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Television Instant Replay

Television Instant Replay

Television Instant Replay

Ampex developed the "instant replay" videodisc recorder at the request of ABC in 1966 for the "Wide World of Sports" program. CBS had started using a "freeze action" videodisc in August 1965 developed by the MVR Corporation of Palo Alto. This single-frame recorder had been demonstrated at the July 1965 SMPTE meeting in San Francisco, capable of recording 20 seconds of black-and-white video as 600 single frames on a shiny aluminum magnetic disc coated with nickel cobalt. MVR built the model VDR-210CF for CBS to use for football games, instantly playing back short action sequences in normal motion, or freezing the motion at a single frame.

Ampex used a new approach, spinning a metal disc at 1800 rpm with a series of recording heads moving across the platter making 30 video tracks per second to record 30 seconds of normal motion. Each track held one video frame. If the heads were slowed down, less than 30 tracks were played back at 1800 rpm, creating the slow motion effect. If the heads were stopped as the platter continued to spin at 1800 rpm, a freeze frame was created. John Poole at Ampex was the project manager, having developed the metal disc for the Videofile Information System at Ampex that would be commercially introduced in 1968. This system retrieved doument images stored on videotape and duplicated them on disc recorder workstations so office personnel could view the documents in "instant replay" stop-action format. In March, 1967, the Ampex HS-100 color video magnetic disc recorder was used for rapid playback in normal, slow, or stop action, for the "World Series of Skiing" program from the U.S. Ski Championships in Vail, Colorado, marking the beginning of instant replay on commercial television.

The Ampex device was another milestone in the history of magnetic recording. Valdemar Poulsen patented the first magnetic recorder, called the telegraphone, using steel wire in Denmark in 1898. George Baird in Britain recorded video programs on magnetic disc in 1927. Fritz Pfleumer in Germany patented the application of magnetic powders to strips of paper or film in 1928, leading AEG to develop the Magnetophone tape recorder by 1935, with cellulose acetate tape from BASF. Clarence Hickman at Bell Labs developed a magnetic telephone message recorder in 1934 that used longitudinal recording with laminated Permalloy heads on cobalt steel wire. Ampex developed a tape recorder for Bing Crosby and the ABC radio network in 1948. Andrew Donald Booth in Britain built the first magnetic drum memory for the Manchester computer in 1948. Ampex introduced the VR-1000 videotape recorder for professional broadcasting in 1956, used by NBC on Nov. 30 to tape delay the news broadcast of Douglas Edwards for the West Coast. In 1959 Toshiba of Japan developed the helical scan videotape recorder, and was joined by Ampex and Sony to produce large 2-inch helical-scan professional recorders. In 1963 Ampex introduced the industry-standard EDITEC electronic video editor allowing frame-by-frame recording control. By 1965, Ampex led the industry with its transistorized color highband VR-2000. in 1967, the briefcase-size portable VR-3000 video recorder was introduced and used at the 1968 Summer Olympics in Mexico City to follow, for the first time, the runners in the cross-country race event.

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- 1999-2002 by Steven E. Schoenherr. All rights reserved.

Return to Recording Technology History Notes | Television and Radio | this page revised 2/6/02
 
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