Cannell passed away at his home in Pasadena, California, on Thursday night from complications associated with melanoma, his family said in a statement on Friday.
During three decades as an independent producer, he distinguished himself as a rangy, outgoing chap with a trim beard who was generally identified with action dramas full of squealing tires and tough guys trading punches.
But his range was greater than what he was given credit for. "Tenspeed and Brown Shoe" was a clever detective drama starring Ben Vereen and a then-unknown Jeff Goldblum in 1980. "Profit" was a shocking saga of a psycho businessman that was unforgettable to the few viewers who saw it: Fox pulled the plug after just four episodes in 1996. With "Wiseguy" (1987-90), Cannell chilled viewers with a film-noir descent into the underworld that predated "The Sopranos" by more than a decade.
"The Rockford Files," of course, became an Emmy-winning TV classic following the misadventures of its hapless ex-con private eye played by James Garner.
"People say, 'How can the guy who did "Wiseguy" do "The A-Team"?' I don't know," said Cannell in an interview with The Associated Press in 1993. "But I do know it's easier to think of me simply as the guy who wrote 'The A-Team.' So they do."
During his TV heyday, Cannell became familiar to viewers from the ID that followed each of his shows: He was seen in his office typing on his Selectric before blithely ripping a sheet of paper from the typewriter carriage, whereupon it morphed into the C-shaped logo of Cannell Entertainment Inc.
That was all the idea of his wife, Marcia, he said, and it "appealed to my sense of hooey. ... I'm a ham."
He was also an occasional actor, most recently with a recurring role on the ABC-TV series, "Castle."
A third-generation Californian, Cannell (rhymes with "channel") got into television writing scripts for "It Takes a Thief," "Ironside" and "Adam 12." It was a remarkable career choice for someone who had suffered since childhood from severe dyslexia (he became an advocate for children and adults with learning disabilities).
Cannell in recent years had focused his attention on writing books. His 16th novel, "The Prostitute's Ball," will be released this month.
"I never thought of myself as being a brilliant writer, and still don't," he said in the AP interview. "I'm a populist. With 'Rockford,' we were never trying to be important. And as thoroughly hated as it was by critics, I loved 'The A-Team.' I thought it was really cool."
He was a producer of the feature film updating "The A-Team," released earlier this year.
Cannell is survived by Marcia, his wife of 46 years, their three children, and three grandchildren.