From 520478972dd3fb1bdb24d28372c3207a18acc212 Mon Sep 17 00:00:00 2001
From: Souryo <mesenemu@gmail.com>
Date: Sat, 23 Jul 2016 12:26:02 -0400
Subject: [PATCH] Mapper 234 support

---
 Core/Core.vcxproj         |  1 +
 Core/Core.vcxproj.filters |  3 ++
 Core/Mapper234.h          | 68 +++++++++++++++++++++++++++++++++++++++
 Core/MapperFactory.cpp    |  4 ++-
 4 files changed, 75 insertions(+), 1 deletion(-)
 create mode 100644 Core/Mapper234.h

diff --git a/Core/Core.vcxproj b/Core/Core.vcxproj
index 68e7d9a3..04752c11 100644
--- a/Core/Core.vcxproj
+++ b/Core/Core.vcxproj
@@ -456,6 +456,7 @@
     <ClInclude Include="Mapper226.h" />
     <ClInclude Include="Mapper227.h" />
     <ClInclude Include="Mapper230.h" />
+    <ClInclude Include="Mapper234.h" />
     <ClInclude Include="Mapper241.h" />
     <ClInclude Include="Mapper35.h" />
     <ClInclude Include="Mapper40.h" />
diff --git a/Core/Core.vcxproj.filters b/Core/Core.vcxproj.filters
index af81d34e..5f205177 100644
--- a/Core/Core.vcxproj.filters
+++ b/Core/Core.vcxproj.filters
@@ -799,6 +799,9 @@
     <ClInclude Include="Txc22211C.h">
       <Filter>Nes\Mappers\Txc</Filter>
     </ClInclude>
+    <ClInclude Include="Mapper234.h">
+      <Filter>Nes\Mappers\Unnamed</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="stdafx.cpp">
diff --git a/Core/Mapper234.h b/Core/Mapper234.h
new file mode 100644
index 00000000..22569461
--- /dev/null
+++ b/Core/Mapper234.h
@@ -0,0 +1,68 @@
+#pragma once
+#include "stdafx.h"
+#include "BaseMapper.h"
+
+class Mapper234 : public BaseMapper
+{
+private:
+	uint8_t _regs[2];
+
+protected:
+	virtual uint16_t RegisterStartAddress() { return 0xFF80; }
+	virtual uint16_t RegisterEndAddress() { return 0xFF9F; }
+	virtual uint16_t GetPRGPageSize() { return 0x8000; }
+	virtual uint16_t GetCHRPageSize() { return 0x2000; }
+	virtual bool AllowRegisterRead() { return true; }
+	virtual bool HasBusConflicts() { return true; }
+
+	void InitMapper()
+	{
+		AddRegisterRange(0xFFE8, 0xFFF8, MemoryOperation::Any);
+		memset(_regs, 0, sizeof(_regs));
+		UpdateState();
+	}
+
+	void UpdateState()
+	{
+		if(_regs[0] & 0x40) {
+			//NINA-03 mode
+			SelectPRGPage(0, (_regs[0] & 0x0E) | (_regs[1] & 0x01));
+			SelectCHRPage(0, ((_regs[0] << 2) & 0x38) | (_regs[1] >> 4) & 0x07);
+		} else {
+			//CNROM mode
+			SelectPRGPage(0, _regs[0] & 0x0F);
+			SelectCHRPage(0, ((_regs[0] << 2) & 0x3C) | (_regs[1] >> 4) & 0x03);
+		}
+
+		SetMirroringType(_regs[0] & 0x80 ? MirroringType::Horizontal : MirroringType::Vertical);
+	}
+
+	uint8_t ReadRegister(uint16_t addr)
+	{
+		uint8_t value = InternalReadRam(addr);
+		if(addr <= 0xFF9F) {
+			if(!(_regs[0] & 0x3F)) {
+				_regs[0] = value;
+				UpdateState();
+			}
+		} else {
+			_regs[1] = value & 0x71;
+			UpdateState();
+		}
+
+		return value;
+	}
+
+	void WriteRegister(uint16_t addr, uint8_t value)
+	{
+		if(addr <= 0xFF9F) {
+			if(!(_regs[0] & 0x3F)) {
+				_regs[0] = value;
+				UpdateState();
+			}
+		} else {
+			_regs[1] = value & 0x71;
+			UpdateState();
+		}		
+	}
+};
\ No newline at end of file
diff --git a/Core/MapperFactory.cpp b/Core/MapperFactory.cpp
index a0f8e652..20952424 100644
--- a/Core/MapperFactory.cpp
+++ b/Core/MapperFactory.cpp
@@ -62,6 +62,7 @@
 #include "Mapper227.h"
 #include "Mapper230.h"
 #include "Mapper231.h"
+#include "Mapper234.h"
 #include "Mapper240.h"
 #include "Mapper241.h"
 #include "Mapper242.h"
@@ -160,7 +161,7 @@ Supported mappers:
 |176|177|178|179|180|   |182|   |184|185|   |   |   |189|   |191|
 |192|193|194|195|   |   |   |   |200|201|202|203|   |205|206|207|
 |   |209|210|211|   |   |   |   |   |   |218|   |   |   |   |   |
-|   |225|226|227|228|   |230|231|232|   |   |235|   |   |   |   |
+|   |225|226|227|228|   |230|231|232|   |234|235|   |   |   |   |
 |240|241|242|243|   |245|246|   |   |   |   |   |252|   |   |   |
 -----------------------------------------------------------------
 */
@@ -340,6 +341,7 @@ BaseMapper* MapperFactory::GetMapperFromID(RomData &romData)
 		case 230: return new Mapper230();
 		case 231: return new Mapper231();
 		case 232: return new BF9096();
+		case 234: return new Mapper234();
 		case 235: return new Bmc235();
 		case 240: return new Mapper240();
 		case 241: return new Mapper241();