Apple Power Macintosh 7600/200 Series - Manual (Page 79)

The computer’s sound input and output ports accept these 3.5-mm connectors:
The “stereo miniplug” is the smaller of the two and is found most often on
stereo equipment. The extended miniplug, which is slightly longer and is
found on voice quality microphones (such as the Apple PlainTalk
Microphone), works only in your computer’s sound input port (≈). (Even
though it will fit into the sound output port, it won’t work there.) If your
equipment has a different type of connector from those shown here, you can
purchase an adapter at an electronics supply store.
Extended miniplug Stereo miniplug
79 Connecting Additional Equipment