even more improvements to low-latency mode

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.

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) {

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) {

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);

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();
 

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);

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();

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();

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();

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();

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) {

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);

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));
+          }
         }
       }
     }

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);

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() {
-}
+}

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();

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) {

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);

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) {

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);

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();

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);

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;

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);

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) {

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);

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) {

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();

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) {

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);

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) {

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();

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();

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);

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();
 

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);

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) {

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);

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) {

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);

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;

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();

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) {

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);

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) {

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);

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();
 

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);

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) {

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);

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();

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);

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) {

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();

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();
 

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);

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) {

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();

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) {

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);

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;

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);

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) {

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);

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);

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);

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);

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);

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;

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);

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;

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);

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) {

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);

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);