Although I was raised on a steady diet of Atari growing up, I did use other machines over the years at school. For example, I remember using a Commodore 64 in kindergarten, and learning to work in LogoWriter on the 64 in third or fourth grade.
I came across this wonderful blog post from the Digital Antiquarian about the creation of the Commodore 64. Great read.
I love this passage about Jack Tramiel, who later went to save (and wreck) Atari:
In January of 1981 some of the engineers at Commodore’s chipmaking subsidiary, MOS Technologies, found themselves without a whole lot to do. … Ideally they would have been working on a 16-bit replacement for the 6502, but Jack Tramiel was uninterested in funding such an expensive and complicated project, a choice that stands as amongst the stupidest of a veritable encyclopedia of stupidity written by Commodore management over the company’s chaotic life.”