diff --git a/android/app/src/main/AndroidManifest.xml b/android/app/src/main/AndroidManifest.xml
index 082cebc3..6c75c8e4 100644
--- a/android/app/src/main/AndroidManifest.xml
+++ b/android/app/src/main/AndroidManifest.xml
@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="org.tildearrow.furnace"
-    android:versionCode="132"
-    android:versionName="0.6pre2"
+    android:versionCode="133"
+    android:versionName="0.6pre3"
     android:installLocation="auto">
 
     <!-- OpenGL ES 2.0 -->
diff --git a/papers/format.md b/papers/format.md
index a192f138..ab8cacd6 100644
--- a/papers/format.md
+++ b/papers/format.md
@@ -32,6 +32,7 @@ these fields are 0 in format versions prior to 100 (0.6pre1).
 
 the format versions are:
 
+- 133: Furnace 0.6pre3
 - 132: Furnace 0.6pre2
 - 131: Furnace dev131
 - 130: Furnace dev130
diff --git a/res/Info.plist b/res/Info.plist
index d7f0f98d..86477d15 100644
--- a/res/Info.plist
+++ b/res/Info.plist
@@ -15,17 +15,17 @@
 	<key>CFBundleInfoDictionaryVersion</key>
 	<string>6.0</string>
 	<key>CFBundleLongVersionString</key>
-	<string>0.6pre2</string>
+	<string>0.6pre3</string>
 	<key>CFBundleName</key>
 	<string>Furnace</string>
 	<key>CFBundlePackageType</key>
 	<string>APPL</string>
 	<key>CFBundleShortVersionString</key>
-	<string>0.6pre2</string>
+	<string>0.6pre3</string>
 	<key>CFBundleSignature</key>
 	<string>????</string>
 	<key>CFBundleVersion</key>
-	<string>0.6pre2</string>
+	<string>0.6pre3</string>
 	<key>NSHumanReadableCopyright</key>
 	<string></string>
 	<key>NSHighResolutionCapable</key>
diff --git a/src/engine/engine.h b/src/engine/engine.h
index faca57d9..7eb5c00c 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -47,8 +47,8 @@
 #define BUSY_BEGIN_SOFT softLocked=true; isBusy.lock();
 #define BUSY_END isBusy.unlock(); softLocked=false;
 
-#define DIV_VERSION "0.6pre2"
-#define DIV_ENGINE_VERSION 132
+#define DIV_VERSION "0.6pre3"
+#define DIV_ENGINE_VERSION 133
 // for imports
 #define DIV_VERSION_MOD 0xff01
 #define DIV_VERSION_FC 0xff02
diff --git a/src/engine/fileOps.cpp b/src/engine/fileOps.cpp
index d56836bf..d5180c80 100644
--- a/src/engine/fileOps.cpp
+++ b/src/engine/fileOps.cpp
@@ -2511,17 +2511,25 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
     }
 
     // ExtCh compat flag
-    if (ds.version<125) {
-      for (int i=0; i<ds.systemLen; i++) {
-        if (ds.system[i]==DIV_SYSTEM_YM2612_EXT ||
-            ds.system[i]==DIV_SYSTEM_YM2612_DUALPCM_EXT ||
-            ds.system[i]==DIV_SYSTEM_YM2610_EXT ||
-            ds.system[i]==DIV_SYSTEM_YM2610_FULL_EXT ||
-            ds.system[i]==DIV_SYSTEM_YM2610B_EXT ||
-            ds.system[i]==DIV_SYSTEM_YM2203_EXT ||
-            ds.system[i]==DIV_SYSTEM_YM2608_EXT) {
+    for (int i=0; i<ds.systemLen; i++) {
+      if (ds.system[i]==DIV_SYSTEM_YM2612_EXT ||
+          ds.system[i]==DIV_SYSTEM_YM2612_DUALPCM_EXT ||
+          ds.system[i]==DIV_SYSTEM_YM2610_EXT ||
+          ds.system[i]==DIV_SYSTEM_YM2610_FULL_EXT ||
+          ds.system[i]==DIV_SYSTEM_YM2610B_EXT ||
+          ds.system[i]==DIV_SYSTEM_YM2203_EXT ||
+          ds.system[i]==DIV_SYSTEM_YM2608_EXT ||
+          ds.system[i]==DIV_SYSTEM_YM2612_CSM ||
+          ds.system[i]==DIV_SYSTEM_YM2203_CSM ||
+          ds.system[i]==DIV_SYSTEM_YM2608_CSM ||
+          ds.system[i]==DIV_SYSTEM_YM2610_CSM ||
+          ds.system[i]==DIV_SYSTEM_YM2610B_CSM) {
+        if (ds.version<125) {
           ds.systemFlags[i].set("noExtMacros",true);
         }
+        if (ds.version<133) {
+          ds.systemFlags[i].set("fbAllOps",true);
+        }
       }
     }
 
diff --git a/src/engine/platform/fmshared_OPN.h b/src/engine/platform/fmshared_OPN.h
index 630a4970..d83ad077 100644
--- a/src/engine/platform/fmshared_OPN.h
+++ b/src/engine/platform/fmshared_OPN.h
@@ -154,7 +154,7 @@ class DivPlatformOPN: public DivPlatformFMBase {
     unsigned int ayDiv;
     unsigned char csmChan;
     unsigned char lfoValue;
-    bool extSys, useCombo;
+    bool extSys, useCombo, fbAllOps;
 
     DivConfig ayFlags;
 
@@ -173,7 +173,8 @@ class DivPlatformOPN: public DivPlatformFMBase {
       csmChan(cc),
       lfoValue(0),
       extSys(isExtSys),
-      useCombo(false) {}
+      useCombo(false),
+      fbAllOps(false) {}
   public:
     void setCombo(bool combo) {
       useCombo=combo;
diff --git a/src/engine/platform/genesis.cpp b/src/engine/platform/genesis.cpp
index bbd9c32e..5ef16efe 100644
--- a/src/engine/platform/genesis.cpp
+++ b/src/engine/platform/genesis.cpp
@@ -1250,6 +1250,7 @@ void DivPlatformGenesis::setFlags(const DivConfig& flags) {
   }
   ladder=flags.getBool("ladderEffect",false);
   noExtMacros=flags.getBool("noExtMacros",false);
+  fbAllOps=flags.getBool("fbAllOps",false);
   OPN2_SetChipType(&fm,ladder?ym3438_mode_ym2612:0);
   CHECK_CUSTOM_CLOCK;
   if (useYMFM) {
diff --git a/src/engine/platform/genesisext.cpp b/src/engine/platform/genesisext.cpp
index f181774a..4eb34bc2 100644
--- a/src/engine/platform/genesisext.cpp
+++ b/src/engine/platform/genesisext.cpp
@@ -46,7 +46,9 @@ int DivPlatformGenesisExt::dispatch(DivCommand c) {
 
       if (opChan[ch].insChanged) {
         chan[2].state.alg=ins->fm.alg;
-        chan[2].state.fb=ins->fm.fb;
+        if (ch==0 || fbAllOps) {
+          chan[2].state.fb=ins->fm.fb;
+        }
         chan[2].state.fms=ins->fm.fms;
         chan[2].state.ams=ins->fm.ams;
         chan[2].state.op[ordch]=ins->fm.op[ordch];
diff --git a/src/engine/platform/ym2203.cpp b/src/engine/platform/ym2203.cpp
index 00df4edb..95ab537f 100644
--- a/src/engine/platform/ym2203.cpp
+++ b/src/engine/platform/ym2203.cpp
@@ -1041,6 +1041,7 @@ void DivPlatformYM2203::setFlags(const DivConfig& flags) {
   }
   CHECK_CUSTOM_CLOCK;
   noExtMacros=flags.getBool("noExtMacros",false);
+  fbAllOps=flags.getBool("fbAllOps",false);
   rate=fm->sample_rate(chipClock);
   for (int i=0; i<6; i++) {
     oscBuf[i]->rate=rate;
diff --git a/src/engine/platform/ym2203ext.cpp b/src/engine/platform/ym2203ext.cpp
index d19276be..701ae9e5 100644
--- a/src/engine/platform/ym2203ext.cpp
+++ b/src/engine/platform/ym2203ext.cpp
@@ -44,7 +44,9 @@ int DivPlatformYM2203Ext::dispatch(DivCommand c) {
 
       if (opChan[ch].insChanged) {
         chan[2].state.alg=ins->fm.alg;
-        chan[2].state.fb=ins->fm.fb;
+        if (ch==0 || fbAllOps) {
+          chan[2].state.fb=ins->fm.fb;
+        }
         chan[2].state.op[ordch]=ins->fm.op[ordch];
       }
 
diff --git a/src/engine/platform/ym2608.cpp b/src/engine/platform/ym2608.cpp
index 0ec5cb48..b5dba5f5 100644
--- a/src/engine/platform/ym2608.cpp
+++ b/src/engine/platform/ym2608.cpp
@@ -1538,6 +1538,7 @@ void DivPlatformYM2608::setFlags(const DivConfig& flags) {
   }
   CHECK_CUSTOM_CLOCK;
   noExtMacros=flags.getBool("noExtMacros",false);
+  fbAllOps=flags.getBool("fbAllOps",false);
   rate=fm->sample_rate(chipClock);
   for (int i=0; i<16; i++) {
     oscBuf[i]->rate=rate;
diff --git a/src/engine/platform/ym2608ext.cpp b/src/engine/platform/ym2608ext.cpp
index b38e1a26..0a6abe7a 100644
--- a/src/engine/platform/ym2608ext.cpp
+++ b/src/engine/platform/ym2608ext.cpp
@@ -44,7 +44,9 @@ int DivPlatformYM2608Ext::dispatch(DivCommand c) {
 
       if (opChan[ch].insChanged) {
         chan[2].state.alg=ins->fm.alg;
-        chan[2].state.fb=ins->fm.fb;
+        if (ch==0 || fbAllOps) {
+          chan[2].state.fb=ins->fm.fb;
+        }
         chan[2].state.fms=ins->fm.fms;
         chan[2].state.ams=ins->fm.ams;
         chan[2].state.op[ordch]=ins->fm.op[ordch];
diff --git a/src/engine/platform/ym2610bext.cpp b/src/engine/platform/ym2610bext.cpp
index a5845461..c8d0b645 100644
--- a/src/engine/platform/ym2610bext.cpp
+++ b/src/engine/platform/ym2610bext.cpp
@@ -40,7 +40,9 @@ int DivPlatformYM2610BExt::dispatch(DivCommand c) {
 
       if (opChan[ch].insChanged) {
         chan[extChanOffs].state.alg=ins->fm.alg;
-        chan[extChanOffs].state.fb=ins->fm.fb;
+        if (ch==0 || fbAllOps) {
+          chan[extChanOffs].state.fb=ins->fm.fb;
+        }
         chan[extChanOffs].state.fms=ins->fm.fms;
         chan[extChanOffs].state.ams=ins->fm.ams;
         chan[extChanOffs].state.op[ordch]=ins->fm.op[ordch];
diff --git a/src/engine/platform/ym2610ext.cpp b/src/engine/platform/ym2610ext.cpp
index 206c904d..54bbd2b7 100644
--- a/src/engine/platform/ym2610ext.cpp
+++ b/src/engine/platform/ym2610ext.cpp
@@ -40,7 +40,9 @@ int DivPlatformYM2610Ext::dispatch(DivCommand c) {
 
       if (opChan[ch].insChanged) {
         chan[extChanOffs].state.alg=ins->fm.alg;
-        chan[extChanOffs].state.fb=ins->fm.fb;
+        if (ch==0 || fbAllOps) {
+          chan[extChanOffs].state.fb=ins->fm.fb;
+        }
         chan[extChanOffs].state.fms=ins->fm.fms;
         chan[extChanOffs].state.ams=ins->fm.ams;
         chan[extChanOffs].state.op[ordch]=ins->fm.op[ordch];
diff --git a/src/engine/platform/ym2610shared.h b/src/engine/platform/ym2610shared.h
index 9671c157..ab1bd052 100644
--- a/src/engine/platform/ym2610shared.h
+++ b/src/engine/platform/ym2610shared.h
@@ -221,6 +221,7 @@ class DivPlatformYM2610Base: public DivPlatformOPN {
       }
       CHECK_CUSTOM_CLOCK;
       noExtMacros=flags.getBool("noExtMacros",false);
+      fbAllOps=flags.getBool("fbAllOps",false);
       rate=fm->sample_rate(chipClock);
       for (int i=0; i<16; i++) {
         oscBuf[i]->rate=rate;
diff --git a/src/gui/presets.cpp b/src/gui/presets.cpp
index 44d1176e..f0e4fe92 100644
--- a/src/gui/presets.cpp
+++ b/src/gui/presets.cpp
@@ -1114,474 +1114,6 @@ void FurnaceGUI::initSystemPresets() {
   );
   CATEGORY_END;
 
-  CATEGORY_BEGIN("FM","chips which use frequency modulation (FM) to generate sound.\nsome of these also pack more (like square and sample channels).");
-  ENTRY(
-    "Yamaha YM2151 (OPM)", {
-      CH(DIV_SYSTEM_YM2151, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2203 (OPN)", {
-      CH(DIV_SYSTEM_YM2203, 64, 0, "clockSel=3")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2203 (extended channel 3)", {
-      CH(DIV_SYSTEM_YM2203_EXT, 64, 0, "clockSel=3")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2608 (OPNA)", {
-      CH(DIV_SYSTEM_YM2608, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2608 (extended channel 3)", {
-      CH(DIV_SYSTEM_YM2608_EXT, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2610 (OPNB)", {
-      CH(DIV_SYSTEM_YM2610_FULL, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2610 (extended channel 2)", {
-      CH(DIV_SYSTEM_YM2610_FULL_EXT, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2610B (OPNB2)", {
-      CH(DIV_SYSTEM_YM2610B, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2610B (extended channel 3)", {
-      CH(DIV_SYSTEM_YM2610B_EXT, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2612 (OPN2)", {
-      CH(DIV_SYSTEM_YM2612, 64, 0, "ladderEffect=true")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2612 (extended channel 3)", {
-      CH(DIV_SYSTEM_YM2612_EXT, 64, 0, "ladderEffect=true")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2612 (OPN2) CSM", {
-      CH(DIV_SYSTEM_YM2612_CSM, 64, 0, "ladderEffect=true")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2612 (OPN2) with DualPCM", {
-      CH(DIV_SYSTEM_YM2612_DUALPCM, 64, 0, "ladderEffect=true")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2612 (extended channel 3) with DualPCM", {
-      CH(DIV_SYSTEM_YM2612_DUALPCM_EXT, 64, 0, "ladderEffect=true")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2413 (OPLL)", {
-      CH(DIV_SYSTEM_OPLL, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2413 (drums mode)", {
-      CH(DIV_SYSTEM_OPLL_DRUMS, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2414 (OPZ)", {
-      CH(DIV_SYSTEM_OPZ, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM3438 (OPN2C)", {
-      CH(DIV_SYSTEM_YM2612, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM3438 (extended channel 3)", {
-      CH(DIV_SYSTEM_YM2612_EXT, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM3438 (OPN2C) CSM", {
-      CH(DIV_SYSTEM_YM2612_CSM, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM3438 (OPN2C) with DualPCM", {
-      CH(DIV_SYSTEM_YM2612_DUALPCM, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM3438 (extended channel 3) with DualPCM", {
-      CH(DIV_SYSTEM_YM2612_DUALPCM_EXT, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM3526 (OPL)", {
-      CH(DIV_SYSTEM_OPL, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM3526 (drums mode)", {
-      CH(DIV_SYSTEM_OPL_DRUMS, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha Y8950", {
-      CH(DIV_SYSTEM_Y8950, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha Y8950 (drums mode)", {
-      CH(DIV_SYSTEM_Y8950_DRUMS, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM3812 (OPL2)", {
-      CH(DIV_SYSTEM_OPL2, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YM3812 (drums mode)", {
-      CH(DIV_SYSTEM_OPL2_DRUMS, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YMF262 (OPL3)", {
-      CH(DIV_SYSTEM_OPL3, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YMF262 (drums mode)", {
-      CH(DIV_SYSTEM_OPL3_DRUMS, 64, 0, "")
-    }
-  );
-  if (settings.hiddenSystems) {
-    ENTRY(
-      "Yamaha YMU759 (MA-2)", {
-        CH(DIV_SYSTEM_YMU759, 64, 0, "")
-      }
-    );
-  }
-  CATEGORY_END;
-
-  CATEGORY_BEGIN("Square","these chips generate square/pulse tones only (but may include noise).");
-  ENTRY(
-    "TI SN76489", {
-      CH(DIV_SYSTEM_SMS, 64, 0, "chipType=1")
-    }
-  );
-  ENTRY(
-    "TI SN76489A", {
-      CH(DIV_SYSTEM_SMS, 64, 0, "chipType=4")
-    }
-  );
-  ENTRY(
-    "TI SN76496", {
-      CH(DIV_SYSTEM_SMS, 64, 0, "chipType=5")
-    }
-  );
-  ENTRY(
-    "NCR 8496", {
-      CH(DIV_SYSTEM_SMS, 64, 0, "chipType=6")
-    }
-  );
-  ENTRY(
-    "Tandy PSSJ 3-voice sound", {
-      CH(DIV_SYSTEM_SMS, 64, 0, "chipType=7")
-      // 8 bit DAC
-    }
-  );
-  ENTRY(
-    "Sega PSG (SN76489-like)", {
-      CH(DIV_SYSTEM_SMS, 64, 0, ""),
-    }
-  );
-  ENTRY(
-    "Sega PSG (SN76489-like, Stereo)", {
-      CH(DIV_SYSTEM_SMS, 64, 0, "chipType=3")
-    }
-  );
-  ENTRY(
-    "TI SN94624", {
-      CH(DIV_SYSTEM_SMS, 64, 0,
-        "clockSel=6\n"
-        "chipType=8\n"
-      )
-    }
-  );
-  ENTRY(
-    "TI SN76494", {
-      CH(DIV_SYSTEM_SMS, 64, 0,
-        "clockSel=6\n"
-        "chipType=9\n"
-      )
-    }
-  );
-  ENTRY(
-    "Toshiba T6W28", {
-      CH(DIV_SYSTEM_T6W28, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "AY-3-8910", {
-      CH(DIV_SYSTEM_AY8910, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "AY-3-8914", {
-      CH(DIV_SYSTEM_AY8910, 64, 0, "chipType=3")
-    }
-  );
-  ENTRY(
-    "Yamaha YM2149(F)", {
-      CH(DIV_SYSTEM_AY8910, 64, 0, "chipType=1")
-    }
-  );
-  ENTRY(
-    "Philips SAA1099", {
-      CH(DIV_SYSTEM_SAA1099, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "PC Speaker", {
-      CH(DIV_SYSTEM_PCSPKR, 32, 0, "")
-    }
-  );
-  ENTRY(
-    "Pokémon Mini", {
-      CH(DIV_SYSTEM_POKEMINI, 32, 0, "")
-    }
-  );
-  ENTRY(
-    "Commodore VIC", {
-      CH(DIV_SYSTEM_VIC20, 64, 0, "clockSel=1")
-    }
-  );
-  ENTRY(
-    "OKI MSM5232", {
-      CH(DIV_SYSTEM_MSM5232, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Pong", {
-      CH(DIV_SYSTEM_PONG, 64, 0, "")
-    }
-  );
-  CATEGORY_END;
-
-  CATEGORY_BEGIN("Sample","chips/systems which use PCM or ADPCM samples for sound synthesis.");
-  ENTRY(
-    "Amiga", {
-      CH(DIV_SYSTEM_AMIGA, 64, 0, "clockSel=1")
-    },
-    "tickRate=50"
-  );
-  ENTRY(
-    "SegaPCM", {
-      CH(DIV_SYSTEM_SEGAPCM, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Capcom QSound", {
-      CH(DIV_SYSTEM_QSOUND, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Seta/Allumer X1-010", {
-      CH(DIV_SYSTEM_X1_010, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Yamaha YMZ280B (PCMD8)", {
-      CH(DIV_SYSTEM_YMZ280B, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Ricoh RF5C68", {
-      CH(DIV_SYSTEM_RF5C68, 64, 0, "")
-    }
-  ); 
-  ENTRY(
-    "OKI MSM6258", {
-      CH(DIV_SYSTEM_MSM6258, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "OKI MSM6295", {
-      CH(DIV_SYSTEM_MSM6295, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "SNES", {
-      CH(DIV_SYSTEM_SNES, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Konami K007232", {
-      CH(DIV_SYSTEM_K007232, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Irem GA20", {
-      CH(DIV_SYSTEM_GA20, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Generic PCM DAC", {
-      CH(DIV_SYSTEM_PCM_DAC, 64, 0, "")
-    }
-  );
-  CATEGORY_END;
-
-  CATEGORY_BEGIN("Wavetable","chips which use user-specified waveforms to generate sound.");
-  ENTRY(
-    "PC Engine", {
-      CH(DIV_SYSTEM_PCE, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Commodore PET (pseudo-wavetable)", {
-      CH(DIV_SYSTEM_PET, 64, 0, "")
-    },
-    "tickRate=50"
-  );
-  ENTRY(
-    "Konami Bubble System WSG", {
-      CH(DIV_SYSTEM_BUBSYS_WSG, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Konami SCC", {
-      CH(DIV_SYSTEM_SCC, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Konami SCC+", {
-      CH(DIV_SYSTEM_SCC_PLUS, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Namco WSG", {
-      CH(DIV_SYSTEM_NAMCO, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Namco C15 (8-channel mono)", {
-      CH(DIV_SYSTEM_NAMCO_15XX, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Namco C30 (8-channel stereo)", {
-      CH(DIV_SYSTEM_NAMCO_CUS30, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Namco 163", {
-      CH(DIV_SYSTEM_N163, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Famicom Disk System (chip)", {
-      CH(DIV_SYSTEM_FDS, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "WonderSwan", {
-      CH(DIV_SYSTEM_SWAN, 64, 0, "")
-    },
-    "tickRate=75.47169811320754716981"
-  );
-  ENTRY(
-    "Virtual Boy", {
-      CH(DIV_SYSTEM_VBOY, 64, 0, "")
-    },
-    "tickRate=50.2734877734878"
-  );
-  ENTRY(
-    "Seta/Allumer X1-010", {
-      CH(DIV_SYSTEM_X1_010, 64, 0, "")
-    }
-  );
-  CATEGORY_END;
-
-  CATEGORY_BEGIN("Specialized","chips/systems with unique sound synthesis methods.");
-  ENTRY(
-    "MOS Technology SID (6581)", {
-      CH(DIV_SYSTEM_C64_6581, 64, 0, "clockSel=1")
-    },
-    "tickRate=50.1245421"
-  );
-  ENTRY(
-    "MOS Technology SID (8580)", {
-      CH(DIV_SYSTEM_C64_8580, 64, 0, "clockSel=1")
-    },
-    "tickRate=50.1245421"
-  );
-  ENTRY(
-    "Microchip AY8930", {
-      CH(DIV_SYSTEM_AY8930, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Game Boy", {
-      CH(DIV_SYSTEM_GB, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Atari Lynx", {
-      CH(DIV_SYSTEM_LYNX, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "POKEY", {
-      CH(DIV_SYSTEM_POKEY, 64, 0, "clockSel=1")
-    },
-    "tickRate=50"
-  );
-  ENTRY(
-    "Atari TIA", {
-      CH(DIV_SYSTEM_TIA, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "NES (Ricoh 2A03)", {
-      CH(DIV_SYSTEM_NES, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "Commander X16 (VERA only)", {
-      CH(DIV_SYSTEM_VERA, 64, 0, "")
-    }
-  );
-  ENTRY(
-    "ZX Spectrum (beeper only)", {
-      CH(DIV_SYSTEM_SFX_BEEPER, 64, 0, "")
-    }
-  );
-  if (settings.hiddenSystems) {
-    ENTRY(
-      "Dummy System", {
-        CH(DIV_SYSTEM_DUMMY, 64, 0, "")
-      }
-    );
-  }
-  ENTRY(
-    "tildearrow Sound Unit", {
-      CH(DIV_SYSTEM_SOUND_UNIT, 64, 0, "")
-    }
-  );
-  CATEGORY_END;
-
   CATEGORY_BEGIN("Arcade systems","INSERT COIN");
   ENTRY(
     "Pong", {
@@ -2564,6 +2096,475 @@ void FurnaceGUI::initSystemPresets() {
   );
   CATEGORY_END;
 
+
+  CATEGORY_BEGIN("FM","chips which use frequency modulation (FM) to generate sound.\nsome of these also pack more (like square and sample channels).");
+  ENTRY(
+    "Yamaha YM2151 (OPM)", {
+      CH(DIV_SYSTEM_YM2151, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2203 (OPN)", {
+      CH(DIV_SYSTEM_YM2203, 64, 0, "clockSel=3")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2203 (extended channel 3)", {
+      CH(DIV_SYSTEM_YM2203_EXT, 64, 0, "clockSel=3")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2608 (OPNA)", {
+      CH(DIV_SYSTEM_YM2608, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2608 (extended channel 3)", {
+      CH(DIV_SYSTEM_YM2608_EXT, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2610 (OPNB)", {
+      CH(DIV_SYSTEM_YM2610_FULL, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2610 (extended channel 2)", {
+      CH(DIV_SYSTEM_YM2610_FULL_EXT, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2610B (OPNB2)", {
+      CH(DIV_SYSTEM_YM2610B, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2610B (extended channel 3)", {
+      CH(DIV_SYSTEM_YM2610B_EXT, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2612 (OPN2)", {
+      CH(DIV_SYSTEM_YM2612, 64, 0, "ladderEffect=true")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2612 (extended channel 3)", {
+      CH(DIV_SYSTEM_YM2612_EXT, 64, 0, "ladderEffect=true")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2612 (OPN2) CSM", {
+      CH(DIV_SYSTEM_YM2612_CSM, 64, 0, "ladderEffect=true")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2612 (OPN2) with DualPCM", {
+      CH(DIV_SYSTEM_YM2612_DUALPCM, 64, 0, "ladderEffect=true")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2612 (extended channel 3) with DualPCM", {
+      CH(DIV_SYSTEM_YM2612_DUALPCM_EXT, 64, 0, "ladderEffect=true")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2413 (OPLL)", {
+      CH(DIV_SYSTEM_OPLL, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2413 (drums mode)", {
+      CH(DIV_SYSTEM_OPLL_DRUMS, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2414 (OPZ)", {
+      CH(DIV_SYSTEM_OPZ, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM3438 (OPN2C)", {
+      CH(DIV_SYSTEM_YM2612, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM3438 (extended channel 3)", {
+      CH(DIV_SYSTEM_YM2612_EXT, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM3438 (OPN2C) CSM", {
+      CH(DIV_SYSTEM_YM2612_CSM, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM3438 (OPN2C) with DualPCM", {
+      CH(DIV_SYSTEM_YM2612_DUALPCM, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM3438 (extended channel 3) with DualPCM", {
+      CH(DIV_SYSTEM_YM2612_DUALPCM_EXT, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM3526 (OPL)", {
+      CH(DIV_SYSTEM_OPL, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM3526 (drums mode)", {
+      CH(DIV_SYSTEM_OPL_DRUMS, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha Y8950", {
+      CH(DIV_SYSTEM_Y8950, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha Y8950 (drums mode)", {
+      CH(DIV_SYSTEM_Y8950_DRUMS, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM3812 (OPL2)", {
+      CH(DIV_SYSTEM_OPL2, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YM3812 (drums mode)", {
+      CH(DIV_SYSTEM_OPL2_DRUMS, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YMF262 (OPL3)", {
+      CH(DIV_SYSTEM_OPL3, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YMF262 (drums mode)", {
+      CH(DIV_SYSTEM_OPL3_DRUMS, 64, 0, "")
+    }
+  );
+  if (settings.hiddenSystems) {
+    ENTRY(
+      "Yamaha YMU759 (MA-2)", {
+        CH(DIV_SYSTEM_YMU759, 64, 0, "")
+      }
+    );
+  }
+  CATEGORY_END;
+
+  CATEGORY_BEGIN("Square","these chips generate square/pulse tones only (but may include noise).");
+  ENTRY(
+    "TI SN76489", {
+      CH(DIV_SYSTEM_SMS, 64, 0, "chipType=1")
+    }
+  );
+  ENTRY(
+    "TI SN76489A", {
+      CH(DIV_SYSTEM_SMS, 64, 0, "chipType=4")
+    }
+  );
+  ENTRY(
+    "TI SN76496", {
+      CH(DIV_SYSTEM_SMS, 64, 0, "chipType=5")
+    }
+  );
+  ENTRY(
+    "NCR 8496", {
+      CH(DIV_SYSTEM_SMS, 64, 0, "chipType=6")
+    }
+  );
+  ENTRY(
+    "Tandy PSSJ 3-voice sound", {
+      CH(DIV_SYSTEM_SMS, 64, 0, "chipType=7")
+      // 8 bit DAC
+    }
+  );
+  ENTRY(
+    "Sega PSG (SN76489-like)", {
+      CH(DIV_SYSTEM_SMS, 64, 0, ""),
+    }
+  );
+  ENTRY(
+    "Sega PSG (SN76489-like, Stereo)", {
+      CH(DIV_SYSTEM_SMS, 64, 0, "chipType=3")
+    }
+  );
+  ENTRY(
+    "TI SN94624", {
+      CH(DIV_SYSTEM_SMS, 64, 0,
+        "clockSel=6\n"
+        "chipType=8\n"
+      )
+    }
+  );
+  ENTRY(
+    "TI SN76494", {
+      CH(DIV_SYSTEM_SMS, 64, 0,
+        "clockSel=6\n"
+        "chipType=9\n"
+      )
+    }
+  );
+  ENTRY(
+    "Toshiba T6W28", {
+      CH(DIV_SYSTEM_T6W28, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "AY-3-8910", {
+      CH(DIV_SYSTEM_AY8910, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "AY-3-8914", {
+      CH(DIV_SYSTEM_AY8910, 64, 0, "chipType=3")
+    }
+  );
+  ENTRY(
+    "Yamaha YM2149(F)", {
+      CH(DIV_SYSTEM_AY8910, 64, 0, "chipType=1")
+    }
+  );
+  ENTRY(
+    "Philips SAA1099", {
+      CH(DIV_SYSTEM_SAA1099, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "PC Speaker", {
+      CH(DIV_SYSTEM_PCSPKR, 32, 0, "")
+    }
+  );
+  ENTRY(
+    "Pokémon Mini", {
+      CH(DIV_SYSTEM_POKEMINI, 32, 0, "")
+    }
+  );
+  ENTRY(
+    "Commodore VIC", {
+      CH(DIV_SYSTEM_VIC20, 64, 0, "clockSel=1")
+    }
+  );
+  ENTRY(
+    "OKI MSM5232", {
+      CH(DIV_SYSTEM_MSM5232, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Pong", {
+      CH(DIV_SYSTEM_PONG, 64, 0, "")
+    }
+  );
+  CATEGORY_END;
+
+  CATEGORY_BEGIN("Sample","chips/systems which use PCM or ADPCM samples for sound synthesis.");
+  ENTRY(
+    "Amiga", {
+      CH(DIV_SYSTEM_AMIGA, 64, 0, "clockSel=1")
+    },
+    "tickRate=50"
+  );
+  ENTRY(
+    "SegaPCM", {
+      CH(DIV_SYSTEM_SEGAPCM, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Capcom QSound", {
+      CH(DIV_SYSTEM_QSOUND, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Seta/Allumer X1-010", {
+      CH(DIV_SYSTEM_X1_010, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Yamaha YMZ280B (PCMD8)", {
+      CH(DIV_SYSTEM_YMZ280B, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Ricoh RF5C68", {
+      CH(DIV_SYSTEM_RF5C68, 64, 0, "")
+    }
+  ); 
+  ENTRY(
+    "OKI MSM6258", {
+      CH(DIV_SYSTEM_MSM6258, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "OKI MSM6295", {
+      CH(DIV_SYSTEM_MSM6295, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "SNES", {
+      CH(DIV_SYSTEM_SNES, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Konami K007232", {
+      CH(DIV_SYSTEM_K007232, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Irem GA20", {
+      CH(DIV_SYSTEM_GA20, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Generic PCM DAC", {
+      CH(DIV_SYSTEM_PCM_DAC, 64, 0, "")
+    }
+  );
+  CATEGORY_END;
+
+  CATEGORY_BEGIN("Wavetable","chips which use user-specified waveforms to generate sound.");
+  ENTRY(
+    "PC Engine", {
+      CH(DIV_SYSTEM_PCE, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Commodore PET (pseudo-wavetable)", {
+      CH(DIV_SYSTEM_PET, 64, 0, "")
+    },
+    "tickRate=50"
+  );
+  ENTRY(
+    "Konami Bubble System WSG", {
+      CH(DIV_SYSTEM_BUBSYS_WSG, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Konami SCC", {
+      CH(DIV_SYSTEM_SCC, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Konami SCC+", {
+      CH(DIV_SYSTEM_SCC_PLUS, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Namco WSG", {
+      CH(DIV_SYSTEM_NAMCO, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Namco C15 (8-channel mono)", {
+      CH(DIV_SYSTEM_NAMCO_15XX, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Namco C30 (8-channel stereo)", {
+      CH(DIV_SYSTEM_NAMCO_CUS30, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Namco 163", {
+      CH(DIV_SYSTEM_N163, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Famicom Disk System (chip)", {
+      CH(DIV_SYSTEM_FDS, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "WonderSwan", {
+      CH(DIV_SYSTEM_SWAN, 64, 0, "")
+    },
+    "tickRate=75.47169811320754716981"
+  );
+  ENTRY(
+    "Virtual Boy", {
+      CH(DIV_SYSTEM_VBOY, 64, 0, "")
+    },
+    "tickRate=50.2734877734878"
+  );
+  ENTRY(
+    "Seta/Allumer X1-010", {
+      CH(DIV_SYSTEM_X1_010, 64, 0, "")
+    }
+  );
+  CATEGORY_END;
+
+  CATEGORY_BEGIN("Specialized","chips/systems with unique sound synthesis methods.");
+  ENTRY(
+    "MOS Technology SID (6581)", {
+      CH(DIV_SYSTEM_C64_6581, 64, 0, "clockSel=1")
+    },
+    "tickRate=50.1245421"
+  );
+  ENTRY(
+    "MOS Technology SID (8580)", {
+      CH(DIV_SYSTEM_C64_8580, 64, 0, "clockSel=1")
+    },
+    "tickRate=50.1245421"
+  );
+  ENTRY(
+    "Microchip AY8930", {
+      CH(DIV_SYSTEM_AY8930, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Game Boy", {
+      CH(DIV_SYSTEM_GB, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Atari Lynx", {
+      CH(DIV_SYSTEM_LYNX, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "POKEY", {
+      CH(DIV_SYSTEM_POKEY, 64, 0, "clockSel=1")
+    },
+    "tickRate=50"
+  );
+  ENTRY(
+    "Atari TIA", {
+      CH(DIV_SYSTEM_TIA, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "NES (Ricoh 2A03)", {
+      CH(DIV_SYSTEM_NES, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "Commander X16 (VERA only)", {
+      CH(DIV_SYSTEM_VERA, 64, 0, "")
+    }
+  );
+  ENTRY(
+    "ZX Spectrum (beeper only)", {
+      CH(DIV_SYSTEM_SFX_BEEPER, 64, 0, "")
+    }
+  );
+  if (settings.hiddenSystems) {
+    ENTRY(
+      "Dummy System", {
+        CH(DIV_SYSTEM_DUMMY, 64, 0, "")
+      }
+    );
+  }
+  ENTRY(
+    "tildearrow Sound Unit", {
+      CH(DIV_SYSTEM_SOUND_UNIT, 64, 0, "")
+    }
+  );
+  CATEGORY_END;
+
   CATEGORY_BEGIN("DefleMask-compatible","these configurations are compatible with DefleMask.\nselect this if you need to save as .dmf or work with that program.");
   ENTRY(
     "Sega Genesis", {
diff --git a/src/gui/sysConf.cpp b/src/gui/sysConf.cpp
index 9ebe7ec0..8e41fa00 100644
--- a/src/gui/sysConf.cpp
+++ b/src/gui/sysConf.cpp
@@ -31,10 +31,12 @@ bool FurnaceGUI::drawSysConf(int chan, DivSystem type, DivConfig& flags, bool mo
     case DIV_SYSTEM_YM2612:
     case DIV_SYSTEM_YM2612_EXT: 
     case DIV_SYSTEM_YM2612_DUALPCM:
-    case DIV_SYSTEM_YM2612_DUALPCM_EXT: {
+    case DIV_SYSTEM_YM2612_DUALPCM_EXT:
+    case DIV_SYSTEM_YM2612_CSM: {
       int clockSel=flags.getInt("clockSel",0);
       bool ladder=flags.getBool("ladderEffect",0);
       bool noExtMacros=flags.getBool("noExtMacros",false);
+      bool fbAllOps=flags.getBool("fbAllOps",false);
 
       if (ImGui::RadioButton("NTSC (7.67MHz)",clockSel==0)) {
         clockSel=0;
@@ -59,10 +61,13 @@ bool FurnaceGUI::drawSysConf(int chan, DivSystem type, DivConfig& flags, bool mo
       if (ImGui::Checkbox("Enable DAC distortion",&ladder)) {
         altered=true;
       }
-      if (type==DIV_SYSTEM_YM2612_EXT || type==DIV_SYSTEM_YM2612_DUALPCM_EXT) {
+      if (type==DIV_SYSTEM_YM2612_EXT || type==DIV_SYSTEM_YM2612_DUALPCM_EXT || type==DIV_SYSTEM_YM2612_CSM) {
         if (ImGui::Checkbox("Disable ExtCh FM macros (compatibility)",&noExtMacros)) {
           altered=true;
         }
+        if (ImGui::Checkbox("Ins change in ExtCh operator 2-4 affects FB (compatibility)",&fbAllOps)) {
+          altered=true;
+        }
       }
       
       if (altered) {
@@ -70,6 +75,7 @@ bool FurnaceGUI::drawSysConf(int chan, DivSystem type, DivConfig& flags, bool mo
           flags.set("clockSel",clockSel);
           flags.set("ladderEffect",ladder);
           flags.set("noExtMacros",noExtMacros);
+          flags.set("fbAllOps",fbAllOps);
         });
       }
       break;
@@ -457,12 +463,15 @@ bool FurnaceGUI::drawSysConf(int chan, DivSystem type, DivConfig& flags, bool mo
     }
     case DIV_SYSTEM_YM2610:
     case DIV_SYSTEM_YM2610_EXT:
+    case DIV_SYSTEM_YM2610_CSM:
     case DIV_SYSTEM_YM2610_FULL:
     case DIV_SYSTEM_YM2610_FULL_EXT:
     case DIV_SYSTEM_YM2610B:
-    case DIV_SYSTEM_YM2610B_EXT: {
+    case DIV_SYSTEM_YM2610B_EXT:
+    case DIV_SYSTEM_YM2610B_CSM: {
       int clockSel=flags.getInt("clockSel",0);
       bool noExtMacros=flags.getBool("noExtMacros",false);
+      bool fbAllOps=flags.getBool("fbAllOps",false);
 
       if (ImGui::RadioButton("8MHz (Neo Geo MVS)",clockSel==0)) {
         clockSel=0;
@@ -473,16 +482,20 @@ bool FurnaceGUI::drawSysConf(int chan, DivSystem type, DivConfig& flags, bool mo
         altered=true;
       }
 
-      if (type==DIV_SYSTEM_YM2610_EXT || type==DIV_SYSTEM_YM2610_FULL_EXT || type==DIV_SYSTEM_YM2610B_EXT) {
+      if (type==DIV_SYSTEM_YM2610_EXT || type==DIV_SYSTEM_YM2610_FULL_EXT || type==DIV_SYSTEM_YM2610B_EXT || type==DIV_SYSTEM_YM2610_CSM || type==DIV_SYSTEM_YM2610B_CSM) {
         if (ImGui::Checkbox("Disable ExtCh FM macros (compatibility)",&noExtMacros)) {
           altered=true;
         }
+        if (ImGui::Checkbox("Ins change in ExtCh operator 2-4 affects FB (compatibility)",&fbAllOps)) {
+          altered=true;
+        }
       }
 
       if (altered) {
         e->lockSave([&]() {
           flags.set("clockSel",clockSel);
           flags.set("noExtMacros",noExtMacros);
+          flags.set("fbAllOps",fbAllOps);
         });
       }
       break;
@@ -835,10 +848,12 @@ bool FurnaceGUI::drawSysConf(int chan, DivSystem type, DivConfig& flags, bool mo
       break;
     }
     case DIV_SYSTEM_YM2203:
-    case DIV_SYSTEM_YM2203_EXT: {
+    case DIV_SYSTEM_YM2203_EXT:
+    case DIV_SYSTEM_YM2203_CSM: {
       int clockSel=flags.getInt("clockSel",0);
       int prescale=flags.getInt("prescale",0);
       bool noExtMacros=flags.getBool("noExtMacros",false);
+      bool fbAllOps=flags.getBool("fbAllOps",false);
 
       ImGui::Text("Clock rate:");
       if (ImGui::RadioButton("3.58MHz (NTSC)",clockSel==0)) {
@@ -879,10 +894,13 @@ bool FurnaceGUI::drawSysConf(int chan, DivSystem type, DivConfig& flags, bool mo
         altered=true;
       }
 
-      if (type==DIV_SYSTEM_YM2203_EXT) {
+      if (type==DIV_SYSTEM_YM2203_EXT || type==DIV_SYSTEM_YM2203_CSM) {
         if (ImGui::Checkbox("Disable ExtCh FM macros (compatibility)",&noExtMacros)) {
           altered=true;
         }
+        if (ImGui::Checkbox("Ins change in ExtCh operator 2-4 affects FB (compatibility)",&fbAllOps)) {
+          altered=true;
+        }
       }
 
       if (altered) {
@@ -890,15 +908,18 @@ bool FurnaceGUI::drawSysConf(int chan, DivSystem type, DivConfig& flags, bool mo
           flags.set("clockSel",clockSel);
           flags.set("prescale",prescale);
           flags.set("noExtMacros",noExtMacros);
+          flags.set("fbAllOps",fbAllOps);
         });
       }
       break;
     }
     case DIV_SYSTEM_YM2608:
-    case DIV_SYSTEM_YM2608_EXT: {
+    case DIV_SYSTEM_YM2608_EXT:
+    case DIV_SYSTEM_YM2608_CSM: {
       int clockSel=flags.getInt("clockSel",0);
       int prescale=flags.getInt("prescale",0);
       bool noExtMacros=flags.getBool("noExtMacros",false);
+      bool fbAllOps=flags.getBool("fbAllOps",false);
 
       ImGui::Text("Clock rate:");
       if (ImGui::RadioButton("8MHz (Arcade)",clockSel==0)) {
@@ -923,10 +944,13 @@ bool FurnaceGUI::drawSysConf(int chan, DivSystem type, DivConfig& flags, bool mo
         altered=true;
       }
 
-      if (type==DIV_SYSTEM_YM2608_EXT) {
+      if (type==DIV_SYSTEM_YM2608_EXT || type==DIV_SYSTEM_YM2608_CSM) {
         if (ImGui::Checkbox("Disable ExtCh FM macros (compatibility)",&noExtMacros)) {
           altered=true;
         }
+        if (ImGui::Checkbox("Ins change in ExtCh operator 2-4 affects FB (compatibility)",&fbAllOps)) {
+          altered=true;
+        }
       }
 
       if (altered) {
@@ -934,6 +958,7 @@ bool FurnaceGUI::drawSysConf(int chan, DivSystem type, DivConfig& flags, bool mo
           flags.set("clockSel",clockSel);
           flags.set("prescale",prescale);
           flags.set("noExtMacros",noExtMacros);
+          flags.set("fbAllOps",fbAllOps);
         });
       }
       break;