diff --git a/mario/maploader.cpp b/mario/maploader.cpp
index 5b0c56d..697e1f0 100644
--- a/mario/maploader.cpp
+++ b/mario/maploader.cpp
@@ -10,6 +10,13 @@
 #define TERRAIN_TYPE_HAS_ADDITIONAL 0x8
 #define WIDE_TERRAIN_HAS_ADDITIONAL 0x8000
 #define ADDITIONAL_IS_MOD 0x80
+#define FILE_VERSION 0x01
+
+void loadMapV01(std::shared_ptr<SDLPP::Scene> &scene,
+             std::shared_ptr<SDLPP::RenderObject> &mario,
+             std::ifstream &map_file, std::vector<mapColumnType> &objects,
+             bool editor, size_t editor_width,
+             std::shared_ptr<SDLPP::Renderer> &renderer);
 
 void loadMap(std::shared_ptr<SDLPP::Scene> &scene,
              std::shared_ptr<SDLPP::RenderObject> mario,
@@ -48,12 +55,14 @@ std::pair<uint8_t, uint8_t> separateAdditionalData(uint8_t data) {
     auto type = (data & 0xF0) >> 4;
     return { id, type };
 }
+
 uint16_t combineTerrain(uint16_t id, uint8_t type) {
     uint16_t wide_terrain = type;
     wide_terrain = wide_terrain << 12;
     wide_terrain |= 0x0FFF & id;
     return wide_terrain;
 }
+
 uint8_t combineAdditionalData(uint8_t id, uint8_t type) {
     return type << 4 | id;
 }
@@ -73,9 +82,8 @@ MapObject parseBlock(std::ifstream &map_file) {
         if (additional_data & ADDITIONAL_IS_MOD) {
             additional_data &= ~ADDITIONAL_IS_MOD;
             auto modifier = separateAdditionalData(additional_data);
-            // TODO swap modifier id and data
-            modifier_id = modifier.second | 0x6000;
-            modifier_data = modifier.first;
+            modifier_id = modifier.first | 0x6000;
+            modifier_data = modifier.second;
         } else {
             // character
             auto character = separateAdditionalData(additional_data);
@@ -88,6 +96,7 @@ MapObject parseBlock(std::ifstream &map_file) {
 }
 
 // editor loader
+// TODO catch exception in calling functions
 void loadMap(std::shared_ptr<SDLPP::Scene> &scene,
              std::shared_ptr<SDLPP::RenderObject> &mario,
              const std::string &file, std::vector<mapColumnType> &objects,
@@ -95,6 +104,26 @@ void loadMap(std::shared_ptr<SDLPP::Scene> &scene,
     auto renderer = scene->getRendererShared();
     std::ifstream map_file;
     map_file.open(file, std::ios::in | std::ios::binary);
+    if(!map_file.is_open()) {
+        objects.resize(editor_width);
+        return;
+    }
+    uint16_t version;
+    map_file.read((char *)&version, sizeof(uint16_t) / sizeof(char));
+    switch(version) {
+        case 0x01:
+            loadMapV01(scene, mario, map_file, objects, editor, editor_width, renderer);
+            break;
+        default:
+            throw "Invalid file version";
+    }
+}
+
+void loadMapV01(std::shared_ptr<SDLPP::Scene> &scene,
+             std::shared_ptr<SDLPP::RenderObject> &mario,
+             std::ifstream &map_file, std::vector<mapColumnType> &objects,
+             bool editor, size_t editor_width,
+             std::shared_ptr<SDLPP::Renderer> &renderer) {
     uint16_t cols;
     map_file.read((char *)&cols, sizeof(uint16_t) / sizeof(char));
     if (editor) {
@@ -187,12 +216,19 @@ void loadMap(std::shared_ptr<SDLPP::Scene> &scene,
     if (editor && objects.size() < editor_width) {
         objects.resize(editor_width);
     }
+
 }
 
+// TODO catch exception in calling func
 void saveMap(const std::string &file, std::vector<mapColumnType> &objects) {
     std::ofstream output_file;
     output_file.open(file, std::ios::out | std::ios::binary);
-    uint16_t cols = objects.size();
+    if(!output_file.is_open()) {
+        throw "Could not open file '" + file + "'";
+    }
+    const uint16_t version = FILE_VERSION;
+    output_file.write((char *)&version, sizeof(uint16_t) / sizeof(char));
+    const uint16_t cols = objects.size();
     output_file.write((char *)&cols, sizeof(uint16_t) / sizeof(char));
     for (auto &col : objects) {
         for (int i = 0; i < 16; i++) {
@@ -209,11 +245,10 @@ void saveMap(const std::string &file, std::vector<mapColumnType> &objects) {
                 additional_data = combineAdditionalData(
                     block.getCharacterId(), block.getCharacterType());
             } else if (block.hasModifier()) {
-                // TODO seriously change order of id/data!!!
                 // we have IDs like 0x600X but only X is useful data, the 0x6 at
                 // the beginning is to differentiate mods from characters
                 additional_data = combineAdditionalData(
-                    block.getModifierData(), block.getModifierId() & 0x000F);
+                    block.getModifierId() & 0x000F, block.getModifierData());
                 additional_data |= ADDITIONAL_IS_MOD;
             }
             if (additional_data) {