Refactor ITraceable and related types

src/BizHawk.Emulation.Common/Base Implementations/CallbackBasedTraceBuffer.cs

@@ -15,8 +15,10 @@ namespace BizHawk.Emulation.Common
 	/// </summary>
 	public abstract class CallbackBasedTraceBuffer : ITraceable
 	{
+		private const string DEFAULT_HEADER = "Instructions";
+
 		/// <exception cref="InvalidOperationException"><paramref name="debuggableCore"/> does not provide memory callback support or does not implement <see cref="IDebuggable.GetCpuFlagsAndRegisters"/></exception>
-		protected CallbackBasedTraceBuffer(IDebuggable debuggableCore, IMemoryDomains memoryDomains, IDisassemblable disassembler)
+		protected CallbackBasedTraceBuffer(IDebuggable debuggableCore, IMemoryDomains memoryDomains, IDisassemblable disassembler, string header = DEFAULT_HEADER)
 		{
 			if (!debuggableCore.MemoryCallbacksAvailable())
 			{
@@ -32,7 +34,7 @@ namespace BizHawk.Emulation.Common
 				throw new InvalidOperationException($"{nameof(IDebuggable.GetCpuFlagsAndRegisters)} is required");
 			}
 
-			Header = "Instructions";
+			Header = header;
 			DebuggableCore = debuggableCore;
 			MemoryDomains = memoryDomains;
 			Disassembler = disassembler;
@@ -48,20 +50,9 @@ namespace BizHawk.Emulation.Common
 
 		private ITraceSink _sink;
 
-		public bool Enabled => Sink != null;
-
-		public void Put(TraceInfo info)
-		{
-			Sink.Put(info);
-		}
-
 		public ITraceSink Sink
 		{
-			private get
+			get => _sink;
-			{
-				return _sink;
-			}
-
 			set
 			{
 				_sink = value;
@@ -75,7 +66,7 @@ namespace BizHawk.Emulation.Common
 			}
 		}
 
-		public string Header { get; protected set; }
+		public string Header { get; }
 
 		private class TracingMemoryCallback : IMemoryCallback
 		{

src/BizHawk.Emulation.Common/Base Implementations/TraceBuffer.cs

@@ -1,6 +1,4 @@
-#nullable disable
+namespace BizHawk.Emulation.Common
-
-namespace BizHawk.Emulation.Common
 {
 	/// <summary>
 	/// A generic implementation of ITraceable that can be used by any core
@@ -8,15 +6,12 @@ namespace BizHawk.Emulation.Common
 	/// <seealso cref="ITraceable" />
 	public class TraceBuffer : ITraceable
 	{
-		public string Header { get; set; } = "Instructions";
+		private const string DEFAULT_HEADER = "Instructions";
 
-		public ITraceSink Sink { private get; set; }
+		public string Header { get; }
 
-		public bool Enabled => Sink != null;
+		public ITraceSink? Sink { get; set; }
 
-		public void Put(TraceInfo info)
+		public TraceBuffer(string header = DEFAULT_HEADER) => Header = header;
-		{
-			Sink.Put(info);
-		}
 	}
 }

src/BizHawk.Emulation.Common/Extensions.cs

@@ -484,5 +484,10 @@ namespace BizHawk.Emulation.Common
 
 		public static string SystemIDToDisplayName(string sysID)
 			=> SystemIDDisplayNames.TryGetValue(sysID, out var dispName) ? dispName : string.Empty;
+
+		public static bool IsEnabled(this ITraceable core) => core.Sink is not null;
+
+		/// <remarks>TODO no-op instead of NRE when not "enabled"?</remarks>
+		public static void Put(this ITraceable core, TraceInfo info) => core.Sink.Put(info);
 	}
 }

src/BizHawk.Emulation.Common/Interfaces/Services/ITraceable.cs

@@ -1,6 +1,4 @@
-#nullable disable
+namespace BizHawk.Emulation.Common
-
-namespace BizHawk.Emulation.Common
 {
 	public interface ITraceSink
 	{
@@ -23,25 +21,19 @@ namespace BizHawk.Emulation.Common
 		/// that's right, we can only have one sink.
 		/// a sink can route to two other sinks if it has to, though
 		/// </summary>
-		ITraceSink Sink { set; }
+		ITraceSink? Sink { get; set; }
-
-		/// <summary>
-		/// Gets a value indicating whether tracing is enabled
-		/// This is defined as equivalent to Sink != null
-		/// It's put here because it's such a common operation to check whether it's enabled, and it's not nice to write Sink != null all over
-		/// </summary>
-		bool Enabled { get; }
-
-		/// <summary>
-		/// This is defined as equivalent to Sink.Put
-		/// TBD: could it be defined as equivalent to if(Enabled) Sink.Put()? Probably not, that's just a small amount of wasted work
-		/// </summary>
-		void Put(TraceInfo info);
 	}
 
-	public class TraceInfo
+	public readonly struct TraceInfo
 	{
-		public string Disassembly { get; set; }
+		public readonly string Disassembly;
-		public string RegisterInfo { get; set; }
+
+		public readonly string RegisterInfo;
+
+		public TraceInfo(string disassembly, string registerInfo)
+		{
+			Disassembly = disassembly;
+			RegisterInfo = registerInfo;
+		}
 	}
 }

src/BizHawk.Emulation.Cores/CPUs/CP1610/CP1610.Execute.cs

@@ -19,11 +19,9 @@ namespace BizHawk.Emulation.Cores.Components.CP1610
 		public int opcode;
 
 		public TraceInfo CP1610State(bool disassemble = true)
-		{
+			=> new(
-			return new TraceInfo
+				disassembly: $"{RegisterPC - 1:X4}:  {opcode:X2}  {(disassemble ? Disassemble((ushort)(RegisterPC - 1), out _) : "---")} ".PadRight(26),
-			{
+				registerInfo: string.Join(" ",
-				Disassembly = $"{RegisterPC - 1:X4}:  {opcode:X2}  {(disassemble ? Disassemble((ushort)(RegisterPC - 1), out _) : "---")} ".PadRight(26),
-				RegisterInfo = string.Join(" ",
 					new[]
 					{
 						$"Cy:{TotalExecutedCycles}",
@@ -34,10 +32,7 @@ namespace BizHawk.Emulation.Cores.Components.CP1610
 							FlagO ? "O" : "o",
 							FlagI ? "I" : "i",
 							FlagD ? "D" : "d")
-					}
+					}.Concat(Register.Select((r, i) => $"R{i}:{4:X4}"))));
-						.Concat(Register.Select((r, i) => $"R{i}:{4:X4}")))
-			};
-		}	
 
 		private void Calc_FlagC(int result)
 		{

src/BizHawk.Emulation.Cores/CPUs/HuC6280/HuC6280.cs

@@ -381,11 +381,9 @@ namespace BizHawk.Emulation.Cores.Components.H6280
 		public string TraceHeader => "HuC6280: PC, machine code, mnemonic, operands, registers (A, X, Y, P, SP, Cy), flags (NVTBDIZC)";
 
 		public TraceInfo State()
-		{
+			=> new(
-			return new TraceInfo
+				disassembly: $"{MPR[PC >> 13]:X2}:{PC:X4}:  {ReadMemory(PC):X2}  {Disassemble(PC, out _)} ".PadRight(30),
-			{
+				registerInfo: string.Join(" ",
-				Disassembly = $"{MPR[PC >> 13]:X2}:{PC:X4}:  {ReadMemory(PC):X2}  {Disassemble(PC, out _)} ".PadRight(30),
-				RegisterInfo = string.Join(" ",
 					$"A:{A:X2}",
 					$"X:{X:X2}",
 					$"Y:{Y:X2}",
@@ -400,9 +398,7 @@ namespace BizHawk.Emulation.Cores.Components.H6280
 						FlagD ? "D" : "d",
 						FlagI ? "I" : "i",
 						FlagZ ? "Z" : "z",
-						FlagC ? "C" : "c"))
+						FlagC ? "C" : "c")));
-			};
-		}
 
 		private static readonly byte[] TableNZ = 
 		{ 

src/BizHawk.Emulation.Cores/CPUs/Intel8048/I8048.cs

@@ -448,7 +448,7 @@ namespace BizHawk.Emulation.Cores.Components.I8048
 				{
 					IRQPending = false;
 
-					TraceCallback?.Invoke(new TraceInfo { Disassembly = "====IRQ====", RegisterInfo = "" });
+					TraceCallback?.Invoke(new(disassembly: "====IRQ====", registerInfo: string.Empty));
 
 					IRQ_(0);
 					IRQCallback();
@@ -458,7 +458,7 @@ namespace BizHawk.Emulation.Cores.Components.I8048
 				{
 					TIRQPending = false;
 
-					TraceCallback?.Invoke(new TraceInfo { Disassembly = "====TIRQ====", RegisterInfo = "" });
+					TraceCallback?.Invoke(new(disassembly: "====TIRQ====", registerInfo: string.Empty));
 
 					IRQ_(1);
 					IRQCallback();
@@ -522,11 +522,9 @@ namespace BizHawk.Emulation.Cores.Components.I8048
 		public string TraceHeader => "I8048: PC, machine code, mnemonic, operands, registers (A, B, X, Y, US, SP, DP, CC), Cy, flags (CAFBIFT0T1TFR)";
 
 		public TraceInfo State(bool disassemble = true)
-		{
+			=> new(
-			return new TraceInfo
+				disassembly: $"{(disassemble ? Disassemble(Regs[PC], ReadMemory, out _) : "---")} ".PadRight(50),
-			{
+				registerInfo: string.Format(
-				Disassembly = $"{(disassemble ? Disassemble(Regs[PC], ReadMemory, out _) : "---")} ".PadRight(50),
-				RegisterInfo = string.Format(
 					"A:{0:X2} R0:{1:X2} R1:{2:X2} R2:{3:X2} R3:{4:X2} R4:{5:X2} R5:{6:X2} R6:{7:X2} R7:{8:X2} PSW:{9:X4} Cy:{10} LY:{11} {12}{13}{14}{15}{16}{17}{18}{19}{20}{21}{22}",
 					Regs[A],
 					Regs[(ushort)(R0 + RB)],
@@ -550,10 +548,7 @@ namespace BizHawk.Emulation.Cores.Components.I8048
 					T0 ? "T" : "t",
 					T1 ? "T" : "t",
 					TF ? "T" : "t",
-					RB > 0 ? "R" : "r"
+					RB > 0 ? "R" : "r"));
-					)
-			};
-		}
 
 		/// <summary>
 		/// Optimization method to set cur_instr

src/BizHawk.Emulation.Cores/CPUs/LR35902/LR35902.cs

@@ -164,11 +164,7 @@ namespace BizHawk.Emulation.Cores.Components.LR35902
 					{
 						interrupts_enabled = false;
 
-						TraceCallback?.Invoke(new TraceInfo
+						TraceCallback?.Invoke(new(disassembly: "====IRQ====", registerInfo: string.Empty));
-						{
-							Disassembly = "====IRQ====",
-							RegisterInfo = ""
-						});
 
 						// call interrupt processor 
 						// lowest bit set is highest priority
@@ -333,11 +329,7 @@ namespace BizHawk.Emulation.Cores.Components.LR35902
 						{
 							interrupts_enabled = false;
 
-							TraceCallback?.Invoke(new TraceInfo
+							TraceCallback?.Invoke(new(disassembly: "====IRQ====", registerInfo: string.Empty));
-							{
-								Disassembly = "====IRQ====",
-								RegisterInfo = ""
-							});
 
 							RegPC--;
 
@@ -347,11 +339,7 @@ namespace BizHawk.Emulation.Cores.Components.LR35902
 						}
 						else
 						{
-							TraceCallback?.Invoke(new TraceInfo
+							TraceCallback?.Invoke(new(disassembly: "====un-halted====", registerInfo: string.Empty));
-							{
-								Disassembly = "====un-halted====",
-								RegisterInfo = ""
-							});
 
 							OnExecFetch?.Invoke(RegPC);
 							if (TraceCallback != null && !CB_prefix) TraceCallback(State(useRGBDSSyntax));
@@ -364,11 +352,7 @@ namespace BizHawk.Emulation.Cores.Components.LR35902
 					{
 						interrupts_enabled = false;
 
-						TraceCallback?.Invoke(new TraceInfo
+						TraceCallback?.Invoke(new(disassembly: "====IRQ====", registerInfo: string.Empty));
-						{
-							Disassembly = "====IRQ====",
-							RegisterInfo = ""
-						});
 						halted = false;
 
 						if (Halt_bug_4)
@@ -407,11 +391,7 @@ namespace BizHawk.Emulation.Cores.Components.LR35902
 					else if (temp)
 					{
 						// even if interrupt servicing is disabled, any interrupt flag raised still resumes execution
-						TraceCallback?.Invoke(new TraceInfo
+						TraceCallback?.Invoke(new(disassembly: "====un-halted====", registerInfo: string.Empty));
-						{
-							Disassembly = "====un-halted====",
-							RegisterInfo = ""
-						});
 						halted = false;
 
 						if (is_GBC)
@@ -493,21 +473,13 @@ namespace BizHawk.Emulation.Cores.Components.LR35902
 							interrupts_enabled = false;
 							I_use = false;
 
-							TraceCallback?.Invoke(new TraceInfo
+							TraceCallback?.Invoke(new(disassembly: "====un-stop====", registerInfo: string.Empty));
-							{
-								Disassembly = "====un-stop====",
-								RegisterInfo = ""
-							});
 
 							stopped = false;
 							stop_check = false;
 							stop_time = 0;
 
-							TraceCallback?.Invoke(new TraceInfo
+							TraceCallback?.Invoke(new(disassembly: "====IRQ====", registerInfo: string.Empty));
-							{
-								Disassembly = "====IRQ====",
-								RegisterInfo = ""
-							});
 
 							// call interrupt processor 
 							// lowest bit set is highest priority
@@ -527,11 +499,7 @@ namespace BizHawk.Emulation.Cores.Components.LR35902
 
 						if (stop_time == 0)
 						{
-							TraceCallback?.Invoke(new TraceInfo
+							TraceCallback?.Invoke(new(disassembly: "====un-stop====", registerInfo: string.Empty));
-							{
-								Disassembly = "====un-stop====",
-								RegisterInfo = ""
-							});
 
 							stopped = false;
 
@@ -555,11 +523,7 @@ namespace BizHawk.Emulation.Cores.Components.LR35902
 					if ((buttons_pressed & 0xF) != 0xF)
 					{
 						// TODO: On a gameboy, you can only un-STOP once, needs further testing
-						TraceCallback?.Invoke(new TraceInfo
+						TraceCallback?.Invoke(new(disassembly: "====un-stop====", registerInfo: string.Empty));
-						{
-							Disassembly = "====un-stop====",
-							RegisterInfo = ""
-						});
 
 						stopped = false;
 						OnExecFetch?.Invoke(RegPC);
@@ -753,11 +717,9 @@ namespace BizHawk.Emulation.Cores.Components.LR35902
 		public string TraceHeader => "LR35902: PC, machine code, mnemonic, operands, registers (A, F, B, C, D, E, H, L, SP), Cy, flags (ZNHCI)";
 
 		public TraceInfo State(bool useRGBDSSyntax, bool disassemble = true)
-		{
+			=> new(
-			return new TraceInfo
+				disassembly: $"{(disassemble ? Disassemble(RegPC, ReadMemory, useRGBDSSyntax, out _) : "---")} ".PadRight(40),
-			{
+				registerInfo: string.Join(" ",
-				Disassembly = $"{(disassemble ? Disassemble(RegPC, ReadMemory, useRGBDSSyntax, out _) : "---")} ".PadRight(40),
-				RegisterInfo = string.Join(" ",
 					$"A:{Regs[A]:X2}",
 					$"F:{Regs[F]:X2}",
 					$"B:{Regs[B]:X2}",
@@ -775,9 +737,7 @@ namespace BizHawk.Emulation.Cores.Components.LR35902
 						FlagH ? "H" : "h",
 						FlagC ? "C" : "c",
 						FlagI ? "I" : "i",
-						interrupts_enabled ? "E" : "e"))
+						interrupts_enabled ? "E" : "e")));
-			};
-		}
 
 		private void FetchInstruction(int op)
 		{

src/BizHawk.Emulation.Cores/CPUs/MC6800/MC6800.cs

@@ -433,7 +433,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6800
 						irq_pntr = -1;
 						IRQS = 3;
 
-						TraceCallback?.Invoke(new TraceInfo { Disassembly = "====CWAI NMI====", RegisterInfo = "" });
+						TraceCallback?.Invoke(new(disassembly: "====CWAI NMI====", registerInfo: string.Empty));
 					}
 					else if (IRQPending && !FlagI)
 					{
@@ -446,7 +446,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6800
 						irq_pntr = -1;
 						IRQS = 3;
 
-						TraceCallback?.Invoke(new TraceInfo { Disassembly = "====CWAI IRQ====", RegisterInfo = "" });
+						TraceCallback?.Invoke(new(disassembly: "====CWAI IRQ====", registerInfo: string.Empty));
 					}
 					else
 					{
@@ -465,7 +465,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6800
 				{
 					NMIPending = false;
 
-					TraceCallback?.Invoke(new TraceInfo { Disassembly = "====NMI====", RegisterInfo = "" });
+					TraceCallback?.Invoke(new(disassembly: "====NMI====", registerInfo: string.Empty));
 
 					NMI_();
 					NMICallback();
@@ -476,7 +476,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6800
 				{
 					IRQPending = false;
 
-					TraceCallback?.Invoke(new TraceInfo { Disassembly = "====IRQ====", RegisterInfo = "" });
+					TraceCallback?.Invoke(new(disassembly: "====IRQ====", registerInfo: string.Empty));
 
 					IRQ_();
 					IRQCallback();
@@ -501,11 +501,9 @@ namespace BizHawk.Emulation.Cores.Components.MC6800
 		public string TraceHeader => "MC6809: PC, machine code, mnemonic, operands, registers (A, B, X, SP, CC), Cy, flags (EHINZVC)";
 
 		public TraceInfo State(bool disassemble = true)
-		{
+			=> new(
-			return new TraceInfo
+				disassembly: $"{(disassemble ? Disassemble(Regs[PC], ReadMemory, out _) : "---")} ".PadRight(50),
-			{
+				registerInfo: string.Format(
-				Disassembly = $"{(disassemble ? Disassemble(Regs[PC], ReadMemory, out _) : "---")} ".PadRight(50),
-				RegisterInfo = string.Format(
 					"A:{0:X2} B:{1:X2} X:{2:X4} SP:{3:X4} CC:{4:X2} Cy:{5} {6}{7}{8}{9}{10}{11}",
 					Regs[A],
 					Regs[B],
@@ -518,10 +516,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6800
 					FlagN ? "N" : "n",
 					FlagZ ? "Z" : "z",
 					FlagV ? "V" : "v",
-					FlagC ? "C" : "c"
+					FlagC ? "C" : "c"));
-					)
-			};
-		}
 
 		/// <summary>
 		/// Optimization method to set cur_instr

src/BizHawk.Emulation.Cores/CPUs/MC6809/MC6809.cs

@@ -473,7 +473,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6809
 						irq_pntr = -1;
 						IRQS = 3;
 
-						TraceCallback?.Invoke(new TraceInfo { Disassembly = "====CWAI NMI====", RegisterInfo = "" });
+						TraceCallback?.Invoke(new(disassembly: "====CWAI NMI====", registerInfo: string.Empty));
 					}
 					else if (FIRQPending && !FlagF)
 					{
@@ -486,7 +486,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6809
 						irq_pntr = -1;
 						IRQS = 3;
 
-						TraceCallback?.Invoke(new TraceInfo { Disassembly = "====CWAI FIRQ====", RegisterInfo = "" });
+						TraceCallback?.Invoke(new(disassembly: "====CWAI FIRQ====", registerInfo: string.Empty));
 					}
 					else if (IRQPending && !FlagI)
 					{
@@ -499,7 +499,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6809
 						irq_pntr = -1;
 						IRQS = 3;
 
-						TraceCallback?.Invoke(new TraceInfo { Disassembly = "====CWAI IRQ====", RegisterInfo = "" });
+						TraceCallback?.Invoke(new(disassembly: "====CWAI IRQ====", registerInfo: string.Empty));
 					}
 					else
 					{
@@ -522,7 +522,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6809
 						irq_pntr = -1;
 						IRQS = 3;
 
-						TraceCallback?.Invoke(new TraceInfo { Disassembly = "====SYNC NMI====", RegisterInfo = "" });
+						TraceCallback?.Invoke(new(disassembly: "====SYNC NMI====", registerInfo: string.Empty));
 					}
 					else if (FIRQPending)
 					{
@@ -537,7 +537,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6809
 							irq_pntr = -1;
 							IRQS = 3;
 
-							TraceCallback?.Invoke(new TraceInfo { Disassembly = "====SYNC FIRQ====", RegisterInfo = "" });
+							TraceCallback?.Invoke(new(disassembly: "====SYNC FIRQ====", registerInfo: string.Empty));
 						}
 						else
 						{
@@ -563,7 +563,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6809
 							irq_pntr = -1;
 							IRQS = 3;
 
-							TraceCallback?.Invoke(new TraceInfo { Disassembly = "====SYNC IRQ====", RegisterInfo = "" });
+							TraceCallback?.Invoke(new(disassembly: "====SYNC IRQ====", registerInfo: string.Empty));
 						}
 						else
 						{
@@ -593,7 +593,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6809
 				{
 					NMIPending = false;
 
-					TraceCallback?.Invoke(new TraceInfo { Disassembly = "====NMI====", RegisterInfo = "" });
+					TraceCallback?.Invoke(new(disassembly: "====NMI====", registerInfo: string.Empty));
 
 					NMI_();
 					NMICallback();
@@ -604,7 +604,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6809
 				{
 					FIRQPending = false;
 
-					TraceCallback?.Invoke(new TraceInfo { Disassembly = "====FIRQ====", RegisterInfo = "" });
+					TraceCallback?.Invoke(new(disassembly: "====FIRQ====", registerInfo: string.Empty));
 
 					FIRQ_();
 					FIRQCallback();
@@ -615,7 +615,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6809
 				{
 					IRQPending = false;
 
-					TraceCallback?.Invoke(new TraceInfo { Disassembly = "====IRQ====", RegisterInfo = "" });
+					TraceCallback?.Invoke(new(disassembly: "====IRQ====", registerInfo: string.Empty));
 					IRQ_();
 					IRQCallback();
 					instr_pntr = irq_pntr = 0;
@@ -639,11 +639,9 @@ namespace BizHawk.Emulation.Cores.Components.MC6809
 		public string TraceHeader => "MC6809: PC, machine code, mnemonic, operands, registers (A, B, X, Y, US, SP, DP, CC), Cy, flags (EFHINZVC)";
 
 		public TraceInfo State(bool disassemble = true)
-		{
+			=> new(
-			return new TraceInfo
+				disassembly: $"{(disassemble ? Disassemble(Regs[PC], ReadMemory, out _) : "---")} ".PadRight(50),
-			{
+				registerInfo: string.Format(
-				Disassembly = $"{(disassemble ? Disassemble(Regs[PC], ReadMemory, out _) : "---")} ".PadRight(50),
-				RegisterInfo = string.Format(
 					"A:{0:X2} B:{1:X2} X:{2:X4} Y:{3:X4} US:{4:X4} SP:{5:X4} DP:{6:X2} CC:{7:X2} Cy:{8} {9}{10}{11}{12}{13}{14}{15}{16}",
 					Regs[A],
 					Regs[B],
@@ -661,10 +659,7 @@ namespace BizHawk.Emulation.Cores.Components.MC6809
 					FlagN ? "N" : "n",
 					FlagZ ? "Z" : "z",
 					FlagV ? "V" : "v",
-					FlagC ? "C" : "c"
+					FlagC ? "C" : "c"));
-					)
-			};
-		}
 
 		/// <summary>
 		/// Optimization method to set cur_instr

src/BizHawk.Emulation.Cores/CPUs/MOS 6502X/Execute.cs

@@ -561,12 +561,7 @@ namespace BizHawk.Emulation.Cores.Components.M6502
 				interrupt_pending = false;
 				if (NMI)
 				{
-					TraceCallback?.Invoke(new TraceInfo
+					TraceCallback?.Invoke(new(disassembly: "====NMI====", registerInfo: string.Empty));
-					{
-						Disassembly = "====NMI====",
-						RegisterInfo = ""
-					});
-
 					ea = NMIVector;
 					opcode = VOP_NMI;
 					NMI = false;
@@ -577,11 +572,7 @@ namespace BizHawk.Emulation.Cores.Components.M6502
 
 				if (IRQ && !my_iflag)
 				{
-					TraceCallback?.Invoke(new TraceInfo
+					TraceCallback?.Invoke(new(disassembly: "====IRQ====", registerInfo: string.Empty));
-					{
-						Disassembly = "====IRQ====",
-						RegisterInfo = ""
-					});
 					ea = IRQVector;
 					opcode = VOP_IRQ;
 					mi = 0;

src/BizHawk.Emulation.Cores/CPUs/MOS 6502X/MOS6502X.cs

@@ -94,13 +94,7 @@ namespace BizHawk.Emulation.Cores.Components.M6502
 
 		public TraceInfo State(bool disassemble = true)
 		{
-			if (!disassemble)
+			if (!disassemble) return new(disassembly: string.Empty, registerInfo: string.Empty);
-			{
-				return new TraceInfo {
-					Disassembly = "",
-					RegisterInfo = ""
-				};
-			}
 
 			string rawbytes = "";
 			string disasm = Disassemble(PC, out var length);
@@ -110,10 +104,9 @@ namespace BizHawk.Emulation.Cores.Components.M6502
 				rawbytes += $" {_link.PeekMemory((ushort)(PC + i)):X2}";
 			}
 
-			return new TraceInfo
+			return new(
-			{
+				disassembly: $"{PC:X4}: {rawbytes,-9}  {disasm} ".PadRight(32),
-				Disassembly = $"{PC:X4}: {rawbytes,-9}  {disasm} ".PadRight(32),
+				registerInfo: string.Join("  ",
-				RegisterInfo = string.Join("  ",
 					$"A:{A:X2}",
 					$"X:{X:X2}",
 					$"Y:{Y:X2}",
@@ -131,8 +124,7 @@ namespace BizHawk.Emulation.Cores.Components.M6502
 //						!RDY ? "R" : "r"
 						),
 					$"Cy:{TotalExecutedCycles}",
-					$"PPU-Cy:{ext_ppu_cycle}")
+					$"PPU-Cy:{ext_ppu_cycle}"));
-			};
 		}
 
 		public bool AtStart => opcode == VOP_Fetch1 || Microcode[opcode][mi] >= Uop.End;

src/BizHawk.Emulation.Cores/CPUs/Z80A/Z80A.cs

@@ -775,7 +775,7 @@ namespace BizHawk.Emulation.Cores.Components.Z80A
 				{
 					nonMaskableInterruptPending = false;
 
-					TraceCallback?.Invoke(new TraceInfo { Disassembly = "====NMI====", RegisterInfo = "" });
+					TraceCallback?.Invoke(new(disassembly: "====NMI====", registerInfo: string.Empty));
 
 					iff2 = iff1;
 					iff1 = false;
@@ -796,7 +796,7 @@ namespace BizHawk.Emulation.Cores.Components.Z80A
 					iff1 = iff2 = false;
 					EI_pending = 0;
 
-					TraceCallback?.Invoke(new TraceInfo { Disassembly = "====IRQ====", RegisterInfo = "" });
+					TraceCallback?.Invoke(new(disassembly: "====IRQ====", registerInfo: string.Empty));
 
 					switch (interruptMode)
 					{
@@ -867,10 +867,9 @@ namespace BizHawk.Emulation.Cores.Components.Z80A
 				}
 			}
 
-			return new TraceInfo
+			return new(
-			{
+				disassembly: $"{RegPC:X4}: {byte_code.PadRight(12)} {disasm.PadRight(26)}",
-				Disassembly = $"{RegPC:X4}: {byte_code.PadRight(12)} {disasm.PadRight(26)}",
+				registerInfo: string.Join(" ",
-				RegisterInfo = string.Join(" ",
 					$"AF:{(Regs[A] << 8) + Regs[F]:X4}",
 					$"BC:{(Regs[B] << 8) + Regs[C]:X4}",
 					$"DE:{(Regs[D] << 8) + Regs[E]:X4}",
@@ -888,8 +887,7 @@ namespace BizHawk.Emulation.Cores.Components.Z80A
 						Flag5 ? "5" : "-",
 						FlagZ ? "Z" : "z",
 						FlagS ? "S" : "s",
-						FlagI ? "E" : "e"))
+						FlagI ? "E" : "e")));
-			};
 		}
 
 		/// <summary>

src/BizHawk.Emulation.Cores/Calculator/TI83.IEmulator.cs

@@ -13,7 +13,7 @@ namespace BizHawk.Emulation.Cores.Calculators
 			_controller = controller;
 			_lagged = true;
 
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				_cpu.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Calculator/TI83.cs

@@ -32,7 +32,7 @@ namespace BizHawk.Emulation.Cores.Calculators
 			HardReset();
 			SetupMemoryDomains();
 
-			_tracer = new TraceBuffer { Header = _cpu.TraceHeader };
+			_tracer = new TraceBuffer(_cpu.TraceHeader);
 
 			ser.Register<ITraceable>(_tracer);
 			ser.Register<IDisassemblable>(_cpu);

src/BizHawk.Emulation.Cores/Computers/AmstradCPC/AmstradCPC.IEmulator.cs

@@ -27,7 +27,7 @@ namespace BizHawk.Emulation.Cores.Computers.AmstradCPC
 
 			_isLag = true;
 
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				_cpu.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Computers/AmstradCPC/AmstradCPC.cs

@@ -24,7 +24,7 @@ namespace BizHawk.Emulation.Cores.Computers.AmstradCPC
 			CoreComm = lp.Comm;
 			_gameInfo = lp.Roms.Select(r => r.Game).ToList();
 			_cpu = new Z80A();
-			_tracer = new TraceBuffer { Header = _cpu.TraceHeader };
+			_tracer = new TraceBuffer(_cpu.TraceHeader);
 			_files = lp.Roms.Select(r => r.RomData).ToList();
 
 			var settings = lp.Settings ?? new AmstradCPCSettings();

src/BizHawk.Emulation.Cores/Computers/AppleII/AppleII.IDebuggable.cs

@@ -139,7 +139,7 @@ namespace BizHawk.Emulation.Cores.Computers.AppleII
 
 		private void StepInto()
 		{
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				_machine.Cpu.TraceCallback = TracerWrapper;
 			}

src/BizHawk.Emulation.Cores/Computers/AppleII/AppleII.cs

@@ -24,10 +24,8 @@ namespace BizHawk.Emulation.Cores.Computers.AppleII
 			var ser = new BasicServiceProvider(this);
 			ServiceProvider = ser;
 
-			_tracer = new TraceBuffer
+			const string TRACE_HEADER = "6502: PC, opcode, register (A, X, Y, P, SP, Cy), flags (NVTBDIZC)";
-			{
+			_tracer = new TraceBuffer(TRACE_HEADER);
-				Header = "6502: PC, opcode, register (A, X, Y, P, SP, Cy), flags (NVTBDIZC)"
-			};
 
 			_disk1 = _romSet[0];
 
@@ -121,17 +119,11 @@ namespace BizHawk.Emulation.Cores.Computers.AppleII
 		private bool _prevPressed;
 
 		private void TracerWrapper(string[] content)
-		{
+			=> _tracer.Put(new(disassembly: content[0], registerInfo: content[1]));
-			_tracer.Put(new TraceInfo
-			{
-				Disassembly = content[0],
-				RegisterInfo = content[1]
-			});
-		}
 
 		private void FrameAdv(IController controller, bool render, bool renderSound)
 		{
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				_machine.Cpu.TraceCallback = TracerWrapper;
 			}

src/BizHawk.Emulation.Cores/Computers/Commodore64/C64.IEmulator.cs

@@ -12,7 +12,7 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64
 		{
 			_board.Controller = controller;
 
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				_board.Cpu.TraceCallback = s => _tracer.Put(s);
 			}

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

@@ -54,7 +54,7 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64
 			ser.Register<IVideoProvider>(_board.Vic);
 			ser.Register<IDriveLight>(this);
 
-			_tracer = new TraceBuffer { Header = _board.Cpu.TraceHeader };
+			_tracer = new TraceBuffer(_board.Cpu.TraceHeader);
 			ser.Register<ITraceable>(_tracer);
 			ser.Register<IStatable>(new StateSerializer(SyncState));
 

src/BizHawk.Emulation.Cores/Computers/MSX/MSX.IEmulator.cs

@@ -31,7 +31,7 @@ namespace BizHawk.Emulation.Cores.Computers.MSX
 
 			if (current_controller == MSXControllerKB) { kb_rows_check(controller); }		
 			
-			if (Tracer.Enabled)
+			if (Tracer.IsEnabled())
 			{
 				tracecb = MakeTrace;
 			}

src/BizHawk.Emulation.Cores/Computers/MSX/MSX.cs

@@ -81,7 +81,7 @@ namespace BizHawk.Emulation.Cores.Computers.MSX
 
 			Console.WriteLine(Header_Length + " " + Disasm_Length + " " + Reg_String_Length);
 
-			Tracer = new TraceBuffer { Header = newHeader.ToString() };
+			Tracer = new TraceBuffer(newHeader.ToString());
 
 			var serviceProvider = ServiceProvider as BasicServiceProvider;
 			serviceProvider.Register<ITraceable>(Tracer);
@@ -132,11 +132,7 @@ namespace BizHawk.Emulation.Cores.Computers.MSX
 			LibMSX.MSX_getdisassembly(MSX_Pntr, new_d, t, Disasm_Length);
 			LibMSX.MSX_getregisterstate(MSX_Pntr, new_r, t, Reg_String_Length);
 
-			Tracer.Put(new TraceInfo
+			Tracer.Put(new(disassembly: new_d.ToString().PadRight(36), registerInfo: new_r.ToString()));
-			{
-				Disassembly = new_d.ToString().PadRight(36),
-				RegisterInfo = new_r.ToString()
-			});
 		}
 
 		private readonly MemoryCallbackSystem _memorycallbacks = new MemoryCallbackSystem(new[] { "System Bus" });

src/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.IEmulator.cs

@@ -27,7 +27,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 
 			_isLag = true;
 
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				_cpu.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.cs

@@ -29,7 +29,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 
 			_cpu = new Z80A();
 
-			_tracer = new TraceBuffer { Header = _cpu.TraceHeader };
+			_tracer = new TraceBuffer(_cpu.TraceHeader);
 
 			_files = lp.Roms.Select(r => r.RomData).ToList();
 

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

@@ -317,7 +317,7 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 			if (cyc_counter == 3)
 			{
 				_m6532.Timer.Tick();
-				if (Tracer.Enabled && Cpu.AtStart)
+				if (Tracer.IsEnabled() && Cpu.AtStart)
 				{
 					Tracer.Put(Cpu.TraceState());
 				}

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

@@ -47,7 +47,7 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 			RebootCore();
 			SetupMemoryDomains();
 
-			Tracer = new TraceBuffer { Header = Cpu.TraceHeader };
+			Tracer = new TraceBuffer(Cpu.TraceHeader);
 
 			ser.Register<IDisassemblable>(Cpu);
 			ser.Register<ITraceable>(Tracer);

src/BizHawk.Emulation.Cores/Consoles/Atari/A7800Hawk/A7800Hawk.IEmulator.cs

@@ -59,7 +59,7 @@ namespace BizHawk.Emulation.Cores.Atari.A7800Hawk
 
 		public bool FrameAdvance(IController controller, bool render, bool renderSound)
 		{
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				cpu.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Consoles/Atari/A7800Hawk/A7800Hawk.cs

@@ -261,7 +261,7 @@ namespace BizHawk.Emulation.Cores.Atari.A7800Hawk
 			ser.Register<ISoundProvider>(this);
 			ServiceProvider = ser;
 
-			_tracer = new TraceBuffer { Header = cpu.TraceHeader };
+			_tracer = new TraceBuffer(cpu.TraceHeader);
 			ser.Register<ITraceable>(_tracer);
 			ser.Register<IStatable>(new StateSerializer(SyncState));
 			SetupMemoryDomains();

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

@@ -26,7 +26,7 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 			}
 
 			_isLag = true;
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				_cpu.TraceCallback = s => _tracer.Put(s);
 			}

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

@@ -57,15 +57,14 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 			LoadRom(rom, skipBios);
 			SetupMemoryDomains();
 
-			_tracer.Header = _cpu.TraceHeader;
 			ser.Register<IDisassemblable>(_cpu);
-			ser.Register<ITraceable>(_tracer);
+			ser.Register<ITraceable>(_tracer = new TraceBuffer(_cpu.TraceHeader));
 		}
 
 		private readonly Z80A _cpu;
 		private readonly TMS9918A _vdp;
 		private readonly byte[] _biosRom;
-		private readonly TraceBuffer _tracer = new TraceBuffer();
+		private readonly TraceBuffer _tracer;
 
 		private byte[] _romData;
 		private byte[] _ram = new byte[1024];

src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/ChannelF.IEmulator.cs

@@ -31,7 +31,7 @@ namespace BizHawk.Emulation.Cores.Consoles.ChannelF
 			_controller = controller;
 			_isLag = false;
 
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				CPU.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/ChannelF.cs

@@ -25,7 +25,7 @@ namespace BizHawk.Emulation.Cores.Consoles.ChannelF
 				DummyReadMemory = ReadBus
 			};
 
-			_tracer = new TraceBuffer { Header = CPU.TraceHeader };
+			_tracer = new TraceBuffer(CPU.TraceHeader);
 
 			var bios01 = comm.CoreFileProvider.GetFirmwareOrThrow(new("ChannelF", "ChannelF_sl131253"));
 			var bios02 = comm.CoreFileProvider.GetFirmwareOrThrow(new("ChannelF", "ChannelF_sl131254"));

src/BizHawk.Emulation.Cores/Consoles/Fairchild/ChannelF/F8/F3850.cs

@@ -723,14 +723,13 @@ namespace BizHawk.Emulation.Cores.Consoles.ChannelF
 				}
 			}
 
-			return new TraceInfo
+			return new(
-			{
+				disassembly: string.Format(
-				Disassembly = string.Format(
 					"{0:X4}: {1} {2}",
 					pc,
 					byte_code.PadRight(12),
 					disasm.PadRight(26)),
-				RegisterInfo = string.Format(
+				registerInfo: string.Format(
 					"Flags:{75}{76}{77}{78}{79} " + 
 					"PC1:{0:X4} DC0:{1:X4} A:{2:X2} ISAR:{3:X2} DB:{4:X2} IO:{5:X2} J:{6:X2} H:{7:X4} K:{8:X4} Q:{9:X4} " + 
 					"R0:{10:X2} R1:{11:X2} R2:{12:X2} R3:{13:X2} R4:{14:X2} R5:{15:X2} R6:{16:X2} R7:{17:X2} R8:{18:X2} R9:{19:X2} " +
@@ -763,9 +762,7 @@ namespace BizHawk.Emulation.Cores.Consoles.ChannelF
 					FlagO ? "O" : "o",
 					FlagZ ? "Z" : "z",
 					FlagC ? "C" : "c",
-					FlagS ? "S" : "s"),
+					FlagS ? "S" : "s"));
-
-			};
 		}
 
 		/// <summary>

src/BizHawk.Emulation.Cores/Consoles/GCE/Vectrex/VectrexHawk.IEmulator.cs

@@ -12,7 +12,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Vectrex
 
 		public bool FrameAdvance(IController controller, bool render, bool rendersound)
 		{
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				cpu.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Consoles/GCE/Vectrex/VectrexHawk.cs

@@ -102,7 +102,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Vectrex
 			_settings = new object(); // TODO: wtf is this
 			_syncSettings = (VectrexSyncSettings)syncSettings ?? new VectrexSyncSettings();
 
-			_tracer = new TraceBuffer { Header = cpu.TraceHeader };
+			_tracer = new TraceBuffer(cpu.TraceHeader);
 			ser.Register<ITraceable>(_tracer);
 			ser.Register<IStatable>(new StateSerializer(SyncState));
 			SetupMemoryDomains();

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

@@ -10,7 +10,7 @@ namespace BizHawk.Emulation.Cores.Intellivision
 
 		public bool FrameAdvance(IController controller, bool render, bool renderSound)
 		{
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				_cpu.TraceCallback = s => _tracer.Put(s);
 			}

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

@@ -58,7 +58,7 @@ namespace BizHawk.Emulation.Cores.Intellivision
 			LoadExecutiveRom(comm.CoreFileProvider.GetFirmwareOrThrow(new("INTV", "EROM"), "Executive ROM is required."));
 			LoadGraphicsRom(comm.CoreFileProvider.GetFirmwareOrThrow(new("INTV", "GROM"), "Graphics ROM is required."));
 
-			_tracer = new TraceBuffer { Header = _cpu.TraceHeader };
+			_tracer = new TraceBuffer(_cpu.TraceHeader);
 			ser.Register<ITraceable>(_tracer);
 			ser.Register<IStatable>(new StateSerializer(SyncState));
 			SetupMemoryDomains();

src/BizHawk.Emulation.Cores/Consoles/Magnavox/Odyssey2/O2Hawk.IEmulator.cs

@@ -18,7 +18,7 @@ namespace BizHawk.Emulation.Cores.Consoles.O2Hawk
 		{
 			//Console.WriteLine("-----------------------FRAME-----------------------");
 
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				cpu.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Consoles/Magnavox/Odyssey2/O2Hawk.cs

@@ -79,7 +79,7 @@ namespace BizHawk.Emulation.Cores.Consoles.O2Hawk
 			ser.Register<IVideoProvider>(this);
 			ServiceProvider = ser;
 
-			_tracer = new TraceBuffer { Header = cpu.TraceHeader };
+			_tracer = new TraceBuffer(cpu.TraceHeader);
 			ser.Register(_tracer);
 			ser.Register<IStatable>(new StateSerializer(SyncState));
 			SetupMemoryDomains();

src/BizHawk.Emulation.Cores/Consoles/Nintendo/BSNES/BsnesCore.IEmulator.cs

@@ -48,7 +48,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.BSNES
 			};
 			// TODO: I really don't think stuff like this should be set every single frame (only on change)
 			Api.core.snes_set_layer_enables(ref enables);
-			Api.core.snes_set_trace_enabled(_tracer.Enabled);
+			Api.core.snes_set_trace_enabled(_tracer.IsEnabled());
 			Api.core.snes_set_video_enabled(render);
 			Api.core.snes_set_audio_enabled(renderSound);
 

src/BizHawk.Emulation.Cores/Consoles/Nintendo/BSNES/BsnesCore.cs

@@ -138,10 +138,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.BSNES
 
 			SetMemoryDomains();
 
-			_tracer = new TraceBuffer
+			const string TRACE_HEADER = "65816: PC, mnemonic, operands, registers (A, X, Y, S, D, B, flags (NVMXDIZC), V, H)";
-			{
+			_tracer = new TraceBuffer(TRACE_HEADER);
-				Header = "65816: PC, mnemonic, operands, registers (A, X, Y, S, D, B, flags (NVMXDIZC), V, H)"
-			};
 			ser.Register<IDisassemblable>(new W65816_DisassemblerService());
 			ser.Register(_tracer);
 
@@ -381,12 +379,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.BSNES
 		}
 
 		private void snes_trace(string disassembly, string registerInfo)
-		{
+			=> _tracer.Put(new(disassembly: disassembly, registerInfo: registerInfo));
-			_tracer.Put(new TraceInfo
-			{
-				Disassembly = disassembly,
-				RegisterInfo = registerInfo
-			});
-		}
 	}
 }

src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBA/MGBAHawk.cs

@@ -66,10 +66,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBA
 				ServiceProvider = ser;
 				PutSettings(_settings);
 
-				Tracer = new TraceBuffer
+				const string TRACE_HEADER = "ARM7: PC, machine code, mnemonic, operands, registers";
-				{
+				Tracer = new TraceBuffer(TRACE_HEADER);
-					Header = "ARM7: PC, machine code, mnemonic, operands, registers"
-				};
 				_tracecb = msg => Tracer.Put(_traceInfo(msg));
 				ser.Register(Tracer);
 				MemoryCallbacks = new MGBAMemoryCallbackSystem(this);
@@ -107,11 +105,9 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBA
 				sb.Append($" { RegisterNames[i] }:{ regs[RegisterNames[i]].Value:X8}");
 			}
 
-			return new TraceInfo
+			return new(
-			{
+				disassembly: $"{pc:X8}: { machineCode }  { instruction }".PadRight(50),
-				Disassembly = $"{pc:X8}: { machineCode }  { instruction }".PadRight(50),
+				registerInfo: sb.ToString());
-				RegisterInfo = sb.ToString()
-			};
 		}
 
 		public bool FrameAdvance(IController controller, bool render, bool renderSound = true)
@@ -124,7 +120,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBA
 				WireMemoryDomainPointers();
 			}
 
-			LibmGBA.BizSetTraceCallback(Core, Tracer.Enabled ? _tracecb : null);
+			LibmGBA.BizSetTraceCallback(Core, Tracer.IsEnabled() ? _tracecb : null);
 
 			IsLagFrame = LibmGBA.BizAdvance(
 				Core,

src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GBHawk.IEmulator.cs

@@ -45,7 +45,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 				ppu.color_palette[3] = color_palette_Gr[3];
 			}
 
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				cpu.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GBHawk.cs

@@ -187,7 +187,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 			_ = PutSettings(settings ?? new GBSettings());
 			_syncSettings = (GBSyncSettings)syncSettings ?? new GBSyncSettings();
 
-			_tracer = new TraceBuffer { Header = cpu.TraceHeader };
+			_tracer = new TraceBuffer(cpu.TraceHeader);
 			ser.Register<ITraceable>(_tracer);
 			ser.Register<IStatable>(new StateSerializer(SyncState));
             ser.Register<IDisassemblable>(_disassembler);

src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawkLink/GBHawkLink.IEmulator.cs

@@ -44,7 +44,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawkLink
 				R.ppu.color_palette[3] = color_palette_Gr[3];
 			}
 
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				L.cpu.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawkLink/GBHawkLink.cs

@@ -61,7 +61,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawkLink
 			ser.Register<IVideoProvider>(this);
 			ser.Register<ISoundProvider>(this); 
 
-			_tracer = new TraceBuffer { Header = L.cpu.TraceHeader };
+			_tracer = new TraceBuffer(L.cpu.TraceHeader);
 			ser.Register<ITraceable>(_tracer);
 
 			_lStates = L.ServiceProvider.GetService<IStatable>();

src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawkLink3x/GBHawkLink3x.IEmulator.cs

@@ -59,7 +59,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawkLink3x
 				R.ppu.color_palette[3] = color_palette_Gr[3];
 			}
 
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				L.cpu.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawkLink3x/GBHawkLink3x.cs

@@ -68,7 +68,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawkLink3x
 			ser.Register<IVideoProvider>(this);
 			ser.Register<ISoundProvider>(this); 
 
-			_tracer = new TraceBuffer { Header = L.cpu.TraceHeader };
+			_tracer = new TraceBuffer(L.cpu.TraceHeader);
 			ser.Register(_tracer);
 
 			_lStates = L.ServiceProvider.GetService<IStatable>();

src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawkLink4x/GBHawkLink4x.IEmulator.cs

@@ -74,7 +74,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawkLink4x
 				D.ppu.color_palette[3] = color_palette_Gr[3];
 			}
 
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				A.cpu.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawkLink4x/GBHawkLink4x.cs

@@ -96,7 +96,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawkLink4x
 			ser.Register<IVideoProvider>(this);
 			ser.Register<ISoundProvider>(this); 
 
-			_tracer = new TraceBuffer { Header = A.cpu.TraceHeader };
+			_tracer = new TraceBuffer(A.cpu.TraceHeader);
 			ser.Register(_tracer);
 
 			ServiceProvider = ser;

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

@@ -15,16 +15,13 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 			int[] s = new int[14];
 			System.Runtime.InteropServices.Marshal.Copy(_s, s, 0, 14);
 
-			Tracer.Put(new TraceInfo
+			Tracer.Put(new(
-			{
+				disassembly: LR35902.Disassemble(
-				Disassembly =
-					LR35902.Disassemble(
 					(ushort) s[1],
 					addr => (addr == (ushort)s[1]) ? (byte)((s[12] >> 16) & 0xFF) : ((addr == (ushort)s[1] + 1) ? (byte)((s[12] >> 8) & 0xFF) : (byte)(s[12] & 0xFF)),
 					_settings.RgbdsSyntax,
 					out _).PadRight(36),
-				RegisterInfo =
+				registerInfo: string.Format(
-					string.Format(
 					"A:{3:x2} F:{8:x2} B:{4:x2} C:{5:x2} D:{6:x2} E:{7:x2} H:{9:x2} L:{10:x2} LY:{13:x2} SP:{2:x2} {11} Cy:{0}",
 					s[0],
 					s[1] & 0xffff,
@@ -39,8 +36,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 					s[10] & 0xff,
 					s[11] != 0 ? "skip" : "",
 					s[12] & 0xffffff,
-					s[13] & 0xff)
+					s[13] & 0xff)));
-			});
 		}
 	}
 }

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

@@ -24,10 +24,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 			var ser = new BasicServiceProvider(this);
 			ser.Register<IDisassemblable>(_disassembler);
 			ServiceProvider = ser;
-			Tracer = new TraceBuffer
+			const string TRACE_HEADER = "LR35902: PC, opcode, registers (A, F, B, C, D, E, H, L, LY, SP, CY)";
-			{
+			Tracer = new TraceBuffer(TRACE_HEADER);
-				Header = "LR35902: PC, opcode, registers (A, F, B, C, D, E, H, L, LY, SP, CY)"
-			};
 			ser.Register<ITraceable>(Tracer);
 			InitMemoryCallbacks();
 
@@ -327,7 +325,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 				LibGambatte.gambatte_reset(GambatteState);
 			}
 
-			if (Tracer.Enabled)
+			if (Tracer.IsEnabled())
 			{
 				_tracecb = MakeTrace;
 			}

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

@@ -17,11 +17,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.N64
 			var length = 0;
 			var disasm = Disassemble(MemoryDomains.SystemBus, pc, out length);
 
-			var traceInfo = new TraceInfo
-			{
-				Disassembly = $"{pc:X}:  {disasm.PadRight(32)}"
-			};
-
 			var sb = new StringBuilder();
 
 			for (int i = 1; i < 32; i++) // r0 is always zero
@@ -45,16 +40,14 @@ namespace BizHawk.Emulation.Cores.Nintendo.N64
 
 			// drop MMU co-processor regs for now
 
-			traceInfo.RegisterInfo = sb.ToString().Trim();
+			Tracer.Put(new(disassembly: $"{pc:X}:  {disasm.PadRight(32)}", registerInfo: sb.ToString().Trim()));
-
-			Tracer.Put(traceInfo);
 		}
 
 		private const string TraceHeader = "r3400: PC, mnemonic, operands, registers (GPRs, Load/Link Bit, MultHI, MultLO, Implementation/Revision, Control/Status, FGRs)";
 
 		private void ConnectTracer()
 		{
-			Tracer = new TraceBuffer { Header = TraceHeader };
+			Tracer = new TraceBuffer(TraceHeader);
 			(ServiceProvider as BasicServiceProvider).Register<ITraceable>(Tracer);
 			_tracecb = new mupen64plusApi.TraceCallback(MakeTrace);
 		}

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

@@ -214,14 +214,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.N64
 
 			IsVIFrame = false;
 
-			if (Tracer != null && Tracer.Enabled)
+			api.setTraceCallback(Tracer?.IsEnabled() is true ? _tracecb : null);
-			{
-				api.setTraceCallback(_tracecb);
-			}
-			else
-			{
-				api.setTraceCallback(null);
-			}
 
 			_audioProvider.RenderSound = rendersound;
 

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

@@ -287,7 +287,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 		{
 			_controller = controller;
 
-			if (Tracer.Enabled)
+			if (Tracer.IsEnabled())
 				cpu.TraceCallback = s => Tracer.Put(s);
 			else
 				cpu.TraceCallback = null;

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

@@ -52,7 +52,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 
 			ser.Register<IDisassemblable>(cpu);
 
-			Tracer = new TraceBuffer { Header = cpu.TraceHeader };
+			Tracer = new TraceBuffer(cpu.TraceHeader);
 			ser.Register<ITraceable>(Tracer);
 			ser.Register<IVideoProvider>(videoProvider);
 			ser.Register<ISoundProvider>(this);

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

@@ -28,21 +28,19 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.QuickNES
 
 			string opcodeStr = MOS6502X.Disassemble(pc, out _, address => _memoryDomains.SystemBus.PeekByte(address));
 
-			Tracer.Put(new TraceInfo
+			Tracer.Put(new(
-			{
+				disassembly: $"{pc:X4}:  {opcodeStr}".PadRight(26),
-				Disassembly = $"{pc:X4}:  {opcodeStr}".PadRight(26),
+				registerInfo: string.Join(" ",
-				RegisterInfo = string.Join(" ",
 					$"A:{a:X2}",
 					$"X:{x:X2}",
 					$"Y:{y:X2}",
 					$"P:{p:X2}",
-					$"SP:{sp:X2}")
+					$"SP:{sp:X2}")));
-			});
 		}
 
 		private void ConnectTracer()
 		{
-			Tracer = new TraceBuffer { Header = TraceHeader };
+			Tracer = new TraceBuffer(TraceHeader);
 			((BasicServiceProvider) ServiceProvider).Register<ITraceable>(Tracer);
 			_traceCb = MakeTrace;
 		}

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

@@ -194,7 +194,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.QuickNES
 
 				SetPads(controller, out var j1, out var j2);
 
-				QN.qn_set_tracecb(Context, Tracer.Enabled ? _traceCb : null);
+				QN.qn_set_tracecb(Context, Tracer.IsEnabled() ? _traceCb : null);
 
 				LibQuickNES.ThrowStringError(QN.qn_emulate_frame(Context, j1, j2));
 				IsLagFrame = QN.qn_get_joypad_read_count(Context) == 0;

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

@@ -20,7 +20,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.SNES
 
 			IsLagFrame = true;
 
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				//Api.QUERY_set_trace_callback(1<<(int)LibsnesApi.eTRACE.SMP, _tracecb); //TEST -- it works but theres no way to control it from the frontend now
 

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

@@ -36,10 +36,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.SNES
 			var ser = new BasicServiceProvider(this);
 			ServiceProvider = ser;
 
-			_tracer = new TraceBuffer
+			const string TRACE_HEADER = "65816: PC, mnemonic, operands, registers (A, X, Y, S, D, DB, flags (NVMXDIZC), V, H)";
-			{
+			_tracer = new TraceBuffer(TRACE_HEADER);
-				Header = "65816: PC, mnemonic, operands, registers (A, X, Y, S, D, DB, flags (NVMXDIZC), V, H)"
-			};
 
 			ser.Register<IDisassemblable>(new W65816_DisassemblerService());
 
@@ -352,34 +350,17 @@ namespace BizHawk.Emulation.Cores.Nintendo.SNES
 			if (which == (uint)LibsnesApi.eTRACE.CPU)
 			{
 				var split = msg.Split(new[] { splitStr }, 2, StringSplitOptions.None);
-
+				_tracer.Put(new(disassembly: split[0].PadRight(34), registerInfo: splitStr + split[1]));
-				_tracer.Put(new TraceInfo
-				{
-					Disassembly = split[0].PadRight(34),
-					RegisterInfo = splitStr + split[1]
-				});
 			}
 			else if (which == (uint)LibsnesApi.eTRACE.SMP)
 			{
 				int idx = msg.IndexOf("YA:");
-				string dis = msg.Substring(0,idx).TrimEnd();
+				_tracer.Put(new(disassembly: msg.Substring(0, idx).TrimEnd(), registerInfo: msg.Substring(idx)));
-				string regs = msg.Substring(idx);
-				_tracer.Put(new TraceInfo
-				{
-					Disassembly = dis,
-					RegisterInfo = regs
-				});
 			}
 			else if (which == (uint)LibsnesApi.eTRACE.GB)
 			{
 				int idx = msg.IndexOf("AF:");
-				string dis = msg.Substring(0,idx).TrimEnd();
+				_tracer.Put(new(disassembly: msg.Substring(0, idx).TrimEnd(), registerInfo: msg.Substring(idx)));
-				string regs = msg.Substring(idx);
-				_tracer.Put(new TraceInfo
-				{
-					Disassembly = dis,
-					RegisterInfo = regs
-				});
 			}
 		}
 

src/BizHawk.Emulation.Cores/Consoles/Nintendo/SubGBHawk/SubGBHawk.IEmulator.cs

@@ -27,7 +27,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.SubGBHawk
 				_GBCore.ppu.color_palette[2] = GBHawk.GBHawk.color_palette_Gr[2];
 				_GBCore.ppu.color_palette[3] = GBHawk.GBHawk.color_palette_Gr[3];
 			}
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				_GBCore.cpu.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Consoles/Nintendo/SubGBHawk/SubGBHawk.cs

@@ -37,7 +37,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.SubGBHawk
 			ser.Register(_GBCore.ServiceProvider.GetService<IRegionable>());
 			ser.Register(_GBCore.ServiceProvider.GetService<ICodeDataLogger>());
 
-			_tracer = new TraceBuffer { Header = _GBCore.cpu.TraceHeader };
+			_tracer = new TraceBuffer(_GBCore.cpu.TraceHeader);
 			ser.Register(_tracer);
 
 			_GBCore.ControllerDefinition.AddAxis("Input Cycle", 0.RangeTo(70224), 70224);

src/BizHawk.Emulation.Cores/Consoles/Nintendo/SubNESHawk/SubNESHawk.IEmulator.cs

@@ -12,7 +12,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.SubNESHawk
 		public bool FrameAdvance(IController controller, bool render, bool renderSound)
 		{
 			//Console.WriteLine("-----------------------FRAME-----------------------");
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				_nesCore.cpu.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Consoles/Nintendo/SubNESHawk/SubNESHawk.cs

@@ -41,7 +41,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.SubNESHawk
 			ser.Register(_nesCore.ServiceProvider.GetService<IRegionable>());
 			ser.Register(_nesCore.ServiceProvider.GetService<ICodeDataLogger>());
 
-			_tracer = new TraceBuffer { Header = "6502: PC, machine code, mnemonic, operands, registers (A, X, Y, P, SP), flags (NVTBDIZCR), CPU Cycle, PPU Cycle" };
+			const string TRACE_HEADER = "6502: PC, machine code, mnemonic, operands, registers (A, X, Y, P, SP), flags (NVTBDIZCR), CPU Cycle, PPU Cycle";
+			_tracer = new TraceBuffer(TRACE_HEADER);
 			ser.Register(_tracer);
 
 			

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

@@ -16,7 +16,7 @@ namespace BizHawk.Emulation.Cores.PCEngine
 			CheckSpriteLimit();
 			PSG.BeginFrame(Cpu.TotalExecutedCycles);
 
-			Cpu.Debug = Tracer.Enabled;
+			Cpu.Debug = Tracer.IsEnabled();
 
 			if (SuperGrafx)
 			{

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

@@ -225,11 +225,7 @@ namespace BizHawk.Emulation.Cores.PCEngine
 				RomLength = RomData.Length;
 
 				// user request: current value of the SF2MapperLatch on the tracelogger
-				Cpu.Logger = s => Tracer.Put(new TraceInfo
+				Cpu.Logger = s => Tracer.Put(new(disassembly: $"{SF2MapperLatch:X1}:{s}", registerInfo: string.Empty));
-				{
-					Disassembly = $"{SF2MapperLatch:X1}:{s}",
-					RegisterInfo = ""
-				});
 			}
 			else
 			{
@@ -319,7 +315,7 @@ namespace BizHawk.Emulation.Cores.PCEngine
 
 			Cpu.ResetPC();
 
-			Tracer = new TraceBuffer { Header = Cpu.TraceHeader };
+			Tracer = new TraceBuffer(Cpu.TraceHeader);
 			var ser = new BasicServiceProvider(this);
 			ServiceProvider = ser;
 			ser.Register<ITraceable>(Tracer);

src/BizHawk.Emulation.Cores/Consoles/Sega/GGHawkLink/GGHawkLink.IEmulator.cs

@@ -15,7 +15,7 @@ namespace BizHawk.Emulation.Cores.Sega.GGHawkLink
 		public bool FrameAdvance(IController controller, bool render, bool renderSound)
 		{
 			//Console.WriteLine("-----------------------FRAME-----------------------");
-			if (_tracer.Enabled)
+			if (_tracer.IsEnabled())
 			{
 				L.Cpu.TraceCallback = s => _tracer.Put(s);
 			}

src/BizHawk.Emulation.Cores/Consoles/Sega/GGHawkLink/GGHawkLink.cs

@@ -45,7 +45,7 @@ namespace BizHawk.Emulation.Cores.Sega.GGHawkLink
 			ser.Register<IVideoProvider>(this);
 			ser.Register<ISoundProvider>(this); 
 
-			_tracer = new TraceBuffer { Header = L.Cpu.TraceHeader };
+			_tracer = new TraceBuffer(L.Cpu.TraceHeader);
 			ser.Register(_tracer);
 
 			ServiceProvider = ser;

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

@@ -20,7 +20,7 @@ namespace BizHawk.Emulation.Cores.Sega.MasterSystem
 				PSG.Set_Panning(Settings.ForceStereoSeparation ? ForceStereoByte : (byte)0xFF);
 			}
 
-			if (Tracer.Enabled)
+			if (Tracer.IsEnabled())
 			{
 				Cpu.TraceCallback = s => Tracer.Put(s);
 			}

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

@@ -194,7 +194,7 @@ namespace BizHawk.Emulation.Cores.Sega.MasterSystem
 			//this manages the linkage between the cpu and mapper callbacks so it needs running before bootup is complete
 			((ICodeDataLogger)this).SetCDL(null);
 
-			Tracer = new TraceBuffer { Header = Cpu.TraceHeader };
+			Tracer = new TraceBuffer(Cpu.TraceHeader);
 
 			ser.Register(Tracer);
 			ser.Register<IDisassemblable>(Cpu);

src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.ITraceable.cs

@@ -10,11 +10,10 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 
 		public class GPGXTraceBuffer : CallbackBasedTraceBuffer
 		{
+			private const string TRACE_HEADER = "M68K: PC, machine code, mnemonic, operands, registers (D0-D7, A0-A7, SR, USP), flags (XNZVC)";
+
 			public GPGXTraceBuffer(IDebuggable debuggableCore, IMemoryDomains memoryDomains, IDisassemblable disassembler)
-				: base(debuggableCore, memoryDomains, disassembler)
+				: base(debuggableCore, memoryDomains, disassembler, TRACE_HEADER) {}
-			{
-				Header = "M68K: PC, machine code, mnemonic, operands, registers (D0-D7, A0-A7, SR, USP), flags (XNZVC)";
-			}
 
 			protected override void TraceFromCallback(uint addr, uint value, uint flags)
 			{
@@ -22,11 +21,6 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 				uint pc = (uint)regs["M68K PC"].Value;
 				var disasm = Disassembler.Disassemble(MemoryDomains.SystemBus, pc & 0xFFFFFF, out _);
 
-				var traceInfo = new TraceInfo
-				{
-					Disassembly = $"{pc:X6}:  {disasm}".PadRight(50)
-				};
-
 				var sb = new StringBuilder();
 
 				foreach (var r in regs)
@@ -49,9 +43,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 					(sr &  2) > 0 ? "V" : "v",
 					(sr &  1) > 0 ? "C" : "c"));
 
-				traceInfo.RegisterInfo = sb.ToString().Trim();
+				this.Put(new(disassembly: $"{pc:X6}:  {disasm}".PadRight(50), registerInfo: sb.ToString().Trim()));
-
-				Put(traceInfo);
 			}
 		}
 	}

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

@@ -10,7 +10,7 @@ namespace BizHawk.Emulation.Cores.Sony.PSX
 	{
 		public TraceBuffer Tracer { get; private set; }
 
-		public static string TraceHeader = "R3000A: PC, machine code, mnemonic, operands, registers (GPRs, lo, hi, sr, cause, epc)";
+		public const string TraceHeader = "R3000A: PC, machine code, mnemonic, operands, registers (GPRs, lo, hi, sr, cause, epc)";
 
 		private OctoshockDll.ShockCallback_Trace trace_cb;
 
@@ -25,17 +25,13 @@ namespace BizHawk.Emulation.Cores.Sony.PSX
 					sb.Append($"{r.Key}:{r.Value.Value.ToHexString(r.Value.BitSize / 4)} ");
 			}
 
-			Tracer.Put(new TraceInfo
+			Tracer.Put(new(disassembly: $"{PC:X8}:  {inst:X8}  {dis.PadRight(30)}", registerInfo: sb.ToString().Trim()));
-			{
-				Disassembly = $"{PC:X8}:  {inst:X8}  {dis.PadRight(30)}",
-				RegisterInfo = sb.ToString().Trim()
-			});
 		}
 
 		private void ConnectTracer()
 		{
 			trace_cb = new OctoshockDll.ShockCallback_Trace(ShockTraceCallback);
-			Tracer = new TraceBuffer { Header = TraceHeader };
+			Tracer = new TraceBuffer(TraceHeader);
 			ServiceProvider = new BasicServiceProvider(this);
 			(ServiceProvider as BasicServiceProvider).Register<ITraceable>(Tracer);
 		}

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

@@ -829,7 +829,7 @@ namespace BizHawk.Emulation.Cores.Sony.PSX
 			OctoshockDll.shock_SetRenderOptions(psx, ref ropts);
 
 			//prep tracer
-			if (Tracer.Enabled)
+			if (Tracer.IsEnabled())
 				OctoshockDll.shock_SetTraceCallback(psx, IntPtr.Zero, trace_cb);
 			else
 				OctoshockDll.shock_SetTraceCallback(psx, IntPtr.Zero, null);