions. However, testing has demonstrated such degradation of some discs in as little as 18 months under normal storage conditions. This failure is known as <hl> disc rot <hl>, for which there are several, mostly environmental, reasons.

This failure is known as <hl> disc rot <hl> , for which there are several, mostly environmental, reasons.

question: What can cause sudden disc degradation?, context: CD-R recordings are designed to be permanent. Over time, the dye's physical characteristics may change causing read errors and data loss until the reading device cannot recover with error correction methods. The design life is from 20 to 100 years, depending on the quality of the discs, the quality of the writing drive, and storage conditions. However, testing has demonstrated such degradation of some discs in as little as 18 months under normal storage conditions. This failure is known as disc rot, for which there are several, mostly environmental, reasons.


Question: Are CDs meant for permanent or temporary use?

Answer: permanent

<hl> CD-R recordings are designed to be permanent . <hl> Over time, the dye's physical characteristics may change causing read errors and data loss until the reading device cannot recover with error correction methods. The design life is from 20 to 100 years, depending on the quality of the discs, the quality of the writing drive, and storage conditions. However, testing has demonstrated such degradation of some discs in as little as 18 months under normal storage conditions. This failure is known as disc rot, for which there are several, mostly environmental, reasons.

CD-R recordings are designed to be <hl> permanent <hl>. Over time, the dye's physical characteristics may change causing read errors and data loss until the reading device cannot recover with error correction methods. The design life is from 20 to 100 years, depending on the quality of the discs, the quality of the writing drive, and storage conditions. However, testing has demonstrated such degradation of some discs in as little as 18 months under normal storage conditions. This failure is known as disc rot, for which there are several, mostly environmental, reasons.

CD-R recordings are designed to be <hl> permanent <hl> .

question: Are CDs meant for permanent or temporary use?, context: CD-R recordings are designed to be permanent. Over time, the dye's physical characteristics may change causing read errors and data loss until the reading device cannot recover with error correction methods. The design life is from 20 to 100 years, depending on the quality of the discs, the quality of the writing drive, and storage conditions. However, testing has demonstrated such degradation of some discs in as little as 18 months under normal storage conditions. This failure is known as disc rot, for which there are several, mostly environmental, reasons.


Question: What does SCMS stand for?

Answer: Serial Copy Management System

The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. <hl> These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). <hl> The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.

The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. These consumer audio CD recorders use the <hl> Serial Copy Management System <hl> (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.

question: What does SCMS stand for?, context: The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.


Question: What does DRM stand for?

Answer: digital rights management

The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. <hl> These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). <hl> The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.

The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of <hl> digital rights management <hl> (DRM), to conform to the United States' Audio Home Recording Act (AHRA). The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.

question: What does DRM stand for?, context: The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.


Question: What does AHRA stand for?

Answer: Audio Home Recording Act

The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. <hl> These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). <hl> The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.

The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' <hl> Audio Home Recording Act <hl> (AHRA). The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.

question: What does AHRA stand for?, context: The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.


Question: What type of CD is intended to be used in a Consumer audio CD Recorder?

Answer: ReWritable Audio CD

<hl> The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. <hl> These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.

The <hl> ReWritable Audio CD <hl> is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.

question: What type of CD is intended to be used in a Consumer audio CD Recorder?, context: The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.


Question: Which is less expensive, the ReWritable Audio CD or a CD-RW?

Answer: CD-RW

<hl> The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. <hl> These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.

The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard <hl> CD-RW <hl> discs. These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.

question: Which is less expensive, the ReWritable Audio CD or a CD-RW?, context: The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). The ReWritable Audio CD is typically somewhat more expensive than CD-RW due to (a) lower volume and (b) a 3% AHRA royalty used to compensate the music industry for the making of a copy.


Question: How fast could the first ReWritable CD be written?

Answer: 4x speed

<hl> Due to technical limitations, the original ReWritable CD could be written no faster than 4x speed . <hl> High Speed ReWritable CD has a different design, which permits writing at speeds ranging from 4x to 12x. Original CD-RW drives can only write to original ReWritable CDs. High Speed CD-RW drives can typically write to both original ReWritable CDs and High Speed ReWritable CDs. Both types of CD-RW discs can be read in most CD drives. Higher speed CD-RW discs, Ultra Speed (16x to 24x write speed) and Ultra Speed+ (32x write speed) are now available.

Due to technical limitations, the original ReWritable CD could be written no faster than <hl> 4x speed <hl>. High Speed ReWritable CD has a different design, which permits writing at speeds ranging from 4x to 12x. Original CD-RW drives can only write to original ReWritable CDs. High Speed CD-RW drives can typically write to both original ReWritable CDs and High Speed ReWritable CDs. Both types of CD-RW discs can be read in most CD drives. Higher speed CD-RW discs, Ultra Speed (16x to 24x write speed) and Ultra Speed+ (32x write speed) are now available.

Due to technical limitations, the original ReWritable CD could be written no faster than <hl> 4x speed <hl> .

question: How fast could the first ReWritable CD be written?, context: Due to technical limitations, the original ReWritable CD could be written no faster than 4x speed. High Speed ReWritable CD has a different design, which permits writing at speeds ranging from 4x to 12x. Original CD-RW drives can only write to original ReWritable CDs. High Speed CD-RW drives can typically write to both original ReWritable CDs and High Speed ReWritable CDs. Both types of CD-RW discs can be read in most CD drives. Higher speed CD-RW discs, Ultra Speed (16x to 24x write speed) and Ultra Speed+ (32x write speed) are now available.


Question: Which CD has writing speeds betwen 4x and 12x?

Answer: High Speed ReWritable CD

Due to technical limitations, the original ReWritable CD could be written no faster than 4x speed. <hl> High Speed ReWritable CD has a different design, which permits writing at speeds ranging from 4x to 12x. <hl> Original CD-RW drives can only write to original ReWritable CDs. High Speed CD-RW drives can typically write to both original ReWritable CDs and High Speed ReWritable CDs. Both types of CD-RW discs can be read in most CD drives. Higher speed CD-RW discs, Ultra Speed (16x to 24x write speed) and Ultra Speed+ (32x write speed) are now available.

Due to technical limitations, the original ReWritable CD could be written no faster than 4x speed. <hl> High Speed ReWritable CD <hl> has a different design, which permits writing at speeds ranging from 4x to 12x. Original CD-RW drives can only write to original ReWritable CDs. High Speed CD-RW drives can typically write to both original ReWritable CDs and High Speed ReWritable CDs. Both types of CD-RW discs can be read in most CD drives. Higher speed CD-RW discs, Ultra Speed (16x to 24x write speed) and Ultra Speed+ (32x write speed) are now available.

question: Which CD has writing speeds betwen 4x and 12x?, context: Due to technical limitations, the original ReWritable CD could be written no faster than 4x speed. High Speed ReWritable CD has a different design, which permits writing at speeds ranging from 4x to 12x. Original CD-RW drives can only write to original ReWritable CDs. High Speed CD-RW drives can typically write to both original ReWritable CDs and High Speed ReWritable CDs. Both types of CD-RW discs can be read in most CD drives. Higher speed CD-RW discs, Ultra Speed (16x to 24x write speed) and Ultra Speed+ (32x write speed) are now available.


Question: How fast can Ultra Speed+ CDs write?

Answer: 32x

Due to technical limitations, the original ReWritable CD could be written no faster than 4x speed. High Speed ReWritable CD has a different design, which permits writing at speeds ranging from 4x to 12x. Original CD-RW drives can only write to original ReWritable CDs. High Speed CD-RW drives can typically write to both original ReWritable CDs and High Speed ReWritable CDs. Both types of CD-RW discs can be read in most CD drives. <hl> Higher speed CD-RW discs, Ultra Speed (16x to 24x write speed) and Ultra Speed+ ( 32x write speed) are now available. <hl>

Due to technical limitations, the original ReWritable CD could be written no faster than 4x speed. High Speed ReWritable CD has a different design, which permits writing at speeds ranging from 4x to 12x. Original CD-RW drives can only write to original ReWritable CDs. High Speed CD-RW drives can typically write to both original ReWritable CDs and High Speed ReWritable CDs. Both types of CD-RW discs can be read in most CD drives. Higher speed CD-RW discs, Ultra Speed (16x to 24x write speed) and Ultra Speed+ (<hl> 32x <hl> write speed) are now available.

Higher speed CD-RW discs, Ultra Speed (16x to 24x write speed) and Ultra Speed+ ( <hl> 32x <hl> write speed) are now available.

question: How fast can Ultra Speed+ CDs write?, context: Due to technical limitations, the original ReWritable CD could be written no faster than 4x speed. High Speed ReWritable CD has a different design, which permits writing at speeds ranging from 4x to 12x. Original CD-RW drives can only write to original ReWritable CDs. High Speed CD-RW drives can typically write to both original ReWritable CDs and High Speed ReWritable CDs. Both types of CD-RW discs can be read in most CD drives. Higher speed CD-RW discs, Ultra Speed (16x to 24x write speed) and Ultra Speed+ (32x write speed) are now available.


Question: How fast can Ultra Speed CDs write?

Answer: 16x to 24x

Due to technical limitations, the original ReWritable CD could be written no faster than 4x speed. High Speed ReWritable CD has a different design, which permits writing at speeds ranging from 4x to 12x. Original CD-RW drives can only write to original ReWritable CDs. High Speed CD-RW drives can typically write to both original ReWritable CDs and High Speed ReWritable CDs. Both types of CD-RW discs can be read in most CD drives. <hl> Higher speed CD-RW discs, Ultra Speed ( 16x to 24x write speed) and Ultra Speed+ (32x write speed) are now available. <hl>

Due to technical limitations, the original ReWritable CD could be written no faster than 4x speed. High Speed ReWritable CD has a different design, which permits writing at speeds ranging from 4x to 12x. Original CD-RW drives can only write to original ReWritable CDs. High Speed CD-RW drives can typically write to both original ReWritable CDs and High Speed ReWritable CDs. Both types of CD-RW discs can be read in most CD drives. Higher speed CD-RW discs, Ultra Speed (<hl> 16x to 24x <hl> write speed) and Ultra Speed+ (32x write speed) are now available.

Higher speed CD-RW discs, Ultra Speed ( <hl> 16x to 24x <hl> write speed) and Ultra Speed+ (32x write speed) are now available.

question: How fast can Ultra Speed CDs write?, context: Due to technical limitations, the original ReWritable CD could be written no faster than 4x speed. High Speed ReWritable CD has a different design, which permits writing at speeds ranging from 4x to 12x. Original CD-RW drives can only write to original ReWritable CDs. High Speed CD-RW drives can typically write to both original ReWritable CDs and High Speed ReWritable CDs. Both types of CD-RW discs can be read in most CD drives. Higher speed CD-RW discs, Ultra Speed (16x to 24x write speed) and Ultra Speed+ (32x write speed) are now available.


Question: Where is the semiconductor laser found in a CD player?

Answer: on a swing arm

A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. <hl> In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. <hl> This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.

A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed <hl> on a swing arm <hl> within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.

question: Where is the semiconductor laser found in a CD player?, context: A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.


Question: What wavelenght is used to pull data from a CD?

Answer: 780 nm

<hl> A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. <hl> The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.

A CD is read by focusing a <hl> 780 nm <hl> wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.

question: What wavelenght is used to pull data from a CD?, context: A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.


Question: What is used to discern the change of intensity in light on a CD?

Answer: photodiode

A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. <hl> By measuring the intensity change with a photodiode , the data can be read from the disc. <hl> In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.

A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a <hl> photodiode <hl>, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.

By measuring the intensity change with a <hl> photodiode <hl> , the data can be read from the disc.

question: What is used to discern the change of intensity in light on a CD?, context: A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.


Question: In what pattern is data stored on a CD?

Answer: spiral

A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. <hl> In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. <hl> This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.

A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the <hl> spiral <hl> pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.

question: In what pattern is data stored on a CD?, context: A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.


Question: What createds the change in light reflected off of a CD?

Answer: change in height between pits and lands

A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. <hl> The change in height between pits and lands results in a difference in the way the light is reflected. <hl> By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.

A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The <hl> change in height between pits and lands <hl> results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.

question: What createds the change in light reflected off of a CD?, context: A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.


Question: What type of result from a CD will return a one?

Answer: change from pit to land or land to pit

The pits and lands themselves do not directly represent the zeros and ones of binary data. <hl> Instead, non-return-to-zero, inverted encoding is used: a change from pit to land or land to pit indicates a one, while no change indicates a series of zeros. <hl> There must be at least two and no more than ten zeros between each one, which is defined by the length of the pit. This in turn is decoded by reversing the eight-to-fourteen modulation used in mastering the disc, and then reversing the cross-interleaved Reed–Solomon coding, finally revealing the raw data stored on the disc. These encoding techniques (defined in the Red Book) were originally designed for CD Digital Audio, but they later became a standard for almost all CD formats (such as CD-ROM).

The pits and lands themselves do not directly represent the zeros and ones of binary data. Instead, non-return-to-zero, inverted encoding is used: a <hl> change from pit to land or land to pit <hl> indicates a one, while no change indicates a series of zeros. There must be at least two and no more than ten zeros between each one, which is defined by the length of the pit. This in turn is decoded by reversing the eight-to-fourteen modulation used in mastering the disc, and then reversing the cross-interleaved Reed–Solomon coding, finally revealing the raw data stored on the disc. These encoding techniques (defined in the Red Book) were originally designed for CD Digital Audio, but they later became a standard for almost all CD formats (such as CD-ROM).

question: What type of result from a CD will return a one?, context: The pits and lands themselves do not directly represent the zeros and ones of binary data. Instead, non-return-to-zero, inverted encoding is used: a change from pit to land or land to pit indicates a one, while no change indicates a series of zeros. There must be at least two and no more than ten zeros between each one, which is defined by the length of the pit. This in turn is decoded by reversing the eight-to-fourteen modulation used in mastering the disc, and then reversing the cross-interleaved Reed–Solomon coding, finally revealing the raw data stored on the disc. These encoding techniques (defined in the Red Book) were originally designed for CD Digital Audio, but they later became a standard for almost all CD formats (such as CD-ROM).