ATR
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| − | [[ATR]] is an Atari floppy disk image format associated with SIO2PC, a product that connects Atari and PC computers. It is supported by most Atari emulators. | + | [[ATR]] is an Atari floppy disk image format associated with SIO2PC, a product that connects Atari and PC computers. It was created by Nick Kennedy and is supported by most Atari emulators. |
== Format == | == Format == | ||
Files have a 16-byte header, followed by a raw sector-by-sector dump of the disk. | Files have a 16-byte header, followed by a raw sector-by-sector dump of the disk. | ||
| − | == | + | == Header Structure == |
| − | + | There is a 16 byte header with the following information ''(WORDs are in [http://en.wikipedia.org/wiki/Endianness]little endian format)'': | |
| + | |||
| + | <p>'''Identification''' ''<WORD>'': ($9602). This word is the 16 bit sum of the individual ASCII values of the string of bytes: "NICKATARI".</p> | ||
| + | <p>'''Size of disk image''' ''<WORD>'': The size is expressed in "paragraphs". A paragraph is sixteen bytes, thus Size = Image size in bytes / 16.</p> | ||
| + | <p>'''Sector size''' ''<WORD>'': 128 ($80) or 256 ($100) bytes per sector. Note that the original documentation only specifies two sector sizes, in practice however there is also | ||
| + | sector size 512 ($200). 512 byte sectors were introduced by SpartaDOS X, and are sometimes used to create large ATR images. Some Atari Emulators and Peripheral emulators such as Altirra and AspeQt can make use of the 512 byte sectors in ATR files.</p> | ||
| + | |||
== See also == | == See also == | ||
Revision as of 18:14, 18 February 2015
ATR is an Atari floppy disk image format associated with SIO2PC, a product that connects Atari and PC computers. It was created by Nick Kennedy and is supported by most Atari emulators.Contents |
Format
Files have a 16-byte header, followed by a raw sector-by-sector dump of the disk.
Header Structure
There is a 16 byte header with the following information (WORDs are in [1]little endian format):
Identification <WORD>: ($9602). This word is the 16 bit sum of the individual ASCII values of the string of bytes: "NICKATARI".
Size of disk image <WORD>: The size is expressed in "paragraphs". A paragraph is sixteen bytes, thus Size = Image size in bytes / 16.
Sector size <WORD>: 128 ($80) or 256 ($100) bytes per sector. Note that the original documentation only specifies two sector sizes, in practice however there is also sector size 512 ($200). 512 byte sectors were introduced by SpartaDOS X, and are sometimes used to create large ATR images. Some Atari Emulators and Peripheral emulators such as Altirra and AspeQt can make use of the 512 byte sectors in ATR files.
See also
- Atari 810 (physical disk format)
- Atari File Management Subsystem (filesystem)
Specifications
Software
- Atari-FileManagement (Old windows binary. Still works on Windows 7, but only barely.)
- Adir (Untested MS-DOS binary & source code.)
- SIO2PC
