Hewlett-Packard LED Calculator HP 01

The Hewlett-Packard HP 01 is a collector's item. It is a wristwatch with calculator capabilities. It was introduced in 1977 and was offered in two case/band versions, stainless steel and gold. It has a red LED display and runs on three 357 batteries.

It's a digital electronic wristwatch, a personal calculator, an alarm clock, a stopwatch, a timer, a 200 year calendar...and yet it is more than all of these. The HP-01 is a unique, interactive combination of time and computation functions.


The watch face has 28 tiny keys. Four of these are raised for easy finger access. The raised keys are D (date), A (alarm), M (memory), and T (time). Each of these keys recalls the appropriate information when pressed alone, or, when pressed after the shift key, stores the information.

Two more keys are recessed in a way that they aren't accidentally pressed but can still be operated by finger. These are the R (read/recall/reset depending on mode) and S (stopwatch) keys. The other keys are meant to be pressed with a stylus. A pen is included which has a retractable ballpoint in one end and a retractable stylus in the other.

The bracelet is smooth and solid. The links are of solid machined stainless steel and are as smooth on the inside as on the outside. The clasp has a quick release feature that made it easy to lay the bracelet flat while operating the calculator.

Further information is available on the Hewlett Packard Museum website. Full description available in dedicated issue of Hewlett-Packard Journal (December 1977). See a cutaway view of the HP-01 wrist instrument.