diff --git a/Asm65/CharEncoding.cs b/Asm65/CharEncoding.cs
index ab45152..157c0fe 100644
--- a/Asm65/CharEncoding.cs
+++ b/Asm65/CharEncoding.cs
@@ -94,7 +94,16 @@ namespace Asm65 {
         }
 
         //
-        // C64 PETSCII
+        // ATASCII (Atari 400/800)
+        //
+        // Substantially similar to ASCII, but with printable symbols in the control character
+        // range ($00-1f).  Characters $60 and $7b-7f don't correspond to ASCII symbols.
+        //
+        // Characters with the high bit set are shown with colors reversed.
+        //
+
+        //
+        // PETSCII (C64 variant)
         //
         // Assemblers like ACME use the C64 character set 2, a/k/a shifted mode, lower case
         // mode, or text mode.
@@ -126,6 +135,11 @@ namespace Asm65 {
         //  $12 92 - reverse on/off
         //  $07 0a 0d - bell, LF, CR (note CR is favored for EOL)
         //
+        // Other Commodore systems use variants on PETSCII, but the ASCII correspondence remains
+        // the same -- only the non-ASCII symbols change.  (On the original PET, $60-7f was a
+        // duplicate of $20-3f rather than a duplicate of the upper-case letters, which might be
+        // why $c0-df is preferred for upper case.)
+        //
         // For full details, see the chart at https://www.aivosto.com/articles/petscii.pdf
         //
 
diff --git a/SourceGen/ProjectFile.cs b/SourceGen/ProjectFile.cs
index 4140d46..0e06ece 100644
--- a/SourceGen/ProjectFile.cs
+++ b/SourceGen/ProjectFile.cs
@@ -179,7 +179,8 @@ namespace SourceGen {
     /// </summary>
     internal class SerializableProjectFile1 {
         // This appears at the top of the file, not as part of the JSON data.  The version
-        // number refers to the file format version, not the application version.
+        // number refers to the file format version, not the application version.  Only
+        // change this if a change is made that renders the file unreadable by previous versions.
         public const string MAGIC = "### 6502bench SourceGen dis65 v1.0 ###";
 
         public SerializableProjectFile1() { }
@@ -215,12 +216,14 @@ namespace SourceGen {
         }
         public class SerAnalysisParameters {
             public bool AnalyzeUncategorizedData { get; set; }
+            public string DefaultTextScanMode { get; set; }
             public int MinCharsForString { get; set; }
             public bool SeekNearbyTargets { get; set; }
 
             public SerAnalysisParameters() { }
             public SerAnalysisParameters(ProjectProperties.AnalysisParameters src) {
                 AnalyzeUncategorizedData = src.AnalyzeUncategorizedData;
+                DefaultTextScanMode = src.DefaultTextScanMode.ToString();
                 MinCharsForString = src.MinCharsForString;
                 SeekNearbyTargets = src.SeekNearbyTargets;
             }
@@ -475,6 +478,13 @@ namespace SourceGen {
             proj.ProjectProps.AnalysisParams = new ProjectProperties.AnalysisParameters();
             proj.ProjectProps.AnalysisParams.AnalyzeUncategorizedData =
                 spf.ProjectProps.AnalysisParams.AnalyzeUncategorizedData;
+            if (Enum.TryParse<ProjectProperties.AnalysisParameters.TextScanMode>(
+                    spf.ProjectProps.AnalysisParams.DefaultTextScanMode,
+                    out ProjectProperties.AnalysisParameters.TextScanMode mode)) {
+                proj.ProjectProps.AnalysisParams.DefaultTextScanMode = mode;
+            } else {
+                // unknown value, leave as default
+            }
             proj.ProjectProps.AnalysisParams.MinCharsForString =
                 spf.ProjectProps.AnalysisParams.MinCharsForString;
             proj.ProjectProps.AnalysisParams.SeekNearbyTargets =
diff --git a/SourceGen/ProjectProperties.cs b/SourceGen/ProjectProperties.cs
index c1736e3..2d34f5e 100644
--- a/SourceGen/ProjectProperties.cs
+++ b/SourceGen/ProjectProperties.cs
@@ -36,17 +36,28 @@ namespace SourceGen {
         /// Some parameters we feed to the analyzers.
         /// </summary>
         public class AnalysisParameters {
+            public enum TextScanMode {
+                Unknown = 0,
+                LowAscii,
+                LowHighAscii,
+                C64Petscii,
+                C64ScreenCode,
+            }
+
             public bool AnalyzeUncategorizedData { get; set; }
+            public TextScanMode DefaultTextScanMode { get; set; }
             public int MinCharsForString { get; set; }
             public bool SeekNearbyTargets { get; set; }
 
             public AnalysisParameters() {
                 AnalyzeUncategorizedData = true;
+                DefaultTextScanMode = TextScanMode.LowHighAscii;
                 MinCharsForString = DataAnalysis.DEFAULT_MIN_STRING_LENGTH;
                 SeekNearbyTargets = true;
             }
             public AnalysisParameters(AnalysisParameters src) {
                 AnalyzeUncategorizedData = src.AnalyzeUncategorizedData;
+                DefaultTextScanMode = src.DefaultTextScanMode;
                 MinCharsForString = src.MinCharsForString;
                 SeekNearbyTargets = src.SeekNearbyTargets;
             }
diff --git a/SourceGen/WpfGui/EditProjectProperties.xaml b/SourceGen/WpfGui/EditProjectProperties.xaml
index b4f672f..9a030e8 100644
--- a/SourceGen/WpfGui/EditProjectProperties.xaml
+++ b/SourceGen/WpfGui/EditProjectProperties.xaml
@@ -19,6 +19,7 @@ limitations under the License.
         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:system="clr-namespace:System;assembly=mscorlib"
         xmlns:local="clr-namespace:SourceGen.WpfGui"
         mc:Ignorable="d"
         Title="Edit Project Properties"
@@ -31,6 +32,22 @@ limitations under the License.
         <Style TargetType="{x:Type GridViewColumnHeader}">
             <Setter Property="HorizontalContentAlignment" Value="Left" />
         </Style>
+
+        <!-- strings for combo boxes -->
+        <system:String x:Key="str_6502">MOS 6502</system:String>
+        <system:String x:Key="str_65C02">WDC W65C02S</system:String>
+        <system:String x:Key="str_65816">WDC W65C816S</system:String>
+
+        <system:String x:Key="str_LowAscii">Plain ASCII</system:String>
+        <system:String x:Key="str_LowHighAscii">Plain or High ASCII</system:String>
+        <system:String x:Key="str_C64Petscii">C64 PETSCII</system:String>
+        <system:String x:Key="str_C64ScreenCode">C64 Screen Code</system:String>
+
+        <system:String x:Key="str_DisableStringScan">None (disabled)</system:String>
+
+        <system:String x:Key="str_AutoLabelSimple">Simple ("L1234")</system:String>
+        <system:String x:Key="str_AutoLabelAnnotated">Annotated ("W_1234")</system:String>
+        <system:String x:Key="str_AutoLabelFullyAnnotated">Fully Annotated ("DWR_1234")</system:String>
     </Window.Resources>
 
     <DockPanel Margin="8">
@@ -86,10 +103,21 @@ limitations under the License.
                                       IsChecked="{Binding AnalyzeUncategorizedData}"/>
                             <CheckBox Name="seekAltTargetCheckBox" Margin="0,4,0,0" Content="Seek nearby targets"
                                       IsChecked="{Binding SeekNearbyTargets}"/>
-                            <TextBlock Margin="0,8,0,0" Text="Minimum characters for string:"/>
-                            <ComboBox Name="minStringCharsComboBox" Margin="0,2,0,0"
-                                      ItemsSource="{Binding MinCharsItems}" DisplayMemberPath="Name"
-                                      SelectionChanged="MinStringCharsComboBox_SelectionChanged"/>
+
+                            <StackPanel Orientation="Horizontal" Margin="0,4,0,0">
+                                <TextBlock Margin="0,3,0,0" Text="Default text encoding:"/>
+                                <ComboBox Name="defaultTextEncComboBox" Margin="8,2,0,0"
+                                          Width="142"
+                                          ItemsSource="{Binding DefaultTextScanModeItems}" DisplayMemberPath="Name"
+                                          SelectionChanged="DefaultTextEncComboBox_SelectionChanged"/>
+                            </StackPanel>
+
+                            <StackPanel Orientation="Horizontal" Margin="0,4,0,0">
+                                <TextBlock Margin="0,3,0,0" Text="Min chars for string detection:"/>
+                                <ComboBox Name="minStringCharsComboBox" Margin="8,2,0,0" Width="100"
+                                          ItemsSource="{Binding MinCharsItems}" DisplayMemberPath="Name"
+                                          SelectionChanged="MinStringCharsComboBox_SelectionChanged"/>
+                            </StackPanel>
                         </StackPanel>
                     </GroupBox>
 
@@ -98,6 +126,7 @@ limitations under the License.
                         <DockPanel>
                             <TextBlock DockPanel.Dock="Left" Text="Auto-label style:" Margin="0,2,8,0"/>
                             <ComboBox DockPanel.Dock="Left" Name="autoLabelStyleComboBox"
+                                      Width="300" HorizontalAlignment="Left"
                                       ItemsSource="{Binding AutoLabelItems}" DisplayMemberPath="Name"
                                       SelectionChanged="AutoLabelStyleComboBox_SelectionChanged"/>
                         </DockPanel>
diff --git a/SourceGen/WpfGui/EditProjectProperties.xaml.cs b/SourceGen/WpfGui/EditProjectProperties.xaml.cs
index 27c6a0c..83aaab1 100644
--- a/SourceGen/WpfGui/EditProjectProperties.xaml.cs
+++ b/SourceGen/WpfGui/EditProjectProperties.xaml.cs
@@ -29,6 +29,7 @@ using Microsoft.Win32;
 using Asm65;
 using CommonUtil;
 using CommonWPF;
+using TextScanMode = SourceGen.ProjectProperties.AnalysisParameters.TextScanMode;
 
 namespace SourceGen.WpfGui {
     /// <summary>
@@ -88,6 +89,43 @@ namespace SourceGen.WpfGui {
             mWorkProps = new ProjectProperties(props);
             mProjectDir = projectDir;
             mFormatter = formatter;
+
+            // Construct arrays used as item sources for combo boxes.
+            CpuItems = new CpuItem[] {
+                new CpuItem((string)FindResource("str_6502"), CpuDef.CpuType.Cpu6502),
+                new CpuItem((string)FindResource("str_65C02"), CpuDef.CpuType.Cpu65C02),
+                new CpuItem((string)FindResource("str_65816"), CpuDef.CpuType.Cpu65816),
+            };
+            DefaultTextScanModeItems = new DefaultTextScanMode[] {
+                new DefaultTextScanMode((string)FindResource("str_LowAscii"),
+                    TextScanMode.LowAscii),
+                new DefaultTextScanMode((string)FindResource("str_LowHighAscii"),
+                    TextScanMode.LowHighAscii),
+                new DefaultTextScanMode((string)FindResource("str_C64Petscii"),
+                    TextScanMode.C64Petscii),
+                new DefaultTextScanMode((string)FindResource("str_C64ScreenCode"),
+                    TextScanMode.C64ScreenCode),
+            };
+            MinCharsItems = new MinCharsItem[] {
+                new MinCharsItem((string)FindResource("str_DisableStringScan"),
+                    DataAnalysis.MIN_CHARS_FOR_STRING_DISABLED),
+                new MinCharsItem("3", 3),
+                new MinCharsItem("4", 4),
+                new MinCharsItem("5", 5),
+                new MinCharsItem("6", 6),
+                new MinCharsItem("7", 7),
+                new MinCharsItem("8", 8),
+                new MinCharsItem("9", 9),
+                new MinCharsItem("10", 10),
+            };
+            AutoLabelItems = new AutoLabelItem[] {
+                new AutoLabelItem((string)FindResource("str_AutoLabelSimple"),
+                    AutoLabel.Style.Simple),
+                new AutoLabelItem((string)FindResource("str_AutoLabelAnnotated"),
+                    AutoLabel.Style.Annotated),
+                new AutoLabelItem((string)FindResource("str_AutoLabelFullyAnnotated"),
+                    AutoLabel.Style.FullyAnnotated),
+            };
         }
 
         // INotifyPropertyChanged implementation
@@ -173,12 +211,19 @@ namespace SourceGen.WpfGui {
                 Type = type;
             }
         }
-        private static CpuItem[] sCpuItems = {
-            new CpuItem("MOS 6502", CpuDef.CpuType.Cpu6502),
-            new CpuItem("WDC W65C02S", CpuDef.CpuType.Cpu65C02),
-            new CpuItem("WDC W65C816S", CpuDef.CpuType.Cpu65816),
-        };
-        public CpuItem[] CpuItems { get { return sCpuItems; } }
+        public CpuItem[] CpuItems { get; private set; }
+
+        // Default text encoding combo box items
+        public class DefaultTextScanMode {
+            public string Name { get; private set; }
+            public TextScanMode Mode { get; private set; }
+
+            public DefaultTextScanMode(string name, TextScanMode mode) {
+                Name = name;
+                Mode = mode;
+            }
+        }
+        public DefaultTextScanMode[] DefaultTextScanModeItems { get; private set; }
 
         // Min chars for string combo box items
         public class MinCharsItem {
@@ -190,18 +235,7 @@ namespace SourceGen.WpfGui {
                 Value = value;
             }
         }
-        private static MinCharsItem[] sMinCharsItems = {
-            new MinCharsItem("None (disabled)", DataAnalysis.MIN_CHARS_FOR_STRING_DISABLED),
-            new MinCharsItem("3", 3),
-            new MinCharsItem("4", 4),
-            new MinCharsItem("5", 5),
-            new MinCharsItem("6", 6),
-            new MinCharsItem("7", 7),
-            new MinCharsItem("8", 8),
-            new MinCharsItem("9", 9),
-            new MinCharsItem("10", 10),
-        };
-        public MinCharsItem[] MinCharsItems { get { return sMinCharsItems; } }
+        public MinCharsItem[] MinCharsItems { get; private set; }
 
         // Auto-label style combo box items
         public class AutoLabelItem {
@@ -213,12 +247,7 @@ namespace SourceGen.WpfGui {
                 Style = style;
             }
         }
-        private static AutoLabelItem[] sAutoLabelItems = {
-            new AutoLabelItem("Simple (\"L1234\")", AutoLabel.Style.Simple),
-            new AutoLabelItem("Annotated (\"W_1234\")", AutoLabel.Style.Annotated),
-            new AutoLabelItem("Fully Annotated (\"DWR_1234\")", AutoLabel.Style.FullyAnnotated),
-        };
-        public AutoLabelItem[] AutoLabelItems {  get { return sAutoLabelItems; } }
+        public AutoLabelItem[] AutoLabelItems { get; private set; }
 
         // properties for checkboxes
 
@@ -255,7 +284,18 @@ namespace SourceGen.WpfGui {
                 }
             }
             if (cpuComboBox.SelectedItem == null) {
-                cpuComboBox.SelectedIndex = 0;
+                cpuComboBox.SelectedIndex = 0;                  // 6502
+            }
+
+            for (int i = 0; i < DefaultTextScanModeItems.Length; i++) {
+                if (DefaultTextScanModeItems[i].Mode ==
+                        mWorkProps.AnalysisParams.DefaultTextScanMode) {
+                    defaultTextEncComboBox.SelectedItem = DefaultTextScanModeItems[i];
+                    break;
+                }
+            }
+            if (defaultTextEncComboBox.SelectedItem == null) {
+                defaultTextEncComboBox.SelectedIndex = 1;       // low+high ASCII
             }
 
             for (int i = 0; i < MinCharsItems.Length; i++) {
@@ -265,7 +305,7 @@ namespace SourceGen.WpfGui {
                 }
             }
             if (minStringCharsComboBox.SelectedItem == null) {
-                minStringCharsComboBox.SelectedIndex = 2;
+                minStringCharsComboBox.SelectedIndex = 2;       // 4
             }
 
             for (int i = 0; i < AutoLabelItems.Length; i++) {
@@ -275,10 +315,11 @@ namespace SourceGen.WpfGui {
                 }
             }
             if (autoLabelStyleComboBox.SelectedItem == null) {
-                autoLabelStyleComboBox.SelectedIndex = 0;
+                autoLabelStyleComboBox.SelectedIndex = 0;       // simple
             }
 
             UpdateEntryFlags();
+            IsDirty = false;
         }
 
         private void UpdateEntryFlags() {
@@ -305,6 +346,13 @@ namespace SourceGen.WpfGui {
             IsDirty = true;
         }
 
+        private void DefaultTextEncComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e) {
+            DefaultTextScanMode item =
+                (DefaultTextScanMode)defaultTextEncComboBox.SelectedItem;
+            mWorkProps.AnalysisParams.DefaultTextScanMode = item.Mode;
+            IsDirty = true;
+        }
+
         private void MinStringCharsComboBox_SelectionChanged(object sender,
                 SelectionChangedEventArgs e) {
             MinCharsItem item = (MinCharsItem)minStringCharsComboBox.SelectedItem;
@@ -338,7 +386,6 @@ namespace SourceGen.WpfGui {
 
         #endregion General
 
-
         #region Project Symbols
 
         // Item for the project symbol list view.
@@ -619,7 +666,6 @@ namespace SourceGen.WpfGui {
 
         #endregion Platform symbol files
 
-
         #region Extension scripts
 
         public ObservableCollection<string> ExtensionScriptIdentifiers { get; private set; } =