MII equipment can occasionally be found cheaply on the professional video equipment market and online auctions. MII faded earlier than other analog video formats, in favor of digital tapes such as DV, DVCAM and DVCPro, which were themselves superseded by high definition discs and cards. A small number of specialist companies maintain old MII machines in order to offer a transfer service for archive footage to modern formats. Recording method The MII format was completely analog, with four audio channels. Six tracks were recorded on the tape: two by the moving heads and four by the stationary head. Beginning at the top of the tape, the first two tracks were audio channels two and one, recorded linearly by the stationary head. Below these were diagonal tracks recorded by the moving head in a method known as helical scan, which increases the effective tape speed and thus the bandwidth needed for storing video. There were two tracks called C and Y, carrying frequency modulated video components. The C track also contained audio channels three and four, frequency modulated. Below the moving head tracks, the last two tracks carried control and time code information, respectively, from the stationary head. The control signal was used to synchronize the moving heads for playback. Video was split among the C and Y tracks: Luminance was simply frequency modulated and written solely to the Y track. The two chrominance signals, Pr and Pb, were combined by chrominance time compressed multiplexing (CTCM), which is a type of time division multiplexing. The resulting CTCM signal was frequency modulated and written to the C track. Since there was no more room on the face of the tape for the other two audio channels, they were frequency modulated and recorded on the C track. In other words, audio channels three and four and the video chrominance (CTCM) signal were all frequency multiplexed and recorded on one track by the moving heads. Gallery See also M References External links terraguide.com List of Videotape formats, with a mention on MII lionlamb.us List of videotape formats past and present, with a mention of the M format mediacollege.com The M Format ultimatewebdesigning.com List of videotape formats past and present, the M format listed Sony Betamax Case Report DC Video on MII The History of Television, 1942 to 2000, page 194, By Albert Abramson, Christopher H. Sterling Encyclopedia of television, Volume 1, page 251, By