1977: The HP-01 calculator watch can calculate dynamically using time as an argument. The user can watch as the cost of their international call increases on the display. : r/RetroFuturism
File:HP-01 Calculator Watch.jpg - Wikipedia
Prototype of HP's first calculator watch can be yours for $14,500
Hewlett-Packard HP-01 calculator watch-NEVER WORN in original box-Vintage 1977 14k gf Men's Calculator Watch - Etsy Portugal
Top 5 Best Vintage Calculator Watches – Total Watch Repair
HP-01
HP-01] Hewlett-Packard 1977 : r/Watches
HP 01 - Calculator LED watch - 1977 - Catawiki
Historical Perspectives: Meet The Very First Smartwatch: Behold The HP-01, from Hewlett-Packard - Hodinkee
Hewlett Packard HP-01 LED Gold Tone Calculator Watch--WORKS! NO RESERVE! | WatchUSeek Watch Forums