diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 2f2a010e97..70810ba034 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -597,6 +597,7 @@
+
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper035.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper035.cs
new file mode 100644
index 0000000000..0e4ed7107d
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper035.cs
@@ -0,0 +1,133 @@
+using BizHawk.Common;
+using BizHawk.Common.NumberExtensions;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+ public sealed class Mapper035 : NES.NESBoardBase
+ {
+ private ByteBuffer reg = new ByteBuffer(8);
+ private ByteBuffer chr = new ByteBuffer(8);
+
+ private int prg_bank_mask_8k;
+ private int chr_bank_mask_1k;
+
+ private bool IRQa;
+ private int IRQCount;
+
+ public override bool Configure(NES.EDetectionOrigin origin)
+ {
+ switch (Cart.board_type)
+ {
+ case "MAPPER035":
+ break;
+ default:
+ return false;
+ }
+
+ prg_bank_mask_8k = Cart.prg_size / 8 - 1;
+ chr_bank_mask_1k = Cart.chr_size / 1 - 1;
+ SetMirrorType(Cart.pad_h, Cart.pad_v);
+ return true;
+ }
+
+ public override void Dispose()
+ {
+ reg.Dispose();
+ chr.Dispose();
+ base.Dispose();
+ }
+
+ public override void SyncState(Serializer ser)
+ {
+ ser.Sync("reg", ref reg);
+ ser.Sync("chr", ref chr);
+ ser.Sync("IRQa", ref IRQa);
+ ser.Sync("IRQCount", ref IRQCount);
+ base.SyncState(ser);
+ }
+
+ public override byte ReadEXP(int addr)
+ {
+ if (addr == 0x800)
+ {
+ return 0x20;
+ }
+
+ return base.ReadEXP(addr);
+ }
+
+ private void SetMirror()
+ {
+ SetMirrorType(reg[3].Bit(0) ? EMirrorType.Horizontal : EMirrorType.Vertical);
+ }
+
+ public override void WritePRG(int addr, byte value)
+ {
+ addr += 0x8000;
+ switch (addr)
+ {
+ case 0x8000: reg[0] = value; break;
+ case 0x8001: reg[1] = value; break;
+ case 0x8002: reg[2] = value; break;
+ case 0x9000: chr[0] = value; break;
+ case 0x9001: chr[1] = value; break;
+ case 0x9002: chr[2] = value; break;
+ case 0x9003: chr[3] = value; break;
+ case 0x9004: chr[4] = value; break;
+ case 0x9005: chr[5] = value; break;
+ case 0x9006: chr[6] = value; break;
+ case 0x9007: chr[7] = value; break;
+
+ case 0xC002: IRQa = false; IRQSignal = false; break;
+ case 0xC005: IRQCount = value; break;
+ case 0xC003: IRQa = true; break;
+
+ case 0xD001: reg[3] = value;
+ SetMirror(); break;
+ }
+ }
+
+ public override byte ReadPRG(int addr)
+ {
+ int index = addr >> 13;
+
+ int bank = reg[index];
+ if (index == 3) { bank = 0xFF; }
+ bank &= prg_bank_mask_8k;
+
+ return ROM[(bank << 13) + (addr & 0x1FFF)];
+ }
+
+ public override byte ReadPPU(int addr)
+ {
+ if (addr < 0x2000)
+ {
+ int index = addr >> 10;
+ int bank = chr[index];
+ bank &= chr_bank_mask_1k;
+
+ return VROM[(bank << 10) + (addr & 0x3FF)];
+ }
+
+ return base.ReadPPU(addr);
+ }
+
+ public override void ClockCPU()
+ {
+ IrqHook(1);
+ }
+
+ private void IrqHook(int a)
+ {
+ if (IRQa)
+ {
+ IRQCount += a;
+ if (IRQCount > 0x10000)
+ {
+ IRQSignal = true;
+ IRQa = false;
+ }
+ }
+ }
+ }
+}