diff --git a/Cart_Reader/Cart_Reader.ino b/Cart_Reader/Cart_Reader.ino
index fa5bac2..cdaf260 100644
--- a/Cart_Reader/Cart_Reader.ino
+++ b/Cart_Reader/Cart_Reader.ino
@@ -2,8 +2,8 @@
                     Cartridge Reader for Arduino Mega2560
 
    Author:           sanni
-   Date:             2017-06-01
-   Version:          V25A
+   Date:             2017-06-03
+   Version:          V25B
 
    SD  lib:         https://github.com/greiman/SdFat
    LCD lib:         https://github.com/adafruit/Adafruit_SSD1306
@@ -34,7 +34,7 @@
    YamaArashi - GBA flashrom bank switch command
 
 **********************************************************************************/
-char ver[5] = "V25A";
+char ver[5] = "V25B";
 
 /******************************************
    Define Output
diff --git a/Cart_Reader/NP.ino b/Cart_Reader/NP.ino
index a6362a4..9a942ed 100644
--- a/Cart_Reader/NP.ino
+++ b/Cart_Reader/NP.ino
@@ -1745,6 +1745,12 @@ void send_GBM(byte myCommand) {
       writeByte_GBM(0x013F, 0xA5);
       break;
 
+    case 0x03:
+      //CMD_03h -> Undo write Step 2
+      writeByte_GBM(0x0120, 0x03);
+      writeByte_GBM(0x013F, 0xA5);
+      break;
+
     case 0x04:
       //CMD_04h -> Map entire flashrom (MBC4 mode)
       writeByte_GBM(0x0120, 0x04);
@@ -1790,6 +1796,10 @@ void send_GBM(byte myCommand) {
       writeByte_GBM(0x0120, 0x11);
       writeByte_GBM(0x013F, 0xA5);
       break;
+
+    default:
+      print_Error(F("Unknown Command"), true);
+      break;
   }
 }