diff --git a/numidr.ipkg b/numidr.ipkg
index 40eb48c..9ba64da 100644
--- a/numidr.ipkg
+++ b/numidr.ipkg
@@ -12,6 +12,11 @@ readme = "README.md"
 modules = Data.NP,
           Data.Permutation,
           Data.NumIdr,
+          Data.NumIdr.PrimArray,
+          Data.NumIdr.PrimArray.Bytes,
+          Data.NumIdr.PrimArray.Boxed,
+          Data.NumIdr.PrimArray.Linked,
+          Data.NumIdr.PrimArray.Delayed,
           Data.NumIdr.Array,
           Data.NumIdr.Array.Array,
           Data.NumIdr.Array.Coords,
@@ -19,7 +24,6 @@ modules = Data.NP,
           Data.NumIdr.Homogeneous,
           Data.NumIdr.Matrix,
           Data.NumIdr.Interfaces,
-          Data.NumIdr.PrimArray,
           Data.NumIdr.Scalar,
           Data.NumIdr.Vector,
           Data.NumIdr.LArray,
diff --git a/src/Data/NumIdr/PrimArray/Boxed.idr b/src/Data/NumIdr/PrimArray/Boxed.idr
new file mode 100644
index 0000000..9b038bd
--- /dev/null
+++ b/src/Data/NumIdr/PrimArray/Boxed.idr
@@ -0,0 +1,210 @@
+module Data.NumIdr.PrimArray.Boxed
+
+import Data.Buffer
+import System
+import Data.IOArray.Prims
+import Data.Vect
+import Data.NumIdr.Array.Rep
+import Data.NumIdr.Array.Coords
+import Data.NumIdr.PrimArray.Bytes
+
+%default total
+
+
+public export
+data PrimArrayBoxed : Order -> Vect rk Nat -> Type -> Type where
+  MkPABoxed : (sts : Vect rk Nat) -> ArrayData a -> PrimArrayBoxed {rk} o s a
+
+
+-- Private helper functions for ArrayData primitives
+export
+newArrayData : Nat -> a -> IO (ArrayData a)
+newArrayData n x = fromPrim $ prim__newArray (cast n) x
+
+export
+arrayDataGet : Nat -> ArrayData a -> IO a
+arrayDataGet n arr = fromPrim $ prim__arrayGet arr (cast n)
+
+export
+arrayDataSet : Nat -> a -> ArrayData a -> IO ()
+arrayDataSet n x arr = fromPrim $ prim__arraySet arr (cast n) x
+
+
+fromArray : {o : _} -> (s : Vect rk Nat) -> ArrayData a -> PrimArrayBoxed o s a
+fromArray s = MkPABoxed (calcStrides o s)
+
+arrayAction : {o : _} -> (s : Vect rk Nat) -> (ArrayData a -> IO ()) -> PrimArrayBoxed o s a
+arrayAction s action = fromArray s $ unsafePerformIO $ do
+  arr <- newArrayData (product s) (believe_me ())
+  action arr
+  pure arr
+
+||| Construct an array with a constant value.
+export
+constant : {o : _} -> (s : Vect rk Nat) -> a -> PrimArrayBoxed o s a
+constant s x = fromArray s $ unsafePerformIO $ newArrayData (product s) x
+
+
+export
+unsafeDoIns : List (Nat, a) -> PrimArrayBoxed o s a -> IO ()
+unsafeDoIns ins (MkPABoxed _ arr) = for_ ins $ \(i,x) => arrayDataSet i x arr
+
+||| Construct an array from a list of "instructions" to write a value to a
+||| particular index.
+export
+unsafeFromIns : {o : _} -> (s : Vect rk Nat) -> List (Nat, a) -> PrimArrayBoxed o s a
+unsafeFromIns s ins = arrayAction s $ \arr =>
+    for_ ins $ \(i,x) => arrayDataSet i x arr
+
+||| Create an array given its size and a function to generate its elements by
+||| its index.
+export
+create : {o : _} -> (s : Vect rk Nat) -> (Nat -> a) -> PrimArrayBoxed o s a
+create s f = arrayAction s $ \arr =>
+    for_ [0..pred (product s)] $ \i => arrayDataSet i (f i) arr
+
+||| Index into a primitive array. This function is unsafe, as it performs no
+||| boundary check on the index given.
+export
+index : Nat -> PrimArrayBoxed o s a -> a
+index n (MkPABoxed _ arr) = unsafePerformIO $ arrayDataGet n arr
+
+export
+copy : {o,s : _} -> PrimArrayBoxed o s a -> PrimArrayBoxed o s a
+copy arr = create s (\n => index n arr)
+
+
+export
+reorder : {o,o',s : _} -> PrimArrayBoxed o s a -> PrimArrayBoxed o' s a
+reorder arr@(MkPABoxed sts ar) =
+  if o == o' then MkPABoxed sts ar
+  else let sts' = calcStrides o' s
+       in  unsafeFromIns s
+            ((\is => (getLocation' sts' is, index (getLocation' sts is) arr))
+              <$> getAllCoords' s)
+
+export
+bytesToBoxed : {s : _} -> ByteRep a => PrimArrayBytes o s -> PrimArrayBoxed o s a
+bytesToBoxed (MkPABytes sts buf) = MkPABoxed sts $ unsafePerformIO $ do
+  arr <- newArrayData (product s) (believe_me ())
+  for_ [0..pred (product s)] $ \i => arrayDataSet i !(readBuffer i buf) arr
+  pure arr
+
+export
+boxedToBytes : {s : _} -> ByteRep a => PrimArrayBoxed o s a -> PrimArrayBytes o s
+boxedToBytes @{br} (MkPABoxed sts arr) = MkPABytes sts $ unsafePerformIO $ do
+  Just buf <- newBuffer $ cast (product s * bytes @{br})
+    | Nothing => die "Cannot create array"
+  for_ [0..pred (product s)] $ \i => writeBuffer i !(arrayDataGet i arr) buf
+  pure buf
+
+
+export
+fromList : {o : _} -> (s : Vect rk Nat) -> List a -> PrimArrayBoxed o s a
+fromList s xs = arrayAction s $ go xs 0
+  where
+    go : List a -> Nat -> ArrayData a -> IO ()
+    go [] _ buf = pure ()
+    go (x :: xs) i buf = arrayDataSet i x buf >> go xs (S i) buf
+
+
+{-
+export
+updateAt : Nat -> (a -> a) -> PrimArrayBoxed o s a -> PrimArrayBoxed o s a
+updateAt n f arr = if n >= length arr then arr else
+  unsafePerformIO $ do
+    let cpy = copy arr
+    x <- arrayDataGet n cpy.content
+    arrayDataSet n (f x) cpy.content
+    pure cpy
+
+export
+unsafeUpdateInPlace : Nat -> (a -> a) -> PrimArrayBoxed a -> PrimArrayBoxed a
+unsafeUpdateInPlace n f arr = unsafePerformIO $ do
+  x <- arrayDataGet n arr.content
+  arrayDataSet n (f x) arr.content
+  pure arr
+
+||| Convert a primitive array to a list.
+export
+toList : PrimArrayBoxed a -> List a
+toList arr = iter (length arr) []
+  where
+    iter : Nat -> List a -> List a
+    iter Z acc = acc
+    iter (S n) acc = let el = index n arr
+                     in  iter n (el :: acc)
+
+||| Construct a primitive array from a list.
+export
+fromList : List a -> PrimArrayBoxed a
+fromList xs = create (length xs)
+    (\n => assert_total $ fromJust $ getAt n xs)
+  where
+    partial
+    fromJust : Maybe a -> a
+    fromJust (Just x) = x
+
+||| Map a function over a primitive array.
+export
+map : (a -> b) -> PrimArrayBoxed a -> PrimArrayBoxed b
+map f arr = create (length arr) (\n => f $ index n arr)
+
+
+export
+unsafeZipWith : (a -> b -> c) -> PrimArrayBoxed a -> PrimArrayBoxed b -> PrimArrayBoxed c
+unsafeZipWith f a b = create (length a) (\n => f (index n a) (index n b))
+
+export
+unsafeZipWith3 : (a -> b -> c -> d) ->
+                 PrimArrayBoxed a -> PrimArrayBoxed b -> PrimArrayBoxed c -> PrimArrayBoxed d
+unsafeZipWith3 f a b c = create (length a) (\n => f (index n a) (index n b) (index n c))
+
+export
+unzipWith : (a -> (b, c)) -> PrimArrayBoxed a -> (PrimArrayBoxed b, PrimArrayBoxed c)
+unzipWith f arr = (map (fst . f) arr, map (snd . f) arr)
+
+export
+unzipWith3 : (a -> (b, c, d)) -> PrimArrayBoxed a -> (PrimArrayBoxed b, PrimArrayBoxed c, PrimArrayBoxed d)
+unzipWith3 f arr = (map ((\(x,_,_) => x) . f) arr,
+                          map ((\(_,y,_) => y) . f) arr,
+                          map ((\(_,_,z) => z) . f) arr)
+
+
+export
+foldl : (b -> a -> b) -> b -> PrimArrayBoxed a -> b
+foldl f z (MkPABoxed size arr) =
+  if size == 0 then z
+  else unsafePerformIO $ do
+    ref <- newIORef z
+    for_ [0..pred size] $ \n => do
+        x <- readIORef ref
+        y <- arrayDataGet n arr
+        writeIORef ref (f x y)
+    readIORef ref
+
+export
+foldr : (a -> b -> b) -> b -> PrimArrayBoxed a -> b
+foldr f z (MkPABoxed size arr) =
+  if size == 0 then z
+  else unsafePerformIO $ do
+    ref <- newIORef z
+    for_ [pred size..0] $ \n => do
+         x <- arrayDataGet n arr
+         y <- readIORef ref
+         writeIORef ref (f x y)
+    readIORef ref
+
+export
+traverse : Applicative f => (a -> f b) -> PrimArrayBoxed a -> f (PrimArrayBoxed b)
+traverse f = map fromList . traverse f . toList
+
+
+||| Compares two primitive arrays for equal elements. This function assumes the
+||| arrays have the same length; it must not be used in any other case.
+export
+unsafeEq : Eq a => PrimArrayBoxed a -> PrimArrayBoxed a -> Bool
+unsafeEq a b = unsafePerformIO $
+                 map (concat @{All}) $ for [0..pred (arraySize a)] $
+                 \n => (==) <$> arrayDataGet n (content a) <*> arrayDataGet n (content b)
+-}
diff --git a/src/Data/NumIdr/PrimArray/Bytes.idr b/src/Data/NumIdr/PrimArray/Bytes.idr
new file mode 100644
index 0000000..4c0ce72
--- /dev/null
+++ b/src/Data/NumIdr/PrimArray/Bytes.idr
@@ -0,0 +1,244 @@
+module Data.NumIdr.PrimArray.Bytes
+
+import System
+import Data.IORef
+import Data.Bits
+import Data.So
+import Data.Buffer
+import Data.Vect
+import Data.NumIdr.Array.Coords
+import Data.NumIdr.Array.Rep
+
+%default total
+
+
+public export
+interface ByteRep a where
+  bytes : Nat
+
+  toBytes : a -> Vect bytes Bits8
+  fromBytes : Vect bytes Bits8 -> a
+
+export
+ByteRep Bits8 where
+  bytes = 1
+
+  toBytes x = [x]
+  fromBytes [x] = x
+
+export
+ByteRep Bits16 where
+  bytes = 2
+
+  toBytes x = [cast (x `shiftR` 8), cast x]
+  fromBytes [b1,b2] = cast b1 `shiftL` 8 .|. cast b2
+
+export
+ByteRep Bits32 where
+  bytes = 4
+
+  toBytes x = [cast (x `shiftR` 24),
+               cast (x `shiftR` 16),
+               cast (x `shiftR` 8),
+               cast x]
+  fromBytes [b1,b2,b3,b4] =
+    cast b1 `shiftL` 24 .|.
+    cast b2 `shiftL` 16 .|.
+    cast b3 `shiftL` 8 .|.
+    cast b4
+
+export
+ByteRep Bits64 where
+  bytes = 8
+
+  toBytes x = [cast (x `shiftR` 56),
+               cast (x `shiftR` 48),
+               cast (x `shiftR` 40),
+               cast (x `shiftR` 32),
+               cast (x `shiftR` 24),
+               cast (x `shiftR` 16),
+               cast (x `shiftR` 8),
+               cast x]
+  fromBytes [b1,b2,b3,b4,b5,b6,b7,b8] =
+    cast b1 `shiftL` 56 .|.
+    cast b2 `shiftL` 48 .|.
+    cast b3 `shiftL` 40 .|.
+    cast b4 `shiftL` 32 .|.
+    cast b5 `shiftL` 24 .|.
+    cast b6 `shiftL` 16 .|.
+    cast b7 `shiftL` 8 .|.
+    cast b8
+
+export
+ByteRep Int where
+  bytes = 8
+
+  toBytes x = [cast (x `shiftR` 56),
+               cast (x `shiftR` 48),
+               cast (x `shiftR` 40),
+               cast (x `shiftR` 32),
+               cast (x `shiftR` 24),
+               cast (x `shiftR` 16),
+               cast (x `shiftR` 8),
+               cast x]
+  fromBytes [b1,b2,b3,b4,b5,b6,b7,b8] =
+    cast b1 `shiftL` 56 .|.
+    cast b2 `shiftL` 48 .|.
+    cast b3 `shiftL` 40 .|.
+    cast b4 `shiftL` 32 .|.
+    cast b5 `shiftL` 24 .|.
+    cast b6 `shiftL` 16 .|.
+    cast b7 `shiftL` 8 .|.
+    cast b8
+
+export
+ByteRep Int8 where
+  bytes = 1
+
+  toBytes x = [cast x]
+  fromBytes [x] = cast x
+
+export
+ByteRep Int16 where
+  bytes = 2
+
+  toBytes x = [cast (x `shiftR` 8), cast x]
+  fromBytes [b1,b2] = cast b1 `shiftL` 8 .|. cast b2
+
+export
+ByteRep Int32 where
+  bytes = 4
+
+  toBytes x = [cast (x `shiftR` 24),
+               cast (x `shiftR` 16),
+               cast (x `shiftR` 8),
+               cast x]
+  fromBytes [b1,b2,b3,b4] =
+    cast b1 `shiftL` 24 .|.
+    cast b2 `shiftL` 16 .|.
+    cast b3 `shiftL` 8 .|.
+    cast b4
+
+export
+ByteRep Int64 where
+  bytes = 8
+
+  toBytes x = [cast (x `shiftR` 56),
+               cast (x `shiftR` 48),
+               cast (x `shiftR` 40),
+               cast (x `shiftR` 32),
+               cast (x `shiftR` 24),
+               cast (x `shiftR` 16),
+               cast (x `shiftR` 8),
+               cast x]
+  fromBytes [b1,b2,b3,b4,b5,b6,b7,b8] =
+    cast b1 `shiftL` 56 .|.
+    cast b2 `shiftL` 48 .|.
+    cast b3 `shiftL` 40 .|.
+    cast b4 `shiftL` 32 .|.
+    cast b5 `shiftL` 24 .|.
+    cast b6 `shiftL` 16 .|.
+    cast b7 `shiftL` 8 .|.
+    cast b8
+
+export
+ByteRep Bool where
+  bytes = 1
+
+  toBytes b = [if b then 1 else 0]
+  fromBytes [x] = x /= 0
+
+export
+ByteRep a => ByteRep b => ByteRep (a, b) where
+  bytes = bytes {a} + bytes {a=b}
+
+  toBytes (x,y) = toBytes x ++ toBytes y
+  fromBytes = bimap fromBytes fromBytes . splitAt _
+
+export
+{n : _} -> ByteRep a => ByteRep (Vect n a) where
+  bytes = n * bytes {a}
+
+  toBytes xs = concat $ map toBytes xs
+  fromBytes {n = 0} bs = []
+  fromBytes {n = S n} bs =
+    let (bs1, bs2) = splitAt _ bs
+    in  fromBytes bs1 :: fromBytes bs2
+
+
+export
+readBuffer : ByteRep a => (i : Nat) -> Buffer -> IO a
+readBuffer i buf = do
+  let offset : Int = cast (i * bytes {a})
+  map (fromBytes {a}) $ for range $ \n => do
+    getBits8 buf $ offset + cast (finToInteger n)
+
+export
+writeBuffer : ByteRep a => (i : Nat) -> a -> Buffer -> IO ()
+writeBuffer i x buf = do
+  let offset = cast (i * bytes {a})
+      bs = toBytes x
+  n <- newIORef 0
+  for_ bs $ \b => setBits8 buf (offset + !(readIORef n)) b <* modifyIORef n (+1)
+
+
+public export
+data PrimArrayBytes : Order -> Vect rk Nat -> Type where
+  MkPABytes : (sts : Vect rk Nat) -> Buffer -> PrimArrayBytes {rk} o s
+
+export
+getBuffer : PrimArrayBytes o s -> Buffer
+getBuffer (MkPABytes _ buf) = buf
+
+
+fromBuffer : {o : _} -> (s : Vect rk Nat) -> Buffer -> PrimArrayBytes o s
+fromBuffer s buf = MkPABytes (calcStrides o s) buf
+
+bufferAction : {o : _} -> ByteRep a => (s : Vect rk Nat) -> (Buffer -> IO ()) -> PrimArrayBytes o s
+bufferAction @{br} s action = fromBuffer s $ unsafePerformIO $ do
+  Just buf <- newBuffer $ cast (product s * bytes @{br})
+    | Nothing => die "Cannot create array"
+  action buf
+  pure buf
+
+export
+constant : {o : _} -> ByteRep a => (s : Vect rk Nat) -> a -> PrimArrayBytes o s
+constant @{br} s x = bufferAction @{br} s $ \buf => do
+  let size = product s
+  for_ [0..pred size] $ \i => writeBuffer i x buf
+
+export
+unsafeDoIns : ByteRep a => List (Nat, a) -> PrimArrayBytes o s -> IO ()
+unsafeDoIns ins (MkPABytes _ buf) = for_ ins $ \(i,x) => writeBuffer i x buf
+
+export
+unsafeFromIns : {o : _} -> ByteRep a => (s : Vect rk Nat) -> List (Nat, a) -> PrimArrayBytes o s
+unsafeFromIns @{br} s ins = bufferAction @{br} s $ \buf =>
+  for_ ins $ \(i,x) => writeBuffer i x buf
+
+export
+create : {o : _} -> ByteRep a => (s : Vect rk Nat) -> (Nat -> a) -> PrimArrayBytes o s
+create @{br} s f = bufferAction @{br} s $ \buf => do
+  let size = product s
+  for_ [0..pred size] $ \i => writeBuffer i (f i) buf
+
+export
+index : ByteRep a => Nat -> PrimArrayBytes o s -> a
+index i (MkPABytes _ buf) = unsafePerformIO $ readBuffer i buf
+
+export
+reorder : {o,o',s : _} -> ByteRep a => PrimArrayBytes o s -> PrimArrayBytes o' s
+reorder @{br} arr@(MkPABytes sts buf) =
+  if o == o' then MkPABytes sts buf
+  else let sts' = calcStrides o' s
+       in  unsafeFromIns @{br} s
+            ((\is => (getLocation' sts' is, index @{br} (getLocation' sts is) arr))
+              <$> getAllCoords' s)
+
+export
+fromList : {o : _} -> ByteRep a => (s : Vect rk Nat) -> List a -> PrimArrayBytes o s
+fromList @{br} s xs = bufferAction @{br} s $ go xs 0
+  where
+    go : List a -> Nat -> Buffer -> IO ()
+    go [] _ buf = pure ()
+    go (x :: xs) i buf = writeBuffer i x buf >> go xs (S i) buf
diff --git a/src/Data/NumIdr/PrimArray/Delayed.idr b/src/Data/NumIdr/PrimArray/Delayed.idr
new file mode 100644
index 0000000..c7a5825
--- /dev/null
+++ b/src/Data/NumIdr/PrimArray/Delayed.idr
@@ -0,0 +1,23 @@
+module Data.NumIdr.PrimArray.Delayed
+
+import Data.Vect
+import Data.NP
+import Data.NumIdr.Array.Rep
+import Data.NumIdr.Array.Coords
+
+%default total
+
+public export
+PrimArrayDelayed : Vect rk Nat -> Type -> Type
+PrimArrayDelayed s a = Coords s -> a
+
+
+export
+constant : (s : Vect rk Nat) -> a -> PrimArrayDelayed s a
+constant s x _ = x
+
+
+export
+checkRange : (s : Vect rk Nat) -> Vect rk Nat -> Maybe (Coords s)
+checkRange [] [] = Just []
+checkRange (d :: s) (i :: is) = (::) <$> natToFin i d <*> checkRange s is
diff --git a/src/Data/NumIdr/PrimArray/Linked.idr b/src/Data/NumIdr/PrimArray/Linked.idr
new file mode 100644
index 0000000..54af7c0
--- /dev/null
+++ b/src/Data/NumIdr/PrimArray/Linked.idr
@@ -0,0 +1,34 @@
+module Data.NumIdr.PrimArray.Linked
+
+import Data.Vect
+import Data.NP
+import Data.NumIdr.Array.Rep
+import Data.NumIdr.Array.Coords
+
+%default total
+
+
+export
+constant : (s : Vect rk Nat) -> a -> Vects s a
+constant [] x = x
+constant (d :: s) xs = replicate d (constant s xs)
+
+export
+index : Coords s -> Vects s a -> a
+index [] x = x
+index (c :: cs) xs = index cs (index c xs)
+
+
+export
+fromFunction : {s : _} -> (Coords s -> a) -> Vects s a
+fromFunction {s = []} f = f []
+fromFunction {s = d :: s} f = tabulate (\i => fromFunction (f . (i::)))
+
+export
+fromFunctionNB : {s : _} -> (Vect rk Nat -> a) -> Vects {rk} s a
+fromFunctionNB {s = []} f = f []
+fromFunctionNB {s = d :: s} f = tabulate' {n=d} (\i => fromFunctionNB (f . (i::)))
+  where
+    tabulate' : forall a. {n : _} -> (Nat -> a) -> Vect n a
+    tabulate' {n=Z} f = []
+    tabulate' {n=S _} f = f Z :: tabulate' (f . S)