Abstract: An automatic termination system for an end terminated bus especially useful with the SCSI bus. When utilized with a computer device, for example, a storage subsystem, configuration or reconfiguration of the bus can be automatically effectuated without concerns for inappropriate signal termination of the bus. The invention comprises a circuit which determines if any additional devices have been coupled to the bus and enables an active terminator chip if none is detected. Should another device be coupled onto the bus, the active terminator chip is automatically disabled.