Nickelodeon is one of the oldest basic cable channels, having begun under the name Pinwheel on the Warner Cable system in 1977. Unlike most other first-generation cable channels, Nickelodeon has remained largely true to its original focus, producing programming for children, from pre-schoolers through tween and young adolescents. It has remained one of the most successful producers of children's programming, and several of its series have had huge ratings success with young viewers.
Nickelodeon's kid-oriented programming includes animated series such as the break-out hit "SpongeBob SquarePants," live-action series and game/reality series. Its morning block of programming targeting preschoolers includes series such as the popular "Dora the Explorer."
In 1985, Nickelodeon programmers realized that their young target audience had an early bedtime, so the channel introduced its "Nick at Nite" programming line-up. During the night-time hours, the channel aired reruns of classic TV comedy series - first series from 1950s and 60s such as "Mr. Ed," then later series such as "The Cosby Show." The programming proved to be extremely popular, and it has continued into the twenty-first century and has eventually added some original programming. Although night-time programming of Nick at Nite airs on the same channel as the day-time programming of Nickelodeon, the two programming blocks are treated as separate channels for ratings purposes by the Nielsen company.