# D64

> Commodore 64 sector-based disk image

**Wikidata**: [Q28600451](https://www.wikidata.org/wiki/Q28600451)  
**Source**: https://4ort.xyz/entity/d64

## Summary
D64 is a sector-based disk image format associated with the Commodore 64 computer system. It functions as a computer file that contains the complete contents and structure of a disk volume. This format allows for the storage and representation of Commodore 64 data in a single file.

## Key Facts
- **Instance of:** Disk image
- **Description:** Commodore 64 sector-based disk image
- **Primary Function:** Contains the contents and structure of a disk volume
- **Structure Type:** Sector-based
- **Associated Platform:** Commodore 64
- **File Format Wiki Page ID:** D64
- **Related Class:** Computer file
- **Site link count (related concept):** 26

## FAQs
### Q: What exactly is a D64 file?
A: A D64 file is a disk image specifically formatted for the Commodore 64. It is a sector-based computer file that replicates the contents and structure of a physical disk volume.

### Q: How is the data inside a D64 image organized?
A: The data is organized as a sector-based disk image, meaning it replicates the specific structural layout (sectors) of the original disk volume rather than just storing files loosely.

### Q: What is the primary classification of D64?
A: D64 is classified as a type of "disk image," which is defined as a computer file containing the contents and structure of a disk volume.

## Why It Matters
The D64 format plays a critical role in the preservation and usage of legacy software. As a sector-based disk image, it serves as an exact digital replica of the physical media used by the Commodore 64, one of the most historically significant home computers. By encapsulating both the contents and the structure of a disk volume into a single computer file, D64 allows data to be archived, transferred, and accessed without the need for the original physical floppy disks.

This format effectively solves the problem of media decay and hardware obsolescence. Where original 5.25-inch floppy disks are prone to physical degradation over time, the D64 standard ensures that the specific sector layout and data integrity of the software are maintained digitally. It is a fundamental component in the field of digital preservation and retro-computing emulation.

## Notable For
- **Sector-Based Precision:** Unlike simple file archives, it preserves the sector-based structure of the original disk volume.
- **Commodore 64 Association:** It is a standard format specifically linked to the Commodore 64 ecosystem.
- **Structural Fidelity:** It is defined by its ability to contain both the contents and the structure of a disk volume simultaneously.
- **Disk Image Classification:** It is a distinct instance of the "disk image" class of computer files.

## Body
### Definition and Classification
D64 is identified in knowledge bases as a specific instance of a **disk image**. It is technically described as a "Commodore 64 sector-based disk image." This classification distinguishes it from other file types by its specific utility in replicating the storage media of the Commodore 64 system.

### Technical Structure
The format is characterized as **sector-based**. This means the image file maps the data according to the specific sectors found on the original physical disk.
*   **Contents:** The file encapsulates the actual data (contents) from the disk.
*   **Structure:** The file preserves the organizational layout (structure) of the disk volume.

### Relationship to Disk Volumes
D64 acts as a container for a **disk volume**. In computing terms, the related concept of a "disk image" is defined as a computer file containing these contents and structures. The D64 format applies this definition specifically to the hardware context of the Commodore 64.