The Seiko DATA-2000 was an early smart watch sold in late 1983 through 1984 that came with a special PDA calculator interface keyboard. I have read that this was the first watch with a keyboard. The retail price was $195. Click for larger view.

In the docked position the Data-2000 watch face serves as a dot matrix display for the QWERTY keyboard. Together the watch and keyboard provide PDA functionality to do thinkgs like enter and store memos (up to 100 lines), calculator functions, set the alarm, etc. Transmit function was used to store memos on the watch after removing from a docked position. Click for larger view.