diff --git a/BizHawk.Emulation.Cores/Computers/Commodore64/C64.Motherboard.cs b/BizHawk.Emulation.Cores/Computers/Commodore64/C64.Motherboard.cs
index d37a27590f..605277c2ad 100644
--- a/BizHawk.Emulation.Cores/Computers/Commodore64/C64.Motherboard.cs
+++ b/BizHawk.Emulation.Cores/Computers/Commodore64/C64.Motherboard.cs
@@ -100,23 +100,23 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64
 			{
 				case C64.VicType.Ntsc:
 					Vic = Chip6567R8.Create(borderType);
-					Cia0 = Chip6526.Create(C64.CiaType.Ntsc, Input_ReadKeyboard, Input_ReadJoysticks);
-					Cia1 = Chip6526.Create(C64.CiaType.Ntsc, Cia1_ReadPortA);
+					Cia0 = Chip6526.CreateCia0(C64.CiaType.Ntsc, Input_ReadKeyboard, Input_ReadJoysticks);
+					Cia1 = Chip6526.CreateCia1(C64.CiaType.Ntsc, Cia1_ReadPortA, () => 0xFF);
 					break;
 				case C64.VicType.Pal:
 					Vic = Chip6569.Create(borderType);
-					Cia0 = Chip6526.Create(C64.CiaType.Pal, Input_ReadKeyboard, Input_ReadJoysticks);
-					Cia1 = Chip6526.Create(C64.CiaType.Pal, Cia1_ReadPortA);
+					Cia0 = Chip6526.CreateCia0(C64.CiaType.Pal, Input_ReadKeyboard, Input_ReadJoysticks);
+					Cia1 = Chip6526.CreateCia1(C64.CiaType.Pal, Cia1_ReadPortA, () => 0xFF);
 					break;
 				case C64.VicType.NtscOld:
 					Vic = Chip6567R56A.Create(borderType);
-					Cia0 = Chip6526.Create(C64.CiaType.NtscRevA, Input_ReadKeyboard, Input_ReadJoysticks);
-					Cia1 = Chip6526.Create(C64.CiaType.NtscRevA, Cia1_ReadPortA);
+					Cia0 = Chip6526.CreateCia0(C64.CiaType.NtscRevA, Input_ReadKeyboard, Input_ReadJoysticks);
+					Cia1 = Chip6526.CreateCia1(C64.CiaType.NtscRevA, Cia1_ReadPortA, () => 0xFF);
 					break;
 				case C64.VicType.Drean:
 					Vic = Chip6572.Create(borderType);
-					Cia0 = Chip6526.Create(C64.CiaType.Pal, Input_ReadKeyboard, Input_ReadJoysticks);
-					Cia1 = Chip6526.Create(C64.CiaType.Pal, Cia1_ReadPortA);
+					Cia0 = Chip6526.CreateCia0(C64.CiaType.Pal, Input_ReadKeyboard, Input_ReadJoysticks);
+					Cia1 = Chip6526.CreateCia1(C64.CiaType.Pal, Cia1_ReadPortA, () => 0xFF);
 					break;
 			}
 			User = new UserPort();
diff --git a/BizHawk.Emulation.Cores/Computers/Commodore64/MOS/Chip6526.cs b/BizHawk.Emulation.Cores/Computers/Commodore64/MOS/Chip6526.cs
index bddb02b6f1..f7fb0665f1 100644
--- a/BizHawk.Emulation.Cores/Computers/Commodore64/MOS/Chip6526.cs
+++ b/BizHawk.Emulation.Cores/Computers/Commodore64/MOS/Chip6526.cs
@@ -9,7 +9,7 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
 	// * A low RES pin is emulated via HardReset().
 	public static class Chip6526
 	{
-		public static Cia Create(C64.CiaType type, Func<int> readIec, Func<int> readUserPort)
+		public static Cia CreateCia1(C64.CiaType type, Func<int> readIec, Func<int> readUserPort)
 		{
 			switch (type)
 			{
@@ -38,7 +38,7 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
 			}
 		}
 
-		public static Cia Create(C64.CiaType type, Func<bool[]> keyboard, Func<bool[]> joysticks)
+		public static Cia CreateCia0(C64.CiaType type, Func<bool[]> keyboard, Func<bool[]> joysticks)
 		{
 			switch (type)
 			{