diff --git a/main.cpp b/main.cpp
index 53be1ff..8f22b6e 100644
--- a/main.cpp
+++ b/main.cpp
@@ -8,8 +8,31 @@
 #include <SDL2/SDL.h>
 #include <string.h>
 
+SDL_AudioDeviceID sdlAudioDevice;
+
 uint8_t memory[65536];
 uint32_t t = 0;
+uint16_t ts = 0;
+uint8_t ft = 0;
+uint32_t fps=0;
+uint32_t fps_time=0;
+
+uint8_t sound_buffer[1024];
+uint16_t sound_pos;
+
+void audioCallback(void * userdata, uint8_t * stream, int len)
+{
+    uint16_t top = len;
+    if (sound_pos < len)
+    {
+        top = sound_pos;
+        //printf("buffer underrun!\n");
+    }
+    memcpy(stream, sound_buffer, top);
+    sound_pos=0;
+}
+
+uint8_t test = 0;
 
 int main(int argc, char *argv[])
 {
@@ -24,6 +47,10 @@ int main(int argc, char *argv[])
     z80debug::show();
     zxscreen::show();
 
+    SDL_AudioSpec audioSpec{11025, AUDIO_U8, 1, 0, 220, 0, 0, &audioCallback, NULL};
+    sdlAudioDevice = SDL_OpenAudioDevice(NULL, 0, &audioSpec, NULL, 0);
+    SDL_PauseAudioDevice(sdlAudioDevice, 0);
+
     bool should_exit = false;
     SDL_Event e;
 
@@ -48,6 +75,8 @@ int main(int argc, char *argv[])
                     } else if (e.key.keysym.scancode==SDL_SCANCODE_F5) {
                         z80::step();
                         z80debug::cont();
+                        fps=0;
+                        fps_time = SDL_GetTicks();
                         zxscreen::refresh();
                     } else if (e.key.keysym.scancode==SDL_SCANCODE_RETURN) {
                         z80debug::executeConsole();
@@ -72,9 +101,31 @@ int main(int argc, char *argv[])
                 z80debug::stop();
                 zxscreen::refresh();
             } else {
-                t += z80::step();
+                uint8_t t_states = z80::step();
+                t += t_states;
+                ts += t_states;
+                if (ts>=400) {
+                    ts-=400;
+                    uint8_t ear = zx_ula::get_ear();
+                    //if (ear)
+                    sound_buffer[sound_pos++] = ear*128;
+                        //SDL_QueueAudio(sdlAudioDevice, &beep[ear], 1);
+                    //else
+                        //SDL_ClearQueuedAudio(sdlAudioDevice);
+
+                }
                 if (t>=69888) {
-                    t=0;
+                    ft++;
+                    if (ft==16) { ft=0; zxscreen::flash(); }
+/*
+                    fps++;
+                    if (SDL_GetTicks() - fps_time >= 1000) {
+                        printf("FPS: %i\n", fps);
+                        fps = 0;
+                        fps_time = SDL_GetTicks();
+                    }
+*/
+                    t=0;                    
                     zxscreen::refresh();
                     z80::interrupt();
                 }
diff --git a/zx_screen.cpp b/zx_screen.cpp
index 60f60b8..e998a2c 100644
--- a/zx_screen.cpp
+++ b/zx_screen.cpp
@@ -13,6 +13,10 @@ namespace zxscreen
     SDL_Renderer *ren = nullptr;
     SDL_Texture *tex = nullptr;
 
+    bool _flash = false;
+
+    void flash() { _flash = not _flash; }
+
     void show()
     {
         if (win) return;
@@ -48,9 +52,11 @@ namespace zxscreen
 
                 uint16_t address = 0x4000 | (x&0x1f) | ((y&0x7)<<8) | ((y&0x38)<<2) | ((y&0xc0)<<5);
                 uint8_t block = memory[address];
+                uint8_t c1 = color&0x7, c2 = (color>>3)&0x7;
+                if ((color&0x80) && _flash) { c1=c2; c2=color&0x7; }
                 for (int i=0;i<8;++i)
                 {
-                    *(pixels++)=(block&0x80) ? palette[color&0x7] : palette[(color>>3)&0x7];
+                    *(pixels++)=(block&0x80) ? palette[c1] : palette[c2];
                     block = block<<1;
                 }
             }
diff --git a/zx_screen.h b/zx_screen.h
index 0244d79..276bf7b 100644
--- a/zx_screen.h
+++ b/zx_screen.h
@@ -4,4 +4,5 @@ namespace zxscreen
 {
     void show();
     void refresh();
+    void flash();
 }
diff --git a/zx_ula.cpp b/zx_ula.cpp
index a158a37..9985a1a 100644
--- a/zx_ula.cpp
+++ b/zx_ula.cpp
@@ -92,7 +92,9 @@ namespace zx_ula
         border_color = val & 0x7;
         mic = (val>>3)&0x1;
         ear = (val>>4)&0x1;
+        //printf("EAR:%i MIC:%i\n", ear, mic);
     }
 
     uint8_t get_border_color() { return border_color; }
+    uint8_t get_ear() { return ear; }
 }
\ No newline at end of file
diff --git a/zx_ula.h b/zx_ula.h
index f5fdec1..cdaa2b5 100644
--- a/zx_ula.h
+++ b/zx_ula.h
@@ -8,4 +8,5 @@ namespace zx_ula
     void port_out(int port, int val);
 
     uint8_t get_border_color();
+    uint8_t get_ear();
 }