Apple PC Compatibility Card - Manual (Page 14)

14 Chapter 1
14 Plug the ATAPI audio cable (with the plug shown below) into the back of the
CD-ROM drive.
IMPORTANT Use only the cables that came with this PC Compatibility Card.
Do not use cables from other models of the card.
Your PC Compatibility Card came with three audio cables. They may have
different colors of tubing near the ends to help you tell them apart. You’ll
only be using two of these cables (the third one is for a different kind of
CD-ROM drive). Two of the cables have identical plugs on the ends, and work
the same way. The third cable, which is for ATAPI CD-ROM drives, has a
different plug on one end, as shown below.
Audio cable plug for
ATAPI CD-ROM drives