Spectec SDV-841/842 - Manual (Page 19)

Using the Utility Programs
NVD provides several small programs that make NVD functionality more
accessible. These programs can be assigned to hot keys for even greater
control.
VD Settings
Runs the Virtual Display Settings Applet
.
VD Menu
Shows the virtual display popup menu. This is the same menu that is accessed
via the Onscreen Control
.
VD Power
Toggles the display power between on and off. NOTE: This feature is not
available on all devices.
VD Restore
Restores your device to its factory display settings.
VD Previous
Toggles between the last two configurations. For example, this might be used
to toggle between two configurations as you go back and forth between two
applications.