diff --git a/Cargo.lock b/Cargo.lock
index 1ce3631..c5379a3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -217,9 +217,9 @@ dependencies = [
 
 [[package]]
 name = "async-executor"
-version = "1.12.0"
+version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c8828ec6e544c02b0d6691d21ed9f9218d0384a82542855073c2a3f58304aaf0"
+checksum = "d7ebdfa2ebdab6b1760375fa7d6f382b9f486eac35fc994625a00e89280bdbb7"
 dependencies = [
  "async-task",
  "concurrent-queue",
@@ -313,9 +313,9 @@ dependencies = [
 
 [[package]]
 name = "async-signal"
-version = "0.2.8"
+version = "0.2.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "794f185324c2f00e771cd9f1ae8b5ac68be2ca7abb129a87afd6e86d228bc54d"
+checksum = "dfb3634b73397aa844481f814fad23bbf07fdb0eabec10f2eb95e58944b1ec32"
 dependencies = [
  "async-io",
  "async-lock",
@@ -468,10 +468,10 @@ dependencies = [
 ]
 
 [[package]]
-name = "byteorder"
-version = "1.5.0"
+name = "byteorder-lite"
+version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"
+checksum = "8f1fe948ff07f4bd06c30984e69f5b4899c516a3ef74f34df92a2df2ab535495"
 
 [[package]]
 name = "bytes"
@@ -493,13 +493,39 @@ dependencies = [
  "thiserror",
 ]
 
+[[package]]
+name = "calloop"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b99da2f8558ca23c71f4fd15dc57c906239752dd27ff3c00a1d56b685b7cbfec"
+dependencies = [
+ "bitflags 2.6.0",
+ "log",
+ "polling",
+ "rustix",
+ "slab",
+ "thiserror",
+]
+
 [[package]]
 name = "calloop-wayland-source"
 version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0f0ea9b9476c7fad82841a8dbb380e2eae480c21910feba80725b46931ed8f02"
 dependencies = [
- "calloop",
+ "calloop 0.12.4",
+ "rustix",
+ "wayland-backend",
+ "wayland-client",
+]
+
+[[package]]
+name = "calloop-wayland-source"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "95a66a987056935f7efce4ab5668920b5d0dac4a7c99991a67395f13702ddd20"
+dependencies = [
+ "calloop 0.13.0",
  "rustix",
  "wayland-backend",
  "wayland-client",
@@ -507,9 +533,9 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.1.5"
+version = "1.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "324c74f2155653c90b04f25b2a47a8a631360cb908f92a772695f430c7e31052"
+checksum = "2aba8f4e9906c7ce3c73463f62a7f0c65183ada1a2d47e397cc8810827f9694f"
 dependencies = [
  "jobserver",
  "libc",
@@ -794,7 +820,7 @@ version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "330c60081dcc4c72131f8eb70510f1ac07223e5d4163db481a04a0befcffa412"
 dependencies = [
- "libloading 0.8.4",
+ "libloading 0.8.5",
 ]
 
 [[package]]
@@ -1342,7 +1368,7 @@ dependencies = [
  "glutin_glx_sys",
  "glutin_wgl_sys",
  "icrate",
- "libloading 0.8.4",
+ "libloading 0.8.5",
  "objc2 0.4.1",
  "once_cell",
  "raw-window-handle 0.5.2",
@@ -1463,7 +1489,7 @@ dependencies = [
  "bitflags 2.6.0",
  "com",
  "libc",
- "libloading 0.8.4",
+ "libloading 0.8.5",
  "thiserror",
  "widestring",
  "winapi",
@@ -1531,12 +1557,12 @@ dependencies = [
 
 [[package]]
 name = "image"
-version = "0.25.1"
+version = "0.25.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fd54d660e773627692c524beaad361aca785a4f9f5730ce91f42aabe5bce3d11"
+checksum = "99314c8a2152b8ddb211f924cdae532d8c5e4c8bb54728e12fff1b0cd5963a10"
 dependencies = [
  "bytemuck",
- "byteorder",
+ "byteorder-lite",
  "num-traits",
  "png",
 ]
@@ -1619,7 +1645,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6aae1df220ece3c0ada96b8153459b67eebe9ae9212258bb0134ae60416fdf76"
 dependencies = [
  "libc",
- "libloading 0.8.4",
+ "libloading 0.8.5",
  "pkg-config",
 ]
 
@@ -1653,9 +1679,9 @@ dependencies = [
 
 [[package]]
 name = "libloading"
-version = "0.8.4"
+version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e310b3a6b5907f99202fcdb4960ff45b93735d7c7d96b760fcff8db2dc0e103d"
+checksum = "4979f22fdb869068da03c9f7528f8297c6fd2606bc3a4affe42e6a823fdb8da4"
 dependencies = [
  "cfg-if",
  "windows-targets 0.52.6",
@@ -2552,8 +2578,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "922fd3eeab3bd820d76537ce8f582b1cf951eceb5475c28500c7457d9d17f53a"
 dependencies = [
  "bitflags 2.6.0",
- "calloop",
- "calloop-wayland-source",
+ "calloop 0.12.4",
+ "calloop-wayland-source 0.2.0",
  "cursor-icon",
  "libc",
  "log",
@@ -2564,20 +2590,45 @@ dependencies = [
  "wayland-client",
  "wayland-csd-frame",
  "wayland-cursor",
- "wayland-protocols",
- "wayland-protocols-wlr",
+ "wayland-protocols 0.31.2",
+ "wayland-protocols-wlr 0.2.0",
+ "wayland-scanner",
+ "xkeysym",
+]
+
+[[package]]
+name = "smithay-client-toolkit"
+version = "0.19.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3457dea1f0eb631b4034d61d4d8c32074caa6cd1ab2d59f2327bd8461e2c0016"
+dependencies = [
+ "bitflags 2.6.0",
+ "calloop 0.13.0",
+ "calloop-wayland-source 0.3.0",
+ "cursor-icon",
+ "libc",
+ "log",
+ "memmap2",
+ "rustix",
+ "thiserror",
+ "wayland-backend",
+ "wayland-client",
+ "wayland-csd-frame",
+ "wayland-cursor",
+ "wayland-protocols 0.32.3",
+ "wayland-protocols-wlr 0.3.3",
  "wayland-scanner",
  "xkeysym",
 ]
 
 [[package]]
 name = "smithay-clipboard"
-version = "0.7.1"
+version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c091e7354ea8059d6ad99eace06dd13ddeedbb0ac72d40a9a6e7ff790525882d"
+checksum = "cc8216eec463674a0e90f29e0ae41a4db573ec5b56b1c6c1c71615d249b6d846"
 dependencies = [
  "libc",
- "smithay-client-toolkit",
+ "smithay-client-toolkit 0.19.2",
  "wayland-backend",
 ]
 
@@ -2656,18 +2707,18 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.62"
+version = "1.0.63"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2675633b1499176c2dff06b0856a27976a8f9d436737b4cf4f312d4d91d8bbb"
+checksum = "c0342370b38b6a11b6cc11d6a805569958d54cfa061a29969c3b5ce2ea405724"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.62"
+version = "1.0.63"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d20468752b09f49e909e55a5d338caa8bedf615594e9d80bc4c565d30faf798c"
+checksum = "a4558b58466b9ad7ca0f102865eccc95938dca1a74a856f2b57b6629050da261"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2928,9 +2979,9 @@ checksum = "af190c94f2773fdb3729c55b007a722abb5384da03bc0986df4c289bf5567e96"
 
 [[package]]
 name = "wayland-backend"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "269c04f203640d0da2092d1b8d89a2d081714ae3ac2f1b53e99f205740517198"
+checksum = "f90e11ce2ca99c97b940ee83edbae9da2d56a08f9ea8158550fd77fa31722993"
 dependencies = [
  "cc",
  "downcast-rs",
@@ -2942,9 +2993,9 @@ dependencies = [
 
 [[package]]
 name = "wayland-client"
-version = "0.31.4"
+version = "0.31.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08bd0f46c069d3382a36c8666c1b9ccef32b8b04f41667ca1fef06a1adcc2982"
+checksum = "7e321577a0a165911bdcfb39cf029302479d7527b517ee58ab0f6ad09edf0943"
 dependencies = [
  "bitflags 2.6.0",
  "rustix",
@@ -2965,9 +3016,9 @@ dependencies = [
 
 [[package]]
 name = "wayland-cursor"
-version = "0.31.4"
+version = "0.31.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "09414bcf0fd8d9577d73e9ac4659ebc45bcc9cff1980a350543ad8e50ee263b2"
+checksum = "6ef9489a8df197ebf3a8ce8a7a7f0a2320035c3743f3c1bd0bdbccf07ce64f95"
 dependencies = [
  "rustix",
  "wayland-client",
@@ -2986,6 +3037,18 @@ dependencies = [
  "wayland-scanner",
 ]
 
+[[package]]
+name = "wayland-protocols"
+version = "0.32.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62989625a776e827cc0f15d41444a3cea5205b963c3a25be48ae1b52d6b4daaa"
+dependencies = [
+ "bitflags 2.6.0",
+ "wayland-backend",
+ "wayland-client",
+ "wayland-scanner",
+]
+
 [[package]]
 name = "wayland-protocols-plasma"
 version = "0.2.0"
@@ -2995,7 +3058,7 @@ dependencies = [
  "bitflags 2.6.0",
  "wayland-backend",
  "wayland-client",
- "wayland-protocols",
+ "wayland-protocols 0.31.2",
  "wayland-scanner",
 ]
 
@@ -3008,15 +3071,28 @@ dependencies = [
  "bitflags 2.6.0",
  "wayland-backend",
  "wayland-client",
- "wayland-protocols",
+ "wayland-protocols 0.31.2",
+ "wayland-scanner",
+]
+
+[[package]]
+name = "wayland-protocols-wlr"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd993de54a40a40fbe5601d9f1fbcaef0aebcc5fda447d7dc8f6dcbaae4f8953"
+dependencies = [
+ "bitflags 2.6.0",
+ "wayland-backend",
+ "wayland-client",
+ "wayland-protocols 0.32.3",
  "wayland-scanner",
 ]
 
 [[package]]
 name = "wayland-scanner"
-version = "0.31.3"
+version = "0.31.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "edf466fc49a4feb65a511ca403fec3601494d0dee85dbf37fff6fa0dd4eec3b6"
+checksum = "d7b56f89937f1cf2ee1f1259cf2936a17a1f45d8f0aa1019fae6d470d304cfa6"
 dependencies = [
  "proc-macro2",
  "quick-xml",
@@ -3025,9 +3101,9 @@ dependencies = [
 
 [[package]]
 name = "wayland-sys"
-version = "0.31.3"
+version = "0.31.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a6754825230fa5b27bafaa28c30b3c9e72c55530581220cef401fa422c0fae7"
+checksum = "43676fe2daf68754ecf1d72026e4e6c15483198b5d24e888b74d3f22f887a148"
 dependencies = [
  "dlib",
  "log",
@@ -3146,7 +3222,7 @@ dependencies = [
  "js-sys",
  "khronos-egl",
  "libc",
- "libloading 0.8.4",
+ "libloading 0.8.5",
  "log",
  "metal",
  "naga",
@@ -3449,7 +3525,7 @@ dependencies = [
  "atomic-waker",
  "bitflags 2.6.0",
  "bytemuck",
- "calloop",
+ "calloop 0.12.4",
  "cfg_aliases 0.1.1",
  "core-foundation",
  "core-graphics",
@@ -3469,14 +3545,14 @@ dependencies = [
  "raw-window-handle 0.6.2",
  "redox_syscall 0.3.5",
  "rustix",
- "smithay-client-toolkit",
+ "smithay-client-toolkit 0.18.1",
  "smol_str",
  "unicode-segmentation",
  "wasm-bindgen",
  "wasm-bindgen-futures",
  "wayland-backend",
  "wayland-client",
- "wayland-protocols",
+ "wayland-protocols 0.31.2",
  "wayland-protocols-plasma",
  "web-sys",
  "web-time",
@@ -3515,7 +3591,7 @@ dependencies = [
  "as-raw-xcb-connection",
  "gethostname",
  "libc",
- "libloading 0.8.4",
+ "libloading 0.8.5",
  "once_cell",
  "rustix",
  "x11rb-protocol",
@@ -3529,9 +3605,9 @@ checksum = "ec107c4503ea0b4a98ef47356329af139c0a4f7750e621cf2973cd3385ebcb3d"
 
 [[package]]
 name = "xcursor"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a0ccd7b4a5345edfcd0c3535718a4e9ff7798ffc536bb5b5a0e26ff84732911"
+checksum = "d491ee231a51ae64a5b762114c3ac2104b967aadba1de45c86ca42cf051513b7"
 
 [[package]]
 name = "xdg-home"
diff --git a/Cargo.toml b/Cargo.toml
index bd2b72a..c9584ea 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -53,7 +53,7 @@ egui = "0.28.1"
 enum_dispatch = "0.3.13"
 env_logger = "0.11.3"
 gb-core = { path = "./core/gb-core" }
-image = { version = "0.25.1", default-features = false }
+image = { version = "0.25.2", default-features = false }
 itertools = "0.13.0"
 libretro-rs = "0.1.3"
 log = "0.4.22"
@@ -63,6 +63,6 @@ rfd = "0.14.1"
 sdl2 = "0.37.0"
 serde = { version = "1.0.204", features = ["derive"] }
 serde_json = "1.0.120"
-thiserror = "1.0.62"
+thiserror = "1.0.63"
 wasm-bindgen = "0.2.92"
 web-sys = "0.3.69"
diff --git a/DEVELOPMENT.md b/DEVELOPMENT.md
index 92cc294..2ab8535 100644
--- a/DEVELOPMENT.md
+++ b/DEVELOPMENT.md
@@ -25,9 +25,27 @@ cargo +nightly fmt --all && cargo clippy --all-targets
 https://github.com/flamegraph-rs/flamegraph
 
 ```sh
+# cargo
+cargo install flamegraph
+
 # Arch
 sudo pacman -S cargo-flamegraph
 
 cargo flamegraph --dev -- roms/rom.gb
 CARGO_PROFILE_RELEASE_DEBUG=true cargo flamegraph -- roms/rom.gb
 ```
+
+## Upgrading packages
+
+```sh
+# cargo
+cargo install cargo-edit
+
+# brew
+brew install cargo-edit
+
+# Arch
+sudo pacman -S cargo-edit
+
+cargo upgrade -i && cargo update
+```
diff --git a/core/gb-core/src/cartridge.rs b/core/gb-core/src/cartridge.rs
index 2599c32..055d209 100644
--- a/core/gb-core/src/cartridge.rs
+++ b/core/gb-core/src/cartridge.rs
@@ -61,8 +61,11 @@ impl Cartridge {
         log::info!("RAM banks: {ram_banks}");
         log::info!("CGB flag: {cgb_flag}");
         log::info!("SGB flag: {sgb_flag:?}");
-        log::info!("Old licensee code: {:#04X}", licensee_code.old());
-        log::info!("New licensee code: {}", licensee_code.new_as_string());
+        log::info!("Old licensee code: {:#04X}", licensee_code.old_code());
+        log::info!(
+            "New licensee code: {}",
+            licensee_code.new_code().unwrap_or("--")
+        );
 
         Ok(Self {
             rom,
diff --git a/core/gb-core/src/cartridge/compatibility_palettes.rs b/core/gb-core/src/cartridge/compatibility_palettes.rs
index ed799f3..944389b 100644
--- a/core/gb-core/src/cartridge/compatibility_palettes.rs
+++ b/core/gb-core/src/cartridge/compatibility_palettes.rs
@@ -2,12 +2,11 @@
 // 1. https://gbdev.io/pandocs/Power_Up_Sequence.html#compatibility-palettes
 // 2. https://github.com/LIJI32/SameBoy/blob/master/BootROMs/cgb_boot.asm
 
-use self::{
-    palette_combinations::PALETTE_COMBINATIONS,
-    palette_id_lookup_table::PALETTE_ID_LOOKUP_TABLE,
-    title_checksum_lookup_table::TITLE_CHECKSUM_LOOKUP_TABLE,
-};
-use super::{licensee_code::LicenseeCode, title::Title};
+use palette_id::get_palette_id;
+use palette_id_index::get_palette_id_index;
+use palettes::get_palettes_from_id;
+
+use crate::cartridge::{licensee_code::LicenseeCode, title::Title};
 
 pub struct CompatibilityPalettes {
     pub bg0: [u16; 4],
@@ -16,49 +15,24 @@ pub struct CompatibilityPalettes {
 }
 
 impl CompatibilityPalettes {
-    pub const DEFAULT: Self = PALETTE_COMBINATIONS[0].into_palettes();
+    pub const DEFAULT: Self = get_palettes_from_id(0);
 
     pub fn from_header_info(licensee_code: &LicenseeCode, title: &Title) -> Self {
-        match licensee_code.old() {
-            0x33 => {
-                if !(licensee_code.new_as_string() == "01"
-                    || u16::from_le_bytes(*licensee_code.new_as_bytes()) == 0x01)
-                {
-                    return Self::DEFAULT;
-                }
-            }
-
-            0x01 => (),
-
-            _ => return Self::DEFAULT,
-        };
-
-        let title_checksum = title.checksum();
+        if !licensee_code.is_nintendo() {
+            return Self::DEFAULT;
+        }
 
-        let Some(checksum_index) = TITLE_CHECKSUM_LOOKUP_TABLE
-            .into_iter()
-            .position(|x| x == title_checksum)
-        else {
+        let Some(palette_id_index) = get_palette_id_index(title) else {
             return Self::DEFAULT;
         };
 
-        let palette_id = if checksum_index <= 64 {
-            PALETTE_ID_LOOKUP_TABLE[checksum_index]
-        } else {
-            let fourth_byte = title.as_bytes()[3];
-            let row = title_row_lookup_table::find_row(checksum_index - 65, fourth_byte);
-            let index = checksum_index + (14 * row);
-
-            PALETTE_ID_LOOKUP_TABLE[index]
-        };
+        let palette_id = get_palette_id(palette_id_index);
 
-        PALETTE_COMBINATIONS[palette_id].into_palettes()
+        get_palettes_from_id(palette_id)
     }
 }
 
-mod palette_combinations;
-mod palette_id_lookup_table;
-mod palette_lookup_table;
-mod palette_lookup_type;
-mod title_checksum_lookup_table;
-mod title_row_lookup_table;
+mod palette;
+mod palette_id;
+mod palette_id_index;
+mod palettes;
diff --git a/core/gb-core/src/cartridge/compatibility_palettes/palette_lookup_table.rs b/core/gb-core/src/cartridge/compatibility_palettes/palette.rs
similarity index 89%
rename from core/gb-core/src/cartridge/compatibility_palettes/palette_lookup_table.rs
rename to core/gb-core/src/cartridge/compatibility_palettes/palette.rs
index 1e9b43a..1d49903 100644
--- a/core/gb-core/src/cartridge/compatibility_palettes/palette_lookup_table.rs
+++ b/core/gb-core/src/cartridge/compatibility_palettes/palette.rs
@@ -2,7 +2,10 @@
 // 1. https://gbdev.io/pandocs/Power_Up_Sequence.html#compatibility-palettes
 // 2. https://github.com/LIJI32/SameBoy/blob/master/BootROMs/cgb_boot.asm
 
-pub const fn from_index_start(id: usize) -> [u16; 4] {
+/// **Fourth step**
+///
+/// Returns the palette from the id obtained in the previous step.
+pub const fn palette_from_id(id: usize) -> [u16; 4] {
     [
         PALETTE_LOOKUP_TABLE[id],
         PALETTE_LOOKUP_TABLE[id + 1],
@@ -11,7 +14,7 @@ pub const fn from_index_start(id: usize) -> [u16; 4] {
     ]
 }
 
-pub const PALETTE_LOOKUP_TABLE: [u16; 120] = [
+const PALETTE_LOOKUP_TABLE: [u16; 120] = [
     0x7FFF, 0x32BF, 0x00D0, 0x0000, // 0
     0x639F, 0x4279, 0x15B0, 0x04CB, // 1
     0x7FFF, 0x6E31, 0x454A, 0x0000, // 2
diff --git a/core/gb-core/src/cartridge/compatibility_palettes/palette_id_lookup_table.rs b/core/gb-core/src/cartridge/compatibility_palettes/palette_id.rs
similarity index 89%
rename from core/gb-core/src/cartridge/compatibility_palettes/palette_id_lookup_table.rs
rename to core/gb-core/src/cartridge/compatibility_palettes/palette_id.rs
index 4b93781..a38bc63 100644
--- a/core/gb-core/src/cartridge/compatibility_palettes/palette_id_lookup_table.rs
+++ b/core/gb-core/src/cartridge/compatibility_palettes/palette_id.rs
@@ -2,7 +2,15 @@
 // 1. https://gbdev.io/pandocs/Power_Up_Sequence.html#compatibility-palettes
 // 2. https://github.com/LIJI32/SameBoy/blob/master/BootROMs/cgb_boot.asm
 
-pub const PALETTE_ID_LOOKUP_TABLE: [usize; 94] = [
+/// **Second step**
+///
+/// Used to obtain the palette id given its index from the lookup table.
+pub const fn get_palette_id(index: usize) -> usize {
+    PALETTE_ID[index]
+}
+
+/// Indexeded by the index of the title checksum.
+const PALETTE_ID: [usize; 94] = [
     0,  // Default Palette
     4,  // ALLEY WAY
     5,  // YAKUMAN
diff --git a/core/gb-core/src/cartridge/compatibility_palettes/palette_id_index.rs b/core/gb-core/src/cartridge/compatibility_palettes/palette_id_index.rs
new file mode 100644
index 0000000..9f6d2c0
--- /dev/null
+++ b/core/gb-core/src/cartridge/compatibility_palettes/palette_id_index.rs
@@ -0,0 +1,63 @@
+// Taken from
+// 1. https://gbdev.io/pandocs/Power_Up_Sequence.html#compatibility-palettes
+// 2. https://github.com/LIJI32/SameBoy/blob/master/BootROMs/cgb_boot.asm
+
+use crate::cartridge::title::Title;
+
+/// **First step**
+///
+/// Used to obtain the index of the palette id.
+pub fn get_palette_id_index(title: &Title) -> Option<usize> {
+    let title_checksum = title.checksum();
+
+    let checksum_index = TITLE_CHECKSUM
+        .into_iter()
+        .position(|x| x == title_checksum)?;
+
+    if checksum_index <= 64 {
+        Some(checksum_index)
+    } else {
+        let fourth_byte = title.as_bytes()[3];
+        let row = find_title_row(checksum_index - 65, fourth_byte);
+        let index = checksum_index + (14 * row);
+
+        Some(index)
+    }
+}
+
+/// The index will be the index that corresponds to the value of the title checksum in this table.
+const TITLE_CHECKSUM: [u8; 79] = [
+    0x00, 0x88, 0x16, 0x36, 0xD1, 0xDB, 0xF2, 0x3C, 0x8C, 0x92, 0x3D, 0x5C, 0x58, 0xC9, 0x3E, 0x70,
+    0x1D, 0x59, 0x69, 0x19, 0x35, 0xA8, 0x14, 0xAA, 0x75, 0x95, 0x99, 0x34, 0x6F, 0x15, 0xFF, 0x97,
+    0x4B, 0x90, 0x17, 0x10, 0x39, 0xF7, 0xF6, 0xA2, 0x49, 0x4E, 0x43, 0x68, 0xE0, 0x8B, 0xF0, 0xCE,
+    0x0C, 0x29, 0xE8, 0xB7, 0x86, 0x9A, 0x52, 0x01, 0x9D, 0x71, 0x9C, 0xBD, 0x5D, 0x6D, 0x67, 0x3F,
+    0x6B, // <-- 64
+    // Ambiguous. Refer to the fourth byte in the title if the index is >64.
+    0xB3, 0x46, 0x28, 0xA5, 0xC6, 0xD3, 0x27, 0x61, 0x18, 0x66, 0x6A, 0xBF, 0x0D, 0xF4,
+];
+
+/// If the index of the checksum is <= 64, don't use this.
+/// If > 64, this will return the index of the palette id lookup table.
+fn find_title_row(column: usize, fourth_byte: u8) -> usize {
+    const TITLE_ROW_LOOKUP_TABLE: [&str; 3] = ["BEFAARBEKEK R-", "URAR INAILICE ", "R"];
+
+    if let Some(ch) = TITLE_ROW_LOOKUP_TABLE[0].as_bytes().get(column) {
+        if *ch == fourth_byte {
+            return 0;
+        }
+    }
+
+    if let Some(ch) = TITLE_ROW_LOOKUP_TABLE[1].as_bytes().get(column) {
+        if *ch == fourth_byte {
+            return 1;
+        }
+    }
+
+    if let Some(ch) = TITLE_ROW_LOOKUP_TABLE[2].as_bytes().get(column) {
+        if *ch == fourth_byte {
+            return 2;
+        }
+    }
+
+    0
+}
diff --git a/core/gb-core/src/cartridge/compatibility_palettes/palette_lookup_type.rs b/core/gb-core/src/cartridge/compatibility_palettes/palette_lookup_type.rs
deleted file mode 100644
index db826a1..0000000
--- a/core/gb-core/src/cartridge/compatibility_palettes/palette_lookup_type.rs
+++ /dev/null
@@ -1,27 +0,0 @@
-// Taken from
-// 1. https://gbdev.io/pandocs/Power_Up_Sequence.html#compatibility-palettes
-// 2. https://github.com/LIJI32/SameBoy/blob/master/BootROMs/cgb_boot.asm
-
-use super::{palette_lookup_table::from_index_start, CompatibilityPalettes};
-
-/// (OBJ0, OBJ1, BG0)
-#[derive(Debug, Clone, Copy)]
-pub enum PaletteLookupKind {
-    Normal(usize, usize, usize),
-    Raw(usize, usize, usize),
-}
-
-impl PaletteLookupKind {
-    pub const fn into_palettes(self) -> CompatibilityPalettes {
-        let (obj0, obj1, bg0) = match self {
-            Self::Normal(obj0, obj1, bg0) => (obj0 * 4, obj1 * 4, bg0 * 4),
-            Self::Raw(obj0, obj1, bg0) => (obj0, obj1, bg0),
-        };
-
-        CompatibilityPalettes {
-            bg0: from_index_start(bg0),
-            obj0: from_index_start(obj0),
-            obj1: from_index_start(obj1),
-        }
-    }
-}
diff --git a/core/gb-core/src/cartridge/compatibility_palettes/palette_combinations.rs b/core/gb-core/src/cartridge/compatibility_palettes/palettes.rs
similarity index 61%
rename from core/gb-core/src/cartridge/compatibility_palettes/palette_combinations.rs
rename to core/gb-core/src/cartridge/compatibility_palettes/palettes.rs
index 88589d3..d35d42a 100644
--- a/core/gb-core/src/cartridge/compatibility_palettes/palette_combinations.rs
+++ b/core/gb-core/src/cartridge/compatibility_palettes/palettes.rs
@@ -2,10 +2,36 @@
 // 1. https://gbdev.io/pandocs/Power_Up_Sequence.html#compatibility-palettes
 // 2. https://github.com/LIJI32/SameBoy/blob/master/BootROMs/cgb_boot.asm
 
-use super::palette_lookup_type::PaletteLookupKind::{self, Normal, Raw};
+use super::palette::palette_from_id;
+use crate::cartridge::compatibility_palettes::CompatibilityPalettes;
+
+/// **Third step**
+///
+/// From the palette id, get each palette for BG0, OBJ1 and OBJ2.
+pub const fn get_palettes_from_id(id: usize) -> CompatibilityPalettes {
+    let (obj0, obj1, bg0) = match PALETTE_COMBINATIONS[id] {
+        PaletteLookupKind::Normal(obj0, obj1, bg0) => (obj0 * 4, obj1 * 4, bg0 * 4),
+        PaletteLookupKind::Raw(obj0, obj1, bg0) => (obj0, obj1, bg0),
+    };
+
+    CompatibilityPalettes {
+        bg0: palette_from_id(bg0),
+        obj0: palette_from_id(obj0),
+        obj1: palette_from_id(obj1),
+    }
+}
+
+/// (OBJ0, OBJ1, BG0)
+#[derive(Debug, Clone, Copy)]
+enum PaletteLookupKind {
+    Normal(usize, usize, usize),
+    Raw(usize, usize, usize),
+}
+
+use PaletteLookupKind::{Normal, Raw};
 
 #[allow(clippy::erasing_op)]
-pub const PALETTE_COMBINATIONS: [PaletteLookupKind; 51] = [
+const PALETTE_COMBINATIONS: [PaletteLookupKind; 51] = [
     Normal(4, 4, 29),
     Normal(18, 18, 18),
     Normal(20, 20, 20),
diff --git a/core/gb-core/src/cartridge/compatibility_palettes/title_checksum_lookup_table.rs b/core/gb-core/src/cartridge/compatibility_palettes/title_checksum_lookup_table.rs
deleted file mode 100644
index a1d8e7e..0000000
--- a/core/gb-core/src/cartridge/compatibility_palettes/title_checksum_lookup_table.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-// Taken from
-// 1. https://gbdev.io/pandocs/Power_Up_Sequence.html#compatibility-palettes
-// 2. https://github.com/LIJI32/SameBoy/blob/master/BootROMs/cgb_boot.asm
-
-pub const TITLE_CHECKSUM_LOOKUP_TABLE: [u8; 79] = [
-    0x00, 0x88, 0x16, 0x36, 0xD1, 0xDB, 0xF2, 0x3C, 0x8C, 0x92, 0x3D, 0x5C, 0x58, 0xC9, 0x3E, 0x70,
-    0x1D, 0x59, 0x69, 0x19, 0x35, 0xA8, 0x14, 0xAA, 0x75, 0x95, 0x99, 0x34, 0x6F, 0x15, 0xFF, 0x97,
-    0x4B, 0x90, 0x17, 0x10, 0x39, 0xF7, 0xF6, 0xA2, 0x49, 0x4E, 0x43, 0x68, 0xE0, 0x8B, 0xF0, 0xCE,
-    0x0C, 0x29, 0xE8, 0xB7, 0x86, 0x9A, 0x52, 0x01, 0x9D, 0x71, 0x9C, 0xBD, 0x5D, 0x6D, 0x67, 0x3F,
-    0x6B, //
-    // Ambiguous. Refer to the fourth letter.
-    0xB3, 0x46, 0x28, 0xA5, 0xC6, 0xD3, 0x27, 0x61, 0x18, 0x66, 0x6A, 0xBF, 0x0D, 0xF4,
-];
diff --git a/core/gb-core/src/cartridge/compatibility_palettes/title_row_lookup_table.rs b/core/gb-core/src/cartridge/compatibility_palettes/title_row_lookup_table.rs
deleted file mode 100644
index 403a214..0000000
--- a/core/gb-core/src/cartridge/compatibility_palettes/title_row_lookup_table.rs
+++ /dev/null
@@ -1,27 +0,0 @@
-// Taken from
-// 1. https://gbdev.io/pandocs/Power_Up_Sequence.html#compatibility-palettes
-// 2. https://github.com/LIJI32/SameBoy/blob/master/BootROMs/cgb_boot.asm
-
-pub const TITLE_ROW_LOOKUP_TABLE: [&str; 3] = ["BEFAARBEKEK R-", "URAR INAILICE ", "R"];
-
-pub fn find_row(column: usize, byte: u8) -> usize {
-    if let Some(ch) = TITLE_ROW_LOOKUP_TABLE[0].as_bytes().get(column) {
-        if *ch == byte {
-            return 0;
-        }
-    }
-
-    if let Some(ch) = TITLE_ROW_LOOKUP_TABLE[1].as_bytes().get(column) {
-        if *ch == byte {
-            return 1;
-        }
-    }
-
-    if let Some(ch) = TITLE_ROW_LOOKUP_TABLE[2].as_bytes().get(column) {
-        if *ch == byte {
-            return 2;
-        }
-    }
-
-    0
-}
diff --git a/core/gb-core/src/cartridge/header.rs b/core/gb-core/src/cartridge/header.rs
index 6505bf3..bc4856a 100644
--- a/core/gb-core/src/cartridge/header.rs
+++ b/core/gb-core/src/cartridge/header.rs
@@ -2,8 +2,8 @@ use super::error::Error;
 
 /// Not the actual start, we're starting at 0 for convenience, as 0..0x100 is the bootrom area.
 /// The actual start is at 0x100.
-pub const HEADER_START: usize = 0;
-pub const HEADER_END: usize = 0x014F;
+const HEADER_START: usize = 0;
+const HEADER_END: usize = 0x014F;
 
 pub const HEADER_SIZE: usize = HEADER_START + HEADER_END + 1;
 
diff --git a/core/gb-core/src/cartridge/licensee_code.rs b/core/gb-core/src/cartridge/licensee_code.rs
index 1b7ed35..1c43e62 100644
--- a/core/gb-core/src/cartridge/licensee_code.rs
+++ b/core/gb-core/src/cartridge/licensee_code.rs
@@ -1,42 +1,131 @@
 use super::{error::Error, header::Header};
 
-pub const OLD_LICENSEE_CODE_ADDRESS: usize = 0x014B;
+const OLD_LICENSEE_CODE_ADDRESS: usize = 0x014B;
 
-pub const NEW_LICENSEE_CODE_ADDRESS_BEGIN: usize = 0x0144;
-pub const NEW_LICENSEE_CODE_ADDRESS_END: usize = 0x0145;
+const NEW_LICENSEE_CODE_ADDRESS_BEGIN: usize = 0x0144;
+const NEW_LICENSEE_CODE_ADDRESS_END: usize = 0x0145;
 
 pub struct LicenseeCode {
-    old: u8,
-    new_bytes: [u8; 2],
+    old_code: u8,
+    new_code: Option<String>,
 }
 
 impl LicenseeCode {
     pub fn from_header(header: &Header) -> Result<Self, Error> {
-        let old_licensee_code = header[OLD_LICENSEE_CODE_ADDRESS];
-        let new_licensee_code_bytes =
-            &header[NEW_LICENSEE_CODE_ADDRESS_BEGIN..=NEW_LICENSEE_CODE_ADDRESS_END];
+        let old_code = header[OLD_LICENSEE_CODE_ADDRESS];
 
-        Ok(Self {
-            old: old_licensee_code,
-            new_bytes: new_licensee_code_bytes
+        let new_code = if old_code == 0x33 {
+            let new_bytes: [u8; 2] = header
+                [NEW_LICENSEE_CODE_ADDRESS_BEGIN..=NEW_LICENSEE_CODE_ADDRESS_END]
                 .try_into()
-                .map_err(|_err| Error::InvalidRom)?,
-        })
+                .map_err(|_err| Error::InvalidRom)?;
+
+            Some(Self::new_bytes_to_string(new_bytes))
+        } else {
+            None
+        };
+
+        Ok(Self { old_code, new_code })
     }
 
-    pub fn old(&self) -> u8 {
-        self.old
+    pub fn old_code(&self) -> u8 {
+        self.old_code
     }
 
-    pub fn new_as_bytes(&self) -> &[u8; 2] {
-        &self.new_bytes
+    pub fn new_code(&self) -> Option<&str> {
+        self.new_code.as_deref()
     }
 
-    pub fn new_as_string(&self) -> String {
-        String::from_utf8_lossy(&self.new_bytes)
-            .trim()
+    pub fn is_nintendo(&self) -> bool {
+        (self.old_code() == 0x01) || (self.old_code() == 0x33 && self.new_code() == Some("01"))
+    }
+
+    fn new_bytes_to_string(bytes: [u8; 2]) -> String {
+        String::from_utf8_lossy(&bytes)
             .chars()
-            .filter(char::is_ascii)
+            .map(|c| if c.is_alphanumeric() { c } else { '?' })
             .collect()
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::cartridge::header::HEADER_SIZE;
+
+    #[test]
+    fn test_old_licensee_code() {
+        // 0x01
+        let header = generate_header(0x01, [0, 0]);
+        let licensee_code = LicenseeCode::from_header(&header).unwrap();
+
+        assert_eq!(licensee_code.old_code(), 0x01);
+        assert!(licensee_code.is_nintendo());
+
+        // 0x42 (not Nintendo)
+        let header = generate_header(0x42, [0, 0]);
+        let licensee_code = LicenseeCode::from_header(&header).unwrap();
+
+        assert_eq!(licensee_code.old_code(), 0x42);
+        assert!(!licensee_code.is_nintendo());
+    }
+
+    #[test]
+    fn test_new_licensee_code() {
+        let header = generate_header(0x33, [b'0', b'1']);
+        let licensee_code = LicenseeCode::from_header(&header).unwrap();
+
+        assert_eq!(licensee_code.new_code(), Some("01"));
+        assert!(licensee_code.is_nintendo());
+
+        let header = generate_header(0x33, [b'4', b'2']);
+        let licensee_code = LicenseeCode::from_header(&header).unwrap();
+
+        assert_eq!(licensee_code.new_code(), Some("42"));
+        assert!(!licensee_code.is_nintendo());
+
+        let header = generate_header(0x33, [b'A', b'B']);
+        let licensee_code = LicenseeCode::from_header(&header).unwrap();
+
+        assert_eq!(licensee_code.new_code(), Some("AB"));
+        assert!(!licensee_code.is_nintendo());
+    }
+
+    #[test]
+    fn test_invalid_new_licensee_code() {
+        let header = generate_header(0x42, [1, 2]);
+        let licensee_code = LicenseeCode::from_header(&header).unwrap();
+
+        assert_eq!(licensee_code.new_code(), None);
+
+        let header = generate_header(0x42, [1, b'2']);
+        let licensee_code = LicenseeCode::from_header(&header).unwrap();
+
+        assert_eq!(licensee_code.new_code(), None);
+    }
+
+    #[test]
+    fn test_weird_new_licensee_code() {
+        let header = generate_header(0x33, [1, 2]);
+        let licensee_code = LicenseeCode::from_header(&header).unwrap();
+
+        assert_eq!(licensee_code.new_code(), Some("??"));
+
+        let header = generate_header(0x33, [1, b'2']);
+        let licensee_code = LicenseeCode::from_header(&header).unwrap();
+
+        assert_eq!(licensee_code.new_code(), Some("?2"));
+    }
+
+    fn generate_header(old: u8, new: [u8; 2]) -> Header {
+        let mut header = [0; HEADER_SIZE];
+
+        header[OLD_LICENSEE_CODE_ADDRESS] = old;
+
+        let new_code_slice =
+            &mut header[NEW_LICENSEE_CODE_ADDRESS_BEGIN..=NEW_LICENSEE_CODE_ADDRESS_END];
+        new_code_slice.copy_from_slice(&new);
+
+        header
+    }
+}