diff --git a/papers/format.md b/papers/format.md
index fc954ba05..d61e94d43 100644
--- a/papers/format.md
+++ b/papers/format.md
@@ -29,6 +29,7 @@ furthermore, an `or reserved` indicates this field is always present, but is res
 
 the format versions are:
 
+- 72: Furnace dev72
 - 71: Furnace dev71
 - 70: Furnace dev70
 - 69: Furnace dev69
@@ -242,7 +243,9 @@ size | description
   1  | no slides on first tick (>=71) or reserved
   1  | next row reset arp pos (>=71) or reserved
   1  | ignore jump at end (>=71) or reserved
- 28  | reserved
+  1  | buggy portamento after slide (>=72) or reserved
+  1  | new ins affects envelope (Game Boy) (>=72) or reserved
+ 26  | reserved
 ```
 
 # instrument
diff --git a/src/engine/engine.h b/src/engine/engine.h
index 52d400ca0..24c3e1352 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -42,8 +42,8 @@
 #define BUSY_BEGIN_SOFT softLocked=true; isBusy.lock();
 #define BUSY_END isBusy.unlock(); softLocked=false;
 
-#define DIV_VERSION "dev71"
-#define DIV_ENGINE_VERSION 71
+#define DIV_VERSION "dev72"
+#define DIV_ENGINE_VERSION 72
 
 // for imports
 #define DIV_VERSION_MOD 0xff01
diff --git a/src/engine/fileOps.cpp b/src/engine/fileOps.cpp
index 4697d338a..eca105a39 100644
--- a/src/engine/fileOps.cpp
+++ b/src/engine/fileOps.cpp
@@ -148,6 +148,8 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
     ds.noSlidesOnFirstTick=false;
     ds.rowResetsArpPos=false;
     ds.ignoreJumpAtEnd=true;
+    ds.buggyPortaAfterSlide=true;
+    ds.gbInsAffectsEnvelope=true;
 
     // 1.1 compat flags
     if (ds.version>24) {
@@ -833,6 +835,10 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
       ds.rowResetsArpPos=false;
       ds.ignoreJumpAtEnd=true;
     }
+    if (ds.version<72) {
+      ds.buggyPortaAfterSlide=true;
+      ds.gbInsAffectsEnvelope=false;
+    }
     ds.isDMF=false;
 
     reader.readS(); // reserved
@@ -1080,15 +1086,22 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
       // extended compat flags
       ds.brokenSpeedSel=reader.readC();
       if (ds.version>=71) {
-        song.noSlidesOnFirstTick=reader.readC();
-        song.rowResetsArpPos=reader.readC();
-        song.ignoreJumpAtEnd=reader.readC();
+        ds.noSlidesOnFirstTick=reader.readC();
+        ds.rowResetsArpPos=reader.readC();
+        ds.ignoreJumpAtEnd=reader.readC();
       } else {
         reader.readC();
         reader.readC();
         reader.readC();
       }
-      for (int i=0; i<28; i++) {
+      if (ds.version>=72) {
+        ds.buggyPortaAfterSlide=reader.readC();
+        ds.gbInsAffectsEnvelope=reader.readC();
+      } else {
+        reader.readC();
+        reader.readC();
+      }
+      for (int i=0; i<26; i++) {
         reader.readC();
       }
     }
@@ -1939,7 +1952,9 @@ SafeWriter* DivEngine::saveFur(bool notPrimary) {
   w->writeC(song.noSlidesOnFirstTick);
   w->writeC(song.rowResetsArpPos);
   w->writeC(song.ignoreJumpAtEnd);
-  for (int i=0; i<28; i++) {
+  w->writeC(song.buggyPortaAfterSlide);
+  w->writeC(song.gbInsAffectsEnvelope);
+  for (int i=0; i<26; i++) {
     w->writeC(0);
   }
 
diff --git a/src/engine/platform/gb.cpp b/src/engine/platform/gb.cpp
index d25cc2118..d1d580c84 100644
--- a/src/engine/platform/gb.cpp
+++ b/src/engine/platform/gb.cpp
@@ -288,8 +288,11 @@ int DivPlatformGB::dispatch(DivCommand c) {
       if (chan[c.chan].ins!=c.value || c.value2==1) {
         chan[c.chan].ins=c.value;
         if (c.chan!=2) {
-          chan[c.chan].vol=parent->getIns(chan[c.chan].ins)->gb.envVol;
-          // TODO: also change envelope values
+          DivInstrument* ins=parent->getIns(chan[c.chan].ins);
+          chan[c.chan].vol=ins->gb.envVol;
+          if (parent->song.gbInsAffectsEnvelope) {
+            rWrite(16+c.chan*5+2,((chan[c.chan].vol<<4))|(ins->gb.envLen&7)|((ins->gb.envDir&1)<<3));
+          }
         }
       }
       break;
diff --git a/src/engine/playback.cpp b/src/engine/playback.cpp
index 8042e2cde..71fd58ddd 100644
--- a/src/engine/playback.cpp
+++ b/src/engine/playback.cpp
@@ -882,7 +882,7 @@ void DivEngine::processRow(int i, bool afterDelay) {
           chan[i].inPorta=false;
           dispatchCmd(DivCommand(DIV_CMD_PRE_PORTA,i,false,0));
         } else {
-          if (chan[i].note==chan[i].oldNote && !chan[i].inPorta) {
+          if (chan[i].note==chan[i].oldNote && !chan[i].inPorta && song.buggyPortaAfterSlide) {
             chan[i].portaNote=chan[i].note;
             chan[i].portaSpeed=-1;
           } else {
diff --git a/src/engine/song.h b/src/engine/song.h
index 19a89cfa4..9142636e3 100644
--- a/src/engine/song.h
+++ b/src/engine/song.h
@@ -305,6 +305,8 @@ struct DivSong {
   bool noSlidesOnFirstTick;
   bool rowResetsArpPos;
   bool ignoreJumpAtEnd;
+  bool buggyPortaAfterSlide;
+  bool gbInsAffectsEnvelope;
 
   DivOrders orders;
   std::vector<DivInstrument*> ins;
@@ -381,7 +383,9 @@ struct DivSong {
     brokenSpeedSel(false),
     noSlidesOnFirstTick(false),
     rowResetsArpPos(false),
-    ignoreJumpAtEnd(false) {
+    ignoreJumpAtEnd(false),
+    buggyPortaAfterSlide(false),
+    gbInsAffectsEnvelope(true) {
     for (int i=0; i<32; i++) {
       system[i]=DIV_SYSTEM_NULL;
       systemVol[i]=64;
diff --git a/src/gui/compatFlags.cpp b/src/gui/compatFlags.cpp
index ca0538ea6..91aa34c7e 100644
--- a/src/gui/compatFlags.cpp
+++ b/src/gui/compatFlags.cpp
@@ -97,6 +97,14 @@ void FurnaceGUI::drawCompatFlags() {
     if (ImGui::IsItemHovered()) {
       ImGui::SetTooltip("if this is on, a jump to next row effect will not take place when it is on the last order of a song.");
     }
+    ImGui::Checkbox("Buggy portamento after pitch slide",&e->song.buggyPortaAfterSlide);
+    if (ImGui::IsItemHovered()) {
+      ImGui::SetTooltip("simulates a bug in where portamento does not work after sliding.");
+    }
+    ImGui::Checkbox("Apply Game Boy envelope on note-less instrument change",&e->song.gbInsAffectsEnvelope);
+    if (ImGui::IsItemHovered()) {
+      ImGui::SetTooltip("if this is on, an instrument change will also affect the envelope.");
+    }
 
     ImGui::Text("Loop modality:");
     if (ImGui::RadioButton("Reset channels",e->song.loopModality==0)) {