Indian Language Keyboard is categorized into three parts. The characters of Indian language alphabets are divided into Consonants, Vowels, Nasals and Conjuncts. Every consonant represents a combination of a particular sound and a vowel. The vowels are representations of pure sounds. The Nasals are characters representing nasal sounds along with vowels. The conjuncts are combinations of two or more characters. The Indian language alphabet table is divided into Vowels (Swar) and Consonants (Vyanjan).
The INSCRIPT (Indian Script) Keyboard Layout was standardized by the Department of Electronics (DOE) in 1986 with a subsequent revision in 1988. The INSCRIPT keyboard layout was declared as a National Standard by Bureau of Indian Standard (BIS) in 1991. The BIS ISCII document (IS 13194:1991) also describes the keyboard layout for each script.
This keyboard overlay is phonetic in nature and has a common layout for all the scripts provided with this software. It contains the characters required for all the Indian scripts, as defined by the ISCII character set. The Indian script alphabet (ISCII) has a logical structure derived from the phonetic properties of the Indian scripts. The Inscript overlay mirrors this logical structure.
Enhanced Inscript Keyboard Layout
With the advent of Unicode, a few new characters were added to each code-page; characters for which the INSCRIPT keyboard layout (IS 13194:1991) standard had not made any provision. In addition ISO-10646 introduced the concept of ZWJ and ZWNJ as well as that of normalization. These new features had marked repercussion on storage as well as inputting and an urgent need was felt for a revision whereby each and new character introduced in Unicode would be accommodated on the keyboard and a uniform manner of entering data as well as storing data would be devised.
With this urgent requirement, TDIL along with CDAC GIST involved all major players: IBM, Microsoft and RedHat Linux and hence in 2008, a joint meeting was organized to devise a common and uniform strategy for inputting and equally important for storage. This would enable the creation of one single keyboard and more importantly, one single storage, essential for all high-end NLP. A task-force was created with two major briefs:
The result of extensive efforts puts into it by TDIL and C-DAC Gist, BIS has published the Indian Standard - ‘Enhanced Inscript keyboard layouts’ (IS 16350: 2016).
Typing in Inscript Keyboard
This layout uses the standard QWERTY 101 keyboard. The mapping of the characters is such that it remains common for all the Indian languages (written left to right). This is because of the fact that the basic character set of the Indian languages is common. The vowels are divided into long and short vowels and the consonants are divided into vargs. The INSCRIPT layout takes advantage of these facts and thus the organization is simple. Due to the phonetic nature of the keyboard, a person who knows typing in one Indian script can type in any other Indian script. The logical structure allows ease in learning.
In the Inscript keyboard layout, all the vowels are placed on the left side of the keyboard layout and the consonants, on the right side. The placement is such that the characters of one varg are split over two keys. The splitting of the word into keystrokes is based on the phonetic spelling of the word. The sequence required for typing a word is same as the sequence in which the characters of the word are pronounced.
Phonetic English keyboard overlay has the Indian script alphabets phonetically assigned to that of English alphabets on the IBM-PC QWERTY overlay. This keyboard is useful for people who are acquainted with the language but know how to use computer using English.
Typing in Phonetic Keyboard
The Phonetic keyboards are useful for those who can speak but cannot write in their mother-tongue and for those who are comfortable with the QWERTY keyboard and do not want to key in a text using the INSCRIPT keyboard.
Typewriter Keyboard overlay functions in the same manner as the manual typewriter. Users accustomed to working with a typewriter can use this facility with minimal learning and training time.
Typing in Typewriter Keyboard
This type of keyboard has minimal set of aksharas consisting of the basic vowels and consonants together with the matras so that text can be prepared conforming to the writing system for the language. The location of the keys for the vowels and consonants on a regional language typewriter is specific to the language and the data entry method would be different for different languages.