diff --git a/src/NDS.cpp b/src/NDS.cpp
index 346bcb7d..1bb17fee 100644
--- a/src/NDS.cpp
+++ b/src/NDS.cpp
@@ -1161,8 +1161,6 @@ u32 RunFrame()
             GPU3D::Timestamp-SysTimestamp);
 #endif
         SPU::TransferOutput();
-
-        //NDSCart::FlushSRAMFile();
     }
 
     // In the context of TASes, frame count is traditionally the primary measure of emulated time,
diff --git a/src/NDSCart.cpp b/src/NDSCart.cpp
index b78366b1..c24111a3 100644
--- a/src/NDSCart.cpp
+++ b/src/NDSCart.cpp
@@ -672,6 +672,7 @@ u8 CartRetail::SRAMWrite_EEPROMTiny(u8 val, u32 pos, bool last)
         if (pos < 2)
         {
             SRAMAddr = val;
+            SRAMFirstAddr = SRAMAddr;
         }
         else
         {
@@ -679,11 +680,15 @@ u8 CartRetail::SRAMWrite_EEPROMTiny(u8 val, u32 pos, bool last)
             if (SRAMStatus & (1<<1))
             {
                 SRAM[(SRAMAddr + ((SRAMCmd==0x0A)?0x100:0)) & 0x1FF] = val;
-                SRAMFileDirty |= last;
             }
             SRAMAddr++;
         }
-        if (last) SRAMStatus &= ~(1<<1);
+        if (last)
+        {
+            SRAMStatus &= ~(1<<1);
+            Platform::WriteNDSSave(SRAM, SRAMLength,
+                                   (SRAMFirstAddr + ((SRAMCmd==0x0A)?0x100:0)) & 0x1FF, SRAMAddr-SRAMFirstAddr);
+        }
         return 0;
 
     case 0x03: // read low
@@ -731,6 +736,7 @@ u8 CartRetail::SRAMWrite_EEPROM(u8 val, u32 pos, bool last)
         {
             SRAMAddr <<= 8;
             SRAMAddr |= val;
+            SRAMFirstAddr = SRAMAddr;
         }
         else
         {
@@ -738,11 +744,15 @@ u8 CartRetail::SRAMWrite_EEPROM(u8 val, u32 pos, bool last)
             if (SRAMStatus & (1<<1))
             {
                 SRAM[SRAMAddr & (SRAMLength-1)] = val;
-                SRAMFileDirty |= last;
             }
             SRAMAddr++;
         }
-        if (last) SRAMStatus &= ~(1<<1);
+        if (last)
+        {
+            SRAMStatus &= ~(1<<1);
+            Platform::WriteNDSSave(SRAM, SRAMLength,
+                                   SRAMFirstAddr & (SRAMLength-1), SRAMAddr-SRAMFirstAddr);
+        }
         return 0;
 
     case 0x03: // read
@@ -783,6 +793,7 @@ u8 CartRetail::SRAMWrite_FLASH(u8 val, u32 pos, bool last)
         {
             SRAMAddr <<= 8;
             SRAMAddr |= val;
+            SRAMFirstAddr = SRAMAddr;
         }
         else
         {
@@ -790,11 +801,15 @@ u8 CartRetail::SRAMWrite_FLASH(u8 val, u32 pos, bool last)
             {
                 // CHECKME: should it be &=~val ??
                 SRAM[SRAMAddr & (SRAMLength-1)] = 0;
-                SRAMFileDirty |= last;
             }
             SRAMAddr++;
         }
-        if (last) SRAMStatus &= ~(1<<1);
+        if (last)
+        {
+            SRAMStatus &= ~(1<<1);
+            Platform::WriteNDSSave(SRAM, SRAMLength,
+                                   SRAMFirstAddr & (SRAMLength-1), SRAMAddr-SRAMFirstAddr);
+        }
         return 0;
 
     case 0x03: // read
@@ -816,17 +831,22 @@ u8 CartRetail::SRAMWrite_FLASH(u8 val, u32 pos, bool last)
         {
             SRAMAddr <<= 8;
             SRAMAddr |= val;
+            SRAMFirstAddr = SRAMAddr;
         }
         else
         {
             if (SRAMStatus & (1<<1))
             {
                 SRAM[SRAMAddr & (SRAMLength-1)] = val;
-                SRAMFileDirty |= last;
             }
             SRAMAddr++;
         }
-        if (last) SRAMStatus &= ~(1<<1);
+        if (last)
+        {
+            SRAMStatus &= ~(1<<1);
+            Platform::WriteNDSSave(SRAM, SRAMLength,
+                                   SRAMFirstAddr & (SRAMLength-1), SRAMAddr-SRAMFirstAddr);
+        }
         return 0;
 
     case 0x0B: // fast read
@@ -857,6 +877,7 @@ u8 CartRetail::SRAMWrite_FLASH(u8 val, u32 pos, bool last)
         {
             SRAMAddr <<= 8;
             SRAMAddr |= val;
+            SRAMFirstAddr = SRAMAddr;
         }
         if ((pos == 3) && (SRAMStatus & (1<<1)))
         {
@@ -865,9 +886,13 @@ u8 CartRetail::SRAMWrite_FLASH(u8 val, u32 pos, bool last)
                 SRAM[SRAMAddr & (SRAMLength-1)] = 0;
                 SRAMAddr++;
             }
-            SRAMFileDirty = true;
         }
-        if (last) SRAMStatus &= ~(1<<1);
+        if (last)
+        {
+            SRAMStatus &= ~(1<<1);
+            Platform::WriteNDSSave(SRAM, SRAMLength,
+                                   SRAMFirstAddr & (SRAMLength-1), SRAMAddr-SRAMFirstAddr);
+        }
         return 0;
 
     case 0xDB: // page erase
@@ -875,6 +900,7 @@ u8 CartRetail::SRAMWrite_FLASH(u8 val, u32 pos, bool last)
         {
             SRAMAddr <<= 8;
             SRAMAddr |= val;
+            SRAMFirstAddr = SRAMAddr;
         }
         if ((pos == 3) && (SRAMStatus & (1<<1)))
         {
@@ -883,9 +909,13 @@ u8 CartRetail::SRAMWrite_FLASH(u8 val, u32 pos, bool last)
                 SRAM[SRAMAddr & (SRAMLength-1)] = 0;
                 SRAMAddr++;
             }
-            SRAMFileDirty = true;
         }
-        if (last) SRAMStatus &= ~(1<<1);
+        if (last)
+        {
+            SRAMStatus &= ~(1<<1);
+            Platform::WriteNDSSave(SRAM, SRAMLength,
+                                   SRAMFirstAddr & (SRAMLength-1), SRAMAddr-SRAMFirstAddr);
+        }
         return 0;
 
     default:
@@ -974,7 +1004,7 @@ int CartRetailNAND::ROMCommandStart(u8* cmd, u8* data, u32 len)
             if (SRAMLength && SRAMAddr < (SRAMBase+SRAMLength-0x20000))
             {
                 memcpy(&SRAM[SRAMAddr - SRAMBase], SRAMWriteBuffer, 0x800);
-                SRAMFileDirty = true;
+                Platform::WriteNDSSave(SRAM, SRAMLength, SRAMAddr - SRAMBase, 0x800);
             }
 
             SRAMAddr = 0;
diff --git a/src/NDSCart.h b/src/NDSCart.h
index a059b2db..37290ee1 100644
--- a/src/NDSCart.h
+++ b/src/NDSCart.h
@@ -99,11 +99,9 @@ protected:
     u32 SRAMLength;
     u32 SRAMType;
 
-    char SRAMPath[1024];
-    bool SRAMFileDirty;
-
     u8 SRAMCmd;
     u32 SRAMAddr;
+    u32 SRAMFirstAddr;
     u8 SRAMStatus;
 };
 
diff --git a/src/Platform.h b/src/Platform.h
index ec3e0022..aefbf4b0 100644
--- a/src/Platform.h
+++ b/src/Platform.h
@@ -145,8 +145,11 @@ void Mutex_Unlock(Mutex* mutex);
 bool Mutex_TryLock(Mutex* mutex);
 
 
-void WriteNDSSave(const u8* savedata, u32 savelen);
-void WriteGBASave(const u8* savedata, u32 savelen);
+// functions called when the NDS or GBA save files need to be written back to storage
+// savedata and savelen are always the entire save memory buffer and its full length
+// writeoffset and writelen indicate which part of the memory was altered
+void WriteNDSSave(const u8* savedata, u32 savelen, u32 writeoffset, u32 writelen);
+void WriteGBASave(const u8* savedata, u32 savelen, u32 writeoffset, u32 writelen);
 
 
 // local multiplayer comm interface
diff --git a/src/frontend/qt_sdl/CMakeLists.txt b/src/frontend/qt_sdl/CMakeLists.txt
index 634a2c88..2207e4d5 100644
--- a/src/frontend/qt_sdl/CMakeLists.txt
+++ b/src/frontend/qt_sdl/CMakeLists.txt
@@ -25,7 +25,7 @@ SET(SOURCES_QT_SDL
     font.h
     Platform.cpp
     QPathInput.h
-	ROMLoader.cpp
+	ROMManager.cpp
 	SaveManager.cpp
     
     ArchiveUtil.h
diff --git a/src/frontend/qt_sdl/Platform.cpp b/src/frontend/qt_sdl/Platform.cpp
index 843a228b..ebfe6af6 100644
--- a/src/frontend/qt_sdl/Platform.cpp
+++ b/src/frontend/qt_sdl/Platform.cpp
@@ -52,6 +52,7 @@
 
 #include "Platform.h"
 #include "Config.h"
+#include "ROMManager.h"
 #include "LAN_Socket.h"
 #include "LAN_PCap.h"
 #include <string>
@@ -372,12 +373,13 @@ bool Mutex_TryLock(Mutex* mutex)
 }
 
 
-void WriteNDSSave(const u8* savedata, u32 savelen)
+void WriteNDSSave(const u8* savedata, u32 savelen, u32 writeoffset, u32 writelen)
 {
-    //
+    if (ROMManager::NDSSave)
+        ROMManager::NDSSave->RequestFlush(savedata, savelen, writeoffset, writelen);
 }
 
-void WriteGBASave(const u8* savedata, u32 savelen)
+void WriteGBASave(const u8* savedata, u32 savelen, u32 writeoffset, u32 writelen)
 {
     //
 }
diff --git a/src/frontend/qt_sdl/ROMLoader.cpp b/src/frontend/qt_sdl/ROMManager.cpp
similarity index 96%
rename from src/frontend/qt_sdl/ROMLoader.cpp
rename to src/frontend/qt_sdl/ROMManager.cpp
index aeaddbe2..650b87a5 100644
--- a/src/frontend/qt_sdl/ROMLoader.cpp
+++ b/src/frontend/qt_sdl/ROMManager.cpp
@@ -25,26 +25,27 @@
 #ifdef ARCHIVE_SUPPORT_ENABLED
 #include "ArchiveUtil.h"
 #endif
-#include "ROMLoader.h"
+#include "ROMManager.h"
 #include "Config.h"
 #include "Platform.h"
 
 #include "NDS.h"
 #include "DSi.h"
-#include "GBACart.h"
 
 #include "AREngine.h"
 
 
-namespace ROMLoader
+namespace ROMManager
 {
 
-std::string FullROMPath;
-std::string BaseROMDir;
-std::string BaseROMName;
-std::string BaseAssetName;
+std::string FullROMPath = "";
+std::string BaseROMDir = "";
+std::string BaseROMName = "";
+std::string BaseAssetName = "";
 
-int GBACartType;
+int GBACartType = -1;
+
+SaveManager* NDSSave = nullptr;
 
 
 int LastSep(std::string path)
@@ -280,6 +281,9 @@ bool LoadBIOS()
     if (NDS::NeedsDirectBoot())
         return false;
 
+    if (NDSSave) delete NDSSave;
+    NDSSave = nullptr;
+
     FullROMPath = "";
     BaseROMDir = "";
     BaseROMName = "";
@@ -362,6 +366,9 @@ bool LoadROM(QStringList filepath, bool reset)
     else
         return false;
 
+    if (NDSSave) delete NDSSave;
+    NDSSave = nullptr;
+
     FullROMPath = fullpath;
     BaseROMDir = basepath;
     BaseROMName = romname;
@@ -398,6 +405,11 @@ bool LoadROM(QStringList filepath, bool reset)
         }
     }
 
+    if (res)
+    {
+        NDSSave = new SaveManager(savname);
+    }
+
     delete[] savedata;
     delete[] filedata;
     return res;
@@ -405,6 +417,9 @@ bool LoadROM(QStringList filepath, bool reset)
 
 void EjectCart()
 {
+    if (NDSSave) delete NDSSave;
+    NDSSave = nullptr;
+
     NDS::EjectCart();
 
     FullROMPath = "";
@@ -456,6 +471,8 @@ QString GBACartLabel()
 
 
 
+
+
 void ROMIcon(u8 (&data)[512], u16 (&palette)[16], u32* iconRef)
 {
     int index = 0;
diff --git a/src/frontend/qt_sdl/ROMLoader.h b/src/frontend/qt_sdl/ROMManager.h
similarity index 91%
rename from src/frontend/qt_sdl/ROMLoader.h
rename to src/frontend/qt_sdl/ROMManager.h
index 723ce815..c6e7837a 100644
--- a/src/frontend/qt_sdl/ROMLoader.h
+++ b/src/frontend/qt_sdl/ROMManager.h
@@ -16,17 +16,20 @@
     with melonDS. If not, see http://www.gnu.org/licenses/.
 */
 
-#ifndef ROMLOADER_H
-#define ROMLOADER_H
+#ifndef ROMMANAGER_H
+#define ROMMANAGER_H
 
 #include "types.h"
+#include "SaveManager.h"
 
 #include <string>
 #include <vector>
 
-namespace ROMLoader
+namespace ROMManager
 {
 
+extern SaveManager* NDSSave;
+
 QString VerifySetup();
 void Reset();
 bool LoadBIOS();
@@ -81,4 +84,4 @@ enum
 
 }
 
-#endif // ROMLOADER_H
+#endif // ROMMANAGER_H
diff --git a/src/frontend/qt_sdl/SaveManager.cpp b/src/frontend/qt_sdl/SaveManager.cpp
index 968797c8..05200f88 100644
--- a/src/frontend/qt_sdl/SaveManager.cpp
+++ b/src/frontend/qt_sdl/SaveManager.cpp
@@ -23,12 +23,29 @@
 #include "Platform.h"
 
 
-SaveManager::SaveManager()
+SaveManager::SaveManager(std::string path) : QThread()
 {
     SecondaryBuffer = nullptr;
+    SecondaryBufferLength = 0;
     SecondaryBufferLock = new QMutex();
 
     Running = false;
+
+    Path = path;
+
+    Buffer = nullptr;
+    Length = 0;
+    FlushRequested = false;
+
+    FlushVersion = 0;
+    PreviousFlushVersion = 0;
+    TimeAtLastFlushRequest = 0;
+
+    if (!path.empty())
+    {
+        Running = true;
+        start();
+    }
 }
 
 SaveManager::~SaveManager()
@@ -43,49 +60,59 @@ SaveManager::~SaveManager()
     if (SecondaryBuffer) delete[] SecondaryBuffer;
 
     delete SecondaryBufferLock;
+
+    if (Buffer) delete[] Buffer;
 }
 
-void SaveManager::Setup(std::string path, u8* buffer, u32 length)
+void SaveManager::RequestFlush(const u8* savedata, u32 savelen, u32 writeoffset, u32 writelen)
 {
-    // Flush SRAM in case there is unflushed data from previous state.
-    FlushSecondaryBuffer();
-
-    SecondaryBufferLock->lock();
-
-    Path = path;
-
-    Buffer = buffer;
-    Length = length;
-
-    if(SecondaryBuffer) delete[] SecondaryBuffer; // Delete secondary buffer, there might be previous state.
-
-    SecondaryBuffer = new u8[length];
-    SecondaryBufferLength = length;
-
-    FlushVersion = 0;
-    PreviousFlushVersion = 0;
-    TimeAtLastFlushRequest = 0;
-
-    SecondaryBufferLock->unlock();
-
-    if ((!path.empty()) && (!Running))
+    if (Length != savelen)
     {
-        Running = true;
-        start();
+        if (Buffer) delete[] Buffer;
+
+        Length = savelen;
+        Buffer = new u8[Length];
+
+        memcpy(Buffer, savedata, Length);
     }
-    else if (path.empty() && Running)
+    else
     {
-        Running = false;
-        wait();
+        if ((writeoffset+writelen) > savelen)
+        {
+            u32 len = savelen - writeoffset;
+            memcpy(&Buffer[writeoffset], &savedata[writeoffset], len);
+            len = writelen - len;
+            if (len > savelen) len = savelen;
+            memcpy(&Buffer[0], &savedata[0], len);
+        }
+        else
+        {
+            memcpy(&Buffer[writeoffset], &savedata[writeoffset], writelen);
+        }
     }
+
+    FlushRequested = true;
 }
 
-void SaveManager::RequestFlush()
+void SaveManager::CheckFlush()
 {
+    if (!FlushRequested) return;
+
     SecondaryBufferLock->lock();
 
     printf("SaveManager: Flush requested\n");
+
+    if (SecondaryBufferLength != Length)
+    {
+        if (SecondaryBuffer) delete[] SecondaryBuffer;
+
+        SecondaryBufferLength = Length;
+        SecondaryBuffer = new u8[SecondaryBufferLength];
+    }
+
     memcpy(SecondaryBuffer, Buffer, Length);
+
+    FlushRequested = false;
     FlushVersion++;
     TimeAtLastFlushRequest = time(nullptr);
 
@@ -112,6 +139,8 @@ void SaveManager::run()
 
 void SaveManager::FlushSecondaryBuffer(u8* dst, u32 dstLength)
 {
+    if (!SecondaryBuffer) return;
+
     // When flushing to a file, there's no point in re-writing the exact same data.
     if (!dst && !NeedsFlush()) return;
     // When flushing to memory, we don't know if dst already has any data so we only check that we CAN flush.
@@ -141,16 +170,3 @@ bool SaveManager::NeedsFlush()
 {
     return FlushVersion != PreviousFlushVersion;
 }
-
-void SaveManager::UpdateBuffer(u8* src, u32 srcLength)
-{
-    if (!src || srcLength != Length) return;
-
-    // should we create a lock for the primary buffer? this method is not intended to be called from a secondary thread in the way Flush is
-    memcpy(Buffer, src, srcLength);
-    SecondaryBufferLock->lock();
-    memcpy(SecondaryBuffer, src, srcLength);
-    SecondaryBufferLock->unlock();
-
-    PreviousFlushVersion = FlushVersion;
-}
diff --git a/src/frontend/qt_sdl/SaveManager.h b/src/frontend/qt_sdl/SaveManager.h
index 2e8b1d79..5f8d36c5 100644
--- a/src/frontend/qt_sdl/SaveManager.h
+++ b/src/frontend/qt_sdl/SaveManager.h
@@ -34,15 +34,14 @@ class SaveManager : public QThread
     void run() override;
 
 public:
-    SaveManager();
+    SaveManager(std::string path);
     ~SaveManager();
 
-    void Setup(std::string path, u8* buffer, u32 length);
-    void RequestFlush();
+    void RequestFlush(const u8* savedata, u32 savelen, u32 writeoffset, u32 writelen);
+    void CheckFlush();
 
     bool NeedsFlush();
     void FlushSecondaryBuffer(u8* dst = nullptr, u32 dstLength = 0);
-    void UpdateBuffer(u8* src, u32 srcLength);
 
 private:
     std::string Path;
@@ -51,6 +50,7 @@ private:
 
     u8* Buffer;
     u32 Length;
+    bool FlushRequested;
 
     QMutex* SecondaryBufferLock;
     u8* SecondaryBuffer;
diff --git a/src/frontend/qt_sdl/main.cpp b/src/frontend/qt_sdl/main.cpp
index 6836a73d..5f340522 100644
--- a/src/frontend/qt_sdl/main.cpp
+++ b/src/frontend/qt_sdl/main.cpp
@@ -81,7 +81,7 @@
 
 #include "main_shaders.h"
 
-#include "ROMLoader.h"
+#include "ROMManager.h"
 #include "ArchiveUtil.h"
 
 // TODO: uniform variable spelling
@@ -543,6 +543,9 @@ void EmuThread::run()
             // emulate
             u32 nlines = NDS::RunFrame();
 
+            if (ROMManager::NDSSave)
+                ROMManager::NDSSave->CheckFlush();
+
             FrontBufferLock.lock();
             FrontBuffer = GPU::FrontBuffer;
 #ifdef OGLRENDERER_ENABLED
@@ -1308,7 +1311,7 @@ MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent)
 
         menu->addSeparator();
 
-        actCurrentCart = menu->addAction("DS slot: " + ROMLoader::CartLabel());
+        actCurrentCart = menu->addAction("DS slot: " + ROMManager::CartLabel());
         actCurrentCart->setEnabled(false);
 
         actInsertCart = menu->addAction("Insert cart...");
@@ -1319,7 +1322,7 @@ MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent)
 
         menu->addSeparator();
 
-        actCurrentGBACart = menu->addAction("GBA slot: " + ROMLoader::GBACartLabel());
+        actCurrentGBACart = menu->addAction("GBA slot: " + ROMManager::GBACartLabel());
         actCurrentGBACart->setEnabled(false);
 
         actInsertGBACart = menu->addAction("Insert ROM cart...");
@@ -2019,7 +2022,7 @@ void MainWindow::loadROM(QString filename)
 
 bool MainWindow::verifySetup()
 {
-    QString res = ROMLoader::VerifySetup();
+    QString res = ROMManager::VerifySetup();
     if (!res.isEmpty())
     {
          QMessageBox::critical(this, "melonDS", res);
@@ -2145,7 +2148,7 @@ void MainWindow::onOpenFile()
 
     // TODO: add to recent ROM list
 
-    if (!ROMLoader::LoadROM(file, true))
+    if (!ROMManager::LoadROM(file, true))
     {
         // TODO: better error reporting?
         QMessageBox::critical(this, "melonDS", "Failed to load the ROM.");
@@ -2156,7 +2159,7 @@ void MainWindow::onOpenFile()
     NDS::Start();
     emuThread->emuRun();
 
-    actCurrentCart->setText("DS slot: " + ROMLoader::CartLabel());
+    actCurrentCart->setText("DS slot: " + ROMManager::CartLabel());
     actEjectCart->setEnabled(true);
 }
 
@@ -2308,7 +2311,7 @@ void MainWindow::onBootFirmware()
         return;
     }
 
-    if (!ROMLoader::LoadBIOS())
+    if (!ROMManager::LoadBIOS())
     {
         // TODO: better error reporting?
         QMessageBox::critical(this, "melonDS", "This firmware is not bootable.");
@@ -2333,7 +2336,7 @@ void MainWindow::onInsertCart()
 
     // TODO: add to recent ROM list??
 
-    if (!ROMLoader::LoadROM(file, false))
+    if (!ROMManager::LoadROM(file, false))
     {
         // TODO: better error reporting?
         QMessageBox::critical(this, "melonDS", "Failed to load the ROM.");
@@ -2343,7 +2346,7 @@ void MainWindow::onInsertCart()
 
     emuThread->emuUnpause();
 
-    actCurrentCart->setText("DS slot: " + ROMLoader::CartLabel());
+    actCurrentCart->setText("DS slot: " + ROMManager::CartLabel());
     actEjectCart->setEnabled(true);
 }
 
@@ -2351,11 +2354,11 @@ void MainWindow::onEjectCart()
 {
     emuThread->emuPause();
 
-    ROMLoader::EjectCart();
+    ROMManager::EjectCart();
 
     emuThread->emuUnpause();
 
-    actCurrentCart->setText("DS slot: " + ROMLoader::CartLabel());
+    actCurrentCart->setText("DS slot: " + ROMManager::CartLabel());
     actEjectCart->setEnabled(false);
 }
 
@@ -2368,11 +2371,11 @@ void MainWindow::onInsertGBAAddon()
 
     emuThread->emuPause();
 
-    ROMLoader::LoadGBAAddon(type);
+    ROMManager::LoadGBAAddon(type);
 
     emuThread->emuUnpause();
 
-    actCurrentGBACart->setText("GBA slot: " + ROMLoader::GBACartLabel());
+    actCurrentGBACart->setText("GBA slot: " + ROMManager::GBACartLabel());
     actEjectGBACart->setEnabled(true);
 }
 
@@ -2554,7 +2557,7 @@ void MainWindow::onReset()
 
     actUndoStateLoad->setEnabled(false);
 
-    ROMLoader::Reset();
+    ROMManager::Reset();
 
     OSD::AddMessage(0, "Reset");
     emuThread->emuRun();