Published
compact disc
vr.tr.compact-disc · thing-q34467
Let an agent explain the compact disc format, its variants, specifications and preservation, from standards and archival sources.
Thing Registry Physical world and living systems PHY.OBJ
Bundle → Layer → Finding → QuestionsClassifiersWhat it isWhy it existsDistinguishing featuresWhat robots and AI may and may not doMoral aspectsOwnersLinks to other meta-modelsIdentity and identifiersDirect propertiesRecognitionCapabilities and actionsHazards and failure modesStandards and interfacesContext of useSources
Bundle → Layer → Finding → Questions Filled
4 bundles · 8 layers · 8 findings · 16 questions
Disc Which disc.
Format
Type.
Format
Physical medium (pressed, CD-R, CD-RW) and logical format (audio or data), recorded separately.
- CD-DA, CD-ROM, CD-R or CD-RW? boundary
- Per which specification? provenance
Release
Item.
Release
Identifier.
- Which release? provenance
- Which UPC or catalogue number? provenance
Specification Technical data.
Physical
Dimensions.
Physical
Values.
- What diameter and thickness? measurement
- Per which standard? provenance
Data
Capacity.
Capacity
Value.
- What capacity or duration? measurement
- Per which format? provenance
Content Tracks.
Tracks
List.
Track
Title and ISRC.
- Which tracks? provenance
- Which ISRCs? provenance
Rights
Copyright.
Rights
Holder.
- Who holds the rights? provenance
- Per which credit? provenance
Preservation Care.
Condition
State.
Condition
Assessment.
- What is the disc condition? provenance
- Measured by error rate? measurement
Storage
Conditions.
Storage
Recommendation.
- How should it be stored? provenance
- Per which archival guidance? provenance
Classifiers Filled
- Family
- Thing Registry
- Category
- Physical world and living systems
- Entry kind
- thing
- Plane
- PHY
- Domain
- PHY.OBJ
- Other names and narrower kinds
- 5 × CD, 6 × CD, Compact Disc Digital Audio, 5.1 Music Disc, Mini CD, cDVD, audiobook CD, Compressed audio optical disc, High Definition Compatible Digital, CD-MO, CD-RW, gold compact disc
What it is Filled
A digital optical disc data storage format developed by Philips and Sony and released in 1982, typically 120 mm in diameter, read by a 780 nm laser; first used for digital audio (CD-DA, Red Book, 44.1 kHz 16-bit stereo, up to about 74-80 minutes) and later for data (CD-ROM), recordable (CD-R) and rewritable (CD-RW) media.
Why it exists Filled
Let an agent explain the compact disc format, its variants, specifications and preservation, from standards and archival sources.
Distinguishing features Filled
- Audio CD is specified in the Red Book (IEC 60908); CD-ROM in the Yellow Book (ISO/IEC 10149); data uses EFM coding and CIRC error correction.
- Pressed discs have moulded pits; CD-R uses a dye layer and CD-RW a phase-change layer.
- Typical capacity about 650-700 MB of data or 74-80 minutes of audio.
What robots and AI may and may not do Filled
Must not
- help circumvent copy protection unlawfully
May
- explain formats and preservation
Moral aspects Filled
- copyright
- digital preservation
Who is affected
- artists
- archives
Owners Filled
Steward
nobody; a format; the specifications are licensed and standardised
Links to other meta-models Filled
parent
- Q1048236 - registry parent class
- Q117208271 - registry parent class
- Q234870 - registry parent class
- Q354004 - registry parent class
- Q66221 - registry parent class
related
- optical disc - storage medium
- DVD - format
- Super Audio CD - distinct format; hybrids carry a CD layer
- laser - reading technology
What else AI and robots need to interact with it Filled
Identity and identifiers required Filled
- Vercy registry: vr.tr.compact-disc
- Wikidata: Q34467 (https://www.wikidata.org/wiki/Q34467)
- ISRC: 12 characters tracks
- UPC/EAN: 12 or 13 digits releases
- IFPI SID code: on the disc manufacturing plant
Direct properties required Filled
- diameter: 120 mm - 80 mm mini CD also exists
- thickness and centre hole: 1.2 mm thick, 15 mm hole - nominal
- audio format: 44.1 kHz, 16-bit, 2 channels - Red Book
Recognition required Filled
- Iridescent 12 cm disc with the Compact Disc logo
- A thin, shiny polycarbonate disc 120 mm across with a central hole, iridescent on the data side.
Capabilities and actions required Filled
- explain formats and specifications
- explain capacity and audio parameters
- explain care and preservation
- explain identifiers such as ISRC on CDs
Hazards and failure modes required Filled
- Disc rot and dye degradation
- Scratches causing read errors
Standards and interfaces required Filled
- IEC 60908 (Red Book, CD-DA)
- ISO/IEC 10149 (Yellow Book, CD-ROM)
- ISO 9660 file system
- ISO 18927:2013 recordable-CD life expectancy (withdrawn)
Context of use required Filled
- Storing and distributing digital audio and data.
- CD-DA (audio)
- CD-ROM
- CD-R
- CD-RW
- Mini CD
- Video CD
- Enhanced CD
Sources Filled
- Q34467 - identity of the registry item, labels and sitelinks
- Compact disc - general description of the subject
- IEC 60908:1999 - Audio recording - Compact disc digital audio system - Audio-CD standard scope and issuing body.
- ECMA-130: Data interchange on read-only 120 mm optical data disks - CD-ROM dimensions, optical reading, channel coding, error correction and ISO/IEC 10149 correspondence.
- ISO 18927:2013 - Withdrawn status and temperature/humidity life-expectancy test scope.
- Care and Handling of CDs and DVDs: A Guide for Librarians and Archivists - Disc construction, dimensions, dye and phase-change media, degradation and preservation.
- New Sound Recording Formats - Library of Congress Practice - SACD as a distinct format and the existence of hybrid and non-hybrid SACDs.
- International Standard Recording Code - ISRC has 12 alphanumeric characters and identifies recordings rather than physical discs or releases.
Open questions
- The registry merges multi-disc packages and other formats; they need review.
Machine files
Provenance
thing registry research (pass 2) · unreviewed
Built from: models/things/publications/thing-q34467/spec.json