Is this a computer in a keyboard ? Staggering beauty.

Indeed! That's how it was done in the 80's.

The trend was built around keeping the cost down. That and a screen (TV) could cost as much as the whole unit and you probably already had one of those. Nowadays we don't think twice about our laptops coming with a screen, but if I could somehow keep the screen but replace the rest, I'd welcome the price cut that comes with it.