Mattel Children's Discovery System (1981)
The Children's Discovery System was one of the first fully electronic computers aimed directly at kids. It loaded software from interchangeable ROM cartridges, and showed output on a fancy 16-by-48-pixel LCD screen. A total of 18 expansion cartridges were available on such traditional school topics as math, science, language, and history. Each cartridge came with its own overlay that would fit over the Discovery System's keyboard to customize each experience.
The Discovery System was well-received by the press in the early 1980s, and its success triggered the first wave of all-in-one electronic educational computers--ones that didn't require programming or assembly.