diff --git a/Makefile b/Makefile
index baa2aff..acb89df 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-LIBS  =
+LIBS  = -lmingw32 -lSDL2main -lSDL2
 CFLAGS = -Wall
 
 # Should be equivalent to your list of C files, if you don't build selectively
diff --git a/debug.exe b/debug.exe
index 2517208..910da48 100644
Binary files a/debug.exe and b/debug.exe differ
diff --git a/gbt.exe b/gbt.exe
index b051ecf..9b35012 100644
Binary files a/gbt.exe and b/gbt.exe differ
diff --git a/src/groups/aritmetic.c b/src/groups/aritmetic.c
index bf31638..1cd8eb1 100644
--- a/src/groups/aritmetic.c
+++ b/src/groups/aritmetic.c
@@ -567,7 +567,11 @@ void Scf37(struct CPU* cpu, struct MMU* mmu)
     printf("SCF");
 #endif
     // Cycles: 4, (Z N H C): - 0 0 1
-    printf("Not implemented! (Scf37)");
+
+    // update timer
+    (*cpu).tick+=4;
+
+    (*cpu).F = ((*cpu).F & Z_flag) | C_flag;
 }
 
 void Ccf3F(struct CPU* cpu, struct MMU* mmu)
@@ -577,7 +581,12 @@ void Ccf3F(struct CPU* cpu, struct MMU* mmu)
     printf("CCF");
 #endif
     // Cycles: 4, (Z N H C): - 0 0 C
-    printf("Not implemented! (Ccf3F)");
+
+    // update timer
+    (*cpu).tick+=4;
+
+    unsigned char inv_Cflag = (~((*cpu).F & C_flag) & C_flag);
+    (*cpu).F = ((*cpu).F & Z_flag) | inv_Cflag;
 }
 
 void Adc_8(unsigned char* A, unsigned char* B, struct CPU* cpu) {
diff --git a/src/groups/misc.c b/src/groups/misc.c
index 54f837e..378b46f 100644
--- a/src/groups/misc.c
+++ b/src/groups/misc.c
@@ -9,7 +9,7 @@ void Nop00(struct CPU* cpu, struct MMU* mmu)
     printf("NOP");
 #endif
     // Cycles: 4, (Z N H C): - - - -
-    printf("Not implemented! (Nop00)");
+    (*cpu).tick += 4;
 }
 
 void Rlca07(struct CPU* cpu, struct MMU* mmu)
diff --git a/src/main.c b/src/main.c
index 7abb1f1..a764cb7 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,3 +1,4 @@
+//#include <SDL2/SDL.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -5,6 +6,7 @@
 #include "tools.h"
 #include "cpu.h"
 #include "mmu.h"
+#include "ppu.h"
 
 
 #define TETRIS_SIZE 32768
@@ -45,7 +47,7 @@ int main(int argc, char *argv[]) {
     cpu.tick= 0;
 
     //////////////////////////////
-
+/*
     char* var;
     int instruction_nb = 0;
     // TESTING instructions
@@ -69,5 +71,8 @@ int main(int argc, char *argv[]) {
         //printf("\tB register: %x\n", cpu.B);
         patches(&cpu,&mmu);
     }
+*/
+
+    create_window();
     return  0;
 }
diff --git a/src/ppu.c b/src/ppu.c
new file mode 100644
index 0000000..0d8c912
--- /dev/null
+++ b/src/ppu.c
@@ -0,0 +1,63 @@
+#include "ppu.h"
+
+#define SCALE 5
+
+SDL_Window* create_window(){
+
+     SDL_Window *window;
+
+     SDL_Init(SDL_INIT_VIDEO);              // Initialize SDL2
+
+     // Create an application window with the following settings:
+     window =SDL_CreateWindow(
+          "GBT",                  // window title
+          SDL_WINDOWPOS_UNDEFINED,           // initial x position
+          SDL_WINDOWPOS_UNDEFINED,           // initial y position
+          160*SCALE,                               // width, in pixels
+          144*SCALE,                               // height, in pixels
+          SDL_WINDOW_OPENGL                  // flags - see below
+          );
+     unsigned int palette[4] = {0xffe0f8d0, 0xff88c070, 0xff346856, 0xff081820};
+
+     unsigned int* pixels = calloc(160*144,sizeof(unsigned int));
+
+int i, j; for (i = 0; i < 144; ++i)
+               for (j = 0; j < 160; ++j)
+                    if (j < 40) pixels[i*160+j] = palette[0];
+                    else if (j < 80) pixels[i*160+j] = palette[1];
+                    else if (j < 120) pixels[i*160+j] = palette[2];
+                    else pixels[i*160+j] = palette[3];
+
+     SDL_Renderer * renderer = SDL_CreateRenderer(window, -1, 0);
+
+     SDL_RenderSetScale(renderer,
+                        SCALE, SCALE);
+
+     SDL_Texture * texture = SDL_CreateTexture(renderer,
+                                               SDL_PIXELFORMAT_ARGB8888,
+                                               SDL_TEXTUREACCESS_STATIC,
+                                               160,
+                                               144);
+
+     if (window == NULL) {
+          // In the case that the window could not be made...
+          printf("Could not create window: %s\n", SDL_GetError());
+          return NULL;
+     }
+
+     SDL_UpdateTexture(texture, NULL, pixels, 160 * sizeof(Uint32));
+
+     SDL_RenderClear(renderer);
+     SDL_RenderCopy(renderer, texture, NULL, NULL);
+     SDL_RenderPresent(renderer);
+
+     SDL_Delay(30000);  // Pause execution for 3000 milliseconds, for example
+
+     // Close and destroy the window
+     SDL_DestroyWindow(window);
+
+     // Clean up
+     SDL_Quit();
+
+     return window;
+}
diff --git a/src/ppu.h b/src/ppu.h
new file mode 100644
index 0000000..aef17f8
--- /dev/null
+++ b/src/ppu.h
@@ -0,0 +1,4 @@
+#define SDL_MAIN_HANDLED
+#include <SDL2/SDL.h>
+
+SDL_Window* create_window();