diff --git a/C-Sim/Core/AppInfo.cs b/C-Sim/Core/AppInfo.cs
index 7d46743..9d0913d 100644
--- a/C-Sim/Core/AppInfo.cs
+++ b/C-Sim/Core/AppInfo.cs
@@ -9,7 +9,7 @@ public static class AppInfo
 		/// <summary>Author of the app.</summary>
         public const string Author = "jbgarcia@uvigo.es";
 		/// <summary>Version of the app.</summary>
-        public const string Version = "1.7.4 20171201";
+        public const string Version = "1.7.5 20171213";
 		/// <summary>Website for this app.</summary>
 		public const string Web = "http://webs.uvigo.es/jbgarcia/prys/csim/";
 		/// <summary>Extension for files created by this app.</summary>
diff --git a/C-Sim/Ui/MainWindowCore.cs b/C-Sim/Ui/MainWindowCore.cs
index d0f7029..2dac155 100644
--- a/C-Sim/Ui/MainWindowCore.cs
+++ b/C-Sim/Ui/MainWindowCore.cs
@@ -38,6 +38,7 @@ public partial class MainWindow: Form {
 		/// </summary>
         public MainWindow(Machine m)
         {
+            this.updatingMemoryView = false;
             this.machine = m;
 			this.machine.Inputter = (msg) => this.DoUserInput( msg );
             this.machine.Outputter = (string s) => this.rtbOutput.Text += s;
@@ -256,6 +257,49 @@ private void DoDisplayInHex()
 			Literal.Display = Literal.DisplayType.Hex;
 			this.UpdateView();
 		}
+        
+        private void DoCellFormat(DataGridViewCellFormattingEventArgs e)
+        {
+            string val = (string) e.Value;
+            
+            e.Value = val.ToLower();
+            e.FormattingApplied = true;
+        }
+        
+        private void DoCellEdited(int rowIndex, int colIndex)
+        {
+            if ( !this.updatingMemoryView
+              && colIndex > 0 )                     // First row is for indexes
+            {
+                string val = (string)
+                            this.grdMemory.Rows[ rowIndex ].
+                                Cells[ colIndex ].Value;
+    
+                if ( byte.TryParse(
+                                    val,
+                                    NumberStyles.HexNumber,
+                                    NumberFormatInfo.InvariantInfo,
+                                    out byte x ) )
+                {
+                    int pos = ( rowIndex * MaxDataColumns ) + colIndex - 1;
+                    this.machine.Memory.Write( pos, new []{ x } );
+                }
+            }
+            
+            return;
+        }
+        
+        private void DoCellValidate(DataGridViewCellValidatingEventArgs e)
+        {
+            int x = -1;
+            bool isHex = int.TryParse(
+                                    (string) e.FormattedValue,
+                                    NumberStyles.HexNumber,
+                                    NumberFormatInfo.InvariantInfo,
+                                    out x );
+
+            e.Cancel = ( !isHex || x < 0 || x >= byte.MaxValue );
+        }
 
         /// <summary>
         /// Updates the font in all visible controls.
@@ -586,6 +630,8 @@ private void UpdateMemoryView()
 		{
             var memory = this.machine.Memory.Raw;
 
+            this.updatingMemoryView = true;
+        
 			// Row indexes (first cell in each row)
 			for (int i = 0; i < this.grdMemory.RowCount; ++i) {
 				this.grdMemory.Rows[ i ].Cells[ 0 ].Value = FromIntToHex( i );
@@ -600,6 +646,7 @@ private void UpdateMemoryView()
 				this.grdMemory.Rows[ row ].Cells[ col ].ToolTipText = memory[ i ].ToString();
             }
 
+            this.updatingMemoryView = false;
 			this.FocusOnInput();
             return;
         }
@@ -848,6 +895,7 @@ private static string FromIntToPrettyHex(BigInteger value, int wordSize = 1)
         private Machine machine;
         private SchemaDrawer sdDrawingBoard;
 		private string cfgFile = "";
+        private bool updatingMemoryView;
 
 		/// <summary>
 		/// The current dir, the last one from which a file was last loaded.
diff --git a/C-Sim/Ui/MainWindowView.cs b/C-Sim/Ui/MainWindowView.cs
index 7c2283e..b794bae 100644
--- a/C-Sim/Ui/MainWindowView.cs
+++ b/C-Sim/Ui/MainWindowView.cs
@@ -8,7 +8,7 @@ namespace CSim.Ui {
 
     using Core;
 
-    /// <summary>The main window for the application. This builds the view.</summary>
+    /// <summary>The view builder for the application.</summary>
     public partial class MainWindow {
         private void BuildInputPanel()
         {
@@ -131,25 +131,25 @@ private void BuildMemoryViewPanel()
                 BackColor = Color.Black,
                 ForeColor = Color.White
             };
-
+            
             // Create columns
-            DataGridViewTextBoxColumn[] columns =
-                new DataGridViewTextBoxColumn[ MaxDataColumns +1 ];
+            var columns = new DataGridViewTextBoxColumn[ MaxDataColumns +1 ];
 
             for(int i = 0; i < columns.Length; ++i) {
-                columns[ i ] = new DataGridViewTextBoxColumn();
+                columns[ i ] = new DataGridViewTextBoxColumn {
+                    SortMode = DataGridViewColumnSortMode.NotSortable
+                };
 
                 if ( i == 0 ) {
                     columns[ i ].DefaultCellStyle = styleFirstColumn;
                     columns[ i ].HeaderText = "/";
                     columns[ i ].Width = columnWidth + ( (int) ( columnWidth * 0.2 ) );
+                    columns[ i ].ReadOnly = true;
                 } else {
                     columns[ i ].HeaderText = FromIntToHex( i - 1 );
                     columns[ i ].Width = columnWidth;
+                    columns[ i ].ReadOnly = false;
                 }
-
-                columns[ i ].SortMode = DataGridViewColumnSortMode.NotSortable;
-                columns[ i ].ReadOnly = true;
             }
 
             this.grdMemory.Columns.AddRange( columns );
@@ -162,6 +162,15 @@ private void BuildMemoryViewPanel()
             }
 
             this.grdMemory.Rows.AddRange( rows );
+            this.grdMemory.CellValueChanged += 
+                (object sender, DataGridViewCellEventArgs e)
+                    => this.DoCellEdited( e.RowIndex, e.ColumnIndex );
+            this.grdMemory.CellValidating +=
+                (object sender, DataGridViewCellValidatingEventArgs e)
+                    => this.DoCellValidate( e );
+            this.grdMemory.CellFormatting +=
+                (object sender, DataGridViewCellFormattingEventArgs e)
+                    => this.DoCellFormat( e );
 
             this.grdMemory.Dock = DockStyle.Fill;
             this.tcTabs.TabPages[ 0 ].Controls.Add( this.grdMemory );
diff --git a/C-SimTests/C-SimTests.csproj b/C-SimTests/C-SimTests.csproj
index 4070fb6..8f319a1 100644
--- a/C-SimTests/C-SimTests.csproj
+++ b/C-SimTests/C-SimTests.csproj
@@ -43,14 +43,14 @@
   <ItemGroup>
     <Folder Include="C-SimTests\" />
   </ItemGroup>
-  <ItemGroup>
-    <None Include="packages.config" />
-  </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\C-Sim\C-Sim.csproj">
       <Project>{7301AFF5-913F-46D4-A2AE-878100C67B5A}</Project>
       <Name>C-Sim</Name>
     </ProjectReference>
   </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+  </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
 </Project>
\ No newline at end of file