diff --git a/SourceGenWPF/MainController.cs b/SourceGenWPF/MainController.cs
index 6c2eac1..0ac8610 100644
--- a/SourceGenWPF/MainController.cs
+++ b/SourceGenWPF/MainController.cs
@@ -775,6 +775,38 @@ namespace SourceGenWPF {
 
         #region Main window UI event handlers
 
+        public void NewProject() {
+            if (!CloseProject()) {
+                return;
+            }
+
+            string sysDefsPath = RuntimeDataAccess.GetPathName("SystemDefs.json");
+            if (sysDefsPath == null) {
+                MessageBox.Show(Res.Strings.ERR_LOAD_CONFIG_FILE, Res.Strings.OPERATION_FAILED,
+                    MessageBoxButton.OK, MessageBoxImage.Error);
+                return;
+            }
+
+            SystemDefSet sds = null;
+            try {
+                sds = SystemDefSet.ReadFile(sysDefsPath);
+            } catch (Exception ex) {
+                Debug.WriteLine("Failed loading system def set: " + ex);
+                MessageBox.Show(Res.Strings.ERR_LOAD_CONFIG_FILE, Res.Strings.OPERATION_FAILED,
+                    MessageBoxButton.OK, MessageBoxImage.Error);
+                return;
+            }
+
+            NewProject dlg = new NewProject(mMainWin, sds);
+            if (dlg.ShowDialog() != true) {
+                return;
+            }
+            bool ok = PrepareNewProject(Path.GetFullPath(dlg.DataFileName), dlg.SystemDef);
+            if (ok) {
+                FinishPrep();
+            }
+        }
+
         public void OpenRecentProject(int projIndex) {
             if (!CloseProject()) {
                 return;
diff --git a/SourceGenWPF/Res/Strings.xaml b/SourceGenWPF/Res/Strings.xaml
index 5d047f0..a0f63c7 100644
--- a/SourceGenWPF/Res/Strings.xaml
+++ b/SourceGenWPF/Res/Strings.xaml
@@ -35,6 +35,8 @@ limitations under the License.
     <system:String x:Key="str_ErrFileReadOnlyFmt">Cannot write to read-only file {0}.</system:String>
     <system:String x:Key="str_ErrInvalidIntValue">Could not convert value to integer</system:String>
     <system:String x:Key="str_ErrInvalidKeyValue">Key value is out of range</system:String>
+    <system:String x:Key="str_ErrInvalidSysdef" xml:space="preserve"> - INVALID DEFINITION</system:String>
+    <system:String x:Key="str_ErrLoadConfigFile">Unable to load config file</system:String>
     <system:String x:Key="str_ErrNotProjectFile">This does not appear to be a valid .dis65 project file</system:String>
     <system:String x:Key="str_ErrProjectFileCorrupt">Project file may be corrupt</system:String>
     <system:String x:Key="str_ErrProjectLoadFail">Unable to load project file</system:String>
@@ -43,6 +45,7 @@ limitations under the License.
     <system:String x:Key="str_FileFilterCs">C# Source Files(*.cs)|*.cs</system:String>
     <system:String x:Key="str_FileFilterDis65">SourceGen projects(*.dis65)|*.dis65</system:String>
     <system:String x:Key="str_FileFilterSym65">SourceGen symbols (*.sym65)|*.sym65</system:String>
+    <system:String x:Key="str_FileInfoFmt">File is {0:N1} KB of raw data.</system:String>
     <system:String x:Key="str_GeneratedForVersion">Target assembler: {0} v{1} [{2}]</system:String>
     <system:String x:Key="str_InfoFdSumFmt">•Operand format is {0}</system:String>
     <system:String x:Key="str_InfoLineSumNonFmt">Line {0}: {1}</system:String>
diff --git a/SourceGenWPF/Res/Strings.xaml.cs b/SourceGenWPF/Res/Strings.xaml.cs
index 62810d9..fa0e70a 100644
--- a/SourceGenWPF/Res/Strings.xaml.cs
+++ b/SourceGenWPF/Res/Strings.xaml.cs
@@ -50,6 +50,10 @@ namespace SourceGenWPF.Res {
             (string)Application.Current.FindResource("str_ErrInvalidIntValue");
         public static string ERR_INVALID_KEY_VALUE =
             (string)Application.Current.FindResource("str_ErrInvalidKeyValue");
+        public static string ERR_INVALID_SYSDEF =
+            (string)Application.Current.FindResource("str_ErrInvalidSysdef");
+        public static string ERR_LOAD_CONFIG_FILE =
+            (string)Application.Current.FindResource("str_ErrLoadConfigFile");
         public static string ERR_NOT_PROJECT_FILE =
             (string)Application.Current.FindResource("str_ErrNotProjectFile");
         public static string ERR_PROJECT_FILE_CORRUPT =
@@ -66,6 +70,8 @@ namespace SourceGenWPF.Res {
             (string)Application.Current.FindResource("str_FileFilterDis65");
         public static string FILE_FILTER_SYM65 =
             (string)Application.Current.FindResource("str_FileFilterSym65");
+        public static string FILE_INFO_FMT =
+            (string)Application.Current.FindResource("str_FileInfoFmt");
         public static string GENERATED_FOR_VERSION_FMT =
             (string)Application.Current.FindResource("str_GeneratedForVersion");
         public static string INFO_FD_SUM_FMT =
diff --git a/SourceGenWPF/SourceGenWPF.csproj b/SourceGenWPF/SourceGenWPF.csproj
index 58745c4..897816b 100644
--- a/SourceGenWPF/SourceGenWPF.csproj
+++ b/SourceGenWPF/SourceGenWPF.csproj
@@ -87,6 +87,9 @@
     <Compile Include="WpfGui\EditStatusFlags.xaml.cs">
       <DependentUpon>EditStatusFlags.xaml</DependentUpon>
     </Compile>
+    <Compile Include="WpfGui\NewProject.xaml.cs">
+      <DependentUpon>NewProject.xaml</DependentUpon>
+    </Compile>
     <Compile Include="WpfGui\ProjectLoadIssue.xaml.cs">
       <DependentUpon>ProjectLoadIssue.xaml</DependentUpon>
     </Compile>
@@ -179,6 +182,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="WpfGui\NewProject.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="WpfGui\ProjectLoadIssue.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
diff --git a/SourceGenWPF/WpfGui/MainWindow.xaml b/SourceGenWPF/WpfGui/MainWindow.xaml
index 47ae25b..c84b862 100644
--- a/SourceGenWPF/WpfGui/MainWindow.xaml
+++ b/SourceGenWPF/WpfGui/MainWindow.xaml
@@ -71,6 +71,7 @@ limitations under the License.
                     <KeyGesture>Ctrl+Shift+Minus</KeyGesture>
                 </RoutedUICommand.InputGestures>
             </RoutedUICommand>
+            <RoutedUICommand x:Key="NewProjectCmd" Text="New"/>
             <RoutedUICommand x:Key="OpenCmd" Text="Open"/>
             <RoutedUICommand x:Key="RemoveHintsCmd" Text="Remove Hints"/>
             <RoutedUICommand x:Key="RecentProjectCmd"/>
@@ -119,6 +120,8 @@ limitations under the License.
                         CanExecute="CanNavigateBackward" Executed="NavigateBackwardCmd_Executed"/>
         <CommandBinding Command="{StaticResource NavigateForwardCmd}"
                         CanExecute="CanNavigateForward" Executed="NavigateForwardCmd_Executed"/>
+        <CommandBinding Command="{StaticResource NewProjectCmd}"
+                        Executed="NewProjectCmd_Executed"/>
         <CommandBinding Command="{StaticResource OpenCmd}"
                         Executed="OpenCmd_Executed"/>
         <CommandBinding Command="{StaticResource RemoveHintsCmd}"
@@ -141,7 +144,7 @@ limitations under the License.
     <DockPanel>
         <Menu Name="appMenu" DockPanel.Dock="Top">
             <MenuItem Header="_File">
-                <MenuItem Header="New"/>
+                <MenuItem Command="{StaticResource NewProjectCmd}"/>
                 <MenuItem Command="{StaticResource OpenCmd}"/>
                 <MenuItem Command="Save"/>
                 <MenuItem Command="SaveAs"/>
@@ -351,7 +354,8 @@ limitations under the License.
                 </StackPanel>
 
                 <StackPanel Grid.Row="1" HorizontalAlignment="Left">
-                    <Button Content="Start new project" Width="240" Height="50" Margin="10,30,10,10"/>
+                    <Button Content="Start new project" Width="240" Height="50" Margin="10,30,10,10"
+                            Command="{StaticResource NewProjectCmd}"/>
                     <Button Content="Open existing project" Width="240" Height="50" Margin="10"
                             Command="{StaticResource OpenCmd}"/>
                     <Button Name="recentProjectButton1" Width="240" Height="50" Margin="10"
diff --git a/SourceGenWPF/WpfGui/MainWindow.xaml.cs b/SourceGenWPF/WpfGui/MainWindow.xaml.cs
index 59f5dc5..7e62f40 100644
--- a/SourceGenWPF/WpfGui/MainWindow.xaml.cs
+++ b/SourceGenWPF/WpfGui/MainWindow.xaml.cs
@@ -767,6 +767,10 @@ namespace SourceGenWPF.WpfGui {
             mMainCtrl.NavigateForward();
         }
 
+        private void NewProjectCmd_Executed(object sender, ExecutedRoutedEventArgs e) {
+            mMainCtrl.NewProject();
+        }
+
         private void OpenCmd_Executed(object sender, ExecutedRoutedEventArgs e) {
             mMainCtrl.OpenProject();
         }
diff --git a/SourceGenWPF/WpfGui/NewProject.xaml b/SourceGenWPF/WpfGui/NewProject.xaml
new file mode 100644
index 0000000..1234275
--- /dev/null
+++ b/SourceGenWPF/WpfGui/NewProject.xaml
@@ -0,0 +1,65 @@
+<!--
+Copyright 2019 faddenSoft
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+
+<Window x:Class="SourceGenWPF.WpfGui.NewProject"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:local="clr-namespace:SourceGenWPF.WpfGui"
+        mc:Ignorable="d"
+        Title="New Project"
+        SizeToContent="WidthAndHeight" ResizeMode="NoResize"
+        ShowInTaskbar="False" WindowStartupLocation="CenterOwner"
+        Loaded="Window_Loaded">
+    <StackPanel Margin="8">
+        <Grid>
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="300"/>
+                <ColumnDefinition Width="4"/>
+                <ColumnDefinition Width="300"/>
+            </Grid.ColumnDefinitions>
+            <Grid.RowDefinitions>
+                <RowDefinition Height="Auto"/>
+                <RowDefinition Height="250"/>
+            </Grid.RowDefinitions>
+            <TextBlock Grid.Column="0" Grid.Row="0">Target System:</TextBlock>
+            <TreeView Name="targetSystemTree" Grid.Column="0" Grid.Row="1" Margin="0,2,0,0"
+                      SelectedItemChanged="TargetSystemTree_SelectedItemChanged"/>
+
+            <TextBlock Grid.Column="2" Grid.Row="0">Details:</TextBlock>
+            <TextBox Name="systemDescr" Grid.Column="2" Grid.Row="1" Margin="0,2,0,0" IsReadOnly="True"
+                     ScrollViewer.CanContentScroll="True" VerticalScrollBarVisibility="Auto"/>
+        </Grid>
+
+        <GroupBox Header="Data File" Margin="0,4,0,0">
+            <StackPanel Margin="4">
+                <DockPanel>
+                    <Button Name="selectFileButton" DockPanel.Dock="Left" Width="120" Click="SelectFileButton_Click">Select File...</Button>
+                    <TextBox Name="selectedFileText" DockPanel.Dock="Right" IsReadOnly="True" Margin="8,0,0,0">(filename)</TextBox>
+                </DockPanel>
+                <TextBlock Name="dataFileDetails" Margin="0,8,0,0">(details)</TextBlock>
+            </StackPanel>
+        </GroupBox>
+
+        <StackPanel Orientation="Horizontal" HorizontalAlignment="Right" Margin="0,8,0,0">
+            <Button Name="okButton" Content="OK" IsDefault="True"
+                    Width="70" Click="OkButton_Click"/>
+            <Button Name="cancelButton" Content="Cancel" IsCancel="True"
+                    Width="70" Margin="4,0,0,0"/>
+        </StackPanel>
+    </StackPanel>
+</Window>
diff --git a/SourceGenWPF/WpfGui/NewProject.xaml.cs b/SourceGenWPF/WpfGui/NewProject.xaml.cs
new file mode 100644
index 0000000..e3893be
--- /dev/null
+++ b/SourceGenWPF/WpfGui/NewProject.xaml.cs
@@ -0,0 +1,173 @@
+/*
+ * Copyright 2019 faddenSoft
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+using Microsoft.Win32;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Windows;
+using System.Windows.Controls;
+
+namespace SourceGenWPF.WpfGui {
+    /// <summary>
+    /// New project creation dialog.
+    /// </summary>
+    public partial class NewProject : Window {
+        private SystemDefSet mSystemDefs;
+
+        public SystemDef SystemDef {
+            get { return (SystemDef)((TreeViewItem)targetSystemTree.SelectedItem).Tag; }
+        }
+        public string DataFileName {
+            get { return selectedFileText.Text; }
+        }
+
+
+        public NewProject(Window owner, SystemDefSet systemDefs) {
+            InitializeComponent();
+            Owner = owner;
+
+            dataFileDetails.Text = string.Empty;
+            selectedFileText.Text = string.Empty;
+            mSystemDefs = systemDefs;
+        }
+
+        private void Window_Loaded(object sender, RoutedEventArgs e) {
+            LoadSystemDefSet();
+        }
+
+        /// <summary>
+        /// Initializes the "system definition" tree.
+        /// </summary>
+        private void LoadSystemDefSet() {
+            string prevSelSystem = AppSettings.Global.GetString(AppSettings.NEWP_SELECTED_SYSTEM,
+                "[nothing!selected]");
+
+            TreeViewItem selItem = PopulateNodes(prevSelSystem);
+            selItem.IsSelected = true;
+            selItem.BringIntoView();
+
+            targetSystemTree.Focus();
+
+            Debug.WriteLine("selected is " + targetSystemTree.SelectedItem);
+        }
+
+        /// <summary>
+        /// Populates the tree view nodes with the contents of the data file.
+        /// </summary>
+        /// <param name="tv">TreeView to add items to</param>
+        /// <param name="prevSelSystem">Name of previously-selected system.</param>
+        /// <returns>The node that matches prevSelSystem, or null if not found.</returns>
+        private TreeViewItem PopulateNodes(string prevSelSystem) {
+            TreeViewItem selItem = null;
+
+            TreeView tv = targetSystemTree;
+            tv.Items.Clear();
+
+            if (mSystemDefs.Defs == null || mSystemDefs.Defs.Length == 0) {
+                Debug.WriteLine("Empty def set found");
+                TreeViewItem errItem = new TreeViewItem();
+                errItem.Header = Res.Strings.ERR_LOAD_CONFIG_FILE;
+                tv.Items.Add(errItem);
+                return null;
+            }
+
+            var groups = new Dictionary<string, TreeViewItem>();
+            foreach (SystemDef sd in mSystemDefs.Defs) {
+                if (!groups.TryGetValue(sd.GroupName, out TreeViewItem groupItem)) {
+                    groupItem = new TreeViewItem();
+                    groupItem.Header = sd.GroupName;
+                    groupItem.IsExpanded = true;
+                    groups[sd.GroupName] = groupItem;
+                    tv.Items.Add(groupItem);
+                }
+
+                bool isValid = sd.Validate();
+                string treeName = isValid ? sd.Name :
+                    sd.Name + Res.Strings.ERR_INVALID_SYSDEF;
+
+                TreeViewItem newItem = new TreeViewItem();
+                newItem.Header = treeName;
+                newItem.IsEnabled = isValid;
+                newItem.Tag = sd;
+                groupItem.Items.Add(newItem);
+
+                if (isValid && sd.Name == prevSelSystem) {
+                    selItem = newItem;
+                }
+            }
+
+            return selItem;
+        }
+
+        private void TargetSystemTree_SelectedItemChanged(object sender,
+            RoutedPropertyChangedEventArgs<object> e) {
+
+            Debug.WriteLine("Now selected: " + targetSystemTree.SelectedItem);
+            SystemDef sd = (SystemDef)((TreeViewItem)targetSystemTree.SelectedItem).Tag;
+
+            if (sd == null) {
+                systemDescr.Text = string.Empty;
+            } else {
+                systemDescr.Text = sd.GetSummaryString();
+            }
+
+            UpdateOKEnabled();
+        }
+
+        /// <summary>
+        /// Updates the enabled state of the OK button based on the state of the other
+        /// controls.
+        /// </summary>
+        private void UpdateOKEnabled() {
+            TreeViewItem item = (TreeViewItem)targetSystemTree.SelectedItem;
+            okButton.IsEnabled = (item.Tag != null) &&
+                !string.IsNullOrEmpty(selectedFileText.Text);
+        }
+
+        private void OkButton_Click(object sender, RoutedEventArgs e) {
+            Debug.WriteLine("OK: " + targetSystemTree.SelectedItem);
+
+            SystemDef sd = (SystemDef)((TreeViewItem)targetSystemTree.SelectedItem).Tag;
+            AppSettings.Global.SetString(AppSettings.NEWP_SELECTED_SYSTEM, sd.Name);
+            DialogResult = true;
+        }
+
+        private void SelectFileButton_Click(object sender, RoutedEventArgs e) {
+            OpenFileDialog fileDlg = new OpenFileDialog() {
+                Filter = Res.Strings.FILE_FILTER_ALL,
+                FilterIndex = 1
+            };
+            if (fileDlg.ShowDialog() == true) {
+                FileInfo fi = new FileInfo(fileDlg.FileName);
+
+                if (fi.Length > DisasmProject.MAX_DATA_FILE_SIZE) {
+                    string msg = string.Format(Res.Strings.OPEN_DATA_TOO_LARGE_FMT,
+                            fi.Length / 1024, DisasmProject.MAX_DATA_FILE_SIZE / 1024);
+                    MessageBox.Show(msg, Res.Strings.OPEN_DATA_FAIL_CAPTION,
+                        MessageBoxButton.OK, MessageBoxImage.Error);
+                    return;
+                }
+                selectedFileText.Text = fileDlg.FileName;
+
+                this.dataFileDetails.Text =
+                    string.Format(Res.Strings.FILE_INFO_FMT, fi.Length / 1024.0);
+            }
+
+            UpdateOKEnabled();
+        }
+    }
+}