diff --git a/main.cpp b/main.cpp
index 96d3ea3..9c9685c 100644
--- a/main.cpp
+++ b/main.cpp
@@ -10,6 +10,8 @@
 #include <string.h>
 
 uint8_t memory[65536];
+uint32_t time = 0;
+uint32_t t_states = 0;
 
 int main(int argc, char *argv[])
 {
@@ -26,13 +28,16 @@ int main(int argc, char *argv[])
 
     zx_ula::sound_init();
 
-    zx_tape::load("manic.tap");
+    zx_tape::load("abusimbel.tap");
 
     if (argc==3) { z80debug::loadngo(argv[1], argv[2]); }
 
     bool should_exit = false;
     SDL_Event e;
 
+    time = SDL_GetTicks();
+    t_states = 0;
+
     while (!should_exit)
     {
         while (SDL_PollEvent(&e))
@@ -83,16 +88,25 @@ int main(int argc, char *argv[])
                 }
             }
         }
+
         if (!z80debug::debugging()) {
             if (z80debug::isbreak(z80::getPC(), 9)) {
                 z80debug::stop();
                 zxscreen::redraw();
             } else {
-                if (z80::getPC()==0x05C8) zx_tape::go_berserk();
+                //if (z80::getPC()==0x05C8) zx_tape::go_berserk();
                 uint8_t dt = z80::step();
+                t_states += dt;
                 zx_tape::update(dt);
                 zx_ula::sound_update(dt);
                 zxscreen::refresh(dt);
+
+                if (t_states>=350000)
+                {
+                    while (SDL_GetTicks()<time+100) {}
+                    t_states -= 350000;
+                    time = SDL_GetTicks();
+                }
             }
         }
     }
diff --git a/zx_ula.cpp b/zx_ula.cpp
index 6cfe267..877f12b 100644
--- a/zx_ula.cpp
+++ b/zx_ula.cpp
@@ -57,6 +57,8 @@ namespace zx_ula
     static uint8_t ear = 0;
     static uint8_t mic = 0;
 
+    static uint16_t last_1 = 0;
+
     void update_zx_keyboard()
     {
         const uint8_t *keys = SDL_GetKeyboardState(NULL);
@@ -220,15 +222,33 @@ namespace zx_ula
     void audioCallback(void * userdata, uint8_t * stream, int len)
     {
         const uint16_t top = sound_pos < len ? sound_pos : len;
+        printf("top: %i, len: %i, pos: %i\n", top, len, sound_pos);
         memcpy(stream, sound_buffer, top);
         if (top<len) memchr(&stream[top], sound_buffer[top-1], len-top);
-        sound_pos=0;
+        if (top<sound_pos)
+        {
+            if (last_1>top)
+            {
+                memcpy(sound_buffer, &sound_buffer[top], sound_pos-top);
+                sound_pos=sound_pos-top;
+                last_1=last_1-top;
+            }
+            else
+            {
+                sound_pos=last_1=0;
+            }
+        }
+        else
+        {
+            sound_pos=last_1=0;
+        }
     }
 
     void sound_init()
     {
         SDL_AudioSpec audioSpec{11025, AUDIO_U8, 1, 0, 220, 0, 0, &audioCallback, NULL};
         sdlAudioDevice = SDL_OpenAudioDevice(NULL, 0, &audioSpec, NULL, 0);
+        sound_enable();
     }
 
     void sound_enable()
@@ -244,9 +264,20 @@ namespace zx_ula
     void sound_update(const uint8_t dt)
     {
         t_sound += dt;
-        if (t_sound>=317) {
-            t_sound-=317;
-            sound_buffer[sound_pos++] = ear*128;
+        if (t_sound>=318) {
+            t_sound-=318;
+            //sound_pos = (sound_pos+1) & 0x3ff;
+            //sound_buffer[sound_pos] = ear*128;
+
+            if (sound_pos<1024)
+            {
+                sound_buffer[sound_pos++] = ear*128;
+                if (ear) last_1 = sound_pos;
+            }
+            /*else
+            {
+                printf("WARNING! Sound buffer overflow!\n");
+            }*/
         }
     }
 }
\ No newline at end of file