Abstract: Methods and apparatus pertaining to memory resistors are provided. Electronic circuitry determines energy for changing a non-volatile resistance of a memristor from a present value to a target value. An electric charge corresponding to the energy is stored. An electric pulse is applied to the memristor using the stored charge. The newly adjusted resistance of the memristor is sensed and compared to the target value. Additional electric pulses can be applied in accordance with the comparison. Memristor adjustment by way of feedback control is thus contemplated by the present teachings.