1     Character Sets

The DIGITAL UNIX operating system software supports the following Japanese Industrial Standard (JIS) standard character sets:

• JIS X 0201
• JIS X 0208
• JIS X 0212

It also supports the following international standard codesets:

• Unicode
• ISO/IEC 10646

1.1   JIS X 0201

The JIS X 0201 is a national standard for Japanese information interchange. It was first published by the Japanese Industrial Standard Committee in 1976. The current version is JIS X 0208-1997. It is a single-byte character set and consists of Roman letters and Katakana characters.

• Roman letters (00-7F)

• Katakana characters (A1-DF)

Figure 1-1: JIS X 0201 Encoding

1.2   JIS X 0208

The JIS X 0208 is a national standard for a primary set of graphic characters for Japanese information interchange. It was first published by the Japanese Industrial Standard Committee in 1978. The current revision is JIS X 0208-1997.

JIS X 0208 has defined a total of 6,879 characters which include those in Table 1-1.

Table 1-1: Characters Defined in JIS X 0208

Rows	Characters
1 and 2	Special symbols
3	Numerals and Roman alphabets
4	Hiragana characters
5	Katakana characters
6	Greek alphabets
7	Russian alphabets
8	Symbols for drawing graphs, diagrams, and lines
16-47	First level Kanji
48-84	Second level Kanji

The JIS X 0208 code table is divided into 94 rows, numbered from 1 to 94. Each row has 94 columns, also numbered from 1 to 94.

Figure 1-2: JIS X 0208 Character Set

1.3   JIS X 0212

The JIS X 0212 is a national standard for a supplemental set of graphic characters for Japanese information interchange. JIS X 0212 was published by the Japanese Industrial Standard Committee in 1990, and JIS X 0212-1990 is the current revision.

Support for JIS X 0212 characters in DIGITAL UNIX is limited. The DIGITAL UNIX operating system provides no fonts or input methods for JIS X 0212 characters. However, the character data encoded by the codesets which contain the JIS X 0212 character set can be processed properly by internationalized library functions.

JIS X 0212 has defined a total of 6,067 characters which include those in Table 1-2.

Table 1-2: Characters Defined in JIS X 0212

Rows	Characters
1 and 2	Special symbols
6-11	Alphabetic characters
16-77	Supplemental Kanji

The JIS X 0212 code table is divided into 94 rows, numbered from 1 to 94. Each row has 94 columns, also numbered from 1 to 94.

Figure 1-3: JIS X 0212 Character Set

1.4   Unicode

The Unicode Standard, Version 2.0 specifies a universal character set (UCS) that contains definitions for 38,885 characters and also includes a Private Use Area for vendor- or user-defined characters. The main features of this character set are:

• All characters are treated as 16-bit units.
• Some nonspacing diacritic marks are defined, which can be combined with base characters in Unicode. For example, you can encode the character à as the 16-bit character a plus the 16-bit nonspacing grave accent. The result is a 32-bit composed sequence. The Unicode standard provides rules for ordering characters so that parsing of character sequences is unambiguous.
• Characters have properties, such as base, numeric, spacing, combination, and directionality.
• The relationship between Unicode characters and the glyphs in the native language script that users see, type, or print is not necessarily one-to-one. A glyph may be mapped to a single character or a composite sequence. Conversely, more than one glyph can be mapped to a character.
• The ISO 8859-1 character set occupies the first 256 code positions (and the ASCII character set the first 128 positions) of the UCS.

1.5   ISO/IEC 10646

The ISO/IEC 10646 standard, which is specified in Information Technology-Universal Multiple-Octet Coded Character Set, ISO/IEC 10646, allows characters to be specified as either 32-bit units or like Unicode, as 16-bit units. In their 32-bit form, the 16-bit character values in Unicode are zero-extended.