Hand-held Calculators

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Distinctive features: The first calculator in a ball-point pen.

Technical details:
Display is 8 digits, red LED.

4-function, %.

1.5v (1x N).

160 mm x 15 mm (6.3" x 0.6").

About 1975.

Cost: The initial cost was US$79.95 [about £45 GBP], but this fell to US$19.95 [about £11 GBP].

Made in Japan.

"Calculator doubles as a ballpoint pen
   Hosiden Electronics, Japan, has claimed a world first with the development of an 8-digit calculator which doubles as a ball-point pen.  Dubbed the "Calcu-pen", the unit is to be exported to the US market where it is expected to be a popular gift item.
   In size and shape the Calcu-pen resembles an ordinary ball-point pen, being just a little larger in diameter.  The body of the pen contains the display, together with five key switches.  These incorporate the calculating figures, four basic arithmetic signs, and a decimal point.  The key switches move in four distinct directions, vertically and horizontally, enabling the required number or function to be selected.
   Hosiden is a company specialising in the manufacture of keyboard switches and other components for calculators.  The Calcul-pen is a result of the company's technological research, although the LSI circuitry is supplied by Sharp Corporation."

The buttons are 4-way switches. To operate, a finger is placed on a button and moved sideways in the direction of the number or operation required.
The journal Popular Science concluded "While the four-in-one design is a clever idea, actual performance is awkward—so is writing with the thick pen"[2].


Advertisement for the Calcu-pen from November 1977, with heavily discounted price.

Click here to see the article "Unusual Calculators The Calcu-pen" by Guy Ball in the "Collecting Calculators" section of this site.


By 1975 the electronics required for a calculator had shrunk so much that it could be fitted into a, slightly bulbous, ball-point pen.



  1. "Calculator doubles as a ballpoint pen", Electronics Australia, March 1976, p26.
  2. "Novelty Calculators", Popular Science, January 1977, p59.

Hand-held Calculators

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