Some more optimizations on AUDIO. AUDIO option set to false by default.

src/audio.h

@@ -166,6 +166,25 @@ void audioDefevent(uint8_t e);
 #define AUDIO_MIX_WARNING_1() audioDefevent(AU_MIX_WARNING_1)
 #define AUDIO_MIX_WARNING_3() audioDefevent(AU_MIX_WARNING_3)
 
-#define AUDIO_HEARTBEAT()   audio.heartbeat()
+#if defined(PCBSTD)
+#define AUDIO_HEARTBEAT() \
+  if (audio.toneTimeLeft > 0) { \
+    static uint8_t toneCounter; \
+    toneCounter += audio.toneFreq; \
+    if ((toneCounter & 0x80) == 0x80) \
+      PORTE |= (1 << OUT_E_BUZZER); \
+    else \
+      PORTE &= ~(1 << OUT_E_BUZZER); \
+  } \
+  static uint8_t cnt10ms = 77; \
+  if (cnt10ms-- == 0) \
+    cnt10ms = 77; \
+  else \
+    return; \
+  audio.heartbeat()
+#else
+#define AUDIO_HEARTBEAT() \
+  audio.heartbeat()
+#endif
 
 #endif // audio_h