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 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:

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:

Plane 1
A1A1 to FEFE

Plane 2
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:

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

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:

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-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). 

SEE ALSO

Commands: locale(1)

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