eucTW - A character encoding system (codeset) for Traditional Chinese
The Taiwanese EUC (Extended UNIX Code), or eucTW, codeset consists of the
following character sets:
+ CNS 11643 (Plane 1 to Plane 16)
Taiwanese EUC uses a combination of single-byte data and 2-byte data to
represent ASCII characters, symbols, and ideographic characters. Because
too many character planes were included, Taiwanese EUC uses different lead-
ing codes to designate different character planes.
ASCII characters are represented in the form of single byte 7-bit data in
Taiwanese EUC; that is, the most significant bit (MSB) of the byte that
represents an ASCII character is always set off. For more information,
refer to ascii(5).
Although the standard Taiwanese EUC codeset includes all characters defined
by the CNS 11643-1992 standard, the operating system's eucTW implementation
currently supports the following:
+ Characters defined in the first and second planes of CNS 11643
+ The EDPC Recommended Character Set (refer to dechanyu(5) for more
+ CNS 11643-1986 and DTSCS characters that have been remapped into the
third and fourth character planes by the CNS 11643-1992 standard
Characters that were added to CNS 11643-1986 by the CNS 11643-1992 standard
are not supported.
The characters that are defined in plane 1 and plane 2 of CNS 11643-1992
and that are the same as those defined in CNS 11643-1986 are as follows:
Character Plane Character Type Number of Characters
1 Special characters 651
Control characters 33
Frequently-used characters 5401
Less frequently-used char-
The characters defined in plane 3 and plane 4 of CNS 11643-1992 are as fol-
Character Plane Character Type
3 Rarely-used characters (EDPC Part I) 6148
Used for residency system, ISO 2nd
edition DIS 10646 Han characters, 171
EDPC Part II Characters
The characters that have been remapped into the third and fourth character
planes of CNS 11643-1992 as specified by the EDPC are as follows:
EDPC Characters Character Plane Number of Characters
Part I Plane 3 6148
Part II Plane 4 171
Taiwanese EUC Encoding
Except for characters in the first plane of CNS 11643-1986, Taiwanese EUC
makes use of a leading code (the 8-bit Single-Shift 2 control character
(SS2) and an additional byte) to designate characters to a character plane.
The position of a character on a plane is specified by two bytes. The first
byte determines the character's row number and the second byte determines
the character's column number. The MSB of both bytes is set on.
The following table shows the encoding of Taiwanese EUC characters:
CNS 11643-1986 Code Plane Leading Code Code Range
1 [nil] A1A1 - FEFE
2 SS2 A2 A1A1 - FEFE
3 SS2 A3 A1A1 - FEFE
4 SS2 A4 A1A1 - FEFE
5 SS2 A5 A1A1 - FEFE
6 SS2 A6 A1A1 - FEFE
7 SS2 A7 A1A1 - FEFE
8 SS2 A8 A1A1 - FEFE
9 SS2 A9 A1A1 - FEFE
10 SS2 AA A1A1 - FEFE
11 SS2 AB A1A1 - FEFE
12 SS2 AC A1A1 - FEFE
13 SS2 AD A1A1 - FEFE
14 SS2 AE A1A1 - FEFE
15 SS2 AF A1A1 - FEFE
16 SS2 B0 A1A1 - FEFE
The following codeset converter pairs are available for converting Tradi-
tional Chinese characters between eucTW and other encoding formats. Refer
to iconv_intro(5) for an introduction to codeset conversion. For more
information about the other codeset for which eucTW is the input or output,
see the reference page specified in the list item.
+ big5_eucTW, eucTW_big5
Converting from and to the Big-5 codeset: big5(5).
Note that Big-5 encoding is equivalent to the Microsoft code-page for-
mat used on PCs for Traditional Chinese. You can therefore use this
set of converters to convert Traditional Chinese text between the
eucTW and PC code-page formats. For information about how the operat-
ing system supports PC code pages, see code_page(5).
+ dechanyu_eucTW, eucTW_dechanyu
Converting from and to the DEC Hanyu codeset: dechanyu(5).
+ dechanzi_eucTW, eucTW_dechanzi
Converting from and to the DEC Hanzi codeset: dechanzi(5).
+ sbig5_eucTW, eucTW_sbig5
Converting from and to the Shift Big-5 codeset: sbig5(5).
+ telecode_eucTW, eucTW_telecode
Converting from and to the Telecode codeset: telecode(5).
+ UCS-2_eucTW, eucTW_UCS-2
Converting from and to UCS-2 format: Unicode(5).
+ UCS-4_eucTW, eucTW_UCS-4
Converting from and to UCS-4 format: Unicode(5).
+ UTF-8_eucTW, eucTW_UTF-8
Converting from and to UTF--8 format: Unicode(5).
Fonts for Taiwanese EUC
For both display devices and printers, the operating system supports
Taiwanese EUC through internal conversion to DEC Hanyu code and use of DEC
Hanyu fonts (see dechanyu(5)).
For general information on printing non-English text, refer to
Others: ascii(5), big5(5), Chinese(5), code_page(5), dechanzi(5), GBK(5),
iconv_intro(5), i18n_intro(5), i18n_printing(5), l10n_intro(5), sbig5(5),