diff --git a/src/NDS.cpp b/src/NDS.cpp
index de21eb63..1f9597ce 100644
--- a/src/NDS.cpp
+++ b/src/NDS.cpp
@@ -3182,6 +3182,23 @@ void NDS::ARM9IOWrite8(u32 addr, u8 val)
             NDSCartSlot.WriteSPIData(val);
         return;
 
+    case 0x040001A4:
+        if (!(ExMemCnt[0] & (1<<11)))
+            NDSCartSlot.WriteROMCnt((NDSCartSlot.GetROMCnt() & 0xFFFFFF00) | val);
+        return;
+    case 0x040001A5:
+        if (!(ExMemCnt[0] & (1<<11)))
+            NDSCartSlot.WriteROMCnt((NDSCartSlot.GetROMCnt() & 0xFFFF00FF) | (val << 8));
+        return;
+    case 0x040001A6:
+        if (!(ExMemCnt[0] & (1<<11)))
+            NDSCartSlot.WriteROMCnt((NDSCartSlot.GetROMCnt() & 0xFF00FFFF) | (val << 16));
+        return;
+    case 0x040001A7:
+        if (!(ExMemCnt[0] & (1<<11)))
+            NDSCartSlot.WriteROMCnt((NDSCartSlot.GetROMCnt() & 0x00FFFFFF) | (val << 24));
+        return;
+
     case 0x040001A8: if (!(ExMemCnt[0] & (1<<11))) NDSCartSlot.SetROMCommand(0, val); return;
     case 0x040001A9: if (!(ExMemCnt[0] & (1<<11))) NDSCartSlot.SetROMCommand(1, val); return;
     case 0x040001AA: if (!(ExMemCnt[0] & (1<<11))) NDSCartSlot.SetROMCommand(2, val); return;
@@ -3311,6 +3328,15 @@ void NDS::ARM9IOWrite16(u32 addr, u16 val)
             NDSCartSlot.WriteSPIData(val & 0xFF);
         return;
 
+    case 0x040001A4:
+        if (!(ExMemCnt[0] & (1<<11)))
+            NDSCartSlot.WriteROMCnt((NDSCartSlot.GetROMCnt() & 0xFFFF0000) | val);
+        return;
+    case 0x040001A6:
+        if (!(ExMemCnt[0] & (1<<11)))
+            NDSCartSlot.WriteROMCnt((NDSCartSlot.GetROMCnt() & 0x0000FFFF) | (val << 16));
+        return;
+
     case 0x040001A8:
         if (!(ExMemCnt[0] & (1<<11)))
         {
@@ -3954,6 +3980,23 @@ void NDS::ARM7IOWrite8(u32 addr, u8 val)
             NDSCartSlot.WriteSPIData(val);
         return;
 
+    case 0x040001A4:
+        if (ExMemCnt[0] & (1<<11))
+            NDSCartSlot.WriteROMCnt((NDSCartSlot.GetROMCnt() & 0xFFFFFF00) | val);
+        return;
+    case 0x040001A5:
+        if (ExMemCnt[0] & (1<<11))
+            NDSCartSlot.WriteROMCnt((NDSCartSlot.GetROMCnt() & 0xFFFF00FF) | (val << 8));
+        return;
+    case 0x040001A6:
+        if (ExMemCnt[0] & (1<<11))
+            NDSCartSlot.WriteROMCnt((NDSCartSlot.GetROMCnt() & 0xFF00FFFF) | (val << 16));
+        return;
+    case 0x040001A7:
+        if (ExMemCnt[0] & (1<<11))
+            NDSCartSlot.WriteROMCnt((NDSCartSlot.GetROMCnt() & 0x00FFFFFF) | (val << 24));
+        return;
+
     case 0x040001A8: if (ExMemCnt[0] & (1<<11)) NDSCartSlot.SetROMCommand(0, val); return;
     case 0x040001A9: if (ExMemCnt[0] & (1<<11)) NDSCartSlot.SetROMCommand(1, val); return;
     case 0x040001AA: if (ExMemCnt[0] & (1<<11)) NDSCartSlot.SetROMCommand(2, val); return;
@@ -4059,6 +4102,15 @@ void NDS::ARM7IOWrite16(u32 addr, u16 val)
             NDSCartSlot.WriteSPIData(val & 0xFF);
         return;
 
+    case 0x040001A4:
+        if (ExMemCnt[0] & (1<<11))
+            NDSCartSlot.WriteROMCnt((NDSCartSlot.GetROMCnt() & 0xFFFFFF00) | val);
+        return;
+    case 0x040001A6:
+        if (ExMemCnt[0] & (1<<11))
+            NDSCartSlot.WriteROMCnt((NDSCartSlot.GetROMCnt() & 0xFF00FFFF) | (val << 16));
+        return;
+
     case 0x040001A8:
         if (ExMemCnt[0] & (1<<11))
         {