From c96d8f860c44b4ab14a3b149ffbf2ad4437d6918 Mon Sep 17 00:00:00 2001
From: adelikat <adelikat@tasvideos.org>
Date: Wed, 2 Nov 2016 18:29:35 -0500
Subject: [PATCH] NesHawk - Attempt mapper 35, irq logic is wrong, possibly
 mirroring too

---
 .../BizHawk.Emulation.Cores.csproj            |   1 +
 .../Consoles/Nintendo/NES/Boards/Mapper035.cs | 133 ++++++++++++++++++
 2 files changed, 134 insertions(+)
 create mode 100644 BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper035.cs

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 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper029.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper030.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper034.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\Mapper035.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper036.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper038.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper040.cs" />
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;
+				}
+			}
+		}
+	}
+}