Add SetCpuRegister() to IEmulator. Implemented it in Atari 2600, 7800, C64, Neshawk, and technically dual gameboy (passes it to L and R where it will fail). The rest throw NotImplementedExceptions. Lua - add emu.setregister(), catches NotImplementedExceptions and informs the user.

BizHawk.Client.Common/lua/EmuLuaLibrary.Emu.cs

@@ -99,6 +99,24 @@ namespace BizHawk.Client.Common
 			return table;
 		}
 
+		[LuaMethodAttributes(
+			"setregister",
+			"sets the given register name to the given value"
+		)]
+		public void SetRegister(string register, int value)
+		{
+			try
+			{
+				Global.Emulator.SetCpuRegister(register, value);
+			}
+			catch (NotImplementedException)
+			{
+				Log(string.Format(
+					"Error: {0} does not yet implement setregister()",
+					Global.Emulator.Attributes().CoreName));
+			}
+		}
+
 		[LuaMethodAttributes(
 			"getsystemid",
 			"Returns the ID string of the current core loaded. Note: No ROM loaded will return the string NULL"

BizHawk.Emulation.Common/Interfaces/Base Implementations/NullEmulator.cs

@@ -88,6 +88,8 @@ namespace BizHawk.Emulation.Common
 			return new Dictionary<string, int>();
 		}
 
+		public void SetCpuRegister(string register, int value) { }
+
 		bool xmas;
 		Pleg pleg;
 

BizHawk.Emulation.Common/Interfaces/IEmulator.cs

@@ -145,6 +145,13 @@ namespace BizHawk.Emulation.Common
 		/// <returns></returns>
 		Dictionary<string, int> GetCpuFlagsAndRegisters();
 
+		/// <summary>
+		/// Sets a given Cpu register to the given value
+		/// </summary>
+		/// <param name="register"></param>
+		/// <param name="value"></param>
+		void SetCpuRegister(string register, int value);
+
 		// ====settings interface====
 
 		// in addition to these methods, it's expected that the constructor or Load() method

BizHawk.Emulation.Cores/Calculator/TI83.cs

@@ -1046,5 +1046,10 @@ namespace BizHawk.Emulation.Cores.Calculators
 				{ "Flag S", cpu.RegisterF.Bit(7) ? 1 : 0 }
 			};
 		}
+
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
 	}
 }

BizHawk.Emulation.Cores/Computers/Commodore64/C64.Core.cs

@@ -103,6 +103,30 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64
 				{ "Flag T", board.cpu.FlagT ? 1 : 0 }
 			};
 		}
+
+		public void SetCpuRegister(string register, int value)
+		{
+			switch (register)
+			{
+				default:
+					throw new InvalidOperationException();
+				case "A":
+					board.cpu.A = (byte)value;
+					break;
+				case "X":
+					board.cpu.X = (byte)value;
+					break;
+				case "Y":
+					board.cpu.Y = (byte)value;
+					break;
+				case "S":
+					board.cpu.S = (byte)value;
+					break;
+				case "PC":
+					board.cpu.PC = (byte)value;
+					break;
+			}
+		}
 	}
 
 	static public class C64Util

BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.cs

@@ -193,6 +193,33 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 			};
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			switch(register)
+			{
+				default:
+					throw new InvalidOperationException();
+				case "A":
+					Cpu.A = (byte)value;
+					break;
+				case "X":
+					Cpu.X = (byte)value;
+					break;
+				case "Y":
+					Cpu.Y = (byte)value;
+					break;
+				case "S":
+					Cpu.S = (byte)value;
+					break;
+				case "PC":
+					Cpu.PC = (byte)value;
+					break;
+				case "Flag I":
+					Cpu.FlagI = value > 0;
+					break;
+			}
+		}
+
 		public bool StartAsyncSound() { return true; }
 
 		public void EndAsyncSound() { }

BizHawk.Emulation.Cores/Consoles/Atari/7800/Atari7800.Core.cs

@@ -35,5 +35,32 @@ namespace BizHawk.Emulation.Cores.Atari.Atari7800
 				{ "Flag Z", theMachine.CPU.fZ ? 1 : 0 }
 			};
 		}
+
+		public void SetCpuRegister(string register, int value)
+		{
+			switch (register)
+			{
+				default:
+					throw new InvalidOperationException();
+				case "A":
+					theMachine.CPU.A = (byte)value;
+					break;
+				case "P":
+					theMachine.CPU.P = (byte)value;
+					break;
+				case "PC":
+					theMachine.CPU.PC = (byte)value;
+					break;
+				case "S":
+					theMachine.CPU.S = (byte)value;
+					break;
+				case "X":
+					theMachine.CPU.X = (byte)value;
+					break;
+				case "Y":
+					theMachine.CPU.Y = (byte)value;
+					break;
+			}
+		}
 	}
 }

BizHawk.Emulation.Cores/Consoles/Coleco/ColecoVision.cs

@@ -293,5 +293,10 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 				{ "Flag S", Cpu.RegisterF.Bit(7) ? 1 : 0 }
 			};
 		}
+
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
 	}
 }

BizHawk.Emulation.Cores/Consoles/Intellivision/Intellivision.cs

@@ -28,6 +28,11 @@ namespace BizHawk.Emulation.Cores.Intellivision
 			throw new NotImplementedException();
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		public void Connect()
 		{
 			Cpu.SetIntRM(Stic.GetSr1());

BizHawk.Emulation.Cores/Consoles/Nintendo/GBA/Meteor.cs

@@ -26,6 +26,11 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBA
 			return ret;
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		public static readonly ControllerDefinition GBAController =
 		new ControllerDefinition
 		{

BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs

@@ -201,6 +201,11 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 			};
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		/// <summary>
 		/// true if the emulator is currently emulating CGB
 		/// </summary>

BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/GambatteLink.cs

@@ -30,6 +30,21 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 			return left.Union(right).ToList().ToDictionary(pair => pair.Key, pair => pair.Value);
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			if (register.StartsWith("Left "))
+			{
+				L.SetCpuRegister(register.Replace("Left ", ""), value);
+			}
+
+			else if (register.StartsWith("Right "))
+			{
+				L.SetCpuRegister(register.Replace("Right ", ""), value);
+			}
+
+			throw new InvalidOperationException();
+		}
+
 		Gameboy L;
 		Gameboy R;
 		// counter to ensure we do 35112 samples per frame

BizHawk.Emulation.Cores/Consoles/Nintendo/N64/N64.cs

@@ -394,6 +394,11 @@ namespace BizHawk.Emulation.Cores.Nintendo.N64
 			return ret;
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		private mupen64plusApi.MemoryCallback readcb;
 		private mupen64plusApi.MemoryCallback writecb;
 

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

@@ -887,6 +887,33 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 			};
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			switch (register)
+			{
+				default:
+					throw new InvalidOperationException();
+				case "A":
+					cpu.A = (byte)value;
+					break;
+				case "X":
+					cpu.X = (byte)value;
+					break;
+				case "Y":
+					cpu.Y = (byte)value;
+					break;
+				case "S":
+					cpu.S = (byte)value;
+					break;
+				case "PC":
+					cpu.PC = (byte)value;
+					break;
+				case "Flag I":
+					cpu.FlagI = value > 0;
+					break;
+			}
+		}
+
 		NESSettings Settings = new NESSettings();
 		NESSyncSettings SyncSettings = new NESSyncSettings();
 

BizHawk.Emulation.Cores/Consoles/Nintendo/QuickNES/QuickNES.cs

@@ -373,6 +373,11 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.QuickNES
 			return ret;
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		#endregion
 
 		#region settings

BizHawk.Emulation.Cores/Consoles/Nintendo/SNES/LibsnesCore.cs

@@ -125,6 +125,11 @@ namespace BizHawk.Emulation.Cores.Nintendo.SNES
 			};
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		public class MyScanlineHookManager : ScanlineHookManager
 		{
 			public MyScanlineHookManager(LibsnesCore core)

BizHawk.Emulation.Cores/Consoles/PC Engine/PCEngine.cs

@@ -545,6 +545,11 @@ namespace BizHawk.Emulation.Cores.PCEngine
 			};
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		public void Dispose()
 		{
 			if (disc != null)

BizHawk.Emulation.Cores/Consoles/Sega/Genesis/Genesis.cs

@@ -279,6 +279,11 @@ namespace BizHawk.Emulation.Cores.Sega.Genesis
 			};
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		int vdpcallback(int level) // Musashi handler
 		{
 			InterruptCallback(level);

BizHawk.Emulation.Cores/Consoles/Sega/SMS/SMS.cs

@@ -510,6 +510,11 @@ namespace BizHawk.Emulation.Cores.Sega.MasterSystem
 			};
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		public void Dispose() { }
 
 		public object GetSettings() { return Settings.Clone(); }

BizHawk.Emulation.Cores/Consoles/Sega/Saturn/Yabause.cs

@@ -139,6 +139,11 @@ namespace BizHawk.Emulation.Cores.Sega.Saturn
 			throw new NotImplementedException();
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		public bool GLMode { get; private set; }
 
 		public void SetGLRes(int factor, int width, int height)

BizHawk.Emulation.Cores/Consoles/Sega/gpgx/GPGX.cs

@@ -586,6 +586,11 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 			return ret;
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		public void UpdateVDPViewContext(LibGPGX.VDPView view)
 		{
 			LibGPGX.gpgx_get_vdp_view(view);

BizHawk.Emulation.Cores/Consoles/Sony/PSP/PSP.cs

@@ -67,6 +67,11 @@ namespace BizHawk.Emulation.Cores.Sony.PSP
 			throw new NotImplementedException();
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		bool disposed = false;
 		static PSP attachedcore = null;
 		GCHandle vidhandle;

BizHawk.Emulation.Cores/Consoles/Sony/PSX/Octoshock.cs

@@ -36,6 +36,11 @@ namespace BizHawk.Emulation.Cores.Sony.PSX
 			throw new NotImplementedException();
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		public static bool CheckIsPSX(DiscSystem.Disc disc)
 		{
 			bool ret = false;

BizHawk.Emulation.Cores/Consoles/WonderSwan/WonderSwan.cs

@@ -296,6 +296,11 @@ namespace BizHawk.Emulation.Cores.WonderSwan
 			return ret;
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		#endregion
 
 		#region Settings

BizHawk.Emulation.Cores/LibRetroEmulator.cs

@@ -380,6 +380,11 @@ namespace BizHawk.Emulation.Cores
 			throw new NotImplementedException();
 		}
 
+		public void SetCpuRegister(string register, int value)
+		{
+			throw new NotImplementedException();
+		}
+
 		#endregion
 
 		public void Dispose()