diff --git a/Makefile b/Makefile
index 95a9007..fb02c44 100644
--- a/Makefile
+++ b/Makefile
@@ -1,10 +1,10 @@
 
 CC 		:= emcc
 CXX 		:= emcc
-CXXFLAGS	:= -c -fbracket-depth=4800 -O3 -std=c++17 -D NDEBUG=1 -msimd128
+CXXFLAGS	:= -c -fbracket-depth=4800 -O3 -std=c++17 -msimd128
 INCLUDES 	:= -I src/nba/include/ -I src/nba/src
 LDFLAGS 	:= -s ENVIRONMENT=web -s ASSERTIONS=0 -s FILESYSTEM=0 -s STANDALONE_WASM=1 -s ALLOW_MEMORY_GROWTH\
-		   -s EXPORTED_FUNCTIONS=[_getOutput,_cyclePerFrame,_getRom,_getIRam,_getWRam,_go,_run,_main] --lto
+		   -s EXPORTED_FUNCTIONS=[_replay,_getOutput,_cyclePerFrame,_getRom,_getIRam,_getWRam,_go,_run,_main] --lto
 BUILD 		:= build
 OBJECTS		:= $(BUILD)/000-serialization.o $(BUILD)/001-tablegen.o $(BUILD)/002-bus.o \
 		   $(BUILD)/003-io.o $(BUILD)/004-serialization.o $(BUILD)/005-timing.o \
diff --git a/src/nba/include/nba/rom/backup/backup_file.hpp b/src/nba/include/nba/rom/backup/backup_file.hpp
index 6ba8cdf..9f472fb 100644
--- a/src/nba/include/nba/rom/backup/backup_file.hpp
+++ b/src/nba/include/nba/rom/backup/backup_file.hpp
@@ -40,14 +40,14 @@ struct BackupFile {
       auto end = valid_sizes.end();
 
       if(std::find(begin, end, save_size) != end) {
-        file->stream.open(save_path.c_str(), flags);
-        if(file->stream.fail()) {
-          throw std::runtime_error("BackupFile: unable to open file: " + save_path.string());
-        }
+        // file->stream.open(save_path.c_str(), flags);
+        // if(file->stream.fail()) {
+        //   throw std::runtime_error("BackupFile: unable to open file: " + save_path.string());
+        // }
         default_size = save_size;
         file->save_size = save_size;
         file->memory.reset(new u8[file_size]);
-        file->stream.read((char*)file->memory.get(), file_size);
+        // file->stream.read((char*)file->memory.get(), file_size);
         create = false;
       }
     }
@@ -57,10 +57,10 @@ struct BackupFile {
      */
     if(create) {
       file->save_size = default_size;
-      file->stream.open(save_path, flags | std::ios::trunc);
-      if(file->stream.fail()) {
-        throw std::runtime_error("BackupFile: unable to create file: " + save_path.string());
-      }
+      // file->stream.open(save_path, flags | std::ios::trunc);
+      // if(file->stream.fail()) {
+      //   throw std::runtime_error("BackupFile: unable to create file: " + save_path.string());
+      // }
       file->memory.reset(new u8[default_size]);
       file->MemorySet(0, default_size, 0xFF);
     }
@@ -99,8 +99,8 @@ struct BackupFile {
     if((index + length) > save_size) {
       throw std::runtime_error("BackupFile: out-of-bounds index while updating file.");
     }
-    stream.seekg(index);
-    stream.write((char*)&memory[index], length);
+    // stream.seekg(index);
+    // stream.write((char*)&memory[index], length);
   }
 
   auto Buffer() -> u8* {
diff --git a/src/wasm/module.cpp b/src/wasm/module.cpp
index d51adf6..7be7a9a 100644
--- a/src/wasm/module.cpp
+++ b/src/wasm/module.cpp
@@ -175,6 +175,36 @@ void go( u32 framecount, u32 input )
     run(framecount * cyclePerFrame(), input);
 }
 
+void replay()
+{
+    // new backup
+    auto backup = std::unique_ptr<nba::Backup>{};
+    auto gpio = std::unique_ptr<nba::GPIO>{};
+
+    if( backup_value[0] == 0 ) return;
+    
+    vm->Reset();
+    if( backup_value[0] == 1 ) 
+    {
+        backup = std::make_unique<nba::SRAM>( fs::path{"/"} );
+    }
+    else if( backup_value[0] == 2 ) 
+    {
+        backup = std::make_unique<nba::FLASH>( fs::path{"/"}, backup_value[1] > 64*1024 ? nba::FLASH::Size::SIZE_128K : nba::FLASH::Size::SIZE_128K );
+    }
+    else if( backup_value[0] == 3 )
+    {
+        backup = std::make_unique<nba::EEPROM>( fs::path{"/"}, backup_value[1] > 8*1024 ? nba::EEPROM::Size::SIZE_64K : nba::EEPROM::Size::SIZE_4K, vm->GetScheduler() );
+    }
+
+    if( backup_value[2] ){
+        gpio->Attach( vm->CreateRTC() );
+    }
+
+    vm->Attach( nba::ROM(std::vector<u8>(game_data, game_data+data_size), std::move(backup), std::move(gpio), 0xffff'ffff) );
+    vm->Reset();
+}
+
 }
 
 #if __EMSCRIPTEN__