Apple Power Macintosh 7500 Series - Manual (Page 53)

43 Connecting Additional Equipment
About your computer’s sound ports
The sound input port is marked with an icon of a microphone. The sound
output port is marked with an icon of a speaker.
The computer’s sound ports accept these 3.5 mm connectors:
The smaller connector (a “stereo miniplug”) is found most often on stereo
equipment. The slightly longer connector is found on the Apple PlainTalk
Microphone and other voice quality microphones. If your equipment has a
different type of connector, you can purchase an adapter at an electronics
supply store.
Extended miniplug Stereo miniplug
Sound input port
Sound output port