diff --git a/src/engine/fileOps.cpp b/src/engine/fileOps.cpp
index 2757ac27..7eb148ea 100644
--- a/src/engine/fileOps.cpp
+++ b/src/engine/fileOps.cpp
@@ -179,6 +179,7 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
     ds.brokenPortaArp=false;
     ds.snNoLowPeriods=true;
     ds.ignorePCEDACVolume=true;
+    ds.newY8950PCMFreq=false;
     ds.delayBehavior=0;
     ds.jumpTreatment=2;
 
@@ -1102,6 +1103,7 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
       ds.autoSystem=false;
     }
     ds.ignorePCEDACVolume=true;
+    ds.newY8950PCMFreq=false;
     ds.isDMF=false;
 
     reader.readS(); // reserved
diff --git a/src/engine/platform/opl.cpp b/src/engine/platform/opl.cpp
index d3437240..148ce279 100644
--- a/src/engine/platform/opl.cpp
+++ b/src/engine/platform/opl.cpp
@@ -28,6 +28,8 @@
 
 #define KVSL(x,y) ((chan[x].state.op[orderedOpsL1[ops==4][y]].kvs==2 && isOutputL[ops==4][chan[x].state.alg][y]) || chan[x].state.op[orderedOpsL1[ops==4][y]].kvs==1)
 
+#define OPLPCMDiv (parent->song.newY8950PCMFreq?((oplType==3)?288:72):144)
+
 #define CHIP_FREQBASE chipFreqBase
 
 // N = invalid
@@ -274,7 +276,7 @@ double DivPlatformOPL::NOTE_ADPCMB(int note) {
   if (adpcmChan<0) return 0;
   if (chan[adpcmChan].sample>=0 && chan[adpcmChan].sample<parent->song.sampleLen) {
     double off=65535.0*(double)(parent->getSample(chan[adpcmChan].sample)->centerRate)/8363.0;
-    return parent->calcBaseFreq((double)chipClock/((oplType==3)?288:72),off,note,false);
+    return parent->calcBaseFreq((double)chipClock/OPLPCMDiv,off,note,false);
   }
   return 0;
 }
@@ -504,7 +506,7 @@ void DivPlatformOPL::tick(bool sysTick) {
     if (chan[adpcmChan].freqChanged || chan[adpcmChan].keyOn || chan[adpcmChan].keyOff) {
       if (chan[adpcmChan].sample>=0 && chan[adpcmChan].sample<parent->song.sampleLen) {
         double off=65535.0*(double)(parent->getSample(chan[adpcmChan].sample)->centerRate)/8363.0;
-        chan[adpcmChan].freq=parent->calcFreq(chan[adpcmChan].baseFreq,chan[adpcmChan].pitch,false,4,chan[adpcmChan].pitch2,(double)chipClock/((oplType==3)?288:72),off);
+        chan[adpcmChan].freq=parent->calcFreq(chan[adpcmChan].baseFreq,chan[adpcmChan].pitch,false,4,chan[adpcmChan].pitch2,(double)chipClock/OPLPCMDiv,off);
       } else {
         chan[adpcmChan].freq=0;
       }
diff --git a/src/engine/song.h b/src/engine/song.h
index 28a31c75..9f5ca154 100644
--- a/src/engine/song.h
+++ b/src/engine/song.h
@@ -512,6 +512,7 @@ struct DivSong {
   bool brokenPortaArp;
   bool snNoLowPeriods;
   bool ignorePCEDACVolume;
+  bool newY8950PCMFreq;
   bool autoSystem;
 
   std::vector<DivInstrument*> ins;
@@ -618,6 +619,7 @@ struct DivSong {
     brokenPortaArp(false),
     snNoLowPeriods(false),
     ignorePCEDACVolume(true),
+    newY8950PCMFreq(false),
     autoSystem(true) {
     for (int i=0; i<32; i++) {
       system[i]=DIV_SYSTEM_NULL;
diff --git a/src/gui/compatFlags.cpp b/src/gui/compatFlags.cpp
index c3627efa..80e9b0f5 100644
--- a/src/gui/compatFlags.cpp
+++ b/src/gui/compatFlags.cpp
@@ -147,6 +147,10 @@ void FurnaceGUI::drawCompatFlags() {
     if (ImGui::IsItemHovered()) {
       ImGui::SetTooltip("when enabled, PC Engine DAC Volume is ignored.");
     }
+    ImGui::Checkbox("New Y8950 Frequency calculation",&e->song.newY8950PCMFreq);
+    if (ImGui::IsItemHovered()) {
+      ImGui::SetTooltip("when enabled, use corrected Y8950 frequency calculation");
+    }
 
     ImGui::Text("Pitch linearity:");
     if (ImGui::RadioButton("None",e->song.linearPitch==0)) {
diff --git a/src/gui/debug.cpp b/src/gui/debug.cpp
index 602b7fb0..652150ab 100644
--- a/src/gui/debug.cpp
+++ b/src/gui/debug.cpp
@@ -90,8 +90,8 @@
 
 #define OPNB_CHIP_DEBUG \
   FM_OPN_CHIP_DEBUG; \
-  ImGui::Text("- adpcmAMemLen: %.8x",ch->adpcmAMemLen); \
-  ImGui::Text("- adpcmBMemLen: %.8x",ch->adpcmBMemLen); \
+  ImGui::Text("- adpcmAMemLen: %lld",ch->adpcmAMemLen); \
+  ImGui::Text("- adpcmBMemLen: %lld",ch->adpcmBMemLen); \
   ImGui::Text("- sampleBank: %d",ch->sampleBank); \
   ImGui::Text("- writeADPCMAOff: %d",ch->writeADPCMAOff); \
   ImGui::Text("- writeADPCMAOn: %d",ch->writeADPCMAOn); \
@@ -335,7 +335,7 @@ void putDispatchChip(void* data, int type) {
       DivPlatformYM2608* ch=(DivPlatformYM2608*)data;
       ImGui::Text("> YM2608");
       FM_OPN_CHIP_DEBUG;
-      ImGui::Text("- adpcmBMemLen: %.8x",ch->adpcmBMemLen);
+      ImGui::Text("- adpcmBMemLen: %lld",ch->adpcmBMemLen);
       ImGui::Text("- sampleBank: %d",ch->sampleBank);
       ImGui::Text("- writeRSSOff: %d",ch->writeRSSOff);
       ImGui::Text("- writeRSSOn: %d",ch->writeRSSOn);
@@ -397,7 +397,7 @@ void putDispatchChip(void* data, int type) {
       ImGui::Text(" - Pos: %d",ch->dacPos);
       ImGui::Text(" - AntiClick: %d",ch->dacAntiClick);
       ImGui::Text(" - Sample: %d",ch->dacSample);
-      ImGui::Text("- dpcmMemLen: %.8x",ch->dpcmMemLen);
+      ImGui::Text("- dpcmMemLen: %lld",ch->dpcmMemLen);
       ImGui::Text("- dpcmBank: %d",ch->dpcmBank);
       ImGui::Text("- sampleBank: %d",ch->sampleBank);
       ImGui::Text("- writeOscBuf: %d",ch->writeOscBuf);
@@ -504,7 +504,7 @@ void putDispatchChip(void* data, int type) {
       ImGui::Text("* echo:");
       ImGui::Text(" - delay: %d",ch->echoDelay);
       ImGui::Text(" - feedback: %d",ch->echoFeedback);
-      ImGui::Text("- sampleMemLen: %.8x",ch->sampleMemLen);
+      ImGui::Text("- sampleMemLen: %lld",ch->sampleMemLen);
       COMMON_CHIP_DEBUG_BOOL;
       break;
     }
@@ -512,7 +512,7 @@ void putDispatchChip(void* data, int type) {
       DivPlatformX1_010* ch=(DivPlatformX1_010*)data;
       ImGui::Text("> X1-010");
       COMMON_CHIP_DEBUG;
-      ImGui::Text("- sampleMemLen: %.8x",ch->sampleMemLen);
+      ImGui::Text("- sampleMemLen: %lld",ch->sampleMemLen);
       ImGui::Text("- sampleBank: %d",ch->sampleBank);
       ImGui::Text("- bankSlot: [%d,%d,%d,%d,%d,%d,%d,%d]",ch->bankSlot[0],ch->bankSlot[1],ch->bankSlot[2],ch->bankSlot[3],ch->bankSlot[4],ch->bankSlot[5],ch->bankSlot[6],ch->bankSlot[7]);
       COMMON_CHIP_DEBUG_BOOL;