RosettaCodeData/Task/Integer-overflow/360-Assembly/integer-overflow-2.360

         IPM   1                  Insert Program Mask
         O     1,BITFPO           unmask Fixed Overflow
         SPM   1                  Set Program Mask
         ...
         DS    0F                 alignment
BITFPO   DC    BL1'00001000'      bit20=1    [start at 16]