1. Apparatus for controlling functions of a drilling apparatus and automatically searching for an optimized rate of penetration of a drill into a given medium based upon the two drilling parameters of thrust and rotational drill speed, said apparatus comprising: means for applying a given preset start-up value for each drilling parameter to the drill apparatus; means for continuously calculating the rate of penetration of the drill into such medium based upon the two parametric values being input into the drill apparatus at any given time; and means for continually and alternatively applying incremental changes in the value of a first drilling parameter to the drill, while keeping the second drilling parameter constant until the rate of penetration of the drill into the medium is maximized for such first parameter and for applying incremental changes in the value of the second drilling parameter to the drill while keeping the first drilling parameter constant until the rate of penetration is maximized for such second drilling parameter.