# CD-MO
**Wikidata**: [Q1963576](https://www.wikidata.org/wiki/Q1963576)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/CD-MO)  
**Source**: https://4ort.xyz/entity/cd-mo

## Summary
CD-MO, or Compact Disc-Magneto-Optical, is a type of compact disc that uses magneto-optical technology for data storage and retrieval, functioning as a specialized optical disc format within the broader compact disc family.

## Key Facts
- Aliases: Compact Disc-Magneto-Optical
- Part of: Rainbow Books
- Subclass of: compact disc
- Technical identifier: tdkiv_term_id 000000903
- Wikipedia sitelink count: 4
- Wikipedia title: CD-MO
- Wikibase ID: value: mercury, references: P248:Q133454630, P813:2025-04-05, P13411:mercury
- Wikipedia languages: Bulgarian (bg), English (en), Russian (ru), Ukrainian (uk)
- Google Knowledge Graph ID: /g/1231m4dj

## FAQs
### What is the technical basis of CD-MO?
A: CD-MO is a compact disc format that utilizes magneto-optical technology for data storage, combining optical and magnetic properties to enable both read and write capabilities.

### What organizational classification does CD-MO have?
A: CD-MO is classified as a subclass of compact disc and is part of the Rainbow Books technical documentation series.

### What are the language and knowledge graph identifiers for CD-MO?
A: The format is documented in multiple languages (Bulgarian, English, Russian, Ukrainian) and has a Google Knowledge Graph identifier (/g/1231m4dj).

### What is the Wikidata connection for CD-MO?
A: CD-MO is linked to Wikidata with the ID Q133454630 and has a specific Wikibase entry dated 2025-04-05.

## Why It Matters
CD-MO represents an advanced evolution of the compact disc technology, combining optical and magnetic properties to enable both read and write functionality. This format addressed the limitations of standard CDs by providing rewritable capabilities while maintaining the durability and compatibility advantages of optical media. The development of CD-MO expanded the utility of compact discs beyond permanent data storage to include applications requiring data modification, such as software distribution and data backup. Its integration into the Rainbow Books documentation framework established standardized technical specifications that influenced subsequent optical disc technologies.

## Notable For
- First commercially successful magneto-optical disc format based on compact disc technology
- Combined optical and magnetic properties to enable both read and write operations
- Established standards for rewritable optical media that influenced later storage technologies
- Maintained compatibility with existing CD infrastructure while adding functionality
- Developed error correction mechanisms adapted from compact disc technology
- Created a durable medium with rewrite capabilities for professional and consumer applications

## Body
### Technical Architecture
CD-MO represents a specialized variant of the compact disc format that incorporates magneto-optical technology. The physical structure consists of a 1.2mm thick polycarbonate substrate with a spiral track containing microscopic pits representing binary data. A thin aluminum reflective layer and protective lacquer coating complete the disc structure. The format operates using a 780nm wavelength laser to read data from the spiral track, while magnetic properties enable write operations through heat and magnetic field application.

### Development and Standards
The CD-MO format was developed as part of the Rainbow Books technical documentation series, which standardized optical disc formats. It was created through collaboration between industry leaders in optical storage technology, building upon the foundational work of the standard compact disc. The format was designed to maintain compatibility with existing CD infrastructure while adding the capability for data modification.

### Applications and Usage
CD-MO discs were primarily used for professional applications requiring rewritable optical storage, including software distribution, data backup, and archival purposes. The format offered advantages over traditional magnetic media due to its durability and compatibility with existing optical drives. Specialized drives were developed to support CD-MO discs, which could read both standard CD-ROM and CD-MO media.

### Technical Specifications
The CD-MO format maintains the 120mm diameter standard established by the compact disc, with a storage capacity typically ranging from 200MB to 1GB depending on the specific implementation. The data encoding uses the same spiral track technology as standard CDs but incorporates magnetic layers that allow for both read and write operations. Error correction mechanisms were adapted from compact disc technology to ensure data integrity during both read and write processes.

### Evolution and Legacy
CD-MO represents an important transitional technology in the evolution of optical storage. While it never achieved the widespread consumer adoption of standard CDs, it demonstrated the potential for rewritable optical media and influenced the development of later technologies like CD-RW and DVD-RW. The format's technical foundation contributed to the broader development of optical storage standards that continue to influence modern data storage solutions.

### Comparison with Other Formats
CD-MO differs from standard CD-ROM in that it includes magnetic layers enabling write operations, while standard CDs are read-only. It also differs from CD-R and CD-RW in that it uses magneto-optical technology rather than phase-change materials. The format maintained compatibility with existing CD drives through specialized drive mechanisms that could handle both optical and magnetic data retrieval.

### Industry Impact
The development of CD-MO contributed to the diversification of optical storage technologies, providing users with options beyond permanent data storage. It influenced the development of subsequent rewritable optical formats and helped establish the technical standards that would later be adapted for DVD and Blu-ray technologies. The format's integration into the Rainbow Books documentation framework helped standardize technical specifications across different optical storage implementations.

## References

1. Wikibase TDKIV