See the descriptions of the individual DCB subparameters for the DD parameters and DCB subparameters that should not be coded with a specific DCB subparameter.

Do not code the following parameters with the DCB parameter.

AMP
DYNAM

With the DDNAME parameter, code only the BLKSIZE, BUFNO, and DIAGNS DCB subparameters.

With the QNAME parameter, code only the BLKSIZE, LRECL, OPTCD, and RECFM DCB subparameters.

The DD parameter KEYLEN and DCB subparameters KEYLEN, MODE, PRTSP, STACK, and TRTCH apply to specific device types. If you specify one of these subparameters on a DD statement for a device different from the type to which it applies, the system interprets the value incorrectly.

With the SPACE parameter, the value specified for BLKSIZE directly affects the amount of space obtained for data sets allocated in records, and for data sets allocated in blocks where the block length (blklgth) is zero.

For 3540 Diskette Input/Output Units: The VOLUME=SER, DCB=BUFNO, and DSID parameters on a DD * or DD DATA statement are ignored except when they are detected by a diskette reader as a request for an associated data set. See 3540 Programmer's Reference.