diff --git a/src/engine/engine.h b/src/engine/engine.h
index 4d7f7e62..ddf9f581 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -267,7 +267,7 @@ class DivEngine {
     // load a file.
     bool load(unsigned char* f, size_t length);
     // save as .dmf.
-    SafeWriter* saveDMF();
+    SafeWriter* saveDMF(unsigned char version);
     // save as .fur.
     SafeWriter* saveFur();
     // build a ROM file (TODO).
diff --git a/src/engine/fileOps.cpp b/src/engine/fileOps.cpp
index 6240f3f5..299e8607 100644
--- a/src/engine/fileOps.cpp
+++ b/src/engine/fileOps.cpp
@@ -53,6 +53,8 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
       ds.nullWave.data[i]=15;
     }
 
+    ds.isDMF=true;
+
     if (!reader.seek(16,SEEK_SET)) {
       logE("premature end of file!\n");
       lastError="incomplete file";
@@ -724,6 +726,7 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
     if (ds.version<50) {
       ds.ignoreDuplicateSlides=false;
     }
+    ds.isDMF=false;
 
     reader.readS(); // reserved
     int infoSeek=reader.readI();
@@ -1148,6 +1151,9 @@ SafeWriter* DivEngine::saveFur() {
   size_t ptrSeek;
   warnings="";
 
+  song.isDMF=false;
+  song.version=DIV_ENGINE_VERSION;
+
   SafeWriter* w=new SafeWriter;
   w->init();
   /// HEADER
@@ -1375,19 +1381,34 @@ SafeWriter* DivEngine::saveFur() {
   return w;
 }
 
-SafeWriter* DivEngine::saveDMF() {
-  // fail if more than one system
-  if (song.systemLen!=1) {
-    logE("cannot save multiple systems in this format!\n");
-    lastError="multiple systems not possible on .dmf";
+SafeWriter* DivEngine::saveDMF(unsigned char version) {
+  // fail if version is not supported
+  if (version<24 || version>25) {
+    logE("cannot save in this version!\n");
+    lastError="invalid version to save in! this is a bug!";
     return NULL;
   }
+  // fail if more than one system
+  // TODO: fix this mess for the flattening in 0.6
+  if (!(song.system[0]==DIV_SYSTEM_SMS && song.system[1]==DIV_SYSTEM_OPLL)) {
+    if (song.systemLen!=1) {
+      logE("cannot save multiple systems in this format!\n");
+      lastError="multiple systems not possible on .dmf";
+      return NULL;
+    }
+  }
   // fail if this is an YMU759 song
   if (song.system[0]==DIV_SYSTEM_YMU759) {
     logE("cannot save YMU759 song!\n");
     lastError="YMU759 song saving is not supported";
     return NULL;
   }
+  // fail if the system is SMS+OPLL and version<25
+  if (version<25 && song.system[0]==DIV_SYSTEM_SMS && song.system[1]==DIV_SYSTEM_OPLL) {
+    logE("Master System FM expansion not supported in 1.0/legacy .dmf!\n");
+    lastError="Master System FM expansion not supported in 1.0/legacy .dmf!";
+    return NULL;
+  }
   // fail if the system is Furnace-exclusive
   if (systemToFile(song.system[0])&0x80) {
     logE("cannot save Furnace-exclusive system song!\n");
@@ -1395,14 +1416,23 @@ SafeWriter* DivEngine::saveDMF() {
     return NULL;
   }
   warnings="";
+  song.version=version;
+  song.isDMF=true;
 
   SafeWriter* w=new SafeWriter;
   w->init();
   // write magic
   w->write(DIV_DMF_MAGIC,16);
   // version
-  w->writeC(24);
-  w->writeC(systemToFile(song.system[0]));
+  w->writeC(version);
+  DivSystem sys=DIV_SYSTEM_NULL;
+  if (song.system[0]==DIV_SYSTEM_SMS && song.system[1]==DIV_SYSTEM_OPLL) {
+    w->writeC(systemToFile(DIV_SYSTEM_SMS_OPLL));
+    sys=DIV_SYSTEM_SMS_OPLL;
+  } else {
+    w->writeC(systemToFile(song.system[0]));
+    sys=song.system[0];
+  }
 
   // song info
   w->writeString(song.name,true);
@@ -1425,10 +1455,14 @@ SafeWriter* DivEngine::saveDMF() {
   for (int i=0; i<chans; i++) {
     for (int j=0; j<song.ordersLen; j++) {
       w->writeC(song.orders.ord[i][j]);
+      if (version>=25) {
+        DivPattern* pat=song.pat[i].getPattern(j,false);
+        w->writeString(pat->name,true);
+      }
     }
   }
 
-  if (song.system[0]==DIV_SYSTEM_C64_6581 || song.system[0]==DIV_SYSTEM_C64_8580) {
+  if (sys==DIV_SYSTEM_C64_6581 || sys==DIV_SYSTEM_C64_8580) {
     addWarning("absolute duty/cutoff macro not available in .dmf!");
     addWarning("duty precision will be lost");
   }
@@ -1452,10 +1486,10 @@ SafeWriter* DivEngine::saveDMF() {
     w->writeString(i->name,true);
 
     // safety check
-    if (!isFMSystem(song.system[0]) && i->mode) {
+    if (!isFMSystem(sys) && i->mode) {
       i->mode=0;
     }
-    if (!isSTDSystem(song.system[0]) && i->mode==0) {
+    if (!isSTDSystem(sys) && i->mode==0) {
       i->mode=1;
     }
 
@@ -1475,14 +1509,25 @@ SafeWriter* DivEngine::saveDMF() {
         w->writeC(op.rr);
         w->writeC(op.sl);
         w->writeC(op.tl);
-        w->writeC(op.dt2);
-        w->writeC(op.rs);
-        w->writeC(op.dt);
-        w->writeC(op.d2r);
-        w->writeC(op.ssgEnv);
+        if (sys==DIV_SYSTEM_SMS_OPLL && j==0) {
+          w->writeC(i->fm.opllPreset);
+        } else {
+          w->writeC(op.dt2);
+        }
+        if (sys==DIV_SYSTEM_SMS_OPLL) {
+          w->writeC(op.ksr);
+          w->writeC(op.vib);
+          w->writeC(op.ksl);
+          w->writeC(op.ssgEnv);
+        } else {
+          w->writeC(op.rs);
+          w->writeC(op.dt);
+          w->writeC(op.d2r);
+          w->writeC(op.ssgEnv);
+        }
       }
     } else { // STD
-      if (song.system[0]!=DIV_SYSTEM_GB) {
+      if (sys!=DIV_SYSTEM_GB) {
         w->writeC(i->std.volMacroLen);
         w->write(i->std.volMacro,4*i->std.volMacroLen);
         if (i->std.volMacroLen>0) {
@@ -1515,7 +1560,7 @@ SafeWriter* DivEngine::saveDMF() {
         w->writeC(i->std.waveMacroLoop);
       }
 
-      if (song.system[0]==DIV_SYSTEM_C64_6581 || song.system[0]==DIV_SYSTEM_C64_8580) {
+      if (sys==DIV_SYSTEM_C64_6581 || sys==DIV_SYSTEM_C64_8580) {
         w->writeC(i->c64.triOn);
         w->writeC(i->c64.sawOn);
         w->writeC(i->c64.pulseOn);
@@ -1544,7 +1589,7 @@ SafeWriter* DivEngine::saveDMF() {
         w->writeC(i->c64.ch3off);
       }
 
-      if (song.system[0]==DIV_SYSTEM_GB) {
+      if (sys==DIV_SYSTEM_GB) {
         w->writeC(i->gb.envVol);
         w->writeC(i->gb.envDir);
         w->writeC(i->gb.envLen);
@@ -1559,7 +1604,7 @@ SafeWriter* DivEngine::saveDMF() {
     w->write(i->data,4*i->len);
   }
 
-  for (int i=0; i<getChannelCount(song.system[0]); i++) {
+  for (int i=0; i<getChannelCount(sys); i++) {
     w->writeC(song.pat[i].effectRows);
 
     for (int j=0; j<song.ordersLen; j++) {
diff --git a/src/engine/song.h b/src/engine/song.h
index 2dddae52..4582077e 100644
--- a/src/engine/song.h
+++ b/src/engine/song.h
@@ -140,6 +140,7 @@ struct DivSong {
   //   - basic format, no system number, 16 instruments, one speed, YMU759-only
   //   - if somebody manages to find a version 2 or even 1 module, please tell me as it will be worth more than a luxury vehicle
   unsigned short version;
+  bool isDMF;
 
   // system
   DivSystem system[32];
@@ -267,7 +268,8 @@ struct DivSong {
   void unload();
 
   DivSong():
-    version(24),
+    version(0),
+    isDMF(false),
     systemLen(1),
     name(""),
     author(""),
diff --git a/src/engine/sysDef.cpp b/src/engine/sysDef.cpp
index ce13169a..55fb3a19 100644
--- a/src/engine/sysDef.cpp
+++ b/src/engine/sysDef.cpp
@@ -650,6 +650,7 @@ const char* DivEngine::getSystemNameJ(DivSystem sys) {
 bool DivEngine::isFMSystem(DivSystem sys) {
   return (sys==DIV_SYSTEM_GENESIS ||
           sys==DIV_SYSTEM_GENESIS_EXT ||
+          sys==DIV_SYSTEM_SMS_OPLL ||
           sys==DIV_SYSTEM_ARCADE ||
           sys==DIV_SYSTEM_YM2610 ||
           sys==DIV_SYSTEM_YM2610_EXT ||
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index dab64bbb..1997984f 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -2892,7 +2892,7 @@ void FurnaceGUI::doAction(int what) {
       if (curFileName=="") {
         openFileDialog(GUI_FILE_SAVE);
       } else {
-        if (save(curFileName)>0) {
+        if (save(curFileName,e->song.isDMF?e->song.version:0)>0) {
           showError(fmt::sprintf("Error while saving file! (%s)",lastError));
         }
       }
@@ -3809,7 +3809,10 @@ void FurnaceGUI::openFileDialog(FurnaceGUIFileDialogs type) {
       ImGuiFileDialog::Instance()->OpenModal("FileDialog","Open File","compatible files{.fur,.dmf},.*",workingDir);
       break;
     case GUI_FILE_SAVE:
-      ImGuiFileDialog::Instance()->OpenModal("FileDialog","Save File","Furnace song{.fur},DefleMask module{.dmf}",workingDir,1,nullptr,ImGuiFileDialogFlags_ConfirmOverwrite);
+      ImGuiFileDialog::Instance()->OpenModal("FileDialog","Save File","Furnace song{.fur},DefleMask 1.1 module{.dmf}",workingDir,1,nullptr,ImGuiFileDialogFlags_ConfirmOverwrite);
+      break;
+    case GUI_FILE_SAVE_DMF_LEGACY:
+      ImGuiFileDialog::Instance()->OpenModal("FileDialog","Save File","DefleMask 1.0/legacy module{.dmf}",workingDir,1,nullptr,ImGuiFileDialogFlags_ConfirmOverwrite);
       break;
     case GUI_FILE_INS_OPEN:
       ImGuiFileDialog::Instance()->OpenModal("FileDialog","Load Instrument","compatible files{.fui,.dmp},.*",workingDir);
@@ -3857,10 +3860,10 @@ void FurnaceGUI::openFileDialog(FurnaceGUIFileDialogs type) {
 
 #define FURNACE_ZLIB_COMPRESS
 
-int FurnaceGUI::save(String path) {
+int FurnaceGUI::save(String path, int dmfVersion) {
   SafeWriter* w;
-  if (path.rfind(".dmf")==path.size()-4) {
-    w=e->saveDMF();
+  if (dmfVersion) {
+    w=e->saveDMF(dmfVersion);
   } else {
     w=e->saveFur();
   }
@@ -4305,7 +4308,7 @@ bool FurnaceGUI::loop() {
         if (curFileName=="") {
           openFileDialog(GUI_FILE_SAVE);
         } else {
-          if (save(curFileName)>0) {
+          if (save(curFileName,e->song.isDMF?e->song.version:0)>0) {
             showError(fmt::sprintf("Error while saving file! (%s)",lastError));
           }
         }
@@ -4313,6 +4316,9 @@ bool FurnaceGUI::loop() {
       if (ImGui::MenuItem("save as...",BIND_FOR(GUI_ACTION_SAVE_AS))) {
         openFileDialog(GUI_FILE_SAVE);
       }
+      if (ImGui::MenuItem("save as .dmf (1.0/legacy)...",BIND_FOR(GUI_ACTION_SAVE_AS))) {
+        openFileDialog(GUI_FILE_SAVE_DMF_LEGACY);
+      }
       ImGui::Separator();
       if (ImGui::BeginMenu("export audio...")) {
         if (ImGui::MenuItem("one file")) {
@@ -4796,7 +4802,19 @@ bool FurnaceGUI::loop() {
               break;
             case GUI_FILE_SAVE:
               printf("saving: %s\n",copyOfName.c_str());
-              if (save(copyOfName)>0) {
+              if (ImGuiFileDialog::Instance()->GetCurrentFilter()=="Furnace song") {
+                if (save(copyOfName,0)>0) {
+                  showError(fmt::sprintf("Error while saving file! (%s)",lastError));
+                }
+              } else {
+                if (save(copyOfName,25)>0) {
+                  showError(fmt::sprintf("Error while saving file! (%s)",lastError));
+                }
+              }
+              break;
+            case GUI_FILE_SAVE_DMF_LEGACY:
+              printf("saving: %s\n",copyOfName.c_str());
+              if (save(copyOfName,24)>0) {
                 showError(fmt::sprintf("Error while saving file! (%s)",lastError));
               }
               break;
diff --git a/src/gui/gui.h b/src/gui/gui.h
index b8f26e68..96e1c39b 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -132,6 +132,7 @@ enum FurnaceGUIWindows {
 enum FurnaceGUIFileDialogs {
   GUI_FILE_OPEN,
   GUI_FILE_SAVE,
+  GUI_FILE_SAVE_DMF_LEGACY,
   GUI_FILE_INS_OPEN,
   GUI_FILE_INS_SAVE,
   GUI_FILE_WAVE_OPEN,
@@ -690,7 +691,7 @@ class FurnaceGUI {
   void keyUp(SDL_Event& ev);
 
   void openFileDialog(FurnaceGUIFileDialogs type);
-  int save(String path);
+  int save(String path, int dmfVersion);
   int load(String path);
   void exportAudio(String path, DivAudioExportModes mode);