A non-SCSI CD-ROM adapter device driver adheres to the adapter device driver interface defined in DASD, SCSI, and CD-ROM Device Manager Interface Specification. Most commands are received as SCSI-2 command descriptor blocks sent using the IORB ADAPTER_PASSTHRU command. The SCSI command descriptor blocks comply with the ANSI SCSI-2 standard X3T9.2/86-109 (SCSI-2 draft proposed American National Standard Revision 10g).

The following sections describe the mandatory IORB and SCSI-2 commands that a non-SCSI CD-ROM adapter device driver must support. The command structures for the IORB command blocks are defined in IORB Control Blocks.

The C Language definitions for the IORB control blocks are included in I/O Request Block - C Definitions.