notes about dim function and display guessing

experiment/production/Misc-Notes.md

@@ -139,6 +139,20 @@ update-alternatives --config x-window-manager
 update-alternatives --display x-window-manager
 ```
 
+---
+
+Note I was having problems with the 'dim' function as it wasn't executing correctly
+(needed to be root instead of pi) and the display was wrong.
+
+One way to discover which display is being used is:
+
+```
+# ps aux | grep xserver
+root       808  0.0  0.0   3872   704 ?        S    Jan30   0:00 xinit /home/bus/bin/start-kiosk.sh -- /etc/X11/xinit/xserverrc :0 -auth /tmp/serverauth.vJgHr6zsRs
+root      3354  0.0  0.0   3872   788 tty1     S+   Jan30   0:00 xinit /home/bus/bin/start-kiosk.sh -- /etc/X11/xinit/xserverrc :1 vt1 -keeptty -auth /tmp/serverauth.HSj8JTM2IM
+root     27449  0.0  0.0   7348   524 pts/1    S+   05:48   0:00 grep xserver
+```
+
 ### Packages
 
 ```