diff --git a/src/app/rom.cc b/src/app/rom.cc
index 8c6f6310..805855ef 100644
--- a/src/app/rom.cc
+++ b/src/app/rom.cc
@@ -725,6 +725,13 @@ gfx::SNESPalette ROM::ReadPalette(int offset, int num_colors) {
   return palette;
 }
 
+void ROM::Write(int addr, int value) { rom_data_[addr] = value; }
+
+void ROM::WriteShort(int addr, int value) {
+  rom_data_[addr] = (uchar)(value & 0xFF);
+  rom_data_[addr + 1] = (uchar)((value >> 8) & 0xFF);
+}
+
 void ROM::LoadAllPalettes() {
   // 35 colors each, 7x5 (0,2 on grid)
   for (int i = 0; i < 6; i++) {
diff --git a/src/app/rom.h b/src/app/rom.h
index 5e2a59b6..a8266274 100644
--- a/src/app/rom.h
+++ b/src/app/rom.h
@@ -96,6 +96,9 @@ class ROM {
   gfx::SNESColor ReadColor(int offset);
   gfx::SNESPalette ReadPalette(int offset, int num_colors);
 
+  void Write(int addr, int value);
+  void WriteShort(int addr, int value);
+
   void RenderBitmap(gfx::Bitmap* bitmap) const;
 
   absl::Status ApplyAssembly(const absl::string_view& filename,