Reading Time: 2 minutes Unveiled in 1977, the Hewlett Packard HP-01 “was unique due to these unique features: Datatype for time, date, and time interval, and the ability to perform mathematics on these datatypes. The Hewlett-Packard HP-01 is the only calculator wristwatch ever manufactured and sold to the public by Hewlett-Packard. The HP-01 used light-emitting diodes (LEDs) for its digital display. Introduced in 1977 at the height of…… Continue reading Gold Filled Hewlett Packard Calculator Watch was the first!