Indian Standard Code for Information Interchange (ISCII) is a coding scheme for representing various writing systems of India. It encodes the main Indic scripts and a Roman transliteration. The supported scripts are: Bengali–Assamese, Devanagari, Gujarati, Gurmukhi, Kannada, Malayalam, Odia, Tamil, and Telugu. ISCII does not encode the writing systems of India that are based on Persian, but its writing system switching codes nonetheless provide for Kashmiri, Sindhi, Urdu, Persian, Pashto and Arabic. The Persian-based writing systems were subsequently encoded in the PASCII encoding.
ISCII has not been widely used outside certain government institutions, although a variant without the ATR mechanism was used on classic Mac OS, Mac OS Devanagari,[1] and it has now been rendered largely obsolete by Unicode. Unicode uses a separate block for each Indic writing system, and largely preserves the ISCII layout within each block.[2]: 462
The Brahmi-derived writing systems have similar structure.[2]: 462 So ISCII encodes letters with the same phonetic value at the same code point, overlaying the various scripts. For example, the ISCII codes 0xB3 0xDB represent [ki]. This will be rendered as കി in Malayalam, कि in Devanagari, as ਕਿ in Gurmukhi, and as கி in Tamil. The writing system can be selected in rich text by markup or in plain text by means of the ATR code described below.
One motivation for the use of a single encoding is the idea that it will allow easy transliteration from one writing system to another.[2]: 462 However, there are enough incompatibilities that this is not really a practical idea.
ISCII is an 8-bit encoding.[3]: 4 The lower 128 code points are plain ASCII, the upper 128 code points are ISCII-specific. In addition to the code points representing characters, ISCII makes use of a code point with mnemonic ATR that indicates that the following byte contains one of two kinds of information. One set of values changes the writing system until the next writing system indicator or end-of-line. Another set of values select display modes such as bold and italic. ISCII does not provide a means of indicating the default writing system.
The following table shows the character set for Devanagari. The code sets for Assamese, Bengali, Gujarati, Gurmukhi, Kannada, Malayalam, Oriya, Tamil, and Telugu are similar, with each Devanagari form replaced by the equivalent form in each writing system[2]: 462 . Each character is shown with its decimal code and its Unicode equivalent.
E8
094D
E8 E8
094D 200C
E8 E9
094D 200D
To convert from Unicode (UTF-8) to an ISCII / ANSI coding, the following code pages may be used: