From fd3d57b1cba942ded63d532c5db4f0ca3d378ace Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Fri, 15 Apr 2022 15:01:11 -0500
Subject: [PATCH] even more improvements to low-latency mode

---
 src/engine/dispatch.h              |  3 ++-
 src/engine/platform/abstract.cpp   |  2 +-
 src/engine/platform/amiga.cpp      |  2 +-
 src/engine/platform/amiga.h        |  2 +-
 src/engine/platform/arcade.cpp     |  2 +-
 src/engine/platform/arcade.h       |  2 +-
 src/engine/platform/ay.cpp         |  2 +-
 src/engine/platform/ay.h           |  2 +-
 src/engine/platform/ay8930.cpp     |  2 +-
 src/engine/platform/ay8930.h       |  2 +-
 src/engine/platform/bubsyswsg.cpp  |  2 +-
 src/engine/platform/bubsyswsg.h    |  2 +-
 src/engine/platform/c64.cpp        | 16 +++++++++-------
 src/engine/platform/c64.h          |  2 +-
 src/engine/platform/dummy.cpp      | 10 ++++++----
 src/engine/platform/dummy.h        |  2 +-
 src/engine/platform/fds.cpp        |  2 +-
 src/engine/platform/fds.h          |  2 +-
 src/engine/platform/gb.cpp         |  2 +-
 src/engine/platform/gb.h           |  2 +-
 src/engine/platform/genesis.cpp    |  2 +-
 src/engine/platform/genesis.h      |  2 +-
 src/engine/platform/genesisext.cpp |  4 ++--
 src/engine/platform/genesisext.h   |  2 +-
 src/engine/platform/lynx.cpp       |  2 +-
 src/engine/platform/lynx.h         |  2 +-
 src/engine/platform/mmc5.cpp       |  2 +-
 src/engine/platform/mmc5.h         |  2 +-
 src/engine/platform/n163.cpp       |  2 +-
 src/engine/platform/n163.h         |  2 +-
 src/engine/platform/nes.cpp        |  2 +-
 src/engine/platform/nes.h          |  2 +-
 src/engine/platform/opl.cpp        |  2 +-
 src/engine/platform/opl.h          |  2 +-
 src/engine/platform/opll.cpp       |  2 +-
 src/engine/platform/opll.h         |  2 +-
 src/engine/platform/pce.cpp        |  2 +-
 src/engine/platform/pce.h          |  2 +-
 src/engine/platform/pcspkr.cpp     |  2 +-
 src/engine/platform/pcspkr.h       |  2 +-
 src/engine/platform/pet.cpp        |  2 +-
 src/engine/platform/pet.h          |  2 +-
 src/engine/platform/qsound.cpp     |  2 +-
 src/engine/platform/qsound.h       |  2 +-
 src/engine/platform/saa.cpp        |  2 +-
 src/engine/platform/saa.h          |  2 +-
 src/engine/platform/segapcm.cpp    |  2 +-
 src/engine/platform/segapcm.h      |  2 +-
 src/engine/platform/sms.cpp        |  2 +-
 src/engine/platform/sms.h          |  2 +-
 src/engine/platform/swan.cpp       |  2 +-
 src/engine/platform/swan.h         |  2 +-
 src/engine/platform/tia.cpp        |  2 +-
 src/engine/platform/tia.h          |  2 +-
 src/engine/platform/tx81z.cpp      |  2 +-
 src/engine/platform/tx81z.h        |  2 +-
 src/engine/platform/vera.cpp       |  2 +-
 src/engine/platform/vera.h         |  2 +-
 src/engine/platform/vic20.cpp      |  2 +-
 src/engine/platform/vic20.h        |  2 +-
 src/engine/platform/vrc6.cpp       |  2 +-
 src/engine/platform/vrc6.h         |  2 +-
 src/engine/platform/x1_010.cpp     |  2 +-
 src/engine/platform/x1_010.h       |  2 +-
 src/engine/platform/ym2610.cpp     |  4 ++--
 src/engine/platform/ym2610.h       |  2 +-
 src/engine/platform/ym2610b.cpp    |  4 ++--
 src/engine/platform/ym2610b.h      |  2 +-
 src/engine/platform/ym2610bext.cpp |  4 ++--
 src/engine/platform/ym2610bext.h   |  2 +-
 src/engine/platform/ym2610ext.cpp  |  4 ++--
 src/engine/platform/ym2610ext.h    |  2 +-
 src/engine/playback.cpp            |  2 +-
 src/engine/waveSynth.cpp           |  4 ++++
 src/engine/waveSynth.h             |  3 ++-
 75 files changed, 98 insertions(+), 88 deletions(-)

diff --git a/src/engine/dispatch.h b/src/engine/dispatch.h
index 37e36a2bf..c35ff919c 100644
--- a/src/engine/dispatch.h
+++ b/src/engine/dispatch.h
@@ -245,8 +245,9 @@ class DivDispatch {
 
     /**
      * ticks this dispatch.
+     * @param sysTick whether the engine has ticked (if not then this may be a sub-tick used in low-latency mode).
      */
-    virtual void tick();
+    virtual void tick(bool sysTick=true);
 
     /**
      * get the state of a channel.
diff --git a/src/engine/platform/abstract.cpp b/src/engine/platform/abstract.cpp
index b860f6808..343838e73 100644
--- a/src/engine/platform/abstract.cpp
+++ b/src/engine/platform/abstract.cpp
@@ -22,7 +22,7 @@
 void DivDispatch::acquire(short* bufL, short* bufR, size_t start, size_t len) {
 }
 
-void DivDispatch::tick() {
+void DivDispatch::tick(bool sysTick) {
 }
 
 void* DivDispatch::getChanState(int chan) {
diff --git a/src/engine/platform/amiga.cpp b/src/engine/platform/amiga.cpp
index b8419d197..104e66d45 100644
--- a/src/engine/platform/amiga.cpp
+++ b/src/engine/platform/amiga.cpp
@@ -155,7 +155,7 @@ void DivPlatformAmiga::acquire(short* bufL, short* bufR, size_t start, size_t le
   }
 }
 
-void DivPlatformAmiga::tick() {
+void DivPlatformAmiga::tick(bool sysTick) {
   for (int i=0; i<4; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/amiga.h b/src/engine/platform/amiga.h
index 8fbe8fec8..07c44ee7c 100644
--- a/src/engine/platform/amiga.h
+++ b/src/engine/platform/amiga.h
@@ -88,7 +88,7 @@ class DivPlatformAmiga: public DivDispatch {
     void* getChanState(int chan);
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool isStereo();
     bool keyOffAffectsArp(int ch);
diff --git a/src/engine/platform/arcade.cpp b/src/engine/platform/arcade.cpp
index a7ab53ec0..0bcb3b990 100644
--- a/src/engine/platform/arcade.cpp
+++ b/src/engine/platform/arcade.cpp
@@ -219,7 +219,7 @@ inline int hScale(int note) {
   return ((note/12)<<4)+(noteMap[note%12]);
 }
 
-void DivPlatformArcade::tick() {
+void DivPlatformArcade::tick(bool sysTick) {
   for (int i=0; i<8; i++) {
     chan[i].std.next();
 
diff --git a/src/engine/platform/arcade.h b/src/engine/platform/arcade.h
index a6ec82c94..41af49e33 100644
--- a/src/engine/platform/arcade.h
+++ b/src/engine/platform/arcade.h
@@ -107,7 +107,7 @@ class DivPlatformArcade: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void notifyInsChange(int ins);
     void setFlags(unsigned int flags);
diff --git a/src/engine/platform/ay.cpp b/src/engine/platform/ay.cpp
index e8a61b9ae..d3db4ba8b 100644
--- a/src/engine/platform/ay.cpp
+++ b/src/engine/platform/ay.cpp
@@ -172,7 +172,7 @@ void DivPlatformAY8910::updateOutSel(bool immediate) {
   }
 }
 
-void DivPlatformAY8910::tick() {
+void DivPlatformAY8910::tick(bool sysTick) {
   // PSG
   for (int i=0; i<3; i++) {
     chan[i].std.next();
diff --git a/src/engine/platform/ay.h b/src/engine/platform/ay.h
index b1a3ea127..a78f21bc8 100644
--- a/src/engine/platform/ay.h
+++ b/src/engine/platform/ay.h
@@ -90,7 +90,7 @@ class DivPlatformAY8910: public DivDispatch {
     void flushWrites();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void setFlags(unsigned int flags);
     bool isStereo();
diff --git a/src/engine/platform/ay8930.cpp b/src/engine/platform/ay8930.cpp
index 9f684a048..9fa39131c 100644
--- a/src/engine/platform/ay8930.cpp
+++ b/src/engine/platform/ay8930.cpp
@@ -187,7 +187,7 @@ const unsigned char regMode[3]={
   0x0d, 0x14, 0x15
 };
 
-void DivPlatformAY8930::tick() {
+void DivPlatformAY8930::tick(bool sysTick) {
   // PSG
   for (int i=0; i<3; i++) {
     chan[i].std.next();
diff --git a/src/engine/platform/ay8930.h b/src/engine/platform/ay8930.h
index 6bd51bdcd..adbe0be87 100644
--- a/src/engine/platform/ay8930.h
+++ b/src/engine/platform/ay8930.h
@@ -78,7 +78,7 @@ class DivPlatformAY8930: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void setFlags(unsigned int flags);
     bool isStereo();
diff --git a/src/engine/platform/bubsyswsg.cpp b/src/engine/platform/bubsyswsg.cpp
index 4a80bf414..91f50d461 100644
--- a/src/engine/platform/bubsyswsg.cpp
+++ b/src/engine/platform/bubsyswsg.cpp
@@ -81,7 +81,7 @@ void DivPlatformBubSysWSG::updateWave(int ch) {
   }
 }
 
-void DivPlatformBubSysWSG::tick() {
+void DivPlatformBubSysWSG::tick(bool sysTick) {
   for (int i=0; i<2; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/bubsyswsg.h b/src/engine/platform/bubsyswsg.h
index 6c0e2261e..2efcc4d98 100644
--- a/src/engine/platform/bubsyswsg.h
+++ b/src/engine/platform/bubsyswsg.h
@@ -67,7 +67,7 @@ class DivPlatformBubSysWSG: public DivDispatch {
     int getRegisterPoolDepth();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool isStereo();
     bool keyOffAffectsArp(int ch);
diff --git a/src/engine/platform/c64.cpp b/src/engine/platform/c64.cpp
index db5ab46a6..4c3cc32e4 100644
--- a/src/engine/platform/c64.cpp
+++ b/src/engine/platform/c64.cpp
@@ -122,7 +122,7 @@ void DivPlatformC64::updateFilter() {
   rWrite(0x18,(filtControl<<4)|vol);
 }
 
-void DivPlatformC64::tick() {
+void DivPlatformC64::tick(bool sysTick) {
   for (int i=0; i<3; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
@@ -166,12 +166,14 @@ void DivPlatformC64::tick() {
       rWrite(i*7+2,chan[i].duty&0xff);
       rWrite(i*7+3,chan[i].duty>>8);
     }
-    if (chan[i].testWhen>0) {
-      if (--chan[i].testWhen<1) {
-        if (!chan[i].resetMask) {
-          rWrite(i*7+5,0);
-          rWrite(i*7+6,0);
-          rWrite(i*7+4,(chan[i].wave<<4)|8|(chan[i].ring<<2)|(chan[i].sync<<1));
+    if (sysTick) {
+      if (chan[i].testWhen>0) {
+        if (--chan[i].testWhen<1) {
+          if (!chan[i].resetMask) {
+            rWrite(i*7+5,0);
+            rWrite(i*7+6,0);
+            rWrite(i*7+4,(chan[i].wave<<4)|8|(chan[i].ring<<2)|(chan[i].sync<<1));
+          }
         }
       }
     }
diff --git a/src/engine/platform/c64.h b/src/engine/platform/c64.h
index e288940e5..f77e24b97 100644
--- a/src/engine/platform/c64.h
+++ b/src/engine/platform/c64.h
@@ -83,7 +83,7 @@ class DivPlatformC64: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void setFlags(unsigned int flags);
     void notifyInsChange(int ins);
diff --git a/src/engine/platform/dummy.cpp b/src/engine/platform/dummy.cpp
index 308b83722..e751e3b6f 100644
--- a/src/engine/platform/dummy.cpp
+++ b/src/engine/platform/dummy.cpp
@@ -38,10 +38,12 @@ void DivPlatformDummy::muteChannel(int ch, bool mute) {
   isMuted[ch]=mute;
 }
 
-void DivPlatformDummy::tick() {
+void DivPlatformDummy::tick(bool sysTick) {
   for (unsigned char i=0; i<chans; i++) {
-    chan[i].amp-=3;
-    if (chan[i].amp<16) chan[i].amp=16;
+    if (sysTick) {
+      chan[i].amp-=3;
+      if (chan[i].amp<16) chan[i].amp=16;
+    }
 
     if (chan[i].freqChanged) {
       chan[i].freqChanged=false;
@@ -115,4 +117,4 @@ void DivPlatformDummy::quit() {
 }
 
 DivPlatformDummy::~DivPlatformDummy() {
-}
\ No newline at end of file
+}
diff --git a/src/engine/platform/dummy.h b/src/engine/platform/dummy.h
index 055412df3..aa38b33bf 100644
--- a/src/engine/platform/dummy.h
+++ b/src/engine/platform/dummy.h
@@ -41,7 +41,7 @@ class DivPlatformDummy: public DivDispatch {
     int dispatch(DivCommand c);
     void* getChanState(int chan);
     void reset();
-    void tick();
+    void tick(bool sysTick=true);
     int init(DivEngine* parent, int channels, int sugRate, unsigned int flags);
     void quit();
     ~DivPlatformDummy();
diff --git a/src/engine/platform/fds.cpp b/src/engine/platform/fds.cpp
index aefa37541..16e24f130 100644
--- a/src/engine/platform/fds.cpp
+++ b/src/engine/platform/fds.cpp
@@ -97,7 +97,7 @@ void DivPlatformFDS::updateWave() {
   rWrite(0x4089,0);
 }
 
-void DivPlatformFDS::tick() {
+void DivPlatformFDS::tick(bool sysTick) {
   for (int i=0; i<1; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/fds.h b/src/engine/platform/fds.h
index d8d588a23..6d206f3ea 100644
--- a/src/engine/platform/fds.h
+++ b/src/engine/platform/fds.h
@@ -77,7 +77,7 @@ class DivPlatformFDS: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool keyOffAffectsArp(int ch);
     void setFlags(unsigned int flags);
diff --git a/src/engine/platform/gb.cpp b/src/engine/platform/gb.cpp
index 8791e6d4c..c28478a3a 100644
--- a/src/engine/platform/gb.cpp
+++ b/src/engine/platform/gb.cpp
@@ -146,7 +146,7 @@ static unsigned char noiseTable[256]={
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 };
 
-void DivPlatformGB::tick() {
+void DivPlatformGB::tick(bool sysTick) {
   for (int i=0; i<4; i++) {
     chan[i].std.next();
     if (chan[i].std.arp.had) {
diff --git a/src/engine/platform/gb.h b/src/engine/platform/gb.h
index 5a345e45d..df7070ec8 100644
--- a/src/engine/platform/gb.h
+++ b/src/engine/platform/gb.h
@@ -70,7 +70,7 @@ class DivPlatformGB: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool isStereo();
     void notifyInsChange(int ins);
diff --git a/src/engine/platform/genesis.cpp b/src/engine/platform/genesis.cpp
index 7a9a1d51a..bcca663ec 100644
--- a/src/engine/platform/genesis.cpp
+++ b/src/engine/platform/genesis.cpp
@@ -220,7 +220,7 @@ void DivPlatformGenesis::acquire(short* bufL, short* bufR, size_t start, size_t
   }
 }
 
-void DivPlatformGenesis::tick() {
+void DivPlatformGenesis::tick(bool sysTick) {
   for (int i=0; i<6; i++) {
     if (i==2 && extMode) continue;
     chan[i].std.next();
diff --git a/src/engine/platform/genesis.h b/src/engine/platform/genesis.h
index 51d98d807..34db5a252 100644
--- a/src/engine/platform/genesis.h
+++ b/src/engine/platform/genesis.h
@@ -109,7 +109,7 @@ class DivPlatformGenesis: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool isStereo();
     void setYMFM(bool use);
diff --git a/src/engine/platform/genesisext.cpp b/src/engine/platform/genesisext.cpp
index e8ddbdc79..403c1a8cf 100644
--- a/src/engine/platform/genesisext.cpp
+++ b/src/engine/platform/genesisext.cpp
@@ -266,7 +266,7 @@ static int opChanOffsH[4]={
   0xad, 0xae, 0xac, 0xa6
 };
 
-void DivPlatformGenesisExt::tick() {
+void DivPlatformGenesisExt::tick(bool sysTick) {
   if (extMode) {
     bool writeSomething=false;
     unsigned char writeMask=2;
@@ -283,7 +283,7 @@ void DivPlatformGenesisExt::tick() {
     }
   }
 
-  DivPlatformGenesis::tick();
+  DivPlatformGenesis::tick(sysTick);
 
   bool writeNoteOn=false;
   unsigned char writeMask=2;
diff --git a/src/engine/platform/genesisext.h b/src/engine/platform/genesisext.h
index e3320e191..fc9eed892 100644
--- a/src/engine/platform/genesisext.h
+++ b/src/engine/platform/genesisext.h
@@ -41,7 +41,7 @@ class DivPlatformGenesisExt: public DivPlatformGenesis {
     void* getChanState(int chan);
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool keyOffAffectsArp(int ch);
     bool keyOffAffectsPorta(int ch);
diff --git a/src/engine/platform/lynx.cpp b/src/engine/platform/lynx.cpp
index 6120233af..307d2059a 100644
--- a/src/engine/platform/lynx.cpp
+++ b/src/engine/platform/lynx.cpp
@@ -145,7 +145,7 @@ void DivPlatformLynx::acquire(short* bufL, short* bufR, size_t start, size_t len
   mikey->sampleAudio( bufL + start, bufR + start, len );
 }
 
-void DivPlatformLynx::tick() {
+void DivPlatformLynx::tick(bool sysTick) {
   for (int i=0; i<4; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/lynx.h b/src/engine/platform/lynx.h
index 536a874a8..61f6e67df 100644
--- a/src/engine/platform/lynx.h
+++ b/src/engine/platform/lynx.h
@@ -80,7 +80,7 @@ class DivPlatformLynx: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool isStereo();
     bool keyOffAffectsArp(int ch);
diff --git a/src/engine/platform/mmc5.cpp b/src/engine/platform/mmc5.cpp
index a9f9bb796..3c7f3dcab 100644
--- a/src/engine/platform/mmc5.cpp
+++ b/src/engine/platform/mmc5.cpp
@@ -95,7 +95,7 @@ void DivPlatformMMC5::acquire(short* bufL, short* bufR, size_t start, size_t len
   }
 }
 
-void DivPlatformMMC5::tick() {
+void DivPlatformMMC5::tick(bool sysTick) {
   for (int i=0; i<2; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/mmc5.h b/src/engine/platform/mmc5.h
index 6b364d5ad..02ca06e84 100644
--- a/src/engine/platform/mmc5.h
+++ b/src/engine/platform/mmc5.h
@@ -71,7 +71,7 @@ class DivPlatformMMC5: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool keyOffAffectsArp(int ch);
     float getPostAmp();
diff --git a/src/engine/platform/n163.cpp b/src/engine/platform/n163.cpp
index a66157d9e..6a1eb60e0 100644
--- a/src/engine/platform/n163.cpp
+++ b/src/engine/platform/n163.cpp
@@ -214,7 +214,7 @@ void DivPlatformN163::updateWaveCh(int ch) {
   }
 }
 
-void DivPlatformN163::tick() {
+void DivPlatformN163::tick(bool sysTick) {
   for (int i=0; i<=chanMax; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/n163.h b/src/engine/platform/n163.h
index 2f68d6c9d..38ebeace3 100644
--- a/src/engine/platform/n163.h
+++ b/src/engine/platform/n163.h
@@ -93,7 +93,7 @@ class DivPlatformN163: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void setFlags(unsigned int flags);
     void notifyWaveChange(int wave);
diff --git a/src/engine/platform/nes.cpp b/src/engine/platform/nes.cpp
index 4c65ce4f2..7e291446f 100644
--- a/src/engine/platform/nes.cpp
+++ b/src/engine/platform/nes.cpp
@@ -140,7 +140,7 @@ static unsigned char noiseTable[253]={
   15
 };
 
-void DivPlatformNES::tick() {
+void DivPlatformNES::tick(bool sysTick) {
   for (int i=0; i<4; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/nes.h b/src/engine/platform/nes.h
index 1dbb4411b..2cf2a8a15 100644
--- a/src/engine/platform/nes.h
+++ b/src/engine/platform/nes.h
@@ -72,7 +72,7 @@ class DivPlatformNES: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool keyOffAffectsArp(int ch);
     float getPostAmp();
diff --git a/src/engine/platform/opl.cpp b/src/engine/platform/opl.cpp
index add3815c5..e73ca41e4 100644
--- a/src/engine/platform/opl.cpp
+++ b/src/engine/platform/opl.cpp
@@ -228,7 +228,7 @@ void DivPlatformOPL::acquire(short* bufL, short* bufR, size_t start, size_t len)
   //}
 }
 
-void DivPlatformOPL::tick() {
+void DivPlatformOPL::tick(bool sysTick) {
   for (int i=0; i<totalChans; i++) {
     int ops=(slots[3][i]!=255 && chan[i].state.ops==4 && oplType==3)?4:2;
     chan[i].std.next();
diff --git a/src/engine/platform/opl.h b/src/engine/platform/opl.h
index 44d80fda2..76979a54f 100644
--- a/src/engine/platform/opl.h
+++ b/src/engine/platform/opl.h
@@ -104,7 +104,7 @@ class DivPlatformOPL: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool isStereo();
     void setYMFM(bool use);
diff --git a/src/engine/platform/opll.cpp b/src/engine/platform/opll.cpp
index e6579e84b..cb6ceba83 100644
--- a/src/engine/platform/opll.cpp
+++ b/src/engine/platform/opll.cpp
@@ -111,7 +111,7 @@ void DivPlatformOPLL::acquire(short* bufL, short* bufR, size_t start, size_t len
   acquire_nuked(bufL,bufR,start,len);
 }
 
-void DivPlatformOPLL::tick() {
+void DivPlatformOPLL::tick(bool sysTick) {
   for (int i=0; i<11; i++) {
     chan[i].std.next();
 
diff --git a/src/engine/platform/opll.h b/src/engine/platform/opll.h
index 4a7a4c97f..04f4f13a7 100644
--- a/src/engine/platform/opll.h
+++ b/src/engine/platform/opll.h
@@ -100,7 +100,7 @@ class DivPlatformOPLL: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void setYMFM(bool use);
     bool keyOffAffectsArp(int ch);
diff --git a/src/engine/platform/pce.cpp b/src/engine/platform/pce.cpp
index 2c61a5fa1..cff5e534a 100644
--- a/src/engine/platform/pce.cpp
+++ b/src/engine/platform/pce.cpp
@@ -146,7 +146,7 @@ static unsigned char noiseFreq[12]={
   4,13,15,18,21,23,25,27,29,31,0,2  
 };
 
-void DivPlatformPCE::tick() {
+void DivPlatformPCE::tick(bool sysTick) {
   for (int i=0; i<6; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/pce.h b/src/engine/platform/pce.h
index 2e8614ba8..57a4b033f 100644
--- a/src/engine/platform/pce.h
+++ b/src/engine/platform/pce.h
@@ -87,7 +87,7 @@ class DivPlatformPCE: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool isStereo();
     bool keyOffAffectsArp(int ch);
diff --git a/src/engine/platform/pcspkr.cpp b/src/engine/platform/pcspkr.cpp
index ffee3c03f..8e1705f50 100644
--- a/src/engine/platform/pcspkr.cpp
+++ b/src/engine/platform/pcspkr.cpp
@@ -164,7 +164,7 @@ void DivPlatformPCSpeaker::acquire(short* bufL, short* bufR, size_t start, size_
   }
 }
 
-void DivPlatformPCSpeaker::tick() {
+void DivPlatformPCSpeaker::tick(bool sysTick) {
   for (int i=0; i<1; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/pcspkr.h b/src/engine/platform/pcspkr.h
index 17dedf247..68e6bf1a6 100644
--- a/src/engine/platform/pcspkr.h
+++ b/src/engine/platform/pcspkr.h
@@ -77,7 +77,7 @@ class DivPlatformPCSpeaker: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool keyOffAffectsArp(int ch);
     void setFlags(unsigned int flags);
diff --git a/src/engine/platform/pet.cpp b/src/engine/platform/pet.cpp
index 104e2843a..0fe4523db 100644
--- a/src/engine/platform/pet.cpp
+++ b/src/engine/platform/pet.cpp
@@ -85,7 +85,7 @@ void DivPlatformPET::writeOutVol() {
   }
 }
 
-void DivPlatformPET::tick() {
+void DivPlatformPET::tick(bool sysTick) {
   chan.std.next();
   if (chan.std.vol.had) {
     chan.outVol=chan.std.vol.val&chan.vol;
diff --git a/src/engine/platform/pet.h b/src/engine/platform/pet.h
index 3b6af48d9..7647a87fe 100644
--- a/src/engine/platform/pet.h
+++ b/src/engine/platform/pet.h
@@ -65,7 +65,7 @@ class DivPlatformPET: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void notifyInsDeletion(void* ins);
     bool isStereo();
diff --git a/src/engine/platform/qsound.cpp b/src/engine/platform/qsound.cpp
index 2a1460d15..601ea0ea9 100644
--- a/src/engine/platform/qsound.cpp
+++ b/src/engine/platform/qsound.cpp
@@ -274,7 +274,7 @@ void DivPlatformQSound::acquire(short* bufL, short* bufR, size_t start, size_t l
   }
 }
 
-void DivPlatformQSound::tick() {
+void DivPlatformQSound::tick(bool sysTick) {
   for (int i=0; i<16; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/qsound.h b/src/engine/platform/qsound.h
index 16420055d..62b1d647f 100644
--- a/src/engine/platform/qsound.h
+++ b/src/engine/platform/qsound.h
@@ -74,7 +74,7 @@ class DivPlatformQSound: public DivDispatch {
     int getRegisterPoolDepth();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool isStereo();
     bool keyOffAffectsArp(int ch);
diff --git a/src/engine/platform/saa.cpp b/src/engine/platform/saa.cpp
index 20f1005e0..ca91800c2 100644
--- a/src/engine/platform/saa.cpp
+++ b/src/engine/platform/saa.cpp
@@ -132,7 +132,7 @@ inline unsigned char applyPan(unsigned char vol, unsigned char pan) {
   return ((vol*(pan>>4))/15)|(((vol*(pan&15))/15)<<4);
 }
 
-void DivPlatformSAA1099::tick() {
+void DivPlatformSAA1099::tick(bool sysTick) {
   for (int i=0; i<6; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/saa.h b/src/engine/platform/saa.h
index 8df44f616..0542ff513 100644
--- a/src/engine/platform/saa.h
+++ b/src/engine/platform/saa.h
@@ -90,7 +90,7 @@ class DivPlatformSAA1099: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void setCore(DivSAACores core);
     void setFlags(unsigned int flags);
diff --git a/src/engine/platform/segapcm.cpp b/src/engine/platform/segapcm.cpp
index b2a8b3db8..97ff900ae 100644
--- a/src/engine/platform/segapcm.cpp
+++ b/src/engine/platform/segapcm.cpp
@@ -76,7 +76,7 @@ void DivPlatformSegaPCM::acquire(short* bufL, short* bufR, size_t start, size_t
   }
 }
 
-void DivPlatformSegaPCM::tick() {
+void DivPlatformSegaPCM::tick(bool sysTick) {
   for (int i=0; i<16; i++) {
     chan[i].std.next();
 
diff --git a/src/engine/platform/segapcm.h b/src/engine/platform/segapcm.h
index b3c84cd3b..4b05c160c 100644
--- a/src/engine/platform/segapcm.h
+++ b/src/engine/platform/segapcm.h
@@ -78,7 +78,7 @@ class DivPlatformSegaPCM: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void notifyInsChange(int ins);
     void setFlags(unsigned int flags);
diff --git a/src/engine/platform/sms.cpp b/src/engine/platform/sms.cpp
index a0f8abdda..acd2c0726 100644
--- a/src/engine/platform/sms.cpp
+++ b/src/engine/platform/sms.cpp
@@ -53,7 +53,7 @@ int DivPlatformSMS::acquireOne() {
   return v;
 }
 
-void DivPlatformSMS::tick() {
+void DivPlatformSMS::tick(bool sysTick) {
   for (int i=0; i<4; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/sms.h b/src/engine/platform/sms.h
index b49a5e276..0aeb9e81a 100644
--- a/src/engine/platform/sms.h
+++ b/src/engine/platform/sms.h
@@ -63,7 +63,7 @@ class DivPlatformSMS: public DivDispatch {
     void* getChanState(int chan);
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool keyOffAffectsArp(int ch);
     bool keyOffAffectsPorta(int ch);
diff --git a/src/engine/platform/swan.cpp b/src/engine/platform/swan.cpp
index 30be897be..99d819b1f 100644
--- a/src/engine/platform/swan.cpp
+++ b/src/engine/platform/swan.cpp
@@ -141,7 +141,7 @@ void DivPlatformSwan::writeOutVol(int ch) {
   }
 }
 
-void DivPlatformSwan::tick() {
+void DivPlatformSwan::tick(bool sysTick) {
   unsigned char sndCtrl=(pcm?0x20:0)|(sweep?0x40:0)|((noise>0)?0x80:0);
   for (int i=0; i<4; i++) {
     chan[i].std.next();
diff --git a/src/engine/platform/swan.h b/src/engine/platform/swan.h
index 610884b00..0f1643c53 100644
--- a/src/engine/platform/swan.h
+++ b/src/engine/platform/swan.h
@@ -77,7 +77,7 @@ class DivPlatformSwan: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void notifyWaveChange(int wave);
     void notifyInsDeletion(void* ins);
diff --git a/src/engine/platform/tia.cpp b/src/engine/platform/tia.cpp
index 474cd00e3..dc6c607fe 100644
--- a/src/engine/platform/tia.cpp
+++ b/src/engine/platform/tia.cpp
@@ -84,7 +84,7 @@ unsigned char DivPlatformTIA::dealWithFreq(unsigned char shape, int base, int pi
   return 0;
 }
 
-void DivPlatformTIA::tick() {
+void DivPlatformTIA::tick(bool sysTick) {
   for (int i=0; i<2; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/tia.h b/src/engine/platform/tia.h
index ea149ec34..3ec3c7f34 100644
--- a/src/engine/platform/tia.h
+++ b/src/engine/platform/tia.h
@@ -51,7 +51,7 @@ class DivPlatformTIA: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void setFlags(unsigned int flags);
     bool isStereo();
diff --git a/src/engine/platform/tx81z.cpp b/src/engine/platform/tx81z.cpp
index 34b975dd0..6f71be755 100644
--- a/src/engine/platform/tx81z.cpp
+++ b/src/engine/platform/tx81z.cpp
@@ -183,7 +183,7 @@ inline int hScale(int note) {
   return ((note/12)<<4)+(noteMap[note%12]);
 }
 
-void DivPlatformTX81Z::tick() {
+void DivPlatformTX81Z::tick(bool sysTick) {
   for (int i=0; i<8; i++) {
     chan[i].std.next();
 
diff --git a/src/engine/platform/tx81z.h b/src/engine/platform/tx81z.h
index 363d5c234..c61b4bfe7 100644
--- a/src/engine/platform/tx81z.h
+++ b/src/engine/platform/tx81z.h
@@ -102,7 +102,7 @@ class DivPlatformTX81Z: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void notifyInsChange(int ins);
     void setFlags(unsigned int flags);
diff --git a/src/engine/platform/vera.cpp b/src/engine/platform/vera.cpp
index 7e887be80..31d52569a 100644
--- a/src/engine/platform/vera.cpp
+++ b/src/engine/platform/vera.cpp
@@ -156,7 +156,7 @@ int DivPlatformVERA::calcNoteFreq(int ch, int note) {
   }
 }
 
-void DivPlatformVERA::tick() {
+void DivPlatformVERA::tick(bool sysTick) {
   for (int i=0; i<16; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/vera.h b/src/engine/platform/vera.h
index 2b47f99a7..ec6dcde11 100644
--- a/src/engine/platform/vera.h
+++ b/src/engine/platform/vera.h
@@ -63,7 +63,7 @@ class DivPlatformVERA: public DivDispatch {
     unsigned char* getRegisterPool();
     int getRegisterPoolSize();
     void reset();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void notifyInsDeletion(void* ins);
     float getPostAmp();
diff --git a/src/engine/platform/vic20.cpp b/src/engine/platform/vic20.cpp
index b3062a630..7817cd839 100644
--- a/src/engine/platform/vic20.cpp
+++ b/src/engine/platform/vic20.cpp
@@ -91,7 +91,7 @@ void DivPlatformVIC20::writeOutVol(int ch) {
   }
 }
 
-void DivPlatformVIC20::tick() {
+void DivPlatformVIC20::tick(bool sysTick) {
   for (int i=0; i<4; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/vic20.h b/src/engine/platform/vic20.h
index 1c4d384b7..7948c5ef2 100644
--- a/src/engine/platform/vic20.h
+++ b/src/engine/platform/vic20.h
@@ -66,7 +66,7 @@ class DivPlatformVIC20: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     void setFlags(unsigned int flags);
     void notifyInsDeletion(void* ins);
diff --git a/src/engine/platform/vrc6.cpp b/src/engine/platform/vrc6.cpp
index b126deb6e..048b42cdb 100644
--- a/src/engine/platform/vrc6.cpp
+++ b/src/engine/platform/vrc6.cpp
@@ -135,7 +135,7 @@ void DivPlatformVRC6::acquire(short* bufL, short* bufR, size_t start, size_t len
   }
 }
 
-void DivPlatformVRC6::tick() {
+void DivPlatformVRC6::tick(bool sysTick) {
   for (int i=0; i<3; i++) {
     // 16 for pulse; 14 for saw
     int CHIP_DIVIDER=(i==2)?14:16;
diff --git a/src/engine/platform/vrc6.h b/src/engine/platform/vrc6.h
index 05cd89415..d28265a47 100644
--- a/src/engine/platform/vrc6.h
+++ b/src/engine/platform/vrc6.h
@@ -82,7 +82,7 @@ class DivPlatformVRC6: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool keyOffAffectsArp(int ch);
     void setFlags(unsigned int flags);
diff --git a/src/engine/platform/x1_010.cpp b/src/engine/platform/x1_010.cpp
index 1bbd2a809..df6682adb 100644
--- a/src/engine/platform/x1_010.cpp
+++ b/src/engine/platform/x1_010.cpp
@@ -336,7 +336,7 @@ void DivPlatformX1_010::updateEnvelope(int ch) {
   }
 }
 
-void DivPlatformX1_010::tick() {
+void DivPlatformX1_010::tick(bool sysTick) {
   for (int i=0; i<16; i++) {
     chan[i].std.next();
     if (chan[i].std.vol.had) {
diff --git a/src/engine/platform/x1_010.h b/src/engine/platform/x1_010.h
index 2bfb78cc9..bee546473 100644
--- a/src/engine/platform/x1_010.h
+++ b/src/engine/platform/x1_010.h
@@ -126,7 +126,7 @@ class DivPlatformX1_010: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool isStereo();
     bool keyOffAffectsArp(int ch);
diff --git a/src/engine/platform/ym2610.cpp b/src/engine/platform/ym2610.cpp
index a1f5ea658..3d6c8ed29 100644
--- a/src/engine/platform/ym2610.cpp
+++ b/src/engine/platform/ym2610.cpp
@@ -365,9 +365,9 @@ void DivPlatformYM2610::acquire(short* bufL, short* bufR, size_t start, size_t l
   }
 }
 
-void DivPlatformYM2610::tick() {
+void DivPlatformYM2610::tick(bool sysTick) {
   // PSG
-  ay->tick();
+  ay->tick(sysTick);
   ay->flushWrites();
   for (DivRegWrite& i: ay->getRegisterWrites()) {
     immWrite(i.addr&15,i.val);
diff --git a/src/engine/platform/ym2610.h b/src/engine/platform/ym2610.h
index 2fd525b08..e75e24d79 100644
--- a/src/engine/platform/ym2610.h
+++ b/src/engine/platform/ym2610.h
@@ -116,7 +116,7 @@ class DivPlatformYM2610: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool isStereo();
     bool keyOffAffectsArp(int ch);
diff --git a/src/engine/platform/ym2610b.cpp b/src/engine/platform/ym2610b.cpp
index 130eb29a2..aeadeae47 100644
--- a/src/engine/platform/ym2610b.cpp
+++ b/src/engine/platform/ym2610b.cpp
@@ -429,9 +429,9 @@ void DivPlatformYM2610B::acquire(short* bufL, short* bufR, size_t start, size_t
   }
 }
 
-void DivPlatformYM2610B::tick() {
+void DivPlatformYM2610B::tick(bool sysTick) {
   // PSG
-  ay->tick();
+  ay->tick(sysTick);
   ay->flushWrites();
   for (DivRegWrite& i: ay->getRegisterWrites()) {
     immWrite(i.addr&15,i.val);
diff --git a/src/engine/platform/ym2610b.h b/src/engine/platform/ym2610b.h
index d6b616c50..6d46ecb26 100644
--- a/src/engine/platform/ym2610b.h
+++ b/src/engine/platform/ym2610b.h
@@ -107,7 +107,7 @@ class DivPlatformYM2610B: public DivDispatch {
     int getRegisterPoolSize();
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool isStereo();
     bool keyOffAffectsArp(int ch);
diff --git a/src/engine/platform/ym2610bext.cpp b/src/engine/platform/ym2610bext.cpp
index 03e9f8699..496a308e0 100644
--- a/src/engine/platform/ym2610bext.cpp
+++ b/src/engine/platform/ym2610bext.cpp
@@ -212,7 +212,7 @@ static int opChanOffsH[4]={
   0xad, 0xae, 0xac, 0xa6
 };
 
-void DivPlatformYM2610BExt::tick() {
+void DivPlatformYM2610BExt::tick(bool sysTick) {
   if (extMode) {
     bool writeSomething=false;
     unsigned char writeMask=2;
@@ -229,7 +229,7 @@ void DivPlatformYM2610BExt::tick() {
     }
   }
 
-  DivPlatformYM2610B::tick();
+  DivPlatformYM2610B::tick(sysTick);
 
   bool writeNoteOn=false;
   unsigned char writeMask=2;
diff --git a/src/engine/platform/ym2610bext.h b/src/engine/platform/ym2610bext.h
index 25ca59196..e908916e3 100644
--- a/src/engine/platform/ym2610bext.h
+++ b/src/engine/platform/ym2610bext.h
@@ -41,7 +41,7 @@ class DivPlatformYM2610BExt: public DivPlatformYM2610B {
     void* getChanState(int chan);
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool keyOffAffectsArp(int ch);
     void notifyInsChange(int ins);
diff --git a/src/engine/platform/ym2610ext.cpp b/src/engine/platform/ym2610ext.cpp
index 40294733d..dc4625080 100644
--- a/src/engine/platform/ym2610ext.cpp
+++ b/src/engine/platform/ym2610ext.cpp
@@ -212,7 +212,7 @@ static int opChanOffsH[4]={
   0xad, 0xae, 0xac, 0xa6
 };
 
-void DivPlatformYM2610Ext::tick() {
+void DivPlatformYM2610Ext::tick(bool sysTick) {
   if (extMode) {
     bool writeSomething=false;
     unsigned char writeMask=2;
@@ -229,7 +229,7 @@ void DivPlatformYM2610Ext::tick() {
     }
   }
 
-  DivPlatformYM2610::tick();
+  DivPlatformYM2610::tick(sysTick);
 
   bool writeNoteOn=false;
   unsigned char writeMask=2;
diff --git a/src/engine/platform/ym2610ext.h b/src/engine/platform/ym2610ext.h
index 37c9e328d..9fa44d0b1 100644
--- a/src/engine/platform/ym2610ext.h
+++ b/src/engine/platform/ym2610ext.h
@@ -41,7 +41,7 @@ class DivPlatformYM2610Ext: public DivPlatformYM2610 {
     void* getChanState(int chan);
     void reset();
     void forceIns();
-    void tick();
+    void tick(bool sysTick=true);
     void muteChannel(int ch, bool mute);
     bool keyOffAffectsArp(int ch);
     void notifyInsChange(int ins);
diff --git a/src/engine/playback.cpp b/src/engine/playback.cpp
index fe42c73af..0f3789635 100644
--- a/src/engine/playback.cpp
+++ b/src/engine/playback.cpp
@@ -1638,7 +1638,7 @@ bool DivEngine::nextTick(bool noAccum) {
   firstTick=false;
 
   // system tick
-  for (int i=0; i<song.systemLen; i++) disCont[i].dispatch->tick();
+  for (int i=0; i<song.systemLen; i++) disCont[i].dispatch->tick(subticks==tickMult);
 
   if (!freelance) {
     if (stepPlay!=1) {
diff --git a/src/engine/waveSynth.cpp b/src/engine/waveSynth.cpp
index 2b9946ee2..7bae30d9a 100644
--- a/src/engine/waveSynth.cpp
+++ b/src/engine/waveSynth.cpp
@@ -30,8 +30,11 @@ bool DivWaveSynth::activeChanged() {
 }
 
 bool DivWaveSynth::tick() {
+  if (--subDivCounter>0) return false;
+
   bool updated=first;
   first=false;
+  subDivCounter=e->tickMult;
   if (!state.enabled) return updated;
   if (width<1) return false;
 
@@ -167,6 +170,7 @@ void DivWaveSynth::init(DivInstrument* which, int w, int h, bool insChanged) {
     pos=0;
     stage=0;
     divCounter=1+state.rateDivider;
+    subDivCounter=0;
     first=true;
 
     changeWave1(state.wave1);
diff --git a/src/engine/waveSynth.h b/src/engine/waveSynth.h
index ecd6f8a86..f5c89e3ac 100644
--- a/src/engine/waveSynth.h
+++ b/src/engine/waveSynth.h
@@ -28,7 +28,7 @@ class DivEngine;
 class DivWaveSynth {
   DivEngine* e;
   DivInstrumentWaveSynth state;
-  int pos, stage, divCounter, width, height;
+  int pos, stage, divCounter, width, height, subDivCounter;
   bool first, activeChangedB;
   unsigned char wave1[256];
   unsigned char wave2[256];
@@ -78,6 +78,7 @@ class DivWaveSynth {
       divCounter(0),
       width(32),
       height(31),
+      subDivCounter(0),
       first(false),
       activeChangedB(false) {
       memset(wave1,0,256);