diff --git a/docs/source/tools/castool.rst b/docs/source/tools/castool.rst
index b4d8f81467f..73fb095d9b1 100644
--- a/docs/source/tools/castool.rst
+++ b/docs/source/tools/castool.rst
@@ -9,7 +9,7 @@ Castool is part of the MAME project. It shares large portions of code with MAME,
 
 
 Using Castool
-=============
+-------------
 
 Castool is a command line program that contains a simple set of instructions. Commands are invoked in a manner along the lines of this:
 
@@ -30,7 +30,7 @@ Example usage:
 
 
 Castool Formats
-===============
+---------------
 
 These are the formats supported by Castool for conversion to .WAV files.
 
diff --git a/docs/source/tools/chdman.rst b/docs/source/tools/chdman.rst
new file mode 100644
index 00000000000..f23a21cddf5
--- /dev/null
+++ b/docs/source/tools/chdman.rst
@@ -0,0 +1,393 @@
+.. _chdman:
+
+chdman – CHD (Compressed Hunks of Data) File Manager
+====================================================
+
+chdman can be used to create, convert, check the integrity of and extract data
+from media images in CHD (Compressed Hunks of Data) format.
+
+The basic usage is ``chdman <command> <option>...``
+
+.. contents:: :local:
+
+
+.. _chdman-commonopts:
+
+Common options
+--------------
+
+The options available depend on the command, but the following options are
+used by multiple commands:
+
+--input <file> / -i <file>
+   Specify the input file.  This option is required for most commands.  The
+   input file formats supported depend on the command
+--inputparent <chdfile> / -ip <chdfile>
+   Specify the parent CHD file for the input file.  This option is supported for
+   most commands that operate on CHD format input files.  This option must be
+   used if the input file is a *delta CHD*, storing only the hunks that differ
+   from its parent CHD,
+--output <file> / -o <file>
+   Specify the output file name.  This option is required for commands that
+   produce output files.  The output file formats supported depend on the
+   command.
+--outputparent <chdfile> / -op <chdfile>
+   Specify the parent CHD file for the output file.  This option is supported
+   for commands that produce CHD format output files.  Using this option
+   produces a *delta CHD*, storing only the hunks that differ from its parent
+   CHD.  The parent CHD should be the same media type and size, with the same
+   hunk size.
+--compression none|<type>[,<type>]... / -c none|<type>[,<type>]...
+   Specify compression algorithms to use.  This option is supported for commands
+   that produce CHD format output files.  Specify ``none`` to disable
+   compression, or specify up to four comma-separated compression algorithms.
+   See :ref:`compression algorithms <chdman-compression>` for supported
+   compression algorithms.  Compression must be disable to create writable media
+   image files.
+--hunksize <bytes> / -hs <bytes>
+   Specifies the hunk size in bytes.  This option is supported for commands that
+   produce CHD format output files.  The hunk size must be no smaller than
+   16 bytes and no larger than 1048576 bytes (1 MiB).  The hunk size must be a
+   multiple of the sector size or unit size of the media.  Larger hunk sizes may
+   give better compression ratios, but reduce performance for small random
+   reads as an entire hunk needs to be read and decompressed at a time.
+--force / -f
+   Overwrite output files if they already exist.  This option is supported for
+   commands that produce output files.
+--verbose / -v
+    Enable verbose output.  This prints more detailed information for some
+    commands.
+--numprocessors <count> / -np <count>
+   Limit the maximum number of concurrent threads used for data compression.
+   This option is supported for commands that produce CHD format output files.
+
+
+.. _chdman-commands:
+
+Commands
+--------
+
+info
+~~~~
+
+Display information about a CHD format file.  Information includes:
+
+* CHD format version and compression algorithms used.
+* Compressed and uncompressed sizes and overall compression ratio.
+* Hunk size, unit size and number of hunks in the file.
+* SHA1 digests of the data and metadata.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+* ``--verbose`` / ``-v``
+
+verify
+~~~~~~
+
+Verify the integrity of a CHD format file.  The input file must be a read-only
+CHD format file (the integrity of writable CHD files cannot be verified).
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+* ``--inputparent <chdfile>`` / ``-ip <chdfile>``
+
+createraw
+~~~~~~~~~
+
+Create a CHD format file from a raw media image.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+* ``--output <file>`` / ``-o <file>`` (required)
+* ``--outputparent <chdfile>`` / ``-op <chdfile>``
+* ``--compression none|<type>[,<type>]...`` / ``-c none|<type>[,<type>]...``
+* ``--hunksize <bytes>`` / ``-hs <bytes>`` (required)
+* ``--force`` / ``-f``
+* ``--numprocessors <count>`` / ``-np <count>``
+
+Additional options:
+
+* ``--unitsize <bytes>`` / ``-us <bytes>`` (required)
+* ``--inputstartbyte <offset>`` / ``-isb <offset>``
+* ``--inputstarthunk <offset>`` / ``-ish <offset>``
+* ``--inputbytes <length>`` / ``-ib <length>``
+* ``--inputhunks <length>`` / ``-ih <length>``
+
+If the ``--compression`` or ``-c`` option is not supplied, it defaults to
+``lzma,zlib,huff,flac``.
+
+createhd
+~~~~~~~~
+
+Create a CHD format hard disk image file.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+* ``--output <file>`` / ``-o <file>`` (required)
+* ``--outputparent <chdfile>`` / ``-op <chdfile>``
+* ``--compression none|<type>[,<type>]...`` / ``-c none|<type>[,<type>]...``
+* ``--hunksize <bytes>`` / ``-hs <bytes>`` (required)
+* ``--force`` / ``-f``
+* ``--numprocessors <count>`` / ``-np <count>``
+
+Additional options:
+
+* ``--sectorsize <bytes>`` / ``-ss <bytes>``
+* ``--size <bytes>`` / ``-s <bytes>``
+* ``--chs <cylinders>,<heads>,<sectors>`` / ``-chs <cylinders>,<heads>,<sectors>``
+* ``--template <template>`` / ``-tp <template>``
+* ``--inputstartbyte <offset>`` / ``-isb <offset>``
+* ``--inputstarthunk <offset>`` / ``-ish <offset>``
+* ``--inputbytes <length>`` / ``-ib <length>``
+* ``--inputhunks <length>`` / ``-ih <length>``
+
+If the ``--compression`` or ``-c`` option is not supplied, it defaults to
+``lzma,zlib,huff,flac``.
+
+createcd
+~~~~~~~~
+
+Create a CHD format CD-ROM image file.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+* ``--output <file>`` / ``-o <file>`` (required)
+* ``--outputparent <chdfile>`` / ``-op <chdfile>``
+* ``--compression none|<type>[,<type>]...`` / ``-c none|<type>[,<type>]...``
+* ``--hunksize <bytes>`` / ``-hs <bytes>`` (required)
+* ``--force`` / ``-f``
+* ``--numprocessors <count>`` / ``-np <count>``
+
+If the ``--compression`` or ``-c`` option is not supplied, it defaults to
+``cdlz,cdzl,cdfl``.
+
+createdvd
+~~~~~~~~~
+
+Create a CHD format DVD-ROM image file.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+* ``--output <file>`` / ``-o <file>`` (required)
+* ``--outputparent <chdfile>`` / ``-op <chdfile>``
+* ``--compression none|<type>[,<type>]...`` / ``-c none|<type>[,<type>]...``
+* ``--hunksize <bytes>`` / ``-hs <bytes>`` (required)
+* ``--force`` / ``-f``
+* ``--numprocessors <count>`` / ``-np <count>``
+
+If the ``--compression`` or ``-c`` option is not supplied, it defaults to
+``lzma,zlib,huff,flac``.
+
+createld
+~~~~~~~~
+
+Create a CHD format LaserDisc image file.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+* ``--output <file>`` / ``-o <file>`` (required)
+* ``--outputparent <chdfile>`` / ``-op <chdfile>``
+* ``--compression none|<type>[,<type>]...`` / ``-c none|<type>[,<type>]...``
+* ``--hunksize <bytes>`` / ``-hs <bytes>`` (required)
+* ``--force`` / ``-f``
+* ``--numprocessors <count>`` / ``-np <count>``
+
+Additional options:
+
+* ``--inputstartframe <offset>`` / ``-isf <offset>``
+* ``--inputframes <length>`` / ``-if <length>``
+
+If the ``--compression`` or ``-c`` option is not supplied, it defaults to
+``avhu``.
+
+extractraw
+~~~~~~~~~~
+
+Extract data from a CHD format raw media image.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+* ``--inputparent <chdfile>`` / ``-ip <chdfile>``
+* ``--output <file>`` / ``-o <file>`` (required)
+* ``--force`` / ``-f``
+
+Additional options:
+
+* ``--inputstartbyte <offset>`` / ``-isb <offset>``
+* ``--inputstarthunk <offset>`` / ``-ish <offset>``
+* ``--inputbytes <length>`` / ``-ib <length>``
+* ``--inputhunks <length>`` / ``-ih <length>``
+
+extracthd
+~~~~~~~~~
+
+Extract data from a CHD format hard disk image.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+* ``--inputparent <chdfile>`` / ``-ip <chdfile>``
+* ``--output <file>`` / ``-o <file>`` (required)
+* ``--force`` / ``-f``
+
+Additional options:
+
+* ``--inputstartbyte <offset>`` / ``-isb <offset>``
+* ``--inputstarthunk <offset>`` / ``-ish <offset>``
+* ``--inputbytes <length>`` / ``-ib <length>``
+* ``--inputhunks <length>`` / ``-ih <length>``
+
+extractcd
+~~~~~~~~~
+
+Extract data from a CHD format CD-ROM image.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+* ``--inputparent <chdfile>`` / ``-ip <chdfile>``
+* ``--output <file>`` / ``-o <file>`` (required)
+* ``--force`` / ``-f``
+
+Additional options:
+
+* ``--outputbin <file>`` / ``-ob <file>``
+
+extractdvd
+~~~~~~~~~~
+
+Extract data from a CHD format DVD-ROM image.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+* ``--inputparent <chdfile>`` / ``-ip <chdfile>``
+* ``--output <file>`` / ``-o <file>`` (required)
+* ``--force`` / ``-f``
+
+extractld
+~~~~~~~~~
+
+Extract data from a CHD format DVD-ROM image.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+* ``--inputparent <chdfile>`` / ``-ip <chdfile>``
+* ``--output <file>`` / ``-o <file>`` (required)
+* ``--force`` / ``-f``
+
+Additional options:
+
+* ``--inputstartframe <offset>`` / ``-isf <offset>``
+* ``--inputframes <length>`` / ``-if <length>``
+
+addmeta
+~~~~~~~
+
+Add a metadata item to a CHD format file.  Note that this command modifies its
+input file.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+
+Additional options:
+
+* ``--tag <tag>`` / ``-t <tag>`` (required)
+* ``--index <index>`` / ``-ix <index>``
+* ``--valuetext <text>`` / ``-vt <text>``
+* ``--valuefile <file>`` / ``-vf <file>``
+* ``--nochecksum`` / ``-nocs``
+
+delmeta
+~~~~~~~
+
+Delete a metadata item from a CHD format file.  Note that this command modifies
+its input file.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+
+Additional options:
+
+* ``--tag <tag>`` / ``-t <tag>`` (required)
+* ``--index <index>`` / ``-ix <index>``
+
+dumpmeta
+~~~~~~~~
+
+Extract metadata items from a CHD format file to the standard output or to a
+file.
+
+Common options supported:
+
+* ``--input <file>`` / ``-i <file>`` (required)
+* ``--output <file>`` / ``-o <file>``
+* ``--force`` / ``-f``
+
+Additional options:
+
+* ``--tag <tag>`` / ``-t <tag>`` (required)
+* ``--index <index>`` / ``-ix <index>``
+
+listtemplates
+~~~~~~~~~~~~~
+
+List available hard disk templates.  This command does not accept any options.
+
+
+.. _chdman-compression:
+
+Compression algorithms
+----------------------
+
+The following compression algorithms are supported:
+
+zlib – zlib deflate
+   Compresses data using the zlib deflate algorithm.
+zstd – Zstandard
+   Compresses data using the Zstandard algorithm.  This gives very good
+   compression and decompression performance with better compression ratios than
+   zlib deflate, but older software may not support CHD files that use Zstandard
+   compression.
+lzma – Lempel-Ziv-Markov chain algorithm
+   Compresses data using the Lempel-Ziv-Markov-chain algorithm (LZMA).  This
+   gives high compression ratios at the cost of poor compression and
+   decompression performance.
+huff – Huffman coding
+   Compresses data using 8-bit Huffman entropy coding.
+flac – Free Lossless Audio Codec
+   Compresses data as two-channel (stereo) 16-bit 44.1 kHz PCM audio using the
+   Free Lossless Audio Codec (FLAC).  This gives good compression ratios if the
+   media contains 16-bit PCM audio data.
+cdzl – zlib deflate for CD-ROM data
+   Compresses audio data and subchannel data from CD-ROM sectors separately
+   using the zlib deflate algorithm.
+cdzs – Zstandard for CD-ROM data
+   Compresses audio data and subchannel data from CD-ROM sectors separately
+   using the Zstandard algorithm.  This gives very good compression and
+   decompression performance with better compression ratios than zlib deflate,
+   but older software may not support CHD files that use Zstandard compression.
+cdlz - Lempel-Ziv-Markov chain algorithm/zlib deflate for CD-ROM data
+   Compresses audio data and subchannel data from CD-ROM sectors separately
+   using the Lempel-Ziv-Markov chain algorithm (LZMA) for audio data and the
+   zlib deflate algorithm for subchannel data.  This gives high compression
+   ratios at the cost of poor compression and decompression performance.
+cdfl – Free Lossless Audio Codec/zlib deflate for CD-ROM data
+   Compresses audio data and subchannel data from CD-ROM sectors separately
+   using the Free Lossless Audio Codec (FLAC) for audio data and the zlib
+   deflate algorithm for subchannel data.  This gives good compression ratios
+   for audio CD tracks.
+avhu – Huffman coding for audio-visual data
+   This is a specialised compression algorithm for audio-visual (A/V) data.  It
+   should only be used for LaserDisc CHD files.
diff --git a/docs/source/tools/floptool.rst b/docs/source/tools/floptool.rst
index f2e24eac56f..bf71c296aee 100644
--- a/docs/source/tools/floptool.rst
+++ b/docs/source/tools/floptool.rst
@@ -9,7 +9,7 @@ Floptool is part of the MAME project. It shares large portions of code with MAME
 
 
 Using Floptool
-==============
+--------------
 
 Floptool is a command line program that contains a simple set of instructions. Commands are invoked in a manner along the lines of this:
 
@@ -33,7 +33,7 @@ Example usage:
 
 
 Floptool Formats
-================
+----------------
 
 These are the formats supported by Floptool for conversion to other formats.
 
diff --git a/docs/source/tools/imgtool.rst b/docs/source/tools/imgtool.rst
index 7efa850ca93..e54638ea59b 100644
--- a/docs/source/tools/imgtool.rst
+++ b/docs/source/tools/imgtool.rst
@@ -10,7 +10,7 @@ Imgtool is part of the MAME project. It shares large portions of code with MAME,
 **Some portions of Imgtool are Copyright (c) 1989, 1993 The Regents of the University of California.  All rights reserved.**
 
 Using Imgtool
-=============
+-------------
 
 Imgtool is a command line program that contains several "subcommands" that actually do all of the work.  Most commands are invoked in a manner along the lines of this:
 
@@ -32,7 +32,7 @@ Further details vary with each subcommand.  Also note that not all subcommands a
 
 
 Imgtool Subcommands
-===================
+-------------------
 
 **create**
 
@@ -151,7 +151,7 @@ Imgtool Subcommands
 
 
 Imgtool Filters
-===============
+---------------
 
 Filters are a means to process data being written into or read out of an image in a certain way.  Filters can be specified on the get, put, and getall commands by specifying --filter=xxxx on the command line.  Currently, the following filters are supported:
 
diff --git a/docs/source/tools/index.rst b/docs/source/tools/index.rst
index 6d0551bf1d1..4086f924b99 100644
--- a/docs/source/tools/index.rst
+++ b/docs/source/tools/index.rst
@@ -1,12 +1,14 @@
 MAME External Tools
--------------------
+===================
 
-This section covers various extra tools that come with your MAME distribution (e.g. *imgtool*)
+This section describes additional tools that are built alongside and typically
+distributed with MAME.
 
 .. toctree::
-	:titlesonly:
+    :titlesonly:
 
-	imgtool
-	castool
-	floptool
-	othertools
+    chdman
+    imgtool
+    castool
+    floptool
+    othertools
diff --git a/src/tools/chdman.cpp b/src/tools/chdman.cpp
index 3a4277c50d1..c613a968bad 100644
--- a/src/tools/chdman.cpp
+++ b/src/tools/chdman.cpp
@@ -710,6 +710,7 @@ static const command_description s_commands[] =
 			OPTION_OUTPUT_PARENT,
 			OPTION_OUTPUT_FORCE,
 			REQUIRED OPTION_INPUT,
+			OPTION_HUNK_SIZE,
 			OPTION_COMPRESSION,
 			OPTION_NUMPROCESSORS
 		}
@@ -768,7 +769,6 @@ static const command_description s_commands[] =
 	{ COMMAND_EXTRACT_DVD, do_extract_dvd, ": extract DVD file from a CHD input file",
 		{
 			REQUIRED OPTION_OUTPUT,
-			OPTION_OUTPUT_BIN,
 			OPTION_OUTPUT_FORCE,
 			REQUIRED OPTION_INPUT,
 			OPTION_INPUT_PARENT,
@@ -2110,6 +2110,10 @@ static void do_create_dvd(parameters_map &params)
 	chd_file output_parent;
 	std::string *output_chd_str = parse_output_chd_parameters(params, output_parent);
 
+	// process hunk size
+	uint32_t hunk_size = output_parent.opened() ? output_parent.hunk_bytes() : (2 * 2048);
+	parse_hunk_size(params, 2048, hunk_size);
+
 	// process input start/end
 	uint64_t filesize = 0;
 	input_file->length(filesize); // FIXME: check error return
@@ -2146,9 +2150,9 @@ static void do_create_dvd(parameters_map &params)
 		chd.reset(new chd_rawfile_compressor(*input_file, 0, filesize));
 		std::error_condition err;
 		if (output_parent.opened())
-			err = chd->create(output_chd_str->c_str(), uint64_t(totalsectors) * 2048, 2048, compression, output_parent);
+			err = chd->create(output_chd_str->c_str(), uint64_t(totalsectors) * 2048, hunk_size, compression, output_parent);
 		else
-			err = chd->create(output_chd_str->c_str(), uint64_t(totalsectors) * 2048, 2048, 2048, compression);
+			err = chd->create(output_chd_str->c_str(), uint64_t(totalsectors) * 2048, hunk_size, 2048, compression);
 		if (err)
 			report_error(1, "Error creating CHD file (%s): %s", output_chd_str, err.message());