diff --git a/papers/format.md b/papers/format.md
index c346dfee2..23bac80aa 100644
--- a/papers/format.md
+++ b/papers/format.md
@@ -25,6 +25,7 @@ furthermore, an `or reserved` indicates this field is always present, but is res
 
 the format versions are:
 
+- 60: Furnace dev60
 - 59: Furnace dev59
 - 58: Furnace dev58
 - 57: Furnace dev57
@@ -228,7 +229,11 @@ size | description
   1  | fms
   1  | ams
   1  | operator count (always 4)
-  3  | reserved
+  1  | OPLL preset (>=60) or reserved
+     | - 0: custom
+     | - 1-15: pre-defined patches
+     | - 16: drums (compatibility only!)
+  2  | reserved
  --- | **FM operator data** × 4
   1  | am
   1  | ar
diff --git a/src/engine/engine.h b/src/engine/engine.h
index 68c003160..f0ef1833a 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -37,8 +37,8 @@
     warnings+=(String("\n")+x); \
   }
 
-#define DIV_VERSION "dev59"
-#define DIV_ENGINE_VERSION 59
+#define DIV_VERSION "dev60"
+#define DIV_ENGINE_VERSION 60
 
 enum DivStatusView {
   DIV_STATUS_NOTHING=0,
diff --git a/src/engine/instrument.cpp b/src/engine/instrument.cpp
index 57e9cbf47..fa5564c93 100644
--- a/src/engine/instrument.cpp
+++ b/src/engine/instrument.cpp
@@ -40,9 +40,9 @@ void DivInstrument::putInsData(SafeWriter* w) {
   w->writeC(fm.fms);
   w->writeC(fm.ams);
   w->writeC(4); // operator count; always 4
+  w->writeC(fm.opllPreset);
   w->writeC(0); // reserved
   w->writeC(0);
-  w->writeC(0);
 
   for (int j=0; j<4; j++) {
     DivInstrumentFM::Operator& op=fm.op[j];
@@ -325,7 +325,11 @@ DivDataErrors DivInstrument::readInsData(SafeReader& reader, short version) {
   fm.fms=reader.readC();
   fm.ams=reader.readC();
   fm.ops=reader.readC();
-  reader.readC();
+  if (version>=60) {
+    fm.opllPreset=reader.readC();
+  } else {
+    reader.readC();
+  }
   reader.readC();
   reader.readC();
 
diff --git a/src/engine/platform/opll.cpp b/src/engine/platform/opll.cpp
index d941a8d77..205030753 100644
--- a/src/engine/platform/opll.cpp
+++ b/src/engine/platform/opll.cpp
@@ -88,13 +88,13 @@ void DivPlatformOPLL::acquire_nuked(short* bufL, short* bufR, size_t start, size
         printf("write: %x = %.2x\n",w.addr,w.val);
         regPool[w.addr&0xff]=w.val;
         writes.pop();
-        delay=84;
+        delay=21;
       } else {
         //printf("busycounter: %d\n",lastBusy);
         //w.addr=rand()&0x3f;
         OPLL_Write(&fm,0,w.addr);
         w.addrOrVal=true;
-        delay=12;
+        delay=3;
       }
     }
     
@@ -267,7 +267,7 @@ void DivPlatformOPLL::tick() {
     }
     if (chan[i].keyOn) {
       //immWrite(0x28,0xf0|konOffs[i]);
-      immWrite(0x20+i,(chan[i].freqH)|(chan[i].active<<4));
+      immWrite(0x20+i,(chan[i].freqH)|(chan[i].active<<4)|0x20);
       chan[i].keyOn=false;
     }
   }
@@ -657,9 +657,9 @@ void DivPlatformOPLL::setFlags(unsigned int flags) {
   } else if (flags==2) {
     chipClock=8000000.0;
   } else if (flags==1) {
-    chipClock=COLOR_PAL*4.0/5.0;
+    chipClock=COLOR_PAL*1.0/5.0;
   } else {
-    chipClock=COLOR_NTSC;
+    chipClock=COLOR_NTSC/4.0;
   }
   rate=chipClock;
 }