diff --git a/src/engine/platform/pv1000.cpp b/src/engine/platform/pv1000.cpp
index d5f54e6a6..af4cae0c7 100644
--- a/src/engine/platform/pv1000.cpp
+++ b/src/engine/platform/pv1000.cpp
@@ -29,6 +29,7 @@ const char* regCheatSheetPV1000[]={
   "CH1_Pitch", "00",
   "CH2_Pitch", "01",
   "CH3_Pitch", "02",
+  "Control", "03",
   NULL
 };
 
@@ -42,7 +43,7 @@ void DivPlatformPV1000::acquire(short** buf, size_t len) {
     samp=d65010g031_sound_tick(&d65010g031,1);
     buf[0][h]=samp;
     for (int i=0; i<3; i++) {
-      oscBuf[i]->data[oscBuf[i]->needle++]=(d65010g031.square[i].out<<12);
+      oscBuf[i]->data[oscBuf[i]->needle++]=(d65010g031.out[i]);
     }
   }
 }
@@ -73,7 +74,7 @@ void DivPlatformPV1000::tick(bool sysTick) {
     }
     if (chan[i].freqChanged || chan[i].keyOn || chan[i].keyOff) {
       chan[i].freq=0x3f-parent->calcFreq(chan[i].baseFreq,chan[i].pitch,chan[i].fixedArp?chan[i].baseNoteOverride:chan[i].arpOff,chan[i].fixedArp,true,0,chan[i].pitch2,chipClock,CHIP_DIVIDER);
-      if (chan[i].freq<1) chan[i].freq=1;
+      if (chan[i].freq<0) chan[i].freq=0;
       if (chan[i].freq>62) chan[i].freq=62;
       if (isMuted[i]) chan[i].keyOn=false;
       if (chan[i].keyOn) {
@@ -83,7 +84,7 @@ void DivPlatformPV1000::tick(bool sysTick) {
         rWrite(i,(isMuted[i] || (chan[i].outVol<=0)) ? 0 : chan[i].freq);
       }
       if (chan[i].keyOff) {
-        rWrite(i,0);
+        rWrite(i,0x3f);
         chan[i].keyOff=false;
       }
       chan[i].freqChanged=false;
@@ -137,6 +138,13 @@ int DivPlatformPV1000::dispatch(DivCommand c) {
       chan[c.chan].pitch=c.value;
       chan[c.chan].freqChanged=true;
       break;
+    case DIV_CMD_WAVE:
+      if (c.value&1) {
+        rWrite(3,3);
+      } else {
+        rWrite(3,2);
+      }
+      break;
     case DIV_CMD_NOTE_PORTA: {
       int destFreq=NOTE_PERIODIC(c.value2);
       bool return2=false;
@@ -224,16 +232,21 @@ unsigned char* DivPlatformPV1000::getRegisterPool() {
 }
 
 int DivPlatformPV1000::getRegisterPoolSize() {
-  return 3;
+  return 4;
 }
 
 void DivPlatformPV1000::reset() {
-  memset(regPool,0,3);
+  memset(regPool,0,4);
   for (int i=0; i<3; i++) {
     chan[i]=Channel();
     chan[i].std.setEngine(parent);
   }
   d65010g031_reset(&d65010g031);
+  // mute
+  rWrite(0,0x3f);
+  rWrite(1,0x3f);
+  rWrite(2,0x3f);
+  rWrite(3,2);
 }
 
 int DivPlatformPV1000::getOutputCount() {
diff --git a/src/engine/platform/pv1000.h b/src/engine/platform/pv1000.h
index c32540763..852bf1204 100644
--- a/src/engine/platform/pv1000.h
+++ b/src/engine/platform/pv1000.h
@@ -33,7 +33,7 @@ class DivPlatformPV1000: public DivDispatch {
   DivDispatchOscBuffer* oscBuf[3];
   bool isMuted[3];
 
-  unsigned char regPool[3];
+  unsigned char regPool[4];
   d65010g031_t d65010g031;
   friend void putDispatchChip(void*,int);
   friend void putDispatchChan(void*,int,int);
diff --git a/src/engine/platform/sound/d65modified.c b/src/engine/platform/sound/d65modified.c
index 8f53b34c8..5cd49f2fc 100644
--- a/src/engine/platform/sound/d65modified.c
+++ b/src/engine/platform/sound/d65modified.c
@@ -67,7 +67,7 @@ int d65010g031_square_tick(struct d65010g031_square_t *square, const int cycle)
 {
 	if (square->period > 0)
 	{
-		int period = d65010g031_max(1, (0x3f - square->period));
+		const int period = square->period;
 		square->counter += cycle;
 		while (square->counter >= period)
 		{
@@ -92,7 +92,29 @@ int d65010g031_sound_tick(struct d65010g031_t *d65010g031, const int cycle)
 	int out = 0;
 	for (int i = 0; i < 3; i++)
 	{
-		out += d65010g031_square_tick(&d65010g031->square[i], cycle)?d65Volumes[i]:-d65Volumes[i];
+		d65010g031->out[i] = 0;
+	}
+	if (d65010g031->ctrl & 2)
+	{
+		if (d65010g031->ctrl & 1)
+		{
+			int sout[3] = {
+				d65010g031_square_tick(&d65010g031->square[0], cycle),
+				d65010g031_square_tick(&d65010g031->square[1], cycle),
+				d65010g031_square_tick(&d65010g031->square[2], cycle),
+			};
+			d65010g031->out[0] = (sout[0] ^ sout[1]) ? d65Volumes[0] : -d65Volumes[0];
+			d65010g031->out[1] = (sout[1] ^ sout[2]) ? d65Volumes[1] : -d65Volumes[1];
+			d65010g031->out[2] = (sout[2] ? d65Volumes[2] : -d65Volumes[2]);
+		}
+		else
+		{
+			for (int i = 0; i < 3; i++)
+			{
+				d65010g031->out[i] = d65010g031_square_tick(&d65010g031->square[i], cycle)?d65Volumes[i]:-d65Volumes[i];
+			}
+		}
+		out = d65010g031->out[0] + d65010g031->out[1] + d65010g031->out[2];
 	}
 	return out;
 }
@@ -105,12 +127,23 @@ void d65010g031_reset(struct d65010g031_t *d65010g031)
 		d65010g031->square[i].counter = 0;
 		d65010g031->square[i].out = 0;
 	}
+	d65010g031->ctrl = 0;
 }
 
 void d65010g031_write(struct d65010g031_t *d65010g031, const unsigned char a, const unsigned char d)
 {
-	if (a < 3)
+	switch (a)
 	{
-		d65010g031->square[a].period = d & 0x3f;
+		case 3:
+			d65010g031->ctrl = d;
+			break;
+		default:
+			const unsigned char period = ~d & 0x3f;
+			if ((period == 0) && (d65010g031->square[a].period != 0))
+			{
+				d65010g031->square[a].out ^= 1;
+			}
+			d65010g031->square[a].period = period;
+			break;
 	}
 }
diff --git a/src/engine/platform/sound/d65modified.h b/src/engine/platform/sound/d65modified.h
index 49dc13a15..eae0f8988 100644
--- a/src/engine/platform/sound/d65modified.h
+++ b/src/engine/platform/sound/d65modified.h
@@ -54,6 +54,8 @@ struct d65010g031_square_t
 struct d65010g031_t
 {
 	struct d65010g031_square_t square[3];
+	signed short out[3];
+	unsigned char ctrl;
 };
 
 int d65010g031_square_tick(struct d65010g031_square_t *square, const int cycle);
diff --git a/src/engine/sysDef.cpp b/src/engine/sysDef.cpp
index fbb718cb5..c9aef95ef 100644
--- a/src/engine/sysDef.cpp
+++ b/src/engine/sysDef.cpp
@@ -1839,7 +1839,11 @@ void DivEngine::registerSystems() {
     {"Square 1", "Square 2", "Square 3"},
     {"S1", "S2", "S3"},
     {DIV_CH_PULSE, DIV_CH_PULSE, DIV_CH_PULSE},
-    {DIV_INS_PV1000, DIV_INS_PV1000, DIV_INS_PV1000}
+    {DIV_INS_PV1000, DIV_INS_PV1000, DIV_INS_PV1000},
+    {},
+    {
+      {0x10, {DIV_CMD_WAVE, "10xx: Set waveform"}}
+    }
   );
 
   sysDefs[DIV_SYSTEM_SFX_BEEPER_QUADTONE]=new DivSysDef(