diff --git a/sw/in_progress/maptests/osm.c b/sw/in_progress/maptests/osm.c
new file mode 100644
index 0000000000..3f7d69cae0
--- /dev/null
+++ b/sw/in_progress/maptests/osm.c
@@ -0,0 +1,79 @@
+/*
+    http://modestmaps.mapstraction.com/trac/wiki/TileNamingConventions
+    http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection/
+    http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames3
+
+    gcc osm.c -lm -Wall -o osm
+*/
+
+#include <stdio.h>
+#include <math.h>
+
+int long2tile(double lon, int z) 
+{ 
+  return (int)(floor((lon + 180.0) / 360.0 * pow(2.0, z))); 
+}
+  
+int lat2tile(double lat, int z)
+{ 
+  return (int)(floor((1.0 - log( tan(lat * M_PI/180.0) + 1.0 / cos(lat * M_PI/180.0)) / M_PI) / 2.0 * pow(2.0, z))); 
+}
+
+void gm_quadtree(int x, int y, int z, char *buffer)
+{
+    static const char *const quadrant = "qrts";
+    int i;
+    char *ptr = buffer;
+
+    *ptr++ = 't';
+    for (i = z-1; i >= 0; i--)
+    {
+        int xbit = (x >> i) & 1;
+        int ybit = (y >> i) & 1;
+        *ptr++ = quadrant[xbit + 2 * ybit];
+    }
+    *ptr++ = '\0';
+}
+
+void ms_quadtree(int x, int y, int z, char *buffer)
+{
+  int i;
+  char *ptr = buffer;
+  
+  for (i = z; i > 0; i--)
+  {
+    int mask = 1 << (i - 1);
+    char digit = '0';    
+    if ((x & mask) != 0)
+    {
+      digit+=1;
+    }
+    if ((y & mask) != 0)
+    {
+      digit+=2;
+    }
+    *ptr++ = digit;
+  }
+  *ptr++ = '\0';
+}
+
+int main(void)
+{
+  int x, y, z = 14;
+  double lat = 52.26483, lon = 9.99394;
+  char ms_qkey[32];
+  char gm_qkey[32];
+
+  x = long2tile(lon, z);
+  y = lat2tile(lat, z);
+  ms_quadtree(x, y, z, ms_qkey);
+  gm_quadtree(x, y, z, gm_qkey);
+  
+  printf("http://tile.openstreetmap.org/%d/%d/%d.png\n", z, x, y);
+  printf("http://kh.google.com/kh?v=3&t=%s\n", gm_qkey);
+  printf("http://mt1.google.com/mt/v=ap.95&hl=en&x=%d&y=%d&z=%d&s=G\n", x, y, z);
+  printf("http://a0.ortho.tiles.virtualearth.net/tiles/a%s.jpeg?g=%d\n", ms_qkey, z+32);
+  printf("http://r0.ortho.tiles.virtualearth.net/tiles/r%s.png?g=%d\n", ms_qkey, z+32);
+  
+  return(0);
+};