Format
Apple Disk Copy Image
Summary
- Name
- Apple Disk Copy Image
- Version
- 4.2
- Identifiers
- PUID: fmt/625
- Format type
- Aggregate
- Description
- Disk Copy 4.2 (DC42) is the common name used to refer to disk images of floppy disks created by the 4.2 version of Disk Copy provided by the Mac Operating System.
- File extensions
-
dmg,smi,img,image - Submitted by
- Yale University Library / Yale University Library
Internal signatures
Apple Disk Copy Image
- Description
- The byte at position 0x40-43 represent four potential values for data block sizes and 0x44-47 represent 3 potential tag sizes in bytes (there is a possiblity there are additional values for these sequences which may require future adjustment to the signature) 0x50 defines the disk encoding. Byte 0x51 defines the 'format byte'. Bytes 0x52-53 are the private word/magic number used for identification. Further information is found here: http://68kmla.org/wiki/index.php/DiskCopy_4.2_format_specification
Byte sequences
- Min Frag Length
- Absolute from BOF
- Offset
- 64
- Max offset
- None
- Byte Sequence
(00064000|000C8000|000B4000|00168000)(00002580|00004B00|00000000){8}(00|01|02|03)(02|12|22|24|96)0100- Endianness
- None
Changelog
-
V90
- Release date
- 30 March 2017
-
Updated
Apple Disk Copy Image 4.2: Adjusted signature due to findings by National Library New Zealand
-
V74
- Release date
- 31 March 2014
-
Updated
Apple Disk Copy Image: Improved specificity of BOF signature sequence offset.
-
V73
- Release date
- 27 February 2014
-
Added format
Apple Disk Copy Image: Outline Entry Added.Submitted by Yale University Library.
-
Added signature
Apple Disk Copy Image: Signature developed in collaboration with Yale University Library.