Model 200A, was first shipped in April 1948. The first two units, serial numbers 1 and 2, were used to record Bing Crosby's show. The American Broadcasting Company used these recorders along with 3M Scotch 111 gamma ferric oxide coated acetate tape for the first-ever U.S. delayed radio broadcast of Bing Crosby's Philco Radio Time. Ampex tape recorders revolutionized the radio and recording industries because of their superior audio quality and ease of operation over audio disk cutting lathes. The firm's earliest production of multichannel machines wasn't aimed at music recording; it noted in 195354 that "Ampex began the commercial production of multitrack tape recorders about four years ago for those interested in telemetered information from guided missiles and the like. These equipments provided any number of simultaneous channels up to 14. It was a simple step, therefore, to make stereophonic tape recorders with two or more channels." During the early 1950s, Ampex began marketing one- and two-track machines using tape. In May 1953 the firm announced proudction of two- and three-track machines on 1/4 inch tape. The line soon expanded into three- and four-track models using tape. In the early 1950s, Ampex moved to Redwood City, California. Ampex acquired Orradio Industries in 1959, which became the Ampex Magnetic Tape Division, headquartered in Opelika, Alabama. This made Ampex a manufacturer of both recorders and tape. By the end of that decade Ampex products were much in demand by top recording studios worldwide. In 1952, movie producer Mike Todd asked Ampex to develop a high-fidelity movie sound system using sound magnetically recorded on the film itself, as contrasted with the technology of the time, which used magnetic tracks on a separate celluloid base film (later commonly known as mag stock). The result of this development was the CinemaScope/Todd-AO motion picture sound system, which was first used in movies such as The Robe (1953) in 35mm and Oklahoma (1955) in 70mm (and also in 35mm). In 1960, the Academy of Motion Picture Arts and Sciences awarded Ampex an Oscar for technical achievement as a result of this development. Les Paul, a friend of Crosby and a regular guest on his shows, had already been experimenting with overdubbed recordings on disc. He received an early portable Ampex Model 200A from Crosby. Using this machine, Les Paul invented "Sound on Sound" recording technology. He placed an additional playback head, located before the conventional erase/record/playback