Hi I have written the driver for ATA/ATAPI.
The ATA part is working fine but I am facing some problem in the ATAPI.
I am using Plextor DVD-RW.I am sending the ATAPI in the form of command packet.

When I send the Inquiry Command I am getting the proper response from the device,but when I try to send some other commands like Read capacity or Get configuration I am not getting any response.

It is setting the CoD and IO bit in the Sector count register and resetting the DRQ and BSY bit in the status register which it should do when no data is available.Is there any other setting to do before sending command packet.(using set parameter command).

Can somebody help me?
Its urgent.