# CD-ROM

> pre-pressed compact disc containing computer data

**Wikidata**: [Q7982](https://www.wikidata.org/wiki/Q7982)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/CD-ROM)  
**Source**: https://4ort.xyz/entity/cd-rom

## Summary
A CD-ROM (Compact Disc Read-Only Memory) is a pre-pressed compact disc designed to store computer data. It is a type of digital optical disc that was widely used for software distribution, multimedia content, and data storage from the 1980s onward.

## Key Facts
- CD-ROM is a subclass of the compact disc, a digital optical disc data storage format introduced in 1979.
- The CD-ROM was invented in 1982 by Denon.
- It is part of the broader category of machine-readable media and recording media.
- CD-ROMs can be part of Mixed Mode CDs, which combine different data types on a single disc.
- Specialized variants include CD-ROM XA (eXtended Architecture) and DAISY discs for audiobooks.
- Notable early CD-ROMs include Beethoven's Ninth Symphony CD-ROM, one of the earliest examples.
- CD-ROMs have been used for diverse applications, including encyclopedias, educational materials, and music sample libraries.

## FAQs
### Q: What is a CD-ROM?
A: A CD-ROM is a pre-pressed compact disc that contains computer data, used for storing software, multimedia, and other digital content.

### Q: When was the CD-ROM invented?
A: The CD-ROM was invented in 1982 by Denon.

### Q: What are some variants of CD-ROM?
A: Variants include Mixed Mode CD, CD-ROM XA, and DAISY discs, each serving specific purposes like combining data types or formatting audiobooks.

### Q: What was one of the earliest CD-ROMs?
A: Beethoven's Ninth Symphony CD-ROM is one of the earliest known CD-ROMs.

### Q: How is a CD-ROM different from a regular compact disc?
A: While both are compact discs, a CD-ROM is specifically designed to store computer data, whereas a regular compact disc is typically used for audio.

## Why It Matters
The CD-ROM revolutionized data storage and distribution in the late 20th century. Before widespread internet access, CD-ROMs were the primary medium for distributing large software applications, multimedia content, and reference materials like encyclopedias. They enabled the mass distribution of digital data in a portable, durable, and cost-effective format. CD-ROMs played a crucial role in the growth of personal computing, education, and entertainment, bridging the gap between physical media and digital content. Their impact is evident in the proliferation of software, games, and educational resources that became accessible to a broad audience.

## Notable For
- Being one of the first widely adopted digital optical storage media for computer data.
- Enabling the distribution of large software applications and multimedia content before the internet era.
- Introducing specialized formats like CD-ROM XA for enhanced multimedia capabilities.
- Serving as a precursor to modern optical storage technologies like DVDs and Blu-ray discs.
- Facilitating the creation of interactive educational materials and reference works, such as CD-ROM encyclopedias.

## Body
### Overview
A CD-ROM is a type of compact disc designed to store computer data. It is a read-only medium, meaning data is written to the disc during manufacturing and cannot be altered by the end-user. CD-ROMs are part of the broader compact disc family, which includes audio CDs and other optical storage formats.

### History
The compact disc format was introduced in 1979, with the CD-ROM specifically invented in 1982 by Denon. This innovation allowed for the storage of digital data beyond audio, paving the way for software distribution and multimedia applications.

### Technical Specifications
CD-ROMs typically have a storage capacity of around 700 MB, although this can vary slightly depending on the manufacturing process. They use a spiral track of pits and lands on a reflective surface to store data, which is read by a laser in a CD-ROM drive.

### Variants and Specialized Formats
- **Mixed Mode CD**: Combines different data types, such as audio and computer data, on a single disc.
- **CD-ROM XA (eXtended Architecture)**: An enhanced standard for CD-ROMs that supports interleaved audio and video data, improving multimedia capabilities.
- **DAISY Disc**: A format specifically designed for audiobooks, providing structured navigation and accessibility features.
- **Bootable Business Card**: A CD-ROM shaped like a business card, often used for promotional or portable software distribution.

### Applications
CD-ROMs have been used for a wide range of applications, including:
- Software distribution (e.g., operating systems, applications).
- Multimedia content (e.g., games, educational software).
- Reference materials (e.g., encyclopedias, dictionaries).
- Music and sound sample libraries (e.g., "Didgeridoo & Other Primitive Instruments," "Supreme Beats").
- Educational and scientific resources (e.g., "3-D tour of the Solar System," "Alta Reflectance Spectrometer Introduction and Classroom Lessons").

### Notable Examples
- **Beethoven's Ninth Symphony CD-ROM**: One of the earliest CD-ROMs, showcasing the potential of the medium for multimedia content.
- **Clueless CD-ROM**: A 1997 tie-in product demonstrating the use of CD-ROMs for entertainment and marketing.
- **Heart of Africa and Heart of Asia**: Collections of traditional music and instruments distributed on CD-ROM, highlighting cultural preservation efforts.

### Legacy
While CD-ROMs have largely been replaced by DVDs, Blu-ray discs, and digital downloads, their impact on the digital revolution is significant. They played a crucial role in the transition from physical to digital media, enabling the widespread distribution of software and multimedia content.

## Schema Markup
```json
{
  "@context": "https://schema.org",
  "@type": "Thing",
  "name": "CD-ROM",
  "description": "A pre-pressed compact disc containing computer data.",
  "sameAs": [
    "https://www.wikidata.org/wiki/Q15241312",
    "https://en.wikipedia.org/wiki/CD-ROM"
  ],
  "additionalType": "CompactDisc"
}

## References

1. Integrated Authority File
2. [Nuovo soggettario](https://thes.bncf.firenze.sbn.it/termine.php?id=1386)
3. Freebase Data Dumps. 2013
4. Nuovo soggettario
5. YSO-Wikidata mapping project
6. UMLS 2023
7. ASC Leiden Thesaurus dataset of 5 June 2018
8. National Library of Israel
9. KBpedia
10. GF WordNet
11. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)
12. Wikibase TDKIV