diff --git a/src/engine/platform/ym2610.cpp b/src/engine/platform/ym2610.cpp
index 46a66fe07..397f6a8f1 100644
--- a/src/engine/platform/ym2610.cpp
+++ b/src/engine/platform/ym2610.cpp
@@ -461,8 +461,8 @@ double DivPlatformYM2610::NOTE_OPNB(int ch, int note) {
 
 double DivPlatformYM2610::NOTE_ADPCMB(int note) {
   if (chan[13].sample>=0 && chan[13].sample<parent->song.sampleLen) {
-    double off=(double)(parent->getSample(chan[13].sample)->centerRate)/8363.0;
-    return off*parent->calcBaseFreq((double)chipClock/144,65535,note,false);
+    double off=65535.0*(double)(parent->getSample(chan[13].sample)->centerRate)/8363.0;
+    return parent->calcBaseFreq((double)chipClock/144,off,note,false);
   }
   return 0;
 }
@@ -726,7 +726,12 @@ void DivPlatformYM2610::tick(bool sysTick) {
     }
   }
   if (chan[13].freqChanged) {
-    chan[13].freq=parent->calcFreq(chan[13].baseFreq,chan[13].pitch,false,4);
+    if (chan[13].sample>=0 && chan[13].sample<parent->song.sampleLen) {
+      double off=65535.0*(double)(parent->getSample(chan[13].sample)->centerRate)/8363.0;
+      chan[13].freq=parent->calcFreq(chan[13].baseFreq,chan[13].pitch,false,4,chan[13].pitch2,(double)chipClock/144,off);
+    } else {
+      chan[13].freq=0;
+    }
     immWrite(0x19,chan[13].freq&0xff);
     immWrite(0x1a,(chan[13].freq>>8)&0xff);
     chan[13].freqChanged=false;
@@ -742,17 +747,21 @@ void DivPlatformYM2610::tick(bool sysTick) {
   for (int i=0; i<4; i++) {
     if (i==1 && extMode) continue;
     if (chan[i].freqChanged) {
-      int fNum=parent->calcFreq(chan[i].baseFreq&0x7ff,chan[i].pitch,false,4,chan[i].pitch2);
-      int block=(chan[i].baseFreq&0xf800)>>11;
-      if (fNum<0) fNum=0;
-      if (fNum>2047) {
-        while (block<7) {
-          fNum>>=1;
-          block++;
+      if (parent->song.linearPitch==2) {
+        chan[i].freq=parent->calcFreq(chan[i].baseFreq,chan[i].pitch,false,4,chan[i].pitch2,chipClock,CHIP_FREQBASE,11);
+      } else {
+        int fNum=parent->calcFreq(chan[i].baseFreq&0x7ff,chan[i].pitch,false,4,chan[i].pitch2,chipClock,CHIP_FREQBASE,11);
+        int block=(chan[i].baseFreq&0xf800)>>11;
+        if (fNum<0) fNum=0;
+        if (fNum>2047) {
+          while (block<7) {
+            fNum>>=1;
+            block++;
+          }
+          if (fNum>2047) fNum=2047;
         }
-        if (fNum>2047) fNum=2047;
+        chan[i].freq=(block<<11)|fNum;
       }
-      chan[i].freq=(block<<11)|fNum;
       if (chan[i].freq>0x3fff) chan[i].freq=0x3fff;
       immWrite(chanOffs[i]+ADDR_FREQH,chan[i].freq>>8);
       immWrite(chanOffs[i]+ADDR_FREQ,chan[i].freq&0xff);
@@ -993,7 +1002,7 @@ int DivPlatformYM2610::dispatch(DivCommand c) {
       break;
     }
     case DIV_CMD_NOTE_PORTA: {
-      if (c.chan>3) { // PSG, ADPCM-B
+      if (c.chan>3 || parent->song.linearPitch==2) { // PSG, ADPCM-B
         int destFreq=NOTE_OPNB(c.chan,c.value2);
         bool return2=false;
         if (destFreq>chan[c.chan].baseFreq) {
diff --git a/src/engine/platform/ym2610b.cpp b/src/engine/platform/ym2610b.cpp
index 03d8f3a26..cd40fe139 100644
--- a/src/engine/platform/ym2610b.cpp
+++ b/src/engine/platform/ym2610b.cpp
@@ -441,8 +441,8 @@ double DivPlatformYM2610B::NOTE_OPNB(int ch, int note) {
 
 double DivPlatformYM2610B::NOTE_ADPCMB(int note) {
   if (chan[15].sample>=0 && chan[15].sample<parent->song.sampleLen) {
-    double off=(double)(parent->getSample(chan[15].sample)->centerRate)/8363.0;
-    return off*parent->calcBaseFreq((double)chipClock/144,65535,note,false);
+    double off=65535.0*(double)(parent->getSample(chan[15].sample)->centerRate)/8363.0;
+    return parent->calcBaseFreq((double)chipClock/144,off,note,false);
   }
   return 0;
 }
@@ -704,7 +704,12 @@ void DivPlatformYM2610B::tick(bool sysTick) {
     }
   }
   if (chan[15].freqChanged) {
-    chan[15].freq=parent->calcFreq(chan[15].baseFreq,chan[15].pitch,false,4);
+    if (chan[15].sample>=0 && chan[15].sample<parent->song.sampleLen) {
+      double off=65535.0*(double)(parent->getSample(chan[15].sample)->centerRate)/8363.0;
+      chan[15].freq=parent->calcFreq(chan[15].baseFreq,chan[15].pitch,false,4,chan[15].pitch2,(double)chipClock/144,off);
+    } else {
+      chan[15].freq=0;
+    }
     immWrite(0x19,chan[15].freq&0xff);
     immWrite(0x1a,(chan[15].freq>>8)&0xff);
     chan[15].freqChanged=false;
@@ -720,17 +725,21 @@ void DivPlatformYM2610B::tick(bool sysTick) {
   for (int i=0; i<6; i++) {
     if (i==2 && extMode) continue;
     if (chan[i].freqChanged) {
-      int fNum=parent->calcFreq(chan[i].baseFreq&0x7ff,chan[i].pitch,false,4,chan[i].pitch2);
-      int block=(chan[i].baseFreq&0xf800)>>11;
-      if (fNum<0) fNum=0;
-      if (fNum>2047) {
-        while (block<7) {
-          fNum>>=1;
-          block++;
+      if (parent->song.linearPitch==2) {
+        chan[i].freq=parent->calcFreq(chan[i].baseFreq,chan[i].pitch,false,4,chan[i].pitch2,chipClock,CHIP_FREQBASE,11);
+      } else {
+        int fNum=parent->calcFreq(chan[i].baseFreq&0x7ff,chan[i].pitch,false,4,chan[i].pitch2);
+        int block=(chan[i].baseFreq&0xf800)>>11;
+        if (fNum<0) fNum=0;
+        if (fNum>2047) {
+          while (block<7) {
+            fNum>>=1;
+            block++;
+          }
+          if (fNum>2047) fNum=2047;
         }
-        if (fNum>2047) fNum=2047;
+        chan[i].freq=(block<<11)|fNum;
       }
-      chan[i].freq=(block<<11)|fNum;
       if (chan[i].freq>0x3fff) chan[i].freq=0x3fff;
       immWrite(chanOffs[i]+ADDR_FREQH,chan[i].freq>>8);
       immWrite(chanOffs[i]+ADDR_FREQ,chan[i].freq&0xff);
@@ -971,7 +980,7 @@ int DivPlatformYM2610B::dispatch(DivCommand c) {
       break;
     }
     case DIV_CMD_NOTE_PORTA: {
-      if (c.chan>5) { // PSG, ADPCM-B
+      if (c.chan>5 || parent->song.linearPitch==2) { // PSG, ADPCM-B
         int destFreq=NOTE_OPNB(c.chan,c.value2);
         bool return2=false;
         if (destFreq>chan[c.chan].baseFreq) {
diff --git a/src/engine/platform/ym2610bext.cpp b/src/engine/platform/ym2610bext.cpp
index ac991ffb8..440dce6a0 100644
--- a/src/engine/platform/ym2610bext.cpp
+++ b/src/engine/platform/ym2610bext.cpp
@@ -120,6 +120,29 @@ int DivPlatformYM2610BExt::dispatch(DivCommand c) {
       break;
     }
     case DIV_CMD_NOTE_PORTA: {
+      if (parent->song.linearPitch==2) {
+        int destFreq=NOTE_FREQUENCY(c.value2);
+        bool return2=false;
+        if (destFreq>opChan[ch].baseFreq) {
+          opChan[ch].baseFreq+=c.value;
+          if (opChan[ch].baseFreq>=destFreq) {
+            opChan[ch].baseFreq=destFreq;
+            return2=true;
+          }
+        } else {
+          opChan[ch].baseFreq-=c.value;
+          if (opChan[ch].baseFreq<=destFreq) {
+            opChan[ch].baseFreq=destFreq;
+            return2=true;
+          }
+        }
+        opChan[ch].freqChanged=true;
+        if (return2) {
+          //opChan[ch].inPorta=false;
+          return 2;
+        }
+        break;
+      }
       int boundaryBottom=parent->calcBaseFreq(chipClock,CHIP_FREQBASE,0,false);
       int boundaryTop=parent->calcBaseFreq(chipClock,CHIP_FREQBASE,12,false);
       int destFreq=NOTE_FNUM_BLOCK(c.value2,11);
@@ -384,17 +407,21 @@ void DivPlatformYM2610BExt::tick(bool sysTick) {
   unsigned char writeMask=2;
   if (extMode) for (int i=0; i<4; i++) {
     if (opChan[i].freqChanged) {
-      int fNum=parent->calcFreq(opChan[i].baseFreq&0x7ff,opChan[i].pitch,false,4,opChan[i].pitch2);
-      int block=(opChan[i].baseFreq&0xf800)>>11;
-      if (fNum<0) fNum=0;
-      if (fNum>2047) {
-        while (block<7) {
-          fNum>>=1;
-          block++;
+      if (parent->song.linearPitch==2) {
+        opChan[i].freq=parent->calcFreq(opChan[i].baseFreq,opChan[i].pitch,false,4,opChan[i].pitch2,chipClock,CHIP_FREQBASE,11);
+      } else {
+        int fNum=parent->calcFreq(opChan[i].baseFreq&0x7ff,opChan[i].pitch,false,4,opChan[i].pitch2);
+        int block=(opChan[i].baseFreq&0xf800)>>11;
+        if (fNum<0) fNum=0;
+        if (fNum>2047) {
+          while (block<7) {
+            fNum>>=1;
+            block++;
+          }
+          if (fNum>2047) fNum=2047;
         }
-        if (fNum>2047) fNum=2047;
+        opChan[i].freq=(block<<11)|fNum;
       }
-      opChan[i].freq=(block<<11)|fNum;
       if (opChan[i].freq>0x3fff) opChan[i].freq=0x3fff;
       immWrite(opChanOffsH[i],opChan[i].freq>>8);
       immWrite(opChanOffsL[i],opChan[i].freq&0xff);
diff --git a/src/engine/platform/ym2610ext.cpp b/src/engine/platform/ym2610ext.cpp
index 98273bd9a..b12fd3de4 100644
--- a/src/engine/platform/ym2610ext.cpp
+++ b/src/engine/platform/ym2610ext.cpp
@@ -120,6 +120,29 @@ int DivPlatformYM2610Ext::dispatch(DivCommand c) {
       break;
     }
     case DIV_CMD_NOTE_PORTA: {
+      if (parent->song.linearPitch==2) {
+        int destFreq=NOTE_FREQUENCY(c.value2);
+        bool return2=false;
+        if (destFreq>opChan[ch].baseFreq) {
+          opChan[ch].baseFreq+=c.value;
+          if (opChan[ch].baseFreq>=destFreq) {
+            opChan[ch].baseFreq=destFreq;
+            return2=true;
+          }
+        } else {
+          opChan[ch].baseFreq-=c.value;
+          if (opChan[ch].baseFreq<=destFreq) {
+            opChan[ch].baseFreq=destFreq;
+            return2=true;
+          }
+        }
+        opChan[ch].freqChanged=true;
+        if (return2) {
+          //opChan[ch].inPorta=false;
+          return 2;
+        }
+        break;
+      }
       int boundaryBottom=parent->calcBaseFreq(chipClock,CHIP_FREQBASE,0,false);
       int boundaryTop=parent->calcBaseFreq(chipClock,CHIP_FREQBASE,12,false);
       int destFreq=NOTE_FNUM_BLOCK(c.value2,11);
@@ -384,17 +407,21 @@ void DivPlatformYM2610Ext::tick(bool sysTick) {
   unsigned char writeMask=2;
   if (extMode) for (int i=0; i<4; i++) {
     if (opChan[i].freqChanged) {
-      int fNum=parent->calcFreq(opChan[i].baseFreq&0x7ff,opChan[i].pitch,false,4,opChan[i].pitch2);
-      int block=(opChan[i].baseFreq&0xf800)>>11;
-      if (fNum<0) fNum=0;
-      if (fNum>2047) {
-        while (block<7) {
-          fNum>>=1;
-          block++;
+      if (parent->song.linearPitch==2) {
+        opChan[i].freq=parent->calcFreq(opChan[i].baseFreq,opChan[i].pitch,false,4,opChan[i].pitch2,chipClock,CHIP_FREQBASE,11);
+      } else {
+        int fNum=parent->calcFreq(opChan[i].baseFreq&0x7ff,opChan[i].pitch,false,4,opChan[i].pitch2);
+        int block=(opChan[i].baseFreq&0xf800)>>11;
+        if (fNum<0) fNum=0;
+        if (fNum>2047) {
+          while (block<7) {
+            fNum>>=1;
+            block++;
+          }
+          if (fNum>2047) fNum=2047;
         }
-        if (fNum>2047) fNum=2047;
+        opChan[i].freq=(block<<11)|fNum;
       }
-      opChan[i].freq=(block<<11)|fNum;
       if (opChan[i].freq>0x3fff) opChan[i].freq=0x3fff;
       immWrite(opChanOffsH[i],opChan[i].freq>>8);
       immWrite(opChanOffsL[i],opChan[i].freq&0xff);