By technical measures, there is a fine line between PC and game console. After all, just about every console released since 1976 is a special-purpose personal computer designed for playing game software. In a time when computers were an expensive and scarce commodity—I speak of the late 1970s—it seemed a monumental waste to own a perfectly good computer (a game console) and not be able to use it for more functional computing tasks like programming, word processing, databases, and the like. (People were also fixated on printing things; in the un-networked 1970s and '80s, any information you produced with a computer was only truly useful if you printed it out on paper.)
That sentiment led to a common marketing promise among game console makers of the late 1970s and early 1980s that their machines' computing power would not go to waste on entertainment alone. After all, what parent wouldn't feel good about buying a game console that promised to one day metamorphose into a powerful educational computer that could help Johnny with his homework?
Around that time, at least five major console manufacturers announced computer add-on units to unlock the untapped CPU power lurking beneath each console's sculpted plastic exteriors. In the following slideshow, you will see ten game consoles that could be turned into fully programmable general-purpose PCs using commercial add-on hardware. While most hail from the 1970s and '80s, you may encounter a more recent surprise that channels the same educational spirit found in its afro-wearing, disco-dancing forebearers.