I am very interested. I can´t get the pictures of your wonderful project out of my head. I am working on my own cd-drive, based on a CD-Pro II, since months. I have some problems how to to create assembler code, to access the DSA-Bus of the CD-Pro II. I am using an AVR 90S8535. I do not know how to transfer opcode from an AVR controller via DSA to the controller of the CD-Pro II. I know that I have to find a software solution to simulate the DSA-bus in the AVR controller to send the commands. But I don´t know how to handle the opcode of the DSA Command Set (described in the data sheet of the Premium 10501). How can I send a command as opcode like "07h" (just an example). Is this a hex format? How can I transfer this into a byte to send it to the controller of the CD-Pro II? If I would know this, I hope I could create an assembler software to get the same result for the AVR platform. Could anyone help me?