diff --git a/libs/microbit/core.cpp b/libs/microbit/core.cpp
index 821ee4cd..1c1c8fc1 100644
--- a/libs/microbit/core.cpp
+++ b/libs/microbit/core.cpp
@@ -334,65 +334,3 @@ namespace ksrt {
     uBit.panic(code);
   }
 }
-
-
-
-  namespace buffer {
-
-    RefBuffer *mk(uint32_t size)
-    {
-      RefBuffer *r = new RefBuffer();
-      r->data.resize(size);
-      return r;
-    }
-
-    char *cptr(RefBuffer *c)
-    {
-      return (char*)&c->data[0];
-    }
-
-    int count(RefBuffer *c) { return c->data.size(); }
-
-    void fill(RefBuffer *c, int v)
-    {
-      memset(cptr(c), v, count(c));
-    }
-
-    void fill_random(RefBuffer *c)
-    {
-      int len = count(c);
-      for (int i = 0; i < len; ++i)
-        c->data[i] = uBit.random(0x100);
-    }
-
-    void add(RefBuffer *c, uint32_t x) {
-      c->data.push_back(x);
-    }
-
-    inline bool in_range(RefBuffer *c, int x) {
-      return (0 <= x && x < (int)c->data.size());
-    }
-
-    uint32_t at(RefBuffer *c, int x) {
-      if (in_range(c, x)) {
-        return c->data[x];
-      }
-      else {
-        error(ERR_OUT_OF_BOUNDS);
-        return 0;
-      }
-    }
-
-    void set(RefBuffer *c, int x, uint32_t y) {
-      if (!in_range(c, x))
-        return;
-      c->data[x] = y;
-    }
-  }
-
-  namespace bitvm_bits {
-    RefBuffer *create_buffer(int size)
-    {
-      return buffer::mk(size);
-    }
-  }