DBCS code schemes

IBM® supports two DBCS code schemes: one for the host systems and the other for personal computers.

The DBCS code scheme for host systems has the following code-range characteristics:

Shift-control characters

When the host code scheme is used, the system uses shift-control characters to identify the beginning and end of a string of double-byte characters. The shift-out (SO) character, hex 0E, indicates the beginning of a double-byte character string. The shift-in (SI) character, hex 0F, indicates the end of a double-byte character string.

Each shift-control character occupies the same amount of space as one alphanumeric character. By contrast, double-byte characters occupy the same amount of space as two alphanumeric characters.

When double-byte characters are stored in a graphic field or a variable of graphic data type, there is no need to use shift control characters to surround the double-byte characters.

Incorrect and undefined double-byte code

Incorrect double-byte code has a double-byte code value that is not in the valid double-byte code range. This is in contrast to undefined double-byte code where the double-byte code is valid, but no graphic symbol has been defined for the code.

Supported DBCS code ranges

i5/OS™ supports the following DBCS character-set code ranges:

Related concepts
Double-byte character set support
Database file management