8-Track Tape Cartridge 

The 8-track tape (formally Stereo 8; commonly called eight-track cartridge, eight-track tape, and eight-track) is a magnetic-tape sound recording technology that was popular^[2] from the mid-1960s to the early 1980s, when the Compact Cassette tape, which predated 8-track, surpassed it in popularity for pre-recorded music.^[3][4] The format is obsolete and was relatively unknown outside the United States, the United Kingdom, Canada, New Zealand, Australia, Germany, Italy, and Japan.^[3][4][5] The main advantage of the 8-track tape cartridge is that it does not have to be "flipped over" to play the alternative set of tracks.

The Stereo 8 Cartridge was created in 1964 by a consortium led by Bill Lear, of Lear Jet Corporation,^[6] along with Ampex, Ford Motor Company, General Motors, Motorola, and RCA Victor Records (RCA - Radio Corporation of America). It was a further development of the similar Stereo-Pak four-track cartridge, which had been introduced by pioneering businessman and engineer Earl "Madman" Muntz, who promoted and sold consumer electronics to the American public at the time. Lear had tried to create an endless-loop wire recorder in the 1940s but gave up in 1946, only to be reinspired by Muntz's four-track design in 1963. Muntz's design had itself been adapted from the Fidelipac cartridge, which in turn had been developed by George Eash. A later quadraphonic (four-channel sound, as opposed to earlier, more widely used stereo/two-channel sound) version of the format was announced by RCA in April 1970 and called first Quad-8 and later Q8. (Ref: Wikipedia)