EXCLUSIVE

Martin Milner, who starred in the huge hit '60s and '70s show "Adam 12" -- which spawned generations of kids who wanted to become cops -- has died.

L.A. Police Chief Charlie Beck tells TMZ, "Milner's depiction of a professional and tough yet compassionate cop led to thousands of men and women applying to become LAPD officers, including me."

Milner also starred in another enormous show -- "Route 66" -- which was a big hit in the '60s.

The actor had roles on several other big hit shows, like "Columbo," "Swiss Family Robinson," "Valley of the Dolls" and "Murder She Wrote."