# CMD640

> IDE controller

**Wikidata**: [Q5012869](https://www.wikidata.org/wiki/Q5012869)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/CMD640)  
**Source**: https://4ort.xyz/entity/cmd640

Here’s the structured knowledge entry for **CMD640** based on the provided source material:

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## Summary  
The CMD640 is an IDE controller, a type of integrated circuit used to manage communication between a motherboard and peripheral storage devices. It complies with the Parallel ATA standard and functions as a critical component in computing systems for interfacing with hard drives or optical drives.

## Key Facts  
- **Instance of**: Integrated circuit model  
- **Subclass of**: Controller and integrated circuit  
- **Complies with**: Parallel ATA  
- **Used by**: Motherboard  
- **Image**: [CMD640B.jpg](https://commons.wikimedia.org/wiki/Special:FilePath/Cmd640b.jpg)  
- **Wikidata description**: IDE controller  
- **Freebase ID**: `/m/02wcrgm`  
- **Wikipedia title**: `CMD640` (English only)  
- **Documentation**: Described in [Linux kernel documentation](https://www.kernel.org/doc/Documentation/ide/ide.txt) (last accessed February 23, 2020)  

## FAQs  
### Q: What is the primary function of the CMD640?  
A: The CMD640 acts as an IDE controller, facilitating data transfer between a motherboard and storage devices like hard drives using the Parallel ATA standard.  

### Q: Is the CMD640 still used today?  
A: While newer standards like SATA have largely replaced Parallel ATA, the CMD640 remains relevant for legacy systems and historical understanding of early IDE controllers.  

### Q: What devices typically include the CMD640?  
A: The CMD640 was integrated into motherboards to enable connectivity with IDE-compatible storage peripherals, such as hard drives and optical drives.  

## Why It Matters  
The CMD640 played a pivotal role in early computing by standardizing IDE (Integrated Drive Electronics) communication through Parallel ATA. This allowed for faster and more reliable data transfer between motherboards and storage devices compared to earlier interfaces. Its adoption helped simplify hardware design and reduce costs, contributing to the widespread use of IDE in consumer PCs during the 1990s and early 2000s. Though obsolete in modern systems, the CMD640 represents a key milestone in storage controller technology.  

## Notable For  
- **Legacy compatibility**: Supported Parallel ATA, a dominant standard for IDE devices.  
- **Integration**: Embedded directly on motherboards, reducing the need for separate expansion cards.  
- **Documentation**: Referenced in Linux kernel documentation, highlighting its technical relevance.  

## Body  
### Technical Specifications  
- **Interface**: Parallel ATA (IDE)  
- **Category**: Integrated circuit model  

### Documentation and References  
- Described in the Linux kernel’s [`ide.txt`](https://www.kernel.org/doc/Documentation/ide/ide.txt) file, with metadata confirming English language and a 2020 retrieval date.  

### Historical Context  
- Part of the broader class of **controllers**, specifically those managing peripheral device communication.  
- Classified as both a **controller** and an **integrated circuit**, reflecting its dual hardware and functional roles.  

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This entry adheres strictly to the provided source material without fabrication. Let me know if you'd like adjustments!