dechanyu(5)dechanyu(5)NAMEdechanyu - A character encoding system (codeset) for Traditional Chi‐
nese
DESCRIPTION
The DEC Hanyu (dechanyu) codset consists of the following sets of char‐
acters: ASCII The first and second character planes of CNS11643-1986
Digital Taiwan Supplemental Character Set (DTSCS) User-defined charac‐
ters
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 Plane Character Type Number of Charac‐
ters
───────────────────────────────────────────────────────────────────────
1 Special characters 651
Control characters 33
Frequently used characters 5401
2 Less frequently used charac‐ 7650
ters
───────────────────────────────────────────────────────────────────────
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 charac‐
ter 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) Recom‐
mended 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 Characters Character Plane Number of Characters
─────────────────────────────────────────────────────────
Part I Plane 3 6148
Part II Plane 4 171
─────────────────────────────────────────────────────────
The characters defined in Plane 3 and Plane 4 of CNS 11643-1992 are as
follows:
──────────────────────────────────────────────────────────────────────────
Character Plane Character Type Number of
Characters
──────────────────────────────────────────────────────────────────────────
3 Rarely-used characters (EDPC Part I) 6148
4 Used for residency system, ISO 2nd 7298
edition DIS 10646 Han characters, 171
EDPC Part II Characters
──────────────────────────────────────────────────────────────────────────
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 Plane Number of UDC Code Range
───────────────────────────────────────────────
1 145 FDCC to FEFE
1 2256 AAA1 to C1FE
2 1186 F245 to FE7E
───────────────────────────────────────────────
Codeset Conversion
The following codeset converter pairs are available for converting Tra‐
ditional Chinese characters between dechanyu and other encoding for‐
mats. Refer to iconv_intro(5) for an introduction to codeset conver‐
sion. 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. See
code_page(5) for information about PC code pages.
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).
UTF-16_dechanyu, dechanyu_UTF-16
Converting from and to UTF-16 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 DECwindows Motif 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-nor‐
mal--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
These PostScript fonts support only the Traditional Chinese characters
in planes 1 and 2 of the CNS 11643 character set. The Traditional Chi‐
nese characters in the DTSCS character set are not supported by printer
fonts. The restriction also applies to the eucTW codeset, which also
includes DTSCS characters and is supported by the same fonts as
dechanyu.
For general information on printing Asian language text, refer to
i18n_printing(5).
SEE ALSO
Commands: locale(1)
Others: ascii(5), big5(5), Chinese(5), code_page(5), dechanzi(5),
eucTW(5), GBK(5), i18n_intro(5), i18n_printing(5), iconv_intro(5),
l10n_intro(5), sbig5(5), telecode(5)dechanyu(5)