Business: Disc Duel

A $130 million gamble

Ever want to invite friends in for a private screening of a hit movie? That lias long been a favorite entertainment form of super-rich folks who can both obtain films and keep home screening rooms to show them in. But now Magnavox and RCA are betting heavily on a new device they say will make this possible in any of the 70 million U.S. homes that have a television. It is called the videodisc.

Videodisc? Americans are already familiar with videotape recorders, or VTRS, which can be plugged into an ordinary TV set and record up to four hours...