Unicode data is not supported on display devices that currently support the 5250 data stream. Therefore, conversions between the Unicode data and EBCDIC are necessary during input and output operations.
On output, the Unicode data is converted to the CCSID of the device. On input, the data is converted from the device CCSID to the Unicode CCSID.
Because the device CCSID, which is determined from the device configuration, determines what the Unicode data is converted to, the converted data appears differently on different devices. For example, a Unicode character that maps to a SBCS character is displayed as a DBCS replacement character on a graphic-DBCS capable device. On a DBCS or SBCS capable device, the character appears as a SBCS character. A Unicode character that maps to a DBCS character is displayed as a graphic-DBCS character on a graphic-DBCS capable device. On a DBCS device, a DBCS character is bracketed (enclosed in a shift-out and shift-in). A SBCS replacement character is displayed on a SBCS device.
It is also suggested that all Unicode capable fields be initialized in the output buffer before writing the fields to the screen. Unpredictable results can occur if default initialization is allowed to take place.