Sector Dump Format - Revision history

Stefan Haubenthal: /* Standard format */

2022-11-11T22:24:22Z

Standard format

← Older revision		Revision as of 22:24, 11 November 2022
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	== Standard format ==		== Standard format ==
	In the standard format, which is used in many emulators like v9t9, MAME, or ~~js99er~~, the file only consists of the sectors, and no bad sector map is available.		In the standard format, which is used in many emulators like v9t9, MAME, or [[Js99er]], the file only consists of the sectors, and no bad sector map is available.

	In the TI world, all sectors are 256 bytes long. Files can easily be checked for this format by verifying that the total file size is a multiple of 256. Also, single density format defines tracks with 9 sectors per track, while double density contains 18 sectors per track. There is one exception: The original TI DD controllers (or the HX5102 Hexbus floppy) use 16 sectors/track for double density.		In the TI world, all sectors are 256 bytes long. Files can easily be checked for this format by verifying that the total file size is a multiple of 256. Also, single density format defines tracks with 9 sectors per track, while double density contains 18 sectors per track. There is one exception: The original TI DD controllers (or the HX5102 Hexbus floppy) use 16 sectors/track for double density.

Stefan Haubenthal at 17:49, 30 April 2018

2018-04-30T17:49:25Z

← Older revision		Revision as of 17:49, 30 April 2018
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	In very early releases, the MESS emulator (now part of MAME) supported hard disk image files in a sector dump format. However, for quite some time, MESS (and MAME) require images in CHD format.		In very early releases, the MESS emulator (now part of MAME) supported hard disk image files in a sector dump format. However, for quite some time, MESS (and MAME) require images in CHD format.

	[[Category:Format]]		[[Category:File Format]]

Stefan Haubenthal: Category

2018-04-30T17:44:36Z

Mizapf at 19:57, 15 March 2018

2018-03-15T19:57:32Z

← Older revision		Revision as of 19:57, 15 March 2018
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	A disk image in '''Sector Dump Format''' is defined as a concatenation of all sector contents in logical sequence. These disk image files are typically suffixed with ".dsk" or ".DSK". Note that the [[Track Dump Format]] images are also suffixed with ".dsk" or ".DSK", so this cannot be decided by the file suffix alone.		A disk image in '''Sector Dump Format''' is defined as a concatenation of all sector contents in logical sequence. These disk image files are typically suffixed with ".dsk" or ".DSK". Note that the [[Track Dump Format]] images are also suffixed with ".dsk" or ".DSK", so this cannot be decided by the file suffix alone.


	{\| style="width:60%; text-align:center"		{\| style="width:60%; text-align:center"
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	\| style="border: 1px solid black; padding:0.2ex; width:15%; background-color:#aacccc" \| [Bad sectors map]		\| style="border: 1px solid black; padding:0.2ex; width:15%; background-color:#aacccc" \| [Bad sectors map]
	\|}		\|}


	It should be noted that the SDF does not represent the ''physical sequence'' of sectors per track. The sectors on a real floppy disk are arranged by an interleave per track, with a skew from track to track. See more about the real arrangement in the article on the [[Track Dump Format#Interleave \| Interleave]].		It should be noted that the SDF does not represent the ''physical sequence'' of sectors per track. The sectors on a real floppy disk are arranged by an interleave per track, with a skew from track to track. See more about the real arrangement in the article on the [[Track Dump Format#Interleave \| Interleave]].

Mizapf: /* Standard format */

2018-03-15T19:56:13Z

Standard format

← Older revision		Revision as of 19:56, 15 March 2018
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	! Description		! Description
	! Recording		! Recording
			! Cylinder count
	! Head count		! Head count
	~~! Cylinder count~~
	! Sector count		! Sector count
	! File size		! File size

Mizapf: /* Standard format */

2018-03-15T19:52:37Z

Standard format

← Older revision		Revision as of 19:52, 15 March 2018
Line 36:		Line 36:
	! Description		! Description
	! Recording		! Recording
			! Head count
			! Cylinder count
	! Sector count		! Sector count
	~~! Cylinder count~~
	~~! Head count~~
	! File size		! File size
	! Occurance		! Occurance

Mizapf at 19:52, 15 March 2018

2018-03-15T19:52:06Z

← Older revision		Revision as of 19:52, 15 March 2018
Line 1:		Line 1:
	A disk image in '''Sector Dump Format''' is defined as a concatenation of all sector contents in logical sequence. These disk image files are typically suffixed with ".dsk" or ".DSK".		A disk image in '''Sector Dump Format''' is defined as a concatenation of all sector contents in logical sequence. These disk image files are typically suffixed with ".dsk" or ".DSK". Note that the [[Track Dump Format]] images are also suffixed with ".dsk" or ".DSK", so this cannot be decided by the file suffix alone.

	In the ~~TI world~~, ~~all sectors are 256 bytes long~~.

	{\| style="width:60%; text-align:center"		{\| style="width:60%; text-align:center"
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	In the standard format, which is used in many emulators like v9t9, MAME, or js99er, the file only consists of the sectors, and no bad sector map is available.		In the standard format, which is used in many emulators like v9t9, MAME, or js99er, the file only consists of the sectors, and no bad sector map is available.

	Files can easily be checked for this format by verifying that the total file size is a multiple of 256. Also, single density format defines tracks with 9 sectors per track, while double density contains 18 sectors per track. There is one exception: The original TI DD controllers (or the HX5102 Hexbus floppy) use 16 sectors/track for double density.		In the TI world, all sectors are 256 bytes long. Files can easily be checked for this format by verifying that the total file size is a multiple of 256. Also, single density format defines tracks with 9 sectors per track, while double density contains 18 sectors per track. There is one exception: The original TI DD controllers (or the HX5102 Hexbus floppy) use 16 sectors/track for double density.

	Assuming that we have a 9 or 18 sectors/track layout, SDF image sizes should be expected to be a multiple of 9·256 = 2304 bytes.		Assuming that we have a 9 or 18 sectors/track layout, SDF image sizes should be expected to be a multiple of 9·256 = 2304 bytes.

Mizapf at 19:49, 15 March 2018

2018-03-15T19:49:48Z

@@ Line 18: / Line 18: @@
 |}
-It should be noted that the SDF does not represent the ''physical sequence'' of sectors per track. The sectors on a real floppy disk are arranged by an interleave per track, with a skew from track to track. See more about the real arrangement in the article on the [[Track Dump Format]].
+It should be noted that the SDF does not represent the ''physical sequence'' of sectors per track. The sectors on a real floppy disk are arranged by an interleave per track, with a skew from track to track. See more about the real arrangement in the article on the [[Track Dump Format#Interleave | Interleave]].
 == Standard format ==
@@ Line 29: / Line 29: @@
 Since the format does not encode any metadata, there are situations where the original disk format cannot be determined easily. In particular, a double-sided/single density (DSSD) format has the same sector count as a single-sided/double density (SSDD) format. The same issue appears for 80 track images with single density versus 40 track images with double density.
-In these cases, looking into sector 0 may help to unambiguate the format analysis.
+In these cases, looking into sector 0 may help to disambiguate the format analysis. This will only work if the disk image is formatted, of course.
 == Extended format ==

Mizapf: /* Extended format */

2018-03-15T19:26:54Z

Extended format

← Older revision		Revision as of 19:26, 15 March 2018
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	== Extended format ==		== Extended format ==
	There is one extension to the SDF which adds 768 bytes at the end, containing a map of bad sectors. File sizes are a multiple of ~~256~~ plus 768; that is, if the file size is not a multiple of ~~256~~, but is 768 bytes longer, the file is very likely a sector dump with bad sectors map.		There is one extension to the SDF which adds 768 bytes at the end, containing a map of bad sectors. File sizes are a multiple of 9·256 plus 768; that is, if the file size is not a multiple of 9·256, but is 768 bytes longer, the file is very likely a sector dump with bad sectors map.

	This was introduced by a tool to read real TI floppy disks on a PC. Emulators typically ignore these additional bytes. For that reason, this format is really rare to find.		This was introduced by a tool to read real TI floppy disks on a PC. Emulators typically ignore these additional bytes. For that reason, this format is really rare to find.

Mizapf at 19:26, 15 March 2018

2018-03-15T19:26:09Z

@@ Line 1: / Line 1: @@
-Should add something here
+A disk image in '''Sector Dump Format''' is defined as a concatenation of all sector contents in logical sequence. These disk image files are typically suffixed with ".dsk" or ".DSK".
-(Well, in short, SDF is just a concatenation of the contents of sectors 0...max, with max=359 for 90KiB disks etc.)
+In the TI world, all sectors are 256 bytes long.
-'''TODO'''
+{| style="width:60%; text-align:center"

← Older revision		Revision as of 17:44, 30 April 2018
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	== MAME Hard disk format (legacy) ==		== MAME Hard disk format (legacy) ==
	In very early releases, the MESS emulator (now part of MAME) supported hard disk image files in a sector dump format. However, for quite some time, MESS (and MAME) require images in CHD format.		In very early releases, the MESS emulator (now part of MAME) supported hard disk image files in a sector dump format. However, for quite some time, MESS (and MAME) require images in CHD format.

			[[Category:Format]]