Release 3.3 may be installed concurrently with release 3.1.You may switch from 3.3 to 3.1 in a command prompt by using the Real2set utility (/v switch specifying 3.1 as the option).
Page 13-4 of the Workbench User Guide documents this:
Real2Set is used to set up all environmentals needed by the COBOL compiler, linker, and, if installed, the S/390 Assembler. If a command prompt is opened from Start\Programs\Computer Associates\Advantage\CA-Realia33\ CA-Realia Command Prompt, then Real2Set is automatically run. Environmentals such as COBEXT, LIB, OBJ, and the PATH, are set by this batch file. Run Real2Set /? to see which environmentals are initialized by Real2Set. Running Real2Set more than once will not cause duplicate entries in the affected environmental values.
Real2Set has two options switches:
- /C to force a full replacement of COBEXT LIB OBJ SYSLIB BALEXT and if necessary MACEXT MACLIB
- /v 3.1|3.2|3.3 to set system to desired version settings. This will only work
if multiple versions are installed. This change is permanent system wide. See RealVersion for details of what happens.
Going back to 3.3 with this function is not possible because the 3.1 version of Real2set did not support the /v switch.