Apple PC Compatibility Card 12-inch card - Manual (Page 41)

Connecting the CD audio cable to the CD-ROM drive
27 Connect the CD-ROM cable you threaded through the computer’s chassis (in step 21) to
the Audio connector on the CD-ROM drive.
Attach the end of the CD audio cable that you passed through the hole in the upper chassis
into the back of the CD-ROM drive.
(top, back of computer)
27 Installing the Card in a Power Macintosh 7200, 7500, or 7600