A wrist watch with computer ‘UC 2100’ developed by SEIKO in 1984. You can type the keyboard, using a small screen of the watch as a monitor.
I did some searching with google ("UC 2100") and found this page, so actually Seiko has made plenty of these watch computers, not just UC 2100-model.
Retrothing.com already mentioned 2005 Seiko wrist computers on their story, Seiko watches has been used also in James Bond movies ("The Spy Who Loved Me").
So it seems Seiko was 30 years ahead of the markets? I'm wondering what they are currently developing in their hi-tech laboratories? :)
btw. this article was really quick sratch of the surface, if anyone has more information about these Seiko wrist computers, please share it. :)