Samsung SP-A900B - Manual (Page 26)

Connect [PC IN] port on the rear side of the projector to the monitor output port of the PC using a PC video cable.
When connections are all completed, connect both power codes of the projector and the PC.
This product supports plug and play and therefore, if you use Window XP you do not need to setup the driver
on your PC.
Using the Projector
Turn on the projector and press the [PC] button to select <PC>.
If PC Mode is not available, check PC video cable is in place.
Turn on the PC and set the PC Environment when necessary.
Adjust the screen.( Auto Adjustment )
Sound comes out from PC speakers.