Secret City Adventures is a television series on PBS that was popular
among children in the late 1980's and early 1990's. It was hosted by
Mark Kistler who was called Captain Mark. He and Zebtron, his friend
robot instruct their young fans how to do simple illustrations through
drawing exercises. This educational TV program also included characters
that made the drawing lessons more fun like Moonbot, Furbles, Violet,
and Pigasus. Other artists made guest appearances in the show.