diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 78127c2c20..7904687d90 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -416,7 +416,7 @@
       <DependentUpon>Intellivision.cs</DependentUpon>
     </Compile>
     <Compile Include="Consoles\Intellivision\Intellivision.IDisassemblable.cs">
-        <DependentUpon>Intellivision.cs</DependentUpon>
+      <DependentUpon>Intellivision.cs</DependentUpon>
     </Compile>
     <Compile Include="Consoles\Intellivision\Intellivision.IInputPollable.cs">
       <DependentUpon>Intellivision.cs</DependentUpon>
@@ -447,6 +447,9 @@
     <Compile Include="Consoles\Nintendo\Gameboy\Gambatte.IDebuggable.cs">
       <DependentUpon>Gambatte.cs</DependentUpon>
     </Compile>
+    <Compile Include="Consoles\Nintendo\Gameboy\Gambatte.IEmulator.cs">
+        <DependentUpon>Gambatte.cs</DependentUpon>
+    </Compile>
     <Compile Include="Consoles\Nintendo\Gameboy\Gambatte.IMemoryDomains.cs">
       <DependentUpon>Gambatte.cs</DependentUpon>
     </Compile>
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.IEmulator.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.IEmulator.cs
new file mode 100644
index 0000000000..2854a82acf
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.IEmulator.cs
@@ -0,0 +1,107 @@
+using System;
+using System.Diagnostics;
+
+using BizHawk.Emulation.Common;
+
+namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
+{
+	public partial class Gameboy : IEmulator
+	{
+		public IEmulatorServiceProvider ServiceProvider { get; }
+
+		public ControllerDefinition ControllerDefinition => GbController;
+
+		public IController Controller { get; set; }
+
+		public void FrameAdvance(bool render, bool rendersound)
+		{
+			FrameAdvancePrep();
+			if (_syncSettings.EqualLengthFrames)
+			{
+				while (true)
+				{
+					// target number of samples to emit: length of 1 frame minus whatever overflow
+					uint samplesEmitted = TICKSINFRAME - frameOverflow;
+					Debug.Assert(samplesEmitted * 2 <= soundbuff.Length);
+					if (LibGambatte.gambatte_runfor(GambatteState, soundbuff, ref samplesEmitted) > 0)
+					{
+						LibGambatte.gambatte_blitto(GambatteState, VideoBuffer, 160);
+					}
+
+					// account for actual number of samples emitted
+					_cycleCount += samplesEmitted;
+					frameOverflow += samplesEmitted;
+
+					if (rendersound && !Muted)
+					{
+						ProcessSound((int)samplesEmitted);
+					}
+
+					if (frameOverflow >= TICKSINFRAME)
+					{
+						frameOverflow -= TICKSINFRAME;
+						break;
+					}
+				}
+			}
+			else
+			{
+				// target number of samples to emit: always 59.7fps
+				// runfor() always ends after creating a video frame, so sync-up is guaranteed
+				// when the display has been off, some frames can be markedly shorter than expected
+				uint samplesEmitted = TICKSINFRAME;
+				if (LibGambatte.gambatte_runfor(GambatteState, soundbuff, ref samplesEmitted) > 0)
+				{
+					LibGambatte.gambatte_blitto(GambatteState, VideoBuffer, 160);
+				}
+
+				_cycleCount += samplesEmitted;
+				frameOverflow = 0;
+				if (rendersound && !Muted)
+				{
+					ProcessSound((int)samplesEmitted);
+				}
+			}
+
+			if (rendersound && !Muted)
+			{
+				ProcessSoundEnd();
+			}
+
+			FrameAdvancePost();
+		}
+
+		public int Frame { get; private set; }
+
+		public string SystemId => "GB";
+
+		public string BoardName { get; }
+
+		public bool DeterministicEmulation { get; }
+
+		public void ResetCounters()
+		{
+			Frame = 0;
+			LagCount = 0;
+			IsLagFrame = false;
+
+			// reset frame counters is meant to "re-zero" emulation time wherever it was
+			// so these should be reset as well
+			_cycleCount = 0;
+			frameOverflow = 0;
+		}
+
+		public CoreComm CoreComm { get; }
+
+		public void Dispose()
+		{
+			if (GambatteState != IntPtr.Zero)
+			{
+				LibGambatte.gambatte_destroy(GambatteState);
+				GambatteState = IntPtr.Zero;
+			}
+
+			DisposeSound();
+		}
+	}
+}
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs
index 974fc98b76..a3db6902ad 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs
@@ -14,8 +14,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 		isPorted: true,
 		isReleased: true,
 		portedVersion: "SVN 344",
-		portedUrl: "http://gambatte.sourceforge.net/"
-		)]
+		portedUrl: "http://gambatte.sourceforge.net/")]
 	[ServiceNotApplicable(typeof(IDriveLight), typeof(IDriveLight))]
 	public partial class Gameboy : IEmulator, IVideoProvider, ISoundProvider, ISaveRam, IStatable, IInputPollable, ICodeDataLogger,
 		IDebuggable, ISettable<Gameboy.GambatteSettings, Gameboy.GambatteSyncSettings>
@@ -33,59 +32,60 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 		/// <summary>
 		/// keep a copy of the input callback delegate so it doesn't get GCed
 		/// </summary>
-		LibGambatte.InputGetter InputCallback;
+		private LibGambatte.InputGetter InputCallback;
 
 		/// <summary>
 		/// whatever keys are currently depressed
 		/// </summary>
-		LibGambatte.Buttons CurrentButtons = 0;
+		private LibGambatte.Buttons CurrentButtons = 0;
 
 		#region RTC
 
 		/// <summary>
 		/// RTC time when emulation begins.
 		/// </summary>
-		uint zerotime = 0;
+		private readonly uint zerotime = 0;
 
 		/// <summary>
 		/// if true, RTC will run off of real elapsed time
 		/// </summary>
-		bool real_rtc_time = false;
+		private bool real_rtc_time = false;
 
-		LibGambatte.RTCCallback TimeCallback;
+		private LibGambatte.RTCCallback TimeCallback;
 
-		static long GetUnixNow()
+		private static long GetUnixNow()
 		{
 			// because internally the RTC works off of relative time, we don't need to base
 			// this off of any particular canonical epoch.
 			return DateTime.UtcNow.Ticks / 10000000L - 60000000000L;
 		}
 
-		uint GetCurrentTime()
+		private uint GetCurrentTime()
 		{
 			if (real_rtc_time)
 			{
 				return (uint)GetUnixNow();
 			}
-			else
-			{
-				ulong fn = (ulong)Frame;
-				// as we're exactly tracking cpu cycles, this can be pretty accurate
-				fn *= 4389;
-				fn /= 262144;
-				fn += zerotime;
-				return (uint)fn;
-			}
+
+			ulong fn = (ulong)Frame;
+
+			// as we're exactly tracking cpu cycles, this can be pretty accurate
+			fn *= 4389;
+			fn /= 262144;
+			fn += zerotime;
+			return (uint)fn;
 		}
 
-		uint GetInitialTime()
+		private uint GetInitialTime()
 		{
 			if (real_rtc_time)
+			{
 				return (uint)GetUnixNow();
-			else
-				// setting the initial boot time to 0 will cause our zerotime
-				// to function as an initial offset, which is what we want
-				return 0;
+			}
+
+			// setting the initial boot time to 0 will cause our zerotime
+			// to function as an initial offset, which is what we want
+			return 0;
 		}
 
 		#endregion
@@ -119,26 +119,40 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 			GambatteState = LibGambatte.gambatte_create();
 
 			if (GambatteState == IntPtr.Zero)
+			{
 				throw new InvalidOperationException("gambatte_create() returned null???");
+			}
 
 			try
 			{
-				this._syncSettings = (GambatteSyncSettings)SyncSettings ?? new GambatteSyncSettings();
+				_syncSettings = (GambatteSyncSettings)SyncSettings ?? new GambatteSyncSettings();
+
 				// copy over non-loadflag syncsettings now; they won't take effect if changed later
-				zerotime = (uint)this._syncSettings.RTCInitialTime;
-				real_rtc_time = DeterministicEmulation ? false : this._syncSettings.RealTimeRTC;
+				zerotime = (uint)_syncSettings.RTCInitialTime;
+
+				real_rtc_time = !DeterministicEmulation && _syncSettings.RealTimeRTC;
 
 				LibGambatte.LoadFlags flags = 0;
 
-				if (this._syncSettings.ForceDMG)
+				if (_syncSettings.ForceDMG)
+				{
 					flags |= LibGambatte.LoadFlags.FORCE_DMG;
-				if (this._syncSettings.GBACGB)
+				}
+
+				if (_syncSettings.GBACGB)
+				{
 					flags |= LibGambatte.LoadFlags.GBA_CGB;
-				if (this._syncSettings.MulticartCompat)
+				}
+
+				if (_syncSettings.MulticartCompat)
+				{
 					flags |= LibGambatte.LoadFlags.MULTICART_COMPAT;
+				}
 
 				if (LibGambatte.gambatte_load(GambatteState, file, (uint)file.Length, GetCurrentTime(), flags) != 0)
+				{
 					throw new InvalidOperationException("gambatte_load() returned non-zero (is this not a gb or gbc rom?)");
+				}
 
 				// set real default colors (before anyone mucks with them at all)
 				PutSettings((GambatteSettings)Settings ?? new GambatteSettings());
@@ -155,17 +169,12 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 
 				InitMemoryDomains();
 
-				CoreComm.RomStatusDetails = string.Format("{0}\r\nSHA1:{1}\r\nMD5:{2}\r\n",
-					game.Name,
-					file.HashSHA1(),
-					file.HashMD5());
+				CoreComm.RomStatusDetails = $"{game.Name}\r\nSHA1:{file.HashSHA1()}\r\nMD5:{file.HashMD5()}\r\n";
 
-				{
-					byte[] buff = new byte[32];
-					LibGambatte.gambatte_romtitle(GambatteState, buff);
-					string romname = System.Text.Encoding.ASCII.GetString(buff);
-					Console.WriteLine("Core reported rom name: {0}", romname);
-				}
+				byte[] buff = new byte[32];
+				LibGambatte.gambatte_romtitle(GambatteState, buff);
+				string romname = System.Text.Encoding.ASCII.GetString(buff);
+				Console.WriteLine("Core reported rom name: {0}", romname);
 
 				TimeCallback = new LibGambatte.RTCCallback(GetCurrentTime);
 				LibGambatte.gambatte_setrtccallback(GambatteState, TimeCallback);
@@ -181,17 +190,13 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 			}
 		}
 
-	
-		public IEmulatorServiceProvider ServiceProvider { get; private set; }
-
 		#region ALL SAVESTATEABLE STATE GOES HERE
 
 		/// <summary>
 		/// internal gambatte state
 		/// </summary>
-		internal IntPtr GambatteState = IntPtr.Zero;
+		internal IntPtr GambatteState { get; private set; } = IntPtr.Zero;
 
-		public int Frame { get; set; }
 		public int LagCount { get; set; }
 		public bool IsLagFrame { get; set; }
 
@@ -206,7 +211,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 		/// number of extra cycles we overran in the last frame
 		/// </summary>
 		private uint frameOverflow = 0;
-		public ulong CycleCount { get { return _cycleCount; } }
+		public ulong CycleCount => _cycleCount;
 
 		#endregion
 
@@ -221,14 +226,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 			}
 		};
 
-		public ControllerDefinition ControllerDefinition
-		{
-			get { return GbController; }
-		}
-
-		public IController Controller { get; set; }
-
-		LibGambatte.Buttons ControllerCallback()
+		private LibGambatte.Buttons ControllerCallback()
 		{
 			InputCallbacks.Call();
 			IsLagFrame = false;
@@ -240,21 +238,20 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 		/// <summary>
 		/// true if the emulator is currently emulating CGB
 		/// </summary>
-		/// <returns></returns>
 		public bool IsCGBMode()
 		{
-			return (LibGambatte.gambatte_iscgb(GambatteState));
+			return LibGambatte.gambatte_iscgb(GambatteState);
 		}
 
 		private InputCallbackSystem _inputCallbacks = new InputCallbackSystem();
+
 		// low priority TODO: due to certain aspects of the core implementation,
 		// we don't smartly use the ActiveChanged event here.
-		public IInputCallbackSystem InputCallbacks { get { return _inputCallbacks; } }
+		public IInputCallbackSystem InputCallbacks => _inputCallbacks;
 
 		/// <summary>
 		/// for use in dual core
 		/// </summary>
-		/// <param name="ics"></param>
 		public void ConnectInputCallbackSystem(InputCallbackSystem ics)
 		{
 			_inputCallbacks = ics;
@@ -288,12 +285,19 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 			IsLagFrame = true;
 
 			if (Controller.IsPressed("Power"))
+			{
 				LibGambatte.gambatte_reset(GambatteState, GetCurrentTime());
+			}
 
 			if (Tracer.Enabled)
+			{
 				tracecb = MakeTrace;
+			}
 			else
+			{
 				tracecb = null;
+			}
+
 			LibGambatte.gambatte_settracecallback(GambatteState, tracecb);
 
 			LibGambatte.gambatte_setlayers(GambatteState, (_settings.DisplayBG ? 1 : 0) | (_settings.DisplayOBJ ? 2 : 0) | (_settings.DisplayWindow ? 4 : 0 ) );
@@ -302,65 +306,15 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 		internal void FrameAdvancePost()
 		{
 			if (IsLagFrame)
+			{
 				LagCount++;
-
-			if (endofframecallback != null)
-				endofframecallback(LibGambatte.gambatte_cpuread(GambatteState, 0xff40));
-		}
-
-		public void FrameAdvance(bool render, bool rendersound)
-		{
-			FrameAdvancePrep();
-			if (_syncSettings.EqualLengthFrames)
-			{
-				while (true)
-				{
-					// target number of samples to emit: length of 1 frame minus whatever overflow
-					uint samplesEmitted = TICKSINFRAME - frameOverflow;
-					System.Diagnostics.Debug.Assert(samplesEmitted * 2 <= soundbuff.Length);
-					if (LibGambatte.gambatte_runfor(GambatteState, soundbuff, ref samplesEmitted) > 0)
-						LibGambatte.gambatte_blitto(GambatteState, VideoBuffer, 160);
-
-					// account for actual number of samples emitted
-					_cycleCount += (ulong)samplesEmitted;
-					frameOverflow += samplesEmitted;
-
-					if (rendersound && !Muted)
-					{
-						ProcessSound((int)samplesEmitted);
-					}
-
-					if (frameOverflow >= TICKSINFRAME)
-					{
-						frameOverflow -= TICKSINFRAME;
-						break;
-					}
-				}
-			}
-			else
-			{
-				// target number of samples to emit: always 59.7fps
-				// runfor() always ends after creating a video frame, so sync-up is guaranteed
-				// when the display has been off, some frames can be markedly shorter than expected
-				uint samplesEmitted = TICKSINFRAME;
-				if (LibGambatte.gambatte_runfor(GambatteState, soundbuff, ref samplesEmitted) > 0)
-					LibGambatte.gambatte_blitto(GambatteState, VideoBuffer, 160);
-
-				_cycleCount += (ulong)samplesEmitted;
-				frameOverflow = 0;
-				if (rendersound && !Muted)
-				{
-					ProcessSound((int)samplesEmitted);
-				}
 			}
 
-			if (rendersound && !Muted)
-				ProcessSoundEnd();
-
-			FrameAdvancePost();
+			endofframecallback?.Invoke(LibGambatte.gambatte_cpuread(GambatteState, 0xff40));
 		}
 
-		static string MapperName(byte[] romdata)
+
+		private static string MapperName(byte[] romdata)
 		{
 			switch (romdata[0x147])
 			{
@@ -391,11 +345,12 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 		/// <summary>
 		/// throw exception with intelligible message on some kinds of bad rom
 		/// </summary>
-		/// <param name="romdata"></param>
-		static void ThrowExceptionForBadRom(byte[] romdata)
+		private static void ThrowExceptionForBadRom(byte[] romdata)
 		{
 			if (romdata.Length < 0x148)
+			{
 				throw new ArgumentException("ROM is far too small to be a valid GB\\GBC rom!");
+			}
 
 			switch (romdata[0x147])
 			{
@@ -436,30 +391,10 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 				case 0xfd: throw new UnsupportedGameException("\"Bandai TAMA5\" Mapper not supported!");
 				case 0xfe: throw new UnsupportedGameException("\"HuC3\" Mapper not supported!");
 				case 0xff: break;
-				default: throw new UnsupportedGameException(string.Format("Unknown mapper: {0:x2}", romdata[0x147]));
+				default: throw new UnsupportedGameException($"Unknown mapper: {romdata[0x147]:x2}");
 			}
-			return;
 		}
 
-		public string SystemId { get { return "GB"; } }
-
-		public string BoardName { get; private set; }
-
-		public bool DeterministicEmulation { get; private set; }
-
-		public void ResetCounters()
-		{
-			Frame = 0;
-			LagCount = 0;
-			IsLagFrame = false;
-			// reset frame counters is meant to "re-zero" emulation time wherever it was
-			// so these should be reset as well
-			_cycleCount = 0;
-			frameOverflow = 0;
-		}
-
-		public CoreComm CoreComm { get; set; }
-
 		#region ppudebug
 
 		public bool GetGPUMemoryAreas(out IntPtr vram, out IntPtr bgpal, out IntPtr sppal, out IntPtr oam)
@@ -488,7 +423,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 		}
 
 		/// <summary>
-		/// 
 		/// </summary>
 		/// <param name="lcdc">current value of register $ff40 (LCDC)</param>
 		public delegate void ScanlineCallback(int lcdc);
@@ -496,26 +430,31 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 		/// <summary>
 		/// set up callback
 		/// </summary>
-		/// <param name="callback"></param>
 		/// <param name="line">scanline. -1 = end of frame, -2 = RIGHT NOW</param>
 		public void SetScanlineCallback(ScanlineCallback callback, int line)
 		{
 			if (GambatteState == IntPtr.Zero)
-				// not sure how this is being reached.  tried the debugger...
-				return;
+			{
+				return; // not sure how this is being reached.  tried the debugger...
+			}
+
 			endofframecallback = null;
 			if (callback == null || line == -1 || line == -2)
 			{
 				scanlinecb = null;
 				LibGambatte.gambatte_setscanlinecallback(GambatteState, null, 0);
 				if (line == -1)
+				{
 					endofframecallback = callback;
+				}
 				else if (line == -2)
+				{
 					callback(LibGambatte.gambatte_cpuread(GambatteState, 0xff40));
+				}
 			}
 			else if (line >= 0 && line <= 153)
 			{
-				scanlinecb = delegate()
+				scanlinecb = delegate
 				{
 					callback(LibGambatte.gambatte_cpuread(GambatteState, 0xff40));
 				};
@@ -532,16 +471,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 
 		#endregion
 
-		public void Dispose()
-		{
-			if (GambatteState != IntPtr.Zero)
-			{
-				LibGambatte.gambatte_destroy(GambatteState);
-				GambatteState = IntPtr.Zero;
-			}
-			DisposeSound();
-		}
-
 		#region palette
 
 		/// <summary>
@@ -550,7 +479,9 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 		public void ChangeDMGColors(int[] colors)
 		{
 			for (int i = 0; i < 12; i++)
+			{
 				LibGambatte.gambatte_setdmgpalettecolor(GambatteState, (LibGambatte.PalType)(i / 4), (uint)i % 4, (uint)colors[i]);
+			}
 		}
 
 		public void SetCGBColors(GBColors.ColorType type)