diff --git a/SourceGen/MainController.cs b/SourceGen/MainController.cs
index e577ca2..25ca581 100644
--- a/SourceGen/MainController.cs
+++ b/SourceGen/MainController.cs
@@ -151,6 +151,12 @@ namespace SourceGen {
         /// </summary>
         private int mFindStartIndex = -1;
 
+        /// <summary>
+        /// True if previous search was backward, so we can tell if we changed direction
+        /// (otherwise we think we immediately wrapped around and the search stops).
+        /// </summary>
+        private bool mFindBackward = false;
+
         /// <summary>
         /// Used to highlight the line that is the target of the selected line.
         /// </summary>
@@ -2077,30 +2083,45 @@ namespace SourceGen {
             if (dlg.ShowDialog() == true) {
                 mFindString = dlg.TextToFind;
                 mFindStartIndex = -1;
-                FindText();
+                FindText(dlg.IsBackward);
             }
         }
 
         public void FindNext() {
-            FindText();
+            FindText(false);
         }
 
-        private void FindText() {
+        public void FindPrevious() {
+            FindText(true);
+        }
+
+        private void FindText(bool goBackward) {
             if (string.IsNullOrEmpty(mFindString)) {
                 return;
             }
+            int incr = goBackward ? -1 : 1;
+
+            // If we reversed direction, reset the "start index" so we don't tell the user
+            // we've wrapped around.
+            if (mFindBackward != goBackward) {
+                mFindStartIndex = -1;
+                mFindBackward = goBackward;
+            }
 
             // Start from the topmost selected line, or the start of the file if nothing
             // is selected.
+            // TODO(maybe): if multiple lines are selected, search only within the selected set.
             int index = mMainWin.CodeListView_GetFirstSelectedIndex();
             if (index < 0) {
                 index = 0;
             }
 
             // Start one past the selected item.
-            index++;
+            index += incr;
             if (index == CodeLineList.Count) {
                 index = 0;
+            } else if (index == -1) {
+                index = CodeLineList.Count - 1;
             }
             //Debug.WriteLine("FindText index=" + index + " start=" + mFindStartIndex +
             //    " str=" + mFindString);
@@ -2118,12 +2139,19 @@ namespace SourceGen {
                     mMainWin.CodeListView_EnsureVisible(index);
                     mMainWin.CodeListView_DeselectAll();
                     mMainWin.CodeListView_SelectRange(index, 1);
+                    // TODO(someday): I think we need to do something with the ListView
+                    // keyboard nav state here.  Otherwise Shift+F3 is regarded as selection
+                    // movement with shift held down, and it does a range select.  Currently
+                    // working around this by using Ctrl+F3 instead.  See also maybe the
+                    // ItemContainerGenerator stuff in MainWindow.
                     return;
                 }
 
-                index++;
+                index += incr;
                 if (index == CodeLineList.Count) {
                     index = 0;
+                } else if (index == -1) {
+                    index = CodeLineList.Count - 1;
                 }
             }
 
diff --git a/SourceGen/RuntimeData/Help/mainwin.html b/SourceGen/RuntimeData/Help/mainwin.html
index c7c1f6f..0ab159f 100644
--- a/SourceGen/RuntimeData/Help/mainwin.html
+++ b/SourceGen/RuntimeData/Help/mainwin.html
@@ -329,7 +329,10 @@ can also use PgUp/PgDn and the arrow keys.</p>
 
 <p>Use Edit &gt; Find to search for text.  This performs a case-insensitive
 text search on the label, opcode, operand, and comment fields.
-Use Edit &gt; Find Next to find the next match.</p>
+Use Edit &gt; Find Next to find the next match, and
+Edit &gt; Find Previous to find the previous match.  Note "next" is
+always downward, and "previous" is always upward, regardless of the
+direction of the initial search chosen in the Find dialog.</p>
 
 <p>Use Edit &gt; Go To to jump to an offset, address, or label.  Remember
 that offsets and addresses are always hexadecimal, and offsets start
diff --git a/SourceGen/RuntimeData/Help/settings.html b/SourceGen/RuntimeData/Help/settings.html
index a0ef34d..76a35bc 100644
--- a/SourceGen/RuntimeData/Help/settings.html
+++ b/SourceGen/RuntimeData/Help/settings.html
@@ -223,6 +223,8 @@ not part of the chip specification, but most of them have consistent
 behavior and can be used.  If the box is not checked, the instructions
 are treated as invalid and cause the code analyzer to assume that it
 has run into a data area.  This option has no effect on the 65816.</p>
+<p>The "treat BRK as two-byte instruction" checkbox determines whether
+BRK instructions should be handled as if they have an operand.</p>
 
 <p>The entry flags determine the initial value for the processor status
 flag register.  Code that is unreachable internally (requiring a code
diff --git a/SourceGen/WpfGui/FindBox.xaml b/SourceGen/WpfGui/FindBox.xaml
index cb815ba..004a573 100644
--- a/SourceGen/WpfGui/FindBox.xaml
+++ b/SourceGen/WpfGui/FindBox.xaml
@@ -26,9 +26,15 @@ limitations under the License.
         ShowInTaskbar="False" WindowStartupLocation="CenterOwner"
         ContentRendered="Window_ContentRendered"
         PreviewKeyDown="Window_KeyEventHandler">
-    <StackPanel Margin="8" Orientation="Horizontal">
-        <TextBox Name="findTextBox" Width="200" Text="{Binding TextToFind}"/>
-        <Button Content="Find" Width="70" IsDefault="True" Margin="16,0,0,0"
-                Click="OkButton_Click"/>
+    <StackPanel Margin="8">
+        <StackPanel Orientation="Horizontal">
+            <TextBox Name="findTextBox" Width="200" Text="{Binding TextToFind}"/>
+            <Button Content="Find" Width="70" IsDefault="True" Margin="16,0,0,0"
+                    Click="OkButton_Click"/>
+        </StackPanel>
+        <StackPanel Orientation="Horizontal" Margin="0,8,0,0">
+            <RadioButton Content="_Forward" IsChecked="{Binding IsForward}"/>
+            <RadioButton Content="_Backward" Margin="16,0,0,0" IsChecked="{Binding IsBackward}"/>
+        </StackPanel>
     </StackPanel>
 </Window>
diff --git a/SourceGen/WpfGui/FindBox.xaml.cs b/SourceGen/WpfGui/FindBox.xaml.cs
index 03f9d3b..6ed05fe 100644
--- a/SourceGen/WpfGui/FindBox.xaml.cs
+++ b/SourceGen/WpfGui/FindBox.xaml.cs
@@ -25,19 +25,29 @@ namespace SourceGen.WpfGui {
     /// Find text dialog.
     /// </summary>
     public partial class FindBox : Window, INotifyPropertyChanged {
+        static bool sLastSearchBackward = false;
+
         /// <summary>
         /// Text to find.  On success, holds the string searched for.  This is bound to the
         /// text field.
         /// </summary>
         public string TextToFind {
             get { return mTextToFind; }
-            set {
-                mTextToFind = value;
-                OnPropertyChanged();
-            }
+            set { mTextToFind = value; OnPropertyChanged(); }
         }
         private string mTextToFind;
 
+        private bool mIsForward;
+        public bool IsForward {
+            get { return mIsForward; }
+            set { mIsForward = value; OnPropertyChanged(); }
+        }
+        private bool mIsBackward;
+        public bool IsBackward {
+            get { return mIsBackward; }
+            set { mIsBackward = value; OnPropertyChanged(); }
+        }
+
         // INotifyPropertyChanged implementation
         public event PropertyChangedEventHandler PropertyChanged;
         private void OnPropertyChanged([CallerMemberName] string propertyName = "") {
@@ -55,6 +65,12 @@ namespace SourceGen.WpfGui {
 
             Debug.Assert(findStr != null);
             TextToFind = findStr;
+
+            if (sLastSearchBackward) {
+                IsBackward = true;
+            } else {
+                IsForward = true;
+            }
         }
 
         private void Window_ContentRendered(object sender, EventArgs e) {
@@ -77,6 +93,7 @@ namespace SourceGen.WpfGui {
 
         private void OkButton_Click(object sender, RoutedEventArgs e) {
             DialogResult = true;
+            sLastSearchBackward = IsBackward;
         }
     }
 }
diff --git a/SourceGen/WpfGui/MainWindow.xaml b/SourceGen/WpfGui/MainWindow.xaml
index b7d3cde..8c40748 100644
--- a/SourceGen/WpfGui/MainWindow.xaml
+++ b/SourceGen/WpfGui/MainWindow.xaml
@@ -101,6 +101,12 @@ limitations under the License.
                     <KeyGesture>F3</KeyGesture>
                 </RoutedUICommand.InputGestures>
             </RoutedUICommand>
+            <RoutedUICommand x:Key="FindPreviousCmd" Text="Find Previous">
+                <RoutedUICommand.InputGestures>
+                    <!-- should be Shift+F3, but that causes ListView to do range selection -->
+                    <KeyGesture>Ctrl+F3</KeyGesture>
+                </RoutedUICommand.InputGestures>
+            </RoutedUICommand>
             <RoutedUICommand x:Key="FormatAsWordCmd" Text="Format As Word">
                 <RoutedUICommand.InputGestures>
                     <KeyGesture>Ctrl+W</KeyGesture>
@@ -218,6 +224,8 @@ limitations under the License.
                         CanExecute="IsProjectOpen" Executed="FindCmd_Executed"/>
         <CommandBinding Command="{StaticResource FindNextCmd}"
                         CanExecute="IsProjectOpen" Executed="FindNextCmd_Executed"/>
+        <CommandBinding Command="{StaticResource FindPreviousCmd}"
+                        CanExecute="IsProjectOpen" Executed="FindPreviousCmd_Executed"/>
         <CommandBinding Command="{StaticResource FormatAsWordCmd}"
                         CanExecute="CanFormatAsWord" Executed="FormatAsWordCmd_Executed"/>
         <CommandBinding Command="{StaticResource FormatAddressTableCmd}"
@@ -318,6 +326,7 @@ limitations under the License.
                 <MenuItem Command="{StaticResource SelectAllCmd}"/>
                 <MenuItem Command="Find"/>
                 <MenuItem Command="{StaticResource FindNextCmd}"/>
+                <MenuItem Command="{StaticResource FindPreviousCmd}"/>
                 <MenuItem Command="{StaticResource GotoCmd}"/>
                 <Separator/>
                 <MenuItem Command="{StaticResource EditHeaderCommentCmd}"/>
diff --git a/SourceGen/WpfGui/MainWindow.xaml.cs b/SourceGen/WpfGui/MainWindow.xaml.cs
index c92353d..1aac2ed 100644
--- a/SourceGen/WpfGui/MainWindow.xaml.cs
+++ b/SourceGen/WpfGui/MainWindow.xaml.cs
@@ -718,6 +718,11 @@ namespace SourceGen.WpfGui {
             Debug.Assert(start >= 0 && start < CodeDisplayList.Count);
             Debug.Assert(count > 0 && start + count <= CodeDisplayList.Count);
 
+            if (count == 1) {
+                codeListView.SelectedItems.Add(CodeDisplayList[start]);
+                return;
+            }
+
             DisplayList.FormattedParts[] tmpArray = new DisplayList.FormattedParts[count];
             for (int index = 0; index < count; index++) {
                 tmpArray[index] = CodeDisplayList[start + index];
@@ -1139,6 +1144,10 @@ namespace SourceGen.WpfGui {
             mMainCtrl.FindNext();
         }
 
+        private void FindPreviousCmd_Executed(object sender, ExecutedRoutedEventArgs e) {
+            mMainCtrl.FindPrevious();
+        }
+
         private void FormatAsWordCmd_Executed(object sender, ExecutedRoutedEventArgs e) {
             mMainCtrl.FormatAsWord();
         }