diff --git a/.gitignore b/.gitignore
index 3bdae91..fff52d5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,6 @@
 cmake-build-debug/
 .idea/
 .vs/
-out/
\ No newline at end of file
+out/
+build/
+CMakeLists.txt.user
diff --git a/examples/sdl/main.cpp b/examples/sdl/main.cpp
index 1fd35d0..e152105 100644
--- a/examples/sdl/main.cpp
+++ b/examples/sdl/main.cpp
@@ -2,7 +2,6 @@
 #include "Window.h"
 #include "SdlKeyboardController.h"
 
-#include <functional>
 #include <thread>
 
 int main() {
@@ -12,25 +11,34 @@ int main() {
     nes::System device;
     nes::SdlWindow window(nes::Ppu::SCREEN_WIDTH, nes::Ppu::SCREEN_HEIGHT);
     window.setSize(nes::Ppu::SCREEN_WIDTH*2, nes::Ppu::SCREEN_HEIGHT*2);
-
+    bool working = true;
     SDL_Event e;
-    bool frameRendered = false;
-    device.setNewFrameCallback([&window, &e, &frameRendered](auto buffer){
-        window.drawFrame(buffer);
-        while(SDL_PollEvent(&e));
-        frameRendered = true;
-    });
+
     device.connect(std::make_shared<SdlKeyboardController>());
     //device.insertCartridge("/home/selim/Downloads/dk.nes");
-    device.insertCartridge("/Users/selim/Documents/nes/ppu_tests/sprite_ram.nes");
+    device.insertCartridge("/Users/selim/Documents/nes/ppu_tests/vram_access.nes");
     //device.insertCartridge("/Users/selim/Documents/nes/ff.nes");
     //device.insertCartridge("C:\\Users\\selim\\Documents\\nestest.nes");
 
     auto frameStart = std::chrono::steady_clock::now();
-    while (true) {
-        device.tick();
+    while (working) {
 
-        if(frameRendered) {
+        if(auto frameBuffer = device.tick()) {
+
+            // Draw frame
+            window.drawFrame(frameBuffer);
+
+            // Poll all accumulated events
+            while(SDL_PollEvent(&e)) {
+                switch(e.type) {
+                case SDL_EVENT_WINDOW_CLOSE_REQUESTED:
+                case SDL_EVENT_QUIT:
+                    working = false;
+                    break;
+                }
+            }
+
+            // Wait some time for slowing down to 60 fps
             auto renderingTime = std::chrono::steady_clock::now();
             auto elapsedTime = std::chrono::duration_cast<std::chrono::nanoseconds>(renderingTime - frameStart).count();
             int64_t waitTime = 1000000000/60 - elapsedTime;
@@ -38,7 +46,6 @@ int main() {
                 std::this_thread::sleep_for(std::chrono::nanoseconds(waitTime));
             }
             frameStart = std::chrono::steady_clock::now();
-            frameRendered = false;
         }
     }
 
diff --git a/src/Ppu.cpp b/src/Ppu.cpp
index f910cb6..7c307b2 100644
--- a/src/Ppu.cpp
+++ b/src/Ppu.cpp
@@ -34,7 +34,7 @@ namespace nes {
         };
     }
 
-    bool Ppu::tick() {
+    std::tuple<bool, const Pixel*> Ppu::tick() {
 
         _needEmitNmi = false;
 
@@ -148,17 +148,22 @@ namespace nes {
         }
 
         _column++;
+        bool frameReady = false;
+
         if(_column >= 341) {
             _column = 0;
             _scanline++;
 
             if(_scanline >= 261) {
                 _scanline = -1;
-                onNewFrame(_frameBuffer.get());
+                frameReady = true;
             }
         }
 
-        return _needEmitNmi;
+        return {
+            _needEmitNmi,
+            frameReady ? _frameBuffer.get() : nullptr
+        };
     }
 
     uint8_t Ppu::read(uint16_t address) {
diff --git a/src/Ppu.h b/src/Ppu.h
index fe42f27..bef4b9a 100644
--- a/src/Ppu.h
+++ b/src/Ppu.h
@@ -13,6 +13,7 @@
 #include <memory>
 #include <functional>
 #include <vector>
+#include <tuple>
 
 namespace nes {
 
@@ -101,7 +102,7 @@ namespace nes {
 
     public:
         Ppu();
-        bool tick();
+        std::tuple<bool, const Pixel*> tick();
         void write(uint16_t address, uint8_t value);
         uint8_t read(uint16_t address);
         void setPixel(uint16_t row, uint16_t column, Pixel pixel);
@@ -115,9 +116,6 @@ namespace nes {
         void dmaTick(uint64_t cycles) const;
         void startDma(uint8_t page) const;
 
-    public:
-        std::function<void(const Pixel*)> onNewFrame;
-
     private:
         Pixel getColor(uint8_t palette, uint8_t pixel);
         void prepareNextBgTile(uint16_t column);
diff --git a/src/System.cpp b/src/System.cpp
index d99f53f..fa5fec7 100644
--- a/src/System.cpp
+++ b/src/System.cpp
@@ -44,12 +44,8 @@ namespace nes {
         }
     }
 
-    void System::setNewFrameCallback(std::function<void(const Pixel *)> onNewFrame) {
-        _ppu->onNewFrame = std::move(onNewFrame);
-    }
-
-    void System::tick() {
-        bool needInterrupt = _ppu->tick();
+    const Pixel* System::tick() {
+        auto [needInterrupt, frameBuffer] = _ppu->tick();
 
         if(_cycles % 3 == 0) {
             if(_ppu->dmaActive()) {
@@ -64,6 +60,8 @@ namespace nes {
         }
 
         _cycles++;
+
+        return frameBuffer;
     }
 
     // For debug
diff --git a/src/System.h b/src/System.h
index cfcb327..fc8acab 100644
--- a/src/System.h
+++ b/src/System.h
@@ -27,8 +27,7 @@ namespace nes {
         void insertCartridge(const fs::path& path, std::optional<uint16_t> address = std::nullopt);
         void connect(std::shared_ptr<Controller> controller);
         void reset(std::optional<uint16_t> address = std::nullopt);
-        void setNewFrameCallback(std::function<void(const Pixel*)> onNewFrame);
-        void tick();
+        const Pixel* tick();
 
         [[nodiscard]] uint32_t zpHash() const;