diff --git a/src/engine/instrument.h b/src/engine/instrument.h
index 1c8525436..9327c64c6 100644
--- a/src/engine/instrument.h
+++ b/src/engine/instrument.h
@@ -485,6 +485,9 @@ enum DivWaveSynthEffects {
   DIV_WS_SUBTRACT,
   DIV_WS_AVERAGE,
   DIV_WS_PHASE,
+
+  DIV_WS_SINGLE_MAX,
+  
   // two waveform effects
   DIV_WS_NONE_DUAL=128,
   DIV_WS_WIPE,
@@ -493,12 +496,14 @@ enum DivWaveSynthEffects {
   DIV_WS_OVERLAY,
   DIV_WS_NEGATIVE_OVERLAY,
   DIV_WS_PHASE_DUAL,
+
+  DIV_WS_DUAL_MAX
 };
 
 struct DivInstrumentWaveSynth {
   int wave1, wave2;
   unsigned char rateDivider, width, height;
-  DivWaveSynthEffects effect;
+  unsigned char effect;
   bool oneShot, enabled, global;
   unsigned char speed, param1, param2, param3, param4;
   DivInstrumentWaveSynth():
diff --git a/src/engine/waveSynth.cpp b/src/engine/waveSynth.cpp
index ca3f342c7..b82539aaf 100644
--- a/src/engine/waveSynth.cpp
+++ b/src/engine/waveSynth.cpp
@@ -1,5 +1,52 @@
 #include "waveSynth.h"
+#include "engine.h"
 
 bool DivWaveSynth::tick() {
-  return false;
+  bool updated=first;
+  first=false;
+
+  
+  return updated;
+}
+
+void DivWaveSynth::setEngine(DivEngine* engine) {
+  e=engine;
+}
+
+void DivWaveSynth::init(DivInstrument* which, int w, int h, bool insChanged) {
+  if (e==NULL) return;
+  if (which==NULL) {
+    state=DivInstrumentWaveSynth();
+  }
+  state=which->ws;
+  width=w;
+  height=h;
+  pos=0;
+  stage=0;
+  divCounter=0;
+  first=true;
+
+  DivWavetable* w1=e->getWave(state.wave1);
+  DivWavetable* w2=e->getWave(state.wave2);
+  for (int i=0; i<width; i++) {
+    if (w1->max<1 || w1->len<1) {
+      wave1[i]=0;
+    } else {
+      int data=w1->data[i*w1->len/width]*height/w1->max;
+      if (data<0) data=0;
+      if (data>31) data=31;
+      wave1[i]=data;
+    }
+  }
+
+  for (int i=0; i<width; i++) {
+    if (w2->max<1 || w2->len<1) {
+      wave2[i]=0;
+    } else {
+      int data=w2->data[i*w2->len/width]*height/w2->max;
+      if (data<0) data=0;
+      if (data>31) data=31;
+      wave2[i]=data;
+    }
+  }
 }
\ No newline at end of file
diff --git a/src/engine/waveSynth.h b/src/engine/waveSynth.h
index 5e5fd6540..92a5c9a26 100644
--- a/src/engine/waveSynth.h
+++ b/src/engine/waveSynth.h
@@ -23,9 +23,15 @@
 #include "instrument.h"
 #include "wavetable.h"
 
+class DivEngine;
+
 class DivWaveSynth {
-  DivInstrument* ins;
-  int pos, stage, divCounter;
+  DivEngine* e;
+  DivInstrumentWaveSynth state;
+  int pos, stage, divCounter, width, height;
+  bool first;
+  unsigned char wave1[256];
+  unsigned char wave2[256];
   int output[256];
   public:
     /**
@@ -33,12 +39,18 @@ class DivWaveSynth {
      * @return whether the wave has changed.
      */
     bool tick();
-    void init(DivInstrument* ins);
+    void init(DivInstrument* which, int width, int height, bool insChanged=false);
+    void setEngine(DivEngine* engine);
     DivWaveSynth():
-      ins(NULL),
+      e(NULL),
       pos(0),
       stage(0),
-      divCounter(0) {
+      divCounter(0),
+      width(32),
+      height(31),
+      first(false) {
+      memset(wave1,0,sizeof(int)*256);
+      memset(wave2,0,sizeof(int)*256);
       memset(output,0,sizeof(int)*256);
     }
 };
diff --git a/src/gui/insEdit.cpp b/src/gui/insEdit.cpp
index abc4af172..71426dfe9 100644
--- a/src/gui/insEdit.cpp
+++ b/src/gui/insEdit.cpp
@@ -157,6 +157,25 @@ const int orderedOps[4]={
   0, 2, 1, 3
 };
 
+const char* singleWSEffects[6]={
+  "None",
+  "Invert",
+  "Add",
+  "Subtract",
+  "Average",
+  "Phase",
+};
+
+const char* dualWSEffects[7]={
+  "None (dual)",
+  "Wipe",
+  "Fade",
+  "Wipe (ping-pong)",
+  "Overlay",
+  "Negative Overlay",
+  "Phase (dual)",
+};
+
 String macroHoverNote(int id, float val) {
   if (val<-60 || val>=120) return "???";
   return fmt::sprintf("%d: %s",id,noteNames[(int)val+60]);
@@ -2301,6 +2320,107 @@ void FurnaceGUI::drawInsEdit() {
           }
           ImGui::EndTabItem();
         }
+        if (ins->type==DIV_INS_GB ||
+            ins->type==DIV_INS_AMIGA ||
+            ins->type==DIV_INS_X1_010 ||
+            ins->type==DIV_INS_N163 ||
+            ins->type==DIV_INS_FDS ||
+            ins->type==DIV_INS_SWAN ||
+            ins->type==DIV_INS_PCE ||
+            ins->type==DIV_INS_SCC) {
+          if (ImGui::BeginTabItem("Wavetable")) {
+            ImGui::Checkbox("Enable synthesizer",&ins->ws.enabled);
+            ImGui::SameLine();
+            ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
+            if (ins->ws.effect&0x80) {
+              if ((ins->ws.effect&0x7f)>=DIV_WS_DUAL_MAX) {
+                ins->ws.effect=0;
+              }
+            } else {
+              if ((ins->ws.effect&0x7f)>=DIV_WS_SINGLE_MAX) {
+                ins->ws.effect=0;
+              }
+            }
+            if (ImGui::BeginCombo("##WSEffect",(ins->ws.effect&0x80)?dualWSEffects[ins->ws.effect&0x7f]:singleWSEffects[ins->ws.effect&0x7f])) {
+              ImGui::Text("Single-waveform");
+              ImGui::Indent();
+              for (int i=0; i<DIV_WS_SINGLE_MAX; i++) {
+                if (ImGui::Selectable(singleWSEffects[i])) {
+                  ins->ws.effect=i;
+                }
+              }
+              ImGui::Unindent();
+              ImGui::Text("Dual-waveform");
+              ImGui::Indent();
+              for (int i=129; i<DIV_WS_DUAL_MAX; i++) {
+                if (ImGui::Selectable(dualWSEffects[i-128])) {
+                  ins->ws.effect=i;
+                }
+              }
+              ImGui::Unindent();
+              ImGui::EndCombo();
+            }
+            if (ImGui::BeginTable("WSPreview",2)) {
+              DivWavetable* wave1=e->getWave(ins->ws.wave1);
+              DivWavetable* wave2=e->getWave(ins->ws.wave2);
+              float wavePreview1[256];
+              float wavePreview2[256];
+              for (int i=0; i<wave1->len; i++) {
+                if (wave1->data[i]>wave1->max) {
+                  wavePreview1[i]=wave1->max;
+                } else {
+                  wavePreview1[i]=wave1->data[i];
+                }
+              }
+              for (int i=0; i<wave2->len; i++) {
+                if (wave2->data[i]>wave2->max) {
+                  wavePreview2[i]=wave2->max;
+                } else {
+                  wavePreview2[i]=wave2->data[i];
+                }
+              }
+
+              ImGui::TableNextRow();
+              ImGui::TableNextColumn();
+              ImVec2 size1=ImVec2(ImGui::GetContentRegionAvail().x,64.0f*dpiScale);
+              PlotNoLerp("##WaveformP1",wavePreview1,wave1->len+1,0,NULL,0,wave1->max,size1);
+              ImGui::TableNextColumn();
+              ImVec2 size2=ImVec2(ImGui::GetContentRegionAvail().x,64.0f*dpiScale);
+              PlotNoLerp("##WaveformP2",wavePreview2,wave2->len+1,0,NULL,0,wave2->max,size2);
+
+              ImGui::TableNextRow();
+              ImGui::TableNextColumn();
+              ImGui::Text("Wave 1");
+              ImGui::SameLine();
+              ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
+              if (ImGui::InputInt("##SelWave1",&ins->ws.wave1,1,4)) {
+                if (ins->ws.wave1<0) ins->ws.wave1=0;
+                if (ins->ws.wave1>=(int)e->song.wave.size()) ins->ws.wave1=e->song.wave.size()-1;
+              }
+              ImGui::TableNextColumn();
+              ImGui::Text("Wave 2");
+              ImGui::SameLine();
+              ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
+              if (ImGui::InputInt("##SelWave2",&ins->ws.wave2,1,4)) {
+                if (ins->ws.wave2<0) ins->ws.wave2=0;
+                if (ins->ws.wave2>=(int)e->song.wave.size()) ins->ws.wave2=e->song.wave.size()-1;
+              }
+              ImGui::EndTable();
+            }
+
+            ImGui::InputScalar("Update Rate",ImGuiDataType_U8,&ins->ws.rateDivider,&_ONE,&_SEVEN);
+            int speed=ins->ws.speed+1;
+            if (ImGui::InputInt("Speed",&speed,1,16)) {
+              if (speed<1) speed=1;
+              if (speed>256) speed=256;
+              ins->ws.speed=speed-1;
+            }
+
+            ImGui::InputScalar("Amount",ImGuiDataType_U8,&ins->ws.param1,&_ONE,&_SEVEN);
+
+            ImGui::EndTabItem();
+          }
+        }
         if (ImGui::BeginTabItem("Macros")) {
           float asFloat[256];
           int asInt[256];