diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 6738488470..5ad315464c 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -127,11 +127,8 @@
     <Compile Include="Computers\AppleII\Virtu\GamePort.cs" />
     <Compile Include="Computers\AppleII\Virtu\Keyboard.cs" />
     <Compile Include="Computers\AppleII\Virtu\Library\DisposableBase.cs" />
-    <Compile Include="Computers\AppleII\Virtu\Library\IEnumerableExtensions.cs" />
-    <Compile Include="Computers\AppleII\Virtu\Library\MarshalHelpers.cs" />
     <Compile Include="Computers\AppleII\Virtu\Library\MathHelpers.cs" />
     <Compile Include="Computers\AppleII\Virtu\Library\StreamExtensions.cs" />
-    <Compile Include="Computers\AppleII\Virtu\Library\StringBuilderExtensions.cs" />
     <Compile Include="Computers\AppleII\Virtu\Library\Strings.cs" />
     <Compile Include="Computers\AppleII\Virtu\Machine.cs" />
     <Compile Include="Computers\AppleII\Virtu\MachineComponent.cs" />
diff --git a/BizHawk.Emulation.Cores/Computers/AppleII/Virtu/Library/IEnumerableExtensions.cs b/BizHawk.Emulation.Cores/Computers/AppleII/Virtu/Library/IEnumerableExtensions.cs
deleted file mode 100644
index 2b1bb460e5..0000000000
--- a/BizHawk.Emulation.Cores/Computers/AppleII/Virtu/Library/IEnumerableExtensions.cs
+++ /dev/null
@@ -1,25 +0,0 @@
-using System;
-using System.Collections.Generic;
-
-namespace Jellyfish.Library
-{
-    public static class IEnumerableExtensions
-    {
-        public static void ForEach<T>(this IEnumerable<T> source, Action<T> action)
-        {
-            if (source == null)
-            {
-                throw new ArgumentNullException("source");
-            }
-            if (action == null)
-            {
-                throw new ArgumentNullException("action");
-            }
-
-            foreach (T item in source)
-            {
-                action(item);
-            }
-        }
-    }
-}
diff --git a/BizHawk.Emulation.Cores/Computers/AppleII/Virtu/Library/MarshalHelpers.cs b/BizHawk.Emulation.Cores/Computers/AppleII/Virtu/Library/MarshalHelpers.cs
deleted file mode 100644
index eba53940a8..0000000000
--- a/BizHawk.Emulation.Cores/Computers/AppleII/Virtu/Library/MarshalHelpers.cs
+++ /dev/null
@@ -1,35 +0,0 @@
-using System;
-using System.Diagnostics.CodeAnalysis;
-using System.Runtime.InteropServices;
-using System.Security;
-
-namespace Jellyfish.Library
-{
-    public static class MarshalHelpers
-    {
-        [SecurityCritical]
-        public static void FillMemory(IntPtr buffer, int bufferSize, byte value)
-        {
-            NativeMethods.FillMemory(buffer, (IntPtr)bufferSize, value);
-        }
-
-        [SecurityCritical]
-        public static void ZeroMemory(IntPtr buffer, int bufferSize)
-        {
-            NativeMethods.ZeroMemory(buffer, (IntPtr)bufferSize);
-        }
-
-        [SecurityCritical]
-        [SuppressUnmanagedCodeSecurity]
-        private static class NativeMethods
-        {
-            [SuppressMessage("Microsoft.Security", "CA2118:ReviewSuppressUnmanagedCodeSecurityUsage")]
-            [DllImport("kernel32.dll", SetLastError = true)]
-            public static extern void FillMemory(IntPtr destination, IntPtr length, byte fill);
-
-            [SuppressMessage("Microsoft.Security", "CA2118:ReviewSuppressUnmanagedCodeSecurityUsage")]
-            [DllImport("kernel32.dll", SetLastError = true)]
-            public static extern void ZeroMemory(IntPtr destination, IntPtr length);
-        }
-    }
-}
diff --git a/BizHawk.Emulation.Cores/Computers/AppleII/Virtu/Library/StringBuilderExtensions.cs b/BizHawk.Emulation.Cores/Computers/AppleII/Virtu/Library/StringBuilderExtensions.cs
deleted file mode 100644
index 5935c605f5..0000000000
--- a/BizHawk.Emulation.Cores/Computers/AppleII/Virtu/Library/StringBuilderExtensions.cs
+++ /dev/null
@@ -1,54 +0,0 @@
-using System;
-using System.Globalization;
-using System.Text;
-
-namespace Jellyfish.Library
-{
-    public static class StringBuilderExtensions
-    {
-        public static StringBuilder AppendHex(this StringBuilder builder, short value) // little endian
-        {
-            if (builder == null)
-            {
-                throw new ArgumentNullException("builder");
-            }
-
-            return builder.AppendFormat(CultureInfo.InvariantCulture, "{0:X2}{1:X2}", value & 0xFF, value >> 8);
-        }
-
-        public static StringBuilder AppendHex(this StringBuilder builder, int value) // little endian
-        {
-            if (builder == null)
-            {
-                throw new ArgumentNullException("builder");
-            }
-
-            return builder.AppendFormat(CultureInfo.InvariantCulture, "{0:X2}{1:X2}{2:X2}{3:X2}", value & 0xFF, (value >> 8) & 0xFF, (value >> 16) & 0xFF, value >> 24);
-        }
-
-        public static StringBuilder AppendWithoutGarbage(this StringBuilder builder, int value)
-        {
-            if (builder == null)
-            {
-                throw new ArgumentNullException("builder");
-            }
-
-            if (value < 0)
-            {
-                builder.Append('-');
-            }
-
-            int index = builder.Length;
-            do
-            {
-                builder.Insert(index, Digits, (value % 10) + 9, 1);
-                value /= 10;
-            }
-            while (value != 0);
-
-            return builder;
-        }
-
-        private static readonly char[] Digits = new char[] { '9', '8', '7', '6', '5', '4', '3', '2', '1', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
-    }
-}