PRINT121The PRINT121 option controls whether or not MFX is to alter its DCB values for the output message data set (SYSOUT) during JCL-initiated sorts. If you specify PRINT121, the DCB values will be changed as in the figure below.
From:
DCB=(LRECL=125,BLKSIZE=882,RECFM=VBA)
To:
DCB=(LRECL=121,BLKSIZE=121,RECFM=FA)
The default is not to specify PRINT121, and so not to alter the DCB values for the output message data set. The DCB settings cannot be changed during program-invoked sorts.