VS system initial commits

BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/VS_M99.cs

@@ -0,0 +1,152 @@
+using System;
+using BizHawk.Common;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+	//VS System Mapper 99
+
+	[NES.INESBoardImplPriority]
+	public sealed class MAPPER99 : NES.NESBoardBase
+	{
+		//configuration
+		int prg_byte_mask, chr_mask;
+
+		//state
+		int chr;
+
+		[MapperProp]
+		public byte Dip_Switch_1;
+		[MapperProp]
+		public byte Dip_Switch_2;
+		[MapperProp]
+		public byte Dip_Switch_3;
+		[MapperProp]
+		public byte Dip_Switch_4;
+		[MapperProp]
+		public byte Dip_Switch_5;
+		[MapperProp]
+		public byte Dip_Switch_6;
+		[MapperProp]
+		public byte Dip_Switch_7;
+		[MapperProp]
+		public byte Dip_Switch_8;
+
+		//the VS actually does have 2 KB of nametable address space
+		//let's make the extra space here, instead of in the main NES to avoid confusion
+		byte[] CIRAM_VS = new byte[0x800];
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			//configure
+			switch (Cart.board_type)
+			{
+				case "MAPPER099":
+					NES._isVS = true;
+					break;
+				default:
+					return false;
+			}
+
+			prg_byte_mask = Cart.prg_size * 1024 - 1;
+			chr_mask = (Cart.chr_size / 8) - 1;
+
+			AutoMapperProps.Apply(this);
+
+
+			//update the state of the dip switches
+			//this is only done at power on
+			NES.VS_dips[0] = (byte)(Dip_Switch_1 & 1);
+			NES.VS_dips[1] = (byte)(Dip_Switch_2 & 1);
+			NES.VS_dips[2] = (byte)(Dip_Switch_3 & 1);
+			NES.VS_dips[3] = (byte)(Dip_Switch_4 & 1);
+			NES.VS_dips[4] = (byte)(Dip_Switch_5 & 1);
+			NES.VS_dips[5] = (byte)(Dip_Switch_6 & 1);
+			NES.VS_dips[6] = (byte)(Dip_Switch_7 & 1);
+			NES.VS_dips[7] = (byte)(Dip_Switch_8 & 1);
+
+			return true;
+		}
+
+		// this now tracks coins
+		public override void WriteEXP(int addr, byte value)
+		{
+			//but we don't actually need to do anything yet
+		}
+
+		public override byte ReadEXP(int addr)
+		{
+			//what are we reading?
+			return 0;
+		}
+
+		public override byte ReadPPU(int addr)
+		{
+			if (addr < 0x2000)
+			{
+				return VROM[(addr & 0x1FFF) + (NES.VS_chr_reg << 13)];
+			}
+			else
+			{
+				addr = addr - 0x2000;
+				if (addr<0x800)
+				{
+					return NES.CIRAM[addr];
+				}
+				else
+				{
+					return CIRAM_VS[addr-0x800];
+				}
+				
+			}
+		}
+
+		public override void WritePPU(int addr, byte value)
+		{
+			if (addr < 0x2000)
+			{
+				if (VRAM != null)
+					VRAM[addr] = value;
+			}
+			else
+			{
+				addr = addr - 0x2000;
+				if (addr < 0x800)
+				{
+					NES.CIRAM[addr] = value;
+				}
+				else
+				{
+					CIRAM_VS[addr-0x800] = value;
+				}
+			}
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("chr", ref chr);
+			ser.Sync("VS_CIRAM", ref CIRAM_VS, false);
+			ser.Sync("Dip_1", ref Dip_Switch_1);
+			ser.Sync("Dip_2", ref Dip_Switch_2);
+			ser.Sync("Dip_3", ref Dip_Switch_3);
+			ser.Sync("Dip_4", ref Dip_Switch_4);
+			ser.Sync("Dip_5", ref Dip_Switch_5);
+			ser.Sync("Dip_6", ref Dip_Switch_6);
+			ser.Sync("Dip_7", ref Dip_Switch_7);
+			ser.Sync("Dip_8", ref Dip_Switch_8);
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			if (Cart.prg_size==40)
+			{
+				return ROM[(addr & 0x1FFF) + (NES.VS_prg_reg << 13)];
+			}
+			else
+			{
+				return ROM[addr];
+			}
+			
+		}
+	}
+}