disk, too, shall pass

HP-01 (1977)

Hewlett-Packard

The Hewlett-Packard HP-01 is a calculator watch. It was designed and manufactured by Hewlett-Packard.

The HP-01's digital display used 7 light-emitting diodes (LEDs)/digit in a 7-digit + decimal point arrangement. Introduced in 1977, at the height of the LED watch craze, it had five models: two gold-filled and three stainless.

Prices ranged from $450 & $550 for the low-end steel or gold to $850 (the equivalent of $2200 to $4200 in 2023 dollars).

HP also sold a battery replacement kit that allowed customers to change the batteries themselves. The watch uses two batteries for the display and one for the processor IC. It also comes with a ballpoint pen with a stylus on the rear end. Most of the 28 buttons on the HP-01 are recessed and designed to be depressed with a stylus stored in the band.

The production was stopped by the end of 1979.