The HP-01 , code-named “Cricket” 1 , was the first watch / calculator from HP and the first small calculator algebraic. This watch, priced at $ 750 for the gold-plated version and $ 650 for the stainless steel version, was produced from 1977 to 1980 2 .


It is a digital electronic wristwatch , a personal calculator, an alarm clock, a stopwatch, a timer, a calendar of two hundred years, and so on. The HP-01 offers the possibility of combining time and calculation functions 3 .


The watch dial has 28 lowercase keys 2 , four of which are raised for faster access: D (date) , A (alarm) , M (memory) and T (time) . Two additional keys are recessed so that they can be used with the fingers without being accidentally pressed: R (read / recall / reset depending on the mode) and S for the timer and stopwatch. The other keys must be used with a stylus 2 .

The HP-01 consists of 4 integrated circuits 4 , two ROMs 4 and a 9-digit LED display 4 .

Data Types

The HP-01 includes several types of data.

Floating point numbers
Like all HP calculators, the HP-01 recognizes floating-point mathematics . The numerical range is +/- 9.999999E to +/- 99. But there is no way to enter a number in scientific notation .
Time interval data
The keypad has a key (“:”) for numbers in need as HHHHH: MM, HH: MM: SS or MM: SS.CC (CC = hundredths of a second).
Time data
With conversion if necessary; A time interval stored in the time of the place where you entered the alarm, is automatically converted to the time of the desired location.
Daytime data
When pressed (“/”), the HP-01 recognizes the information as a date in one of the two formats DD / MM / YY or DD / MM / YY (depending on the date format chosen by the user) user). There are only two digits for the year, but a key xxi th century has been included to indicate later dates.

The memory of the calculator can contain data in the three formats: number, date or time.


This watch, which was a showcase of HP’s know-how, featured four integrated circuits designed for HP. Since its LED display is very energy intensive, it did not withstand the arrival of liquid crystal displays in the 1970s. However, it is still offered to collectors, for example on Ebay at prices ranging from $ 270 to $ 14,500 in September 2014 5 .

Notes and references

  1. ↑ ( en ) HP-01 wrist instrument, 1977  [ archive ] , on the site hp.com
  2. a , b and c ( en ) + ( in ) Hewlett-Packard HP-01  [ archive ] , the silicium.org website, accessed September 3, 2014.
  3. ↑ ( in ) The HP-01 Was a marvel of miniaturization and intelligent design  [ archive ] , the hpmuseum site.
  4. a , b and c ( in ) HP-01 calculator watch LED technology  [ archive ] , on the site led-forever.com, accessed November 29, 2012
  5. ↑ ( en ) HP-01  [ archive ] , on ebay.com, accessed September 3, 2014.

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