It’s since the end of september that this post was in draft, when a young colleague asked me help on setting up his 19″ external LCD display for his MacBook. I took some screenshots and wrote him a long e-mail, and then thought to share this “guide” with others.
Hope you can make some use of it!
First thing to do is to phisically connect the external display, if all it’s ok the Mac will detect it and turn it on showing the default wallpaper. If not check the cables and with the keyboard combo CMD+F7 “turn on” the video exit.
Then we have to go to System Preferences where we will click on the “Monitor” icon (it’s called so on my italian system, so double check this image below):
So you’ll make appear two new windows, one will sport the LCD Colori title and will represent your Mac’s monitor and the other will display an alphanumerical title (for me it’s SDM-HX-93) which it’s the model name of the connected external display:
… for both of them we can configure (if not cloning the monitor) resolution and color profile. Now choose the “LCD Colori” window and select the second tab, called in italian Disposizione:
Here we can see how spatially are displaced the two monitors, the Mac will respect the different dimension of the screens so, in this screenshot, the smallest it the 13″ display of my MacBook on the right and on the left we see the 19″ external display … this means that moving on the left edge the mouse pointer it will “jump” on the 19 when the 13′ limits are passed.
The white bar in this representation is the position of the Mac OS menu bar, which will make the monitor on which is placed the primary one. This is a fact to remember given the OS GUI interface and behaviour of the menu when you’ll deal with applications.
To change the primary monitor all we have to do is a simple drag’n'drop of the “menu bar” on the display we want.
When we enable the check-box Duplica Monitor (in italian here):
we will clone 1:1 what we see on both the display (resolution too) … so double check what you want to visualize when you use this function … personally this is what I do when using a projector [I have to check how it's really called in english].
Getting back, away from “cloning” monitors, I’ll briefly make notice that we can move the relative position of the two displays, one “around” the other:
OK, time to close this post with a little advice … if you want to use only the external display, with the MacBook display closed and attaching a full featured external mouse and keyboard … clamshell mode as defined by Apple, all you have to do is connect the external display, wait until it’s on then close the MacBook lid making it go into Stop. Then with a click of the mouse or pressing a key we’ll make awakeen the notebook which now will drive only the external one (as we can verify opening the lid).
When we want to exit this mode we just have to follow these instructions:
When you’re finished using your Apple portable in closed-lid mode, the internal display will not function when you open the lid until you have properly disconnected the external display. To properly disconnect the external display, put the computer to sleep and disconnect the display cable from the computer. Open the lid and the computer will reactivate the internal display.
Hope this helps! Enjoy!