Accession No

4529.005


Brief Description

HP-25C electronic pocket calculator, by Hewlett Packard, Singaporean, 1977


Origin

Singapore


Maker

Hewlett Packard


Class

calculating; computer technology


Earliest Date

1977


Latest Date

1977


Inscription Date


Material

Plastic


Dimensions

Length 127mm; width 67mm; thickness 30mm


Special Collection

Francis Hookham Collection of Hand Held Electronic Calculators


Provenance

Donated by Francis Hookham in 1987. Purchased by Francis Hookham on 25/04/1977 for £149.00.


Inscription

“Continuous Memory” (front, bottom)
[Hewlett Packard Logo] “HEWLETT . PACKARD 25C” (bottom-side)


Description Notes

Ivory Hewlett Packard 25C, with white number and arithmetic keys and all other function keys in dark grey except the blue and yellow function control keys. A black on/off switch and a black switch for changing between ‘program’ and ‘run’ mode are at front, top.

Each key has its primary function inscribed on surface, an ‘f’ function inscribed in yellow on the key panel above them, and a ‘g’ function inscribed in blue on the front-side of the key, which is tall and wedge-shaped, and thus readily readable. This way of using the keys was unique to HP.

10-digit (plus a further digit for sign, error and memory indication) red LED display.

Keys are short-travel, well weighted, rock backwards, make a clear but dull thud upon depression and bounce back very well (S Davis 6/7/2007).


References


Events

Description
Pocket Electronic Calculator

The pocket electronic calculator is now familiar to us all. However, these everyday objects were still a novelty in the early 1970s and priced out of the reach of most customers. To our modern eyes, the operation of a calculator is quite simple, at least for basic arithmetic. We just push the buttons and the machine does the hard part for us. Since calculators never make mistakes, we need never worry about what goes on inside.

Behind the buttons and screen lies a complex set of miniature circuits. It is the ability of electronics firms to make smaller and smaller components that has led to the success of the calculator. All the electronic circuits that provide the calculating power can now fit onto tiny ‘chips’ of silicon. By also developing the technology for liquid crystal displays (LCD’s), manufacturers were able to shrink calculators even further. When solar power arrived towards the end of the 1970s they could even be made without batteries. Prices fell whilst popularity soared.

Despite all this technology, successful use of the calculator still relies on the knowledge of the operator. The latest machines pack in countless functions and require a large instruction manual. Their increasing power has led to debates about their proper use in schools. The widespread use of calculators – at school, home and in the office – has been blamed for falling standards of arithmetic.

This is in contrast with the early days of calculator use. During the 1970s, a number of textbooks were published to encourage people to use what was still an unfamiliar instrument. These would give examples of how calculators could help with anything, from income tax forms to the weekly shopping list!


FM:41706

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