diff --git a/gameboy/cartridge/cartridge.cpp b/gameboy/cartridge/cartridge.cpp
index 611b35f5..53d3d66a 100755
--- a/gameboy/cartridge/cartridge.cpp
+++ b/gameboy/cartridge/cartridge.cpp
@@ -3,7 +3,8 @@
 #define CARTRIDGE_CPP
 namespace GameBoy {
 
-#include "mmio/mmio.cpp"
+#include "mbc0/mbc0.cpp"
+#include "mbc1/mbc1.cpp"
 Cartridge cartridge;
 
 void Cartridge::load(uint8_t *data, unsigned size) {
@@ -18,7 +19,18 @@ void Cartridge::load(uint8_t *data, unsigned size) {
 
   info.cgbflag = romdata[0x0143];
   info.sgbflag = romdata[0x0146];
-  info.type    = romdata[0x0147];
+
+  info.mapper = Mapper::Unknown;
+  info.ram = false;
+  info.battery = false;
+  info.rtc = false;
+
+  switch(romdata[0x0147]) { default:
+    case 0x00: info.mapper = Mapper::MBC0; break;
+    case 0x01: info.mapper = Mapper::MBC1; break;
+    case 0x02: info.mapper = Mapper::MBC1; info.ram = true; break;
+    case 0x03: info.mapper = Mapper::MBC1; info.ram = true; info.battery = true; break;
+  }
 
   switch(romdata[0x0148]) { default:
     case 0x00: info.romsize =   2 * 16 * 1024; break;
@@ -42,6 +54,8 @@ void Cartridge::load(uint8_t *data, unsigned size) {
     case 0x03: info.ramsize = 32 * 1024; break;
   }
 
+  ramdata = new uint8_t[ramsize = info.ramsize]();
+
   loaded = true;
 }
 
@@ -53,13 +67,48 @@ void Cartridge::unload() {
   loaded = false;
 }
 
+uint8 Cartridge::rom_read(unsigned addr) {
+  if(addr >= romsize) addr %= romsize;
+  return romdata[addr];
+}
+
+void Cartridge::rom_write(unsigned addr, uint8 data) {
+  if(addr >= romsize) addr %= romsize;
+  romdata[addr] = data;
+}
+
+uint8 Cartridge::ram_read(unsigned addr) {
+  if(ramsize == 0) return 0x00;
+  if(addr >= ramsize) addr %= ramsize;
+  return ramdata[addr];
+}
+
+void Cartridge::ram_write(unsigned addr, uint8 data) {
+  if(ramsize == 0) return;
+  if(addr >= ramsize) addr %= ramsize;
+  ramdata[addr] = data;
+}
+
 void Cartridge::power() {
-  for(unsigned n = 0x0000; n <= 0x7fff; n++) bus.mmio[n] = this;
+  mbc0.power();
+  mbc1.power();
+
+  MMIO *mapper = 0;
+  switch(info.mapper) {
+    case Mapper::MBC0: mapper = &mbc0; break;
+    case Mapper::MBC1: mapper = &mbc1; break;
+  }
+  if(mapper) {
+    for(unsigned n = 0x0000; n <= 0x7fff; n++) bus.mmio[n] = mapper;
+    for(unsigned n = 0xa000; n <= 0xbfff; n++) bus.mmio[n] = mapper;
+  }
 
   reset();
 }
 
 void Cartridge::reset() {
+  mbc1.reset();
+  mbc1.reset();
 }
 
 Cartridge::Cartridge() {
diff --git a/gameboy/cartridge/cartridge.hpp b/gameboy/cartridge/cartridge.hpp
index 4868fc56..03e4a1f2 100755
--- a/gameboy/cartridge/cartridge.hpp
+++ b/gameboy/cartridge/cartridge.hpp
@@ -1,11 +1,23 @@
-struct Cartridge : MMIO, property<Cartridge> {
-  #include "mmio/mmio.hpp"
+struct Cartridge : property<Cartridge> {
+  #include "mbc0/mbc0.hpp"
+  #include "mbc1/mbc1.hpp"
+
+  enum Mapper : unsigned {
+    MBC0,
+    MBC1,
+    Unknown,
+  };
 
   struct Information {
     string   name;
     uint8    cgbflag;
     uint8    sgbflag;
-    uint8    type;
+
+    Mapper   mapper;
+    bool     ram;
+    bool     battery;
+    bool     rtc;
+
     unsigned romsize;
     unsigned ramsize;
   } info;
@@ -21,6 +33,11 @@ struct Cartridge : MMIO, property<Cartridge> {
   void load(uint8_t *data, unsigned size);
   void unload();
 
+  uint8 rom_read(unsigned addr);
+  void rom_write(unsigned addr, uint8 data);
+  uint8 ram_read(unsigned addr);
+  void ram_write(unsigned addr, uint8 data);
+
   void power();
   void reset();
 
diff --git a/gameboy/cartridge/mbc0/mbc0.cpp b/gameboy/cartridge/mbc0/mbc0.cpp
new file mode 100755
index 00000000..85a8a505
--- /dev/null
+++ b/gameboy/cartridge/mbc0/mbc0.cpp
@@ -0,0 +1,17 @@
+#ifdef CARTRIDGE_CPP
+
+uint8 Cartridge::MBC0::mmio_read(uint16 addr) {
+  if(addr >= 0x0000 && addr <= 0x7fff) return cartridge.rom_read(addr);
+  return 0x00;
+}
+
+void Cartridge::MBC0::mmio_write(uint16 addr, uint8 data) {
+}
+
+void Cartridge::MBC0::power() {
+}
+
+void Cartridge::MBC0::reset() {
+}
+
+#endif
diff --git a/gameboy/cartridge/mbc0/mbc0.hpp b/gameboy/cartridge/mbc0/mbc0.hpp
new file mode 100755
index 00000000..fef9f9a9
--- /dev/null
+++ b/gameboy/cartridge/mbc0/mbc0.hpp
@@ -0,0 +1,6 @@
+struct MBC0 : MMIO {
+  uint8 mmio_read(uint16 addr);
+  void mmio_write(uint16 addr, uint8 data);
+  void power();
+  void reset();
+} mbc0;
diff --git a/gameboy/cartridge/mbc1/mbc1.cpp b/gameboy/cartridge/mbc1/mbc1.cpp
new file mode 100755
index 00000000..fedb6b79
--- /dev/null
+++ b/gameboy/cartridge/mbc1/mbc1.cpp
@@ -0,0 +1,62 @@
+#ifdef CARTRIDGE_CPP
+
+uint8 Cartridge::MBC1::mmio_read(uint16 addr) {
+  if(addr >= 0x0000 && addr <= 0x3fff) {
+    return cartridge.rom_read(addr);
+  }
+
+  if(addr >= 0x4000 && addr <= 0x7fff) {
+    return cartridge.rom_read(rom_bank | (addr & 0x3fff));
+  }
+
+  if(addr >= 0xa000 && addr <= 0xbfff) {
+    if(ram_enable) return cartridge.ram_read(ram_bank | (addr & 0x1fff));
+    return 0x00;
+  }
+}
+
+void Cartridge::MBC1::mmio_write(uint16 addr, uint8 data) {
+  if(addr >= 0x0000 && addr <= 0x1fff) {
+    ram_enable = (data & 0x0f) == 0x0a;
+  }
+
+  if(addr >= 0x2000 && addr <= 0x3fff) {
+    rom_select = data & 0x1f;
+    if(rom_select == 0) rom_select = 1;
+  }
+
+  if(addr >= 0x4000 && addr <= 0x5fff) {
+    ram_select = data & 0x03;
+  }
+
+  if(addr >= 0x6000 && addr <= 0x7fff) {
+    mode_select = data & 0x01;
+  }
+
+  if(mode_select == 0) {
+    rom_bank = (ram_select << 19) | (rom_select << 14);
+    ram_bank = 0x00;
+  } else {
+    rom_bank = (rom_select << 14);
+    ram_bank = (ram_select << 13);
+  }
+
+  if(addr >= 0xa000 && addr <= 0xbfff) {
+    if(ram_enable) cartridge.ram_write(ram_bank | (addr & 0x1fff), data);
+  }
+}
+
+void Cartridge::MBC1::power() {
+}
+
+void Cartridge::MBC1::reset() {
+  ram_enable = false;
+  rom_select = 0x01;
+  ram_select = 0x00;
+  mode_select = 0;
+
+  rom_bank = 0x4000;
+  ram_bank = 0x0000;
+}
+
+#endif
diff --git a/gameboy/cartridge/mbc1/mbc1.hpp b/gameboy/cartridge/mbc1/mbc1.hpp
new file mode 100755
index 00000000..516acde8
--- /dev/null
+++ b/gameboy/cartridge/mbc1/mbc1.hpp
@@ -0,0 +1,14 @@
+struct MBC1 : MMIO {
+  bool  ram_enable;   //0000-1fff
+  uint8 rom_select;   //2000-3fff
+  uint8 ram_select;   //4000-5fff
+  bool  mode_select;  //6000-7fff
+
+  unsigned rom_bank;
+  unsigned ram_bank;
+
+  uint8 mmio_read(uint16 addr);
+  void mmio_write(uint16 addr, uint8 data);
+  void power();
+  void reset();
+} mbc1;
diff --git a/gameboy/cartridge/mmio/mmio.cpp b/gameboy/cartridge/mmio/mmio.cpp
deleted file mode 100755
index 749b5895..00000000
--- a/gameboy/cartridge/mmio/mmio.cpp
+++ /dev/null
@@ -1,10 +0,0 @@
-#ifdef CARTRIDGE_CPP
-
-uint8 Cartridge::mmio_read(uint16 addr) {
-  if(addr >= 0x0000 && addr <= 0x7fff) return romdata[addr];
-}
-
-void Cartridge::mmio_write(uint16 addr, uint8 data) {
-}
-
-#endif
diff --git a/gameboy/cartridge/mmio/mmio.hpp b/gameboy/cartridge/mmio/mmio.hpp
deleted file mode 100755
index 92b8f614..00000000
--- a/gameboy/cartridge/mmio/mmio.hpp
+++ /dev/null
@@ -1,2 +0,0 @@
-uint8 mmio_read(uint16 addr);
-void mmio_write(uint16 addr, uint8 data);
diff --git a/gameboy/cpu/core/core.cpp b/gameboy/cpu/core/core.cpp
index 317b936b..e1e226e2 100755
--- a/gameboy/cpu/core/core.cpp
+++ b/gameboy/cpu/core/core.cpp
@@ -566,11 +566,13 @@ void CPU::op_nop() {
 }
 
 void CPU::op_halt() {
-  //TODO
+  status.halt = true;
+  while(status.halt == true) op_io();
 }
 
 void CPU::op_stop() {
-  //TODO
+  status.stop = true;
+  while(status.stop == true) op_io();
 }
 
 void CPU::op_di() {
diff --git a/gameboy/cpu/cpu.cpp b/gameboy/cpu/cpu.cpp
index 70b4130f..f01523e4 100755
--- a/gameboy/cpu/cpu.cpp
+++ b/gameboy/cpu/cpu.cpp
@@ -21,6 +21,17 @@ void CPU::main() {
   }
 }
 
+void CPU::interrupt_raise(CPU::Interrupt id) {
+  switch(id) {
+    case Interrupt::Vblank: status.interrupt_request_vblank = 1; break;
+    case Interrupt::Stat  : status.interrupt_request_stat   = 1; break;
+    case Interrupt::Timer : status.interrupt_request_timer  = 1; break;
+    case Interrupt::Serial: status.interrupt_request_serial = 1; break;
+    case Interrupt::Joypad: status.interrupt_request_joypad = 1; break;
+  }
+  status.halt = false;
+}
+
 void CPU::interrupt_test() {
   if(status.ime) {
     if(status.interrupt_request_vblank && status.interrupt_enable_vblank) {
@@ -80,6 +91,9 @@ void CPU::reset() {
   r[DE] = 0x0000;
   r[HL] = 0x0000;
 
+  status.halt = false;
+  status.stop = false;
+
   status.ime = 0;
   status.timer0 = 0;
   status.timer1 = 0;
diff --git a/gameboy/cpu/cpu.hpp b/gameboy/cpu/cpu.hpp
index 28f4d211..7d410b35 100755
--- a/gameboy/cpu/cpu.hpp
+++ b/gameboy/cpu/cpu.hpp
@@ -3,7 +3,18 @@ struct CPU : Processor, MMIO {
   #include "mmio/mmio.hpp"
   #include "timing/timing.hpp"
 
+  enum class Interrupt : unsigned {
+    Vblank,
+    Stat,
+    Timer,
+    Serial,
+    Joypad,
+  };
+
   struct Status {
+    bool halt;
+    bool stop;
+
     bool ime;
     unsigned timer0;
     unsigned timer1;
@@ -48,6 +59,7 @@ struct CPU : Processor, MMIO {
 
   static void Main();
   void main();
+  void interrupt_raise(Interrupt id);
   void interrupt_test();
   void interrupt_exec(uint16 pc);
   void power();
diff --git a/gameboy/cpu/mmio/mmio.cpp b/gameboy/cpu/mmio/mmio.cpp
index e18b1e5e..610474b9 100755
--- a/gameboy/cpu/mmio/mmio.cpp
+++ b/gameboy/cpu/mmio/mmio.cpp
@@ -16,7 +16,7 @@ void CPU::mmio_joyp_poll() {
   status.joyp = 0x0f;
   if(status.p15 == 0) status.joyp &= button ^ 0x0f;
   if(status.p14 == 0) status.joyp &= dpad ^ 0x0f;
-  if(status.joyp != 0x0f) status.interrupt_request_joypad = 1;
+  if(status.joyp != 0x0f) interrupt_raise(Interrupt::Joypad);
 }
 
 uint8 CPU::mmio_read(uint16 addr) {
diff --git a/gameboy/cpu/timing/timing.cpp b/gameboy/cpu/timing/timing.cpp
index 0d96e62e..b62c5995 100755
--- a/gameboy/cpu/timing/timing.cpp
+++ b/gameboy/cpu/timing/timing.cpp
@@ -21,10 +21,10 @@ void CPU::add_clocks(unsigned clocks) {
 }
 
 void CPU::timer_stage0() {  //262144hz
-  if(status.timer_clock == 1) {
+  if(status.timer_enable && status.timer_clock == 1) {
     if(++status.tima == 0) {
       status.tima = status.tma;
-      status.interrupt_request_timer = 1;
+      interrupt_raise(Interrupt::Timer);
     }
   }
 
@@ -33,10 +33,10 @@ void CPU::timer_stage0() {  //262144hz
 }
 
 void CPU::timer_stage1() {  // 65536hz
-  if(status.timer_clock == 2) {
+  if(status.timer_enable && status.timer_clock == 2) {
     if(++status.tima == 0) {
       status.tima = status.tma;
-      status.interrupt_request_timer = 1;
+      interrupt_raise(Interrupt::Timer);
     }
   }
 
@@ -45,10 +45,10 @@ void CPU::timer_stage1() {  // 65536hz
 }
 
 void CPU::timer_stage2() {  // 16384hz
-  if(status.timer_clock == 3) {
+  if(status.timer_enable && status.timer_clock == 3) {
     if(++status.tima == 0) {
       status.tima = status.tma;
-      status.interrupt_request_timer = 1;
+      interrupt_raise(Interrupt::Timer);
     }
   }
 
@@ -59,10 +59,10 @@ void CPU::timer_stage2() {  // 16384hz
 }
 
 void CPU::timer_stage3() {  //  4096hz
-  if(status.timer_clock == 0) {
+  if(status.timer_enable && status.timer_clock == 0) {
     if(++status.tima == 0) {
       status.tima = status.tma;
-      status.interrupt_request_timer = 1;
+      interrupt_raise(Interrupt::Timer);
     }
   }
 
diff --git a/gameboy/gameboy.hpp b/gameboy/gameboy.hpp
index 4c131b7f..13c62158 100755
--- a/gameboy/gameboy.hpp
+++ b/gameboy/gameboy.hpp
@@ -5,7 +5,7 @@
 namespace GameBoy {
   namespace Info {
     static const char Name[] = "bgameboy";
-    static const char Version[] = "000.05";
+    static const char Version[] = "000.06";
   }
 }
 
diff --git a/gameboy/lcd/lcd.cpp b/gameboy/lcd/lcd.cpp
index be9818bc..abcf26ad 100755
--- a/gameboy/lcd/lcd.cpp
+++ b/gameboy/lcd/lcd.cpp
@@ -13,6 +13,10 @@ void LCD::Main() {
 void LCD::main() {
   while(true) {
     add_clocks(4);
+
+    if(status.lx == 320) {
+      if(status.interrupt_hblank) cpu.interrupt_raise(CPU::Interrupt::Stat);
+    }
   }
 }
 
@@ -28,8 +32,14 @@ void LCD::scanline() {
   status.lx -= 456;
   status.ly++;
 
-  if(status.ly == 144) cpu.status.interrupt_request_vblank = 1;
-//print("Vblank - ", cpu.status.ime, " - ", cpu.status.interrupt_enable_vblank, "\n"); }
+  if(status.interrupt_lyc == true) {
+    if(status.ly == status.lyc) cpu.interrupt_raise(CPU::Interrupt::Stat);
+  }
+
+  if(status.ly == 144) {
+    cpu.interrupt_raise(CPU::Interrupt::Vblank);
+    if(status.interrupt_vblank) cpu.interrupt_raise(CPU::Interrupt::Stat);
+  }
   if(status.ly == 154) frame();
 
   if(status.ly < 144) render();
@@ -45,54 +55,130 @@ void LCD::frame() {
 }
 
 void LCD::render() {
-  uint8_t *output = screen + status.ly * 160;
-  uint8 y = status.ly + status.scy;
-  uint16 tmaddr = (status.bg_tilemap_select == 0 ? 0x1800 : 0x1c00);
-  tmaddr += (y >> 3) * 32;
-  tmaddr += (status.scx >> 3);
-
-  for(unsigned t = 0; t < 20; t++) {
-    unsigned tdaddr;
-    if(status.bg_tiledata_select == 0) {
-      tdaddr = 0x1000 + (int8)vram[tmaddr + t] * 16;
-    } else {
-      tdaddr = 0x0000 + vram[tmaddr + t] * 16;
-    }
-    tdaddr += (status.ly & 7) * 2;
-
-    uint8 d0 = vram[tdaddr + 0];
-    uint8 d1 = vram[tdaddr + 1];
-
-    for(unsigned x = 0; x < 8; x++) {
-      uint8 palette = ((d0 & 0x80) >> 7) + ((d1 & 0x80) >> 6);
-      d0 <<= 1, d1 <<= 1;
-      *output++ = (3 - status.bgp[palette]) * 0x55;
-    }
+  for(unsigned n = 0; n < 160; n++) {
+    line[n].source = Line::Source::None;
+    line[n].output = 0;
   }
 
-  output = screen + status.ly * 160;
+  if(status.display_enable == true) {
+    if(status.bg_enable == true) render_bg();
+    if(status.obj_enable == true) render_obj();
+    if(status.window_display_enable == true) render_window();
+  }
+
+  uint8_t *output = screen + status.ly * 160;
+  for(unsigned n = 0; n < 160; n++) {
+    output[n] = (3 - line[n].output) * 0x55;
+  }
+}
+
+void LCD::render_bg() {
+  unsigned iy = (status.ly + status.scy) & 255;
+  unsigned ix = status.scx;
+
+  unsigned tmaddr = (status.bg_tilemap_select == 0 ? 0x1800 : 0x1c00);
+
+  unsigned tx = (ix - 7) & 7;
+  uint8 d0 = 0, d1 = 0;
+  for(signed ox = -7; ox < 160; ox++) {
+    if(tx == 0) {
+      unsigned tile = (((iy >> 3) * 32) + (ix >> 3)) & 0x3fff;
+      unsigned tdaddr;
+      if(status.bg_tiledata_select == 0) {
+        tdaddr = 0x1000 + (int8)vram[tmaddr + tile] * 16;
+      } else {
+        tdaddr = 0x0000 + vram[tmaddr + tile] * 16;
+      }
+      tdaddr += (iy & 7) * 2;
+
+      d0 = vram[tdaddr + 0];
+      d1 = vram[tdaddr + 1];
+    }
+
+    uint8 palette = ((d0 & 0x80) >> 7) + ((d1 & 0x80) >> 6);
+    d0 <<= 1, d1 <<= 1;
+
+    if(ox >= 0) {
+      line[ox].source = Line::Source::BG;
+      line[ox].output = status.bgp[palette];
+    }
+
+    ix = (ix + 1) & 255;
+    tx = (tx + 1) & 7;
+  }
+}
+
+void LCD::render_window() {
+  if(status.wy > status.ly) return;
+  unsigned iy = (status.ly + status.wy) & 255;
+  unsigned ix = (status.wx - 7) & 255;
+
+  unsigned tmaddr = (status.window_tilemap_select == 0 ? 0x1800 : 0x1c00);
+
+  unsigned tx = (ix - 7) & 7;
+  uint8 d0 = 0, d1 = 0;
+  for(signed ox = -7; ox < 160; ox++) {
+    if(tx == 0) {
+      unsigned tile = (((iy >> 3) * 32) + (ix >> 3)) & 0x3fff;
+      unsigned tdaddr;
+      if(status.bg_tiledata_select == 0) {
+        tdaddr = 0x1000 + (int8)vram[tmaddr + tile] * 16;
+      } else {
+        tdaddr = 0x0000 + vram[tmaddr + tile] * 16;
+      }
+      tdaddr += (iy & 7) * 2;
+
+      d0 = vram[tdaddr + 0];
+      d1 = vram[tdaddr + 1];
+    }
+
+    uint8 palette = ((d0 & 0x80) >> 7) + ((d1 & 0x80) >> 6);
+    d0 <<= 1, d1 <<= 1;
+
+    if(ox >= 7) {
+      line[ox].source = Line::Source::Window;
+      line[ox].output = status.bgp[palette];
+    }
+
+    ix = (ix + 1) & 255;
+    tx = (tx + 1) & 7;
+  }
+}
+
+void LCD::render_obj() {
+  unsigned obj_size = (status.obj_size == 0 ? 8 : 16);
+
   for(unsigned s = 0; s < 40; s++) {
-    unsigned sy = oam[(s << 2) + 0] - 9;
-    unsigned sx = oam[(s << 2) + 1] - 8;
+    unsigned sy = oam[(s << 2) + 0] - 16;
+    unsigned sx = oam[(s << 2) + 1] -  8;
     unsigned tile = oam[(s << 2) + 2];
     unsigned attribute = oam[(s << 2) + 3];
 
-    sy -= status.ly;
-    if(sy >= 8) continue;
-    if(attribute & 0x40||1) sy ^= 7;
+    sy = status.ly - sy;
+    if(sy >= obj_size) continue;
+    if(attribute & 0x40) sy ^= (obj_size - 1);
 
-    unsigned addr = tile * 16 + sy * 2;
+    unsigned tdaddr = tile * 16 + sy * 2;
 
-    uint8 d0 = vram[addr + 0];
-    uint8 d1 = vram[addr + 1];
-    unsigned xflip = attribute & 0x20 ? -7 : 0;
+    uint8 d0 = vram[tdaddr + 0];
+    uint8 d1 = vram[tdaddr + 1];
+    unsigned xflip = attribute & 0x20 ? 7 : 0;
 
-    for(unsigned x = 0; x < 8; x++) {
+    for(unsigned tx = 0; tx < 8; tx++) {
       uint8 palette = ((d0 & 0x80) >> 7) + ((d1 & 0x80) >> 6);
       d0 <<= 1, d1 <<= 1;
       if(palette == 0) continue;
+
       palette = status.obp[(bool)(attribute & 0x10)][palette];
-      output[sx + (x ^ xflip)] = (3 - palette) * 0x55;
+      unsigned ox = sx + (tx ^ xflip);
+
+      if(ox <= 159) {
+        if((attribute & 0x80) == 1) {
+          if(line[ox].source == Line::Source::BG && line[ox].output > 0) continue;
+        }
+        line[ox].source = Line::Source::OBJ;
+        line[ox].output = palette;
+      }
     }
   }
 }
@@ -121,21 +207,16 @@ void LCD::reset() {
   status.bg_tilemap_select = 0;
   status.obj_size = 0;
   status.obj_enable = 0;
-  status.bg_display = 0;
+  status.bg_enable = 0;
 
   status.interrupt_lyc = 0;
   status.interrupt_oam = 0;
   status.interrupt_vblank = 0;
   status.interrupt_hblank = 0;
-  status.coincidence = 0;
-  status.mode = 0;
 
   status.scy = 0;
-
   status.scx = 0;
-
   status.ly = 0;
-
   status.lyc = 0;
 
   for(unsigned n = 0; n < 4; n++) {
@@ -145,7 +226,6 @@ void LCD::reset() {
   }
 
   status.wy = 0;
-
   status.wx = 0;
 }
 
diff --git a/gameboy/lcd/lcd.hpp b/gameboy/lcd/lcd.hpp
index d819b3b0..cd3dcc12 100755
--- a/gameboy/lcd/lcd.hpp
+++ b/gameboy/lcd/lcd.hpp
@@ -12,15 +12,13 @@ struct LCD : Processor, MMIO {
     bool bg_tilemap_select;
     bool obj_size;
     bool obj_enable;
-    bool bg_display;
+    bool bg_enable;
 
     //$ff41  STAT
     bool interrupt_lyc;
     bool interrupt_oam;
     bool interrupt_vblank;
     bool interrupt_hblank;
-    bool coincidence;
-    unsigned mode;
 
     //$ff42  SCY
     uint8 scy;
@@ -52,12 +50,20 @@ struct LCD : Processor, MMIO {
   uint8 vram[8192];
   uint8 oam[160];
 
+  struct Line {
+    enum class Source : unsigned { None, BG, OBJ, Window } source;
+    uint8 output;
+  } line[160];
+
   static void Main();
   void main();
   void add_clocks(unsigned clocks);
   void scanline();
   void frame();
   void render();
+  void render_bg();
+  void render_window();
+  void render_obj();
 
   void power();
   void reset();
diff --git a/gameboy/lcd/mmio/mmio.cpp b/gameboy/lcd/mmio/mmio.cpp
index 230ba463..aafef096 100755
--- a/gameboy/lcd/mmio/mmio.cpp
+++ b/gameboy/lcd/mmio/mmio.cpp
@@ -12,16 +12,21 @@ uint8 LCD::mmio_read(uint16 addr) {
          | (status.bg_tilemap_select << 3)
          | (status.obj_size << 2)
          | (status.obj_enable << 1)
-         | (status.bg_display << 0);
+         | (status.bg_enable << 0);
   }
 
   if(addr == 0xff41) {  //STAT
+    unsigned mode;
+    if(status.ly >= 144) mode = 1;  //Vblank
+    else if(status.lx >= 320) mode = 0;  //Hblank
+    else mode = 3;  //LCD transfer
+
     return (status.interrupt_lyc << 6)
          | (status.interrupt_oam << 5)
          | (status.interrupt_vblank << 4)
          | (status.interrupt_hblank << 3)
-         | (status.coincidence << 2)
-         | (status.mode << 0);
+         | ((status.ly == status.lyc) << 2)
+         | (mode << 0);
   }
 
   if(addr == 0xff42) {  //SCY
@@ -84,7 +89,7 @@ void LCD::mmio_write(uint16 addr, uint8 data) {
     status.bg_tilemap_select = data & 0x08;
     status.obj_size = data & 0x04;
     status.obj_enable = data & 0x02;
-    status.bg_display = data & 0x01;
+    status.bg_enable = data & 0x01;
     return;
   }
 
diff --git a/ui/general/main-window.cpp b/ui/general/main-window.cpp
index 7aa7541e..9aa81741 100755
--- a/ui/general/main-window.cpp
+++ b/ui/general/main-window.cpp
@@ -33,7 +33,7 @@ void MainWindow::create() {
   };
 
   systemLoadCartridge.onTick = []() {
-    string filename = OS::fileOpen(mainWindow, "Game Boy cartridges\t*.gb", "/media/sdb1/root/gameboy_images/");
+    string filename = OS::fileOpen(mainWindow, "Game Boy cartridges\t*.gb,*.gbc", "/media/sdb1/root/gameboy_images/");
     if(filename != "") utility.loadCartridge(filename);
   };