dechanyu(5)							File Formats Manual						       dechanyu(5)

NAME

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

DESCRIPTION

       The  DEC Hanyu (dechanyu) codset 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 char-
       acters.

   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 Characters
       -------------------------------------------------------------------------
       1		 Special characters		   651
			 Control characters		   33
			 Frequently used characters	   5401
       2		 Less frequently used characters   7650
       -------------------------------------------------------------------------

       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 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 edi-   7298
			 tion 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 Traditional Chinese characters between dechanyu and other encoding for-
       mats.  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. 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).  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 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-nor-
       mal--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

       These  PostScript  fonts  support only the Traditional Chinese characters in planes 1 and 2 of the CNS 11643 character set. The Traditional
       Chinese 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)