Seiko DATA-2000 - The First "Smartwatch" (1983-1984)

Seiko DATA-2000

Seiko, a watch company that had recently purchased the first digital watch brand, Pulsar, released the DATA-2000 in 1983 for a price of $195. This watch was notable for its separate attachable keyboard, that was used to input information into the watch. The external keyboard connected using a magnet. Without the keyboard, the watch could be used as a standard digital watch. The watch was the first watch to come with a full keyboard, and is often considered to be the first "smartwatch". The technology of this watch helped pave the way for modern smartwatches, which were produced most notably by Apple, Google, and for a short time, Pebble. 

Source: eBay.com