diff --git a/lib/camlboy.ml b/lib/camlboy.ml
index c22cf0b..036f7a6 100644
--- a/lib/camlboy.ml
+++ b/lib/camlboy.ml
@@ -104,7 +104,6 @@ module Make (Cartridge : Cartridge_intf.S) = struct
     let oam_table = Oam_table.create
         ~start_addr:(of_int 0xFE00)
         ~end_addr:(of_int 0xFE9F)
-        ~oam_ram:(Ram.create ~start_addr:(of_int 0xFE00) ~end_addr:(of_int 0xFE9F))
     in
     let lcd_stat = Lcd_stat.create ~addr:lcd_stat_addr in
     let joypad = Joypad.create
diff --git a/lib/gpu/gpu.ml b/lib/gpu/gpu.ml
index 59a46cc..3e79c5f 100644
--- a/lib/gpu/gpu.ml
+++ b/lib/gpu/gpu.ml
@@ -129,38 +129,38 @@ let render_sprite_line t ly =
     | `_8x16 -> 16
   in
   Oam_table.get_all_sprites t.oam
-  |> List.filter (fun sprite -> sprite.y_pos <= ly && ly <= sprite.y_pos + y_sprite_size - 1)
-  |> List.iter (fun sprite ->
-      let row = ly - sprite.y_pos in
-      let pallete = match sprite.pallete with
-        | `OBP0 -> t.obp0
-        | `OBP1 -> t.obp1
-      in
-      for col = 0 to 7 do
-        let lx = sprite.x_pos + col in
-        if lx < 0 || lx >= screen_w then
-          ()
-        else
-          let color_id = Tile_data.get_pixel t.td
-              ~area:Area1
-              ~index:sprite.tile_index
-              ~row:(if sprite.y_flip then y_sprite_size - row - 1 else row)
-              ~col:(if sprite.x_flip then 7 - col else col)
-          in
-          match color_id with
-          | ID_00 ->
-            () (* transparant *)
-          | ID_01 | ID_10 | ID_11 ->
-            match sprite.priority, t.frame_buffer.(ly).(lx) with
-            | `Sprite_top, _
-            | _, `White ->
-              let color = Pallete.lookup pallete color_id in
-              t.frame_buffer.(ly).(lx) <- color
-            | `Sprite_bottom, `Black
-            | `Sprite_bottom, `Dark_gray
-            | `Sprite_bottom, `Light_gray ->
-              ()
-      done)
+  |> Array.iter (fun sprite ->
+      if sprite.y_pos <= ly && ly <= sprite.y_pos + y_sprite_size - 1 then
+        let row = ly - sprite.y_pos in
+        let pallete = match sprite.pallete with
+          | `OBP0 -> t.obp0
+          | `OBP1 -> t.obp1
+        in
+        for col = 0 to 7 do
+          let lx = sprite.x_pos + col in
+          if lx < 0 || lx >= screen_w then
+            ()
+          else
+            let color_id = Tile_data.get_pixel t.td
+                ~area:Area1
+                ~index:sprite.tile_index
+                ~row:(if sprite.y_flip then y_sprite_size - row - 1 else row)
+                ~col:(if sprite.x_flip then 7 - col else col)
+            in
+            match color_id with
+            | ID_00 ->
+              () (* transparant *)
+            | ID_01 | ID_10 | ID_11 ->
+              match sprite.priority, t.frame_buffer.(ly).(lx) with
+              | `Sprite_top, _
+              | _, `White ->
+                let color = Pallete.lookup pallete color_id in
+                t.frame_buffer.(ly).(lx) <- color
+              | `Sprite_bottom, `Black
+              | `Sprite_bottom, `Dark_gray
+              | `Sprite_bottom, `Light_gray ->
+                ()
+        done)
 
 let render_line t =
   let ly = Lcd_position.get_ly t.lp in
diff --git a/lib/gpu/oam_table.ml b/lib/gpu/oam_table.ml
index 6755905..2d48f5f 100644
--- a/lib/gpu/oam_table.ml
+++ b/lib/gpu/oam_table.ml
@@ -8,66 +8,77 @@ type sprite = {
   y_flip : bool;
   x_flip : bool;
   pallete : [`OBP0 | `OBP1];
+  tile_vram_bank : [`Bank0 | `Bank1];
+  pallete_num : int;
 } [@@deriving show]
 
 type t = {
-  oam_ram : Ram.t;
+  sprites : sprite array;
   start_addr : uint16;
   end_addr : uint16;
 }
 
-let create ~start_addr ~end_addr ~oam_ram = { start_addr; end_addr; oam_ram; }
-
-let read_byte t = Ram.read_byte t.oam_ram
+let create ~start_addr ~end_addr =
+  let default_sprite = {
+    y_pos = 0;
+    x_pos = 0;
+    tile_index = Uint8.zero;
+    priority = `Sprite_top;
+    y_flip = false;
+    x_flip = false;
+    pallete = `OBP0;
+    tile_vram_bank = `Bank0;
+    pallete_num = 0; }
+  in
+  let sprites = Array.make 40 default_sprite in
+  { sprites;
+    start_addr;
+    end_addr; }
 
-let write_byte t = Ram.write_byte t.oam_ram
+let read_byte t addr =
+  let offset = Uint16.to_int addr - (Uint16.to_int t.start_addr) in
+  let sprite = t.sprites.(offset / 4) in
+  match offset mod 4 with
+  | 0 -> sprite.y_pos + 16 |> Uint8.of_int
+  | 1 -> sprite.x_pos +  8 |> Uint8.of_int
+  | 2 -> sprite.tile_index
+  | 3 ->
+    Bit_util.byte_of_bitflags
+      (sprite.priority = `Sprite_bottom)
+      sprite.y_flip
+      sprite.x_flip
+      (sprite.pallete = `OBP1)
+      (sprite.tile_vram_bank = `Bank1)
+      (sprite.pallete_num land 0b100 <> 0)
+      (sprite.pallete_num land 0b010 <> 0)
+      (sprite.pallete_num land 0b001 <> 0)
+  | _ -> assert false
 
-let accepts t = Ram.accepts t.oam_ram
+let write_byte t ~addr ~data =
+  let offset = Uint16.to_int addr - (Uint16.to_int t.start_addr) in
+  let data' = Uint8.to_int data in
+  let sprite_index = offset / 4 in
+  match offset mod 4 with
+  | 0 ->
+    t.sprites.(sprite_index) <- {t.sprites.(sprite_index) with y_pos = (data' - 16)}
+  | 1 ->
+    t.sprites.(sprite_index) <- {t.sprites.(sprite_index) with x_pos = (data' - 8)}
+  | 2 ->
+    t.sprites.(sprite_index) <- {t.sprites.(sprite_index) with tile_index = data}
+  | 3 ->
+    let (b7, y_flip, x_flip, b4, b3, b2, b1, b0) = data |> Bit_util.bitflags_of_byte in
+    let priority = if b7 then `Sprite_bottom else `Sprite_top in
+    let pallete = if b4 then `OBP1 else `OBP0 in
+    let tile_vram_bank = if b3 then `Bank1 else `Bank0 in
+    let pallete_num = (Bool.to_int b2 lsl 2) lor (Bool.to_int b1 lsl 1) lor (Bool.to_int b0) in
+    t.sprites.(sprite_index) <-
+      { t.sprites.(sprite_index) with
+        y_flip; x_flip; priority; pallete; tile_vram_bank; pallete_num; }
+  | _ -> assert false
 
-let get_sprite t ~index =
-  let offset = (Uint16.to_int t.start_addr) + (index * 4) in
-  let y_pos =
-    offset
-    |> Uint16.of_int
-    |> Ram.read_byte t.oam_ram
-    |> Uint8.to_int
-    |> (fun y -> y - 16)
-  in
-  let x_pos =
-    (offset + 1)
-    |> Uint16.of_int
-    |> Ram.read_byte t.oam_ram
-    |> Uint8.to_int
-    |> (fun x -> x - 8)
-  in
-  let tile_index =
-    (offset + 2)
-    |> Uint16.of_int
-    |> Ram.read_byte t.oam_ram
-  in
-  let (b7, y_flip, x_flip, b4, _, _, _, _) =
-    (offset + 3)
-    |> Uint16.of_int
-    |> Ram.read_byte t.oam_ram
-    |> Bit_util.bitflags_of_byte
-  in
-  let priority = if b7 then `Sprite_bottom else `Sprite_top in
-  let pallete = if b4 then `OBP1 else `OBP0 in
-  {
-    y_pos;
-    x_pos;
-    tile_index;
-    priority;
-    y_flip;
-    x_flip;
-    pallete;
-  }
+let accepts t addr = Uint16.(t.start_addr <= addr && addr <= t.end_addr)
 
-(* TODO: Optimize *)
-let sprite_indexes = List.init 40 (fun i -> i)
-let get_all_sprites t =
-  sprite_indexes
-  |> List.map (fun index -> get_sprite t ~index)
+let get_all_sprites t = t.sprites
 
 let write_with_offset t ~offset ~data =
-  Ram.write_byte t.oam_ram ~addr:Uint16.(t.start_addr + of_int offset) ~data
+  write_byte t ~addr:Uint16.(t.start_addr + of_int offset) ~data
diff --git a/lib/gpu/oam_table.mli b/lib/gpu/oam_table.mli
index 721adc8..483feba 100644
--- a/lib/gpu/oam_table.mli
+++ b/lib/gpu/oam_table.mli
@@ -10,11 +10,13 @@ type sprite = {
   y_flip : bool;
   x_flip : bool;
   pallete : [`OBP0 | `OBP1];
+  tile_vram_bank : [`Bank0 | `Bank1];
+  pallete_num : int;
 } [@@deriving show]
 
-val create : start_addr:uint16 -> end_addr:uint16 -> oam_ram:Ram.t -> t
+val create : start_addr:uint16 -> end_addr:uint16 -> t
 
-val get_all_sprites : t -> sprite list
+val get_all_sprites : t -> sprite array
 
 val write_with_offset : t -> offset:int -> data:uint8 -> unit
 
diff --git a/lib/gpu/tile_data.ml b/lib/gpu/tile_data.ml
index aa129da..73bdc0b 100644
--- a/lib/gpu/tile_data.ml
+++ b/lib/gpu/tile_data.ml
@@ -18,6 +18,7 @@ let create ~tile_data_ram ~area1_start_addr ~area0_start_addr = {
   area0_start_addr;
 }
 
+(* TODO: Optimize *)
 let get_pixel t ~area ~(index:uint8) ~row ~col =
   let row_offset = 2 * row |> Uint16.of_int in
   let low_bit_row_addr = match area with
diff --git a/test/unit_tests/test_gpu.ml b/test/unit_tests/test_gpu.ml
index 0508568..6e41b32 100644
--- a/test/unit_tests/test_gpu.ml
+++ b/test/unit_tests/test_gpu.ml
@@ -24,7 +24,6 @@ let create ()=
   let oam_table = Oam_table.create
       ~start_addr:(of_int 0xFE00)
       ~end_addr:(of_int 0xFE9F)
-      ~oam_ram:(Ram.create ~start_addr:(of_int 0xFE00) ~end_addr:(of_int 0xFE9F))
   in
   Interrupt_controller.write_byte ic ~addr:(Uint16.of_int 0xFFFF) ~data:(Uint8.of_int 0xFF);
   Gpu.create
diff --git a/test/unit_tests/test_oam_table.ml b/test/unit_tests/test_oam_table.ml
index eeb4750..b2f5cbb 100644
--- a/test/unit_tests/test_oam_table.ml
+++ b/test/unit_tests/test_oam_table.ml
@@ -6,9 +6,29 @@ let create () =
   Oam_table.create
     ~start_addr:(of_int 0xFE00)
     ~end_addr:(of_int 0xFE9F)
-    ~oam_ram:(Ram.create ~start_addr:(of_int 0xFE00) ~end_addr:(of_int 0xFE9F))
 
-let%expect_test "test" =
+let%expect_test "test write then read" =
+  let t = create () in
+
+  let addr0 = Uint16.(of_int 0xFE00 + of_int 2 * of_int 4) in
+  let addr1 = Uint16.(addr0 + one) in
+  let addr2 = Uint16.(addr0 + of_int 2) in
+  let addr3 = Uint16.(addr0 + of_int 3) in
+  Oam_table.write_byte t ~addr:addr0 ~data:Uint8.(of_int 0x78);
+  Oam_table.write_byte t ~addr:addr1 ~data:Uint8.(of_int 0x4D);
+  Oam_table.write_byte t ~addr:addr2 ~data:Uint8.(of_int 0x90);
+  Oam_table.write_byte t ~addr:addr3 ~data:Uint8.(of_int 0x30);
+
+  [ Oam_table.read_byte t addr0;
+    Oam_table.read_byte t addr1;
+    Oam_table.read_byte t addr2;
+    Oam_table.read_byte t addr3; ]
+  |> List.iter (fun x -> Printf.printf "%s " (Uint8.show x));
+
+  [%expect {| $78 $4D $90 $30 |}]
+
+
+let%expect_test "test get_all_sprites" =
   let t = create () in
 
   let offset = Uint16.(of_int 0xFE00 + of_int 2 * of_int 4) in
@@ -18,10 +38,11 @@ let%expect_test "test" =
   Oam_table.write_byte t ~addr:Uint16.(offset + of_int 3) ~data:Uint8.(of_int 0x30);
 
   Oam_table.get_all_sprites t
-  |> (fun l -> List.nth l 2)
+  |> (fun a -> Array.get a 2)
   |> Oam_table.show_sprite
   |> print_endline;
 
   [%expect {|
     { Oam_table.y_pos = 104; x_pos = 69; tile_index = $90;
-      priority = `Sprite_top; y_flip = false; x_flip = true; pallete = `OBP1 } |}]
+      priority = `Sprite_top; y_flip = false; x_flip = true; pallete = `OBP1;
+      tile_vram_bank = `Bank0; pallete_num = 0 } |}]