diff --git a/Sound/OpenSoundControl/Cast.hs b/Sound/OpenSoundControl/Cast.hs
--- a/Sound/OpenSoundControl/Cast.hs
+++ b/Sound/OpenSoundControl/Cast.hs
@@ -21,6 +21,17 @@
 f64_i64 :: Double -> Int64
 f64_i64 d = runST ((from_array =<< castSTUArray =<< unit_array d) :: ST s Int64)
 
+{-
+http://www.haskell.org/pipermail/haskell-cafe/2008-February/040000.html
+
+{-# LANGUAGE MagicHash #-}
+import Data.Int
+import GHC.Exts
+
+f64_i64 :: Double -> Int64 --ghc only
+f64_i64 (D# x) = I64# (unsafeCoerce# x)
+-}
+
 -- | Inverse of 'f64_i64'.
 i64_f64 :: Int64 -> Double
 i64_f64 d = runST ((from_array =<< castSTUArray =<< unit_array d) :: ST s Double)
diff --git a/Sound/OpenSoundControl/Coerce.hs b/Sound/OpenSoundControl/Coerce.hs
new file mode 100644
--- /dev/null
+++ b/Sound/OpenSoundControl/Coerce.hs
@@ -0,0 +1,29 @@
+module Sound.OpenSoundControl.Coerce where
+
+import Sound.OpenSoundControl.OSC
+
+-- | Map a normalizing function over datum at an osc packet.
+coerce :: (Datum -> Datum) -> OSC -> OSC
+coerce f (Message s xs) = Message s (map f xs)
+coerce f (Bundle t xs) = Bundle t (map (coerce f) xs)
+
+-- | Coerce Float to Double.
+f_to_d :: Datum -> Datum
+f_to_d (Float n) = Double n
+f_to_d x = x
+
+-- | Coerce Int and Float to Double.
+if_to_d :: Datum -> Datum
+if_to_d (Int n) = Double (fromIntegral n)
+if_to_d (Float n) = Double n
+if_to_d x = x
+
+-- | Coerce Float and Double to Int.
+fd_to_i :: Datum -> Datum
+fd_to_i (Float n) = Int (round n)
+fd_to_i (Double n) = Int (round n)
+fd_to_i x = x
+
+-- | A normalized osc packet has only Int and Double numerical values.
+normalize :: OSC -> OSC
+normalize = coerce f_to_d
diff --git a/Sound/OpenSoundControl/OSC.hs b/Sound/OpenSoundControl/OSC.hs
--- a/Sound/OpenSoundControl/OSC.hs
+++ b/Sound/OpenSoundControl/OSC.hs
@@ -1,6 +1,6 @@
 module Sound.OpenSoundControl.OSC ( OSC(..)
                                   , Datum(..)
-                                  , encodeOSC, encodeOSCNTP
+                                  , encodeOSC
                                   , decodeOSC ) where
 
 import qualified Data.ByteString.Lazy as B
@@ -21,7 +21,7 @@
 
 -- | An OSC packet.
 data OSC = Message String [Datum]
-         | Bundle Double [OSC]
+         | Bundle Time [OSC]
            deriving (Eq, Show)
 
 -- | OSC bundles can be ordered (time ascending).
@@ -69,25 +69,18 @@
 encode_osc_blob = Blob . B.unpack . encodeOSC
 
 -- Encode an OSC bundle.
-encode_bundle_ntp :: Double -> [OSC] -> B.ByteString
-encode_bundle_ntp t l =
+encode_bundle_ntpi :: Integer -> [OSC] -> B.ByteString
+encode_bundle_ntpi t l =
     B.concat [ encode_datum (String "#bundle")
-             , encode_u64 (ntpr_ntp t)
+             , encode_u64 t
              , B.concat (map (encode_datum . encode_osc_blob) l) ]
 
--- | Encode an OSC packet (NTP epoch).
-encodeOSCNTP :: OSC -> B.ByteString
-encodeOSCNTP (Message c l) = encode_message c l
-encodeOSCNTP (Bundle t l) = encode_bundle_ntp t l
-
--- Offset from UTC to NTP epoch.
-utc_ntp_diff :: Double
-utc_ntp_diff = (70 * 365 + 17) * 24 * 60 * 60
-
 -- | Encode an OSC packet.
 encodeOSC :: OSC -> B.ByteString
 encodeOSC (Message c l) = encode_message c l
-encodeOSC (Bundle t l) = encode_bundle_ntp (t + utc_ntp_diff) l
+encodeOSC (Bundle (NTPi t) l) = encode_bundle_ntpi t l
+encodeOSC (Bundle (NTPr t) l) = encode_bundle_ntpi (ntpr_ntpi t) l
+encodeOSC (Bundle (UTCr t) l) = encode_bundle_ntpi (utcr_ntpi t) l
 
 -- The plain byte count of an OSC value.
 size :: Char -> B.ByteString -> Int
diff --git a/Sound/OpenSoundControl/Time.hs b/Sound/OpenSoundControl/Time.hs
--- a/Sound/OpenSoundControl/Time.hs
+++ b/Sound/OpenSoundControl/Time.hs
@@ -4,19 +4,30 @@
 import Control.Monad
 import qualified Data.Time as T
 
--- | UTC time is represented as a real number.
-type UTC = Double
+-- | Time is represented in either UTC or NTP form.
+data Time = UTCr Double | NTPr Double | NTPi Integer
+            deriving (Eq, Show)
 
--- | NTP time is represented as an integer.
-type NTP = Integer
+-- | Coerce to NTPi form.
+as_ntpi :: Time -> Integer
+as_ntpi (UTCr t) = utcr_ntpi t
+as_ntpi (NTPr t) = ntpr_ntpi t
+as_ntpi (NTPi t) = t
 
+-- | Times can be ordered, avoid coercion if not required.
+instance Ord Time where
+    compare (UTCr p) (UTCr q) = compare p q
+    compare (NTPr p) (NTPr q) = compare p q
+    compare (NTPi p) (NTPi q) = compare p q
+    compare p q = compare (as_ntpi p) (as_ntpi q)
+
 -- | Convert a real-valued NTP timestamp to an NTP timestamp.
-ntpr_ntp :: Double -> NTP
-ntpr_ntp t = round (t * 2^(32::Int))
+ntpr_ntpi :: Double -> Integer
+ntpr_ntpi t = round (t * 2^(32::Int))
 
 -- | Convert UTC timestamp to NTP timestamp.
-utc_ntp :: UTC -> NTP
-utc_ntp t = ntpr_ntp (t + secdif)
+utcr_ntpi :: Double -> Integer
+utcr_ntpi t = ntpr_ntpi (t + secdif)
     where secdif = (70 * 365 + 17) * 24 * 60 * 60
 
 -- | The time at 1970-01-01:00:00:00.
@@ -25,19 +36,19 @@
     where d = T.fromGregorian 1970 1 1
           s = T.secondsToDiffTime 0
 
--- | Read current UTC timestamp.
-utc :: IO UTC
-utc = do t <- T.getCurrentTime
-         return (realToFrac (T.diffUTCTime t utc_base))
+-- | Read current UTCr timestamp.
+utcr :: IO Double
+utcr = do t <- T.getCurrentTime
+          return (realToFrac (T.diffUTCTime t utc_base))
 
 -- | Read current NTP timestamp.
-ntp :: IO NTP
-ntp = liftM utc_ntp utc
+ntpi :: IO Integer
+ntpi = liftM utcr_ntpi utcr
 
 -- | Pause current thread for the indicated duration, given in seconds.
-pause :: Double -> IO ()
-pause n = when (n > 1e-4) (threadDelay (floor (n * 1e6)))
+pauseThread :: Double -> IO ()
+pauseThread n = when (n > 1e-4) (threadDelay (floor (n * 1e6)))
 
--- | Pause current thread until the given utc time.
-pauseUntil :: UTC -> IO ()
-pauseUntil t = pause . (t -) =<< utc
+-- | Pause current thread until the given utcr time.
+pauseThreadUntil :: Double -> IO ()
+pauseThreadUntil t = pauseThread . (t -) =<< utcr
diff --git a/Sound/OpenSoundControl/Transport.hs b/Sound/OpenSoundControl/Transport.hs
--- a/Sound/OpenSoundControl/Transport.hs
+++ b/Sound/OpenSoundControl/Transport.hs
@@ -1,6 +1,6 @@
 module Sound.OpenSoundControl.Transport ( Transport(..)
                                         , withTransport
-                                        , wait ) where
+                                        , waitFor, wait ) where
 
 import Control.Exception
 import Sound.OpenSoundControl.OSC
@@ -19,15 +19,21 @@
 has_address x (Message y _) = x == y
 has_address _ _ = False
 
--- Repeat action until predicate holds on result.
-untilM :: Monad m => (a -> Bool) -> m a -> m a
-untilM p act = recurse
-    where recurse = act >>= (\r -> if p r then return r else recurse)
+-- Repeat action until function does not give Nothing when applied to result.
+untilM :: Monad m => (a -> Maybe b) -> m a -> m b
+untilM f act = recurse
+    where g p = let q = f p in case q of { Nothing -> recurse
+                                         ; Just r -> return r }
+          recurse = act >>= g
 
--- | Wait for an OSC message with the specified address, 
---   discarding intervening messages.
+-- | Wait for an OSC message where the supplied function does not give
+--   Nothing, discarding intervening messages.
+waitFor :: Transport t => t -> (OSC -> Maybe a) -> IO a
+waitFor t f = untilM f (recv t)
+
+-- | A 'waitFor' for variant matching on address string of messages.
 wait :: Transport t => t -> String -> IO OSC
-wait t s = untilM (has_address s) (recv t)
+wait t s = waitFor t (\o -> if has_address s o then Just o else Nothing)
 
 -- | Bracket OSC communication.
 withTransport :: Transport t => IO t -> (t -> IO a) -> IO a
diff --git a/hosc.cabal b/hosc.cabal
--- a/hosc.cabal
+++ b/hosc.cabal
@@ -1,5 +1,5 @@
 Name:              hosc
-Version:           0.4
+Version:           0.5
 Synopsis:          Haskell Open Sound Control
 Description:       hosc provides Sound.OpenSoundControl, a haskell
                    module implementing a subset of the Open Sound
@@ -11,17 +11,18 @@
 Maintainer:        rd@slavepianos.org
 Stability:         Experimental
 Homepage:          http://slavepianos.org/rd/f/269573/
-Tested-With:       GHC==6.8.2
+Tested-With:       GHC==6.10.1
 Build-Type:        Simple
 Cabal-Version:     >= 1.2
 Data-Files:        README
 
 Library
   Build-Depends:   array, base, bytestring, binary, network, time
-  GHC-Options:     -Wall -fwarn-tabs -O2
+  GHC-Options:     -Wall -fwarn-tabs
   Exposed-modules: Sound.OpenSoundControl
                    Sound.OpenSoundControl.Byte
                    Sound.OpenSoundControl.Cast
+                   Sound.OpenSoundControl.Coerce
                    Sound.OpenSoundControl.OSC
                    Sound.OpenSoundControl.Time
                    Sound.OpenSoundControl.Transport