Updating hex dump to better handle 7F/FF bytes for display. #54

lib/ac-api/src/main/java/com/webcodepro/applecommander/util/AppleUtil.java

@@ -43,12 +43,6 @@ public class AppleUtil {
 	 */
 	private static final int BYTES_PER_LINE = 16;
 
-	/**
-	 * This is the ASCII space character as used by the Apple ][.
-	 * The high bit is off.
-	 */
-	private static final int APPLE_SPACE = 0x20;
-
 	/**
 	 * Bit masks used for the bit shifting or testing operations.
 	 */
@@ -582,11 +576,11 @@ public class AppleUtil {
 				int index = offset+a;
 				if (index < bytes.length) {
 					char ch = (char) (bytes[index] & 0x7f);
-					if ((byte)ch >= (byte)APPLE_SPACE) {
-						printer.print(ch);
-					} else {
-						printer.print('.');
-					}
+					if (Character.isISOControl(ch)) {
+                        printer.print('.');
+                    } else {
+                        printer.print(ch);
+                    }
 				} else {
 					printer.print(' ');
 				}

lib/ac-api/src/test/java/com/webcodepro/applecommander/util/AppleUtilTest.java

@@ -19,6 +19,7 @@
  */
 package com.webcodepro.applecommander.util;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
@@ -113,4 +114,26 @@ public class AppleUtilTest {
 		// Confirm that these disks are identical:
 		assertTrue(AppleUtil.disksEqualByBlock(prodosDiskDosOrder, prodosDiskNibbleOrder));
 	}
+	
+	@Test
+	public void testGetHexDump_expectedWidth() {
+        final int expectedWidth = 76;
+        
+        // Setup an array of all byte values
+	    byte[] data = new byte[256];
+	    for (int i=0; i<data.length; i++) {
+	        data[i] = (byte)i;
+	    }
+
+	    // Ensure the width is expected and there are no control characters
+	    String result = AppleUtil.getHexDump(data);
+	    String[] lines = result.split("\n");
+	    for (String line : lines) {
+            System.out.println(line);
+	        if (line.startsWith("$")) {
+	            assertEquals(expectedWidth, line.length());
+	            line.chars().forEach(i -> assertTrue(Integer.toString(i), i >= ' '));
+	        }
+	    }
+	}
 }