ExtCh: fix forceIns after 1800

src/engine/platform/genesisext.cpp

@@ -772,6 +772,9 @@ void DivPlatformGenesisExt::forceIns() {
     chan[csmChan].freqChanged=true;
     chan[csmChan].keyOn=true;
   }
+  if (!extMode) {
+    immWrite(0x27,0x00);
+  }
 }
 
 void* DivPlatformGenesisExt::getChanState(int ch) {

src/engine/platform/ym2203ext.cpp

@@ -671,6 +671,9 @@ void DivPlatformYM2203Ext::forceIns() {
       opChan[i].freqChanged=true;
     }
   }
+  if (!extMode) {
+    immWrite(0x27,0x00);
+  }
 }
 
 void* DivPlatformYM2203Ext::getChanState(int ch) {

src/engine/platform/ym2608ext.cpp

@@ -721,6 +721,9 @@ void DivPlatformYM2608Ext::forceIns() {
       opChan[i].freqChanged=true;
     }
   }
+  if (!extMode) {
+    immWrite(0x27,0x00);
+  }
 }
 
 void* DivPlatformYM2608Ext::getChanState(int ch) {

src/engine/platform/ym2610bext.cpp

@@ -711,6 +711,9 @@ void DivPlatformYM2610BExt::forceIns() {
       opChan[i].freqChanged=true;
     }
   }
+  if (!extMode) {
+    immWrite(0x27,0x00);
+  }
 }
 
 void* DivPlatformYM2610BExt::getChanState(int ch) {

src/engine/platform/ym2610ext.cpp

@@ -711,6 +711,9 @@ void DivPlatformYM2610Ext::forceIns() {
       opChan[i].freqChanged=true;
     }
   }
+  if (!extMode) {
+    immWrite(0x27,0x00);
+  }
 }
 
 void* DivPlatformYM2610Ext::getChanState(int ch) {