Keyboard layout
Keyboard structure
A key labeled with only a single letter (usually the capital form) can generally be struck to type either a lower case or a capital letter, the latter requiring the simultaneous holding of the shift key, often labeled "⇧". The shift key is also used to type the upper of two symbols on a given key, the lower being typed without using the shift key.
Many languages use the Latin alphabet but have diacritically marked or other special letters and punctuation for which unique keys do not exist on all keyboards. Therefore, keyboards often have what is effectively a secondary shift key, labeled Alt Gr or option. It can be used to type symbols beyond the two otherwise available with each key. On the visual layout, the secondary symbols may appear to the right of the main symbols engraved on the keys, or they may be unmarked.
The shift and Alt Gr or option keys, along with e.g. caps lock, control and alternative (alt) keys, are called modifier keys. There are also function keys, with various functions as determined by software.
Scan codes
Most computer keyboards are designed to send scan codes to the operating system, rather than directly sending characters. From there, the series of scan codes is converted into a character stream by keyboard layout software. This allows a physical keyboard to be dynamically mapped to any number of layouts without switching hardware components — merely by changing the software that interprets the keystrokes.
Dead key
Compose key
History
Mechanical, visual and functional layouts
QWERTY based layouts for Latin script
QWERTY
Canadian French (Quebec)
Canadian Multilingual Standard
Czech
Danish
Dutch (Netherlands)
Estonian
Faroese
Finnish multilingual
Icelandic
Irish
Italian
Maltese
Norwegian
Persian (Farsi)
Polish
Most typewriters use a QWERTZ keyboard with Polish accented letters accessed directly (officially approved as "Typist's keyboard", Polish: klawiatura maszynistki, PN-87), which is mainly ignored in Poland as impractical (except custom-made, e.g., in public sector and some Apple computers); the "Polish programmer's" (Polish: polski programisty) layout has become the de facto standard, used on virtually all computers sold on the Polish market.
Polish programmers use QWERTY keyboards identical with the standard US layout. In this layout Polish letters are accessed in the same manner as the usage of keyboard shortcuts, with Latin letter keys in combination with right Alt (actually working as AltGr) key. These key combinations (excluding one for "€") obey states of both Shift and Caps Lock keys, preserving normal capitalization while typing Polish characters. For example, to obtain capital "Ź" pressing Shift-rightAlt-X is needed, with Caps Lock off. Note that usage of right Alt in Polish programmers layout may be confusive with Alt-A, Alt-C etc. (which are common shortcuts in most programs and can be obtained only with left Alt) because the key really acting as AltGr is also marked as Alt. This fact is based on usage (and thus selling) in Poland almost only US-layout keyboards (with Alt marked both keys, without AltGr) although Microsoft officially depicts it as AltGr. It can be easily verified by examining the pictures of models offered everywhere in Poland.
Portuguese (Brazil)
Portuguese (Portugal)
Romanian (in Romania and Moldova)
Slovak
In Slovakia, similarly to the Czech Republic, both QWERTZ and QWERTY keyboard layouts are used. QWERTZ is the default keyboard layout for Slovak in Microsoft Windows.
Spanish (Spain), aka Spanish (International sort)
Spanish (Latin America)
Swedish
United Kingdom
United States
Vietnamese
The Vietnamese keyboard layout is an extended Latin QWERTY layout. The letters Ă, Â, Ê, and Ô are found on what would be the number keys 1–4 on the American English keyboard, with 5–9 producing the tonal marks (grave accent, hook, tilde, acute accent, and dot below, in that order), 0 producing Đ, = producing the đồng sign (₫) when not shifted, and brackets ([]) producing Ư and Ơ.
International
International layouts are available which are capable of generating a wide variety of characters used in different countries, based on UK and US physical keyboards. The UK extended keyboard retains the normal use of all keys except the rarely used grave accent (`), using the AltGr key for most functions; the US-international layout changes the effect of the apostrophe/single-quote ('), grave accent (`), double-quote ("), caret (^) and tilde (~) keys, making them dead keys used to modify the following keystroke.
United Kingdom extended
Windows XP SP2 and later also offer a "United Kingdom Extended" keyboard layout which allows input on a standard physical UK keyboard for many languages (including Welsh) without changing any of the allocations of frequently used keys (the rarely used grave accent key becomes a dead key). In particular, the apostrophe, double-quote, tilde and caret keys are not changed into dead keys modifying the character generated by the next key pressed, as used by the US International layout. The extended keyboard is software installed from the Windows control panel, and the extended characters are not normally engraved on keyboards.
The layout provides support for adding diacritics to the vowels a, e, i, o, u, w and y (the last two being used in Welsh) as well as capitals:
QWERTZ
Czech
Hungary
Germany and Austria (but not Switzerland)
Slovak
Bosnian, Croatian, Serbian Latin and Slovene
Serbian Cyrillic
Switzerland(German, French, Italian, Romansh), Liechtenstein, Luxembourg
AZERTY
French
Belgian
Lithuanian
Lithuanian keyboards use a layout known as ĄŽERTY, where Ą appears in place of Q above A, Ž in place of W above S, with Q and W being available either on the far right-hand side or by use of the Alt Gr key. Depending on the software used, the Lithuanian symbols can also be positioned in the place of digits: 1 for Ą, 2 for Č, 3 for Ę, 4 for Ė, 5 for Į, 6 for Š, 7 for Ų, 8 for Ū and = for Ž.
QZERTY
The QZERTY layout is used mostly, if not exclusively, in Italy, where it is very common on typewriters. Computer keyboards are usually QWERTY, although non-alphanumeric characters vary.
Non-QWERTY keyboards for Latin scripts
There are also keyboard layouts that do not resemble QWERTY very closely, if at all. These are designed to reduce finger movement and are claimed by some proponents to offer higher typing speed along with ergonomic benefits.
Some languages use the Latin script but with non-QWERTY-based keyboard layouts, such as Latvian and Turkish (the majority of Turkish keyboards are QWERTY, though the "Turkish-F keyboard layout" is older and said to be better suited to the language).
Dvorak
Colemak
JCUKEN
Neo
Bépo
Turkish
Chorded keyboards and mobile devices
Other original layouts and layout design software
Keyboard layouts for non-Latin alphabetic scripts
Some keyboard layouts for non-Latin alphabetic scripts, most notably the Greek layout, are based on the QWERTY layout, in that glyphs are assigned as far as possible to keys that bear similar-sounding or appearing glyphs in QWERTY. This saves learning time for those familiar with QWERTY.
This is not a general rule, and many non-Latin keyboard layouts have been invented from scratch.
All non-Latin computer keyboard layouts can also input Latin letters as well as the script of the language, for example, when typing in URLs or names. This may be done through a special key on the keyboard devoted to this task, or through some special combination of keys, or through software programs that do not interact with the keyboard much.
Arabic
Armenian
Greek
Hebrew
InScript
Russian
Sinhalese
Moldovan
Ukrainian
Bulgarian
Devanagari
Thai
Khmer
Tibetan
Tibetan (China)
Dzongkha (Bhutan)
East Asian languages
Chinese, Japanese and Korean require special input methods, often abbreviated to CJK IMEs (Input Method Editors), due to the thousands of possible characters in these languages. Various methods have been invented to fit all these possibilities into a QWERTY keyboard, so East Asian keyboards are essentially the same as those in other countries. However, their input methods are considerably more complex, without one-to-one mappings between keys and characters.
In general, first the range of possibilities is narrowed down (most often by entering the desired character's pronunciation), then, if there remains more than one possibility, selecting the desired ideogram either by typing the number before the character, or using a graphical menu to select it. The computer assists the typist by using heuristics to guess which character is most likely desired. Although this may sound clumsy, East Asian input methods are today sufficiently sophisticated that, even for beginners, typing in these languages is only slightly slower than typing English.
In Japanese, the QWERTY-based JIS keyboard layout is used, and the pronunciation of each character is entered using Hepburn romanization or Kunrei-shiki romanization. There are several kana-based typing methods. See also Japanese language and computers.
Chinese has the most complex and varied input methods. Characters can be entered by pronunciation (like Japanese and Hanja in Korean) or by structure. Most of the structural methods are the most difficult to learn, but they are extremely fast for experienced typists, as they do away with the need for selecting characters from a menu. For a detailed treatment, see Chinese input methods for computers.
There exist a variety of other, slower ways a character may be entered. If the pronunciation of a character is not known, the selection can be narrowed down by giving its component shapes, radicals, and stroke count. Also, many input systems include a "drawing pad" permitting "handwriting" of a character using a mouse. Finally, if the computer does not have CJK software installed, it may be possible to enter a character directly through its encoding number (e.g. Unicode).
In contrast to Chinese and Japanese, Korean is typed in a similar way to Western languages. There are two major kinds of keyboard layouts: dubeolsik and sebeolsik. Dubeolsik, which shares its symbol layout with the QWERTY layout, is more commonly used. While Korean consonants and vowels (jamo) are grouped together into syllabic grids when written, the script is essentially alphabetical, and therefore typing in Korean is quite simple for those who understand the Korean alphabet Hangul. Each jamo is assigned to a single key. As the user types letters, the computer automatically groups them into syllabic characters. Given a sequence of jamo, there is only one unambiguous way letters can be validly grouped into syllables, so the computer seamlessly groups them together as the user types.
Japanese
Chinese
A Chinese keyboard is simply a US layout with Chinese input method labels printed on the keys. Without an input method handler, these keyboards would respond to Latin characters, provided that US keyboard layout is selected in the operating system.
Most modern input methods allow input of both simplified and traditional characters, and will simply default to one or the other based on the locale setting.
See the section on Chinese languages, and also Chinese input methods for computers.
Mainland China
Keyboards used in the mainland of the People's Republic of China typically use an English US (QWERTY) keyboard and input Chinese characters using Hanyu pinyin, which represents the sounds of Chinese characters using Latin letters. Keyboards can occasionally be found with labels for alternative input methods such as Wubi method, but those are rare.
Taiwan
Hong Kong
In Hong Kong, both Chinese (Taiwan) and US keyboards are found. Japanese keyboards are occasionally found, but UK keyboards are rare.
Other input methods include the Cantonese Input Method for the Cantonese language speakers. The romanisation, which mirrors the Hong Kong government romanisation of Cantonese, requires users to spell out the Cantonese sound of each character without tone marks, e.g. 'heung' and 'kong' (or 'gong') for 'Hong Kong'/香港 and to choose the characters from a list.
- Chinese writing characters are pieces of ideograms / monographs organised in structured strokes. A Chinese word may be composed of a single ideogram, or two ideograms in combinations. Each monograph can have only one single syllable to pronounce it. However, the same monograph may carry more than one different syllable to denote an entirely different contextual meaning.
The disadvantage of the Cantonese Input Method is that there are many characters that can have the same syllable in the spelling only (they sound the same but are written with different characters) that needed to be differentiated by different intonations for speech communication. Unless a user has also input a phonetic intonation or an accent numeral (i.e., 1, 2, 3, or 4.) to narrow down the list of possible combinations, he or she can have a substantial set of ambiguous Chinese characters of the same pronunciation to select. The selection process can slow down the input speed for those do have not input an accent numeral after each and every Cantonese spelling.
The advantage of the Cantonese Input Method is that nearly all Cantonese Speakers can input Traditional Chinese characters on their very instinct; no particular training and practice is required at all. The advantage available to a Hanyu Pinyin user is that any keyboard with just an English layout, i.e., without BoPoMoFo markings engraved, can deploy the Pinyin IME for bilingual (both Chinese and English on the same document) input. All those who have received formal education in Mainland China can easily input with Hanyu Pinyin without any formal training. The drawback of Hanyu Pinyin to a Hong Kong native Cantonese speaker is that the alphabets are not pronounced exactly in the same way as the common English language syllables should be pronounced because it is only the Latin letters in the keyboard that have been used by the Hanyu Pinyin Method.
Thorough training and practice are required to input correctly with Changjie or Cangjie, yet it is, by impression, the quickest Chinese input method. Many Cantonese speakers have taken Changjie or Cangjie input courses because of the fast typing speed availed by the input method. This method is the fastest because it has the capability to fetch the exact, unambiguous Chinese character which the user has in mind to input, pinpointing to only one character in most cases. This is also the reason why no provision for an input of phonetic accent is needed to complement this Input Method. The Changjie or Cangjie character feature is available on both Mac OS X and Windows. On Mac OS X the use of the multitouch pads of modern Macs makes it possible to write a glyph with a finger and the correct character is recognised by the computer.
The clumsiest Chinese Input method is the Stroke Input Method which is ideal for those who are not so proficient in spelling the Cantonese language in English Alphabets nor Mandarin in Pinyin. The method is widely installed in mobile phones with small screens because the method only requires five key taps for the 5,000 commonly used Chinese characters. It is also considered too tedious requiring a user to type out all the strokes constituting a single Chinese character. Chinese characters sharing the same 3 to 5 beginning brush strokes are grouped to response to users' tapping sequences. Thus, there yields a lengthly list of more than 40 some Chinese characters having these similar beginning strokes for the user to confirm which one of the listed characters should be the intended one to input.
The character picking process is a must for the Stroke Input Method users regardless of whether the Traditional or Simplified Chinese character set is to be used. To a native Hong Kong Cantonese speaker who can spell the Cantonese dialect fairly accurately in English alphabets and, who types Chinese in ad-hoc occasions only; Cantonese Input Method is, by far, the most convenient Chinese input method both for phone book searching and for word processing using laptops and smart phones.
Hangul (for Korean)
Dubeolsik
Sebeolsik 390
Sebeolsik Final
Sebeolsik Noshift
See also
Notes and references
External links
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