DisplayLink Plugable USB-VGA-165 modprobe udlfb
this modified module allows you to use xrandr
download con2fb.c and compile
gcc -o con2fb con2fb.c
chmod a+x con2fb
cp to /usr/bin/
con2fb 1 6
(multiuser)
59 click to enlarge
xorg.conf
needs driver! x11-drivers/xf86-video-fbdev
Section "Device"
# RPi builtin video, framebuffer 0
Identifier "Raspberry Pi FBDEV"
Driver "fbdev"
Option "fbdev" "/dev/fb0"
Option "ShadowFB" "off"
Option "SwapbuffersWait" "true"
EndSection
Section "Device"
# USB DisplayLink video, framebuffer 1
Identifier "uga"
Driver "fbdev"
Option "fbdev" "/dev/fb1"
Option "ShadowFB" "off"
EndSection
Section "Monitor"
# Primary monitor.
Identifier "PrimaryMonitor"
EndSection
Section "Monitor"
# Secondary monitor.
Identifier "SecondaryMonitor"
EndSection
Section "Screen"
Identifier "primary"
Device "Raspberry Pi FBDEV"
Monitor "PrimaryMonitor"
EndSection
Section "Screen"
Identifier "secondary"
Device "uga"
Monitor "SecondaryMonitor"
EndSection
Section "ServerLayout"
Identifier "default"
Screen 0 "primary" 0 0
Screen 1 "secondary" RightOf "primary"
Option "Xinerama" "1" # enable XINERAMA extension. Default is disabled.
EndSection
Accelerated X driver
An accelerated x.org video driver is available (fbturbo), though this is limited to hardware accelerated window moving/scrolling on the Raspberry Pi:
install x11-drivers/xf86-video-fbturbo (mrueg overlay)
Then add this to /etc/X11/xorg.conf (create if it does not already exist):
Section "Device"
Identifier "Raspberry Pi FBDEV"
Driver "fbturbo"
Option "fbdev" "/dev/fb0"
Option "SwapbuffersWait" "true"
EndSection
dmesg
[75659.958923] udlfb: /dev/fb1 FB_BLANK mode 1 --> 0
[75659.959043] udlfb: set_par mode 1280x1024
Product link: http://plugable.com/products/usb-vga-165/ buy @ amazon 
