After the organization of a direct data set has been determined, the process of creating it is almost identical to creating a sequential data set. The BSAM DCB macro should be used with the WRITE macro (the form used to allocate a direct data set). Issue the WRITE and CHECK macros in 24-bit mode. The following parameters must be specified in the DCB macro:

• DSORG=PS or PSU
• DEVD=DA or omitted
• MACRF=WL

The DD statement must specify direct access (DSORG=DA or DAU). If keys are used, a key length (KEYLEN) must also be specified. Record length (LRECL) need not be specified, but can provide compatibility with sequential access method processing of a direct data set.

DSORG and KEYLEN can be specified through data class. For more information about data class see Specifying and Initializing Data Control Blocks.