Talk about too little, too late! Did you realize there was a television "spin-off" to Fast Times at Ridgemont High? Neither did I, and I was alive back in 1986 when it premiered. In 1982, I was among the target audience for the movie, being 15 (going on 16) that August, as summer was ending, and my awkward sophomore year in high school was about to begin.
I can pretty much pinpoint the exact moment my adolescence began (not kidding here) as being during the classic pool scene with Phoebe Cates. I doubt I'm alone. My point is though, if I wasn't aware there was a TV version, there was a problem. The producers at CBS somehow failed.
Maybe part of the problem was Fast Times (the television show) came out four years after the movie, when the target audience (i.e., me and my pimple-faced friends) were entering their twenties and moving on from such fare to more mature stuff like, uh...Weird Science. Or maybe it was just a stupid idea and a stupid show. I don't know, I never saw it! Here's the Wikipedia blurb:
The movie inspired a short-lived (seven episodes) 1986 television series called Fast Times.
Moon Unit Zappa provided "teenage consultation" for this TV series. She was hired in order to research slang terms and mannerisms of teenagers, as she had just graduated from high school at the time and had a much better grasp of then-current high school behavior than the writers.
An actress named Claudia Wells was cast in the Phoebe Cates part. You might recognize her as Marty McFly's girlfriend from Back to the Future. She would of course be replaced in the two sequels by Elisabeth Shue. I guess she was too busy acting in Fast Times to sign on for those two sequels, with all the exposure and fame she would have earned by doing so. Actually, according to her IMDb:Was unable to reprise the role of Jennifer Parker, Marty McFly's girlfriend in the sequels to Back to the Future (1985) because her mother had been diagnosed with cancer.
So never mind, she's most certainly excused from her fateful (and costly) career decisions!
Fulfilling the 1980's teen exploitation flick requirement that a blond babe with a hyphenated last name appear at some point was Courtney Thorne-Smith. Or was it that Courtney Thorne-Smith was just a very busy actress (Lucas, Revenge of the Nerds II, Summer School, etc.) during that decade?
James Nardini was no Judge Reinhold, but as it would turn out, neither was Judge Reinhold.
Vincent Schiavelli reprised his role as Mr. Vargas. Man, was he creepy in The Hills Have Eyes (and later in Weird Science)!
Ray Walston also returned to play Mr. Hand. I remember clearly how hilarious (and delightfully strange) I though the name "Mr. Hand" was. And to show what a sci-fi/pop culture nerd I was even back when I was 15, I couldn't see Ray Walston and not think about My Favorite Martian.
In addition to requiring the appearance of Courtney Thorne-Smith (or her clones/amazing facsimiles), most teen exploitation created during the '80s (Meatballs III: Summer Job, In the Mood, Can't Buy Me Love, Some Girls, Loverboy, etc., etc.) required Patrick Dempsey, or his type. His role in Grey's Anatomy must be one of the greatest examples of a second act within a Hollywood acting career. 
Finally, there was the poor schlub who had to fill in for Sean Penn, and try to come close to replicating Penn's groundbreaking, career-making performance as Spicoli. Dean Cameron would go on to star in such films as Summer School (with Courtney Thorne-Smith!), Ski School (1991), and Ski School 2 (1994).