additional info added to doc

README.md

@@ -34,7 +34,7 @@ In the following sections we will describe in detail all the parameters that can
 
 # 1) Interaction with iDraw OSC
 
-**iDraw OSC** is an application that is able to send OSC messages through the network to a target, depending on what the users draw on the device (color, type of pen, x and y location of the pen, etc...). Using these OSC messages, we can control the parameters of our synth. The diagram below shows briefly what should be the network setup to make the application and synthesizer work together.
+**iDraw OSC** is an application that is able to send OSC messages through the network to a target, depending on what the users draw on the device (color, type of pen, x and y location of the pen, etc...). The user is asked to insert the IP address of the machine hosting SuperCollider, as well as the port number, which is 57120 (the default port for OSC messages in SuperCollider). Using these OSC messages, we can control the parameters of our synth. The diagram below shows briefly what should be the network setup to make the application and synthesizer work together.
 
 ![Network diagram](documentation/rsc/network_diagram.png)
 
@@ -209,3 +209,7 @@ TBD
 
 TBD
 
+
+# 5) Graphical User Interface
+
+The Graphical User Interface (GUI) has been developed using Processing. To ensure the ineraction between SuperCollider et Processing, OSC messages are sent through the loopback network interface of the computer, using the port 57122. (WIP)