I have a PL/1 program, executing on two different mainframes, each using the z/OS PL/1 compiler: V3.R9.M0. On one mainframe, uninitalized variables are written out with LOW_VALUES in the written record. On the other mainframe, the SAME program, with the same copybooks, is writing out that records with "garbage" in the program-uninitialized variables, causing a S0C7 ABEND.... The compiler options on both mainframes are fairly different. I am trying to hone-in on a particular compiler option that may be responsible for this variance.

Anyone know of such a compiler option that would cause this conundrum?

Rich S.