(c) Copyright 1989-1999 Amiga, Inc. All rights reserved. The information contained herein is subject to change without notice, and is provided "as is" without warranty of any kind, either expressed or implied. The entire risk as to the use of this information is assumed by the user. INTERNATIONAL KEYBOARD INPUT Eric Cotton and Carolyn Scheppner The Amiga computers are sold internationally with a variety of local keyboards which match the standards of particular countries. The 1.2 Enhancer manual contains diagrams of the keyboards which are currently distributed. If you look at the diagrams, you will see that some letters and special symbols are in different physical positions on the various keyboards. For instance, on the German and Italian keyboards, the Y and Z keys are swapped when compared to the USA keyboard. Since the physical position of a key determines the raw key code that it generates, straight RAWKEY input is not internationally compatible. Pressing the second key on the fifth row will generate the same raw key code on all Amiga keyboards, but will be decoded as a Z on a US keyboard and as a Y on a German. The 1.2 Amiga console device supports national keyboards by providing mapping of raw key codes to the proper ASCII characters and strings as specified in a Keymap. In addition, the console device provides handling of the "dead keys" used to generate accented characters. Any keyboard input which is processed by the console device will be automatically translated to the installed keymap. The new 1.2 Setmap command is used to install the default keymap to be used by the console device. If you wish to experiment with the national keymaps, the KeyToy program on Extras 1.2 provides a graphic presentation of the various keyboards. All of the national Keymaps, including USA, contain dead keys. Basically, a dead key is a key that produces no output until a second key is pressed. Thus the dead key modifies the output of another key. Often a dead key is used to indicate that a particular accent mark is to be placed on the next character typed. The ASCII values for these characters are all greater than 127. They are listed in the International Character Codes table in the AmigaDOS manual. If a dead key is used to request an invalid accent for a character, the normal unaccented character results. If you look at the U.S. keyboard diagram in the Enhancer manual, you'll see that the F, G, H, J, and K keys (shadowed) are defined as dead keys. In the diagram, various accent marks are printed in the lower half of each of these keys. Pressing Alt and one of these shadowed keys is a request for the illustrated accent to be placed on the next character you type. For example, try typing these with the default usa keymap: ALT/F (') then A results in an A accented with ' ALT/H (^) then E results in an E accented with ^ ALT/J (~) then C results in a plain C (invalid accent for C) Under 1.2, the console.device, IDCMP VANILLAKEY, and AmigaDOS CON: and RAW: all provide automatic handling of dead keys and translation of raw keycodes to ASCII based on the current keymap. If your software requires non-VANILLA keys such as the cursor and function keys, using console device keyboard input in your Intuition window will allow you to receive the escape sequences generated by these keys. If you are using IDCMP RAWKEY input in international software, you must properly use the console device's RawKeyConvert() function to get keymap translation and dead key handling. See the example DeadKeyConvert() in the 1.2 Enhancer manual (P. 65) or the 1.2 Readmes for more on this. Use NULL for the kmap argument to get translation to the currently installed Keymap. Be sure to test your code with ASCII characters greater than 127 such as accented characters like Alt-F-A wherever your code accepts keyboard input to ensure that your logic and data structures work properly with high ASCII values. In addition, test your code after using SetMap to install various keymaps, using the Enhancer manual keyboard diagrams as a guide for what the keycaps would show in that country. You won't be able to test all of the keys of some national keyboards, but you can test enough keys to be sure you are getting translation. The following information is a supplement to chapter 8, The Console Device, in the Rom Kernel Manual: Libraries and Devices, which describes the Keymap format and console.device handling of dead keys. Dead-Class Keys The term "dead-class key" 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 the key pressed immediately following it. For example, in all keymaps the H key acts as a carat ("^") dead key when pressed along with the Alt or Shift-Alt qualifiers. When followed by the A key for instance, the combination will produce the accented character @@ (international character code $E2). A deadable key is is one that can be pre-fixed by a dead key. The A key in this 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. Consider the following example KeyMap excerpt: Example 1: Dead-Class Keys new LoKeyMapTypes: DC.B KCF_DEAD+KCF_SHIFT+KCF_ALT+KCF_CONTROL ;aA (Key 20) ... ;(more...) DC.B KCF_DEAD+KCF_SHIFT+KCF_ALT+KCF_CONTROL ;hH (Key 25) ... ;(more...) new LoKeyMap: DC.L key20 ; a, A, ae, AE ... ;(more...) DC.L key25 ;h, H, dead ^ ... ;(more...) ;------ possible dead keys key25: DC.B 0,'h',0,'H' ;h, H DC.B DPF_DEAD,3,DPF_DEAD,3 ;dead ^ DC.B 0,$08,0,$08,0,$88,0,$88 ;control translation ... ;(more...) ;------ deadable keys (modified by dead keys) key20: DC.B DPF_MOD,key20u-key20 ;deadable flag, number of ;bytes from start of key20 ;descriptor to start of un- ;shifted data DC.B DPF_MOD,key20s-key20 ;deadable flag, number of ;bytes from start of key20 ;descriptor to start of shift- ;ed data DC.B 0,$E6,0,$C6 ;null flags followed by rest DC.B 0,$01,0,$01,0,$81,0,$81 ;of values (ALT, CTRL...) key20u: DC.B 'a',$E0,$E1,$E2,$E3,$E4 ;'a' alone and characters to ;output when key alone is ;prefixed by a dead key key20s: DC.B 'A',$C0,$C1,$C2,$C3,$C4 ;SHIFTed 'a' and characters to ;output when SHIFTed key is ;prefixed by a dead key 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. Table 1 below 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. Table 1: Dead Key Qualifier Bits If type Then the pair of bytes in this position in the dead-class key byte is: descriptor data is output when the key is pressed along with: NOQUAL alone - - - - - - - A alone A - - - - - - C alone C - - - - - - S alone S - - - - - - A+C alone A C A+C - - - - A+S alone S A A+S - - - - C+S alone S C C+S - - - - S+A+C (VANILLA) alone S A S+A C C+S C+A C+S+A NOTE: the abbreviations A, C, S stand for ALT, Control, and Shift, respectively. Also note that the ordering is reversed from that in the normal KeyMap table. 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: key alone and Alt-key. As mentioned earlier, the first byte of data pair in the descriptor data area specifies how to interpret the second byte. There are three possible type values: 0, DPF_DEAD and DPF_MOD. In Example 1, DPF_DEAD appears in the data for key 25, while DPF_MOD is used for key 20. It is the use of these flags which 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 type 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 parts of the data area for ALL the deadable keys (DPF_MOD set). 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 1 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 a dead key. 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 byte in the first position is the value to output if the key was not prefixed by a dead key.) Thus, if Alt-H is pressed (carat) and then Shift-A, an @@ will be output. This is because: o The byte pair for the Alt position of the H key (key 25) is DPF_DEAD,3 so the index is 3. o The byte pair for the SHIFT position of the A key (key 20) is DPF_MOD,key20s-key20, so we refer to the table-of-bytes at key20s. o The third+1 byte of the table-of-bytes is $C2, a @@ character. Note that the number of bytes in the table-of-bytes for all deadable keys must be equal to the highest index value of all dead keys plus 1.