Apple Partition Map

File Format
Name	Apple Partition Map
Ontology	Electronic File Formats Filesystem Apple Partition Map
Extension(s)	.iso, .dmg, .cdr, .toast
PRONOM	fmt/1740

Apple Partition Map (APM) is a format that describes the partition layout of a disk. When in the form of a disk image file, it can be thought of as a container format for multiple filesystem image files. Can be found in DMG and Roxio TOAST images.

Identification

Files using APM generally begin with hex values 4552 follow by 0200 for standard 512 block size and 0800 for 2048 block size.

The ASCII characters "PM" appear at offset 512, and (usually?) also at offset 1024. They may also appear at larger multiples of 512. Also found in multiples of 2048.

Software

• HFSExplorer
• 7-Zip [Ed. note: Seems unreliable. Supports GoldenOrchard1.2.iso but not GoldenOrchard1.0.iso.]
• Supported natively by some Apple Macintosh operating systems.

Sample files

• https://archive.org/details/cdrom-golden-orchard-10 → GoldenOrchard1.0.iso
• https://archive.org/details/cdrom-golden-orchard-12 → GoldenOrchard1.2.iso
• iWork install DVD in Toast format

Links

• Wikipedia article
• Kaitai Struct for APM
• Apple's Transition from Apple Partition Map to the GUID Partition Table
• Apple Partition Scheme code