Les Crane, called the “bad boy of late-night television” when he vied for ratings against talk-show king Johnny Carson in the mid-1960s, died of natural causes Sunday at Marin General Hospital north of San Francisco. He was 74.

His death was announced by his daughter, Caprice Crane.

Crane was host of a popular radio call-in show in San Francisco when ABC tapped him in 1964 to star in “The Les Crane Show.” Attempting to be both serious and witty, it was touted as combining the approaches of Jack Paar, Mike Wallace and David Susskind, and featured conversation with major news figures, such as civil rights leader Malcolm X and Alabama Gov. George Wallace, as well as lighter chit-chat with movie stars and other celebrities.

The show fizzled, but Crane had the last laugh. In 1984 he founded a software company that made him a multimillionaire, largely from the sales of the computer game “Chessmaster” and a widely-used typing tutorial.