diff --git a/colourterm/connectdialog.py b/colourterm/connectdialog.py
index ab5d449..1af7fd7 100644
--- a/colourterm/connectdialog.py
+++ b/colourterm/connectdialog.py
@@ -1,8 +1,9 @@
 # -*- coding: utf-8 -*-
-
+import os
 from PyQt4 import QtCore, QtGui
-from serial import FIVEBITS, SIXBITS, SEVENBITS, EIGHTBITS, PARITY_NONE, PARITY_EVEN, PARITY_ODD, PARITY_MARK,\
-    PARITY_SPACE, STOPBITS_ONE, STOPBITS_ONE_POINT_FIVE, STOPBITS_TWO
+from serial import Serial, FIVEBITS, SIXBITS, SEVENBITS, EIGHTBITS, PARITY_NONE, PARITY_EVEN, PARITY_ODD, PARITY_MARK,\
+    PARITY_SPACE, STOPBITS_ONE, STOPBITS_ONE_POINT_FIVE, STOPBITS_TWO, SerialException
+from serial.tools import list_ports
 
 from colourterm import fromUtf8, translate
 
@@ -36,9 +37,9 @@ class Ui_ConnectDialog(object):
         self.portLabel = QtGui.QLabel(connectDialog)
         self.portLabel.setObjectName(fromUtf8('portLabel'))
         self.deviceLayout.addWidget(self.portLabel, 0, 0, 1, 1)
-        self.portEdit = QtGui.QLineEdit(connectDialog)
-        self.portEdit.setText(fromUtf8('/dev/ttyUSB0'))
+        self.portEdit = QtGui.QComboBox(connectDialog)
         self.portEdit.setObjectName(fromUtf8('portEdit'))
+        self.portEdit.setEditable(True)
         self.deviceLayout.addWidget(self.portEdit, 0, 1, 1, 1)
         self.baudLabel = QtGui.QLabel(connectDialog)
         self.baudLabel.setObjectName(fromUtf8('baudLabel'))
@@ -151,7 +152,6 @@ class Ui_ConnectDialog(object):
         self.readingCheckBox.setText(translate('ConnectDialog', 'Reading'))
         self.writingCheckBox.setText(translate('ConnectDialog', 'Writing'))
 
-
 class ConnectDialog(QtGui.QDialog, Ui_ConnectDialog):
 
     def __init__(self):
@@ -159,7 +159,7 @@ class ConnectDialog(QtGui.QDialog, Ui_ConnectDialog):
         self.setupUi(self)
 
     def getPort(self):
-        return unicode(self.portEdit.text())
+        return unicode(self.portEdit.currentText())
 
     def getBaud(self):
         return int(unicode(self.baudComboBox.currentText()))
@@ -178,3 +178,33 @@ class ConnectDialog(QtGui.QDialog, Ui_ConnectDialog):
 
     def getHardwareHandshake(self):
         return self.hardwareCheckBox.isChecked()
+
+    def updatePortCombobox(self):
+        self.portEdit.clear()
+        ports = []
+        for port in self._getSerialPorts():
+            ports.append(port)
+        ports.sort()
+        self.portEdit.addItems(ports)
+
+    def _getSerialPorts(self):
+        """
+        Returns a generator for all available serial ports
+        """
+        if os.name == 'nt':
+            # windows
+            for i in range(256):
+                try:
+                    s = Serial(i)
+                    s.close()
+                    yield 'COM' + str(i + 1)
+                except SerialException:
+                    pass
+        else:
+            # unix
+            try:
+                for port in list_ports.comports():
+                    yield port[0]
+            except NameError:
+                # pyserial 2.6 cannot handle serial usb ports very well, in that case just do not provide a list
+                pass
diff --git a/colourterm/mainwindow.py b/colourterm/mainwindow.py
index 6443125..46358e7 100644
--- a/colourterm/mainwindow.py
+++ b/colourterm/mainwindow.py
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+import os
 import threading
 
 from PyQt4 import QtCore, QtGui
@@ -166,6 +167,7 @@ class MainWindow(QtGui.QMainWindow, Ui_MainWindow):
                 output = ''
 
     def onOpenActionTriggered(self):
+        self.connectDialog.updatePortCombobox()
         if self.connectDialog.exec_() == QtGui.QDialog.Accepted:
             if not self.deviceClosed:
                 self.deviceClosed = True
@@ -239,7 +241,7 @@ class MainWindow(QtGui.QMainWindow, Ui_MainWindow):
             self.sendComboBox.insertItem(0, output)
             self.sendComboBox.setCurrentIndex(0)
             self.sendComboBox.clearEditText()
-            self.device.write(output + u'\r\n')
+            self.device.write(output + '\r\n')
 
     def onContentsSizeChanged(self, size):
         if self.followOutput:
@@ -291,13 +293,13 @@ class MainWindow(QtGui.QMainWindow, Ui_MainWindow):
                     style = u'%sbackground-color: %s; ' % (style, highlight.background)
                 break
         if style:
-	  try:
-	    output = u'<div style="%s">%s</div>' % (style, unicode(output, u'utf-8'))
-	  except TypeError: 
-	    output = u'<div style="%s">%s</div>' % (style, output)
+            try:
+                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
+        return output
 
     def saveHighlights(self, highlights):
         settings = QtCore.QSettings()