diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/ExROM.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/ExROM.cs
index 84ff0edd29..9bd5a3ff2b 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/ExROM.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/ExROM.cs
@@ -20,31 +20,29 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 	[NES.INESBoardImplPriorityAttribute]
 	public sealed class ExROM : NesBoardBase
 	{
-		//configuraton
-		int prg_bank_mask_8k, chr_bank_mask_1k; //board setup (to be isolated from mmc5 code later, when we need the separate mmc5 class)
+		private int prg_bank_mask_8k, chr_bank_mask_1k; //board setup (to be isolated from mmc5 code later, when we need the separate mmc5 class)
 
-		//state
-		int irq_target, irq_counter;
-		bool irq_enabled, irq_pending, in_frame;
-		int exram_mode, chr_mode, prg_mode;
-		int chr_reg_high;
-		int ab_mode;
-		int[] regs_a = new int[8];
-		int[] regs_b = new int[4];
-		int[] regs_prg = new int[4];
-		int[] nt_modes = new int[4];
-		byte nt_fill_tile, nt_fill_attrib;
-		int wram_bank;
-		byte[] EXRAM = new byte[1024];
-		byte multiplicand, multiplier;
-		MMC5Audio audio;
-		//regeneratable state
-		int[] a_banks_1k = new int[8];
-		int[] b_banks_1k = new int[8];
-		int[] prg_banks_8k = new int[4];
-		byte product_low, product_high;
-		int last_nt_read;
-		bool irq_audio;
+		private int irq_target, irq_counter;
+		private bool irq_enabled, irq_pending, in_frame;
+		private int exram_mode, chr_mode, prg_mode;
+		private int chr_reg_high;
+		private int ab_mode;
+		private int[] regs_a = new int[8];
+		private int[] regs_b = new int[4];
+		private int[] regs_prg = new int[4];
+		private int[] nt_modes = new int[4];
+		private byte nt_fill_tile, nt_fill_attrib;
+		private int wram_bank;
+		private byte[] EXRAM = new byte[1024];
+		private byte multiplicand, multiplier;
+		private MMC5Audio audio;
+
+		private int[] _aBanks1K = new int[8];
+		private int[] _bBanks1K = new int[8];
+		private int[] _prgBanks8K = new int[4];
+		private byte product_low, product_high;
+		private int last_nt_read;
+		private bool irq_audio;
 
 		public MemoryDomain GetExRAM()
 		{
@@ -61,6 +59,9 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 		public override void SyncState(Serializer ser)
 		{
 			base.SyncState(ser);
+			ser.Sync(nameof(_aBanks1K), ref _aBanks1K, false);
+			ser.Sync(nameof(_bBanks1K), ref _bBanks1K, false);
+			ser.Sync(nameof(_prgBanks8K), ref _prgBanks8K, false);
 			ser.Sync(nameof(irq_target), ref irq_target);
 			ser.Sync(nameof(irq_counter), ref irq_counter);
 			ser.Sync(nameof(irq_enabled), ref irq_enabled);
@@ -147,7 +148,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 		int PRGGetBank(int addr, out bool ram)
 		{
 			int bank_8k = addr >> 13;
-			bank_8k = prg_banks_8k[bank_8k];
+			bank_8k = _prgBanks8K[bank_8k];
 			ram = (bank_8k & 0x80) == 0;
 			if (!ram)
 				bank_8k &= prg_bank_mask_8k;
@@ -248,19 +249,19 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 			{
 				bool isPattern = NES.ppu.PPUON;
 				if (NES.ppu.ppuphase == PPU.PPU_PHASE_OBJ && isPattern)
-					bank_1k = a_banks_1k[bank_1k];
+					bank_1k = _aBanks1K[bank_1k];
 				else if (NES.ppu.ppuphase == PPU.PPU_PHASE_BG && isPattern)
-					bank_1k = b_banks_1k[bank_1k];
+					bank_1k = _bBanks1K[bank_1k];
 				else
 				{
 					bank_1k = ab_mode == 0
-						? a_banks_1k[bank_1k]
-						: b_banks_1k[bank_1k];
+						? _aBanks1K[bank_1k]
+						: _bBanks1K[bank_1k];
 				}
 			}
 			else
 			{
-				bank_1k = a_banks_1k[bank_1k];
+				bank_1k = _aBanks1K[bank_1k];
 			}
 		
 			bank_1k &= chr_bank_mask_1k;
@@ -724,22 +725,22 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 			switch (prg_mode)
 			{
 				case 0:
-					SetBank(prg_banks_8k, 0, 4, regs_prg[3]&~3);
+					SetBank(_prgBanks8K, 0, 4, regs_prg[3]&~3);
 					break;
 				case 1:
-					SetBank(prg_banks_8k, 0, 2, regs_prg[1] & ~1);
-					SetBank(prg_banks_8k, 2, 2, regs_prg[3] & ~1);
+					SetBank(_prgBanks8K, 0, 2, regs_prg[1] & ~1);
+					SetBank(_prgBanks8K, 2, 2, regs_prg[3] & ~1);
 					break;
 				case 2:
-					SetBank(prg_banks_8k, 0, 2, regs_prg[1] & ~1);
-					SetBank(prg_banks_8k, 2, 1, regs_prg[2]);
-					SetBank(prg_banks_8k, 3, 1, regs_prg[3]);
+					SetBank(_prgBanks8K, 0, 2, regs_prg[1] & ~1);
+					SetBank(_prgBanks8K, 2, 1, regs_prg[2]);
+					SetBank(_prgBanks8K, 3, 1, regs_prg[3]);
 					break;
 				case 3:
-					SetBank(prg_banks_8k, 0, 1, regs_prg[0]);
-					SetBank(prg_banks_8k, 1, 1, regs_prg[1]);
-					SetBank(prg_banks_8k, 2, 1, regs_prg[2]);
-					SetBank(prg_banks_8k, 3, 1, regs_prg[3]);
+					SetBank(_prgBanks8K, 0, 1, regs_prg[0]);
+					SetBank(_prgBanks8K, 1, 1, regs_prg[1]);
+					SetBank(_prgBanks8K, 2, 1, regs_prg[2]);
+					SetBank(_prgBanks8K, 3, 1, regs_prg[3]);
 					break;
 			}
 		}
@@ -753,42 +754,42 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 			switch (chr_mode)
 			{
 				case 0:
-					SetBank(a_banks_1k, 0, 8, regs_a[7] * 8);
-					SetBank(b_banks_1k, 0, 8, regs_b[3] * 8);
+					SetBank(_aBanks1K, 0, 8, regs_a[7] * 8);
+					SetBank(_bBanks1K, 0, 8, regs_b[3] * 8);
 					break;
 				case 1:
-					SetBank(a_banks_1k, 0, 4, regs_a[3] * 4);
-					SetBank(a_banks_1k, 4, 4, regs_a[7] * 4);
-					SetBank(b_banks_1k, 0, 4, regs_b[3] * 4);
-					SetBank(b_banks_1k, 4, 4, regs_b[3] * 4);
+					SetBank(_aBanks1K, 0, 4, regs_a[3] * 4);
+					SetBank(_aBanks1K, 4, 4, regs_a[7] * 4);
+					SetBank(_bBanks1K, 0, 4, regs_b[3] * 4);
+					SetBank(_bBanks1K, 4, 4, regs_b[3] * 4);
 					break;
 				case 2:
-					SetBank(a_banks_1k, 0, 2, regs_a[1] * 2);
-					SetBank(a_banks_1k, 2, 2, regs_a[3] * 2);
-					SetBank(a_banks_1k, 4, 2, regs_a[5] * 2);
-					SetBank(a_banks_1k, 6, 2, regs_a[7] * 2);
-					SetBank(b_banks_1k, 0, 2, regs_b[1] * 2);
-					SetBank(b_banks_1k, 2, 2, regs_b[3] * 2);
-					SetBank(b_banks_1k, 4, 2, regs_b[1] * 2);
-					SetBank(b_banks_1k, 6, 2, regs_b[3] * 2);
+					SetBank(_aBanks1K, 0, 2, regs_a[1] * 2);
+					SetBank(_aBanks1K, 2, 2, regs_a[3] * 2);
+					SetBank(_aBanks1K, 4, 2, regs_a[5] * 2);
+					SetBank(_aBanks1K, 6, 2, regs_a[7] * 2);
+					SetBank(_bBanks1K, 0, 2, regs_b[1] * 2);
+					SetBank(_bBanks1K, 2, 2, regs_b[3] * 2);
+					SetBank(_bBanks1K, 4, 2, regs_b[1] * 2);
+					SetBank(_bBanks1K, 6, 2, regs_b[3] * 2);
 					break;
 				case 3:
-					SetBank(a_banks_1k, 0, 1, regs_a[0]);
-					SetBank(a_banks_1k, 1, 1, regs_a[1]);
-					SetBank(a_banks_1k, 2, 1, regs_a[2]);
-					SetBank(a_banks_1k, 3, 1, regs_a[3]);
-					SetBank(a_banks_1k, 4, 1, regs_a[4]);
-					SetBank(a_banks_1k, 5, 1, regs_a[5]);
-					SetBank(a_banks_1k, 6, 1, regs_a[6]);
-					SetBank(a_banks_1k, 7, 1, regs_a[7]);
-					SetBank(b_banks_1k, 0, 1, regs_b[0]);
-					SetBank(b_banks_1k, 1, 1, regs_b[1]);
-					SetBank(b_banks_1k, 2, 1, regs_b[2]);
-					SetBank(b_banks_1k, 3, 1, regs_b[3]);
-					SetBank(b_banks_1k, 4, 1, regs_b[0]);
-					SetBank(b_banks_1k, 5, 1, regs_b[1]);
-					SetBank(b_banks_1k, 6, 1, regs_b[2]);
-					SetBank(b_banks_1k, 7, 1, regs_b[3]);
+					SetBank(_aBanks1K, 0, 1, regs_a[0]);
+					SetBank(_aBanks1K, 1, 1, regs_a[1]);
+					SetBank(_aBanks1K, 2, 1, regs_a[2]);
+					SetBank(_aBanks1K, 3, 1, regs_a[3]);
+					SetBank(_aBanks1K, 4, 1, regs_a[4]);
+					SetBank(_aBanks1K, 5, 1, regs_a[5]);
+					SetBank(_aBanks1K, 6, 1, regs_a[6]);
+					SetBank(_aBanks1K, 7, 1, regs_a[7]);
+					SetBank(_bBanks1K, 0, 1, regs_b[0]);
+					SetBank(_bBanks1K, 1, 1, regs_b[1]);
+					SetBank(_bBanks1K, 2, 1, regs_b[2]);
+					SetBank(_bBanks1K, 3, 1, regs_b[3]);
+					SetBank(_bBanks1K, 4, 1, regs_b[0]);
+					SetBank(_bBanks1K, 5, 1, regs_b[1]);
+					SetBank(_bBanks1K, 6, 1, regs_b[2]);
+					SetBank(_bBanks1K, 7, 1, regs_b[3]);
 					break;
 			}
 		}
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Namcot1xx/Mapper112.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Namcot1xx/Mapper112.cs
index 1472654b1d..247980dfa0 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Namcot1xx/Mapper112.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Namcot1xx/Mapper112.cs
@@ -12,16 +12,15 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 		int reg_addr;
 		byte[] regs = new byte[8];
 
-		//volatile state
-		int[] chr_regs_1k = new int[8];
-		byte[] prg_regs_8k = new byte[4];
+		private int[] _chrRegs1K = new int[8];
+		private byte[] _prgRegs8K = new byte[4];
 
 		public override bool Configure(NES.EDetectionOrigin origin)
 		{
 			//analyze board type
 			switch (Cart.board_type)
 			{
-				case "MAPPER112":	
+				case "MAPPER112":
 					break;
 				default:
 					return false;
@@ -42,6 +41,9 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 			ser.Sync(nameof(reg_addr), ref reg_addr);
 			ser.Sync(nameof(regs), ref regs, false);
 			ser.Sync(nameof(chr_outer_reg), ref chr_outer_reg);
+			ser.Sync(nameof(_chrRegs1K), ref _chrRegs1K, false);
+			ser.Sync(nameof(_prgRegs8K), ref _prgRegs8K, false);
+
 			Sync();
 		}
 
@@ -77,10 +79,10 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 
 		void Sync()
 		{
-			prg_regs_8k[0] = regs[0];
-			prg_regs_8k[1] = regs[1];
-			prg_regs_8k[2] = 0xFE;
-			prg_regs_8k[3] = 0xFF;
+			_prgRegs8K[0] = regs[0];
+			_prgRegs8K[1] = regs[1];
+			_prgRegs8K[2] = 0xFE;
+			_prgRegs8K[3] = 0xFF;
 
 			byte r0_0 = (byte)(regs[2] & ~1);
 			byte r0_1 = (byte)(regs[2] | 1);
@@ -92,27 +94,27 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 			int temp6 = (chr_outer_reg & 0x40) << 2;
 			int temp7 = (chr_outer_reg & 0x80) << 1;
 
-			chr_regs_1k[0] = r0_0;
-			chr_regs_1k[1] = r0_1;
-			chr_regs_1k[2] = r1_0;
-			chr_regs_1k[3] = r1_1;
-			chr_regs_1k[4] = temp4 | regs[4];
-			chr_regs_1k[5] = temp5 | regs[5];
-			chr_regs_1k[6] = temp6 | regs[6];
-			chr_regs_1k[7] = temp7 | regs[7];
+			_chrRegs1K[0] = r0_0;
+			_chrRegs1K[1] = r0_1;
+			_chrRegs1K[2] = r1_0;
+			_chrRegs1K[3] = r1_1;
+			_chrRegs1K[4] = temp4 | regs[4];
+			_chrRegs1K[5] = temp5 | regs[5];
+			_chrRegs1K[6] = temp6 | regs[6];
+			_chrRegs1K[7] = temp7 | regs[7];
 		}
 
 		public int Get_PRGBank_8K(int addr)
 		{
 			int bank_8k = addr >> 13;
-			bank_8k = prg_regs_8k[bank_8k];
+			bank_8k = _prgRegs8K[bank_8k];
 			return bank_8k;
 		}
 
 		public int Get_CHRBank_1K(int addr)
 		{
 			int bank_1k = addr >> 10;
-			bank_1k = chr_regs_1k[bank_1k];
+			bank_1k = _chrRegs1K[bank_1k];
 			return bank_1k;
 		}
 
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/VRC2_4.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/VRC2_4.cs
index e3cdec3754..31162a326f 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/VRC2_4.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/VRC2_4.cs
@@ -11,6 +11,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 	public sealed class VRC2_4 : NesBoardBase
 	{
 		#region addressmaps
+
 		// remaps addresses into vrc2b form
 		// all varieties of vrc2&4 require A15 = 1 (ie, we're in 8000:ffff), and key on A14:A12 in the same way
 		// in addition, each variety has two other bits; a "low bit" and a "high bit"
@@ -56,35 +57,35 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 
 		#endregion
 
-		//configuration
-		int prg_bank_mask_8k, chr_bank_mask_1k;
-		int prg_reg_mask_8k;
-		Func<int, int> remap;
-		Func<int, int> fix_chr;
-		int type;
-		bool latch6k_exists = false;
+		private int prg_bank_mask_8k, chr_bank_mask_1k;
+		private int prg_reg_mask_8k;
+		private Func<int, int> remap;
+		private Func<int, int> fix_chr;
+		private int type;
+		private bool latch6k_exists = false;
+
 		// it's been verified that this should be true on all real VRC4 chips, and
 		// that some vrc4 boards support it: http://forums.nesdev.com/viewtopic.php?t=8569
 		// but no vrc4 game ever used it
-		bool extrabig_chr = false;
+		private bool extrabig_chr = false;
 
 		//state
-		public int[] prg_bank_reg_8k = new int[2];
+		private int[] prg_bank_reg_8k = new int[2];
 		public int[] chr_bank_reg_1k = new int[16];
-		bool prg_mode;
+		private bool _prgMode;
 		public byte[] prg_banks_8k = new byte[4];
 		public int[] chr_banks_1k = new int[8];
-		bool irq_mode;
-		bool irq_enabled, irq_pending, irq_autoen;
-		byte irq_reload;
-		byte irq_counter;
-		int irq_prescaler;
+		private bool irq_mode;
+		private bool irq_enabled, irq_pending, irq_autoen;
+		private byte irq_reload;
+		private byte irq_counter;
+		private int irq_prescaler;
 		public int extra_vrom;
-		int latch6k_value;
+		private int latch6k_value;
 
-		bool isPirate = false;
+		private bool isPirate = false;
 		// needed for 2-in-1 - Yuu Yuu + Dragonball Z [p1][!]
-		bool _isBMC = false;
+		private bool _isBMC = false;
 
 		public override void SyncState(Serializer ser)
 		{
@@ -99,6 +100,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 			ser.Sync(nameof(irq_counter), ref irq_counter);
 			ser.Sync(nameof(irq_prescaler), ref irq_prescaler);
 			ser.Sync(nameof(extra_vrom), ref extra_vrom);
+			ser.Sync(nameof(_prgMode), ref _prgMode);
 			if (latch6k_exists)
 				ser.Sync(nameof(latch6k_value), ref latch6k_value);
 			//SyncPRG();
@@ -113,7 +115,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 		{
 			if (!_isBMC)
 			{
-				if (prg_mode)
+				if (_prgMode)
 				{
 					prg_banks_8k[0] = 0xFE;
 					prg_banks_8k[1] = (byte)(prg_bank_reg_8k[1]);
@@ -308,7 +310,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 			{
 				if (addr < 0x1000)
 				{
-					prg_banks_8k[prg_mode?1:0] = (byte)((prg_banks_8k[0] & 0x20) | (value & 0x1F));
+					prg_banks_8k[_prgMode?1:0] = (byte)((prg_banks_8k[0] & 0x20) | (value & 0x1F));
 					return;
 				}
 				else if (addr >= 0x2000 && addr < 0x3000)
@@ -358,7 +360,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 
 				case 0x1002: //$9002
 				case 0x1003: //$9003
-					if (type == 4) prg_mode = value.Bit(1);
+					if (type == 4) _prgMode = value.Bit(1);
 					else goto case 0x1000;
 					SyncPRG();
 					break;