nes-support vrc3

BizHawk.Emulation/BizHawk.Emulation.csproj

@@ -138,6 +138,7 @@
       <SubType>Code</SubType>
     </Compile>
     <Compile Include="Consoles\Nintendo\NES\Boards\VRC2_4.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\VRC3.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\VRC6.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\VRC7.cs" />
     <Compile Include="Consoles\Nintendo\NES\Core.cs" />

BizHawk.Emulation/Consoles/Nintendo/Docs/compatibility.txt

@@ -60,7 +60,7 @@ Open bus and bus conflict emulation is not considered complete or thorough in an
 070	Misc		Complete
 071	Camerica	Complete
 072	Misc (J)	Nothing
-073	VRC3		Nothing
+073	VRC3		Good
 074	Pirate (CN)	Junk
 075	VRC1		Nothing
 076	Misc (J)	Nothing

BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC2_4.cs

@@ -5,7 +5,7 @@ using System.Diagnostics;
 namespace BizHawk.Emulation.Consoles.Nintendo
 {
 	//mapper 21 + 22 + 23 + 25 (docs largely in 021.txt for VRC4 and 22.txt for VRC2)
-	//If you change any of the IRQ logic here, be sure to change it in VRC 6/7 as well.
+	//If you change any of the IRQ logic here, be sure to change it in VRC 3/6/7 as well.
 	public class VRC2_4 : NES.NESBoardBase
 	{
 		//configuration

BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC3.cs

@@ -0,0 +1,183 @@
+using System;
+using System.IO;
+using System.Diagnostics;
+
+namespace BizHawk.Emulation.Consoles.Nintendo
+{
+	//mapper 73 AKA salamander
+	//different IRQ logic than other VRC
+	public class VRC3 : NES.NESBoardBase
+	{
+		//configuration
+		int prg_bank_mask_16k;
+
+		//state
+		IntBuffer prg_banks_16k = new IntBuffer(2);
+		bool irq_mode;
+		bool irq_enabled, irq_pending, irq_autoen;
+		ushort irq_reload;
+		ushort irq_counter;
+		int irq_cycles;
+
+		public override void Dispose()
+		{
+			base.Dispose();
+			prg_banks_16k.Dispose();
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("prg_banks_16k", ref prg_banks_16k);
+			ser.Sync("irq_mode", ref irq_mode);
+			ser.Sync("irq_enabled", ref irq_enabled);
+			ser.Sync("irq_pending", ref irq_pending);
+			ser.Sync("irq_autoen", ref irq_autoen);
+			ser.Sync("irq_reload", ref irq_reload);
+			ser.Sync("irq_counter", ref irq_counter);
+			ser.Sync("irq_cycles", ref irq_cycles);
+		}
+
+		void SyncIRQ()
+		{
+			NES.irq_cart = (irq_pending && irq_enabled);
+		}
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "KONAMI-VRC-3":
+					AssertPrg(128,512); AssertChr(0,128); AssertVram(0,8); AssertWram(0,8);
+					break;
+				default:
+					return false;
+			}
+
+			prg_bank_mask_16k = Cart.prg_size / 16 - 1;
+
+			SetMirrorType(EMirrorType.Vertical);
+
+			prg_banks_16k[1] = (byte)(0xFF & prg_bank_mask_16k);
+
+			return true;
+		}
+		public override byte ReadPRG(int addr)
+		{
+			int bank_16k = addr >> 14;
+			int ofs = addr & ((1 << 14) - 1);
+			bank_16k = prg_banks_16k[bank_16k];
+			addr = (bank_16k << 14) | ofs;
+			return ROM[addr];
+		}
+
+		void WriteIrqReload(int bit, byte value)
+		{
+			int mask = 0xF << bit;
+			irq_reload = (ushort)((irq_reload & ~mask) | (value << bit));
+		}
+		public override void WritePRG(int addr, byte value)
+		{
+			switch (addr)
+			{
+				case 0x0000: WriteIrqReload(0, value); break;
+				case 0x1000: WriteIrqReload(4, value); break;
+				case 0x2000: WriteIrqReload(8, value); break;
+				case 0x3000: WriteIrqReload(12, value); break;
+
+				case 0x4000:
+					irq_mode = value.Bit(2);
+					irq_autoen = value.Bit(0);
+
+					if (value.Bit(1))
+					{
+						//enabled
+						irq_enabled = true;
+						if (irq_mode)
+						{
+							//8bit..
+							irq_counter &= 0xFF00;
+							irq_counter |= (ushort)(irq_reload & 0xFF);
+						}
+						else
+						{
+							irq_counter = irq_reload;
+						}
+						irq_cycles = 3;
+					}
+					else
+					{
+						//disabled
+						irq_enabled = false;
+					}
+
+					//acknowledge
+					irq_pending = false;
+
+					SyncIRQ();
+
+					break;
+
+				case 0x5000:
+					irq_pending = false;
+					irq_enabled = irq_autoen;
+					SyncIRQ();
+					break;
+
+				case 0x7000:
+					prg_banks_16k[0] = value & 0xF;
+					prg_banks_16k[0] &= prg_bank_mask_16k;
+					break;
+
+			}
+		}
+
+		void ClockIRQ()
+		{
+			if (irq_mode)
+			{
+				//8 bit mode
+				ushort temp = irq_counter;
+				temp &= 0xFF;
+				irq_counter &= 0xFF00;
+				if (temp == 0xFF)
+				{
+					irq_pending = true;
+					irq_counter = irq_reload;
+					irq_counter |= (ushort)(irq_reload & 0xFF);
+					SyncIRQ();
+				}
+				else
+				{
+					temp++;
+					irq_counter |= temp;
+				}
+			}
+			else
+			{
+				//16 bit mode
+				if (irq_counter == 0xFFFF)
+				{
+					irq_pending = true;
+					irq_counter = irq_reload;
+					SyncIRQ();
+				}
+				else
+					irq_counter++;
+			}
+		}
+
+		public override void ClockPPU()
+		{
+			if (!irq_enabled) return;
+
+			irq_cycles--;
+			if (irq_cycles == 0)
+			{
+				irq_cycles += 3;
+				ClockIRQ();
+			}
+		}
+
+	}
+}

BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC6.cs

@@ -5,7 +5,7 @@ using System.Diagnostics;
 namespace BizHawk.Emulation.Consoles.Nintendo
 {
 	//mapper 24 + 26
-	//If you change any of the IRQ logic here, be sure to change it in VRC 2/4/7 as well.
+	//If you change any of the IRQ logic here, be sure to change it in VRC 2/3/4/7 as well.
 	public class VRC6 : NES.NESBoardBase
 	{
 		//configuration

BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC7.cs

@@ -5,7 +5,7 @@ using System.Diagnostics;
 namespace BizHawk.Emulation.Consoles.Nintendo
 {
 	//mapper 85
-	//If you change any of the IRQ logic here, be sure to change it in VRC 2/4/6 as well.
+	//If you change any of the IRQ logic here, be sure to change it in VRC 2/3/4/6 as well.
 	public class VRC7 : NES.NESBoardBase
 	{
 		//configuration