$XABTRM_STORE

   The $XABTRM_STORE macro moves user-specified values into fields
   of the specified XABTRM. The expanded $XABTRM_STORE code executes
   at run time on a previously initialized (allocated) XABTRM, in
   contrast to the $XABTRM macro, which initializes a XABTRM at
   assembly time. The $XABTRM_STORE macro must reside in a code
   program section.

   Format

     $XABTRM_STORE  XAB=xabtrm-address,

                    ITMLST=item-list-address,

                    ITMLST_LEN=#item-list-length,

                    NXT=next-xab-address