Compact Disc Lecture Notes

Introduction to Compact Discs

• Definition: A compact disc (CD) is a digital optical disc data storage format.
• Developed by: Co-developed by Philips and Sony.
• Purpose: Originally created to store and play digital audio recordings and later adapted for general-purpose data storage.
• Release Dates:
  • Japan: October 1982
  • North America and Europe: March 1983

Technical Specifications

• Media Type: Optical disc
• Capacity: Ranges from 650 MiB to 870 MiB, or 74 to 99 minutes of audio.
• Read/Write Mechanism: Uses a 780 nm laser diode.
• Physical Dimensions:
  • Diameter: 120 mm
  • Thickness: 1.2 mm
• Standardization: Described in the Rainbow Books.

Historical Development

• Origins: Evolved from LaserDisc technology.
• Key Developers: Philips and Sony, with contributions from engineers like Kees Schouhamer Immink.
• Standardization Efforts: Red Book CD-DA standard published in 1980.

Adoption and Popularity

• Market Growth: Surpassed phonograph records and cassette tapes by 1991 in the US.
• Peak Sales: Dominated the U.S. music market by 2000.
• First Commercial CD: A recording of Chopin's waltzes by Claudio Arrau.
• Major Releases: Billy Joel's "52nd Street" was the first album released on CD.

Formats and Variants

• Extensions: Led to formats like CD-ROM, CD-R, CD-RW, Video CD, and Super Audio CD.
• Writable CDs: CD-R and CD-RW allowed users to record data.
• Other Uses: Used for Photo CDs, CD+Graphics, and CD-Text.

Manufacturing and Cost

• Material Cost: In 1995, a CD cost approximately $0.75 to $1.15 to produce.
• Retail Pricing: CDs typically retailed for $16.98.

Decline and Current Trends

• Shift in Music Consumption: Digital downloads and streaming services led to a decline in CD sales.
• Resurgence: A minor resurgence in sales in recent years, with vinyl and cassettes also experiencing increased popularity.

Awards and Recognition

• Awards: Received a Technical Grammy Award in 1998 and an IEEE Milestone award in 2009.

Conclusion

The compact disc revolutionized the music and data storage industries, leading to a new era of digital media. Despite the decline in popularity due to digital streaming, CDs remain an important part of media history.