NES - implement mappers 74 and 194. Added gamedb entries for the games I could find that correspond to these mappers

BizHawk.Emulation/BizHawk.Emulation.csproj

@@ -195,6 +195,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\MMC3_family\Mapper189.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\MMC3_family\Mapper191.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\MMC3_family\Mapper192.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\MMC3_family\Mapper194.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\MMC3_family\Mapper205.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\MMC3_family\Mapper245.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\MMC3_family\MMC3.cs" />

BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/Mapper074.cs

@@ -8,8 +8,6 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 	class Mapper074 : MMC3Board_Base
 	{
 		//http://wiki.nesdev.com/w/index.php/INES_Mapper_074
-		
-		//TODO: fix CHR-RAM behavior
 
 		public override bool Configure(NES.EDetectionOrigin origin)
 		{
@@ -52,23 +50,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				int bank = GetBankNum(addr);
 				if (bank == 0x08)
 				{
-					byte value = VRAM[addr & 0x03FF];
+					return VRAM[addr & 0x03FF];
-					
-					
-					//adelikat: value ==255 is a hack to prevent a regression.
-					//Without any chr-ram mapping this game works fine other than the missing chinese characters.  This current mapping does not fix that issue.  
-					//In addition, the blue caret on the title screen is missing without this hack, so I put it in to prevent a regression.
-					//Note: FCEUX and Nintendulator are missing this blue caret (and chinese characters) suggesting a possible logical flaw in the mapper documentation.  
-					//Nestopia achieves the correct behavior but I was unable to determine how its logic was any different.
-					if (value == 255) 
-					{
-						return VROM[(addr & 0x03FF) + 0x2000];
-					}
-					else
-					{
-						return value;
-					}
-					
 				}
 				else if (bank == 0x09)
 				{

BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/Mapper194.cs

@@ -0,0 +1,69 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BizHawk.Emulation.Consoles.Nintendo
+{
+	class Mapper194 : MMC3Board_Base
+	{
+		//http://wiki.nesdev.com/w/index.php/INES_Mapper_194
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			//analyze board type
+			switch (Cart.board_type)
+			{
+				case "MAPPER194":
+					break;
+				default:
+					return false;
+			}
+
+			BaseSetup();
+			return true;
+		}
+
+		public override void WritePPU(int addr, byte value)
+		{
+			if (addr < 0x2000)
+			{
+				VRAM[addr & 0x7FF] = value;
+			}
+			else
+			{
+				base.WritePPU(addr, value);
+			}
+		}
+
+		private int GetBankNum(int addr)
+		{
+			int bank_1k = Get_CHRBank_1K(addr);
+			bank_1k &= chr_mask;
+			return bank_1k;
+		}
+
+		public override byte ReadPPU(int addr)
+		{
+			if (addr < 0x2000)
+			{
+				int bank = GetBankNum(addr);
+				if (bank == 0x00)
+				{
+					return VRAM[addr & 0x03FF];
+				}
+				else if (bank == 0x01)
+				{
+					return VRAM[(addr & 0x03FF) + 0x400];
+				}
+				else
+				{
+					addr = MapCHR(addr);
+					return VROM[addr + extra_vrom];
+				}
+
+			}
+			else return base.ReadPPU(addr);
+		}
+	}
+}

BizHawk.MultiClient/output/gamedb.txt

@@ -134,8 +134,11 @@ sha1:B6D1C372A38D196112AA98905C709AD844BD6627		Super 35-in-1 (6-in-1 VT5201)	NES
 sha1:BFA31777E077E64AF0E274B5A22B57C6765D36E1		Fan Kong Jing Ying (Unl) (Ch)	NES		board=MAPPER241;MIR=H
 sha1:17473C223453D2D80FCB9DCFA317947287DC5C52		Xing He Zhan Shi (Ch)	NES		board=MAPPER176
 sha1:0B58E16B7FD5ABE62B1D9B1841875582DF5A9195		Ying Lie Qun Xia Zhuan (Ch)	NES		board=MAPPER192
-sha1:27CB8AEAF0EA97A6C69D3D90BC056C5EB61695F6		Dai-2-Ji - Super Robot Taisen (Ch)	NES		board=MAPPER074;VRAM=2
+sha1:27CB8AEAF0EA97A6C69D3D90BC056C5EB61695F6		Dai-2-Ji - Super Robot Taisen (Ch)	NES		board=MAPPER194;VRAM=2
 sha1:0B58E16B7FD5ABE62B1D9B1841875582DF5A9195		Ying Lie Qun Xia Zhuan (Ch)	NES		board=MAPPER192;VRAM=4
+sha1:F5FA7807F2B70ADFE5707D9BF88F90DAC1436DB0		Di 4 Ci - Ji Qi Ren Dai Zhan (Ch)	NES		board=MAPPER074;VRAM=2
+sha1:A9887C308C5D0659C3AA45D003A603C9DFFB148A	B	Ji Jia Zhan Shi (Asia)	NES		board=MAPPER074;VRAM=2
+sha1:5084F25F14A61AB2799BD85D363B57B9B494601D		Ji Jia Zhan Shi (Asia)	NES		board=MAPPER074;VRAM=2
 ;;;;;;;;;;;;;;;;;;;-----------------------------------------------------------------------
 
 ;;;;;;;;;;;;;;;;;;;-----------------------------------------------------------------------