Toshiba 2400 - Manual (Page 57)

57 Getting Started
Using external display devices
5.375 x 8.375 ver 2.4.0
Sample Multiple Monitors window
5 Click the Dual button in Controller Options.
6 Click OK.
Adjusting the quality of the external display
To obtain the best picture quality from your external display
device, you may need to adjust the video settings. See the
documentation supplied with the device for additional
configuration steps.
TECHNICAL NOTE: In order to use the simultaneous mode, you
must set the resolution of the internal display panel to match the
resolution of the external display device. The external display
device must support a resolution of 640 X 480 or higher.