openUTM provides a function that allows you to test for errors when the program units of the application access the address zero. This is achieved by openUTM is setting up a local task memory pool at the address zero. It can therefore only be used in applications that do not themselves work with a memory pool at the address zero, or that are loaded themselves to the address zero (24-bit application).
Activating/deactivating the test function
To activate the test method, you set up a FILE-LINK to the name KDCWRPR in the start procedure or in the ENTER job:
/SET-FILE-LINK LINK-NAME=KDCWRPR
If an error occurs when setting up the memory pool because, for example, there is already a memory pool working at the address zero in the application, openUTM outputs message K078 at startup:
K078 ENAMP xxxxxxxx. In KDCRTST.
In this case, the method cannot be used.
You can deactivate the test method again by restarting the application without the above SET-FILE-LINK command.
Accessing the address zero
If the address zero is accessed while the application is running, the program unit is terminated by an STXIT event (STXIT with IW = 48 or 5C).
The program unit can then be modified.