diff --git a/src/engine/dispatchContainer.cpp b/src/engine/dispatchContainer.cpp
index 15e03aea2..7ae9da6a2 100644
--- a/src/engine/dispatchContainer.cpp
+++ b/src/engine/dispatchContainer.cpp
@@ -196,6 +196,7 @@ void DivDispatchContainer::init(DivSystem sys, DivEngine* eng, int chanCount, do
       break;
     case DIV_SYSTEM_OPLL:
     case DIV_SYSTEM_OPLL_DRUMS:
+    case DIV_SYSTEM_VRC7:
       dispatch=new DivPlatformOPLL;
       break;
     case DIV_SYSTEM_SAA1099: {
diff --git a/src/engine/fileOps.cpp b/src/engine/fileOps.cpp
index 562c85460..7bb53c408 100644
--- a/src/engine/fileOps.cpp
+++ b/src/engine/fileOps.cpp
@@ -299,10 +299,16 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
         for (int j=0; j<ins->fm.ops; j++) {
           ins->fm.op[j].am=reader.readC();
           ins->fm.op[j].ar=reader.readC();
+          if (ds.system[0]==DIV_SYSTEM_SMS_OPLL || ds.system[0]==DIV_SYSTEM_NES_VRC7) {
+            ins->fm.op[j].ar&=15;
+          }
           if (ds.version<0x13) {
             ins->fm.op[j].dam=reader.readC();
           }
           ins->fm.op[j].dr=reader.readC();
+          if (ds.system[0]==DIV_SYSTEM_SMS_OPLL || ds.system[0]==DIV_SYSTEM_NES_VRC7) {
+            ins->fm.op[j].dr&=15;
+          }
           if (ds.version<0x13) {
             ins->fm.op[j].dvb=reader.readC();
             ins->fm.op[j].egt=reader.readC();
diff --git a/src/engine/instrument.h b/src/engine/instrument.h
index bfc60531a..366bd87d6 100644
--- a/src/engine/instrument.h
+++ b/src/engine/instrument.h
@@ -54,7 +54,7 @@ struct DivInstrumentFM {
   unsigned char alg, fb, fms, ams, ops, opllPreset;
   struct Operator {
     unsigned char am, ar, dr, mult, rr, sl, tl, dt2, rs, dt, d2r, ssgEnv;
-    unsigned char dam, dvb, egt, ksl, sus, vib, ws, ksr; // YMU759
+    unsigned char dam, dvb, egt, ksl, sus, vib, ws, ksr; // YMU759/OPL
     Operator():
       am(0),
       ar(0),
diff --git a/src/engine/platform/opll.cpp b/src/engine/platform/opll.cpp
index 205030753..ad3b3a22e 100644
--- a/src/engine/platform/opll.cpp
+++ b/src/engine/platform/opll.cpp
@@ -85,13 +85,12 @@ void DivPlatformOPLL::acquire_nuked(short* bufL, short* bufR, size_t start, size
       QueuedWrite& w=writes.front();
       if (w.addrOrVal) {
         OPLL_Write(&fm,1,w.val);
-        printf("write: %x = %.2x\n",w.addr,w.val);
+        //printf("write: %x = %.2x\n",w.addr,w.val);
         regPool[w.addr&0xff]=w.val;
         writes.pop();
         delay=21;
       } else {
         //printf("busycounter: %d\n",lastBusy);
-        //w.addr=rand()&0x3f;
         OPLL_Write(&fm,0,w.addr);
         w.addrOrVal=true;
         delay=3;
@@ -240,8 +239,7 @@ void DivPlatformOPLL::tick() {
     }*/
 
     if (chan[i].keyOn || chan[i].keyOff) {
-      // TODO: FIX
-      immWrite(0x20+i,0x00);
+      immWrite(0x20+i,(chan[i].freqH)|(chan[i].state.alg?0x20:0));
       //chan[i].keyOn=false;
       chan[i].keyOff=false;
     }
@@ -262,31 +260,32 @@ void DivPlatformOPLL::tick() {
       chan[i].freqH=freqt>>8;
       chan[i].freqL=freqt&0xff;
       immWrite(0x10+i,freqt&0xff);
-      
-      chan[i].freqChanged=false;
     }
-    if (chan[i].keyOn) {
+    if (chan[i].keyOn || chan[i].freqChanged) {
       //immWrite(0x28,0xf0|konOffs[i]);
-      immWrite(0x20+i,(chan[i].freqH)|(chan[i].active<<4)|0x20);
+      immWrite(0x20+i,(chan[i].freqH)|(chan[i].active<<4)|(chan[i].state.alg?0x20:0));
       chan[i].keyOn=false;
     }
+    chan[i].freqChanged=false;
   }
 }
 
+#define OPLL_C_NUM 343
+
 int DivPlatformOPLL::octave(int freq) {
-  if (freq>=32768) {
+  if (freq>=OPLL_C_NUM*64) {
     return 128;
-  } else if (freq>=16384) {
+  } else if (freq>=OPLL_C_NUM*32) {
     return 64;
-  } else if (freq>=8192) {
+  } else if (freq>=OPLL_C_NUM*16) {
     return 32;
-  } else if (freq>=4096) {
+  } else if (freq>=OPLL_C_NUM*8) {
     return 16;
-  } else if (freq>=2048) {
+  } else if (freq>=OPLL_C_NUM*4) {
     return 8;
-  } else if (freq>=1024) {
+  } else if (freq>=OPLL_C_NUM*2) {
     return 4;
-  } else if (freq>=512) {
+  } else if (freq>=OPLL_C_NUM) {
     return 2;
   } else {
     return 1;
@@ -295,19 +294,19 @@ int DivPlatformOPLL::octave(int freq) {
 }
 
 int DivPlatformOPLL::toFreq(int freq) {
-  if (freq>=32768) {
+  if (freq>=OPLL_C_NUM*64) {
     return 0xe00|((freq>>7)&0x1ff);
-  } else if (freq>=16384) {
+  } else if (freq>=OPLL_C_NUM*32) {
     return 0xc00|((freq>>6)&0x1ff);
-  } else if (freq>=8192) {
+  } else if (freq>=OPLL_C_NUM*16) {
     return 0xa00|((freq>>5)&0x1ff);
-  } else if (freq>=4096) {
+  } else if (freq>=OPLL_C_NUM*8) {
     return 0x800|((freq>>4)&0x1ff);
-  } else if (freq>=2048) {
+  } else if (freq>=OPLL_C_NUM*4) {
     return 0x600|((freq>>3)&0x1ff);
-  } else if (freq>=1024) {
+  } else if (freq>=OPLL_C_NUM*2) {
     return 0x400|((freq>>2)&0x1ff);
-  } else if (freq>=512) {
+  } else if (freq>=OPLL_C_NUM) {
     return 0x200|((freq>>1)&0x1ff);
   } else {
     return freq&0x1ff;
@@ -346,39 +345,23 @@ int DivPlatformOPLL::dispatch(DivCommand c) {
         chan[c.chan].outVol=chan[c.chan].vol;
       }
       
-      /*
-      for (int i=0; i<2; i++) {
-        unsigned short baseAddr=chanOffs[c.chan]|opOffs[i];
-        DivInstrumentFM::Operator& op=chan[c.chan].state.op[i];
-        if (isMuted[c.chan]) {
-          rWrite(baseAddr+ADDR_TL,127);
-        } else {
-          if (isOutput[chan[c.chan].state.alg][i]) {
-            if (!chan[c.chan].active || chan[c.chan].insChanged) {
-              rWrite(baseAddr+ADDR_TL,127-(((127-op.tl)*(chan[c.chan].outVol&0x7f))/127));
-            }
-          } else {
-            if (chan[c.chan].insChanged) {
-              rWrite(baseAddr+ADDR_TL,op.tl);
-            }
-          }
-        }
-        if (chan[c.chan].insChanged) {
-          rWrite(baseAddr+ADDR_MULT_DT,(op.mult&15)|(dtTable[op.dt&7]<<4));
-          rWrite(baseAddr+ADDR_RS_AR,(op.ar&31)|(op.rs<<6));
-          rWrite(baseAddr+ADDR_AM_DR,(op.dr&31)|(op.am<<7));
-          rWrite(baseAddr+ADDR_DT2_D2R,op.d2r&31);
-          rWrite(baseAddr+ADDR_SL_RR,(op.rr&15)|(op.sl<<4));
-          rWrite(baseAddr+ADDR_SSG,op.ssgEnv&15);
-        }
-      }
       if (chan[c.chan].insChanged) {
-        rWrite(chanOffs[c.chan]+ADDR_FB_ALG,(chan[c.chan].state.alg&7)|(chan[c.chan].state.fb<<3));
-        rWrite(chanOffs[c.chan]+ADDR_LRAF,(isMuted[c.chan]?0:(chan[c.chan].pan<<6))|(chan[c.chan].state.fms&7)|((chan[c.chan].state.ams&3)<<4));
+        // update custom preset
+        if (chan[c.chan].state.opllPreset==0) {
+          DivInstrumentFM::Operator& mod=chan[c.chan].state.op[0];
+          DivInstrumentFM::Operator& car=chan[c.chan].state.op[1];
+          rWrite(0x00,(mod.am<<7)|(mod.vib<<6)|((mod.ssgEnv&8)<<2)|(mod.ksr<<4)|(mod.mult));
+          rWrite(0x01,(car.am<<7)|(car.vib<<6)|((car.ssgEnv&8)<<2)|(car.ksr<<4)|(car.mult));
+          rWrite(0x02,(car.ksl<<6)|(mod.tl&63));
+          rWrite(0x03,(mod.ksl<<6)|((chan[c.chan].state.fms&1)<<4)|((chan[c.chan].state.ams&1)<<3)|chan[c.chan].state.fb);
+          rWrite(0x04,(mod.ar<<4)|(mod.dr));
+          rWrite(0x05,(car.ar<<4)|(car.dr));
+          rWrite(0x06,(mod.sl<<4)|(mod.rr));
+          rWrite(0x07,(car.sl<<4)|(car.rr));
+        }
+        rWrite(0x30+c.chan,(15-(chan[c.chan].outVol*(15-chan[c.chan].state.op[1].tl))/15)|(chan[c.chan].state.opllPreset<<4));
       }
-      */
-      // for now
-      rWrite(0x30+c.chan,0x0|(ins->fm.opllPreset<<4));
+
       chan[c.chan].insChanged=false;
 
       if (c.value!=DIV_NOTE_NULL) {
@@ -409,20 +392,7 @@ int DivPlatformOPLL::dispatch(DivCommand c) {
       if (!chan[c.chan].std.hasVol) {
         chan[c.chan].outVol=c.value;
       }
-      /*
-      for (int i=0; i<4; i++) {
-        unsigned short baseAddr=chanOffs[c.chan]|opOffs[i];
-        DivInstrumentFM::Operator& op=chan[c.chan].state.op[i];
-        if (isMuted[c.chan]) {
-          rWrite(baseAddr+ADDR_TL,127);
-        } else {
-          if (isOutput[chan[c.chan].state.alg][i]) {
-            rWrite(baseAddr+ADDR_TL,127-(((127-op.tl)*(chan[c.chan].outVol&0x7f))/127));
-          } else {
-            rWrite(baseAddr+ADDR_TL,op.tl);
-          }
-        }
-      }*/
+      rWrite(0x30+c.chan,(15-(chan[c.chan].outVol*(15-chan[c.chan].state.op[1].tl))/15)|(chan[c.chan].state.opllPreset<<4));
       break;
     }
     case DIV_CMD_GET_VOLUME: {
@@ -457,12 +427,12 @@ int DivPlatformOPLL::dispatch(DivCommand c) {
           return2=true;
         }
       }
-      if (!chan[c.chan].portaPause) {
+      /*if (!chan[c.chan].portaPause) {
         if (octave(chan[c.chan].baseFreq)!=octave(newFreq)) {
           chan[c.chan].portaPause=true;
           break;
         }
-      }
+      }*/
       chan[c.chan].baseFreq=newFreq;
       chan[c.chan].portaPause=false;
       chan[c.chan].freqChanged=true;
@@ -528,7 +498,7 @@ int DivPlatformOPLL::dispatch(DivCommand c) {
       return 0;
       break;
     case DIV_CMD_GET_VOLMAX:
-      return 127;
+      return 15;
       break;
     case DIV_CMD_PRE_PORTA:
       chan[c.chan].inPorta=c.value;
@@ -543,38 +513,26 @@ int DivPlatformOPLL::dispatch(DivCommand c) {
 }
 
 void DivPlatformOPLL::forceIns() {
-  /*
-  for (int i=0; i<6; i++) {
-    for (int j=0; j<4; j++) {
-      unsigned short baseAddr=chanOffs[i]|opOffs[j];
-      DivInstrumentFM::Operator& op=chan[i].state.op[j];
-      if (isMuted[i]) {
-        rWrite(baseAddr+ADDR_TL,127);
-      } else {
-        if (isOutput[chan[i].state.alg][j]) {
-          rWrite(baseAddr+ADDR_TL,127-(((127-op.tl)*(chan[i].outVol&0x7f))/127));
-        } else {
-          rWrite(baseAddr+ADDR_TL,op.tl);
-        }
-      }
-      rWrite(baseAddr+ADDR_MULT_DT,(op.mult&15)|(dtTable[op.dt&7]<<4));
-      rWrite(baseAddr+ADDR_RS_AR,(op.ar&31)|(op.rs<<6));
-      rWrite(baseAddr+ADDR_AM_DR,(op.dr&31)|(op.am<<7));
-      rWrite(baseAddr+ADDR_DT2_D2R,op.d2r&31);
-      rWrite(baseAddr+ADDR_SL_RR,(op.rr&15)|(op.sl<<4));
-      rWrite(baseAddr+ADDR_SSG,op.ssgEnv&15);
+  for (int i=0; i<9; i++) {
+    // update custom preset
+    if (chan[i].state.opllPreset==0) {
+      DivInstrumentFM::Operator& mod=chan[i].state.op[0];
+      DivInstrumentFM::Operator& car=chan[i].state.op[1];
+      rWrite(0x00,(mod.am<<7)|(mod.vib<<6)|((mod.ssgEnv&8)<<2)|(mod.ksr<<4)|(mod.mult));
+      rWrite(0x01,(car.am<<7)|(car.vib<<6)|((car.ssgEnv&8)<<2)|(car.ksr<<4)|(car.mult));
+      rWrite(0x02,(car.ksl<<6)|(mod.tl&63));
+      rWrite(0x03,(mod.ksl<<6)|((chan[i].state.fms&1)<<4)|((chan[i].state.ams&1)<<3)|chan[i].state.fb);
+      rWrite(0x04,(mod.ar<<4)|(mod.dr));
+      rWrite(0x05,(car.ar<<4)|(car.dr));
+      rWrite(0x06,(mod.sl<<4)|(mod.rr));
+      rWrite(0x07,(car.sl<<4)|(car.rr));
     }
-    rWrite(chanOffs[i]+ADDR_FB_ALG,(chan[i].state.alg&7)|(chan[i].state.fb<<3));
-    rWrite(chanOffs[i]+ADDR_LRAF,(isMuted[i]?0:(chan[i].pan<<6))|(chan[i].state.fms&7)|((chan[i].state.ams&3)<<4));
+    rWrite(0x30+i,(15-(chan[i].outVol*(15-chan[i].state.op[1].tl))/15)|(chan[i].state.opllPreset<<4));
     if (chan[i].active) {
       chan[i].keyOn=true;
       chan[i].freqChanged=true;
     }
   }
-  if (dacMode) {
-    rWrite(0x2b,0x80);
-  }
-  immWrite(0x22,lfoValue);*/
 }
 
 void DivPlatformOPLL::toggleRegisterDump(bool enable) {
@@ -590,7 +548,7 @@ unsigned char* DivPlatformOPLL::getRegisterPool() {
 }
 
 int DivPlatformOPLL::getRegisterPoolSize() {
-  return 256;
+  return 64;
 }
 
 void DivPlatformOPLL::reset() {
diff --git a/src/gui/insEdit.cpp b/src/gui/insEdit.cpp
index 22775dbc8..6ead6353a 100644
--- a/src/gui/insEdit.cpp
+++ b/src/gui/insEdit.cpp
@@ -58,13 +58,13 @@ const char* ssgEnvTypes[8]={
   "Down Down Down", "Down.", "Down Up Down Up", "Down UP", "Up Up Up", "Up.", "Up Down Up Down", "Up DOWN"
 };
 
-const char* fmParamNames[3][16]={
-  {"Algorithm", "Feedback", "LFO > Freq", "LFO > Amp", "Attack", "Decay", "Decay 2", "Release", "Sustain", "Level", "EnvScale", "Multiplier", "Detune", "Detune 2", "SSG-EG", "AM"},
-  {"ALG", "FB", "FMS/PMS", "AMS", "AR", "DR", "SR", "RR", "SL", "TL", "KS", "MULT", "DT", "DT2", "SSG-EG", "AM"},
-  {"ALG", "FB", "FMS/PMS", "AMS", "AR", "DR", "D2R", "RR", "SL", "TL", "RS", "MULT", "DT", "DT2", "SSG-EG", "AM"}
+const char* fmParamNames[3][27]={
+  {"Algorithm", "Feedback", "LFO > Freq", "LFO > Amp", "Attack", "Decay", "Decay 2", "Release", "Sustain", "Level", "EnvScale", "Multiplier", "Detune", "Detune 2", "SSG-EG", "AM", "AM Depth", "Vibrato Depth", "EnvAlternate", "EnvAlternate", "LevelScale/key", "Sustain", "Vibrato", "Waveform", "EnvScale/key", "OP2 HalfSine", "OP1 HalfSine"},
+  {"ALG", "FB", "FMS/PMS", "AMS", "AR", "DR", "SR", "RR", "SL", "TL", "KS", "MULT", "DT", "DT2", "SSG-EG", "AM", "AMD", "FMD", "EGT", "EGT", "KSL", "SUS", "VIB", "WS", "KSR", "DC", "DM"},
+  {"ALG", "FB", "FMS/PMS", "AMS", "AR", "DR", "D2R", "RR", "SL", "TL", "RS", "MULT", "DT", "DT2", "SSG-EG", "AM", "DAM", "DVB", "EGT", "EGS", "KSL", "SUS", "VIB", "WS", "KSR", "DC", "DM"}
 };
 
-const char* opllInsNames[18]={
+const char* opllInsNames[17]={
   "User",
   "Violin",
   "Guitar",
@@ -100,7 +100,18 @@ enum FMParams {
   FM_DT=12,
   FM_DT2=13,
   FM_SSG=14,
-  FM_AM=15
+  FM_AM=15,
+  FM_DAM=16,
+  FM_DVB=17,
+  FM_EGT=18,
+  FM_EGS=19,
+  FM_KSL=20,
+  FM_SUS=21,
+  FM_VIB=22,
+  FM_WS=23,
+  FM_KSR=24,
+  FM_DC=25,
+  FM_DM=26
 };
 
 #define FM_NAME(x) fmParamNames[settings.fmNames][x]
@@ -429,6 +440,41 @@ void FurnaceGUI::drawAlgorithm(unsigned char alg, FurnaceGUIFMAlgs algType, cons
           }
         }
         break;
+      case FM_ALGS_2OP_OPL:
+        switch (alg) {
+          case 0: { // 1 > 2
+            ImVec2 pos1=ImLerp(rect.Min,rect.Max,ImVec2(0.33,0.5));
+            ImVec2 pos2=ImLerp(rect.Min,rect.Max,ImVec2(0.67,0.5));
+            dl->AddCircleFilled(pos1,4.0f*dpiScale+1.0f,color);
+            dl->AddCircle(pos1,6.0f*dpiScale+1.0f,color);
+            dl->AddLine(pos1,pos2,colorL);
+            dl->AddCircleFilled(pos2,4.0f*dpiScale+1.0f,color);
+
+            pos1.x-=ImGui::CalcTextSize("2").x+circleRadius+3.0*dpiScale;
+            pos2.x+=circleRadius+3.0*dpiScale;
+            pos1.y-=ImGui::CalcTextSize("1").y*0.5;
+            pos2.y-=ImGui::CalcTextSize("2").y*0.5;
+            dl->AddText(pos1,color,"1");
+            dl->AddText(pos2,color,"2");
+            break;
+          }
+          case 1: { // 1 + 2
+            ImVec2 pos1=ImLerp(rect.Min,rect.Max,ImVec2(0.33,0.5));
+            ImVec2 pos2=ImLerp(rect.Min,rect.Max,ImVec2(0.67,0.5));
+            dl->AddCircleFilled(pos1,4.0f*dpiScale+1.0f,color);
+            dl->AddCircle(pos1,6.0f*dpiScale+1.0f,color);
+            dl->AddCircleFilled(pos2,4.0f*dpiScale+1.0f,color);
+
+            pos1.x-=ImGui::CalcTextSize("2").x+circleRadius+3.0*dpiScale;
+            pos2.x+=circleRadius+3.0*dpiScale;
+            pos1.y-=ImGui::CalcTextSize("1").y*0.5;
+            pos2.y-=ImGui::CalcTextSize("2").y*0.5;
+            dl->AddText(pos1,color,"1");
+            dl->AddText(pos2,color,"2");
+            break;
+          }
+        }
+        break;
       default:
         break;
     }
@@ -735,7 +781,7 @@ void FurnaceGUI::drawInsEdit() {
       }
 
       if (ImGui::BeginTabBar("insEditTab")) {
-        if (ins->type==DIV_INS_FM) {
+        if (ins->type==DIV_INS_FM || ins->type==DIV_INS_OPL || ins->type==DIV_INS_OPLL || ins->type==DIV_INS_OPZ) {
           char label[32];
           float asFloat[256];
           int asInt[256];
@@ -746,19 +792,72 @@ void FurnaceGUI::drawInsEdit() {
               ImGui::TableSetupColumn("c1",ImGuiTableColumnFlags_WidthStretch,0.0);
               ImGui::TableSetupColumn("c2",ImGuiTableColumnFlags_WidthStretch,0.0);
               ImGui::TableNextRow();
-              ImGui::TableNextColumn();
-              P(ImGui::SliderScalar(FM_NAME(FM_FB),ImGuiDataType_U8,&ins->fm.fb,&_ZERO,&_SEVEN));
-              P(ImGui::SliderScalar(FM_NAME(FM_FMS),ImGuiDataType_U8,&ins->fm.fms,&_ZERO,&_SEVEN));
-              ImGui::TableNextColumn();
-              P(ImGui::SliderScalar(FM_NAME(FM_ALG),ImGuiDataType_U8,&ins->fm.alg,&_ZERO,&_SEVEN));
-              P(ImGui::SliderScalar(FM_NAME(FM_AMS),ImGuiDataType_U8,&ins->fm.ams,&_ZERO,&_THREE));
-              ImGui::TableNextColumn();
-              drawAlgorithm(ins->fm.alg,FM_ALGS_4OP,ImVec2(ImGui::GetContentRegionAvail().x,48.0*dpiScale));
+              switch (ins->type) {
+                case DIV_INS_FM:
+                case DIV_INS_OPZ:
+                  ImGui::TableNextColumn();
+                  P(ImGui::SliderScalar(FM_NAME(FM_FB),ImGuiDataType_U8,&ins->fm.fb,&_ZERO,&_SEVEN));
+                  P(ImGui::SliderScalar(FM_NAME(FM_FMS),ImGuiDataType_U8,&ins->fm.fms,&_ZERO,&_SEVEN));
+                  ImGui::TableNextColumn();
+                  P(ImGui::SliderScalar(FM_NAME(FM_ALG),ImGuiDataType_U8,&ins->fm.alg,&_ZERO,&_SEVEN));
+                  P(ImGui::SliderScalar(FM_NAME(FM_AMS),ImGuiDataType_U8,&ins->fm.ams,&_ZERO,&_THREE));
+                  ImGui::TableNextColumn();
+                  drawAlgorithm(ins->fm.alg,FM_ALGS_4OP,ImVec2(ImGui::GetContentRegionAvail().x,48.0*dpiScale));
+                  break;
+                case DIV_INS_OPL:
+                case DIV_INS_OPLL: {
+                  bool dc=ins->fm.fms;
+                  bool dm=ins->fm.ams;
+                  bool sus=ins->fm.alg;
+                  ImGui::TableNextColumn();
+                  ImGui::BeginDisabled(ins->fm.opllPreset!=0);
+                  P(ImGui::SliderScalar(FM_NAME(FM_FB),ImGuiDataType_U8,&ins->fm.fb,&_ZERO,&_SEVEN));
+                  if (ImGui::Checkbox(FM_NAME(FM_DC),&dc)) { PARAMETER
+                    ins->fm.fms=dc;
+                  }
+                  ImGui::EndDisabled();
+                  ImGui::TableNextColumn();
+                  if (ImGui::Checkbox(FM_NAME(FM_SUS),&sus)) { PARAMETER
+                    ins->fm.alg=sus;
+                  }
+                  ImGui::BeginDisabled(ins->fm.opllPreset!=0);
+                  if (ImGui::Checkbox(FM_NAME(FM_DM),&dm)) { PARAMETER
+                    ins->fm.ams=dm;
+                  }
+                  ImGui::EndDisabled();
+                  ImGui::TableNextColumn();
+                  drawAlgorithm(0,FM_ALGS_2OP_OPL,ImVec2(ImGui::GetContentRegionAvail().x,24.0*dpiScale));
+                  ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
+                  if (ImGui::BeginCombo("##LLPreset",opllInsNames[ins->fm.opllPreset])) {
+                    for (int i=0; i<17; i++) {
+                      if (ImGui::Selectable(opllInsNames[i])) {
+                        ins->fm.opllPreset=i;
+                      }
+                    }
+                    ImGui::EndCombo();
+                  }
+                  break;
+                }
+                default:
+                  break;
+              }
               ImGui::EndTable();
             }
-            if (ImGui::BeginTable("FMOperators",2,ImGuiTableFlags_SizingStretchSame)) {
-              for (int i=0; i<4; i++) {
-                DivInstrumentFM::Operator& op=ins->fm.op[opOrder[i]];
+
+            if (ins->type==DIV_INS_OPLL && ins->fm.opllPreset==16) {
+              ImGui::Text("the Drums patch is only there for compatibility.\nit is highly encouraged you use the OPLL (drums) system instead!");
+            }
+
+            bool willDisplayOps=true;
+            int opCount=4;
+            if (ins->type==DIV_INS_OPLL && ins->fm.opllPreset!=0) willDisplayOps=false;
+            if (ins->type==DIV_INS_OPL || ins->type==DIV_INS_OPLL) opCount=2;
+            if (!willDisplayOps && ins->type==DIV_INS_OPLL) {
+              P(ImGui::SliderScalar("Volume##TL",ImGuiDataType_U8,&ins->fm.op[1].tl,&_FIFTEEN,&_ZERO));
+            }
+            if (willDisplayOps) if (ImGui::BeginTable("FMOperators",2,ImGuiTableFlags_SizingStretchSame)) {
+              for (int i=0; i<opCount; i++) {
+                DivInstrumentFM::Operator& op=ins->fm.op[(opCount==4)?opOrder[i]:i];
                 if ((i+1)&1) ImGui::TableNextRow();
                 ImGui::TableNextColumn();
                 ImGui::Separator();
@@ -775,13 +874,27 @@ void FurnaceGUI::drawInsEdit() {
 
                 ImGui::SameLine();
 
+                int maxTl=127;
+                if (ins->type==DIV_INS_OPLL) {
+                  if (i==1) {
+                    maxTl=15;
+                  } else {
+                    maxTl=63;
+                  }
+                }
+
                 bool ssgOn=op.ssgEnv&8;
+                bool ksrOn=op.ksr;
+                bool vibOn=op.vib;
                 unsigned char ssgEnv=op.ssgEnv&7;
-                if (ImGui::Checkbox("SSG On",&ssgOn)) { PARAMETER
+                int maxArDr=(ins->type==DIV_INS_FM || ins->type==DIV_INS_OPZ)?31:15;
+                if (ImGui::Checkbox((ins->type==DIV_INS_OPL || ins->type==DIV_INS_OPLL)?FM_NAME(FM_EGS):"SSG On",&ssgOn)) { PARAMETER
                   op.ssgEnv=(op.ssgEnv&7)|(ssgOn<<3);
                 }
-                if (ImGui::IsItemHovered()) {
-                  ImGui::SetTooltip("Only for Genesis and Neo Geo systems");
+                if (ins->type==DIV_INS_FM) {
+                  if (ImGui::IsItemHovered()) {
+                    ImGui::SetTooltip("Only for Genesis and Neo Geo systems");
+                  }
                 }
 
                 //52.0 controls vert scaling; default 96
@@ -794,14 +907,14 @@ void FurnaceGUI::drawInsEdit() {
                   ImGui::TableNextRow();
                   ImGui::TableNextColumn();
                   ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
-                  P(ImGui::SliderScalar("##AR",ImGuiDataType_U8,&op.ar,&_THIRTY_ONE,&_ZERO));
+                  P(ImGui::SliderScalar("##AR",ImGuiDataType_U8,&op.ar,&maxArDr,&_ZERO));
                   ImGui::TableNextColumn();
                   ImGui::Text("%s",FM_NAME(FM_AR));
 
                   ImGui::TableNextRow();
                   ImGui::TableNextColumn();
                   ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
-                  P(ImGui::SliderScalar("##DR",ImGuiDataType_U8,&op.dr,&_THIRTY_ONE,&_ZERO));
+                  P(ImGui::SliderScalar("##DR",ImGuiDataType_U8,&op.dr,&maxArDr,&_ZERO));
                   ImGui::TableNextColumn();
                   ImGui::Text("%s",FM_NAME(FM_DR));
 
@@ -812,12 +925,14 @@ void FurnaceGUI::drawInsEdit() {
                   ImGui::TableNextColumn();
                   ImGui::Text("%s",FM_NAME(FM_SL));
 
-                  ImGui::TableNextRow();
-                  ImGui::TableNextColumn();
-                  ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
-                  P(ImGui::SliderScalar("##D2R",ImGuiDataType_U8,&op.d2r,&_THIRTY_ONE,&_ZERO));
-                  ImGui::TableNextColumn();
-                  ImGui::Text("%s",FM_NAME(FM_D2R));
+                  if (ins->type==DIV_INS_FM || ins->type==DIV_INS_OPZ) {
+                    ImGui::TableNextRow();
+                    ImGui::TableNextColumn();
+                    ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
+                    P(ImGui::SliderScalar("##D2R",ImGuiDataType_U8,&op.d2r,&_THIRTY_ONE,&_ZERO));
+                    ImGui::TableNextColumn();
+                    ImGui::Text("%s",FM_NAME(FM_D2R));
+                  }
 
                   ImGui::TableNextRow();
                   ImGui::TableNextColumn();
@@ -829,7 +944,7 @@ void FurnaceGUI::drawInsEdit() {
                   ImGui::TableNextRow();
                   ImGui::TableNextColumn();
                   ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
-                  P(ImGui::SliderScalar("##TL",ImGuiDataType_U8,&op.tl,&_ONE_HUNDRED_TWENTY_SEVEN,&_ZERO));
+                  P(ImGui::SliderScalar("##TL",ImGuiDataType_U8,&op.tl,&maxTl,&_ZERO));
                   ImGui::TableNextColumn();
                   ImGui::Text("%s",FM_NAME(FM_TL));
 
@@ -842,9 +957,15 @@ void FurnaceGUI::drawInsEdit() {
                   ImGui::TableNextRow();
                   ImGui::TableNextColumn();
                   ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
-                  P(ImGui::SliderScalar("##RS",ImGuiDataType_U8,&op.rs,&_ZERO,&_THREE));
-                  ImGui::TableNextColumn();
-                  ImGui::Text("%s",FM_NAME(FM_RS));
+                  if (ins->type==DIV_INS_FM || ins->type==DIV_INS_OPZ) {
+                    P(ImGui::SliderScalar("##RS",ImGuiDataType_U8,&op.rs,&_ZERO,&_THREE));
+                    ImGui::TableNextColumn();
+                    ImGui::Text("%s",FM_NAME(FM_RS));
+                  } else {
+                    P(ImGui::SliderScalar("##KSL",ImGuiDataType_U8,&op.ksl,&_ZERO,&_THREE));
+                    ImGui::TableNextColumn();
+                    ImGui::Text("%s",FM_NAME(FM_KSL));
+                  }
 
                   ImGui::TableNextRow();
                   ImGui::TableNextColumn();
@@ -853,37 +974,50 @@ void FurnaceGUI::drawInsEdit() {
                   ImGui::TableNextColumn();
                   ImGui::Text("%s",FM_NAME(FM_MULT));
                   
-                  int detune=(op.dt&7)-3;
-                  ImGui::TableNextRow();
-                  ImGui::TableNextColumn();
-                  ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
-                  if (ImGui::SliderInt("##DT",&detune,-3,3)) { PARAMETER
-                    op.dt=detune+3;
-                  }
-                  ImGui::TableNextColumn();
-                  ImGui::Text("%s",FM_NAME(FM_DT));
+                  if (ins->type==DIV_INS_FM || ins->type==DIV_INS_OPZ) {
+                    int detune=(op.dt&7)-3;
+                    ImGui::TableNextRow();
+                    ImGui::TableNextColumn();
+                    ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
+                    if (ImGui::SliderInt("##DT",&detune,-3,3)) { PARAMETER
+                      op.dt=detune+3;
+                    }
+                    ImGui::TableNextColumn();
+                    ImGui::Text("%s",FM_NAME(FM_DT));
 
-                  ImGui::TableNextRow();
-                  ImGui::TableNextColumn();
-                  ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
-                  P(ImGui::SliderScalar("##DT2",ImGuiDataType_U8,&op.dt2,&_ZERO,&_THREE));
-                  if (ImGui::IsItemHovered()) {
-                    ImGui::SetTooltip("Only for Arcade system");
-                  }
-                  ImGui::TableNextColumn();
-                  ImGui::Text("%s",FM_NAME(FM_DT2));
+                    ImGui::TableNextRow();
+                    ImGui::TableNextColumn();
+                    ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
+                    P(ImGui::SliderScalar("##DT2",ImGuiDataType_U8,&op.dt2,&_ZERO,&_THREE));
+                    if (ImGui::IsItemHovered()) {
+                      ImGui::SetTooltip("Only for Arcade system");
+                    }
+                    ImGui::TableNextColumn();
+                    ImGui::Text("%s",FM_NAME(FM_DT2));
 
-                  ImGui::TableNextRow();
-                  ImGui::TableNextColumn();
-                  ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
-                  if (ImGui::SliderScalar("##SSG",ImGuiDataType_U8,&ssgEnv,&_ZERO,&_SEVEN,ssgEnvTypes[ssgEnv])) { PARAMETER
-                    op.ssgEnv=(op.ssgEnv&8)|(ssgEnv&7);
+                    ImGui::TableNextRow();
+                    ImGui::TableNextColumn();
+                    ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
+                    if (ImGui::SliderScalar("##SSG",ImGuiDataType_U8,&ssgEnv,&_ZERO,&_SEVEN,ssgEnvTypes[ssgEnv])) { PARAMETER
+                      op.ssgEnv=(op.ssgEnv&8)|(ssgEnv&7);
+                    }
+                    ImGui::TableNextColumn();
+                    ImGui::Text("%s",FM_NAME(FM_SSG));
                   }
-                  ImGui::TableNextColumn();
-                  ImGui::Text("%s",FM_NAME(FM_SSG));
                   
                   ImGui::EndTable();
                 }
+
+                if (ins->type==DIV_INS_OPLL || ins->type==DIV_INS_OPL) {
+                  if (ImGui::Checkbox(FM_NAME(FM_VIB),&vibOn)) { PARAMETER
+                    op.vib=vibOn;
+                  }
+                  ImGui::SameLine();
+                  if (ImGui::Checkbox(FM_NAME(FM_KSR),&ksrOn)) { PARAMETER
+                    op.ksr=ksrOn;
+                  }
+                }
+
                 ImGui::PopID();
               }
               ImGui::EndTable();