diff --git a/colourterm/mainwindow.py b/colourterm/mainwindow.py
index d221577..32d09a0 100644
--- a/colourterm/mainwindow.py
+++ b/colourterm/mainwindow.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 import os
 import threading
+from string import printable
 
 from PyQt4 import QtCore, QtGui
 from serial import Serial, SerialException
@@ -10,6 +11,16 @@ from colourterm import SettingsDialog, ConnectDialog, SComboBox, Highlight, from
 from colourterm.cwebview import CWebView
 
 
+class MessageType(object):
+    """
+    An enumeration for message types
+    """
+    Info = 1
+    Question = 2
+    Warning = 3
+    Critical = 4
+
+
 class UiMainWindow(object):
     def __init__(self):
         """
@@ -147,6 +158,7 @@ class UiMainWindow(object):
 
 class MainWindow(QtGui.QMainWindow, UiMainWindow):
     updateOutput = QtCore.pyqtSignal(str)
+    showMessage = QtCore.pyqtSignal(str, str, int)
 
     def __init__(self):
         super(MainWindow, self).__init__()
@@ -174,6 +186,7 @@ class MainWindow(QtGui.QMainWindow, UiMainWindow):
         self.output_browser.page().mainFrame().contentsSizeChanged.connect(self.on_contents_size_changed)
         self.output_browser.onScroll.connect(self.on_output_browser_scrolled)
         self.updateOutput.connect(self.on_update_output)
+        self.showMessage.connect(self.on_show_message)
 
     def close(self):
         if not self.device_closed:
@@ -184,12 +197,17 @@ class MainWindow(QtGui.QMainWindow, UiMainWindow):
         return QtGui.QMainWindow.close(self)
 
     def document_body(self):
-        return self.output_browser.page().mainFrame().documentElement().findFirst('pre')
+        return self.output_browser.page().mainFrame().documentElement().findFirst(u'pre')
 
     def receive_text(self):
         output = ''
         while not self.device_closed:
-            output += self.device.read(1)
+            try:
+                output += self.device.read(1)
+            except SerialException as e:
+                self.showMessage.emit(u'Port Error', u'Error reading from serial port: %s' % e, MessageType.Critical)
+                self.on_close_action_triggered()
+                continue
             if output.endswith('\r\n'):
                 #self.terminal_lines.append(output.strip('\r\n'))
                 #if len(self.terminal_lines) > self.max_lines:
@@ -306,6 +324,16 @@ class MainWindow(QtGui.QMainWindow, UiMainWindow):
             self.on_follow_action_toggled(True)
             self.follow_action.setChecked(True)
 
+    def on_show_message(self, title, message, type_=MessageType.Info):
+        if type_ == MessageType.Info:
+            QtGui.QMessageBox.information(self, title, message)
+        elif type_ == MessageType.Question:
+            QtGui.QMessageBox.question(self, title, message)
+        elif type_ == MessageType.Warning:
+            QtGui.QMessageBox.warning(self, title, message)
+        elif type_ == MessageType.Critical:
+            QtGui.QMessageBox.critical(self, title, message)
+
     def refresh_output(self):
         elements = self.output_browser.page().mainFrame().findAllElements('div')
         lines = [unicode(element.toPlainText()) for element in elements]
@@ -330,13 +358,22 @@ class MainWindow(QtGui.QMainWindow, UiMainWindow):
                 break
         if style:
             try:
-                output = u'<div style="%s">%s</div>' % (style, unicode(output, u'utf-8'))
+                output = u'<div style="%s">%s</div>' % (style, self.filter_printable(output))
+                #output = u'<div style="%s">%s</div>' % (style, unicode(output, u'utf-8'))
             except TypeError:
                 output = u'<div style="%s">%s</div>' % (style, output)
         else:
             output = u'<div>%s</div>' % output
         return output
 
+    def filter_printable(self, output):
+        printable_output = u''
+        for char in output:
+            if char not in printable:
+                printable_output += u'\\x{:02x}'.format(ord(char))
+	    else:
+                printable_output += unicode(char, u'utf8')
+
     def save_highlights(self, highlights):
         settings = QtCore.QSettings()
         settings.setValue(u'highlights/count', len(highlights))