diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 9f85a1c6ee..cf3905e0c5 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -287,6 +287,7 @@
+
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper188.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper188.cs
new file mode 100644
index 0000000000..dfa03fb586
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper188.cs
@@ -0,0 +1,61 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using BizHawk.Common;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+ public sealed class Mapper188 : NES.NESBoardBase
+ {
+ // config
+ int prg_16k_mask;
+ // state
+ int prg;
+
+ public override bool Configure(NES.EDetectionOrigin origin)
+ {
+ switch (Cart.board_type)
+ {
+ case "MAPPER188":
+ AssertVram(8);
+ AssertChr(0);
+ AssertPrg(128, 256);
+ Cart.wram_size = 0;
+ break;
+ default:
+ return false;
+ }
+
+ SetMirrorType(Cart.pad_h, Cart.pad_v);
+ prg_16k_mask = Cart.prg_size / 16 - 1;
+ return true;
+ }
+
+ public override void WritePRG(int addr, byte value)
+ {
+ prg = value;
+ }
+
+ public override void SyncState(Serializer ser)
+ {
+ ser.Sync("prg", ref prg);
+ base.SyncState(ser);
+ }
+
+ public override byte ReadPRG(int addr)
+ {
+ int bank = prg;
+ if (addr >= 0x4000)
+ bank = 15;
+ bank ^= 8; // bad dumps?
+ bank &= prg_16k_mask;
+ return ROM[addr & 0x3fff | bank << 14];
+ }
+
+ public override byte ReadWRAM(int addr)
+ {
+ return 3;
+ }
+ }
+}