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dechanyu - A character encoding system (codeset) for Traditional Chinese  


The DEC Hanyu (dechanyu) codeset consists of the following sets of characters: ASCII The first and second character planes of CNS11643-1986 Digital Taiwan Supplemental Character Set (DTSCS) User-defined characters

DEC Hanyu uses a combination of single-byte data, 2-byte data, and 4-byte data to represent ASCII characters, symbols, or ideographic characters.

ASCII characters

All ASCII characters are represented in the form of single-byte, 7-bit data in DEC Hanyu; that is, the most significant bit (MSB) of a byte that represents an ASCII character is always set off. Refer to ascii(5) for more information about the ASCII character set.

CNS11643-1986 Characters (Planes 1 and 2)

Each plane of the CNS 11643-1986 character set is divided into 94 rows and each of these rows has 94 columns. The characters defined in plane 1 and plane 2 of CNS 11643-1986 are as follows:

Character PlaneCharacter TypeNumber of Characters

1Special characters651
Control characters33
Frequently used characters5401
2Less frequently used characters7650

Note that the first two planes of the CNS11643-1986 character set are the same as those specified for the revised CNS11643-1992 character set.

In DEC Hanyu, each CNS 11643-1986 character is represented by two bytes, in conformance with the CNS 11643-1986 standard. The MSB of the first byte is always turned on while that of the second byte is on for the first character plane and off for the second character plane.

The first byte of CNS 11643-1986 encoding determines the row number of the character, while the second byte determines its column number. Code ranges for the two character planes are as follows: A1A1 to FEFE A121 to FE7E

The following formulas determine the value of a CNS 11643-1986 character in relation to its row and column numbers. For a CNS 11643-1986 Plane 1 character:

1st byte = A0(hex) + Row number
2nd byte = A0(hex) + Column number For a CNS 11643-1986 Plane 2 character:
1st byte = A0(hex) + Row number
2nd byte = 20(hex) + Column number

For example, if a character is positioned at the first column of the 36th row on CNS 11643 plane 1, its value is C4A1, which is calculated as follows:

1st byte = A0(hex) + 36 = C4(hex)
2nd byte = A0(hex) + 01 = A1(hex)

Similarly, if a character is positioned at the first column of the 36th row on CNS 11643 plane 2, its value is C421, which is calculated as follows:

1st byte = A0(hex) + 36 = C4(hex)
2nd byte = 20(hex) + 01 = 21(hex)


DTSCS Characters

Currently, only the EDPC (Electronic Data Processing Centre) Recommended Character Set, which defines a total of 6319 characters (rows 1 to 68), is included in the Digital Taiwan Supplementary Character Set (DTSCS). In the revised CNS 11643-1992 standard, the 6319 characters in the EDPC Recommended Character Set are assigned to the third and fourth character planes as follows:

EDPC CharactersCharacter PlaneNumber of Characters

Part IPlane 36148
Part IIPlane 4171

The characters defined in Plane 3 and Plane 4 of CNS 11643-1992 are as follows:

Character PlaneCharacter Type Number of Characters

3Rarely-used characters (EDPC Part I)6148
4 Used for residency system, ISO 2nd edition DIS 10646 Han characters, 171 EDPC Part II Characters 7298

In DEC Hanyu, each DTSCS character is represented by a 4-byte value. The first two bytes are the leading value, specifically C2CB, which is used as a designator sequence for the DTSCS character set. The MSB of the third and fourth bytes is set on for the EDPC Recommended Character Set.

User-Defined Characters

In addition to the two Chinese character sets described in preceding sections, DEC Hanyu provides an area of 3587 positions for user-defined characters (UDC). The positions for UDC are those positions that are unused (but not reserved) code points on the first and second character planes of CNS 11643-1986.

The encoding for UDC is exactly the same as that for CNS11643-1986 except that the two sets of characters occupy different regions. Code ranges for UDC are as follows:

Character PlaneNumber of UDCCode Range

1145FDCC to FEFE
12256AAA1 to C1FE
21186F245 to FE7E


Codeset Conversion

The following codeset converter pairs are available for converting Traditional Chinese characters between dechanyu and other encoding formats. Refer to iconv_intro(5) for an introduction to codeset conversion. For more information about the other codeset for which dechanyu is the input or output, see the reference page specified in the list item. big5_dechanyu, dechanyu_big5

Converting from and to the Big-5 codeset: big5(5). Note that Big-5 encoding is equivalent to the Microsoft code-page format used on PCs for Traditional Chinese. dechanzi_dechanyu, dechanyu_dechanzi
Converting from and to the DEC Hanzi codeset: dechanzi(5). eucTW_dechanyu, dechanyu_eucTW
Converting from and to Taiwanese Extended UNIX Code: eucTW(5). telecode_dechanyu, dechanyu_telecode
Converting from and to the Telecode codeset: telecode(5). UCS-2_dechanyu, dechanyu_UCS-2
Converting from and to UCS-2 format: Unicode(5). UCS-4_dechanyu, dechanyu_UCS-4
Converting from and to UCS-4 format: Unicode(5). UTF-8_dechanyu, dechanyu_UTF-8
Converting from and to UTF--8 format: Unicode(5).

Fonts for DEC Hanyu Characters

The operating system provides both screen and printer fonts for DEC Hanyu characters.

The following bitmap fonts are grouped according to character set and family; they reflect various sizes and typefaces for 75dpi and 100dpi display devices:

CNS 11643-1986 Fonts (Hei family):

-adecw-hei-medium-r-normal--16-160-75-75-m-160-dec.cns11643.1986-2 -adecw-hei-medium-r-normal--24-240-75-75-m-240-dec.cns11643.1986-2 -adecw-hei-medium-r-normal--16-160-100-100-m-160-dec.cns11643.1986-2 -adecw-hei-medium-r-normal--24-240-100-100-m-240-dec.cns11643.1986-2

CNS 11643-1986 fonts (Screen family):

-adecw-screen-medium-r-normal--18-180-75-75-m-160-dec.cns11643.1986-2 -adecw-screen-medium-r-normal--24-240-75-75-m-240-dec.cns11643.1986-2 -adecw-screen-medium-r-normal--18-180-100-100-m-160-dec.cns11643.1986-2 -adecw-screen-medium-r-normal--24-240-100-100-m-240-dec.cns11643.1986-2 -adecw-screen-medium-r-normal--18-180-100-100-m-160-dec.cns11643.1986-UDC -adecw-screen-medium-r-normal--24-240-100-100-m-240-dec.cns11643.1986-UDC

CNS 11643-1986 fonts (Sung family):

-adecw-sung-medium-r-normal--24-240-75-75-m-240-dec.cns11643.1986-2 -adecw-sung-medium-r-normal--32-320-75-75-m-320-dec.cns11643.1986-2 -adecw-sung-medium-r-normal--24-240-100-100-m-240-dec.cns11643.1986-2 -adecw-sung-medium-r-normal--32-320-100-100-m-320-dec.cns11643.1986-2

DTSCS fonts (Hei family):

-adecw-hei-medium-r-normal--16-160-75-75-m-160-dec.dtscs.1990-2 -adecw-hei-medium-r-normal--24-240-75-75-m-240-dec.dtscs.1990-2 -adecw-hei-medium-r-normal--16-160-100-100-m-160-dec.dtscs.1990-2 -adecw-hei-medium-r-normal--24-240-100-100-m-240-dec.dtscs.1990-2

DTSCS fonts (Screen family):

-adecw-screen-medium-r-normal--18-180-75-75-m-160-dec.dtscs.1990-2 -adecw-screen-medium-r-normal--24-240-75-75-m-240-dec.dtscs.1990-2 -adecw-screen-medium-r-normal--18-180-100-100-m-160-dec.dtscs.1990-2 -adecw-screen-medium-r-normal--24-240-100-100-m-240-dec.dtscs.1990-2

DTSCS fonts (Sung family):

-adecw-sung-medium-r-normal--24-240-75-75-m-240-dec.dtscs.1990-2 -adecw-sung-medium-r-normal--32-320-75-75-m-320-dec.dtscs.1990-2 -adecw-sung-medium-r-normal--24-240-100-100-m-240-dec.dtscs.1990-2 -adecw-sung-medium-r-normal--32-320-100-100-m-320-dec.dtscs.1990-2

The operating system provides the following PostScript printer fonts for CNS 11643-1986 characters: Hei-Light-CNS11643 Sung-Light-CNS11643

Printer fonts for DTSCS characters are not available.

For general information on printing Asian language text, refer to i18n_printing(5).


Commands: locale(1)

Others: ascii(5), big5(5), Chinese(5), dechanzi(5), eucTW(5), i18n_intro(5), i18n_printing(5), iconv_intro(5), l10n_intro(5), sbig5(5), telecode(5), Unicode(5)



ASCII characters
CNS11643-1986 Characters (Planes 1 and 2)
DTSCS Characters
User-Defined Characters
Codeset Conversion
Fonts for DEC Hanyu Characters

This document was created by man2html, using the manual pages.
Time: 02:43:08 GMT, October 02, 2010