JCL: How to concatenate more than one TAPE dataset

In cases where you need to concatenate more than one TAPE DATASETS  as INPUT then you can use UNIT=AFF=ddname parameter so that all such tape datasets will use the SAME TAPE DRIVE.

For example,

//IN  DD DSN=TAPE.DATASET1,DISP=SHR

//    DD DSN=TAPE.DATASET2,DISP=SHR,UNIT=AFF=IN

//    DD DSN=TAPE.DATASET3,DISP=SHR,UNIT=AFF=IN

//    DD DSN=TAPE.DATASET4,DISP=SHR,UNIT=AFF=IN