Techniques and mechanisms for providing access to a storage device of a computer platform. The control gate electrode may have an edge portion spaced farther apart from the blocking insulating layer than a central portion of the control gate electrode to concentrate charge density distribution on a central portion of a memory cell. Also provided by the invention are tissue cultures of the soybean variety A1026649 and the plants regenerated therefrom. The shielding mechanism has a shielding arm that is mounted to move between a shielding position where the rotation sensor cannot detect the detection element and a detection position where the rotation sensor can detect the detection element.