diff --git a/companion/src/firmwares/edgetx/edgetxinterface.cpp b/companion/src/firmwares/edgetx/edgetxinterface.cpp
index ad31f1f15..e75428b2b 100644
--- a/companion/src/firmwares/edgetx/edgetxinterface.cpp
+++ b/companion/src/firmwares/edgetx/edgetxinterface.cpp
@@ -42,7 +42,7 @@ static void writeYamlToByteArray(const YAML::Node& node, QByteArray& data)
     qDebug() << data_ostream.str().c_str();
 }
 
-bool loadModelsListFromYaml(std::vector<CategoryData> categories,
+bool loadModelsListFromYaml(std::vector<CategoryData>& categories,
                             EtxModelfiles& modelFiles,
                             const QByteArray& data)
 {
@@ -102,16 +102,42 @@ bool loadRadioSettingsFromYaml(GeneralSettings& settings, const QByteArray& data
   return true;
 }
 
+// TODO:
+//   'modelFiles' should be ordered by Category index to avoid
+//   turning the sequence into a map.
+//
+bool writeModelsListToYaml(const std::vector<CategoryData>& categories,
+                           const EtxModelfiles& modelFiles,
+                           QByteArray& data)
+{
+  YAML::Node node;
+  for (const auto& modelFile: modelFiles) {
+
+    YAML::Node cat_attrs;
+    cat_attrs["filename"] = modelFile.first;
+
+    const std::string cat_name = categories[modelFile.second].name;
+    node[modelFile.second][cat_name].push_back(cat_attrs);
+  }
+
+  writeYamlToByteArray(node, data);
+  return true;
+}
+
 bool writeModelToYaml(const ModelData& model, QByteArray& data)
 {
-    return false;
+  YAML::Node node;
+  node = model;
+  
+  writeYamlToByteArray(node, data);
+  return true;
 }
 
 bool writeRadioSettingsToYaml(const GeneralSettings& settings, QByteArray& data)
 {
   YAML::Node node;
   node = settings;
-  writeYamlToByteArray(node, data);
 
+  writeYamlToByteArray(node, data);
   return false;
 }
diff --git a/companion/src/firmwares/edgetx/edgetxinterface.h b/companion/src/firmwares/edgetx/edgetxinterface.h
index 641f080ee..e3743c829 100644
--- a/companion/src/firmwares/edgetx/edgetxinterface.h
+++ b/companion/src/firmwares/edgetx/edgetxinterface.h
@@ -30,12 +30,16 @@
 typedef std::pair<std::string, int> EtxModelfileCategoryPair;
 typedef std::list<EtxModelfileCategoryPair> EtxModelfiles;
 
-bool loadModelsListFromYaml(std::vector<CategoryData> categories,
+bool loadModelsListFromYaml(std::vector<CategoryData>& categories,
                             EtxModelfiles& modelFiles,
                             const QByteArray& data);
 
 bool loadModelFromYaml(ModelData& model, const QByteArray& data);
 bool loadRadioSettingsFromYaml(GeneralSettings& settings, const QByteArray& data);
 
+bool writeModelsListToYaml(const std::vector<CategoryData>& categories,
+                           const EtxModelfiles& modelFiles,
+                           QByteArray& data);
+
 bool writeModelToYaml(const ModelData& model, QByteArray& data);
 bool writeRadioSettingsToYaml(const GeneralSettings& settings, QByteArray& data);
diff --git a/companion/src/firmwares/edgetx/yaml_modeldata.cpp b/companion/src/firmwares/edgetx/yaml_modeldata.cpp
index 968f7949a..e31989958 100644
--- a/companion/src/firmwares/edgetx/yaml_modeldata.cpp
+++ b/companion/src/firmwares/edgetx/yaml_modeldata.cpp
@@ -21,7 +21,7 @@
 #include "yaml_modeldata.h"
 #include "modeldata.h"
 
-const YamlLookupTable timerModeLut = {
+static const YamlLookupTable timerModeLut = {
     {TimerData::TIMERMODE_OFF, "OFF"},
     {TimerData::TIMERMODE_ON, "ON"},
     {TimerData::TIMERMODE_START, "START"},
@@ -30,7 +30,7 @@ const YamlLookupTable timerModeLut = {
     {TimerData::TIMERMODE_THR_START, "THR_START"},
 };
 
-const YamlLookupTable trainerModeLut = {
+static const YamlLookupTable trainerModeLut = {
   {  TRAINER_MODE_OFF, "OFF"  },
   {  TRAINER_MODE_MASTER_JACK, "MASTER_TRAINER_JACK"  },
   {  TRAINER_MODE_SLAVE_JACK, "SLAVE"  },
@@ -41,3 +41,172 @@ const YamlLookupTable trainerModeLut = {
   {  TRAINER_MODE_SLAVE_BLUETOOTH, "SLAVE_BT"  },
   {  TRAINER_MODE_MULTI, "MASTER_MULTI"  },
 };
+
+namespace YAML
+{
+Node convert<TimerData>::encode(const TimerData& rhs)
+{
+  Node node;
+  node["swtch"] = rhs.swtch;
+  node["mode"] = timerModeLut << rhs.mode;
+  node["name"] = rhs.name;
+  node["minuteBeep"] = rhs.minuteBeep;
+  node["countdownBeep"] = rhs.countdownBeep;
+  node["start"] = rhs.val;
+  node["persistent"] = rhs.persistent;
+  node["countdownStart"] = rhs.countdownStart;
+  node["value"] = rhs.pvalue;
+  return node;
+}
+
+bool convert<TimerData>::decode(const Node& node, TimerData& rhs)
+{
+  node["swtch"] >> rhs.swtch;
+  node["mode"] >> timerModeLut >> rhs.mode;
+  node["name"] >> rhs.name;
+  node["minuteBeep"] >> rhs.minuteBeep;
+  node["countdownBeep"] >> rhs.countdownBeep;
+  node["start"] >> rhs.val;
+  node["persistent"] >> rhs.persistent;
+  node["countdownStart"] >> rhs.countdownStart;
+  node["value"] >> rhs.pvalue;
+  return true;
+}
+
+Node convert<ModelData>::encode(const ModelData& rhs)
+{
+  Node node;
+  node["header"]["name"] = rhs.name;
+  node["header"]["bitmap"] = rhs.bitmap;
+  // TODO: modelId
+
+  for (int i=0; i<CPN_MAX_TIMERS; i++) {
+    Node timer;
+    timer = rhs.timers[i];
+    node["timers"][std::to_string(i)] = timer;
+  }
+
+  node["noGlobalFunctions"] = rhs.noGlobalFunctions;
+  node["thrTrim"] = rhs.thrTrim;
+  node["trimInc"] = rhs.trimInc;
+  node["displayTrims"] = rhs.trimsDisplay;
+  node["disableThrottleWarning"] = rhs.disableThrottleWarning;
+  // node[] = rhs.beepANACenter;
+  node["extendedLimits"] = rhs.extendedLimits;
+  node["extendedTrims"] = rhs.extendedTrims;
+  node["throttleReversed"] = rhs.throttleReversed;
+
+  // flightModeData[]
+  // mixData[]
+  // limitData[]
+  // inputNames[]
+  // expoData[]
+  // curves[]
+  // logicalSw[]
+  // customFn[]
+
+  // swashRingData
+  // thrTraceSrc
+  // switchWarningStates
+  // thrTrimSwitch
+  // potsWarningMode
+  // potsWarnEnabled[]
+  // potsWarnPosition[]
+
+  node["displayChecklist"] = rhs.displayChecklist;
+
+  // gvarData[]
+  // mavlink ???
+  // telemetryProtocol ???
+  // frsky
+  // rssiSource
+  // rssiAlarms
+
+  node["trainerMode"] = trainerModeLut << rhs.trainerMode;
+
+  // moduleData[]
+  // scriptData[]
+  // sensorData[]
+
+  node["toplcdTimer"] = rhs.toplcdTimer;
+
+  // customScreens
+  // topBarData
+  node["view"] = rhs.view;
+  node["modelRegistrationID"] = rhs.registrationId;
+
+  return node;
+}
+
+bool convert<ModelData>::decode(const Node& node, ModelData& rhs)
+{
+  if (!node.IsMap()) return false;
+
+  if (node["header"]) {
+    const auto& header = node["header"];
+    if (!header.IsMap()) return false;
+
+    header["name"] >> rhs.name;
+    header["bitmap"] >> rhs.bitmap;
+    // TODO: modelId
+  }
+
+  if (node["timers"]) {
+    const auto& timers = node["timers"];
+    if (!timers.IsMap()) return false;
+    timers >> rhs.timers;
+  }
+
+  node["noGlobalFunctions"] >> rhs.noGlobalFunctions;
+  node["thrTrim"] >> rhs.thrTrim;
+  node["trimInc"] >> rhs.trimInc;
+  node["displayTrims"] >> rhs.trimsDisplay;
+  node["disableThrottleWarning"] >> rhs.disableThrottleWarning;
+  // node[] >> rhs.beepANACenter;
+  node["extendedLimits"] >> rhs.extendedLimits;
+  node["extendedTrims"] >> rhs.extendedTrims;
+  node["throttleReversed"] >> rhs.throttleReversed;
+
+  // flightModeData[]
+  // mixData[]
+  // limitData[]
+  // inputNames[]
+  // expoData[]
+  // curves[]
+  // logicalSw[]
+  // customFn[]
+
+  // swashRingData
+  // thrTraceSrc
+  // switchWarningStates
+  // thrTrimSwitch
+  // potsWarningMode
+  // potsWarnEnabled[]
+  // potsWarnPosition[]
+
+  node["displayChecklist"] >> rhs.displayChecklist;
+
+  // gvarData[]
+  // mavlink ???
+  // telemetryProtocol ???
+  // frsky
+  // rssiSource
+  // rssiAlarms
+
+  node["trainerMode"] >> trainerModeLut >> rhs.trainerMode;
+
+  // moduleData[]
+  // scriptData[]
+  // sensorData[]
+
+  node["toplcdTimer"] >> rhs.toplcdTimer;
+
+  // customScreens
+  // topBarData
+  node["view"] >> rhs.view;
+  node["modelRegistrationID"] >> rhs.registrationId;
+
+  return true;
+}
+
+}  // namespace YAML
diff --git a/companion/src/firmwares/edgetx/yaml_modeldata.h b/companion/src/firmwares/edgetx/yaml_modeldata.h
index afdee120f..5150d25da 100644
--- a/companion/src/firmwares/edgetx/yaml_modeldata.h
+++ b/companion/src/firmwares/edgetx/yaml_modeldata.h
@@ -25,118 +25,17 @@
 
 #include <string>
 
-extern const YamlLookupTable timerModeLut;
-extern const YamlLookupTable trainerModeLut;
-
-// extern const YamlLookupTable backlightModeLut;
-// extern const YamlLookupTable bluetoothModeLut;
-// extern const YamlLookupTable uartModeLut;
-// extern const YamlLookupTable antennaModeLut;
-
 namespace YAML {
 
-// ENUM_CONVERTER(GeneralSettings::BeeperMode, beeperModeLut);
-
 template <>
 struct convert<TimerData> {
-  // static YAML::Node encode(const GeneralSettings& rhs) {
-  //       Node node;
-  //       // TODO: convert struct into Node
-  //       return node;
-  // }
-
-  static bool decode(const Node& node, TimerData& rhs)
-  {
-    node["swtch"] >> rhs.swtch;
-    node["mode"] >> timerModeLut >> rhs.mode;
-    node["name"] >> rhs.name;
-    node["minuteBeep"] >> rhs.minuteBeep;
-    node["countdownBeep"] >> rhs.countdownBeep;
-    node["start"] >> rhs.val;
-    node["persistent"] >> rhs.persistent;
-    node["countdownStart"] >> rhs.countdownStart;
-    node["value"] >> rhs.pvalue;
-    return true;
-  }
+  static Node encode(const TimerData& rhs);
+  static bool decode(const Node& node, TimerData& rhs);
 };
 
 template <>
 struct convert<ModelData> {
-  // static YAML::Node encode(const GeneralSettings& rhs) {
-  //       Node node;
-  //       // TODO: convert struct into Node
-  //       return node;
-  // }
-
-  static bool decode(const Node& node, ModelData& rhs)
-  {
-    if (!node.IsMap()) return false;
-
-    if (node["header"]) {
-      const auto& header = node["header"];
-      if (!header.IsMap()) return false;
-
-      header["name"] >> rhs.name;
-      header["bitmap"] >> rhs.bitmap;
-      // TODO: modelId
-    }
-
-    if (node["timers"]) {
-      const auto& timers = node["timers"];
-      if (!timers.IsMap()) return false;
-      timers >> rhs.timers;
-    }
-
-    node["noGlobalFunctions"] >> rhs.noGlobalFunctions;
-    node["thrTrim"] >> rhs.thrTrim;
-    node["trimInc"] >> rhs.trimInc;
-    node["displayTrims"] >> rhs.trimsDisplay;
-    node["disableThrottleWarning"] >> rhs.disableThrottleWarning;
-    //node[] >> rhs.beepANACenter;
-    node["extendedLimits"] >> rhs.extendedLimits;
-    node["extendedTrims"] >> rhs.extendedTrims;
-    node["throttleReversed"] >> rhs.throttleReversed;
-
-    //flightModeData[]
-    //mixData[]
-    //limitData[]
-    //inputNames[]
-    //expoData[]
-    //curves[]
-    //logicalSw[]
-    //customFn[]
-
-    //swashRingData
-    //thrTraceSrc
-    //switchWarningStates
-    //thrTrimSwitch
-    //potsWarningMode
-    //potsWarnEnabled[]
-    //potsWarnPosition[]
-
-    node["displayChecklist"] >> rhs.displayChecklist;
-
-    //gvarData[]
-    //mavlink ???
-    //telemetryProtocol ???
-    //frsky
-    //rssiSource
-    //rssiAlarms
-
-    node["trainerMode"] >> trainerModeLut >> rhs.trainerMode;
-
-    //moduleData[]
-    //scriptData[]
-    //sensorData[]
-
-    node["toplcdTimer"] >> rhs.toplcdTimer;
-
-    //customScreens
-    //topBarData
-    node["view"] >> rhs.view;
-    node["modelRegistrationID"] >> rhs.registrationId;
-    
-    return true;
-  }
+  static Node encode(const ModelData& rhs);
+  static bool decode(const Node& node, ModelData& rhs);
 };
 }  // namespace YAML
diff --git a/companion/src/firmwares/edgetx/yaml_ops.cpp b/companion/src/firmwares/edgetx/yaml_ops.cpp
index 4cb877175..ed7983fb3 100644
--- a/companion/src/firmwares/edgetx/yaml_ops.cpp
+++ b/companion/src/firmwares/edgetx/yaml_ops.cpp
@@ -56,7 +56,7 @@ void operator >> (const YAML::Node& node, bool& value)
 
 namespace YAML {
 
-Node operator << (const YamlLookupTable& lut, const int& value)
+std::string LookupValue(const YamlLookupTable& lut, const int& value)
 {
   const auto& it =
     find_if(lut.begin(), lut.end(), [=](const YamlLookupTableElmt& elmt) {
@@ -65,7 +65,17 @@ Node operator << (const YamlLookupTable& lut, const int& value)
       });
   
   if (it != lut.end()) {
-    return Node(it->second);
+    return it->second;
+  }
+
+  return std::string();
+}
+
+Node operator << (const YamlLookupTable& lut, const int& value)
+{
+  std::string str = LookupValue(lut, value);
+  if (!str.empty()) {
+    return Node(str);
   }
   return Node();
 }
diff --git a/companion/src/firmwares/edgetx/yaml_ops.h b/companion/src/firmwares/edgetx/yaml_ops.h
index 9b5c81d26..52f90082a 100644
--- a/companion/src/firmwares/edgetx/yaml_ops.h
+++ b/companion/src/firmwares/edgetx/yaml_ops.h
@@ -113,6 +113,7 @@ void operator>>(const YAML::Node& node, T (&value)[N])
 
 namespace YAML {
 
+std::string LookupValue(const YamlLookupTable& lut, const int& value);
 Node operator << (const YamlLookupTable& lut, const int& value);
 
 template <typename T>
diff --git a/companion/src/firmwares/edgetx/yaml_rawswitch.cpp b/companion/src/firmwares/edgetx/yaml_rawswitch.cpp
index 4794dc2f4..9bad86be9 100644
--- a/companion/src/firmwares/edgetx/yaml_rawswitch.cpp
+++ b/companion/src/firmwares/edgetx/yaml_rawswitch.cpp
@@ -50,6 +50,55 @@ namespace YAML {
 
 ENUM_CONVERTER(RawSwitchType, switchTypeLut);
 
+Node convert<RawSwitch>::encode(const RawSwitch& rhs)
+{
+  std::string sw_str;
+
+  int32_t sval = rhs.index;
+  if (rhs.index < 0) {
+    sval = -sval;
+    sw_str += "!";
+  }
+
+  switch (rhs.type) {
+  case SWITCH_TYPE_SWITCH:
+    sw_str += 'S';
+    sw_str += 'A' + sval;
+    break;
+
+  case SWITCH_TYPE_VIRTUAL:
+    sw_str += "L";
+    sw_str += std::to_string(sval + 1);
+    break;
+
+  case SWITCH_TYPE_MULTIPOS_POT:
+    sw_str += "6P";
+    sw_str += std::to_string(sval / XPOTS_MULTIPOS_COUNT);
+    sw_str += std::to_string(sval % XPOTS_MULTIPOS_COUNT);
+    break;
+
+  case SWITCH_TYPE_TRIM:
+    sw_str += LookupValue(trimSwitchLut, sval);
+    break;
+
+  case SWITCH_TYPE_FLIGHT_MODE:
+    sw_str += "FM";
+    sw_str += std::to_string(sval);
+    break;
+
+  case SWITCH_TYPE_SENSOR:
+    sw_str += "T";
+    sw_str += std::to_string(sval + 1);
+    break;
+
+  default:
+    sw_str += LookupValue(switchTypeLut, rhs.type);
+    break;
+  }
+
+  return Node(sw_str);
+}
+
 bool convert<RawSwitch>::decode(const Node& node, RawSwitch& rhs)
 {
   const std::string& sw_str = node.Scalar();
diff --git a/companion/src/firmwares/edgetx/yaml_rawswitch.h b/companion/src/firmwares/edgetx/yaml_rawswitch.h
index ce0031e57..95128aac2 100644
--- a/companion/src/firmwares/edgetx/yaml_rawswitch.h
+++ b/companion/src/firmwares/edgetx/yaml_rawswitch.h
@@ -25,7 +25,7 @@ namespace YAML {
 
 template <>
 struct convert<RawSwitch> {
-  // static YAML::Node encode(const GeneralSettings& rhs);
+  static Node encode(const RawSwitch& rhs);
   static bool decode(const Node& node, RawSwitch& rhs);
 };
 
diff --git a/companion/src/storage/categorized.cpp b/companion/src/storage/categorized.cpp
index 420a9b666..a32442587 100644
--- a/companion/src/storage/categorized.cpp
+++ b/companion/src/storage/categorized.cpp
@@ -290,5 +290,30 @@ bool CategorizedStorageFormat::writeYaml(const RadioData & radioData)
     return false;
   }
 
-  return writeFile(radioSettingsBuffer, "RADIO/radio.yml");
+  if (!writeFile(radioSettingsBuffer, "RADIO/radio.yml")) {
+    return false;
+  }
+
+  EtxModelfiles modelFiles;
+  for (const auto& model : radioData.models) {
+
+    // TODO: verify '.yml' (in case we moved from '.bin') 
+    QString modelFilename = QString("MODELS/%1").arg(model.filename);
+    QByteArray modelData;
+    writeModelToYaml(model, modelData);
+    if (!writeFile(modelData, modelFilename)) {
+      return false;
+    }
+
+    modelFiles.push_back({ std::string(model.filename), model.category });
+  }
+
+  // TODO: sort 'modelFiles' by category index
+  QByteArray modelslistBuffer;
+  if (!writeModelsListToYaml(radioData.categories, modelFiles, modelslistBuffer)
+      || writeFile(modelslistBuffer, "MODELS/models.yml")) {
+    return false;
+  }
+
+  return true;
 }