TheApple USB SuperDrivealso lacks any mechanical ejection capacities.
How do I eject a CD from my Mac?
I inserted a CD into my Mac, and now I can’t figure out how to eject it.

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Where is the eject button?
Thats too bad because Terminal offers a few capabilities missing from other methods.
If it thinks there is no disc present, it will not perform the eject command.

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This includes multiple internal or external drives.
The hole allows a thin steel wire, usually a handy paperclip, to be pressed into the hole.
In other words, a case of design trumping function.

Courtesy of Apple

Screen shot courtesy of Coyote Moon, Inc.