diff --git a/cmds/cmds.ts b/cmds/cmds.ts
index 727387d5..f4b99f42 100644
--- a/cmds/cmds.ts
+++ b/cmds/cmds.ts
@@ -9,16 +9,16 @@ let execAsync: (cmd: string, options?: { cwd?: string }) => Promise<Buffer> = Pr
 let readDirAsync = Promise.promisify(fs.readdir)
 
 
-export function deployCoreAsync(res: ts.pxt.CompileResult) {
+export function deployCoreAsync(res: pxtc.CompileResult) {
     return getBitDrivesAsync()
         .then(drives => {
             if (drives.length == 0) {
                 console.log("cannot find any drives to deploy to")
             } else {
-                console.log(`copy ${ts.pxt.BINARY_HEX} to ` + drives.join(", "))
+                console.log(`copy ${pxtc.BINARY_HEX} to ` + drives.join(", "))
             }
             return Promise.map(drives, d =>
-                writeFileAsync(d + ts.pxt.BINARY_HEX, res.outfiles[ts.pxt.BINARY_HEX])
+                writeFileAsync(d + pxtc.BINARY_HEX, res.outfiles[pxtc.BINARY_HEX])
                     .then(() => {
                         console.log("wrote hex file to " + d)
                     }))
diff --git a/docs/favicon.ico b/docs/favicon.ico
new file mode 100644
index 00000000..9e681b2e
Binary files /dev/null and b/docs/favicon.ico differ
diff --git a/includes/docs-meta.html b/includes/docs-meta.html
index 1593bfb3..32ba224e 100644
--- a/includes/docs-meta.html
+++ b/includes/docs-meta.html
@@ -1,21 +1,28 @@
-    <meta name="twitter:card" content="summary" />
-    <meta name="twitter:site" content="@codethemicrobit" />
-    <meta name="twitter:title" content="@name@" />
-    <meta name="twitter:description" content="@description@" />
-    <meta name="twitter:image" content="@cardLogo@" />
+<meta name="twitter:card" content="summary" />
+<meta name="twitter:site" content="@codethemicrobit" />
+<meta name="twitter:title" content="@name@" />
+<meta name="twitter:description" content="@description@" />
+<meta name="twitter:image" content="@cardLogo@" />
 
-    <meta property="og:title" content="@name@" />
-    <meta property="og:site_name" content="code the micro:bit" />
-    <meta property="og:description" content="@description@" />
-    <meta property="og:image" content="@cardLogo@" />
-    <!--
+<meta property="og:title" content="@name@" />
+<meta property="og:site_name" content="code the micro:bit" />
+<meta property="og:description" content="@description@" />
+<meta property="og:image" content="@cardLogo@" />
+<!--
     <meta property="og:type" content="website" />
     <meta property="fb:app_id" content="" />
     -->
 
-    <link rel="apple-touch-icon" href="@appLogo@">
-    <link rel="icon" type="image/png" href="@appLogo@">
-    <link rel="mask-icon" href="https://az851932.vo.msecnd.net/pub/zwxazere/safari-pinned-tab.svg" color="#000000">
-    <link rel="shortcut icon" href="@appLogo@">
-    <meta name="theme-color" content="@accentColor@">
-    
\ No newline at end of file
+<link rel="apple-touch-icon" href="@appLogo@">
+<link rel="icon" type="image/png" href="@appLogo@">
+<link rel="mask-icon" href="https://az851932.vo.msecnd.net/pub/zwxazere/safari-pinned-tab.svg" color="#000000">
+<link rel="shortcut icon" href="@appLogo@">
+<meta name="theme-color" content="@accentColor@">
+
+<style>
+    #root .avatar .avatar-image {
+        background-image: url(https://az851932.vo.msecnd.net/pub/jovrytni/microbit.simplified.svg);
+        background-size: contain;
+        background-repeat: no-repeat;
+    }
+</style>
\ No newline at end of file
diff --git a/libs/microbit/core.cpp b/libs/microbit/core.cpp
index ab1638b4..212e0d6e 100644
--- a/libs/microbit/core.cpp
+++ b/libs/microbit/core.cpp
@@ -261,36 +261,6 @@ namespace pxtrt {
     r->unref();
   }
 
-  //%
-  uint32_t ldglb(int idx) {
-    check(0 <= idx && idx < numGlobals, ERR_OUT_OF_BOUNDS, 7);
-    return globals[idx];
-  }
-
-  //%
-  uint32_t ldglbRef(int idx) {
-    check(0 <= idx && idx < numGlobals, ERR_OUT_OF_BOUNDS, 7);
-    uint32_t tmp = globals[idx];
-    incr(tmp);
-    return tmp;
-  }
-
-  // note the idx comes last - it's more convenient that way in the emitter
-  //%
-  void stglb(uint32_t v, int idx)
-  {
-    check(0 <= idx && idx < numGlobals, ERR_OUT_OF_BOUNDS, 7);
-    globals[idx] = v;
-  }
-
-  //%
-  void stglbRef(uint32_t v, int idx)
-  {
-    check(0 <= idx && idx < numGlobals, ERR_OUT_OF_BOUNDS, 7);
-    decr(globals[idx]);
-    globals[idx] = v;
-  }
-
   // Store a captured local in a closure. It returns the action, so it can be chained.
   //%
   RefAction *stclo(RefAction *a, int idx, uint32_t v)
@@ -306,6 +276,34 @@ namespace pxtrt {
     microbit_panic(code);
   }
 
+  //%
+  int stringToBool(StringData *s) {
+    if (s == NULL) return 0;
+    if (s->len == 0) {
+      s->decr();
+      return 0;
+    }
+    s->decr();
+    return 1;
+  }
+
+  //%
+  StringData* emptyToNull(StringData *s) {
+    if (!s || s->len == 0)
+      return NULL;
+    return s;
+  }
+
+  //%
+  int ptrToBool(uint32_t p) {
+    if (p) {
+      decr(p);
+      return 1;
+    } else {
+      return 0;
+    }
+  }
+
   //
   // Debugger
   //
diff --git a/package.json b/package.json
index 9ffd2af5..bb15b41e 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "pxt-microbit",
-  "version": "0.3.47",
+  "version": "0.3.48",
   "description": "micro:bit target for PXT",
   "keywords": [
     "JavaScript",
@@ -29,6 +29,6 @@
     "typescript": "^1.8.7"
   },
   "dependencies": {
-    "pxt-core": "0.3.52"
+    "pxt-core": "0.3.55"
   }
 }
diff --git a/tests/base/tsconfig.json b/tests/base/tsconfig.json
new file mode 100644
index 00000000..1ba59f2c
--- /dev/null
+++ b/tests/base/tsconfig.json
@@ -0,0 +1,8 @@
+{
+    "compilerOptions": {
+        "target": "es5",
+        "noImplicitAny": true,
+        "outDir": "built",
+        "rootDir": "."
+    }
+}