diff --git a/source/fs.c b/source/fs.c
index 62c0ef2..8d4d9b2 100644
--- a/source/fs.c
+++ b/source/fs.c
@@ -162,16 +162,24 @@ bool GetTempFileName(char* path) {
     return (cc - tempname < 8) ? true : false;
 }
 
-bool FileSetData(const char* path, u8* data, size_t size, size_t foffset) {
-    FIL file;
-    UINT bytes_written = 0;
-    if (!CheckWritePermissions(path)) return false;
-    if (f_open(&file, path, FA_WRITE | FA_OPEN_ALWAYS) != FR_OK)
-        return false;
-    f_lseek(&file, foffset);
-    f_write(&file, data, size, &bytes_written);
-    f_close(&file);
-    return (bytes_written == size);
+bool FileSetData(const char* path, const u8* data, size_t size, size_t foffset) {
+    if (PathToNumFS(path) >= 0) {
+        UINT bytes_written = 0;
+        FIL file;
+        if (!CheckWritePermissions(path)) return false;
+        if (f_open(&file, path, FA_WRITE | FA_OPEN_ALWAYS) != FR_OK)
+            return false;
+        f_lseek(&file, foffset);
+        f_write(&file, data, size, &bytes_written);
+        f_close(&file);
+        return (bytes_written == size);
+    } else if (GetVirtualSource(path)) {
+        VirtualFile vfile;
+        if (!FindVirtualFile(&vfile, path, 0))
+            return 0;
+        return (WriteVirtualFile(&vfile, data, foffset, size, NULL) == 0);
+    }
+    return false;
 }
 
 size_t FileGetData(const char* path, u8* data, size_t size, size_t foffset)
diff --git a/source/fs.h b/source/fs.h
index 8396b6b..bcb82ee 100644
--- a/source/fs.h
+++ b/source/fs.h
@@ -39,7 +39,7 @@ bool SetWritePermissions(u32 level);
 u32 GetWritePermissions();
 
 /** Create / open file and write the provided data to it **/
-bool FileSetData(const char* path, u8* data, size_t size, size_t foffset);
+bool FileSetData(const char* path, const u8* data, size_t size, size_t foffset);
 
 /** Read data from file@offset **/
 size_t FileGetData(const char* path, u8* data, size_t size, size_t foffset);
diff --git a/source/nand/virtual.c b/source/nand/virtual.c
index 58672c9..6f2fde1 100644
--- a/source/nand/virtual.c
+++ b/source/nand/virtual.c
@@ -126,14 +126,13 @@ int ReadVirtualFile(const VirtualFile* vfile, u8* buffer, u32 offset, u32 count,
     if (bytes_read) *bytes_read = count;
     
     if (vfile->flags & VFLAG_ON_NAND) {
+        u32 nand_src = vfile->flags & (VRT_SYSNAND | VRT_EMUNAND | VRT_IMGNAND);
+        u32 keyslot = vfile->keyslot;
         if (!(foffset % 0x200) && !(count % 0x200)) { // aligned data -> simple case 
             // simple wrapper function for ReadNandSectors(u8* buffer, u32 sector, u32 count, u32 keyslot, u32 src)
-            return ReadNandSectors(buffer, foffset / 0x200, count / 0x200, vfile->keyslot,
-                vfile->flags & (VRT_SYSNAND | VRT_EMUNAND | VRT_IMGNAND));
-        } else { // nonaligned data -> -___-
+            return ReadNandSectors(buffer, foffset / 0x200, count / 0x200, keyslot, nand_src);
+        } else { // misaligned data -> -___-
             u8 l_buffer[0x200];
-            u32 nand_src = vfile->flags & (VRT_SYSNAND | VRT_EMUNAND | VRT_IMGNAND);
-            u32 keyslot = vfile->keyslot;
             int errorcode = 0;
             if (foffset % 0x200) { // handle misaligned offset
                 u32 offset_fix = 0x200 - (foffset % 0x200);
@@ -175,11 +174,40 @@ int WriteVirtualFile(const VirtualFile* vfile, const u8* buffer, u32 offset, u32
     if (bytes_written) *bytes_written = count;
     
     if (vfile->flags & VFLAG_ON_NAND) {
+        u32 nand_dst = vfile->flags & (VRT_SYSNAND | VRT_EMUNAND | VRT_IMGNAND);
+        u32 keyslot = vfile->keyslot;
         if (!(foffset % 0x200) && !(count % 0x200)) { // aligned data -> simple case 
             // simple wrapper function for WriteNandSectors(const u8* buffer, u32 sector, u32 count, u32 keyslot, u32 dest)
-            return WriteNandSectors(buffer, foffset / 0x200, count / 0x200, vfile->keyslot,
-                vfile->flags & (VRT_SYSNAND | VRT_EMUNAND | VRT_IMGNAND));
-        } else return -1; // misaligned data -> not implemented (!!!)
+            return WriteNandSectors(buffer, foffset / 0x200, count / 0x200, keyslot, nand_dst);
+        } else { // misaligned data -> -___-
+            u8 l_buffer[0x200];
+            int errorcode = 0;
+            if (foffset % 0x200) { // handle misaligned offset
+                u32 offset_fix = 0x200 - (foffset % 0x200);
+                errorcode = ReadNandSectors(l_buffer, foffset / 0x200, 1, keyslot, nand_dst);
+                if (errorcode != 0) return errorcode;
+                memcpy(l_buffer + 0x200 - offset_fix, buffer, min(offset_fix, count));
+                errorcode = WriteNandSectors((const u8*) l_buffer, foffset / 0x200, 1, keyslot, nand_dst);
+                if (errorcode != 0) return errorcode;
+                if (count <= offset_fix) return 0;
+                foffset += offset_fix;
+                buffer += offset_fix;
+                count -= offset_fix;
+            } // foffset is now aligned and part of the data is written
+            if (count >= 0x200) { // otherwise this is misaligned and will be handled below
+                errorcode = WriteNandSectors(buffer, foffset / 0x200, count / 0x200, keyslot, nand_dst);
+                if (errorcode != 0) return errorcode;
+            }
+            if (count % 0x200) { // handle misaligned count
+                u32 count_fix = count % 0x200;
+                errorcode = ReadNandSectors(l_buffer, (foffset + count) / 0x200, 1, keyslot, nand_dst);
+                if (errorcode != 0) return errorcode;
+                memcpy(l_buffer, buffer + count - count_fix, count_fix);
+                errorcode = WriteNandSectors((const u8*) l_buffer, (foffset + count) / 0x200, 1, keyslot, nand_dst);
+                if (errorcode != 0) return errorcode;
+            }
+            return errorcode;
+        }
     } else if (vfile->flags & VFLAG_ON_MEMORY) {
         memcpy((u8*) foffset, buffer, count);
         return 0;