diff --git a/src/engine/cmdStream.cpp b/src/engine/cmdStream.cpp
index d8c77030f..40542ef98 100644
--- a/src/engine/cmdStream.cpp
+++ b/src/engine/cmdStream.cpp
@@ -215,6 +215,10 @@ bool DivCSPlayer::tick() {
           case DIV_CMD_HINT_VOL_SLIDE:
             arg0=(short)stream.readS();
             break;
+          case DIV_CMD_HINT_VOL_SLIDE_TARGET:
+            arg0=(short)stream.readS();
+            arg1=(short)stream.readS();
+            break;
           case DIV_CMD_HINT_LEGATO:
             arg0=(unsigned char)stream.readC();
             if (arg0==0xff) {
@@ -321,6 +325,11 @@ bool DivCSPlayer::tick() {
             break;
           case DIV_CMD_HINT_VOL_SLIDE:
             chan[i].volSpeed=arg0;
+            chan[i].volSpeedTarget=-1;
+            break;
+          case DIV_CMD_HINT_VOL_SLIDE_TARGET:
+            chan[i].volSpeed=arg0;
+            chan[i].volSpeedTarget=arg0==0 ? -1 : arg1;
             break;
           case DIV_CMD_HINT_PITCH:
             chan[i].pitch=arg0;
@@ -356,13 +365,29 @@ bool DivCSPlayer::tick() {
 
     if (sendVolume || chan[i].volSpeed!=0) {
       chan[i].volume+=chan[i].volSpeed;
+      if (chan[i].volSpeedTarget!=-1) {
+        bool atTarget=false;
+        if (chan[i].volSpeed>0) {
+          atTarget=(chan[i].volume>=chan[i].volSpeedTarget);
+        } else if (chan[i].volSpeed<0) {
+          atTarget=(chan[i].volume<=chan[i].volSpeedTarget);
+        } else {
+          atTarget=true;
+          chan[i].volSpeedTarget=chan[i].volume;
+        }
+
+        if (atTarget) {
+          chan[i].volume=chan[i].volSpeedTarget;
+          chan[i].volSpeed=0;
+          chan[i].volSpeedTarget=-1;
+        }
+      }
       if (chan[i].volume<0) {
         chan[i].volume=0;
       }
       if (chan[i].volume>chan[i].volMax) {
         chan[i].volume=chan[i].volMax;
       }
-
       e->dispatchCmd(DivCommand(DIV_CMD_VOLUME,i,chan[i].volume>>8));
     }
 
diff --git a/src/engine/cmdStream.h b/src/engine/cmdStream.h
index 4704b41b9..2d8e6e97e 100644
--- a/src/engine/cmdStream.h
+++ b/src/engine/cmdStream.h
@@ -34,7 +34,7 @@ struct DivCSChannelState {
   int lastWaitLen;
 
   int note, pitch;
-  int volume, volMax, volSpeed;
+  int volume, volMax, volSpeed, volSpeedTarget;
   int vibratoDepth, vibratoRate, vibratoPos;
   int portaTarget, portaSpeed;
   unsigned char arp, arpStage, arpTicks;
@@ -56,6 +56,7 @@ struct DivCSChannelState {
     volume(0x7f00),
     volMax(0),
     volSpeed(0),
+    volSpeedTarget(-1),
     vibratoDepth(0),
     vibratoRate(0),
     vibratoPos(0),
diff --git a/src/engine/cmdStreamOps.cpp b/src/engine/cmdStreamOps.cpp
index 0710e650e..1f3d81ee2 100644
--- a/src/engine/cmdStreamOps.cpp
+++ b/src/engine/cmdStreamOps.cpp
@@ -59,6 +59,7 @@ void writePackedCommandValues(SafeWriter* w, const DivCommand& c) {
     case DIV_CMD_HINT_VOLUME:
     case DIV_CMD_HINT_PORTA:
     case DIV_CMD_HINT_VOL_SLIDE:
+    case DIV_CMD_HINT_VOL_SLIDE_TARGET:
     case DIV_CMD_HINT_LEGATO:
       w->writeC((unsigned char)c.cmd+0xb4);
       break;
@@ -100,6 +101,10 @@ void writePackedCommandValues(SafeWriter* w, const DivCommand& c) {
     case DIV_CMD_HINT_VOL_SLIDE:
       w->writeS(c.value);
       break;
+    case DIV_CMD_HINT_VOL_SLIDE_TARGET:
+      w->writeS(c.value);
+      w->writeS(c.value2);
+      break;
     case DIV_CMD_SAMPLE_MODE:
     case DIV_CMD_SAMPLE_FREQ:
     case DIV_CMD_SAMPLE_BANK:
diff --git a/src/engine/dispatch.h b/src/engine/dispatch.h
index e89d3d6f7..031beeef9 100644
--- a/src/engine/dispatch.h
+++ b/src/engine/dispatch.h
@@ -67,6 +67,7 @@ enum DivDispatchCmds {
   DIV_CMD_HINT_ARPEGGIO, // (note1, note2)
   DIV_CMD_HINT_VOLUME, // (vol)
   DIV_CMD_HINT_VOL_SLIDE, // (amount, oneTick)
+  DIV_CMD_HINT_VOL_SLIDE_TARGET, // (amount, target)
   DIV_CMD_HINT_PORTA, // (target, speed)
   DIV_CMD_HINT_LEGATO, // (note)
 
diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index 92cc5ab87..34c8d9edb 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -98,6 +98,10 @@ const char* DivEngine::getEffectDesc(unsigned char effect, int chan, bool notNul
       break;
     case 0xc0: case 0xc1: case 0xc2: case 0xc3:
       return _("Cxxx: Set tick rate (hz)");
+    case 0xd3:
+      return _("D3xx: Volume portamento");
+    case 0xd4:
+      return _("D4xx: Volume portamento (fast)");
     case 0xdc:
       return _("DCxx: Delayed mute");
     case 0xe0:
diff --git a/src/engine/engine.h b/src/engine/engine.h
index c29dc59b2..95cf30210 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -133,7 +133,7 @@ struct DivAudioExportOptions {
 struct DivChannelState {
   std::vector<DivDelayedCommand> delayed;
   int note, oldNote, lastIns, pitch, portaSpeed, portaNote;
-  int volume, volSpeed, cut, volCut, legatoDelay, legatoTarget, rowDelay, volMax;
+  int volume, volSpeed, volSpeedTarget, cut, volCut, legatoDelay, legatoTarget, rowDelay, volMax;
   int delayOrder, delayRow, retrigSpeed, retrigTick;
   int vibratoDepth, vibratoRate, vibratoPos, vibratoPosGiant, vibratoShape, vibratoFine;
   int tremoloDepth, tremoloRate, tremoloPos;
@@ -157,6 +157,7 @@ struct DivChannelState {
     portaNote(-1),
     volume(0x7f00),
     volSpeed(0),
+    volSpeedTarget(-1),
     cut(-1),
     volCut(-1),
     legatoDelay(-1),
diff --git a/src/engine/instrument.cpp b/src/engine/instrument.cpp
index ff34b77fc..94b768121 100644
--- a/src/engine/instrument.cpp
+++ b/src/engine/instrument.cpp
@@ -409,6 +409,141 @@ void DivInstrument::writeFeatureFM(SafeWriter* w, bool fui) {
   FEATURE_END;
 }
 
+bool MemPatch::calcDiff(const void* pre, const void* post, size_t inputSize) {
+  bool diffValid=false;
+  size_t firstDiff=0;
+  size_t lastDiff=0;
+  const unsigned char* preBytes=(const unsigned char*)pre;
+  const unsigned char* postBytes=(const unsigned char*)post;
+
+  // @NOTE: consider/profile using a memcmp==0 check to early-out, if it's potentially faster
+  // for the common case, which is no change
+  for (size_t ii=0; ii<inputSize; ++ii) {
+    if (preBytes[ii] != postBytes[ii]) {
+      lastDiff=ii;
+      firstDiff=diffValid ? firstDiff : ii;
+      diffValid=true;
+    }
+  }
+
+  if (diffValid) {
+    offset=firstDiff;
+    size=lastDiff - firstDiff + 1;
+    data=new unsigned char[size];
+
+    // the diff is to make pre into post (MemPatch is general, not specific to
+    // undo), so copy from postBytes
+    memcpy(data, postBytes+offset, size);
+  }
+
+  return diffValid;
+}
+
+void MemPatch::applyAndReverse(void* target, size_t targetSize) {
+  if (size==0) return;
+  if (offset+size>targetSize) {
+    logW("MemPatch (offset %d, size %d) exceeds target size (%d), can't apply!",offset,size,targetSize);
+    return;
+  }
+
+  unsigned char* targetBytes=(unsigned char*)target;
+
+  // swap this->data and its segment on target
+  for (size_t ii=0; ii<size; ++ii) {
+    unsigned char tmp=targetBytes[offset+ii];
+    targetBytes[offset+ii] = data[ii];
+    data[ii] = tmp;
+  }
+}
+
+void DivInstrumentUndoStep::applyAndReverse(DivInstrument* target) {
+  if (nameValid) {
+    name.swap(target->name);
+  }
+  podPatch.applyAndReverse((DivInstrumentPOD*)target, sizeof(DivInstrumentPOD));
+}
+
+bool DivInstrumentUndoStep::makeUndoPatch(size_t processTime_, const DivInstrument* pre, const DivInstrument* post) {
+  processTime=processTime_;
+
+  // create the patch that will make post into pre
+  podPatch.calcDiff((const DivInstrumentPOD*)post, (const DivInstrumentPOD*)pre, sizeof(DivInstrumentPOD));
+  if (pre->name!=post->name) {
+    nameValid=true;
+    name=pre->name;
+  }
+
+  return nameValid || podPatch.isValid();
+}
+
+bool DivInstrument::recordUndoStepIfChanged(size_t processTime, const DivInstrument* old) {
+  DivInstrumentUndoStep step;
+
+  // generate a patch to go back to old
+  if (step.makeUndoPatch(processTime, old, this)) {
+    
+      // make room
+    if (undoHist.size()>=undoHist.capacity()) {
+      delete undoHist.front();
+      undoHist.pop_front();
+    }
+
+    // clear redo
+    while (!redoHist.empty()) {
+      delete redoHist.back();
+      redoHist.pop_back();
+    }
+
+    DivInstrumentUndoStep* stepPtr=new DivInstrumentUndoStep;
+    *stepPtr=step;
+    step.podPatch.data=NULL; // don't let it delete the data ptr that's been copied!
+    undoHist.push_back(stepPtr);
+
+    // logI("DivInstrument::undoHist push (%u off, %u size)", stepPtr->podPatch.offset, stepPtr->podPatch.size);
+    return true;
+  }
+
+  return false;
+}
+
+int DivInstrument::undo() {
+  if (undoHist.empty()) return 0;
+
+  DivInstrumentUndoStep* step=undoHist.back();
+  undoHist.pop_back();
+  // logI("DivInstrument::undo (%u off, %u size)", step->podPatch.offset, step->podPatch.size);
+  step->applyAndReverse(this);
+
+  // make room
+  if (redoHist.size()>=redoHist.capacity()) {
+      DivInstrumentUndoStep* step=redoHist.front();
+      delete step;
+      redoHist.pop_front();
+  }
+  redoHist.push_back(step);
+
+  return 1;
+}
+
+int DivInstrument::redo() {
+  if (redoHist.empty()) return 0;
+
+  DivInstrumentUndoStep* step = redoHist.back();
+  redoHist.pop_back();
+  // logI("DivInstrument::redo (%u off, %u size)", step->podPatch.offset, step->podPatch.size);
+  step->applyAndReverse(this);
+
+  // make room
+  if (undoHist.size()>=undoHist.capacity()) {
+      DivInstrumentUndoStep* step=undoHist.front();
+      delete step;
+      undoHist.pop_front();
+  }
+  undoHist.push_back(step);
+
+  return 1;
+}
+
 void DivInstrument::writeMacro(SafeWriter* w, const DivInstrumentMacro& m) {
   if (!m.len) return;
 
@@ -3538,3 +3673,28 @@ bool DivInstrument::saveDMP(const char* path) {
   w->finish();
   return true;
 }
+
+DivInstrument::~DivInstrument() {
+  // free undoHist/redoHist
+  while (!undoHist.empty()) {
+    delete undoHist.back();
+    undoHist.pop_back();
+  }
+  while (!redoHist.empty()) {
+    delete redoHist.back();
+    redoHist.pop_back();
+  }
+}
+
+DivInstrument::DivInstrument( const DivInstrument& ins ) {
+  // undo/redo history is specifically not copied
+  *(DivInstrumentPOD*)this=ins;
+  name=ins.name;
+}
+
+DivInstrument& DivInstrument::operator=( const DivInstrument& ins ) {
+  // undo/redo history is specifically not copied
+  *(DivInstrumentPOD*)this=ins;
+  name=ins.name;
+  return *this;
+}
\ No newline at end of file
diff --git a/src/engine/instrument.h b/src/engine/instrument.h
index d18cbc329..dbd8e4455 100644
--- a/src/engine/instrument.h
+++ b/src/engine/instrument.h
@@ -23,8 +23,10 @@
 #include "dataErrors.h"
 #include "../ta-utils.h"
 #include "../pch.h"
+#include "../fixedQueue.h"
 
 struct DivSong;
+struct DivInstrument;
 
 // NOTICE!
 // before adding new instrument types to this struct, please ask me first.
@@ -951,7 +953,7 @@ struct DivInstrumentSID3
     }
 };
 
-struct DivInstrument {
+struct DivInstrumentPOD {
   String name;
   DivInstrumentType type;
   DivInstrumentFM fm;
@@ -972,6 +974,77 @@ struct DivInstrument {
   DivInstrumentSID2 sid2;
   DivInstrumentSID3 sid3;
 
+  DivInstrumentPOD() :
+    type(DIV_INS_FM) {
+  }
+};
+
+struct MemPatch {
+  MemPatch() :
+    data(NULL)
+    , offset(0)
+    , size(0) {
+  }
+
+  ~MemPatch() {
+    if (data) {
+      delete[] data;
+      data=NULL;
+    }
+  }
+
+  bool calcDiff(const void* pre, const void* post, size_t size);
+  void applyAndReverse(void* target, size_t inputSize);
+  bool isValid() const { return size>0; }
+
+  unsigned char* data;
+  size_t offset;
+  size_t size;
+};
+
+struct DivInstrumentUndoStep {
+  DivInstrumentUndoStep() :
+    name(""),
+    nameValid(false),
+    processTime(0) {
+  }
+
+  MemPatch podPatch;
+  String name;
+  bool nameValid;
+  size_t processTime;
+
+  void applyAndReverse(DivInstrument* target);
+  bool makeUndoPatch(size_t processTime_, const DivInstrument* pre, const DivInstrument* post);
+};
+
+struct DivInstrument : DivInstrumentPOD {
+  String name;
+
+  DivInstrument() :
+    name("") {
+      // clear and construct DivInstrumentPOD so it doesn't have any garbage in the padding
+      memset((unsigned char*)(DivInstrumentPOD*)this, 0, sizeof(DivInstrumentPOD));
+      new ((DivInstrumentPOD*)this) DivInstrumentPOD;
+  }
+
+  ~DivInstrument();
+
+  /**
+   * copy/assignment to specifically avoid leaking or dangling pointers to undo step
+   */
+  DivInstrument( const DivInstrument& ins );
+  DivInstrument& operator=( const DivInstrument& ins );
+
+  /**
+   * undo stuff
+   */
+  FixedQueue<DivInstrumentUndoStep*, 128> undoHist;
+  FixedQueue<DivInstrumentUndoStep*, 128> redoHist;
+  bool recordUndoStepIfChanged(size_t processTime, const DivInstrument* old);
+  int undo();
+  int redo();
+
   /**
    * these are internal functions.
    */
@@ -1058,9 +1131,5 @@ struct DivInstrument {
    * @return whether it was successful.
    */
   bool saveDMP(const char* path);
-  DivInstrument():
-    name(""),
-    type(DIV_INS_FM) {
-  }
 };
 #endif
diff --git a/src/engine/platform/ay.cpp b/src/engine/platform/ay.cpp
index 4e5357722..11ce83389 100644
--- a/src/engine/platform/ay.cpp
+++ b/src/engine/platform/ay.cpp
@@ -423,11 +423,11 @@ void DivPlatformAY8910::tick(bool sysTick) {
         chan[i].tfx.counter = 0;
         chan[i].tfx.out = 0;
         if (chan[i].nextPSGMode.val&8) {
-          if (dumpWrites) addWrite(0xffff0002+(i<<8),0);
+          //if (dumpWrites) addWrite(0xffff0002+(i<<8),0);
           if (chan[i].dac.sample<0 || chan[i].dac.sample>=parent->song.sampleLen) {
             if (dumpWrites) {
               rWrite(0x08+i,0);
-              addWrite(0xffff0000+(i<<8),chan[i].dac.sample);
+              //addWrite(0xffff0000+(i<<8),chan[i].dac.sample);
             }
             if (chan[i].dac.setPos) {
               chan[i].dac.setPos=false;
@@ -517,7 +517,7 @@ void DivPlatformAY8910::tick(bool sysTick) {
           }
         }
         chan[i].dac.rate=((double)rate*((sunsoft||clockSel)?8.0:16.0))/(double)(MAX(1,off*chan[i].freq));
-        if (dumpWrites) addWrite(0xffff0001+(i<<8),chan[i].dac.rate);
+        //if (dumpWrites) addWrite(0xffff0001+(i<<8),chan[i].dac.rate);
       }
       if (chan[i].freq<0) chan[i].freq=0;
       if (chan[i].freq>4095) chan[i].freq=4095;
@@ -604,12 +604,12 @@ int DivPlatformAY8910::dispatch(DivCommand c) {
           }
           if (chan[c.chan].dac.sample<0 || chan[c.chan].dac.sample>=parent->song.sampleLen) {
             chan[c.chan].dac.sample=-1;
-            if (dumpWrites) addWrite(0xffff0002+(c.chan<<8),0);
+            //if (dumpWrites) addWrite(0xffff0002+(c.chan<<8),0);
             break;
           } else {
             if (dumpWrites) {
               rWrite(0x08+c.chan,0);
-              addWrite(0xffff0000+(c.chan<<8),chan[c.chan].dac.sample);
+              //addWrite(0xffff0000+(c.chan<<8),chan[c.chan].dac.sample);
             }
           }
           if (chan[c.chan].dac.setPos) {
@@ -637,10 +637,10 @@ int DivPlatformAY8910::dispatch(DivCommand c) {
           chan[c.chan].dac.sample=12*sampleBank+chan[c.chan].note%12;
           if (chan[c.chan].dac.sample>=parent->song.sampleLen) {
             chan[c.chan].dac.sample=-1;
-            if (dumpWrites) addWrite(0xffff0002+(c.chan<<8),0);
+            //if (dumpWrites) addWrite(0xffff0002+(c.chan<<8),0);
             break;
           } else {
-            if (dumpWrites) addWrite(0xffff0000+(c.chan<<8),chan[c.chan].dac.sample);
+            //if (dumpWrites) addWrite(0xffff0000+(c.chan<<8),chan[c.chan].dac.sample);
           }
           if (chan[c.chan].dac.setPos) {
             chan[c.chan].dac.setPos=false;
@@ -651,7 +651,7 @@ int DivPlatformAY8910::dispatch(DivCommand c) {
           chan[c.chan].dac.rate=parent->getSample(chan[c.chan].dac.sample)->rate*2048;
           if (dumpWrites) {
             rWrite(0x08+c.chan,0);
-            addWrite(0xffff0001+(c.chan<<8),chan[c.chan].dac.rate);
+            //addWrite(0xffff0001+(c.chan<<8),chan[c.chan].dac.rate);
           }
           chan[c.chan].dac.furnaceDAC=false;
         }
@@ -686,7 +686,7 @@ int DivPlatformAY8910::dispatch(DivCommand c) {
     }
     case DIV_CMD_NOTE_OFF:
       chan[c.chan].dac.sample=-1;
-      if (dumpWrites) addWrite(0xffff0002+(c.chan<<8),0);
+      //if (dumpWrites) addWrite(0xffff0002+(c.chan<<8),0);
       chan[c.chan].nextPSGMode.val&=~8;
       chan[c.chan].keyOff=true;
       chan[c.chan].active=false;
@@ -867,7 +867,7 @@ int DivPlatformAY8910::dispatch(DivCommand c) {
     case DIV_CMD_SAMPLE_POS:
       chan[c.chan].dac.pos=c.value;
       chan[c.chan].dac.setPos=true;
-      if (dumpWrites) addWrite(0xffff0005,chan[c.chan].dac.pos);
+      //if (dumpWrites) addWrite(0xffff0005,chan[c.chan].dac.pos);
       break;
     case DIV_CMD_MACRO_OFF:
       chan[c.chan].std.mask(c.value,true);
diff --git a/src/engine/playback.cpp b/src/engine/playback.cpp
index 70cac4d6b..0ce2bd699 100644
--- a/src/engine/playback.cpp
+++ b/src/engine/playback.cpp
@@ -67,6 +67,7 @@ const char* cmdName[]={
   "HINT_ARPEGGIO",
   "HINT_VOLUME",
   "HINT_VOL_SLIDE",
+  "HINT_VOL_SLIDE_TARGET",
   "HINT_PORTA",
   "HINT_LEGATO",
 
@@ -662,7 +663,23 @@ void DivEngine::processRow(int i, bool afterDelay) {
   }
 
   // volume
-  if (pat->data[whatRow][3]!=-1) {
+  int volPortaTarget=-1;
+  bool noApplyVolume=false;
+  for (int j=0; j<curPat[i].effectCols; j++) {
+    short effect=pat->data[whatRow][4+(j<<1)];
+    if (effect==0xd3 || effect==0xd4) { // vol porta
+      volPortaTarget=pat->data[whatRow][3]<<8; // can be -256
+
+      short effectVal=pat->data[whatRow][5+(j<<1)];
+      if (effectVal==-1) effectVal=0;
+      effectVal&=255;
+
+      noApplyVolume=effectVal>0; // "D3.." or "D300" shouldn't stop volume from applying
+      break; // technically you could have both D3 and D4... let's not care
+    }
+  }
+  
+  if (pat->data[whatRow][3]!=-1 && !noApplyVolume) {
     if (!song.oldAlwaysSetVolume || disCont[dispatchOfChan[i]].dispatch->getLegacyAlwaysSetVolume() || (MIN(chan[i].volMax,chan[i].volume)>>8)!=pat->data[whatRow][3]) {
       if (pat->data[whatRow][0]==0 && pat->data[whatRow][1]==0) {
         chan[i].midiAftertouch=true;
@@ -851,6 +868,7 @@ void DivEngine::processRow(int i, bool afterDelay) {
         } else {
           chan[i].volSpeed=0;
         }
+        chan[i].volSpeedTarget=-1;
         dispatchCmd(DivCommand(DIV_CMD_HINT_VOL_SLIDE,i,chan[i].volSpeed));
         break;
       case 0x06: // vol slide + porta
@@ -892,6 +910,7 @@ void DivEngine::processRow(int i, bool afterDelay) {
         } else {
           chan[i].volSpeed=0;
         }
+        chan[i].volSpeedTarget=-1;
         dispatchCmd(DivCommand(DIV_CMD_HINT_VOL_SLIDE,i,chan[i].volSpeed));
         break;
       case 0x07: // tremolo
@@ -902,6 +921,7 @@ void DivEngine::processRow(int i, bool afterDelay) {
         chan[i].tremoloRate=effectVal>>4;
         if (chan[i].tremoloDepth!=0) {
           chan[i].volSpeed=0;
+          chan[i].volSpeedTarget=-1;
         } else {
           dispatchCmd(DivCommand(DIV_CMD_VOLUME,i,chan[i].volume>>8));
           dispatchCmd(DivCommand(DIV_CMD_HINT_VOLUME,i,chan[i].volume>>8));
@@ -921,6 +941,7 @@ void DivEngine::processRow(int i, bool afterDelay) {
         } else {
           chan[i].volSpeed=0;
         }
+        chan[i].volSpeedTarget=-1;
         dispatchCmd(DivCommand(DIV_CMD_HINT_VOL_SLIDE,i,chan[i].volSpeed));
         break;
       case 0x00: // arpeggio
@@ -963,6 +984,22 @@ void DivEngine::processRow(int i, bool afterDelay) {
           chan[i].cutType=0;
         }
         break;
+      case 0xd3: // volume portamento (vol porta)
+        // tremolo and vol slides are incompatible
+        chan[i].tremoloDepth=0;
+        chan[i].tremoloRate=0;
+        chan[i].volSpeed=volPortaTarget<0 ? 0 : volPortaTarget>chan[i].volume ? effectVal : -effectVal;
+        chan[i].volSpeedTarget=chan[i].volSpeed==0 ? -1 : volPortaTarget;
+        dispatchCmd(DivCommand(DIV_CMD_HINT_VOL_SLIDE_TARGET,i,chan[i].volSpeed,chan[i].volSpeedTarget));
+        break;
+      case 0xd4: // volume portamento fast (vol porta fast)
+        // tremolo and vol slides are incompatible
+        chan[i].tremoloDepth=0;
+        chan[i].tremoloRate=0;
+        chan[i].volSpeed=volPortaTarget<0 ? 0 : volPortaTarget>chan[i].volume ? 256*effectVal : -256*effectVal;
+        chan[i].volSpeedTarget=chan[i].volSpeed==0 ? -1 : volPortaTarget;
+        dispatchCmd(DivCommand(DIV_CMD_HINT_VOL_SLIDE_TARGET,i,chan[i].volSpeed,chan[i].volSpeedTarget));
+        break;
       case 0xe0: // arp speed
         if (effectVal>0) {
           curSubSong->arpLen=effectVal;
@@ -1100,6 +1137,7 @@ void DivEngine::processRow(int i, bool afterDelay) {
         chan[i].tremoloDepth=0;
         chan[i].tremoloRate=0;
         chan[i].volSpeed=effectVal;
+        chan[i].volSpeedTarget=-1;
         dispatchCmd(DivCommand(DIV_CMD_HINT_VOL_SLIDE,i,chan[i].volSpeed));
         break;
       case 0xf4: // fine volume ramp down
@@ -1107,6 +1145,7 @@ void DivEngine::processRow(int i, bool afterDelay) {
         chan[i].tremoloDepth=0;
         chan[i].tremoloRate=0;
         chan[i].volSpeed=-effectVal;
+        chan[i].volSpeedTarget=-1;
         dispatchCmd(DivCommand(DIV_CMD_HINT_VOL_SLIDE,i,chan[i].volSpeed));
         break;
       case 0xf5: // disable macro
@@ -1120,12 +1159,14 @@ void DivEngine::processRow(int i, bool afterDelay) {
         break;
       case 0xf8: // single volume ramp up
         chan[i].volSpeed=0; // add compat flag?
+        chan[i].volSpeedTarget=-1;
         chan[i].volume=MIN(chan[i].volume+effectVal*256,chan[i].volMax);
         dispatchCmd(DivCommand(DIV_CMD_VOLUME,i,chan[i].volume>>8));
         dispatchCmd(DivCommand(DIV_CMD_HINT_VOLUME,i,chan[i].volume>>8));
         break;
       case 0xf9: // single volume ramp down
         chan[i].volSpeed=0; // add compat flag?
+        chan[i].volSpeedTarget=-1;
         chan[i].volume=MAX(chan[i].volume-effectVal*256,0);
         dispatchCmd(DivCommand(DIV_CMD_VOLUME,i,chan[i].volume>>8));
         dispatchCmd(DivCommand(DIV_CMD_HINT_VOLUME,i,chan[i].volume>>8));
@@ -1143,9 +1184,9 @@ void DivEngine::processRow(int i, bool afterDelay) {
         } else {
           chan[i].volSpeed=0;
         }
+        chan[i].volSpeedTarget=-1;
         dispatchCmd(DivCommand(DIV_CMD_HINT_VOL_SLIDE,i,chan[i].volSpeed));
         break;
-
       case 0xfc: // delayed note release
         if (song.delayBehavior==2 || effectVal<nextSpeed) {
           chan[i].cut=effectVal+1;
@@ -1613,9 +1654,30 @@ bool DivEngine::nextTick(bool noAccum, bool inhibitLowLat) {
           if (chan[i].volSpeed!=0) {
             chan[i].volume=(chan[i].volume&0xff)|(dispatchCmd(DivCommand(DIV_CMD_GET_VOLUME,i))<<8);
             chan[i].volume+=chan[i].volSpeed;
+            if (chan[i].volSpeedTarget!=-1) {
+              bool atTarget=false;
+              if (chan[i].volSpeed>0) {
+                atTarget=(chan[i].volume>=chan[i].volSpeedTarget);
+              } else if (chan[i].volSpeed<0) {
+                atTarget=(chan[i].volume<=chan[i].volSpeedTarget);
+              } else {
+                atTarget=true;
+                chan[i].volSpeedTarget=chan[i].volume;
+              }
+
+              if (atTarget) {
+                chan[i].volume=chan[i].volSpeedTarget;
+                chan[i].volSpeed=0;
+                chan[i].volSpeedTarget=-1;
+                dispatchCmd(DivCommand(DIV_CMD_HINT_VOLUME,i,chan[i].volume>>8));
+                dispatchCmd(DivCommand(DIV_CMD_VOLUME,i,chan[i].volume>>8));
+                dispatchCmd(DivCommand(DIV_CMD_HINT_VOL_SLIDE,i,0));
+              }
+            }
             if (chan[i].volume>chan[i].volMax) {
               chan[i].volume=chan[i].volMax;
               chan[i].volSpeed=0;
+              chan[i].volSpeedTarget=-1;
               dispatchCmd(DivCommand(DIV_CMD_HINT_VOLUME,i,chan[i].volume>>8));
               dispatchCmd(DivCommand(DIV_CMD_VOLUME,i,chan[i].volume>>8));
               dispatchCmd(DivCommand(DIV_CMD_HINT_VOL_SLIDE,i,0));
@@ -1627,6 +1689,7 @@ bool DivEngine::nextTick(bool noAccum, bool inhibitLowLat) {
               } else {
                 chan[i].volume=0;
               }
+              chan[i].volSpeedTarget=-1;
               dispatchCmd(DivCommand(DIV_CMD_VOLUME,i,chan[i].volume>>8));
               dispatchCmd(DivCommand(DIV_CMD_HINT_VOLUME,i,chan[i].volume>>8));
             } else {
diff --git a/src/engine/vgmOps.cpp b/src/engine/vgmOps.cpp
index 9529631a1..0050ab6e6 100644
--- a/src/engine/vgmOps.cpp
+++ b/src/engine/vgmOps.cpp
@@ -2169,8 +2169,8 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
       w->writeI(0);
       w->write(writeADPCM_Y8950[i]->getSampleMem(0),writeADPCM_Y8950[i]->getSampleMemUsage(0));
     }
-    if (writeQSound[i]!=NULL && writeQSound[i]->getSampleMemUsage()>0) {
-      unsigned int blockSize=(writeQSound[i]->getSampleMemUsage()+0xffff)&(~0xffff);
+    if (writeQSound[i]!=NULL && writeQSound[i]->getSampleMemUsage(1)>0) {
+      unsigned int blockSize=(writeQSound[i]->getSampleMemUsage(1)+0xffff)&(~0xffff);
       if (blockSize > 0x1000000) {
         blockSize = 0x1000000;
       }
@@ -2178,7 +2178,7 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
       w->writeC(0x66);
       w->writeC(0x8F);
       w->writeI((blockSize+8)|(i*0x80000000));
-      w->writeI(writeQSound[i]->getSampleMemCapacity());
+      w->writeI(writeQSound[i]->getSampleMemCapacity(1));
       w->writeI(0);
       w->write(writeQSound[i]->getSampleMem(),blockSize);
     }
@@ -2679,7 +2679,8 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
   w->writeWString(ws,false); // japanese author name
   w->writeS(0); // date
   w->writeWString(L"Furnace (chiptune tracker)",false); // ripper
-  w->writeS(0); // notes
+  ws=utf8To16(song.notes.c_str());
+  w->writeWString(ws,false); // notes
 
   int gd3Len=w->tell()-gd3Off-12;
 
diff --git a/src/fixedQueue.h b/src/fixedQueue.h
index 68f883edc..f67f70946 100644
--- a/src/fixedQueue.h
+++ b/src/fixedQueue.h
@@ -42,6 +42,7 @@ template<typename T, size_t items> struct FixedQueue {
   void clear();
   bool empty();
   size_t size();
+  size_t capacity();
   FixedQueue():
     readPos(0),
     writePos(0) {}
@@ -177,4 +178,8 @@ template <typename T, size_t items> size_t FixedQueue<T,items>::size() {
   return writePos-readPos;
 }
 
+template <typename T, size_t items> size_t FixedQueue<T,items>::capacity() {
+  return items-1;
+}
+
 #endif
diff --git a/src/gui/about.cpp b/src/gui/about.cpp
index 1c407c009..2b2d9c0b3 100644
--- a/src/gui/about.cpp
+++ b/src/gui/about.cpp
@@ -35,6 +35,7 @@ const char* aboutLine[]={
   _N("-- program --"),
   "tildearrow",
   _N("A M 4 N (intro tune)"),
+  "Adam Lederer",
   "akumanatt",
   "cam900",
   "djtuBIG-MaliceX",
diff --git a/src/gui/csPlayer.cpp b/src/gui/csPlayer.cpp
index 6bbae43ce..7be1f4e1d 100644
--- a/src/gui/csPlayer.cpp
+++ b/src/gui/csPlayer.cpp
@@ -161,6 +161,8 @@ void FurnaceGUI::drawCSPlayer() {
             ImGui::TableNextColumn();
             ImGui::Text(_("vols"));
             ImGui::TableNextColumn();
+            ImGui::Text(_("volst"));
+            ImGui::TableNextColumn();
             ImGui::Text(_("vib"));
             ImGui::TableNextColumn();
             ImGui::Text(_("porta"));
@@ -189,6 +191,8 @@ void FurnaceGUI::drawCSPlayer() {
               ImGui::TableNextColumn();
               ImGui::Text("%+d",state->volSpeed);
               ImGui::TableNextColumn();
+              ImGui::Text("%+d",state->volSpeedTarget);
+              ImGui::TableNextColumn();
               ImGui::Text("%d/%d (%d)",state->vibratoDepth,state->vibratoRate,state->vibratoPos);
               ImGui::TableNextColumn();
               ImGui::Text("-> %d (%d)",state->portaTarget,state->portaSpeed);
diff --git a/src/gui/debugWindow.cpp b/src/gui/debugWindow.cpp
index b08c60532..b28126fc5 100644
--- a/src/gui/debugWindow.cpp
+++ b/src/gui/debugWindow.cpp
@@ -145,6 +145,7 @@ void FurnaceGUI::drawDebug() {
           ImGui::Text("- portaNote = %d",ch->portaNote);
           ImGui::Text("- volume = %.4x",ch->volume);
           ImGui::Text("- volSpeed = %d",ch->volSpeed);
+          ImGui::Text("- volSpeedTarget = %d",ch->volSpeedTarget);
           ImGui::Text("- cut = %d",ch->cut);
           ImGui::Text("- rowDelay = %d",ch->rowDelay);
           ImGui::Text("- volMax = %.4x",ch->volMax);
diff --git a/src/gui/doAction.cpp b/src/gui/doAction.cpp
index 00bfe95ea..48edf51e2 100644
--- a/src/gui/doAction.cpp
+++ b/src/gui/doAction.cpp
@@ -73,6 +73,8 @@ void FurnaceGUI::doAction(int what) {
     case GUI_ACTION_UNDO:
       if (curWindow==GUI_WINDOW_SAMPLE_EDIT) {
         doUndoSample();
+      } else if (curWindow==GUI_WINDOW_INS_EDIT) {
+        doUndoInstrument();
       } else {
         doUndo();
       }
@@ -80,6 +82,8 @@ void FurnaceGUI::doAction(int what) {
     case GUI_ACTION_REDO:
       if (curWindow==GUI_WINDOW_SAMPLE_EDIT) {
         doRedoSample();
+      } else if (curWindow==GUI_WINDOW_INS_EDIT) {
+        doRedoInstrument();
       } else {
         doRedo();
       }
@@ -677,30 +681,7 @@ void FurnaceGUI::doAction(int what) {
       latchNibble=false;
       break;
     case GUI_ACTION_PAT_ABSORB_INSTRUMENT: {
-      DivPattern* pat=e->curPat[cursor.xCoarse].getPattern(e->curOrders->ord[cursor.xCoarse][curOrder],false);
-      if (!pat) break;
-      bool foundIns=false;
-      bool foundOctave=false;
-      for (int i=cursor.y; i>=0 && !(foundIns && foundOctave); i--) {
-        // absorb most recent instrument
-        if (!foundIns && pat->data[i][2] >= 0) {
-          curIns=pat->data[i][2];
-          foundIns=true;
-        }
-        // absorb most recent octave (i.e. set curOctave such that the "main row" (QWERTY) of notes
-        // will result in an octave number equal to the previous note).
-        if (!foundOctave && pat->data[i][0] != 0) {
-          // decode octave data (was signed cast to unsigned char)
-          int octave=pat->data[i][1];
-          if (octave>128) octave-=256;
-          // @NOTE the special handling when note==12, which is really an octave above what's
-          // stored in the octave data. without this handling, if you press Q, then
-          // "ABSORB_INSTRUMENT", then Q again, you'd get a different octave!
-          if (pat->data[i][0]==12) octave++;
-          curOctave=CLAMP(octave-1, GUI_EDIT_OCTAVE_MIN, GUI_EDIT_OCTAVE_MAX);
-          foundOctave=true;
-        }
-      }
+      doAbsorbInstrument();
       break;
     }
 
diff --git a/src/gui/editControls.cpp b/src/gui/editControls.cpp
index 34beff48b..40269259e 100644
--- a/src/gui/editControls.cpp
+++ b/src/gui/editControls.cpp
@@ -508,7 +508,7 @@ void FurnaceGUI::drawMobileControls() {
           mobileMenuOpen=false;
           doAction(GUI_ACTION_SAVE_AS);
         }
-
+        ImGui::SameLine();
         if (ImGui::Button(_("Export"))) {
           doAction(GUI_ACTION_EXPORT);
         }
@@ -533,6 +533,10 @@ void FurnaceGUI::drawMobileControls() {
             drawSpeed(true);
             ImGui::EndTabItem();
           }
+          if (ImGui::BeginTabItem(_("Comments"))) {
+            drawNotes(true);
+            ImGui::EndTabItem();
+          }
           ImGui::EndTabBar();
         }
         break;
diff --git a/src/gui/editing.cpp b/src/gui/editing.cpp
index 1a4449098..8a49f4ecf 100644
--- a/src/gui/editing.cpp
+++ b/src/gui/editing.cpp
@@ -1823,6 +1823,52 @@ void FurnaceGUI::doExpandSong(int multiplier) {
   if (e->isPlaying()) e->play();
 }
 
+void FurnaceGUI::doAbsorbInstrument() {
+  bool foundIns=false;
+  bool foundOctave=false;
+  auto foundAll = [&]() { return foundIns && foundOctave; };
+
+  // search this order and all prior until we find all the data we need
+  int orderIdx=curOrder;
+  for (; orderIdx>=0 && !foundAll(); orderIdx--) {
+    DivPattern* pat=e->curPat[cursor.xCoarse].getPattern(e->curOrders->ord[cursor.xCoarse][orderIdx],false);
+    if (!pat) continue;
+
+    // start on current row when searching current order, but start from end when searching
+    // prior orders.
+    int searchStartRow=orderIdx==curOrder ? cursor.y : e->curSubSong->patLen-1;
+    for (int i=searchStartRow; i>=0 && !foundAll(); i--) {
+
+      // absorb most recent instrument
+      if (!foundIns && pat->data[i][2] >= 0) {
+        foundIns=true;
+        curIns=pat->data[i][2];
+      }
+
+      // absorb most recent octave (i.e. set curOctave such that the "main row" (QWERTY) of
+      // notes will result in an octave number equal to the previous note).
+      if (!foundOctave && pat->data[i][0] != 0) {
+        foundOctave=true;
+
+        // decode octave data (was signed cast to unsigned char)
+        int octave=pat->data[i][1];
+        if (octave>128) octave-=256;
+
+        // @NOTE the special handling when note==12, which is really an octave above what's
+        // stored in the octave data. without this handling, if you press Q, then
+        // "ABSORB_INSTRUMENT", then Q again, you'd get a different octave!
+        if (pat->data[i][0]==12) octave++;
+        curOctave=CLAMP(octave-1, GUI_EDIT_OCTAVE_MIN, GUI_EDIT_OCTAVE_MAX);
+      }
+    }
+  }
+
+  // if no instrument has been set at this point, the only way to match it is to use "none"
+  if (!foundIns) curIns=-1;
+
+  logD("doAbsorbInstrument -- searched %d orders", curOrder-orderIdx);
+}
+
 void FurnaceGUI::doDrag() {
   int len=dragEnd.xCoarse-dragStart.xCoarse+1;
 
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 254065992..608be1e56 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -3739,6 +3739,7 @@ bool FurnaceGUI::loop() {
       ImGui::GetIO().AddKeyEvent(ImGuiKey_Backspace,false);
       injectBackUp=false;
     }
+
     while (SDL_PollEvent(&ev)) {
       WAKE_UP;
       ImGui_ImplSDL2_ProcessEvent(&ev);
@@ -3755,13 +3756,16 @@ bool FurnaceGUI::loop() {
         }
         case SDL_MOUSEBUTTONUP:
           pointUp(ev.button.x,ev.button.y,ev.button.button);
+          insEditMayBeDirty=true;
           break;
         case SDL_MOUSEBUTTONDOWN:
           pointDown(ev.button.x,ev.button.y,ev.button.button);
+          insEditMayBeDirty=true;
           break;
         case SDL_MOUSEWHEEL:
           wheelX+=ev.wheel.x;
           wheelY+=ev.wheel.y;
+          insEditMayBeDirty=true;
           break;
         case SDL_WINDOWEVENT:
           switch (ev.window.event) {
@@ -3838,12 +3842,14 @@ bool FurnaceGUI::loop() {
           if (!ImGui::GetIO().WantCaptureKeyboard) {
             keyDown(ev);
           }
+          insEditMayBeDirty=true;
 #ifdef IS_MOBILE
           injectBackUp=true;
 #endif
           break;
         case SDL_KEYUP:
           // for now
+          insEditMayBeDirty=true;
           break;
         case SDL_DROPFILE:
           if (ev.drop.file!=NULL) {
@@ -4482,7 +4488,7 @@ bool FurnaceGUI::loop() {
         } else {
           if (ImGui::BeginMenu(_("add chip..."))) {
             exitDisabledTimer=1;
-            DivSystem picked=systemPicker();
+            DivSystem picked=systemPicker(false);
             if (picked!=DIV_SYSTEM_NULL) {
               if (!e->addSystem(picked)) {
                 showError(fmt::sprintf(_("cannot add chip! (%s)"),e->getLastError()));
@@ -4513,7 +4519,7 @@ bool FurnaceGUI::loop() {
             ImGui::Checkbox(_("Preserve channel positions"),&preserveChanPos);
             for (int i=0; i<e->song.systemLen; i++) {
               if (ImGui::BeginMenu(fmt::sprintf("%d. %s##_SYSC%d",i+1,getSystemName(e->song.system[i]),i).c_str())) {
-                DivSystem picked=systemPicker();
+                DivSystem picked=systemPicker(false);
                 if (picked!=DIV_SYSTEM_NULL) {
                   if (e->changeSystem(i,picked,preserveChanPos)) {
                     MARK_MODIFIED;
@@ -5856,6 +5862,7 @@ bool FurnaceGUI::loop() {
 
     centerNextWindow(_("Rendering..."),canvasW,canvasH);
     if (ImGui::BeginPopupModal(_("Rendering..."),NULL,ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove)) {
+      WAKE_UP;
       if(audioExportOptions.mode != DIV_EXPORT_MODE_MANY_CHAN)
       {
         ImGui::Text(_("Please wait..."));
@@ -5916,7 +5923,7 @@ bool FurnaceGUI::loop() {
         ImGui::Text(_("Channel %d of %d"), curFile + 1, totalFiles);
       }
 
-      ImGui::ProgressBar(curProgress,ImVec2(-FLT_MIN,0), fmt::sprintf("%.2f%%", curProgress * 100.0f).c_str());
+      ImGui::ProgressBar(curProgress,ImVec2(320.0f*dpiScale,0), fmt::sprintf("%.2f%%", curProgress * 100.0f).c_str());
 
       if (ImGui::Button(_("Abort"))) {
         if (e->haltAudioFile()) {
@@ -7241,6 +7248,11 @@ bool FurnaceGUI::loop() {
       willCommit=false;
     }
 
+    // To check for instrument editor modification, we need an up-to-date `insEditMayBeDirty`
+    // (based on incoming user input events), and we want any possible instrument modifications
+    // to already have been made.
+    checkRecordInstrumentUndoStep();
+
     if (shallDetectScale) {
       if (--shallDetectScale<1) {
         if (settings.dpiScale<0.5f) {
@@ -8414,6 +8426,8 @@ FurnaceGUI::FurnaceGUI():
   localeRequiresChineseTrad(false),
   localeRequiresKorean(false),
   prevInsData(NULL),
+  cachedCurInsPtr(NULL),
+  insEditMayBeDirty(false),
   pendingLayoutImport(NULL),
   pendingLayoutImportLen(0),
   pendingLayoutImportStep(0),
diff --git a/src/gui/gui.h b/src/gui/gui.h
index 29eb4e1a5..f6b2cb9a9 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -2270,6 +2270,9 @@ class FurnaceGUI {
   std::vector<ImWchar> localeExtraRanges;
 
   DivInstrument* prevInsData;
+  DivInstrument cachedCurIns;
+  DivInstrument* cachedCurInsPtr;
+  bool insEditMayBeDirty;
 
   unsigned char* pendingLayoutImport;
   size_t pendingLayoutImportLen;
@@ -2834,7 +2837,7 @@ class FurnaceGUI {
   void drawMemory();
   void drawCompatFlags();
   void drawPiano();
-  void drawNotes();
+  void drawNotes(bool asChild=false);
   void drawChannels();
   void drawPatManager();
   void drawSysManager();
@@ -2924,13 +2927,14 @@ class FurnaceGUI {
   void doExpand(int multiplier, const SelectionPoint& sStart, const SelectionPoint& sEnd);
   void doCollapseSong(int divider);
   void doExpandSong(int multiplier);
+  void doAbsorbInstrument();
   void doUndo();
   void doRedo();
   void doFind();
   void doReplace();
   void doDrag();
   void editOptions(bool topMenu);
-  DivSystem systemPicker();
+  DivSystem systemPicker(bool fullWidth);
   void noteInput(int num, int key, int vol=-1);
   void valueInput(int num, bool direct=false, int target=-1);
   void orderInput(int num);
@@ -2940,6 +2944,10 @@ class FurnaceGUI {
   void doUndoSample();
   void doRedoSample();
 
+  void checkRecordInstrumentUndoStep();
+  void doUndoInstrument();
+  void doRedoInstrument();
+
   void play(int row=0);
   void setOrder(unsigned char order, bool forced=false);
   void stop();
diff --git a/src/gui/guiConst.cpp b/src/gui/guiConst.cpp
index dc5e97ea7..49af3205a 100644
--- a/src/gui/guiConst.cpp
+++ b/src/gui/guiConst.cpp
@@ -474,8 +474,8 @@ const FurnaceGUIColors fxColors[256]={
   GUI_COLOR_PATTERN_EFFECT_INVALID,
   GUI_COLOR_PATTERN_EFFECT_INVALID,
   GUI_COLOR_PATTERN_EFFECT_INVALID,
-  GUI_COLOR_PATTERN_EFFECT_INVALID,
-  GUI_COLOR_PATTERN_EFFECT_INVALID,
+  GUI_COLOR_PATTERN_EFFECT_VOLUME,
+  GUI_COLOR_PATTERN_EFFECT_VOLUME,
   GUI_COLOR_PATTERN_EFFECT_INVALID,
   GUI_COLOR_PATTERN_EFFECT_INVALID,
   GUI_COLOR_PATTERN_EFFECT_INVALID,
diff --git a/src/gui/insEdit.cpp b/src/gui/insEdit.cpp
index 4082670a0..fbec0da97 100644
--- a/src/gui/insEdit.cpp
+++ b/src/gui/insEdit.cpp
@@ -6438,6 +6438,7 @@ void FurnaceGUI::drawInsEdit() {
     ImGui::SetNextWindowSizeConstraints(ImVec2(440.0f*dpiScale,400.0f*dpiScale),ImVec2(canvasW,canvasH));
   }
   if (ImGui::Begin("Instrument Editor",&insEditOpen,globalWinFlags|(settings.allowEditDocking?0:ImGuiWindowFlags_NoDocking),_("Instrument Editor"))) {
+    DivInstrument* ins=NULL;
     if (curIns==-2) {
       ImGui::SetCursorPosY(ImGui::GetCursorPosY()+(ImGui::GetContentRegionAvail().y-ImGui::GetFrameHeightWithSpacing()+ImGui::GetStyle().ItemSpacing.y)*0.5f);
       CENTER_TEXT(_("waiting..."));
@@ -6465,6 +6466,7 @@ void FurnaceGUI::drawInsEdit() {
                 curIns=i;
                 wavePreviewInit=true;
                 updateFMPreview=true;
+                ins = e->song.ins[curIns];
               }
             }
             ImGui::EndCombo();
@@ -6487,7 +6489,7 @@ void FurnaceGUI::drawInsEdit() {
         ImGui::EndTable();
       }
     } else {
-      DivInstrument* ins=e->song.ins[curIns];
+      ins=e->song.ins[curIns];
       if (updateFMPreview) {
         renderFMPreview(ins);
         updateFMPreview=false;
@@ -8146,6 +8148,8 @@ void FurnaceGUI::drawInsEdit() {
                 macroList.push_back(FurnaceGUIMacroDesc(_("Noise"),&ins->std.dutyMacro,0,8,160,uiColors[GUI_COLOR_MACRO_NOISE]));
               }
               macroList.push_back(FurnaceGUIMacroDesc(_("Waveform"),&ins->std.waveMacro,0,waveCount,160,uiColors[GUI_COLOR_MACRO_WAVE],false,NULL,NULL,false,NULL));
+              macroList.push_back(FurnaceGUIMacroDesc(_("Panning (left)"),&ins->std.panLMacro,0,15,46,uiColors[GUI_COLOR_MACRO_OTHER],false,NULL));
+              macroList.push_back(FurnaceGUIMacroDesc(_("Panning (right)"),&ins->std.panRMacro,0,15,46,uiColors[GUI_COLOR_MACRO_OTHER]));
               macroList.push_back(FurnaceGUIMacroDesc(_("Pitch"),&ins->std.pitchMacro,-2048,2047,160,uiColors[GUI_COLOR_MACRO_PITCH],true,macroRelativeMode));
               macroList.push_back(FurnaceGUIMacroDesc(_("Phase Reset"),&ins->std.phaseResetMacro,0,1,32,uiColors[GUI_COLOR_MACRO_OTHER],false,NULL,NULL,true));
               break;
@@ -8703,6 +8707,63 @@ void FurnaceGUI::drawInsEdit() {
       ImGui::EndPopup();
     }
   }
+
   if (ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows)) curWindow=GUI_WINDOW_INS_EDIT;
   ImGui::End();
 }
+
+void FurnaceGUI::checkRecordInstrumentUndoStep() {
+  if (insEditOpen && curIns>=0 && curIns<(int)e->song.ins.size()) {
+    DivInstrument* ins=e->song.ins[curIns];
+
+    // invalidate cachedCurIns/any possible changes if the cachedCurIns was referencing a different
+    // instrument altgoether
+    bool insChanged=ins!=cachedCurInsPtr;
+    if (insChanged) {
+      insEditMayBeDirty=false;
+      cachedCurInsPtr=ins;
+      cachedCurIns=*ins;
+    }
+
+    cachedCurInsPtr=ins;
+
+    // check against the last cached to see if diff -- note that modifications to instruments
+    // happen outside drawInsEdit (e.g. cursor inputs are processed and can directly modify
+    // macro data).  but don't check until we think the user input is complete.
+    bool delayDiff=ImGui::IsMouseDown(ImGuiMouseButton_Left) || ImGui::IsMouseDown(ImGuiMouseButton_Right) || ImGui::GetIO().WantCaptureKeyboard;
+    if (!delayDiff && insEditMayBeDirty) {
+      bool hasChange=ins->recordUndoStepIfChanged(e->processTime, &cachedCurIns);
+      if (hasChange) {
+        cachedCurIns=*ins;
+      }
+      insEditMayBeDirty=false;
+    }
+  } else {
+    cachedCurInsPtr=NULL;
+    insEditMayBeDirty=false;
+  }
+}
+
+void FurnaceGUI::doUndoInstrument() {
+  if (!insEditOpen) return;
+  if (curIns<0 || curIns>=(int)e->song.ins.size()) return;
+  DivInstrument* ins=e->song.ins[curIns];
+  // is locking the engine necessary? copied from doUndoSample
+  e->lockEngine([this,ins]() {
+    ins->undo();
+    cachedCurInsPtr=ins;
+    cachedCurIns=*ins;
+  });
+}
+
+void FurnaceGUI::doRedoInstrument() {
+  if (!insEditOpen) return;
+  if (curIns<0 || curIns>=(int)e->song.ins.size()) return;
+  DivInstrument* ins=e->song.ins[curIns];
+  // is locking the engine necessary? copied from doRedoSample
+  e->lockEngine([this,ins]() {
+    ins->redo();
+    cachedCurInsPtr=ins;
+    cachedCurIns=*ins;
+  });
+}
diff --git a/src/gui/pattern.cpp b/src/gui/pattern.cpp
index 4111a4d83..b2c4ee9f3 100644
--- a/src/gui/pattern.cpp
+++ b/src/gui/pattern.cpp
@@ -1507,6 +1507,7 @@ void FurnaceGUI::drawPattern() {
             i.cmd==DIV_CMD_HINT_PORTA ||
             i.cmd==DIV_CMD_HINT_LEGATO ||
             i.cmd==DIV_CMD_HINT_VOL_SLIDE ||
+            i.cmd==DIV_CMD_HINT_VOL_SLIDE_TARGET ||
             i.cmd==DIV_CMD_HINT_ARPEGGIO ||
             i.cmd==DIV_CMD_HINT_PITCH ||
             i.cmd==DIV_CMD_HINT_VIBRATO ||
diff --git a/src/gui/settings.cpp b/src/gui/settings.cpp
index ab3523bc8..33151945f 100644
--- a/src/gui/settings.cpp
+++ b/src/gui/settings.cpp
@@ -1084,15 +1084,19 @@ void FurnaceGUI::drawSettings() {
           ImGui::PushID(i);
 
           ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x-ImGui::CalcTextSize(_("Invert")).x-ImGui::GetFrameHeightWithSpacing()*2.0-ImGui::GetStyle().ItemSpacing.x*2.0);
-          if (ImGui::BeginCombo("##System",getSystemName(sysID))) {
-            for (int j=0; availableSystems[j]; j++) {
-              if (ImGui::Selectable(getSystemName((DivSystem)availableSystems[j]),sysID==availableSystems[j])) {
-                sysID=(DivSystem)availableSystems[j];
-                settings.initialSys.set(fmt::sprintf("id%d",i),(int)e->systemToFileFur(sysID));
-                settings.initialSys.set(fmt::sprintf("flags%d",i),"");
-                settingsChanged=true;
-              }
+            if (ImGui::BeginCombo("##System",getSystemName(sysID),ImGuiComboFlags_HeightLargest)) {
+
+            sysID=systemPicker(true);
+
+            if (sysID!=DIV_SYSTEM_NULL)
+            {
+              settings.initialSys.set(fmt::sprintf("id%d",i),(int)e->systemToFileFur(sysID));
+              settings.initialSys.set(fmt::sprintf("flags%d",i),"");
+              settingsChanged=true;
+
+              ImGui::CloseCurrentPopup();
             }
+
             ImGui::EndCombo();
           }
 
diff --git a/src/gui/songNotes.cpp b/src/gui/songNotes.cpp
index cf55b7aef..15ecb2a82 100644
--- a/src/gui/songNotes.cpp
+++ b/src/gui/songNotes.cpp
@@ -22,18 +22,23 @@
 
 // NOTE: please don't ask me to enable text wrap.
 //       Dear ImGui doesn't have that feature. D:
-void FurnaceGUI::drawNotes() {
+void FurnaceGUI::drawNotes(bool asChild) {
   if (nextWindow==GUI_WINDOW_NOTES) {
     notesOpen=true;
     ImGui::SetNextWindowFocus();
     nextWindow=GUI_WINDOW_NOTHING;
   }
-  if (!notesOpen) return;
-  if (ImGui::Begin("Song Comments",&notesOpen,globalWinFlags,_("Song Comments"))) {
+  if (!notesOpen && !asChild) return;
+  bool began=asChild?ImGui::BeginChild("Song Info##Song Information"):ImGui::Begin("Song Comments",&notesOpen,globalWinFlags,_("Song Comments"));
+  if (began) {
     if (ImGui::InputTextMultiline("##SongNotes",&e->song.notes,ImGui::GetContentRegionAvail(),ImGuiInputTextFlags_UndoRedo)) {
       MARK_MODIFIED;
     }
   }
-  if (ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows)) curWindow=GUI_WINDOW_NOTES;
-  ImGui::End();
+  if (!asChild && ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows)) curWindow=GUI_WINDOW_NOTES;
+  if (asChild) {
+    ImGui::EndChild();
+  } else {
+    ImGui::End();
+  }
 }
diff --git a/src/gui/sysManager.cpp b/src/gui/sysManager.cpp
index b4e08fc36..c118c1d77 100644
--- a/src/gui/sysManager.cpp
+++ b/src/gui/sysManager.cpp
@@ -102,7 +102,7 @@ void FurnaceGUI::drawSysManager() {
         ImGui::SameLine();
         ImGui::Button(_("Change##SysChange"));
         if (ImGui::BeginPopupContextItem("SysPickerC",ImGuiPopupFlags_MouseButtonLeft)) {
-          DivSystem picked=systemPicker();
+          DivSystem picked=systemPicker(false);
           if (picked!=DIV_SYSTEM_NULL) {
             if (e->changeSystem(i,picked,preserveChanPos)) {
               MARK_MODIFIED;
@@ -138,7 +138,7 @@ void FurnaceGUI::drawSysManager() {
         ImGui::TableNextColumn();
         ImGui::Button(ICON_FA_PLUS "##SysAdd");
         if (ImGui::BeginPopupContextItem("SysPickerA",ImGuiPopupFlags_MouseButtonLeft)) {
-          DivSystem picked=systemPicker();
+          DivSystem picked=systemPicker(false);
           if (picked!=DIV_SYSTEM_NULL) {
             if (!e->addSystem(picked)) {
               showError(fmt::sprintf(_("cannot add chip! (%s)"),e->getLastError()));
diff --git a/src/gui/sysPicker.cpp b/src/gui/sysPicker.cpp
index 3eb7f5015..6d10ac754 100644
--- a/src/gui/sysPicker.cpp
+++ b/src/gui/sysPicker.cpp
@@ -23,7 +23,7 @@
 #include "guiConst.h"
 #include <imgui.h>
 
-DivSystem FurnaceGUI::systemPicker() {
+DivSystem FurnaceGUI::systemPicker(bool fullWidth) {
   DivSystem ret=DIV_SYSTEM_NULL;
   DivSystem hoveredSys=DIV_SYSTEM_NULL;
   bool reissueSearch=false;
@@ -61,7 +61,7 @@ DivSystem FurnaceGUI::systemPicker() {
       }
     }
   }
-  if (ImGui::BeginTable("SysList",1,ImGuiTableFlags_ScrollY,ImVec2(500.0f*dpiScale,200.0*dpiScale))) {
+ if (ImGui::BeginTable("SysList",1,ImGuiTableFlags_ScrollY,ImVec2(fullWidth ? ImGui::GetContentRegionAvail().x : 500.0f*dpiScale,200.0f*dpiScale))) {
     if (sysSearchQuery.empty()) {
       // display chip list
       for (int j=0; curSysSection[j]; j++) {
diff --git a/src/gui/userPresets.cpp b/src/gui/userPresets.cpp
index 14e6f9d7b..d2999c6cc 100644
--- a/src/gui/userPresets.cpp
+++ b/src/gui/userPresets.cpp
@@ -392,7 +392,7 @@ void FurnaceGUI::drawUserPresets() {
               tempID=fmt::sprintf("%s##USystem",getSystemName(chip.sys));
               ImGui::Button(tempID.c_str(),ImVec2(ImGui::GetContentRegionAvail().x-ImGui::CalcTextSize(_("Invert")).x-ImGui::GetFrameHeightWithSpacing()*2.0-ImGui::GetStyle().ItemSpacing.x*2.0,0));
               if (ImGui::BeginPopupContextItem("SysPickerCU",ImGuiPopupFlags_MouseButtonLeft)) {
-                DivSystem picked=systemPicker();
+                DivSystem picked=systemPicker(false);
                 if (picked!=DIV_SYSTEM_NULL) {
                   chip.sys=picked;
                   mustBake=true;
@@ -456,7 +456,7 @@ void FurnaceGUI::drawUserPresets() {
 
             ImGui::Button(ICON_FA_PLUS "##SysAddU");
             if (ImGui::BeginPopupContextItem("SysPickerU",ImGuiPopupFlags_MouseButtonLeft)) {
-              DivSystem picked=systemPicker();
+              DivSystem picked=systemPicker(false);
               if (picked!=DIV_SYSTEM_NULL) {
                 preset->orig.push_back(FurnaceGUISysDefChip(picked,1.0f,0.0f,""));
                 mustBake=true;