The present invention relates to a computer with a touch screen, and the user can execute one of \u201cundo\u201d, \u201ccut\u201d, \u201ccopy\u201d and \u201cpaste\u201d editing commands by a continuous stroke movement to increase the input operational efficiency. With this configuration, fine chips such as fine semiconductor chips can be mounted at desired positions on a mounting board with a high efficiency and a high yield. The voltage regulator is utilized in reducing the frequency of switching and the conductive losses, thus improving overall performance. 2 percent cobalt, and the balance tungsten carbide, wherein the wear resistant material has a hardness of at least about 2,900 kgmm2 and a microstructure in which the tungsten carbide average grain size is no greater than about 0. When the tilt of the object is adjusted, the supporting member rotates relative to the shelf member so that the outer side of supporting member slides relative to a friction member of the friction device to generate a friction which balances a difference between a torque generated by the weight of the object and an elastic force generated by the resilient member so as to fix the tilt.