diff --git a/src/ide/ui.ts b/src/ide/ui.ts
index d2a78d59..12b403fa 100644
--- a/src/ide/ui.ts
+++ b/src/ide/ui.ts
@@ -1141,6 +1141,39 @@ async function _downloadProjectZipFile(e) {
   });
 }
 
+function _downloadSymFile(e) {
+  var sym = platform.debugSymbols.addr2symbol;
+  var text = "";
+  $.each(sym, function(k, v) {
+    let symType;
+    if (k < 0x2000) {
+      k = k % 0x800;
+      symType = "R";
+    } else if (k < 0x6000) symType = "G";
+    else if (k < 0x8000) {
+      k = k - 0x6000;
+      symType = "S";
+    } else { 
+      k = k - 0x8000;
+      symType = "P";
+    }
+    let addr = Number(k).toString(16).padStart(4, '0').toUpperCase();
+    // Mesen doesn't allow lables to start with digits
+    if (v[0] >= '0' && v[0] <= '9') {
+    v = "L" + v;
+    }
+    // nor does it allow dots
+    v = v.replaceAll('.', '_');
+    text += `${symType}:${addr}:${v}\n`;
+  });
+  
+  var prefix = getFilenamePrefix(getCurrentMainFilename());
+  var blob = new Blob([text], {type:"text/plain;charset=utf-8"});
+  saveAs(blob, prefix + ".mlb", {autoBom:false});
+
+}
+
+
 async function _downloadAllFilesZipFile(e) {
   var zip = await newJSZip();
   var keys = await store.keys();
@@ -1907,6 +1940,7 @@ function setupDebugControls() {
   $("#item_download_rom").click(_downloadROMImage);
   $("#item_download_file").click(_downloadSourceFile);
   $("#item_download_zip").click(_downloadProjectZipFile);
+  $("#item_download_sym").click(_downloadSymFile);
   $("#item_download_allzip").click(_downloadAllFilesZipFile);
   $("#item_record_video").click(_recordVideo);
   if (platform_id.startsWith('apple2') || platform_id.startsWith('vcs')) // TODO: look for function