. . . and I never knew of it until I stumbled on it today while looking for something unrelated. Jeff Hawkins' Palm team actually toyed with the idea of a clamshell device with a keyboard back in the infancy of Palm OS:
https://www.computerhistory.org/revolution/mobile-computing/18/321/1...
Since it clearly had an identical footprint to the keyboardless Pilot that ultimately became its signature device, I'm guessing the clamshell was abandoned because a keyboard that tiny wasn't practical. Having had a Sony UX40, I know firsthand how difficult it is to type on a tiny keyboard with big fingers.
