IMG (DOSIMG) - Revision history

Sembiance: software

2024-05-12T13:50:12Z

software

Sembiance: sample files

2024-05-12T13:49:36Z

sample files

JTN: /* Overview */ lk raw disk image

2023-02-28T19:22:19Z

‎Overview: lk raw disk image

Dzhang: A Python implementation to extract IMG files

2018-06-08T10:15:33Z

A Python implementation to extract IMG files

Jsummers: /* Overview */

2016-02-09T15:47:53Z

‎Overview

Jsummers: Jsummers moved page IMG to IMG (DOSIMG): This isn't the dominant format named IMG

2016-02-09T15:46:40Z

Jsummers moved page IMG to IMG (DOSIMG): This isn't the dominant format named IMG

Dan Tobias: /* Format description */

2014-03-24T00:48:11Z

‎Format description

Darkstar: first version

2014-03-23T20:19:14Z

first version

New page

{{FormatInfo
|formattype=electronic
|subcat=Disk Image Formats
|extensions={{ext|img}}
}}

==Overview==
'''IMG''' is an RLE-compressed sector-based disk image format probably used by the DOS program HD-Copy and/or others. It should not be confused with raw image files (sector dumps).

There is a Pascal program floating around the internet which includes source code and can convert these IMG files to raw sector dumps. It is called '''DOSIMG''' and can be found mainly on various Chinese websites<ref>http://download.pchome.net/system/disk/down-13054-1.html</ref><ref>http://roy.orz.hm/soft/DOSIMG.zip</ref>

==Format description==
{|
!align="left"|byte
!align="left"|description
|-
|0
|last track on the original disk (either 39 or 79)
|-
|1
|number of sectors per track
|-
|2-166
|one byte for each track, 0x01 if the track is included in the file, 0x00 otherwise (empty/unformatted)
|-
|colspan="2"|For each track:
|-
|2 bytes
|compressed size of this track, little-endian, not including this size field but including the next byte
|-
|1 byte
|the escape-byte for the RLE coding
|-
|n-1 bytes
|The actual sector data, RLE compressed. Should uncompress to at most num_sectors * 512 bytes, rest is filled with zero.
Each byte is copied 1:1 to the output buffer, except when the escape-byte is encountered. Then, the next 2 bytes specify a byte-value and a count-value. To uncompress, copy the first byte after the escape-byte as many times as the second byte implies to the output buffer.
|}

==References==
<references/>

@@ Line 38: / Line 38: @@
 Each byte is copied 1:1 to the output buffer, except when the escape-byte is encountered. Then, the next 2 bytes specify a byte-value and a count-value. To uncompress, copy the first byte after the escape-byte as many times as the second byte implies to the output buffer.
 |}
 == Sample files ==

@@ Line 6: / Line 6: @@
 ==Overview==
-'''IMG''' is an RLE-compressed sector-based disk image format probably used by the DOS program HD-Copy and/or others. It should not be confused with raw image files (sector dumps).
+'''IMG''' is an RLE-compressed sector-based disk image format probably used by the DOS program HD-Copy and/or others. It should not be confused with [[raw disk image|raw image files]] (sector dumps).
 There is a Pascal program floating around the internet which includes source code and can convert these IMG files to raw sector dumps. It is called '''DOSIMG''' and can be found mainly on various Chinese websites<ref>http://download.pchome.net/system/disk/down-13054-1.html</ref><ref>http://roy.orz.hm/soft/DOSIMG.zip</ref><ref>https://bitbucket.org/snippets/tifan/EeLAay/python-script-to-extract-compressed-img</ref>

@@ Line 8: / Line 8: @@
 '''IMG''' is an RLE-compressed sector-based disk image format probably used by the DOS program HD-Copy and/or others. It should not be confused with raw image files (sector dumps).
-There is a Pascal program floating around the internet which includes source code and can convert these IMG files to raw sector dumps. It is called '''DOSIMG''' and can be found mainly on various Chinese websites<ref>http://download.pchome.net/system/disk/down-13054-1.html</ref><ref>http://roy.orz.hm/soft/DOSIMG.zip</ref>
+There is a Pascal program floating around the internet which includes source code and can convert these IMG files to raw sector dumps. It is called '''DOSIMG''' and can be found mainly on various Chinese websites<ref>http://download.pchome.net/system/disk/down-13054-1.html</ref><ref>http://roy.orz.hm/soft/DOSIMG.zip</ref><ref>https://bitbucket.org/snippets/tifan/EeLAay/python-script-to-extract-compressed-img</ref>
 ''[Ed. note: This article needs a better title. We've named it "IMG (DOSIMG)" because the only thing we know for sure about this format is that it is supported by the DOSIMG utility.]''

← Older revision		Revision as of 15:47, 9 February 2016
Line 9:		Line 9:

	There is a Pascal program floating around the internet which includes source code and can convert these IMG files to raw sector dumps. It is called '''DOSIMG''' and can be found mainly on various Chinese websites<ref>http://download.pchome.net/system/disk/down-13054-1.html</ref><ref>http://roy.orz.hm/soft/DOSIMG.zip</ref>		There is a Pascal program floating around the internet which includes source code and can convert these IMG files to raw sector dumps. It is called '''DOSIMG''' and can be found mainly on various Chinese websites<ref>http://download.pchome.net/system/disk/down-13054-1.html</ref><ref>http://roy.orz.hm/soft/DOSIMG.zip</ref>
		+
		+	''[Ed. note: This article needs a better title. We've named it "IMG (DOSIMG)" because the only thing we know for sure about this format is that it is supported by the DOSIMG utility.]''

	==Format description==		==Format description==

@@ Line 27: / Line 27: @@
 |-
 |2 bytes
-|compressed size of this track, little-endian, not including this size field but including the next byte
+|compressed size of this track, [[Endianness|little-endian]], not including this size field but including the next byte
 |-
 |1 byte