Step Count and Memory Window enhancements

Introduces several changes requested by Mario Keller. The simulator now has a variable step count that can be selected by a drop-down box on the main window. This change also displays ASCII characters in the Memory window.

README.md

@@ -1,12 +1,11 @@
 SYMON - A 6502 System Simulator
 ===============================
 
-**NOTE: THIS IS BETA QUALITY SOFTWARE UNDER ACTIVE DEVELOPMENT.  Feedback is
+**NOTE: THIS SOFTWARE IS UNDER ACTIVE DEVELOPMENT. Feedback is welcome!**
-welcome!**
 
-**Version:** 0.8.4
+**Version:** 0.8.5
 
-**Last Updated:** 4 March, 2013
+**Last Updated:** 30 March, 2013
 
 Copyright (c) 2008-2013 Seth J. Morabito <web@loomcom.com>
 
@@ -98,7 +97,7 @@ Maven will build Symon, run unit tests, and produce a jar file in the
 Symon is meant to be invoked directly from the jar file. To run with
 Java 1.5 or greater, just type:
 
-    $ java -jar symon-0.8.4.jar
+    $ java -jar symon-0.8.5.jar
 
 When Symon is running, you should be presented with a simple graphical
 interface.
@@ -140,6 +139,9 @@ running.
 
 ## 5.0 Revision History
 
+  - **0.8.5:** 30 March, 2013 - ASCII display for memory window.
+    Allows user to select a step count from a drop-down box.
+
   - **0.8.4:** 4 March, 2013 - Fix for ZPX, ZPY display in the trace log
     (change contributed by jsissom)
 
@@ -169,7 +171,7 @@ running.
   - Feedback (in the form of dialogs, status bar, etc).
 
   - Better debugging tools from the UI, including breakpoints
-    and disassebly.
+    and disassembly.
 
   - More accurate timing.
   

pom.xml

@@ -4,7 +4,7 @@
     <groupId>com.loomcom.symon</groupId>
     <artifactId>symon</artifactId>
     <packaging>jar</packaging>
-    <version>0.8.4</version>
+    <version>0.8.5</version>
     <name>symon</name>
     <url>http://www.loomcom.com/symon</url>
     <properties>
@@ -38,7 +38,7 @@
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
-            <version>4.7</version>
+            <version>4.10</version>
             <scope>test</scope>
         </dependency>
         <dependency>

src/main/java/com/loomcom/symon/Preferences.java

@@ -29,16 +29,12 @@ public interface Preferences {
 
     public static final int DEFAULT_PROGRAM_LOAD_ADDRESS = 0x0300;
 
-    public static final int DEFAULT_BORDER_WIDTH = 10;
-
     public static final boolean DEFAULT_HALT_ON_BREAK = true;
 
     public JDialog getDialog();
 
     public int getProgramStartAddress();
 
-    public int getBorderWidth();
-
     public boolean getHaltOnBreak();
 
     public void updateUi();

src/main/java/com/loomcom/symon/Simulator.java

@@ -37,6 +37,8 @@ import javax.swing.*;
 import javax.swing.border.EmptyBorder;
 import java.awt.*;
 import java.awt.event.*;
+import java.beans.PropertyChangeEvent;
+import java.beans.PropertyChangeListener;
 import java.io.*;
 import java.util.Observable;
 import java.util.Observer;
@@ -51,7 +53,7 @@ import java.util.logging.Logger;
  * and a simulated ACIA for serial I/O. The ACIA is attached to a dumb terminal
  * with a basic 80x25 character display.
  */
-public class Simulator implements Observer {
+public class Simulator {
 
     // Constants used by the simulated system. These define the memory map.
     private static final int BUS_BOTTOM = 0x0000;
@@ -71,8 +73,10 @@ public class Simulator implements Observer {
     private static final int ROM_BASE = 0xC000;
     private static final int ROM_SIZE = 0x4000;
 
-    private static final int  DEFAULT_FONT_SIZE = 12;
+    // UI constants
-    private static final Font DEFAULT_FONT      = new Font(Font.MONOSPACED, Font.PLAIN, DEFAULT_FONT_SIZE);
+    private static final int  DEFAULT_FONT_SIZE    = 12;
+    private static final Font DEFAULT_FONT         = new Font(Font.MONOSPACED, Font.PLAIN, DEFAULT_FONT_SIZE);
+    private static final int  CONSOLE_BORDER_WIDTH = 10;
 
     // Since it is very expensive to update the UI with Swing's Event Dispatch Thread, we can't afford
     // to refresh the status view on every simulated clock cycle. Instead, we will only refresh the status view
@@ -99,6 +103,9 @@ public class Simulator implements Observer {
     // requested
     private int stepsSinceLastUpdate = 0;
 
+    // The number of steps to run per click of the "Step" button
+    private int stepsPerClick = 1;
+
     /**
      * The Main Window is the primary control point for the simulator.
      * It is in charge of the menu, and sub-windows. It also shows the
@@ -130,10 +137,16 @@ public class Simulator implements Observer {
     private JButton runStopButton;
     private JButton stepButton;
     private JButton resetButton;
+    private JComboBox stepCountBox;
 
     private JFileChooser      fileChooser;
     private PreferencesDialog preferences;
 
+    /**
+     * The list of step counts that will appear in the "Step" drop-down.
+     */
+    private static final String[] STEPS = {"1", "5", "10", "20", "50", "100"};
+
     public Simulator() throws MemoryRangeException, IOException {
         this.acia = new Acia(ACIA_BASE);
         this.via = new Via(VIA_BASE);
@@ -172,10 +185,11 @@ public class Simulator implements Observer {
         this.console = new com.loomcom.symon.ui.Console(80, 25, DEFAULT_FONT);
         this.statusPane = new StatusPanel();
 
+        console.setBorderWidth(CONSOLE_BORDER_WIDTH);
+
         // File Chooser
         fileChooser = new JFileChooser(System.getProperty("user.dir"));
         preferences = new PreferencesDialog(mainWindow, true);
-        preferences.addObserver(this);
 
         // Panel for Console and Buttons
         JPanel consoleContainer = new JPanel();
@@ -189,8 +203,22 @@ public class Simulator implements Observer {
         stepButton = new JButton("Step");
         resetButton = new JButton("Reset");
 
+        stepCountBox = new JComboBox(STEPS);
+        stepCountBox.addActionListener(new ActionListener() {
+            public void actionPerformed(ActionEvent actionEvent) {
+                try {
+                    JComboBox cb = (JComboBox) actionEvent.getSource();
+                    stepsPerClick = Integer.parseInt((String) cb.getSelectedItem());
+                } catch (NumberFormatException ex) {
+                    stepsPerClick = 1;
+                    stepCountBox.setSelectedIndex(0);
+                }
+            }
+        });
+
         buttonContainer.add(runStopButton);
         buttonContainer.add(stepButton);
+        buttonContainer.add(stepCountBox);
         buttonContainer.add(resetButton);
 
         // Left side - console
@@ -215,7 +243,7 @@ public class Simulator implements Observer {
 
         stepButton.addActionListener(new ActionListener() {
             public void actionPerformed(ActionEvent actionEvent) {
-                handleStep();
+                handleStep(stepsPerClick);
             }
         });
 
@@ -290,11 +318,13 @@ public class Simulator implements Observer {
     }
 
     /**
-     * Step once, and immediately refresh the UI.
+     * Step the requested number of times, and immediately refresh the UI.
      */
-    private void handleStep() {
+    private void handleStep(int numSteps) {
         try {
-            step();
+            for (int i = 0; i < numSteps; i++) {
+                step();
+            }
             SwingUtilities.invokeLater(new Runnable() {
                 public void run() {
                     if (traceLog.isVisible()) {
@@ -378,24 +408,6 @@ public class Simulator implements Observer {
         });
     }
 
-    /**
-     * The configuration has changed. Re-load.
-     *
-     * @param observable
-     * @param o
-     */
-    public void update(Observable observable, Object o) {
-        // Instance equality should work here, there is only one instance.
-        if (observable == preferences) {
-            int oldBorderWidth = console.getBorderWidth();
-            if (oldBorderWidth != preferences.getBorderWidth()) {
-                // Resize the main window if the border width has changed.
-                console.setBorderWidth(preferences.getBorderWidth());
-                mainWindow.pack();
-            }
-        }
-    }
-
     /**
      * Main entry point to the simulator. Creates a simulator and shows the main
      * window.
@@ -441,6 +453,7 @@ public class Simulator implements Observer {
                 public void run() {
                     // Don't allow step while the simulator is running
                     stepButton.setEnabled(false);
+                    stepCountBox.setEnabled(false);
                     menuBar.simulatorDidStart();
                     // Toggle the state of the run button
                     runStopButton.setText("Stop");
@@ -461,6 +474,7 @@ public class Simulator implements Observer {
                     statusPane.updateState(cpu);
                     runStopButton.setText("Run");
                     stepButton.setEnabled(true);
+                    stepCountBox.setEnabled(true);
                     if (traceLog.isVisible()) {
                         traceLog.refresh();
                     }

src/main/java/com/loomcom/symon/ui/MemoryWindow.java

@@ -28,11 +28,19 @@ import com.loomcom.symon.exceptions.MemoryAccessException;
 import com.loomcom.symon.util.HexUtil;
 
 import javax.swing.*;
+import javax.swing.border.Border;
+import javax.swing.border.CompoundBorder;
 import javax.swing.border.EmptyBorder;
+import javax.swing.border.MatteBorder;
 import javax.swing.table.AbstractTableModel;
+import javax.swing.table.DefaultTableCellRenderer;
+import javax.swing.table.TableCellRenderer;
+import javax.swing.table.TableModel;
+import javax.swing.text.JTextComponent;
 import java.awt.*;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
+import java.util.EventObject;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -45,8 +53,22 @@ public class MemoryWindow extends JFrame implements ActionListener {
     private MemoryTableModel memoryTableModel;
     private JTable memoryTable;
     private JTextField pageNumberTextField;
+    private JButton previousPageButton;
+    private JButton nextPageButton;
 
-    private static final Dimension MINIMUM_SIZE = new Dimension(380, 400);
+    private static final Dimension MINIMUM_SIZE = new Dimension(320, 600);
+
+    // The width of column 0 (address), in pixels
+    private static final int ADDR_COL_WIDTH = 48;
+
+    private static final int HEX_COL_WIDTH = 32;
+
+    // The width of the ASCII cells, in pixels
+    private static final int ASCII_COL_WIDTH = 8;
+
+    // The start/end columns of the ASCII view
+    private static final int ASCII_COL_START = 9;
+    private static final int ASCII_COL_END = 16;
 
     /**
      * Initialize a new MemoryWindow frame with the specified Bus.
@@ -81,8 +103,12 @@ public class MemoryWindow extends JFrame implements ActionListener {
      * Set the contents of the page number text field with the current
      * page number, in hex.
      */
-    private void updatePageNumberTextField() {
+    private void updateControls() {
-        pageNumberTextField.setText(HexUtil.byteToHex(getPageNumber()));
+        int pageNumber = getPageNumber();
+
+        previousPageButton.setEnabled(pageNumber > 0x00);
+        nextPageButton.setEnabled(pageNumber < 0xff);
+        pageNumberTextField.setText(HexUtil.byteToHex(pageNumber));
     }
 
     /**
@@ -90,35 +116,54 @@ public class MemoryWindow extends JFrame implements ActionListener {
      */
     private void createUi() {
         setTitle("Memory Contents");
-        this.memoryTable = new JTable(memoryTableModel);
+        this.memoryTable = new MemoryTable(memoryTableModel);
 
         memoryTable.setDragEnabled(false);
         memoryTable.setCellSelectionEnabled(false);
-        memoryTable.setShowGrid(true);
+        memoryTable.setIntercellSpacing(new Dimension(0, 0));
-        memoryTable.setShowHorizontalLines(true);
-        memoryTable.setShowVerticalLines(true);
-        memoryTable.setGridColor(Color.LIGHT_GRAY);
         memoryTable.getTableHeader().setReorderingAllowed(false);
         memoryTable.getTableHeader().setResizingAllowed(false);
         memoryTable.getTableHeader().setVisible(false);
 
+        memoryTable.getColumnModel().getColumn(0).setMaxWidth(ADDR_COL_WIDTH);
+
+        for (int i = 1; i < ASCII_COL_START; i++) {
+            memoryTable.getColumnModel().getColumn(i).setMaxWidth(HEX_COL_WIDTH);
+        }
+
+        for (int i = ASCII_COL_START; i <= ASCII_COL_END; i++) {
+            memoryTable.getColumnModel().getColumn(i).setMaxWidth(ASCII_COL_WIDTH);
+        }
+
+        MemoryTableCellRenderer memoryTableCellRenderer = new MemoryTableCellRenderer();
+
+        memoryTableCellRenderer.setHorizontalAlignment(JLabel.CENTER);
+        memoryTable.setDefaultRenderer(String.class, memoryTableCellRenderer);
+
         // Turn off tool-tips for the table.
         ToolTipManager.sharedInstance().unregisterComponent(memoryTable);
         ToolTipManager.sharedInstance().unregisterComponent(memoryTable.getTableHeader());
 
-        JLabel pageNumberLabel = new JLabel("Page Number");
+        JLabel pageNumberLabel = new JLabel("Page");
         pageNumberTextField = new JTextField(8);
         pageNumberTextField.addActionListener(this);
 
-        updatePageNumberTextField();
+        nextPageButton = new JButton("Next >>");
+        previousPageButton = new JButton("<< Prev");
+        nextPageButton.addActionListener(this);
+        previousPageButton.addActionListener(this);
+
+        updateControls();
 
         JPanel controlPanel = new JPanel();
         JPanel memoryPanel = new JPanel();
         memoryPanel.setLayout(new BorderLayout());
         memoryPanel.setBorder(new EmptyBorder(10, 10, 10, 10));
 
+        controlPanel.add(previousPageButton);
         controlPanel.add(pageNumberLabel);
         controlPanel.add(pageNumberTextField);
+        controlPanel.add(nextPageButton);
 
         JScrollPane scrollPane = new JScrollPane(memoryTable);
         scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
@@ -131,7 +176,8 @@ public class MemoryWindow extends JFrame implements ActionListener {
         getContentPane().add(memoryPanel, BorderLayout.CENTER);
 
         setMinimumSize(MINIMUM_SIZE);
-        setPreferredSize(MINIMUM_SIZE);
+        memoryPanel.setPreferredSize(memoryTable.getPreferredSize());
+        setPreferredSize(memoryPanel.getPreferredSize());
 
         pack();
     }
@@ -142,8 +188,21 @@ public class MemoryWindow extends JFrame implements ActionListener {
      * @param e The action event
      */
     public void actionPerformed(ActionEvent e) {
-        if (e.getSource() == pageNumberTextField) {
+        if (e.getSource() == previousPageButton) {
-
+            int currentPage = getPageNumber();
+            if (currentPage > 0x00) {
+                setPageNumber(currentPage - 1);
+                updateControls();
+                memoryTable.updateUI();
+            }
+        } else if (e.getSource() == nextPageButton) {
+            int currentPage = getPageNumber();
+            if (currentPage < 0xff) {
+                setPageNumber(currentPage + 1);
+                updateControls();
+                memoryTable.updateUI();
+            }
+        } else if (e.getSource() == pageNumberTextField) {
             String pageNumberInput = pageNumberTextField.getText();
             try {
                 // Try to parse a hex value out of the pageNumber.
@@ -156,7 +215,50 @@ public class MemoryWindow extends JFrame implements ActionListener {
                 Logger.getLogger(this.getClass().getName()).log(Level.WARNING, "Can't parse page number " +
                         pageNumberInput);
             }
-            updatePageNumberTextField();
+            updateControls();
+        }
+    }
+
+    /**
+     * A JTable that will automatically select all text in a cell
+     * being edited.
+     */
+    private class MemoryTable extends JTable {
+
+        public MemoryTable(TableModel tableModel) {
+            super(tableModel);
+        }
+
+        @Override
+        public boolean editCellAt(int row, int col, EventObject e) {
+            boolean result = super.editCellAt(row, col, e);
+
+            final Component editor = getEditorComponent();
+
+            if (editor != null && editor instanceof JTextComponent) {
+                ((JTextComponent) editor).selectAll();
+            }
+
+            return result;
+        }
+    }
+
+    private class MemoryTableCellRenderer extends DefaultTableCellRenderer {
+
+        @Override
+        public Component getTableCellRendererComponent(JTable table, Object value,
+                                                       boolean isSelected, boolean hasFocus,
+                                                       int row, int col) {
+            final Component cell = super.getTableCellRendererComponent(table, value,
+                                                                       isSelected, hasFocus,
+                                                                       row, col);
+
+            if (isSelected) {
+                cell.setBackground(Color.LIGHT_GRAY);
+                cell.setForeground(Color.BLACK);
+            }
+
+            return cell;
         }
     }
 
@@ -168,7 +270,7 @@ public class MemoryWindow extends JFrame implements ActionListener {
         private Bus bus;
         private int pageNumber;
 
-        private static final int COLUMN_COUNT = 9;
+        private static final int COLUMN_COUNT = 17;
         private static final int ROW_COUNT = 32;
 
         public MemoryTableModel(Bus bus) {
@@ -213,15 +315,19 @@ public class MemoryWindow extends JFrame implements ActionListener {
 
         @Override
         public boolean isCellEditable(int row, int column) {
-            return column > 0;
+            return (column > 0 && column < ASCII_COL_START);
         }
 
         public Object getValueAt(int row, int column) {
             try {
                 if (column == 0) {
                     return HexUtil.wordToHex(fullAddress(row, 1));
-                } else {
+                } else if (column < 9) {
+                    // Display hex value of the data
                     return HexUtil.byteToHex(bus.read(fullAddress(row, column)));
+                } else {
+                    // Display the ASCII equivalent (if printable)
+                    return HexUtil.byteToAscii(bus.read(fullAddress(row, column - 8)));
                 }
             } catch (MemoryAccessException ex) {
                 return "??";
@@ -234,7 +340,7 @@ public class MemoryWindow extends JFrame implements ActionListener {
                 try {
                     String hexValue = (String)o;
                     int fullAddress = fullAddress(row, column);
-                    int newValue = Integer.parseInt(hexValue, 16);
+                    int newValue = Integer.parseInt(hexValue, 16) & 0xff;
                     bus.write(fullAddress, newValue);
                 } catch (MemoryAccessException ex) {
                     ;

src/main/java/com/loomcom/symon/ui/PreferencesDialog.java

@@ -40,10 +40,8 @@ public class PreferencesDialog extends Observable implements Preferences {
 
     private JCheckBox  haltOnBreakCheckBox;
     private JTextField programLoadAddressField;
-    private JTextField borderWidthField;
 
     private int programLoadAddress = DEFAULT_PROGRAM_LOAD_ADDRESS;
-    private int borderWidth = DEFAULT_BORDER_WIDTH;
     private boolean haltOnBreak = DEFAULT_HALT_ON_BREAK;
 
     public PreferencesDialog(Frame parent, boolean modal) {
@@ -72,14 +70,11 @@ public class PreferencesDialog extends Observable implements Preferences {
 
         final JLabel haltOnBreakLabel = new JLabel("Halt on BRK");
         final JLabel programLoadAddressLabel = new JLabel("Program Load Address");
-        final JLabel borderWidthLabel = new JLabel("Console Border Width");
 
         haltOnBreakCheckBox = new JCheckBox();
         programLoadAddressField = new JTextField(8);
-        borderWidthField = new JTextField(8);
 
         programLoadAddressLabel.setLabelFor(programLoadAddressField);
-        borderWidthLabel.setLabelFor(borderWidthField);
 
         GridBagConstraints constraints = new GridBagConstraints();
 
@@ -99,17 +94,9 @@ public class PreferencesDialog extends Observable implements Preferences {
         constraints.gridx = 1;
         settingsContainer.add(programLoadAddressField, constraints);
 
-        constraints.gridy = 2;
-        constraints.gridx = 0;
-        settingsContainer.add(borderWidthLabel, constraints);
-
-        constraints.gridx = 1;
-        settingsContainer.add(borderWidthField, constraints);
-
         JButton applyButton = new JButton("Apply");
         JButton cancelButton = new JButton("Cancel");
 
-
         cancelButton.addActionListener(new ActionListener() {
             public void actionPerformed(ActionEvent actionEvent) {
                 updateUi();
@@ -121,7 +108,6 @@ public class PreferencesDialog extends Observable implements Preferences {
             public void actionPerformed(ActionEvent actionEvent) {
                 haltOnBreak = haltOnBreakCheckBox.isSelected();
                 programLoadAddress = hexToInt(programLoadAddressField.getText());
-                borderWidth = Integer.parseInt(borderWidthField.getText());
                 updateUi();
                 // TODO: Actually check to see if values have changed, don't assume.
                 setChanged();
@@ -143,13 +129,6 @@ public class PreferencesDialog extends Observable implements Preferences {
         return programLoadAddress;
     }
 
-    /**
-     * @return The width of the console border, in pixels.
-     */
-    public int getBorderWidth() {
-        return borderWidth;
-    }
-
     /**
      * @return True if 'halt on break' is desired, false otherwise.
      */
@@ -160,7 +139,6 @@ public class PreferencesDialog extends Observable implements Preferences {
     public void updateUi() {
         haltOnBreakCheckBox.setSelected(haltOnBreak);
         programLoadAddressField.setText(intToHex(programLoadAddress));
-        borderWidthField.setText(Integer.toString(borderWidth));
     }
 
     private String intToHex(int i) {

src/main/java/com/loomcom/symon/util/HexUtil.java

@@ -42,38 +42,67 @@ package com.loomcom.symon.util;
  *
  */
 public class HexUtil {
-    private static final String[] HEX_CONSTANTS = {"00", "01", "02", "03", "04", "05", "06", "07",
+
-                                                   "08", "09", "0A", "0B", "0C", "0D", "0E", "0F",
+    static final String NON_PRINTABLE = ".";
-                                                   "10", "11", "12", "13", "14", "15", "16", "17",
+
-                                                   "18", "19", "1A", "1B", "1C", "1D", "1E", "1F",
+    static final String[] ASCII_CONSTANTS = {" ", "!", "\"", "#", "$", "%", "&", "'",
-                                                   "20", "21", "22", "23", "24", "25", "26", "27",
+                                             "(", ")", "*", "+", ",", "-", ".", "/",
-                                                   "28", "29", "2A", "2B", "2C", "2D", "2E", "2F",
+                                             "0", "1", "2", "3", "4", "5", "6", "7",
-                                                   "30", "31", "32", "33", "34", "35", "36", "37",
+                                             "8", "9", ":", ";", "<", "=", ">", "?",
-                                                   "38", "39", "3A", "3B", "3C", "3D", "3E", "3F",
+                                             "@", "A", "B", "C", "D", "E", "F", "G",
-                                                   "40", "41", "42", "43", "44", "45", "46", "47",
+                                             "H", "I", "J", "K", "L", "M", "N", "O",
-                                                   "48", "49", "4A", "4B", "4C", "4D", "4E", "4F",
+                                             "P", "Q", "R", "S", "T", "U", "V", "W",
-                                                   "50", "51", "52", "53", "54", "55", "56", "57",
+                                             "X", "Y", "Z", "[", "\\", "]", "^", "_",
-                                                   "58", "59", "5A", "5B", "5C", "5D", "5E", "5F",
+                                             "`", "a", "b", "c", "d", "e", "f", "g",
-                                                   "60", "61", "62", "63", "64", "65", "66", "67",
+                                             "h", "i", "j", "k", "l", "m", "n", "o",
-                                                   "68", "69", "6A", "6B", "6C", "6D", "6E", "6F",
+                                             "p", "q", "r", "s", "t", "u", "v", "w",
-                                                   "70", "71", "72", "73", "74", "75", "76", "77",
+                                             "x", "y", "z", "{", "|", "}", "~"};
-                                                   "78", "79", "7A", "7B", "7C", "7D", "7E", "7F",
+
-                                                   "80", "81", "82", "83", "84", "85", "86", "87",
+    static final String[] HEX_CONSTANTS = {"00", "01", "02", "03", "04", "05", "06", "07",
-                                                   "88", "89", "8A", "8B", "8C", "8D", "8E", "8F",
+                                           "08", "09", "0A", "0B", "0C", "0D", "0E", "0F",
-                                                   "90", "91", "92", "93", "94", "95", "96", "97",
+                                           "10", "11", "12", "13", "14", "15", "16", "17",
-                                                   "98", "99", "9A", "9B", "9C", "9D", "9E", "9F",
+                                           "18", "19", "1A", "1B", "1C", "1D", "1E", "1F",
-                                                   "A0", "A1", "A2", "A3", "A4", "A5", "A6", "A7",
+                                           "20", "21", "22", "23", "24", "25", "26", "27",
-                                                   "A8", "A9", "AA", "AB", "AC", "AD", "AE", "AF",
+                                           "28", "29", "2A", "2B", "2C", "2D", "2E", "2F",
-                                                   "B0", "B1", "B2", "B3", "B4", "B5", "B6", "B7",
+                                           "30", "31", "32", "33", "34", "35", "36", "37",
-                                                   "B8", "B9", "BA", "BB", "BC", "BD", "BE", "BF",
+                                           "38", "39", "3A", "3B", "3C", "3D", "3E", "3F",
-                                                   "C0", "C1", "C2", "C3", "C4", "C5", "C6", "C7",
+                                           "40", "41", "42", "43", "44", "45", "46", "47",
-                                                   "C8", "C9", "CA", "CB", "CC", "CD", "CE", "CF",
+                                           "48", "49", "4A", "4B", "4C", "4D", "4E", "4F",
-                                                   "D0", "D1", "D2", "D3", "D4", "D5", "D6", "D7",
+                                           "50", "51", "52", "53", "54", "55", "56", "57",
-                                                   "D8", "D9", "DA", "DB", "DC", "DD", "DE", "DF",
+                                           "58", "59", "5A", "5B", "5C", "5D", "5E", "5F",
-                                                   "E0", "E1", "E2", "E3", "E4", "E5", "E6", "E7",
+                                           "60", "61", "62", "63", "64", "65", "66", "67",
-                                                   "E8", "E9", "EA", "EB", "EC", "ED", "EE", "EF",
+                                           "68", "69", "6A", "6B", "6C", "6D", "6E", "6F",
-                                                   "F0", "F1", "F2", "F3", "F4", "F5", "F6", "F7",
+                                           "70", "71", "72", "73", "74", "75", "76", "77",
-                                                   "F8", "F9", "FA", "FB", "FC", "FD", "FE", "FF"};
+                                           "78", "79", "7A", "7B", "7C", "7D", "7E", "7F",
+                                           "80", "81", "82", "83", "84", "85", "86", "87",
+                                           "88", "89", "8A", "8B", "8C", "8D", "8E", "8F",
+                                           "90", "91", "92", "93", "94", "95", "96", "97",
+                                           "98", "99", "9A", "9B", "9C", "9D", "9E", "9F",
+                                           "A0", "A1", "A2", "A3", "A4", "A5", "A6", "A7",
+                                           "A8", "A9", "AA", "AB", "AC", "AD", "AE", "AF",
+                                           "B0", "B1", "B2", "B3", "B4", "B5", "B6", "B7",
+                                           "B8", "B9", "BA", "BB", "BC", "BD", "BE", "BF",
+                                           "C0", "C1", "C2", "C3", "C4", "C5", "C6", "C7",
+                                           "C8", "C9", "CA", "CB", "CC", "CD", "CE", "CF",
+                                           "D0", "D1", "D2", "D3", "D4", "D5", "D6", "D7",
+                                           "D8", "D9", "DA", "DB", "DC", "DD", "DE", "DF",
+                                           "E0", "E1", "E2", "E3", "E4", "E5", "E6", "E7",
+                                           "E8", "E9", "EA", "EB", "EC", "ED", "EE", "EF",
+                                           "F0", "F1", "F2", "F3", "F4", "F5", "F6", "F7",
+                                           "F8", "F9", "FA", "FB", "FC", "FD", "FE", "FF"};
+
+    /**
+     * Very fast 8-bit int to ASCII conversion.
+     * @param val The value of an ASCII character.
+     * @return A string representing the ASCII character.
+     */
+    public static String byteToAscii(int val) {
+         if (val >= 32 && val <= 126) {
+             return ASCII_CONSTANTS[val - 32];
+         } else {
+             return NON_PRINTABLE;
+         }
+    }
 
     /**
      * Very fast 8-bit int to hex conversion, with zero-padded output.