Pinwheel was the first program ever shown on Nickelodeon, and was actually the beginning of the network. The program showed mostly programming for younger children, similar to Nick Jr. today. The most notable programs were Paddington Bear, Picture Pages, and Curious George.
One show, Simon in the Land of the Chalk Drawings, was the inspiration for the Nicktoon ChalkZone.
Pinwheel was relaunched as Nickelodeon, not coincidentally, on April Fool's Day of 1979.