Saved by the Bell and its spinoffs are sitcoms produced by NBC Productions, Inc. Saved by the Bell first began with 13 episodes as "Good Morning Miss Bliss" on the Disney Cable Channel. Then show changed its name to Saved by the Bell and moved to NBC as part of NBC's Saturday morning T-NBC line up in the fall of 1989. "The Original Series" ended with its last series in 1993, and it is now syndicated on local stations and the cable stations TBS and WGN. Saved by the Bell spun-off two shows:

Saved by the Bell: The College Years(1993-94)
Saved by the Bell: The New Class(1993-2000)

Cast from the original includes:
Mark Paul Gosselaar - Zack Morris
Tiffani-Amber Thiessen - Kelly Kapowski
Lark Voories - Lisa Turtle
Elizabeth Berkley - Jessie Spano
Dustin Diamond - Samuel "Screech" Powers
Mario Lopez - A.C. Slater
Denis Hastings - Principal Richard Belding

Information found at:
http://members.aol.com/IJBall/WWW/SbtB/Home.html
http://hubcap.clemson.edu/~tsalmon/sbtb/index3.htm

On a personal note, my parents recently saw Dustin Diamond ("Screech") at a comedy club in Indianapolis. They said that he was funnier than they had expected (they didn't clarify about what their expectations were). They also said that at one point he mentioned that Mark Paul Gosselaar is a homosexual. I couldn't verify this. But, I don't see why it couldn't be true.