A large part of the CD-ROM drive market used to be dominated by the proprietary Sound Blaster type interface drive. Noticeable drives that fit this designation are Panasonic 56x, Matsushta, and Kotobuki drives. It is worth noting that not all of these drives must be connected to a Sound Blaster. Some ``compatible'' sound cards have this type of interface attached. There are interface cards that are not part of a sound card at all that will work with this driver too (one in particular is the ``Sun Moon Star'' board).
These drives also have a 40 pin connector, just like an IDE drive. The cannot, however, be connected to a normal IDE or EIDE interface.