A catheter includes a steering mechanism for manipulating the distal end of the catheter to obtain a plurality of deflection profiles, a torque transfer system to enhance torque transfer from the handle to the distal tip, and a support system to reduce undesirable deformation of the distal-end region during steering. The adjacent layers have differing widths between their longitudinal edges, whereby the wider layer bulges away from the narrower layer to impart an open configuration to the channel. The encryption coprocessor is built such that certain critical operations are allowed only if physical presence of an operator has been detected. The furnace roller includes at least two helical-shaped tires attached to the roller body in either side of a roller body bisecting centerline. More particularly, embodiments of the invention relate to improving the performance of execution of VMREAD and VMWRITE instructions.