Keymap Library - Revision history

Costel Mincea: Text replacement - "" to ""

2025-01-26T19:10:32Z

Text replacement - "<syntaxhighlight>" to "<syntaxhighlight lang="C" line>"

← Older revision		Revision as of 19:10, 26 January 2025
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	All of these commands deal with a set of pointers to key translation arrays, known as the KeyMap structure. The KeyMap structure is defined in <devices/keymap.h> and is shown below.		All of these commands deal with a set of pointers to key translation arrays, known as the KeyMap structure. The KeyMap structure is defined in <devices/keymap.h> and is shown below.

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	struct KeyMap		struct KeyMap
	{		{
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	{{Note\|title=Ask/SetKeyMap()\|text=These functions assume that you have already opened the ''console.device'' and that ''request'' is a valid IOStdReq structure for the newly opened console. These functions are not part of the keymap.library, nor of the console.device. These merely demonstrate '''CD_ASKKEYMAP''' and '''CD_SETKEYMAP''' which are console.device commands.}}		{{Note\|title=Ask/SetKeyMap()\|text=These functions assume that you have already opened the ''console.device'' and that ''request'' is a valid IOStdReq structure for the newly opened console. These functions are not part of the keymap.library, nor of the console.device. These merely demonstrate '''CD_ASKKEYMAP''' and '''CD_SETKEYMAP''' which are console.device commands.}}

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	/* These functions require that you have created a port and an IO request,		/* These functions require that you have created a port and an IO request,
	* and have opened the console device as shown in the "Console Device" section.		* and have opened the console device as shown in the "Console Device" section.
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	'''MapRawKey()''' converts raw key codes in ANSI characters based on a default or supplied keymap.		'''MapRawKey()''' converts raw key codes in ANSI characters based on a default or supplied keymap.

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	WORD MapRawKey(struct InputEvent inputevent, STRPTR buffer, WORD bufferlength, struct Keymap keymap);		WORD MapRawKey(struct InputEvent inputevent, STRPTR buffer, WORD bufferlength, struct Keymap keymap);
	</syntaxhighlight>		</syntaxhighlight>
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	The following example shows how to implement the '''MapRawKey()''' function.		The following example shows how to implement the '''MapRawKey()''' function.

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	/*		/*
	* maprawkey.c - Map Intuition RAWKEY events to ANSI with MapRawKey();		* maprawkey.c - Map Intuition RAWKEY events to ANSI with MapRawKey();
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	The '''MapANSI()''' function translates ANSI strings into raw key codes, complete with qualifiers and (double) dead keys, based on a default or supplied keymap.		The '''MapANSI()''' function translates ANSI strings into raw key codes, complete with qualifiers and (double) dead keys, based on a default or supplied keymap.

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	LONG MapANSI(UBYTE string, LONG stringlength, UBYTE buffer, LONG bufferlength, struct KeyMap *keymap);		LONG MapANSI(UBYTE string, LONG stringlength, UBYTE buffer, LONG bufferlength, struct KeyMap *keymap);
	</syntaxhighlight>		</syntaxhighlight>
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	The following example shows the usage of '''MapANSI()''' and demonstrates how returned key codes can be processed.		The following example shows the usage of '''MapANSI()''' and demonstrates how returned key codes can be processed.

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	/*		/*
	mapansi.c - converts a string to input events using MapANSI() function.		mapansi.c - converts a string to input events using MapANSI() function.
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	A '''KeyMap''' structure contains pointers to arrays which determine the translation from raw key codes to ANSI characters.		A '''KeyMap''' structure contains pointers to arrays which determine the translation from raw key codes to ANSI characters.

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	struct KeyMap		struct KeyMap
	{		{
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	The low key map provides translation of the key values from hex 00-3F; the high key map provides translation of key values from hex 40-7F. Key values from hex 68-7F are not used by the existing keyboards, but this may change in the future. A raw key value (hex 00-7F) plus hex 80 is the release of that key. If you need to check for raw key releases do it like this:		The low key map provides translation of the key values from hex 00-3F; the high key map provides translation of key values from hex 40-7F. Key values from hex 68-7F are not used by the existing keyboards, but this may change in the future. A raw key value (hex 00-7F) plus hex 80 is the release of that key. If you need to check for raw key releases do it like this:

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	if (keyvalue & 0x80) { /* do key up processing */ }		if (keyvalue & 0x80) { /* do key up processing */ }
	else { /* do key down processing */ }		else { /* do key down processing */ }

Frédéric Khannouf: Fixed small typos in MapRawKey.c preventing accurate value to be printed to the console

2019-08-18T15:54:50Z

Fixed small typos in MapRawKey.c preventing accurate value to be printed to the console

← Older revision		Revision as of 15:54, 18 August 2019
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	inputevent.ie_Qualifier = imsg->Qualifier;		inputevent.ie_Qualifier = imsg->Qualifier;

	IDOS->Printf("RAWKEY: Code=$%~~04x~~ Qualifier=$%04lx\en",		IDOS->Printf("RAWKEY: Code=$%04lx Qualifier=$%04lx\n",
	imsg->Code, imsg->Qualifier);		imsg->Code, imsg->Qualifier);

Steven Solie at 20:33, 3 November 2015

2015-11-03T20:33:29Z

← Older revision		Revision as of 20:33, 3 November 2015
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	The Amiga uses the [http://www.ecma-international.org/publications/standards/Ecma-094.htm ECMA-94 Latin 1 International 8-bit] character set, and can map raw key codes to any desired ANSI character value, string, or escape sequence. This allows national keyboards to be supported by using keymaps. A keymap is a file which describes what character or string is tied to what key code. Generally, the user's startup-sequence will set a system default keymap that is correct for the user's keyboard. The console.device translates the raw key codes into the correct characters based on the installed keymap. This includes the translation of special deadkey sequential key combinations to produce accented international characters.		The Amiga uses the [http://www.ecma-international.org/publications/standards/Ecma-094.htm ECMA-94 Latin 1 International 8-bit] character set, and can map raw key codes to any desired ANSI character value, string, or escape sequence. This allows national keyboards to be supported by using keymaps. A keymap is a file which describes what character or string is tied to what key code. Generally, the user's startup-sequence will set a system default keymap that is correct for the user's keyboard. The console.device translates the raw key codes into the correct characters based on the installed keymap. This includes the translation of special deadkey sequential key combinations to produce accented international characters.

	Programs which perform keyboard input using the console.device, CON:, RAW:, or Intuition VANILLAKEY, will receive custom keymaps, or may need to perform their own translation between raw key codes and ANSI characters. In this ~~chapter~~, the term ANSI refers to the standard 8-bit character definitions which include printable ASCII characters, special characters, and escape sequences.		Programs which perform keyboard input using the console.device, CON:, RAW:, or Intuition VANILLAKEY, will receive custom keymaps, or may need to perform their own translation between raw key codes and ANSI characters. In this article, the term ANSI refers to the standard 8-bit character definitions which include printable ASCII characters, special characters, and escape sequences.

	Keymap.library offers some of the keymap commands of the console.device, enabling applications to inquire after the default keymap and map key codes to ANSI characters. It also provides the ability to map ANSI characters back into raw codes. Unlike the console.device however, it can not be used to select a keymap for only one application, i.e., one console window.		Keymap.library offers some of the keymap commands of the console.device, enabling applications to inquire after the default keymap and map key codes to ANSI characters. It also provides the ability to map ANSI characters back into raw codes. Unlike the console.device however, it can not be used to select a keymap for only one application, i.e., one console window.
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	== Function Reference ==		== Function Reference ==

	The following are brief descriptions of the functions covered in this ~~chapter~~. See the SDK for details on each function call.		The following are brief descriptions of the functions covered in this article. See the SDK for details on each function call.

	{\| class="wikitable"		{\| class="wikitable"

Steven Solie: /* Keymap Library */

2015-09-25T16:11:08Z

Keymap Library

← Older revision		Revision as of 16:11, 25 September 2015
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	Amiga computers are sold internationally with a variety of local keyboards which match the standards of particular countries. All Amigas have keyboards which are physically similar, and keys which output the same low-level raw key code for any particular physical key. However, in different countries, the keycaps of the keys may contain different letters or symbols. Since the physical position of a key determines the raw key code that it generates, raw key codes are not internationally compatible. For instance, on the German keyboard, the Y and Z keys are swapped when compared to the USA keyboard. The second key on the fifth row will generate the same raw key code on all Amiga keyboards, but should be decoded as a Z on a US keyboard and as a Y on a German keyboard.		Amiga computers are sold internationally with a variety of local keyboards which match the standards of particular countries. All Amigas have keyboards which are physically similar, and keys which output the same low-level raw key code for any particular physical key. However, in different countries, the keycaps of the keys may contain different letters or symbols. Since the physical position of a key determines the raw key code that it generates, raw key codes are not internationally compatible. For instance, on the German keyboard, the Y and Z keys are swapped when compared to the USA keyboard. The second key on the fifth row will generate the same raw key code on all Amiga keyboards, but should be decoded as a Z on a US keyboard and as a Y on a German keyboard.

	The Amiga uses the ECMA-94 Latin 1 International 8-bit character set, and can map raw key codes to any desired ANSI character value, string, or escape sequence. This allows national keyboards to be supported by using keymaps. A keymap is a file which describes what character or string is tied to what key code. Generally, the user's startup-sequence will set a system default keymap that is correct for the user's keyboard. The console.device translates the raw key codes into the correct characters based on the installed keymap. This includes the translation of special deadkey sequential key combinations to produce accented international characters.		The Amiga uses the [http://www.ecma-international.org/publications/standards/Ecma-094.htm ECMA-94 Latin 1 International 8-bit] character set, and can map raw key codes to any desired ANSI character value, string, or escape sequence. This allows national keyboards to be supported by using keymaps. A keymap is a file which describes what character or string is tied to what key code. Generally, the user's startup-sequence will set a system default keymap that is correct for the user's keyboard. The console.device translates the raw key codes into the correct characters based on the installed keymap. This includes the translation of special deadkey sequential key combinations to produce accented international characters.

	Programs which perform keyboard input using the console.device, CON:, RAW:, or Intuition VANILLAKEY, will receive custom keymaps, or may need to perform their own translation between raw key codes and ANSI characters. In this chapter, the term ANSI refers to the standard 8-bit character definitions which include printable ASCII characters, special characters, and escape sequences.		Programs which perform keyboard input using the console.device, CON:, RAW:, or Intuition VANILLAKEY, will receive custom keymaps, or may need to perform their own translation between raw key codes and ANSI characters. In this chapter, the term ANSI refers to the standard 8-bit character definitions which include printable ASCII characters, special characters, and escape sequences.

Steven Solie: /* Raw Key Table */

2014-04-30T15:15:37Z

Raw Key Table

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	\|-		\|-
	\| 0105 \|\| 0007 \|\| 006A \|\| 0066 \|\| 0018 \|\| F15 \|\| F15		\| 0105 \|\| 0007 \|\| 006A \|\| 0066 \|\| 0018 \|\| F15 \|\| F15
			\|-
			\| 0180 - 0185 \|\| \|\| \|\| \|\| \|\| \|\| Up transition (release or unpress key) (0180 for 0100)
	\|}		\|}

Steven Solie: /* Raw Key Table */

2014-04-26T17:53:23Z

Raw Key Table

← Older revision		Revision as of 17:53, 26 April 2014
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	\| 000D \|\| 0007 \|\| 0031 \|\| \|\| \|\| \|\| <nowiki>\\|</nowiki> near Backspace		\| 000D \|\| 0007 \|\| 0031 \|\| \|\| \|\| \|\| <nowiki>\\|</nowiki> near Backspace
	\|-		\|-
	\| 000E \|\| \|\| \|\| \|\| \|\| \|\| ~~undefined~~		\| 000E \|\| 0007 \|\| 0089 \|\| 007D \|\| 006A \|\| \|\| Intl 3 Yen
	\|-		\|-
	\| 000F \|\| 0007 \|\| 0062 \|\| 0052 \|\| 0070 \|\| \|\| NP <nowiki>0</nowiki>		\| 000F \|\| 0007 \|\| 0062 \|\| 0052 \|\| 0070 \|\| \|\| NP <nowiki>0</nowiki>
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	\|-		\|-
	\| 00FF \|\| \|\| \|\| \|\| \|\| \|\| No key code defined		\| 00FF \|\| \|\| \|\| \|\| \|\| \|\| No key code defined
			\|-
			\| 0100 \|\| 0007 \|\| 0088 \|\| 0070 \|\| 0013 \|\| \|\| Intl 2 Hiragana/Katakana
			\|-
			\| 0101 \|\| 0007 \|\| 008A \|\| 0079 \|\| 0064 \|\| \|\| Intl 4 Henkan
			\|-
			\| 0102 \|\| 0007 \|\| 008B \|\| 007B \|\| 0067 \|\| \|\| Intl 5 Muhenkan
			\|-
			\| 0103 \|\| 0007 \|\| 0068 \|\| 0064 \|\| 0008 \|\| F13 \|\| F13
			\|-
			\| 0104 \|\| 0007 \|\| 0069 \|\| 0065 \|\| 0010 \|\| F14 \|\| F14
			\|-
			\| 0105 \|\| 0007 \|\| 006A \|\| 0066 \|\| 0018 \|\| F15 \|\| F15
	\|}		\|}

Steven Solie: /* Raw Key Table */

2014-03-12T16:47:07Z

Raw Key Table

← Older revision		Revision as of 16:47, 12 March 2014
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	\| 0067 \|\| 0007 \|\| 00E7 \|\| 00E05C \|\| 00E027 \|\| RCOMMAND \|\| RAmiga, RWin, RApple, RMeta		\| 0067 \|\| 0007 \|\| 00E7 \|\| 00E05C \|\| 00E027 \|\| RCOMMAND \|\| RAmiga, RWin, RApple, RMeta
	\|-		\|-
	\| 0068 \|\| \|\| \|\| \|\| \|\| LBUTTON \|\| ~~0068~~ LMouse reserved		\| 0068 \|\| \|\| \|\| \|\| \|\| LBUTTON \|\| LMouse reserved
	\|-		\|-
	\| 0069 \|\| \|\| \|\| \|\| \|\| RBUTTON \|\| ~~0069~~ RMouse reserved		\| 0069 \|\| \|\| \|\| \|\| \|\| RBUTTON \|\| RMouse reserved
	\|-		\|-
	\| 006A \|\| \|\| \|\| \|\| \|\| MBUTTON \|\| ~~006A~~ MMouse reserved		\| 006A \|\| \|\| \|\| \|\| \|\| MBUTTON \|\| MMouse reserved
	\|-		\|-
	\| 006B \|\| 0007 \|\| 0065 \|\| 00E05D \|\| 00E02F \|\| MENU \|\| Menu, Windows, Compose (mappable to RAmiga in Firmware)		\| 006B \|\| 0007 \|\| 0065 \|\| 00E05D \|\| 00E02F \|\| MENU \|\| Menu, Windows, Compose (mappable to RAmiga in Firmware)

Steven Solie: /* Double-Dead Keys */

2014-02-09T03:55:42Z

Double-Dead Keys

← Older revision		Revision as of 03:55, 9 February 2014
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	Double-dead keys are an extension of the dead-class keys explained above. Unlike normal dead keys wherein one dead key of type DPF_DEAD can modify a second of type DPF_MOD, double-dead keys employ two consecutive keys of type DPF_DEAD to together modify a third of type DPF_MOD.		Double-dead keys are an extension of the dead-class keys explained above. Unlike normal dead keys wherein one dead key of type DPF_DEAD can modify a second of type DPF_MOD, double-dead keys employ two consecutive keys of type DPF_DEAD to together modify a third of type DPF_MOD.

	For example, the key on the German keyboard labeled with single quotes (`') is a double-dead key. When this key is pressed alone and then pressed again shifted, there is no output. But when followed by an appropriate third key, for example the ~~'''~~A~~'''~~ key, the three keypresses combine to produce an `a' with a circumflex (^) accent (character code $E2). Thus the double-dead pair qualify the output of the A key.		For example, the key on the German keyboard labeled with single quotes (<nowiki>''</nowiki>) is a double-dead key. When this key is pressed alone and then pressed again shifted, there is no output. But when followed by an appropriate third key, for example the A key, the three keypresses combine to produce an 'a' with a circumflex (^) accent (character code $E2). Thus the double-dead pair qualify the output of the A key.

	The system always keeps the last two down key codes for possible further translation. If they are both of type DPF_DEAD and the key immediately following is DPF_MOD then the two are used to form an index into the (third) key's translation table as follows:		The system always keeps the last two down key codes for possible further translation. If they are both of type DPF_DEAD and the key immediately following is DPF_MOD then the two are used to form an index into the (third) key's translation table as follows:
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	</pre>		</pre>

	Raw key0C, the German single quotes ( `' ) key, is a double dead key. Pressing this key alone, then again while the shift key is down will produce no output but will form a double-dead qualifier. The output of key20 (A), a deadable key, will consequently be modified, producing an ``a'' with a circumflex (^) accent. The mechanics are as follows:		Raw key0C, the German single quotes (<nowiki>''</nowiki>) key, is a double dead key. Pressing this key alone, then again while the shift key is down will produce no output but will form a double-dead qualifier. The output of key20 (A), a deadable key, will consequently be modified, producing an "a" with a circumflex (^) accent. The mechanics are as follows:

	* When key0C is pressed alone the DPF_DEAD of the first byte pair in the key's table indicates that the key as dead. The second byte is then held by the system.		* When key0C is pressed alone the DPF_DEAD of the first byte pair in the key's table indicates that the key as dead. The second byte is then held by the system.
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	* Finally, when the A key is pressed the system recalls the latter of the two bytes it has saved. The upper nibble, $6, is multiplied by		* Finally, when the A key is pressed the system recalls the latter of the two bytes it has saved. The upper nibble, $6, is multiplied by
	the lower nibble, $2. The result, $0C, is then added to the lower nibble of the earlier of the two saved bytes, $1. This new value, $0D, is used as an index into the (unshifted) translation table of key20. The character at position $0D is character $E2, an `a' with a circumflex (^) accent.		the lower nibble, $2. The result, $0C, is then added to the lower nibble of the earlier of the two saved bytes, $1. This new value, $0D, is used as an index into the (unshifted) translation table of key20. The character at position $0D is character $E2, an 'a' with a circumflex (^) accent.

	{{Note\|title=Note About Double Dead Keys\|text=If only one double-dead key is pressed before a deadable key then the output is the same as if the double-dead were a normal dead key. If shifted key0C is pressed on the German keyboard and then immediately followed by key20, the output produced is character $E0, ~~` \o~~'~~a\`'~~ '. As before, the upper nibble is multiplied with the lower, resulting in $0C. But because there was no second dead-key, this product is used as the final index.}}		{{Note\|title=Note About Double Dead Keys\|text=If only one double-dead key is pressed before a deadable key then the output is the same as if the double-dead were a normal dead key. If shifted key0C is pressed on the German keyboard and then immediately followed by key20, the output produced is character $E0 'à'. As before, the upper nibble is multiplied with the lower, resulting in $0C. But because there was no second dead-key, this product is used as the final index.}}

	== Keyboard Layout ==		== Keyboard Layout ==

Steven Solie: /* Dead-Class Keys */

2014-02-09T03:48:36Z

Dead-Class Keys

← Older revision		Revision as of 03:48, 9 February 2014
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	\| NOQUAL \|\| alone \|\| - \|\| - \|\| - \|\| - \|\| - \|\| - \|\| -		\| NOQUAL \|\| alone \|\| - \|\| - \|\| - \|\| - \|\| - \|\| - \|\| -
	\|-		\|-
	\| A \|\| alone \|\| - \|\| - \|\| - \|\| - \|\| - \|\| -		\| A \|\| alone \|\| - \|\| - \|\| - \|\| - \|\| - \|\| - \|\| -
	\|-		\|-
	\| C \|\| alone \|\| C \|\| - \|\| - \|\| - \|\| - \|\| - \|\| -		\| C \|\| alone \|\| C \|\| - \|\| - \|\| - \|\| - \|\| - \|\| -

Steven Solie: /* Dead-Class Keys */

2014-02-09T03:43:12Z

Dead-Class Keys

← Older revision		Revision as of 03:43, 9 February 2014
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	=== Dead-Class Keys ===		=== Dead-Class Keys ===

		⚫	All of the national keymaps, including USA, contain ''dead-class'' keys. This term refers to keys that either modify or can themselves be modified by other dead-class keys. There are two types of dead-class keys: dead and deadable. A dead key is one which can modify certain keys pressed immediately following. For example, on the German keyboard there is a dead key marked with the grave accent (`). The dead key produces no console output, but when followed by (for instance) the A key, the combination will produce the a-grave (à) character (National Character Code $E0). On the U.S. keyboard, Alt-G is the deadkey used to add the grave accent (`) to the next appropriate character typed.
	All of the national keymaps, including USA, contain ''dead-class'' keys. This term refers to keys that either modify or can themselves
	be modified by other dead-class keys. There are two types of dead-class keys: dead and deadable. A dead key is one which can modify certain keys pressed immediately following. For example, on the German keyboard there is a dead key marked with the grave accent (\`).
⚫	The dead key produces no console output, but when followed by (for instance) the A key, the combination will produce the a-grave (~~\o'a\`'~~) character (National Character Code $E0). On the U.S. keyboard, Alt-G is the deadkey used to add the grave accent (\`) to the next appropriate character typed.

	A deadable key is one that can be prefixed by a dead key. The A key in the previous example is a deadable key. Thus, a dead key can only affect the output of a deadable key.		A deadable key is one that can be prefixed by a dead key. The A key in the previous example is a deadable key. Thus, a dead key can only affect the output of a deadable key.

	For any key that is to have a dead-class function, whether dead or deadable, the qualifier KCF_DEAD flag must be included in the entry for the key in the KeyMapTypes table. The KCF_DEAD type may also be used in conjunction with the other qualifiers. Furthermore, the key's keymap table entry must contain the longword address of the key's dead-key descriptor data area in place of the usual 4 ASCII character mapping.		For any key that is to have a dead-class function, whether dead or deadable, the qualifier KCF_DEAD flag must be included in the entry for the key in the KeyMapTypes table. The KCF_DEAD type may also be used in conjunction with the other qualifiers. Furthermore, the key's keymap table entry must contain the longword address of the key's dead-key descriptor data area in place of the usual 4 ASCII character mapping.

	Below is an excerpt from the Amiga 1000 German key map which is referred to in the following discussion.		Below is an excerpt from the Amiga 1000 German key map which is referred to in the following discussion.
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	</pre>		</pre>

	In the example, key 25 (the H key) is a dead key and key 20 (the A key) is a deadable key. Both keys use the addresses of their descriptor data areas as entries in the LoKeyMap table. The LoKeyMapTypes table says that there are four qualifiers for both: the requisite KCF_DEAD, as well as KCF_SHIFT, KCF_ALT, and KCF_CONTROL. The number of qualifiers determine length and arrangement of the descriptor data areas for each key. The next table shows how to interpret the KeyMapTypes for various combinations of the qualifier bits. For each possible position a pair of bytes is needed. The first byte in each pair tells how to interpret the second byte (more about this below).		In the example, key 25 (the H key) is a dead key and key 20 (the A key) is a deadable key. Both keys use the addresses of their descriptor data areas as entries in the LoKeyMap table. The LoKeyMapTypes table says that there are four qualifiers for both: the requisite KCF_DEAD, as well as KCF_SHIFT, KCF_ALT, and KCF_CONTROL. The number of qualifiers determine length and arrangement of the descriptor data areas for each key. The next table shows how to interpret the KeyMapTypes for various combinations of the qualifier bits. For each possible position a pair of bytes is needed. The first byte in each pair tells how to interpret the second byte (more about this below).

	{\| class="wikitable"		{\| class="wikitable"
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	Because keys 20 and 25 each use three qualifier bits (not including KCF_DEAD), according to the table there must be 8 pairs of data, arranged as shown. Had only KCF_ALT been set, for instance, (not including KCF_DEAD), just two pairs would have been needed.		Because keys 20 and 25 each use three qualifier bits (not including KCF_DEAD), according to the table there must be 8 pairs of data, arranged as shown. Had only KCF_ALT been set, for instance, (not including KCF_DEAD), just two pairs would have been needed.

	As mentioned earlier, the first byte of each data pair in the descriptor data area specifies how to interpret the second byte. There are three possible values: 0, DPF_DEAD and DPF_MOD. In the Amiga 1000 German keymap listed above, DPF_DEAD appears in the data for key 25, while DPF_MOD is used for key 20. It is the use of these flags that determines whether a dead-class key has dead or deadable function. A value of zero causes the unrestricted output of the following byte.		As mentioned earlier, the first byte of each data pair in the descriptor data area specifies how to interpret the second byte. There are three possible values: 0, DPF_DEAD and DPF_MOD. In the Amiga 1000 German keymap listed above, DPF_DEAD appears in the data for key 25, while DPF_MOD is used for key 20. It is the use of these flags that determines whether a dead-class key has dead or deadable function. A value of zero causes the unrestricted output of the following byte.

	If the flag byte is DPF_DEAD, then that particular key combination (determined by the placement of the pair of bytes in the data table) is dead and will modify the output of the next key pressed (if deadable). How it modifies is controlled by the second byte of the pair which is used as an index into part(s) of the data area for ALL the deadable (DPF_MOD set) keys.		If the flag byte is DPF_DEAD, then that particular key combination (determined by the placement of the pair of bytes in the data table) is dead and will modify the output of the next key pressed (if deadable). How it modifies is controlled by the second byte of the pair which is used as an index into part(s) of the data area for ALL the deadable (DPF_MOD set) keys.

	Before going further, an understanding of the structure of a descriptor data area wherein DPF_MOD is set for one (or more) of its members is necessary. Referring to the example, we see that DPF_MOD is set for the first and second pairs of bytes. According to its LoKeyMapTypes entry, and using table ~~\n(H1-5~~ (Dead Key Qualifier Bits) as a guide, these pairs represent the alone and SHIFTed values for the key. When DPF_MOD is set, the byte immediately following the flag must be the offset from the start of the key's descriptor data area to the start of a table of bytes describing the characters to output when this key combination is preceded by any dead keys. This is where the index mentioned above comes in. The value of the index from a prefixing dead key is used to determine which of the bytes from the deadable keys special table to output. The byte in the index+1 position is sent out. (The very first byte is the value to output if the key was not prefixed by a dead key.) Thus, if Alt-H is pressed (dead) and then Shift-A, an `a' with a circumflex (^) accent will be output. This is because:		Before going further, an understanding of the structure of a descriptor data area wherein DPF_MOD is set for one (or more) of its members is necessary. Referring to the example, we see that DPF_MOD is set for the first and second pairs of bytes. According to its LoKeyMapTypes entry, and using table above (Dead Key Qualifier Bits) as a guide, these pairs represent the alone and SHIFTed values for the key. When DPF_MOD is set, the byte immediately following the flag must be the offset from the start of the key's descriptor data area to the start of a table of bytes describing the characters to output when this key combination is preceded by any dead keys. This is where the index mentioned above comes in. The value of the index from a prefixing dead key is used to determine which of the bytes from the deadable keys special table to output. The byte in the index+1 position is sent out. (The very first byte is the value to output if the key was not prefixed by a dead key.) Thus, if Alt-H is pressed (dead) and then Shift-A, an 'a' with a circumflex (^) accent will be output. This is because:

	* The byte pair for the ALT position of the "H" key (key 25) is DPF_DEAD,3 so the index is 3.		* The byte pair for the ALT position of the "H" key (key 25) is DPF_DEAD,3 so the index is 3.