VTxxx national mode

VTxxx national mode supports the national replacement character set, which is a group of 7-bit character sets.

Only one character set from the group is available for use at any one time. VT220 also supports the standard 7-bit ASCII character set as part of the national mode. The VT220 terminal supports the following national languages in 7-bit ASCII character sets:

British
Danish
Dutch
Finnish
French
French/Canadian
German
Italian
Norwegian
Spanish
Swedish
Swiss
U.S. English

To use a national mode, the system requires mapping tables to map incoming ASCII data into EBCDIC and outgoing EBCDIC data into ASCII when operating in VTxxx full-screen mode.

Use the CCSID parameter on the Telnet command to select a national mode that is, a NLS mapping table.

Entering a numeric value representing a registered CCSID value in the range 1-65553, is one way to identify the appropriate mapping table. The International Application Development book contains details of registered CCSIDs.

The NLS mapping tables are built dynamically to a remote system the first time Telnet is used, and are based on DEC national replacement character sets. Because the character sets are 7-bit based, they can contain only the unique characters from one country. Because the DEC multinational character set is 8-bit based, it allows for the inclusion of the unique characters from a group of countries.

Identify table objects

You can identify the table objects (*TBL) using the Work with Object command: WRKOBJ OBJ(QUSRSYS/Q*) OBJTYPE(*TBL)

All of the system table objects are in QUSRSYS library.

The table objects are named Qxxxyyyzzz where xxx is the FROM code page, yyy is the TO character set and zzz is the TO code page.

For the outgoing (EBCDIC-to-ASCII) table:

The FROM code page ID is taken from the code page ID in QCHRID of message description CPX8416 (use WRKMSGD CPX8416 to display), 037 in the figure below from a US English based system.
The TO character set and code page are derived from the CCSID parameter used with the Telnet command.

For the incoming (ASCII-to-EBCDIC) table:

The FROM code page ID is derived from the CCSID parameter used with the Telnet command.
The TO character set and code page are taken from the character set ID and code page ID in QCHRID of message description CPX8416 (use WRKMSGD CPX8416 to display), 697 and 037 in the figure below from a US English based system.

Figure 1. Example CPX8416 message

+--------------------------------------------------------------------------------+
|                             System: SYSNAM01                                   |
|Message ID . . . . . . . . . :     CPX8416                                      |
|Message file . . . . . . . . :     QCPFMSG                                      |
|Library . . . . . . . . . :        QSYS                                         |
|                                                                                |
|Message . . . . :                                                               |
|QCHRID     697 37      QCURSYM           $ QDATFMT         MDY QDATSEP /        |
|QDECFMT          QLEAPADJ    0 QCCSID 37       QTIMSEP         : QLANGID ENU    |
|QCNTRYID   US QIGCCDEFNT *NONE                                                  |
|                                                                                |
+--------------------------------------------------------------------------------+

CCSID	Character set actual ID	Character set table ID	Code page actual ID	Code page actual ID
MULTINAT	1290	A05	1100	A5U
BRITISH	1291	A06	1101	A5V
1292	A07	1102	A5W
1293	A08	1103	A5X
289	289	1104	A5Y
1192	A8E	1020	A3M
265	265	1011	A3D
293	293	1012	A3E
1297	BAB	1107	A52
1195	A8H	1023	A3P
1296	BAA	1106	A51
1193	A8F	1021	A3N

For example, on a British system with a QCHRID of 697 285 (character set 697 code page 285) in message CPX8416 that uses Telnet with CCSID(*BRITISH), the tables will have the following names:

Outgoing (EBCDIC-to-ASCII) Q285A06A5V
Incoming (ASCII-to-EBCDIC) QA5V697285

User-Defined mapping tables (ASCII Mode)

Where the multinational or NLS mapping tables do not meet the requirements of a user, user-defined character mapping tables can be created and used.

You also have the ability to specify user-defined mapping tables using the outgoing ASCII-to-EBCDIC table (TBLVTOUT) and incoming ASCII-to-EBCDIC table (TBLVTIN) parameters of the STRTCPTELN command. You can specify a user-defined mapping table for either the outgoing mapping table or the incoming mapping table, and then use the system default value for the other.