Apple Power Macintosh 7300 series - PC Compatibility Card - Manual (Page 116)

Connecting the CD In cable to the card
19 Plug the other SCSI audio cable into the connector labeled “CD IN” on the far upper-left
corner of the PC Compatibility Card.
Insert the cable’s smaller plug into the connector labeled “CD IN” on the PC
Compatibility Card.
Connector labeled “CD IN” on the PC Compatibility Card
Do not plug any cable into this middle connector.
116 Appendix B