Exchange/SNA Manual

Modifying Your Translation Table
Character Set Translation
B–10 104700 Tandem Computers Incorporated
Modifying Your
Translation Table
This section explains how to modify the translation tables that Exchange/SNA uses to
translate from ASCII to EBCDIC and back. You may want to modify these tables to
support a national character set other than USASCII or to implement a translation
other than the supplied translation.
The Exchange/SNA line server (SNAXSV) uses two tables for translating from ASCII
to EBCDIC and back. The array ASCII^TO^EBCDIC contains the ASCII code for each
EBCDIC character. The array EBCDIC^TO^ASCII contains the EBCDIC code for each
ASCII character. For both of the tables, the nth byte of the table contains the translated
code for the nth character. For example, in ASCII^TO^EBCDIC, the forty-eighth
character (%H30), which is the ASCII code for 0 (zero), contains %HF0, which is the
EBCDIC code for 0. In EBCDIC^TO^ASCII, the two-hundred-fortieth character
(%HF0) contains the ASCII code for 0, %H30. Note that the index for each table begins
with 0 (rather than 1).
You can use the BINDER program to examine and modify both ASCII^TO^EBCDIC
and EBCDIC^TO^ASCII. To examine the tables, use the BINDER DUMP command.
To modify the tables, use the BINDER MODIFY command.
When you use the BINDER program, you refer to each table by its name (which
specifies the base of the table) and then specify an offset into the table. The offset is
interpreted as an octal value and is a word offset. You must modify the table one
word (two bytes) at a time. To modify only one byte, specify the new value for that
byte and the old value for the other byte in that word.
Example Modification This section shows you how to modify a translation table. If you follow the steps in
this example, you change the translation code for an exclamation point (!) to a right
square bracket (]). Note that these instructions assume that the file SNAXSV is located
in your current default volume and subvolume.
Step 1. Rename Your Line Server
Rename the Exchange/SNA line server object file to something other than SNAXSV.
For this example, rename it to SNAXSVO:
>rename snaxsv, snaxsvo
Step 2. Start the BINDER Program
Start the BINDER program by issuing the following command:
>bind
Step 3. Access Your File
Make the Exchange/SNA line server the current file in the BINDER program. Be sure
to use the name you gave the file in step 1 above:
@file snaxsvo
Then add the contents of the line server file to the include list:
@add *