diff --git a/.travis.yml b/.travis.yml
index 508fc37..cf5d239 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,9 +4,21 @@ git:
 compiler:
  - clang
  - gcc
-script: mkdir build && cd build && cmake -DUSE_ALLEGRO=OFF -DUSE_PROFILING=ON -DCOVERALLS=ON -DCMAKE_BUILD_TYPE=Debug .. && cmake --build . && cmake --build . --target coveralls
+script: 
+ - mkdir build
+ - cd build 
+ - cmake -DUSE_ALLEGRO=OFF -DUSE_PROFILING=OFF -DCOVERALLS=OFF -DCMAKE_BUILD_TYPE=Release .. 
+ - cmake --build . 
+ - cd ..
+ - mkdir coverage 
+ - cd coverage
+ - cmake -DUSE_ALLEGRO=OFF -DUSE_PROFILING=OFF -DCOVERALLS=ON -DCMAKE_BUILD_TYPE=Debug ..
+ - cmake --build .
+ - cmake --build . --target coveralls
 install: true
-
+env:
+  global:
+    - CODECOV_TOKEN=$COVERALLS_REPO_TOKEN
 addons:
   apt:
     sources:
@@ -14,3 +26,5 @@ addons:
     packages:
       - cmake
       - cmake-data
+      - lcov
+      - curl
diff --git a/data/bad_apple_2.nes b/data/bad_apple_2.nes
new file mode 100644
index 0000000..2671987
Binary files /dev/null and b/data/bad_apple_2.nes differ
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index fdc3df9..b56c87b 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -64,8 +64,9 @@ if (USE_PROFILING)
 endif (USE_PROFILING)
 
 if (COVERALLS)
-    include(Coveralls)
-    coveralls_turn_on_coverage()
+   add_definitions (-DRUN_COVERAGE)
+   include(Coveralls)
+   coveralls_turn_on_coverage()
 endif()
 
 include_directories(include)
@@ -101,3 +102,4 @@ endif()
 
 add_executable(tines main.c paddle.c NESCarts.c)
 target_link_libraries(tines apu corecpu mappermanager memorymanager pluginsmanager ppu oslib ${PTHREADLIB})
+add_test(tines_test ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/src/tines ${PROJECT_SOURCE_DIR}/data/bad_apple_2.nes)
diff --git a/src/NESCarts.c b/src/NESCarts.c
index 90ca8c2..c223c81 100755
--- a/src/NESCarts.c
+++ b/src/NESCarts.c
@@ -57,7 +57,7 @@ int LoadCart(const char *filename, NesCart * cart)
     cart->File = (byte *)LoadFilePtr((char *)filename);
     
     
-    if ((cart->File == NULL) || ((int)cart->File == -1))
+    if (cart->File == NULL)
       return -1;
     
 	sprintf(buffer, "%c%c%c%c", 0x4E, 0x45, 0x53, 0x1A);
diff --git a/src/main.c b/src/main.c
index 3cb0e30..d5f3d10 100755
--- a/src/main.c
+++ b/src/main.c
@@ -150,7 +150,7 @@ void SaveSaveRam(char *name)
    FILE *fp;
    int i;
    char fname[512];
-   int ret;
+
    strcpy(fname, name);
    strcat(fname, ".svt");
    if ((fp = fopen(fname, "wb")))
@@ -158,7 +158,7 @@ void SaveSaveRam(char *name)
 	 console_printf(Console_Default, "Saving savestate '%s'\n", fname);
 	 for( i = 0x60; i < 0x80; i++)
 	 {
-	    ret = fwrite(get_page_ptr(i), 1, 0x100, fp);
+	    fwrite(get_page_ptr(i), 1, 0x100, fp);
 	 }
 	 
 	 fclose(fp);
@@ -170,7 +170,7 @@ void LoadSaveRam(char *name)
    FILE *fp;
    int i;
    char fname[512];
-   int ret;
+
    strcpy(fname, name);
    strcat(fname, ".svt");
    if ((fp = fopen(fname, "rb")))
@@ -178,7 +178,7 @@ void LoadSaveRam(char *name)
 	 console_printf(Console_Default, "Loading savestate '%s'\n", fname);
 	 for( i = 0x60; i < 0x80; i++)
 	 {
-	    ret = fread(get_page_ptr(i), 1, 0x0100, fp);
+	    fread(get_page_ptr(i), 1, 0x0100, fp);
 	 }    
 	 fclose(fp);
 	 
@@ -189,7 +189,6 @@ void LoadSaveRam(char *name)
 void LoadPalette(char *filename, Palette *pal)
 {
    FILE *fp;
-   int ret;
    unsigned char r, v, b, i;
    console_printf(Console_Default, "%s: try to load pallette file '%s'", __func__, filename);
    if ((fp = fopen(filename, "rb")) != NULL)
@@ -198,9 +197,9 @@ void LoadPalette(char *filename, Palette *pal)
 	 for (i = 0; i < 64; i++)
 	 {
 	    
-	    ret = fread(&r, 1, 1, fp);
-	    ret = fread(&v, 1, 1, fp);
-	    ret = fread(&b, 1, 1, fp);
+	    fread(&r, 1, 1, fp);
+	    fread(&v, 1, 1, fp);
+	    fread(&b, 1, 1, fp);
 	    
 	    /*            r = (r * 64) / 255;
 		v = (v * 64) / 255;
@@ -258,12 +257,20 @@ void LoadPalette(char *filename, Palette *pal)
    }
 }
 
+#ifdef RUN_COVERAGE
+void alarmHandler(int sig)
+{
+   signal(SIGALRM, SIG_IGN);
+   WantClosing = 1;
+}
+#endif
+
 void signalhandler(int sig)
 {
    static int state=0;
 
    char name[512];
-   
+
    static FILE *fp = NULL;
    sprintf(name, "crashdump-%d.txt", (int)time(NULL));
    if (state != 0)
@@ -643,7 +650,11 @@ int main(int argc, char *argv[])
    console_printf(Console_Default, "S");
    signal(SIGTERM, signalhandler);
    console_printf(Console_Default, "T]\n");
-   
+
+#ifdef RUN_COVERAGE
+   signal(SIGALRM, alarmHandler);
+#endif
+  
    /*  */
    console_printf(Console_Default, "Initialize memory...\t\t");
    InitMemory();
@@ -957,6 +968,10 @@ int main(int argc, char *argv[])
  */
    
    gettimeofday(&timeStart, NULL);
+
+#ifdef RUN_COVERAGE
+   alarm(1 * 60); /* Run for 1 minutes */
+#endif
    
    while(!WantClosing)
    {
diff --git a/src/os/unix/CMakeLists.txt b/src/os/unix/CMakeLists.txt
index b199b18..79a9e20 100644
--- a/src/os/unix/CMakeLists.txt
+++ b/src/os/unix/CMakeLists.txt
@@ -10,10 +10,10 @@
 # $Revision$
 
 if (COVERALLS)
-    set(COVERAGE_SRCS src/os/unix/loadfile.c src/os/unix/graphics.c src/os/unix/sound.c src/os/unix/io.c ${COVERAGE_SRCS} PARENT_SCOPE)
+    set(COVERAGE_SRCS src/os/unix/loadfile.c src/os/unix/graphics_dummy.c src/os/unix/sound.c src/os/unix/io.c ${COVERAGE_SRCS} PARENT_SCOPE)
+    add_library(oslib loadfile.c graphics_dummy.c sound.c io.c)
+else()
+    add_library(oslib loadfile.c graphics.c sound.c io.c)
 endif()
 
-
-add_library(oslib loadfile.c graphics.c sound.c io.c)
-
 target_link_libraries(oslib glfw ${OPENGL_glu_LIBRARY} ${OPENGL_gl_LIBRARY})
diff --git a/src/os/unix/graphics_dummy.c b/src/os/unix/graphics_dummy.c
new file mode 100644
index 0000000..f652014
--- /dev/null
+++ b/src/os/unix/graphics_dummy.c
@@ -0,0 +1,138 @@
+/*
+ *  Graphic Manager - The TI-NESulator Project
+ *  os/macos/graphics.c
+ *
+ *  Created by Manoel TRAPIER on 08/05/08.
+ *  Copyright (c) 2003-2016 986-Studio. All rights reserved.
+ *
+ *  $LastChangedDate$
+ *  $Author$
+ *  $HeadURL$
+ *  $Revision$
+ *
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+
+#include <os_dependent.h>
+
+#include <GLFW/glfw3.h>
+//#include <OpenGL/glext.h>
+
+#include <palette.h>
+
+typedef struct GLWindow_t GLWindow;
+
+struct KeyArray
+{
+   unsigned char lastState;
+   unsigned char curState;
+   unsigned char debounced;
+   GLFWwindow* window;
+};
+
+struct GLWindow_t
+{
+   struct KeyArray keyArray[512];
+   GLFWwindow* windows;
+   unsigned char *videoMemory;
+   GLint videoTexture;
+   int WIDTH;
+   int HEIGHT;
+};
+
+#ifndef GL_TEXTURE_RECTANGLE_EXT
+#define GL_TEXTURE_RECTANGLE_EXT GL_TEXTURE_RECTANGLE_NV
+#endif
+
+void GLWindowInitEx(GLWindow *g, int w, int h)
+{
+}
+
+void GLWindowInit(GLWindow *g)
+{
+}
+
+void ShowScreen(GLWindow *g, int w, int h)
+{
+}
+
+void setupGL(GLWindow *g, int w, int h)
+{
+}
+
+void restoreGL(GLWindow *g, int w, int h)
+{
+}
+
+void kbHandler(GLFWwindow* window, int key, int scan, int action, int mod )
+{
+}
+
+void sizeHandler(GLFWwindow* window,int xs,int ys)
+{
+}
+
+
+void initDisplay(GLWindow *g)
+{
+}
+
+void drawPixel(GLWindow *gw, int x, int y, uint32_t colour)
+{
+}
+
+void drawLine(GLWindow *g, int x0, int y0, int x1, int y1, uint32_t colour)
+{
+}
+
+void drawCircle(GLWindow *g, int xc, int yc, int radius, uint32_t colour)
+{
+}
+
+void drawRect(GLWindow *g, int x0, int y0, int w, int h, uint32_t colour)
+{
+}
+
+void drawFillrect(GLWindow *g, int x0, int y0, int w, int h, uint32_t colour)
+{
+}
+
+void clearScreen(GLWindow *g)
+{
+}
+
+void updateScreen(GLWindow *g)
+{
+}
+
+void updateScreenAndWait(GLWindow *g)
+{
+}
+
+int graphics_init()
+{
+   return 0;
+}
+
+int graphics_drawpixel(long x, long y, long color)
+{
+   return 0;
+}
+
+int graphics_drawline(long x, long y, long x1, long y1, long color)
+{
+   return 0;
+}
+
+int graphics_blit(long x, long y, long w, long h)
+{
+   return 0;
+}
+
+int getKeyStatus(int key)
+{
+   return 0;
+}
diff --git a/src/os/unix/io.c b/src/os/unix/io.c
index 171a611..b1d9a76 100644
--- a/src/os/unix/io.c
+++ b/src/os/unix/io.c
@@ -40,11 +40,10 @@ int console_vprintf(const ConsoleLevel level, const char *format, va_list ap)
 
 int console_printf(const ConsoleLevel level, const char *format, ...)
 {
-   int ret = 0;
    va_list ap;
    va_start(ap, format);
 
-   ret = console_vprintf(level, format, ap);
+   console_vprintf(level, format, ap);
 
    va_end(ap);
    return 0;
@@ -58,4 +57,4 @@ int console_printf_d(const char *format, ...)
    console_vprintf (Console_Debug, format, ap);
    
    return 0;
-}
\ No newline at end of file
+}
diff --git a/src/os/unix/loadfile.c b/src/os/unix/loadfile.c
index 4d79168..8235591 100644
--- a/src/os/unix/loadfile.c
+++ b/src/os/unix/loadfile.c
@@ -30,5 +30,10 @@ void *LoadFilePtr(char * filename)
 	
 	close(fd);
 
+	if ( RetPtr == MAP_FAILED )
+	{
+                RetPtr = NULL;
+	}
+
 	return RetPtr;
 }
diff --git a/src/ppu/ppu.c b/src/ppu/ppu.c
index df3c09b..088063c 100755
--- a/src/ppu/ppu.c
+++ b/src/ppu/ppu.c
@@ -36,8 +36,8 @@
 
 extern int VBLANK_TIME;
 
-volatile extern int frame;
-volatile extern unsigned long IPS, FPS;
+extern volatile int frame;
+extern volatile unsigned long IPS, FPS;
 
 extern unsigned long ColorPalette[9 * 63];
 extern short IRQScanHit;