diff --git a/src/engine/platform/sms.cpp b/src/engine/platform/sms.cpp
index 5dc5aeac..ec0286da 100644
--- a/src/engine/platform/sms.cpp
+++ b/src/engine/platform/sms.cpp
@@ -4,7 +4,7 @@
 
 #define FREQ_BASE 1712.0f
 
-#define rWrite(v) {sn->write(v); if (dumpWrites) {addWrite(0x200,v);} }
+#define rWrite(v) {if (!skipRegisterWrites) {sn->write(v); if (dumpWrites) {addWrite(0x200,v);}}}
 
 void DivPlatformSMS::acquire(short* bufL, short* bufR, size_t start, size_t len) {
   sn->sound_stream_update(bufL+start,len);
@@ -178,6 +178,15 @@ void DivPlatformSMS::muteChannel(int ch, bool mute) {
   if (chan[ch].active) rWrite(0x90|ch<<5|(isMuted[ch]?15:(15-(chan[ch].outVol&15))));
 }
 
+void DivPlatformSMS::forceIns() {
+  for (int i=0; i<4; i++) {
+    if (chan[i].active) {
+      chan[i].insChanged=true;
+      chan[i].freqChanged=true;
+    }
+  }
+}
+
 void DivPlatformSMS::reset() {
   for (int i=0; i<4; i++) {
     chan[i]=DivPlatformSMS::Channel();
diff --git a/src/engine/platform/sms.h b/src/engine/platform/sms.h
index 01dad852..5dc75411 100644
--- a/src/engine/platform/sms.h
+++ b/src/engine/platform/sms.h
@@ -36,6 +36,7 @@ class DivPlatformSMS: public DivDispatch {
     void acquire(short* bufL, short* bufR, size_t start, size_t len);
     int dispatch(DivCommand c);
     void reset();
+    void forceIns();
     void tick();
     void muteChannel(int ch, bool mute);
     bool keyOffAffectsArp(int ch);