diff --git a/docs/projects/radio-challenges.md b/docs/projects/radio-challenges.md
index 12f2f331..1ddb7b39 100644
--- a/docs/projects/radio-challenges.md
+++ b/docs/projects/radio-challenges.md
@@ -58,7 +58,9 @@ After running this simulation several seconds by moving the micro:bit side to si
 ![](/static/mb/acc2.png)
 
 ### ~
-Finally, you must open the Excel CSV file by clicking on the data.xls file that was downloaded to Downloads Folder. 
+
+Finally, you must open the Excel CSV file by clicking on the `data.csv` file
+that was downloaded to Downloads Folder. 
 
 ![](/static/mb/data3.png)
 
@@ -93,4 +95,4 @@ NEXT: The Watch
 
 ```package
 microbit-radio
-```
\ No newline at end of file
+```
diff --git a/libs/microbit/core.cpp b/libs/microbit/core.cpp
index 2ef9de04..4a8969eb 100644
--- a/libs/microbit/core.cpp
+++ b/libs/microbit/core.cpp
@@ -166,6 +166,7 @@ namespace Array_ {
     int removeElement(RefCollection *c, uint32_t x) { return c->removeElement(x); }
 }
 
+
 // Import some stuff directly
 namespace pxt {
   //%
@@ -181,10 +182,12 @@ namespace pxt {
   //%
   Action mkAction(int reflen, int totallen, int startptr);
   //%
-  RefRecord* mkRecord(int reflen, int totallen);
-  //%
   RefRecord* mkClassInstance(int offset);
   //%
+  void RefRecord_destroy(RefRecord *r);
+  //%
+  void RefRecord_print(RefRecord *r);
+  //%
   void debugMemLeaks();
   //%
   int incr(uint32_t e);
diff --git a/package.json b/package.json
index d847eeb3..96940a41 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "pxt-microbit",
-  "version": "0.3.84",
+  "version": "0.3.85",
   "description": "micro:bit target for PXT",
   "keywords": [
     "JavaScript",
@@ -29,6 +29,6 @@
     "typescript": "^1.8.7"
   },
   "dependencies": {
-    "pxt-core": "0.3.96"
+    "pxt-core": "0.3.97"
   }
 }
diff --git a/pxtarget.json b/pxtarget.json
index 531b153f..6f7a6285 100644
--- a/pxtarget.json
+++ b/pxtarget.json
@@ -93,7 +93,7 @@
         "yottaTarget": "bbc-microbit-classic-gcc",
         "yottaCorePackage": "pxt-microbit-core",
         "githubCorePackage": "microsoft/pxt-microbit-core",
-        "gittag": "v0.4.4",
+        "gittag": "v0.5.0",
         "serviceId": "ws"
     },
     "serial": {
@@ -149,4 +149,4 @@
         "userVoiceApiKey": "WEkkIGaj1WtJnSUF59iwaA",
         "userVoiceForumId": 402381
     }
-}
\ No newline at end of file
+}