diff --git a/SourceGen/AppSettings.cs b/SourceGen/AppSettings.cs
index f662b12..9d17e8e 100644
--- a/SourceGen/AppSettings.cs
+++ b/SourceGen/AppSettings.cs
@@ -138,6 +138,10 @@ namespace SourceGen {
         public const string EXPORT_LONG_LABEL_NEW_LINE = "export-long-label-new-line";
         public const string EXPORT_GENERATE_IMAGE_FILES = "export-generate-image-files";
 
+        // OMF export settings.
+        public const string OMF_ADD_NOTES = "omf-add-notes";
+        public const string OMF_OFFSET_SEGMENT_START = "omf-offset-segment-start";
+
         // Internal debugging features.
         public const string DEBUG_MENU_ENABLED = "debug-menu-enabled";
 
diff --git a/SourceGen/RuntimeData/Help/tools.html b/SourceGen/RuntimeData/Help/tools.html
index ae1bff3..fc1d4a0 100644
--- a/SourceGen/RuntimeData/Help/tools.html
+++ b/SourceGen/RuntimeData/Help/tools.html
@@ -101,6 +101,25 @@ created with some basic attributes filled in.</p>
 <p>Only "Load" files (S16, PIF, TOL, etc) may be converted.  Compiler object
 files and libraries contain unresolved references and are not supported.</p>
 
+<p>To convert a file, extract it from the Apple II disk image, using a
+mode that does not modify the original (e.g. extract with "configure to
+preserve Apple II formats" in CiderPress).  Open it with the OMF
+Converter tool.  Click "Generate" to create a modified binary and a
+SourceGen project file.</p>
+
+<p>If "offset segment start by $0100" is checked, the converter will try
+to shift the segment's load address from <code>$xx/0000</code> to
+<code>$xx/0100</code>.  This can make the generated code a little nicer
+to work with because it removes potential ambiguity with direct page
+addresses.  For example, <code>LDA $56</code> and <code>LDA $0056</code>
+may be interpreted as the same thing by the assembler, requiring
+generation of operand width disambiguators.  By shifting the initial
+address we avoid the potential ambiguity.</p>
+<p>Check "add comments and notes for each segment" to add a long comment
+and a note at the start of each segment.  The comments include the
+segment name, type, and optional flags.  The notes just provide a quick
+way to jump to a segment.</p>
+
 <p>The binary generated by the tool is not in OMF format and will not
 execute on an Apple IIgs.  To be functional, the sources must be
 assembled by a program capable of generating OMF output, such as Merlin.</p>
diff --git a/SourceGen/SGTestData/20212-reloc-data.dis65 b/SourceGen/SGTestData/20212-reloc-data.dis65
index 0f16e2e..b240371 100644
--- a/SourceGen/SGTestData/20212-reloc-data.dis65
+++ b/SourceGen/SGTestData/20212-reloc-data.dis65
@@ -19,6 +19,8 @@
 "SmartPlbHandling":true},
 
 "PlatformSymbolFileIdentifiers":["RT:Apple/Cxxx-IO.sym65",
+"RT:Apple/C08x-DiskII.sym65",
+"RT:Apple/E0Cxxx-IO.sym65",
 "RT:Apple/IIgs-ROM.sym65",
 "RT:Apple/GSOS.sym65"],
 "ExtensionScriptFileIdentifiers":["RT:Apple/GSOS.cs",
@@ -60,66 +62,10 @@
 },
 
 "LongComments":{
-"0":{
-"Text":"Segment 02: Kind=Code; Attrs=NoSpecial; Name=\u0027          \u0027",
-"BoxMode":false,
-"MaxWidth":80,
-"BackgroundColor":0},
-
-"143":{
-"Text":"Segment 03: Kind=Data; Attrs=BankRel, Dynamic; Name=\u0027PosFFE0   \u0027",
-"BoxMode":false,
-"MaxWidth":80,
-"BackgroundColor":0},
-
-"195":{
-"Text":"Segment 04: Kind=Code; Attrs=NoSpecial; Name=\u0027Bank2     \u0027",
-"BoxMode":false,
-"MaxWidth":80,
-"BackgroundColor":0},
-
-"230":{
-"Text":"Segment 05: Kind=Code; Attrs=AbsBank, Dynamic; Name=\u0027Bank8     \u0027",
-"BoxMode":false,
-"MaxWidth":80,
-"BackgroundColor":0},
-
-"284":{
-"Text":"Segment 06: Kind=Data; Attrs=0; Name=\u0027Filler    \u0027",
-"BoxMode":false,
-"MaxWidth":80,
-"BackgroundColor":0}},
+},
 
 "Notes":{
-"0":{
-"Text":"Seg02: 03/0000 \u0027          \u0027",
-"BoxMode":false,
-"MaxWidth":80,
-"BackgroundColor":0},
-
-"143":{
-"Text":"Seg03: 04/ffe0 \u0027PosFFE0   \u0027",
-"BoxMode":false,
-"MaxWidth":80,
-"BackgroundColor":0},
-
-"195":{
-"Text":"Seg04: 02/3456 \u0027Bank2     \u0027",
-"BoxMode":false,
-"MaxWidth":80,
-"BackgroundColor":0},
-
-"230":{
-"Text":"Seg05: 08/0000 \u0027Bank8     \u0027",
-"BoxMode":false,
-"MaxWidth":80,
-"BackgroundColor":0},
-
-"284":{
-"Text":"Seg06: 06/0000 \u0027Filler    \u0027",
-"BoxMode":false,
-"MaxWidth":80,
-"BackgroundColor":0}},
+},
 
 "UserLabels":{
 },
diff --git a/SourceGen/SGTestData/Source/20212-reloc-data-lnk.S b/SourceGen/SGTestData/Source/20212-reloc-data-lnk.S
index 81a207d..4934cc6 100644
--- a/SourceGen/SGTestData/Source/20212-reloc-data-lnk.S
+++ b/SourceGen/SGTestData/Source/20212-reloc-data-lnk.S
@@ -19,9 +19,9 @@
 ;    "PosFFE0" -> E0 FF 00
 ;    "Bank2"   -> 56 34 02
 ;    "Bank8"   -> 00 10 08
-; - Convert out.20212 to "20212-reloc-data" with OMF converter.
-; - The project file generally requires no edits, except to delete the
-;   header comment.  Leaving the segment-start comments in seems fine.
+; - Convert out.20212 to "20212-reloc-data" with OMF converter.  Disable
+;   "offset segment by $0100" and "add comments and notes".
+; - The project file requires no edits, except to delete the header comment.
 
         DSK     out.20212           ;output file name, must be ProDOS-compat
         TYP     $b3                 ;S16
diff --git a/SourceGen/Tools/Omf/Loader.cs b/SourceGen/Tools/Omf/Loader.cs
index db1716a..4014878 100644
--- a/SourceGen/Tools/Omf/Loader.cs
+++ b/SourceGen/Tools/Omf/Loader.cs
@@ -31,8 +31,15 @@ namespace SourceGen.Tools.Omf {
     public class Loader {
         private const string IIGS_SYSTEM_DEF = "Apple IIgs (GS/OS)";
 
+        [Flags]
+        public enum Flags {
+            AddNotes            = 1 << 0,
+            OffsetSegmentStart  = 1 << 1,
+        }
+
         private OmfFile mOmfFile;
         private Formatter mFormatter;
+        private Flags mFlags;
 
         private byte[] mLoadedData;
         private DisasmProject mNewProject;
@@ -57,11 +64,12 @@ namespace SourceGen.Tools.Omf {
         /// </summary>
         /// <param name="omfFile">OMF file to load.</param>
         /// <param name="formatter">Text formatter.</param>
-        public Loader(OmfFile omfFile, Formatter formatter) {
+        public Loader(OmfFile omfFile, Formatter formatter, Flags flags) {
             Debug.Assert(omfFile.OmfFileKind == OmfFile.FileKind.Load);
 
             mOmfFile = omfFile;
             mFormatter = formatter;
+            mFlags = flags;
         }
 
         /// <summary>
@@ -259,6 +267,19 @@ namespace SourceGen.Tools.Omf {
                     }
                 }
 
+                // If possible, shift the address to xx/$0100.  This is useful because it means
+                // we won't have to put width disambiguators on any data accesses to $00xx
+                // locations.  We can't do this if the address is fixed, aligned to a 64K
+                // boundary, or is too large.
+                if ((mFlags & Flags.OffsetSegmentStart) != 0 && !fixedAddr && !bankRel &&
+                        omfSeg.Align <= 0x0100 && omfSeg.Length <= (65536-256)) {
+                    if ((addr & 0x0000ffff) == 0x0000) {
+                        addr |= 0x0100;
+                    } else {
+                        Debug.Assert(false, "Unexpected nonzero bank address found");
+                    }
+                }
+
                 SegmentMapEntry ent = new SegmentMapEntry(omfSeg, addr);
                 mSegmentMap.Add(ent);
             }
@@ -352,20 +373,22 @@ namespace SourceGen.Tools.Omf {
                 // can straddle multiple pages.)
                 AddAddressEntries(proj, ent, bufOffset, cs);
 
-                // Add a comment identifying the segment and its attributes.
-                string segCmt = string.Format(Res.Strings.OMF_SEG_COMMENT_FMT,
-                    ent.Segment.SegNum, ent.Segment.Kind, ent.Segment.Attrs, ent.Segment.SegName);
-                uc = UndoableChange.CreateLongCommentChange(bufOffset, null,
-                    new MultiLineComment(segCmt));
-                cs.Add(uc);
+                if ((mFlags & Flags.AddNotes) != 0) {
+                    // Add a comment identifying the segment and its attributes.
+                    string segCmt = string.Format(Res.Strings.OMF_SEG_COMMENT_FMT,
+                        ent.Segment.SegNum, ent.Segment.Kind, ent.Segment.Attrs, ent.Segment.SegName);
+                    uc = UndoableChange.CreateLongCommentChange(bufOffset, null,
+                        new MultiLineComment(segCmt));
+                    cs.Add(uc);
 
-                // Add a note identifying the segment.
-                string segNote = string.Format(Res.Strings.OMF_SEG_NOTE_FMT,
-                    ent.Segment.SegNum, mFormatter.FormatAddress(ent.Address, true),
-                    ent.Segment.SegName);
-                uc = UndoableChange.CreateNoteChange(bufOffset, null,
-                    new MultiLineComment(segNote));
-                cs.Add(uc);
+                    // Add a note identifying the segment.
+                    string segNote = string.Format(Res.Strings.OMF_SEG_NOTE_FMT,
+                        ent.Segment.SegNum, mFormatter.FormatAddress(ent.Address, true),
+                        ent.Segment.SegName);
+                    uc = UndoableChange.CreateNoteChange(bufOffset, null,
+                        new MultiLineComment(segNote));
+                    cs.Add(uc);
+                }
 
                 bufOffset += ent.Segment.Length;
             }
diff --git a/SourceGen/Tools/Omf/WpfGui/OmfViewer.xaml b/SourceGen/Tools/Omf/WpfGui/OmfViewer.xaml
index 773aef4..e80d806 100644
--- a/SourceGen/Tools/Omf/WpfGui/OmfViewer.xaml
+++ b/SourceGen/Tools/Omf/WpfGui/OmfViewer.xaml
@@ -51,6 +51,7 @@ limitations under the License.
             <RowDefinition Height="Auto"/>
             <RowDefinition Height="Auto"/>
             <RowDefinition Height="Auto"/>
+            <RowDefinition Height="Auto"/>
         </Grid.RowDefinitions>
         
         <DockPanel Grid.Row="0">
@@ -95,10 +96,19 @@ limitations under the License.
                  IsReadOnly="True" VerticalScrollBarVisibility="Auto">
         </TextBox>
 
-        <DockPanel Grid.Row="5" LastChildFill="False" Margin="0,16,0,0">
-            <Button DockPanel.Dock="Left" Content="Generate SourceGen Project" Padding="4,0"
-                    IsEnabled="{Binding IsLoadFile}" Click="GenerateProject_Click"/>
-            <Button DockPanel.Dock="Right" Content="Cancel" Width="70" IsCancel="True"/>
+        <GroupBox Grid.Row="5" Header="Generate SourceGen Project" Padding="2,0" Margin="0,8,0,0">
+            <StackPanel>
+                <CheckBox Content="Offset segment start by $0100" Margin="0,4,0,0"
+                          IsChecked="{Binding OffsetSegmentStart}"/>
+                <CheckBox Content="Add comments and notes for each segment" Margin="0,4,0,0"
+                          IsChecked="{Binding AddNotes}"/>
+                <Button Content="Generate" Width="100" Margin="0,8" HorizontalAlignment="Left"
+                        IsEnabled="{Binding IsLoadFile}" Click="GenerateProject_Click"/>
+            </StackPanel>
+        </GroupBox>
+
+        <DockPanel Grid.Row="6" LastChildFill="False" Margin="0,16,0,0">
+            <Button DockPanel.Dock="Right" Content="Close" Width="70" IsCancel="True"/>
         </DockPanel>
     </Grid>
 </Window>
diff --git a/SourceGen/Tools/Omf/WpfGui/OmfViewer.xaml.cs b/SourceGen/Tools/Omf/WpfGui/OmfViewer.xaml.cs
index c9cd731..3941b7d 100644
--- a/SourceGen/Tools/Omf/WpfGui/OmfViewer.xaml.cs
+++ b/SourceGen/Tools/Omf/WpfGui/OmfViewer.xaml.cs
@@ -101,6 +101,22 @@ namespace SourceGen.Tools.Omf.WpfGui {
             get { return mOmfFile.OmfFileKind == OmfFile.FileKind.Load; }
         }
 
+        public bool OffsetSegmentStart {
+            get { return AppSettings.Global.GetBool(AppSettings.OMF_OFFSET_SEGMENT_START, true); }
+            set {
+                AppSettings.Global.SetBool(AppSettings.OMF_OFFSET_SEGMENT_START, value);
+                OnPropertyChanged();
+            }
+        }
+
+        public bool AddNotes {
+            get { return AppSettings.Global.GetBool(AppSettings.OMF_ADD_NOTES, false); }
+            set {
+                AppSettings.Global.SetBool(AppSettings.OMF_ADD_NOTES, value);
+                OnPropertyChanged();
+            }
+        }
+
 
         /// <summary>
         /// Constructor.
@@ -166,7 +182,15 @@ namespace SourceGen.Tools.Omf.WpfGui {
         }
 
         private void GenerateProject_Click(object sender, RoutedEventArgs e) {
-            Loader loader = new Loader(mOmfFile, mFormatter);
+            Loader.Flags flags = 0;
+            if (AddNotes) {
+                flags |= Loader.Flags.AddNotes;
+            }
+            if (OffsetSegmentStart) {
+                flags |= Loader.Flags.OffsetSegmentStart;
+            }
+
+            Loader loader = new Loader(mOmfFile, mFormatter, flags);
             if (!loader.Prepare()) {
                 // Unexpected.  If there's a valid reason for this, we need to add details
                 // to the error message.