diff --git a/CHS.cs b/CHS.cs
new file mode 100644
index 0000000..d2e8e75
--- /dev/null
+++ b/CHS.cs
@@ -0,0 +1,42 @@
+// /***************************************************************************
+// The Disc Image Chef
+// ----------------------------------------------------------------------------
+//
+// Filename       : CHS.cs
+// Author(s)      : Natalia Portillo <claunia@claunia.com>
+//
+// Component      : Component
+//
+// --[ Description ] ----------------------------------------------------------
+//
+//     Description
+//
+// --[ License ] --------------------------------------------------------------
+//
+//     This library is free software; you can redistribute it and/or modify
+//     it under the terms of the GNU Lesser General Public License as
+//     published by the Free Software Foundation; either version 2.1 of the
+//     License, or (at your option) any later version.
+//
+//     This library is distributed in the hope that it will be useful, but
+//     WITHOUT ANY WARRANTY; without even the implied warranty of
+//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+//     Lesser General Public License for more details.
+//
+//     You should have received a copy of the GNU Lesser General Public
+//     License along with this library; if not, see <http://www.gnu.org/licenses/>.
+//
+// ----------------------------------------------------------------------------
+// Copyright © 2011-2017 Natalia Portillo
+// ****************************************************************************/
+using System;
+namespace DiscImageChef.Helpers
+{
+    public static class CHS
+    {
+        public static uint ToLBA(uint cyl, uint head, uint sector, uint maxHead, uint maxSector)
+        {
+            return maxHead == 0 || maxSector == 0 ? (cyl * 16 + head) * 63 + sector - 1 : (cyl * maxHead + head) * maxSector + sector - 1;
+        }
+    }
+}
diff --git a/DiscImageChef.Helpers.csproj b/DiscImageChef.Helpers.csproj
index 78c4a7b..d509b87 100644
--- a/DiscImageChef.Helpers.csproj
+++ b/DiscImageChef.Helpers.csproj
@@ -54,6 +54,7 @@
     <Compile Include="Extents\ExtentsByte.cs" />
     <Compile Include="Extents\ExtentsSByte.cs" />
     <Compile Include="CountBits.cs" />
+    <Compile Include="CHS.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <ItemGroup>
@@ -82,7 +83,7 @@
             <inheritsSet />
             <inheritsScope />
           </TextStylePolicy>
-          <CSharpFormattingPolicy IndentBlock="True" IndentBraces="False" IndentSwitchSection="True" IndentSwitchCaseSection="True" LabelPositioning="OneLess" NewLinesForBracesInTypes="True" NewLinesForBracesInMethods="True" NewLinesForBracesInProperties="True" NewLinesForBracesInAccessors="True" NewLinesForBracesInAnonymousMethods="True" NewLinesForBracesInControlBlocks="True" NewLinesForBracesInAnonymousTypes="True" NewLinesForBracesInObjectCollectionArrayInitializers="True" NewLinesForBracesInLambdaExpressionBody="True" NewLineForElse="True" NewLineForCatch="True" NewLineForFinally="True" NewLineForMembersInObjectInit="True" NewLineForMembersInAnonymousTypes="True" NewLineForClausesInQuery="True" SpacingAfterMethodDeclarationName="False" SpaceWithinMethodDeclarationParenthesis="False" SpaceBetweenEmptyMethodDeclarationParentheses="False" SpaceAfterMethodCallName="False" SpaceWithinMethodCallParentheses="False" SpaceBetweenEmptyMethodCallParentheses="False" SpaceWithinExpressionParentheses="False" SpaceWithinCastParentheses="False" SpaceWithinOtherParentheses="False" SpaceAfterCast="False" SpacesIgnoreAroundVariableDeclaration="False" SpaceBeforeOpenSquareBracket="False" SpaceBetweenEmptySquareBrackets="False" SpaceWithinSquareBrackets="False" SpaceAfterColonInBaseTypeDeclaration="True" SpaceAfterComma="True" SpaceAfterDot="False" SpaceAfterSemicolonsInForStatement="True" SpaceBeforeColonInBaseTypeDeclaration="True" SpaceBeforeComma="False" SpaceBeforeDot="False" SpaceBeforeSemicolonsInForStatement="False" SpacingAroundBinaryOperator="Single" WrappingPreserveSingleLine="True" WrappingKeepStatementsOnSingleLine="True" PlaceSystemDirectiveFirst="True" SpaceAfterControlFlowStatementKeyword="False" scope="text/x-csharp">
+          <CSharpFormattingPolicy IndentBlock="True" IndentBraces="False" IndentSwitchSection="True" IndentSwitchCaseSection="True" LabelPositioning="OneLess" NewLinesForBracesInTypes="True" NewLinesForBracesInMethods="True" NewLinesForBracesInProperties="True" NewLinesForBracesInAccessors="True" NewLinesForBracesInAnonymousMethods="True" NewLinesForBracesInControlBlocks="True" NewLinesForBracesInAnonymousTypes="True" NewLinesForBracesInObjectCollectionArrayInitializers="True" NewLinesForBracesInLambdaExpressionBody="True" NewLineForElse="True" NewLineForCatch="True" NewLineForFinally="True" SpacingAfterMethodDeclarationName="False" SpaceWithinMethodDeclarationParenthesis="False" SpaceBetweenEmptyMethodDeclarationParentheses="False" SpaceAfterMethodCallName="False" SpaceWithinMethodCallParentheses="False" SpaceBetweenEmptyMethodCallParentheses="False" SpaceAfterControlFlowStatementKeyword="False" SpaceWithinExpressionParentheses="False" SpaceWithinCastParentheses="False" SpaceWithinOtherParentheses="False" SpaceAfterCast="False" SpacesIgnoreAroundVariableDeclaration="False" SpaceBeforeOpenSquareBracket="False" SpaceBetweenEmptySquareBrackets="False" SpaceWithinSquareBrackets="False" SpaceAfterColonInBaseTypeDeclaration="True" SpaceAfterComma="True" SpaceAfterDot="False" SpaceAfterSemicolonsInForStatement="True" SpaceBeforeColonInBaseTypeDeclaration="True" SpaceBeforeComma="False" SpaceBeforeDot="False" SpaceBeforeSemicolonsInForStatement="False" SpacingAroundBinaryOperator="Single" WrappingPreserveSingleLine="True" WrappingKeepStatementsOnSingleLine="True" PlaceSystemDirectiveFirst="True" NewLineForMembersInObjectInit="True" NewLineForMembersInAnonymousTypes="True" NewLineForClausesInQuery="True" scope="text/x-csharp">
             <inheritsSet />
             <inheritsScope />
           </CSharpFormattingPolicy>