Samsung SP-L300 Owner's Instructions Manual page 21

Connecting an External Monitor
You can view an image on both your projector and a separate monitor at the same time.
Check that your PC and projector are turned off.
Connect the [PC IN 1] terminal at the back of the projector to the D-Sub terminal of your PC using a D-Sub cable.
Connect the [PC OUT] terminal of the projector to the D-Sub terminal of a monitor using a D-Sub cable.
- When connecting a monitor using the [PC OUT] function, make sure to connect your PC to the [PC IN 1] terminal.
- The monitor output which is connected to the [PC OUT] termininal will be normal even if you see a blank screen on
your projector.
- The [PC OUT] function also operates in standby mode.
Connecting an HDMI-Compatible Device