diff --git a/README.md b/README.md
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@@ -9,6 +9,6 @@ You can download it from [Release Page](https://github.com/unlimitedsola/dmt-io-
 ## Usage
 
 0. First thing first, you must have the `net` icon on for your DJMax Technica 3 machine, with that being said, you must have a connection to someone's private server.
-1. After that, you're gonna need a virtual serial port to connect COM9 with COM6 bidirectionally, there are many software out there can do this, e.g. [vspd-driver](https://www.eltima.com/products/vspdxp/)
+1. After that, you're gonna need a virtual serial port to connect `COM9 with COM6` and `COM7 with COM8` bidirectionally, there are many software out there can do this, e.g. [vspd-driver](https://www.eltima.com/products/vspdxp/)
 2. Open the program you've compiled or downloaded from the releases page. Open it up and you should be good to go.
 3. If you want to change the card id of your login, edit the `card.json` file according to its format.