IBM Mainframe Forum

below are two sentences found on the web:

When the Enterprise COBOL, COBOL for OS/390 & VM, or COBOL for MVS & VM program is running, R13 has the address of a DSA (dynamic save area) for the COBOL program. The address of the COBOL program's TGT is located at x"5C" in the DSA.
If R13 has the address of a save area associated with a called assembler program or COBOL runtime routine, use the save area back chain to find the DSA for the COBOL program. Then add x"5C" to find the address of the TGT.

can i samply think DSA = RSA(register save area)?

besides, can somebody explain what's the main purpose of TGT and DSA?

thanks.

This is a distinctly Cobol question. It will be moved to that part of the Forum here once we know that you've read this.

What have you already discovered about the TGT and DSA? Their names? Anything else?

Have you ever looked at a COBOL compile output listing? If you have, then you SHOULD have noticed the TGT and would understand its use. If you haven't, that is the first thing you should do.