diff --git a/src/engine/cmdStream.cpp b/src/engine/cmdStream.cpp
index f6aa7f120..7e24c7d42 100644
--- a/src/engine/cmdStream.cpp
+++ b/src/engine/cmdStream.cpp
@@ -24,7 +24,7 @@
 #include "../ta-log.h"
 
 bool DivCSChannelState::doCall(unsigned int addr) {
-  if (callStackPos>=8) {
+  if (callStackPos>=16) {
     readPos=0;
     return false;
   }
@@ -47,6 +47,10 @@ DivCSChannelState* DivCSPlayer::getChanState(int ch) {
   return &chan[ch];
 }
 
+unsigned int DivCSPlayer::getFileChans() {
+  return fileChans;
+}
+
 unsigned char* DivCSPlayer::getFastDelays() {
   return fastDelays;
 }
@@ -471,9 +475,9 @@ bool DivCSPlayer::init() {
 
   if (memcmp(magic,"FCS",4)!=0) return false;
 
-  unsigned int chans=stream.readI();
+  fileChans=stream.readI();
 
-  for (unsigned int i=0; i<chans; i++) {
+  for (unsigned int i=0; i<fileChans; i++) {
     if (i>=DIV_MAX_CHANS) {
       stream.readI();
       continue;
diff --git a/src/engine/cmdStream.h b/src/engine/cmdStream.h
index 85d106e15..58f27a83f 100644
--- a/src/engine/cmdStream.h
+++ b/src/engine/cmdStream.h
@@ -39,7 +39,7 @@ struct DivCSChannelState {
   int portaTarget, portaSpeed;
   unsigned char arp, arpStage, arpTicks, loopCount;
 
-  unsigned int callStack[8];
+  unsigned int callStack[16];
   unsigned char callStackPos;
 
   unsigned int trace[DIV_MAX_CSTRACE];
@@ -83,12 +83,14 @@ class DivCSPlayer {
   unsigned char fastDelays[16];
   unsigned char fastCmds[16];
   unsigned char arpSpeed;
+  unsigned int fileChans;
 
   short vibTable[64];
   public:
     unsigned char* getData();
     size_t getDataLen();
     DivCSChannelState* getChanState(int ch);
+    unsigned int getFileChans();
     unsigned char* getFastDelays();
     unsigned char* getFastCmds();
     void cleanup();
@@ -101,4 +103,9 @@ class DivCSPlayer {
       stream(buf,len) {}
 };
 
+// command stream utilities
+namespace DivCS {
+  int getInsLength(unsigned char ins, unsigned char ext=0);
+};
+
 #endif
diff --git a/src/engine/cmdStreamOps.cpp b/src/engine/cmdStreamOps.cpp
index 589686a3c..04c5c1858 100644
--- a/src/engine/cmdStreamOps.cpp
+++ b/src/engine/cmdStreamOps.cpp
@@ -23,7 +23,7 @@
 
 //#define DISABLE_BLOCK_SEARCH
 
-int getInsLength(unsigned char ins) {
+int DivCS::getInsLength(unsigned char ins, unsigned char ext) {
   switch (ins) {
     case 0xb8: // ins
     case 0xc0: // pre porta
@@ -49,8 +49,11 @@ int getInsLength(unsigned char ins) {
     case 0xf0: // opt
       return 4;
     case 0xf2: // opt command
-    case 0xf7: // cmd
+    case 0xf7: { // cmd
+      // determine length from secondary
+      if (ext==0) return 0;
       return 0;
+    }
     case 0xf8: // callb16
     case 0xfc: // waits
       return 3;
@@ -232,6 +235,8 @@ void writePackedCommandValues(SafeWriter* w, const DivCommand& c) {
   }
 }
 
+using namespace DivCS;
+
 void reloc(unsigned char* buf, size_t len, unsigned int sourceAddr, unsigned int destAddr) {
   unsigned int delta=destAddr-sourceAddr;
   for (size_t i=0; i<len;) {
@@ -325,6 +330,7 @@ SafeWriter* findSubBlocks(SafeWriter* stream, std::vector<SafeWriter*>& subBlock
       size_t subBlockID=subBlocks.size();
       int insLen=getInsLength(buf[searchPos]);
       bool haveSub=false;
+      bool onlyCalls=true;
 
       if (insLen<1) {
         logE("INS %x NOT IMPLEMENTED...",buf[searchPos]);
@@ -333,6 +339,7 @@ SafeWriter* findSubBlocks(SafeWriter* stream, std::vector<SafeWriter*>& subBlock
 
       // register this block
       for (size_t i=0; i<groupSize && i<stream->size();) {
+        if (buf[searchPos+i]!=0xf4) onlyCalls=false;
         int insLenI=getInsLength(buf[searchPos+i]);
         if (insLenI<1) {
           logE("INS %x NOT IMPLEMENTED...",buf[searchPos+i]);
@@ -356,6 +363,13 @@ SafeWriter* findSubBlocks(SafeWriter* stream, std::vector<SafeWriter*>& subBlock
         continue;
       }
 
+      // don't do anything if this block only consists of calls
+      if (onlyCalls) {
+        logW("nothing but calls.");
+        searchPos+=insLen;
+        continue;
+      }
+
       // find identical blocks
       for (size_t i=searchPos+groupLen; i+groupLen<stream->size();) {
         int insLenI=getInsLength(buf[i]);
@@ -564,6 +578,12 @@ SafeWriter* DivEngine::saveCommand() {
   logV("%d",tick);
   cmdStreamEnabled=oldCmdStreamEnabled;
 
+  remainingLoops=-1;
+  playing=false;
+  freelance=false;
+  extValuePresent=false;
+  BUSY_END;
+
   // PASS 1: condense delays
   // calculate delay usage
   for (int h=0; h<chans; h++) {
@@ -928,11 +948,5 @@ SafeWriter* DivEngine::saveCommand() {
     if (sortedCmdPopularity[i]) logD("- %s: %d",cmdName[sortedCmd[i]],sortedCmdPopularity[i]);
   }
 
-  remainingLoops=-1;
-  playing=false;
-  freelance=false;
-  extValuePresent=false;
-  BUSY_END;
-
   return w;
 }
diff --git a/src/gui/csPlayer.cpp b/src/gui/csPlayer.cpp
index 491f51477..d0a46533b 100644
--- a/src/gui/csPlayer.cpp
+++ b/src/gui/csPlayer.cpp
@@ -273,7 +273,7 @@ void FurnaceGUI::drawCSPlayer() {
             for (int i=0; i<chans; i++) {
               DivCSChannelState* state=cs->getChanState(i);
               ImGui::TableNextColumn();
-              ImGui::Text("%d: $%.4x",i,state->readPos);
+              ImGui::Text("%d: $%.4x (>>%d)",i,state->readPos,state->callStackPos);
             }
 
             ImGui::TableNextRow();
@@ -303,6 +303,90 @@ void FurnaceGUI::drawCSPlayer() {
           ImGui::EndTabItem();
         }
         if (ImGui::BeginTabItem(_("Disassemble"))) {
+          bool mustProceed=false;
+          ImGui::AlignTextToFramePadding();
+          ImGui::Text("Address");
+          ImGui::SameLine();
+          ImGui::InputScalar("##DisAsmAddr",ImGuiDataType_U32,&csDisAsmAddr,0,0,"%.8X",ImGuiInputTextFlags_CharsHexadecimal);
+          ImGui::SameLine();
+          if (ImGui::Button("Go")) {
+            mustProceed=true;
+          }
+
+          if (mustProceed) {
+            csDisAsm.clear();
+            unsigned char* buf=cs->getData();
+            for (size_t i=csDisAsmAddr; i<cs->getDataLen();) {
+              int insLen=DivCS::getInsLength(buf[i]);
+              if (insLen<1) {
+                logE("INS %x NOT IMPLEMENTED...",buf[i]);
+                break;
+              }
+
+              CSDisAsmIns ins;
+              ins.addr=i;
+              memcpy(ins.data,&buf[i],insLen);
+              ins.len=insLen;
+              csDisAsm.push_back(ins);
+
+              i+=insLen;
+            }
+          }
+          
+          if (!csDisAsm.empty()) {
+            ImGui::PushFont(patFont);
+            if (ImGui::BeginTable("CSDisAsm",chans,ImGuiTableFlags_SizingFixedFit|ImGuiTableFlags_ScrollY)) {
+              ImGui::TableSetupColumn("c0",ImGuiTableColumnFlags_WidthFixed,oneChar.x*2.0f);
+              ImGui::TableSetupColumn("c1",ImGuiTableColumnFlags_WidthFixed,oneChar.x*9.0f);
+              ImGui::TableSetupColumn("c3",ImGuiTableColumnFlags_WidthFixed,oneChar.x*3.0f*6.0f);
+              ImGui::TableSetupColumn("c2",ImGuiTableColumnFlags_WidthStretch);
+              ImGui::TableNextRow(ImGuiTableRowFlags_Headers);
+              ImGui::TableNextColumn();
+              ImGui::Text("pc");
+              ImGui::TableNextColumn();
+              ImGui::Text("addr");
+              ImGui::TableNextColumn();
+              ImGui::Text("hex");
+              ImGui::TableNextColumn();
+              ImGui::Text("ins");
+
+              for (CSDisAsmIns& i: csDisAsm) {
+                ImGui::TableNextRow(0,oneChar.y);
+                ImGui::TableNextColumn();
+                // this is the "PC is here row"...
+
+
+                ImGui::TableNextColumn();
+                ImGui::Text("%.8x",i.addr);
+
+                ImGui::TableNextColumn();
+                for (int j=0; j<i.len; j++) {
+                  ImGui::Text("%.2x",i.data[j]);
+                  ImGui::SameLine();
+                }
+
+                ImGui::TableNextColumn();
+                String dis=disasmCmd(i.data,8,0);
+                ImGui::Text("%s",dis.c_str());
+
+                // jmp/ret separator
+                if (i.data[0]==0xf9 || i.data[0]==0xfa) {
+                  ImGui::TableNextRow(0,oneChar.y);
+                  ImGui::TableNextColumn();
+                  ImGui::Separator();
+                  ImGui::TableNextColumn();
+                  ImGui::Separator();
+                  ImGui::TableNextColumn();
+                  ImGui::Separator();
+                  ImGui::TableNextColumn();
+                  ImGui::Separator();
+                }
+              }
+
+              ImGui::EndTable();
+            }
+            ImGui::PopFont();
+          }
           ImGui::EndTabItem();
         }
         if (ImGui::BeginTabItem(_("Hex"))) {
@@ -422,6 +506,21 @@ void FurnaceGUI::drawCSPlayer() {
           ImGui::PopFont();
           ImGui::EndTabItem();
         }
+        if (ImGui::BeginTabItem(_("Stream Info"))) {
+          ImGui::Text("%d bytes",(int)cs->getDataLen());
+          ImGui::Text("%u channels",cs->getFileChans());
+          ImGui::Text("preset delays:");
+          for (int i=0; i<16; i++) {
+            ImGui::SameLine();
+            ImGui::Text("%d",cs->getFastDelays()[i]);
+          }
+          ImGui::Text("speed dial commands:");
+          for (int i=0; i<16; i++) {
+            ImGui::SameLine();
+            ImGui::Text("%d",cs->getFastCmds()[i]);
+          }
+          ImGui::EndTabItem();
+        }
         ImGui::EndTabBar();
       }
     }
diff --git a/src/gui/gui.h b/src/gui/gui.h
index f60cc6c02..95032fa2c 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -1613,6 +1613,17 @@ struct MappedInput {
     scan(s), val(v) {}
 };
 
+struct CSDisAsmIns {
+  unsigned int addr;
+  unsigned char data[8];
+  unsigned char len;
+  CSDisAsmIns():
+    addr(0),
+    len(0) {
+    memset(data,0,8);
+  }
+};
+
 struct FurnaceCV;
 
 class FurnaceGUI {
@@ -2743,6 +2754,8 @@ class FurnaceGUI {
 
   // command stream player
   ImGuiListClipper csClipper;
+  unsigned int csDisAsmAddr;
+  std::vector<CSDisAsmIns> csDisAsm;
 
   // export options
   DivAudioExportOptions audioExportOptions;