Borneo Rectified Skew Orthomorphic (BRSO) on Timbalai datum is a map coordinate system commonly used in the East Malaysian states of Sabah and Sarawak, and the Sultanate of Brunei. This mapplet will display BRSO (Timbalai) easting, northing coordinates on Google Maps. As Google Maps are using the Mercator projection on WGS84 datum, the mapplet will perform a datum transformation from WGS84 to the Timbalai datum using the Standard Molodensky 3-parameters transformation. Then it will do a projection conversion from Mercator to RSO projection to get the BRSO (Timbalai) coordinates. The mapplet can also locate the position on the map given a BRSO (Timbalai) coordinates.
The datum transformation between the WGS84 datum used by Google Maps and the local Timbalai projection datum is done using the Standard Molodensky transformation. Parameters for the datums and ellipsoids are taken from the University of Colorado.