Electronic access controls are discussed in terms of their history, applicability of various types of systems to particular situations, and specific components. Techniques for improving the security of entrances equipped with panic exit devices are described. The use of a signature log or sign-in sheet for entry control is explained, followed by descriptions of lock and key control systems that provide high security. Other technological applications considered are nature, advantages, and components of closed-circuit television (CCTV); and the use of videotape recorders to supplement CCTV systems by providing monitoring after normal business hours. The uses of fiberoptic technology in security communications is explained, as is the use of cable television. Drawings, diagrams, and figures are included.