diff --git a/src/GB/CPU.hs b/src/GB/CPU.hs
index 1205a8c..eada713 100644
--- a/src/GB/CPU.hs
+++ b/src/GB/CPU.hs
@@ -61,17 +61,13 @@ data Registers = Registers { _a     :: Word8
 
 makeLenses ''Registers
 
-getBC :: Registers -> Word16
-getBC r = (( .<<. 8) . fromIntegral $ r ^. b) + (fromIntegral $ r ^. c)
+bc :: Lens' Registers Word16
+bc = lens (\r -> (( .<<. 8) . fromIntegral $ r ^. b) + (fromIntegral $ r ^. c))
+          (\r w -> r & b %~ (const $ fromIntegral $ w .>>. 8) & c %~ (const $ fromIntegral $ w .&. 255))
 
-setBC :: Registers -> Word16 -> Registers
-setBC r w = r & b %~ (const $ fromIntegral $ w .>>. 8) & c %~ (const $ fromIntegral $ w .&. 255)
-
-getHL :: Registers -> Word16
-getHL r = ((.<<. 8) . fromIntegral $ r ^. h) + (fromIntegral $ r ^. l)
-
-setHL :: Registers -> Word16 -> Registers
-setHL r w = r & h %~ (const $ fromIntegral $ w .>>. 8) & l %~ (const $ fromIntegral $ w .&. 255)
+hl :: Lens' Registers Word16
+hl = lens (\r -> ((.<<. 8) . fromIntegral $ r ^. h) + (fromIntegral $ r ^. l))
+          (\r w -> r & h %~ (const $ fromIntegral $ w .>>. 8) & l %~ (const $ fromIntegral $ w .&. 255))
 
 data CPU = CPU { _registers :: Registers
                , _pc :: Word16
@@ -108,7 +104,7 @@ execute cpu = \case
   AddR t _c -> let value = cpu ^. registers . t
                    (newValue, newFlags) = add (cpu ^. registers . a) value $ _c && cpu ^. registers . flags . carry in
                cpu & registers . a .~ newValue & registers . flags .~ newFlags
-  AddHL _c -> let value = fetch cpu . getHL $ cpu ^. registers
+  AddHL _c -> let value = fetch cpu $ cpu ^. registers . hl
                   (newValue, newFlags) = add (cpu ^. registers . a) value $ _c && cpu ^. registers . flags . carry in
               cpu & registers . a .~ newValue & registers . flags .~ newFlags
   AddN value _c -> let (newValue, newFlags) = add (cpu ^. registers . a) value $ _c && cpu ^. registers .flags . carry in
@@ -116,7 +112,7 @@ execute cpu = \case
   SubR t _c -> let value =  cpu ^. registers . t
                    (newValue, newFlags) = sub (cpu ^. registers . a) value $ _c && cpu ^. registers . flags . carry in
                cpu & registers . a .~ newValue & registers . flags .~ newFlags
-  SubHL _c -> let value = fetch cpu . getHL $ cpu ^. registers
+  SubHL _c -> let value = fetch cpu $ cpu ^. registers . hl
                   (newValue, newFlags) = sub (cpu ^. registers . a) value $ _c && cpu ^. registers . flags . carry in
               cpu & registers . a .~ newValue & registers . flags .~ newFlags
   SubN value _c -> let (newValue, newFlags) = sub (cpu ^. registers . a) value $ _c && cpu ^. registers .flags . carry in
@@ -124,27 +120,27 @@ execute cpu = \case
   CpR t _c -> let value = cpu ^. registers . t
                   (_, newFlags) = sub (cpu ^. registers . a) value $ _c && cpu ^. registers . flags . carry in
               cpu & registers . flags .~ newFlags
-  CpHL _c -> let value = fetch cpu . getHL $ cpu ^. registers
+  CpHL _c -> let value = fetch cpu $ cpu ^. registers . hl
                  (_, newFlags) = sub (cpu ^. registers . a) value $ _c && cpu ^. registers . flags . carry in
            cpu & registers . flags .~ newFlags
   CpN value _c -> let (_, newFlags) = sub (cpu ^. registers . a) value $ _c && cpu ^. registers .flags . carry in
                 cpu & registers . flags .~ newFlags
   IncR t -> let (value, newFlags) = add (cpu ^. registers . t) 1 False in
             cpu & registers . t .~ value & registers . flags .~ newFlags
-  IncHL -> let target = getHL $ cpu ^. registers
+  IncHL -> let target = cpu ^. registers . hl
                value = fetch cpu target
                (newValue, newFlags) = add value 1 False in
            write cpu target newValue & registers . flags .~ newFlags
   DecR t -> let (value, newFlags) = sub (cpu ^. registers . t) 1 False in
             cpu & registers . t .~ value & registers . flags .~ newFlags
-  DecHL -> let target = getHL $ cpu ^. registers
+  DecHL -> let target = cpu ^. registers . hl
                value = fetch cpu target
                (newValue, newFlags) = sub value 1 False in
            write cpu target newValue & registers . flags .~ newFlags
   BOR t op _f -> let newValue = (cpu ^. registers . a) `op` (cpu ^. registers . t)
                      newFlags = _f {_zero = newValue == 0} in
                 cpu & registers . a .~ newValue & registers . flags .~ newFlags
-  BOHL op _f -> let target = getHL $ cpu ^. registers
+  BOHL op _f -> let target = cpu ^. registers . hl
                     value = fetch cpu target
                     newValue = (cpu ^. registers . a) `op` value
                     newFlags = _f {_zero = value == 0} in