To mirror what is displayed on a laptop's screen to an external monitor under Apple's OS X operating system, take the following steps after connecting the external monitor:
- Click on the Apple icon on the upper, left-hand of the screen and select System Preferences.
- Under Hardware, click on Displays.
Click on the Arrangement tab for the display and check the check box
next to Mirror Displays.
You should then see a copy of the information displayed on the laptop's builtin monitor also displayed on the external monitor.
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