Developed as a competitor to Sony's Betacam format, M used the same videocassette (and the same oxide-formulated magnetic tape stock) as VHS, much the same way that Betacam was designed to take advantage of cheap and readily available Betamax videocassettes, The format was called "M" due to the shape of the threading path of the tape around the helical scan video head drum, which resembles a letter M. (This is also how the U-matic format got its name, for its U-shaped tape path in the VCR.)
[2] Like Betacam, M recorded component video and used a much faster linear tape speed.
This might have been due to RCA's Broadcast Products division, which marketed the M format in the United States under the "Hawkeye" brand name, going out of business in 1984.
M was also marketed by Panasonic (a division of Matsushita) under the Recam (REcording CAMera) name, and by RCA as Hawkeye.
[3][4][5][6] M was succeeded in 1986 by the MII format developed by Panasonic, using a similar-sized cassette with completely different signal processing and a metal-particle tape formulation.