The FILES=n parameter specifies the number of input files that an E32 exit will supply to the merge. The n value can be any number up to 100.
Specifying the FILES parameter both on the MERGE control statement and in the 24-bit parameter list will cause MFX to terminate with a critical error.
The FILES parameter cannot be specified as a PARM on the EXEC statement or in a $ORTPARM data set.