NES - add mapper 230, contra mode is working, still todo: implement mode toggling on soft reset

BizHawk.Emulation/BizHawk.Emulation.csproj

@@ -159,6 +159,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper200.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper207.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper227.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\Mapper230.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper231.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper240.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper241.cs" />

BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper230.cs

@@ -0,0 +1,155 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BizHawk.Emulation.Consoles.Nintendo
+{
+	class Mapper230 : NES.NESBoardBase
+	{
+		/*
+			* Here are Disch's original notes:  
+		========================
+		=  Mapper 230          =
+		========================
+
+		Example Game:
+		--------------------------
+		22-in-1
+
+
+		Reset Driven:
+		---------------------------
+		The mapper has 2 main modes:  Contra mode, and multicart mode.  Performing a Soft Reset switches between
+		them.
+
+
+		Notes:
+		---------------------------
+
+		This multicart has an odd PRG size (not power of 2).  This is because there are 2 PRG chips.
+		The first is 128k and contains Contra, the other is 512k and contains the multicart.
+
+		A soft reset changes which chip is used as well as other stuff relating to the mode
+
+
+		Registers:
+		---------------------------
+
+
+		Contra Mode $8000-FFFF:     [.... .PPP]
+
+		Multicart Mode $8000-FFFF:  [.MOP PPPP]
+
+		M = Mirroring (0=Horz, 1=Vert)
+		O = PRG Mode
+		P = PRG Page
+
+		Note:
+		Mirroring is always Vert in Contra Mode.
+
+
+
+		PRG Setup:
+		---------------------------
+
+						$8000   $A000   $C000   $E000  
+						+---------------+---------------+
+		Contra Mode:    |     $8000     |     { 7 }     |  <---  use chip 0
+						+-------------------------------+
+		Multi Mode 0:   |             <Reg>             |  <---  use chip 1
+						+-------------------------------+
+		Multi Mode 1:   |      Reg      |      Reg      |  <---  use chip 1
+						+---------------+---------------+
+ 
+ 
+		chip 0 = 128k PRG  (offset 0x00010-0x2000F)
+		chip 1 = 512k PRG  (offset 0x20010-0xA000F)
+		*/
+
+		public int prg_page;
+		public bool prg_mode;
+		public bool contra_mode;
+		public int prg_bank_mask_16k;
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "MAPPER230":
+					break;
+				default:
+					return false;
+			}
+			contra_mode = true;
+			SetMirrorType(EMirrorType.Vertical);
+			prg_mode = false;
+			prg_bank_mask_16k = Cart.prg_size / 16 - 1;
+			return true;
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			ser.Sync("contra_mode", ref contra_mode);
+			ser.Sync("prg_page", ref prg_page);
+			ser.Sync("prg_mode", ref prg_mode);
+			base.SyncState(ser);
+		}
+
+		public override void WritePRG(int addr, byte value)
+		{
+			if (contra_mode)
+			{
+				prg_page = value & 0x07;
+			}
+			else
+			{
+				prg_page = value & 0x0F;
+				prg_mode = value.Bit(5);
+				
+				if (addr.Bit(6))
+				{
+					SetMirrorType(EMirrorType.Horizontal);
+				}
+				else
+				{
+					SetMirrorType(EMirrorType.Vertical);
+				}
+			}
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			if (contra_mode)
+			{
+				if (addr < 0x4000)
+				{
+					return ROM[((prg_page & prg_bank_mask_16k) * 0x4000) + addr];
+				}
+				else
+				{
+					return ROM[(7 * 0x4000) + addr - 0x4000];
+				}
+			}
+			else
+			{
+				if (prg_mode)
+				{
+					return ROM[(prg_page * 0x8000) + addr]; //TODO
+				}
+				else
+				{
+					if (addr < 0x4000)
+					{
+						return ROM[((prg_page & prg_bank_mask_16k) * 0x4000) + addr];
+					}
+					else
+					{
+						return ROM[((prg_page & prg_bank_mask_16k) * 0x4000) + (addr - 0x4000)];
+					}
+					
+				}
+			}
+		}
+	}
+}