Sony stops MiniDisc stereo production The MiniDisc, the Sony digital storage format intended to replace the audio cassette, only ever had limited success outside of Japan. Though Sony will continue to manufacture the discs themselves, it will no longer make MiniDisc-based stereo systems. Other manufacturers are expected to continue to make MiniDisc players, however. The company ceased production of the portable MiniDisc player in July 2011. The portable players had declined in popularity since the late 1990s and Japan was one of the few places where they could still be bought. Sony launched the format in 1992, more than a decade after the first cassette Walkman. Like cassettes, MiniDiscs were recordable but they also delivered digital music quality. Sony still produced the cassette Walkman in Japan as recently as 2010 and it still makes a small number of the devices for the Chinese market. The Japanese firm has been struggling recently and chief executive Kaz Hirai, who took over the job a year ago, has been attempting to bring together the various divisions of the electronics and media giant. At the Consumer Electronics Show in Las Vegas last month, Sony unveiled its new flasgship smartphone, the Xperia Z. Last week, the company sent out invitations to a PlayStation event in New York on February 20 at which it is widely expected to announce the PlayStation 4.