still fussing with GPRS

experiment/production/Misc-Notes.md

@@ -160,6 +160,13 @@ I followed [this](https://raspberrypi.stackexchange.com/questions/39165/how-can-
 systemctl stop serial-getty@ttyAMA0.service
 ```
 
+Disable permanently:
+
+
+```
+systemctl disable serial-getty@ttyAMA0.service
+```
+
 
 
 ### Other References