diff --git a/serial/urlhandler/protocol_spy.py b/serial/urlhandler/protocol_spy.py
index 06620ed..3db8773 100644
--- a/serial/urlhandler/protocol_spy.py
+++ b/serial/urlhandler/protocol_spy.py
@@ -16,13 +16,15 @@
 # options:
 # - dev=X   a file or device to write to
 # - color   use escape code to colorize output
-# - hex     hex encode the output
+# - raw     forward raw bytes instead of hexdump
 #
 # example:
 #   redirect output to an other terminal window on Posix (Linux):
-#   python -m serial.tools.miniterm spy:///dev/ttyUSB0?dev=/dev/pts/12\&color
+#   python -m serial.tools.miniterm spy:///dev/ttyUSB0?dev=/dev/pts/14\&color
 
 import sys
+import time
+
 import serial
 
 try:
@@ -30,16 +32,100 @@
 except ImportError:
     import urllib.parse as urlparse
 
+
+def sixteen(data):
+    n = 0
+    for b in serial.iterbytes(data):
+        yield ('{:02X} '.format(ord(b)), b if b' ' <= b < b'\x7f' else b'.')
+        n += 1
+        if n == 8:
+            yield ' ', ' '
+        elif n > 16:
+            yield None, None
+            n = 0
+    while n < 16:
+        yield ('   ', ' ')
+        n += 1
+    yield None, None
+
+
+
+def hexdump(data):
+    values = []
+    ascii = []
+    for h, a in sixteen(data):
+        if h is None:
+            yield ' '.join([
+                    ''.join(values),
+                    ''.join(ascii)])
+            del values[:]
+            del ascii[:]
+        else:
+            values.append(h)
+            ascii.append(a)
+
+
+
+class FormatRaw(object):
+    def __init__(self, output, color):
+        self.output = output
+        self.color = color
+        self.rx_color = '\x1b[32m'
+        self.tx_color = '\x1b[31m'
+
+    def rx(self, data):
+        if self.color:
+            self.output.write(self.rx_color)
+        self.output.write(data)
+        self.output.flush()
+
+    def tx(self, data):
+        if self.color:
+            self.output.write(self.tx_color)
+        self.output.write(data)
+        self.output.flush()
+
+    def control(self, name, value):
+        pass
+
+
+class FormatHexdump(object):
+    def __init__(self, output, color):
+        self.start_time = time.time()
+        self.output = output
+        self.color = color
+        self.rx_color = '\x1b[32m'
+        self.tx_color = '\x1b[31m'
+        self.control_color = '\x1b[37m'
+
+    def write_line(self, timestamp, label, value):
+        self.output.write('{:010.3f} {:4} {}\n'.format(timestamp, label, value))
+        self.output.flush()
+
+    def rx(self, data):
+        if self.color:
+            self.output.write(self.rx_color)
+        for row in hexdump(data):
+            self.write_line(time.time() - self.start_time, 'RX', row)
+
+    def tx(self, data):
+        if self.color:
+            self.output.write(self.tx_color)
+        for row in hexdump(data):
+            self.write_line(time.time() - self.start_time, 'TX', row)
+
+    def control(self, name, value):
+        if self.color:
+            self.output.write(self.control_color)
+        self.write_line(time.time() - self.start_time, name, value)
+
+
 class Serial(serial.Serial):
     """Just inherit the native Serial port implementation and patch the port property."""
 
     def __init__(self, *args, **kwargs):
         super(Serial, self).__init__(*args, **kwargs)
-        self.output = sys.stderr
-        self.hexlify = False
-        self.color = False
-        self.rx_color = '\x1b[32m'
-        self.tx_color = '\x1b[31m'
+        self.formatter = None
 
     @serial.Serial.port.setter
     def port(self, value):
@@ -52,38 +138,78 @@
         if parts.scheme != 'spy':
             raise serial.SerialException('expected a string in the form "spy://port[?option[=value][&option[=value]]]": not starting with spy:// (%r)' % (parts.scheme,))
         # process options now, directly altering self
+        formatter = FormatHexdump
+        color = False
+        output = sys.stderr
         for option, values in urlparse.parse_qs(parts.query, True).items():
             if option == 'dev':
-                self.output = open(values[0], 'w')
+                output = open(values[0], 'w')
             elif option == 'color':
-                self.color = True
-            elif option == 'hex':
-                self.hexlify = True
+                color = True
+            elif option == 'raw':
+                formatter = FormatRaw
+        self.formatter = formatter(output, color)
         return ''.join([parts.netloc, parts.path])
 
     def write(self, tx):
-        if self.color:
-            self.output.write(self.tx_color)
-        if self.hexlify:
-            self.output.write(tx.encode('hex'))
-        else:
-            self.output.write(tx)
-        self.output.flush()
+        self.formatter.tx(tx)
         return super(Serial, self).write(tx)
 
     def read(self, size=1):
         rx = super(Serial, self).read(size)
         if rx:
-            if self.color:
-                self.output.write(self.rx_color)
-            if self.hexlify:
-                self.output.write(rx.encode('hex'))
-            else:
-                self.output.write(rx)
-            self.output.flush()
+            self.formatter.rx(rx)
         return rx
 
 
+    def flush(self):
+        self.formatter.control('FLSH', 'flush')
+        super(Serial, self).flush()
+
+    def flushInput(self):
+        self.formatter.control('FLSH', 'flushInput')
+        super(Serial, self).flush()
+
+    def flushOutput(self):
+        self.formatter.control('FLSH', 'flushOutput')
+        super(Serial, self).flushOutput()
+
+    def sendBreak(self, duration=0.25):
+        self.formatter.control('FLSH', 'sendBreak')
+        super(Serial, self).sendBreak(duration)
+
+    def setBreak(self, level=1):
+        self.formatter.control('BRK', 'active' if level else 'inactive')
+        super(Serial, self).setBreak(level)
+
+    def setRTS(self, level=1):
+        self.formatter.control('RTS', 'active' if level else 'inactive')
+        super(Serial, self).setRTS(level)
+
+    def setDTR(self, level=1):
+        self.formatter.control('DTR', 'active' if level else 'inactive')
+        super(Serial, self).setDTR(level)
+
+    def getCTS(self):
+        level = super(Serial, self).getCTS()
+        self.formatter.control('CTS', 'active' if level else 'inactive')
+        return level
+
+    def getDSR(self):
+        level = super(Serial, self).getDSR()
+        self.formatter.control('DSR', 'active' if level else 'inactive')
+        return level
+
+    def getRI(self):
+        level = super(Serial, self).getRI()
+        self.formatter.control('RI', 'active' if level else 'inactive')
+        return level
+
+    def getCD(self):
+        self.formatter.control('CD', 'active' if level else 'inactive')
+        level = super(Serial, self).getCD()
+        return level
+
 # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 if __name__ == '__main__':
     s = Serial(None)