diff --git a/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_HANG.cs b/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_HANG.cs
index 15816c65c7..602f015ae0 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_HANG.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_HANG.cs
@@ -10,7 +10,7 @@
 
 		public mapper_HANG(byte[] rom)
 		{
-			ROM = new byte[0xFFFF - 0x800];
+			ROM = new byte[0x10000 - 0x800];
 			for (int i = 0; i < rom.Length; i++)
 			{
 				ROM[i] = rom[i];
@@ -26,6 +26,10 @@
 		public override byte ReadBus(ushort addr)
 		{
 			var off = addr - 0x800;
+			if (off >= ROM.Length)
+			{
+				System.Diagnostics.Debugger.Break();
+			}
 			return ROM[off];
 		}
 
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_MAZE.cs b/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_MAZE.cs
index 391a84cc1c..79eab02e6f 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_MAZE.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_MAZE.cs
@@ -9,7 +9,7 @@
 
 		public mapper_MAZE(byte[] rom)
 		{
-			ROM = new byte[0xFFFF - 0x800];
+			ROM = new byte[0x10000 - 0x800];
 			for (int i = 0; i < rom.Length; i++)
 			{
 				ROM[i] = rom[i];
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_RIDDLE.cs b/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_RIDDLE.cs
index d62326ef67..c15ac11282 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_RIDDLE.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_RIDDLE.cs
@@ -9,7 +9,7 @@
 
 		public mapper_RIDDLE(byte[] rom)
 		{
-			ROM = new byte[0xFFFF - 0x800];
+			ROM = new byte[0x10000 - 0x800];
 			for (int i = 0; i < rom.Length; i++)
 			{
 				ROM[i] = rom[i];
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_SCHACH.cs b/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_SCHACH.cs
index 35a527d44f..128828758f 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_SCHACH.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_SCHACH.cs
@@ -11,7 +11,7 @@
 
 		public mapper_SCHACH(byte[] rom)
 		{
-			ROM = new byte[0xFFFF - 0x800];
+			ROM = new byte[0x10000 - 0x800];
 			for (int i = 0; i < rom.Length; i++)
 			{
 				ROM[i] = rom[i];
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_STD.cs b/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_STD.cs
index 93ddc4d786..03aae45a39 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_STD.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/Cart/mapper_STD.cs
@@ -10,7 +10,7 @@
 
 		public mapper_STD(byte[] rom)
 		{
-			ROM = new byte[0xFFFF - 0x800];
+			ROM = new byte[0x10000 - 0x800];
 			for (int i = 0; i < rom.Length; i++)
 			{
 				ROM[i] = rom[i];