Instance Property


Issues a READ_DISC_INFORMATION command to the device as defined in MMC-2.


IOReturn (*ReadDiscInformation)(void *self, void *buffer, SCSICmdField2Byte bufferSize, SCSITaskStatus *taskStatus, SCSI_Sense_Data *senseDataBuffer);



Pointer to an MMCDeviceInterface for one IOService.


Pointer to the buffer to be used for this function.


The size of the data transfer requested.


Pointer to a SCSITaskStatus to get the status of the SCSITask which was executed. Valid SCSITaskStatus values are defined in SCSITask.h


Pointer to a buffer the size of the SCSI_Sense_Data struct found in SCSICmds_REQUEST_SENSE_Defs.h. The sense data is only valid if the SCSITaskStatus is kSCSITaskStatus_CHECK_CONDITION.

Return Value

Returns kIOReturnSuccess if successful, kIOReturnNoDevice if there is no connection to an IOService, kIOReturnNoMemory if a SCSITask couldn't be created, or kIOReturnExclusiveAccess if the device is already opened for exclusive access by another client.


Once an MMCDeviceInterface is opened the client may send this command to read information about the disc (CD-R/RW, (un)finalized, etc..

Beta Software

This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.

Learn more about using Apple's beta software