# Apple Partition Map Disk Image

> disc image format

**Wikidata**: [Q113866096](https://www.wikidata.org/wiki/Q113866096)  
**Source**: https://4ort.xyz/entity/apple-partition-map-disk-image

## Summary
Apple Partition Map Disk Image is a disc image format based on the Apple Partition Map disk partitioning scheme. It is a computer file containing the contents and structure of a disk volume, commonly used in Apple systems.

## Key Facts
- Instance of: disk image
- Based on: Apple Partition Map
- PRONOM file format ID: fmt/1740
- File extensions: .toast, .iso, .cdr, .dmg, .bin, .img
- Wikidata description: disc image format
- Last updated in PRONOM: September 9, 2022

## FAQs
### Q: What is an Apple Partition Map Disk Image?
A: It's a disc image format that contains the contents and structure of a disk volume, based on the Apple Partition Map partitioning scheme used in Apple systems.

### Q: What file extensions are associated with Apple Partition Map Disk Images?
A: Common file extensions include .toast, .iso, .cdr, .dmg, .bin, and .img.

### Q: How is Apple Partition Map Disk Image classified?
A: It's classified as a disk image format and has the PRONOM file format ID of fmt/1740.

## Why It Matters
Apple Partition Map Disk Image plays a crucial role in preserving and distributing Apple-specific disk images. As a format based on the Apple Partition Map, it maintains compatibility with legacy Apple systems and allows for accurate representation of Apple disk structures. This format is particularly important for digital preservation efforts, as it enables archivists and researchers to create exact copies of Apple disk volumes that can be mounted and examined on compatible systems. The multiple file extensions associated with this format also provide flexibility in how these disk images are created and used across different applications and platforms.

## Notable For
- Based on Apple's proprietary partitioning scheme
- Supports multiple file extensions for versatility
- Recognized in PRONOM digital preservation registry
- Maintains exact disk volume structure and contents
- Used for both archival and distribution purposes

## Body
### Technical Foundation
Apple Partition Map Disk Image is built upon the Apple Partition Map (APM) scheme, which was Apple's standard partitioning method before the adoption of GUID Partition Table. This foundation ensures compatibility with older Mac systems and preserves the original disk structure.

### File Format Specifications
The format supports various file extensions, each potentially serving different purposes:
- .toast: Commonly used for CD/DVD images
- .iso: Standard disc image format
- .cdr: Mac-specific disc image format
- .dmg: Mac disk image format
- .bin and .img: Generic disc image formats

### Digital Preservation
Registered in PRONOM (the UK National Archives' file format registry) with ID fmt/1740, this format is recognized for its importance in digital preservation. The September 9, 2022 update in PRONOM indicates ongoing maintenance and recognition of the format's significance.

### Usage Context
These disk images are particularly valuable for:
- Creating exact copies of Apple disk volumes
- Distributing software for older Mac systems
- Preserving legacy Apple software and data
- Forensic analysis of Apple systems

### Compatibility Considerations
While based on Apple's partitioning scheme, the format's support for multiple file extensions allows for broader compatibility across different systems and applications, making it versatile for both Apple and non-Apple environments.

## References

1. [Source](https://www.nationalarchives.gov.uk/PRONOM/fmt/1740)