Apple Macbook Pro Retina 13-inch (early 2013)

These instructions cover the Macbook Pro with Retina Display, 13" model. This model does *not* have the dual graphics cards and only has the Intel HD 4000 card. It has the model code 10,2

System hardware
The output from command:

The output from command:

X display configuration
This works:

To adjust the built in display's backlight level use KDE/Gnome or use this command:

Alternatively, install which automates this via the  command.