diff --git a/src/components/HexDump.vue b/src/components/HexDump.vue
index 313d903..62aa4ef 100644
--- a/src/components/HexDump.vue
+++ b/src/components/HexDump.vue
@@ -14,8 +14,12 @@ const hexDump = computed(() => {
     return ''.padEnd(80, ' ')
   }
 
+  let lastLine = ''
+  let repeat = false
+
   while (offset < total) {
-    const values = [offset.toString(16).padStart(8, '0')]
+    const offsetStr = offset.toString(16).padStart(8, '0')
+    const values = []
     const asciiValues: string[] = []
     let cnt = 0
     while (offset < total && cnt < 16) {
@@ -31,7 +35,7 @@ const hexDump = computed(() => {
       values.push(byte.toString(16).padStart(2, '0'))
 
       const char = String.fromCharCode(byte)
-      if (char > ' ' && char <= 'a') {
+      if (char >= ' ' && char <= '~') {
         asciiValues.push(char)
       } else {
         asciiValues.push('.')
@@ -60,7 +64,21 @@ const hexDump = computed(() => {
       asciiValues.push('|')
     }
 
-    lines.push(values.join(' ') + asciiValues.join(''))
+    const line = values.join(' ')
+    if (line !== lastLine) {
+      if (repeat) {
+        lines.push('*'.padEnd(80, ' '))
+      }
+      repeat = false
+
+      lines.push([offsetStr, line].join(' ') + asciiValues.join(''))
+      lastLine = line
+    } else {
+      repeat = true
+    }
+  }
+  if (repeat) {
+    lines.push('*'.padEnd(80, ' '))
   }
   lines.push(offset.toString(16).padStart(8, '0').padEnd(80, ' '))
   return lines.join('\n')