DBCS code scheme

IBM supports two DBCS code schemes: one for the host systems, the other for personal computers. The IBM-host code scheme has the following code-range characteristics:

First byte

hex 41 to hex FE

Second byte

hex 41 to hex FE

Double-byte blank

hex 4040

In the following figure, using the first byte as the vertical axis and the second byte as the horizontal axis, 256 x 256 intersections or code points are expressed. The lower-right code area is designated as the valid double-byte code area and x is assigned to the double-byte blank.

Figure 18. IBM-Host Code Scheme

By assigning the values hex 41 to hex FE in the first and second bytes as the DBCS codes, the codes can be grouped in wards with 192 code points in each ward. For example, the code group with the first byte starting with hex 42 is called ward 42. Ward 42 has the same alphanumeric characters as those in a corresponding single-byte EBCDIC code page, but with double-byte codes. For example, the character A is represented in single-byte EBCDIC code as hex C1 and in IBM-host code as hex 42C1.

The AS/400 system supports the following double-byte character sets:

• IBM Japanese Character Set
• IBM Korean Character Set
• IBM Simplified Chinese Character Set
• IBM Traditional Chinese Character Set

The following tables show the code ranges for each character set and the number of characters supported in each character set.

Table 28. IBM Japanese Character Set

Wards	Content	Number of Characters
40	Space in 4040	1
41 to 44	Non-Kanji characters Greek, Russian, Roman numeric (Ward 41) Alphanumeric and related symbols (Ward 42) Katakana, Hiragana, and special symbols (Ward 43-44)	549
45 to 55	Basic Kanji characters	3226
56 to 68	Extended Kanji characters	3487
69 to 7F	User-defined characters	Up to 4370
80 to FE	Reserved
Total number of IBM-defined characters: 7263

Table 29. IBM Korean Character Set

Wards	Content	Number of Characters
40	Space in 4040	1
41 to 46	Non-Hangeul/Hanja characters (Latin alphabet, Greek, Roman, Japanese Kana, numeric, special symbols)	939
47 to 4F	Reserved
50 to 6C	Hanja characters	5265
6D to 83	Reserved
84 to D3	Hangeul characters (Jamo included)	2672
D4 to DD	User-defined characters	Up to 1880
DE to FE	Reserved
Total number of IBM-defined characters: 8877

Table 30. IBM Simplified Chinese Character Set

Wards	Content	Number of Characters
40	Space in 4040	1
41 to 47	Non-Chinese characters (Latin alphabet, Greek, Russian, Japanese Kana, numeric, special symbols)	712
48 to 6F	Chinese characters: Level 1 and Level 2	3755 and 3008
70 to 75	Reserved
76 to 7F	User-defined characters	Up to 1880
80 to FE	Reserved
Total number of IBM-defined characters: 7476

Table 31. IBM Traditional Chinese Character Set

Wards	Content	Number of Characters
40	Space in 4040	1
41 to 49	Non-Chinese characters (Latin alphabet, Greek, Roman, Japanese Kana, numeric, special symbols)	1003
4A to 4B	Reserved
4C to 68	Primary Chinese characters	5402
69 to 91	Secondary Chinese characters	7654
92 to C1	Reserved
C2 to E2	User-defined characters	Up to 6204
E3 to FE	Reserved
Total number of IBM-defined characters: 14060

This code scheme applies to the AS/400 system, System/36, System/38, as well as the System/370 system. A different DBCS code scheme, called the IBM Personal Computer DBCS code scheme, is used on the Personal System/55. For details of the IBM Personal Computer DBCS code scheme, refer to IBM PS/55 publications.