Register 1 contains the address of the ADRRBLKB parameter list. You can use the ADRRBLKB mapping macro to map this parameter list. These sections are shown in Table 1.

First word

Pointer to a 140-byte work area that has the Format 1 DSCB from the first volume. See z/OS DFSMSdfp Advanced Services for the Format 1 DSCB description. If it is a sequential extended-format data set, the block size in the sixth word of the parameter list excludes the 32-byte suffix.

Second word

Pointer to the 6-byte volume serial number of the input volume. For a multivolume data set, this volume serial number is for the first input volume.

Third word

Pointer to the 4-byte device type field of the input volume. This is in the same format as the UCBTYP field in the UCB.

Fourth word

Pointer to the 6-byte volume serial number of the output volume. For a data set that spans multiple output volumes, the serial number is for the first volume.

Fifth word

Pointer to the 4-byte device type field of the output volume. Its format is similar to that for the input volume.

Sixth word

The high-order bit (bit 0) is on to indicate the end of the parameter list. If bit 1 is on, the system calculated the optimum block size for the target data set. If bit 1 is off, DFSMSdss calculated the block size. If bit 2 is off, the request is COPY, if bit 2 is on the request is RESTORE.

Bytes 2 and 3 of the sixth word contain the block size selected by DFSMSdss for the data set on the output volume. This field is in fixed binary.