diff --git a/Nitro/CommonHeader.cs b/Nitro/CommonHeader.cs
index 9796c7f..5fad6b3 100644
--- a/Nitro/CommonHeader.cs
+++ b/Nitro/CommonHeader.cs
@@ -1,214 +1,232 @@
+using System.Runtime.InteropServices;
+
 namespace SabreTools.Models.Nitro
 {
     /// <summary>
     /// Nintendo DS / DSi cartridge header
     /// </summary>
     /// <see href="https://dsibrew.org/wiki/DSi_cartridge_header"/>
+    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
     public sealed class CommonHeader
     {
         /// <summary>
         /// Game Title
         /// </summary>
-        public string? GameTitle { get; set; }
+        /// <remarks>12 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 12)]
+        public string? GameTitle;
 
         /// <summary>
         /// Gamecode
         /// </summary>
-        public uint GameCode { get; set; }
+        public uint GameCode;
 
         /// <summary>
         /// Makercode
         /// </summary>
-        public string? MakerCode { get; set; }
+        /// <remarks>2 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 2)]
+        public string? MakerCode;
 
         /// <summary>
         /// Unitcode
         /// </summary>
-        public Unitcode UnitCode { get; set; }
+        [MarshalAs(UnmanagedType.U1)]
+        public Unitcode UnitCode;
 
         /// <summary>
         /// Encryption seed select (device code. 0 = normal)
         /// </summary>
-        public byte EncryptionSeedSelect { get; set; }
+        public byte EncryptionSeedSelect;
 
         /// <summary>
         /// Devicecapacity
         /// </summary>
-        public byte DeviceCapacity { get; set; }
+        public byte DeviceCapacity;
 
         /// <summary>
         /// Reserved
         /// </summary>
-        public byte[]? Reserved1 { get; set; }
+        /// <remarks>7 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 7)]
+        public byte[]? Reserved1;
 
         /// <summary>
         /// Game Revision (used by DSi titles)
         /// </summary>
-        public ushort GameRevision { get; set; }
+        public ushort GameRevision;
 
         /// <summary>
         /// ROM Version
         /// </summary>
-        public byte RomVersion { get; set; }
+        public byte RomVersion;
 
         /// <summary>
         /// Internal flags, (Bit2: Autostart)
         /// </summary>
-        public byte InternalFlags { get; set; }
+        public byte InternalFlags;
 
         /// <summary>
         /// ARM9 rom offset
         /// </summary>
-        public uint ARM9RomOffset { get; set; }
+        public uint ARM9RomOffset;
 
         /// <summary>
         /// ARM9 entry address
         /// </summary>
-        public uint ARM9EntryAddress { get; set; }
+        public uint ARM9EntryAddress;
 
         /// <summary>
         /// ARM9 load address
         /// </summary>
-        public uint ARM9LoadAddress { get; set; }
+        public uint ARM9LoadAddress;
 
         /// <summary>
         /// ARM9 size
         /// </summary>
-        public uint ARM9Size { get; set; }
+        public uint ARM9Size;
 
         /// <summary>
         /// ARM7 rom offset
         /// </summary>
-        public uint ARM7RomOffset { get; set; }
+        public uint ARM7RomOffset;
 
         /// <summary>
         /// ARM7 entry address
         /// </summary>
-        public uint ARM7EntryAddress { get; set; }
+        public uint ARM7EntryAddress;
 
         /// <summary>
         /// ARM7 load address
         /// </summary>
-        public uint ARM7LoadAddress { get; set; }
+        public uint ARM7LoadAddress;
 
         /// <summary>
         /// ARM7 size
         /// </summary>
-        public uint ARM7Size { get; set; }
+        public uint ARM7Size;
 
         /// <summary>
         /// File Name Table (FNT) offset
         /// </summary>
-        public uint FileNameTableOffset { get; set; }
+        public uint FileNameTableOffset;
 
         /// <summary>
         /// File Name Table (FNT) length
         /// </summary>
-        public uint FileNameTableLength { get; set; }
+        public uint FileNameTableLength;
 
         /// <summary>
         /// File Allocation Table (FNT) offset
         /// </summary>
-        public uint FileAllocationTableOffset { get; set; }
+        public uint FileAllocationTableOffset;
 
         /// <summary>
         /// File Allocation Table (FNT) length
         /// </summary>
-        public uint FileAllocationTableLength { get; set; }
+        public uint FileAllocationTableLength;
 
         /// <summary>
         /// File Name Table (FNT) offset
         /// </summary>
-        public uint ARM9OverlayOffset { get; set; }
+        public uint ARM9OverlayOffset;
 
         /// <summary>
         /// File Name Table (FNT) length
         /// </summary>
-        public uint ARM9OverlayLength { get; set; }
+        public uint ARM9OverlayLength;
 
         /// <summary>
         /// File Name Table (FNT) offset
         /// </summary>
-        public uint ARM7OverlayOffset { get; set; }
+        public uint ARM7OverlayOffset;
 
         /// <summary>
         /// File Name Table (FNT) length
         /// </summary>
-        public uint ARM7OverlayLength { get; set; }
+        public uint ARM7OverlayLength;
 
         /// <summary>
         /// Normal card control register settings (0x00416657 for OneTimePROM)
         /// </summary>
-        public uint NormalCardControlRegisterSettings { get; set; }
+        public uint NormalCardControlRegisterSettings;
 
         /// <summary>
         /// Secure card control register settings (0x081808F8 for OneTimePROM)
         /// </summary>
-        public uint SecureCardControlRegisterSettings { get; set; }
+        public uint SecureCardControlRegisterSettings;
 
         /// <summary>
         /// Icon Banner offset (NDSi same as NDS, but with new extra entries)
         /// </summary>
-        public uint IconBannerOffset { get; set; }
+        public uint IconBannerOffset;
 
         /// <summary>
         /// Secure area (2K) CRC
         /// </summary>
-        public ushort SecureAreaCRC { get; set; }
+        public ushort SecureAreaCRC;
 
         /// <summary>
         /// Secure transfer timeout (0x0D7E for OneTimePROM)
         /// </summary>
-        public ushort SecureTransferTimeout { get; set; }
+        public ushort SecureTransferTimeout;
 
         /// <summary>
         /// ARM9 autoload
         /// </summary>
-        public uint ARM9Autoload { get; set; }
+        public uint ARM9Autoload;
 
         /// <summary>
         /// ARM7 autoload
         /// </summary>
-        public uint ARM7Autoload { get; set; }
+        public uint ARM7Autoload;
 
         /// <summary>
         /// Secure disable
         /// </summary>
-        public byte[]? SecureDisable { get; set; }
+        /// <remarks>8 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
+        public byte[]? SecureDisable;
 
         /// <summary>
         /// NTR region ROM size (excluding DSi area)
         /// </summary>
-        public uint NTRRegionRomSize { get; set; }
+        public uint NTRRegionRomSize;
 
         /// <summary>
         /// Header size
         /// </summary>
-        public uint HeaderSize { get; set; }
+        public uint HeaderSize;
 
         /// <summary>
-        ///Reserved (0x88, 0x8C, 0x90 = Unknown, used by DSi)
+        /// Reserved (0x88, 0x8C, 0x90 = Unknown, used by DSi)
         /// </summary>
-        public byte[]? Reserved2 { get; set; }
+        /// <remarks>56 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 56)]
+        public byte[]? Reserved2;
 
         /// <summary>
         /// Nintendo Logo
         /// </summary>
-        public byte[]? NintendoLogo { get; set; }
+        /// <remarks>156 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 156)]
+        public byte[]? NintendoLogo;
 
         /// <summary>
         /// Nintendo Logo CRC
         /// </summary>
-        public ushort NintendoLogoCRC { get; set; }
+        public ushort NintendoLogoCRC;
 
         /// <summary>
         /// Header CRC
         /// </summary>
-        public ushort HeaderCRC { get; set; }
+        public ushort HeaderCRC;
 
         /// <summary>
         /// Debugger reserved
         /// </summary>
-        public byte[]? DebuggerReserved { get; set; }
+        /// <remarks>0x20 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 0x20)]
+        public byte[]? DebuggerReserved;
     }
 }
\ No newline at end of file
diff --git a/Nitro/ExtendedDSiHeader.cs b/Nitro/ExtendedDSiHeader.cs
index 943fe82..cf4a766 100644
--- a/Nitro/ExtendedDSiHeader.cs
+++ b/Nitro/ExtendedDSiHeader.cs
@@ -1,259 +1,298 @@
+using System.Runtime.InteropServices;
+
 namespace SabreTools.Models.Nitro
 {
     /// <summary>
     /// Nintendo DSi extended cart header
     /// </summary>
     /// <see href="https://dsibrew.org/wiki/DSi_cartridge_header"/>
+    [StructLayout(LayoutKind.Sequential)]
     public sealed class ExtendedDSiHeader
     {
         /// <summary>
         /// Global MBK1..MBK5 Settings
         /// </summary>
-        public uint[]? GlobalMBK15Settings { get; set; }
+        /// <remarks>5 entries</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 5)]
+        public uint[]? GlobalMBK15Settings;
 
         /// <summary>
         ///	Local MBK6..MBK8 Settings for ARM9
         /// </summary>
-        public uint[]? LocalMBK68SettingsARM9 { get; set; }
+        /// <remarks>3 entries</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
+        public uint[]? LocalMBK68SettingsARM9;
 
         /// <summary>
         /// Local MBK6..MBK8 Settings for ARM7
         /// </summary>
-        public uint[]? LocalMBK68SettingsARM7 { get; set; }
+        /// <remarks>3 entries</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
+        public uint[]? LocalMBK68SettingsARM7;
 
         /// <summary>
         /// Global MBK9 Setting
         /// </summary>
-        public uint GlobalMBK9Setting { get; set; }
+        public uint GlobalMBK9Setting;
 
         /// <summary>
         /// Region Flags
         /// </summary>
-        public uint RegionFlags { get; set; }
+        public uint RegionFlags;
 
         /// <summary>
         /// Access control
         /// </summary>
-        public uint AccessControl { get; set; }
+        public uint AccessControl;
 
         /// <summary>
         /// ARM7 SCFG EXT mask (controls which devices to enable)
         /// </summary>
-        public uint ARM7SCFGEXTMask { get; set; }
+        public uint ARM7SCFGEXTMask;
 
         /// <summary>
         /// Reserved/flags? When bit2 of byte 0x1bf is set, usage of banner.sav from the title data dir is enabled.(additional banner data)
         /// </summary>
-        public uint ReservedFlags { get; set; }
+        public uint ReservedFlags;
 
         /// <summary>
         /// ARM9i rom offset
         /// </summary>
-        public uint ARM9iRomOffset { get; set; }
+        public uint ARM9iRomOffset;
 
         /// <summary>
         /// Reserved
         /// </summary>
-        public uint Reserved3 { get; set; }
+        public uint Reserved3;
 
         /// <summary>
         /// ARM9i load address
         /// </summary>
-        public uint ARM9iLoadAddress { get; set; }
+        public uint ARM9iLoadAddress;
 
         /// <summary>
-        /// ARM9i size { get; set; }
+        /// ARM9i size;
         /// </summary>
-        public uint ARM9iSize { get; set; }
+        public uint ARM9iSize;
 
         /// <summary>
         /// ARM7i rom offset
         /// </summary>
-        public uint ARM7iRomOffset { get; set; }
+        public uint ARM7iRomOffset;
 
         /// <summary>
         /// Pointer to base address where various structures and parameters are passed to the title - what is that???
         /// </summary>
-        public uint Reserved4 { get; set; }
+        public uint Reserved4;
 
         /// <summary>
         /// ARM7i load address
         /// </summary>
-        public uint ARM7iLoadAddress { get; set; }
+        public uint ARM7iLoadAddress;
 
         /// <summary>
-        /// ARM7i size { get; set; }
+        /// ARM7i size;
         /// </summary>
-        public uint ARM7iSize { get; set; }
+        public uint ARM7iSize;
 
         /// <summary>
         /// Digest NTR region offset
         /// </summary>
-        public uint DigestNTRRegionOffset { get; set; }
+        public uint DigestNTRRegionOffset;
 
         /// <summary>
         /// Digest NTR region length
         /// </summary>
-        public uint DigestNTRRegionLength { get; set; }
+        public uint DigestNTRRegionLength;
 
         // <summary>
         /// Digest TWL region offset
         /// </summary>
-        public uint DigestTWLRegionOffset { get; set; }
+        public uint DigestTWLRegionOffset;
 
         /// <summary>
         /// Digest TWL region length
         /// </summary>
-        public uint DigestTWLRegionLength { get; set; }
+        public uint DigestTWLRegionLength;
 
         // <summary>
         /// Digest Sector Hashtable region offset
         /// </summary>
-        public uint DigestSectorHashtableRegionOffset { get; set; }
+        public uint DigestSectorHashtableRegionOffset;
 
         /// <summary>
         /// Digest Sector Hashtable region length
         /// </summary>
-        public uint DigestSectorHashtableRegionLength { get; set; }
+        public uint DigestSectorHashtableRegionLength;
 
         // <summary>
         /// Digest Block Hashtable region offset
         /// </summary>
-        public uint DigestBlockHashtableRegionOffset { get; set; }
+        public uint DigestBlockHashtableRegionOffset;
 
         /// <summary>
         /// Digest Block Hashtable region length
         /// </summary>
-        public uint DigestBlockHashtableRegionLength { get; set; }
+        public uint DigestBlockHashtableRegionLength;
 
         /// <summary>
         /// Digest Sector size
         /// </summary>
-        public uint DigestSectorSize { get; set; }
+        public uint DigestSectorSize;
 
         /// <summary>
         /// Digeset Block Sectorount
         /// </summary>
-        public uint DigestBlockSectorCount { get; set; }
+        public uint DigestBlockSectorCount;
 
         /// <summary>
         /// Icon Banner Size (usually 0x23C0)
         /// </summary>
-        public uint IconBannerSize { get; set; }
+        public uint IconBannerSize;
 
         /// <summary>
         /// Unknown (used by DSi)
         /// </summary>
-        public uint Unknown1 { get; set; }
+        public uint Unknown1;
 
         /// <summary>
         /// NTR+TWL region ROM size (total size including DSi area)
         /// </summary>
-        public uint NTRTWLRegionRomSize { get; set; }
+        public uint NTRTWLRegionRomSize;
 
         /// <summary>
         /// Unknown (used by DSi)
         /// </summary>
-        public byte[]? Unknown2 { get; set; }
+        /// <remarks>12 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 12)]
+        public byte[]? Unknown2;
 
         /// <summary>
         /// Modcrypt area 1 offset
         /// </summary>
-        public uint ModcryptArea1Offset { get; set; }
+        public uint ModcryptArea1Offset;
 
         /// <summary>
         /// Modcrypt area 1 size
         /// </summary>
-        public uint ModcryptArea1Size { get; set; }
+        public uint ModcryptArea1Size;
 
         /// <summary>
         /// Modcrypt area 2 offset
         /// </summary>
-        public uint ModcryptArea2Offset { get; set; }
+        public uint ModcryptArea2Offset;
 
         /// <summary>
         /// Modcrypt area 2 size
         /// </summary>
-        public uint ModcryptArea2Size { get; set; }
+        public uint ModcryptArea2Size;
 
         /// <summary>
         /// Title ID
         /// </summary>
-        public byte[]? TitleID { get; set; }
+        /// <remarks>8 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
+        public byte[]? TitleID;
 
         /// <summary>
         /// DSiWare: "public.sav" size
         /// </summary>
-        public uint DSiWarePublicSavSize { get; set; }
+        public uint DSiWarePublicSavSize;
 
         /// <summary>
         /// DSiWare: "private.sav" size
         /// </summary>
-        public uint DSiWarePrivateSavSize { get; set; }
+        public uint DSiWarePrivateSavSize;
 
         /// <summary>
         /// Reserved (zero)
         /// </summary>
-        public byte[]? ReservedZero { get; set; }
+        /// <remarks>176 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 176)]
+        public byte[]? ReservedZero;
 
         /// <summary>
         /// Unknown (used by DSi)
         /// </summary>
-        public byte[]? Unknown3 { get; set; }
+        /// <remarks>16 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
+        public byte[]? Unknown3;
 
         /// <summary>
         /// ARM9 (with encrypted secure area) SHA1 HMAC hash
         /// </summary>
-        public byte[]? ARM9WithSecureAreaSHA1HMACHash { get; set; }
+        /// <remarks>20 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 20)]
+        public byte[]? ARM9WithSecureAreaSHA1HMACHash;
 
         /// <summary>
         /// ARM7 SHA1 HMAC hash
         /// </summary>
-        public byte[]? ARM7SHA1HMACHash { get; set; }
+        /// <remarks>20 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 20)]
+        public byte[]? ARM7SHA1HMACHash;
 
         /// <summary>
         /// Digest master SHA1 HMAC hash
         /// </summary>
-        public byte[]? DigestMasterSHA1HMACHash { get; set; }
+        /// <remarks>20 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 20)]
+        public byte[]? DigestMasterSHA1HMACHash;
 
         /// <summary>
         /// Banner SHA1 HMAC hash
         /// </summary>
-        public byte[]? BannerSHA1HMACHash { get; set; }
+        /// <remarks>20 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 20)]
+        public byte[]? BannerSHA1HMACHash;
 
         /// <summary>
         /// ARM9i (decrypted) SHA1 HMAC hash
         /// </summary>
-        public byte[]? ARM9iDecryptedSHA1HMACHash { get; set; }
+        /// <remarks>20 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 20)]
+        public byte[]? ARM9iDecryptedSHA1HMACHash;
 
         /// <summary>
         /// ARM7i (decrypted) SHA1 HMAC hash
         /// </summary>
-        public byte[]? ARM7iDecryptedSHA1HMACHash { get; set; }
+        /// <remarks>20 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 20)]
+        public byte[]? ARM7iDecryptedSHA1HMACHash;
 
         /// <summary>
         /// Reserved
         /// </summary>
-        public byte[]? Reserved5 { get; set; }
+        /// <remarks>40 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 40)]
+        public byte[]? Reserved5;
 
         /// <summary>
         /// ARM9 (without secure area) SHA1 HMAC hash
         /// </summary>
-        public byte[]? ARM9NoSecureAreaSHA1HMACHash { get; set; }
+        /// <remarks>20 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 20)]
+        public byte[]? ARM9NoSecureAreaSHA1HMACHash;
 
         /// <summary>
         /// Reserved
         /// </summary>
-        public byte[]? Reserved6 { get; set; }
+        /// <remarks>2636 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 2636)]
+        public byte[]? Reserved6;
 
         /// <summary>
         /// Reserved and unchecked region, always zero. Used for passing arguments in debug environment.
         /// </summary>
-        public byte[]? ReservedAndUnchecked { get; set; }
+        /// <remarks>0x180 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 0x180)]
+        public byte[]? ReservedAndUnchecked;
 
         /// <summary>
         /// RSA signature (the first 0xE00 bytes of the header are signed with an 1024-bit RSA signature).
         /// </summary>
-        public byte[]? RSASignature { get; set; }
+        /// <remarks>0x80 bytes</remarks>
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 0x80)]
+        public byte[]? RSASignature;
     }
 }
\ No newline at end of file
diff --git a/Nitro/FileAllocationTableEntry.cs b/Nitro/FileAllocationTableEntry.cs
index 47817e1..43c4819 100644
--- a/Nitro/FileAllocationTableEntry.cs
+++ b/Nitro/FileAllocationTableEntry.cs
@@ -1,3 +1,5 @@
+using System.Runtime.InteropServices;
+
 namespace SabreTools.Models.Nitro
 {
     /// <summary>
@@ -5,16 +7,17 @@ namespace SabreTools.Models.Nitro
     /// it's just a table of 8 byte entries
     /// </summary>
     /// <see href="https://github.com/Deijin27/RanseiLink/wiki/NDS-File-System"/>
+    [StructLayout(LayoutKind.Sequential)]
     public sealed class FileAllocationTableEntry
     {
         /// <summary>
         /// Start offset of file
         /// </summary>
-        public uint StartOffset { get; set; }
+        public uint StartOffset;
 
         /// <summary>
         /// End offset of file (after this is padding)
         /// </summary>
-        public uint EndOffset { get; set; }
+        public uint EndOffset;
     }
 }
\ No newline at end of file
diff --git a/Nitro/FolderAllocationTableEntry.cs b/Nitro/FolderAllocationTableEntry.cs
index e177991..7a8e5a3 100644
--- a/Nitro/FolderAllocationTableEntry.cs
+++ b/Nitro/FolderAllocationTableEntry.cs
@@ -1,3 +1,5 @@
+using System.Runtime.InteropServices;
+
 namespace SabreTools.Models.Nitro
 {
     /// <summary>
@@ -6,28 +8,29 @@ namespace SabreTools.Models.Nitro
     /// point to the file system.
     /// </summary>
     /// <see href="https://github.com/Deijin27/RanseiLink/wiki/NDS-File-System"/>
+    [StructLayout(LayoutKind.Sequential)]
     public sealed class FolderAllocationTableEntry
     {
         /// <summary>
         /// Start offset of folder contents within Name List
         /// relative to start of NameTable
         /// </summary>
-        public uint StartOffset { get; set; }
+        public uint StartOffset;
 
         /// <summary>
         /// Index of first file within folder in File Allocation Table
         /// </summary>
-        public ushort FirstFileIndex { get; set; }
+        public ushort FirstFileIndex;
 
         /// <summary>
         /// Index of parent folder in current table; for root folder
         /// this holds the number of entries in the table
         /// </summary>
-        public byte ParentFolderIndex { get; set; }
+        public byte ParentFolderIndex;
 
         /// <summary>
         /// Unknown, always 0xF0 except for root folder
         /// </summary>
-        public byte Unknown { get; set; }
+        public byte Unknown;
     }
 }
\ No newline at end of file