NEW/NOS RARE Vintage ROYAL 8 HP D LCD pocket printing calculator | eBay
HP 35 - First Handheld Scientific Calculator - HP History
HP Design Studies
My cold war relic. HP 34C scientific programmable. Bought this from the University bookstore back in '81. I've rebuilt the battery pack twice, and it's still chugging along. : r/BuyItForLife
Hewlett-Packard HP-28C Handheld Electronic Calculator | National Museum of American History