Showtime began scrambling its cable-TV signal.

Showtime/The Movie Channel successfully scrambled its cable-television programming, confounding viewers who previously had used satellite dishes to receive its programs for free. The scrambling system, which will soon be used by more than 20 programmers, was developed and operated by M/A-Com Corp. in San Diego. M/A-Com, which has sold 11,000 satellite descramblers to pay-TV subscribers since introducing them in January, sees an immediate “potential of between 1.5 million and 2 million sales to owners of home dishes,” according to a company official.