diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Taito_X1_005.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Taito_X1_005.cs
index 19b74f80a7..59b4b8ab39 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Taito_X1_005.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Taito_X1_005.cs
@@ -44,11 +44,22 @@ PRG Setup:
 
 	class TAITO_X1_005 : NES.NESBoardBase
 	{
-		int prg, chr;
+		int prg_bank_mask, chr_bank_mask;
+		ByteBuffer chr_regs_2k = new ByteBuffer(6);
+		ByteBuffer prg_regs_8k = new ByteBuffer(4);
 
 		public override void SyncState(Serializer ser)
 		{
 			base.SyncState(ser);
+			ser.Sync("chr_regs_2k", ref chr_regs_2k);
+			ser.Sync("prg_regs_8k", ref prg_regs_8k);
+		}
+
+		public override void Dispose()
+		{
+			base.Dispose();
+			chr_regs_2k.Dispose();
+			prg_regs_8k.Dispose();
 		}
 
 		public override bool Configure(NES.EDetectionOrigin origin)
@@ -62,7 +73,10 @@ PRG Setup:
 					return false;
 			}
 
-			SetMirrorType(Cart.pad_h, Cart.pad_v);
+			SetMirrorType(EMirrorType.Vertical);
+			chr_bank_mask = Cart.chr_size / 2 - 1;
+			prg_bank_mask = Cart.prg_size / 8 - 1;
+			prg_regs_8k[3] = 0xFF;
 			return true;
 		}
 
@@ -78,50 +92,57 @@ PRG Setup:
 					break;
 
 				case 0x7EF0:
-					chr = 0;
+					chr_regs_2k[0] = value;
 					break;
 				case 0x7EF1:
-					chr = 1;
+					chr_regs_2k[1] = value;
 					break;
 				case 0x7EF2:
-					chr = 2;
+					chr_regs_2k[2] = value;
 					break;
 				case 0x7EF3:
-					chr = 3;
+					chr_regs_2k[3] = value;
 					break;
 				case 0x7EF4:
-					chr = 4;
+					chr_regs_2k[4] = value;
 					break;
 				case 0X7EF5:
-					chr = 5;
+					chr_regs_2k[5] = value;
 					break;
 
 				case 0x7EFA: //PRG Reg 0
 				case 0x7EFB:
-					prg = 0;
+					prg_regs_8k[0] = value;
 					break;
 				case 0x7EFC: //PRG Reg 1
 				case 0x7EFD:
-					prg = 1;
+					prg_regs_8k[1] = value;
 					break;
 				case 0x7EFE: //PRG Reg 2
 				case 0x7EFF:
-					prg = 2;
+					prg_regs_8k[2] = value;
 					break;
 			}
 		}
 
 		public override byte ReadPRG(int addr)
 		{
-			return ROM[(addr & 0x01FFF)+ (prg * 0x2000)];
+			int bank_8k = addr >> 13;
+			int ofs = addr & ((1 << 13) - 1);
+			bank_8k = prg_regs_8k[bank_8k];
+			bank_8k &= prg_bank_mask;
+			addr = (bank_8k << 13) | ofs;
+			return ROM[addr];
 		}
 
 		public override byte ReadPPU(int addr)
 		{
-			if (chr < 2)
-				return VROM[(addr & 0x7FF) + (chr * 0x800)];
-			else
-				return VROM[(addr & 0x3FF) + 0x800 + (chr * 0x400)];
+			int bank_2k = addr >> 11;
+			int ofs = addr & ((1 << 11) - 1);
+			bank_2k = chr_regs_2k[bank_2k];
+			bank_2k &= chr_bank_mask;
+			addr = (bank_2k << 11) | ofs;
+			return VROM[addr];
 		}
 	}
 }
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