diff --git a/src/devices/rtc_ds1307.cc b/src/devices/rtc_ds1307.cc
index cf6335b4..acc99ece 100644
--- a/src/devices/rtc_ds1307.cc
+++ b/src/devices/rtc_ds1307.cc
@@ -37,7 +37,7 @@
     } else      \
         printf
 
-enum { DS_SECONDS = 0, DS_MINUTES, DS_HOURS, DS_DAY, DS_DATE, DS_MONTH, DS_YEAR, DS_CONTROL };
+enum { DS_SECONDS = 0, DS_MINUTES, DS_HOURS, DS_DAY, DS_DATE, DS_MONTH, DS_YEAR, DS_CTRL };
 
 #ifdef _DEBUG
 static char buff[30];
@@ -69,7 +69,7 @@ const char* get_addr_str(const unsigned char addr, const unsigned char data) {
         case DS_YEAR:
             sprintf(buff, "YEAR    [%02X] = %02X", addr, data);
             break;
-        case DS_CONTROL:
+        case DS_CTRL:
             sprintf(buff, "CONTROL [%02X] = %02X", addr, data);
             break;
         default:
@@ -265,7 +265,7 @@ void rtc_ds1307_init(rtc_ds1307_t* rtc, board* pboard_) {
 
     memset(rtc->data, 0xFF, 8);
     rtc->data[DS_HOURS] &= 0x3F;  // 24h mode
-    rtc->data[DS_CONTROL] = 0;
+    rtc->data[DS_CTRL] = 0;
     rtc_ds1307_rst(rtc);
 
     utime = time(NULL);
@@ -404,4 +404,4 @@ unsigned char rtc_ds1307_I2C_io(rtc_ds1307_t* rtc, unsigned char scl, unsigned c
     return ret;
 }
 
-// TODO int output
\ No newline at end of file
+// TODO int output
diff --git a/src/parts/output_Buzzer.cc b/src/parts/output_Buzzer.cc
index 7e1f1688..a43c1fb1 100644
--- a/src/parts/output_Buzzer.cc
+++ b/src/parts/output_Buzzer.cc
@@ -305,14 +305,16 @@ void cpart_Buzzer::PostProcess(void) {
             }
         }
     } else if (btype == PASSIVE) {
-        buffer[buffercount - 1] = 0;
-        short* ptr[2];
-        ptr[0] = (short int*)&buffercount;
-        ptr[1] = buffer;
-        /*int ret =*/PICSimLab.SystemCmd(PSC_AUDIOCHSOUNDPLAY, (const char*)&buzzerId, ptr);
-        // printf("ret=%i buffercount=%i sample=%i time=%f timer=%i\n", ret, buffercount, samplerate,
-        //        ((float)(buffercount)) / samplerate, timer->GetTime());
-        buffercount = 0;
+        if (buffercount) {
+            buffer[buffercount - 1] = 0;
+            short* ptr[2];
+            ptr[0] = (short int*)&buffercount;
+            ptr[1] = buffer;
+            /*int ret =*/PICSimLab.SystemCmd(PSC_AUDIOCHSOUNDPLAY, (const char*)&buzzerId, ptr);
+            // printf("ret=%i buffercount=%i sample=%i time=%f timer=%i\n", ret, buffercount, samplerate,
+            //        ((float)(buffercount)) / samplerate, timer->GetTime());
+            buffercount = 0;
+        }
     } else  // TONE
     {
         float freq;