diff --git a/src/engine/dispatch.h b/src/engine/dispatch.h
index 6963dfb8..ffd9e247 100644
--- a/src/engine/dispatch.h
+++ b/src/engine/dispatch.h
@@ -324,7 +324,7 @@ class DivDispatch {
      * @param rate stream rate (e.g. 44100 for VGM).
      * @param len number of samples.
      */
-    virtual void fillStream(std::vector<DivDelayedWrite>& stream, int rate, size_t len);
+    virtual void fillStream(std::vector<DivDelayedWrite>& stream, int sRate, size_t len);
 
     /**
      * send a command to this dispatch.
diff --git a/src/engine/engine.h b/src/engine/engine.h
index e524f0a4..f4ed7cf5 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -431,7 +431,7 @@ class DivEngine {
   void processRow(int i, bool afterDelay);
   void nextOrder();
   void nextRow();
-  void performVGMWrite(SafeWriter* w, DivSystem sys, DivRegWrite& write, int streamOff, double* loopTimer, double* loopFreq, int* loopSample, bool* sampleDir, bool isSecond);
+  void performVGMWrite(SafeWriter* w, DivSystem sys, DivRegWrite& write, int streamOff, double* loopTimer, double* loopFreq, int* loopSample, bool* sampleDir, bool isSecond, bool directStream);
   // returns true if end of song.
   bool nextTick(bool noAccum=false, bool inhibitLowLat=false);
   bool perSystemEffect(int ch, unsigned char effect, unsigned char effectVal);
@@ -515,7 +515,7 @@ class DivEngine {
     // specify system to build ROM for.
     SafeWriter* buildROM(int sys);
     // dump to VGM.
-    SafeWriter* saveVGM(bool* sysToExport=NULL, bool loop=true, int version=0x171, bool patternHints=false);
+    SafeWriter* saveVGM(bool* sysToExport=NULL, bool loop=true, int version=0x171, bool patternHints=false, bool directStream=false);
     // dump to ZSM.
     SafeWriter* saveZSM(unsigned int zsmrate=60, bool loop=true);
     // dump command stream.
diff --git a/src/engine/platform/abstract.cpp b/src/engine/platform/abstract.cpp
index cdff34f3..8b3239f0 100644
--- a/src/engine/platform/abstract.cpp
+++ b/src/engine/platform/abstract.cpp
@@ -22,7 +22,7 @@
 void DivDispatch::acquire(short* bufL, short* bufR, size_t start, size_t len) {
 }
 
-void DivDispatch::fillStream(std::vector<DivDelayedWrite>& stream, int rate, size_t len) {
+void DivDispatch::fillStream(std::vector<DivDelayedWrite>& stream, int sRate, size_t len) {
 }
 
 void DivDispatch::tick(bool sysTick) {
diff --git a/src/engine/sysDef.cpp b/src/engine/sysDef.cpp
index 63ff23ee..67f58a67 100644
--- a/src/engine/sysDef.cpp
+++ b/src/engine/sysDef.cpp
@@ -1553,7 +1553,7 @@ void DivEngine::registerSystems() {
   );
 
   sysDefs[DIV_SYSTEM_MSM6258]=new DivSysDef(
-    "OKI MSM6258", NULL, 0xab, 0, 1, false, true, 0, false, 1U<<DIV_SAMPLE_DEPTH_VOX,
+    "OKI MSM6258", NULL, 0xab, 0, 1, false, true, 0x150, false, 1U<<DIV_SAMPLE_DEPTH_VOX,
     "an ADPCM sound chip manufactured by OKI and used in the Sharp X68000.",
     {"Sample"},
     {"PCM"},
@@ -1632,7 +1632,7 @@ void DivEngine::registerSystems() {
   );
 
   sysDefs[DIV_SYSTEM_YM2612_FRAC]=new DivSysDef(
-    "Yamaha YM2612 (OPN2) with DualPCM", NULL, 0xbe, 0, 7, true, false, 0, false, 1U<<DIV_SAMPLE_DEPTH_8BIT,
+    "Yamaha YM2612 (OPN2) with DualPCM", NULL, 0xbe, 0, 7, true, false, 0x150, false, 1U<<DIV_SAMPLE_DEPTH_8BIT,
     "this chip is mostly known for being in the Sega Genesis (but it also was on the FM Towns computer).\nthis system uses software mixing to provide two sample channels.",
     {"FM 1", "FM 2", "FM 3", "FM 4", "FM 5", "FM 6/PCM 1", "PCM 2"},
     {"F1", "F2", "F3", "F4", "F5", "P1", "P2"},
@@ -1644,7 +1644,7 @@ void DivEngine::registerSystems() {
   );
 
   sysDefs[DIV_SYSTEM_YM2612_FRAC_EXT]=new DivSysDef(
-    "Yamaha YM2612 (OPN2) Extended Channel 3 with DualPCM and CSM", NULL, 0xbd, 0, 11, true, false, 0, false, 1U<<DIV_SAMPLE_DEPTH_8BIT,
+    "Yamaha YM2612 (OPN2) Extended Channel 3 with DualPCM and CSM", NULL, 0xbd, 0, 11, true, false, 0x150, false, 1U<<DIV_SAMPLE_DEPTH_8BIT,
     "this chip is mostly known for being in the Sega Genesis (but it also was on the FM Towns computer).\nthis system uses software mixing to provide two sample channels.\nthis one is in Extended Channel mode, which turns the third FM channel into four operators with independent notes/frequencies.",
     {"FM 1", "FM 2", "FM 3 OP1", "FM 3 OP2", "FM 3 OP3", "FM 3 OP4", "FM 4", "FM 5", "FM 6/PCM 1", "PCM 2", "CSM Timer"},
     {"F1", "F2", "O1", "O2", "O3", "O4", "F4", "F5", "P1", "P2", "CSM"},
diff --git a/src/engine/vgmOps.cpp b/src/engine/vgmOps.cpp
index 883e1e46..582eafbd 100644
--- a/src/engine/vgmOps.cpp
+++ b/src/engine/vgmOps.cpp
@@ -24,7 +24,7 @@
 
 constexpr int MASTER_CLOCK_PREC=(sizeof(void*)==8)?8:0;
 
-void DivEngine::performVGMWrite(SafeWriter* w, DivSystem sys, DivRegWrite& write, int streamOff, double* loopTimer, double* loopFreq, int* loopSample, bool* sampleDir, bool isSecond) {
+void DivEngine::performVGMWrite(SafeWriter* w, DivSystem sys, DivRegWrite& write, int streamOff, double* loopTimer, double* loopFreq, int* loopSample, bool* sampleDir, bool isSecond, bool directStream) {
   unsigned char baseAddr1=isSecond?0xa0:0x50;
   unsigned char baseAddr2=isSecond?0x80:0;
   unsigned short baseAddr2S=isSecond?0x8000:0;
@@ -515,7 +515,7 @@ void DivEngine::performVGMWrite(SafeWriter* w, DivSystem sys, DivRegWrite& write
         break;
     }
   }
-  if (write.addr>=0xffff0000) { // Furnace special command
+  if (write.addr>=0xffff0000 && !directStream) { // Furnace special command
     unsigned char streamID=streamOff+((write.addr&0xff00)>>8);
     logD("writing stream command %x:%x with stream ID %d",write.addr,write.val,streamID);
     switch (write.addr&0xff) {
@@ -843,7 +843,7 @@ void DivEngine::performVGMWrite(SafeWriter* w, DivSystem sys, DivRegWrite& write
   chipVol.push_back((_id)|(0x80000100)|(((unsigned int)_vol)<<16)); \
 }
 
-SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool patternHints) {
+SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool patternHints, bool directStream) {
   if (version<0x150) {
     lastError="VGM version is too low";
     return NULL;
@@ -947,6 +947,7 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
   int loopSample[DIV_MAX_CHANS];
   bool sampleDir[DIV_MAX_CHANS];
   std::vector<unsigned int> chipVol; 
+  std::vector<DivDelayedWrite> delayedWrites[32];
 
   for (int i=0; i<DIV_MAX_CHANS; i++) {
     loopTimer[i]=0;
@@ -1585,7 +1586,7 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
     sampleSeek+=sample->length8;
   }
 
-  if (writeDACSamples) for (int i=0; i<song.sampleLen; i++) {
+  if (writeDACSamples && !directStream) for (int i=0; i<song.sampleLen; i++) {
     DivSample* sample=song.sample[i];
     w->writeC(0x67);
     w->writeC(0x66);
@@ -1596,7 +1597,7 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
     }
   }
 
-  if (writeNESSamples) for (int i=0; i<song.sampleLen; i++) {
+  if (writeNESSamples && !directStream) for (int i=0; i<song.sampleLen; i++) {
     DivSample* sample=song.sample[i];
     w->writeC(0x67);
     w->writeC(0x66);
@@ -1607,7 +1608,7 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
     }
   }
 
-  if (writePCESamples) for (int i=0; i<song.sampleLen; i++) {
+  if (writePCESamples && !directStream) for (int i=0; i<song.sampleLen; i++) {
     DivSample* sample=song.sample[i];
     w->writeC(0x67);
     w->writeC(0x66);
@@ -1785,87 +1786,89 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
 
   // initialize streams
   int streamID=0;
-  for (int i=0; i<song.systemLen; i++) {
-    if (!willExport[i]) continue;
-    streamIDs[i]=streamID;
-    switch (song.system[i]) {
-      case DIV_SYSTEM_YM2612:
-      case DIV_SYSTEM_YM2612_EXT:
-        w->writeC(0x90);
-        w->writeC(streamID);
-        w->writeC(0x02);
-        w->writeC(0); // port
-        w->writeC(0x2a); // DAC
-
-        w->writeC(0x91);
-        w->writeC(streamID);
-        w->writeC(0);
-        w->writeC(1);
-        w->writeC(0);
-
-        w->writeC(0x92);
-        w->writeC(streamID);
-        w->writeI(32000); // default
-        streamID++;
-        break;
-      case DIV_SYSTEM_NES:
-        w->writeC(0x90);
-        w->writeC(streamID);
-        w->writeC(20);
-        w->writeC(0); // port
-        w->writeC(0x11); // DAC
-
-        w->writeC(0x91);
-        w->writeC(streamID);
-        w->writeC(7);
-        w->writeC(1);
-        w->writeC(0);
-
-        w->writeC(0x92);
-        w->writeC(streamID);
-        w->writeI(32000); // default
-        streamID++;
-        break;
-      case DIV_SYSTEM_PCE:
-        for (int j=0; j<6; j++) {
+  if (!directStream) {
+    for (int i=0; i<song.systemLen; i++) {
+      if (!willExport[i]) continue;
+      streamIDs[i]=streamID;
+      switch (song.system[i]) {
+        case DIV_SYSTEM_YM2612:
+        case DIV_SYSTEM_YM2612_EXT:
           w->writeC(0x90);
           w->writeC(streamID);
-          w->writeC(27);
-          w->writeC(j); // port
-          w->writeC(0x06); // select+DAC
+          w->writeC(0x02);
+          w->writeC(0); // port
+          w->writeC(0x2a); // DAC
 
           w->writeC(0x91);
           w->writeC(streamID);
-          w->writeC(5);
+          w->writeC(0);
           w->writeC(1);
           w->writeC(0);
 
           w->writeC(0x92);
           w->writeC(streamID);
-          w->writeI(16000); // default
+          w->writeI(32000); // default
           streamID++;
-        }
-        break;
-      case DIV_SYSTEM_SWAN:
-        w->writeC(0x90);
-        w->writeC(streamID);
-        w->writeC(isSecond[i]?0xa1:0x21);
-        w->writeC(0); // port
-        w->writeC(0x09); // DAC
+          break;
+        case DIV_SYSTEM_NES:
+          w->writeC(0x90);
+          w->writeC(streamID);
+          w->writeC(20);
+          w->writeC(0); // port
+          w->writeC(0x11); // DAC
 
-        w->writeC(0x91);
-        w->writeC(streamID);
-        w->writeC(0);
-        w->writeC(1);
-        w->writeC(0);
+          w->writeC(0x91);
+          w->writeC(streamID);
+          w->writeC(7);
+          w->writeC(1);
+          w->writeC(0);
 
-        w->writeC(0x92);
-        w->writeC(streamID);
-        w->writeI(24000); // default
-        streamID++;
-        break;
-      default:
-        break;
+          w->writeC(0x92);
+          w->writeC(streamID);
+          w->writeI(32000); // default
+          streamID++;
+          break;
+        case DIV_SYSTEM_PCE:
+          for (int j=0; j<6; j++) {
+            w->writeC(0x90);
+            w->writeC(streamID);
+            w->writeC(27);
+            w->writeC(j); // port
+            w->writeC(0x06); // select+DAC
+
+            w->writeC(0x91);
+            w->writeC(streamID);
+            w->writeC(5);
+            w->writeC(1);
+            w->writeC(0);
+
+            w->writeC(0x92);
+            w->writeC(streamID);
+            w->writeI(16000); // default
+            streamID++;
+          }
+          break;
+        case DIV_SYSTEM_SWAN:
+          w->writeC(0x90);
+          w->writeC(streamID);
+          w->writeC(isSecond[i]?0xa1:0x21);
+          w->writeC(0); // port
+          w->writeC(0x09); // DAC
+
+          w->writeC(0x91);
+          w->writeC(streamID);
+          w->writeC(0);
+          w->writeC(1);
+          w->writeC(0);
+
+          w->writeC(0x92);
+          w->writeC(streamID);
+          w->writeI(24000); // default
+          streamID++;
+          break;
+        default:
+          break;
+      }
     }
   }
 
@@ -1894,10 +1897,12 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
         break;
       }
       // stop all streams
-      for (int i=0; i<streamID; i++) {
-        w->writeC(0x94);
-        w->writeC(i);
-        loopSample[i]=-1;
+      if (!directStream) {
+        for (int i=0; i<streamID; i++) {
+          w->writeC(0x94);
+          w->writeC(i);
+          loopSample[i]=-1;
+        }
       }
 
       if (!playing) {
@@ -1929,63 +1934,69 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
     for (int i=0; i<song.systemLen; i++) {
       std::vector<DivRegWrite>& writes=disCont[i].dispatch->getRegisterWrites();
       for (DivRegWrite& j: writes) {
-        performVGMWrite(w,song.system[i],j,streamIDs[i],loopTimer,loopFreq,loopSample,sampleDir,isSecond[i]);
+        performVGMWrite(w,song.system[i],j,streamIDs[i],loopTimer,loopFreq,loopSample,sampleDir,isSecond[i],directStream);
         writeCount++;
       }
       writes.clear();
     }
     // check whether we need to loop
     int totalWait=cycles>>MASTER_CLOCK_PREC;
-    for (int i=0; i<streamID; i++) {
-      if (loopSample[i]>=0) {
-        loopTimer[i]-=(loopFreq[i]/44100.0)*(double)totalWait;
+    if (directStream) {
+      for (int i=0; i<song.systemLen; i++) {
+        disCont[i].dispatch->fillStream(delayedWrites[i],44100,totalWait);
       }
-    }
-    bool haveNegatives=false;
-    for (int i=0; i<streamID; i++) {
-      if (loopSample[i]>=0) {
-        if (loopTimer[i]<0) {
-          haveNegatives=true;
+    } else {
+      for (int i=0; i<streamID; i++) {
+        if (loopSample[i]>=0) {
+          loopTimer[i]-=(loopFreq[i]/44100.0)*(double)totalWait;
         }
       }
-    }
-    while (haveNegatives) {
-      // finish all negatives
-      int nextToTouch=-1;
+      bool haveNegatives=false;
       for (int i=0; i<streamID; i++) {
         if (loopSample[i]>=0) {
           if (loopTimer[i]<0) {
-            if (nextToTouch>=0) {
-              if (loopTimer[nextToTouch]>loopTimer[i]) nextToTouch=i;
-            } else {
-              nextToTouch=i;
-            }
+            haveNegatives=true;
           }
         }
       }
-      if (nextToTouch>=0) {
-        double waitTime=totalWait+(loopTimer[nextToTouch]*(44100.0/MAX(1,loopFreq[nextToTouch])));
-        if (waitTime>0) {
-          w->writeC(0x61);
-          w->writeS(waitTime);
-          logV("wait is: %f",waitTime);
-          totalWait-=waitTime;
-          tickCount+=waitTime;
-        }
-        if (loopSample[nextToTouch]<song.sampleLen) {
-          DivSample* sample=song.sample[loopSample[nextToTouch]];
-          // insert loop
-          if (sample->getLoopStartPosition(DIV_SAMPLE_DEPTH_8BIT)<sample->getLoopEndPosition(DIV_SAMPLE_DEPTH_8BIT)) {
-            w->writeC(0x93);
-            w->writeC(nextToTouch);
-            w->writeI(sampleOff8[loopSample[nextToTouch]]+sample->getLoopStartPosition(DIV_SAMPLE_DEPTH_8BIT));
-            w->writeC(0x81);
-            w->writeI(sample->getLoopEndPosition(DIV_SAMPLE_DEPTH_8BIT)-sample->getLoopStartPosition(DIV_SAMPLE_DEPTH_8BIT));
+      while (haveNegatives) {
+        // finish all negatives
+        int nextToTouch=-1;
+        for (int i=0; i<streamID; i++) {
+          if (loopSample[i]>=0) {
+            if (loopTimer[i]<0) {
+              if (nextToTouch>=0) {
+                if (loopTimer[nextToTouch]>loopTimer[i]) nextToTouch=i;
+              } else {
+                nextToTouch=i;
+              }
+            }
           }
         }
-        loopSample[nextToTouch]=-1;
-      } else {
-        haveNegatives=false;
+        if (nextToTouch>=0) {
+          double waitTime=totalWait+(loopTimer[nextToTouch]*(44100.0/MAX(1,loopFreq[nextToTouch])));
+          if (waitTime>0) {
+            w->writeC(0x61);
+            w->writeS(waitTime);
+            logV("wait is: %f",waitTime);
+            totalWait-=waitTime;
+            tickCount+=waitTime;
+          }
+          if (loopSample[nextToTouch]<song.sampleLen) {
+            DivSample* sample=song.sample[loopSample[nextToTouch]];
+            // insert loop
+            if (sample->getLoopStartPosition(DIV_SAMPLE_DEPTH_8BIT)<sample->getLoopEndPosition(DIV_SAMPLE_DEPTH_8BIT)) {
+              w->writeC(0x93);
+              w->writeC(nextToTouch);
+              w->writeI(sampleOff8[loopSample[nextToTouch]]+sample->getLoopStartPosition(DIV_SAMPLE_DEPTH_8BIT));
+              w->writeC(0x81);
+              w->writeI(sample->getLoopEndPosition(DIV_SAMPLE_DEPTH_8BIT)-sample->getLoopStartPosition(DIV_SAMPLE_DEPTH_8BIT));
+            }
+          }
+          loopSample[nextToTouch]=-1;
+        } else {
+          haveNegatives=false;
+        }
       }
     }
     // write wait
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 3a1931b6..a66567ed 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -3390,6 +3390,14 @@ bool FurnaceGUI::loop() {
               "pattern indexes are ordered as they appear in the song."
             );
           }
+          ImGui::Checkbox("direct stream mode",&vgmExportDirectStream);
+          if (ImGui::IsItemHovered()) {
+            ImGui::SetTooltip(
+              "required for DualPCM and MSM6258 export.\n\n"
+              "allows for volume/direction changes when playing samples,\n"
+              "at the cost of a massive increase in file size."
+            );
+          }
           ImGui::Text("chips to export:");
           bool hasOneAtLeast=false;
           for (int i=0; i<e->song.systemLen; i++) {
@@ -4161,7 +4169,7 @@ bool FurnaceGUI::loop() {
               break;
             }
             case GUI_FILE_EXPORT_VGM: {
-              SafeWriter* w=e->saveVGM(willExport,vgmExportLoop,vgmExportVersion,vgmExportPatternHints);
+              SafeWriter* w=e->saveVGM(willExport,vgmExportLoop,vgmExportVersion,vgmExportPatternHints,vgmExportDirectStream);
               if (w!=NULL) {
                 FILE* f=ps_fopen(copyOfName.c_str(),"wb");
                 if (f!=NULL) {
@@ -5309,6 +5317,7 @@ FurnaceGUI::FurnaceGUI():
   vgmExportLoop(true),
   zsmExportLoop(true),
   vgmExportPatternHints(false),
+  vgmExportDirectStream(false),
   portrait(false),
   mobileMenuOpen(false),
   wantCaptureKeyboard(false),
diff --git a/src/gui/gui.h b/src/gui/gui.h
index dd1fa92f..fc47d6d8 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -1035,6 +1035,7 @@ class FurnaceGUI {
   std::deque<String> recentFile;
 
   bool quit, warnQuit, willCommit, edit, modified, displayError, displayExporting, vgmExportLoop, zsmExportLoop, vgmExportPatternHints;
+  bool vgmExportDirectStream;
   bool portrait, mobileMenuOpen;
   bool wantCaptureKeyboard, oldWantCaptureKeyboard, displayMacroMenu;
   bool displayNew, fullScreen, preserveChanPos, wantScrollList, noteInputPoly;