These tutorials need a few files in the directory you run Grasp in. Type grasp to start the program.
Total charge calculated is shown in the textport.
Full Spheres will result in a display of CPK-like structure and a color bar at the top specifying the color coding. The net result will be a change in the contrast. This will result in a display where the white surface envelops the bond display. Changing the surface display requires the calculation of some property according which the surface can be colored. At the time of coloring, the surface display type can also be changed.