diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index 64577efef..14db71853 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -3,6 +3,7 @@
 #include "safeReader.h"
 #include "../ta-log.h"
 #include "../audio/sdl.h"
+#include <cstring>
 #ifdef HAVE_JACK
 #include "../audio/jack.h"
 #endif
@@ -20,6 +21,7 @@
 #include <math.h>
 #include <zlib.h>
 #include <sndfile.h>
+#include <fmt/printf.h>
 
 void process(void* u, float** in, float** out, int inChans, int outChans, unsigned int size) {
   ((DivEngine*)u)->nextBuf(in,out,inChans,outChans,size);
@@ -1045,6 +1047,12 @@ static double samplePitches[11]={
   2, 3, 4, 5, 6
 };
 
+void DivEngine::renderSamplesP() {
+  isBusy.lock();
+  renderSamples();
+  isBusy.unlock();
+}
+
 void DivEngine::renderSamples() {
   if (jediTable==NULL) {
     jediTable=new int[16*49];
@@ -1063,6 +1071,10 @@ void DivEngine::renderSamples() {
       delete[] s->adpcmRendData;
     }
     s->rendLength=(double)s->length/samplePitches[s->pitch];
+    if (s->rendLength==0) {
+      s->adpcmRendLength=0;
+      continue;
+    }
     s->rendData=new short[s->rendLength];
     size_t adpcmLen=((s->rendLength>>1)+255)&0xffffff00;
     s->adpcmRendLength=adpcmLen;
@@ -1227,6 +1239,135 @@ bool DivEngine::isPlaying() {
   return playing;
 }
 
+int DivEngine::addInstrument() {
+  isBusy.lock();
+  DivInstrument* ins=new DivInstrument;
+  int insCount=(int)song.ins.size();
+  ins->name=fmt::sprintf("Instrument %d",insCount);
+  song.ins.push_back(ins);
+  song.insLen=insCount+1;
+  isBusy.unlock();
+  return insCount;
+}
+
+void DivEngine::delInstrument(int index) {
+  isBusy.lock();
+  if (index>=0 && index<(int)song.ins.size()) {
+    delete song.ins[index];
+    song.ins.erase(song.ins.begin()+index);
+    song.insLen=song.ins.size();
+  }
+  isBusy.unlock();
+}
+
+int DivEngine::addWave() {
+  isBusy.lock();
+  DivWavetable* wave=new DivWavetable;
+  int waveCount=(int)song.wave.size();
+  song.wave.push_back(wave);
+  song.waveLen=waveCount+1;
+  isBusy.unlock();
+  return waveCount;
+}
+
+void DivEngine::delWave(int index) {
+  isBusy.lock();
+  if (index>=0 && index<(int)song.wave.size()) {
+    delete song.wave[index];
+    song.wave.erase(song.wave.begin()+index);
+    song.waveLen=song.wave.size();
+  }
+  isBusy.unlock();
+}
+
+int DivEngine::addSample() {
+  isBusy.lock();
+  DivSample* sample=new DivSample;
+  int sampleCount=(int)song.sample.size();
+  sample->name=fmt::sprintf("Sample %d",sampleCount);
+  song.sample.push_back(sample);
+  song.sampleLen=sampleCount+1;
+  renderSamples();
+  isBusy.unlock();
+  return sampleCount;
+}
+
+bool DivEngine::addSampleFromFile(const char* path) {
+  isBusy.lock();
+  SF_INFO si;
+  SNDFILE* f=sf_open(path,SFM_READ,&si);
+  if (f==NULL) {
+    isBusy.unlock();
+    return false;
+  }
+  if (si.frames>1000000) {
+    sf_close(f);
+    isBusy.unlock();
+    return false;
+  }
+  short* buf=new short[si.channels*si.frames];
+  if (sf_readf_short(f,buf,si.frames)!=si.frames) {
+    logW("sample read size mismatch!\n");
+  }
+  sf_close(f);
+  DivSample* sample=new DivSample;
+  int sampleCount=(int)song.sample.size();
+  const char* sName=strrchr(path,'/');
+  if (sName==NULL) {
+    sName=path;
+  } else {
+    sName++;
+  }
+  sample->name=sName;
+
+  int index=0;
+  sample->length=si.frames;
+  sample->data=new short[si.frames];
+  sample->depth=16;
+  sample->vol=50;
+  sample->pitch=5;
+  for (int i=0; i<si.frames*si.channels; i+=si.channels) {
+    int averaged=0;
+    for (int j=0; j<si.channels; j++) {
+      averaged+=buf[i+j];
+    }
+    averaged/=si.channels;
+    sample->data[index++]=averaged;
+  }
+  delete[] buf;
+  // 4000, 8000, 11025, 16000, 22050, 32000
+  if (si.samplerate>26000) {
+    sample->rate=5;
+  } else if (si.samplerate>18000) {
+    sample->rate=4;
+  } else if (si.samplerate>14000) {
+    sample->rate=3;
+  } else if (si.samplerate>9500) {
+    sample->rate=2;
+  } else if (si.samplerate>6000) {
+    sample->rate=1;
+  } else {
+    sample->rate=0;
+  }
+
+  song.sample.push_back(sample);
+  song.sampleLen=sampleCount+1;
+  renderSamples();
+  isBusy.unlock();
+  return sampleCount;
+}
+
+void DivEngine::delSample(int index) {
+  isBusy.lock();
+  if (index>=0 && index<(int)song.sample.size()) {
+    delete song.sample[index];
+    song.sample.erase(song.sample.begin()+index);
+    song.sampleLen=song.sample.size();
+    renderSamples();
+  }
+  isBusy.unlock();
+}
+
 void DivEngine::setOrder(unsigned char order) {
   isBusy.lock();
   curOrder=order;
diff --git a/src/engine/engine.h b/src/engine/engine.h
index 945f7c745..5c4c13ee8 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -156,6 +156,27 @@ class DivEngine {
     // is playing
     bool isPlaying();
 
+    // add instrument
+    int addInstrument();
+
+    // delete instrument
+    void delInstrument(int index);
+
+    // add wavetable
+    int addWave();
+
+    // delete wavetable
+    void delWave(int index);
+
+    // add sample
+    int addSample();
+
+    // add sample from file
+    bool addSampleFromFile(const char* path);
+
+    // delete sample
+    void delSample(int index);
+
     // go to order
     void setOrder(unsigned char order);
 
@@ -171,6 +192,9 @@ class DivEngine {
     // set the view mode.
     void setView(DivStatusView which);
 
+    // public render samples
+    void renderSamplesP();
+
     // init dispatch
     void initDispatch();
 
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 300a8e2a1..4f78b40da 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -23,6 +23,7 @@ const int _ZERO=0;
 const int _ONE=1;
 const int _THREE=3;
 const int _SEVEN=7;
+const int _TEN=10;
 const int _FIFTEEN=15;
 const int _THIRTY_ONE=31;
 const int _SIXTY_FOUR=64;
@@ -84,6 +85,14 @@ const char* noteNames[120]={
   "C-9", "C#9", "D-9", "D#9", "E-9", "F-9", "F#9", "G-9", "G#9", "A-9", "A#9", "B-9"
 };
 
+const char* rateLabel[6]={
+  "4000Hz", "8000Hz", "11025Hz", "16000Hz", "22050Hz", "32000Hz"
+};
+
+const char* pitchLabel[11]={
+  "1/6", "1/5", "1/4", "1/3", "1/2", "1x", "2x", "3x", "4x", "5x", "6x"
+};
+
 void FurnaceGUI::bindEngine(DivEngine* eng) {
   e=eng;
 }
@@ -263,6 +272,25 @@ void FurnaceGUI::drawOrders() {
 void FurnaceGUI::drawInsList() {
   if (!insListOpen) return;
   if (ImGui::Begin("Instruments",&insListOpen)) {
+    if (ImGui::Button("Add##InsAdd")) {
+      curIns=e->addInstrument();
+    }
+    ImGui::SameLine();
+    if (ImGui::ArrowButton("InsUp",ImGuiDir_Up)) {
+      // TODO
+    }
+    ImGui::SameLine();
+    if (ImGui::ArrowButton("InsDown",ImGuiDir_Down)) {
+      // TODO
+    }
+    ImGui::SameLine();
+    if (ImGui::Button("Delete##InsDelete")) {
+      e->delInstrument(curIns);
+      if (curIns>=(int)e->song.ins.size()) {
+        curIns--;
+      }
+    }
+    ImGui::Separator();
     for (int i=0; i<(int)e->song.ins.size(); i++) {
       DivInstrument* ins=e->song.ins[i];
       if (ImGui::Selectable(fmt::sprintf("%d: %s##_INS%d\n",i,ins->name,i).c_str(),curIns==i)) {
@@ -282,7 +310,7 @@ void FurnaceGUI::drawInsList() {
 void FurnaceGUI::drawInsEdit() {
   if (!insEditOpen) return;
   if (ImGui::Begin("Instrument Editor",&insEditOpen,ImGuiWindowFlags_NoDocking)) {
-    if (curIns>=(int)e->song.ins.size()) {
+    if (curIns<0 || curIns>=(int)e->song.ins.size()) {
       ImGui::Text("no instrument selected");
     } else {
       DivInstrument* ins=e->song.ins[curIns];
@@ -585,6 +613,25 @@ void FurnaceGUI::drawWaveList() {
   if (!waveListOpen) return;
   float wavePreview[256];
   if (ImGui::Begin("Wavetables",&waveListOpen)) {
+    if (ImGui::Button("Add##WaveAdd")) {
+      curWave=e->addWave();
+    }
+    ImGui::SameLine();
+    if (ImGui::ArrowButton("WaveUp",ImGuiDir_Up)) {
+      // TODO
+    }
+    ImGui::SameLine();
+    if (ImGui::ArrowButton("WaveDown",ImGuiDir_Down)) {
+      // TODO
+    }
+    ImGui::SameLine();
+    if (ImGui::Button("Delete##WaveDelete")) {
+      e->delWave(curWave);
+      if (curWave>=(int)e->song.wave.size()) {
+        curWave--;
+      }
+    }
+    ImGui::Separator();
     for (int i=0; i<(int)e->song.wave.size(); i++) {
       DivWavetable* wave=e->song.wave[i];
       for (int i=0; i<wave->len; i++) {
@@ -620,6 +667,33 @@ void FurnaceGUI::drawWaveEdit() {
 void FurnaceGUI::drawSampleList() {
   if (!sampleListOpen) return;
   if (ImGui::Begin("Samples",&sampleListOpen)) {
+    if (ImGui::Button("Add##SampleAdd")) {
+      curSample=e->addSample();
+    }
+    ImGui::SameLine();
+    if (ImGui::Button("Load##SampleLoad")) {
+      openFileDialog(GUI_FILE_SAMPLE_OPEN);
+    }
+    ImGui::SameLine();
+    if (ImGui::Button("Save##SampleSave")) {
+      openFileDialog(GUI_FILE_SAMPLE_SAVE);
+    }
+    ImGui::SameLine();
+    if (ImGui::ArrowButton("SampleUp",ImGuiDir_Up)) {
+      // TODO
+    }
+    ImGui::SameLine();
+    if (ImGui::ArrowButton("SampleDown",ImGuiDir_Down)) {
+      // TODO
+    }
+    ImGui::SameLine();
+    if (ImGui::Button("Delete##SampleDelete")) {
+      e->delSample(curSample);
+      if (curSample>=(int)e->song.sample.size()) {
+        curSample--;
+      }
+    }
+    ImGui::Separator();
     for (int i=0; i<(int)e->song.sample.size(); i++) {
       DivSample* sample=e->song.sample[i];
       if (ImGui::Selectable(fmt::sprintf("%d: %s##_SAM%d\n",i,sample->name,i).c_str(),curSample==i)) {
@@ -639,6 +713,27 @@ void FurnaceGUI::drawSampleList() {
 void FurnaceGUI::drawSampleEdit() {
   if (!sampleEditOpen) return;
   if (ImGui::Begin("Sample Editor",&sampleEditOpen)) {
+    if (curSample<0 || curSample>=(int)e->song.sample.size()) {
+      ImGui::Text("no sample selected");
+    } else {
+      DivSample* sample=e->song.sample[curSample];
+      ImGui::InputText("Name",&sample->name);
+      if (ImGui::SliderInt("Rate",&sample->rate,0,5,rateLabel[sample->rate])) {
+        if (sample->rate<0) sample->rate=0;
+        if (sample->rate>5) sample->rate=5;
+      }
+      if (ImGui::SliderScalar("Volume",ImGuiDataType_S8,&sample->vol,&_ZERO,&_ONE_HUNDRED,fmt::sprintf("%d%%%%",sample->vol*2).c_str())) {
+        if (sample->vol<0) sample->vol=0;
+        if (sample->vol>100) sample->vol=100;
+      }
+      if (ImGui::SliderScalar("Pitch",ImGuiDataType_S8,&sample->pitch,&_ZERO,&_TEN,pitchLabel[sample->pitch])) {
+        if (sample->pitch<0) sample->pitch=0;
+        if (sample->pitch>10) sample->pitch=10;
+      }
+      if (ImGui::Button("Apply")) {
+        e->renderSamplesP();
+      }
+    }
   }
   if (ImGui::IsWindowFocused()) curWindow=GUI_WINDOW_SAMPLE_EDIT;
   ImGui::End();
@@ -1038,6 +1133,24 @@ void FurnaceGUI::keyUp(SDL_Event& ev) {
   
 }
 
+void FurnaceGUI::openFileDialog(FurnaceGUIFileDialogs type) {
+  switch (type) {
+    case GUI_FILE_OPEN:
+      ImGuiFileDialog::Instance()->OpenDialog("FileDialog","Open File","DefleMask module{.dmf},.*",workingDir);
+      break;
+    case GUI_FILE_SAVE:
+      ImGuiFileDialog::Instance()->OpenDialog("FileDialog","Save File","DefleMask module{.dmf}",workingDir);
+      break;
+    case GUI_FILE_SAMPLE_OPEN:
+      ImGuiFileDialog::Instance()->OpenDialog("FileDialog","Load Sample","Wave file{.wav},.*",workingDir);
+      break;
+    case GUI_FILE_SAMPLE_SAVE:
+      ImGuiFileDialog::Instance()->OpenDialog("FileDialog","Save Sample","Wave file{.wav}",workingDir);
+      break;
+  }
+  curFileDialog=type;
+}
+
 #define FURNACE_ZLIB_COMPRESS
 
 int FurnaceGUI::save(String path) {
@@ -1234,14 +1347,13 @@ bool FurnaceGUI::loop() {
     if (ImGui::BeginMenu("file")) {
       ImGui::MenuItem("new");
       if (ImGui::MenuItem("open...")) {
-        ImGuiFileDialog::Instance()->OpenDialog("FileDialog","Open File","DefleMask module{.dmf},.*",workingDir);
-        isSaving=false;
+        openFileDialog(GUI_FILE_OPEN);
+        
       }
       ImGui::Separator();
       ImGui::MenuItem("save");
       if (ImGui::MenuItem("save as...")) {
-        ImGuiFileDialog::Instance()->OpenDialog("FileDialog","Save File","DefleMask module{.dmf}",workingDir);
-        isSaving=true;
+        openFileDialog(GUI_FILE_SAVE);
       }
       ImGui::Separator();
       ImGui::MenuItem("change platform...");
@@ -1305,19 +1417,32 @@ bool FurnaceGUI::loop() {
       if (ImGuiFileDialog::Instance()->IsOk()) {
         fileName=ImGuiFileDialog::Instance()->GetFilePathName();
         if (fileName!="") {
-          if (isSaving) {
+          if (curFileDialog==GUI_FILE_SAVE) {
             if (fileName.size()<4 || fileName.rfind(".dmf")!=fileName.size()-4) {
               fileName+=".dmf";
             }
           }
-          String copyOfName=fileName;
-          if (isSaving) {
-            printf("saving: %s\n",copyOfName.c_str());
-            save(copyOfName);
-            isSaving=false;
-          } else {
-            load(copyOfName);
+          if (curFileDialog==GUI_FILE_SAMPLE_SAVE) {
+            if (fileName.size()<4 || fileName.rfind(".wav")!=fileName.size()-4) {
+              fileName+=".wav";
+            }
           }
+          String copyOfName=fileName;
+          switch (curFileDialog) {
+            case GUI_FILE_OPEN:
+              load(copyOfName);
+              break;
+            case GUI_FILE_SAVE:
+              printf("saving: %s\n",copyOfName.c_str());
+              save(copyOfName);
+              break;
+            case GUI_FILE_SAMPLE_OPEN:
+              e->addSampleFromFile(copyOfName.c_str());
+              break;
+            case GUI_FILE_SAMPLE_SAVE:
+              break;
+          }
+          curFileDialog=GUI_FILE_OPEN;
         }
       }
       workingDir=ImGuiFileDialog::Instance()->GetCurrentPath();
@@ -1403,7 +1528,7 @@ bool FurnaceGUI::init() {
 FurnaceGUI::FurnaceGUI():
   e(NULL),
   quit(false),
-  isSaving(false),
+  curFileDialog(GUI_FILE_OPEN),
   scrW(1280),
   scrH(800),
   dpiScale(1),
diff --git a/src/gui/gui.h b/src/gui/gui.h
index 237fc3483..6fc0badff 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -47,6 +47,13 @@ enum FurnaceGUIWindows {
   GUI_WINDOW_SAMPLE_EDIT
 };
 
+enum FurnaceGUIFileDialogs {
+  GUI_FILE_OPEN,
+  GUI_FILE_SAVE,
+  GUI_FILE_SAMPLE_OPEN,
+  GUI_FILE_SAMPLE_SAVE
+};
+
 struct SelectionPoint {
   int xCoarse, xFine;
   int y;
@@ -62,7 +69,9 @@ class FurnaceGUI {
 
   String workingDir, fileName;
 
-  bool quit, isSaving;
+  bool quit;
+
+  FurnaceGUIFileDialogs curFileDialog;
 
   int scrW, scrH;
 
@@ -124,6 +133,7 @@ class FurnaceGUI {
   void keyDown(SDL_Event& ev);
   void keyUp(SDL_Event& ev);
 
+  void openFileDialog(FurnaceGUIFileDialogs type);
   int save(String path);
   int load(String path);