Abstract: A system for sensing, computing, and displaying the length and the speed of chain or cable payout or reel in. The system employs only a single sensor which measures cable drum movement. The calculation function is accomplished by a microprocessor or minicomputer which is programmed with the basic dimensions of the cable and cable drum and with the required calculation formulae. A display gives continuous readout to the operator of the cable payout and speed values from a predetermined cable reference point. The system is directly employable in drum payout and recovery systems regardless of their application. The cable references may be of steel, rope or even chain and the system may be incorporated in helicopter or aircraft cable systems, mine hoists or elevator systems wherever a precise control or readout of cable payout is required.