diff --git a/src/BizHawk.Bizware.Graphics/BitmapBuffer.cs b/src/BizHawk.Bizware.Graphics/BitmapBuffer.cs
index df8a1fcdaf..d10795f6d4 100644
--- a/src/BizHawk.Bizware.Graphics/BitmapBuffer.cs
+++ b/src/BizHawk.Bizware.Graphics/BitmapBuffer.cs
@@ -1,6 +1,7 @@
 // TODO - introduce Trim for ArtManager
 // TODO - add a small buffer reuse manager.. small images can be stored in larger buffers which we happen to have held. use a timer to wait to free it until some time has passed
 
+using System.Buffers.Binary;
 using System.Diagnostics;
 using System.Drawing;
 using System.Drawing.Drawing2D;
@@ -468,8 +469,13 @@ namespace BizHawk.Bizware.Graphics
 			r = (r * a) >> 8;
 			g = (g * a) >> 8;
 			b = (b * a) >> 8;
-			srcVal = b | (g << 8) | (r << 16) | (a << 24);
-			return srcVal;
+			return BinaryPrimitives.ReadInt32BigEndian(unchecked(stackalloc byte[]
+			{
+				(byte) a,
+				(byte) r,
+				(byte) g,
+				(byte) b,
+			}));
 		}
 
 		/// <summary>
diff --git a/src/BizHawk.Client.EmuHawk/AVOut/AviWriter.cs b/src/BizHawk.Client.EmuHawk/AVOut/AviWriter.cs
index ae16339af6..eb623727c9 100644
--- a/src/BizHawk.Client.EmuHawk/AVOut/AviWriter.cs
+++ b/src/BizHawk.Client.EmuHawk/AVOut/AviWriter.cs
@@ -640,13 +640,6 @@ namespace BizHawk.Client.EmuHawk
 			/// <exception cref="InvalidOperationException">unmanaged call failed</exception>
 			public void OpenFile(string destPath, Parameters parameters, CodecToken videoCodecToken)
 			{
-				static int mmioFOURCC(string str) => (
-					(byte)str[0] |
-					((byte)str[1] << 8) |
-					((byte)str[2] << 16) |
-					((byte)str[3] << 24)
-				);
-
 				this._parameters = parameters;
 				this._currVideoCodecToken = videoCodecToken;
 
@@ -670,7 +663,7 @@ namespace BizHawk.Client.EmuHawk
 				var vidstream_header = default(AVIWriterImports.AVISTREAMINFOW);
 				var bmih = default(AVIWriterImports.BITMAPINFOHEADER);
 				parameters.PopulateBITMAPINFOHEADER24(ref bmih);
-				vidstream_header.fccType = mmioFOURCC("vids");
+				vidstream_header.fccType = /*BinaryPrimitives.ReadInt32LittleEndian("vids"u8)*/0x73646976;
 				vidstream_header.dwRate = parameters.fps;
 				vidstream_header.dwScale = parameters.fps_scale;
 				vidstream_header.dwSuggestedBufferSize = (int)bmih.biSizeImage;
@@ -687,7 +680,7 @@ namespace BizHawk.Client.EmuHawk
 				var audstream_header = default(AVIWriterImports.AVISTREAMINFOW);
 				var wfex = default(AVIWriterImports.WAVEFORMATEX);
 				parameters.PopulateWAVEFORMATEX(ref wfex);
-				audstream_header.fccType = mmioFOURCC("auds");
+				audstream_header.fccType = /*BinaryPrimitives.ReadInt32LittleEndian("auds"u8)*/0x73647561;
 				audstream_header.dwQuality = -1;
 				audstream_header.dwScale = wfex.nBlockAlign;
 				audstream_header.dwRate = (int)wfex.nAvgBytesPerSec;
diff --git a/src/BizHawk.Client.EmuHawk/RetroAchievements/RCheevos.cs b/src/BizHawk.Client.EmuHawk/RetroAchievements/RCheevos.cs
index fb9b25fe90..1bce64e241 100644
--- a/src/BizHawk.Client.EmuHawk/RetroAchievements/RCheevos.cs
+++ b/src/BizHawk.Client.EmuHawk/RetroAchievements/RCheevos.cs
@@ -1,3 +1,4 @@
+using System.Buffers.Binary;
 using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
@@ -660,7 +661,13 @@ namespace BizHawk.Client.EmuHawk
 		{
 			1 => Peek(address),
 			2 => Peek(address) | (Peek(address + 1) << 8),
-			4 => Peek(address) | (Peek(address + 1) << 8) | (Peek(address + 2) << 16) | (Peek(address + 3) << 24),
+			4 => BinaryPrimitives.ReadUInt32LittleEndian(unchecked(stackalloc byte[]
+			{
+				(byte) Peek(address),
+				(byte) Peek(address + 1),
+				(byte) Peek(address + 2),
+				(byte) Peek(address + 3),
+			})),
 			_ => throw new InvalidOperationException($"Requested {num_bytes} in {nameof(PeekCallback)}"),
 		};
 
diff --git a/src/BizHawk.Client.EmuHawk/RetroAchievements/RetroAchievements.GameVerification.cs b/src/BizHawk.Client.EmuHawk/RetroAchievements/RetroAchievements.GameVerification.cs
index 58bfac9ee1..7a4a20c41e 100644
--- a/src/BizHawk.Client.EmuHawk/RetroAchievements/RetroAchievements.GameVerification.cs
+++ b/src/BizHawk.Client.EmuHawk/RetroAchievements/RetroAchievements.GameVerification.cs
@@ -75,8 +75,8 @@ namespace BizHawk.Client.EmuHawk
 						var slba = FirstDataTrackLBA();
 						dsr.ReadLBA_2048(slba + 1, buf2048, 0);
 						bitsToHash.Add(new(buf2048, offset: 0, count: 128));
-						var bootSector = (buf2048[35] << 24) | (buf2048[34] << 16) | (buf2048[33] << 8) | buf2048[32];
-						var numSectors = (buf2048[39] << 24) | (buf2048[38] << 16) | (buf2048[37] << 8) | buf2048[36];
+						var bootSector = BinaryPrimitives.ReadInt32LittleEndian(buf2048.AsSpan(start: 32));
+						var numSectors = BinaryPrimitives.ReadInt32LittleEndian(buf2048.AsSpan(start: 36));
 						for (var i = 0; i < numSectors; i++)
 						{
 							dsr.ReadLBA_2048(slba + bootSector + i, buf2048, 0);
@@ -103,7 +103,7 @@ namespace BizHawk.Client.EmuHawk
 								}
 								else
 								{
-									var directoryRecordLength = (uint)((buf2048[169] << 24) | (buf2048[168] << 16) | (buf2048[167] << 8) | buf2048[166]);
+									var directoryRecordLength = BinaryPrimitives.ReadUInt32LittleEndian(buf2048.AsSpan(start: 166));
 									numSectors = (int)(directoryRecordLength / logicalBlockSize);
 								}
 							}
@@ -133,7 +133,7 @@ namespace BizHawk.Client.EmuHawk
 										var fn = Encoding.ASCII.GetString(buf2048, index + 33, filename.Length);
 										if (filename.EqualsIgnoreCase(fn))
 										{
-											filesize = (buf2048[index + 13] << 24) | (buf2048[index + 12] << 16) | (buf2048[index + 11] << 8) | buf2048[index + 10];
+											filesize = BinaryPrimitives.ReadInt32LittleEndian(buf2048.AsSpan(start: index + 10));
 											return (buf2048[index + 4] << 16) | (buf2048[index + 3] << 8) | buf2048[index + 2];
 										}
 									}
@@ -203,7 +203,7 @@ namespace BizHawk.Client.EmuHawk
 
 						if ("PS-X EXE" == Encoding.ASCII.GetString(buf2048, 0, 8))
 						{
-							exeSize = ((buf2048[31] << 24) | (buf2048[30] << 16) | (buf2048[29] << 8) | buf2048[28]) + 2048;
+							exeSize = BinaryPrimitives.ReadInt32LittleEndian(buf2048.AsSpan(start: 28)) + 2048;
 						}
 
 						bitsToHash.Add(new(buf2048, offset: 0, count: Math.Min(2048, exeSize)));
diff --git a/src/BizHawk.Common/Colors.cs b/src/BizHawk.Common/Colors.cs
index a770e3e334..4149e3b897 100644
--- a/src/BizHawk.Common/Colors.cs
+++ b/src/BizHawk.Common/Colors.cs
@@ -1,11 +1,14 @@
-namespace BizHawk.Common
+using System.Buffers.Binary;
+
+namespace BizHawk.Common
 {
 #pragma warning disable MA0104 // unlikely to conflict with System.Windows.Media.Colors
 	public static class Colors
 #pragma warning restore MA0104
 	{
 		/// <remarks>This is just <c>Color.FromArgb(alpha, red, green, blue).ToArgb()</c> with extra steps.</remarks>
-		public static int ARGB(byte red, byte green, byte blue, byte alpha = 0xFF) => unchecked((int) ((uint) (alpha << 24) | (uint) (red << 16) | (uint) (green << 8) | blue));
+		public static int ARGB(byte red, byte green, byte blue, byte alpha = 0xFF)
+			=> BinaryPrimitives.ReadInt32BigEndian(stackalloc byte[] { alpha, red, green, blue });
 
 #if false
 		public static int Luminosity(byte lum) => ARGB(lum, lum, lum);
diff --git a/src/BizHawk.Emulation.Common/Base Implementations/MemoryDomain.cs b/src/BizHawk.Emulation.Common/Base Implementations/MemoryDomain.cs
index bca3ed177e..78abca3fa8 100644
--- a/src/BizHawk.Emulation.Common/Base Implementations/MemoryDomain.cs	
+++ b/src/BizHawk.Emulation.Common/Base Implementations/MemoryDomain.cs	
@@ -1,5 +1,7 @@
 #nullable disable
 
+using System.Buffers.Binary;
+
 using BizHawk.Common;
 
 namespace BizHawk.Emulation.Common
@@ -46,18 +48,16 @@ namespace BizHawk.Emulation.Common
 
 		public virtual uint PeekUint(long addr, bool bigEndian)
 		{
-			if (bigEndian)
+			ReadOnlySpan<byte> scratch = stackalloc byte[]
 			{
-				return (uint)((PeekByte(addr) << 24)
-					| (PeekByte(addr + 1) << 16)
-					| (PeekByte(addr + 2) << 8)
-					| (PeekByte(addr + 3) << 0));
-			}
-
-			return (uint)((PeekByte(addr) << 0)
-				| (PeekByte(addr + 1) << 8)
-				| (PeekByte(addr + 2) << 16)
-				| (PeekByte(addr + 3) << 24));
+				PeekByte(addr),
+				PeekByte(addr + 1),
+				PeekByte(addr + 2),
+				PeekByte(addr + 3),
+			};
+			return bigEndian
+				? BinaryPrimitives.ReadUInt32BigEndian(scratch)
+				: BinaryPrimitives.ReadUInt32LittleEndian(scratch);
 		}
 
 		public virtual void PokeUshort(long addr, ushort val, bool bigEndian)
diff --git a/src/BizHawk.Emulation.Cores/Computers/Commodore64/Cartridge/CartridgeDevice.cs b/src/BizHawk.Emulation.Cores/Computers/Commodore64/Cartridge/CartridgeDevice.cs
index 8347073a53..9a397dbed2 100644
--- a/src/BizHawk.Emulation.Cores/Computers/Commodore64/Cartridge/CartridgeDevice.cs
+++ b/src/BizHawk.Emulation.Cores/Computers/Commodore64/Cartridge/CartridgeDevice.cs
@@ -1,3 +1,4 @@
+using System.Buffers.Binary;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -136,12 +137,13 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.Cartridge
 		}
 
 		private static int ReadCRTInt(BinaryReader reader)
-		{
-			return (reader.ReadByte() << 24) |
-				(reader.ReadByte() << 16) |
-				(reader.ReadByte() << 8) |
-				reader.ReadByte();
-		}
+			=> BinaryPrimitives.ReadInt32BigEndian(stackalloc byte[]
+			{
+				reader.ReadByte(),
+				reader.ReadByte(),
+				reader.ReadByte(),
+				reader.ReadByte(),
+			});
 
 		protected bool pinExRom;
 
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/BSNES/SNESGraphicsDecoder.cs b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/BSNES/SNESGraphicsDecoder.cs
index f89217476d..2d59205968 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/BSNES/SNESGraphicsDecoder.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/BSNES/SNESGraphicsDecoder.cs
@@ -1,3 +1,4 @@
+using System.Buffers.Binary;
 using System.Drawing;
 using BizHawk.Emulation.Cores.Nintendo.SNES;
 using static BizHawk.Emulation.Cores.Nintendo.BSNES.BsnesApi.SNES_REGISTER;
@@ -20,7 +21,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.BSNES
 		private readonly short[] directColorTable = new short[256];
 		private void generate_palette()
 		{
-			const int a = 0xFF;
+			Span<byte> scratch = stackalloc byte[4];
+			scratch[0] = 0xFF;
 			for (int color = 0; color < 32768; color++) {
 				int r = (color >> 10) & 31;
 				int g = (color >>  5) & 31;
@@ -30,7 +32,13 @@ namespace BizHawk.Emulation.Cores.Nintendo.BSNES
 				g = g << 3 | g >> 2; g = g << 8 | g << 0;
 				b = b << 3 | b >> 2; b = b << 8 | b << 0;
 
-				palette[color] = a << 24 | b >> 8 << 16 | g >> 8 <<  8 | r >> 8 << 0;
+				unchecked
+				{
+					scratch[1] = (byte) (b >> 8);
+					scratch[2] = (byte) (g >> 8);
+					scratch[3] = (byte) (r >> 8);
+				}
+				palette[color] = BinaryPrimitives.ReadInt32BigEndian(scratch);
 			}
 		}
 
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBA/ArmV4Disassembler.cs b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBA/ArmV4Disassembler.cs
index cedcfe5173..743e22e05e 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBA/ArmV4Disassembler.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBA/ArmV4Disassembler.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System.Buffers.Binary;
+using System.Collections.Generic;
 
 using BizHawk.BizInvoke;
 using BizHawk.Common;
@@ -35,11 +36,14 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBA
 			else
 			{
 				addr &= unchecked((uint)~3);
-				int op = m.PeekByte((int)addr)
-					| m.PeekByte((int)addr + 1) << 8
-					| m.PeekByte((int)addr + 2) << 16
-					| m.PeekByte((int)addr + 3) << 24;
-				string ret = _libdarm.DisassembleStuff(addr, (uint)op);
+				var op = BinaryPrimitives.ReadUInt32LittleEndian(stackalloc byte[]
+				{
+					m.PeekByte(addr),
+					m.PeekByte(addr + 1L),
+					m.PeekByte(addr + 2L),
+					m.PeekByte(addr + 3L),
+				});
+				var ret = _libdarm.DisassembleStuff(addr, op);
 				length = 4;
 				return ret;
 			}
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/GBColors.cs b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/GBColors.cs
index 651b27abfb..8a49946830 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/GBColors.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/GBColors.cs
@@ -1,3 +1,5 @@
+using BizHawk.Common;
+
 namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 {
 	public static class GBColors
@@ -69,9 +71,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 			}
 
 			public int ToARGB32()
-			{
-				return b | g << 8 | r << 16 | 255 << 24;
-			}
+				=> unchecked(Colors.ARGB(red: (byte) r, green: (byte) g, blue: (byte) b));
 		}
 
 		// sameboy's "emulate hardware" color conversion
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/NDSDisassembler.cs b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/NDSDisassembler.cs
index 7ee3c86d1a..56c3bc3a20 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/NDSDisassembler.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/NDSDisassembler.cs
@@ -1,3 +1,4 @@
+using System.Buffers.Binary;
 using System.Collections.Generic;
 using System.Text;
 
@@ -49,10 +50,13 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.NDS
 			else
 			{
 				addr &= ~3u;
-				var op = m.PeekByte(addr)
-					| (uint)m.PeekByte(addr + 1) << 8
-					| (uint)m.PeekByte(addr + 2) << 16
-					| (uint)m.PeekByte(addr + 3) << 24;
+				var op = BinaryPrimitives.ReadUInt32LittleEndian(stackalloc byte[]
+				{
+					m.PeekByte(addr),
+					m.PeekByte(addr + 1),
+					m.PeekByte(addr + 2),
+					m.PeekByte(addr + 3),
+				});
 				_core.GetDisassembly(type, op, ret);
 				length = 4;
 			}
diff --git a/src/BizHawk.Emulation.DiscSystem/DiscHasher.cs b/src/BizHawk.Emulation.DiscSystem/DiscHasher.cs
index 8e35e2e8b4..3799572dc7 100644
--- a/src/BizHawk.Emulation.DiscSystem/DiscHasher.cs
+++ b/src/BizHawk.Emulation.DiscSystem/DiscHasher.cs
@@ -1,5 +1,6 @@
 #nullable enable
 
+using System.Buffers.Binary;
 using System.Collections.Generic;
 using System.Text;
 using BizHawk.Common;
@@ -158,8 +159,7 @@ namespace BizHawk.Emulation.DiscSystem
 						{
 							if (_jaguarHeader == Encoding.ASCII.GetString(buf2352, j, 32 - 1))
 							{
-								bootLen = (buf2352[j + bootLenOffset + 0] << 24) | (buf2352[j + bootLenOffset + 1] << 16) |
-									(buf2352[j + bootLenOffset + 2] << 8) | buf2352[j + bootLenOffset + 3];
+								bootLen = BinaryPrimitives.ReadInt32BigEndian(buf2352.AsSpan(start: bootLenOffset + j));
 								bootLba = startLba + i;
 								bootOff = j + bootLenOffset + 4;
 								// byteswapped = false;
@@ -171,8 +171,9 @@ namespace BizHawk.Emulation.DiscSystem
 						{
 							if (_jaguarBSHeader == Encoding.ASCII.GetString(buf2352, j, 32 - 2))
 							{
-								bootLen = (buf2352[j + bootLenOffset + 1] << 24) | (buf2352[j + bootLenOffset + 0] << 16) |
-									(buf2352[j + bootLenOffset + 3] << 8) | buf2352[j + bootLenOffset + 2];
+								var slice = buf2352.AsSpan(start: bootLenOffset + j, length: sizeof(int)).ToArray();
+								EndiannessUtils.MutatingByteSwap16(slice);
+								bootLen = BinaryPrimitives.ReadInt32BigEndian(slice);
 								bootLba = startLba + i;
 								bootOff = j + bootLenOffset + 4;
 								byteswapped = true;