Abstract: An automatic drilling control system is disclosed for a conventional drilling apparatus and rig having a drill line rolled up or fed off the drum during drilling by the engine and extending through a crown block and traveling block to a fixed point providing a dead line. The crown block and traveling block form a pulley system for supporting a drill pipe during drilling. A weight indicator gauge on the drilling console is hydraulically actuated from a pressure sensor connected to the dead line. A conventional brake drum controls the rate of feed out of the drill line to determine the tension of the dead line. A double-acting, fluid-actuated cylinder and piston connected to the brake handle positively move it to control the brake force on the drum. A three-way electric solenoid valve controls the application of pressurized fluid selectively to the piston in response to a pressure transducer in the hydraulic line from the pressure sensor.