diff --git a/src/cpu.rs b/src/cpu.rs
index 7c0592a..5c6eef1 100644
--- a/src/cpu.rs
+++ b/src/cpu.rs
@@ -22,7 +22,7 @@ const FLAG_H: u8 = 1 << 5;
 const FLAG_C: u8 = 1 << 4;
 
 use interconnect::TickResult;
-enum CpuTickResult {
+pub enum CpuTickResult {
     Continue { cycles_executed: usize },
     Shutdown { cycles_executed: usize },
 }
@@ -585,9 +585,6 @@ impl CPU {
                 }
                 self.set_8bit_reg(reg_id, reg_content | (1 << 7));
             }
-            _ => {
-                panic!("Unsupported prefix instruction: {:x}", instruction);
-            }
         }
     }
 
@@ -1755,7 +1752,6 @@ impl CPU {
                     8
                 }
                 0xFF => self.rst(0x38),
-                _ => panic!("Unknown instruction: {:02x}", instruction),
             };
         }
 
diff --git a/src/display.rs b/src/display.rs
index 008e0d1..776abee 100644
--- a/src/display.rs
+++ b/src/display.rs
@@ -43,7 +43,7 @@ const STAT_MODE_HBLANK_INT: u8 = 1 << 3;
 const SPRITE_OBJ_BG_PRIORITY: u8 = 1 << 7;
 const SPRITE_Y_FLIP: u8 = 1 << 6;
 const SPRITE_X_FLIP: u8 = 1 << 5;
-const SPRITE_PALETTE_NO: u8 = 1 << 4; // NonCGB only
+//const SPRITE_PALETTE_NO: u8 = 1 << 4; // NonCGB only
 const SPRITE_TILE_VRAM_BANK: u8 = 1 << 3; // CGB only
 
 // Display color
@@ -54,13 +54,13 @@ const MONOCHROME_PALETTE: &'static [[f64; 3]; 4] = &[
     [0.188, 0.383, 0.188],
     [0.059, 0.219, 0.059],
 ];
-*/
 const MONOCHROME_PALETTE: &'static [[u8; 3]; 4] = &[
     [255, 255, 255],
     [200, 200, 200],
     [125, 125, 12],
     [50, 50, 50],
 ];
+*/
 
 #[derive(Copy, Clone)]
 struct CgbPalette([u8; 8]);
@@ -78,10 +78,10 @@ impl CgbPalette {
         let r = r as u16;
         let g = g as u16;
         let b = b as u16;
-        let rR = ((r * 13 + g * 2 + b) >> 1) as u8;
-        let rG = ((g * 3 + b) << 1) as u8;
-        let rB = ((r * 3 + g * 2 + b * 11) >> 1) as u8;
-        sdl2::pixels::Color::RGB(rR, rG, rB)
+        let mapped_r = ((r * 13 + g * 2 + b) >> 1) as u8;
+        let mapped_g = ((g * 3 + b) << 1) as u8;
+        let mapped_b = ((r * 3 + g * 2 + b * 11) >> 1) as u8;
+        sdl2::pixels::Color::RGB(mapped_r, mapped_g, mapped_b)
     }
 }
 
@@ -700,10 +700,12 @@ impl Display {
     pub fn dump_vram(&self) {
         std::fs::File::create("vram0.dat")
             .unwrap()
-            .write_all(&self.vram0);
+            .write_all(&self.vram0)
+            .unwrap();
         std::fs::File::create("vram1.dat")
             .unwrap()
-            .write_all(&self.vram1);
+            .write_all(&self.vram1)
+            .unwrap();
     }
 
     #[inline]