"[The #Atari] #A300 project [...] involved a new series of Atari computers which would work as modules and plug together to form a complete computer system.

[...] an evolution of the A-300 project [...] shed all of the expansion and modular design for a low profile, high tech computer system which became the Atari 1200XL"

#conceptart

http://www.atarimuseum.com/computers/CONCEPTS/1200/concepts.html