Restrictions

Do not use this macro in any routine that might run in a C/I FSS address space.
The data pointed to by the IATXOSP macro must reside below 16 megabytes in virtual storage. This means that if your code issues an AGETMAIN macro, the AGETMAIN must specify the LOC=(BELOW) parameter.
For output requests that will be handled at the STARTIO level (such as devices opened with IATXOSOO...LABEL=REAL...), when the device is operated at the STARTIO level, the user of the macro must page-fix the data pointed to in the IATXOSP macro and also obtain storage below 16 megabytes for the data.