TXACCBUF is not documented in the CA Top Secret manuals.
The data area is formatted as follows:
0-1 Binary halfword which contains the length of the data structure, including the header.
2-3 Binary halfword which contains the length of the header.
4- Character field containing the TSS command.
For example, consider the following TSS command -
TSS LIST(USER123) DATA(ALL)
This command consists of twenty-seven (27) characters, so the data structure passed to the TSS Installation Exit point COMMAND will contain -
0-1 Binary halfword constant (31).
2-3 Binary halfword constant (4).
4-30 Character constant ("TSS LIST(USER123) DATA(ALL)").