diff --git a/src/processor/gpu.rs b/src/processor/gpu.rs
index 0534e39..af711fe 100644
--- a/src/processor/gpu.rs
+++ b/src/processor/gpu.rs
@@ -1,122 +1,17 @@
-use self::tile_window::TileWindow;
+use self::{
+    tile_window::TileWindow,
+    types::{
+        Colour, DrawMode, ObjSize, Object, ObjectFlags, Palette, TiledataArea, TilemapArea, LCDC,
+    },
+};
 use crate::{
-    processor::{as_signed, get_bit, set_bit, set_or_clear_bit, CPU},
+    processor::{get_bit, set_bit, set_or_clear_bit, CPU},
     FACTOR, HEIGHT, WIDTH,
 };
 use minifb::{Window, WindowOptions};
 
 mod tile_window;
-
-#[derive(PartialEq)]
-enum DrawMode {
-    HBlank,
-    VBlank,
-    Mode2,
-    Mode3,
-}
-
-#[derive(Debug)]
-enum TilemapArea {
-    T9800,
-    T9C00,
-}
-
-impl TilemapArea {
-    fn get_addr(&self, addr: u16) -> u16 {
-        match self {
-            TilemapArea::T9800 => 0x9800 + addr,
-            TilemapArea::T9C00 => 0x9C00 + addr,
-        }
-    }
-}
-
-#[derive(Debug)]
-enum TiledataArea {
-    D8000,
-    D9000,
-}
-
-impl TiledataArea {
-    fn get_addr(&self, addr: u8) -> u16 {
-        match self {
-            TiledataArea::D8000 => 0x8000 + ((addr as u16) * 16),
-            TiledataArea::D9000 => 0x9000_u16.wrapping_add_signed((as_signed(addr) as i16) * 16),
-        }
-    }
-}
-
-#[derive(Debug, PartialEq)]
-enum ObjSize {
-    S8x8,
-    S8x16,
-}
-
-impl ObjSize {
-    fn get_height(&self) -> u8 {
-        match self {
-            ObjSize::S8x8 => 8,
-            ObjSize::S8x16 => 16,
-        }
-    }
-}
-
-#[derive(Debug)]
-struct LCDC {
-    enable: bool,
-    window_tilemap: TilemapArea,
-    window_enable: bool,
-    tile_area: TiledataArea,
-    bg_tilemap: TilemapArea,
-    obj_size: ObjSize,
-    obj_enable: bool,
-    bg_window_enable: bool,
-}
-
-#[derive(Clone, Copy, Debug)]
-enum Colour {
-    White,
-    LightGray,
-    DarkGray,
-    Black,
-}
-
-impl Colour {
-    fn to_rgb(&self) -> u32 {
-        match self {
-            Colour::White => Self::from_u8_rgb(0xFF, 0xFF, 0xFF),
-            Colour::LightGray => Self::from_u8_rgb(0xAA, 0xAA, 0xAA),
-            Colour::DarkGray => Self::from_u8_rgb(0x55, 0x55, 0x55),
-            Colour::Black => Self::from_u8_rgb(0x00, 0x00, 0x00),
-        }
-    }
-
-    fn from_u8_rgb(r: u8, g: u8, b: u8) -> u32 {
-        let (r, g, b) = (r as u32, g as u32, b as u32);
-        (r << 16) | (g << 8) | b
-    }
-}
-
-#[derive(Clone, Copy)]
-struct Palette {
-    zero: Colour,
-    one: Colour,
-    two: Colour,
-    three: Colour,
-}
-
-struct ObjectFlags {
-    behind_bg_and_window: bool,
-    y_flip: bool,
-    x_flip: bool,
-    palette: Palette,
-}
-
-struct Object {
-    x: u8,
-    y: u8,
-    tile_index: u8,
-    flags: ObjectFlags,
-}
+mod types;
 
 const TILE_WINDOW_WIDTH: usize = 16 * 8;
 const TILE_WINDOW_HEIGHT: usize = 24 * 8;
diff --git a/src/processor/gpu/types.rs b/src/processor/gpu/types.rs
new file mode 100644
index 0000000..3b37887
--- /dev/null
+++ b/src/processor/gpu/types.rs
@@ -0,0 +1,112 @@
+use crate::processor::as_signed;
+
+#[derive(PartialEq)]
+pub(super) enum DrawMode {
+    HBlank,
+    VBlank,
+    Mode2,
+    Mode3,
+}
+
+#[derive(Debug)]
+pub(super) enum TilemapArea {
+    T9800,
+    T9C00,
+}
+
+impl TilemapArea {
+    pub(super) fn get_addr(&self, addr: u16) -> u16 {
+        match self {
+            TilemapArea::T9800 => 0x9800 + addr,
+            TilemapArea::T9C00 => 0x9C00 + addr,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub(super) enum TiledataArea {
+    D8000,
+    D9000,
+}
+
+impl TiledataArea {
+    pub(super) fn get_addr(&self, addr: u8) -> u16 {
+        match self {
+            TiledataArea::D8000 => 0x8000 + ((addr as u16) * 16),
+            TiledataArea::D9000 => 0x9000_u16.wrapping_add_signed((as_signed(addr) as i16) * 16),
+        }
+    }
+}
+
+#[derive(Debug, PartialEq)]
+pub(super) enum ObjSize {
+    S8x8,
+    S8x16,
+}
+
+impl ObjSize {
+    pub(super) fn get_height(&self) -> u8 {
+        match self {
+            ObjSize::S8x8 => 8,
+            ObjSize::S8x16 => 16,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub(super) struct LCDC {
+    pub(super) enable: bool,
+    pub(super) window_tilemap: TilemapArea,
+    pub(super) window_enable: bool,
+    pub(super) tile_area: TiledataArea,
+    pub(super) bg_tilemap: TilemapArea,
+    pub(super) obj_size: ObjSize,
+    pub(super) obj_enable: bool,
+    pub(super) bg_window_enable: bool,
+}
+
+#[derive(Clone, Copy, Debug)]
+pub(super) enum Colour {
+    White,
+    LightGray,
+    DarkGray,
+    Black,
+}
+
+impl Colour {
+    pub(super) fn to_rgb(&self) -> u32 {
+        match self {
+            Colour::White => Self::from_u8_rgb(0xFF, 0xFF, 0xFF),
+            Colour::LightGray => Self::from_u8_rgb(0xAA, 0xAA, 0xAA),
+            Colour::DarkGray => Self::from_u8_rgb(0x55, 0x55, 0x55),
+            Colour::Black => Self::from_u8_rgb(0x00, 0x00, 0x00),
+        }
+    }
+
+    pub(super) fn from_u8_rgb(r: u8, g: u8, b: u8) -> u32 {
+        let (r, g, b) = (r as u32, g as u32, b as u32);
+        (r << 16) | (g << 8) | b
+    }
+}
+
+#[derive(Clone, Copy)]
+pub(super) struct Palette {
+    pub(super) zero: Colour,
+    pub(super) one: Colour,
+    pub(super) two: Colour,
+    pub(super) three: Colour,
+}
+
+pub(super) struct ObjectFlags {
+    pub(super) behind_bg_and_window: bool,
+    pub(super) y_flip: bool,
+    pub(super) x_flip: bool,
+    pub(super) palette: Palette,
+}
+
+pub(super) struct Object {
+    pub(super) x: u8,
+    pub(super) y: u8,
+    pub(super) tile_index: u8,
+    pub(super) flags: ObjectFlags,
+}