diff --git a/src/calibre/devices/interface.py b/src/calibre/devices/interface.py
index e2959cd49f..85d25d82a4 100644
--- a/src/calibre/devices/interface.py
+++ b/src/calibre/devices/interface.py
@@ -20,7 +20,9 @@ class Device(object):
     FORMATS     = ["lrf", "rtf", "pdf", "txt"]
     VENDOR_ID   = 0x0000
     PRODUCT_ID  = 0x0000
-    BCD         = 0x0000
+    # BCD can be either None to not distinguish between devices based on BCD, or 
+    # it can be a list of the BCD numbers of all devices supported by this driver.
+    BCD         = None
     THUMBNAIL_HEIGHT = 68 # Height for thumbnails on device
     
     def __init__(self, key='-1', log_packets=False, report_progress=None) :
diff --git a/src/calibre/devices/prs500/driver.py b/src/calibre/devices/prs500/driver.py
index 177f57b15f..232d2c758c 100755
--- a/src/calibre/devices/prs500/driver.py
+++ b/src/calibre/devices/prs500/driver.py
@@ -85,7 +85,7 @@ class PRS500(Device):
 
     VENDOR_ID    = 0x054c #: SONY Vendor Id
     PRODUCT_ID   = 0x029b #: Product Id for the PRS-500
-    BCD          = 0x100
+    BCD          = [0x100]
     PRODUCT_NAME = 'PRS-500'
     VENDOR_NAME  = 'SONY'
     INTERFACE_ID = 0      #: The interface we use to talk to the device
diff --git a/src/calibre/devices/prs505/driver.py b/src/calibre/devices/prs505/driver.py
index 0f60d7238b..61004ca005 100644
--- a/src/calibre/devices/prs505/driver.py
+++ b/src/calibre/devices/prs505/driver.py
@@ -29,7 +29,7 @@ class File(object):
 class PRS505(Device):
     VENDOR_ID    = 0x054c #: SONY Vendor Id
     PRODUCT_ID   = 0x031e #: Product Id for the PRS-505
-    BCD          = 0x229  #: Needed to disambiguate 505 and 700 on linux
+    BCD          = [0x229]  #: Needed to disambiguate 505 and 700 on linux
     PRODUCT_NAME = 'PRS-505'
     VENDOR_NAME  = 'SONY'
     FORMATS      = ['lrf', 'epub', "rtf", "pdf", "txt"]
diff --git a/src/calibre/devices/prs700/driver.py b/src/calibre/devices/prs700/driver.py
index 812ac0f911..5db60ef506 100644
--- a/src/calibre/devices/prs700/driver.py
+++ b/src/calibre/devices/prs700/driver.py
@@ -9,7 +9,7 @@ from calibre.devices.prs505.driver import PRS505
 
 class PRS700(PRS505):
     
-    BCD          = 0x31a
+    BCD          = [0x31a]
     PRODUCT_NAME = 'PRS-700'
     OSX_NAME     = 'Sony PRS-700'
      
diff --git a/src/calibre/devices/scanner.py b/src/calibre/devices/scanner.py
index 40573114a7..3487987d67 100644
--- a/src/calibre/devices/scanner.py
+++ b/src/calibre/devices/scanner.py
@@ -39,20 +39,35 @@ class DeviceScanner(object):
         '''Fetch list of connected USB devices from operating system'''
         self.devices = self.scanner()
 
+    def test_bcd_windows(self, device_id, bcd):
+        if bcd is None or len(bcd) == 0:
+            return True
+        for c in bcd:
+            # Bug in winutil.get_usb_devices converts a to :
+            rev = ('rev_%4.4x'%c).replace(':', 'a')
+            if rev in device_id:
+                return True
+        return False 
+            
+    def test_bcd(self, bcdDevice, bcd):
+        if bcd is None or len(bcd) == 0:
+            return True
+        for c in bcd:
+            if c == bcdDevice:
+                return True
+        return False
+    
     def is_device_connected(self, device):
         if iswindows:
             for device_id in self.devices:
                 vid, pid = 'vid_%4.4x'%device.VENDOR_ID, 'pid_%4.4x'%device.PRODUCT_ID
-                rev = ('rev_%4.4x'%device.BCD).replace('a', ':') # Bug in winutil.get_usb_devices converts a to :
-                if vid in device_id and pid in device_id and rev in device_id:
-                    return True
-            return False
+                if vid in device_id and pid in device_id:
+                    return self.test_bcd_windows(device_id, getattr(device, 'BCD', None))
         else:
             for vendor, product, bcdDevice in self.devices:
                 if device.VENDOR_ID == vendor and device.PRODUCT_ID == product:
-                    if hasattr(device, 'BCD') and device.BCD == bcdDevice:
-                        return True
-            return False
+                    return self.test_bcd(bcdDevice, getattr(device, 'BCD', None))
+        return False
 
 
 def main(args=sys.argv):